WorldWideScience

Sample records for rapid earthquake localization

  1. Seismogeodesy for rapid earthquake and tsunami characterization

    Science.gov (United States)

    Bock, Y.

    2016-12-01

    Rapid estimation of earthquake magnitude and fault mechanism is critical for earthquake and tsunami warning systems. Traditionally, the monitoring of earthquakes and tsunamis has been based on seismic networks for estimating earthquake magnitude and slip, and tide gauges and deep-ocean buoys for direct measurement of tsunami waves. These methods are well developed for ocean basin-wide warnings but are not timely enough to protect vulnerable populations and infrastructure from the effects of local tsunamis, where waves may arrive within 15-30 minutes of earthquake onset time. Direct measurements of displacements by GPS networks at subduction zones allow for rapid magnitude and slip estimation in the near-source region, that are not affected by instrumental limitations and magnitude saturation experienced by local seismic networks. However, GPS displacements by themselves are too noisy for strict earthquake early warning (P-wave detection). Optimally combining high-rate GPS and seismic data (in particular, accelerometers that do not clip), referred to as seismogeodesy, provides a broadband instrument that does not clip in the near field, is impervious to magnitude saturation, and provides accurate real-time static and dynamic displacements and velocities in real time. Here we describe a NASA-funded effort to integrate GPS and seismogeodetic observations as part of NOAA's Tsunami Warning Centers in Alaska and Hawaii. It consists of a series of plug-in modules that allow for a hierarchy of rapid seismogeodetic products, including automatic P-wave picking, hypocenter estimation, S-wave prediction, magnitude scaling relationships based on P-wave amplitude (Pd) and peak ground displacement (PGD), finite-source CMT solutions and fault slip models as input for tsunami warnings and models. For the NOAA/NASA project, the modules are being integrated into an existing USGS Earthworm environment, currently limited to traditional seismic data. We are focused on a network of

  2. PAGER--Rapid assessment of an earthquake?s impact

    Science.gov (United States)

    Wald, D.J.; Jaiswal, K.; Marano, K.D.; Bausch, D.; Hearne, M.

    2010-01-01

    PAGER (Prompt Assessment of Global Earthquakes for Response) is an automated system that produces content concerning the impact of significant earthquakes around the world, informing emergency responders, government and aid agencies, and the media of the scope of the potential disaster. PAGER rapidly assesses earthquake impacts by comparing the population exposed to each level of shaking intensity with models of economic and fatality losses based on past earthquakes in each country or region of the world. Earthquake alerts--which were formerly sent based only on event magnitude and location, or population exposure to shaking--now will also be generated based on the estimated range of fatalities and economic losses.

  3. Rapid telemetry and earthquake early warning

    Science.gov (United States)

    Allen, R.; Bose, M.; Brown, H.; Cua, G.; Given, D.; Hauksson, E.; Heaton, T.; Hellweg, M.; Jordan, T.; Kireev, A.; Maechling, P.; Neuhauser, D.; Oppenheimer, D.; Solanki, K.; Zeleznik, M.

    2008-05-01

    The California Integrated Seismic Network (CISN) is currently testing algorithms for earthquake early warning on the realtime seismic systems in the state. An earthquake warning system rapidly detects the initiation of earthquakes and assesses the associated hazard. The goal is to provide warning of potentially damaging ground motion in a target region prior to the arrival of seismic waves. The network-based approach to early warning requires station data to be gathered at a central site for joint processing. ElarmS, one network-based approach being tested, currently runs 15 sec behind realtime in order to gather ~90% of station data before processing. Even with this delay the recent Mw 5.4 Alum Rock earthquake near San Jose was detected and an accurate hazard assessment was available before ground shaking in San Francisco. The Virtual Seismologist (VS) method, another network-based approach, is a Bayesian method that incorporates information such as network topology, previously observed seismicity, and the Gutenberg-Richter relationship in magnitude and location estimation. The VS method is currently being transitioned from off-line to real-time testing and will soon be running 15 sec behind real-time, as in the case of ElarmS. We are also testing an on-site warning approach, which is based on single-station observations. On-site systems can deliver earthquake information faster than regional systems, and the warning could possibly reach potential users at much closer epicentral distances before the damaging shaking starts. By definition, on-site systems do not require a central processing facility or delivery of data from a distant seismic station, but they are less robust that networked-based systems and need a fast and reliable telemetry to deliver warnings to local users. The range of possible warning times is typically seconds to tens of seconds and every second of data latency translates into an equal reduction in the available warning time. Minimal latency

  4. Localization of intermediate-term earthquake prediction

    Energy Technology Data Exchange (ETDEWEB)

    Kossobokov, V.G.; Keilis-Borok, V.I. (International Inst. of Earthquake Prediction Theory and Mathematical Geophysics, Moscow (USSR)); Smith, S.W. (Univ. of Washington, Seattle (USA))

    1990-11-10

    Relative seismic quiescence within a region which has already been diagnosed as having entered a Time of Increased Probability (TIP) for the occurrence of a strong earthquake can be used to refine the locality in which the earthquake may be expected to occur. A simple algorithm with parameters fitted from the data in Northern California preceding the 1980 magnitude 7.0 earthquake offshore from Eureka depicts relative quiescence within the region of a TIP. The procedure was tested, without readaptation of parameter, on 17 other strong earthquake occurrences in North America, Japan, and Eurasia, most of which were in regions for which a TIP had been previously diagnosed. The localizing algorithm successfully outlined a region within which the subsequent earthquake occurred for 16 of these 17 strong earthquakes. The area of prediction in each case was reduced significantly, ranging between 7% and 25% of the total area covered by the TIP.

  5. Local tsunamis and earthquake source parameters

    Science.gov (United States)

    Geist, Eric L.; Dmowska, Renata; Saltzman, Barry

    1999-01-01

    This chapter establishes the relationship among earthquake source parameters and the generation, propagation, and run-up of local tsunamis. In general terms, displacement of the seafloor during the earthquake rupture is modeled using the elastic dislocation theory for which the displacement field is dependent on the slip distribution, fault geometry, and the elastic response and properties of the medium. Specifically, nonlinear long-wave theory governs the propagation and run-up of tsunamis. A parametric study is devised to examine the relative importance of individual earthquake source parameters on local tsunamis, because the physics that describes tsunamis from generation through run-up is complex. Analysis of the source parameters of various tsunamigenic earthquakes have indicated that the details of the earthquake source, namely, nonuniform distribution of slip along the fault plane, have a significant effect on the local tsunami run-up. Numerical methods have been developed to address the realistic bathymetric and shoreline conditions. The accuracy of determining the run-up on shore is directly dependent on the source parameters of the earthquake, which provide the initial conditions used for the hydrodynamic models.

  6. Rapid Inventory of Earthquake Damage (RIED)

    NARCIS (Netherlands)

    Duque, Adriana; Hack, Robert; Montoya, L.; Scarpas, Tom; Slob, Siefko; Soeters, Rob; van Westen, Cees

    2001-01-01

    The 25 January 1999 Quindío earthquake in Colombia was a major disaster for the coffee-growing region in Colombia. Most of the damage occurred in the city of Armenia and surrounding villages. Damage due to earthquakes is strongly related to topographic and subsurface geotechnical conditions

  7. Explosion-Earthquake Discrimination at Local Distances

    Science.gov (United States)

    O'Rourke, C. T.; Baker, G. E.; Sheehan, A. F.; Harder, S. H.

    2014-12-01

    Event discrimination research has largely focused on regional distances over the last couple of decades. Most regional discriminants have not been thoroughly tested at local distances, and a recent investigation of P/S ratios from the Source Physics Experiment (SPE) found that they were less effective locally. As discrimination thresholds are reduced, local methods will need to be validated and the physical bases for their performance will need to be understood. We are assessing new and existing methods of source discrimination at 10 to 200 km distance. We use data from a temporary array deployed around the Bighorn Mountains in Wyoming and from nearby US Array stations. Small magnitude local earthquakes, coal mine explosions, and controlled borehole shots were recorded at over 200 broadband and short-period seismometers spaced at 5-35 km intervals across the tectonically complex area. We assess the local discrimination performance of the P/S amplitude ratio, the presence of the fundamental Rayleigh wave Rg, and the signature of scattered Rg in the coda. P/S amplitudes are used because earthquakes typically have higher S-wave energy relative to P than shallow explosions, but the separation of populations is not always effective at local distances. Site effects have a significant impact that may need to be accounted for, along with propagation effects. Specifically, relative P and S site amplifications at basin and mountain stations vary in such a way that they limit separation of the event populations. The Rg phase is only excited by near-surface events, so its presence indicates the likelihood of a man-made source since most earthquakes occur at too great a depth to excite Rg. We implement two methods for detecting Rg: one that uses the cross-correlation of the Hilbert transformed vertical and the radial seismograms, and one that scans a time-frequency representation for the signature of scattered Rg in the coda. These methods are effective in low signal

  8. Heating, weakening and shear localization in earthquake rupture

    Science.gov (United States)

    Rice, James R.

    2017-08-01

    Field and borehole observations of active earthquake fault zones show that shear is often localized to principal deforming zones of order 0.1-10 mm width. This paper addresses how frictional heating in rapid slip weakens faults dramatically, relative to their static frictional strength, and promotes such intense localization. Pronounced weakening occurs even on dry rock-on-rock surfaces, due to flash heating effects, at slip rates above approximately 0.1 m s-1 (earthquake slip rates are typically of the order of 1 m s-1). But weakening in rapid shear is also predicted theoretically in thick fault gouge in the presence of fluids (whether native ground fluids or volatiles such as H2O or CO2 released by thermal decomposition reactions), and the predicted localizations are compatible with such narrow shear zones as have been observed. The underlying concepts show how fault zone materials with high static friction coefficients, approximately 0.6-0.8, can undergo strongly localized shear at effective dynamic friction coefficients of the order of 0.1, thus fitting observational constraints, e.g. of earthquakes producing negligible surface heat outflow and, for shallow events, only rarely creating extensive melt. The results to be summarized include those of collaborative research published with Nicolas Brantut (University College London), Eric Dunham (Stanford University), Nadia Lapusta (Caltech), Hiroyuki Noda (JAMSTEC, Japan), John D. Platt (Carnegie Institution for Science, now at *gramLabs), Alan Rempel (Oregon State University) and John W. Rudnicki (Northwestern University). This article is part of the themed issue 'Faulting, friction and weakening: from slow to fast motion'.

  9. Rapid estimation of the economic consequences of global earthquakes

    Science.gov (United States)

    Jaiswal, Kishor; Wald, David J.

    2011-01-01

    The U.S. Geological Survey's (USGS) Prompt Assessment of Global Earthquakes for Response (PAGER) system, operational since mid 2007, rapidly estimates the most affected locations and the population exposure at different levels of shaking intensities. The PAGER system has significantly improved the way aid agencies determine the scale of response needed in the aftermath of an earthquake. For example, the PAGER exposure estimates provided reasonably accurate assessments of the scale and spatial extent of the damage and losses following the 2008 Wenchuan earthquake (Mw 7.9) in China, the 2009 L'Aquila earthquake (Mw 6.3) in Italy, the 2010 Haiti earthquake (Mw 7.0), and the 2010 Chile earthquake (Mw 8.8). Nevertheless, some engineering and seismological expertise is often required to digest PAGER's exposure estimate and turn it into estimated fatalities and economic losses. This has been the focus of PAGER's most recent development. With the new loss-estimation component of the PAGER system it is now possible to produce rapid estimation of expected fatalities for global earthquakes (Jaiswal and others, 2009). While an estimate of earthquake fatalities is a fundamental indicator of potential human consequences in developing countries (for example, Iran, Pakistan, Haiti, Peru, and many others), economic consequences often drive the responses in much of the developed world (for example, New Zealand, the United States, and Chile), where the improved structural behavior of seismically resistant buildings significantly reduces earthquake casualties. Rapid availability of estimates of both fatalities and economic losses can be a valuable resource. The total time needed to determine the actual scope of an earthquake disaster and to respond effectively varies from country to country. It can take days or sometimes weeks before the damage and consequences of a disaster can be understood both socially and economically. The objective of the U.S. Geological Survey's PAGER system is

  10. Rapid Estimation of Tsunami Impact Following the Samoa Earthquake

    Science.gov (United States)

    Thio, H. K.; Polet, J.

    2009-12-01

    Rapid estimation of the tsunami waveheight after a large earthquake can significantly aid in disaster recovery efforts, planning of post-tsunami surveys and even early warning for more distant regions. We are exploring methods for refining these estimates by addressing variability due to uncertainties in the source parameters. After the Samoa earthquake, we used the solution from the near real-time Research CMT system at the National Earthquake Information Center to compute the tsunami wavefield. Given the close proximity to Samoa and American Samoa, details of the rupture geometry are very important for the character of the tsunami wavefield and we computed tsunami waveforms for several different geometries that are consistent with the rCMT solution. We will evaluate these results by comparing them with observed runups and explore ways to express the uncertainties in the simulated runup maps. We will also evaluate other real-time source estimates for use in rapid tsunami impact simulation.

  11. Rapid Earthquake Magnitude Estimation for Early Warning Applications

    Science.gov (United States)

    Goldberg, Dara; Bock, Yehuda; Melgar, Diego

    2017-04-01

    Earthquake magnitude is a concise metric that provides invaluable information about the destructive potential of a seismic event. Rapid estimation of magnitude for earthquake and tsunami early warning purposes requires reliance on near-field instrumentation. For large magnitude events, ground motions can exceed the dynamic range of near-field broadband seismic instrumentation (clipping). Strong motion accelerometers are designed with low gains to better capture strong shaking. Estimating earthquake magnitude rapidly from near-source strong-motion data requires integration of acceleration waveforms to displacement. However, integration amplifies small errors, creating unphysical drift that must be eliminated with a high pass filter. The loss of the long period information due to filtering is an impediment to magnitude estimation in real-time; the relation between ground motion measured with strong-motion instrumentation and magnitude saturates, leading to underestimation of earthquake magnitude. Using station displacements from Global Navigation Satellite System (GNSS) observations, we can supplement the high frequency information recorded by traditional seismic systems with long-period observations to better inform rapid response. Unlike seismic-only instrumentation, ground motions measured with GNSS scale with magnitude without saturation [Crowell et al., 2013; Melgar et al., 2015]. We refine the current magnitude scaling relations using peak ground displacement (PGD) by adding a large GNSS dataset of earthquakes in Japan. Because it does not suffer from saturation, GNSS alone has significant advantages over seismic-only instrumentation for rapid magnitude estimation of large events. The earthquake's magnitude can be estimated within 2-3 minutes of earthquake onset time [Melgar et al., 2013]. We demonstrate that seismogeodesy, the optimal combination of GNSS and seismic data at collocated stations, provides the added benefit of improving the sensitivity of

  12. Rapid characterisation of large earthquakes by multiple seismic broadband arrays

    Directory of Open Access Journals (Sweden)

    D. Roessler

    2010-04-01

    Full Text Available An automatic procedure is presented to retrieve rupture parameters for large earthquakes along the Sunda arc subduction zone. The method is based on standard array analysis and broadband seismograms registered within 30°–100° epicentral distance. No assumptions on source mechanism are required. By means of semblance the coherency of P waveforms is analysed at separate large-aperture arrays. Waveforms are migrated to a 10°×10° wide source region to study the spatio-temporal evolution of earthquakes at each array. The multiplication of the semblance source maps resulting at each array increases resolution. Start, duration, extent, direction, and propagation velocity are obtained and published within 25 min after the onset of the event. First preliminary results can be obtained even within 16 min. Their rapid determination may improve the mitigation of the earthquake and tsunami hazard. Real-time application will provide rupture parameters to the GITEWS project (German Indonesian Tsunami Early Warning System. The method is applied to the two M8.0 Sumatra earthquakes on 12 September 2007, to the M7.4 Java earthquake on 2 September 2009, and to major subduction earthquakes that have occurred along Sumatra and Java since 2000. Obtained rupture parameters are most robust for the largest earthquakes with magnitudes M≥8. The results indicate that almost the entire seismogenic part of the subduction zone off the coast of Sumatra has been ruptured. Only the great Sumatra event in 2004 and the M7.7 Java event on 17 July 2006 could reach to or close to the surface at the trench. Otherwise, the rupturing was apparently confined to depths below 25 km. Major seismic gaps seem to remain off the coast of Padang and the southern tip of Sumatra.

  13. Mapping Natech risk due to earthquakes using RAPID-N

    Science.gov (United States)

    Girgin, Serkan; Krausmann, Elisabeth

    2013-04-01

    Natural hazard-triggered technological accidents (so-called Natech accidents) at hazardous installations are an emerging risk with possibly serious consequences due to the potential for release of hazardous materials, fires or explosions. For the reduction of Natech risk, one of the highest priority needs is the identification of Natech-prone areas and the systematic assessment of Natech risks. With hardly any Natech risk maps existing within the EU the European Commission's Joint Research Centre has developed a Natech risk analysis and mapping tool called RAPID-N, that estimates the overall risk of natural-hazard impact to industrial installations and its possible consequences. The results are presented as risk summary reports and interactive risk maps which can be used for decision making. Currently, RAPID-N focuses on Natech risk due to earthquakes at industrial installations. However, it will be extended to also analyse and map Natech risk due to floods in the near future. The RAPID-N methodology is based on the estimation of on-site natural hazard parameters, use of fragility curves to determine damage probabilities of plant units for various damage states, and the calculation of spatial extent, severity, and probability of Natech events potentially triggered by the natural hazard. The methodology was implemented as a web-based risk assessment and mapping software tool which allows easy data entry, rapid local or regional risk assessment and mapping. RAPID-N features an innovative property estimation framework to calculate on-site natural hazard parameters, industrial plant and plant unit characteristics, and hazardous substance properties. Custom damage states and fragility curves can be defined for different types of plant units. Conditional relationships can be specified between damage states and Natech risk states, which describe probable Natech event scenarios. Natech consequences are assessed using a custom implementation of U.S. EPA's Risk Management

  14. Rapid estimate of earthquake source duration: application to tsunami warning.

    Science.gov (United States)

    Reymond, Dominique; Jamelot, Anthony; Hyvernaud, Olivier

    2016-04-01

    We present a method for estimating the source duration of the fault rupture, based on the high-frequency envelop of teleseismic P-Waves, inspired from the original work of (Ni et al., 2005). The main interest of the knowledge of this seismic parameter is to detect abnormal low velocity ruptures that are the characteristic of the so called 'tsunami-earthquake' (Kanamori, 1972). The validation of the results of source duration estimated by this method are compared with two other independent methods : the estimated duration obtained by the Wphase inversion (Kanamori and Rivera, 2008, Duputel et al., 2012) and the duration calculated by the SCARDEC process that determines the source time function (M. Vallée et al., 2011). The estimated source duration is also confronted to the slowness discriminant defined by Newman and Okal, 1998), that is calculated routinely for all earthquakes detected by our tsunami warning process (named PDFM2, Preliminary Determination of Focal Mechanism, (Clément and Reymond, 2014)). Concerning the point of view of operational tsunami warning, the numerical simulations of tsunami are deeply dependent on the source estimation: better is the source estimation, better will be the tsunami forecast. The source duration is not directly injected in the numerical simulations of tsunami, because the cinematic of the source is presently totally ignored (Jamelot and Reymond, 2015). But in the case of a tsunami-earthquake that occurs in the shallower part of the subduction zone, we have to consider a source in a medium of low rigidity modulus; consequently, for a given seismic moment, the source dimensions will be decreased while the slip distribution increased, like a 'compact' source (Okal, Hébert, 2007). Inversely, a rapid 'snappy' earthquake that has a poor tsunami excitation power, will be characterized by higher rigidity modulus, and will produce weaker displacement and lesser source dimensions than 'normal' earthquake. References: CLément, J

  15. Flash-sourcing or the rapid detection and characterisation of earthquake effects through clickstream data analysis

    Science.gov (United States)

    Bossu, R.; Mazet-Roux, G.; Roussel, F.; Frobert, L.

    2011-12-01

    Rapid characterisation of earthquake effects is essential for a timely and appropriate response in favour of victims and/or of eyewitnesses. In case of damaging earthquakes, any field observations that can fill the information gap characterising their immediate aftermath can contribute to more efficient rescue operations. This paper presents the last developments of a method called "flash-sourcing" addressing these issues. It relies on eyewitnesses, the first informed and the first concerned by an earthquake occurrence. More precisely, their use of the EMSC earthquake information website (www.emsc-csem.org) is analysed in real time to map the area where the earthquake was felt and identify, at least under certain circumstances zones of widespread damage. The approach is based on the natural and immediate convergence of eyewitnesses on the website who rush to the Internet to investigate cause of the shaking they just felt causing our traffic to increase The area where an earthquake was felt is mapped simply by locating Internet Protocol (IP) addresses during traffic surges. In addition, the presence of eyewitnesses browsing our website within minutes of an earthquake occurrence excludes the possibility of widespread damage in the localities they originate from: in case of severe damage, the networks would be down. The validity of the information derived from this clickstream analysis is confirmed by comparisons with EMS98 macroseismic map obtained from online questionnaires. The name of this approach, "flash-sourcing", is a combination of "flash-crowd" and "crowdsourcing" intending to reflect the rapidity of the data collation from the public. For computer scientists, a flash-crowd names a traffic surge on a website. Crowdsourcing means work being done by a "crowd" of people; It also characterises Internet and mobile applications collecting information from the public such as online macroseismic questionnaires. Like crowdsourcing techniques, flash-sourcing is a

  16. RICHTER: A Smartphone Application for Rapid Collection of Geo-Tagged Pictures of Earthquake Damage

    Science.gov (United States)

    Skinnemoen, H.; Bossu, R.; Furuheim, K.; Bjorgo, E.

    2010-12-01

    RICHTER (Rapid geo-Images for Collaborative Help Targeting Earthquake Response) is a smartphone version of a professional application developed to provide high quality geo-tagged image communication over challenging network links, such as satellites and poor mobile links. Developed for Android mobile phones, it allows eyewitnesses to share their pictures of earthquake damage easily and without cost with the Euro-Mediterranean Seismological Centre (EMSC). The goal is to engage citizens in the collection of the most up-to-date visual information on local damage for improved rapid impact assessment. RICHTER integrates the innovative and award winning ASIGN protocol initially developed for satellite communication between cameras / computers / satcom terminals and servers at HQ. ASIGN is a robust and optimal image and video communication management solution for bandwidth-limited communication networks which was developed for use particularly in emergency and disaster situations. Contrary to a simple Multimedia Messaging System (MMS), RICHTER allows access to high definition images with embedded location information. Location is automatically assigned from either the internal GPS, derived from the mobile network (triangulation) or the current Wi-Fi domain, in that order, as this corresponds to the expected positioning accuracy. Pictures are compressed to 20-30KB of data typically for fast transfer and to avoid network overload. Full size images can be requested by the EMSC either fully automatically, or on a case-by-case basis, depending on the user preferences. ASIGN was initially developed in coordination with INMARSAT and the European Space Agency. It was used by the Rapid Mapping Unit of the United Nations notably for the damage assessment of the January 12, 2010 Haiti earthquake where more than 700 photos were collected. RICHTER will be freely distributed on the EMSC website to eyewitnesses in the event of significantly damaging earthquakes. The EMSC is the second

  17. Prompt Assessment of Global Earthquakes for Response (PAGER): A System for Rapidly Determining the Impact of Earthquakes Worldwide

    Science.gov (United States)

    Earle, Paul S.; Wald, David J.; Jaiswal, Kishor S.; Allen, Trevor I.; Hearne, Michael G.; Marano, Kristin D.; Hotovec, Alicia J.; Fee, Jeremy

    2009-01-01

    Within minutes of a significant earthquake anywhere on the globe, the U.S. Geological Survey (USGS) Prompt Assessment of Global Earthquakes for Response (PAGER) system assesses its potential societal impact. PAGER automatically estimates the number of people exposed to severe ground shaking and the shaking intensity at affected cities. Accompanying maps of the epicentral region show the population distribution and estimated ground-shaking intensity. A regionally specific comment describes the inferred vulnerability of the regional building inventory and, when available, lists recent nearby earthquakes and their effects. PAGER's results are posted on the USGS Earthquake Program Web site (http://earthquake.usgs.gov/), consolidated in a concise one-page report, and sent in near real-time to emergency responders, government agencies, and the media. Both rapid and accurate results are obtained through manual and automatic updates of PAGER's content in the hours following significant earthquakes. These updates incorporate the most recent estimates of earthquake location, magnitude, faulting geometry, and first-hand accounts of shaking. PAGER relies on a rich set of earthquake analysis and assessment tools operated by the USGS and contributing Advanced National Seismic System (ANSS) regional networks. A focused research effort is underway to extend PAGER's near real-time capabilities beyond population exposure to quantitative estimates of fatalities, injuries, and displaced population.

  18. Twitter as Information Source for Rapid Damage Estimation after Major Earthquakes

    Science.gov (United States)

    Eggert, Silke; Fohringer, Joachim

    2014-05-01

    Natural disasters like earthquakes require a fast response from local authorities. Well trained rescue teams have to be available, equipment and technology has to be ready set up, information have to be directed to the right positions so the head quarter can manage the operation precisely. The main goal is to reach the most affected areas in a minimum of time. But even with the best preparation for these cases, there will always be the uncertainty of what really happened in the affected area. Modern geophysical sensor networks provide high quality data. These measurements, however, are only mapping disjoint values from their respective locations for a limited amount of parameters. Using observations of witnesses represents one approach to enhance measured values from sensors ("humans as sensors"). These observations are increasingly disseminated via social media platforms. These "social sensors" offer several advantages over common sensors, e.g. high mobility, high versatility of captured parameters as well as rapid distribution of information. Moreover, the amount of data offered by social media platforms is quite extensive. We analyze messages distributed via Twitter after major earthquakes to get rapid information on what eye-witnesses report from the epicentral area. We use this information to (a) quickly learn about damage and losses to support fast disaster response and to (b) densify geophysical networks in areas where there is sparse information to gain a more detailed insight on felt intensities. We present a case study from the Mw 7.1 Philippines (Bohol) earthquake that happened on Oct. 15 2013. We extract Twitter messages, so called tweets containing one or more specified keywords from the semantic field of "earthquake" and use them for further analysis. For the time frame of Oct. 15 to Oct 18 we get a data base of in total 50.000 tweets whereof 2900 tweets are geo-localized and 470 have a photo attached. Analyses for both national level and locally for

  19. Rapid earthquake characterization using MEMS accelerometers and volunteer hosts following the M 7.2 Darfield, New Zealand, Earthquake

    Science.gov (United States)

    Lawrence, J. F.; Cochran, E.S.; Chung, A.; Kaiser, A.; Christensen, C. M.; Allen, R.; Baker, J.W.; Fry, B.; Heaton, T.; Kilb, Debi; Kohler, M.D.; Taufer, M.

    2014-01-01

    We test the feasibility of rapidly detecting and characterizing earthquakes with the Quake‐Catcher Network (QCN) that connects low‐cost microelectromechanical systems accelerometers to a network of volunteer‐owned, Internet‐connected computers. Following the 3 September 2010 M 7.2 Darfield, New Zealand, earthquake we installed over 180 QCN sensors in the Christchurch region to record the aftershock sequence. The sensors are monitored continuously by the host computer and send trigger reports to the central server. The central server correlates incoming triggers to detect when an earthquake has occurred. The location and magnitude are then rapidly estimated from a minimal set of received ground‐motion parameters. Full seismic time series are typically not retrieved for tens of minutes or even hours after an event. We benchmark the QCN real‐time detection performance against the GNS Science GeoNet earthquake catalog. Under normal network operations, QCN detects and characterizes earthquakes within 9.1 s of the earthquake rupture and determines the magnitude within 1 magnitude unit of that reported in the GNS catalog for 90% of the detections.

  20. The Technical Efficiency of Earthquake Medical Rapid Response Teams Following Disasters: The Case of the 2010 Yushu Earthquake in China.

    Science.gov (United States)

    Liu, Xu; Tang, Bihan; Yang, Hongyang; Liu, Yuan; Xue, Chen; Zhang, Lulu

    2015-12-04

    Performance assessments of earthquake medical rapid response teams (EMRRTs), particularly the first responders deployed to the hardest hit areas following major earthquakes, should consider efficient and effective use of resources. This study assesses the daily technical efficiency of EMRRTs in the emergency period immediately following the 2010 Yushu earthquake in China. Data on EMRRTs were obtained from official daily reports of the general headquarters for Yushu earthquake relief, the emergency office of the National Ministry of Health, and the Health Department of Qinghai Province, for a sample of data on 15 EMRRTs over 62 days. Data envelopment analysis was used to examine the technical efficiency in a constant returns to scale model, a variable returns to scale model, and the scale efficiency of EMRRTs. Tobit regression was applied to analyze the effects of corresponding influencing factors. The average technical efficiency scores under constant returns to scale, variable returns to scale, and the scale efficiency scores of the 62 units of analysis were 77.95%, 89.00%, and 87.47%, respectively. The staff-to-bed ratio was significantly related to global technical efficiency. The date of rescue was significantly related to pure technical efficiency. The type of institution to which an EMRRT belonged and the staff-to-bed ratio were significantly related to scale efficiency. This study provides evidence that supports improvements to EMRRT efficiency and serves as a reference for earthquake emergency medical rapid assistance leaders and teams.

  1. The Technical Efficiency of Earthquake Medical Rapid Response Teams Following Disasters: The Case of the 2010 Yushu Earthquake in China

    Directory of Open Access Journals (Sweden)

    Xu Liu

    2015-12-01

    Full Text Available Purpose: Performance assessments of earthquake medical rapid response teams (EMRRTs, particularly the first responders deployed to the hardest hit areas following major earthquakes, should consider efficient and effective use of resources. This study assesses the daily technical efficiency of EMRRTs in the emergency period immediately following the 2010 Yushu earthquake in China. Methods: Data on EMRRTs were obtained from official daily reports of the general headquarters for Yushu earthquake relief, the emergency office of the National Ministry of Health, and the Health Department of Qinghai Province, for a sample of data on 15 EMRRTs over 62 days. Data envelopment analysis was used to examine the technical efficiency in a constant returns to scale model, a variable returns to scale model, and the scale efficiency of EMRRTs. Tobit regression was applied to analyze the effects of corresponding influencing factors. Results: The average technical efficiency scores under constant returns to scale, variable returns to scale, and the scale efficiency scores of the 62 units of analysis were 77.95%, 89.00%, and 87.47%, respectively. The staff-to-bed ratio was significantly related to global technical efficiency. The date of rescue was significantly related to pure technical efficiency. The type of institution to which an EMRRT belonged and the staff-to-bed ratio were significantly related to scale efficiency. Conclusions: This study provides evidence that supports improvements to EMRRT efficiency and serves as a reference for earthquake emergency medical rapid assistance leaders and teams.

  2. Letter to the Editor : Rapidly-deployed small tent hospitals: lessons from the earthquake in Haiti.

    Energy Technology Data Exchange (ETDEWEB)

    Rosen, Y.; Gurman , P.; Verna, E.; Elman , N.; Labor, E. (Materials Science Division); (Superior NanoBioSystems LLC); (Fast Israeli Rescue & Search Team); (Clinique Adonai); (Mass. Inst. Tech.); (Univ. Haifa)

    2012-06-01

    The damage to medical facilities resulting form the January 2010 earthquake in haiti necessitated the establishment of field tent hospitals. Much of the local medical infrastructure was destroyed or limited operationally when the Fast Israel Rescue and Search Team (FIRST) arrived in Haiti shortly after the January 2010 earthquake. The FIRST deployed small tent hospitals in Port-au-Prince and in 11 remote areas outside of the city. Each tent was set up in less than a half hour. The tents were staffed with an orthopedic surgeon, gynecologists, primary care and emergency care physicians, a physician with previous experience in tropical medicine, nurses, paramedics, medics, and psychologists. The rapidly deployable and temporary nature of the effort allowed the team to treat and educate, as well as provide supplies for, thousands of refugees throughout Haiti. In addition, a local Haitian physician and his team created a small tent hospital to serve the Petion Refugee Camp and its environs. FIRST personnel also took shifts at this hospital.

  3. Rapid landslide risk assessment of transport infrastructure following the 13 November 2016 Kaikoura, New Zealand, earthquake

    Science.gov (United States)

    Robinson, Tom; Rosser, Nick

    2017-04-01

    Earthquake-generated landslides pose a significant risk to critical infrastructure, especially transport networks. For post-earthquake emergency response, identifying where landslides have affected transport networks is vital for understanding the ground access available to affected locations. However, post-earthquake landslide mapping is a difficult and time-consuming task, hindered by issues relating to the collection and processing of satellite images, cloud cover, and manual mapping. The development of rapid landslide modelling techniques for post-earthquake application can allow landslide hazard and risk to be modelled within hours of the earthquake occurring, leading to faster understanding of the likely losses to transport infrastructure. This study presents the results of efforts to rapidly model the extent of and losses related to landsliding following the 13 November 2016 Kaikoura earthquake in New Zealand. Using previously published data on landslide pre-disposing factors, the landslide hazard resulting from this earthquake was modelled in order to identify locations where landslides were most likely. This was combined with a simple horizon-scanning method along critical transport lines to identify zones in which landslides could potentially impact the networks. Landslide hazard in these zones was subsequently weighted by the reach angle to the respective network and averaged for the entire zone. The results show the relative risk of landslides impacting different sections of the transport networks and were derived within 48 hours of the earthquake occurring. These models rapidly and correctly highlighted the numerous blockages along the vital State Highway 1 link between Christchurch and Kaikoura, as well as those on the only alternative inland route. This demonstrates that accurate and rapid analysis of landslide losses can be undertaken immediately post-earthquake, with results potentially available within hours of the event, far sooner than current

  4. A digital social network for rapid collection of earthquake disaster information

    Science.gov (United States)

    Xu, J. H.; Nie, G. Z.; Xu, X.

    2013-02-01

    Acquiring disaster information quickly after an earthquake is crucial for disaster and emergency rescue management. This study examines a digital social network - an earthquake disaster information reporting network - for rapid collection of earthquake disaster information. Based on the network, the disaster information rapid collection method is expounded in this paper. The structure and components of the reporting network are introduced. Then the work principles of the reporting network are discussed, in which the rapid collection of disaster information is realised by using Global System for Mobile Communications (GSM) messages to report the disaster information and Geographic information system (GIS) to analyse and extract useful disaster information. This study introduces some key technologies for the work principles, including the methods of mass sending and receiving of SMS for disaster management, the reporting network grouping management method, brief disaster information codes, and the GIS modelling of the reporting network. Finally, a city earthquake disaster information quick reporting system is developed and with the support of this system the reporting network obtained good results in a real earthquake and earthquake drills. This method is a semi-real time disaster information collection method which extends current SMS based method and meets the need of small and some moderate earthquakes.

  5. On locating local earthquakes at the Messina Strait network

    Directory of Open Access Journals (Sweden)

    G. NERI

    1980-06-01

    Full Text Available A computer program (HYPOSTRE has been elaborated to determine
    the hypocentral parameters of local earthquakes, even when they are recorded
    by a small number of stations. These are the most frequent conditions
    prevailing around the Strait of Messina.
    The program employs the first arrivals of P and S waves, a model of
    local crust consisting of four plane and parallel layers, and an algorithm
    based on that of Geiger.
    HYPOSTRE can determine simultaneously the four unknowns X, cp, h
    and H (HYPOSTRE 4 and can calculate the epicentral coordinate separately
    from focal depth (HYPOSTRE 2. In both cases the program follows
    an iterative process. In particular, HYPOSTRE 2 shows convergence towards
    a final solution, through a series of « damped » approximations.
    The application of HYPOSTRE to about twenty earthquakes, which
    have occured in the Strait of Messina and in the Gulf of Patti, demonstrates
    a good convergence and a general stability of results.
    Finally, comparison with analogous determinations — carried out by
    other programs, with different crustal models and using a greater number
    of recorded data — confirms the reliability of HYPOSTRE.

  6. Rapid and robust characterization of the earthquake source for tsunami early-warning

    Science.gov (United States)

    Lomax, Anthony; Michelini, Alberto; Bernardi, Fabrizio; Lauciani, Valentino

    2015-04-01

    Effective tsunami early-warning after an earthquake is difficult when the distances and tsunami travel-times between earthquake/tsunami source regions and coast lines at risk are small, especially since the density of seismic and other monitoring stations is very low in most regions of risk. For tsunami warning worldwide, seismic monitoring and analysis currently provide the majority of information available within the first tens of minutes after an earthquake. This information is used for direct tsunami hazard assessment, and as basic input to real-time, tsunami hazard modeling. It is thus crucial that key earthquake parameters are determined as rapidly and reliably as possible, in a probabilistic, time-evolving manner, along with full uncertainties. Early-est (EArthquake Rapid Location sYstem with EStimation of Tsunamigenesis) is the module for rapid earthquake detection, location and analysis at the INGV tsunami alert center (CAT, "Centro di Allerta Tsunami"), part of the Italian, candidate Tsunami Watch Provider. Here we present the information produced by Early-est within the first 10 min after an earthquake to characterize the location, depth, magnitude, mechanism and tsunami potential of an earthquake. We discuss key algorithms in Early-est that produce fully automatic, robust results and their uncertainties in the shortest possible time using sparse observations. For example, a broadband picker and a robust, probabilistic, global-search detector/associator/locator component of Early-est can detect and locate a seismic event with as few as 4 to 5 P onset observations. We also discuss how these algorithms may be further evolved to provide even earlier and more robust results. Finally, we illustrate how the real-time, evolutionary and probabilistic earthquake information produced by Early-est, along with prior and non-seismic information and later seismic information (e.g., full-waveform moment-tensors), may be used within time-evolving, decision and modeling

  7. Global earthquake casualties due to secondary effects: A quantitative analysis for improving rapid loss analyses

    Science.gov (United States)

    Marano, K.D.; Wald, D.J.; Allen, T.I.

    2010-01-01

    This study presents a quantitative and geospatial description of global losses due to earthquake-induced secondary effects, including landslide, liquefaction, tsunami, and fire for events during the past 40 years. These processes are of great importance to the US Geological Survey's (USGS) Prompt Assessment of Global Earthquakes for Response (PAGER) system, which is currently being developed to deliver rapid earthquake impact and loss assessments following large/significant global earthquakes. An important question is how dominant are losses due to secondary effects (and under what conditions, and in which regions)? Thus, which of these effects should receive higher priority research efforts in order to enhance PAGER's overall assessment of earthquakes losses and alerting for the likelihood of secondary impacts? We find that while 21.5% of fatal earthquakes have deaths due to secondary (non-shaking) causes, only rarely are secondary effects the main cause of fatalities. The recent 2004 Great Sumatra-Andaman Islands earthquake is a notable exception, with extraordinary losses due to tsunami. The potential for secondary hazards varies greatly, and systematically, due to regional geologic and geomorphic conditions. Based on our findings, we have built country-specific disclaimers for PAGER that address potential for each hazard (Earle et al., Proceedings of the 14th World Conference of the Earthquake Engineering, Beijing, China, 2008). We will now focus on ways to model casualties from secondary effects based on their relative importance as well as their general predictability. ?? Springer Science+Business Media B.V. 2009.

  8. The Key Role of Eyewitnesses in Rapid Impact Assessment of Global Earthquake

    Science.gov (United States)

    Bossu, R.; Steed, R.; Mazet-Roux, G.; Roussel, F.; Etivant, C.; Frobert, L.; Godey, S.

    2014-12-01

    Uncertainties in rapid impact assessments of global earthquakes are intrinsically large because they rely on 3 main elements (ground motion prediction models, building stock inventory and related vulnerability) which values and/or spatial variations are poorly constrained. Furthermore, variations of hypocentral location and magnitude within their respective uncertainty domain can lead to significantly different shaking level for centers of population and change the scope of the disaster. We present the strategy and methods implemented at the Euro-Med Seismological Centre (EMSC) to rapidly collect in-situ observations on earthquake effects from eyewitnesses for reducing uncertainties of rapid earthquake impact assessment. It comprises crowdsourced information (online questionnaires, pics) as well as information derived from real time analysis of web traffic (flashourcing technique), and more recently deployment of QCN (Quake Catcher Network) low cost sensors. We underline the importance of merging results of different methods to improve performances and reliability of collected data.We try to better understand and respond to public demands and expectations after earthquakes through improved information services and diversification of information tools (social networks, smartphone app., browsers adds-on…), which, in turn, drive more eyewitnesses to our services and improve data collection. We will notably present our LastQuake Twitter feed (Quakebot) and smartphone applications (IOs and android) which only report earthquakes that matter for the public and authorities, i.e. felt and damaging earthquakes identified thanks to citizen generated information.

  9. Rapid earthquake detection through GPU-Based template matching

    Science.gov (United States)

    Mu, Dawei; Lee, En-Jui; Chen, Po

    2017-12-01

    The template-matching algorithm (TMA) has been widely adopted for improving the reliability of earthquake detection. The TMA is based on calculating the normalized cross-correlation coefficient (NCC) between a collection of selected template waveforms and the continuous waveform recordings of seismic instruments. In realistic applications, the computational cost of the TMA is much higher than that of traditional techniques. In this study, we provide an analysis of the TMA and show how the GPU architecture provides an almost ideal environment for accelerating the TMA and NCC-based pattern recognition algorithms in general. So far, our best-performing GPU code has achieved a speedup factor of more than 800 with respect to a common sequential CPU code. We demonstrate the performance of our GPU code using seismic waveform recordings from the ML 6.6 Meinong earthquake sequence in Taiwan.

  10. Rapid response seismic networks in Europe: lessons learnt from the L'Aquila earthquake emergency

    Directory of Open Access Journals (Sweden)

    Angelo Strollo

    2011-08-01

    Full Text Available

    The largest dataset ever recorded during a normal fault seismic sequence was acquired during the 2009 seismic emergency triggered by the damaging earthquake in L'Aquila (Italy. This was possible through the coordination of different rapid-response seismic networks in Italy, France and Germany. A seismic network of more than 60 stations recorded up to 70,000 earthquakes. Here, we describe the different open-data archives where it is possible to find this unique set of data for studies related to hazard, seismotectonics and earthquake physics. Moreover, we briefly describe some immediate and direct applications of emergency seismic networks. At the same time, we note the absence of communication platforms between the different European networks. Rapid-response networks need to agree on common strategies for network operations. Hopefully, over the next few years, the European Rapid-Response Seismic Network will became a reality.

  11. How citizen seismology is transforming rapid public earthquake information and interactions between seismologists and society

    Science.gov (United States)

    Bossu, Rémy; Steed, Robert; Mazet-Roux, Gilles; Roussel, Fréderic; Caroline, Etivant

    2015-04-01

    Historical earthquakes are only known to us through written recollections and so seismologists have a long experience of interpreting the reports of eyewitnesses, explaining probably why seismology has been a pioneer in crowdsourcing and citizen science. Today, Internet has been transforming this situation; It can be considered as the digital nervous system comprising of digital veins and intertwined sensors that capture the pulse of our planet in near real-time. How can both seismology and public could benefit from this new monitoring system? This paper will present the strategy implemented at Euro-Mediterranean Seismological Centre (EMSC) to leverage this new nervous system to detect and diagnose the impact of earthquakes within minutes rather than hours and how it transformed information systems and interactions with the public. We will show how social network monitoring and flashcrowds (massive website traffic increases on EMSC website) are used to automatically detect felt earthquakes before seismic detections, how damaged areas can me mapped through concomitant loss of Internet sessions (visitors being disconnected) and the benefit of collecting felt reports and geolocated pictures to further constrain rapid impact assessment of global earthquakes. We will also describe how public expectations within tens of seconds of ground shaking are at the basis of improved diversified information tools which integrate this user generated contents. A special attention will be given to LastQuake, the most complex and sophisticated Twitter QuakeBot, smartphone application and browser add-on, which deals with the only earthquakes that matter for the public: the felt and damaging earthquakes. In conclusion we will demonstrate that eyewitnesses are today real time earthquake sensors and active actors of rapid earthquake information.

  12. Locating Local Earthquakes Using Single 3-Component Broadband Seismological Data

    Science.gov (United States)

    Das, S. B.; Mitra, S.

    2015-12-01

    We devised a technique to locate local earthquakes using single 3-component broadband seismograph and analyze the factors governing the accuracy of our result. The need for devising such a technique arises in regions of sparse seismic network. In state-of-the-art location algorithms, a minimum of three station recordings are required for obtaining well resolved locations. However, the problem arises when an event is recorded by less than three stations. This may be because of the following reasons: (a) down time of stations in a sparse network; (b) geographically isolated regions with limited logistic support to setup large network; (c) regions of insufficient economy for financing multi-station network and (d) poor signal-to-noise ratio for smaller events at most stations, except the one in its closest vicinity. Our technique provides a workable solution to the above problematic scenarios. However, our methodology is strongly dependent on the velocity model of the region. Our method uses a three step processing: (a) ascertain the back-azimuth of the event from the P-wave particle motion recorded on the horizontal components; (b) estimate the hypocentral distance using the S-P time; and (c) ascertain the emergent angle from the vertical and radial components. Once this is obtained, one can ray-trace through the 1-D velocity model to estimate the hypocentral location. We test our method on synthetic data, which produces results with 99% precision. With observed data, the accuracy of our results are very encouraging. The precision of our results depend on the signal-to-noise ratio (SNR) and choice of the right band-pass filter to isolate the P-wave signal. We used our method on minor aftershocks (3 < mb < 4) of the 2011 Sikkim earthquake using data from the Sikkim Himalayan network. Location of these events highlight the transverse strike-slip structure within the Indian plate, which was observed from source mechanism study of the mainshock and larger aftershocks.

  13. Seismoelectric ground response to local and regional earthquakes

    Science.gov (United States)

    Dzieran, Laura; Rabbel, Wolfgang; Thorwart, Martin; Ritter, Oliver

    2017-04-01

    During earthquakes magnetotelluric stations occasionally record electric and magnetic signals similar to seismograms. The major part of these magnetic signals is induced by the seismic movement of the magnetometers (induction coils) in the static magnetic field. In contrast, the electric field signals are caused by the seismoelectric effect. Based on more than 600 earthquakes from Chile, Costa Rica and Europe we established a logarithmic magnitude-distance-relationship describing the magnitude threshold to be exceeded for observing seismoelectric (SE) signals with standard magnetotelluric (MT) recording units at given hypocentral distance r and for noise levels less than 3 μV/m. The log(r) term results from the geometric spreading of the radiated seismic waves. A comparison of SE signals at different hypocentral distances shows that observability is not only influenced by the amplitude of the incoming seismic wave. It also depends on the geological structure underneath the station which causes a unique frequency dependent SE response. To quantify these site effects we computed spectral seismoelectric transfer functions representing the ratios of the spectral amplitudes of SE records and acceleration seismograms (SESRs). Some stations show constant SESRs in the major frequency range, while others show a decrease with increasing frequencies. Based on the current Biot-type seismoelectric theory constant SESRs can be explained by coseismic SE waves alone. The observed SESR amplitudes at some sites are indeed consistent with theoretical expectations for electrically highly resistive soils or rocks, in agreement with the local geology of the investigated areas. The frequency dependence of SESRs observed at other locations can be explained if the incident SE waves consist not only of coseismic arrivals but also of a significant contribution from SE interface response waves which are generated at electrical or mechanical boundaries. Therefore, frequency-dependent SESRs

  14. Earthquake Magnitude and Shaking Intensity Dependent Fragility Functions for Rapid Risk Assessment of Buildings

    Directory of Open Access Journals (Sweden)

    Marie-José Nollet

    2018-01-01

    Full Text Available An integrated web application, referred to as ER2 for rapid risk evaluator, is under development for a user-friendly seismic risk assessment by the non-expert public safety community. The assessment of likely negative consequences is based on pre-populated databases of seismic, building inventory and vulnerability parameters. To further accelerate the computation for near real-time analyses, implicit building fragility curves were developed as functions of the magnitude and the intensity of the seismic shaking defined with a single intensity measure, input spectral acceleration at 1.0 s implicitly considering the epicentral distance and local soil conditions. Damage probabilities were compared with those obtained with the standard fragility functions explicitly considering epicentral distances and local site classes in addition to the earthquake magnitudes and respective intensity of the seismic shaking. Different seismic scenarios were considered first for 53 building classes common in Eastern Canada, and then a reduced number of 24 combined building classes was proposed. Comparison of results indicate that the damage predictions with implicit fragility functions for short (M ≤ 5.5 and medium strong motion duration (5.5 < M ≤ 7.5 show low variation with distance and soil class, with average error of less than 3.6%.

  15. Rapid Assessment of Earthquakes with Radar and Optical Geodetic Imaging and Finite Fault Models (Invited)

    Science.gov (United States)

    Fielding, E. J.; Sladen, A.; Simons, M.; Rosen, P. A.; Yun, S.; Li, Z.; Avouac, J.; Leprince, S.

    2010-12-01

    Earthquake responders need to know where the earthquake has caused damage and what is the likely intensity of damage. The earliest information comes from global and regional seismic networks, which provide the magnitude and locations of the main earthquake hypocenter and moment tensor centroid and also the locations of aftershocks. Location accuracy depends on the availability of seismic data close to the earthquake source. Finite fault models of the earthquake slip can be derived from analysis of seismic waveforms alone, but the results can have large errors in the location of the fault ruptures and spatial distribution of slip, which are critical for estimating the distribution of shaking and damage. Geodetic measurements of ground displacements with GPS, LiDAR, or radar and optical imagery provide key spatial constraints on the location of the fault ruptures and distribution of slip. Here we describe the analysis of interferometric synthetic aperture radar (InSAR) and sub-pixel correlation (or pixel offset tracking) of radar and optical imagery to measure ground coseismic displacements for recent large earthquakes, and lessons learned for rapid assessment of future events. These geodetic imaging techniques have been applied to the 2010 Leogane, Haiti; 2010 Maule, Chile; 2010 Baja California, Mexico; 2008 Wenchuan, China; 2007 Tocopilla, Chile; 2007 Pisco, Peru; 2005 Kashmir; and 2003 Bam, Iran earthquakes, using data from ESA Envisat ASAR, JAXA ALOS PALSAR, NASA Terra ASTER and CNES SPOT5 satellite instruments and the NASA/JPL UAVSAR airborne system. For these events, the geodetic data provided unique information on the location of the fault or faults that ruptured and the distribution of slip that was not available from the seismic data and allowed the creation of accurate finite fault source models. In many of these cases, the fault ruptures were on previously unknown faults or faults not believed to be at high risk of earthquakes, so the area and degree of

  16. The potential of imaging subsurface heterogeneities by local, natural earthquakes

    NARCIS (Netherlands)

    Nishitsuji, Y.; Doi, I.; Draganov, D.S.

    2014-01-01

    We have developed a new imaging technique of subsurface heterogeneities that uses Sp-waves from natural earthquakes. This technique can be used as a first screening tool in frontier exploration areas before conventional active exploration. Analyzing Sp-waves from 28 earthquakes (Mj 2.0 to 4.2)

  17. Conceptualizing ¬the Abstractions of Earthquakes Through an Instructional Sequence Using SeisMac and the Rapid Earthquake Viewer

    Science.gov (United States)

    Taber, J.; Hubenthal, M.; Wysession, M.

    2007-12-01

    Newsworthy earthquakes provide an engaging hook for students in Earth science classes, particularly when discussing their effects on people and the landscape. However, engaging students in an analysis of earthquakes that extends beyond death and damage, is frequently hampered by the abstraction of recorded ground motion data in the form of raw seismograms and the inability of most students to personally relate to ground accelerations. To overcome these challenges, an educational sequence has been developed using two software tools: SeisMac by Daniel Griscom, and the Rapid Earthquake Viewer (REV) developed by the University of South Carolina in collaboration with IRIS and DLESE. This sequence presents a unique opportunity for Earth Science teachers to "create" foundational experiences for students as they construction a framework of understanding of abstract concepts. The first activity is designed to introduce the concept of a three-component seismogram and to directly address the very abstract nature of seismograms through a kinesthetic experience. Students first learn to take the pulse of their classroom through a guided exploration of SeisMac, which displays the output of the laptop's built-in Sudden Motion Sensor (a 3-component accelerometer). This exploration allows students to view a 3-component seismogram as they move or tap the laptop and encourages them to propose and carry out experiments to explain the meaning of the 3-component seismogram. Once completed students are then asked to apply this new knowledge to a real 3-component seismogram printed from REV. Next the activity guides students through the process of identifying P and S waves and using SeisMac to connect the physical motion of the laptop to the "wiggles" they see on the SeisMac display and then comparing those to the "wiggles" they see on their seismogram. At this point students are more fully prepared to engage in an S-P location exercise such as those included in many state standards

  18. Automated rapid finite fault inversion for megathrust earthquakes: Application to the Maule (2010), Iquique (2014) and Illapel (2015) great earthquakes

    Science.gov (United States)

    Benavente, Roberto; Cummins, Phil; Dettmer, Jan

    2016-04-01

    Rapid estimation of the spatial and temporal rupture characteristics of large megathrust earthquakes by finite fault inversion is important for disaster mitigation. For example, estimates of the spatio-temporal evolution of rupture can be used to evaluate population exposure to tsunami waves and ground shaking soon after the event by providing more accurate predictions than possible with point source approximations. In addition, rapid inversion results can reveal seismic source complexity to guide additional, more detailed subsequent studies. This work develops a method to rapidly estimate the slip distribution of megathrust events while reducing subjective parameter choices by automation. The method is simple yet robust and we show that it provides excellent preliminary rupture models as soon as 30 minutes for three great earthquakes in the South-American subduction zone. This may slightly change for other regions depending on seismic station coverage but method can be applied to any subduction region. The inversion is based on W-phase data since it is rapidly and widely available and of low amplitude which avoids clipping at close stations for large events. In addition, prior knowledge of the slab geometry (e.g. SLAB 1.0) is applied and rapid W-phase point source information (time delay and centroid location) is used to constrain the fault geometry and extent. Since the linearization by multiple time window (MTW) parametrization requires regularization, objective smoothing is achieved by the discrepancy principle in two fully automated steps. First, the residuals are estimated assuming unknown noise levels, and second, seeking a subsequent solution which fits the data to noise level. The MTW scheme is applied with positivity constraints and a solution is obtained by an efficient non-negative least squares solver. Systematic application of the algorithm to the Maule (2010), Iquique (2014) and Illapel (2015) events illustrates that rapid finite fault inversion with

  19. Rapid post-earthquake modelling of coseismic landslide intensity and distribution for emergency response decision support

    Directory of Open Access Journals (Sweden)

    T. R. Robinson

    2017-09-01

    Full Text Available Current methods to identify coseismic landslides immediately after an earthquake using optical imagery are too slow to effectively inform emergency response activities. Issues with cloud cover, data collection and processing, and manual landslide identification mean even the most rapid mapping exercises are often incomplete when the emergency response ends. In this study, we demonstrate how traditional empirical methods for modelling the total distribution and relative intensity (in terms of point density of coseismic landsliding can be successfully undertaken in the hours and days immediately after an earthquake, allowing the results to effectively inform stakeholders during the response. The method uses fuzzy logic in a GIS (Geographic Information Systems to quickly assess and identify the location-specific relationships between predisposing factors and landslide occurrence during the earthquake, based on small initial samples of identified landslides. We show that this approach can accurately model both the spatial pattern and the number density of landsliding from the event based on just several hundred mapped landslides, provided they have sufficiently wide spatial coverage, improving upon previous methods. This suggests that systematic high-fidelity mapping of landslides following an earthquake is not necessary for informing rapid modelling attempts. Instead, mapping should focus on rapid sampling from the entire affected area to generate results that can inform the modelling. This method is therefore suited to conditions in which imagery is affected by partial cloud cover or in which the total number of landslides is so large that mapping requires significant time to complete. The method therefore has the potential to provide a quick assessment of landslide hazard after an earthquake and may therefore inform emergency operations more effectively compared to current practice.

  20. Rapid post-earthquake modelling of coseismic landslide intensity and distribution for emergency response decision support

    Science.gov (United States)

    Robinson, Tom R.; Rosser, Nicholas J.; Densmore, Alexander L.; Williams, Jack G.; Kincey, Mark E.; Benjamin, Jessica; Bell, Heather J. A.

    2017-09-01

    Current methods to identify coseismic landslides immediately after an earthquake using optical imagery are too slow to effectively inform emergency response activities. Issues with cloud cover, data collection and processing, and manual landslide identification mean even the most rapid mapping exercises are often incomplete when the emergency response ends. In this study, we demonstrate how traditional empirical methods for modelling the total distribution and relative intensity (in terms of point density) of coseismic landsliding can be successfully undertaken in the hours and days immediately after an earthquake, allowing the results to effectively inform stakeholders during the response. The method uses fuzzy logic in a GIS (Geographic Information Systems) to quickly assess and identify the location-specific relationships between predisposing factors and landslide occurrence during the earthquake, based on small initial samples of identified landslides. We show that this approach can accurately model both the spatial pattern and the number density of landsliding from the event based on just several hundred mapped landslides, provided they have sufficiently wide spatial coverage, improving upon previous methods. This suggests that systematic high-fidelity mapping of landslides following an earthquake is not necessary for informing rapid modelling attempts. Instead, mapping should focus on rapid sampling from the entire affected area to generate results that can inform the modelling. This method is therefore suited to conditions in which imagery is affected by partial cloud cover or in which the total number of landslides is so large that mapping requires significant time to complete. The method therefore has the potential to provide a quick assessment of landslide hazard after an earthquake and may therefore inform emergency operations more effectively compared to current practice.

  1. Urban MEMS based seismic network for post-earthquakes rapid disaster assessment

    Science.gov (United States)

    D'Alessandro, Antonino; Luzio, Dario; D'Anna, Giuseppe

    2014-05-01

    Life losses following disastrous earthquake depends mainly by the building vulnerability, intensity of shaking and timeliness of rescue operations. In recent decades, the increase in population and industrial density has significantly increased the exposure to earthquakes of urban areas. The potential impact of a strong earthquake on a town center can be reduced by timely and correct actions of the emergency management centers. A real time urban seismic network can drastically reduce casualties immediately following a strong earthquake, by timely providing information about the distribution of the ground shaking level. Emergency management centers, with functions in the immediate post-earthquake period, could be use this information to allocate and prioritize resources to minimize loss of human life. However, due to the high charges of the seismological instrumentation, the realization of an urban seismic network, which may allow reducing the rate of fatalities, has not been achieved. Recent technological developments in MEMS (Micro Electro-Mechanical Systems) technology could allow today the realization of a high-density urban seismic network for post-earthquakes rapid disaster assessment, suitable for the earthquake effects mitigation. In the 1990s, MEMS accelerometers revolutionized the automotive-airbag system industry and are today widely used in laptops, games controllers and mobile phones. Due to their great commercial successes, the research into and development of MEMS accelerometers are actively pursued around the world. Nowadays, the sensitivity and dynamics of these sensors are such to allow accurate recording of earthquakes with moderate to strong magnitude. Due to their low cost and small size, the MEMS accelerometers may be employed for the realization of high-density seismic networks. The MEMS accelerometers could be installed inside sensitive places (high vulnerability and exposure), such as schools, hospitals, public buildings and places of

  2. The 1448 earthquake in Catalonia. Some effects and local reactions

    Directory of Open Access Journals (Sweden)

    R. Salicrù i Lluch

    1995-06-01

    Full Text Available The May 1448 earthquake. the last destructive one that took place in Catalonia in the Middle Ages, was known chiefly from several chronistic and narrative medieval sources. To these sources I add new previously unknown data proceeding Eroin documentary archival sources in Barcelona, and other data that up to now have been wrongly considered as a consequence of the weak quake recorded in September 1450. They allow us to locate the epicentre in the Vall&s Oriental, around Llinars, to deny the existence of two almost simultaneous earthquakes, and to extend the range of the earthquake damage. to pinpoint them better and to suppose that the effects of the 1448 earthquake were more important than we had previously thought. All this information leads to several reflections on compulsory critical analysis of historical seismic documentary sources in order for them to be useful to historical seismicity. Finally. by the opposition of the three lands of documentary sources that refer to the damage caused by the earthquake in the township of Mataro. I show how natural catastrophes could be manipulated, and the skill of a society in exploiting them to deal with an adverse situation.

  3. Software Toolbox Development for Rapid Earthquake Source Optimisation Combining InSAR Data and Seismic Waveforms

    Science.gov (United States)

    Isken, Marius P.; Sudhaus, Henriette; Heimann, Sebastian; Steinberg, Andreas; Bathke, Hannes M.

    2017-04-01

    We present a modular open-source software framework (pyrocko, kite, grond; http://pyrocko.org) for rapid InSAR data post-processing and modelling of tectonic and volcanic displacement fields derived from satellite data. Our aim is to ease and streamline the joint optimisation of earthquake observations from InSAR and GPS data together with seismological waveforms for an improved estimation of the ruptures' parameters. Through this approach we can provide finite models of earthquake ruptures and therefore contribute to a timely and better understanding of earthquake kinematics. The new kite module enables a fast processing of unwrapped InSAR scenes for source modelling: the spatial sub-sampling and data error/noise estimation for the interferogram is evaluated automatically and interactively. The rupture's near-field surface displacement data are then combined with seismic far-field waveforms and jointly modelled using the pyrocko.gf framwork, which allows for fast forward modelling based on pre-calculated elastodynamic and elastostatic Green's functions. Lastly the grond module supplies a bootstrap-based probabilistic (Monte Carlo) joint optimisation to estimate the parameters and uncertainties of a finite-source earthquake rupture model. We describe the developed and applied methods as an effort to establish a semi-automatic processing and modelling chain. The framework is applied to Sentinel-1 data from the 2016 Central Italy earthquake sequence, where we present the earthquake mechanism and rupture model from which we derive regions of increased coulomb stress. The open source software framework is developed at GFZ Potsdam and at the University of Kiel, Germany, it is written in Python and C programming languages. The toolbox architecture is modular and independent, and can be utilized flexibly for a variety of geophysical problems. This work is conducted within the BridGeS project (http://www.bridges.uni-kiel.de) funded by the German Research Foundation DFG

  4. Earthquakes

    Science.gov (United States)

    ... earthquake occurs in a populated area, it may cause property damage, injuries, and even deaths. If you live in a coastal area, there is the possibility of a tsunami. Damage from earthquakes can also lead to floods or fires. Although there are no guarantees of ...

  5. An Efficient Rapid Warning System For Earthquakes In The European-mediterranean Region

    Science.gov (United States)

    Bossu, R.; Mazet-Roux, G.; di Giovambattista, R.; Tome, M.

    Every year a few damaging earthquakes occur in the European-Mediterranean region. It is therefore indispensable to operate a real-time warning system in order to pro- vide rapidly reliable estimates of the location, depth and magnitude of these seismic events. In order to provide this information in a timely manner both to the scientific community and to the European and national authorities dealing with natural hazards and relief organisation, the European-Mediterranean Seismological Centre (EMSC) has federated a network of seismic networks exchanging their data in quasi real-time. Today, thanks to the Internet, the EMSC receives real-time information about earth- quakes from about thirty seismological institutes. As soon as data reach the EMSC, they are displayed on the EMSC Web pages (www.emsc-csem.org). A seismic alert is generated for any potentially damaging earthquake in the European-Mediterranean re- gion, potentially damaging earthquakes being defined as seismic events of magnitude 5 or more. The warning system automatically issues a message to the duty seismolo- gist mobile phone and pager. The seismologist log in to the EMSC computers using a laptop PC and relocates the earthquake by processing together all information pro- vided by the networks. The new location and magnitude are then send, by fax, telex, and email, within one hour following the earthquake occurrence, to national and inter- national organisations whose activities are related to seismic risks, and to the EMSC members. The EMSC rapid warning system has been fully operational for more than 4 years. Its distributed architecture has proved to be an efficient and reliable way for the monitoring of potentially damaging earthquakes. Furthermore, if a major problem disrupts the operational system more than 30 minutes, the duty is taken, over either by the Instituto Geografico National in Spain or by the Istituto Nazionale di Geofisica in Italy. The EMSC operational centre, located at the

  6. Seismogeodetic monitoring techniques for tsunami and earthquake early warning and rapid assessment of structural damage

    Science.gov (United States)

    Haase, J. S.; Bock, Y.; Saunders, J. K.; Goldberg, D.; Restrepo, J. I.

    2016-12-01

    As part of an effort to promote the use of NASA-sponsored Earth science information for disaster risk reduction, real-time high-rate seismogeodetic data are being incorporated into early warning and structural monitoring systems. Seismogeodesy combines seismic acceleration and GPS displacement measurements using a tightly-coupled Kalman filter to provide absolute estimates of seismic acceleration, velocity and displacement. Traditionally, the monitoring of earthquakes and tsunamis has been based on seismic networks for estimating earthquake magnitude and slip, and tide gauges and deep-ocean buoys for direct measurement of tsunami waves. Real-time seismogeodetic observations at subduction zones allow for more robust and rapid magnitude and slip estimation that increase warning time in the near-source region. A NASA-funded effort to utilize GPS and seismogeodesy in NOAA's Tsunami Warning Centers in Alaska and Hawaii integrates new modules for picking, locating, and estimating magnitudes and moment tensors for earthquakes into the USGS earthworm environment at the TWCs. In a related project, NASA supports the transition of this research to seismogeodetic tools for disaster preparedness, specifically by implementing GPS and low-cost MEMS accelerometers for structural monitoring in partnership with earthquake engineers. Real-time high-rate seismogeodetic structural monitoring has been implemented on two structures. The first is a parking garage at the Autonomous University of Baja California Faculty of Medicine in Mexicali, not far from the rupture of the 2011 Mw 7.2 El Mayor Cucapah earthquake enabled through a UCMexus collaboration. The second is the 8-story Geisel Library at University of California, San Diego (UCSD). The system has also been installed for several proof-of-concept experiments at the UCSD Network for Earthquake Engineering Simulation (NEES) Large High Performance Outdoor Shake Table. We present MEMS-based seismogeodetic observations from the 10 June

  7. Damage Localization and Quantification of Earthquake Excited RC-Frames

    DEFF Research Database (Denmark)

    Skjærbæk, P. S.; Nielsen, Søren R. K.; Kirkegaard, Poul Henning

    1998-01-01

    of the ground motion events the storey accelerations were measured by accelerometers. After application of the last earthquake sequence to the structure the frames were cut into pieces and each of the beams and columns was statically tested and damage assessment was performed using the obtained stiffnesses...

  8. A detailed analysis of some local earthquakes at Somma-Vesuvius

    OpenAIRE

    C. Troise; C. Godano; F. Di Sena; G. De Natale; U. Coppa; P. Capuano

    1999-01-01

    In this paper, we analyze local earthquakes which occurred at Somma-Vesuvius during two episodes of intense seismic swarms, in 1989 and 1995 respectively. For the selected earthquakes we have computed accurate hypocentral locations, focal mechanisms and spectral parameters. We have also studied the ground acceleration produced by the largest events of the sequences (ML 3.0), at various digital stations installed in the area during the periods of higher seismic activity. The main result is tha...

  9. Thumbnail‐based questionnaires for the rapid and efficient collection of macroseismic data from global earthquakes

    Science.gov (United States)

    Bossu, Remy; Landes, Matthieu; Roussel, Frederic; Steed, Robert; Mazet-Roux, Gilles; Martin, Stacey S.; Hough, Susan E.

    2017-01-01

    The collection of earthquake testimonies (i.e., qualitative descriptions of felt shaking) is essential for macroseismic studies (i.e., studies gathering information on how strongly an earthquake was felt in different places), and when done rapidly and systematically, improves situational awareness and in turn can contribute to efficient emergency response. In this study, we present advances made in the collection of testimonies following earthquakes around the world using a thumbnail‐based questionnaire implemented on the European‐Mediterranean Seismological Centre (EMSC) smartphone app and its website compatible for mobile devices. In both instances, the questionnaire consists of a selection of thumbnails, each representing an intensity level of the European Macroseismic Scale 1998. We find that testimonies are collected faster, and in larger numbers, by way of thumbnail‐based questionnaires than by more traditional online questionnaires. Responses were received from all seismically active regions of our planet, suggesting that thumbnails overcome language barriers. We also observed that the app is not sufficient on its own, because the websites are the main source of testimonies when an earthquake strikes a region for the first time in a while; it is only for subsequent shocks that the app is widely used. Notably though, the speed of the collection of testimonies increases significantly when the app is used. We find that automated EMSC intensities as assigned by user‐specified thumbnails are, on average, well correlated with “Did You Feel It?” (DYFI) responses and with the three independently and manually derived macroseismic datasets, but there is a tendency for EMSC to be biased low with respect to DYFI at moderate and large intensities. We address this by proposing a simple adjustment that will be verified in future earthquakes.

  10. Earthquakes

    Science.gov (United States)

    Shedlock, Kaye M.; Pakiser, Louis Charles

    1998-01-01

    One of the most frightening and destructive phenomena of nature is a severe earthquake and its terrible aftereffects. An earthquake is a sudden movement of the Earth, caused by the abrupt release of strain that has accumulated over a long time. For hundreds of millions of years, the forces of plate tectonics have shaped the Earth as the huge plates that form the Earth's surface slowly move over, under, and past each other. Sometimes the movement is gradual. At other times, the plates are locked together, unable to release the accumulating energy. When the accumulated energy grows strong enough, the plates break free. If the earthquake occurs in a populated area, it may cause many deaths and injuries and extensive property damage. Today we are challenging the assumption that earthquakes must present an uncontrollable and unpredictable hazard to life and property. Scientists have begun to estimate the locations and likelihoods of future damaging earthquakes. Sites of greatest hazard are being identified, and definite progress is being made in designing structures that will withstand the effects of earthquakes.

  11. Rapid repair techniques for severely earthquake-damaged circular bridge piers with flexural failure mode

    Science.gov (United States)

    Sun, Zhiguo; Li, Hongnan; Bi, Kaiming; Si, Bingjun; Wang, Dongsheng

    2017-04-01

    In this study, three rapid repair techniques are proposed to retrofit circular bridge piers that are severely damaged by the flexural failure mode in major earthquakes. The quasi-static tests on three 1:2.5 scaled circular pier specimens are conducted to evaluate the efficiency of the proposed repair techniques. For the purpose of rapid repair, the repair procedure for all the specimens is conducted within four days, and the behavior of the repaired specimens is evaluated and compared with the original ones. A finite element model is developed to predict the cyclic behavior of the repaired specimens and the numerical results are compared with the test data. It is found that all the repaired specimens exhibit similar or larger lateral strength and deformation capacity than the original ones. The initial lateral stiffness of all the repaired specimens is lower than that of the original ones, while they show a higher lateral stiffness at the later stage of the test. No noticeable difference is observed for the energy dissipation capacity between the original and repaired pier specimens. It is suggested that the repair technique using the early-strength concrete jacket confined by carbon fiber reinforced polymer (CFRP) sheets can be an optimal method for the rapid repair of severely earthquake-damaged circular bridge piers with flexural failure mode.

  12. An algorithm of local earthquake detection from digital records

    Directory of Open Access Journals (Sweden)

    A. PROZOROV

    1978-06-01

    Full Text Available The problem of automatical detection of earthquake signals in seismograms
    and definition of first arrivals of p and s waves is considered.
    The algorithm is based on the analysis of t(A function which represents
    the time of first appearence of a number of going one after another
    swings of amplitudes greather than A in seismic signals. It allows to explore
    such common features of seismograms of earthquakes as sudden
    first p-arrivals of amplitude greater than general amplitude of noise and
    after the definite interval of time before s-arrival the amplitude of which
    overcomes the amplitude of p-arrival. The method was applied to
    3-channel recods of Friuli aftershocks, ¿'-arrivals were defined correctly
    in all cases; p-arrivals were defined in most cases using strict criteria of
    detection. Any false signals were not detected. All p-arrivals were defined
    using soft criteria of detection but less reliability and two false events
    were obtained.

  13. Rapid Source Characterization of the 2011 Mw 9.0 off the Pacific coast of Tohoku Earthquake

    Science.gov (United States)

    Hayes, Gavin P.

    2011-01-01

    On March 11th, 2011, a moment magnitude 9.0 earthquake struck off the coast of northeast Honshu, Japan, generating what may well turn out to be the most costly natural disaster ever. In the hours following the event, the U.S. Geological Survey National Earthquake Information Center led a rapid response to characterize the earthquake in terms of its location, size, faulting source, shaking and slip distributions, and population exposure, in order to place the disaster in a framework necessary for timely humanitarian response. As part of this effort, fast finite-fault inversions using globally distributed body- and surface-wave data were used to estimate the slip distribution of the earthquake rupture. Models generated within 7 hours of the earthquake origin time indicated that the event ruptured a fault up to 300 km long, roughly centered on the earthquake hypocenter, and involved peak slips of 20 m or more. Updates since this preliminary solution improve the details of this inversion solution and thus our understanding of the rupture process. However, significant observations such as the up-dip nature of rupture propagation and the along-strike length of faulting did not significantly change, demonstrating the usefulness of rapid source characterization for understanding the first order characteristics of major earthquakes.

  14. Local earthquake tomography of the Jalisco, Mexico region

    Science.gov (United States)

    Watkins, W. David; Thurber, Clifford H.; Abbott, Elizabeth R.; Brudzinski, Michael R.

    2018-01-01

    The states of Jalisco, Colima, and Michoacán in western Mexico overlie the boundary of the subducting Rivera and Cocos plates, presenting an ideal target for seismological inquiry to better understand the resulting mantle flow and regional volcanism. The different dips between the two subducting plates are thought to provide a mantle conduit that has contributed to the Colima Volcanic Complex (CVC), but there is considerable debate on the depth of the Rivera plate and width of the resulting conduit. With data from the Mapping the Rivera Subduction Zone (MARS) and Colima Deep Seismic Experiment (CODEX) networks, two temporary broadband arrays deployed in the region between 2006 and 2008, we inverted for three-dimensional P- and S-wave velocity as well as Vp/Vs structure of the upper 70 km of the crust and mantle in the Jalisco region. Using a newly-developed automatic P- and S-wave picker, we increased P picks by 74% and S picks by more than a factor of four compared to a database of manual picks for the 803 earthquakes used in the inversion. Additional relocated earthquakes extending to the trench are consistent with previous interpretations of the Rivera and Cocos plate interfaces. Areas of high Vp/Vs above both subducting slabs suggest the presence of fluids resulting from dehydration of subducted material. Extensive crustal seismicity occurs near these anomalies. A zone of high Vp/Vs is also present under the CVC. We also compare the results of different methods for obtaining Vp/Vs: a direct inversion for Vp/Vs from S minus P times versus simply dividing the Vp model by the Vs model. We find direct inversions of S minus P times to be more reliable.

  15. Fractal dimension variability in ULF magnetic field with reference to local earthquakes at MPGO, Ghuttu

    Directory of Open Access Journals (Sweden)

    Gautam Rawat

    2016-11-01

    Full Text Available Ultra-low frequency (ULF geomagnetic data recorded during 1 January 2010 to 31 December 2010 at multi-parametric geophysical observatory (30.53°N, 78.74°E in Garhwal Himalaya region of Uttarakhand, India, are analyzed. From the temporal variation of polarization ratio, the presence of seismo-magnetic disturbances superposed upon background geomagnetic variations are inferred. Considering earthquake process as a self-organized critical system based on flicker noise characteristics, fractal dimension for each day is estimated using two methods namely power spectral (FFT method and Higuchi method. Variability in fractal dimension is studied in the background of local earthquakes (M ≥ 3.5 within a zone of radius 150 km from observing station multi-parametric geophysical observatory (MPGO, Ghuttu. Fractal dimension variability indicates that average fractal dimension for first half of the year is increased as compared to average fractal dimension of second half of the year and there is gradual increase in the fractal dimension before earthquakes. It is also observed that during the first half of the year, there is seismic activity within zone of 150 Km radius centred at around MPGO, Ghuttu. There are no earthquakes during the second half of the year. Gradual increase in the fractal dimension before earthquakes, observed elsewhere in the world, is considered precursory signature of seismo-electromagnetic field emissions.

  16. Damage Localization and Quantification of Earthquake Excited RC-Frames

    DEFF Research Database (Denmark)

    Skjærbæk, P.S.; Nielsen, Søren R.K.; Kirkegaard, Poul Henning

    In the paper a recently proposed method for damage localization and quantification of RC-structures from response measurements is tested on experimental data. The method investigated requires at least one response measurement along the structure and the ground surface acceleration. Further, the t...

  17. Rapid establishment of an internally displaced persons disease surveillance system after an earthquake --- Haiti, 2010.

    Science.gov (United States)

    2010-08-06

    On January 12, 2010, a 7.0-magnitude earthquake in Haiti disrupted infrastructure and displaced approximately 2 million persons, causing increased risk for communicable diseases from overcrowding and poor living conditions. Hundreds of nongovernmental organizations (NGOs) established health-care clinics in camps of internally displaced persons (IDPs). To monitor conditions of outbreak potential identified at NGO camp clinics, on February 18, the Haiti Ministry of Public Health and Population (MSPP), the Pan-American Health Organization (PAHO), and CDC implemented the IDP Surveillance System (IDPSS). The Inter-Agency Standing Committee (IASC) "cluster approach" was used to coordinate the Haiti humanitarian response. One of 11 clusters, the Global Health Cluster (GHC), builds global capacity, whereas the country-level cluster (in this case, the Haitian Health Cluster [HHC], led by PAHO) responds locally. During the Haiti response, HHC engaged NGOs serving large camps, established IDPSS, followed trends of reportable conditions, undertook epidemiologic and laboratory investigations, and fostered implementation of control measures. This report describes the design and implementation of IDPSS in the post-earthquake period. The primary challenges to implementing IDPSS were communication difficulties with an ever-changing group of NGO partners and limitations to the utility of IDPSS data because of lack of reliable camp population denominator estimates. The IDPSS experience reinforces the need to improve local communication and coordination strategies. Improving future humanitarian response requires advance development and distribution of easily adaptable standard surveillance tools, development of an interdisciplinary strategy for an early and reliable population census, and development of communication strategies using locally available Internet and cellular networks.

  18. Interactive terrain visualization enables virtual field work during rapid scientific response to the 2010 Haiti earthquake

    Science.gov (United States)

    Cowgill, Eric; Bernardin, Tony S.; Oskin, Michael E.; Bowles, Christopher; Yikilmaz, M. Burak; Kreylos, Oliver; Elliott, Austin J.; Bishop, Scott; Gold, Ryan D.; Morelan, Alexander; Bawden, Gerald W.; Hamann, Bernd; Kellogg, Louise

    2012-01-01

    The moment magnitude (Mw) 7.0 12 January 2010 Haiti earthquake is the first major earthquake for which a large-footprint LiDAR (light detection and ranging) survey was acquired within several weeks of the event. Here, we describe the use of virtual reality data visualization to analyze massive amounts (67 GB on disk) of multiresolution terrain data during the rapid scientific response to a major natural disaster. In particular, we describe a method for conducting virtual field work using both desktop computers and a 4-sided, 22 m3 CAVE immersive virtual reality environment, along with KeckCAVES (Keck Center for Active Visualization in the Earth Sciences) software tools LiDAR Viewer, to analyze LiDAR point-cloud data, and Crusta, for 2.5 dimensional surficial geologic mapping on a bare-earth digital elevation model. This system enabled virtual field work that yielded remote observations of the topographic expression of active faulting within an ∼75-km-long section of the eastern Enriquillo–Plantain Garden fault spanning the 2010 epicenter. Virtual field observations indicated that the geomorphic evidence of active faulting and ancient surface rupture varies along strike. Landform offsets of 6–50 m along the Enriquillo–Plantain Garden fault east of the 2010 epicenter and closest to Port-au-Prince attest to repeated recent surface-rupturing earthquakes there. In the west, the fault trace is well defined by displaced landforms, but it is not as clear as in the east. The 2010 epicenter is within a transition zone between these sections that extends from Grand Goâve in the west to Fayette in the east. Within this transition, between L'Acul (lat 72°40′W) and the Rouillone River (lat 72°35′W), the Enriquillo–Plantain Garden fault is undefined along an embayed low-relief range front, with little evidence of recent surface rupture. Based on the geometry of the eastern and western faults that show evidence of recent surface rupture, we propose that the 2010

  19. Intermediate-depth earthquakes linked to localized heating in dunite and harzburgite

    Science.gov (United States)

    Ohuchi, Tomohiro; Lei, Xinglin; Ohfuji, Hiroaki; Higo, Yuji; Tange, Yoshinori; Sakai, Takeshi; Fujino, Kiyoshi; Irifune, Tetsuo

    2017-10-01

    The occurrence of intermediate-depth and deep earthquakes at depths greater than 60 km in subducting slabs has long puzzled geoscientists. These earthquakes require some mechanism to accelerate the fault movement at high pressures above 1.8 GPa. Localized heating would contribute to faulting, but experimental evidence for this mechanism has been limited to pressures of up to 0.5 GPa. Here we conduct deformation experiments on dry dunite samples at pressures of 1.0 to 2.6 GPa and temperatures of 860 to 1,350 K--conditions close to those for relatively shallow intermediate-depth earthquakes. We observe plastic deformation of the dunite, followed by faulting and acoustic emissions at an accelerated strain rate of about 5 × 10-5 s-1 or higher. We find that ultrafine-grained gouge layers containing iron-rich melt films, which is indicative of a very high peak temperature of about 2,110 K along the fault planes. We also observe faulting in wet harzburgite--a dehydration product of antigorite--at natural stress levels of 0.3 to 0.4 gigapascals. We therefore suggest that intermediate-depth earthquakes can be induced by localized heating both in dry and wet subducting slabs, if the background strain rate exceeds a threshold value in the range from 10-16 to 10-13 s-1.

  20. A new tool for rapid and automatic estimation of earthquake source parameters and generation of seismic bulletins

    Science.gov (United States)

    Zollo, Aldo

    2016-04-01

    RISS S.r.l. is a Spin-off company recently born from the initiative of the research group constituting the Seismology Laboratory of the Department of Physics of the University of Naples Federico II. RISS is an innovative start-up, based on the decade-long experience in earthquake monitoring systems and seismic data analysis of its members and has the major goal to transform the most recent innovations of the scientific research into technological products and prototypes. With this aim, RISS has recently started the development of a new software, which is an elegant solution to manage and analyse seismic data and to create automatic earthquake bulletins. The software has been initially developed to manage data recorded at the ISNet network (Irpinia Seismic Network), which is a network of seismic stations deployed in Southern Apennines along the active fault system responsible for the 1980, November 23, MS 6.9 Irpinia earthquake. The software, however, is fully exportable and can be used to manage data from different networks, with any kind of station geometry or network configuration and is able to provide reliable estimates of earthquake source parameters, whichever is the background seismicity level of the area of interest. Here we present the real-time automated procedures and the analyses performed by the software package, which is essentially a chain of different modules, each of them aimed at the automatic computation of a specific source parameter. The P-wave arrival times are first detected on the real-time streaming of data and then the software performs the phase association and earthquake binding. As soon as an event is automatically detected by the binder, the earthquake location coordinates and the origin time are rapidly estimated, using a probabilistic, non-linear, exploration algorithm. Then, the software is able to automatically provide three different magnitude estimates. First, the local magnitude (Ml) is computed, using the peak-to-peak amplitude

  1. Rapid decision tool to predict earthquake destruction in Sumatra by using first motion study

    Science.gov (United States)

    Bhakta, Shardul Sanjay

    The main idea of this project is to build an interactive and smart Geographic Information system tool which can help predict intensity of real time earthquakes in Sumatra Island of Indonesia. The tool has an underlying intelligence to predict the intensity of an earthquake depending on analysis of similar earthquakes in the past in that specific region. Whenever an earthquake takes place in Sumatra, a First Motion Study is conducted; this decides its type, depth, latitude and longitude. When the user inputs this information into the input string, the tool will try to find similar earthquakes with a similar First Motion Survey and depth. It will do a survey of similar earthquakes and predict if this real time earthquake can be disastrous or not. This tool has been developed in JAVA. I have used MOJO (Map Objects JAVA Objects) to show map of Indonesia and earthquake locations in the form of points. ESRI has created MOJO which is a set of JAVA API's. The Indonesia map, earthquake location points and its co-relation was all designed using MOJO. MOJO is a powerful tool which made it easy to design the tool. This tool is easy to use and the user has to input only a few parameters for the end result. I hope this tool justifies its use in prediction of earthquakes and help save lives in Sumatra.

  2. Rapid monitoring in vaccination campaigns during emergencies: the post-earthquake campaign in Haiti.

    Science.gov (United States)

    Rainey, Jeanette J; Sugerman, David; Brennan, Muireann; Cadet, Jean Ronald; Ernsly, Jackson; Lacapère, François; Danovaro-Holliday, M Carolina; Mubalama, Jean-Claude; Nandy, Robin

    2013-12-01

    The earthquake that struck Haiti in January 2010 caused 1.5 million people to be displaced to temporary camps. The Haitian Ministry of Public Health and Population and global immunization partners developed a plan to deliver vaccines to those residing in these camps. A strategy was needed to determine whether the immunization targets set for the campaign were achieved. Following the vaccination campaign, staff from the Ministry of Public Health and Population interviewed convenience samples of households - in specific predetermined locations in each of the camps - regarding receipt of the emergency vaccinations. A camp was targeted for "mop-up vaccination" - i.e. repeat mass vaccination - if more than 25% of the children aged 9 months to 7 years in the sample were found not to have received the emergency vaccinations. Rapid monitoring was implemented in camps located in the Port-au-Prince metropolitan area. Camps that housed more than 5000 people were monitored first. By the end of March 2010, 72 (23%) of the 310 vaccinated camps had been monitored. Although 32 (44%) of the monitored camps were targeted for mop-up vaccination, only six of them had received such repeat mass vaccination when checked several weeks after monitoring. Rapid monitoring was only marginally beneficial in achieving immunization targets in the temporary camps in Port-au-Prince. More research is needed to evaluate the utility of conventional rapid monitoring, as well as other strategies, during post-disaster vaccination campaigns that involve mobile populations, particularly when there is little capacity to conduct repeat mass vaccination.

  3. Earthquakes

    Science.gov (United States)

    ... or Traumatic Event Resources for Families Resources for Leaders Resources for State and Local Governments Emergency Responders: ... Emergency Wound Care Wound Management for Healthcare Pros Power Outages When the Power Goes Out Worker Safety ...

  4. Rapid assessment survey of earthquake affected Bhuj block of Kachchh District,FNx01 Gujarat, India

    OpenAIRE

    Pawar A; Shelke S; Kakrani V

    2005-01-01

    RESEARCH QUESTIONS: How much human loss would have caused by the earthquake in Bhuj block? What is the environmental sanitation status? OBJECTIVES: (1) To assess human loss and injuries after the earthquake in Bhuj block.(2) To study the status of some relief activities.(3) To study the environmental sanitation status of the earthquake affected Bhuj block. STUDY DESIGN: Cross-sectional study. SETTINGS: Bhuj block. Participants: All villages excluding Bhuj city of Bhuj block. Statist...

  5. How citizen seismology is transforming rapid public earthquake information: the example of LastQuake smartphone application and Twitter QuakeBot

    Science.gov (United States)

    Bossu, R.; Etivant, C.; Roussel, F.; Mazet-Roux, G.; Steed, R.

    2014-12-01

    Smartphone applications have swiftly become one of the most popular tools for rapid reception of earthquake information for the public. Wherever someone's own location is, they can be automatically informed when an earthquake has struck just by setting a magnitude threshold and an area of interest. No need to browse the internet: the information reaches you automatically and instantaneously! One question remains: are the provided earthquake notifications always relevant for the public? A while after damaging earthquakes many eyewitnesses scrap the application they installed just after the mainshock. Why? Because either the magnitude threshold is set too high and many felt earthquakes are missed, or it is set too low and the majority of the notifications are related to unfelt earthquakes thereby only increasing anxiety among the population at each new update. Felt and damaging earthquakes are the ones of societal importance even when of small magnitude. LastQuake app and Twitter feed (QuakeBot) focuses on these earthquakes that matter for the public by collating different information threads covering tsunamigenic, damaging and felt earthquakes. Non-seismic detections and macroseismic questionnaires collected online are combined to identify felt earthquakes regardless their magnitude. Non seismic detections include Twitter earthquake detections, developed by the USGS, where the number of tweets containing the keyword "earthquake" is monitored in real time and flashsourcing, developed by the EMSC, which detect traffic surges on its rapid earthquake information website caused by the natural convergence of eyewitnesses who rush to the Internet to investigate the cause of the shaking that they have just felt. We will present the identification process of the felt earthquakes, the smartphone application and the 27 automatically generated tweets and how, by providing better public services, we collect more data from citizens.

  6. A detailed analysis of some local earthquakes at Somma-Vesuvius

    Directory of Open Access Journals (Sweden)

    C. Troise

    1999-06-01

    Full Text Available In this paper, we analyze local earthquakes which occurred at Somma-Vesuvius during two episodes of intense seismic swarms, in 1989 and 1995 respectively. For the selected earthquakes we have computed accurate hypocentral locations, focal mechanisms and spectral parameters. We have also studied the ground acceleration produced by the largest events of the sequences (ML 3.0, at various digital stations installed in the area during the periods of higher seismic activity. The main result is that seismicity during the two swarm episodes presents similar features in both locations and focal mechanisms. Strong site dependent effects are evidenced in the seismic radiation and strong amplifications in the frequency band 10-15 Hz are evident at stations located on the younger Vesuvius structure, with respect to one located on the ancient Somma structure. Furthermore, seismic stations show peak accelerations for the same events of more than one order of magnitude apart.

  7. Local changes in the total electron content immediately before the 2009 Abruzzo earthquake

    CERN Document Server

    Nenovski, Petko; Ciraolo, Luigi; Vellante, Massimo; Villante, Umberto; DeLauretis, Marcello

    2014-01-01

    Ionospheric TEC (Total Electron Content) variations derived from GPS measurements at 17 stations before and after the 2009 Abruzzo earthquake (EQ) of magnitude Mw6.3 were processed and analyzed. The analysis included interpolated and non-interpolated TEC data. Variations in the TEC of both regional and local characteristics were revealed. Several regional changes were observed in the studied period: 1 Jan-21 Apr. 2009. After analyzing non-interpolated TEC data of 5 GPS stations in Central Italy (Unpg (Perugia), Untr, Aqui (Aquila), M0se (Roma) and Paca (Palma)), a local disturbance of TEC was also found. This local TEC disturbance arises preparatory to the EQ main shock occurred at 01:32 UT on 06 April 2009, maximizes its amplitude of ~ 0.8 TECu after the shock moment and disappears after it. The TEC disturbance was localized at heights below 160 km, i.e. in the lower ionosphere.

  8. LastQuake: a comprehensive strategy for rapid engagement of earthquake eyewitnesses, massive crowdsourcing and risk reduction

    Science.gov (United States)

    Bossu, R.; Roussel, F.; Mazet-Roux, G.; Steed, R.; Frobert, L.

    2015-12-01

    LastQuake is a smartphone app, browser add-on and the most sophisticated Twitter robot (quakebot) for earthquakes currently in operation. It fulfills eyewitnesses' needs by offering information on felt earthquakes and their effects within tens of seconds of their occurrence. Associated with an active presence on Facebook, Pinterest and on websites, this proves a very efficient engagement strategy. For example, the app was installed thousands of times after the Ghorka earthquake in Nepal. Language barriers have been erased by using visual communication; for example, felt reports are collected through a set of cartoons representing different shaking levels. Within 3 weeks of the magnitude 7.8 Ghorka earthquakes, 7,000 felt reports with thousands of comments were collected related to the mainshock and tens of its aftershocks as well as 100 informative geo-located pics. The QuakeBot was essential in allowing us to be identified so well and interact with those affected. LastQuake is also a risk reduction tool since it provides rapid information. Rapid information is similar to prevention since when it does not exist, disasters can happen. When no information is available after a felt earthquake, the public block emergency lines by trying to find out the cause of the shaking, crowds form potentially leading to unpredictable crowd movement, rumors spread. In its next release LastQuake will also provide people with guidance immediately after a shaking through a number of pop-up cartoons illustrating "do/don't do" items (go to open places, do not phone emergency services except if people are injured…). LastQuake's app design is simple and intuitive and has a global audience. It benefited from a crowdfunding campaign (and the support of the Fondation MAIF) and more improvements have been planned after an online feedback campaign organized in early June with the Ghorka earthquake eyewitnesses. LastQuake is also a seismic risk reduction tools thanks to its very rapid

  9. ShakeMap implementation for Pyrenees in France-Spain border: regional adaptation and earthquake rapid response process.

    OpenAIRE

    Bertil, Didier; Roviró, Jordi; Antonio Jara, Jose; Susagna, Teresa; Nus, Eduard; Goula, Xavier; Colas, Bastien; Dumont, Guillaume; Cabañas, Luis; Anton, Resurección; Calvet, Marie

    2012-01-01

    International audience; The USGS-ShakeMap package is used with a regional adaptation to provide automatic shake maps in rapid response for Pyrenean earthquakes. The Near Real Time system relies on servers designed for data exchange between transborder organizations involved in the Sispyr project. First maps will be provide as soon as possible after the shock, and updated with observed macroseismic intensities on the following hours. Regional Predictive Equations Tapia (2006) and Goula et al. ...

  10. Drug-coated microneedles for rapid and painless local anesthesia.

    Science.gov (United States)

    Baek, Sung-Hyun; Shin, Ju-Hyung; Kim, Yeu-Chun

    2017-03-01

    This study showed that drug-coated PLLA (Poly (L-lactide)) microneedle arrays can induce rapid and painless local anesthesia. Microneedle arrays were fabricated using a micro-molding technique, and the needle tips were coated with 290.6 ± 45.9 μg of lidocaine, the most widely used local anesthetic worldwide. A dip-coating device was newly designed for the coating step using an optimized coating formulation. Lidocaine coated on the arrays was released rapidly into PBS within 2 min, and its stability in storage lasted 3 weeks at 4, 25, and 37°C. Furthermore, the microneedle arrays showed consistent in vitro skin penetration and delivered 200.8 ± 43.9, 224.2 ± 39.3, and 244.1 ± 19.6 μg of lidocaine into the skin 1, 2, and 5 min after application with a high delivery efficiency of 69, 77, and 84%. Compared to a commercially available topical anesthetic EMLA® cream, a 22.0, 13.6, and 14.0-fold higher amount of lidocaine was delivered into the skin. Note, in vitro skin permeation of Lidocaine was also notably enhanced by a 2-min-application of the lidocaine-coated microneedle arrays. Altogether, these results suggest that the biocompatible lidocaine-coated PLLA microneedle arrays could provide significantly rapid local anesthesia in a painless manner without any of the issues from topical applications or hypodermic injections of local anesthetics.

  11. Why local people did not present a problem in the 2016 Kumamoto earthquake, Japan though people accused in the 2009 L'Aquila earthquake?

    Science.gov (United States)

    Sugimoto, M.

    2016-12-01

    Risk communication is a big issues among seismologists after the 2009 L'Aquila earthquake all over the world. A lot of people remember 7 researchers as "L'Aquila 7" were accused in Italy. Seismologists said it is impossible to predict an earthquake by science technology today and join more outreach activities. "In a subsequent inquiry of the handling of the disaster, seven members of the Italian National Commission for the Forecast and Prevention of Major Risks were accused of giving "inexact, incomplete and contradictory" information about the danger of the tremors prior to the main quake. On 22 October 2012, six scientists and one ex-government official were convicted of multiple manslaughter for downplaying the likelihood of a major earthquake six days before it took place. They were each sentenced to six years' imprisonment (Wikipedia)". Finally 6 scientists are not guilty. The 2016 Kumamoto earthquake hit Kyushu, Japan in April. They are very similar seismological situations between the 2016 Kumamoto earthquake and the 2009 L'Aquila earthquake. The foreshock was Mj6.5 and Mw6.2 in 14 April 2016. The main shock was Mj7.3 and Mw7.0. Japan Metrological Agency (JMA) misleaded foreshock as mainshock before main shock occured. 41 people died by the main shock in Japan. However local people did not accused scientists in Japan. It has been less big earhquakes around 100 years in Kumamoto. Poeple was not so matured that they treated earthquake information in Kyushu, Japan. How are there differences between Japan and Italy? We learn about outreach activities for sciencits from this case.

  12. Localized damage caused by topographic amplification during the 2010 M7.0 Haiti earthquake

    Science.gov (United States)

    Hough, S.E.; Altidor, J.R.; Anglade, D.; Given, D.; Janvier, M.G.; Maharrey, J.Z.; Meremonte, M.; Mildor, B.S.-L.; Prepetit, C.; Yong, A.

    2010-01-01

    Local geological conditions, including both near-surface sedimentary layers and topographic features, are known to significantly influence ground motions caused by earthquakes. Microzonation maps use local geological conditions to characterize seismic hazard, but commonly incorporate the effect of only sedimentary layers. Microzonation does not take into account local topography, because significant topographic amplification is assumed to be rare. Here we show that, although the extent of structural damage in the 2010 Haiti earthquake was primarily due to poor construction, topographic amplification contributed significantly to damage in the district of Petionville, south of central Port-au-Prince. A large number of substantial, relatively well-built structures situated along a foothill ridge in this district sustained serious damage or collapse. Using recordings of aftershocks, we calculate the ground motion response at two seismic stations along the topographic ridge and at two stations in the adjacent valley. Ground motions on the ridge are amplified relative to both sites in the valley and a hard-rock reference site, and thus cannot be explained by sediment-induced amplification. Instead, the amplitude and predominant frequencies of ground motion indicate the amplification of seismic waves by a narrow, steep ridge. We suggest that microzonation maps can potentially be significantly improved by incorporation of topographic effects. ?? 2010 Macmillan Publishers Limited. All rights reserved.

  13. Rapid local anesthesia in humans using minimally invasive microneedles.

    Science.gov (United States)

    Gupta, Jyoti; Denson, Donald D; Felner, Eric I; Prausnitz, Mark R

    2012-02-01

    This study tested the hypothesis that minimally invasive microneedles cause less pain during injection of lidocaine, but induce local anesthesia in humans with the same rapid onset and efficacy as intradermal lidocaine injection using hypodermic needles. This study was a randomized, single-blinded, within participants, controlled design. Hollow, 500-μm long microneedles were used to inject lidocaine to the forearm of 15 human participants. The associated pain was recorded using a visual analog (VAS) scale. The area and depth of numbness were determined at 0, 7.5, and 15 minutes after injection. Lidocaine was also injected to the dorsum of the hand near a vein, followed by placement of an intravenous catheter and measurement of associated pain. A 26-gauge intradermal bevel hypodermic needle similarly administered lidocaine on the opposite forearm/hand to serve as the positive control. VAS pain scores revealed that injection using microneedles was significantly less painful than hypodermic needles for both the forearm and dorsum of the hand injections. However, there was no significant difference in the area or depth of the resulting numbness between the 2 treatment methods at any time point (0, 7.5, and 15 min) indicating that microneedles had immediate onset and were as effective as hypodermic needles in inducing dermal anesthesia. Moreover, insertion of an intravenous catheter immediately after lidocaine injection on the dorsum of the hand led to comparable pain scores for the microneedle and hypodermic needle treated sites, further confirming efficacy of microneedles in inducing rapid local anesthesia. Lastly, 77% of the participants preferred microneedles and 80% indicated that they did not consider microneedles to be painful. This study demonstrates for the first time that microneedle-based lidocaine injection is as rapid and as effective as hypodermic injection in inducing local anesthesia while resulting in significantly less pain during injection.

  14. The impact of Bam earthquake on substance users in the first 2 weeks: a rapid assessment.

    Science.gov (United States)

    Movaghar, Afarin Rahimi; Goodarzi, Reza Rad; Izadian, Elaheh; Mohammadi, Mohammad Reza; Hosseini, Mehdi; Vazirian, Mohsen

    2005-09-01

    In the final days of the year 2003, an earthquake in the city of Bam, Iran, led to the death of some 35,000 of its inhabitants. The rate of opium abuse, which had been high among the male population in this city, caused problems after the earthquake. The aim of the following study was to examine the status of substance abusers during the first 2 weeks after the earthquake. The study was carried out in the city of Bam, one of its nearby villages and eight hospitals admitting earthquake victims. One hundred and sixty-three individuals were interviewed, including substance abusers, their family members, people living in Bam, service providers, and the authorities. During the first 2 weeks after the earthquake, about half of drug-dependent interviewees suffered from withdrawal symptoms. About half reported their problems to health care providers and asked for morphine or other analgesics. Around one third had used opium on the first day and two thirds in the course of the second day to the end of the second week after the earthquake. Although smoking had been the most common means of abuse before the earthquake, oral intake has become the most prevalent route after the disaster. Almost all obtained their opium from inhabitants of other cities as gifts. Members of rescue and health delivery systems had a lot of encounters with opium abusers, especially in the first 3 days after the earthquake, and had prescribed morphine and other analgesics. In societies with a considerable prevalence of substance abuse, this issue becomes a matter of utmost health care and social importance at times of disasters, and the necessary arrangements to deal with it should be present beforehand.

  15. Application and evaluation of a rapid response earthquake-triggered landslide model to the 25 April 2015 Mw 7.8 Gorkha earthquake, Nepal

    Science.gov (United States)

    Gallen, Sean F.; Clark, Marin K.; Godt, Jonathan W.; Roback, Kevin; Niemi, Nathan A.

    2017-09-01

    The 25 April 2015 Mw 7.8 Gorkha earthquake produced strong ground motions across an approximately 250 km by 100 km swath in central Nepal. To assist disaster response activities, we modified an existing earthquake-triggered landslide model based on a Newmark sliding block analysis to estimate the extent and intensity of landsliding and landslide dam hazard. Landslide hazard maps were produced using Shuttle Radar Topography Mission (SRTM) digital topography, peak ground acceleration (PGA) information from the U.S. Geological Survey (USGS) ShakeMap program, and assumptions about the regional rock strength based on end-member values from previous studies. The instrumental record of seismicity in Nepal is poor, so PGA estimates were based on empirical Ground Motion Prediction Equations (GMPEs) constrained by teleseismic data and felt reports. We demonstrate a non-linear dependence of modeled landsliding on aggregate rock strength, where the number of landslides decreases exponentially with increasing rock strength. Model estimates are less sensitive to PGA at steep slopes (> 60°) compared to moderate slopes (30-60°). We compare forward model results to an inventory of landslides triggered by the Gorkha earthquake. We show that moderate rock strength inputs over estimate landsliding in regions beyond the main slip patch, which may in part be related to poorly constrained PGA estimates for this event at far distances from the source area. Directly above the main slip patch, however, the moderate strength model accurately estimates the total number of landslides within the resolution of the model (landslides ≥ 0.0162 km2; observed n = 2214, modeled n = 2987), but the pattern of landsliding differs from observations. This discrepancy is likely due to the unaccounted for effects of variable material strength and local topographic amplification of strong ground motion, as well as other simplifying assumptions about source characteristics and their relationship to

  16. Probabilistic seismic hazard assessments of Sabah, east Malaysia: accounting for local earthquake activity near Ranau

    Science.gov (United States)

    Khalil, Amin E.; Abir, Ismail A.; Ginsos, Hanteh; Abdel Hafiez, Hesham E.; Khan, Sohail

    2018-02-01

    Sabah state in eastern Malaysia, unlike most of the other Malaysian states, is characterized by common seismological activity; generally an earthquake of moderate magnitude is experienced at an interval of roughly every 20 years, originating mainly from two major sources, either a local source (e.g. Ranau and Lahad Dato) or a regional source (e.g. Kalimantan and South Philippines subductions). The seismicity map of Sabah shows the presence of two zones of distinctive seismicity, these zones are near Ranau (near Kota Kinabalu) and Lahad Datu in the southeast of Sabah. The seismicity record of Ranau begins in 1991, according to the international seismicity bulletins (e.g. United States Geological Survey and the International Seismological Center), and this short record is not sufficient for seismic source characterization. Fortunately, active Quaternary fault systems are delineated in the area. Henceforth, the seismicity of the area is thus determined as line sources referring to these faults. Two main fault systems are believed to be the source of such activities; namely, the Mensaban fault zone and the Crocker fault zone in addition to some other faults in their vicinity. Seismic hazard assessments became a very important and needed study for the extensive developing projects in Sabah especially with the presence of earthquake activities. Probabilistic seismic hazard assessments are adopted for the present work since it can provide the probability of various ground motion levels during expected from future large earthquakes. The output results are presented in terms of spectral acceleration curves and uniform hazard curves for periods of 500, 1000 and 2500 years. Since this is the first time that a complete hazard study has been done for the area, the output will be a base and standard for any future strategic plans in the area.

  17. Rapid assessment survey of earthquake affected Bhuj block of Kachchh District, Gujarat, India.

    Science.gov (United States)

    Pawar, A T; Shelke, S; Kakrani, V A

    2005-11-01

    How much human loss would have caused by the earthquake in Bhuj block? What is the environmental sanitation status? (1) To assess human loss and injuries after the earthquake in Bhuj block.(2) To study the status of some relief activities.(3) To study the environmental sanitation status of the earthquake affected Bhuj block. Cross-sectional study. Bhuj block. All villages excluding Bhuj city of Bhuj block. Proportions, chi-square test, chi-square for trend. Survey was done in 144 villages; there were total 541 deaths with death rate of 3.18 per 1000 population. Death rate was significantly associated with distance of village from epicenter (chi-square for trend significant, P open-air defecation was practiced. Diseases such as URTIs, diarrheal diseases, fever and conjunctivitis were commonly observed in the field area.

  18. Aftershock Study of the 2014 Duncan, Arizona Mw = 5.2 Earthquake Using Local Seismic Data

    Science.gov (United States)

    Dorn, K. M.; Young, J.; Barstow, N.; Peavey, H.; Braunmiller, J.

    2016-12-01

    On June 29, 2014, at 4:59:35.4 UTC, a Mw = 5.2 earthquake struck near Duncan, just west of the Arizona-New Mexico border. This event is the strongest instrumentally recorded earthquake yet in southeastern Arizona, which experiences low seismicity due to slow roughly east-west-trending extension in the transition zone between the Basin and Range region and the stable Colorado Plateau to the north. An approximately 15-by-20-km-wide temporary network of four short-period and two broadband seismometers was deployed to study the aftershock sequence, as the nearest permanent stations are located over one hundred kilometers away. We used the BRTT Antelope "dbdetect" and "dbgrassoc" tools to obtain locations for about 10,000 aftershocks from July 8 through August 28, 2014, when at least four local stations were operational. Our preliminary results suggest that most of the activity occurred in a north-south-elongated area, within 32.57-32.64° N and 109.11-109.15° W and about 4-7 km deep. We have not observed distinct event migrations, but found several event clusters within the aftershock region that were active for short time periods, implying a complex pattern of strain release. The aftershock sequence has continued for more than two years after the mainshock event.

  19. 3D Velocity Structure in Southern Haiti from Local Earthquake Tomography

    Science.gov (United States)

    Douilly, R.; Ellsworth, W. L.; Kissling, E. H.; Freed, A. M.; Deschamps, A.; de Lepinay, B. M.

    2016-12-01

    We investigate 3D local earthquake tomography for high-quality travel time arrivals from aftershocks following the 2010 M7.0 Haiti earthquake on the Léogâne fault. The data were recorded by 35 stations, including 19 ocean bottom seismometers, from which we selected 595 events to simultaneously invert for hypocenter location and 3D Vp and Vs velocity structures in southern Haiti. We performed several resolution tests and concluded that clear features can be recovered to a depth of 15 km. At 5km depth we distinguish a broad low velocity zone in the Vp and Vs structure offshore near Gonave Island, which correlate with layers of marine sediments. Results show a pronounced low velocity zone in the upper 5 km across the city of Léogâne, which is consistent with the sedimentary basin location from geologic map. At 10 km depth, we detect a low velocity anomaly offshore near the Trois Baies fault and a NW-SE directed low velocity zone onshore across Petit-Goâve and Jacmel, which is consistent with a suspected fault from a previous study and that we refer to it in our study as the Petit-Goâve-Jacmel fault (PGJF). These observations suggest that low velocity structures delineate fault structures and the sedimentary basins across the southern peninsula, which is extremely useful for seismic hazard assessment in Haiti.

  20. 3D dynamic rupture simulation and local tomography studies following the 2010 Haiti earthquake

    Science.gov (United States)

    Douilly, Roby

    The 2010 M7.0 Haiti earthquake was the first major earthquake in southern Haiti in 250 years. As this event could represent the beginning of a new period of active seismicity in the region, and in consideration of how vulnerable the population is to earthquake damage, it is important to understand the nature of this event and how it has influenced seismic hazards in the region. Most significantly, the 2010 earthquake occurred on the secondary Leogâne thrust fault (two fault segments), not the Enriquillo Fault, the major strike-slip fault in the region, despite it being only a few kilometers away. We first use a finite element model to simulate rupture along the Leogâne fault. We varied friction and background stress to investigate the conditions that best explain observed surface deformations and why the rupture did not to jump to the nearby Enriquillo fault. Our model successfully replicated rupture propagation along the two segments of the Leogâne fault, and indicated that a significant stress increase occurred on the top and to the west of the Enriquillo fault. We also investigated the potential ground shaking level in this region if a rupture similar to the Mw 7.0 2010 Haiti earthquake were to occur on the Enriquillo fault. We used a finite element method and assumptions on regional stress to simulate low frequency dynamic rupture propagation for the segment of the Enriquillo fault closer to the capital. The high-frequency ground motion components were calculated using the specific barrier model, and the hybrid synthetics were obtained by combining the low-frequencies ( 1Hz) from the stochastic simulation using matched filtering at a crossover frequency of 1 Hz. The average horizontal peak ground acceleration, computed at several sites of interest through Port-au-Prince (the capital), has a value of 0.35g. Finally, we investigated the 3D local tomography of this region. We considered 897 high-quality records from the earthquake catalog as recorded by

  1. Citizen earthquake alert using near real time PGA estimation from a local array combining a variety of accelerometric instruments

    Science.gov (United States)

    Melis, Nikolaos S.; Konstantinou, Konstantinos; Kalogeras, Ioannis; Sokos, Efthimios; Tselentis, G.-Akis

    2017-04-01

    It is of a great importance to assess rapidly the intensity of a felt event in a highly populated environment. Rapid and reliable information plays a key role to decision making responses, by performing correctly the first steps after a felt ground shaking. Thus, it is important to accurately respond to urgent societal demand using reliable information. A strong motion array is under deployment and trial operation in the area of Patras, Greece. It combines: (a) standard accelerometric stations operated by the National Observatory of Athens, Institute of Geodynamics (NOA), (b) QCN-type USB MEMS acceleration sensors deployed in schools and (c) P-alert MEMS acceleration devices deployed in public sector buildings as well as in private dwellings. The array intends to cover the whole city of Patras and the populated suburbs. All instruments are operating in near real time and they are linked to a combined Earthworm - SeisComP3 server at NOA, Athens. Rapid intensity estimation can be also performed by the P-alert accelerometers locally, but the performance of a near real time intensity estimation system is under operation at NOA. The procedure is based on observing the maximum PGA value at each instrument and empirically estimate the corresponding intensity. The values are also fed to a SeisComP3 based ShakeMap procedure that is served at NOA and uses the scwfparam module of SeisComP3. Earthquake activity has been recorded so far from the western Corinth Gulf, the Ionian Islands and Achaia-Elia area, western Peloponnesus. The first phase involves correlation tests of collocated instruments and assessment of their performance to low intensity as well as to strongly felt events in the Patras city area. Steps of expanding the array are also under consideration, in order to cover the wider area of northwestern Peloponnesus and Ionian islands.

  2. The potential of continuous, local atomic clock measurements for earthquake prediction and volcanology

    Directory of Open Access Journals (Sweden)

    Bondarescu Mihai

    2015-01-01

    Full Text Available Modern optical atomic clocks along with the optical fiber technology currently being developed can measure the geoid, which is the equipotential surface that extends the mean sea level on continents, to a precision that competes with existing technology. In this proceeding, we point out that atomic clocks have the potential to not only map the sea level surface on continents, but also look at variations of the geoid as a function of time with unprecedented timing resolution. The local time series of the geoid has a plethora of applications. These include potential improvement in the predictions of earthquakes and volcanoes, and closer monitoring of ground uplift in areas where hydraulic fracturing is performed.

  3. Case Study of Local Damage Indicators for a 2-Bay, 6-Storey RC-Frame subject to Earthquakes

    DEFF Research Database (Denmark)

    Skjærbæk, P. S.; Nielsen, Søren R. K.; Kirkegaard, Poul Henning

    A simulation study of a 2-bay, 6storey model test RC-frame(scale 1:5) subject to earthquakes is considered in this paper. Based on measured (simulated) storey accelerations and ground surface accelerations several indices for the storey damage, including interstorey drift, flexural damage ratios......, normalized cumulative dissipated energy, Park and Ang's indicator, a low-cycle fatigue damage index and a recently proposed local softening damage index estimated from time-varying eigenfrequencies are used to evaluate the damage state of the structure after the earthquake. Storey displacements are obtained...

  4. Case Study of Local Damage Indicators for a 2-Bay, 6-Storey RC-Frame subject to Earthquakes

    DEFF Research Database (Denmark)

    Skjærbæk, P. S.; Nielsen, Søren R. K.; Kirkegaard, Poul Henning

    1997-01-01

    A simulation study of a 2-bay, 6storey model test RC-frame(scale 1:5) subject to earthquakes is considered in this paper. Based on measured (simulated) storey accelerations and ground surface accelerations several indices for the storey damage, including interstorey drift, flexural damage ratios......, normalized cumulative dissipated energy, Park and Ang's indicator, a low-cycle fatigue damage index and a recently proposed local softening damage index estimated from time-varying eigenfrequencies are used to evaluate the damage state of the structure after the earthquake. Storey displacements are obtained...

  5. P-Wave Velocity Tomography from Local Earthquakes in Western Mexico

    Science.gov (United States)

    Ochoa-Chávez, Juan A.; Escudero, Christian R.; Núñez-Cornú, Francisco J.; Bandy, William L.

    2016-10-01

    In western Mexico, the subduction of the Rivera and Cocos plates beneath the North America plate has deformed and fragmented the overriding plate, forming several structural rifts and crustal blocks. To obtain a reliable subsurface image of the continental crust and uppermost mantle in this complex area, we used P-wave arrivals of local earthquakes along with the Fast Marching Method tomography technique. We followed an inversion scheme consisting of (1) the use of a high-quality earthquake catalog and corrected phase picks, (2) the selection of earthquakes using a maximum location error threshold, (3) the estimation of an improved 1-D reference velocity model, and (4) the use of checkerboard testing to determine the optimum configuration of the velocity nodes and inversion parameters. Surprisingly, the tomography results show a very simple δVp distribution that can be described as being controlled by geologic structures formed during two stages of the separation of the Rivera and Cocos plates. The earlier period represents the initial stages of the separation of the Rivera and Cocos plates beneath western Mexico; the later period represents the more advanced stage of rifting where the Rivera and Cocos plates had separated sufficiently to allow melt to accumulate below the Colima Volcanic complex. During the earlier period (14 or 10-1.6 Ma), NE-SW-oriented structures/lineaments (such as the Southern Colima Rift) were formed as the two plates separated. During the second period (1.6 Ma to the present), the deformation is attributed to magma, generated within and above the tear zone between the Rivera and Cocos plates, rising beneath the region of the Colima Volcanic Complex. The rising magma fractured the overlying crust, forming a classic triple-rift junction geometry. This triple-rift system is confined to the mid- to lower crust perhaps indicating that this rifting process is still in an early stage. This fracturing, along with fluid circulation and associated

  6. Localized surface disruptions observed by InSAR during strong earthquakes in Java and Hawai'i

    Science.gov (United States)

    Poland, M.

    2010-01-01

    Interferometric Synthetic Aperture Radar data spanning strong earthquakes on the islands of Java and Hawai‘i in 2006 reveal patches of subsidence and incoherence indicative of localized ground failure. Interferograms spanning the 26 May 2006 Java earthquake suggest an area of about 7.5 km2 of subsidence (~2 cm) and incoherence south of the city of Yogyakarta that correlates with significant damage to housing, high modeled peak ground accelerations, and poorly consolidated geologic deposits. The subsidence and incoherence is inferred to be a result of intense shaking and/or damage. At least five subsidence patches on the west side of the Island of Hawai‘i, ranging 0.3–2.2 km2 in area and 3–8 cm in magnitude, occurred as a result of a pair of strong earthquakes on 15 October 2006. Although no felt reports or seismic data are available from the areas in Hawai‘i, the Java example suggests that the subsidence patches indicate areas of amplified earthquake shaking. Surprisingly, all subsidence areas in Hawai‘i were limited to recent, and supposedly stable, lava flows and may reflect geological conditions not detectable at the surface. In addition, two ‘a‘ā lava flows in Hawai‘i were partially incoherent in interferograms spanning the earthquakes, indicating surface disruption as a result of the earthquake shaking. Coearthquake incoherence of rubbly deposits, like ‘a‘ā flows, should be explored as a potential indicator of earthquake intensity and past strong seismic activity.

  7. Localize Earthquake Detection Through Low-cost Wireless Ad-Hoc Network

    OpenAIRE

    NGUYEN, PHU HUU

    2015-01-01

    Seismic activities can cause significant damages to infrastructures and human lives. An early earthquake alert system (EWW) could help save our lives and protect properties. Constructing a reliable and affordable earthquake detection and alert system is a challenging job. Seismic activities do not have any specific statistical patterns that we can observe and study over the time but we only have a couple seconds to detect and trigger alert. Traditionally, earthquake can be detected by either ...

  8. Rapid Estimation of Macroseismic Intensity for On-site Earthquake Early Warning in Italy from Early Radiated Energ

    Science.gov (United States)

    Emolo, A.; Zollo, A.; Brondi, P.; Picozzi, M.; Mucciarelli, M.

    2015-12-01

    Earthquake Early Warning System (EEWS) are effective tools for the risk mitigation in active seismic regions. Recently, a feasibility study of a nation-wide earthquake early warning systems has been conducted for Italy considering the RAN Network and the EEW software platform PRESTo. This work showed that a reliable estimations in terms of magnitude and epicentral localization would be available within 3-4 seconds after the first P-wave arrival. On the other hand, given the RAN's density, a regional EEWS approach would result in a Blind Zone (BZ) of 25-30 km in average. Such BZ dimension would provide lead-times greater than zero only for events having magnitude larger than 6.5. Considering that in Italy also smaller events are capable of generating great losses both in human and economic terms, as dramatically experienced during the recent 2009 L'Aquila (ML 5.9) and 2012 Emilia (ML 5.9) earthquakes, it has become urgent to develop and test on-site approaches. The present study is focused on the development of a new on-site EEW metodology for the estimation of the macroseismic intensity at a target site or area. In this analysis we have used a few thousands of accelerometric traces recorded by RAN related to the largest earthquakes (ML>4) occurred in Italy in the period 1997-2013. The work is focused on the integral EW parameter Squared Velocity Integral (IV2) and on its capability to predict the peak ground velocity PGV and the Housner Intensity IH, as well as from these latters we parameterized a new relation between IV2 and the Macroseismic Intensity. To assess the performance of the developed on-site EEW relation, we used data of the largest events occurred in Italy in the last 6 years recorded by the Osservatorio Sismico delle Strutture, as well as on the recordings of the moderate earthquake reported by INGV Strong Motion Data. The results shows that the macroseismic intensity values predicted by IV2 and the one estimated by PGV and IH are in good agreement.

  9. Prediction of Global and Localized Damage and Future Reliability for RC Structures subject to Earthquakes

    DEFF Research Database (Denmark)

    Köyluoglu, H.U.; Nielsen, Søren R.K.; Cakmak, A.S.

    1994-01-01

    the arrival of the first earthquake from non-destructive vibration tests or via structural analysis. The previous excitation and displacement response time series is employed for the identification of the instantaneous softening using an ARMA model. The hysteresis parameters are updated after each earthquake....... The proposed model is next generalized for the MDOF system. Using the adapted models for the structure and the global damage state, the global damage in a future earthquake can then be estimated when a suitable earthquake model is applied. The performance of the model is illustrated on RC frames which were...

  10. Prediction of Global and Localized Damage and Future Reliability for RC Structures subject to Earthquakes

    DEFF Research Database (Denmark)

    Köyluoglu, H.U.; Nielsen, Søren R.K.; Cakmak, A.S.

    1997-01-01

    the arrival of the first earthquake from non-destructive vibration tests or via structural analysis. The previous excitation and displacement response time series is employed for the identification of the instantaneous softening using an ARMA model. The hysteresis parameters are updated after each earthquake....... The proposed model is next generalized for the MDOF system. Using the adapted models for the structure and the global damage state, the global damage in a future earthquake can then be estimated when a suitable earthquake model is applied. The performance of the model is illustrated on RC frames which were...

  11. Rapid automated W-phase slip inversion for the Illapel great earthquake (2015, Mw = 8.3)

    Science.gov (United States)

    Benavente, Roberto; Cummins, Phil R.; Dettmer, Jan

    2016-03-01

    We perform rapid W-phase finite fault inversion for the 2015 Illapel great earthquake (Mw = 8.3). To evaluate the performance of the inversion in a near real time context, we divide seismic stations into four groups. The groups consider stations up to epicentral distances of 30°, 50°, 75°, and 90°, respectively. The results for the first group could have been available within 25 min after the origin time and the results for the last group within 1 h. The four results consistently show a peak slip of ˜10 m near the trench with trench perpendicular rake which is consistent with the tsunami genesis of the event. The slip location is similar to that in the preliminary U.S. Geological Survey solution. The inversion is automated and provides meaningful results within 25 min after the event. This makes the method particularly suited to emergency management and early warning at regional and teletsunami distances.

  12. ANISOMAT+: An automatic tool to retrieve seismic anisotropy from local earthquakes

    Science.gov (United States)

    Piccinini, Davide; Pastori, Marina; Margheriti, Lucia

    2013-07-01

    An automatic analysis code called ANISOMAT+ has been developed and improved to automatically retrieve the crustal anisotropic parameters fast polarization direction (ϕ) and delay time (δt) related to the shear wave splitting phenomena affecting seismic S-wave. The code is composed of a set of MatLab scripts and functions able to evaluate the anisotropic parameters from the three-component seismic recordings of local earthquakes using the cross-correlation method. Because the aim of the code is to achieve a fully automatic evaluation of anisotropic parameters, during the development of the code we focus our attention to devise several automatic checks intended to guarantee the quality and the stability of the results obtained. The basic idea behind the development of this automatic code is to build a tool able to work on a huge amount of data in a short time, obtaining stable results and minimizing the errors due to the subjectivity. These behaviors, coupled to a three component digital seismic network and a monitoring system that performs automatic pickings and locations, are required to develop a real-time monitoring of the anisotropic parameters.

  13. Rapid uncertainty estimation in finite fault inversion: Case study for the 2015, Mw 8.3 Illapel earthquake

    Science.gov (United States)

    Cummins, P. R.; Benavente, R. F.; Dettmer, J.; Williamson, A.

    2016-12-01

    Rapid estimation of the slip distribution for large earthquakes can be useful for the early phases of emergency response, in rapid impact assessment and tsunami early warning. Model parameter uncertainties can be crucial for meaningful interpretation of such slip models, but they are often ignored. However, estimation of uncertainty in linear finite fault inversion is difficult because of the positivity constraints that are almost always applied. We have shown in previous work that positivity can be realized by imposing a prior such that the logs of each subfault scalar moment are smoothly distributed on the fault surface, and each scalar moment is intrinsically non-negative while the posterior PDF can still be approximated as Gaussian. The inversion is nonlinear, but we showed that the most probable solution can be found by iterative methods that are not computationally demanding. In addition, the posterior covariance matrix (which provides uncertainties) can be estimated from the most probable solution, using an analytic expression for the Hessian of the cost function. We have studied this approach previously for synthetic W-phase data and showed that a first order estimation of the uncertainty in the slip model can be obtained.Here we apply this method to seismic W-phase recorded following the 2015, Mw 8.3 Illapel earthquake. Our results show a slip distrubtion with maximum slip near the subduction zone trench axis, and having uncertainties that scale roughly with the slip value. We also consider application of this method to multiple data types: seismic W-phase, geodetic, and tsunami.

  14. Localization of b-values and maximum earthquakes; B chi to saidai jishin no chiikisei

    Energy Technology Data Exchange (ETDEWEB)

    Kurimoto, H.

    1996-05-01

    There is a thought that hourly and spacial blanks in earthquake activity contribute to earthquake occurrence probability. Based on an idea that if so, this tendency may appear also in statistical parameters of earthquake, earthquake activities in every ten years were investigated in the relation between locational distribution of inclined b values of a line relating to the number of earthquake and the magnitude, and the center focus of earthquakes which are M{ge}7.0. The field surveyed is the Japanese Islands and the peripheral ocean, and the area inside the circle with a radius of 100km with a lattice-like point divided in 1{degree} in every direction of latitude and longitude as center was made a unit region. The depth is divided by above 60km or below 60km. As a result, the following were found out: as to epicenters of earthquakes with M{ge}7.0 during the survey period of 100 years, many are in a range of b(b value){le}0.75, and sometimes they may be in a range of b{ge}0.75 in the area from the ocean near Izu peninsula to the ocean off the west Hokkaido; the position of epicenters in a range of b{le}0.75 seems not to come close to the center of contour which indicates the maximum b value. 7 refs., 2 figs.

  15. One-dimensional velocity model of the Middle Kura Depresion from local earthquakes data of Azerbaijan

    Science.gov (United States)

    Yetirmishli, G. C.; Kazimova, S. E.; Kazimov, I. E.

    2011-09-01

    We present the method for determining the velocity model of the Earth's crust and the parameters of earthquakes in the Middle Kura Depression from the data of network telemetry in Azerbaijan. Application of this method allowed us to recalculate the main parameters of the hypocenters of the earthquake, to compute the corrections to the arrival times of P and S waves at the observation station, and to significantly improve the accuracy in determining the coordinates of the earthquakes. The model was constructed using the VELEST program, which calculates one-dimensional minimal velocity models from the travel times of seismic waves.

  16. The M 7.7 Tocopilla earthquake and its aftershock sequence: deployment of a Task Force local network

    Science.gov (United States)

    Sobiesiak, M.; Eggert, S.; Woith, H.; Grosser, H.; Peyrat, S.; Vilotte, J.; Medina, E.; Ruch, J.; Walter, T.; Victor, P.; Barrientos, S.; Gonzalez, G.

    2008-05-01

    After the November 14, 2007 Tocopilla earthquake in northern Chile, a local network of 20 short period seismic stations, 5 strong motion instruments, 6 GPS stations and 3 extensometers has been installed in the fault plane area between Tocopilla and Antofagasta by the German Task Force for earthquakes (GFZ Potsdam). The hydrogeology group of the TF sampled 20 thermal water sources in the area of the El Tatio geyser field, located about 170 km E of the epicentre. In collaboration with the IPG Paris, 4 broad band stations were deployed at the northern end of the fault plane between Tocopilla and Maria Elena. Major targets of the investigations of the aftershock sequence are the segment boundary between the 1995 Antofagasta earthquake and the recent Tocopilla event, stress transfer between both successively ruptured subduction zone segments, structural properties of the fault plane, possible consequences for the northern adjacent Iquique segment, and the influence of earthquake seismic waves on the El Tatio hydrothermal field. In our presentation we would like to show first results on the spatial distribution of the aftershocks and discuss these in relation to studies we have made on the Antofagasta aftershock sequence.

  17. Earthquake impact scale

    Science.gov (United States)

    Wald, D.J.; Jaiswal, K.S.; Marano, K.D.; Bausch, D.

    2011-01-01

    With the advent of the USGS prompt assessment of global earthquakes for response (PAGER) system, which rapidly assesses earthquake impacts, U.S. and international earthquake responders are reconsidering their automatic alert and activation levels and response procedures. To help facilitate rapid and appropriate earthquake response, an Earthquake Impact Scale (EIS) is proposed on the basis of two complementary criteria. On the basis of the estimated cost of damage, one is most suitable for domestic events; the other, on the basis of estimated ranges of fatalities, is generally more appropriate for global events, particularly in developing countries. Simple thresholds, derived from the systematic analysis of past earthquake impact and associated response levels, are quite effective in communicating predicted impact and response needed after an event through alerts of green (little or no impact), yellow (regional impact and response), orange (national-scale impact and response), and red (international response). Corresponding fatality thresholds for yellow, orange, and red alert levels are 1, 100, and 1,000, respectively. For damage impact, yellow, orange, and red thresholds are triggered by estimated losses reaching $1M, $100M, and $1B, respectively. The rationale for a dual approach to earthquake alerting stems from the recognition that relatively high fatalities, injuries, and homelessness predominate in countries in which local building practices typically lend themselves to high collapse and casualty rates, and these impacts lend to prioritization for international response. In contrast, financial and overall societal impacts often trigger the level of response in regions or countries in which prevalent earthquake resistant construction practices greatly reduce building collapse and resulting fatalities. Any newly devised alert, whether economic- or casualty-based, should be intuitive and consistent with established lexicons and procedures. Useful alerts should

  18. High Resolution Vp and Vp/Vs Local Earthquake Tomography of the Val d'Agri Region (Southern Apennines, Italy).

    Science.gov (United States)

    Improta, L.; Bagh, S.; De Gori, P.; Pastori, M.; Piccinini, D.; Valoroso, L.; Anselmi, M.; Buttinelli, M.; Chiarabba, C.

    2015-12-01

    The Val d'Agri (VA) Quaternary basin in the southern Apennines extensional belt hosts the largest oilfield in onshore Europe and normal-fault systems with high (up to M7) seismogenic potential. Frequent small-magnitude swarms related to both active crustal extension and anthropogenic activity have occurred in the region. Causal factors for induced seismicity are a water impoundment with severe seasonal oscillations and a high-rate wastewater injection well. We analyzed around 1200 earthquakes (MLENI petroleum company. We used local earthquake tomography to investigate static and transient features of the crustal velocity structure and to accurately locate earthquakes. Vp and Vp/Vs models are parameterized by a 3x3x2 km spacing and well resolved down to about 12 km depth. The complex Vp model illuminates broad antiformal structures corresponding to wide ramp-anticlines involving Mesozoic carbonates of the Apulia hydrocarbon reservoir, and NW-SE trending low Vp regions related to thrust-sheet-top clastic basins. The VA basin corresponds to shallow low-Vp region. Focal mechanisms show normal faulting kinematics with minor strike slip solutions in agreement with the local extensional regime. Earthquake locations and focal solutions depict shallow (< 5 km depth) E-dipping extensional structures beneath the artificial lake located in the southern sector of the basin, and along the western margin of the VA. A few swarms define relatively deep transfer structures accommodating the differential extension between main normal faults. The spatio-temporal distribution of around 220 events correlates with wastewater disposal activity, illuminating a NE-dipping fault between 2-5 km depth in the carbonate reservoir. The fault measures 5 km along dip and corresponds to a pre-existing thrust fault favorably oriented with respect to the local extensional field.

  19. Slow slip, tremor, and local earthquakes prior to the Mw 7.4 megathrust event in Oaxaca

    Science.gov (United States)

    Sit, S. M.; Brudzinski, M. R.; Graham, S. E.; Colella, H. V.; Holtkamp, S. G.; Ghouse, N.; Cabral-Cano, E.; Arciniega-Ceballos, A.; DeMets, C.

    2013-05-01

    The search for observations to demonstrate slow slip phenomena can trigger large and damaging earthquakes is fueled by theoretical predictions that slip in the deeper transitional zone can promote failure in the shallow seismogenic zone. If such a link is verified, then operational earthquake forecasting could be improved by incorporating more slow slip behaviors. The subduction zone in Oaxaca, Mexico provides an ideal locality to investigate this potential relationship, where a joint seismic-geodetic network provides a multi-year record of traditional earthquakes, tectonic tremor, and slow slip events (SSE) prior to the recent March 12, 2012 Mw 7.4 megathrust Ometepec earthquake. Geodetically detected SSEs are observed for 2-3 months every 1-2 years, where stronger signals originate in the updip portion of the transition zone. In the months preceding the Ometepec mainshock, visual inspection of GPS time series for the 2011-2012 SSE suggests a migration of slip from east to west, along strike toward the source region of the earthquake. Preliminary models of the time series confirm slip ends just downdip of the epicenter in the weeks prior to the earthquake. While slow slip activity is prominent in the months leading up to the mainshock, tremor activity remains near background levels for much of that time, particularly in the days leading up to the earthquake. Observations from single station frequency scanning, beginning in mid-2006 show tremor activity is located further down-dip than SSE and occur over relatively short time periods, 2-10 days and recurs as often as every 2-3 months. Curiously, if we look at the preceding year, more tremor activity is detected during the nearly 6-month 2011 slow slip event. To further investigate the relationship between SSEs, tremor, and megathrust earthquakes, we use a multi-station template waveform matching technique to detect and locate events several of orders of magnitude smaller than would be possible using traditional

  20. Scaling Relations of Local Magnitude versus Moment Magnitude for Sequences of Similar Earthquakes in Switzerland

    KAUST Repository

    Bethmann, F.

    2011-03-22

    Theoretical considerations and empirical regressions show that, in the magnitude range between 3 and 5, local magnitude, ML, and moment magnitude, Mw, scale 1:1. Previous studies suggest that for smaller magnitudes this 1:1 scaling breaks down. However, the scatter between ML and Mw at small magnitudes is usually large and the resulting scaling relations are therefore uncertain. In an attempt to reduce these uncertainties, we first analyze the ML versus Mw relation based on 195 events, induced by the stimulation of a geothermal reservoir below the city of Basel, Switzerland. Values of ML range from 0.7 to 3.4. From these data we derive a scaling of ML ~ 1:5Mw over the given magnitude range. We then compare peak Wood-Anderson amplitudes to the low-frequency plateau of the displacement spectra for six sequences of similar earthquakes in Switzerland in the range of 0:5 ≤ ML ≤ 4:1. Because effects due to the radiation pattern and to the propagation path between source and receiver are nearly identical at a particular station for all events in a given sequence, the scatter in the data is substantially reduced. Again we obtain a scaling equivalent to ML ~ 1:5Mw. Based on simulations using synthetic source time functions for different magnitudes and Q values estimated from spectral ratios between downhole and surface recordings, we conclude that the observed scaling can be explained by attenuation and scattering along the path. Other effects that could explain the observed magnitude scaling, such as a possible systematic increase of stress drop or rupture velocity with moment magnitude, are masked by attenuation along the path.

  1. Prospects for rapid gamma-ray burst localization with INTEGRAL

    DEFF Research Database (Denmark)

    Mereghetti, S.; Jennings, D.; Pedersen, H.

    1999-01-01

    The SPI and IRIS instruments on INTEGRAL will detect greater than or similar to 1 GRB/month within their large fields of view. The accuracy of localization with IBIS will be a few arcminutes, hence adequate for follow-up studies at large, ground-based telescopes. We report on the current studies ...

  2. A framework for rapid post-earthquake assessment of bridges and restoration of transportation network functionality using structural health monitoring

    Science.gov (United States)

    Omenzetter, Piotr; Ramhormozian, Shahab; Mangabhai, Poonam; Singh, Ravikash; Orense, Rolando

    2013-04-01

    Quick and reliable assessment of the condition of bridges in a transportation network after an earthquake can greatly assist immediate post-disaster response and long-term recovery. However, experience shows that available resources, such as qualified inspectors and engineers, will typically be stretched for such tasks. Structural health monitoring (SHM) systems can therefore make a real difference in this context. SHM, however, needs to be deployed in a strategic manner and integrated into the overall disaster response plans and actions to maximize its benefits. This study presents, in its first part, a framework of how this can be achieved. Since it will not be feasible, or indeed necessary, to use SHM on every bridge, it is necessary to prioritize bridges within individual networks for SHM deployment. A methodology for such prioritization based on structural and geotechnical seismic risks affecting bridges and their importance within a network is proposed in the second part. An example using the methodology application to selected bridges in the medium-sized transportation network of Wellington, New Zealand is provided. The third part of the paper is concerned with using monitoring data for quick assessment of bridge condition and damage after an earthquake. Depending on the bridge risk profile, it is envisaged that data will be obtained from either local or national seismic monitoring arrays or SHM systems installed on bridges. A method using artificial neural networks is proposed for using data from a seismic array to infer key ground motion parameters at an arbitrary bridges site. The methodology is applied to seismic data collected in Christchurch, New Zealand. Finally, how such ground motion parameters can be used in bridge damage and condition assessment is outlined.

  3. Nanozyme-strip for rapid local diagnosis of Ebola.

    Science.gov (United States)

    Duan, Demin; Fan, Kelong; Zhang, Dexi; Tan, Shuguang; Liang, Mifang; Liu, Yang; Zhang, Jianlin; Zhang, Panhe; Liu, Wei; Qiu, Xiangguo; Kobinger, Gary P; Gao, George Fu; Yan, Xiyun

    2015-12-15

    Ebola continues to rage in West Africa. In the absence of an approved vaccine or treatment, the priority in controlling this epidemic is to promptly identify and isolate infected individuals. To this end, a rapid, highly sensitive, and easy-to-use test for Ebola diagnosis is urgently needed. Here, by using Fe3O4 magnetic nanoparticle (MNP) as a nanozyme probe, we developed a MNP-based immunochromatographic strip (Nanozyme-strip), which detects the glycoprotein of Ebola virus (EBOV) as low as 1 ng/mL, which is 100-fold more sensitive than the standard strip method. The sensitivity of the Nanozyme-strip for EBOV detection and diagnostic accuracy for New Bunyavirus clinical samples is comparable with ELISA, but is much faster (within 30 min) and simpler (without need of specialist facilities). The results demonstrate that the Nanozyme-strip test can rapidly and sensitively detect EBOV, providing a valuable simple screening tool for diagnosis of infection in Ebola-stricken areas. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Irreversible Local Markov Chains with Rapid Convergence towards Equilibrium

    Science.gov (United States)

    Kapfer, Sebastian C.; Krauth, Werner

    2017-12-01

    We study the continuous one-dimensional hard-sphere model and present irreversible local Markov chains that mix on faster time scales than the reversible heat bath or Metropolis algorithms. The mixing time scales appear to fall into two distinct universality classes, both faster than for reversible local Markov chains. The event-chain algorithm, the infinitesimal limit of one of these Markov chains, belongs to the class presenting the fastest decay. For the lattice-gas limit of the hard-sphere model, reversible local Markov chains correspond to the symmetric simple exclusion process (SEP) with periodic boundary conditions. The two universality classes for irreversible Markov chains are realized by the totally asymmetric SEP (TASEP), and by a faster variant (lifted TASEP) that we propose here. We discuss how our irreversible hard-sphere Markov chains generalize to arbitrary repulsive pair interactions and carry over to higher dimensions through the concept of lifted Markov chains and the recently introduced factorized Metropolis acceptance rule.

  5. Tweeting after an earthquake: user localization and communication patterns during the 2012 Emilia seismic sequence

    Directory of Open Access Journals (Sweden)

    Francesca Comunello

    2016-11-01

    Full Text Available The main goal of this paper is analysing how user’s location, relative to the epicenter of an earthquake, affects the different tweeting strategies adopted. For this purpose, we analyze a dataset of tweets that were generated around the 2012 Emilia earthquakes and that are geolocalized in Italy. In our analysis, we rely on existing literature on social media and natural disasters, considering literature exploring interactions and influence on Twitter, and literature focusing on the role of geolocalized user-generated information in disaster response.

  6. Local three-dimensional earthquake tomography by trans-dimensional Monte Carlo sampling

    Science.gov (United States)

    Piana Agostinetti, Nicola; Giacomuzzi, Genny; Malinverno, Alberto

    2015-06-01

    Local earthquake tomography is a non-linear and non-unique inverse problem that uses event arrival times to solve for the spatial distribution of elastic properties. The typical approach is to apply iterative linearization and derive a preferred solution, but such solutions are biased by a number of subjective choices: the starting model that is iteratively adjusted, the degree of regularization used to obtain a smooth solution, and the assumed noise level in the arrival time data. These subjective choices also affect the estimation of the uncertainties in the inverted parameters. The method presented here is developed in a Bayesian framework where a priori information and measurements are combined to define a posterior probability density of the parameters of interest: elastic properties in a subsurface 3-D model, hypocentre coordinates and noise level in the data. We apply a trans-dimensional Markov chain Monte Carlo algorithm that asymptotically samples the posterior distribution of the investigated parameters. This approach allows us to overcome the issues raised above. First, starting a number of sampling chains from random samples of the prior probability distribution lessens the dependence of the solution from the starting point. Secondly, the number of elastic parameters in the 3-D subsurface model is one of the unknowns in the inversion, and the parsimony of Bayesian inference ensures that the degree of detail in the solution is controlled by the information in the data, given realistic assumptions for the error statistics. Finally, the noise level in the data, which controls the uncertainties of the solution, is also one of the inverted parameters, providing a first-order estimate of the data errors. We apply our method to both synthetic and field arrival time data. The synthetic data inversion successfully recovers velocity anomalies, hypocentre coordinates and the level of noise in the data. The Bayesian inversion of field measurements gives results

  7. Clustering and interpretation of local earthquake tomography models in the southern Dead Sea basin

    Science.gov (United States)

    Bauer, Klaus; Braeuer, Benjamin

    2016-04-01

    The Dead Sea transform (DST) marks the boundary between the Arabian and the African plates. Ongoing left-lateral relative plate motion and strike-slip deformation started in the Early Miocene (20 MA) and produced a total shift of 107 km until presence. The Dead Sea basin (DSB) located in the central part of the DST is one of the largest pull-apart basins in the world. It was formed from step-over of different fault strands at a major segment boundary of the transform fault system. The basin development was accompanied by deposition of clastics and evaporites and subsequent salt diapirism. Ongoing deformation within the basin and activity of the boundary faults are indicated by increased seismicity. The internal architecture of the DSB and the crustal structure around the DST were subject of several large scientific projects carried out since 2000. Here we report on a local earthquake tomography study from the southern DSB. In 2006-2008, a dense seismic network consisting of 65 stations was operated for 18 months in the southern part of the DSB and surrounding regions. Altogether 530 well-constrained seismic events with 13,970 P- and 12,760 S-wave arrival times were used for a travel time inversion for Vp, Vp/Vs velocity structure and seismicity distribution. The work flow included 1D inversion, 2.5D and 3D tomography, and resolution analysis. We demonstrate a possible strategy how several tomographic models such as Vp, Vs and Vp/Vs can be integrated for a combined lithological interpretation. We analyzed the tomographic models derived by 2.5D inversion using neural network clustering techniques. The method allows us to identify major lithologies by their petrophysical signatures. Remapping the clusters into the subsurface reveals the distribution of basin sediments, prebasin sedimentary rocks, and crystalline basement. The DSB shows an asymmetric structure with thickness variation from 5 km in the west to 13 km in the east. Most importantly, a well-defined body

  8. The First Results of Testing Methods and Algorithms for Automatic Real Time Identification of Waveforms Introduction from Local Earthquakes in Increased Level of Man-induced Noises for the Purposes of Ultra-short-term Warning about an Occurred Earthquake

    Science.gov (United States)

    Gravirov, V. V.; Kislov, K. V.

    2009-12-01

    The chief hazard posed by earthquakes consists in their suddenness. The number of earthquakes annually recorded is in excess of 100,000; of these, over 1000 are strong ones. Great human losses usually occur because no devices exist for advance warning of earthquakes. It is therefore high time that mobile information automatic systems should be developed for analysis of seismic information at high levels of manmade noise. The systems should be operated in real time with the minimum possible computational delays and be able to make fast decisions. The chief statement of the project is that sufficiently complete information about an earthquake can be obtained in real time by examining its first onset as recorded by a single seismic sensor or a local seismic array. The essential difference from the existing systems consists in the following: analysis of local seismic data at high levels of manmade noise (that is, when the noise level may be above the seismic signal level), as well as self-contained operation. The algorithms developed during the execution of the project will be capable to be used with success for individual personal protection kits and for warning the population in earthquake-prone areas over the world. The system being developed for this project uses P and S waves as well. The difference in the velocities of these seismic waves permits a technique to be developed for identifying a damaging earthquake. Real time analysis of first onsets yields the time that remains before surface waves arrive and the damage potential of these waves. Estimates show that, when the difference between the earthquake epicenter and the monitored site is of order 200 km, the time difference between the arrivals of P waves and surface waves will be about 30 seconds, which is quite sufficient to evacuate people from potentially hazardous space, insertion of moderators at nuclear power stations, pipeline interlocking, transportation stoppage, warnings issued to rescue services

  9. Rapid evolution of mimicry following local model extinction.

    Science.gov (United States)

    Akcali, Christopher K; Pfennig, David W

    2014-06-01

    Batesian mimicry evolves when individuals of a palatable species gain the selective advantage of reduced predation because they resemble a toxic species that predators avoid. Here, we evaluated whether-and in which direction-Batesian mimicry has evolved in a natural population of mimics following extirpation of their model. We specifically asked whether the precision of coral snake mimicry has evolved among kingsnakes from a region where coral snakes recently (1960) went locally extinct. We found that these kingsnakes have evolved more precise mimicry; by contrast, no such change occurred in a sympatric non-mimetic species or in conspecifics from a region where coral snakes remain abundant. Presumably, more precise mimicry has continued to evolve after model extirpation, because relatively few predator generations have passed, and the fitness costs incurred by predators that mistook a deadly coral snake for a kingsnake were historically much greater than those incurred by predators that mistook a kingsnake for a coral snake. Indeed, these results are consistent with prior theoretical and empirical studies, which revealed that only the most precise mimics are favoured as their model becomes increasingly rare. Thus, highly noxious models can generate an 'evolutionary momentum' that drives the further evolution of more precise mimicry-even after models go extinct. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  10. Migration of local earthquakes in the Gulf of Aqaba, North Red Sea

    Directory of Open Access Journals (Sweden)

    Al-Arifi Nassir

    2012-10-01

    Full Text Available

    ABSTRACT

    The Gulf of Aqabah has been considered one of the most seismically-active regions in the Middle East during the last 15 years; a catalogue of 1,415 earthquakes (duration magnitude Md > 2. 8 during 19851995, compiled by Al-Arifi (1996 and Al-Shaabi (1998, mainly based on data from King Saud University. Seismic Studies Center (SSC, Saudi Arabia, for 28°- 30°N and 30°-36°E, has been used for studying local aftershock migration . Aftershocks migrated northwards about 60 km for the 1993 sequence and about 70 km for the 1995 sequence and also to shallow focal depths (15 km focal depth for 1993 main-shock . Depths reduced as time elapsed until reaching 2 km for the last strong aftershock (Md=5 . 2 which occurred during the late stage of the sequence . The 1993 main-shock caused a redistribution of stresses to the parallel faults' segment where the largest 1993 aftershock occurred triggering these faults' segment to become an area of stress nucleation and generated the 1995 main-shock

    RESUMEN

    El Golfo de Aqabah ha sido considerada una de las regiones con más actividad sísmica del Medio Oriente durante los últimos 15 años . Un catalogo de 1415 terremotos (magnitud de duración Md>2. 8 entre 1985-1995, compilado por Al-Arifi (1996 y Al-Shaabi (1998, basado principalmente en datos de la Universidad King Saud, Centro de Estudios Sísmicos (SSC, Arabia Saudita, para la zona ubicada entre 28°- 30°N y 30°-36°E, ha sido usado para estudiar la migración de replicas locales Las replicas migraron unos 60 km al norte para la secuencia correspondiente al año 1993 y unos 70 km para la secuencia por el año 1995 y también hacia bajas profundidades focales (15km de profundidad focal para el evento principal en el año 1993 . Las profundidades se

  11. An exploratory study for rapid estimation of critical source parameters of great subduction-zone earthquakes in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S. K; Perez-Campos, X, Iglesias, A; Pacheco, J. F [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Mexico D.F. (Mexico)

    2008-10-15

    The rapid and reliable estimation of moment magnitude M{sub w}, location, and size of rupture area, and radiated energy E{sub s} of great Mexican subduction zone earthquakes is critical for a quick assessment of tsunami and/or damage potential of the event and for issuing an early tsunami alert. To accomplish this goal, the Mexican broadband seismic network needs to be supplemented by permanent GPS stations along the Pacific coast, spaced about 65 km apart or less. The data from the GPS network must be transmitted to a central location and processed in near-real time to track the position of the stations. Assuming that this can be implemented, we develop a procedure for near-real time estimation of the critical source parameters. We demonstrate the viability of the procedure by processing near-source GPS data and regional seismograms for the earthquakes of Colima-Jalisco in 1995 (M{sub w}=8.0) and Sumatra-Andaman in 2004 (M{sub w}=9.0-9.3). The procedure yields estimates of M{sub w} and E{sub s} in excellent agreement with those reported from earlier solutions. In the case of the Colima-Jalisco earthquake, the estimated location and size of rupture area agree with that mapped from aftershock locations. Presently, there are 13 permanent GPS stations along the Pacific coast of Mexico with an average spacing of {approx}200 km which operate in an autonomous mode. It is urgent to increase the number of stations to {>=}28 thus decreasing the spacing of stations to {<=}65 km. Data must be transmitted in near-real time to a central station to track the position of the stations, preferably every second. [Spanish] Para una estimacion oportuna del potencial de dano y tsunami asociado a los grandes temblores de subduccion en Mexico, resulta critica la determinacion rapida y confiable de parametros sismologicos como lo son la magnitud de momento (M{sub w}), la energia sismica radiada (E{sub s}) y la localizacion y el tamano de la ruptura. Para alcanzar este objetivo, la red

  12. The role of local soil-induced amplification in the 27 July 1980 northeastern Kentucky earthquake

    Science.gov (United States)

    Woolery, E.W.; Lin, T.-L.; Wang, Z.; Shi, B.

    2008-01-01

    Amplification of earthquake ground motions by near-surface soil deposits was believed to have occurred in Maysville, Kentucky, U.S.A. during the northeast Kentucky (Sharpsburg) earthquake (mb,Lg 5.3) of July 27, 1980. The city of Maysville, founded on approximately 30 m of Late Quaternary Ohio River flood plain alluvium, was 52 km from the epicenter, but experienced equivalent or higher Modified Mercalli Intensity (MMI) VII, compared with the epicentral area of the earthquake (i.e., MMI VI-VII). In this study, dynamic soil properties were obtained at 10 sites in Maysville using seismic P-wave and S-wave (SH-mode) refraction and reflection methods. Synthetically generated composite time histories and limited geotechnical information, along with the measured dynamic properties, were used to perform one-dimensional linear-equivalent amplification analyses. The results indicated the soils generated ground-motion amplification factors between 3.0 and 6.0 and at a frequency range between 2.0 and 5.0 Hz (0.2 to 0.5 s). The building damage in Maysville from the Sharpsburg earthquake was predominantly found in one- to three-story masonry structures. The estimated fundamental period for one- to three-story masonry buildings is approximately 0.11 to 0.26 s (3.8 to 9 Hz). These correlations suggest the elevated ground motion intensity in Maysville can be accounted for by near-surface soil-amplification effects and resonance of the ground motion by the buildings (i.e., double resonance).

  13. Crustal seismic anisotropy beneath Shillong plateau - Assam valley in North East India: Shear-wave splitting analysis using local earthquakes

    Science.gov (United States)

    Sharma, Antara; Baruah, Santanu; Piccinini, Davide; Saikia, Sowrav; Phukan, Manoj K.; Chetia, Monisha; Kayal, J. R.

    2017-10-01

    We present crustal anisotropy estimates constrained by shear wave splitting (SWS) analysis using local earthquakes in the Shillong plateau and Assam valley area, North East India (NE India) region. Splitting parameters are determined using an automated cross-correlation (CC) method. We located 330 earthquakes recorded by 17 broadband seismic stations during 2001-2014 in the study area. Out of these 330 events, seismograms of 163 events are selected for the SWS analysis. Relatively small average delay times (0.039-0.084 s) indicate existence of moderate crack density in the crust below the study area. It is found that fast polarization directions vary from station to station depending on the regional stress system as well as geological conditions. The spatial pattern of crustal anisotropy in the area is controlled mostly by tectonic movement of the Indian plate towards NE. Presence of several E-W and N-S trending active faults in the area also play an important role on the observed pattern of crustal anisotropy.

  14. ‘Interrupted’ Landscapes: Post-Earthquake Reconstruction in between Urban Renewal and Social Identity of Local Communities

    Directory of Open Access Journals (Sweden)

    Matteo Clemente

    2017-11-01

    Full Text Available The present study deals with the topic of post-seismic reconstruction focusing on landscape and social issues. Sustainable reconstruction requires a connection between the physical context of a given territory and the immaterial (historical, cultural, productive values that constitute the place’s identity. In this perspective, those places that have been destroyed by severe earthquakes or other disasters could be labelled as “interrupted landscapes”, meaning a drastic break in the individual stories attaching the people to their own territory, as well as an abrupt alteration of the continuous process by which people attribute a sense to their own territory. The study discusses selected cases of post-earthquake reconstruction in Italy, providing an overview of different visions for development of the new towns, that oscillate between two contrasting approaches: the “new town” model, implying the construction of a new town off-site and the “in loco” model. Looking for the reasons for failures of the new town model reconstruction, the study also debates the social dimension of urban landscapes, reflecting upon the notion of ‘collective identity’ connecting place attachment to cultural heritage. These issues were finally considered when defining strategic guidelines for sustainable urban reconstruction promoting place identity and preserving the intimate characteristics of the affected landscapes. Governance actions were defined along with sustainability strategies based on the investigated case studies, outlining a series of best practices that may promote the permanent involvement of local communities.

  15. “PLAFKER RULE OF THUMB” RELOADED: EXPERIMENTAL INSIGHTS INTO THE SCALING AND VARIABILITY OF LOCAL TSUNAMIS TRIGGERED BY GREAT SUBDUCTION MEGATHRUST EARTHQUAKES

    Science.gov (United States)

    Rosenau, M.; Nerlich, R.; Brune, S.; Oncken, O.

    2009-12-01

    Great subduction megathrust earthquakes pose a significant tsunami risk in coastal regions. In order to constrain natural tsunamigenic source heterogeneity and its effect on tsunami variability in different subduction settings (accretive, erosive), we here analyze a sequence of experimentally simulated great megathrust earthquakes. We use an elastoplastic wedge overlying a rate- and state-dependent frictional interface as an analog model of the subduction forearc overlying a seismogenic megathrust. Near-field (local) tsunami heights are derived by means of analytical versus numerical hydrodynamic calculations from the surface deformation of the analog model in comparison to predictions of an elastic dislocation model. The cumulative slip distribution over the simulated earthquake sequence resembles widely used skewed parameterizations supporting their use in worst case scenarios. Due to body forces and strain localization, tsunamis predicted by the analog model are enriched in kinetic energy compared to EDM predictions. The tsunami height-to-slip-ratio (“Plafker rule of thumb”) and its variance scale inversely to forearc slope according to a power law from ~ 1 at accretionary to ~ 1/4 in erosive settings (Cv ~ 0.6). Tsunami height scales exponentially with earthquake magnitude, has a power-law dependence on forearc slope and a variability characterized by Cv ~ 0.5 (see Figure). In terms of predicting tsunami scale and variability the analog model outperforms the elastic dislocation model which tends to overestimate local tsunami height and underscore its variability when tested against empirical data. Based on the experimentally derived earthquake-tsunami scaling law we infer the distribution of tsunami hazard on a global scale. Because of the exponential scaling of tsunamis with earthquake magnitude, its sensitivity to forearc slope and the possible non-linear kinetic enrichment of tsunamis triggered by giant earthquakes, disaster hotspots occur preferentially

  16. Local and regional minimum 1D models for earthquake location and data quality assessment in complex tectonic regions: application to Switzerland

    Energy Technology Data Exchange (ETDEWEB)

    Husen, S.; Clinton, J. F. [Swiss Seismological Service, ETH Zuerich, Zuerich (Switzerland); Kissling, E. [Institute of Geophysics, ETH Zuerich, Zuerich (Switzerland)

    2011-10-15

    One-dimensional (1D) velocity models are still widely used for computing earthquake locations at seismological centers or in regions where three-dimensional (3D) velocity models are not available due to the lack of data of sufficiently high quality. The concept of the minimum 1D model with appropriate station corrections provides a framework to compute initial hypocenter locations and seismic velocities for local earthquake tomography. Since a minimum 1D model represents a solution to the coupled hypocenter-velocity problem it also represents a suitable velocity model for earthquake location and data quality assessment, such as evaluating the consistency in assigning pre-defined weighting classes and average picking error. Nevertheless, the use of a simple 1D velocity structure in combination with station delays raises the question of how appropriate the minimum 1D model concept is when applied to complex tectonic regions with significant three-dimensional (3D) variations in seismic velocities. In this study we compute one regional minimum 1D model and three local minimum 1D models for selected subregions of the Swiss Alpine region, which exhibits a strongly varying Moho topography. We compare the regional and local minimum 1D models in terms of earthquake locations and data quality assessment to measure their performance. Our results show that the local minimum 1D models provide more realistic hypocenter locations and better data fits than a single model for the Alpine region. We attribute this to the fact that in a local minimum 1D model local and regional effects of the velocity structure can be better separated. Consequently, in tectonically complex regions, minimum 1D models should be computed in sub-regions defined by similar structure, if they are used for earthquake location and data quality assessment. (authors)

  17. Local Earthquake Velocity and Attenuation Tomography of the Jalisco, Mexico Region

    Science.gov (United States)

    Watkins, W. D.; Thurber, C. H.; Abbott, E. R.; Brudzinski, M.; Grand, S. P.

    2015-12-01

    The states of Jalisco, Colima, and Michoacan in western Mexico overlie the boundary of the subducting Rivera and Cocos plates, presenting an appealing target for seismological inquiry to better understand the resulting mantle flow and regional volcanism. The different dips between the subducting plates is thought to provide a mantle conduit that has contributed to the Colima Volcanic Complex, but there is considerable debate on the shallowness of the Rivera plate and width of the resulting conduit. With data from the Mapping the Rivera Subduction Zone (MARS) and Colima Deep Seismic Experiment (CODEX) networks, two temporary broadband arrays deployed in the region between 2006-2008, we invert for three-dimensional P- and S- wave velocity and later attenuation structure of the upper ~80 km of the crust and mantle in the Jalisco region. We improve upon previous tomography work by utilizing double-difference tomography, which enables the use of higher-accuracy differential times to sharpen the earthquake locations, and the inclusion of S-wave data. Current models that utilize only analyst-picked phase arrivals from 590 earthquakes yield P-wave high velocity anomalies that suggest a slab under the coastal regions at 15-25 km depth, and low velocity anomalies that may be related to Colima Volcano or other geologic features. Most of the S-wave model is poorly resolved. We will use a newly developed auto-picker to attempt to substantially increase the size of the S-wave dataset and to a lesser extent the P wave dataset, in order to densify ray coverage and improve model resolution. Additionally, we plan to employ the waveforms from this expanded dataset to compute a path attenuation operator for each arrival, which will then be used to invert for 3D P and S-wave attenuation models. The attenuation models combined with the velocity models will provide multiple constraints on physical properties of the crust in this region as well as those of specific geologic features.

  18. Local and Modal Damage Indicators for Reinforced Concrete Shear Frames Subject to Earthquakes

    DEFF Research Database (Denmark)

    Köylüoglu, H. U.; Nielsen, Søren R. K.; Abbott, J.

    Local, modal and overall damage indicators for reinforced concrete shear frames subject to seismic excitation are defined and studied. Each storey of the shear frame is represented by a Clough and Johnston hysteretic oscillator with degrading elastic fraction of the restoring force. The local max...

  19. DETECTION OF LOCAL SITE CONDITIONS INFLUENCING EARTHQUAKE SHOCK AND SECONDARY EFFECTS IN THE VALPARAISO AREA IN CENTRAL-CHILE USING REMOTE SENSING AND GIS METHODS

    Directory of Open Access Journals (Sweden)

    Barbara Theilen-Willige

    2011-01-01

    Full Text Available The potential contribution of remote sensing and GIS techniques to earthquake hazard analysis was investigated in Valparaiso in Chile in order to improve the systematic, standardized inventory of those areas that are more susceptible to earthquake ground motions or to earthquake related secondary effects such as landslides, liquefaction, soil amplifications, compaction or even tsunami-waves. Geophysical, topographical, geological data and satellite images were collected, processed, and integrated into a spatial database using Geoinformation Systems (GIS and image processing techniques. The GIS integrated evaluation of satellite imageries, of digital topographic data and of various open-source geodata can contribute to the acquisition of those specific tectonic, geomorphologic/ topographic settings influencing local site conditions in Valparaiso, Chile. Using the weighted overlay techniques in GIS, susceptibility maps were produced indicating areas, where causal factors influencing near- surface earthquake shock occur aggregated. Causal factors (such as unconsolidated sedimentary layers within a basin’s topography, higher groundwater tables, etc. summarizing and interfering each other, rise the susceptibility of soil amplification and of earthquake related secondary effects. This approach was used as well to create a tsunami flooding susceptibility map. LANDSAT Thermal Band 6-imageries were analysed to get information of surface water currents in this area.

  20. Imaging of the First Five Seconds in the Rupture Process of the 2008 Iwate-Miyagi Nairiku (Inland, Japan) Earthquake From the Local Strong-motion Records

    Science.gov (United States)

    Takenaka, H.; Yamamoto, Y.

    2008-12-01

    From local P-wave records we can get not only point information on earthquake source such as hypocenter location or magnitude but also plane information such as fault plane or asperity distribution. As an effective method for imaging asperity on fault plane in the initial stage of the rupture, we introduced a backprojection technique using near-source P-wave records to map the "radiation strength" on the fault planes, where high radiation strength zones are considered to be "asperity", for the 2005 West off Fukuoka earthquake (Mw6.6) (Yamamoto and Takenaka, 2006), the 2007 Noto-hanto earthquake (Mw6.7) (Yamamoto and Takenaka, 2007) and the 2007 Niigataken Chuetsu-oki earthquake (Mw6.6) (Takenaka et al., 2008). In this study we apply this method to the 2008 Iwate-Miyagi Nairiku (Inland, Japan) earthquake (Mw6.8), which occurred on 14 June 2008 (JST) in north Japan, to image the first 5 seconds of the rupture process from the local strong- motion records (K-NET and KiK-net). Using the hypocenter by JMA (depth of 7.8 km) and the fault plane by the F-net CMT (strike: N186, dip: 47), from the imaging the asperity area is then found to be located updidward and strikeward (southward) a little away from the hypocenter on the fault plane. The line passing the hypocenter and the imaged asperity area is pointing to Ichinoseki city. In the presentation we show the imaging results with discussion on the relation to the observed strong ground motion. [Acknowledgements] We used the strong-motion records supplied by the National Institute for Earth Science and Disaster Prevention (NIED; K-NET, KiK-net, F-net), and the mainshock hypocenter determined by the Japan Meteorological Agency (JMA). This study is partially supported by "Special Project for Earthquake Disaster Mitigation in Metropolitan Tokyo Area".

  1. LOCAL SITE CONDITIONS INFLUENCING EARTHQUAKE INTENSITIES AND SECONDARY COLLATERAL IMPACTS IN THE SEA OF MARMARA REGION - Application of Standardized Remote Sensing and GIS-Methods in Detecting Potentially Vulnerable Areas to Earthquakes, Tsunamis and Other Hazards.

    Directory of Open Access Journals (Sweden)

    George Pararas-Carayannis

    2011-01-01

    Full Text Available The destructive earthquake that struck near the Gulf of Izmit along the North Anatolian fault in Northwest Turkey on August 17, 1999, not only generated a local tsunami that was destructive at Golcuk and other coastal cities in the eastern portion of the enclosed Sea of Marmara, but was also responsible for extensive damage from collateral hazards such as subsidence, landslides, ground liquefaction, soil amplifications, compaction and underwater slumping of unconsolidated sediments. This disaster brought attention in the need to identify in this highly populated region, local conditions that enhance earthquake intensities, tsunami run-up and other collateral disaster impacts. The focus of the present study is to illustrate briefly how standardized remote sensing techniques and GIS-methods can help detect areas that are potentially vulnerable, so that disaster mitigation strategies can be implemented more effectively. Apparently, local site conditions exacerbate earthquake intensities and collateral disaster destruction in the Marmara Sea region. However, using remote sensing data, the causal factors can be determined systematically. With proper evaluation of satellite imageries and digital topographic data, specific geomorphologic/topographic settings that enhance disaster impacts can be identified. With a systematic GIS approach - based on Digital Elevation Model (DEM data - geomorphometric parameters that influence the local site conditions can be determined. Digital elevation data, such as SRTM (Shuttle Radar Topography Mission, with 90m spatial resolution and ASTER-data with 30m resolution, interpolated up to 15 m is readily available. Areas with the steepest slopes can be identified from slope gradient maps. Areas with highest curvatures susceptible to landslides can be identified from curvature maps. Coastal areas below the 10 m elevation susceptible to tsunami inundation can be clearly delineated. Height level maps can also help locate

  2. Development of lidocaine-coated microneedle product for rapid, safe, and prolonged local analgesic action.

    Science.gov (United States)

    Zhang, Ying; Brown, Ken; Siebenaler, Kris; Determan, Amy; Dohmeier, Daniel; Hansen, Kris

    2012-01-01

    To demonstrate rapid (~1 min) lidocaine delivery using 3M's solid microstructured transdermal system (sMTS) for prolonged, local analgesic action. Polymeric microneedles were fabricated via injection molding and then dip-coated using an aqueous lidocaine formulation. The amount of lidocaine coated onto the microneedles was determined by high performance liquid chromatography (HPLC). To assess drug delivery and dermal pharmacokinetics, lidocaine-coated microneedles were inserted into domestic swine. Skin punch biopsies were collected and analyzed to determine lidocaine concentration in skin using HPLC-mass spectrometry (LC-MS). Commercial lidocaine/prilocaine EMLA (Eutectic Mixture of Local Anesthetic) cream was used as comparative control. Lidocaine dissolves rapidly off the microneedles and into skin such that the 1-min wear time achieves or exceeds lidocaine tissue levels needed to cause analgesia. This therapeutic threshold (100 ng/mg) was estimated by measuring the total amount of lidocaine and prilocaine in skin following a 1 h EMLA application. When co-formulated with 0.03 wt% vasoconstrictor-epinephrine, the concentration of lidocaine in tissue was maintained above 100 ng/mg for approximately 90 min. 3M's sMTS can be used to provide rapid delivery of lidocaine for local analgesia up to 90 min.

  3. Earthquake induced rapid landslide in Nikawa, Nishinomiya-city, Japan; Nishinomiyashi Nikawa de hasseishita jishinji kosoku jisuberi

    Energy Technology Data Exchange (ETDEWEB)

    Sassa, K. [Kyoto Univ., Kyoto (Japan). Disaster Prevention Research Inst.

    1996-02-01

    A landslide occurred in the Nikawa area of Nishinomiya-city when the Southern Hyogo Earthquake shook on the 17th of January, 1995 was estimated to affect 110,000-120,000m{sup 3} in soil volume, not so much in scale, but became a big disaster in which 11 houses were smashed and 34 people were killed. Regarding the landslide of this area, its moving speed was estimated to be several m/sec in average, although the exact figure is unknown. Kyoto University photographed from the air the landslide site of the Nikawa area on the 21st of January and also collected various kinds of earth clods at the landslide site. The sampled soil was a bluish gray sandy soil mixed with clay and is distributed widely in the landslide area. The collected samples were tested with a ring shearing tester filled with the water after saturating the samples. The discovered causes of the landslide are that the gradient of the slope was about 20{degree} and its safety factor was high, nevertheless due to the earthquake force, the slope soil layers showed shearing fractures, the saturated water basin layers existed in the slope soil layers despite the dry season, and the decrease of strength of the earth and soil of Nikawa was big when saturated. 5 refs., 7 figs.

  4. Along-strike Variations in the Himalayas Illuminated by the Aftershock Sequence of the 2015 Mw 7.8 Gorkha Earthquake Using the NAMASTE Local Seismic Network

    Science.gov (United States)

    Mendoza, M.; Ghosh, A.; Karplus, M. S.; Nabelek, J.; Sapkota, S. N.; Adhikari, L. B.; Klemperer, S. L.; Velasco, A. A.

    2016-12-01

    As a result of the 2015 Mw 7.8 Gorkha earthquake, more than 8,000 people were killed from a combination of infrastructure failure and triggered landslides. This earthquake produced 4 m of peak co-seismic slip as the fault ruptured 130 km east under densely populated cities, such as Kathmandu. To understand earthquake dynamics in this part of the Himalayas and help mitigate similar future calamities by the next destructive event, it is imperative to study earthquake activities in detail and improve our understanding of the source and structural complexities. In response to the Gorkha event, multiple institutions developed and deployed a 10-month long dense seismic network called NAMASTE. It blanketed a 27,650 km2 area, mainly covering the rupture area of the Gorkha earthquake, in order to capture the dynamic sequence of aftershock behavior. The network consisted of a mix of 45 broadband, short-period, and strong motion sensors, with an average spacing of 20 km. From the first 6 months of data, starting approximately 1.5 after the mainshock, we develop a robust catalog containing over 3,000 precise earthquake locations, and local magnitudes that range between 0.3 and 4.9. The catalog has a magnitude of completeness of 1.5, and an overall low b-value of 0.78. Using the HypoDD algorithm, we relocate earthquake hypocenters with high precision, and thus illustrate the fault geometry down to depths of 25 km where we infer the location of the gently-dipping Main Frontal Thrust (MFT). Above the MFT, the aftershocks illuminate complex structure produced by relatively steeply dipping faults. Interestingly, we observe sharp along-strike change in the seismicity pattern. The eastern part of the aftershock area is significantly more active than the western part. The change in seismicity may reflect structural and/or frictional lateral heterogeneity in this part of the Himalayan fault system. Such along-strike variations play an important role in rupture complexities and

  5. Detection of local site conditions influencing earthquake shaking and secondary effects in Southwest-Haiti using remote sensing and GIS-methods

    Directory of Open Access Journals (Sweden)

    B. Theilen-Willige

    2010-06-01

    Full Text Available The potential contribution of remote sensing and GIS techniques to earthquake hazard analysis was investigated in SW-Haiti in order to improve the systematic, standardized inventory of those areas that are more susceptible to earthquake ground motions or to earthquake related secondary effects such as landslides, liquefaction, soil amplifications, compaction or even tsunami-waves. Geophysical, topographical, geological data and satellite images were collected, processed, and integrated into a spatial database using Geoinformation Systems (GIS and image processing techniques. The GIS integrated evaluation of satellite imageries, of digital topographic data and of various open-source geodata can contribute to the acquisition of those specific tectonic, geomorphologic/topographic settings influencing local site conditions in Haiti and, thus, to a first data base stock. Using the weighted overlay techniques in GIS susceptibility maps were produced indicating areas where causal factors influencing surface-near earthquake shock occur aggregated and interfering each other and, thus, rise the susceptibility to soil amplification. This approach was used as well to create landslide and flooding susceptibility maps.

  6. Catalog of relocated earthquake hypocenters and local velocity model for the 2016 Mw 5.8 Pawnee, Oklahoma, sequence

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset contains the supplemental information for the article "Oklahoma experiences largest earthquake during ongoing regional wastewater injection hazard...

  7. Development and utilization of USGS ShakeCast for rapid post-earthquake assessment of critical facilities and infrastructure

    Science.gov (United States)

    Wald, David J.; Lin, Kuo-wan; Kircher, C.A.; Jaiswal, Kishor; Luco, Nicolas; Turner, L.; Slosky, Daniel

    2017-01-01

    The ShakeCast system is an openly available, near real-time post-earthquake information management system. ShakeCast is widely used by public and private emergency planners and responders, lifeline utility operators and transportation engineers to automatically receive and process ShakeMap products for situational awareness, inspection priority, or damage assessment of their own infrastructure or building portfolios. The success of ShakeCast to date and its broad, critical-user base mandates improved software usability and functionality, including improved engineering-based damage and loss functions. In order to make the software more accessible to novice users—while still utilizing advanced users’ technical and engineering background—we have developed a “ShakeCast Workbook”, a well documented, Excel spreadsheet-based user interface that allows users to input notification and inventory data and export XML files requisite for operating the ShakeCast system. Users will be able to select structure based on a minimum set of user-specified facility (building location, size, height, use, construction age, etc.). “Expert” users will be able to import user-modified structural response properties into facility inventory associated with the HAZUS Advanced Engineering Building Modules (AEBM). The goal of the ShakeCast system is to provide simplified real-time potential impact and inspection metrics (i.e., green, yellow, orange and red priority ratings) to allow users to institute customized earthquake response protocols. Previously, fragilities were approximated using individual ShakeMap intensity measures (IMs, specifically PGA and 0.3 and 1s spectral accelerations) for each facility but we are now performing capacity-spectrum damage state calculations using a more robust characterization of spectral deamnd.We are also developing methods for the direct import of ShakeMap’s multi-period spectra in lieu of the assumed three-domain design spectrum (at 0.3s for

  8. [Personal resilience and post-traumatic stress symptoms of local government employees: six months after the 2011 magnitude 9.0 East Japan Earthquake].

    Science.gov (United States)

    Tsuno, Kanami; Oshima, Kazuki; Kubota, Kazumi; Kawakami, Norito

    2014-01-01

    The Great East Japan Earthquake caused severe infrastructure damage in the Kanto and Tohoku regions, but the psychological stress of public sector employees in the Kanto region where tsunami damage was small has received little attention. This study examined the association between personal resilience and post-traumatic stress symptoms of local government employees in the Kanto region. In this cross-sectional study, all employees (N=2,069) of a single municipality in the Kanto region were recruited in September 2011, six months after the earthquake, and 991 completed the questionnaire (response rate, 47.9%). After excluding respondents who had missing values, the data from 825 respondents (607 males and 218 females) were analyzed. Post-traumatic stress symptoms were measured using the Impact Event Scale-Revised. Resilience was measured using the Connor-Davidson Resilience Scale and divided into three groups on the basis of scores; low, moderate, and high. House damage and respondents or their families' experience of injury that were caused by the earthquake were assessed using single-item questions. Participants who reported house damage or injury were defined as being affected. Using multiple logistic regression analysis, the odds ratio of post-traumatic stress symptoms (IES-R score ≥25) was calculated for the upper, middle, and low resilience score groups. Among the respondents, 4.6% experienced injuries within their families, 82.3% reported house damage, and thus 83.3% were affected by the Great East Japan Earthquake. Post-traumatic stress symptoms were significantly higher among the affected group and those with chronic diseases. After adjusting for the demographic and occupational characteristics, the likelihood of post-traumatic stress symptoms was greater in the low resilience group (Odds ratio: 2.10 [95% confidence interval = 1.31-3.37]). A significant negative relationship was observed between resilience and post-traumatic stress symptoms particularly in

  9. Possibility between earthquake and explosion seismogram differentiation by discrete stochastic non-Markov processes and local Hurst exponent analysis.

    Science.gov (United States)

    Yulmetyev, R; Gafarov, F; Hänggi, P; Nigmatullin, R; Kayumov, S

    2001-12-01

    The basic scientific point of this paper is to draw the attention of researchers to new possibilities of differentiation of similar signals having different nature. One example of such kinds of signals is presented by seismograms containing recordings of earthquakes (EQ's) and technogenic explosions (TE's). EQ's are among the most dramatic phenomena in nature. We propose here a discrete stochastic model for possible solution of a problem of strong EQ forecasting and differentiation of TE's from the weak EQ's. Theoretical analysis is performed by two independent methods: by using statistical theory of discrete non-Markov stochastic processes [Phys. Rev. E 62, 6178 (2000)] and the local Hurst exponent. The following Earth states have been considered among them: before (Ib) and during (I) strong EQ, during weak EQ (II) and during TE (III), and in a calm state of Earth's core (IV). The estimation of states I, II, and III has been made on the particular examples of Turkey (1999) EQ's, state IV has been taken as an example of Earth's state before underground TE. Time recordings of seismic signals of the first four dynamic orthogonal collective variables, six various planes of phase portrait of four-dimensional phase space of orthogonal variables and the local Hurst exponent have been calculated for the dynamic analysis of states of systems I-IV. The analysis of statistical properties of seismic time series I-IV has been realized with the help of a set of discrete time-dependent functions (time correlation function and first three memory functions), their power spectra, and the first three points in the statistical spectrum of non-Markovity parameters. In all systems studied we have found a bizarre combination of the following spectral characteristics: the fractal frequency spectra adjustable by phenomena of usual and restricted self-organized criticality, spectra of white and color noises and unusual alternation of Markov and non-Markov effects of long-range memory

  10. Prioritizing earthquake and tsunami alerting efforts

    Science.gov (United States)

    Allen, R. M.; Allen, S.; Aranha, M. A.; Chung, A. I.; Hellweg, M.; Henson, I. H.; Melgar, D.; Neuhauser, D. S.; Nof, R. N.; Strauss, J. A.

    2015-12-01

    The timeline of hazards associated with earthquakes ranges from seconds for the strong shaking at the epicenter, to minutes for strong shaking at more distant locations in big quakes, to tens of minutes for a local tsunami. Earthquake and tsunami warning systems must therefore include very fast initial alerts, while also taking advantage of available time in bigger and tsunami-generating quakes. At the UC Berkeley Seismological Laboratory we are developing a suite of algorithms to provide the fullest possible information about earthquake shaking and tsunami inundation from seconds to minutes after a quake. The E-larmS algorithm uses the P-wave to rapidly detect an earthquake and issue a warning. It is currently issuing alerts to test users in as little as 3 sec after the origin time. Development of a new waveform detector may lead to even faster alerts. G-larmS uses permanent deformation estimates from GNSS stations to estimate the geometry and extent of rupture underway providing more accurate ground shaking estimates in big (M>~7) earthquakes. It performed well in the M6.0 2014 Napa earthquake. T-larmS is a new algorithm designed to extend alert capabilities to tsunami inundation. Rapid estimates of source characteristics for subduction zones event can not only be used to warn of the shaking hazard, but also the local tsunami inundation hazard. These algorithms are being developed, implemented and tested with a focus on the western US, but are also now being tested in other parts of the world including Israel, Turkey, Korea and Chile. Beta users in the Bay Area are receiving the alerts and beginning to implement automated actions. They also provide feedback on users needs, which has led to the development of the MyEEW smartphone app. This app allows beta users to receive the alerts on their cell phones. All these efforts feed into our ongoing assessment of directions and priorities for future development and implementation efforts.

  11. Rapid assessment of insect fauna based on local knowledge: comparing ecological and ethnobiological methods.

    Science.gov (United States)

    Lima, Daniele Cristina de Oliveira; Ramos, Marcelo Alves; da Silva, Henrique Costa Hermenegildo; Alves, Angelo Giuseppe Chaves

    2016-03-01

    The rapid assessment of biodiversity making use of surveys of local knowledge has been successful for different biological taxa. However, there are no reports on the testing of such tools for sampling insect fauna. The present study aimed to evaluate the efficiency of different ethnobiological techniques for rapid sampling of insect fauna. Field research for the conventional survey of insect fauna was conducted on a private farm (9 ° 43'38.95 "S, 37 ° 45'11.97" W) , where there was intensive cultivation of okra (Abelmoschus esculentus L. (Moench)). The survey of local entomological knowledge was conducted among all the producers of okra living in the rural villages Pereira, Santa Luzia, and Nassau de Souza, within the Jacaré Curituba irrigated settlement scheme. The combined use of the techniques "free list" and projective interviews was analyzed, using two types of visual stimuli: stock photos and an entomological box. During the conventional survey of insect fauna, the species Bemisia tabaci biotype B, Aphis gossypii, Phenacoccus sp., Icerya purchasi and Lagria villosa were the primary pests found in the okra crop. Regarding the survey of insect pests, the results were convergent  in both techniques (conventional sampling and free list). Comparing the interview with visual stimuli (pictures) and specimen witnesses (entomological box) revealed that the latter was more effective. Techniques based on the recording and analysis of local knowledge about insects are effective for quick sampling of pest insects, but ineffective in sampling predator insects. The utilization of collected insects, infested branches, or photos of the symptoms of damage caused by pests in projective interviews is recommended.

  12. Earthquake science in resilient societies

    Science.gov (United States)

    Stahl, T.; Clark, M. K.; Zekkos, D.; Athanasopoulos-Zekkos, A.; Willis, M.; Medwedeff, William; Knoper, Logan; Townsend, Kirk; Jin, Jonson

    2017-04-01

    Earthquake science is critical in reducing vulnerability to a broad range of seismic hazards. Evidence-based studies drawing from several branches of the Earth sciences and engineering can effectively mitigate losses experienced in earthquakes. Societies that invest in this research have lower fatality rates in earthquakes and can recover more rapidly. This commentary explores the scientific pathways through which earthquake-resilient societies are developed. We highlight recent case studies of evidence-based decision making and how modern research is improving the way societies respond to earthquakes.

  13. Monitoring and evaluation of disaster response efforts undertaken by local health departments: a rapid realist review.

    Science.gov (United States)

    Gossip, Kate; Gouda, Hebe; Lee, Yong Yi; Firth, Sonja; Bermejo, Raoul; Zeck, Willibald; Jimenez Soto, Eliana

    2017-06-29

    Local health departments are often at the forefront of a disaster response, attending to the immediate trauma inflicted by the disaster and also the long term health consequences. As the frequency and severity of disasters are projected to rise, monitoring and evaluation (M&E) efforts are critical to help local health departments consolidate past experiences and improve future response efforts. Local health departments often conduct M&E work post disaster, however, many of these efforts fail to improve response procedures. We undertook a rapid realist review (RRR) to examine why M&E efforts undertaken by local health departments do not always result in improved disaster response efforts. We aimed to complement existing frameworks by focusing on the most basic and pragmatic steps of a M&E cycle targeted towards continuous system improvements. For these purposes, we developed a theoretical framework that draws on the quality improvement literature to 'frame' the steps in the M&E cycle. This framework encompassed a M&E cycle involving three stages (i.e., document and assess, disseminate and implement) that must be sequentially completed to learn from past experiences and improve future disaster response efforts. We used this framework to guide our examination of the literature and to identify any context-mechanism-outcome (CMO) configurations which describe how M&E may be constrained or enabled at each stage of the M&E cycle. This RRR found a number of explanatory CMO configurations that provide valuable insights into some of the considerations that should be made when using M&E to improve future disaster response efforts. Firstly, to support the accurate documentation and assessment of a disaster response, local health departments should consider how they can: establish a culture of learning within health departments; use embedded training methods; or facilitate external partnerships. Secondly, to enhance the widespread dissemination of lessons learned and facilitate

  14. Earthquakes in British Columbia

    National Research Council Canada - National Science Library

    1991-01-01

    This pamphlet provides information about the causes of earthquakes, where earthquakes occur, British Columbia plate techtonics, earthquake patterns, earthquake intensity, geology and earthquake impact...

  15. Crustal Velocity Structure of the Rio Grande Rift and Rocky Mountains from Local Earthquakes and Blasts Recorded by USArray and CREST

    Science.gov (United States)

    Nakai, J.; Sheehan, A. F.; Bilek, S. L.

    2015-12-01

    Arrival times from over 3,100 earthquakes and 2,800 mine blasts recorded at USArray Transportable Array (TA) and other regional broadband seismic stations are inverted to find the regional P and S velocity structure in Colorado and New Mexico. Knowledge of the crustal structure in Colorado will help inform to what extent this structure and composition influences the isostatic compensation of high topography in the region. The relationship between the Rio Grande rift and the surrounding physiographic provinces remains enigmatic, and neither the geology nor geophysical surveys have clearly resolved the rift in Colorado. Therefore, tomography may supply more information about velocity variations along the rift within the context of the Colorado Plateau, the Great Plains, and the Rocky Mountains. Thus far, applications with the TA data to resolve P wave crustal structure are rare due to distant station spacing and small magnitude and shallow (mid to upper crustal) local earthquakes. The depths of the earthquakes range from 4 km to the mid-crust, so we expect dense ray coverage in the upper crust. In order to increase the number of crossing rays, we use mine blast P wave arrivals to constrain shallow surface structure. A total of 70,000 P wave arrivals and 18,000 S wave arrivals constitute the dataset. We develop a reliable 1D regional velocity model using 500 of the largest earthquakes with a fixed Vp/Vs ratio from the arrival data, then use this model as an input to investigate the feasibility of utilization of a 3D inversion algorithm. While use of a 3D inversion algorithm will be explored, construction of a series of 1D velocity and Vp/Vs models may prove to be more robust.

  16. Determining the Source Parameters of the Jambi Earthquake (1 October 2009, Mw =6.4 Using Three-Component Local Waveforms

    Directory of Open Access Journals (Sweden)

    Madlazim

    2013-04-01

    Full Text Available The purpose of this research was to estimate the source parameters of a mainshock earthquake (Mw=6.4 that occurred on 1 October 2009 in the Dikit major segment of theSumatran Fault Zone (SFZ. The source parameters were analyzed by the inversion of three-component local waveformsrecorded by the GEOFON broadband IA network. Moment tensorof the event was determined using the Discrete Wave number method to calculate the Green function and the iterative deconvolution method to invert the moment tensors. From the analysis, we obtained the fault parameters of the mainshock, which are strike=324°, dip= 80° and rake= -173°.

  17. Two-dimensional joint inversion of Magnetotelluric and local earthquake data: Discussion on the contribution to the solution of deep subsurface structures

    Science.gov (United States)

    Demirci, İsmail; Dikmen, Ünal; Candansayar, M. Emin

    2018-02-01

    Joint inversion of data sets collected by using several geophysical exploration methods has gained importance and associated algorithms have been developed. To explore the deep subsurface structures, Magnetotelluric and local earthquake tomography algorithms are generally used individually. Due to the usage of natural resources in both methods, it is not possible to increase data quality and resolution of model parameters. For this reason, the solution of the deep structures with the individual usage of the methods cannot be fully attained. In this paper, we firstly focused on the effects of both Magnetotelluric and local earthquake data sets on the solution of deep structures and discussed the results on the basis of the resolving power of the methods. The presence of deep-focus seismic sources increase the resolution of deep structures. Moreover, conductivity distribution of relatively shallow structures can be solved with high resolution by using MT algorithm. Therefore, we developed a new joint inversion algorithm based on the cross gradient function in order to jointly invert Magnetotelluric and local earthquake data sets. In the study, we added a new regularization parameter into the second term of the parameter correction vector of Gallardo and Meju (2003). The new regularization parameter is enhancing the stability of the algorithm and controls the contribution of the cross gradient term in the solution. The results show that even in cases where resistivity and velocity boundaries are different, both methods influence each other positively. In addition, the region of common structural boundaries of the models are clearly mapped compared with original models. Furthermore, deep structures are identified satisfactorily even with using the minimum number of seismic sources. In this paper, in order to understand the future studies, we discussed joint inversion of Magnetotelluric and local earthquake data sets only in two-dimensional space. In the light of these

  18. Non-volcanic tremor characteristics and tremor generation environment in Taiwan and a case study of their stress interaction with local earthquakes

    Science.gov (United States)

    Chao, K.; Obara, K.; Nagai, S.; Hirata, N.; Pu, H.; Peng, Z.; Hsu, Y.; Wech, A.; Ching, K.; Leu, P.; Shin, T.; Huang, B.

    2013-12-01

    Recent finding of tremor in Taiwan provides an ideal place to study tremor in collision tectonic environment and its relationship with local earthquakes. Although several studies have identified triggered and ambient tremor beneath the southern Central Range of Taiwan, a number of fundamental questions of tremor remain unclear. For example, it is still not clear whether tremor occurred in the low-angle detachment fault beneath the Central Range, or high-angle thrust fault beneath the Chaochou-Lishan fault. Here we present comprehensive study of tremor in Taiwan by utilizing two different seismic datasets. First, we applied the Waveform Envelope Correlation and Clustering (WECC) method and a spatio-temporal clustering criterion to automatically detect tremor from 2004 to 2012, using continuous data recorded by ten permanent stations operated by the Central Weather Bureau Seismic Network (CWBSN) and the Broadband Array in Taiwan for Seismology (BATS). The tremor activity in this region is characterized by frequent occurrence with short duration of 5~24 min. We found that ambient tremor surrounds an active triggered tremor source and that its spectrum is similar to that of triggered tremor but with lower amplitude, suggesting similar source mechanisms but different driving forces. We also quantified tremor activity before and after the 4 March 2010, Mw6.3 Jiashian earthquake that occurred about 20km southwest from active tremor sources. We found that maximum tremor activity occurred at around 10 days after the Jiashian mainshock and the long-term tremor rate increased 51.7% in a 14-month period, possibly caused by a static Coulomb stress increase with a maximum 20KPa around tremor sources based on the detachment fault model. Interestingly, the tremor rate started to increase about 20 days before the mainshock. We have examined the borehole dilatometer data located at ~36km northeast of the tremor sources, but found no clear change of volumetric strain before the

  19. Modeling Features of Both the Rupture Process and the Local Tsunami Wave Field from the 2011 Tohoku Earthquake

    Science.gov (United States)

    Lobkovsky, L.; Garagash, I.; Baranov, B.; Mazova, R.; Baranova, N.

    2017-10-01

    This paper presents the numerical simulation of the displacement distribution in the source of the 2011 Tohoku earthquake, based on the following assumptions on the geometry and mechanics of the source, and features of the subduction zone structure: displacement in the source is determined by specifying a reduced friction coefficient on the plate interface, considering heterogeneous initial stress state of the medium; source is considered in the framework of the Lay-Kanamori model as two consecutive subsources with deep and shallow location; a nonlinear elasto-plastic model of behavior of the medium under the Mohr-Coulomb yield criterion is applied. For the numerical modeling, a program code FLAC 3D implementing an explicit finite-difference scheme solution is used. The resulting lithosphere displacement distribution was used for computation of the tsunami source for given earthquake. The numerical simulation of the corresponding tsunami wave field was performed.

  20. Rupture planes of the Gazli earthquakes deduced from local stress tensor calculation and geodetic data inversion: Geotectonic implications

    Science.gov (United States)

    AmorèSe, D.; Grasso, J.-R.

    1996-05-01

    Three major earthquakes (with Ms ≥ 7) were clustered in space and time (1976-1984) near Gazli, Uzbekistan, without reported evidence for fault scarps. To constrain the kinematics of the seismic sequence, we invert both focal mechanism solutions of the mainshocks and major aftershocks and vertical surface displacements associated with the three major shocks. For seven M > 4 earthquakes that occurred in the 1976-1984 period, we find that all the focal mechanisms agree with a single stress tensor. One of the mechanical implications of this mathematical solution is the choice of the seismic fault plane. The 1976 earthquake fracture planes are well constrained by the stress tensor to be striking E-W and ENE-WSW and dipping to the south and the NNW respectively. From stress tensor inversion alone, it is impossible to determine if the fracture plane of the 1984 event dips to the SE or to the NW. Coseismic vertical surface displacements allow us to infer possible fault plane orientations of the 1976 and 1984 events. The best fit to the surface displacement for the 1976 earthquakes is obtained from the geometries that are derived from the homogeneous stress tensor inversion. The inversion of vertical surface displacements for the 1984 event constrains the associated fault plane to correspond to a NE-WS striking and SE dipping plane. The inversions of complementary geophysical data argue for the complexity of the orientations of the faults activated by the 1976-1984 seismic sequence. The 1984 earthquake fault plane is well orientated to allow failure to be activated by a horizontal σ1 under a Mohr-Coulomb failure criterion. Under the same failure criterion and stress conditions, unlike the 1984 fracture plane, the 1976 fault planes are misorientated and likely to correspond to preexisting discontinuities. Concerning the principle stress orientations, the Gazli region seems to be under control of the regional tectonic setting. From a regional point of view, the WNW

  1. Rapid object indexing using locality sensitive hashing and joint 3D-signature space estimation.

    Science.gov (United States)

    Matei, Bogdan; Shan, Ying; Sawhney, Harpreet S; Tan, Yi; Kumar, Rakesh; Huber, Daniel; Hebert, Martial

    2006-07-01

    We propose a new method for rapid 3D object indexing that combines feature-based methods with coarse alignment-based matching techniques. Our approach achieves a sublinear complexity on the number of models, maintaining at the same time a high degree of performance for real 3D sensed data that is acquired in largely uncontrolled settings. The key component of our method is to first index surface descriptors computed at salient locations from the scene into the whole model database using the Locality Sensitive Hashing (LSH), a probabilistic approximate nearest neighbor method. Progressively complex geometric constraints are subsequently enforced to further prune the initial candidates and eliminate false correspondences due to inaccuracies in the surface descriptors and the errors of the LSH algorithm. The indexed models are selected based on the MAP rule using posterior probability of the models estimated in the joint 3D-signature space. Experiments with real 3D data employing a large database of vehicles, most of them very similar in shape, containing 1,000,000 features from more than 365 models demonstrate a high degree of performance in the presence of occlusion and obscuration, unmodeled vehicle interiors and part articulations, with an average processing time between 50 and 100 seconds per query.

  2. Orthopedic Activity in Field Hospitals Following Earthquakes in Nepal and Haiti : Variability in Injuries Encountered and Collaboration with Local Available Resources Drive Optimal Response.

    Science.gov (United States)

    Bar-On, Elhanan; Blumberg, Nehemia; Joshi, Amit; Gam, Arnon; Peyser, Amos; Lee, Evgeny; Kashichawa, Shree Krishna; Morose, Alexander; Schein, Ophir; Lehavi, Amit; Kreiss, Yitshak; Bader, Tarif

    2016-09-01

    Field hospitals have been deployed by the Israel Defense Forces (IDF) Medical Corps in numerous disaster events. Two recent deployments were following earthquakes in Haiti in 2010 and in Nepal in 2015. Despite arrival in similar timetables, the mode of operation was different-independently in Haiti and in collaboration with a local hospital in Nepal. The pathology encountered in the two hospitals and the resultant treatment requirements were significantly different between the two events. The purpose of this study was to analyze these differences and their implications for preparation and planning of future deployments. Data were obtained from IDF records and analyzed using SPSS™ software. 1686 patients were treated in Nepal versus 1111 in Haiti. The caseload in Nepal included significantly less earthquake-related injuries (26 vs. 66 %) with 28 % of them sustaining fractures versus 47 % in Haiti. Femoral fractures accounted for 7.9 % of fractures in Nepal versus 26.4 % in Haiti with foot fractures accounting for 23.8 and 6.4 %, respectively. The rate of open fracture was similar at 29.4 % in Nepal and 27.5 % in Haiti. 18.1 % of injured patients in Nepal underwent surgery, and 32.9 % of which was skeletal compared to 32 % surgical cases (58.8 % skeletal) in Haiti. 74.2 % of patients in Nepal and 34.3 % in Haiti were treated for pathology unrelated to the earthquake. The reasons for the variability in activities between the two hospitals include the magnitude of the disaster, the functionality of the local medical system which was relatively preserved in Nepal and destroyed in Haiti and the mode of operation which was independent in Haiti and collaborative with a functioning local hospital in Nepal. Emergency medical teams (EMTs) may encounter variable caseloads despite similar disaster scenarios. Advance knowledge of the magnitude of the disaster, the functionality of the local medical system, and the collaborative possibilities will help in planning

  3. On the involvement of the Citizens for an improved earthquake response

    Science.gov (United States)

    Bossu, R.; Gilles, S.; Roussel, F.

    2009-04-01

    Because of their key role in earthquake response, the Civil Protection Agencies are more interested in the effects of an earthquake rather than on the phenomenon itself. An earthquake effects are not easy to predict from seismological data only. Firstly because the many elements required to estimate these effects are either affected by non-negligible uncertainties (e.g. earthquake depth and location, site effects, seismic attenuation) and/or poorly constrained (e.g. building vulnerability, distribution of the population with time…). Secondly, because the reaction of the population is not always easy to predict especially in areas of low seismic hazard where there is little or no experience of felt earthquake. In order to complement its services of rapid earthquake information, the Euro-Med Seismological Centre (EMSC) developed a number of tools to rapidly collect in-situ observations of the earthquake effects and better evaluate the reaction of the population. The first tool is an original development by EMSC. It uses the observed surge of traffic on EMSC web site (www.emsc-csem.org) to rapidly (within 5 to 10 minutes of the earthquake's occurrence) map the area where an earthquake was felt and it determines whether there has been significant widespread damage. When an earthquake is felt, people rush on the Internet to find out the cause of the shaking generating brutal surge of traffic on our web site. The area where the earthquake was felt is determined by locating the IP addresses and identifying the localities which exhibit a significant increase of visitors. Damaged areas are characterised by a lack or an absence of connections. This approach, which is the fastest way to collect in-situ observations on earthquake effects, is being implemented in several institutes in Europe. Online macroseismic questionnaires in more than 20 languages complement this first approach. It provides a refined description of the effects and shaking levels through a quantitative

  4. Nowcasting Earthquakes

    Science.gov (United States)

    Rundle, J. B.; Donnellan, A.; Grant Ludwig, L.; Turcotte, D. L.; Luginbuhl, M.; Gail, G.

    2016-12-01

    Nowcasting is a term originating from economics and finance. It refers to the process of determining the uncertain state of the economy or markets at the current time by indirect means. We apply this idea to seismically active regions, where the goal is to determine the current state of the fault system, and its current level of progress through the earthquake cycle. In our implementation of this idea, we use the global catalog of earthquakes, using "small" earthquakes to determine the level of hazard from "large" earthquakes in the region. Our method does not involve any model other than the idea of an earthquake cycle. Rather, we define a specific region and a specific large earthquake magnitude of interest, ensuring that we have enough data to span at least 20 or more large earthquake cycles in the region. We then compute the earthquake potential score (EPS) which is defined as the cumulative probability distribution P(nearthquakes in the region. From the count of small earthquakes since the last large earthquake, we determine the value of EPS = P(nearthquake cycle in the defined region at the current time.

  5. Twitter earthquake detection: earthquake monitoring in a social world

    National Research Council Canada - National Science Library

    Daniel C. Bowden; Paul S. Earle; Michelle Guy

    2011-01-01

    ... messages, can augment USGS earthquake response products and the delivery of hazard information. Rapid detection and qualitative assessment of shaking events are possible because people begin sending public Twitter messages...

  6. Earthquakes Sources Parameter Estimation of 20080917 and 20081114 Near Semangko Fault, Sumatra Using Three Components of Local Waveform Recorded by IA Network Station

    Directory of Open Access Journals (Sweden)

    Madlazim

    2012-04-01

    Full Text Available The 17/09/2008 22:04:80 UTC and 14/11/2008 00:27:31.70 earthquakes near Semangko fault were analyzed to identify the fault planes. The two events were relocated to assess physical insight against the hypocenter uncertainty. The datas used to determine source parameters of both earthquakes were three components of local waveform recorded by Geofon broadband IA network stations, (MDSI, LWLI, BLSI and RBSI for the event of 17/09/2008 and (MDSI, LWLI, BLSI and KSI for the event of 14/11/2008. Distance from the epicenter to all station was less than 5°. Moment tensor solution of two events was simultaneously analyzed by determination of the centroid position. Simultaneous analysis covered hypocenter position, centroid position and nodal planes of two events indicated Semangko fault planes. Considering that the Semangko fault zone is a high seismicity area, the identification of the seismic fault is important for the seismic hazard investigation in the region.

  7. Somatosensory Space Abridged: Rapid Change in Tactile Localization Using a Motion Stimulus

    Science.gov (United States)

    Seizova-Cajic, Tatjana; Taylor, Janet L.

    2014-01-01

    Introduction Organization of tactile input into somatotopic maps enables us to localize stimuli on the skin. Temporal relationships between stimuli are important in maintaining the maps and influence perceived locations of discrete stimuli. This points to the spatiotemporal stimulation sequences experienced as motion as a potential powerful organizing principle for spatial maps. We ask whether continuity of the motion determines perceived location of areas in the motion path using a novel tactile stimulus designed to ‘convince’ the brain that a patch of skin does not exist by rapidly skipping over it. Method Two brushes, fixed 9 cm apart, moved back and forth along the forearm (at 14.5 cm s−1), crossing a 10-cm long ‘occluder’, which prevented skin stimulation in the middle of the motion path. Crucially, only one brush contacted the skin at any one time, and the occluder was traversed almost instantaneously. Participants pointed with the other arm towards the felt location of the brush when it was briefly halted during repetitive motion, and also reported where they felt they had been brushed. Results Participants did not report the 10-cm gap in stimulation – the motion path was perceptually completed. Pointing results showed that brush path was ‘abridged’: locations immediately on either side of the occluder, as well as location at the ends of the brush path, were perceived to be >3 cm closer to each other than in the control condition (F(1,9) = 7.19; p = .025 and F(1,9) = 6.02, p = .037 respectively). This bias increased with prolonged stimulation. Conclusions An illusion of completion induced by our Abridging stimulus is accompanied by gross mislocalization, suggesting that motion determines perceived locations. The effect reveals the operation of Gestalt principles in touch and suggests the existence of dynamic maps that quickly adjust to the current input pattern. PMID:24603595

  8. Earthquake Early Warning for the 2016 Kumamoto Earthquake: Performance Evaluation of the Current System and Simulations of the Next-Generation Methods of the Japan Meteorological Agency

    Science.gov (United States)

    Kodera, Y.; Saitou, J.; Hayashimoto, N.; Adachi, S.; Morimoto, M.; Nishimae, Y.; Hoshiba, M.

    2016-12-01

    The sequence of the 2016 Kumamoto earthquake (the Kumamoto earthquake) is extremely high seismic activity that occurred across Kumamoto and Oita prefectures in Japan since April 14, 2016 at 21:26 (JST). The Earthquake Early Warning (EEW) system of the Japan Meteorological Agency (JMA) processed large amount of earthquake data and issued 19 warnings (higher grade alerts) and 175 forecasts (lower grade alerts) for the Kumamoto earthquake from April 14 to 30. Especially on April 14 and 16, the system operated under one of the highest workload conditions since JMA started its EEW service. We evaluated the system performance for cases where the warning was issued and/or the maximum seismic intensity of ≥5L (on the JMA scale) was actually observed, calculating prediction scores and lapse times from detection. The result shows that the system rapidly disseminated high accurate EEW announcements for most of the devastating earthquakes and did not miss or seriously under-predict strong motions. On the other hand, the system issued over-predicted warnings when multiple simultaneous earthquakes occurred within a short distance, comparable with the interval of the seismic observation network. We also simulated the Integrated Particle Filter (IPF) and Propagation of Local Undamped Motion (PLUM) methods, scheduled to be implemented in the JMA EEW system to minimize over-prediction with multiple simultaneous earthquakes and under-prediction with huge earthquakes (M> 8). The simulation results indicate that the IPF method is highly effective for the cases where the current system issued the over-predicted warnings, owing to its classification algorithm using amplitude data and its robust hypocenter determination against outliers among trigger data. The results also show that the PLUM method contributes to more rapid warning issuance for the devastating earthquakes, owing to its denser seismic observation network.

  9. Case report of a child's anxiety disorder precipitated by tremors from a distant earthquake that was extensively covered in local news stories

    OpenAIRE

    Bhatia, M.S.; Gautam, Priyanka

    2016-01-01

    Earthquakes are relatively common natural disasters in many parts of the world, but research about the mental health effects of earthquakes remains limited. Individuals experiencing an earthquake often suffer significant loss and are at increased risk for developing mental disorders. However, the prevalence of mental disorders following less dramatic or non-destructive earthquake phenomena is unknown. We report the case of a 10-year-old girl who came to a psychiatric outpatient department wit...

  10. An attenuation study in Southern Italy using local and regional earthquakes recorded by seismic network of Basilicata

    Directory of Open Access Journals (Sweden)

    M. Mucciarelli

    2004-06-01

    Full Text Available We determined a set of empirical functions that describe the spectral amplitude decay of S-waves with distance in Southern Italy. We analyzed 32 earthquakes with magnitudes ML 2.0-5.4 and hypocentral distances ranging between 12 and 216 km. We obtained attenuation functions for 14 frequencies(1.0< f<20.0 Hz. We compared these functions with average non-parametric attenuation functions reported by Castro et al. (1999 for different regions of Italy, and we observe that at low frequencies (f<5.0 Hz the spectral amplitudes from earthquakes in Southern Italy decay faster than the average. However, at high frequencies ( f > 5.0 Hz, the spectral amplitudes are above the average. At higher frequencies ( f > 10 Hz, the attenuation functions obtained for Southern Italy are slightly above the standard deviation of the average attenuation functions. It is possible that in this frequency range (10-20 Hz site effects may influence the amplitude decay. In order to quantify the attenuation of the S-waves, we estimated the quality factor Q modeling the empirical attenuation functions using the following parametric form: A( f , r=10/r b·e- pfR/Q ß; where 1.6 = f = 10.0 Hz is the frequency band with minimum effect of instrument and site response, r = 120 km is the distance range where the rate of decay of the spectral amplitudes is approximately constant, R=(r-10 and ß=3.2 km/s. We found that the exponent b=1.0±0.2 in the frequency band analyzed and Q shows a frequency dependence that can be approximated by the function Q=32.1 f 1.7.

  11. Mechanical response of local rapid cooling by spray water on constrained steel frame structure at high temperature in fire

    Directory of Open Access Journals (Sweden)

    Xia Yunchun

    2015-01-01

    Full Text Available Locally rapid cooling of spray water had strong impact on high temperature steel structure. When temperature of beam reached 600°C and cooling rate was more than 20°C/s, the maximum axial tension could reach more than 5 times of the originally compressive force. The compressive bending moment at joint of beam-to-column changed to tensile bending moment, and the maximum bending moment could reach above 4 times as that when heated. After rapid cooling by spray water, deflection at mid-span increased slightly.

  12. Methodology for Computer-aided, Interactive Rapid Assessment of Local or Regional Stress Fields on Mars

    Science.gov (United States)

    Colton, S. L.; Ferrill, D. A.; Sims, D. W.; Wyrick, D. Y.; Franklin, N. M.

    2003-03-01

    We present a method for rapid assessment of stress fields on Mars: (i) mapping geologic structures, (ii) calculating stress fields, and (iii) determining resolved stresses on faults. Preliminary results are presented for northern Utopia Planitia.

  13. Assessment of earthquake effects - contribution from online communication

    Science.gov (United States)

    D'Amico, Sebastiano; Agius, Matthew; Galea, Pauline

    2014-05-01

    The rapid increase of social media and online newspapers in the last years have given the opportunity to make a national investigation on macroseismic effects on the Maltese Islands based on felt earthquake reports. A magnitude 4.1 earthquake struck close to Malta on Sunday 24th April 2011 at 13:02 GMT. The earthquake was preceded and followed by a series of smaller magnitude quakes throughout the day, most of which were felt by the locals on the island. The continuous news media coverage during the day and the extensive sharing of the news item on social media resulted in a strong public response to fill in the 'Did you feel it?' online form on the website of the Seismic Monitoring and Research Unit (SMRU) at the University of Malta (http://seismic.research.um.edu.mt/). The results yield interesting information about the demographics of the island, and the different felt experiences possibly relating to geological settings and diverse structural and age-classified buildings. Based on this case study, the SMRU is in the process of developing a mobile phone application dedicated to share earthquake information to the local community. The application will automatically prompt users to fill in a simplified 'Did you feel it?' report to potentially felt earthquakes. Automatic location using Global Positioning Systems can be incorporated to provide a 'real time' intensity map that can be used by the Civil Protection Department.

  14. Scenario-based earthquake hazard and risk assessment for Baku (Azerbaijan

    Directory of Open Access Journals (Sweden)

    G. Babayev

    2010-12-01

    Full Text Available A rapid growth of population, intensive civil and industrial building, land and water instabilities (e.g. landslides, significant underground water level fluctuations, and the lack of public awareness regarding seismic hazard contribute to the increase of vulnerability of Baku (the capital city of the Republic of Azerbaijan to earthquakes. In this study, we assess an earthquake risk in the city determined as a convolution of seismic hazard (in terms of the surface peak ground acceleration, PGA, vulnerability (due to building construction fragility, population features, the gross domestic product per capita, and landslide's occurrence, and exposure of infrastructure and critical facilities. The earthquake risk assessment provides useful information to identify the factors influencing the risk. A deterministic seismic hazard for Baku is analysed for four earthquake scenarios: near, far, local, and extreme events. The seismic hazard models demonstrate the level of ground shaking in the city: PGA high values are predicted in the southern coastal and north-eastern parts of the city and in some parts of the downtown. The PGA attains its maximal values for the local and extreme earthquake scenarios. We show that the quality of buildings and the probability of their damage, the distribution of urban population, exposure, and the pattern of peak ground acceleration contribute to the seismic risk, meanwhile the vulnerability factors play a more prominent role for all earthquake scenarios. Our results can allow elaborating strategic countermeasure plans for the earthquake risk mitigation in the Baku city.

  15. Chance findings about early holocene tidal marshes of Grays Harbor, Washington, in relation to rapidly rising seas and great subduction earthquakes

    Science.gov (United States)

    Phipps, James B.; Hemphill-Haley, Eileen; Atwater, Brian F.

    2015-06-18

    Tidal marshes commonly build upward apace with gradual rise in the level of the sea. It is expected, however, that few tidal marshes will keep up with accelerated sea-level rise later in this century. Tidal marshes have been drowned, moreover, after subsiding during earthquakes.

  16. A simple, rapid, and reliable protocol to localize hydrogen peroxide in large plant organs by DAB-mediated tissue printing.

    Science.gov (United States)

    Liu, Yong-Hua; Offler, Christina E; Ruan, Yong-Ling

    2014-01-01

    Hydrogen peroxide (H2O2) is a major reactive oxygen species (ROS) and plays diverse roles in plant development and stress responses. However, its localization in large and thick plant organs (e.g., stem, roots, and fruits), other than leaves, has proven to be challenging due to the difficulties for the commonly used H2O2-specific chemicals, such as 3,3'-diaminobenzidine (DAB), cerium chloride (CeCl3), and 2',7'-dichlorofluorescin diacetate (H2DCF-DA), to penetrate those organs. Theoretically, the reaction of endogenous H2O2 with these chemicals could be facilitated by using thin organ sections. However, the rapid production of wound-induced H2O2 associated with this procedure inevitably disturbs the original distribution of H2O2 in vivo. Here, by employing tomato seedling stems and fruits as testing materials, we report a novel, simple, and rapid protocol to localize H2O2 in those organs using DAB-mediated tissue printing. The rapidity of the protocol (within 15 s) completely avoided the interference of wound-induced H2O2 during experimentation. Moreover, the H2O2 signal on the printing was stable for at least 1 h with no or little background produced. We conclude that DAB-mediated tissue printing developed here provide a new feasible and reliable method to localize H2O2 in large plant organs, hence should have broad applications in studying ROS biology.

  17. Have the tsunami and nuclear accident following the Great East Japan Earthquake affected the local distribution of hospital physicians?

    Science.gov (United States)

    Kashima, Saori; Inoue, Kazuo; Matsumoto, Masatoshi

    2017-01-01

    The Great East Japan Earthquake occurred on 11 March 2011 near the northeast coast of the main island, 'Honshu', of Japan. It wreaked enormous damage in two main ways: a giant tsunami and an accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP). This disaster may have affected the distribution of physicians in the region. Here, we evaluate the effect of the disaster on the distribution of hospital physicians in the three most severely affected prefectures (Iwate, Miyagi, and Fukushima). We obtained individual information about physicians from the Physician Census in 2010 (pre-disaster) and 2012 (post-disaster). We examined geographical distributions of physicians in two ways: (1) municipality-based analysis for demographic evaluation; and (2) hospital-based analysis for geographic evaluation. In each analysis, we calculated the rate of change in physician distributions between pre- and post-disaster years at various distances from the tsunami-affected coast, and from the restricted area due to the FDNPP accident. The change in all, hospital, and clinic physicians were 0.2%, 0.7%, and -0.7%, respectively. In the municipality-based analysis, after taking account of the decreased population, physician numbers only decreased within the restricted area. In the hospital-based analysis, hospital physician numbers did not decrease at any distance from the tsunami-affected coast. In contrast, there was a 3.3% and 2.3% decrease in hospital physicians 0-25 km and 25-50 km from the restricted area surrounding the FDNPP, respectively. Additionally, decreases were larger and increases were smaller in areas close to the FDNPP than in areas further away. Our results suggest that the tsunami did not affect the distribution of physicians in the affected regions. However, the FDNPP accident changed physician distribution in areas close to the power plant.

  18. Evaluation of a locally produced rapid urease test for the diagnosis ...

    African Journals Online (AJOL)

    To validate our practice of reading the RUT immediately after endoscopy (RUT0), by comparing this with a reading at 24 hours (RUT24) and with histological analysis. Design. Ninety consecutive patients undergoing upper endoscopy over a 6-week period from October 2005 to November 2005, and in whom rapid urease ...

  19. GEM - The Global Earthquake Model

    Science.gov (United States)

    Smolka, A.

    2009-04-01

    Over 500,000 people died in the last decade due to earthquakes and tsunamis, mostly in the developing world, where the risk is increasing due to rapid population growth. In many seismic regions, no hazard and risk models exist, and even where models do exist, they are intelligible only by experts, or available only for commercial purposes. The Global Earthquake Model (GEM) answers the need for an openly accessible risk management tool. GEM is an internationally sanctioned public private partnership initiated by the Organisation for Economic Cooperation and Development (OECD) which will establish an authoritative standard for calculating and communicating earthquake hazard and risk, and will be designed to serve as the critical instrument to support decisions and actions that reduce earthquake losses worldwide. GEM will integrate developments on the forefront of scientific and engineering knowledge of earthquakes, at global, regional and local scale. The work is organized in three modules: hazard, risk, and socio-economic impact. The hazard module calculates probabilities of earthquake occurrence and resulting shaking at any given location. The risk module calculates fatalities, injuries, and damage based on expected shaking, building vulnerability, and the distribution of population and of exposed values and facilities. The socio-economic impact module delivers tools for making educated decisions to mitigate and manage risk. GEM will be a versatile online tool, with open source code and a map-based graphical interface. The underlying data will be open wherever possible, and its modular input and output will be adapted to multiple user groups: scientists and engineers, risk managers and decision makers in the public and private sectors, and the public-at- large. GEM will be the first global model for seismic risk assessment at a national and regional scale, and aims to achieve broad scientific participation and independence. Its development will occur in a

  20. Toward automated directivity estimates in earthquake moment tensor inversion

    OpenAIRE

    Huang, Hsin-Hua; Aso, Naofumi; Tsai, Victor C.

    2017-01-01

    Rapid estimates of earthquake rupture properties are useful for both scientific characterization of earthquakes and emergency response to earthquake hazards. Rupture directivity is a particularly important property to constrain since seismic waves radiated in the direction of rupture can be greatly amplified, and even moderate magnitude earthquakes can sometimes cause serious damage. Knowing the directivity of earthquakes is important for ground shaking prediction and hazard mitigation, and i...

  1. Testing earthquake source inversion methodologies

    KAUST Repository

    Page, Morgan T.

    2011-01-01

    Source Inversion Validation Workshop; Palm Springs, California, 11-12 September 2010; Nowadays earthquake source inversions are routinely performed after large earthquakes and represent a key connection between recorded seismic and geodetic data and the complex rupture process at depth. The resulting earthquake source models quantify the spatiotemporal evolution of ruptures. They are also used to provide a rapid assessment of the severity of an earthquake and to estimate losses. However, because of uncertainties in the data, assumed fault geometry and velocity structure, and chosen rupture parameterization, it is not clear which features of these source models are robust. Improved understanding of the uncertainty and reliability of earthquake source inversions will allow the scientific community to use the robust features of kinematic inversions to more thoroughly investigate the complexity of the rupture process and to better constrain other earthquakerelated computations, such as ground motion simulations and static stress change calculations.

  2. Analog earthquakes

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, R.B. [Center for Nuclear Waste Regulatory Analyses, San Antonio, TX (United States)

    1995-09-01

    Analogs are used to understand complex or poorly understood phenomena for which little data may be available at the actual repository site. Earthquakes are complex phenomena, and they can have a large number of effects on the natural system, as well as on engineered structures. Instrumental data close to the source of large earthquakes are rarely obtained. The rare events for which measurements are available may be used, with modfications, as analogs for potential large earthquakes at sites where no earthquake data are available. In the following, several examples of nuclear reactor and liquified natural gas facility siting are discussed. A potential use of analog earthquakes is proposed for a high-level nuclear waste (HLW) repository.

  3. Global interference during early visual processing:ERP evidence from a rapid global/local selective task

    Directory of Open Access Journals (Sweden)

    Virginie eBeaucousin

    2013-08-01

    Full Text Available Visual perception depends on the integration of local elements of a visual scene into a global frame. Evidence from behavioral studies shows that (1 the detection of the global frame is faster than the detection of the local parts, a phenomenon called the global advantage, and that (2 an interference of the global shape is also present during local processing. Together, these effects are called the global precedence effect. Even if the global advantage appears to impact neural processing as early as the first 100 msec post-stimulus, previous studies failed to find a global interference effect before 200 msec post-stimulus. Using for the first time a rapid display of letter component stimuli during a global/local selective task in which conditions with perceptual conflict, congruent and incongruent conditions were considered, the present event-related potential study shows a global interference effect occurring as early as the time range of the N1 component. In particular, only congruent stimuli elicited similar N1 amplitude during the global and local tasks, whereas an increased of the N1 amplitude during the global task was observed (as compared to the local task for both stimuli with perceptual conflict and incongruent stimuli. This finding corroborates the recent neural models of human visual perception.

  4. Facilitating Follow-up of LIGO–Virgo Events Using Rapid Sky Localization

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hsin-Yu [Department of Astronomy and Astrophysics and Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637 (United States); Holz, Daniel E. [Enrico Fermi Institute, Department of Physics, Department of Astronomy and Astrophysics, and Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637 (United States)

    2017-05-10

    We discuss an algorithm for accurate and very low-latency (<1 s) localization of gravitational-wave (GW) sources using only the relative times of arrival, relative phases, and relative signal-to-noise ratios for pairs of detectors. The algorithm is independent of distances and masses to leading order, and can be generalized to all discrete (as opposed to stochastic and continuous) sources detected by ground-based detector networks. Our approach is similar to that of BAYESTAR with a few modifications, which result in increased computational efficiency. For the LIGO two-detector configuration (Hanford+Livingston) operating in O1 we find a median 50% (90%) localization of 143 deg{sup 2} (558 deg{sup 2}) for binary neutron stars. We use our algorithm to explore the improvement in localization resulting from loud events, finding that the loudest out of the first 4 (or 10) events reduces the median sky-localization area by a factor of 1.9 (3.0) for the case of two GW detectors, and 2.2 (4.0) for three detectors. We also consider the case of multi-messenger joint detections in both the gravitational and the electromagnetic radiation, and show that joint localization can offer significant improvements (e.g., in the case of LIGO and Fermi /GBM joint detections). We show that a prior on the binary inclination, potentially arising from GRB observations, has a negligible effect on GW localization. Our algorithm is simple, fast, and accurate, and may be of particular utility in the development of multi-messenger astronomy.

  5. Rapid adjustment of bird community compositions to local climatic variations and its functional consequences.

    Science.gov (United States)

    Gaüzère, Pierre; Jiguet, Frédéric; Devictor, Vincent

    2015-09-01

    The local spatial congruence between climate changes and community changes has rarely been studied over large areas. We proposed one of the first comprehensive frameworks tracking local changes in community composition related to climate changes. First, we investigated whether and how 12 years of changes in the local composition of bird communities were related to local climate variations. Then, we tested the consequences of this climate-induced adjustment of communities on Grinnellian (habitat-related) and Eltonian (function-related) homogenization. A standardized protocol monitoring spatial and temporal trends of birds over France from 2001 to 2012 was used. For each plot and each year, we used the spring temperature and the spring precipitations and calculated three indices reflecting the thermal niche, the habitat specialization, and the functional originality of the species within a community. We then used a moving-window approach to estimate the spatial distribution of the temporal trends in each of these indices and their congruency with local climatic variations. Temperature fluctuations and community dynamics were found to be highly variable in space, but their variations were finely congruent. More interestingly, the community adjustment to temperature variations was nonmonotonous. Instead, unexplained fluctuations in community composition were observed up to a certain threshold of climate change intensity, above which a change in community composition was observed. This shift corresponded to a significant decrease in the relative abundance of habitat specialists and functionally original species within communities, regardless of the direction of temperature change. The investigation of variations in climate and community responses appears to be a central step toward a better understanding of climate change effects on biodiversity. Our results suggest a fine-scale and short-term adjustment of community composition to temperature changes. Moreover

  6. Joko Tingkir program for estimating tsunami potential rapidly

    Energy Technology Data Exchange (ETDEWEB)

    Madlazim,, E-mail: m-lazim@physics.its.ac.id; Hariyono, E., E-mail: m-lazim@physics.its.ac.id [Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Surabaya (UNESA) , Jl. Ketintang, Surabaya 60231 (Indonesia)

    2014-09-25

    The purpose of the study was to estimate P-wave rupture durations (T{sub dur}), dominant periods (T{sub d}) and exceeds duration (T{sub 50Ex}) simultaneously for local events, shallow earthquakes which occurred off the coast of Indonesia. Although the all earthquakes had parameters of magnitude more than 6,3 and depth less than 70 km, part of the earthquakes generated a tsunami while the other events (Mw=7.8) did not. Analysis using Joko Tingkir of the above stated parameters helped understand the tsunami generation of these earthquakes. Measurements from vertical component broadband P-wave quake velocity records and determination of the above stated parameters can provide a direct procedure for assessing rapidly the potential for tsunami generation. The results of the present study and the analysis of the seismic parameters helped explain why the events generated a tsunami, while the others did not.

  7. Rapid localized spread and immunologic containment define Herpes simplex virus-2 reactivation in the human genital tract.

    Science.gov (United States)

    Schiffer, Joshua T; Swan, David; Al Sallaq, Ramzi; Magaret, Amalia; Johnston, Christine; Mark, Karen E; Selke, Stacy; Ocbamichael, Negusse; Kuntz, Steve; Zhu, Jia; Robinson, Barry; Huang, Meei-Li; Jerome, Keith R; Wald, Anna; Corey, Lawrence

    2013-04-16

    Herpes simplex virus-2 (HSV-2) is shed episodically, leading to occasional genital ulcers and efficient transmission. The biology explaining highly variable shedding patterns, in an infected person over time, is poorly understood. We sampled the genital tract for HSV DNA at several time intervals and concurrently at multiple sites, and derived a spatial mathematical model to characterize dynamics of HSV-2 reactivation. The model reproduced heterogeneity in shedding episode duration and viral production, and predicted rapid early viral expansion, rapid late decay, and wide spatial dispersion of HSV replication during episodes. In simulations, HSV-2 spread locally within single ulcers to thousands of epithelial cells in genital epithelium. DOI:http://dx.doi.org/10.7554/eLife.00288.001.

  8. LV Barcoding: locality sensitive hashing-based tool for rapid species identification in DNA barcoding

    OpenAIRE

    Fan, Long; Chu, Ka Hou

    2014-01-01

    DNA barcoding has emerged as a cost-effective approach for species identification. However, the scarcity of tools used for searching the booming reference database becomes an obstacle, currently with BLAST as the only practical choice. Here, we propose a program - LV Barcoding - based on both the random hyperplane projection-based locality sensitive hashing method and the composition vector-based VIP Barcoding for fast species identification. The performance of LV Barcoding is assessed on the...

  9. Portfolio optimization using local linear regression ensembles in RapidMiner

    OpenAIRE

    Nagy, Gabor; Barta, Gergo; Henk, Tamas

    2015-01-01

    In this paper we implement a Local Linear Regression Ensemble Committee (LOLREC) to predict 1-day-ahead returns of 453 assets form the S&P500. The estimates and the historical returns of the committees are used to compute the weights of the portfolio from the 453 stock. The proposed method outperforms benchmark portfolio selection strategies that optimize the growth rate of the capital. We investigate the effect of algorithm parameter m: the number of selected stocks on achieved average annua...

  10. A simple, rapid and reliable protocol to localize hydrogen peroxide in large plant organs by DAB-mediated tissue printing

    Directory of Open Access Journals (Sweden)

    Yonghua eLiu

    2014-12-01

    Full Text Available Hydrogen peroxide (H2O2 is a major reactive oxygen species (ROS and plays diverse roles in plant development and stress responses. However, its localization in large and thick plant organs (e.g. stem, roots and fruits, other than leaves, has proven to be challenging due to the difficulties for the commonly used H2O2-specific chemicals, such as 3, 3’-diaminobenzidine (DAB, cerium chloride (CeCl3 and 2’, 7’-dichlorofluorescin diacetate (H2DCF-DA, to penetrate those organs. Theoretically, the reaction of endogenous H2O2 with these chemicals could be facilitated by using thin organ sections. However, the rapid production of wound-induced H2O2 associated with this procedure inevitably disturbs the original distribution of H2O2 in vivo. Here, by employing tomato seedling stems and fruits as testing materials, we report a novel, simple and rapid protocol to localize H2O2 in those organs using DAB-mediated tissue printing. The rapidity of the protocol (within 15 s completely avoided the interference of wound-induced H2O2 during experimentation. Moreover, the H2O2 signal on the printing was stable for at least 1 h with no or little background produced. We conclude that DAB-mediated tissue printing developed here provide a new feasible and reliable method to localize H2O2 in large plant organs, hence should have broad applications in studying ROS biology.

  11. Earthquake number forecasts testing

    Science.gov (United States)

    Kagan, Yan Y.

    2017-10-01

    and kurtosis both tend to zero for large earthquake rates: for the Gaussian law, these values are identically zero. A calculation of the NBD skewness and kurtosis levels based on the values of the first two statistical moments of the distribution, shows rapid increase of these upper moments levels. However, the observed catalogue values of skewness and kurtosis are rising even faster. This means that for small time intervals, the earthquake number distribution is even more heavy-tailed than the NBD predicts. Therefore for small time intervals, we propose using empirical number distributions appropriately smoothed for testing forecasted earthquake numbers.

  12. ElarmS Earthquake Early Warning System Updates and Performance

    Science.gov (United States)

    Chung, A. I.; Allen, R. M.; Hellweg, M.; Henson, I. H.; Neuhauser, D. S.

    2015-12-01

    The ElarmS earthquake early warning algorithm has been detecting earthquakes throughout California since 2007. It is one of the algorithms that contributes to CISN's ShakeAlert, a prototype earthquake early warning system being developed for California. Overall, ElarmS performance has been excellent. Over the past year (July 1, 2014 - July 1, 2015), ElarmS successfully detected all but three of the significant earthquakes (M4+) that occurred within California. Of the 24 events that were detected, the most notable was the M6.0 South Napa earthquake that occurred on August 24, 2014. The first alert for this event was sent in 5.1 seconds with an initial magnitude estimate of M5.7. This alert provided approximately 8 seconds of warning of the impending S-wave arrival to the city of San Francisco. The magnitude estimate increased to the final value of M6.0 within 15 seconds of the initial alert. One of the two events that were not detected by ElarmS occurred within 30 seconds of the M6.0 Napa mainshock. The two other missed events occurred offshore in a region with sparse station coverage in the Eureka area. Since its inception, ElarmS has evolved and adapted to meet new challenges. On May 30, 2015, an extraordinarily deep (678km) M7.8 teleseism in Japan generated 5 false event detections for earthquakes greater than M4 within a minute due to the simultaneous arrival of the P-waves at stations throughout California. In order to improve the speed and accuracy of the ElarmS detections, we are currently exploring new methodologies to quickly evaluate incoming triggers from individual stations. Rapidly determining whether or not a trigger at a given station is due to a local earthquake or some other source (such as a distant teleseism) could dramatically increase the confidence in individual triggers and reduce false alerts.

  13. Plaque-Like Sclerodermiform Localized Mucinosis Rapidly Responsive to Topical Tacrolimus

    Directory of Open Access Journals (Sweden)

    R. Schmaltz

    2010-08-01

    Full Text Available We report the successful treatment of plaque-like sclerodermiform mucinosis using tacrolimus ointment topically. We present a 70-year-old male with a large chronic erythema and hardening of the nuchal skin and shoulder area. Subjective symptoms were a moderate pruritus and a rather disabling stiffness. A biopsy specimen revealed typical features of lichen myxedematosus. In a subsequent clinical examination, no associated illnesses such as hypothyroidism or gammopathy were found. Since no established therapy exists for this condition, and as there was a lack of response to potent topical glucocorticosteroids, tacrolimus 0.03% ointment was used off-label twice daily. Surprisingly, this resulted in a rapid, almost complete clearance of the skin within three weeks of treatment.

  14. Dissolving microneedles to obtain rapid local anesthetic effect of lidocaine at skin tissue.

    Science.gov (United States)

    Ito, Yukako; Ohta, Junichi; Imada, Kazuki; Akamatsu, Shingo; Tsuchida, Nozomi; Inoue, Genta; Inoue, Nana; Takada, Kanji

    2013-09-01

    Dissolving microneedles (DMs) were applied to lidocaine for local anesthesia of the skin. Three DM array chips were prepared where lidocaine was localized at the acral portion of DMs (type 1), loaded in whole DMs (type 2), and lidocaine was loaded both in whole DMs and the chip (type 3). DM chips were 15-mm diameter with 225 DMs, each 500-μm long with a 300-μm diameter base. The lidocaine contents were (type 1) 0.08 ± 0.01 mg, (type 2) 0.22 ± 0.01 mg and (type 3) 8.52 ± 0.49 mg. Lidocaine was released from type 1 and 2 DM array chips within 10 min. Pharmacological activity of DMs were compared to lidocaine cream by the suppression of idiospasm of hair-removed rat skin. Type 1, 2 and 3 DMs showed faster onset time, 5 min, than lidocaine cream. Type 2 and 3 DMs showed stronger anti-idioplasmic activity than type 1 DMs. Pharmacokinetic study showed that tissue lidocaine levels, 62.8 ± 3.6 (type 1), 89.1 ± 9.9 (type 2) and 131.2 ± 10.2(type 3) μg/g wet weight at 5 min after the removal of DM were obtained higher than lidocaine cream, 26.2 ± 12.5 μg/g wet weight. Those results suggest the usefulness of type 2 DMs to obtain fast onset time for the local anesthesia in the skin.

  15. Earthquake Facts

    Science.gov (United States)

    ... to the Atlantic Ocean, around Africa, Asia, and Australia, and under the Pacific Ocean to the west ... are similar to earthquakes, but occur within the ice sheet itself instead of the land underneath the ...

  16. Rapid local acceleration of relativistic radiation-belt electrons by magnetospheric chorus.

    Science.gov (United States)

    Thorne, R M; Li, W; Ni, B; Ma, Q; Bortnik, J; Chen, L; Baker, D N; Spence, H E; Reeves, G D; Henderson, M G; Kletzing, C A; Kurth, W S; Hospodarsky, G B; Blake, J B; Fennell, J F; Claudepierre, S G; Kanekal, S G

    2013-12-19

    Recent analysis of satellite data obtained during the 9 October 2012 geomagnetic storm identified the development of peaks in electron phase space density, which are compelling evidence for local electron acceleration in the heart of the outer radiation belt, but are inconsistent with acceleration by inward radial diffusive transport. However, the precise physical mechanism responsible for the acceleration on 9 October was not identified. Previous modelling has indicated that a magnetospheric electromagnetic emission known as chorus could be a potential candidate for local electron acceleration, but a definitive resolution of the importance of chorus for radiation-belt acceleration was not possible because of limitations in the energy range and resolution of previous electron observations and the lack of a dynamic global wave model. Here we report high-resolution electron observations obtained during the 9 October storm and demonstrate, using a two-dimensional simulation performed with a recently developed time-varying data-driven model, that chorus scattering explains the temporal evolution of both the energy and angular distribution of the observed relativistic electron flux increase. Our detailed modelling demonstrates the remarkable efficiency of wave acceleration in the Earth's outer radiation belt, and the results presented have potential application to Jupiter, Saturn and other magnetized astrophysical objects.

  17. Earthquake technology fights crime

    Science.gov (United States)

    Lahr, John C.; Ward, Peter L.; Stauffer, Peter H.; Hendley, James W.

    1996-01-01

    Scientists with the U.S. Geological Survey have adapted their methods for quickly finding the exact source of an earthquake to the problem of locating gunshots. On the basis of this work, a private company is now testing an automated gunshot-locating system in a San Francisco Bay area community. This system allows police to rapidly pinpoint and respond to illegal gunfire, helping to reduce crime in our neighborhoods.

  18. Rapid exposure and loss estimates for the May 12, 2008 Mw 7.9 Wenchuan earthquake provided by the U.S. Geological Survey's PAGER system

    Science.gov (United States)

    Earle, P.S.; Wald, D.J.; Allen, T.I.; Jaiswal, K.S.; Porter, K.A.; Hearne, M.G.

    2008-01-01

    One half-hour after the May 12th Mw 7.9 Wenchuan, China earthquake, the U.S. Geological Survey’s Prompt Assessment of Global Earthquakes for Response (PAGER) system distributed an automatically generated alert stating that 1.2 million people were exposed to severe-to-extreme shaking (Modified Mercalli Intensity VIII or greater). It was immediately clear that a large-scale disaster had occurred. These alerts were widely distributed and referenced by the major media outlets and used by governments, scientific, and relief agencies to guide their responses. The PAGER alerts and Web pages included predictive ShakeMaps showing estimates of ground shaking, maps of population density, and a list of estimated intensities at impacted cities. Manual, revised alerts were issued in the following hours that included the dimensions of the fault rupture. Within a half-day, PAGER’s estimates of the population exposed to strong shaking levels stabilized at 5.2 million people. A coordinated research effort is underway to extend PAGER’s capability to include estimates of the number of casualties. We are pursuing loss models that will allow PAGER the flexibility to use detailed inventory and engineering results in regions where these data are available while also calculating loss estimates in regions where little is known about the type and strength of the built infrastructure. Prototype PAGER fatality estimates are currently implemented and can be manually triggered. In the hours following the Wenchuan earthquake, these models predicted fatalities in the tens of thousands.

  19. Earthquakes for Kids

    Science.gov (United States)

    ... dug across a fault to learn about past earthquakes. Science Fair Projects A GPS instrument measures slow movements of the ground. Become an Earthquake Scientist Cool Earthquake Facts Today in Earthquake History ...

  20. NGC 1266 As a local candidate for rapid cessation of star formation

    Energy Technology Data Exchange (ETDEWEB)

    Alatalo, Katherine; Graves, Genevieve; Blitz, Leo [Department of Astronomy, Hearst Field Annex, University of California, Berkeley, CA 94720 (United States); Nyland, Kristina; Young, Lisa M. [Physics Department, New Mexico Technology, Socorro, NM 87801 (United States); Deustua, Susana [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Griffin, Kristen Shapiro [Space Sciences Research Group, Northrop Grumman Aerospace Systems, Redondo Beach, CA 90278 (United States); Duc, Pierre-Alain; Bournaud, Frédéric [Laboratoire AIM Paris-Saclay, CEA/IRFU/SAp—CNRS—Université Paris Diderot, F-91191 Gif-sur-Yvette, Cedex (France); Cappellari, Michele; Bayet, Estelle; Bureau, Martin; Davies, Roger L. [Sub-Department of Astrophysics, Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); McDermid, Richard M. [Australian Astronomical Observatory, P.O. Box 296, Epping, NSW 1710 (Australia); Davis, Timothy A. [European Southern Observatory, Karl-Schwarzschild-Street 2, D-85748 Garching (Germany); Crocker, Alison F. [Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 (United States); Chang, Philip [Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, WI 53201 (United States); Scott, Nicholas [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, P.O. Box 218, Hawthorn VIC 3122 (Australia); Cales, Sabrina L. [Department of Astronomy, Faculty of Physical and Mathematical Sciences, Universidad de Concepción, Casilla 160-C, Concepción (Chile); Bois, Maxime [Observatoire de Paris, LERMA and CNRS, 61 Avenue de l' Observatoire, F-75014 Paris (France); and others

    2014-01-10

    We present new Spectrographic Areal Unit for Research on Optical Nebulae (SAURON) integral-field spectroscopy and Swift Ultraviolet Optical Telescope (UVOT) observations of molecular outflow host galaxy NGC 1266 that indicate NGC 1266 has experienced a rapid cessation of star formation. Both the SAURON maps of stellar population age and the Swift UVOT observations demonstrate the presence of young (<1 Gyr) stellar populations within the central 1 kpc, while existing Combined Array for Research in Millimeter-Wave Astronomy CO(1-0) maps indicate that the sites of current star formation are constrained to only the inner few hundred parsecs of the galaxy. The optical spectrum of NGC 1266 from Moustakas and Kennicutt reveal a characteristic poststarburst (K+A) stellar population, and Davis et al. confirm that ionized gas emission in the system originate from a shock. Galaxies with K+A spectra and shock-like ionized gas line ratios may comprise an important, overlooked segment of the poststarburst population, containing exactly those objects in which the active galactic nucleus (AGN) is actively expelling the star-forming material. While AGN activity is not the likely driver of the poststarburst event that occurred 500 Myr ago, the faint spiral structure seen in the Hubble Space Telescope Wide-field Camera 3 Y-, J- and H-band imaging seems to point to the possibility of gravitational torques being the culprit. If the molecular gas were driven into the center at the same time as the larger scale galaxy disk underwent quenching, the AGN might be able to sustain the presence of molecular gas for ≳ 1 Gyr by cyclically injecting turbulent energy into the dense molecular gas via a radio jet, inhibiting star formation.

  1. Earthquake Hazards Program: Earthquake Scenarios

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A scenario represents one realization of a potential future earthquake by assuming a particular magnitude, location, and fault-rupture geometry and estimating...

  2. Active Crustal Deformation in the Area of San Carlos, Baja California Sur, Mexico as Shown by Data of Local Earthquake Sequences

    Science.gov (United States)

    Munguía, Luis; González-Escobar, Mario; Navarro, Miguel; Valdez, Tito; Mayer, Sergio; Aguirre, Alfredo; Wong, Victor; Luna, Manuel

    2016-10-01

    We analyzed earthquakes of sequences that occurred at different times near San Carlos, a town of approximately 5000 inhabitants. The seismic sequences happened during March-April 1989, October 2000-June 2001, and 5-15 February 2004 at about 200 km west of the Pacific-North America plate boundary. The strong shaking from initial earthquakes of the first two sequences prompted the installation of temporary seismic stations in the area. With data recorded by these stations, we found an earthquake distribution that is consistent with the northwest segment of the Santa Margarita fault. Both the focal depth, that seemed to increase in E-NE direction, and a composite fault-plane solution, obtained from polarity data of the small earthquakes, were also consistent with the main characteristics of that fault. We also found that our normal-faulting mechanism (east side down) was quite similar to centroid moment tensor solutions for earthquakes with M w 5.4 and 5.3 that occurred in the area in February 2004. It is likely, then, that these larger earthquakes also occurred along the Santa Margarita Fault. To get some insight into the regional stress pattern, we compared the above mechanisms with mechanisms reported for other earthquakes of the Pacific margin of Baja California Sur and the Gulf of California regions. We observed that focal mechanisms of the two regions have T axes of stress that plunge sub horizontally in E-NE average direction. The corresponding P axes have N-NW average trend, but for the Pacific earthquakes these axes plunge at angles that are ~35° larger than those for the Gulf earthquakes. These more vertically inclined P axes of compressive stress mean substantial oblique fault motions. The mixture of oblique and strike-slip components of fault motions, as the focal mechanisms show, confirms a transtensional stress regime for the region. Before this research, we knew little about the seismicity and styles of faulting in the area. Now we know that

  3. Connecting slow earthquakes to huge earthquakes

    OpenAIRE

    Obara, Kazushige; Kato, Aitaro

    2016-01-01

    Slow earthquakes are characterized by a wide spectrum of fault slip behaviors and seismic radiation patterns that differ from those of traditional earthquakes. However, slow earthquakes and huge megathrust earthquakes can have common slip mechanisms and are located in neighboring regions of the seismogenic zone. The frequent occurrence of slow earthquakes may help to reveal the physics underlying megathrust events as useful analogs. Slow earthquakes may function as stress meters because of th...

  4. USGS GNSS Applications to Earthquake Disaster Response and Hazard Mitigation

    Science.gov (United States)

    Hudnut, K. W.; Murray, J. R.; Minson, S. E.

    2015-12-01

    Rapid characterization of earthquake rupture is important during a disaster because it establishes which fault ruptured and the extent and amount of fault slip. These key parameters, in turn, can augment in situ seismic sensors for identifying disruption to lifelines as well as localized damage along the fault break. Differential GNSS station positioning, along with imagery differencing, are important methods for augmenting seismic sensors. During response to recent earthquakes (1989 Loma Prieta, 1992 Landers, 1994 Northridge, 1999 Hector Mine, 2010 El Mayor - Cucapah, 2012 Brawley Swarm and 2014 South Napa earthquakes), GNSS co-seismic and post-seismic observations proved to be essential for rapid earthquake source characterization. Often, we find that GNSS results indicate key aspects of the earthquake source that would not have been known in the absence of GNSS data. Seismic, geologic, and imagery data alone, without GNSS, would miss important details of the earthquake source. That is, GNSS results provide important additional insight into the earthquake source properties, which in turn help understand the relationship between shaking and damage patterns. GNSS also adds to understanding of the distribution of slip along strike and with depth on a fault, which can help determine possible lifeline damage due to fault offset, as well as the vertical deformation and tilt that are vitally important for gravitationally driven water systems. The GNSS processing work flow that took more than one week 25 years ago now takes less than one second. Formerly, portable receivers needed to be set up at a site, operated for many hours, then data retrieved, processed and modeled by a series of manual steps. The establishment of continuously telemetered, continuously operating high-rate GNSS stations and the robust automation of all aspects of data retrieval and processing, has led to sub-second overall system latency. Within the past few years, the final challenges of

  5. Haïti, en situation post-séisme : quelques effets de la catastrophe du 12 janvier 2010 sur la population locale Haïti, in post-earthquake mode: some effects of the earthquake of January 12 2010 on the local population

    Directory of Open Access Journals (Sweden)

    Evens Jabouin

    2012-01-01

    Full Text Available Le violent séisme qui a secoué Haïti et sa capitale le 12 janvier 2010 dernier a laissé des séquelles au sein de la population haïtienne déjà fragilisée par la violence, la pauvreté et aussi par des catastrophes naturelles répétées (ouragans, inondations, érosion, etc.. Ce séisme, aussi prévisible qu’il soit, est une catastrophe naturelle et humanitaire sans précédent dont les principales causes sont l’absence de constructions et d’infrastructures solides, bâties selon les normes parasismiques, l’occupation anarchique de l’espace urbain par les populations et les nombreuses irrégularités incontestées observées dans le domaine de l’urbanisme. En outre, ce séisme s’est produit à un moment où l’on commençait à observer dans le pays un élan de stabilisation sur le plan politique, un mouvement de croissance économique ainsi qu’un début d’amélioration des conditions de vie des populations. La catastrophe est venue freiner cette dynamique socioéconomique tout en amplifiant les problèmes existants et en engendrant d’autres difficultés et d’autres défis. Cet article analyse, à travers des témoignages de première main et un état des lieux, les différents impacts de cette catastrophe sur la population locale ainsi que les interrogations et les incertitudes diverses de cette population concernant son avenir.On January the twelfth 2010, Haiti and its capital have been devastated by a very strong earthquake that has provoked many aftereffects among the local population since that population had already been weakened before by street violence, poverty and by frequent natural disasters such as hurricanes, floods... That earthquake, even foreseeable, has given way to an important disaster whose causes are the absence of well built infrastructures and buildings, the anarchic use of urban spaces by the population, and multiple irregularities in town planning issues. Furthermore, that earthquake took

  6. A smartphone application for earthquakes that matter!

    Science.gov (United States)

    Bossu, Rémy; Etivant, Caroline; Roussel, Fréderic; Mazet-Roux, Gilles; Steed, Robert

    2014-05-01

    Smartphone applications have swiftly become one of the most popular tools for rapid reception of earthquake information for the public, some of them having been downloaded more than 1 million times! The advantages are obvious: wherever someone's own location is, they can be automatically informed when an earthquake has struck. Just by setting a magnitude threshold and an area of interest, there is no longer the need to browse the internet as the information reaches you automatically and instantaneously! One question remains: are the provided earthquake notifications always relevant for the public? What are the earthquakes that really matters to laypeople? One clue may be derived from some newspaper reports that show that a while after damaging earthquakes many eyewitnesses scrap the application they installed just after the mainshock. Why? Because either the magnitude threshold is set too high and many felt earthquakes are missed, or it is set too low and the majority of the notifications are related to unfelt earthquakes thereby only increasing anxiety among the population at each new update. Felt and damaging earthquakes are the ones that matter the most for the public (and authorities). They are the ones of societal importance even when of small magnitude. A smartphone application developed by EMSC (Euro-Med Seismological Centre) with the financial support of the Fondation MAIF aims at providing suitable notifications for earthquakes by collating different information threads covering tsunamigenic, potentially damaging and felt earthquakes. Tsunamigenic earthquakes are considered here to be those ones that are the subject of alert or information messages from the PTWC (Pacific Tsunami Warning Centre). While potentially damaging earthquakes are identified through an automated system called EQIA (Earthquake Qualitative Impact Assessment) developed and operated at EMSC. This rapidly assesses earthquake impact by comparing the population exposed to each expected

  7. Medical complications associated with earthquakes.

    Science.gov (United States)

    Bartels, Susan A; VanRooyen, Michael J

    2012-02-25

    Major earthquakes are some of the most devastating natural disasters. The epidemiology of earthquake-related injuries and mortality is unique for these disasters. Because earthquakes frequently affect populous urban areas with poor structural standards, they often result in high death rates and mass casualties with many traumatic injuries. These injuries are highly mechanical and often multisystem, requiring intensive curative medical and surgical care at a time when the local and regional medical response capacities have been at least partly disrupted. Many patients surviving blunt and penetrating trauma and crush injuries have subsequent complications that lead to additional morbidity and mortality. Here, we review and summarise earthquake-induced injuries and medical complications affecting major organ systems. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Twitter earthquake detection: Earthquake monitoring in a social world

    Science.gov (United States)

    Earle, Paul S.; Bowden, Daniel C.; Guy, Michelle R.

    2011-01-01

    The U.S. Geological Survey (USGS) is investigating how the social networking site Twitter, a popular service for sending and receiving short, public text messages, can augment USGS earthquake response products and the delivery of hazard information. Rapid detection and qualitative assessment of shaking events are possible because people begin sending public Twitter messages (tweets) with in tens of seconds after feeling shaking. Here we present and evaluate an earthquake detection procedure that relies solely on Twitter data. A tweet-frequency time series constructed from tweets containing the word "earthquake" clearly shows large peaks correlated with the origin times of widely felt events. To identify possible earthquakes, we use a short-term-average, long-term-average algorithm. When tuned to a moderate sensitivity, the detector finds 48 globally-distributed earthquakes with only two false triggers in five months of data. The number of detections is small compared to the 5,175 earthquakes in the USGS global earthquake catalog for the same five-month time period, and no accurate location or magnitude can be assigned based on tweet data alone. However, Twitter earthquake detections are not without merit. The detections are generally caused by widely felt events that are of more immediate interest than those with no human impact. The detections are also fast; about 75% occur within two minutes of the origin time. This is considerably faster than seismographic detections in poorly instrumented regions of the world. The tweets triggering the detections also provided very short first-impression narratives from people who experienced the shaking.

  9. Inferring Peak Ground Acceleration (PGA) from observed building damage and EO-derived exposure development to develop rapid loss estimates following the April 2015 Nepal earthquake.

    Science.gov (United States)

    Huyck, C. K.

    2016-12-01

    The April 25th 7.8 Gorkha earthquake in Nepal occurred in an area with very few seismic stations. Ground motions were estimated primarily by Ground Motion Prediction Equations (GMPEs) over a very large region, with a very high degree of uncertainty. Accordingly, initial fatality estimates and their distribution was highly uncertain, with a 65% chance of fatalities ranging from 1,000 to 100,000. With an aim to developing estimates of: 1) the number of buildings damaged by category (slight, moderate, extensive, complete), 2) fatalities and their distribution, and 3) rebuilding costs, researchers at ImageCat have developed a preliminary inferred Peak Ground Acceleration product in %g (PGA). The inferred PGA is determined by using observations of building collapse from the National Geospatial Agency and building exposure estimates derived from EO data to determine the percentage of buildings collapsed in key locations. The percentage of building collapse is adjusted for accuracy and cross referenced with composite building damage functions for 4 development patterns in Nepal: 1) sparsely populated, 2) rural, 3) dense development, and 4) urban development to yield an inferred PGA. Composite damage functions are derived from USGS Pager collapse fragility functions (Jaiswal et al., 2011) and are weighted by building type frequencies developed by ImageCat. The PGA is interpolated to yield a surface. An initial estimate of the fatalities based on ATC 13 (Rojan and Sharpe, 1985) using these PGA yields an estimate of: Extensively damaged or destroyed buildings: 225,000 to 450,000 Fatalities: 8,700 to 22,000, with a mean estimate of 15,700. The total number of displaced persons is estimated between 1 and 2 million. Rebuilding costs for building damage only are estimated to be between 2 and 3 billion USD. The inferred PGA product is recommended for use solely in loss estimation processes.

  10. Great Hanshin-Awaji (Kobe) Earthquake, January 17, 1995

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Earthquake - At 5:46 A.M. local time on January 17, 1995, a major earthquake occurred near the City of Kobe, Japan. The 6.9 magnitude earthquake had 40 km of...

  11. Rapid and in-depth analysis for seismic risk evaluation

    Science.gov (United States)

    Dwi Astuti, Novi; Anta Alvita, Meli; Sangadji, Senot; Rahmadi, AP; Purwanto, Edy

    2017-11-01

    The high public demand on housing in urban areas requires the government of Indonesia to adopt a policy of encouraging the development of vertical housing. Cilacap has been allocated Rusunawa (low-income apartment) development in 2006. Evident from some earthquakes occurrence in recent years, however, Cilacap may be seen as an earthquake prone region which posing some risk to this type of vertical structures. The Appropriate strategy should be performed to evaluate the seismic risks of this local government owned four stories low-income apartment. This paper demonstrates two tier evaluation strategy; rapid evaluation and in-depth analysis and compares both results. First evaluation was conducted by means of Building Rapid Visual Screening (RVS) of FEMA 154 of the Rusunawa block A and B. The result was used further to calculate seismic risk score (SR) which exhibit the probability of the building damage given the Maximum Considered Earthquake (MCER) that will occur during the Rusunawa service life. The in-depth analysis was conducted by developing fragility function expressed in the form of fragility curves for the Rusunawa. The fragility shows the probability that certain damage states will be exceeded given the intensity of earthquakes which will occur during building service life. The fragility was developed as lognormal curves in which the building response to earthquake input was analyzed by means of pushover.

  12. Risk assessment of people trapped in earthquake based on km grid: a case study of the 2014 Ludian earthquake

    Science.gov (United States)

    Wei, Ben-Yong; Nie, Gao-Zhong; Su, Gui-Wu; Sun, Lei

    2017-04-01

    China is one of the most earthquake prone countries in the world. The priority during earthquake emergency response is saving lives and minimizing casualties. Rapid judgment of the trapped location is the important basis for government to reasonable arrange the emergency rescue forces and resources after the earthquake. Through analyzing the key factors resulting in people trapped, we constructed an assessment model of personal trapped (PTED)in collapsed buildings caused by earthquake disaster. Then taking the 2014 Ludian Earthquake as a case, this study evaluated the distribution of trapped personal during this earthquake using the assessment model based on km grid data. Results showed that, there are two prerequisites for people might be trapped by the collapse of buildings in earthquake: earthquake caused buildings collapse and there are people in building when building collapsing; the PTED model could be suitable to assess the trapped people in collapsed buildings caused by earthquake. The distribution of people trapped by the collapse of buildings in the Ludian earthquake assessed by the model is basically the same as that obtained by the actual survey. Assessment of people trapped in earthquake based on km grid can meet the requirements of search-and-rescue zone identification and rescue forces allocation in the early stage of the earthquake emergency. In future, as the basic data become more complete, assessment of people trapped in earthquake based on km grid should provide more accurate and valid suggestions for earthquake emergency search and rescue.

  13. Connecting slow earthquakes to huge earthquakes.

    Science.gov (United States)

    Obara, Kazushige; Kato, Aitaro

    2016-07-15

    Slow earthquakes are characterized by a wide spectrum of fault slip behaviors and seismic radiation patterns that differ from those of traditional earthquakes. However, slow earthquakes and huge megathrust earthquakes can have common slip mechanisms and are located in neighboring regions of the seismogenic zone. The frequent occurrence of slow earthquakes may help to reveal the physics underlying megathrust events as useful analogs. Slow earthquakes may function as stress meters because of their high sensitivity to stress changes in the seismogenic zone. Episodic stress transfer to megathrust source faults leads to an increased probability of triggering huge earthquakes if the adjacent locked region is critically loaded. Careful and precise monitoring of slow earthquakes may provide new information on the likelihood of impending huge earthquakes. Copyright © 2016, American Association for the Advancement of Science.

  14. Defeating Earthquakes

    Science.gov (United States)

    Stein, R. S.

    2012-12-01

    The 2004 M=9.2 Sumatra earthquake claimed what seemed an unfathomable 228,000 lives, although because of its size, we could at least assure ourselves that it was an extremely rare event. But in the short space of 8 years, the Sumatra quake no longer looks like an anomaly, and it is no longer even the worst disaster of the Century: 80,000 deaths in the 2005 M=7.6 Pakistan quake; 88,000 deaths in the 2008 M=7.9 Wenchuan, China quake; 316,000 deaths in the M=7.0 Haiti, quake. In each case, poor design and construction were unable to withstand the ferocity of the shaken earth. And this was compounded by inadequate rescue, medical care, and shelter. How could the toll continue to mount despite the advances in our understanding of quake risk? The world's population is flowing into megacities, and many of these migration magnets lie astride the plate boundaries. Caught between these opposing demographic and seismic forces are 50 cities of at least 3 million people threatened by large earthquakes, the targets of chance. What we know for certain is that no one will take protective measures unless they are convinced they are at risk. Furnishing that knowledge is the animating principle of the Global Earthquake Model, launched in 2009. At the very least, everyone should be able to learn what his or her risk is. At the very least, our community owes the world an estimate of that risk. So, first and foremost, GEM seeks to raise quake risk awareness. We have no illusions that maps or models raise awareness; instead, earthquakes do. But when a quake strikes, people need a credible place to go to answer the question, how vulnerable am I, and what can I do about it? The Global Earthquake Model is being built with GEM's new open source engine, OpenQuake. GEM is also assembling the global data sets without which we will never improve our understanding of where, how large, and how frequently earthquakes will strike, what impacts they will have, and how those impacts can be lessened by

  15. Great Sumatra Earthquake registers on electrostatic sensor

    Science.gov (United States)

    Röder, Helmut; Schuhmann, Wolfram; Büttner, Ralf; Zimanowski, Bernard; Braun, Thomas; Boschi, Enzo

    Strong electrical signals that correspond to the Mw = 9.3 earthquake of 26 December 2004, whichoccurred at 0058:50.7 UTC off the west coast of northern Sumatra, Indonesia, were recorded by an electrostatic sensor (a device that detects short-term variations in Earth's electrostatic field) at a seismic station in Italy, which had been installed to study the influence of local earthquakes on a new landslide monitoring system.Electrical signals arrived at the station practically instantaneously and were detected up to several hours before the onset of the Sumatra earthquake (Figure 1) as well as before local quakes. The corresponding seismic signals (p-waves) arrived 740 seconds after the start of the earthquake. Because the electrical signals travel at the speed of light, electrical monitoring for the global detection of very strong earthquakes could be an important tool in significantly increasing the hazard alert window.

  16. Twitter earthquake detection: earthquake monitoring in a social world

    Directory of Open Access Journals (Sweden)

    Daniel C. Bowden

    2011-06-01

    Full Text Available The U.S. Geological Survey (USGS is investigating how the social networking site Twitter, a popular service for sending and receiving short, public text messages, can augment USGS earthquake response products and the delivery of hazard information. Rapid detection and qualitative assessment of shaking events are possible because people begin sending public Twitter messages (tweets with in tens of seconds after feeling shaking. Here we present and evaluate an earthquake detection procedure that relies solely on Twitter data. A tweet-frequency time series constructed from tweets containing the word “earthquake” clearly shows large peaks correlated with the origin times of widely felt events. To identify possible earthquakes, we use a short-term-average, long-term-average algorithm. When tuned to a moderate sensitivity, the detector finds 48 globally-distributed earthquakes with only two false triggers in five months of data. The number of detections is small compared to the 5,175 earthquakes in the USGS global earthquake catalog for the same five-month time period, and no accurate location or magnitude can be assigned based on tweet data alone. However, Twitter earthquake detections are not without merit. The detections are generally caused by widely felt events that are of more immediate interest than those with no human impact. The detections are also fast; about 75% occur within two minutes of the origin time. This is considerably faster than seismographic detections in poorly instrumented regions of the world. The tweets triggering the detections also provided very short first-impression narratives from people who experienced the shaking.

  17. Insights into earthquake rupture and recovery from paleoseismic faults

    Science.gov (United States)

    Rowe, C. D.; Griffith, W. A.; Ross, C.; Melosh, B. L.; Young, E.

    2016-12-01

    There are two key factors distinguishing earthquake slip from creep that have the potential to be preserved in rocks from ancient fault zones. First, slip velocity is sufficiently high that the frictional heat production on the slip surface outpaces conductive heat dissipation, resulting in a net temperature rise. If the slip is sufficiently localized and the normal stress is high enough, this temperature rise can dissociate hydrous minerals, cause rapid maturation of organic compounds, and melt fault rock. These reactions are recorded in fault rock mineralogy and composition and can be used to estimate coseismic temperatures from 250 C to greater than 1400 C. Second, seismic slip is *dynamic*, that is, that the slipping area expands in size at rates comparable to the shear wave velocity in the rocks ( 3 km/s), which results in extreme stress gradients in the wall rock at the rupture tip. The stressing rate exceeds the speed at which fractures can propagate through the wall rock, resulting in distinctive patterns of very tightly spaced and branching fractures, and sometimes pulverization. These fractures can be the dominant form of off-fault damage and may cause permeability spikes through the fresh fracture networks. Using both types of fossil earthquake signatures, we can identify ancient seismic rupture planes and use these to map out the geometry of earthquake rupture networks at the outcrop scale (10^-3 - 10^3 meters), which is below the resolution and location uncertainty of earthquake seismology in most active faults. Using examples from the Pofadder and Norumbega Shear Zones, I will show that earthquakes can rupture multiple parallel and non-parallel surfaces simultaneously, and that healing during afterslip can affect damage zones as well as the rupture surface. Outcrop studies may be able to elucidate the consequences for slip distribution and help explain spatial variations in fracture energy and stress drop that are barely resolvable in seismic data.

  18. April 25, 2015, Gorkha Earthquake, Nepal and Sequence of Aftershocks: Key Lessons

    Science.gov (United States)

    Guragain, R.; Dixit, A. M.; Shrestha, S. N.

    2015-12-01

    The Gorkha Earthquake of M7.8 hit Nepal on April 25, 2015 at 11:56 am local time. The epicenter of this earthquake was Barpak, Gorkha, 80 km northwest of Kathmandu Valley. The main shock was followed by hundreds of aftershocks including M6.6 and M6.7 within 48 hours and M7.3 on May 12, 2015. According to the Government of Nepal, a total of 8,686 people lost their lives, 16,808 people injured, over 500,000 buildings completely collapsed and more than 250,000 building partially damaged. The National Society for Earthquake Technology - Nepal (NSET), a not-for-profit civil society organization that has been focused on earthquake risk reduction in Nepal for past 21 years, conducted various activities to support people and the government in responding to the earthquake disaster. The activities included: i) assisting people and critical facility institutions to conduct rapid visual building damage assessment including the training; ii) information campaign to provide proper information regarding earthquake safety; iii) support rescue organizations on search and rescue operations; and iv) provide technical support to common people on repair, retrofit of damaged houses. NSET is also involved in carrying out studies related to earthquake damage, geotechnical problems, and causes of building damages. Additionally, NSET has done post-earthquake detail damage assessment of buildings throughout the affected areas. Prior to the earthquake, NSET has been working with several institutions to improve seismic performance of school buildings, private residential houses, and other critical structures. Such activities implemented during the past decade have shown the effectiveness of risk reduction. Retrofitted school buildings performed very well during the earthquake. Preparedness activities implemented at community levels have helped communities to respond immediately and save lives. Higher level of earthquake awareness achieved including safe behavior, better understanding of

  19. The relationship between earthquake exposure and posttraumatic stress disorder in 2013 Lushan earthquake

    Science.gov (United States)

    Wang, Yan; Lu, Yi

    2018-01-01

    The objective of this study is to explore the relationship between earthquake exposure and the incidence of PTSD. A stratification random sample survey was conducted to collect data in the Longmenshan thrust fault after Lushan earthquake three years. We used the Children's Revised Impact of Event Scale (CRIES-13) and the Earthquake Experience Scale. Subjects in this study included 3944 school student survivors in local eleven schools. The prevalence of probable PTSD is relatively higher, when the people was trapped in the earthquake, was injured in the earthquake or have relatives who died in the earthquake. It concluded that researchers need to pay more attention to the children and adolescents. The government should pay more attention to these people and provide more economic support.

  20. Enhanced Photoelectrochemical Behavior of H-TiO2 Nanorods Hydrogenated by Controlled and Local Rapid Thermal Annealing.

    Science.gov (United States)

    Wang, Xiaodan; Estradé, Sonia; Lin, Yuanjing; Yu, Feng; Lopez-Conesa, Lluis; Zhou, Hao; Gurram, Sanjeev Kumar; Peiró, Francesca; Fan, Zhiyong; Shen, Hao; Schaefer, Lothar; Braeuer, Guenter; Waag, Andreas

    2017-12-01

    Recently, colored H-doped TiO2 (H-TiO2) has demonstrated enhanced photoelectrochemical (PEC) performance due to its unique crystalline core-disordered shell nanostructures and consequent enhanced conduction behaviors between the core-shell homo-interfaces. Although various hydrogenation approaches to obtain H-TiO2 have been developed, such as high temperature hydrogen furnace tube annealing, high pressure hydrogen annealing, hydrogen-plasma assisted reaction, aluminum reduction and electrochemical reduction etc., there is still a lack of a hydrogenation approach in a controlled manner where all processing parameters (temperature, time and hydrogen flux) were precisely controlled in order to improve the PEC performance of H-TiO2 and understand the physical insight of enhanced PEC performance. Here, we report for the first time a controlled and local rapid thermal annealing (RTA) approach to prepare hydrogenated core-shell H-TiO2 nanorods grown on F:SnO2 (FTO) substrate in order to address the degradation issue of FTO in the typical TiO2 nanorods/FTO system observed in the conventional non-RTA treated approaches. Without the FTO degradation in the RTA approach, we systematically studied the intrinsic relationship between the annealing temperature, structural, optical, and photoelectrochemical properties in order to understand the role of the disordered shell on the improved photoelectrochemical behavior of H-TiO2 nanorods. Our investigation shows that the improvement of PEC performance could be attributed to (i) band gap narrowing from 3.0 to 2.9 eV; (ii) improved optical absorption in the visible range induced by the three-dimensional (3D) morphology and rough surface of the disordered shell; (iii) increased proper donor density; (iv) enhanced electron-hole separation and injection efficiency due to the formation of disordered shell after hydrogenation. The RTA approach developed here can be used as a suitable hydrogenation process for TiO2 nanorods/FTO system for

  1. Assessing the impact of Syrian refugees on earthquake fatality estimations in southeast Turkey

    Science.gov (United States)

    Wilson, Bradley; Paradise, Thomas

    2018-01-01

    The influx of millions of Syrian refugees into Turkey has rapidly changed the population distribution along the Dead Sea Rift and East Anatolian fault zones. In contrast to other countries in the Middle East where refugees are accommodated in camp environments, the majority of displaced individuals in Turkey are integrated into local cities, towns, and villages - placing stress on urban settings and increasing potential exposure to strong earthquake shaking. Yet displaced populations are often unaccounted for in the census-based population models used in earthquake fatality estimations. This study creates a minimally modeled refugee gridded population model and analyzes its impact on semi-empirical fatality estimations across southeast Turkey. Daytime and nighttime fatality estimates were produced for five fault segments at earthquake magnitudes 5.8, 6.4, and 7.0. Baseline fatality estimates calculated from census-based population estimates for the study area varied in scale from tens to thousands of fatalities, with higher death totals in nighttime scenarios. Refugee fatality estimations were analyzed across 500 semi-random building occupancy distributions. Median fatality estimates for refugee populations added non-negligible contributions to earthquake fatalities at four of five fault locations, increasing total fatality estimates by 7-27 %. These findings communicate the necessity of incorporating refugee statistics into earthquake fatality estimations in southeast Turkey and the ongoing importance of placing environmental hazards in their appropriate regional and temporal context.

  2. Real Time Earthquake Information System in Japan

    Science.gov (United States)

    Doi, K.; Kato, T.

    2003-12-01

    An early earthquake notification system in Japan had been developed by the Japan Meteorological Agency (JMA) as a governmental organization responsible for issuing earthquake information and tsunami forecasts. The system was primarily developed for prompt provision of a tsunami forecast to the public with locating an earthquake and estimating its magnitude as quickly as possible. Years after, a system for a prompt provision of seismic intensity information as indices of degrees of disasters caused by strong ground motion was also developed so that concerned governmental organizations can decide whether it was necessary for them to launch emergency response or not. At present, JMA issues the following kinds of information successively when a large earthquake occurs. 1) Prompt report of occurrence of a large earthquake and major seismic intensities caused by the earthquake in about two minutes after the earthquake occurrence. 2) Tsunami forecast in around three minutes. 3) Information on expected arrival times and maximum heights of tsunami waves in around five minutes. 4) Information on a hypocenter and a magnitude of the earthquake, the seismic intensity at each observation station, the times of high tides in addition to the expected tsunami arrival times in 5-7 minutes. To issue information above, JMA has established; - An advanced nationwide seismic network with about 180 stations for seismic wave observation and about 3,400 stations for instrumental seismic intensity observation including about 2,800 seismic intensity stations maintained by local governments, - Data telemetry networks via landlines and partly via a satellite communication link, - Real-time data processing techniques, for example, the automatic calculation of earthquake location and magnitude, the database driven method for quantitative tsunami estimation, and - Dissemination networks, via computer-to-computer communications and facsimile through dedicated telephone lines. JMA operationally

  3. Tsunami early warning using earthquake rupture duration (Invited)

    Science.gov (United States)

    Michelini, A.; Lomax, A.

    2009-12-01

    Real-time seismological data collected through the International Monitoring System and acquired at the International Data Center can be used for civil applications including rapid earthquake location and magnitude determination, and tsunami early warning. Effective tsunami early warning for coastlines near a tsunamigenic earthquake requires notification within 5-15 minutes. We have shown recently that the high-frequency, apparent rupture duration, T0, allows rapid estimation of moment magnitude, Mw, for large earthquakes, that tsunamigenic earthquakes have T0 greater than about 50 s, and that T0 gives more information on tsunami importance than moment magnitude, Mw. A “duration-exceedance” procedure using seismograms recorded near an earthquake to rapidly determine if T0 is likely to exceed 50 s correctly identifies within about 10 min after the earthquake occurrence most recent earthquakes which produced large or devastating tsunamis. This identification forms a complement to initial estimates of the location, depth and magnitude of an earthquake to improve the reliability of tsunami early warning, and, in some cases, may make possible such warning. The IMS global seismological network appears well suited for rapid determination of all of these earthquake parameters.

  4. Impact of natural disaster combined with nuclear power plant accidents on local medical services: a case study of Minamisoma Municipal General Hospital after the Great East Japan Earthquake.

    Science.gov (United States)

    Kodama, Yuko; Oikawa, Tomoyoshi; Hayashi, Kaoru; Takano, Michiko; Nagano, Mayumi; Onoda, Katsuko; Yoshida, Toshiharu; Takada, Akemi; Hanai, Tatsuo; Shimada, Shunji; Shimada, Satoko; Nishiuchi, Yasuyuki; Onoda, Syuichi; Monma, Kazuo; Tsubokura, Masaharu; Matsumura, Tomoko; Kami, Masahiro; Kanazawa, Yukio

    2014-12-01

    To elucidate the impacts of nuclear plant accidents on neighboring medical centers, we investigated the operations of our hospital within the first 10 days of the Great East Japan Earthquake followed by the Fukushima Daiichi nuclear power plant accident. Data were extracted from medical records and hospital administrative records covering 11 to 20 March 2011. Factual information on the disaster was obtained from public access media. A total of 622 outpatients and 241 inpatients were treated. Outpatients included 43 injured, 6 with cardiopulmonary arrest, and 573 with chronic diseases. Among the 241 inpatients, 5 died, 137 were discharged, and the other 99 were transferred to other hospitals. No communication methods or medical or food supplies were available for 4 days after the earthquake. Hospital directors allowed employees to leave the hospital on day 4. All 39 temporary workers were evacuated immediately, and 71 of 239 full-time employees remained. These employees handled extra tasks besides patient care and patient transfer to other hospitals. Committed effective doses indicating the magnitude of health risks due to an intake of radioactive cesium into the human body were found to be minimal according to internal radiation exposure screening carried out from July to August 2011. After the disaster, hospitals located within the evacuation zone of a 30-km radius of the nuclear power plant were isolated. Maintenance of the health care system in such an event becomes difficult.

  5. Sedimentary thickness and velocity in the northeast boundary of the Parana Basin with Andean earthquakes and local events; Espessura e velocidade das camadas sedimentares na borda nordeste da Bacia do Parana utilizando telessismos da regiao andina e sismos locais

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Josimar A.; Souza, Luiz M. [Universidade de Sao Paulo (USP), SP (Brazil). Dept. de Geofisica; Assumpcao, Marcelo S. [Universidade de Sao Paulo (USP), SP (Brazil)

    2008-07-01

    Deep Andean earthquakes are a suitable source of high-frequency P-waves (with good signal to noise ratio up to {approx} 10 Hz) that can be used to obtain high-resolution receiver functions at stations in intra-cratonic basins in Brazil. Receiver functions (Gaussian width 20) at five stations in the Bebedouro seismic area (NE Parana Basin) were calculated using the time domain deconvolution of Ligorria and Ammon (1999). Inter-station Rayleigh wave phase velocities were measured using local earthquakes. Joint inversion of receiver functions and Rayleigh phase velocities provided reasonably well constrained S-wave velocity profiles. Shallow seismic refraction surveys were used to fix the velocities of the surface layers during the inversion. The area is characterized by a thin surface layer of sandstones ({approx}60 m), followed by a {approx}500 m thick basalt layer. Beneath the basalts, low-velocity layers define another sedimentary sequence. These features are consistent with the expected values based on well data at regional distances and confirm the usefulness of high-frequency receiver functions to study sedimentary basins. (author)

  6. The California Earthquake Advisory Plan: A history

    Science.gov (United States)

    Roeloffs, Evelyn A.; Goltz, James D.

    2017-01-01

    Since 1985, the California Office of Emergency Services (Cal OES) has issued advisory statements to local jurisdictions and the public following seismic activity that scientists on the California Earthquake Prediction Evaluation Council view as indicating elevated probability of a larger earthquake in the same area during the next several days. These advisory statements are motivated by statistical studies showing that about 5% of moderate earthquakes in California are followed by larger events within a 10-km, five-day space-time window (Jones, 1985; Agnew and Jones, 1991; Reasenberg and Jones, 1994). Cal OES issued four earthquake advisories from 1985 to 1989. In October, 1990, the California Earthquake Advisory Plan formalized this practice, and six Cal OES Advisories have been issued since then. This article describes that protocol’s scientific basis and evolution.

  7. Seismicity map tools for earthquake studies

    Science.gov (United States)

    Boucouvalas, Anthony; Kaskebes, Athanasios; Tselikas, Nikos

    2014-05-01

    We report on the development of new and online set of tools for use within Google Maps, for earthquake research. We demonstrate this server based and online platform (developped with PHP, Javascript, MySQL) with the new tools using a database system with earthquake data. The platform allows us to carry out statistical and deterministic analysis on earthquake data use of Google Maps and plot various seismicity graphs. The tool box has been extended to draw on the map line segments, multiple straight lines horizontally and vertically as well as multiple circles, including geodesic lines. The application is demonstrated using localized seismic data from the geographic region of Greece as well as other global earthquake data. The application also offers regional segmentation (NxN) which allows the studying earthquake clustering, and earthquake cluster shift within the segments in space. The platform offers many filters such for plotting selected magnitude ranges or time periods. The plotting facility allows statistically based plots such as cumulative earthquake magnitude plots and earthquake magnitude histograms, calculation of 'b' etc. What is novel for the platform is the additional deterministic tools. Using the newly developed horizontal and vertical line and circle tools we have studied the spatial distribution trends of many earthquakes and we here show for the first time the link between Fibonacci Numbers and spatiotemporal location of some earthquakes. The new tools are valuable for examining visualizing trends in earthquake research as it allows calculation of statistics as well as deterministic precursors. We plan to show many new results based on our newly developed platform.

  8. Crustal Deformation in Southcentral Alaska: The 1964 Prince William Sound Earthquake Subduction Zone

    Science.gov (United States)

    Cohen, Steven C.; Freymueller, Jeffrey T.

    2003-01-01

    This article, for Advances in Geophysics, is a summary of crustal deformation studies in southcentral Alaska. In 1964, southcentral Alaska was struck by the largest earthquake (moment magnitude 9.2) occurring in historical times in North America and the second largest earthquake occurring in the world during the past century. Conventional and space-based geodetic measurements have revealed a complex temporal-spatial pattern of crustal movement. Numerical models suggest that ongoing convergence between the North America and Pacific Plates, viscoelastic rebound, aseismic creep along the tectonic plate interface, and variable plate coupling all play important roles in controlling both the surface and subsurface movements. The geodetic data sets include tide-gauge observations that in some cases provide records back to the decades preceding the earthquake, leveling data that span a few decades around the earthquake, VLBI data from the late 1980s, and GPS data since the mid-1990s. Geologic data provide additional estimates of vertical movements and a chronology of large seismic events. Some of the important features that are revealed by the ensemble of studies that are reviewed in this paper include: (1) Crustal uplift in the region that subsided by up 2 m at the time of the earthquake is as much as 1 m since the earthquake. In the Turnagain Arm and Kenai Peninsula regions of southcentral Alaska, uplift rates in the immediate aftermath of the earthquake reached 150 mm/yr , but this rapid uplift decayed rapidly after the first few years following the earthquake. (2) At some other locales, notably those away the middle of the coseismic rupture zone, postseismic uplift rates were initially slower but the rates decay over a longer time interval. At Kodiak Island, for example, the uplift rates have been decreasing at a rate of about 7mm/yr per decade. At yet other locations, the uplift rates have shown little time dependence so far, but are thought not to be sustainable

  9. Tohoku earthquake: a surprise?

    CERN Document Server

    Kagan, Yan Y

    2011-01-01

    We consider three issues related to the 2011 Tohoku mega-earthquake: (1) how to evaluate the earthquake maximum size in subduction zones, (2) what is the repeat time for the largest earthquakes in Tohoku area, and (3) what are the possibilities of short-term forecasts during the 2011 sequence. There are two quantitative methods which can be applied to estimate the maximum earthquake size: a statistical analysis of the available earthquake record and the moment conservation principle. The latter technique studies how much of the tectonic deformation rate is released by earthquakes. For the subduction zones, the seismic or historical record is not sufficient to provide a reliable statistical measure of the maximum earthquake. The moment conservation principle yields consistent estimates of maximum earthquake size: for all the subduction zones the magnitude is of the order 9.0--9.7, and for major subduction zones the maximum earthquake size is statistically indistinguishable. Starting in 1999 we have carried out...

  10. Report on the 2010 Chilean earthquake and tsunami response

    Science.gov (United States)

    ,

    2011-01-01

    In July 2010, in an effort to reduce future catastrophic natural disaster losses for California, the American Red Cross coordinated and sent a delegation of 20 multidisciplinary experts on earthquake response and recovery to Chile. The primary goal was to understand how the Chilean society and relevant organizations responded to the magnitude 8.8 Maule earthquake that struck the region on February 27, 2010, as well as how an application of these lessons could better prepare California communities, response partners and state emergency partners for a comparable situation. Similarities in building codes, socioeconomic conditions, and broad extent of the strong shaking make the Chilean earthquake a very close analog to the impact of future great earthquakes on California. To withstand and recover from natural and human-caused disasters, it is essential for citizens and communities to work together to anticipate threats, limit effects, and rapidly restore functionality after a crisis. The delegation was hosted by the Chilean Red Cross and received extensive briefings from both national and local Red Cross officials. During nine days in Chile, the delegation also met with officials at the national, regional, and local government levels. Technical briefings were received from the President’s Emergency Committee, emergency managers from ONEMI (comparable to FEMA), structural engineers, a seismologist, hospital administrators, firefighters, and the United Nations team in Chile. Cities visited include Santiago, Talca, Constitución, Concepción, Talcahuano, Tumbes, and Cauquenes. The American Red Cross Multidisciplinary Team consisted of subject matter experts, who carried out special investigations in five Teams on the (1) science and engineering findings, (2) medical services, (3) emergency services, (4) volunteer management, and (5) executive and management issues (see appendix A for a full list of participants and their titles and teams). While developing this

  11. 7th U.S. / Japan Natural Resources (UJNR) Panel on Earthquake Research: Abstract Volume and Technical Program

    Science.gov (United States)

    Detweiler, Shane T.; Ellsworth, William L.

    2008-01-01

    The U.S. / Japan Natural Resources (UJNR) Panel on Earthquake Research promotes advanced study toward a more fundamental understanding of the earthquake process and hazard estimation. The Panel promotes basic and applied research to improve our understanding of the causes and effects of earthquakes and to facilitate the transmission of research results to those who implement hazard reduction measures on both sides of the Pacific and around the world. Meetings are held every other year, and alternate between countries with short presentation on current research and local field trips being the highlights. The 5th Joint Panel meeting was held at Asilomar, California in October, 2004. The technical sessions featured reports on the September 28, 2004 Parkfield, California earthquake, progress on earthquake early warning and rapid post-event assessment technology, probabilistic earthquake forecasting and the newly discovered phenomenon of nonvolcanic tremor. The Panel visited the epicentral region of the M 6.0 Parkfield earthquake and viewed the surface ruptures along the San Andreas Fault. They also visited the San Andreas Fault Observatory at Depth (SAFOD), which had just completed the first phase of drilling into the fault. The 6th Joint Panel meeting was held in Tokushima, Japan in November, 2006. The meeting included very productive exchanges of information on approaches to systematic observation of earthquake processes. Sixty eight technical papers were presented during the meeting on a wide range of subjects, including interplate earthquakes in subduction zones, slow slip and nonvolcanic tremor, crustal deformation, recent earthquake activity and hazard mapping. Through our discussion, we reaffirmed the benefits of working together to achieve our common goal of reducing earthquake hazard, continued cooperation on issues involving densification of observation networks and the open exchange of data among scientific communities. We also reaffirmed the importance of

  12. POST Earthquake Debris Management - AN Overview

    Science.gov (United States)

    Sarkar, Raju

    Every year natural disasters, such as fires, floods, earthquakes, hurricanes, landslides, tsunami, and tornadoes, challenge various communities of the world. Earthquakes strike with varying degrees of severity and pose both short- and long-term challenges to public service providers. Earthquakes generate shock waves and displace the ground along fault lines. These seismic forces can bring down buildings and bridges in a localized area and damage buildings and other structures in a far wider area. Secondary damage from fires, explosions, and localized flooding from broken water pipes can increase the amount of debris. Earthquake debris includes building materials, personal property, and sediment from landslides. The management of this debris, as well as the waste generated during the reconstruction works, can place significant challenges on the national and local capacities. Debris removal is a major component of every post earthquake recovery operation. Much of the debris generated from earthquake is not hazardous. Soil, building material, and green waste, such as trees and shrubs, make up most of the volume of earthquake debris. These wastes not only create significant health problems and a very unpleasant living environment if not disposed of safely and appropriately, but also can subsequently impose economical burdens on the reconstruction phase. In practice, most of the debris may be either disposed of at landfill sites, reused as materials for construction or recycled into useful commodities Therefore, the debris clearance operation should focus on the geotechnical engineering approach as an important post earthquake issue to control the quality of the incoming flow of potential soil materials. In this paper, the importance of an emergency management perspective in this geotechnical approach that takes into account the different criteria related to the operation execution is proposed by highlighting the key issues concerning the handling of the construction

  13. POST Earthquake Debris Management — AN Overview

    Science.gov (United States)

    Sarkar, Raju

    Every year natural disasters, such as fires, floods, earthquakes, hurricanes, landslides, tsunami, and tornadoes, challenge various communities of the world. Earthquakes strike with varying degrees of severity and pose both short- and long-term challenges to public service providers. Earthquakes generate shock waves and displace the ground along fault lines. These seismic forces can bring down buildings and bridges in a localized area and damage buildings and other structures in a far wider area. Secondary damage from fires, explosions, and localized flooding from broken water pipes can increase the amount of debris. Earthquake debris includes building materials, personal property, and sediment from landslides. The management of this debris, as well as the waste generated during the reconstruction works, can place significant challenges on the national and local capacities. Debris removal is a major component of every post earthquake recovery operation. Much of the debris generated from earthquake is not hazardous. Soil, building material, and green waste, such as trees and shrubs, make up most of the volume of earthquake debris. These wastes not only create significant health problems and a very unpleasant living environment if not disposed of safely and appropriately, but also can subsequently impose economical burdens on the reconstruction phase. In practice, most of the debris may be either disposed of at landfill sites, reused as materials for construction or recycled into useful commodities Therefore, the debris clearance operation should focus on the geotechnical engineering approach as an important post earthquake issue to control the quality of the incoming flow of potential soil materials. In this paper, the importance of an emergency management perspective in this geotechnical approach that takes into account the different criteria related to the operation execution is proposed by highlighting the key issues concerning the handling of the construction

  14. ELER software – a new tool for urban earthquake loss assessment

    Directory of Open Access Journals (Sweden)

    U. Hancilar

    2010-12-01

    .0 (Molina et al., 2008 and ATC-55 (Yang, 2005. An urban loss assessment exercise for a scenario earthquake for the city of Istanbul is conducted and physical and social losses are presented. Damage to the urban environment is compared to the results obtained from similar software, i.e. KOERILoss (KOERI, 2002 and DBELA (Crowley et al., 2004. The European rapid loss estimation tool is expected to help enable effective emergency response, on both local and global level, as well as public information.

  15. Astronomical background of global huge earthquakes

    Science.gov (United States)

    Hu, Hui; Han, Yan-Ben

    2006-03-01

    This paper analyzes the astronomical background of the global huge earthquakes with M≥8.5. The result shows that most of the earthquakes has occurred in the seismic belts (regions) where is being corresponding seismic active period with the lunar path, solar active falling period and accelerating period of earth rotation. This is as for the variation of long period of astronomical factors. For the variation of short period of astronomical factors, whether for local time or local sidereal time and lunar phase there is the phenomenon of occurrence of concentrating a interval time for the earthquakes. For the short variation of earth rotation this phenomenon is clear; either the earthquakes occur in most fast or in lowest of earth rotation. The above-mentioned results indicate that the eartquakes occurrence is affected by astronomical factors. The astronomical factors are one of motive force causing earthquake from external world. The astronomical factors with long period may act as modulation for the earthquake-pregnant process. And the astronomical factors with short period will causing huge fluctuations of the system and earthquake occur when it act on seismic structure of away from balance state.

  16. The earthquake disaster risk characteristic and the problem in the earthquake emergency rescue of mountainous southwestern Sichuan

    Science.gov (United States)

    Yuan, S.; Xin, C.; Ying, Z.

    2016-12-01

    In recent years, earthquake disaster occurred frequently in Chinese mainland, the secondary disaster which have been caused by it is more serious in mountainous region. Because of the influence of terrain and geological conditions, the difficulty of earthquake emergency rescue work greatly increased, rescue force is also urged. Yet, it has been studied less on earthquake emergency rescue in mountainous region, the research in existing equipment whether can meet the actual needs of local earthquake emergency rescue is poorly. This paper intends to discuss and solve these problems. Through the mountainous regions Ganzi and Liangshan states in Sichuan field research, we investigated the process of earthquake emergency response and the projects for rescue force after an earthquake, and we also collected and collated local rescue force based data. By consulting experts and statistical analyzing the basic data, there are mainly two problems: The first is about local rescue force, they are poorly equipped and lack in the knowledge of medical help or identify architectural structure. There are no countries to establish a sound financial investment protection mechanism. Also, rescue equipment's updates and maintenance; The second problem is in earthquake emergency rescue progress. In the complicated geologic structure of mountainous regions, traffic and communication may be interrupted by landslides and mud-rock flows after earthquake. The outside rescue force may not arrive in time, rescue equipment was transported by manpower. Because of unknown earthquake disaster information, the local rescue force was deployed unreasonable. From the above, the local government worker should analyze the characteristics of the earthquake disaster in mountainous regions, and research how to improve their earthquake emergency rescue ability. We think they can do that by strengthening and regulating the rescue force structure, enhancing the skills and knowledge, training rescue workers

  17. [Titration comparative study of TOPINA Tablets in patients with localization related epilepsy: double-blind comparative study by rapid and slow titration methods].

    Science.gov (United States)

    Kaneko, Sunao; Inoue, Yushi; Sasagawa, Mutsuo; Kato, Masaaki

    2012-04-01

    To compare the tolerability and efficacy of two titration methods (rapid and slow titration) for TOPINA Tablets with different dosages and periods of escalation, a double-blind comparative study was conducted in patients with localization-related epilepsy. A total of 183 patients were randomized to either rapid titration (initial dosage 100 mg/day increased by 100-200 mg at weekly intervals) or to slow titration (initial dosage 50 mg/day increased in 50 mg/day increments at weekly intervals). TOPINA Tablets were administered for 12 weeks to the maximum dosage of 400 mg/day. The incident of adverse events leading to treatment interruptions or withdrawals was 18.9% in rapid titration and 14.8% in slow titration, with no statistical significance (p = 0.554). The incident of adverse events and adverse reactions of slow titration was slightly lower than that of rapid titration. The common adverse events and adverse reactions reported in the two titration methods were comparable and were well tolerated. On the other hand, the efficacy of slow titration, percent reduction in seizure rate and responder rate, was comparable with that of rapid titration. In conclusion, there were no significant differences of therapeutic response to TOPINA Tablets between the two titration methods.

  18. Earthquakes: hydrogeochemical precursors

    Science.gov (United States)

    Ingebritsen, Steven E.; Manga, Michael

    2014-01-01

    Earthquake prediction is a long-sought goal. Changes in groundwater chemistry before earthquakes in Iceland highlight a potential hydrogeochemical precursor, but such signals must be evaluated in the context of long-term, multiparametric data sets.

  19. Earthquake Damage - General

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — An earthquake is the motion or trembling of the ground produced by sudden displacement of rock in the Earth's crust. Earthquakes result from crustal strain,...

  20. Earthquakes in Southern California

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — There have been many earthquake occurrences in Southern California. This set of slides shows earthquake damage from the following events: Imperial Valley, 1979,...

  1. Earthquake Notification Service

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Earthquake Notification Service (ENS) is a free service that sends you automated notifications to your email or cell phone when earthquakes happen.

  2. Clinical application of a rapid microbiological test based on capillary zone electrophoresis to assess local skin infection

    Directory of Open Access Journals (Sweden)

    Szeliga Jacek

    2011-10-01

    Full Text Available Abstract Background The basic clinical problem associated with infection treatment is the fact that classic, commonly and routinely used isolation and identification methods are based on long-term processes of a phenotypic analysis of microorganisms. Consequently sometimes, especially in small centres, rapid implementation of antibacterial treatment becomes delayed. The work presents the initial results of rapid microbiological identification based on an original method of capillary zone electrophoresis (CZE. The study involved the analysis of 78 biological samples from post-operative wounds and trophic ulcers. Results The attempt was made to identify individual bacterial species based on characteristic features of electropherograms achieved. Finally, G(+ cocci type bacteria and different G(- rods were identified with sensitivity of 88.1% and specificity of 100%. Conclusions Based on the clinical trials using an electrophoretic technique in the field of microbiological diagnostics of infected exudate from a post-operative wound it can be concluded that it is a rapid and relatively sensitive method for initial identification of infectious pathogens.

  3. Criticism by community people and poor workplace communication as risk factors for the mental health of local welfare workers after the Great East Japan Earthquake: A cross-sectional study.

    Science.gov (United States)

    Ueda, Ikki; Sakuma, Atsushi; Takahashi, Yoko; Shoji, Wataru; Nagao, Ayami; Abe, Mikika; Suzuki, Yuriko; Matsuoka, Hiroo; Matsumoto, Kazunori

    2017-01-01

    After a large-scale natural disaster, demand for social welfare services increases, and the mental health of local social welfare workers becomes a matter of great concern because of their dual role as support providers and disaster survivors. We examined whether work-related social stressors, including criticism by community people and poor workplace communication, were associated with increased risk of post-traumatic stress disorder (PTSD), depression, or psychological distress 20-22 months after the Great East Japan Earthquake (GEJE; March 11, 2011) in local social welfare workers. Demographic characteristics, disaster-related risk factors (near-death experience, dead/missing family members, loss of housing), and work-related social risk factors (criticism, lack of communication) were obtained 20-22 months after the GEJE from 822 local workers. Questionnaires measured PTSD, depression, and psychological stress. Bivariate and multivariate regression analyses were applied. More local social welfare workers suffered from mental health problems than would be expected. Criticism by community people was significantly associated with probable PTSD and high psychological distress (adjusted odds ratio = 2.31 and 2.55, respectively). Furthermore, lack of workplace communication was associated with probable PTSD, depression, and high psychological distress (adjusted odds ratio = 3.97, 4.27, and 4.65, respectively). Almost 2 years after the disaster, local relief workers still suffered from mental health problems. Because post-disaster work-related social stressors constitute risk factors for these mental health problems, measures to improve working conditions and prevent and treat mental disorders should be a priority.

  4. Earthquake Warning Performance in Vallejo for the South Napa Earthquake

    Science.gov (United States)

    Wurman, G.; Price, M.

    2014-12-01

    In 2002 and 2003, Seismic Warning Systems, Inc. installed first-generation QuakeGuardTM earthquake warning devices at all eight fire stations in Vallejo, CA. These devices are designed to detect the P-wave of an earthquake and initiate predetermined protective actions if the impending shaking is estimated at approximately Modifed Mercalli Intensity V or greater. At the Vallejo fire stations the devices were set up to sound an audio alert over the public address system and to command the equipment bay doors to open. In August 2014, after more than 11 years of operating in the fire stations with no false alarms, the five units that were still in use triggered correctly on the MW 6.0 South Napa earthquake, less than 16 km away. The audio alert sounded in all five stations, providing fire fighters with 1.5 to 2.5 seconds of warning before the arrival of the S-wave, and the equipment bay doors opened in three of the stations. In one station the doors were disconnected from the QuakeGuard device, and another station lost power before the doors opened completely. These problems highlight just a small portion of the complexity associated with realizing actionable earthquake warnings. The issues experienced in this earthquake have already been addressed in subsequent QuakeGuard product generations, with downstream connection monitoring and backup power for critical systems. The fact that the fire fighters in Vallejo were afforded even two seconds of warning at these epicentral distances results from the design of the QuakeGuard devices, which focuses on rapid false positive rejection and ground motion estimates. We discuss the performance of the ground motion estimation algorithms, with an emphasis on the accuracy and timeliness of the estimates at close epicentral distances.

  5. Redefining Earthquakes and the Earthquake Machine

    Science.gov (United States)

    Hubenthal, Michael; Braile, Larry; Taber, John

    2008-01-01

    The Earthquake Machine (EML), a mechanical model of stick-slip fault systems, can increase student engagement and facilitate opportunities to participate in the scientific process. This article introduces the EML model and an activity that challenges ninth-grade students' misconceptions about earthquakes. The activity emphasizes the role of models…

  6. Children's Ideas about Earthquakes

    Science.gov (United States)

    Simsek, Canan Lacin

    2007-01-01

    Earthquake, a natural disaster, is among the fundamental problems of many countries. If people know how to protect themselves from earthquake and arrange their life styles in compliance with this, damage they will suffer will reduce to that extent. In particular, a good training regarding earthquake to be received in primary schools is considered…

  7. Using Smartphones to Detect Earthquakes

    Science.gov (United States)

    Kong, Q.; Allen, R. M.

    2012-12-01

    We are using the accelerometers in smartphones to record earthquakes. In the future, these smartphones may work as a supplement network to the current traditional network for scientific research and real-time applications. Given the potential number of smartphones, and small separation of sensors, this new type of seismic dataset has significant potential provides that the signal can be separated from the noise. We developed an application for android phones to record the acceleration in real time. These records can be saved on the local phone or transmitted back to a server in real time. The accelerometers in the phones were evaluated by comparing performance with a high quality accelerometer while located on controlled shake tables for a variety of tests. The results show that the accelerometer in the smartphone can reproduce the characteristic of the shaking very well, even the phone left freely on the shake table. The nature of these datasets is also quite different from traditional networks due to the fact that smartphones are moving around with their owners. Therefore, we must distinguish earthquake signals from other daily use. In addition to the shake table tests that accumulated earthquake records, we also recorded different human activities such as running, walking, driving etc. An artificial neural network based approach was developed to distinguish these different records. It shows a 99.7% successful rate of distinguishing earthquakes from the other typical human activities in our database. We are now at the stage ready to develop the basic infrastructure for a smartphone seismic network.

  8. Full Aftershock Sequence of the M w 6.9 2003 Boumerdes Earthquake, Algeria: Space-Time Distribution, Local Tomography and Seismotectonic Implications

    Science.gov (United States)

    Kherroubi, Abdelaziz; Yelles-Chaouche, Abdelkrim; Koulakov, Ivan; Déverchère, Jacques; Beldjoudi, Hamoud; Haned, Abderrahmane; Semmane, Fethi; Aidi, Chafik

    2017-07-01

    We present a detailed analysis of the aftershocks of the May 21, 2003 Boumerdes earthquake ( M w = 6.9) recorded by 35 seismological stations and 2 OBS deployed in the epicentral area. This network recorded the aftershock activity for about 1 year and resulted in locating about 2500 events. The five main aftershocks (4.7 < M <5.8) display thrust faulting consistent with the main shock, except for the second event (M5.8, 29/05/2003) which depicts a strike-slip focal solution at the western tip of the rupture zone. Most aftershocks are clustered near the main rupture plane, in the footwall or at the westernmost tip of the 2003 Boumerdes rupture area. Many aftershocks last over the whole seismic crisis ahead (north) of the main rupture zone, forming a diffuse, low-angle surface within the footwall where the coseismic static stress change is predicted to increase. At the SW tip of the rupture, short-lived clusters locate at intersections of faults near the contact between the inner (Kabylia) and outer (Tell) zones. The tomographic inversion depicts high-velocity P- and S-wave anomalies coinciding with Miocene magmatic intrusive bodies in the upper crust, partially hidden by surrounding basins. The area of the main shock is associated with a large low-velocity body subdivided into sub-domains, including Neogene basins on land and offshore. Our results support a rupture model strongly controlled by geological inhomogeneities and extending as ramp-flat-ramp systems upward, favoring heterogeneous slip and segmentation in the fault plane with strong afterslip toward the surface. The diffuse aftershock activity in the footwall evidences an inherited discontinuity at mid-crustal depth that we interpret as the contact of Kabylian and African (Tethyan) continental crusts that were stacked during the Upper Miocene collision.

  9. Crowdsourced earthquake early warning

    Science.gov (United States)

    Minson, Sarah E.; Brooks, Benjamin A.; Glennie, Craig L.; Murray, Jessica R.; Langbein, John O.; Owen, Susan E.; Heaton, Thomas H.; Iannucci, Robert A.; Hauser, Darren L.

    2015-01-01

    Earthquake early warning (EEW) can reduce harm to people and infrastructure from earthquakes and tsunamis, but it has not been implemented in most high earthquake-risk regions because of prohibitive cost. Common consumer devices such as smartphones contain low-cost versions of the sensors used in EEW. Although less accurate than scientific-grade instruments, these sensors are globally ubiquitous. Through controlled tests of consumer devices, simulation of an Mw (moment magnitude) 7 earthquake on California’s Hayward fault, and real data from the Mw 9 Tohoku-oki earthquake, we demonstrate that EEW could be achieved via crowdsourcing.

  10. Coilin is rapidly recruited to UVA-induced DNA lesions and γ-radiation affects localized movement of Cajal bodies.

    Science.gov (United States)

    Bártová, Eva; Foltánková, Veronika; Legartová, Soňa; Sehnalová, Petra; Sorokin, Dmitry V; Suchánková, Jana; Kozubek, Stanislav

    2014-01-01

    Cajal bodies are important nuclear structures containing proteins that preferentially regulate RNA-related metabolism. We investigated the cell-type specific nuclear distribution of Cajal bodies and the level of coilin, a protein of Cajal bodies, in non-irradiated and irradiated human tumor cell lines and embryonic stem (ES) cells. Cajal bodies were localized in different nuclear compartments, including DAPI-poor regions, in the proximity of chromocenters, and adjacent to nucleoli. The number of Cajal bodies per nucleus was cell cycle-dependent, with higher numbers occurring during G2 phase. Human ES cells contained a high coilin level in the nucleoplasm, but coilin-positive Cajal bodies were also identified in nuclei of mouse and human ES cells. Coilin, but not SMN, recognized UVA-induced DNA lesions, which was cell cycle-independent. Treatment with γ-radiation reduced the localized movement of Cajal bodies in many cell types and GFP-coilin fluorescence recovery after photobleaching was very fast in nucleoplasm in comparison with GFP-coilin recovery in DNA lesions. By contrast, nucleolus-localized coilin displayed very slow fluorescence recovery after photobleaching, which indicates very slow rates of protein diffusion, especially in nucleoli of mouse ES cells.

  11. A rapid method for quantifying cytoplasmic versus nuclear localization in endogenous peripheral blood leukocytes by conventional flow cytometry

    Science.gov (United States)

    Gulnik, Sergei

    2017-01-01

    Abstract A biochemical system and method have been developed to enable the quantitative measurement of cytoplasmic versus nuclear localization within cells in whole blood. Compared with the analyses of nuclear localization by western blot or fluorescence microscopy, this system saves a lot of time and resources by eliminating the necessity of purification and culturing steps, and generates data that are free from the errors and artifacts associated with using tumor cell lines or calculating nuclear signals from 2D images. This user‐friendly system enables the analysis of cell signaling within peripheral blood cells in their endogenous environment, including measuring the kinetics of nuclear translocation for transcription factors without requiring protein modifications. We first demonstrated the efficiency and specificity of this system for targeting nuclear epitopes, and verified the results by fluorescence microscopy. Next, the power of the technique to analyze LPS‐induced signaling in peripheral blood monocytes was demonstrated. Finally, both FoxP3 localization and IL‐2‐induced STAT5 signaling in regulatory T cells were analyzed. We conclude that this system can be a useful tool for enabling multidimensional molecular‐biological analyses of cell signaling within endogenous peripheral blood cells by conventional flow cytometry. © 2017 The Authors. Cytometry Part A Published by Wiley Periodicals, Inc. on behalf of ISAC. PMID:28371169

  12. Earthquake Fingerprints: Representing Earthquake Waveforms for Similarity-Based Detection

    Science.gov (United States)

    Bergen, K.; Beroza, G. C.

    2016-12-01

    New earthquake detection methods, such as Fingerprint and Similarity Thresholding (FAST), use fast approximate similarity search to identify similar waveforms in long-duration data without templates (Yoon et al. 2015). These methods have two key components: fingerprint extraction and an efficient search algorithm. Fingerprint extraction converts waveforms into fingerprints, compact signatures that represent short-duration waveforms for identification and search. Earthquakes are detected using an efficient indexing and search scheme, such as locality-sensitive hashing, that identifies similar waveforms in a fingerprint database. The quality of the search results, and thus the earthquake detection results, is strongly dependent on the fingerprinting scheme. Fingerprint extraction should map similar earthquake waveforms to similar waveform fingerprints to ensure a high detection rate, even under additive noise and small distortions. Additionally, fingerprints corresponding to noise intervals should have mutually dissimilar fingerprints to minimize false detections. In this work, we compare the performance of multiple fingerprint extraction approaches for the earthquake waveform similarity search problem. We apply existing audio fingerprinting (used in content-based audio identification systems) and time series indexing techniques and present modified versions that are specifically adapted for seismic data. We also explore data-driven fingerprinting approaches that can take advantage of labeled or unlabeled waveform data. For each fingerprinting approach we measure its ability to identify similar waveforms in a low signal-to-noise setting, and quantify the trade-off between true and false detection rates in the presence of persistent noise sources. We compare the performance using known event waveforms from eight independent stations in the Northern California Seismic Network.

  13. High Attenuation Rate for Shallow, Small Earthquakes in Japan

    Science.gov (United States)

    Si, Hongjun; Koketsu, Kazuki; Miyake, Hiroe

    2017-09-01

    We compared the attenuation characteristics of peak ground accelerations (PGAs) and velocities (PGVs) of strong motion from shallow, small earthquakes that occurred in Japan with those predicted by the equations of Si and Midorikawa (J Struct Constr Eng 523:63-70, 1999). The observed PGAs and PGVs at stations far from the seismic source decayed more rapidly than the predicted ones. The same tendencies have been reported for deep, moderate, and large earthquakes, but not for shallow, moderate, and large earthquakes. This indicates that the peak values of ground motion from shallow, small earthquakes attenuate more steeply than those from shallow, moderate or large earthquakes. To investigate the reason for this difference, we numerically simulated strong ground motion for point sources of M w 4 and 6 earthquakes using a 2D finite difference method. The analyses of the synthetic waveforms suggested that the above differences are caused by surface waves, which are predominant at stations far from the seismic source for shallow, moderate earthquakes but not for shallow, small earthquakes. Thus, although loss due to reflection at the boundaries of the discontinuous Earth structure occurs in all shallow earthquakes, the apparent attenuation rate for a moderate or large earthquake is essentially the same as that of body waves propagating in a homogeneous medium due to the dominance of surface waves.

  14. Localized fast neutron flux enhancement for damage experiments in a research reactor; Accroissement local du flux rapide pour des experiences de dommages dans un reacteur de recherche

    Energy Technology Data Exchange (ETDEWEB)

    Malouch, F

    2003-06-01

    In irradiation experiments on materials in the core of the Osiris reactor (CEA-Saclay) we seek to increase damage in irradiated samples and to reduce the duration of their stay in the core. Damage is essentially caused by fast neutrons (E {>=} 1 MeV); we have therefore pursued the possibility of a localized increase of their level in an irradiation experiment by using a flux converter device made up of fissile material arranged according to a suitable geometry that allows the converter to receive experiments. We have studied several parameters that are influential in the increase of fast neutron flux within the converter. We have also considered the problem of the converter's cooling in the core and its effect on the operation of the reactor. We have carried out a specific neutron calculation scheme based on the modular 2D-transport code APOLLO2 using a two-level transport method. Experimental validation of the flux calculation scheme was carried out in the ISIS reactor, the mock-up of OSIRIS, by optimizing the loading of fuel elements in the core. The experimental results show that the neutron calculation scheme computes the fluxes in close agreement with the measurements especially the fast flux. This study allows us to master the essential physical parameters needed for the design of a flux converter in an MTR reactor. (author)

  15. Is It Possible to Predict Strong Earthquakes?

    CERN Document Server

    Polyakov, Yuriy S; Solovyeva, Anna B; Timashev, Serge F

    2015-01-01

    The possibility of earthquake prediction is one of the key open questions in modern geophysics. We propose an approach based on the analysis of common short-term candidate precursors (2 weeks to 3 months prior to strong earthquake) with the subsequent processing of brain activity signals generated in specific types of rats (kept in laboratory settings) who reportedly sense an impending earthquake few days prior to the event. We illustrate the identification of short-term precursors using the groundwater sodium-ion concentration data in the time frame from 2010 to 2014 (a major earthquake occurred on February 28, 2013), recorded at two different sites in the south-eastern part of the Kamchatka peninsula, Russia. The candidate precursors are observed as synchronized peaks in the nonstationarity factors, introduced within the flicker-noise spectroscopy framework for signal processing, for the high-frequency component of both time series. These peaks correspond to the local reorganizations of the underlying geoph...

  16. Sichuan Earthquake in China

    Science.gov (United States)

    2008-01-01

    The Sichuan earthquake in China occurred on May 12, 2008, along faults within the mountains, but near and almost parallel the mountain front, northwest of the city of Chengdu. This major quake caused immediate and severe damage to many villages and cities in the area. Aftershocks pose a continuing danger, but another continuing hazard is the widespread occurrence of landslides that have formed new natural dams and consequently new lakes. These lakes are submerging roads and flooding previously developed lands. But an even greater concern is the possible rapid release of water as the lakes eventually overflow the new dams. The dams are generally composed of disintegrated rock debris that may easily erode, leading to greater release of water, which may then cause faster erosion and an even greater release of water. This possible 'positive feedback' between increasing erosion and increasing water release could result in catastrophic debris flows and/or flooding. The danger is well known to the Chinese earthquake response teams, which have been building spillways over some of the new natural dams. This ASTER image, acquired on June 1, 2008, shows two of the new large landslide dams and lakes upstream from the town of Chi-Kua-Kan at 32o12'N latitude and 104o50'E longitude. Vegetation is green, water is blue, and soil is grayish brown in this enhanced color view. New landslides appear bright off-white. The northern (top) lake is upstream from the southern lake. Close inspection shows a series of much smaller lakes in an elongated 'S' pattern along the original stream path. Note especially the large landslides that created the dams. Some other landslides in this area, such as the large one in the northeast corner of the image, occur only on the mountain slopes, so do not block streams, and do not form lakes.

  17. Harnessing the Collective Power of Eyewitnesses for Improved Earthquake Information

    Science.gov (United States)

    Bossu, R.; Lefebvre, S.; Mazet-Roux, G.; Steed, R.

    2013-12-01

    The Euro-Med Seismological Centre (EMSC) operates the second global earthquake information website (www.emsc-csem.org) which attracts 2 million visits a month from about 200 different countries. We collect information about earthquakes' effects from eyewitnesses such as online questionnaires, geolocated pics to rapidly constrain impact scenario. At the beginning, the collection was purely intended to address a scientific issue: the rapid evaluation of earthquake's impact. However, it rapidly appears that the understanding of eyewitnesses' expectations and motivations in the immediate aftermath of an earthquake was essential to optimise this data collection. Crowdsourcing information on earthquake's effects does not apply to a pre-existing community. By definition, eyewitnesses only exist once the earthquake has struck. We developed a strategy on social networks (Facebook, Google+, Twitter...) to interface with spontaneously emerging online communities of eyewitnesses. The basic idea is to create a positive feedback loop: attract eyewitnesses and engage with them by providing expected earthquake information and services, collect their observations, collate them for improved earthquake information services to attract more witnesses. We will present recent examples to illustrate how important the use of social networks is to engage with eyewitnesses especially in regions of low seismic activity where people are unaware of existing Internet resources dealing with earthquakes. A second type of information collated in our information services is derived from the real time analysis of the traffic on our website in the first minutes following an earthquake occurrence, an approach named flashsourcing. We show, using the example of the Mineral, Virginia earthquake that the arrival times of eyewitnesses of our website follows the propagation of the generated seismic waves and then, that eyewitnesses can be considered as ground motion sensors. Flashsourcing discriminates felt

  18. Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) syndrome may have a hypothalamus-periaqueductal gray localization.

    Science.gov (United States)

    Chow, Cristelle; Fortier, Marielle Valerie; Das, Lena; Menon, Anuradha P; Vasanwala, Rashida; Lam, Joyce C M; Ng, Zhi Min; Ling, Simon Robert; Chan, Derrick W S; Choong, Chew Thye; Liew, Wendy K M; Thomas, Terrence

    2015-05-01

    Anatomical localization of the rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) syndrome has proved elusive. Most patients had neuroimaging after cardiorespiratory collapse, revealing a range of ischemic lesions. A 15-year-old obese boy with an acute febrile encephalopathy had hypoventilation, autonomic dysfunction, visual hallucinations, hyperekplexia, and disordered body temperature, and saltwater regulation. These features describe the ROHHAD syndrome. Cerebrospinal fluid analysis showed pleocytosis, elevated neopterins, and oligoclonal bands, and serology for systemic and antineuronal antibodies was negative. He improved after receiving intravenous steroids, immunoglobulins, and long-term mycophenolate. Screening for neural crest tumors was negative. Magnetic resonance imaging of the brain early in his illness showed focal inflammation in the periaqueductal gray matter and hypothalamus. This unique localization explains almost all symptoms of this rare autoimmune encephalitis. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Brief communication: Co-seismic displacement on 26 and 30 October 2016 (Mw = 5.9 and 6.5) - earthquakes in central Italy from the analysis of a local GNSS network

    Science.gov (United States)

    De Guidi, Giorgio; Vecchio, Alessia; Brighenti, Fabio; Caputo, Riccardo; Carnemolla, Francesco; Di Pietro, Adriano; Lupo, Marco; Maggini, Massimiliano; Marchese, Salvatore; Messina, Danilo; Monaco, Carmelo; Naso, Salvatore

    2017-11-01

    On 24 August 2016 a strong earthquake (Mw = 6.0) affected central Italy and an intense seismic sequence started. Field observations, DInSAR (Differential INterferometry Synthetic-Aperture Radar) analyses and preliminary focal mechanisms, as well as the distribution of aftershocks, suggested the reactivation of the northern sector of the Laga fault, the southern part of which was already rebooted during the 2009 L'Aquila sequence, and of the southern segment of the Mt Vettore fault system (MVFS). Based on this preliminary information and following the stress-triggering concept (Stein, 1999; Steacy et al., 2005), we tentatively identified a potential fault zone that is very vulnerable to future seismic events just north of the earlier epicentral area. Accordingly, we planned a local geodetic network consisting of five new GNSS (Global Navigation Satellite System) stations located a few kilometres away from both sides of the MVFS. This network was devoted to working out, at least partially but in some detail, the possible northward propagation of the crustal network ruptures. The building of the stations and a first set of measurements were carried out during a first campaign (30 September and 2 October 2016). On 26 October 2016, immediately north of the epicentral area of the 24 August event, another earthquake (Mw = 5.9) occurred, followed 4 days later (30 October) by the main shock (Mw = 6.5) of the whole 2016 summer-autumn seismic sequence. Our local geodetic network was fully affected by the new events and therefore we performed a second campaign soon after (11-13 November 2016). In this brief note, we provide the results of our geodetic measurements that registered the co-seismic and immediately post-seismic deformation of the two major October shocks, documenting in some detail the surface deformation close to the fault trace. We also compare our results with the available surface deformation field of the broader area, obtained on the basis of the DIn

  20. Earthquake detection through computationally efficient similarity search.

    Science.gov (United States)

    Yoon, Clara E; O'Reilly, Ossian; Bergen, Karianne J; Beroza, Gregory C

    2015-12-01

    Seismology is experiencing rapid growth in the quantity of data, which has outpaced the development of processing algorithms. Earthquake detection-identification of seismic events in continuous data-is a fundamental operation for observational seismology. We developed an efficient method to detect earthquakes using waveform similarity that overcomes the disadvantages of existing detection methods. Our method, called Fingerprint And Similarity Thresholding (FAST), can analyze a week of continuous seismic waveform data in less than 2 hours, or 140 times faster than autocorrelation. FAST adapts a data mining algorithm, originally designed to identify similar audio clips within large databases; it first creates compact "fingerprints" of waveforms by extracting key discriminative features, then groups similar fingerprints together within a database to facilitate fast, scalable search for similar fingerprint pairs, and finally generates a list of earthquake detections. FAST detected most (21 of 24) cataloged earthquakes and 68 uncataloged earthquakes in 1 week of continuous data from a station located near the Calaveras Fault in central California, achieving detection performance comparable to that of autocorrelation, with some additional false detections. FAST is expected to realize its full potential when applied to extremely long duration data sets over a distributed network of seismic stations. The widespread application of FAST has the potential to aid in the discovery of unexpected seismic signals, improve seismic monitoring, and promote a greater understanding of a variety of earthquake processes.

  1. Do weak global stresses synchronize earthquakes?

    Science.gov (United States)

    Bendick, R.; Bilham, R.

    2017-08-01

    Insofar as slip in an earthquake is related to the strain accumulated near a fault since a previous earthquake, and this process repeats many times, the earthquake cycle approximates an autonomous oscillator. Its asymmetric slow accumulation of strain and rapid release is quite unlike the harmonic motion of a pendulum and need not be time predictable, but still resembles a class of repeating systems known as integrate-and-fire oscillators, whose behavior has been shown to demonstrate a remarkable ability to synchronize to either external or self-organized forcing. Given sufficient time and even very weak physical coupling, the phases of sets of such oscillators, with similar though not necessarily identical period, approach each other. Topological and time series analyses presented here demonstrate that earthquakes worldwide show evidence of such synchronization. Though numerous studies demonstrate that the composite temporal distribution of major earthquakes in the instrumental record is indistinguishable from random, the additional consideration of event renewal interval serves to identify earthquake groupings suggestive of synchronization that are absent in synthetic catalogs. We envisage the weak forces responsible for clustering originate from lithospheric strain induced by seismicity itself, by finite strains over teleseismic distances, or by other sources of lithospheric loading such as Earth's variable rotation. For example, quasi-periodic maxima in rotational deceleration are accompanied by increased global seismicity at multidecadal intervals.

  2. Estimation of earthquake source parameters in the Kachchh seismic ...

    Indian Academy of Sciences (India)

    Durgada Nagamani

    2017-07-25

    Jul 25, 2017 ... Earthquake source parameters and crustal Q0 values for the 138 selected local events of (Mw:2.5−4.4) the 2001 Bhuj earthquake sequence have been computed through inversion modelling of S-waves from three-component broadband seismometer data. SEISAN software has been used to locate the ...

  3. Midbroken Reinforced Concrete Shear Frames Due to Earthquakes

    DEFF Research Database (Denmark)

    Köylüoglu, H. U.; Cakmak, A. S.; Nielsen, Søren R. K.

    A non-linear hysteretic model for the response and local damage analyses of reinforced concrete shear frames subject to earthquake excitation is proposed, and, the model is applied to analyse midbroken reinforced concrete (RC) structures due to earthquake loads. Each storey of the shear frame...

  4. Benchtop chemistry for the rapid prototyping of label-free biosensors: Transmission localized surface plasmon resonance platforms

    Science.gov (United States)

    Liao, Wei-Ssu; Chen, Xin; Yang, Tinglu; Castellana, Edward T.; Chen, Jixin; Cremer, Paul S.

    2012-01-01

    Herein, a simple label-free biosensor fabrication method is demonstrated based on transmission localized surface plasmon resonance (T-LSPR). The platform, which consists of a silver nanoparticle array, can be prepared in just a few minutes using benchtop chemistry. The array was made by a templating technique in conjunction with the photoreduction of Ag ions from solution. This metal surface was functionalized with biotin-linked thiol ligands for binding streptavidin molecules from solution. For an array of 19 nm diameter silver nanoparticles, a redshift in the T-LSPR spectrum of 24 nm was observed upon protein-ligand binding at saturation. The binding constant was found to be 2 × 1012 M–1. Platforms were also fabricated with silver nanoparticles of 34, 55, and 72 nm diameters. The maximum LSPR wavelength shift was nanoparticle size dependent and the maximum sensitivity was obtained with the smaller nanoparticles. PMID:20408728

  5. [Comparative analysis of the clinical characteristics of orthopedic inpatients in Lushan and Wenchuan earthquakes].

    Science.gov (United States)

    Shi, Xiao-Jun; Wang, Guang-Lin; Pei, Fu-Xing; Song, Yue-Ming; Yang, Tian-Fu; Tu, Chong-Qi; Huang, Fu-Guo; Liu, Hao; Lin, Wei

    2013-10-18

    To systematically analyze and compare the clinical characteristics of orthopedic inpatients in Lushan and Wenchuan earthquake, so as to provide useful references for future earthquakes injury rescue. Based on the orthopedic inpatients in Lushan and Wenchuan earthquakes, the data of the age, gender, injury causes, body injured parts and speed of transport were classified and compared. The duration of patients admitted to hospital lasted long and the peak appeared late in Wenchuan earthquake, which is totally opposed to Lushan earthquake. There was no significant difference in the patient's age and gender between the two earthquakes. However, the occurrence rate of crush syndrome, amputation, gas gangrene, vascular injury and multiple organ dysfunction syndrome (MODS) in Wenchuan earthquake was much higher than that in Lushan earthquake. Blunt traumas or crush-related injuries (79.6%) are the major injury cause in Wenchuan earthquake, however, high falling injuries and falls (56.8%) are much higher than blunt trauma or crush-related injuries (39.2%) in Lushan earthquake. The incidence rate of foot fractures, spine fractures and multiple fractures in Lushan earthquake was higher than that in Wenchuan earthquake, but that of open fractures and lower limb fractures was lower than that in Wenchuan earthquake. The rapid rescue scene is the cornerstone of successful treatment, early rescue and transport obviously reduce the incidence of the wound infection, crush syndrome, MODS and amputation. Popularization of correct knowledge of emergency shelters will help to reduce the damage caused by blindly jumping or escaping while earthquake happens.

  6. Wave-equation Based Earthquake Location

    Science.gov (United States)

    Tong, P.; Yang, D.; Yang, X.; Chen, J.; Harris, J.

    2014-12-01

    Precisely locating earthquakes is fundamentally important for studying earthquake physics, fault orientations and Earth's deformation. In industry, accurately determining hypocenters of microseismic events triggered in the course of a hydraulic fracturing treatment can help improve the production of oil and gas from unconventional reservoirs. We develop a novel earthquake location method based on solving full wave equations to accurately locate earthquakes (including microseismic earthquakes) in complex and heterogeneous structures. Traveltime residuals or differential traveltime measurements with the waveform cross-correlation technique are iteratively inverted to obtain the locations of earthquakes. The inversion process involves the computation of the Fréchet derivative with respect to the source (earthquake) location via the interaction between a forward wavefield emitting from the source to the receiver and an adjoint wavefield reversely propagating from the receiver to the source. When there is a source perturbation, the Fréchet derivative not only measures the influence of source location but also the effects of heterogeneity, anisotropy and attenuation of the subsurface structure on the arrival of seismic wave at the receiver. This is essential for the accuracy of earthquake location in complex media. In addition, to reduce the computational cost, we can first assume that seismic wave only propagates in a vertical plane passing through the source and the receiver. The forward wavefield, adjoint wavefield and Fréchet derivative with respect to the source location are all computed in a 2D vertical plane. By transferring the Fréchet derivative along the horizontal direction of the 2D plane into the ones along Latitude and Longitude coordinates or local 3D Cartesian coordinates, the source location can be updated in a 3D geometry. The earthquake location obtained with this combined 2D-3D approach can then be used as the initial location for a true 3D wave

  7. Thermal ecology on an exposed algal reef: infrared imagery a rapid tool to survey temperature at local spatial scales

    Science.gov (United States)

    Cox, T. E.; Smith, C. M.

    2011-12-01

    We tested the feasibility of infra-red (IR) thermography as a tool to survey in situ temperatures in intertidal habitats. We employed this method to describe aspects of thermal ecology for an exposed algal reef in the tropics (O`ahu, Hawai`i). In addition, we compared temperatures of the surrounding habitat as determined by IR thermography and traditional waterproof loggers. Images of reef organisms (6 macroalgae, 9 molluscs, 1 anthozoan, and 2 echinoderms), loggers, and landscapes were taken during two diurnal low tides. Analysis of IR thermographs revealed remarkable thermal complexity on a narrow tropical shore, as habitats ranged from 18.1 to 38.3°C and surfaces of organisms that ranged from 21.1 to 33.2°C. The near 20°C difference between abiotic habitats and the mosaic of temperatures experienced by reef organisms across the shore are similar to findings from temperate studies using specialized longterm loggers. Further, IR thermography captured rapid temperature fluctuations that were related to tidal height and cross-correlated to wave action. Finally, we gathered evidence that tidal species were associated with particular temperature ranges and that two species possess morphological characteristics that limit thermal stress. Loggers provided similar results as thermography but lack the ability to resolve variation in fine-scale spatial and temporal patterns. Our results support the utility of IR thermography in exploring thermal ecology, and demonstrate the steps needed to calibrate data leading to establishment of baseline conditions in a changing and heterogeneous environment.

  8. Earthquake triggering in southeast Africa following the 2012 Indian Ocean earthquake

    Science.gov (United States)

    Neves, Miguel; Custódio, Susana; Peng, Zhigang; Ayorinde, Adebayo

    2018-02-01

    In this paper we present evidence of earthquake dynamic triggering in southeast Africa. We analysed seismic waveforms recorded at 53 broad-band and short-period stations in order to identify possible increases in the rate of microearthquakes and tremor due to the passage of teleseismic waves generated by the Mw8.6 2012 Indian Ocean earthquake. We found evidence of triggered local earthquakes and no evidence of triggered tremor in the region. We assessed the statistical significance of the increase in the number of local earthquakes using β-statistics. Statistically significant dynamic triggering of local earthquakes was observed at 7 out of the 53 analysed stations. Two of these stations are located in the northeast coast of Madagascar and the other five stations are located in the Kaapvaal Craton, southern Africa. We found no evidence of dynamically triggered seismic activity in stations located near the structures of the East African Rift System. Hydrothermal activity exists close to the stations that recorded dynamic triggering, however, it also exists near the East African Rift System structures where no triggering was observed. Our results suggest that factors other than solely tectonic regime and geothermalism are needed to explain the mechanisms that underlie earthquake triggering.

  9. Rapid and Sensitive Detection of Lung Cancer Biomarker Using Nanoporous Biosensor Based on Localized Surface Plasmon Resonance Coupled with Interferometry

    Directory of Open Access Journals (Sweden)

    Jae-Sung Lee

    2015-01-01

    Full Text Available We propose a nanobiosensor to evaluate a lung cancer-specific biomarker. The nanobiosensor is based on an anodic aluminum oxide (AAO chip and functions on the principles of localized surface plasmon resonance (LSPR and interferometry. The pore-depth of the fabricated nanoporous AAO chip was 1 µm and was obtained using a two-step electrochemical anodization process. The sensor chip is sensitive to the refractive index (RI changes of the surrounding medium and also provides simple and label-free detection when specific antibodies are immobilized on the gold-deposited surface of the AAO chip. In order to confirm the effectiveness of the sensor, the antibodies were immobilized on the surface of the AAO chip, and the lung cancer-specific biomarker was applied atop of the immobilized-antibody layer using the self-assembled monolayer method. The nanoporous AAO chip was used as a sensor system to detect serum amyloid A1, which is a lung cancer-specific biomarker. The specific reaction of the antigen-antibody contributes to the change in the RI. This in turn causes a shift in the resonance spectrum in the refractive interference pattern. The limit of detection (LOD was found to be 100 ag/mL and the biosensor had high sensitivity over a wide concentration range.

  10. Low-Temperature Rapid Fabrication of ZnO Nanowire UV Sensor Array by Laser-Induced Local Hydrothermal Growth

    Directory of Open Access Journals (Sweden)

    Sukjoon Hong

    2013-01-01

    Full Text Available We demonstrate ZnO nanowire based UV sensor by laser-induced hydrothermal growth of ZnO nanowire. By inducing a localized temperature rise using focused laser, ZnO nanowire array at ~15 μm size consists of individual nanowires with ~8 μm length and 200~400 nm diameter is readily synthesized on gold electrode within 30 min at the desired position. The laser-induced growth process is consecutively applied on two different points to bridge the micron gap between the electrodes. The resultant photoconductive ZnO NW interconnections display 2~3 orders increase in the current upon the UV exposure at a fixed voltage bias. It is also confirmed that the amount of photocurrent can be easily adjusted by changing the number of ZnO NW array junctions. The device exhibits clear response to the repeated UV illumination, suggesting that this process can be usefully applied for the facile fabrication of low-cost UV sensor array.

  11. Encyclopedia of earthquake engineering

    CERN Document Server

    Kougioumtzoglou, Ioannis; Patelli, Edoardo; Au, Siu-Kui

    2015-01-01

    The Encyclopedia of Earthquake Engineering is designed to be the authoritative and comprehensive reference covering all major aspects of the science of earthquake engineering, specifically focusing on the interaction between earthquakes and infrastructure. The encyclopedia comprises approximately 265 contributions. Since earthquake engineering deals with the interaction between earthquake disturbances and the built infrastructure, the emphasis is on basic design processes important to both non-specialists and engineers so that readers become suitably well-informed without needing to deal with the details of specialist understanding. The content of this encyclopedia provides technically inclined and informed readers about the ways in which earthquakes can affect our infrastructure and how engineers would go about designing against, mitigating and remediating these effects. The coverage ranges from buildings, foundations, underground construction, lifelines and bridges, roads, embankments and slopes. The encycl...

  12. Analysis of pre-earthquake ionospheric anomalies before the global M = 7.0+ earthquakes in 2010

    Directory of Open Access Journals (Sweden)

    W. F. Peng

    2012-03-01

    Full Text Available The pre-earthquake ionospheric anomalies that occurred before the global M = 7.0+ earthquakes in 2010 are investigated using the total electron content (TEC from the global ionosphere map (GIM. We analyze the possible causes of the ionospheric anomalies based on the space environment and magnetic field status. Results show that some anomalies are related to the earthquakes. By analyzing the time of occurrence, duration, and spatial distribution of these ionospheric anomalies, a number of new conclusions are drawn, as follows: earthquake-related ionospheric anomalies are not bound to appear; both positive and negative anomalies are likely to occur; and the earthquake-related ionospheric anomalies discussed in the current study occurred 0–2 days before the associated earthquakes and in the afternoon to sunset (i.e. between 12:00 and 20:00 local time. Pre-earthquake ionospheric anomalies occur mainly in areas near the epicenter. However, the maximum affected area in the ionosphere does not coincide with the vertical projection of the epicenter of the subsequent earthquake. The directions deviating from the epicenters do not follow a fixed rule. The corresponding ionospheric effects can also be observed in the magnetically conjugated region. However, the probability of the anomalies appearance and extent of the anomalies in the magnetically conjugated region are smaller than the anomalies near the epicenter. Deep-focus earthquakes may also exhibit very significant pre-earthquake ionospheric anomalies.

  13. Rapid and Localized Mechanical Stimulation and Adhesion Assay: TRPM7 Involvement in Calcium Signaling and Cell Adhesion.

    Directory of Open Access Journals (Sweden)

    Wagner Shin Nishitani

    Full Text Available A cell mechanical stimulation equipment, based on cell substrate deformation, and a more sensitive method for measuring adhesion of cells were developed. A probe, precisely positioned close to the cell, was capable of a vertical localized mechanical stimulation with a temporal frequency of 207 Hz, and strain magnitude of 50%. This setup was characterized and used to probe the response of Human Umbilical Endothelial Vein Cells (HUVECs in terms of calcium signaling. The intracellular calcium ion concentration was measured by the genetically encoded Cameleon biosensor, with the Transient Receptor Potential cation channel, subfamily M, member 7 (TRPM7 expression inhibited. As TRPM7 expression also regulates adhesion, a relatively simple method for measuring adhesion of cells was also developed, tested and used to study the effect of adhesion alone. Three adhesion conditions of HUVECs on polyacrylamide gel dishes were compared. In the first condition, the substrate is fully treated with Sulfo-SANPAH crosslinking and fibronectin. The other two conditions had increasingly reduced adhesion: partially treated (only coated with fibronectin, with no use of Sulfo-SANPAH, at 5% of the normal amount and non-treated polyacrylamide gels. The cells showed adhesion and calcium response to the mechanical stimulation correlated to the degree of gel treatment: highest for fully treated gels and lowest for non-treated ones. TRPM7 inhibition by siRNA on HUVECs caused an increase in adhesion relative to control (no siRNA treatment and non-targeting siRNA, but a decrease to 80% of calcium response relative to non-targeting siRNA which confirms the important role of TRPM7 in mechanotransduction despite the increase in adhesion.

  14. Earthquakes trigger the loss of groundwater biodiversity

    Science.gov (United States)

    Galassi, Diana M. P.; Lombardo, Paola; Fiasca, Barbara; di Cioccio, Alessia; di Lorenzo, Tiziana; Petitta, Marco; di Carlo, Piero

    2014-09-01

    Earthquakes are among the most destructive natural events. The 6 April 2009, 6.3-Mw earthquake in L'Aquila (Italy) markedly altered the karstic Gran Sasso Aquifer (GSA) hydrogeology and geochemistry. The GSA groundwater invertebrate community is mainly comprised of small-bodied, colourless, blind microcrustaceans. We compared abiotic and biotic data from two pre-earthquake and one post-earthquake complete but non-contiguous hydrological years to investigate the effects of the 2009 earthquake on the dominant copepod component of the obligate groundwater fauna. Our results suggest that the massive earthquake-induced aquifer strain biotriggered a flushing of groundwater fauna, with a dramatic decrease in subterranean species abundance. Population turnover rates appeared to have crashed, no longer replenishing the long-standing communities from aquifer fractures, and the aquifer became almost totally deprived of animal life. Groundwater communities are notorious for their low resilience. Therefore, any major disturbance that negatively impacts survival or reproduction may lead to local extinction of species, most of them being the only survivors of phylogenetic lineages extinct at the Earth surface. Given the ecological key role played by the subterranean fauna as decomposers of organic matter and ``ecosystem engineers'', we urge more detailed, long-term studies on the effect of major disturbances to groundwater ecosystems.

  15. Earthquakes trigger the loss of groundwater biodiversity

    Science.gov (United States)

    Galassi, Diana M. P.; Lombardo, Paola; Fiasca, Barbara; Di Cioccio, Alessia; Di Lorenzo, Tiziana; Petitta, Marco; Di Carlo, Piero

    2014-01-01

    Earthquakes are among the most destructive natural events. The 6 April 2009, 6.3-Mw earthquake in L'Aquila (Italy) markedly altered the karstic Gran Sasso Aquifer (GSA) hydrogeology and geochemistry. The GSA groundwater invertebrate community is mainly comprised of small-bodied, colourless, blind microcrustaceans. We compared abiotic and biotic data from two pre-earthquake and one post-earthquake complete but non-contiguous hydrological years to investigate the effects of the 2009 earthquake on the dominant copepod component of the obligate groundwater fauna. Our results suggest that the massive earthquake-induced aquifer strain biotriggered a flushing of groundwater fauna, with a dramatic decrease in subterranean species abundance. Population turnover rates appeared to have crashed, no longer replenishing the long-standing communities from aquifer fractures, and the aquifer became almost totally deprived of animal life. Groundwater communities are notorious for their low resilience. Therefore, any major disturbance that negatively impacts survival or reproduction may lead to local extinction of species, most of them being the only survivors of phylogenetic lineages extinct at the Earth surface. Given the ecological key role played by the subterranean fauna as decomposers of organic matter and “ecosystem engineers”, we urge more detailed, long-term studies on the effect of major disturbances to groundwater ecosystems. PMID:25182013

  16. 2016 update on induced earthquakes in the United States

    Science.gov (United States)

    Petersen, Mark D.

    2016-01-01

    During the past decade people living in numerous locations across the central U.S. experienced many more small to moderate sized earthquakes than ever before. This earthquake activity began increasing about 2009 and peaked during 2015 and into early 2016. For example, prior to 2009 Oklahoma typically experienced 1 or 2 small earthquakes per year with magnitude greater than 3.0 but by 2015 this number rose to over 900 earthquakes per year of that size and over 30 earthquakes greater than 4.0. These earthquakes can cause damage. In 2011 a magnitude 5.6 earthquake struck near the town of Prague, Oklahoma on a preexisting fault and caused severe damage to several houses and school buildings. During the past 6 years more than 1500 reports of damaging shaking levels were reported in areas of induced seismicity. This rapid increase and the potential for damaging ground shaking from induced earthquakes caused alarm to about 8 million people living nearby and officials responsible for public safety. They wanted to understand why earthquakes were increasing and the potential threats to society and buildings located nearby.

  17. Napa earthquake: An earthquake in a highly connected world

    Science.gov (United States)

    Bossu, R.; Steed, R.; Mazet-Roux, G.; Roussel, F.

    2014-12-01

    The Napa earthquake recently occurred close to Silicon Valley. This makes it a good candidate to study what social networks, wearable objects and website traffic analysis (flashsourcing) can tell us about the way eyewitnesses react to ground shaking. In the first part, we compare the ratio of people publishing tweets and with the ratio of people visiting EMSC (European Mediterranean Seismological Centre) real time information website in the first minutes following the earthquake occurrence to the results published by Jawbone, which show that the proportion of people waking up depends (naturally) on the epicentral distance. The key question to evaluate is whether the proportions of inhabitants tweeting or visiting the EMSC website are similar to the proportion of people waking up as shown by the Jawbone data. If so, this supports the premise that all methods provide a reliable image of the relative ratio of people waking up. The second part of the study focuses on the reaction time for both Twitter and EMSC website access. We show, similarly to what was demonstrated for the Mineral, Virginia, earthquake (Bossu et al., 2014), that hit times on the EMSC website follow the propagation of the P waves and that 2 minutes of website traffic is sufficient to determine the epicentral location of an earthquake on the other side of the Atlantic. We also compare with the publication time of messages on Twitter. Finally, we check whether the number of tweets and the number of visitors relative to the number of inhabitants is correlated to the local level of shaking. Together these results will tell us whether the reaction of eyewitnesses to ground shaking as observed through Twitter and the EMSC website analysis is tool specific (i.e. specific to Twitter or EMSC website) or whether they do reflect people's actual reactions.

  18. The USGS Earthquake Scenario Project

    Science.gov (United States)

    Wald, D. J.; Petersen, M. D.; Wald, L. A.; Frankel, A. D.; Quitoriano, V. R.; Lin, K.; Luco, N.; Mathias, S.; Bausch, D.

    2009-12-01

    The U.S. Geological Survey’s (USGS) Earthquake Hazards Program (EHP) is producing a comprehensive suite of earthquake scenarios for planning, mitigation, loss estimation, and scientific investigations. The Earthquake Scenario Project (ESP), though lacking clairvoyance, is a forward-looking project, estimating earthquake hazard and loss outcomes as they may occur one day. For each scenario event, fundamental input includes i) the magnitude and specified fault mechanism and dimensions, ii) regional Vs30 shear velocity values for site amplification, and iii) event metadata. A grid of standard ShakeMap ground motion parameters (PGA, PGV, and three spectral response periods) is then produced using the well-defined, regionally-specific approach developed by the USGS National Seismic Hazard Mapping Project (NHSMP), including recent advances in empirical ground motion predictions (e.g., the NGA relations). The framework also allows for numerical (3D) ground motion computations for specific, detailed scenario analyses. Unlike NSHMP ground motions, for ESP scenarios, local rock and soil site conditions and commensurate shaking amplifications are applied based on detailed Vs30 maps where available or based on topographic slope as a proxy. The scenario event set is comprised primarily by selection from the NSHMP events, though custom events are also allowed based on coordination of the ESP team with regional coordinators, seismic hazard experts, seismic network operators, and response coordinators. The event set will be harmonized with existing and future scenario earthquake events produced regionally or by other researchers. The event list includes approximate 200 earthquakes in CA, 100 in NV, dozens in each of NM, UT, WY, and a smaller number in other regions. Systematic output will include all standard ShakeMap products, including HAZUS input, GIS, KML, and XML files used for visualization, loss estimation, ShakeCast, PAGER, and for other systems. All products will be

  19. Dosimetric study of RapidArc plans with flattened beam (FB and flattening filter-free (FFF beam for localized prostate cancer based on physical indices

    Directory of Open Access Journals (Sweden)

    Birendra Kumar Rout

    2014-12-01

    Full Text Available Purpose: To identify the continual diversity between flattening photon beam (FB and Flattening Filter Free (FFF photon beams for localized prostate cancer; and to determine potential benefits and drawbacks of using unflattened beam for this type of treatment.Methods: Eight prostate cases including seminal vesicles selected for this study. The primary planning target volume (PTVP and boost planning target volume (PTVB were contoured. The total prescription dose was 78 Gy (56 Gy to PTVP and an additional 22 Gy to PTVB. For all cases, treatment plans using 6MV with FB and FFF beams with identical dose-volume constraints, arc angles and number of arcs were developed. The dose volume histograms for both techniques were compared for primary target volume and critical structures.Results: A low Sigma index (FFF: 1.65 + 0.361; FB: 1.725 + 0.39 indicating improved dose homogeneity in FFF beam. Conformity index (FFF: 0.994 + 0.01; FB: 0.993 + 0.01 is comparable for both techniques. Minimal difference of Organ at risk mean dose was observed. Normal tissue integral dose in FB plan resulted 1.5% lower than FFF plan. All the plans displayed significant increase (1.18 times for PTVP and 1.11 for PTBB in the average number of necessary MU with FFF beam.Conclusion: Diversity between FB and FFF beam plans were found. FFF beam accelerator has been utilized to develop clinically acceptable Rapid Arc treatment plans for prostate cancer with 6 MV.---------------------------------Cite this article as: Rout BK, Muralidhar KR, Ali M, Shekar MC, Kumar A. Dosimetric study of RapidArc plans with flattened beam (FB and flattening filter-free (FFF beam for localized prostate cancer based on physical indices. Int J Cancer Ther Oncol 2014; 2(4:02046.  DOI: 10.14319/ijcto.0204.6

  20. SU-F-P-30: Clinical Assessment of Auto Beam-Hold Triggered by Fiducial Localization During Prostate RapidArc Delivery

    Energy Technology Data Exchange (ETDEWEB)

    Atkinson, P; Chen, Q [Flower Hospital, Sylvania, OH (United States)

    2016-06-15

    Purpose: To assess the clinical efficacy of auto beam hold during prostate RapidArc delivery, triggered by fiducial localization on kV imaging with a Varian True Beam. Methods: Prostate patients with four gold fiducials were candidates in this study. Daily setup was accomplished by aligning to fiducials using orthogonal kV imaging. During RapidArc delivery, a kV image was automatically acquired with a momentary beam hold every 60 degrees of gantry rotation. The position of each fiducial was identified by a search algorithm and compared to a predetermined 1.4 cm diameter target area. Treatment continued if all the fiducials were within the target area. If any fiducial was outside the target area the beam hold was not released, and the operators determined if the patient needed re-alignment using the daily setup method. Results: Four patients were initially selected. For three patients, the auto beam hold performed seamlessly. In one instance, the system correctly identified misaligned fiducials, stopped treatment, and the patient was re-positioned. The fourth patient had a prosthetic hip which sometimes blocked the fiducials and caused the fiducial search algorithm to fail. The auto beam hold was disabled for this patient and the therapists manually monitored the fiducial positions during treatment. Average delivery time for a 2-arc fraction was increased by 59 seconds. Phantom studies indicated the dose discrepancy related to multiple beam holds is <0.1%. For a plan with 43 fractions, the additional imaging increased dose by an estimated 68 cGy. Conclusion: Automated intrafraction kV imaging can effectively perform auto beam holds due to patient movement, with the exception of prosthetic hip patients. The additional imaging dose and delivery time are clinically acceptable. It may be a cost-effective alternative to Calypso in RapidArc prostate patient delivery. Further study is warranted to explore its feasibility under various clinical conditions.

  1. Earthquake Damage, Armenian SSR, December 7, 1988

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — On December 7, 1988, at 11:41 A.M. local time a magnitude 6.9 earthquake shook northwestern Armenia and was followed four minutes later by a magnitude 5.8...

  2. Earthquakes and Schools

    Science.gov (United States)

    National Clearinghouse for Educational Facilities, 2008

    2008-01-01

    Earthquakes are low-probability, high-consequence events. Though they may occur only once in the life of a school, they can have devastating, irreversible consequences. Moderate earthquakes can cause serious damage to building contents and non-structural building systems, serious injury to students and staff, and disruption of building operations.…

  3. Bam Earthquake in Iran

    CERN Multimedia

    2004-01-01

    Following their request for help from members of international organisations, the permanent Mission of the Islamic Republic of Iran has given the following bank account number, where you can donate money to help the victims of the Bam earthquake. Re: Bam earthquake 235 - UBS 311264.35L Bubenberg Platz 3001 BERN

  4. Demand surge following earthquakes

    Science.gov (United States)

    Olsen, Anna H.

    2012-01-01

    Demand surge is understood to be a socio-economic phenomenon where repair costs for the same damage are higher after large- versus small-scale natural disasters. It has reportedly increased monetary losses by 20 to 50%. In previous work, a model for the increased costs of reconstruction labor and materials was developed for hurricanes in the Southeast United States. The model showed that labor cost increases, rather than the material component, drove the total repair cost increases, and this finding could be extended to earthquakes. A study of past large-scale disasters suggested that there may be additional explanations for demand surge. Two such explanations specific to earthquakes are the exclusion of insurance coverage for earthquake damage and possible concurrent causation of damage from an earthquake followed by fire or tsunami. Additional research into these aspects might provide a better explanation for increased monetary losses after large- vs. small-scale earthquakes.

  5. Modeling the Interaction between Fluid Pressure and Faulting in an Earthquake Swarm at Long Valley Caldera

    Science.gov (United States)

    Hsieh, P. A.; Shelly, D. R.; Hill, D. P.

    2016-12-01

    Rapid migration of hypocenters during the 2014 Long Valley Caldera, California, earthquake swarm suggests that the activity was initiated and sustained by fluids, composed primarily of water and carbon dioxide, exsolved from underlying magma (Shelly et al., 2016, JGR, doi:10.1002/2015JB012719). To investigate how fluid pressure and faulting may co-evolve, we develop a simulation model that couples fluid flow with mechanical stress, while treating earthquakes with the "static/dynamic friction" approach developed by McClure and Horne (2010, Geotherm. Resour. Counc. Trans., 34, 381-396). We set up the model to represent a vertical, permeable fault (divided into a grid of elements) bounded by impermeable rock in a strike-slip tectonic environment. At the start of the simulation, a high-pressure source is introduced at depth to represent the injection of magmatic-derived fluids along the fault. The fluid flow component of the model simulates diffusion of the source pressure into the fault, and halts when the pressure increase at a fault element is sufficient to cause failure (slip). Next, the mechanical stress component of the model calculates the stress changes that result from the slip. Because these stress changes could induce surrounding elements to slip, the model iterates through this chain-reaction process until a stable configuration is achieved (i.e., slipped elements do not induce further slips).The patch of slipped elements represents an earthquake in the model. The permeability of the patch is increased to represent the effect of shear displacement, and the pressure diffusion simulation resumes. Although this model implements a simplified representation of the earthquake mechanism, it is able to mimic (using reasonable rock properties) the overall character of a local swarm of approximately 1000 earthquakes (-0.9 < M < 2.8) that occurred during 7 July 2014 in Long Valley Caldera.

  6. Landslides from the February 4, 1976, Guatemala earthquake

    Science.gov (United States)

    Harp, Edwin L.; Wilson, Raymond C.; Wieczorek, Gerald F.

    1981-01-01

    The M (Richter magnitude) = 7.5 Guatemala earthquake of February 4, 1976, generated more than 10,000 landslides throughout an area of approximately 16,000 km2. These landslides caused hundreds of fatalities as well as extensive property damage. Landslides disrupted both highways and the railroad system and thus severely hindered early rescue efforts. In Guatemala City, extensive property damage and loss of life were due to ground failure beneath dwellings built too close to the edges of steeply incised canyons. We have recorded the distribution of landslides from this earthquake by mapping individual slides at a scale of 1:50,000 for most of the landslide-affected area, using high-altitude aerial photography. The highest density of landslides was in the highlands west of Guatemala City. The predominant types of earthquake-triggered landslides were rock falls and debris slides of less than 15,000 m3 volume; in addition to these smaller landslides, 11 large landslides had volumes of more than 100,000 m3. Several of these large landslides posed special hazards to people and property from lakes impounded by the landslide debris and from the ensuing floods that occurred upon breaching and rapid erosion of the debris. The regional landslide distribution was observed to depend on five major factors: (1) seismic intensity; (2) lithology: 90 percent of all landslides were within Pleistocene pumice deposits; (3) slope steepness; (4) topographic amplification of seismic ground motion; and (5) regional fractures. The presence of preearthquake landslides had no apparent effect on the landslide distribution, and landslide concentration in the Guatemala City area does not correlate with local seismic-intensity data. The landslide concentration, examined at this scale, appears to be governed mainly by lithologic differences within the pumice deposits, preexisting fractures, and amplification of ground motion by topography-all factors related to site conditions.

  7. Phenology of Spondias tuberosa Arruda (Anacardiaceae under different landscape management regimes and a proposal for a rapid phenological diagnosis using local knowledge

    Directory of Open Access Journals (Sweden)

    Neto Ernani MF Lins

    2013-01-01

    Full Text Available Abstract Background Studies aimed at investigating the influence of habitat change on species phenology. Studies that investigate people's perceptions of the phenology of certain species still area few; yet this approach is important for effective decision-making for conservation. The aim of this study was to investigate the phenology of Spondias tuberosa Arruda (Anacardiaceae, a native species of economic and ecological importance in northeastern Brazil, in five landscape units (LUs (Mountain, Mountain Base, Pasture, Cultivated Areas and Homegardens of a Caatinga region in Altinho, Pernambuco, northeastern Brazil. These data could then be compared with local people's perceptions of the species’ phenophases. Method Collection of phenological data was carried out monthly from February 2007 to January 2009 and included activity, intensity and synchronization of reproductive and vegetative phenophases. Ethnobotanical data were gathered using a collaborative approach to access local people’s knowledge about the species’ phenological schedule. Results There were no significant differences in the intensity of phenophases among LUs, and there was a correspondence between people’s perception of phenophases and the phenological data collected. The data show that the different management practices for LUs did not influence the phenology of the species. Conclusion The main conclusion of this study is the use of traditional knowledge as interesting tool for rapid phenological diagnosis. However further studies need to be developed to test this tool in other environments and cultural contexts.

  8. Phenology of Spondias tuberosa Arruda (Anacardiaceae) under different landscape management regimes and a proposal for a rapid phenological diagnosis using local knowledge.

    Science.gov (United States)

    Lins Neto, Ernani M F; Almeida, Alyson L S; Peroni, Nivaldo; Castro, Cibele C; Albuquerque, Ulysses P

    2013-01-31

    Studies aimed at investigating the influence of habitat change on species phenology. Studies that investigate people's perceptions of the phenology of certain species still area few; yet this approach is important for effective decision-making for conservation. The aim of this study was to investigate the phenology of Spondias tuberosa Arruda (Anacardiaceae), a native species of economic and ecological importance in northeastern Brazil, in five landscape units (LUs) (Mountain, Mountain Base, Pasture, Cultivated Areas and Homegardens) of a Caatinga region in Altinho, Pernambuco, northeastern Brazil. These data could then be compared with local people's perceptions of the species' phenophases. Collection of phenological data was carried out monthly from February 2007 to January 2009 and included activity, intensity and synchronization of reproductive and vegetative phenophases. Ethnobotanical data were gathered using a collaborative approach to access local people's knowledge about the species' phenological schedule. There were no significant differences in the intensity of phenophases among LUs, and there was a correspondence between people's perception of phenophases and the phenological data collected. The data show that the different management practices for LUs did not influence the phenology of the species. The main conclusion of this study is the use of traditional knowledge as interesting tool for rapid phenological diagnosis. However further studies need to be developed to test this tool in other environments and cultural contexts.

  9. The Future of USGS Earthquake Geodesy

    Science.gov (United States)

    Hudnut, K. W.; King, N. E.; Murray-Moraleda, J.; Roeloffs, E.; Zeng, Y.

    2008-05-01

    Earthquake Geodesy, an important third prong of USGS Earthquake Hazards Program (EHP) along with seismology and geology, is at a crossroads. Initiatives by NASA and NSF have built global and national geodetic arrays that promise to contribute greatly to the EHP mission of helping to reduce the nation's loss of life and property from earthquakes. These geodetic arrays pose great opportunities and challenges for USGS scientists who now operate under tight constraints of either a flat or, at best, a moderately increasing budget. While availability of vast new data streams represents a great opportunity for USGS, the challenge is how to best exploit new data streams for risk mitigation and loss reduction. Geodetic data need to be fully embedded into the suite of USGS products, from the National Seismic Hazard Maps for long-term planning to ShakeMaps for rapid response. The USGS needs to be in a position to authoritatively review all geodetic data being collected nationwide (notably including those of the Plate Boundary Observatory) so that we can fulfill our Stafford Act responsibility of advising public officials on earthquake hazard issues in large urban areas and diverse geographic regions. Furthermore, USGS has the mandate and liability protection required to take the lead on Earthquake Early Warning (EEW) system development and implementation, in which geodesy may provide vital independent measurement methods in real-time so as to improve overall EEW system robustness.

  10. Development of the U.S. Geological Survey's PAGER system (Prompt Assessment of Global Earthquakes for Response)

    Science.gov (United States)

    Wald, D.J.; Earle, P.S.; Allen, T.I.; Jaiswal, K.; Porter, K.; Hearne, M.

    2008-01-01

    The Prompt Assessment of Global Earthquakes for Response (PAGER) System plays a primary alerting role for global earthquake disasters as part of the U.S. Geological Survey’s (USGS) response protocol. We provide an overview of the PAGER system, both of its current capabilities and our ongoing research and development. PAGER monitors the USGS’s near real-time U.S. and global earthquake origins and automatically identifies events that are of societal importance, well in advance of ground-truth or news accounts. Current PAGER notifications and Web pages estimate the population exposed to each seismic intensity level. In addition to being a useful indicator of potential impact, PAGER’s intensity/exposure display provides a new standard in the dissemination of rapid earthquake information. We are currently developing and testing a more comprehensive alert system that will include casualty estimates. This is motivated by the idea that an estimated range of possible number of deaths will aid in decisions regarding humanitarian response. Underlying the PAGER exposure and loss models are global earthquake ShakeMap shaking estimates, constrained as quickly as possible by finite-fault modeling and observed ground motions and intensities, when available. Loss modeling is being developed comprehensively with a suite of candidate models that range from fully empirical to largely analytical approaches. Which of these models is most appropriate for use in a particular earthquake depends on how much is known about local building stocks and their vulnerabilities. A first-order country-specific global building inventory has been developed, as have corresponding vulnerability functions. For calibrating PAGER loss models, we have systematically generated an Atlas of 5,000 ShakeMaps for significant global earthquakes during the last 36 years. For many of these, auxiliary earthquake source and shaking intensity data are also available. Refinements to the loss models are ongoing

  11. An atlas of ShakeMaps for selected global earthquakes

    Science.gov (United States)

    Allen, Trevor I.; Wald, David J.; Hotovec, Alicia J.; Lin, Kuo-Wan; Earle, Paul S.; Marano, Kristin D.

    2008-01-01

    An atlas of maps of peak ground motions and intensity 'ShakeMaps' has been developed for almost 5,000 recent and historical global earthquakes. These maps are produced using established ShakeMap methodology (Wald and others, 1999c; Wald and others, 2005) and constraints from macroseismic intensity data, instrumental ground motions, regional topographically-based site amplifications, and published earthquake-rupture models. Applying the ShakeMap methodology allows a consistent approach to combine point observations with ground-motion predictions to produce descriptions of peak ground motions and intensity for each event. We also calculate an estimated ground-motion uncertainty grid for each earthquake. The Atlas of ShakeMaps provides a consistent and quantitative description of the distribution and intensity of shaking for recent global earthquakes (1973-2007) as well as selected historic events. As such, the Atlas was developed specifically for calibrating global earthquake loss estimation methodologies to be used in the U.S. Geological Survey Prompt Assessment of Global Earthquakes for Response (PAGER) Project. PAGER will employ these loss models to rapidly estimate the impact of global earthquakes as part of the USGS National Earthquake Information Center's earthquake-response protocol. The development of the Atlas of ShakeMaps has also led to several key improvements to the Global ShakeMap system. The key upgrades include: addition of uncertainties in the ground motion mapping, introduction of modern ground-motion prediction equations, improved estimates of global seismic-site conditions (VS30), and improved definition of stable continental region polygons. Finally, we have merged all of the ShakeMaps in the Atlas to provide a global perspective of earthquake ground shaking for the past 35 years, allowing comparison with probabilistic hazard maps. The online Atlas and supporting databases can be found at http://earthquake.usgs.gov/eqcenter/shakemap/atlas.php/.

  12. The Great East Japan Earthquake Disaster and cardiovascular diseases.

    Science.gov (United States)

    Aoki, Tatsuo; Fukumoto, Yoshihiro; Yasuda, Satoshi; Sakata, Yasuhiko; Ito, Kenta; Takahashi, Jun; Miyata, Satoshi; Tsuji, Ichiro; Shimokawa, Hiroaki

    2012-11-01

    While previous studies reported a short-term increase in individual cardiovascular disease (CVD) after great earthquakes, mid-term occurrences of all types of CVDs after great earthquakes are unknown. We addressed this important issue in our experience with the Great East Japan Earthquake (11 March 2011). We retrospectively examined the impact of the Earthquake on the occurrences of CVDs and pneumonia by comparing the ambulance records made by doctors in our Miyagi Prefecture, the centre of the disaster area, during the periods of 2008-11 (n = 124,152). The weekly occurrences of CVDs, including heart failure (HF), acute coronary syndrome (ACS), stroke, cardiopulmonary arrest (CPA), and pneumonia were all significantly increased after the Earthquake compared with the previous 3 years. The occurrences of ACS and CPA showed the rapid increase followed by a sharp decline, whereas those of HF and pneumonia showed a prolonged increase for more than 6 weeks and those of stroke and CPA showed a second peak after the largest aftershock (7 April 2011). Furthermore, the occurrence of CPA was increased in the first 24 h after the Earthquake, followed by other diseases later on. These increases were independent of age, sex, or residence area (seacoast vs. inland). These results indicate that the occurrences of all types of CVDs and pneumonia were increased in somewhat different time courses after the Earthquake, including the first observation of the marked and prolonged increase in HF, emphasizing the importance of intensive medical management of all types of CVDs after great earthquakes.

  13. Earthquakes and emergence

    Science.gov (United States)

    Earthquakes and emerging infections may not have a direct cause and effect relationship like tax evasion and jail, but new evidence suggests that there may be a link between the two human health hazards. Various media accounts have cited a massive 1993 earthquake in Maharashtra as a potential catalyst of the recent outbreak of plague in India that has claimed more than 50 lives and alarmed the world. The hypothesis is that the earthquake may have uprooted underground rat populations that carry the fleas infected with the bacterium that causes bubonic plague and can lead to the pneumonic form of the disease that is spread through the air.

  14. Earthquake engineering in Peru

    Science.gov (United States)

    Vargas, N.J

    1983-01-01

    During the last decade, earthquake engineering research in Peru has been carried out at the Catholic University of Peru and at the Universidad Nacional de Ingeniera (UNI). The Geophysical Institute (IGP) under the auspices of the Organization of American States (OAS) has initiated in Peru other efforts in regional seismic hazard assessment programs with direct impact to the earthquake engineering program. Further details on these programs have been reported by L. Ocola in the Earthquake Information Bulletin, January-February 1982, vol. 14, no. 1, pp. 33-38. 

  15. Induced seismicity provides insight into why earthquake ruptures stop

    KAUST Repository

    Galis, Martin

    2017-12-21

    Injection-induced earthquakes pose a serious seismic hazard but also offer an opportunity to gain insight into earthquake physics. Currently used models relating the maximum magnitude of injection-induced earthquakes to injection parameters do not incorporate rupture physics. We develop theoretical estimates, validated by simulations, of the size of ruptures induced by localized pore-pressure perturbations and propagating on prestressed faults. Our model accounts for ruptures growing beyond the perturbed area and distinguishes self-arrested from runaway ruptures. We develop a theoretical scaling relation between the largest magnitude of self-arrested earthquakes and the injected volume and find it consistent with observed maximum magnitudes of injection-induced earthquakes over a broad range of injected volumes, suggesting that, although runaway ruptures are possible, most injection-induced events so far have been self-arrested ruptures.

  16. Prospective testing of Coulomb short-term earthquake forecasts

    Science.gov (United States)

    Jackson, D. D.; Kagan, Y. Y.; Schorlemmer, D.; Zechar, J. D.; Wang, Q.; Wong, K.

    2009-12-01

    Earthquake induced Coulomb stresses, whether static or dynamic, suddenly change the probability of future earthquakes. Models to estimate stress and the resulting seismicity changes could help to illuminate earthquake physics and guide appropriate precautionary response. But do these models have improved forecasting power compared to empirical statistical models? The best answer lies in prospective testing in which a fully specified model, with no subsequent parameter adjustments, is evaluated against future earthquakes. The Center of Study of Earthquake Predictability (CSEP) facilitates such prospective testing of earthquake forecasts, including several short term forecasts. Formulating Coulomb stress models for formal testing involves several practical problems, mostly shared with other short-term models. First, earthquake probabilities must be calculated after each “perpetrator” earthquake but before the triggered earthquakes, or “victims”. The time interval between a perpetrator and its victims may be very short, as characterized by the Omori law for aftershocks. CSEP evaluates short term models daily, and allows daily updates of the models. However, lots can happen in a day. An alternative is to test and update models on the occurrence of each earthquake over a certain magnitude. To make such updates rapidly enough and to qualify as prospective, earthquake focal mechanisms, slip distributions, stress patterns, and earthquake probabilities would have to be made by computer without human intervention. This scheme would be more appropriate for evaluating scientific ideas, but it may be less useful for practical applications than daily updates. Second, triggered earthquakes are imperfectly recorded following larger events because their seismic waves are buried in the coda of the earlier event. To solve this problem, testing methods need to allow for “censoring” of early aftershock data, and a quantitative model for detection threshold as a function of

  17. A P-wave based, on-site method for Earthquake Early Warning

    Science.gov (United States)

    Zollo, Aldo

    2016-04-01

    Can we rapidly predict the potential damage of earthquakes by-passing the estimation of its location and magnitude? One possible approach is to predict the expected peak ground shaking at the site and the earthquake magnitude from the initial P-peak amplitude and characteristic period, respectively. The idea, first developed by Wu and Kanamori (2005), is to combine the two parameters for declaring the alert once the real-time measured quantities have passed pre-defined thresholds. Our proposed on-site early warning method generalized this approach, based on the analysis of strong motion data from modern accelerograph networks in Japan, Taiwan and Italy (Zollo et al., 2010). It is based on the real-time measurement of the period (τc) and peak displacement (Pd) parameters at one or more co-located stations at a given target site to be protected against the earthquake effects. By converting these real-time proxies in predicted values of Peak Ground Velocity (PGV) or instrumental intensity (IMM) and magnitude, an alert level is issued at the recording site based on a decisional table with four entries defined upon threshold values of the parameters Pd and Tc. The latter ones are set according to the error bounds estimated on the derived prediction equations. A near-source network of stations running the onsite method can provide the event location and transmit the information about the alert levels recorded at near-source stations to more distant sites, before the arrival of the most destructive phase. The network-based approach allows for the rapid and robust estimation of the Potential Damage Zone (PDZ), that is the area where most of earthquake damage is expected (Colombelli et al., 2012). A new strategy for a P-wave based, on-site earthquake early warning system has been developed and tested on Japanese strong motion data and under testing on Italian data. The key elements are the real-time, continuous measurement of three peak amplitude parameters and their

  18. The 2010-2011 Canterbury Earthquake Sequence: Environmental effects, seismic triggering thresholds and geologic legacy

    Science.gov (United States)

    Quigley, Mark C.; Hughes, Matthew W.; Bradley, Brendon A.; van Ballegooy, Sjoerd; Reid, Catherine; Morgenroth, Justin; Horton, Travis; Duffy, Brendan; Pettinga, Jarg R.

    2016-03-01

    Seismic shaking and tectonic deformation during strong earthquakes can trigger widespread environmental effects. The severity and extent of a given effect relates to the characteristics of the causative earthquake and the intrinsic properties of the affected media. Documentation of earthquake environmental effects in well-instrumented, historical earthquakes can enable seismologic triggering thresholds to be estimated across a spectrum of geologic, topographic and hydrologic site conditions, and implemented into seismic hazard assessments, geotechnical engineering designs, palaeoseismic interpretations, and forecasts of the impacts of future earthquakes. The 2010-2011 Canterbury Earthquake Sequence (CES), including the moment magnitude (Mw) 7.1 Darfield earthquake and Mw 6.2, 6.0, 5.9, and 5.8 aftershocks, occurred on a suite of previously unidentified, primarily blind, active faults in the eastern South Island of New Zealand. The CES is one of Earth's best recorded historical earthquake sequences. The location of the CES proximal to and beneath a major urban centre enabled rapid and detailed collection of vast amounts of field, geospatial, geotechnical, hydrologic, biologic, and seismologic data, and allowed incremental and cumulative environmental responses to seismic forcing to be documented throughout a protracted earthquake sequence. The CES caused multiple instances of tectonic surface deformation (≥ 3 events), surface manifestations of liquefaction (≥ 11 events), lateral spreading (≥ 6 events), rockfall (≥ 6 events), cliff collapse (≥ 3 events), subsidence (≥ 4 events), and hydrological (10s of events) and biological shifts (≥ 3 events). The terrestrial area affected by strong shaking (e.g. peak ground acceleration (PGA) ≥ 0.1-0.3 g), and the maximum distances between earthquake rupture and environmental response (Rrup), both generally increased with increased earthquake Mw, but were also influenced by earthquake location and source

  19. Study of Earthquake Disaster Prediction System of Langfang city Based on GIS

    Science.gov (United States)

    Huang, Meng; Zhang, Dian; Li, Pan; Zhang, YunHui; Zhang, RuoFei

    2017-07-01

    In this paper, according to the status of China’s need to improve the ability of earthquake disaster prevention, this paper puts forward the implementation plan of earthquake disaster prediction system of Langfang city based on GIS. Based on the GIS spatial database, coordinate transformation technology, GIS spatial analysis technology and PHP development technology, the seismic damage factor algorithm is used to predict the damage of the city under different intensity earthquake disaster conditions. The earthquake disaster prediction system of Langfang city is based on the B / S system architecture. Degree and spatial distribution and two-dimensional visualization display, comprehensive query analysis and efficient auxiliary decision-making function to determine the weak earthquake in the city and rapid warning. The system has realized the transformation of the city’s earthquake disaster reduction work from static planning to dynamic management, and improved the city’s earthquake and disaster prevention capability.

  20. A New Mechanism for Pore Pressure Changes Induced by Distant Earthquakes

    Science.gov (United States)

    Brodsky, E. E.; Roeloffs, E.; Woodcock, D.; Gall, I.; Manga, M.

    2001-12-01

    Observations during the Mw=7.3 1992 Landers earthquake, Mw=7.4 Izmit earthquake and Mw=7.2 Hector Mine earthquake suggest that seismicity is triggered hundreds of kilometers from a mainshock epicenter. This puzzling phenomenon is not explained by traditional elastic models of seismic stresses. The fact that the triggered sites are often geothermal or magmatic suggests that fluids may be an important part of the triggering process. Rapid changes in pore pressure either reduce the effective stress on faults locally or prompt hydrofracturing to initiate local earthquakes. The challenge is to discover how the seismic waves generate a change in pore fluid pressure. We constrain a mechanism for seismically-induced pore pressure changes by studying coseismic water level drops at a well in Grants Pass, Oregon. Water level drops at the site have been associated with earthquakes for nearly 20 years. High-sample rate (up to 1 Hz) digital water level data is available for the two coseismic drops that have occurred since 1994. The approach of this study is to use the amplification of the seismic waves in the well to constrain variations of the aquifer properties during the water level drops. We find that the amplification of the seismic waves in the well is consistent with standard theory for 7 digitally recorded events without drops, but during an earthquake with a drop a dramatic change in amplification occurs during the passage of the Rayleigh waves. The change in amplification indicates that the transmissivity increases by a factor of 50 during the 11 cm coseismic water level drop accompanying the 1999 Mw=7.5 1999 Oaxaca, Mexico earthquake. Based on these observations, we propose a new model for coseismic pore pressure changes. Drops occur if an earthquake occurs when the well has become temporarily clogged by a solid precipitate or sediment. The seismic shaking induces a flow which removes the obstruction. Once a barrier is removed, water flows rapidly to generate dramatic

  1. Injection-induced earthquakes

    National Research Council Canada - National Science Library

    Ellsworth, William L

    2013-01-01

    ...s. It has long been understood that earthquakes can be induced by impoundment of reservoirs, surface and underground mining, withdrawal of fluids and gas from the subsurface, and injection of fluids...

  2. 1988 Spitak Earthquake Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 1988 Spitak Earthquake database is an extensive collection of geophysical and geological data, maps, charts, images and descriptive text pertaining to the...

  3. Earthquakes and plate tectonics

    Science.gov (United States)

    Spall, H.

    1977-01-01

    The world's earthquakes are not randomly distributed over the Earth's surface. They tend to be concentrated in narrow zones. Why is this? And why are volcanoes and mountain ranges also found in these zones too?

  4. Tweet Earthquake Dispatch (TED)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The USGS is offering earthquake alerts via two twitter accounts: @USGSted and @USGSBigQuakes. On average, @USGSted and @USGSBigQuakes will produce about one tweet...

  5. Earthquake Damage to Schools

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This set of slides graphically illustrates the potential danger that major earthquakes pose to school structures and to the children and adults who happen to be...

  6. Earthquake Ground Motion Selection

    Science.gov (United States)

    2012-05-01

    Nonlinear analyses of soils, structures, and soil-structure systems offer the potential for more accurate characterization of geotechnical and structural response under strong earthquake shaking. The increasing use of advanced performance-based desig...

  7. Seismology: energy radiation from the Sumatra earthquake.

    Science.gov (United States)

    Ni, Sidao; Kanamori, Hiroo; Helmberger, Don

    2005-03-31

    We determined the duration of high-frequency energy radiation from Indonesia's great Sumatra-Andaman earthquake (26 December 2004) to be about 500 seconds. This duration can be translated into a rupture length of about 1,200 km, which is more than twice as long as that inferred from body-wave analyses performed soon after the event. Our analysis was able rapidly to define the extent of rupture, thereby aiding the assessment of seismic hazard in the immediate future.

  8. Correlating precursory declines in groundwater radon with earthquake magnitude.

    Science.gov (United States)

    Kuo, T

    2014-01-01

    Both studies at the Antung hot spring in eastern Taiwan and at the Paihe spring in southern Taiwan confirm that groundwater radon can be a consistent tracer for strain changes in the crust preceding an earthquake when observed in a low-porosity fractured aquifer surrounded by a ductile formation. Recurrent anomalous declines in groundwater radon were observed at the Antung D1 monitoring well in eastern Taiwan prior to the five earthquakes of magnitude (Mw ): 6.8, 6.1, 5.9, 5.4, and 5.0 that occurred on December 10, 2003; April 1, 2006; April 15, 2006; February 17, 2008; and July 12, 2011, respectively. For earthquakes occurring on the longitudinal valley fault in eastern Taiwan, the observed radon minima decrease as the earthquake magnitude increases. The above correlation has been proven to be useful for early warning local large earthquakes. In southern Taiwan, radon anomalous declines prior to the 2010 Mw 6.3 Jiasian, 2012 Mw 5.9 Wutai, and 2012 ML 5.4 Kaohsiung earthquakes were also recorded at the Paihe spring. For earthquakes occurring on different faults in southern Taiwan, the correlation between the observed radon minima and the earthquake magnitude is not yet possible. © 2013, National Ground Water Association.

  9. Searching for Unknown Earthquakes in the Guy-Greenbrier, Arkansas, Earthquake Sequence using Efficient Waveform Similarity Search

    Science.gov (United States)

    Yoon, C. E.; OReilly, O. J.; Bergen, K.; Huang, Y.; Beroza, G. C.

    2015-12-01

    Recent seismicity rate increases in the central United States have been attributed to injection of wastewater from oil and gas production. One example is the Guy-Greenbrier, Arkansas, earthquake sequence, which occurred from July 2010 through October 2011, and was potentially induced by fluid injection into nearby disposal wells (Horton, 2012). Although the Arkansas seismic network is sparse, a single 3-component station WHAR recorded continuous data before, during, and after this earthquake sequence at distances ranging from 2-9 km. Huang and Beroza (2015) used template matching to detect over 100 times the number of cataloged earthquakes by cross-correlating the continuous data with waveform templates based on known earthquakes to search for additional low-magnitude events. Because known waveform templates do not necessarily fully represent all seismic signals in the continuous data, small earthquakes from unknown sources could have escaped detection. We use a method called Fingerprint And Similarity Thresholding (FAST) to detect additional low-magnitude earthquakes that were missed by template matching. FAST enables fast, scalable search for earthquakes with similar waveforms without making prior assumptions about the seismic signal of interest. FAST, based on a data mining technique, first creates compact "fingerprints" of waveforms by extracting discriminative features, then uses locality-sensitive hashing to organize and efficiently search for similar fingerprints (and therefore similar earthquake waveforms) in a probabilistic manner. With FAST, each search query is processed in near-constant time, independent of the dataset size; this computational efficiency is gained at the expense of an approximate, rather than exact, search. During one week of continuous data at station WHAR, from 2010-07-01 to 2010-07-08, FAST detected over 200 uncataloged earthquakes that were not found through template matching. These newly detected earthquakes have the potential to

  10. Earthquake precursors: spatial-temporal gravity changes before the great earthquakes in the Sichuan-Yunnan area

    Science.gov (United States)

    Zhu, Yi-Qing; Liang, Wei-Feng; Zhang, Song

    2017-09-01

    Using multiple-scale mobile gravity data in the Sichuan-Yunnan area, we systematically analyzed the relationships between spatial-temporal gravity changes and the 2014 Ludian, Yunnan Province Ms6.5 earthquake and the 2014 Kangding Ms6.3, 2013 Lushan Ms7.0, and 2008 Wenchuan Ms8.0 earthquakes in Sichuan Province. Our main results are as follows. (1) Before the occurrence of large earthquakes, gravity anomalies occur in a large area around the epicenters. The directions of gravity change gradient belts usually agree roughly with the directions of the main fault zones of the study area. Such gravity changes might reflect the increase of crustal stress, as well as the significant active tectonic movements and surface deformations along fault zones, during the period of gestation of great earthquakes. (2) Continuous significant changes of the multiple-scale gravity fields, as well as greater gravity changes with larger time scales, can be regarded as medium-range precursors of large earthquakes. The subsequent large earthquakes always occur in the area where the gravity changes greatly. (3) The spatial-temporal gravity changes are very useful in determining the epicenter of coming large earthquakes. The large gravity networks are useful to determine the general areas of coming large earthquakes. However, the local gravity networks with high spatial-temporal resolution are suitable for determining the location of epicenters. Therefore, denser gravity observation networks are necessary for better forecasts of the epicenters of large earthquakes. (4) Using gravity changes from mobile observation data, we made medium-range forecasts of the Kangding, Ludian, Lushan, and Wenchuan earthquakes, with especially successful forecasts of the location of their epicenters. Based on the above discussions, we emphasize that medium-/long-term potential for large earthquakes might exist nowadays in some areas with significant gravity anomalies in the study region. Thus, the monitoring

  11. Unusual geologic evidence of coeval seismic shaking and tsunamis shows variability in earthquake size and recurrence in the area of the giant 1960 Chile earthquake

    Science.gov (United States)

    Cisternas, M.; Garrett, E; Wesson, Robert L.; Dura, T.; Ely, L. L

    2017-01-01

    An uncommon coastal sedimentary record combines evidence for seismic shaking and coincident tsunami inundation since AD 1000 in the region of the largest earthquake recorded instrumentally: the giant 1960 southern Chile earthquake (Mw 9.5). The record reveals significant variability in the size and recurrence of megathrust earthquakes and ensuing tsunamis along this part of the Nazca-South American plate boundary. A 500-m long coastal outcrop on Isla Chiloé, midway along the 1960 rupture, provides continuous exposure of soil horizons buried locally by debris-flow diamicts and extensively by tsunami sand sheets. The diamicts flattened plants that yield geologically precise ages to correlate with well-dated evidence elsewhere. The 1960 event was preceded by three earthquakes that probably resembled it in their effects, in AD 898 - 1128, 1300 - 1398 and 1575, and by five relatively smaller intervening earthquakes. Earthquakes and tsunamis recurred exceptionally often between AD 1300 and 1575. Their average recurrence interval of 85 years only slightly exceeds the time already elapsed since 1960. This inference is of serious concern because no earthquake has been anticipated in the region so soon after the 1960 event, and current plate locking suggests that some segments of the boundary are already capable of producing large earthquakes. This long-term earthquake and tsunami history of one of the world's most seismically active subduction zones provides an example of variable rupture mode, in which earthquake size and recurrence interval vary from one earthquake to the next.

  12. Developing and Testing the Automated Post-Event Earthquake Loss Estimation and Visualisation (APE-ELEV) Technique

    OpenAIRE

    Astoul, Anthony; Filliter, Christopher; Mason,Eric; Rau-Chaplin, Andrew; Shridhar, Kunal; Varghese, Blesson; Varshney, Naman

    2013-01-01

    An automated, real-time, multiple sensor data source relying and globally applicable earthquake loss model and visualiser is desirable for post-event earthquake analysis. To achieve this there is a need to support rapid data ingestion, loss estimation and integration of data from multiple data sources and rapid visualisation at multiple geographic levels. In this paper, the design and development of the Automated Post-Event Earthquake Loss Estimation and Visualisation (APE-ELEV) system for re...

  13. Smartphone-Based Earthquake and Tsunami Early Warning in Chile

    Science.gov (United States)

    Brooks, B. A.; Baez, J. C.; Ericksen, T.; Barrientos, S. E.; Minson, S. E.; Duncan, C.; Guillemot, C.; Smith, D.; Boese, M.; Cochran, E. S.; Murray, J. R.; Langbein, J. O.; Glennie, C. L.; Dueitt, J.; Parra, H.

    2016-12-01

    Many locations around the world face high seismic hazard, but do not have the resources required to establish traditional earthquake and tsunami warning systems (E/TEW) that utilize scientific grade seismological sensors. MEMs accelerometers and GPS chips embedded in, or added inexpensively to, smartphones are sensitive enough to provide robust E/TEW if they are deployed in sufficient numbers. We report on a pilot project in Chile, one of the most productive earthquake regions world-wide. There, magnitude 7.5+ earthquakes occurring roughly every 1.5 years and larger tsunamigenic events pose significant local and trans-Pacific hazard. The smartphone-based network described here is being deployed in parallel to the build-out of a scientific-grade network for E/TEW. Our sensor package comprises a smartphone with internal MEMS and an external GPS chipset that provides satellite-based augmented positioning and phase-smoothing. Each station is independent of local infrastructure, they are solar-powered and rely on cellular SIM cards for communications. An Android app performs initial onboard processing and transmits both accelerometer and GPS data to a server employing the FinDer-BEFORES algorithm to detect earthquakes, producing an acceleration-based line source model for smaller magnitude earthquakes or a joint seismic-geodetic finite-fault distributed slip model for sufficiently large magnitude earthquakes. Either source model provides accurate ground shaking forecasts, while distributed slip models for larger offshore earthquakes can be used to infer seafloor deformation for local tsunami warning. The network will comprise 50 stations by Sept. 2016 and 100 stations by Dec. 2016. Since Nov. 2015, batch processing has detected, located, and estimated the magnitude for Mw>5 earthquakes. Operational since June, 2016, we have successfully detected two earthquakes > M5 (M5.5, M5.1) that occurred within 100km of our network while producing zero false alarms.

  14. Charles Darwin's earthquake reports

    Science.gov (United States)

    Galiev, Shamil

    2010-05-01

    As it is the 200th anniversary of Darwin's birth, 2009 has also been marked as 170 years since the publication of his book Journal of Researches. During the voyage Darwin landed at Valdivia and Concepcion, Chile, just before, during, and after a great earthquake, which demolished hundreds of buildings, killing and injuring many people. Land was waved, lifted, and cracked, volcanoes awoke and giant ocean waves attacked the coast. Darwin was the first geologist to observe and describe the effects of the great earthquake during and immediately after. These effects sometimes repeated during severe earthquakes; but great earthquakes, like Chile 1835, and giant earthquakes, like Chile 1960, are rare and remain completely unpredictable. This is one of the few areas of science, where experts remain largely in the dark. Darwin suggested that the effects were a result of ‘ …the rending of strata, at a point not very deep below the surface of the earth…' and ‘…when the crust yields to the tension, caused by its gradual elevation, there is a jar at the moment of rupture, and a greater movement...'. Darwin formulated big ideas about the earth evolution and its dynamics. These ideas set the tone for the tectonic plate theory to come. However, the plate tectonics does not completely explain why earthquakes occur within plates. Darwin emphasised that there are different kinds of earthquakes ‘...I confine the foregoing observations to the earthquakes on the coast of South America, or to similar ones, which seem generally to have been accompanied by elevation of the land. But, as we know that subsidence has gone on in other quarters of the world, fissures must there have been formed, and therefore earthquakes...' (we cite the Darwin's sentences following researchspace. auckland. ac. nz/handle/2292/4474). These thoughts agree with results of the last publications (see Nature 461, 870-872; 636-639 and 462, 42-43; 87-89). About 200 years ago Darwin gave oneself airs by the

  15. Recovering from the ShakeOut earthquake

    Science.gov (United States)

    Wein, Anne; Johnson, Laurie; Bernknopf, Richard

    2011-01-01

    Recovery from an earthquake like the M7.8 ShakeOut Scenario will be a major endeavor taking many years to complete. Hundreds of Southern California municipalities will be affected; most lack recovery plans or previous disaster experience. To support recovery planning this paper 1) extends the regional ShakeOut Scenario analysis into the recovery period using a recovery model, 2) localizes analyses to identify longer-term impacts and issues in two communities, and 3) considers the regional context of local recovery.Key community insights about preparing for post-disaster recovery include the need to: geographically diversify city procurement; set earthquake mitigation priorities for critical infrastructure (e.g., airport), plan to replace mobile homes with earthquake safety measures, consider post-earthquake redevelopment opportunities ahead of time, and develop post-disaster recovery management and governance structures. This work also showed that communities with minor damages are still sensitive to regional infrastructure damages and their potential long-term impacts on community recovery. This highlights the importance of community and infrastructure resilience strategies as well.

  16. Real-time performance of probabilistic, first-motion earthquake mechanisms to improve tsunami early-warning

    Science.gov (United States)

    Lomax, Anthony; Michelni, Alberto; Bernardi, Fabrizio; Scognamiglio, Laura

    2017-04-01

    The first tsunami warning messages are typically based on simple earthquake parameters: epicenter location, hypocenter depth, and magnitude. The addition of early information on the faulting mechanism can enable more reliable estimates of seafloor uplift, tsunami excitation, tsunami potential and impact, and earlier, real-time tsunami scenario forecasting. Full-waveform, centroid moment tensor solutions (CMT) are typically available in 3-15min for local/near-regional earthquakes and in 10-30min for regional/teleseismic distances. In contrast, classic, P first-motion (FM) focal-mechanisms can be available within 3min for local/near-regional events and in 5-10 min for regional/teleseismic distances. We present fmamp, a robust, probabilistic, adaptive grid-search, FM mechanism determination procedure which generates a comprehensive set of "acceptable" FM mechanisms and related uncertainties. This FM solution, combined with fast magnitude estimates such as Mwp, forms a CMT proxy for rapid source characterization and analysis before a definitive, waveform CMT is available. Currently, fmamp runs in real-time in Early-est*, the module for rapid earthquake detection, location and analysis at the INGV tsunami alert center (CAT, "Centro di Allerta Tsunami"), part of the Italian, candidate Tsunami Watch Provider. We show the real-time performance of fmamp and compare its speed and accuracy to CMT results. For large earthquakes in areas of sparse seismic station coverage, fmamp mechanisms are typically available in 5-10min, while CMT results take 10-30min. The fmamp solutions usually agree with CMT results for larger events, but sometimes differ, due to insufficient or noisy FM readings, or real difference between the FM mechanism, representing the faulting at the hypocenter, and the CMT mechanism representing some average, centroid faulting. * http://early-est.alomax.net, http://early-est.rm.ingv.it, http://alomax.free.fr/posters/early-est

  17. Quantification of social contributions to earthquake mortality

    Science.gov (United States)

    Main, I. G.; NicBhloscaidh, M.; McCloskey, J.; Pelling, M.; Naylor, M.

    2013-12-01

    Death tolls in earthquakes, which continue to grow rapidly, are the result of complex interactions between physical effects, such as strong shaking, and the resilience of exposed populations and supporting critical infrastructures and institutions. While it is clear that the social context in which the earthquake occurs has a strong effect on the outcome, the influence of this context can only be exposed if we first decouple, as much as we can, the physical causes of mortality from our consideration. (Our modelling assumes that building resilience to shaking is a social factor governed by national wealth, legislation and enforcement and governance leading to reduced levels of corruption.) Here we attempt to remove these causes by statistically modelling published mortality, shaking intensity and population exposure data; unexplained variance from this physical model illuminates the contribution of socio-economic factors to increasing earthquake mortality. We find that this variance partitions countries in terms of basic socio-economic measures and allows the definition of a national vulnerability index identifying both anomalously resilient and anomalously vulnerable countries. In many cases resilience is well correlated with GDP; people in the richest countries are unsurprisingly safe from even the worst shaking. However some low-GDP countries rival even the richest in resilience, showing that relatively low cost interventions can have a positive impact on earthquake resilience and that social learning between these countries might facilitate resilience building in the absence of expensive engineering interventions.

  18. Small repeating earthquakes and inter-plate aseismic slip in and around the Kanto district after the 2011 off the Pacific coast of Tohoku earthquake

    Science.gov (United States)

    Igarashi, T.; Iidaka, T.; Sakai, S.; Obara, K.; Hirata, N.

    2013-12-01

    the limit to the thickness of 5 km. Using these plate configurations, we classified small repeating earthquakes and estimated inter-plate aseismic slip at each plate. Although the resultant slip-rates before the 2011 main-shock correspond to the relative plate motion in these areas, they increased in both plates after the event. At the PAC plate, they occur around the coseismic slip area of the largest aftershock and cannot detect within it. Furthermore, the slip areas expanded to the deeper part beyond the northeastern limit of the PHS plate. The slip-rate peaked immediately after the 2011 main-shock and gradually decreases to the velocity of relative plate motion in the next one year or two. The rate of decrease was rapid at the trench-side of the largest aftershock. On the other hand, the slip-rate at the PHS plate increased significantly at relatively deeper part of the west of the largest aftershock. The location with fast slip-rates changes at different times. These slip-rates increases may be caused by localized stress changes with coseismic slips and/or post-seismic deformation.

  19. Rupture, waves and earthquakes

    Science.gov (United States)

    UENISHI, Koji

    2017-01-01

    Normally, an earthquake is considered as a phenomenon of wave energy radiation by rupture (fracture) of solid Earth. However, the physics of dynamic process around seismic sources, which may play a crucial role in the occurrence of earthquakes and generation of strong waves, has not been fully understood yet. Instead, much of former investigation in seismology evaluated earthquake characteristics in terms of kinematics that does not directly treat such dynamic aspects and usually excludes the influence of high-frequency wave components over 1 Hz. There are countless valuable research outcomes obtained through this kinematics-based approach, but “extraordinary” phenomena that are difficult to be explained by this conventional description have been found, for instance, on the occasion of the 1995 Hyogo-ken Nanbu, Japan, earthquake, and more detailed study on rupture and wave dynamics, namely, possible mechanical characteristics of (1) rupture development around seismic sources, (2) earthquake-induced structural failures and (3) wave interaction that connects rupture (1) and failures (2), would be indispensable. PMID:28077808

  20. Rupture, waves and earthquakes.

    Science.gov (United States)

    Uenishi, Koji

    2017-01-01

    Normally, an earthquake is considered as a phenomenon of wave energy radiation by rupture (fracture) of solid Earth. However, the physics of dynamic process around seismic sources, which may play a crucial role in the occurrence of earthquakes and generation of strong waves, has not been fully understood yet. Instead, much of former investigation in seismology evaluated earthquake characteristics in terms of kinematics that does not directly treat such dynamic aspects and usually excludes the influence of high-frequency wave components over 1 Hz. There are countless valuable research outcomes obtained through this kinematics-based approach, but "extraordinary" phenomena that are difficult to be explained by this conventional description have been found, for instance, on the occasion of the 1995 Hyogo-ken Nanbu, Japan, earthquake, and more detailed study on rupture and wave dynamics, namely, possible mechanical characteristics of (1) rupture development around seismic sources, (2) earthquake-induced structural failures and (3) wave interaction that connects rupture (1) and failures (2), would be indispensable.

  1. WHY WE CANNOT PREDICT STRONG EARTHQUAKES IN THE EARTH’S CRUST

    Directory of Open Access Journals (Sweden)

    Iosif L. Gufeld

    2011-01-01

    Full Text Available In the past decade, earthquake disasters caused multiple fatalities and significant economic losses and challenged the modern civilization. The wellknown achievements and growing power of civilization are backstrapped when facing the Nature. The question arises, what hinders solving a problem of earthquake prediction, while longterm and continuous seismic monitoring systems are in place in many regions of the world. For instance, there was no forecast of the Japan Great Earthquake of March 11, 2011, despite the fact that monitoring conditions for its prediction were unique. Its focal zone was 100–200 km away from the monitoring network installed in the area of permanent seismic hazard, which is subject to nonstop and longterm seismic monitoring. Lesson should be learned from our common fiasco in forecasting, taking into account research results obtained during the past 50–60 years. It is now evident that we failed to identify precursors of the earthquakes. Prior to the earthquake occurrence, the observed local anomalies of various fields reflected other processes that were mistakenly viewed as processes of preparation for largescale faulting. For many years, geotectonic situations were analyzed on the basis of the physics of destruction of laboratory specimens, which was applied to the lithospheric conditions. Many researchers realize that such an approach is inaccurate. Nonetheless, persistent attempts are being undertaken with application of modern computation to detect anomalies of various fields, which may be interpreted as earthquake precursors. In our opinion, such illusory intentions were smashed by the Great Japan Earthquake (Figure 6. It is also obvious that sufficient attention has not been given yet to fundamental studies of seismic processes.This review presents the authors’ opinion concerning the origin of the seismic process and strong earthquakes, being part of the process. The authors realize that a wide discussion is

  2. WHY WE CANNOT PREDICT STRONG EARTHQUAKES IN THE EARTH’S CRUST

    Directory of Open Access Journals (Sweden)

    Iosif L. Gufeld

    2015-09-01

    Full Text Available In the past decade, earthquake disasters caused multiple fatalities and significant economic losses and challenged the modern civilization. The wellknown achievements and growing power of civilization are backstrapped when facing the Nature. The question arises, what hinders solving a problem of earthquake prediction, while longterm and continuous seismic monitoring systems are in place in many regions of the world. For instance, there was no forecast of the Japan Great Earthquake of March 11, 2011, despite the fact that monitoring conditions for its prediction were unique. Its focal zone was 100–200 km away from the monitoring network installed in the area of permanent seismic hazard, which is subject to nonstop and longterm seismic monitoring. Lesson should be learned from our common fiasco in forecasting, taking into account research results obtained during the past 50–60 years. It is now evident that we failed to identify precursors of the earthquakes. Prior to the earthquake occurrence, the observed local anomalies of various fields reflected other processes that were mistakenly viewed as processes of preparation for largescale faulting. For many years, geotectonic situations were analyzed on the basis of the physics of destruction of laboratory specimens, which was applied to the lithospheric conditions. Many researchers realize that such an approach is inaccurate. Nonetheless, persistent attempts are being undertaken with application of modern computation to detect anomalies of various fields, which may be interpreted as earthquake precursors. In our opinion, such illusory intentions were smashed by the Great Japan Earthquake (Figure 6. It is also obvious that sufficient attention has not been given yet to fundamental studies of seismic processes.This review presents the authors’ opinion concerning the origin of the seismic process and strong earthquakes, being part of the process. The authors realize that a wide discussion is

  3. The 2012 Mw5.6 earthquake in Sofia seismogenic zone - is it a slow earthquake

    Science.gov (United States)

    Raykova, Plamena; Solakov, Dimcho; Slavcheva, Krasimira; Simeonova, Stela; Aleksandrova, Irena

    2017-04-01

    very low rupture velocity. The low rupture velocity can mean slow-faulting, which brings to slow release of accumulated seismic energy. The slow release energy does principally little to moderate damages. Additionally wave form of the earthquake shows low frequency content of P-waves (the maximum P-wave is at 1.19 Hz) and the specific P- wave displacement spectral is characterise with not expressed spectrum plateau and corner frequency. These and other signs suggest us to the conclusion, that the 2012 Mw5.6 earthquake can be considered as types of slow earthquake, like a low frequency quake. The study is based on data from Bulgarian seismological network (NOTSSI), the local network (LSN) deployed around Kozloduy NPP and System of Accelerographs for Seismic Monitoring of Equipment and Structures (SASMES) installed in the Kozloduy NPP. NOTSSI jointly with LSN and SASMES provide reliable information for multiple studies on seismicity in regional scale.

  4. Earthquake Damage to Transportation Systems

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Earthquakes represent one of the most destructive natural hazards known to man. A serious result of large-magnitude earthquakes is the disruption of transportation...

  5. InSAR observations of the 2009 Racha earthquake, Georgia

    Science.gov (United States)

    Nikolaeva, Elena; Walter, Thomas R.

    2016-09-01

    Central Georgia is an area strongly affected by earthquake and landslide hazards. On 29 April 1991 a major earthquake (Mw  =  7.0) struck the Racha region in Georgia, followed by aftershocks and significant afterslip. The same region was hit by another major event (Mw  =  6.0) on 7 September 2009. The aim of the study reported here was to utilize interferometric synthetic aperture radar (InSAR) data to improve knowledge about the spatial pattern of deformation due to the 2009 earthquake. There were no actual earthquake observations by InSAR in Georgia. We considered all available SAR data images from different space agencies. However, due to the long wavelength and the frequent acquisitions, only the multi-temporal ALOS L-band SAR data allowed us to produce interferograms spanning the 2009 earthquake. We detected a local uplift around 10 cm (along the line-of-sight propagation) in the interferogram near the earthquake's epicenter, whereas evidence of surface ruptures could not be found in the field along the active thrust fault. We simulated a deformation signal which could be created by the 2009 Racha earthquake on the basis of local seismic records and by using an elastic dislocation model. We compared our modeled fault surface of the September 2009 with the April 1991 Racha earthquake fault surfaces and identify the same fault or a sub-parallel fault of the same system as the origin. The patch that was active in 2009 is just adjacent to the 1991 patch, indicating a possible mainly westward propagation direction, with important implications for future earthquake hazards.

  6. Earthquake mechanism and seafloor deformation for tsunami generation

    Science.gov (United States)

    Geist, Eric L.; Oglesby, David D.; Beer, Michael; Kougioumtzoglou, Ioannis A.; Patelli, Edoardo; Siu-Kui Au, Ivan

    2014-01-01

    Tsunamis are generated in the ocean by rapidly displacing the entire water column over a significant area. The potential energy resulting from this disturbance is balanced with the kinetic energy of the waves during propagation. Only a handful of submarine geologic phenomena can generate tsunamis: large-magnitude earthquakes, large landslides, and volcanic processes. Asteroid and subaerial landslide impacts can generate tsunami waves from above the water. Earthquakes are by far the most common generator of tsunamis. Generally, earthquakes greater than magnitude (M) 6.5–7 can generate tsunamis if they occur beneath an ocean and if they result in predominantly vertical displacement. One of the greatest uncertainties in both deterministic and probabilistic hazard assessments of tsunamis is computing seafloor deformation for earthquakes of a given magnitude.

  7. Middle school students' earthquake content and preparedness knowledge - A mixed method study

    Science.gov (United States)

    Henson, Harvey, Jr.

    The purpose of this study was to assess the effect of earthquake instruction on students' earthquake content and preparedness for earthquakes. This study used an innovative direct instruction on earthquake science content and concepts with an inquiry-based group activity on earthquake safety followed by an earthquake simulation and preparedness video to help middle school students understand and prepare for the regional seismic threat. A convenience sample of 384 sixth and seventh grade students at two small middle schools in southern Illinois was used in this study. Qualitative information was gathered using open-ended survey questions, classroom observations, and semi-structured interviews. Quantitative data were collected using a 21 item content questionnaire administered to test students' General Earthquake Knowledge, Local Earthquake Knowledge, and Earthquake Preparedness Knowledge before and after instruction. A pre-test and post-test survey Likert scale with 21 items was used to collect students' perceptions and attitudes. Qualitative data analysis included quantification of student responses to the open-ended questions and thematic analysis of observation notes and interview transcripts. Quantitative datasets were analyzed using descriptive and inferential statistical methods, including t tests to evaluate the differences in means scores between paired groups before and after interventions and one-way analysis of variance (ANOVA) to test for differences between mean scores of the comparison groups. Significant mean differences between groups were further examined using a Dunnett's C post hoc statistical analysis. Integration and interpretation of the qualitative and quantitative results of the study revealed a significant increase in general, local and preparedness earthquake knowledge among middle school students after the interventions. The findings specifically indicated that these students felt most aware and prepared for an earthquake after an

  8. Source modeling of the 2015 Mw 7.8 Nepal (Gorkha) earthquake sequence: Implications for geodynamics and earthquake hazards

    Science.gov (United States)

    McNamara, Daniel E.; Yeck, William; Barnhart, William D.; Schulte-Pelkum, V.; Bergman, E.; Adhikari, L. B.; Dixit, Amod; Hough, S.E.; Benz, Harley M.; Earle, Paul

    2017-01-01

    The Gorkha earthquake on April 25th, 2015 was a long anticipated, low-angle thrust-faulting event on the shallow décollement between the India and Eurasia plates. We present a detailed multiple-event hypocenter relocation analysis of the Mw 7.8 Gorkha Nepal earthquake sequence, constrained by local seismic stations, and a geodetic rupture model based on InSAR and GPS data. We integrate these observations to place the Gorkha earthquake sequence into a seismotectonic context and evaluate potential earthquake hazard.Major results from this study include (1) a comprehensive catalog of calibrated hypocenters for the Gorkha earthquake sequence; (2) the Gorkha earthquake ruptured a ~ 150 × 60 km patch of the Main Himalayan Thrust (MHT), the décollement defining the plate boundary at depth, over an area surrounding but predominantly north of the capital city of Kathmandu (3) the distribution of aftershock seismicity surrounds the mainshock maximum slip patch; (4) aftershocks occur at or below the mainshock rupture plane with depths generally increasing to the north beneath the higher Himalaya, possibly outlining a 10–15 km thick subduction channel between the overriding Eurasian and subducting Indian plates; (5) the largest Mw 7.3 aftershock and the highest concentration of aftershocks occurred to the southeast the mainshock rupture, on a segment of the MHT décollement that was positively stressed towards failure; (6) the near surface portion of the MHT south of Kathmandu shows no aftershocks or slip during the mainshock. Results from this study characterize the details of the Gorkha earthquake sequence and provide constraints on where earthquake hazard remains high, and thus where future, damaging earthquakes may occur in this densely populated region. Up-dip segments of the MHT should be considered to be high hazard for future damaging earthquakes.

  9. Source modeling of the 2015 Mw 7.8 Nepal (Gorkha) earthquake sequence: Implications for geodynamics and earthquake hazards

    Science.gov (United States)

    McNamara, D. E.; Yeck, W. L.; Barnhart, W. D.; Schulte-Pelkum, V.; Bergman, E.; Adhikari, L. B.; Dixit, A.; Hough, S. E.; Benz, H. M.; Earle, P. S.

    2017-09-01

    The Gorkha earthquake on April 25th, 2015 was a long anticipated, low-angle thrust-faulting event on the shallow décollement between the India and Eurasia plates. We present a detailed multiple-event hypocenter relocation analysis of the Mw 7.8 Gorkha Nepal earthquake sequence, constrained by local seismic stations, and a geodetic rupture model based on InSAR and GPS data. We integrate these observations to place the Gorkha earthquake sequence into a seismotectonic context and evaluate potential earthquake hazard. Major results from this study include (1) a comprehensive catalog of calibrated hypocenters for the Gorkha earthquake sequence; (2) the Gorkha earthquake ruptured a 150 × 60 km patch of the Main Himalayan Thrust (MHT), the décollement defining the plate boundary at depth, over an area surrounding but predominantly north of the capital city of Kathmandu (3) the distribution of aftershock seismicity surrounds the mainshock maximum slip patch; (4) aftershocks occur at or below the mainshock rupture plane with depths generally increasing to the north beneath the higher Himalaya, possibly outlining a 10-15 km thick subduction channel between the overriding Eurasian and subducting Indian plates; (5) the largest Mw 7.3 aftershock and the highest concentration of aftershocks occurred to the southeast the mainshock rupture, on a segment of the MHT décollement that was positively stressed towards failure; (6) the near surface portion of the MHT south of Kathmandu shows no aftershocks or slip during the mainshock. Results from this study characterize the details of the Gorkha earthquake sequence and provide constraints on where earthquake hazard remains high, and thus where future, damaging earthquakes may occur in this densely populated region. Up-dip segments of the MHT should be considered to be high hazard for future damaging earthquakes.

  10. The Mw 7.7 Bhuj earthquake: Global lessons for earthquake hazard in intra-plate regions

    Science.gov (United States)

    Schweig, E.; Gomberg, J.; Petersen, M.; Ellis, M.; Bodin, P.; Mayrose, L.; Rastogi, B.K.

    2003-01-01

    The Mw 7.7 Bhuj earthquake occurred in the Kachchh District of the State of Gujarat, India on 26 January 2001, and was one of the most damaging intraplate earthquakes ever recorded. This earthquake is in many ways similar to the three great New Madrid earthquakes that occurred in the central United States in 1811-1812, An Indo-US team is studying the similarities and differences of these sequences in order to learn lessons for earthquake hazard in intraplate regions. Herein we present some preliminary conclusions from that study. Both the Kutch and New Madrid regions have rift type geotectonic setting. In both regions the strain rates are of the order of 10-9/yr and attenuation of seismic waves as inferred from observations of intensity and liquefaction are low. These strain rates predict recurrence intervals for Bhuj or New Madrid sized earthquakes of several thousand years or more. In contrast, intervals estimated from paleoseismic studies and from other independent data are significantly shorter, probably hundreds of years. All these observations together may suggest that earthquakes relax high ambient stresses that are locally concentrated by rheologic heterogeneities, rather than loading by plate-tectonic forces. The latter model generally underlies basic assumptions made in earthquake hazard assessment, that the long-term average rate of energy released by earthquakes is determined by the tectonic loading rate, which thus implies an inherent average periodicity of earthquake occurrence. Interpreting the observations in terms of the former model therefore may require re-examining the basic assumptions of hazard assessment.

  11. Organizational changes at Earthquakes & Volcanoes

    Science.gov (United States)

    Gordon, David W.

    1992-01-01

    Primary responsibility for the preparation of Earthquakes & Volcanoes within the Geological Survey has shifted from the Office of Scientific Publications to the Office of Earthquakes, Volcanoes, and Engineering (OEVE). As a consequence of this reorganization, Henry Spall has stepepd down as Science Editor for Earthquakes & Volcanoes(E&V).

  12. Sensing the earthquake

    Science.gov (United States)

    Bichisao, Marta; Stallone, Angela

    2017-04-01

    Making science visual plays a crucial role in the process of building knowledge. In this view, art can considerably facilitate the representation of the scientific content, by offering a different perspective on how a specific problem could be approached. Here we explore the possibility of presenting the earthquake process through visual dance. From a choreographer's point of view, the focus is always on the dynamic relationships between moving objects. The observed spatial patterns (coincidences, repetitions, double and rhythmic configurations) suggest how objects organize themselves in the environment and what are the principles underlying that organization. The identified set of rules is then implemented as a basis for the creation of a complex rhythmic and visual dance system. Recently, scientists have turned seismic waves into sound and animations, introducing the possibility of "feeling" the earthquakes. We try to implement these results into a choreographic model with the aim to convert earthquake sound to a visual dance system, which could return a transmedia representation of the earthquake process. In particular, we focus on a possible method to translate and transfer the metric language of seismic sound and animations into body language. The objective is to involve the audience into a multisensory exploration of the earthquake phenomenon, through the stimulation of the hearing, eyesight and perception of the movements (neuromotor system). In essence, the main goal of this work is to develop a method for a simultaneous visual and auditory representation of a seismic event by means of a structured choreographic model. This artistic representation could provide an original entryway into the physics of earthquakes.

  13. Extension of the Slowness Parameter, Θ, to Distances >80° with Application to the 1947 Hikurangi Tsunami Earthquakes

    Science.gov (United States)

    Saloor, N.; Okal, E.

    2016-12-01

    In order to rapidly determine the slow character of earthquakes, Newman & Okal [1998] introduced the parameter Θ=log10(EE/M0) as a measure of slowness in the earthquake source, where EE is the estimated radiated energy [Boatwright & Choy, 1986]. This method is robust and has been successfully tested on large datasets. However, it uses an analytically derived distance correction, which breaks down at distances D80° due to interaction with reflected and possibly diffracted phases in D''. Yet, in the case of historical earthquakes, the only available short-period stations may be beyond 80°; in particular, this is the case for the two Hikurangi, New Zealand earthquakes of 25 March and 17 May 1947, which generated locally damaging tsunamis, the only available stations being PAS and TUC. In this context, we use a recent event in the same source area, for which Θ can be routinely computed from modern digital data, and develop empirical corrections to match energy values at North American stations (including USArray) at distances D as large as 98°, regressed as Θcorrected=Θ + 0.14659Δ - 12.835 (1) This correction is then applied to records of the 1947 doublet at TUC and PAS, yielding Θ = -5.81 (March 25) and Θ = -6.27 (May 17) respectively, which confirms the events as featuring strong source slowness. This character is also supported by the growth with period of mantle magnitudes obtained from surface waves. This definitely qualifies the two shocks as "tsunami earthquakes"; we recall that they are the only confirmed large interplate thrust events along the Hikurangi segment of the Pacific-Australia plate boundary. This method could be applied in other geometries, but we emphasize that the resulting correction (1) is valid only for identical source-station geometries, since it also reflects a possible focal mechanism effect.

  14. Earthquake history of Virginia

    Science.gov (United States)

    von Hake, C. A.

    1977-01-01

    Virginia is a State of considerable seismic activity, although the earthquakes are rarely strong. Thirty-five shocks, intensity MM V or greater (Modified Mercalli Scale), are listed with epicenters within its borders. The locations of several of the older events are not precise; thus, the above count i subject to alteration. A detailed study of Virginia earthquakes by G. A. Bollinger and M. G. Hopper of the Virginia Polytechnic Institute and State University listed 137 shocks (71 from 1774 to 1899, 66 from 1900 to 1970). Many of these were felt with intensities below MM V. 

  15. Deterministic and Nondeterministic Behavior of Earthquakes and Hazard Mitigation Strategy

    Science.gov (United States)

    Kanamori, H.

    2014-12-01

    Earthquakes exhibit both deterministic and nondeterministic behavior. Deterministic behavior is controlled by length and time scales such as the dimension of seismogenic zones and plate-motion speed. Nondeterministic behavior is controlled by the interaction of many elements, such as asperities, in the system. Some subduction zones have strong deterministic elements which allow forecasts of future seismicity. For example, the forecasts of the 2010 Mw=8.8 Maule, Chile, earthquake and the 2012 Mw=7.6, Costa Rica, earthquake are good examples in which useful forecasts were made within a solid scientific framework using GPS. However, even in these cases, because of the nondeterministic elements uncertainties are difficult to quantify. In some subduction zones, nondeterministic behavior dominates because of complex plate boundary structures and defies useful forecasts. The 2011 Mw=9.0 Tohoku-Oki earthquake may be an example in which the physical framework was reasonably well understood, but complex interactions of asperities and insufficient knowledge about the subduction-zone structures led to the unexpected tragic consequence. Despite these difficulties, broadband seismology, GPS, and rapid data processing-telemetry technology can contribute to effective hazard mitigation through scenario earthquake approach and real-time warning. A scale-independent relation between M0 (seismic moment) and the source duration, t, can be used for the design of average scenario earthquakes. However, outliers caused by the variation of stress drop, radiation efficiency, and aspect ratio of the rupture plane are often the most hazardous and need to be included in scenario earthquakes. The recent development in real-time technology would help seismologists to cope with, and prepare for, devastating tsunamis and earthquakes. Combining a better understanding of earthquake diversity and modern technology is the key to effective and comprehensive hazard mitigation practices.

  16. Implications of fault constitutive properties for earthquake prediction

    Science.gov (United States)

    Dieterich, J.H.; Kilgore, B.

    1996-01-01

    The rate- and state-dependent constitutive formulation for fault slip characterizes an exceptional variety of materials over a wide range of sliding conditions. This formulation provides a unified representation of diverse sliding phenomena including slip weakening over a characteristic sliding distance D(c), apparent fracture energy at a rupture front, time- dependent healing after rapid slip, and various other transient and slip rate effects. Laboratory observations and theoretical models both indicate that earthquake nucleation is accompanied by long intervals of accelerating slip. Strains from the nucleation process on buried faults generally could not be detected if laboratory values of D, apply to faults in nature. However, scaling of D(c) is presently an open question and the possibility exists that measurable premonitory creep may precede some earthquakes. Earthquake activity is modeled as a sequence of earthquake nucleation events. In this model, earthquake clustering arises from sensitivity of nucleation times to the stress changes induced by prior earthquakes. The model gives the characteristic Omori aftershock decay law and assigns physical interpretation to aftershock parameters. The seismicity formulation predicts large changes of earthquake probabilities result from stress changes. Two mechanisms for foreshocks are proposed that describe observed frequency of occurrence of foreshock-mainshock pairs by time and magnitude. With the first mechanism, foreshocks represent a manifestation of earthquake clustering in which the stress change at the time of the foreshock increases the probability of earthquakes at all magnitudes including the eventual mainshock. With the second model, accelerating fault slip on the mainshock nucleation zone triggers foreshocks.

  17. Earthquake scenarios based on lessons from the past

    Science.gov (United States)

    Solakov, Dimcho; Simeonova, Stella; Aleksandrova, Irena; Popova, Iliana

    2010-05-01

    scenarios was guided by the perception that usable and realistic (also in the sense of being compatible with seismic histories of cities that are several centuries long) ground motion maps had to be produced for urban areas. By deterministic scenario it is mean a representation of the severity of ground shaking over an urban area, using one or more hazard descriptors. Such representation can be obtained: - either from the assumption of a "reference earthquake" specified by a magnitude or an epicentral intensity, associated to a particular earthquake source - or, directly, showing values of local macroseimic intensity generated by a damaging, real earthquakes of the past. In the study we chose for the second method using the values of macroseimic intensity caused by damaging historical earthquakes (the 1928 quakes in southern Bulgaria; the 1940 and the 1977 Vrancea intermediate earthquakes) - lessons from the past. Such scenarios are intended as a basic input for developing detailed earthquake damage scenarios for the cities and can be used in earthquake-safe town and infrastructure planning.

  18. Thermal Radiation Anomalies Associated with Major Earthquakes

    Science.gov (United States)

    Ouzounov, Dimitar; Pulinets, Sergey; Kafatos, Menas C.; Taylor, Patrick

    2017-01-01

    Recent developments of remote sensing methods for Earth satellite data analysis contribute to our understanding of earthquake related thermal anomalies. It was realized that the thermal heat fluxes over areas of earthquake preparation is a result of air ionization by radon (and other gases) and consequent water vapor condensation on newly formed ions. Latent heat (LH) is released as a result of this process and leads to the formation of local thermal radiation anomalies (TRA) known as OLR (outgoing Longwave radiation, Ouzounov et al, 2007). We compare the LH energy, obtained by integrating surface latent heat flux (SLHF) over the area and time with released energies associated with these events. Extended studies of the TRA using the data from the most recent major earthquakes allowed establishing the main morphological features. It was also established that the TRA are the part of more complex chain of the short-term pre-earthquake generation, which is explained within the framework of a lithosphere-atmosphere coupling processes.

  19. Compiling an earthquake catalogue for the Arabian Plate, Western Asia

    Science.gov (United States)

    Deif, Ahmed; Al-Shijbi, Yousuf; El-Hussain, Issa; Ezzelarab, Mohamed; Mohamed, Adel M. E.

    2017-10-01

    The Arabian Plate is surrounded by regions of relatively high seismicity. Accounting for this seismicity is of great importance for seismic hazard and risk assessments, seismic zoning, and land use. In this study, a homogenous earthquake catalogue of moment-magnitude (Mw) for the Arabian Plate is provided. The comprehensive and homogenous earthquake catalogue provided in the current study spatially involves the entire Arabian Peninsula and neighboring areas, covering all earthquake sources that can generate substantial hazard for the Arabian Plate mainland. The catalogue extends in time from 19 to 2015 with a total number of 13,156 events, of which 497 are historical events. Four polygons covering the entire Arabian Plate were delineated and different data sources including special studies, local, regional and international catalogues were used to prepare the earthquake catalogue. Moment magnitudes (Mw) that provided by original sources were given the highest magnitude type priority and introduced to the catalogues with their references. Earthquakes with magnitude differ from Mw were converted into this scale applying empirical relationships derived in the current or in previous studies. The four polygons catalogues were included in two comprehensive earthquake catalogues constituting the historical and instrumental periods. Duplicate events were identified and discarded from the current catalogue. The present earthquake catalogue was declustered in order to contain only independent events and investigated for the completeness with time of different magnitude spans.

  20. Regional changes in streamflow after a megathrust earthquake

    Science.gov (United States)

    Mohr, Christian H.; Manga, Michael; Wang, Chi-Yuen; Korup, Oliver

    2017-01-01

    Moderate to large earthquakes can increase the amount of water feeding stream flows, mobilizing excess water from deep groundwater, shallow groundwater, or the vadose zone. Here we examine the regional pattern of streamflow response to the Maule M8.8 earthquake across Chile's diverse topographic and hydro-climatic gradients. We combine streamflow analyses with groundwater flow modeling and a random forest classifier, and find that, after the earthquake, at least 85 streams had a change in flow. Discharge mostly increased (n = 78) shortly after the earthquake, liberating an excess water volume of >1.1 km3, which is the largest ever reported following an earthquake. Several catchments had increased discharge of >50 mm, locally exceeding seasonal streamflow discharge under undisturbed conditions. Our modeling results favor enhanced vertical permeability induced by dynamic strain as the most probable process explaining the observed changes at the regional scale. Supporting this interpretation, our random forest classification identifies peak ground velocity and elevation extremes as most important for predicting streamflow response. Given the mean recurrence interval of ∼25 yr for >M8.0 earthquakes along the Peru-Chile Trench, our observations highlight the role of earthquakes in the regional water cycle, especially in arid environments.

  1. Landslides and Earthquake Lakes from the Wenchuan, China Earthquake - Can it Happen in the U.S.?

    Science.gov (United States)

    Stenner, H.; Cydzik, K.; Hamilton, D.; Cattarossi, A.; Mathieson, E.

    2008-12-01

    The May 12, 2008 M7.9 Wenchuan, China earthquake destroyed five million homes and schools, causing over 87,650 deaths. Landslides, a secondary effect of the shaking, caused much of the devastation. Debris flows buried homes, rock falls crushed cars, and landslides dammed rivers. Blocked roads greatly impeded emergency access, delaying response. Our August 2008 field experience in the affected area reminded us that the western United States faces serious risks posed by earthquake-induced landslides. The topography of the western U.S. is less extreme than that near Wenchuan, but earthquakes may still cause devastating landslides, damming rivers and blocking access to affected areas. After the Wenchuan earthquake, lakes rapidly rose behind landslide dams, threatening millions of lives. One landslide above Beichuan City created Tangjiashan Lake, a massive body of water upstream of Mianyang, an area with 5.2 million people, 30,000 of whom were killed in the quake. Potential failure of the landslide dam put thousands more people at risk from catastrophic flooding. In 1959, the M7.4 Hebgen Lake earthquake in Montana caused a large landslide, which killed 19 people and dammed the Madison River. The Army Corps excavated sluices to keep the dam from failing catastrophically. The Hebgen Lake earthquake ultimately caused 28 deaths, mostly from landslides, but the affected region was sparsely populated. Slopes prone to strong earthquake shaking and landslides in California, Washington, and Oregon have much larger populations at risk. Landslide hazards continue after the earthquake due to the effect strong shaking has on hillslopes, particularly when subjected to subsequent rain. These hazards must be taken into account. Once a landslide blocks a river, rapid and thoughtful action is needed. The Chinese government quickly and safely mitigated landslide dams that posed the greatest risk to people downstream. It took expert geotechnical advice, the speed and resources of the army

  2. Postseismic Deformation Following the 2010 El Mayor-Cucapah Earthquake: Observations, Kinematic Inversions, and Dynamic Models

    Science.gov (United States)

    Rollins, Christopher; Barbot, Sylvain; Avouac, Jean-Philippe

    2015-05-01

    Due to its location on a transtensional section of the Pacific-North American plate boundary, the Salton Trough is a region featuring large strike-slip earthquakes within a regime of shallow asthenosphere, high heat flow, and complex faulting, and so postseismic deformation there may feature enhanced viscoelastic relaxation and afterslip that is particularly detectable at the surface. The 2010 El Mayor-Cucapah earthquake was the largest shock in the Salton Trough since 1892 and occurred close to the US-Mexico border, and so the postseismic deformation recorded by the continuous GPS network of southern California provides an opportunity to study the rheology of this region. Three-year postseismic transients extracted from GPS displacement time-series show four key features: (1) 1-2 cm of cumulative uplift in the Imperial Valley and 1 cm of subsidence in the Peninsular Ranges, (2) relatively large cumulative horizontal displacements 150 km from the rupture in the Peninsular Ranges, (3) rapidly decaying horizontal displacement rates in the first few months after the earthquake in the Imperial Valley, and (4) sustained horizontal velocities, following the rapid early motions, that were still visibly ongoing 3 years after the earthquake. Kinematic inversions show that the cumulative 3-year postseismic displacement field can be well fit by afterslip on and below the coseismic rupture, though these solutions require afterslip with a total moment equivalent to at least a earthquake and higher slip magnitudes than those predicted by coseismic stress changes. Forward modeling shows that stress-driven afterslip and viscoelastic relaxation in various configurations within the lithosphere can reproduce the early and later horizontal velocities in the Imperial Valley, while Newtonian viscoelastic relaxation in the asthenosphere can reproduce the uplift in the Imperial Valley and the subsidence and large westward displacements in the Peninsular Ranges. We present two forward

  3. Rapid Arc, helical tomotherapy, sliding window intensity modulated radiotherapy and three dimensional conformal radiation for localized prostate cancer: A dosimetric comparison

    Directory of Open Access Journals (Sweden)

    Rajesh A Kinhikar

    2014-01-01

    Full Text Available Objective: The objective of this study was to investigate the potential role of RapidArc (RA compared with helical tomotherapy (HT, sliding window intensity modulated radiotherapy (SW IMRT and three-dimensional conformal radiation therapy (3D CRT for localized prostate cancer. Materials and Methods: Prescription doses ranged from 60 Gy to planning target volume (PTV and 66.25 Gy for clinical target volume prostate (CTV-P over 25-30 fractions. PTV and CTV-P coverage were evaluated by conformity index (CI and homogeneity index (HI. Organ sparing comparison was done with mean doses to rectum and bladder. Results: CI 95 were 1.0 ± 0.01 (RA, 0.99 ± 0.01 (HT, 0.97 ± 0.02 (IMRT, 0.98 ± 0.02 (3D CRT for PTV and 1.0 ± 0.00 (RA, HT, SW IMRT and 3D CRT for CTV-P. HI was 0.11 ± 0.03 (RA, 0.16 ± 0.08 (HT, 0.12 ± 0.03 (IMRT, 0.06 ± 0.01 (3D CRT for PTV and 0.03 ± 0.00 (RA, 0.05 ± 0.01 (HT, 0.03 ± 0.01 (SW IMRT and 3D CRT for CTV-P. Mean dose to bladder were 23.68 ± 13.23 Gy (RA, 24.55 ± 12.51 Gy (HT, 19.82 ± 11.61 Gy (IMRT and 23.56 ± 12.81 Gy (3D CRT, whereas mean dose to rectum was 36.85 ± 12.92 Gy (RA, 33.18 ± 11.12 Gy (HT, IMRT and 38.67 ± 12.84 Gy (3D CRT. Conclusion: All studied intensity-modulated techniques yield treatment plans of significantly improved quality when compared with 3D CRT, with HT providing best organs at risk sparing and RA being the most efficient treatment option, reducing treatment time to 1.45-3.7 min and monitor unit to <400 for a 2 Gy fraction.

  4. Earthquake simulations with time-dependent nucleation and long-range interactions

    Directory of Open Access Journals (Sweden)

    J. H. Dieterich

    1995-01-01

    Full Text Available A model for rapid simulation of earthquake sequences is introduced which incorporates long-range elastic interactions among fault elements and time-dependent earthquake nucleation inferred from experimentally derived rate- and state-dependent fault constitutive properties. The model consists of a planar two-dimensional fault surface which is periodic in both the x- and y-directions. Elastic interactions among fault elements are represented by an array of elastic dislocations. Approximate solutions for earthquake nucleation and dynamics of earthquake slip are introduced which permit computations to proceed in steps that are determined by the transitions from one sliding state to the next. The transition-driven time stepping and avoidance of systems of simultaneous equations permit rapid simulation of large sequences of earthquake events on computers of modest capacity, while preserving characteristics of the nucleation and rupture propagation processes evident in more detailed models. Earthquakes simulated with this model reproduce many of the observed spatial and temporal characteristics of clustering phenomena including foreshock and aftershock sequences. Clustering arises because the time dependence of the nucleation process is highly sensitive to stress perturbations caused by nearby earthquakes. Rate of earthquake activity following a prior earthquake decays according to Omori's aftershock decay law and falls off with distance.

  5. Engineering geological aspect of Gorkha Earthquake 2015, Nepal

    Science.gov (United States)

    Adhikari, Basanta Raj; Andermann, Christoff; Cook, Kristen

    2016-04-01

    Strong shaking by earthquake causes massif landsliding with severe effects on infrastructure and human lives. The distribution of landslides and other hazards are depending on the combination of earthquake and local characteristics which influence the dynamic response of hillslopes. The Himalayas are one of the most active mountain belts with several kilometers of relief and is very prone to catastrophic mass failure. Strong and shallow earthquakes are very common and cause wide spread collapse of hillslopes, increasing the background landslide rate by several magnitude. The Himalaya is facing many small and large earthquakes in the past i.e. earthquakes i.e. Bihar-Nepal earthquake 1934 (Ms 8.2); Large Kangra earthquake of 1905 (Ms 7.8); Gorkha earthquake 2015 (Mw 7.8). The Mw 7.9 Gorkha earthquake has occurred on and around the main Himalayan Thrust with a hypocentral depth of 15 km (GEER 2015) followed by Mw 7.3 aftershock in Kodari causing 8700+ deaths and leaving hundreds of thousands of homeless. Most of the 3000 aftershocks located by National Seismological Center (NSC) within the first 45 days following the Gorkha Earthquake are concentrated in a narrow 40 km-wide band at midcrustal to shallow depth along the strike of the southern slope of the high Himalaya (Adhikari et al. 2015) and the ground shaking was substantially lower in the short-period range than would be expected for and earthquake of this magnitude (Moss et al. 2015). The effect of this earthquake is very unique in affected areas by showing topographic effect, liquefaction and land subsidence. More than 5000 landslides were triggered by this earthquake (Earthquake without Frontiers, 2015). Most of the landslides are shallow and occurred in weathered bedrock and appear to have mobilized primarily as raveling failures, rock slides and rock falls. Majority of landslides are limited to a zone which runs east-west, approximately parallel the lesser and higher Himalaya. There are numerous cracks in

  6. Toward a comprehensive areal model of earthquake-induced landslides

    Science.gov (United States)

    Miles, S.B.; Keefer, D.K.

    2009-01-01

    This paper provides a review of regional-scale modeling of earthquake-induced landslide hazard with respect to the needs for disaster risk reduction and sustainable development. Based on this review, it sets out important research themes and suggests computing with words (CW), a methodology that includes fuzzy logic systems, as a fruitful modeling methodology for addressing many of these research themes. A range of research, reviewed here, has been conducted applying CW to various aspects of earthquake-induced landslide hazard zonation, but none facilitate comprehensive modeling of all types of earthquake-induced landslides. A new comprehensive areal model of earthquake-induced landslides (CAMEL) is introduced here that was developed using fuzzy logic systems. CAMEL provides an integrated framework for modeling all types of earthquake-induced landslides using geographic information systems. CAMEL is designed to facilitate quantitative and qualitative representation of terrain conditions and knowledge about these conditions on the likely areal concentration of each landslide type. CAMEL is highly modifiable and adaptable; new knowledge can be easily added, while existing knowledge can be changed to better match local knowledge and conditions. As such, CAMEL should not be viewed as a complete alternative to other earthquake-induced landslide models. CAMEL provides an open framework for incorporating other models, such as Newmark's displacement method, together with previously incompatible empirical and local knowledge. ?? 2009 ASCE.

  7. Earthquakes in India and the Himalaya: tectonics, geodesy and history

    Directory of Open Access Journals (Sweden)

    R. Bilham

    2004-06-01

    Full Text Available The record of earthquakes in India is patchy prior to 1800 and its improvement is much impeded by its dispersal in a dozen local languages, and several colonial archives. Although geological studies will necessarily complement the historical record, only two earthquakes of the dozens of known historical events have resulted in surface ruptures, and it is likely that geological data in the form of liquefaction features will be needed to extend the historical record beyond the most recent few centuries. Damage from large Himalayan earthquakes recorded in Tibet and in Northern India suggests that earthquakes may attain M = 8.2. Seismic gaps along two-thirds of the Himalaya that have developed in the past five centuries, when combined with geodetic convergence rates of approximately 1.8 m/cy, suggests that one or more M = 8 earthquakes may be overdue. The mechanisms of recent earthquakes in Peninsular India are consistent with stresses induced in the Indian plate flexed by its collision with Tibet. A region of abnormally high seismicity in western India appears to be caused by local convergence across the Rann of Kachchh and possibly other rift zones of India. Since the plate itself deforms little, this deformation may be related to incipient plate fragmentation in Sindh or over a larger region of NW India.

  8. Global risk of big earthquakes has not recently increased.

    Science.gov (United States)

    Shearer, Peter M; Stark, Philip B

    2012-01-17

    The recent elevated rate of large earthquakes has fueled concern that the underlying global rate of earthquake activity has increased, which would have important implications for assessments of seismic hazard and our understanding of how faults interact. We examine the timing of large (magnitude M≥7) earthquakes from 1900 to the present, after removing local clustering related to aftershocks. The global rate of M≥8 earthquakes has been at a record high roughly since 2004, but rates have been almost as high before, and the rate of smaller earthquakes is close to its historical average. Some features of the global catalog are improbable in retrospect, but so are some features of most random sequences--if the features are selected after looking at the data. For a variety of magnitude cutoffs and three statistical tests, the global catalog, with local clusters removed, is not distinguishable from a homogeneous Poisson process. Moreover, no plausible physical mechanism predicts real changes in the underlying global rate of large events. Together these facts suggest that the global risk of large earthquakes is no higher today than it has been in the past.

  9. Rupture Velocities of Intermediate- and Deep-Focus Earthquakes

    Science.gov (United States)

    Warren, L. M.

    2014-12-01

    The rupture velocities of intermediate- and deep-focus earthquakes --- how they vary between subduction zones, how they vary with depth, and what their maximum values are --- may help constrain the mechanism(s) of the earthquakes. As part of a global study of intermediate- and deep-focus earthquakes, I have used rupture directivity to estimate the rupture vector (speed and orientation) for 422 earthquakes >70 km depth with MW ≥5.7 since 1990. I estimate the rupture velocity relative to the local P-wave velocity (vr/α). Since the same method is used for all earthquakes, the results can be readily compared across study areas. The study areas --- Middle America, South America, Tonga-Kermadec, Izu-Bonin-Marianas, and Japan-Kurils-Kamchatka --- include some of the warmest and coldest subduction zones: subducting plate ages range from 9-150 Myr and descent rates range from 1-13 cm/yr. Across all subduction zones and depth ranges, for the 193 earthquakes with observable directivity and well-constrained rupture vectors, most earthquakes rupture on the more horizontal of the two possible nodal planes. However, the rupture vectors appear to be randomly-oriented relative to the slip vector, so the earthquakes span the continuum from Mode II (i.e., parallel slip and rupture vectors) to Mode III rupture (i.e., perpendicular slip and rupture vectors). For this earthquake population, the mean rupture velocity is 0.43 vr/α ± 0.14 vr/α. The mean earthquake rupture velocities are similar between all subduction zones. Since the local seismic wavespeed is faster in colder subduction zones, absolute rupture velocities are faster in colder subduction zones. Overall, the fastest rupture velocities exceed the local S-wave speed. The supershear ruptures are associated with earthquakes closer to Mode II than Mode III faulting. This is consistent with theoretical calculations, which limit the rupture velocity to the S-wave speed for Mode III rupture but the P-wave speed for Mode II

  10. Indigenous people's detection of rapid ecological change.

    Science.gov (United States)

    Aswani, Shankar; Lauer, Matthew

    2014-06-01

    When sudden catastrophic events occur, it becomes critical for coastal communities to detect and respond to environmental transformations because failure to do so may undermine overall ecosystem resilience and threaten people's livelihoods. We therefore asked how capable of detecting rapid ecological change following massive environmental disruptions local, indigenous people are. We assessed the direction and periodicity of experimental learning of people in the Western Solomon Islands after a tsunami in 2007. We compared the results of marine science surveys with local ecological knowledge of the benthos across 3 affected villages and 3 periods before and after the tsunami. We sought to determine how people recognize biophysical changes in the environment before and after catastrophic events such as earthquakes and tsunamis and whether people have the ability to detect ecological changes over short time scales or need longer time scales to recognize changes. Indigenous people were able to detect changes in the benthos over time. Detection levels differed between marine science surveys and local ecological knowledge sources over time, but overall patterns of statistically significant detection of change were evident for various habitats. Our findings have implications for marine conservation, coastal management policies, and disaster-relief efforts because when people are able to detect ecological changes, this, in turn, affects how they exploit and manage their marine resources. © 2014 Society for Conservation Biology.

  11. The Global Earthquake Model - Past, Present, Future

    Science.gov (United States)

    Smolka, Anselm; Schneider, John; Stein, Ross

    2014-05-01

    Source Models • Ground Motion (Attenuation) Models • Physical Exposure Models • Physical Vulnerability Models • Composite Index Models (social vulnerability, resilience, indirect loss) • Repository of national hazard models • Uniform global hazard model Armed with these tools and databases, stakeholders worldwide will then be able to calculate, visualise and investigate earthquake risk, capture new data and to share their findings for joint learning. Earthquake hazard information will be able to be combined with data on exposure (buildings, population) and data on their vulnerability, for risk assessment around the globe. Furthermore, for a truly integrated view of seismic risk, users will be able to add social vulnerability and resilience indices and estimate the costs and benefits of different risk management measures. Having finished its first five-year Work Program at the end of 2013, GEM has entered into its second five-year Work Program 2014-2018. Beyond maintaining and enhancing the products developed in Work Program 1, the second phase will have a stronger focus on regional hazard and risk activities, and on seeing GEM products used for risk assessment and risk management practice at regional, national and local scales. Furthermore GEM intends to partner with similar initiatives underway for other natural perils, which together are needed to meet the need for advanced risk assessment methods, tools and data to underpin global disaster risk reduction efforts under the Hyogo Framework for Action #2 to be launched in Sendai/Japan in spring 2015

  12. Gravitational body forces focus North American intraplate earthquakes

    Science.gov (United States)

    Levandowski, William Brower; Zellman, Mark; Briggs, Richard

    2017-01-01

    Earthquakes far from tectonic plate boundaries generally exploit ancient faults, but not all intraplate faults are equally active. The North American Great Plains exemplify such intraplate earthquake localization, with both natural and induced seismicity generally clustered in discrete zones. Here we use seismic velocity, gravity and topography to generate a 3D lithospheric density model of the region; subsequent finite-element modelling shows that seismicity focuses in regions of high-gravity-derived deviatoric stress. Furthermore, predicted principal stress directions generally align with those observed independently in earthquake moment tensors and borehole breakouts. Body forces therefore appear to control the state of stress and thus the location and style of intraplate earthquakes in the central United States with no influence from mantle convection or crustal weakness necessary. These results show that mapping where gravitational body forces encourage seismicity is crucial to understanding and appraising intraplate seismic hazard.

  13. Preliminary quantitative assessment of earthquake casualties and damages

    DEFF Research Database (Denmark)

    Badal, J.; Vázquez-Prada, M.; González, Á.

    2005-01-01

    Prognostic estimations of the expected number of killed or injured people and about the approximate cost associated with the damages caused by earthquakes are made following a suitable methodology of wide-ranging application. For the preliminary assessment of human life losses due to the occurrence...... of a relatively strong earthquake we use a quantitative model consisting of a correlation between the number of casualties and the earthquake magnitude as a function of population density. The macroseismic intensity field is determined in accordance with an updated anelastic attenuation law, and the number...... the local social wealth as a function of the gross domestic product of the country. This last step is performed on the basis of the relationship of the macroseismic intensity to the earthquake economic loss in percentage of the wealth. Such an approach to the human casualty and damage levels is carried out...

  14. a Real-Time Earthquake Moment Tensor Scanning Code for the Antelope System (brtt, Inc)

    Science.gov (United States)

    Macpherson, K. A.; Ruppert, N. A.; Freymueller, J. T.; Lindquist, K.; Harvey, D.; Dreger, D. S.; Lombard, P. N.; Guilhem, A.

    2015-12-01

    While all seismic observatories routinely determine hypocentral location and local magnitude within a few minutes of an earthquake's occurrence, the ability to estimate seismic moment and sense of slip in a similar time frame is less widespread. This is unfortunate, because moment and mechanism are critical parameters for rapid hazard assessment; for larger events, moment magnitude is more reliable due to the tendency of local magnitude to saturate, and certain mechanisms such as off-shore thrust events might indicate earthquakes with tsunamigenic potential. In order to increase access to this capability, we have developed a continuous moment tensor scanning code for Antelope, the ubiquitous open-architecture seismic acquisition and processing software in use around the world. The scanning code, which uses an algorithm that has previously been employed for real-time monitoring at the University of California, Berkeley, is able to produce full moment tensor solutions for moderate events from regional seismic data. The algorithm monitors a grid of potential sources by continuously cross-correlating pre-computed synthetic seismograms with long-period recordings from a sparse network of broad-band stations. The code package consists of 3 modules. One module is used to create a monitoring grid by constructing source-receiver geometry, calling a frequency-wavenumber code to produce synthetics, and computing the generalized linear inverse of the array of synthetics. There is a real-time scanning module that correlates streaming data with pre-inverted synthetics, monitors the variance reduction, and writes the moment tensor solution to a database if an earthquake detection occurs. Finally, there is an 'off-line' module that is very similar to the real-time scanner, with the exception that it utilizes pre-recorded data stored in Antelope databases and is useful for testing purposes or for quickly producing moment tensor catalogs for long time series. The code is open source

  15. The HayWired earthquake scenario—Earthquake hazards

    Science.gov (United States)

    Detweiler, Shane T.; Wein, Anne M.

    2017-01-01

    The HayWired scenario is a hypothetical earthquake sequence that is being used to better understand hazards for the San Francisco Bay region during and after an earthquake of magnitude 7 on the Hayward Fault. The 2014 Working Group on California Earthquake Probabilities calculated that there is a 33-percent likelihood of a large (magnitude 6.7 or greater) earthquake occurring on the Hayward Fault within three decades. A large Hayward Fault earthquake will produce strong ground shaking, permanent displacement of the Earth’s surface, landslides, liquefaction (soils becoming liquid-like during shaking), and subsequent fault slip, known as afterslip, and earthquakes, known as aftershocks. The most recent large earthquake on the Hayward Fault occurred on October 21, 1868, and it ruptured the southern part of the fault. The 1868 magnitude-6.8 earthquake occurred when the San Francisco Bay region had far fewer people, buildings, and infrastructure (roads, communication lines, and utilities) than it does today, yet the strong ground shaking from the earthquake still caused significant building damage and loss of life. The next large Hayward Fault earthquake is anticipated to affect thousands of structures and disrupt the lives of millions of people. Earthquake risk in the San Francisco Bay region has been greatly reduced as a result of previous concerted efforts; for example, tens of billions of dollars of investment in strengthening infrastructure was motivated in large part by the 1989 magnitude 6.9 Loma Prieta earthquake. To build on efforts to reduce earthquake risk in the San Francisco Bay region, the HayWired earthquake scenario comprehensively examines the earthquake hazards to help provide the crucial scientific information that the San Francisco Bay region can use to prepare for the next large earthquake, The HayWired Earthquake Scenario—Earthquake Hazards volume describes the strong ground shaking modeled in the scenario and the hazardous movements of

  16. Dynamic strains for earthquake source characterization

    Science.gov (United States)

    Barbour, Andrew J.; Crowell, Brendan W

    2017-01-01

    Strainmeters measure elastodynamic deformation associated with earthquakes over a broad frequency band, with detection characteristics that complement traditional instrumentation, but they are commonly used to study slow transient deformation along active faults and at subduction zones, for example. Here, we analyze dynamic strains at Plate Boundary Observatory (PBO) borehole strainmeters (BSM) associated with 146 local and regional earthquakes from 2004–2014, with magnitudes from M 4.5 to 7.2. We find that peak values in seismic strain can be predicted from a general regression against distance and magnitude, with improvements in accuracy gained by accounting for biases associated with site–station effects and source–path effects, the latter exhibiting the strongest influence on the regression coefficients. To account for the influence of these biases in a general way, we include crustal‐type classifications from the CRUST1.0 global velocity model, which demonstrates that high‐frequency strain data from the PBO BSM network carry information on crustal structure and fault mechanics: earthquakes nucleating offshore on the Blanco fracture zone, for example, generate consistently lower dynamic strains than earthquakes around the Sierra Nevada microplate and in the Salton trough. Finally, we test our dynamic strain prediction equations on the 2011 M 9 Tohoku‐Oki earthquake, specifically continuous strain records derived from triangulation of 137 high‐rate Global Navigation Satellite System Earth Observation Network stations in Japan. Moment magnitudes inferred from these data and the strain model are in agreement when Global Positioning System subnetworks are unaffected by spatial aliasing.

  17. Mass wasting triggered by the 5 March 1987 Ecuador earthquakes

    Science.gov (United States)

    Schuster, R.L.; Nieto, A.S.; O'Rourke, T. D.; Crespo, E.; Plaza-Nieto, G.

    1996-01-01

    On 5 March 1987, two earthquakes (Ms=6.1 and Ms=6.9) occurred about 25 km north of Reventador Volcano, along the eastern slopes of the Andes Mountains in northeastern Ecuador. Although the shaking damaged structures in towns and villages near the epicentral area, the economic and social losses directly due to earthquake shaking were small compared to the effects of catastrophic earthquake-triggered mass wasting and flooding. About 600 mm of rain fell in the region in the month preceding the earthquakes; thus, the surficial soils had high moisture contents. Slope failures commonly started as thin slides, which rapidly turned into fluid debris avalanches and debris flows. The surficial soils and thick vegetation covering them flowed down the slopes into minor tributaries and then were carried into major rivers. Rock and earth slides, debris avalanches, debris and mud flows, and resulting floods destroyed about 40 km of the Trans-Ecuadorian oil pipeline and the only highway from Quito to Ecuador's northeastern rain forests and oil fields. Estimates of total volume of earthquake-induced mass wastage ranged from 75-110 million m3. Economic losses were about US$ 1 billion. Nearly all of the approximately 1000 deaths from the earthquakes were a consequence of mass wasting and/ or flooding.

  18. Christchurch earthquakes: how did former refugees cope?

    Science.gov (United States)

    Osman, Mohamud; Hornblow, Andrew; Macleod, Sandy; Coope, Pat

    2012-06-29

    This study investigated how former refugees now living in Christchurch (Canterbury Province, New Zealand) communities coped after the 4 September 2010 and subsequent earthquakes. A systematic sample of one in three former refugees from five ethnic groupings (Afghanistan, Kurdistan, Ethiopia, Somalia and Bhutan) was selected from a list of 317 refugees provided by the Canterbury Refugee Council and invited to participate in the study. Seventy-two out of 105 potential participants completed a 26 item questionnaire regarding the impact of the quakes, their concerns and anxieties, coping strategies and social supports. The methodology was complicated by ongoing aftershocks, particularly that of 22 February 2011. Three-quarters of participants reported that they had coped well, spirituality and religious practice being an important support for many, despite less then 20% receiving support from mainstream agencies. Most participants (72%) had not experienced a traumatic event or natural disaster before. Older participants and married couples with children were more likely to worry about the earthquakes and their impact than single individuals. There was a significant difference in the level of anxiety between males and females. Those who completed the questionnaire after the 22 February 2011 quake were more worried overall than those interviewed before this. Overall, the former refugees reported they had coped well despite most of them not experiencing an earthquake before and few receiving support from statutory relief agencies. More engagement from local services is needed in order to build trust and cooperation between the refugee and local communities.

  19. Izmit (Kocaeli) Turkey Earthquake, August 17 1999, Set 2, Structural Damage

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — On August 17, 1999, at 3:01 A.M. local time (00:01:39.8 UTC) a magnitude (Mw) 7.4 earthquake occurred along the westernmost North Anatolian fault. The earthquake...

  20. The Alaska earthquake, March 27, 1964: lessons and conclusions

    Science.gov (United States)

    Eckel, Edwin B.

    1970-01-01

    One of the greatest earthquakes of all time struck south-central Alaska on March 27, 1964. Strong motion lasted longer than for most recorded earthquakes, and more land surface was dislocated, vertically and horizontally, than by any known previous temblor. Never before were so many effects on earth processes and on the works of man available for study by scientists and engineers over so great an area. The seismic vibrations, which directly or indirectly caused most of the damage, were but surface manifestations of a great geologic event-the dislocation of a huge segment of the crust along a deeply buried fault whose nature and even exact location are still subjects for speculation. Not only was the land surface tilted by the great tectonic event beneath it, with resultant seismic sea waves that traversed the entire Pacific, but an enormous mass of land and sea floor moved several tens of feet horizontally toward the Gulf of Alaska. Downslope mass movements of rock, earth, and snow were initiated. Subaqueous slides along lake shores and seacoasts, near-horizontal movements of mobilized soil (“landspreading”), and giant translatory slides in sensitive clay did the most damage and provided the most new knowledge as to the origin, mechanics, and possible means of control or avoidance of such movements. The slopes of most of the deltas that slid in 1964, and that produced destructive local waves, are still as steep or steeper than they were before the earthquake and hence would be unstable or metastable in the event of another great earthquake. Rockslide avalanches provided new evidence that such masses may travel on cushions of compressed air, but a widely held theory that glaciers surge after an earthquake has not been substantiated. Innumerable ground fissures, many of them marked by copious emissions of water, caused much damage in towns and along transportation routes. Vibration also consolidated loose granular materials. In some coastal areas, local

  1. Rapid scenarios and observed intensities

    OpenAIRE

    Franco Pettenati; Livio Sirovich

    2012-01-01

    After a destructive earthquake, national Governments need to know the approximate amount of damage, the number of casualties, and the financial losses as soon as possible. Rapid scenarios are also used to inform the general public; see the widely used Shakemap package [Wald et al. 1999, 2006] of the US Geological Survey (USGS) and the one modified by the Istituto Nazionale di Geofisica e Vulcanologia (INGV; National Institute of Geophysics and Volcanology), which is reproduced for Figure 1. T...

  2. Historical earthquake research in Austria

    Science.gov (United States)

    Hammerl, Christa

    2017-12-01

    Austria has a moderate seismicity, and on average the population feels 40 earthquakes per year or approximately three earthquakes per month. A severe earthquake with light building damage is expected roughly every 2 to 3 years in Austria. Severe damage to buildings ( I 0 > 8° EMS) occurs significantly less frequently, the average period of recurrence is about 75 years. For this reason the historical earthquake research has been of special importance in Austria. The interest in historical earthquakes in the past in the Austro-Hungarian Empire is outlined, beginning with an initiative of the Austrian Academy of Sciences and the development of historical earthquake research as an independent research field after the 1978 "Zwentendorf plebiscite" on whether the nuclear power plant will start up. The applied methods are introduced briefly along with the most important studies and last but not least as an example of a recently carried out case study, one of the strongest past earthquakes in Austria, the earthquake of 17 July 1670, is presented. The research into historical earthquakes in Austria concentrates on seismic events of the pre-instrumental period. The investigations are not only of historical interest, but also contribute to the completeness and correctness of the Austrian earthquake catalogue, which is the basis for seismic hazard analysis and as such benefits the public, communities, civil engineers, architects, civil protection, and many others.

  3. Seismologic study of Los Humeros geothermal field, Puebla, Mexico. Part II: Seismic tomography by attenuation of coda waves (Qc-1) of local earthquakes; Estudio sismologico del campo geotermico de Los Humeros, Puebla, Mexico. Parte II: Tomografia sismica por atenuacion a partir de ondas de coda (Qc-1) de sismos locales

    Energy Technology Data Exchange (ETDEWEB)

    Antayhua, Yanet; Lermo, Javier [Instituto de Ingenieria, Universidad Nacional Autonoma de Mexico, D.F (Mexico); Carlos, Vargas [Departamento de Geociencias, Universidad Nacional de Colombia (Colombia)]. E-mail: jles@pumas.iingen.unam.mx

    2008-07-15

    In the Los Humeros geothermal field, Puebla, seismic tomography has been studied using the attenuation of coda waves (Qc{sup -1}). Ninety-five local earthquakes (Md{<=}3.6) have been used with depths up to 4.0 km registered in the seismic network stations from December 1997 to December 2004. A simple backscattering model was used, filtered in four ranks of frequencies (2, 4, 6, and 8 Hz) and one window of 5 seconds. For the 3D-representation, we used an approximation based on first-order scattering of ellipsoids. The results show that values of Qc for the used frequencies have a frequency dependency shown in the equation: Qc=24{+-}12f{sup 0.86}{+-}{sup 0.06}, where the low values of Qc were observed in the zone of higher seismic and tectonic activity and in the location of injection and production wells. The high values are located in the periphery of the geothermal field. The distribution of the Qc{sup -1} attenuation in 3D and 2D shows the anomalies of high-seismic attenuation are located in the north, south, and southwestern ends of the zone presently under operation, at depths greater than 2.5 km. [Spanish] Para realizar la tomografia sismica por atenuacion de ondas de coda (Qc{sup -1}) en el campo geotermico de Los Humeros, Puebla, se han utilizado 95 sismos locales (Md{<=}3.6) con profundidades hasta 4.0 km, registrados en las estaciones de su red sismica, durante el periodo de diciembre 1997 a diciembre 2004. Se utilizo el modelo de retrodispersion simple, filtrados en cuatro rangos de frecuencias (2, 4, 6, y 8 Hz) y una ventana de 5 segundos. Para la representacion en 3D, se utilizo una aproximacion basada en elipsoides que representan dispersion de primer orden. Los resultados muestran que los valores de Qc para las frecuencias utilizadas tienen una dependencia con la frecuencia de la forma: Qc=24{+-}12f{sup 0.86}{+-}{sup 0.06}, donde los valores bajos de Qc fueron observados en la zona de mayor actividad sismica y en la ubicacion de pozos inyectores y

  4. Seismology: earthquake risk on the Sunda trench.

    Science.gov (United States)

    Nalbant, Suleyman S; Steacy, Sandy; Sieh, Kerry; Natawidjaja, Danny; McCloskey, John

    2005-06-09

    On 28 March 2005 the Sunda megathrust in Indonesia ruptured again, producing another great earthquake three months after the previous one. The rupture was contiguous with that of the December 2004 Sumatra-Andaman earthquake, and is likely to have been sparked by local stress, although the triggering stresses at its hypocentre were very small - of the order of just 0.1 bar. Calculations show that stresses imposed by the second rupture have brought closer to failure the megathrust immediately to the south, under the Batu and Mentawai islands, and have expanded the area of increased stress on the Sumatra fault. Palaeoseismologic studies show that the Mentawai segment of the Sunda megathrust is well advanced in its seismic cycle and is therefore a good candidate for triggered failure.

  5. The new <Earthquakes>>

    Directory of Open Access Journals (Sweden)

    G. Valensise

    1995-06-01

    Full Text Available We describe a new catalogue of strong ltalian earthquakes that the Istituto Nazionale di Geofisica in collaboration with SGA, has recently made available to the international scientific community and to the general public. The new catalogue differs from previous efforts in that for each event the usual seismic parameters are complemented by a list of intensity rated localities, a complete list of relevant references, a series of synoptic comments describing different aspects of the earthquake phenomenology. and in most cases even the text of the original written sources. The printed part of the catalogue has been published as a special monograph which contains also a computer version of the full database in the form of a CD-ROM. The software package includes a computer program for retrieving, selecting and displaying the catalogue data.

  6. Researchers study tsunami generated by Mexican earthquake

    Science.gov (United States)

    Filonov, Anatoliy E.

    Barra de Navidad is a small Mexican tourist town on the coast of a lagoon that is buffered from the Pacific Ocean by a narrow strip of sand. The town is a favorite rest spot of American and Canadian tourists. On October 9, 1995, at 9:36 local time (1536 GMT), a strong earthquake that measured Mx = 8.0 disrupted the lives of the townspeople. The epicenter of the earthquake was located in the ocean at 18°51.5‧N and 104°8.4‧W [Ortiz and Synolakis, 1996], but it destroyed many hotels and homes, and the shifting of the land tore up the highway that connects Barra de Navidad and Manzanillo. Crevices of up to 3 m wide opened across the road, and bridges over small rivers were knocked down. In an instant, the town was disconnected from the outside world. Frightened townspeople roamed the streets, assessing the destruction.

  7. Future Earth: Reducing Loss By Automating Response to Earthquake Shaking

    Science.gov (United States)

    Allen, R. M.

    2014-12-01

    Earthquakes pose a significant threat to society in the U.S. and around the world. The risk is easily forgotten given the infrequent recurrence of major damaging events, yet the likelihood of a major earthquake in California in the next 30 years is greater than 99%. As our societal infrastructure becomes ever more interconnected, the potential impacts of these future events are difficult to predict. Yet, the same inter-connected infrastructure also allows us to rapidly detect earthquakes as they begin, and provide seconds, tens or seconds, or a few minutes warning. A demonstration earthquake early warning system is now operating in California and is being expanded to the west coast (www.ShakeAlert.org). In recent earthquakes in the Los Angeles region, alerts were generated that could have provided warning to the vast majority of Los Angelinos who experienced the shaking. Efforts are underway to build a public system. Smartphone technology will be used not only to issue that alerts, but could also be used to collect data, and improve the warnings. The MyShake project at UC Berkeley is currently testing an app that attempts to turn millions of smartphones into earthquake-detectors. As our development of the technology continues, we can anticipate ever-more automated response to earthquake alerts. Already, the BART system in the San Francisco Bay Area automatically stops trains based on the alerts. In the future, elevators will stop, machinery will pause, hazardous materials will be isolated, and self-driving cars will pull-over to the side of the road. In this presentation we will review the current status of the earthquake early warning system in the US. We will illustrate how smartphones can contribute to the system. Finally, we will review applications of the information to reduce future losses.

  8. Education for Earthquake Disaster Prevention in the Tokyo Metropolitan Area

    Science.gov (United States)

    Oki, S.; Tsuji, H.; Koketsu, K.; Yazaki, Y.

    2008-12-01

    Japan frequently suffers from all types of disasters such as earthquakes, typhoons, floods, volcanic eruptions, and landslides. In the first half of this year, we already had three big earthquakes and heavy rainfall, which killed more than 30 people. This is not just for Japan but Asia is the most disaster-afflicted region in the world, accounting for about 90% of all those affected by disasters, and more than 50% of the total fatalities and economic losses. One of the most essential ways to reduce the damage of natural disasters is to educate the general public to let them understand what is going on during those desasters. This leads individual to make the sound decision on what to do to prevent or reduce the damage. The Ministry of Education, Culture, Sports, Science and Technology (MEXT), therefore, offered for public subscription to choose several model areas to adopt scientific education to the local elementary schools, and ERI, the Earthquake Research Institute, is qualified to develop education for earthquake disaster prevention in the Tokyo metropolitan area. The tectonic setting of this area is very complicated; there are the Pacific and Philippine Sea plates subducting beneath the North America and the Eurasia plates. The subduction of the Philippine Sea plate causes mega-thrust earthquakes such as the 1703 Genroku earthquake (M 8.0) and the 1923 Kanto earthquake (M 7.9) which had 105,000 fatalities. A magnitude 7 or greater earthquake beneath this area is recently evaluated to occur with a probability of 70 % in 30 years. This is of immediate concern for the devastating loss of life and property because the Tokyo urban region now has a population of 42 million and is the center of approximately 40 % of the nation's activities, which may cause great global economic repercussion. To better understand earthquakes in this region, "Special Project for Earthquake Disaster Mitigation in Tokyo Metropolitan Area" has been conducted mainly by ERI. It is a 4-year

  9. Food, water, and fault lines: Remote sensing opportunities for earthquake-response management of agricultural water

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Jenna, E-mail: jmmartin@ucdavis.edu; Ustin, Susan; Sandoval-Solis, Samuel; O' Geen, Anthony Toby

    2016-09-15

    Earthquakes often cause destructive and unpredictable changes that can affect local hydrology (e.g. groundwater elevation or reduction) and thus disrupt land uses and human activities. Prolific agricultural regions overlie seismically active areas, emphasizing the importance to improve our understanding and monitoring of hydrologic and agricultural systems following a seismic event. A thorough data collection is necessary for adequate post-earthquake crop management response; however, the large spatial extent of earthquake's impact makes challenging the collection of robust data sets for identifying locations and magnitude of these impacts. Observing hydrologic responses to earthquakes is not a novel concept, yet there is a lack of methods and tools for assessing earthquake's impacts upon the regional hydrology and agricultural systems. The objective of this paper is to describe how remote sensing imagery, methods and tools allow detecting crop responses and damage incurred after earthquakes because a change in the regional hydrology. Many remote sensing datasets are long archived with extensive coverage and with well-documented methods to assess plant-water relations. We thus connect remote sensing of plant water relations to its utility in agriculture using a post-earthquake agrohydrologic remote sensing (PEARS) framework; specifically in agro-hydrologic relationships associated with recent earthquake events that will lead to improved water management. - Highlights: • Remote sensing to improve agricultural disaster management • Introduce post-earthquake agrohydrologic remote sensing (PEARS) framework • Apply PEARS framework to 2010 Maule Earthquake in Central Chile.

  10. Mountain rivers may need centuries to adjust to earthquake-triggered sediment pulses, Pokhara, Nepal

    Science.gov (United States)

    Stolle, Amelie; Korup, Oliver; Schwanghart, Wolfgang; Bernhardt, Anne; Adhikari, Basanta Raj; Andermann, Christoff; Wittmann, Hella; Merchel, Silke

    2017-04-01

    Mountain rivers respond to strong earthquakes by not only adjusting to changes in local base level, but also by rapidly aggrading to accommodate excess sediment delivered by co- and post-seismic landslides. A growing number of detailed sediment budgets suggests that it takes rivers several years to decades to recover from such seismic disturbances, depending on how recovery is defined. We test this notion and study how rivers adjusted to catastrophic sedimentation triggered by at least three medieval earthquakes in the central Nepal Himalaya. In the vicinity of Pokhara, the nation's second largest city, rapid aggradation formed a large fan covering 150 km2 of mountainous terrain over a length of some 70 km. The fan prograded into several tributary valleys, rapidly infilling their lower reaches with several tens of meters of sediment from a major point source tens of kilometers away. A robust radiocarbon chronology of these valley fills provides an ideal framework for gauging average rates of fluvial incision and adjustment. We use high-resolution digital elevation data, geodetic field surveys, aerial photos documenting historic channel changes, and several re-exhumed tree trunks in growth position to define dated geomorphic marker surfaces. We compare various methods of computing the volumes lost from these surfaces to arrive at net sediment yields averaged over decades to centuries. We find that contemporary rates of river incision into the medieval earthquake debris are between 160 and 220 mm yr-1, with corresponding sediment yields of 103 to 105 t km-2 yr-1, several hundred years after the last traceable seismic disturbance. These rates greatly exceed the density-adjusted background rates of catchment-wide denudation inferred from concentrations of cosmogenic 10Be in river sands sampled in different tributaries. The lithological composition of active channel-bed load differs largely from local bedrock and confirms that rivers are still busy with excavating

  11. Breaking the oceanic lithosphere of a subducting slab: the 2013 Khash, Iran earthquake

    Science.gov (United States)

    Barnhart, William D.; Hayes, Gavin P.; Samsonov, S.; Fielding, E.; Seidman, L.

    2014-01-01

    [1] Large intermediate depth, intraslab normal faulting earthquakes are a common, dangerous, but poorly understood phenomenon in subduction zones owing to a paucity of near field geophysical observations. Seismological and high quality geodetic observations of the 2013 Mw7.7 Khash, Iran earthquake reveal that at least half of the oceanic lithosphere, including the mantle and entire crust, ruptured in a single earthquake, confirming with unprecedented resolution that large earthquakes can nucleate in and rupture through the oceanic mantle. A rupture width of at least 55 km is required to explain both InSAR observations and teleseismic waveforms, with the majority of slip occurring in the oceanic mantle. Combining our well-constrained earthquake slip distributions with the causative fault orientation and geometry of the local subduction zone, we hypothesize that the Khash earthquake likely occurred as the combined result of slab bending forces and dehydration of hydrous minerals along a preexisting fault formed prior to subduction.

  12. Incredibly distant ionospheric responses to earthquake

    Science.gov (United States)

    Yusupov, Kamil; Akchurin, Adel

    2015-04-01

    area of medium-scale wave (387 km), which ionograms showed F-spread rather than MCS. Obviously, this is due to the vertical structure of the disturbance in the near zone. Another interesting feature associated with the vertical structure is a 1-2 minute advance of the appearance MCS in ionograms in relation to the advent of large-scale TEC disturbance. Naturally, such appearance time comparison can only be in such distances, when there are large-scale TEC disturbances ( 8) during the period from 1957-2011. This indirectly explains why it had to wait 50 years to recognize the MCS as a response to the earthquake. Previously performed statistical analyses showed that the MCS appear mainly from 9 to 15 LT and the epicentre distances range is the 800-6000 km. The MCS signatures at distances removing from earthquake epicentre more than 6000 km seen in ionosondes in Kazan, Kaliningrad and Sodankyla. These MCS in Kazan (as well in Kaliningrad, in Sodankyla) observed during the daytime from 9 to 15 LT. At this time, the height electron concentration gradient is significantly reducing in the F1-layer. This leads to the fact that a small disturbance of this gradient distorts some area of electron density profile and it reduces the value of the local gradient to zero (or even negative) values. Observations in our ionosonde first showed that the ionospheric response to the strong earthquakes (magnitude more than 8) could be observing at distances more than 15,000 km. In the daytime such responses appearance distort the form of the electron density profile of the F-layer, which is appearing in the ionograms as a multiple trace stratification of F1-layer.

  13. Identified EM Earthquake Precursors

    Science.gov (United States)

    Jones, Kenneth, II; Saxton, Patrick

    2014-05-01

    Many attempts have been made to determine a sound forecasting method regarding earthquakes and warn the public in turn. Presently, the animal kingdom leads the precursor list alluding to a transmission related source. By applying the animal-based model to an electromagnetic (EM) wave model, various hypotheses were formed, but the most interesting one required the use of a magnetometer with a differing design and geometry. To date, numerous, high-end magnetometers have been in use in close proximity to fault zones for potential earthquake forecasting; however, something is still amiss. The problem still resides with what exactly is forecastable and the investigating direction of EM. After a number of custom rock experiments, two hypotheses were formed which could answer the EM wave model. The first hypothesis concerned a sufficient and continuous electron movement either by surface or penetrative flow, and the second regarded a novel approach to radio transmission. Electron flow along fracture surfaces was determined to be inadequate in creating strong EM fields, because rock has a very high electrical resistance making it a high quality insulator. Penetrative flow could not be corroborated as well, because it was discovered that rock was absorbing and confining electrons to a very thin skin depth. Radio wave transmission and detection worked with every single test administered. This hypothesis was reviewed for propagating, long-wave generation with sufficient amplitude, and the capability of penetrating solid rock. Additionally, fracture spaces, either air or ion-filled, can facilitate this concept from great depths and allow for surficial detection. A few propagating precursor signals have been detected in the field occurring with associated phases using custom-built loop antennae. Field testing was conducted in Southern California from 2006-2011, and outside the NE Texas town of Timpson in February, 2013. The antennae have mobility and observations were noted for

  14. Earthquake engineering for nuclear facilities

    CERN Document Server

    Kuno, Michiya

    2017-01-01

    This book is a comprehensive compilation of earthquake- and tsunami-related technologies and knowledge for the design and construction of nuclear facilities. As such, it covers a wide range of fields including civil engineering, architecture, geotechnical engineering, mechanical engineering, and nuclear engineering, for the development of new technologies providing greater resistance against earthquakes and tsunamis. It is crucial both for students of nuclear energy courses and for young engineers in nuclear power generation industries to understand the basics and principles of earthquake- and tsunami-resistant design of nuclear facilities. In Part I, "Seismic Design of Nuclear Power Plants", the design of nuclear power plants to withstand earthquakes and tsunamis is explained, focusing on buildings, equipment's, and civil engineering structures. In Part II, "Basics of Earthquake Engineering", fundamental knowledge of earthquakes and tsunamis as well as the dynamic response of structures and foundation ground...

  15. Do Earthquakes Shake Stock Markets?

    Science.gov (United States)

    Ferreira, Susana; Karali, Berna

    2015-01-01

    This paper examines how major earthquakes affected the returns and volatility of aggregate stock market indices in thirty-five financial markets over the last twenty years. Results show that global financial markets are resilient to shocks caused by earthquakes even if these are domestic. Our analysis reveals that, in a few instances, some macroeconomic variables and earthquake characteristics (gross domestic product per capita, trade openness, bilateral trade flows, earthquake magnitude, a tsunami indicator, distance to the epicenter, and number of fatalities) mediate the impact of earthquakes on stock market returns, resulting in a zero net effect. However, the influence of these variables is market-specific, indicating no systematic pattern across global capital markets. Results also demonstrate that stock market volatility is unaffected by earthquakes, except for Japan.

  16. Earthquake Source Mechanics

    Science.gov (United States)

    The past 2 decades have seen substantial progress in our understanding of the nature of the earthquake faulting process, but increasingly, the subject has become an interdisciplinary one. Thus, although the observation of radiated seismic waves remains the primary tool for studying earthquakes (and has been increasingly focused on extracting the physical processes occurring in the “source”), geological studies have also begun to play a more important role in understanding the faulting process. Additionally, defining the physical underpinning for these phenomena has come to be an important subject in experimental and theoretical rock mechanics.In recognition of this, a Maurice Ewing Symposium was held at Arden House, Harriman, N.Y. (the former home of the great American statesman Averill Harriman), May 20-23, 1985. The purpose of the meeting was to bring together the international community of experimentalists, theoreticians, and observationalists who are engaged in the study of various aspects of earthquake source mechanics. The conference was attended by more than 60 scientists from nine countries (France, Italy, Japan, Poland, China, the United Kingdom, United States, Soviet Union, and the Federal Republic of Germany).

  17. Fault lubrication during earthquakes.

    Science.gov (United States)

    Di Toro, G; Han, R; Hirose, T; De Paola, N; Nielsen, S; Mizoguchi, K; Ferri, F; Cocco, M; Shimamoto, T

    2011-03-24

    The determination of rock friction at seismic slip rates (about 1 m s(-1)) is of paramount importance in earthquake mechanics, as fault friction controls the stress drop, the mechanical work and the frictional heat generated during slip. Given the difficulty in determining friction by seismological methods, elucidating constraints are derived from experimental studies. Here we review a large set of published and unpublished experiments (∼300) performed in rotary shear apparatus at slip rates of 0.1-2.6 m s(-1). The experiments indicate a significant decrease in friction (of up to one order of magnitude), which we term fault lubrication, both for cohesive (silicate-built, quartz-built and carbonate-built) rocks and non-cohesive rocks (clay-rich, anhydrite, gypsum and dolomite gouges) typical of crustal seismogenic sources. The available mechanical work and the associated temperature rise in the slipping zone trigger a number of physicochemical processes (gelification, decarbonation and dehydration reactions, melting and so on) whose products are responsible for fault lubrication. The similarity between (1) experimental and natural fault products and (2) mechanical work measures resulting from these laboratory experiments and seismological estimates suggests that it is reasonable to extrapolate experimental data to conditions typical of earthquake nucleation depths (7-15 km). It seems that faults are lubricated during earthquakes, irrespective of the fault rock composition and of the specific weakening mechanism involved.

  18. Twitter Seismology: Earthquake Monitoring and Response in a Social World

    Science.gov (United States)

    Bowden, D. C.; Earle, P. S.; Guy, M.; Smoczyk, G.

    2011-12-01

    The U.S. Geological Survey (USGS) is investigating how the social networking site Twitter, a popular service for sending and receiving short, public, text messages, can augment USGS earthquake response products and the delivery of hazard information. The potential uses of Twitter for earthquake response include broadcasting earthquake alerts, rapidly detecting widely felt events, qualitatively assessing earthquake damage effects, communicating with the public, and participating in post-event collaboration. Several seismic networks and agencies are currently distributing Twitter earthquake alerts including the European-Mediterranean Seismological Centre (@LastQuake), Natural Resources Canada (@CANADAquakes), and the Indonesian meteorological agency (@infogempabmg); the USGS will soon distribute alerts via the @USGSted and @USGSbigquakes Twitter accounts. Beyond broadcasting alerts, the USGS is investigating how to use tweets that originate near the epicenter to detect and characterize shaking events. This is possible because people begin tweeting immediately after feeling an earthquake, and their short narratives and exclamations are available for analysis within 10's of seconds of the origin time. Using five months of tweets that contain the word "earthquake" and its equivalent in other languages, we generate a tweet-frequency time series. The time series clearly shows large peaks correlated with the origin times of widely felt events. To identify possible earthquakes, we use a simple Short-Term-Average / Long-Term-Average algorithm similar to that commonly used to detect seismic phases. As with most auto-detection algorithms, the parameters can be tuned to catch more or less events at the cost of more or less false triggers. When tuned to a moderate sensitivity, the detector found 48 globally-distributed, confirmed seismic events with only 2 false triggers. A space-shuttle landing and "The Great California ShakeOut" caused the false triggers. This number of

  19. Earthquake Drill using the Earthquake Early Warning System at an Elementary School

    Science.gov (United States)

    Oki, Satoko; Yazaki, Yoshiaki; Koketsu, Kazuki

    2010-05-01

    Japan frequently suffers from many kinds of disasters such as earthquakes, typhoons, floods, volcanic eruptions, and landslides. On average, we lose about 120 people a year due to natural hazards in this decade. Above all, earthquakes are noteworthy, since it may kill thousands of people in a moment like in Kobe in 1995. People know that we may have "a big one" some day as long as we live on this land and that what to do; retrofit houses, appliance heavy furniture to walls, add latches to kitchen cabinets, and prepare emergency packs. Yet most of them do not take the action, and result in the loss of many lives. It is only the victims that learn something from the earthquake, and it has never become the lore of the nations. One of the most essential ways to reduce the damage is to educate the general public to be able to make the sound decision on what to do at the moment when an earthquake hits. This will require the knowledge of the backgrounds of the on-going phenomenon. The Ministry of Education, Culture, Sports, Science and Technology (MEXT), therefore, offered for public subscription to choose several model areas to adopt scientific education to the local elementary schools. This presentation is the report of a year and half courses that we had at the model elementary school in Tokyo Metropolitan Area. The tectonic setting of this area is very complicated; there are the Pacific and Philippine Sea plates subducting beneath the North America and the Eurasia plates. The subduction of the Philippine Sea plate causes mega-thrust earthquakes such as the 1923 Kanto earthquake (M 7.9) making 105,000 fatalities. A magnitude 7 or greater earthquake beneath this area is recently evaluated to occur with a probability of 70 % in 30 years. This is of immediate concern for the devastating loss of life and property because the Tokyo urban region now has a population of 42 million and is the center of approximately 40 % of the nation's activities, which may cause great global

  20. On the modal characteristics of damaging structures subjected to earthquakes

    Science.gov (United States)

    Carlo Ponzo, Felice; Ditommaso, Rocco; Auletta, Gianluca; Iacovino, Chiara; Mossucca, Antonello; Nigro, Antonella; Nigro, Domenico

    2015-04-01

    Structural Health Monitoring, especially for structures located in seismic prone areas, has assumed a meaning of great importance in last years, for the possibility to make a more objective and more rapid estimation of the damage occurred on buildings after a seismic event. In the last years many researchers are working to set-up new methodologies for Non-destructive Damage Evaluation based on the variation of the dynamic behaviour of structures under seismic loads. The NDE methods for damage detection and evaluation can be classified into four levels, according to the specific criteria provided by the Rytter. Each level of identification is correlated with specific information related to monitored structure. In fact, by increasing the level it is possible to obtain more information about the state of the health of the structures, to know if damage occurred on the structures, to quantify and localize the damage and to evaluate its impact on the monitored structure. Several authors discussed on the possibility to use the mode shape curvature to localize damage on structural elements, for example, by applying the curvature-based method to frequency response function instead of mode shape, and demonstrated the potential of this approach by considering real data. Damage detection approach based on dynamic monitoring of structural properties over time has received a considerable attention in recent scientific literature. In earthquake engineering field, the recourse to experimental research is necessary to understand the mechanical behaviour of the various structural and non-structural components. In this paper a new methodology to detect and localize a possible damage occurred on a framed structure after an earthquake is presented and discussed. The main outcomes retrieved from many numerical non linear dynamic models of reinforced concrete framed structures characterized by 3, 5 and 8 floors with different geometric configurations and designed for gravity loads only

  1. Generalized statistical mechanics approaches to earthquakes and tectonics.

    Science.gov (United States)

    Vallianatos, Filippos; Papadakis, Giorgos; Michas, Georgios

    2016-12-01

    Despite the extreme complexity that characterizes the mechanism of the earthquake generation process, simple empirical scaling relations apply to the collective properties of earthquakes and faults in a variety of tectonic environments and scales. The physical characterization of those properties and the scaling relations that describe them attract a wide scientific interest and are incorporated in the probabilistic forecasting of seismicity in local, regional and planetary scales. Considerable progress has been made in the analysis of the statistical mechanics of earthquakes, which, based on the principle of entropy, can provide a physical rationale to the macroscopic properties frequently observed. The scale-invariant properties, the (multi) fractal structures and the long-range interactions that have been found to characterize fault and earthquake populations have recently led to the consideration of non-extensive statistical mechanics (NESM) as a consistent statistical mechanics framework for the description of seismicity. The consistency between NESM and observations has been demonstrated in a series of publications on seismicity, faulting, rock physics and other fields of geosciences. The aim of this review is to present in a concise manner the fundamental macroscopic properties of earthquakes and faulting and how these can be derived by using the notions of statistical mechanics and NESM, providing further insights into earthquake physics and fault growth processes.

  2. Generalized statistical mechanics approaches to earthquakes and tectonics

    Science.gov (United States)

    Papadakis, Giorgos; Michas, Georgios

    2016-01-01

    Despite the extreme complexity that characterizes the mechanism of the earthquake generation process, simple empirical scaling relations apply to the collective properties of earthquakes and faults in a variety of tectonic environments and scales. The physical characterization of those properties and the scaling relations that describe them attract a wide scientific interest and are incorporated in the probabilistic forecasting of seismicity in local, regional and planetary scales. Considerable progress has been made in the analysis of the statistical mechanics of earthquakes, which, based on the principle of entropy, can provide a physical rationale to the macroscopic properties frequently observed. The scale-invariant properties, the (multi) fractal structures and the long-range interactions that have been found to characterize fault and earthquake populations have recently led to the consideration of non-extensive statistical mechanics (NESM) as a consistent statistical mechanics framework for the description of seismicity. The consistency between NESM and observations has been demonstrated in a series of publications on seismicity, faulting, rock physics and other fields of geosciences. The aim of this review is to present in a concise manner the fundamental macroscopic properties of earthquakes and faulting and how these can be derived by using the notions of statistical mechanics and NESM, providing further insights into earthquake physics and fault growth processes. PMID:28119548

  3. Creating a Global Building Inventory for Earthquake Loss Assessment and Risk Management

    Science.gov (United States)

    Jaiswal, Kishor; Wald, David J.

    2008-01-01

    Earthquakes have claimed approximately 8 million lives over the last 2,000 years (Dunbar, Lockridge and others, 1992) and fatality rates are likely to continue to rise with increased population and urbanizations of global settlements especially in developing countries. More than 75% of earthquake-related human casualties are caused by the collapse of buildings or structures (Coburn and Spence, 2002). It is disheartening to note that large fractions of the world's population still reside in informal, poorly-constructed & non-engineered dwellings which have high susceptibility to collapse during earthquakes. Moreover, with increasing urbanization half of world's population now lives in urban areas (United Nations, 2001), and half of these urban centers are located in earthquake-prone regions (Bilham, 2004). The poor performance of most building stocks during earthquakes remains a primary societal concern. However, despite this dark history and bleaker future trends, there are no comprehensive global building inventories of sufficient quality and coverage to adequately address and characterize future earthquake losses. Such an inventory is vital both for earthquake loss mitigation and for earthquake disaster response purposes. While the latter purpose is the motivation of this work, we hope that the global building inventory database described herein will find widespread use for other mitigation efforts as well. For a real-time earthquake impact alert system, such as U.S. Geological Survey's (USGS) Prompt Assessment of Global Earthquakes for Response (PAGER), (Wald, Earle and others, 2006), we seek to rapidly evaluate potential casualties associated with earthquake ground shaking for any region of the world. The casualty estimation is based primarily on (1) rapid estimation of the ground shaking hazard, (2) aggregating the population exposure within different building types, and (3) estimating the casualties from the collapse of vulnerable buildings. Thus, the

  4. MyShake: A smartphone seismic network for earthquake early warning and beyond.

    Science.gov (United States)

    Kong, Qingkai; Allen, Richard M; Schreier, Louis; Kwon, Young-Woo

    2016-02-01

    Large magnitude earthquakes in urban environments continue to kill and injure tens to hundreds of thousands of people, inflicting lasting societal and economic disasters. Earthquake early warning (EEW) provides seconds to minutes of warning, allowing people to move to safe zones and automated slowdown and shutdown of transit and other machinery. The handful of EEW systems operating around the world use traditional seismic and geodetic networks that exist only in a few nations. Smartphones are much more prevalent than traditional networks and contain accelerometers that can also be used to detect earthquakes. We report on the development of a new type of seismic system, MyShake, that harnesses personal/private smartphone sensors to collect data and analyze earthquakes. We show that smartphones can record magnitude 5 earthquakes at distances of 10 km or less and develop an on-phone detection capability to separate earthquakes from other everyday shakes. Our proof-of-concept system then collects earthquake data at a central site where a network detection algorithm confirms that an earthquake is under way and estimates the location and magnitude in real time. This information can then be used to issue an alert of forthcoming ground shaking. MyShake could be used to enhance EEW in regions with traditional networks and could provide the only EEW capability in regions without. In addition, the seismic waveforms recorded could be used to deliver rapid microseism maps, study impacts on buildings, and possibly image shallow earth structure and earthquake rupture kinematics.

  5. Using geoelectric field skewness and kurtosis to forecast the 2016/2/6, ML 6.6 Meinong, Taiwan Earthquake

    Directory of Open Access Journals (Sweden)

    Hong-Jia Chen

    2017-01-01

    Full Text Available The earthquake-alarm model developed by Chen and Chen (Nat. Hazards 2016 is investigated to validate its forecasting performance for the 2016/2/6, ML 6.6 Meinong, Taiwan earthquake. This alarm model is based on geoelectric field skewness and kurtosis anomalies. The model parameters, such as the detection range and predicted time window, allow us to estimate the empirical relationships between geoelectric anomalies and large earthquakes. As a result, the skewness and kurtosis anomalies are shown to appear before the Meinong earthquake on the four neighboring stations (LIOQ, WANL, KAOH, and CHCH. According to the model analysis a time lag exists between anomaly clusters and earthquakes, depending on local geological features, as well as the durations over which anomalies are continuously observed, which might also display time dependence. In conclusion, this alarm model is able to correlate earthquakes and geoelectrical anomalies, with promising usefulness in forecasting large earthquakes.

  6. A Case Study of Excreta Disposal Following the 2006 Java Earthquake

    Directory of Open Access Journals (Sweden)

    Thye Yoke Pean

    2015-05-01

    Full Text Available Providing safe excreta disposal following disasters is important for disease prevention and the safety and dignity of the affected population. This is challenging because every emergency varies due to the nature of the disaster, local conditions and the characteristics of the affected population. This paper investigates the impact of the 2006 Java earthquake on excreta disposal needs and the response to those needs. Relevant documents were retrieved from the ReliefWeb database, complemented by a literature search. The case study highlights gaps in rapidly providing latrines on a large scale. Three months after the disaster, only 57% of the latrines targeted had been provided. One way to address this problem is to better understand the factors affecting excreta disposal needs and response, allowing appropriate solutions to be identified more effectively.

  7. 1964 Great Alaska Earthquake: a photographic tour of Anchorage, Alaska

    Science.gov (United States)

    Thoms, Evan E.; Haeussler, Peter J.; Anderson, Rebecca D.; McGimsey, Robert G.

    2014-01-01

    On March 27, 1964, at 5:36 p.m., a magnitude 9.2 earthquake, the largest recorded earthquake in U.S. history, struck southcentral Alaska (fig. 1). The Great Alaska Earthquake (also known as the Good Friday Earthquake) occurred at a pivotal time in the history of earth science, and helped lead to the acceptance of plate tectonic theory (Cox, 1973; Brocher and others, 2014). All large subduction zone earthquakes are understood through insights learned from the 1964 event, and observations and interpretations of the earthquake have influenced the design of infrastructure and seismic monitoring systems now in place. The earthquake caused extensive damage across the State, and triggered local tsunamis that devastated the Alaskan towns of Whittier, Valdez, and Seward. In Anchorage, the main cause of damage was ground shaking, which lasted approximately 4.5 minutes. Many buildings could not withstand this motion and were damaged or collapsed even though their foundations remained intact. More significantly, ground shaking triggered a number of landslides along coastal and drainage valley bluffs underlain by the Bootlegger Cove Formation, a composite of facies containing variably mixed gravel, sand, silt, and clay which were deposited over much of upper Cook Inlet during the Late Pleistocene (Ulery and others, 1983). Cyclic (or strain) softening of the more sensitive clay facies caused overlying blocks of soil to slide sideways along surfaces dipping by only a few degrees. This guide is the document version of an interactive web map that was created as part of the commemoration events for the 50th anniversary of the 1964 Great Alaska Earthquake. It is accessible at the U.S. Geological Survey (USGS) Alaska Science Center website: http://alaska.usgs.gov/announcements/news/1964Earthquake/. The website features a map display with suggested tour stops in Anchorage, historical photographs taken shortly after the earthquake, repeat photography of selected sites, scanned documents

  8. Seismic imaging under the 2013 Ms 7.0 Lushan Earthquake, China

    Science.gov (United States)

    Wang, Z.

    2013-12-01

    On 20 April 2013, a large earthquake (Ms 7.0) occurred at southern end of the Longmen-Shan fault zone. More than 200 people were killed and about 14,000 people were hurt by the earthquake. The earthquake occurred with some distinct features: 1) The hypocenter of the Lushan earthquake is located close to the devastating 2008 M 8.0 Wenchuan earthquake occurred at the Longmen-Shan fault zone; 2) The time scale of the earthquake generation is not more than five years after the M 8.0 earthquake; 3) The magnitude of the Lushan earthquake is as large as 7.0 within such a close time of the Wenchuan earthquake; 4) The hypocenter of the Lushan earthquake seems to be located at the southern part of the Longmen-Shan faut zone with a 70-km distance away from the Wenchuan source. These features of the Lushan earthquake leads to a number of researcher wonder of its nucleation mechanism, rupture process and the correlation of the wenchuan earthquakes. Global seismic waveform data analyzing shows where the rupture initiated and how it expanded for the 2013 Ms 7.0 Lushan earthquake. Our seismic imaging and crustal stress analyzing indicates that the hypocenter of the Lushan earthquake occurred at a strong high-velocity (Vp, Vs) and low-Poisson's ratio zone with high crustal stress. Similarly, high-velocity (Vp, Vs) and low-Poisson's ratio with high crustal stress is revealed under the 2008 Wenchuan earthquake (Ms 8.0) source area. However, a sharp contrast gap zone with low-velocity, high-Poisson's ratio anomalies is clearly imaged under the conjunction area between the two earthquake sources. We suggest that the strong structural variation and high crustal stress together with high coseismic stress by the Wenchuan Earthquake triggered the 2013 Lushan Earthquake (Ms 7.0) and controlling its rupture process. We believe that the rapid seismic imaging together with the crustal stress analysis could help to understand the Lushan earthquake generation and to evaluate the possibility of

  9. The Kresna earthquake of 1904 in Bulgaria

    Directory of Open Access Journals (Sweden)

    N. N. Ambraseys

    2001-06-01

    Full Text Available The Kresna earthquake in 1904 in Bulgaria is one of the largest shallow 20th century events on land in the Balkans. This event, which was preceded by a large foreshock, has hitherto been assigned a range of magnitudes up to M S = 7.8 but the reappraisal of instrumental data yields a much smaller value of M S = 7.2 and a re-assement of the intensity distribution suggests 7.1. Thus both instrumental and macroseismic data appear consistent with a magnitude which is also compatible with the fault segmentation and local morphology of the region which cannot accommodate shallow events much larger than about 7.0. The relatively large size of the main shock suggests surface faulting but the available field evidence is insufficient to establish the dimensions, attitude andamount of dislocation, except perhaps in the vicinity of Krupnik. This downsizing of the Kresna earthquake has important consequences for tectonics and earthquake hazard estimates in the Balkans.

  10. Distributed Fiber Optic Sensing of Earthquake Wavefields

    Science.gov (United States)

    Lindsey, N.; Dreger, D. S.; Wagner, A. M.; James, S. R.; Ajo Franklin, J. B.

    2016-12-01

    Seismic hazard strongly depends on local site response, which is rarely captured by even the densest seismometer arrays. Using laser-based Rayleigh scattering with fiber optic telecommunication cables, seismic wavefield information can be recorded as strain-rate at a meter-scale resolution over 10's of kilometers, a technique known as distributed acoustic sensing (DAS). Recent active and passive DAS experiments confirm trade-offs in directionality and sensitivity compared with standard seismic sensors, however the possibility of using inexpensive fiber optics and a single instrument to characterize and monitor entire earthquake-prone regions with field-scale accuracy could represent a complimentary new direction for array seismology, seismic hazard analysis, and earthquake early warning. We present earthquake observations recorded using two different trenched fiber optic cables: (1) a 200m L-shaped test array at the Richmond Field Station in Richmond, CA; and (2) a 4000 linear meter sparse grid array at the Permafrost Experiment Station in Fairbanks, Alaska. We compare wavefield observations made using DAS to broadband recordings collocated with the two arrays, as well as spatial variations in amplitude and signal duration across the DAS arrays. We then perform 2-D beamforming across the array to locate the events. We discuss the quality of the wavefield reconstruction, the uncertainty in the beamformed hypocenter location, and implications for site response characterization.

  11. Sediment gravity flows triggered by remotely generated earthquake waves

    Science.gov (United States)

    Johnson, H. Paul; Gomberg, Joan S.; Hautala, Susan; Salmi, Marie

    2017-01-01

    Recent great earthquakes and tsunamis around the world have heightened awareness of the inevitability of similar events occurring within the Cascadia Subduction Zone of the Pacific Northwest. We analyzed seafloor temperature, pressure, and seismic signals, and video stills of sediment-enveloped instruments recorded during the 2011–2015 Cascadia Initiative experiment, and seafloor morphology. Our results led us to suggest that thick accretionary prism sediments amplified and extended seismic wave durations from the 11 April 2012 Mw8.6 Indian Ocean earthquake, located more than 13,500 km away. These waves triggered a sequence of small slope failures on the Cascadia margin that led to sediment gravity flows culminating in turbidity currents. Previous studies have related the triggering of sediment-laden gravity flows and turbidite deposition to local earthquakes, but this is the first study in which the originating seismic event is extremely distant (> 10,000 km). The possibility of remotely triggered slope failures that generate sediment-laden gravity flows should be considered in inferences of recurrence intervals of past great Cascadia earthquakes from turbidite sequences. Future similar studies may provide new understanding of submarine slope failures and turbidity currents and the hazards they pose to seafloor infrastructure and tsunami generation in regions both with and without local earthquakes.

  12. Sediment gravity flows triggered by remotely generated earthquake waves

    Science.gov (United States)

    Johnson, H. Paul; Gomberg, Joan S.; Hautala, Susan L.; Salmi, Marie S.

    2017-06-01

    Recent great earthquakes and tsunamis around the world have heightened awareness of the inevitability of similar events occurring within the Cascadia Subduction Zone of the Pacific Northwest. We analyzed seafloor temperature, pressure, and seismic signals, and video stills of sediment-enveloped instruments recorded during the 2011-2015 Cascadia Initiative experiment, and seafloor morphology. Our results led us to suggest that thick accretionary prism sediments amplified and extended seismic wave durations from the 11 April 2012 Mw8.6 Indian Ocean earthquake, located more than 13,500 km away. These waves triggered a sequence of small slope failures on the Cascadia margin that led to sediment gravity flows culminating in turbidity currents. Previous studies have related the triggering of sediment-laden gravity flows and turbidite deposition to local earthquakes, but this is the first study in which the originating seismic event is extremely distant (> 10,000 km). The possibility of remotely triggered slope failures that generate sediment-laden gravity flows should be considered in inferences of recurrence intervals of past great Cascadia earthquakes from turbidite sequences. Future similar studies may provide new understanding of submarine slope failures and turbidity currents and the hazards they pose to seafloor infrastructure and tsunami generation in regions both with and without local earthquakes.

  13. Neo-deterministic definition of earthquake hazard scenarios: a multiscale application to India

    Science.gov (United States)

    Peresan, Antonella; Magrin, Andrea; Parvez, Imtiyaz A.; Rastogi, Bal K.; Vaccari, Franco; Cozzini, Stefano; Bisignano, Davide; Romanelli, Fabio; Panza, Giuliano F.; Ashish, Mr; Mir, Ramees R.

    2014-05-01

    performed to understand the influence of the model characteristics on the computed ground shaking scenarios. For massive parametric tests, or for the repeated generation of large scale hazard maps, the methodology can take advantage of more advanced computational platforms, ranging from GRID computing infrastructures to HPC dedicated clusters up to Cloud computing. In such a way, scientists can deal efficiently with the variety and complexity of the potential earthquake sources, and perform parametric studies to characterize the related uncertainties. NDSHA provides realistic time series of expected ground motion readily applicable for seismic engineering analysis and other mitigation actions. The methodology has been successfully applied to strategic buildings, lifelines and cultural heritage sites, and for the purpose of seismic microzoning in several urban areas worldwide. A web application is currently being developed that facilitates the access to the NDSHA methodology and the related outputs by end-users, who are interested in reliable territorial planning and in the design and construction of buildings and infrastructures in seismic areas. At the same, the web application is also shaping up as an advanced educational tool to explore interactively how seismic waves are generated at the source, propagate inside structural models, and build up ground shaking scenarios. We illustrate the preliminary results obtained from a multiscale application of NDSHA approach to the territory of India, zooming from large scale hazard maps of ground shaking at bedrock, to the definition of local scale earthquake scenarios for selected sites in the Gujarat state (NW India). The study aims to provide the community (e.g. authorities and engineers) with advanced information for earthquake risk mitigation, which is particularly relevant to Gujarat in view of the rapid development and urbanization of the region.

  14. Automated Determination of Magnitude and Source Extent of Large Earthquakes

    Science.gov (United States)

    Wang, Dun

    2017-04-01

    Rapid determination of earthquake magnitude is of importance for estimating shaking damages, and tsunami hazards. However, due to the complexity of source process, accurately estimating magnitude for great earthquakes in minutes after origin time is still a challenge. Mw is an accurate estimate for large earthquakes. However, calculating Mw requires the whole wave trains including P, S, and surface phases, which takes tens of minutes to reach stations at tele-seismic distances. To speed up the calculation, methods using W phase and body wave are developed for fast estimating earthquake sizes. Besides these methods that involve Green's Functions and inversions, there are other approaches that use empirically simulated relations to estimate earthquake magnitudes, usually for large earthquakes. The nature of simple implementation and straightforward calculation made these approaches widely applied at many institutions such as the Pacific Tsunami Warning Center, the Japan Meteorological Agency, and the USGS. Here we developed an approach that was originated from Hara [2007], estimating magnitude by considering P-wave displacement and source duration. We introduced a back-projection technique [Wang et al., 2016] instead to estimate source duration using array data from a high-sensitive seismograph network (Hi-net). The introduction of back-projection improves the method in two ways. Firstly, the source duration could be accurately determined by seismic array. Secondly, the results can be more rapidly calculated, and data derived from farther stations are not required. We purpose to develop an automated system for determining fast and reliable source information of large shallow seismic events based on real time data of a dense regional array and global data, for earthquakes that occur at distance of roughly 30°- 85° from the array center. This system can offer fast and robust estimates of magnitudes and rupture extensions of large earthquakes in 6 to 13 min (plus

  15. Chi-Chi, Taiwan Earthquake, September 21, 1999

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — On September 21, 1999, at 1:47 AM local time, a magnitude MW 7.6 earthquake was felt throughout the island of Taiwan. A five county area, including the city of...

  16. Northridge, California Earthquake, January 17, 1994, Set 1

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — At 4:31 A.M. (Local time) on Monday, January 17, 1994, a magnitude 6.8 earthquake twenty miles west northwest of downtown Los Angeles awoke nearly everyone in...

  17. Estimation of earthquake source parameters in the Kachchh seismic ...

    Indian Academy of Sciences (India)

    SEISAN software has been used to locate the identified local earthquakes, which were recorded at least three or more stations of the Kachchh seismological network. Three component spectra of S-wave are being inverted by using the Levenberg–Marquardt non-linear inversion technique, wherein the inversion scheme is ...

  18. Aftershock activity of Bhuj earthquake of January 26th, 2001

    Indian Academy of Sciences (India)

    Following a large-sized Bhuj earthquake ( = 7.6) of January 26th, 2001, a small aperture 4- station temporary local network was deployed, in the epicentral area, for a period of about three weeks and resulted in the recording of more than 1800 aftershocks (-0.07 ≤ < 5.0). Preliminary locations of epicenters of 297 ...

  19. InSAR Analysis of the 2011 Hawthorne (Nevada) Earthquake Swarm: Implications of Earthquake Migration and Stress Transfer

    Science.gov (United States)

    Zha, X.; Dai, Z.; Lu, Z.

    2015-12-01

    The 2011 Hawthorne earthquake swarm occurred in the central Walker Lane zone, neighboring the border between California and Nevada. The swarm included an Mw 4.4 on April 13, Mw 4.6 on April 17, and Mw 3.9 on April 27. Due to the lack of the near-field seismic instrument, it is difficult to get the accurate source information from the seismic data for these moderate-magnitude events. ENVISAT InSAR observations captured the deformation mainly caused by three events during the 2011 Hawthorne earthquake swarm. The surface traces of three seismogenic sources could be identified according to the local topography and interferogram phase discontinuities. The epicenters could be determined using the interferograms and the relocated earthquake distribution. An apparent earthquake migration is revealed by InSAR observations and the earthquake distribution. Analysis and modeling of InSAR data show that three moderate magnitude earthquakes were produced by slip on three previously unrecognized faults in the central Walker Lane. Two seismogenic sources are northwest striking, right-lateral strike-slip faults with some thrust-slip components, and the other source is a northeast striking, thrust-slip fault with some strike-slip components. The former two faults are roughly parallel to each other, and almost perpendicular to the latter one. This special spatial correlation between three seismogenic faults and nature of seismogenic faults suggest the central Walker Lane has been undergoing southeast-northwest horizontal compressive deformation, consistent with the region crustal movement revealed by GPS measurement. The Coulomb failure stresses on the fault planes were calculated using the preferred slip model and the Coulomb 3.4 software package. For the Mw4.6 earthquake, the Coulomb stress change caused by the Mw4.4 event increased by ~0.1 bar. For the Mw3.9 event, the Coulomb stress change caused by the Mw4.6 earthquake increased by ~1.0 bar. This indicates that the preceding

  20. Make an Earthquake: Ground Shaking!

    Science.gov (United States)

    Savasci, Funda

    2011-01-01

    The main purposes of this activity are to help students explore possible factors affecting the extent of the damage of earthquakes and learn the ways to reduce earthquake damages. In these inquiry-based activities, students have opportunities to develop science process skills and to build an understanding of the relationship among science,…

  1. Earthquakes Threaten Many American Schools

    Science.gov (United States)

    Bailey, Nancy E.

    2010-01-01

    Millions of U.S. children attend schools that are not safe from earthquakes, even though they are in earthquake-prone zones. Several cities and states have worked to identify and repair unsafe buildings, but many others have done little or nothing to fix the problem. The reasons for ignoring the problem include political and financial ones, but…

  2. Tectonic summaries of magnitude 7 and greater earthquakes from 2000 to 2015

    Science.gov (United States)

    Hayes, Gavin P.; Meyers, Emma K.; Dewey, James W.; Briggs, Richard W.; Earle, Paul S.; Benz, Harley M.; Smoczyk, Gregory M.; Flamme, Hanna E.; Barnhart, William D.; Gold, Ryan D.; Furlong, Kevin P.

    2017-01-11

    This paper describes the tectonic summaries for all magnitude 7 and larger earthquakes in the period 2000–2015, as produced by the U.S. Geological Survey National Earthquake Information Center during their routine response operations to global earthquakes. The goal of such summaries is to provide important event-specific information to the public rapidly and concisely, such that recent earthquakes can be understood within a global and regional seismotectonic framework. We compile these summaries here to provide a long-term archive for this information, and so that the variability in tectonic setting and earthquake history from region to region, and sometimes within a given region, can be more clearly understood.

  3. Impacts of the 2010 Haitian earthquake in the diaspora: findings from Little Haiti, Miami, FL.

    Science.gov (United States)

    Kobetz, Erin; Menard, Janelle; Kish, Jonathan; Bishop, Ian; Hazan, Gabrielle; Nicolas, Guerda

    2013-04-01

    In January 2010, a massive earthquake struck Haiti resulting in unprecedented damage. Little attention, however, has focused on the earthquake's mental health impact in the Haitian diaspora community. As part of an established community-based participatory research initiative in Little Haiti, the predominately Haitian neighborhood in Miami, FL, USA, community health workers conducted surveys with neighborhood residents about earthquake-related losses, coping strategies, and depressive/traumatic symptomology. Findings reveal the earthquake strongly impacted the diaspora community and highlights prominent coping strategies. Following the earthquake, only a small percentage of participants self-reported engaging in any negative health behaviors. Instead, a majority relied on their social networks for support. This study contributes to the discourse on designing culturally-responsive mental health initiatives for the Haitian diaspora and the ability of existing community-academic partnerships to rapidly adapt to community needs.

  4. Aftereffects of Subduction-Zone Earthquakes: Potential Tsunami Hazards along the Japan Sea Coast.

    Science.gov (United States)

    Minoura, Koji; Sugawara, Daisuke; Yamanoi, Tohru; Yamada, Tsutomu

    2015-10-01

    The 2011 Tohoku-Oki Earthquake is a typical subduction-zone earthquake and is the 4th largest earthquake after the beginning of instrumental observation of earthquakes in the 19th century. In fact, the 2011 Tohoku-Oki Earthquake displaced the northeast Japan island arc horizontally and vertically. The displacement largely changed the tectonic situation of the arc from compressive to tensile. The 9th century in Japan was a period of natural hazards caused by frequent large-scale earthquakes. The aseismic tsunamis that inflicted damage on the Japan Sea coast in the 11th century were related to the occurrence of massive earthquakes that represented the final stage of a period of high seismic activity. Anti-compressive tectonics triggered by the subduction-zone earthquakes induced gravitational instability, which resulted in the generation of tsunamis caused by slope failing at the arc-back-arc boundary. The crustal displacement after the 2011 earthquake infers an increased risk of unexpected local tsunami flooding in the Japan Sea coastal areas.

  5. Are Earthquakes a Critical Phenomenon?

    Science.gov (United States)

    Ramos, O.

    2014-12-01

    Earthquakes, granular avalanches, superconducting vortices, solar flares, and even stock markets are known to evolve through power-law distributed events. During decades, the formalism of equilibrium phase transition has coined these phenomena as critical, which implies that they are also unpredictable. This work revises these ideas and uses earthquakes as the paradigm to demonstrate that slowly driven systems evolving through uncorrelated and power-law distributed avalanches (UPLA) are not necessarily critical systems, and therefore not necessarily unpredictable. By linking the correlation length to the pdf of the distribution, and comparing it with the one obtained at a critical point, a condition of criticality is introduced. Simulations in the classical Olami-Feder-Christensen (OFC) earthquake model confirm the findings, showing that earthquakes are not a critical phenomenon. However, one single catastrophic earthquake may show critical properties and, paradoxically, the emergence of this temporal critical behaviour may eventually carry precursory signs of catastrophic events.

  6. Early Earthquakes of the Americas

    Science.gov (United States)

    Ni, James

    2004-11-01

    Robert Kovach's second book looks at the interplay of earthquake and volcanic events, archeology, and history in the Americas. Throughout history, major earthquakes have caused the deaths of millions of people and have damaged countless cities. Earthquakes undoubtedly damaged prehistoric cities in the Americas, and evidence of these events could be preserved in archeological records. Kovach asks, Did indigenous native cultures-Indians of the Pacific Northwest, Aztecs, Mayas, and Incas-document their natural history? Some events have been explicitly documented, for example, in Mayan codices, but many may have been recorded as myth and legend. Kovach's discussions of how early cultures dealt with fearful events such as earthquakes and volcanic eruptions are colorful, informative, and entertaining, and include, for example, a depiction of how the Maya would talk to maize plants in their fields during earthquakes to reassure them.

  7. Information for action? Analysis of 2005 South Asian earthquake reports posted on Reliefweb.

    Science.gov (United States)

    von Schreeb, Johan; Legha, Jaswinder K; Karlsson, Niklas; Garfield, Richard

    2013-06-01

    Following a sudden-onset disaster (SOD), rapid information is needed. We assessed the relevance of information available for relief planning on a main Internet portal following a major SOD. We reviewed all information posted on the Reliefweb Web site in the first 7 days following the 2005 South Asian earthquake using a predeveloped registration form focusing on essential indicators. These data were compared with Pakistani government figures posted by the Centre for Research on the Epidemiology of Disasters. A total of 820 reports were reviewed. More reports came from nongovernmental organizations (NGOs; 35%) than any other source. A total of 42% of reports addressed only national level information, while 32% specified information at the provincial level. Fewer than 12% of all reports discussed the earthquake at the more local division and district levels. Only 13 reports provided pre-earthquake estimates of the number of people living in the affected areas. A third of all reports cited a common figure of 2.5 million made homeless. These were lower than official figures of 5 million homeless. A total of 43% reported on the estimated number of deaths. The estimated number peaked on day 4 at 40 000. All of these reports were lower than official data, which reported 73 000 deaths in total. Early reports heavily underestimated the number of affected, homeless, injured, and dead. Many reports repeated information provided from previous unnamed sources rather than providing unique contributions from eyewitness reports or from contextual information based on previous work in the area. Better information on predisaster essential indicators should be available and used in combination with post-SOD information to better adapt humanitarian relief and funding according to needs.

  8. Rapid and efficient localization of depth electrodes and cortical labeling using free and open source medical software in epilepsy surgery candidates

    Directory of Open Access Journals (Sweden)

    Juan Pablo Princich

    2013-12-01

    Full Text Available Depth intracranial electrodes (IEs placement is one of the most used procedures to identify the epileptogenic zone (EZ in surgical treatment of drug resistant epilepsy patients, about 20-30% of this population. IEs localization is therefore a critical issue defining the EZ and its relation with eloquent functional areas. That information is then used to target the resective surgery and has great potential to affect outcome.We designed a methodological procedure intended to avoid the need for highly specialized medical resources and reduce time to identify the anatomical location of IEs, during the first instances of intracranial EEG recordings. This workflow is based on established open source software; 3D Slicer and Freesurfer that uses MRI and Post-implant CT fusion for the localization of IEs and its relation with automatic labeled surrounding cortex. To test this hypothesis we assessed the time elapsed between the surgical implantation process and the final anatomical localization of IEs by means of our proposed method compared against traditional visual analysis of raw post-implant imaging in two groups of patients.All IEs were identified in the first 24 Hs (6-24 Hs of implantation using our method in 4 patients of the first group. For the control group; all IEs were identified by experts with an overall time range of 36 h to 3 days using traditional visual analysis. It included (7 patients, 3 patients implanted with IEs and the same 4 patients from the first group. Time to localization was restrained in this group by the specialized personnel and the image quality available.To validate our method; we trained two inexperienced operators to assess the position of IEs contacts on four patients (5 intracranial electrodes using the proposed method. We quantified the discrepancies between operators and we also assessed the efficiency of our method to define the EZ comparing the findings against the results of traditional analysis.

  9. Accounting for orphaned aftershocks in the earthquake background rate

    Science.gov (United States)

    Van Der Elst, Nicholas

    2017-01-01

    Aftershocks often occur within cascades of triggered seismicity in which each generation of aftershocks triggers an additional generation, and so on. The rate of earthquakes in any particular generation follows Omori's law, going approximately as 1/t. This function decays rapidly, but is heavy-tailed, and aftershock sequences may persist for long times at a rate that is difficult to discriminate from background. It is likely that some apparently spontaneous earthquakes in the observational catalogue are orphaned aftershocks of long-past main shocks. To assess the relative proportion of orphaned aftershocks in the apparent background rate, I develop an extension of the ETAS model that explicitly includes the expected contribution of orphaned aftershocks to the apparent background rate. Applying this model to California, I find that the apparent background rate can be almost entirely attributed to orphaned aftershocks, depending on the assumed duration of an aftershock sequence. This implies an earthquake cascade with a branching ratio (the average number of directly triggered aftershocks per main shock) of nearly unity. In physical terms, this implies that very few earthquakes are completely isolated from the perturbing effects of other earthquakes within the fault system. Accounting for orphaned aftershocks in the ETAS model gives more accurate estimates of the true background rate, and more realistic expectations for long-term seismicity patterns.

  10. Accounting for orphaned aftershocks in the earthquake background rate

    Science.gov (United States)

    van der Elst, Nicholas J.

    2017-11-01

    Aftershocks often occur within cascades of triggered seismicity in which each generation of aftershocks triggers an additional generation, and so on. The rate of earthquakes in any particular generation follows Omori's law, going approximately as 1/t. This function decays rapidly, but is heavy-tailed, and aftershock sequences may persist for long times at a rate that is difficult to discriminate from background. It is likely that some apparently spontaneous earthquakes in the observational catalogue are orphaned aftershocks of long-past main shocks. To assess the relative proportion of orphaned aftershocks in the apparent background rate, I develop an extension of the ETAS model that explicitly includes the expected contribution of orphaned aftershocks to the apparent background rate. Applying this model to California, I find that the apparent background rate can be almost entirely attributed to orphaned aftershocks, depending on the assumed duration of an aftershock sequence. This implies an earthquake cascade with a branching ratio (the average number of directly triggered aftershocks per main shock) of nearly unity. In physical terms, this implies that very few earthquakes are completely isolated from the perturbing effects of other earthquakes within the fault system. Accounting for orphaned aftershocks in the ETAS model gives more accurate estimates of the true background rate, and more realistic expectations for long-term seismicity patterns.

  11. The CATDAT damaging earthquakes database

    Directory of Open Access Journals (Sweden)

    J. E. Daniell

    2011-08-01

    Full Text Available The global CATDAT damaging earthquakes and secondary effects (tsunami, fire, landslides, liquefaction and fault rupture database was developed to validate, remove discrepancies, and expand greatly upon existing global databases; and to better understand the trends in vulnerability, exposure, and possible future impacts of such historic earthquakes.

    Lack of consistency and errors in other earthquake loss databases frequently cited and used in analyses was a major shortcoming in the view of the authors which needed to be improved upon.

    Over 17 000 sources of information have been utilised, primarily in the last few years, to present data from over 12 200 damaging earthquakes historically, with over 7000 earthquakes since 1900 examined and validated before insertion into the database. Each validated earthquake includes seismological information, building damage, ranges of social losses to account for varying sources (deaths, injuries, homeless, and affected, and economic losses (direct, indirect, aid, and insured.

    Globally, a slightly increasing trend in economic damage due to earthquakes is not consistent with the greatly increasing exposure. The 1923 Great Kanto ($214 billion USD damage; 2011 HNDECI-adjusted dollars compared to the 2011 Tohoku (>$300 billion USD at time of writing, 2008 Sichuan and 1995 Kobe earthquakes show the increasing concern for economic loss in urban areas as the trend should be expected to increase. Many economic and social loss values not reported in existing databases have been collected. Historical GDP (Gross Domestic Product, exchange rate, wage information, population, HDI (Human Development Index, and insurance information have been collected globally to form comparisons.

    This catalogue is the largest known cross-checked global historic damaging earthquake database and should have far-reaching consequences for earthquake loss estimation, socio-economic analysis, and the global

  12. Macroseismic manifestations of the Romanian earthquake (September 24, 2016) on the territory of Ukraine.

    Science.gov (United States)

    Kulynych, Anna; Illyenko, Volodymyr

    2017-04-01

    presents the results of seismic interpretation of the earthquake that occurred on September 24, 2016 at 02h. 11min (local time) in Romania with magnitude 5.6 and was felt in different regions in Ukraine. The essence of the work was, based on the spatial distribution of instrumental and macroseismic manifestation, to study the nature of investigated earthquake, its origin, parameters of focus and local attenuation laws of seismic shaking energy, which are necessary factors for predicting the magnitude and intensity of the future earthquakes. The seismotectonic situation in the epicenter of the earthquake was analyzed. The registered records of seismic waves and their spectrogram on the territory of Ukraine and global seismic networks were thoroughly processed. A scientific expedition collected data of macroseismic survey to study the distribution of seismic displays and detect the tangible effects of the earthquake. The maps of earthquake`s manifestations in Kyiv region were plotted by visual observation and processing of information, which was obtained by a population survey and field studies. The research results are important for seismic protection of industrial facilities and people`s lives against potential earthquakes from Vrancea area that can have a significant impact on Ukraine and border areas.

  13. Calibration and validation of earthquake catastrophe models. Case study: Impact Forecasting Earthquake Model for Algeria

    Science.gov (United States)

    Trendafiloski, G.; Gaspa Rebull, O.; Ewing, C.; Podlaha, A.; Magee, B.

    2012-04-01

    Calibration and validation are crucial steps in the production of the catastrophe models for the insurance industry in order to assure the model's reliability and to quantify its uncertainty. Calibration is needed in all components of model development including hazard and vulnerability. Validation is required to ensure that the losses calculated by the model match those observed in past events and which could happen in future. Impact Forecasting, the catastrophe modelling development centre of excellence within Aon Benfield, has recently launched its earthquake model for Algeria as a part of the earthquake model for the Maghreb region. The earthquake model went through a detailed calibration process including: (1) the seismic intensity attenuation model by use of macroseismic observations and maps from past earthquakes in Algeria; (2) calculation of the country-specific vulnerability modifiers by use of past damage observations in the country. The use of Benouar, 1994 ground motion prediction relationship was proven as the most appropriate for our model. Calculation of the regional vulnerability modifiers for the country led to 10% to 40% larger vulnerability indexes for different building types compared to average European indexes. The country specific damage models also included aggregate damage models for residential, commercial and industrial properties considering the description of the buildings stock given by World Housing Encyclopaedia and the local rebuilding cost factors equal to 10% for damage grade 1, 20% for damage grade 2, 35% for damage grade 3, 75% for damage grade 4 and 100% for damage grade 5. The damage grades comply with the European Macroseismic Scale (EMS-1998). The model was validated by use of "as-if" historical scenario simulations of three past earthquake events in Algeria M6.8 2003 Boumerdes, M7.3 1980 El-Asnam and M7.3 1856 Djidjelli earthquake. The calculated return periods of the losses for client market portfolio align with the

  14. The 2015 Gorkha Nepal Earthquake: Insights from Earthquake Damage Survey

    Directory of Open Access Journals (Sweden)

    Katsuichiro eGoda

    2015-06-01

    Full Text Available The 2015 Gorkha Nepal earthquake caused tremendous damage and loss. To gain valuable lessons from this tragic event, an earthquake damage investigation team was dispatched to Nepal from 1 May 2015 to 7 May 2015. A unique aspect of the earthquake damage investigation is that first-hand earthquake damage data were obtained 6 to 11 days after the mainshock. To gain deeper understanding of the observed earthquake damage in Nepal, the paper reviews the seismotectonic setting and regional seismicity in Nepal and analyzes available aftershock data and ground motion data. The earthquake damage observations indicate that the majority of the damaged buildings were stone/brick masonry structures with no seismic detailing, whereas the most of RC buildings were undamaged. This indicates that adequate structural design is the key to reduce the earthquake risk in Nepal. To share the gathered damage data widely, the collected damage data (geo-tagged photos and observation comments are organized using Google Earth and the kmz file is made publicly available.

  15. Great earthquakes hazard in slow subduction zones

    Science.gov (United States)

    Marcaillou, B.; Gutscher, M.; Westbrook, G. K.

    2008-12-01

    Research on the Sumatra-Andaman earthquake of 2004 has challenged two popular paradigms; that the strongest subduction earthquakes strike in regions of rapid plate convergence and that rupture occurs primarily along the contact between the basement of the overriding plate and the downgoing plate. Subduction zones presenting similar structural and geodynamic characteristics (slow convergence and thick wedges of accreted sediment) may be capable of generating great megathrust earthquakes (M>8.5) despite an absence of thrust type earthquakes over the past 40 years. Existing deep seismic sounding data and hypocenters are used to constrain the geometry of several key slow subduction zones (Antilles, Hellenic, Sumatra). This geometry forms the basis for numerical modelling of fore-arc thermal structure, which is applied to calculate the estimated width of the seismogenic portion of the subduction fault plane. The margins with the thickest accretionary wedges are commonly found to have the widest (predicted) seismogenic zone. Furthermore, for these margins there exists a substantial (20-60 km wide) region above the up-dip limit for which the contribution to tsunami generation is poorly understood. As the rigidity (mu) of these high-porosity sediments is low, co-seismic slip here can be expected to be slow. Accordingly, the contribution to seismic moment will be low, but the contribution to tsunami generation may be very high. Indeed, recent seismological data from Nankai indicate very low frequency shallow-thrust earthquakes beneath this portion of the accretionary wedge, long-considered to be "aseismic". We propose that thick accumulations of sediment on the downgoing plate and the presence of a thick accretionary wedge can increase the maximum size of the potential rupture fault plane in two ways; 1) by thermally insulating the downgoing plate and thereby increasing the total downdip length of the fault which can rupture seismically and 2) by "smoothing out" the

  16. Inter-Disciplinary Validation of Pre Earthquake Signals. Case Study for Major Earthquakes in Asia (2004-2010) and for 2011 Tohoku Earthquake

    Science.gov (United States)

    Ouzounov, D.; Pulinets, S.; Hattori, K.; Liu, J.-Y.; Yang. T. Y.; Parrot, M.; Kafatos, M.; Taylor, P.

    2012-01-01

    We carried out multi-sensors observations in our investigation of phenomena preceding major earthquakes. Our approach is based on a systematic analysis of several physical and environmental parameters, which we found, associated with the earthquake processes: thermal infrared radiation, temperature and concentration of electrons in the ionosphere, radon/ion activities, and air temperature/humidity in the atmosphere. We used satellite and ground observations and interpreted them with the Lithosphere-Atmosphere- Ionosphere Coupling (LAIC) model, one of possible paradigms we study and support. We made two independent continues hind-cast investigations in Taiwan and Japan for total of 102 earthquakes (M>6) occurring from 2004-2011. We analyzed: (1) ionospheric electromagnetic radiation, plasma and energetic electron measurements from DEMETER (2) emitted long-wavelength radiation (OLR) from NOAA/AVHRR and NASA/EOS; (3) radon/ion variations (in situ data); and 4) GPS Total Electron Content (TEC) measurements collected from space and ground based observations. This joint analysis of ground and satellite data has shown that one to six (or more) days prior to the largest earthquakes there were anomalies in all of the analyzed physical observations. For the latest March 11 , 2011 Tohoku earthquake, our analysis shows again the same relationship between several independent observations characterizing the lithosphere /atmosphere coupling. On March 7th we found a rapid increase of emitted infrared radiation observed from satellite data and subsequently an anomaly developed near the epicenter. The GPS/TEC data indicated an increase and variation in electron density reaching a maximum value on March 8. Beginning from this day we confirmed an abnormal TEC variation over the epicenter in the lower ionosphere. These findings revealed the existence of atmospheric and ionospheric phenomena occurring prior to the 2011 Tohoku earthquake, which indicated new evidence of a distinct

  17. Researches on Application of GPS to Earthquake Monitoring and Prediction

    Directory of Open Access Journals (Sweden)

    Wanju BO

    2007-10-01

    Full Text Available The earliest researches on application of GPS to earthquake monitoring and prediction in China began in 1980s, and it was limited to learn some relative technology from other countries and do some test with a few of equipments. As the improvement of software for data processing and the depreciating of hardware, several local GPS network had been gradually set up till the end of 1990s, and then more systematically GPS monitoring, data processing and its application research have been done gradually. In this paper, 3 research examples of the application of GPS to earthquake monitoring and prediction are presented.

  18. Growth of a tectonic ridge during the Landers earthquake

    Science.gov (United States)

    Fleming, R.W.; Johnson, A.M.

    1997-01-01

    The formation of tectonic ridges by localized vertical uplift along strike-slip faults has long been suspected, but the actual growth of a tectonic ridge during an earthquake has never been documented. During the 1992 Landers, California, earthquake sequence, an awl-shaped, dome-like topographic ridge along the Emerson fault zone increased its height at least 1 m concurrently with 3 m of right-lateral shift across the fault zone containing the ridge. Five deformation vectors within the ridge reveal dilatant behavior in addition to the uplift and shift on boundary faults.

  19. Determination of Design Basis Earthquake ground motion

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Muneaki [Japan Atomic Power Co., Tokyo (Japan)

    1997-03-01

    This paper describes principle of determining of Design Basis Earthquake following the Examination Guide, some examples on actual sites including earthquake sources to be considered, earthquake response spectrum and simulated seismic waves. In sppendix of this paper, furthermore, seismic safety review for N.P.P designed before publication of the Examination Guide was summarized with Check Basis Earthquake. (J.P.N.)

  20. Earthquake Emergency Education in Dushanbe, Tajikistan

    Science.gov (United States)

    Mohadjer, Solmaz; Bendick, Rebecca; Halvorson, Sarah J.; Saydullaev, Umed; Hojiboev, Orifjon; Stickler, Christine; Adam, Zachary R.

    2010-01-01

    We developed a middle school earthquake science and hazards curriculum to promote earthquake awareness to students in the Central Asian country of Tajikistan. These materials include pre- and post-assessment activities, six science activities describing physical processes related to earthquakes, five activities on earthquake hazards and mitigation…

  1. Laboratory Studies of Fault Stability and Slow Earthquakes

    Science.gov (United States)

    Leeman, John R.

    Fault zones are areas of localized deformation that accommodate strain in the Earth's crust accumulated over time due to tectonic motion or stress transfer from adjacent areas. Faults are traditionally considered to accommodate this strain by either constant slow movement (creep), or by rapid catastrophic failure events (earthquakes). The behavior of faults which produce earthquakes has been extensively studied, including characterization of the time and slip predictability of earthquakes, frequency-magnitude distributions, aftershock decay patterns, dynamic triggering, and frictional processes. Chance observations in global positioning system (GPS) data from the Vancouver Island area in 2001 revealed a new kind of fault slip that had not been considered before, slowslip events. Since those early observations, slow-slip events have been observed at most major subduction interfaces and even in glacial systems. In this dissertation, I strive to answer some of the fundamental questions about slow-slip systems. Little is known about the dynamics of these systems and how they operate. Scattered laboratory observations have provided clues, but this study is the first systematic examination of slow-slip earthquakes and their frictional behavior in the laboratory. I examine questions such as what controls how a fault zone will fail and what the velocity and normal stress sensitives are, then connect those mechanisms to observations from a natural slow-slip system beneath Whillans Ice Stream in western Antarctica. In chapter 1, I demonstrate how to modify the stiffness of the testing machine to create slow-slip events in the laboratory inartificial granular material. I also present a method to automatically calculate the stiffness of each slip event in a given experiment. Chapter 2 extends this work into a synthetic fault gouge material and carefully examines the sensitivity of the system to the stiffness of the testing apparatus. Chapter 3 introduces the new parameter of

  2. Global Earthquake Casualties due to Secondary Effects: A Quantitative Analysis for Improving PAGER Losses

    Science.gov (United States)

    Wald, David J.

    2010-01-01

    This study presents a quantitative and geospatial description of global losses due to earthquake-induced secondary effects, including landslide, liquefaction, tsunami, and fire for events during the past 40 years. These processes are of great importance to the US Geological Survey’s (USGS) Prompt Assessment of Global Earthquakes for Response (PAGER) system, which is currently being developed to deliver rapid earthquake impact and loss assessments following large/significant global earthquakes. An important question is how dominant are losses due to secondary effects (and under what conditions, and in which regions)? Thus, which of these effects should receive higher priority research efforts in order to enhance PAGER’s overall assessment of earthquakes losses and alerting for the likelihood of secondary impacts? We find that while 21.5% of fatal earthquakes have deaths due to secondary (non-shaking) causes, only rarely are secondary effects the main cause of fatalities. The recent 2004 Great Sumatra–Andaman Islands earthquake is a notable exception, with extraordinary losses due to tsunami. The potential for secondary hazards varies greatly, and systematically, due to regional geologic and geomorphic conditions. Based on our findings, we have built country-specific disclaimers for PAGER that address potential for each hazard (Earle et al., Proceedings of the 14th World Conference of the Earthquake Engineering, Beijing, China, 2008). We will now focus on ways to model casualties from secondary effects based on their relative importance as well as their general predictability.

  3. Local seismic response studies in the north-western portion of the August 24th, 2016 Mw 6.0 earthquake affected area. The case of Visso village (central Apennines

    Directory of Open Access Journals (Sweden)

    Iolanda Gaudiosi

    2016-12-01

    Full Text Available In this work, we investigate the possible causes of the differential damaging observed in Visso village (central Apennines, about 28 km north from the August 24th, 2016 Mw 6.0 earthquake epicenter. Following insights from the available geological cartography at 1:10.000 scale, a preliminary geophysical survey has been performed in the damaged area in order to constrain geometries and extent of the subsoil lithotypes. Then, these results have been used to retrieve a Vs profile close to the most heavily damaged buildings. This latter has been used as input for a numerical analysis aimed at deriving the motion at the ground level in the study area. In particular, a linear equivalent simulation has been performed by means of EERA code and the waveform has been obtained convolving the time history recorded during the August 24th, 2016 mainshock at Spoleto Monteluco (SPM site. Our preliminary results indicate a possible correlation of damaging to the thickness and shape of the geological units. Nevertheless, further analyses are necessary to highlight any 2D basin and / non - linear soil behaviour effects in order to compare them to the intrinsic buildings vulnerability, according to the EMS98 guidelines.

  4. Ionospheric phenomena before strong earthquakes

    Directory of Open Access Journals (Sweden)

    A. S. Silina

    2001-01-01

    Full Text Available A statistical analysis of several ionospheric parameters before earthquakes with magnitude M > 5.5 located less than 500 km from an ionospheric vertical sounding station is performed. Ionospheric effects preceding "deep" (depth h > 33 km and "crust" (h 33 km earthquakes were analysed separately. Data of nighttime measurements of the critical frequencies foF2 and foEs, the frequency fbEs and Es-spread at the middle latitude station Dushanbe were used. The frequencies foF2 and fbEs are proportional to the square root of the ionization density at heights of 300 km and 100 km, respectively. It is shown that two days before the earthquakes the values of foF2 averaged over the morning hours (00:00 LT–06:00 LT and of fbEs averaged over the nighttime hours (18:00 LT–06:00 LT decrease; the effect is stronger for the "deep" earthquakes. Analysing the coefficient of semitransparency which characterizes the degree of small-scale turbulence, it was shown that this value increases 1–4 days before "crust" earthquakes, and it does not change before "deep" earthquakes. Studying Es-spread which manifests itself as diffuse Es track on ionograms and characterizes the degree of large-scale turbulence, it was found that the number of Es-spread observations increases 1–3 days before the earthquakes; for "deep" earthquakes the effect is more intensive. Thus it may be concluded that different mechanisms of energy transfer from the region of earthquake preparation to the ionosphere occur for "deep" and "crust" events.

  5. Fracking, wastewater disposal, and earthquakes

    Science.gov (United States)

    McGarr, Arthur

    2016-03-01

    In the modern oil and gas industry, fracking of low-permeability reservoirs has resulted in a considerable increase in the production of oil and natural gas, but these fluid-injection activities also can induce earthquakes. Earthquakes induced by fracking are an inevitable consequence of the injection of fluid at high pressure, where the intent is to enhance permeability by creating a system of cracks and fissures that allow hydrocarbons to flow to the borehole. The micro-earthquakes induced during these highly-controlled procedures are generally much too small to be felt at the surface; indeed, the creation or reactivation of a large fault would be contrary to the goal of enhancing permeability evenly throughout the formation. Accordingly, the few case histories for which fracking has resulted in felt earthquakes have been due to unintended fault reactivation. Of greater consequence for inducing earthquakes, modern techniques for producing hydrocarbons, including fracking, have resulted in considerable quantities of coproduced wastewater, primarily formation brines. This wastewater is commonly disposed by injection into deep aquifers having high permeability and porosity. As reported in many case histories, pore pressure increases due to wastewater injection were channeled from the target aquifers into fault zones that were, in effect, lubricated, resulting in earthquake slip. These fault zones are often located in the brittle crystalline rocks in the basement. Magnitudes of earthquakes induced by wastewater disposal often exceed 4, the threshold for structural damage. Even though only a small fraction of disposal wells induce earthquakes large enough to be of concern to the public, there are so many of these wells that this source of seismicity contributes significantly to the seismic hazard in the United States, especially east of the Rocky Mountains where standards of building construction are generally not designed to resist shaking from large earthquakes.

  6. Fault Structural Control on Earthquake Strong Ground Motions: The 2008 Wenchuan Earthquake as an Example

    Science.gov (United States)

    Zhang, Yan; Zhang, Dongli; Li, Xiaojun; Huang, Bei; Zheng, Wenjun; Wang, Yuejun

    2017-12-01

    Continental thrust faulting earthquakes pose severe threats to megacities across the world. Recent events show the possible control of fault structures on strong ground motions. The seismogenic structure of the 2008 Wenchuan earthquake is associated with high-angle listric reverse fault zones. Its peak ground accelerations (PGAs) show a prominent feature of fault zone amplification: the values within the 30- to 40-km-wide fault zone block are significantly larger than those on both the hanging wall and the footwall. The PGA values attenuate asymmetrically: they decay much more rapidly in the footwall than in the hanging wall. The hanging wall effects can be seen on both the vertical and horizontal components of the PGAs, with the former significantly more prominent than the latter. All these characteristics can be adequately interpreted by upward extrusion of the high-angle listric reverse fault zone block. Through comparison with a low-angle planar thrust fault associated with the 1999 Chi-Chi earthquake, we conclude that different fault structures might have controlled different patterns of strong ground motion, which should be taken into account in seismic design and construction.

  7. From a physical approach to earthquake prediction, towards long and short term warnings ahead of large earthquakes

    Science.gov (United States)

    Stefansson, R.; Bonafede, M.

    2012-04-01

    approach of statistics of universal precursors or stress level. The approach is more related to failure physics, by studying the ongoing failure. But it requires watching and relevant modeling for years, even decades. Useful information on fault process and warnings can be issued along the way, starting when we discover a fault showing signs of preparatory processes, up to the time of the earthquake. Such information and warnings could be issued by government agencies in cooperation with scientists to the local Civil Protection committee closest to the fault with information about how to prepare, including directives about enhanced watching. For such a warning service we need a continuously operating geo-watching system, applying modern computing technology to the multidisciplinary data, and a rule based schedule to prepare adequate warnings.

  8. USGS Tweet Earthquake Dispatch (@USGSted): Using Twitter for Earthquake Detection and Characterization

    Science.gov (United States)

    Liu, S. B.; Bouchard, B.; Bowden, D. C.; Guy, M.; Earle, P.

    2012-12-01

    The U.S. Geological Survey (USGS) is investigating how online social networking services like Twitter—a microblogging service for sending and reading public text-based messages of up to 140 characters—can augment USGS earthquake response products and the delivery of hazard information. The USGS Tweet Earthquake Dispatch (TED) system is using Twitter not only to broadcast seismically-verified earthquake alerts via the @USGSted and @USGSbigquakes Twitter accounts, but also to rapidly detect widely felt seismic events through a real-time detection system. The detector algorithm scans for significant increases in tweets containing the word "earthquake" or its equivalent in other languages and sends internal alerts with the detection time, tweet text, and the location of the city where most of the tweets originated. It has been running in real-time for 7 months and finds, on average, two or three felt events per day with a false detection rate of less than 10%. The detections have reasonable coverage of populated areas globally. The number of detections is small compared to the number of earthquakes detected seismically, and only a rough location and qualitative assessment of shaking can be determined based on Tweet data alone. However, the Twitter detections are generally caused by widely felt events that are of more immediate interest than those with no human impact. The main benefit of the tweet-based detections is speed, with most detections occurring between 19 seconds and 2 minutes from the origin time. This is considerably faster than seismic detections in poorly instrumented regions of the world. Going beyond the initial detection, the USGS is developing data mining techniques to continuously archive and analyze relevant tweets for additional details about the detected events. The information generated about an event is displayed on a web-based map designed using HTML5 for the mobile environment, which can be valuable when the user is not able to access a

  9. Seismology: dynamic triggering of earthquakes.

    Science.gov (United States)

    Gomberg, Joan; Johnson, Paul

    2005-10-06

    After an earthquake, numerous smaller shocks are triggered over distances comparable to the dimensions of the mainshock fault rupture, although they are rare at larger distances. Here we analyse the scaling of dynamic deformations (the stresses and strains associated with seismic waves) with distance from, and magnitude of, their triggering earthquake, and show that they can cause further earthquakes at any distance if their amplitude exceeds several microstrain, regardless of their frequency content. These triggering requirements are remarkably similar to those measured in the laboratory for inducing dynamic elastic nonlinear behaviour, which suggests that the underlying physics is similar.

  10. Earthquakes, July-August 1992

    Science.gov (United States)

    Person, W.J.

    1992-01-01

    There were two major earthquakes (7.0≤Mearthquake occurred in Kyrgyzstan on August 19 and a magnitude 7.0 quake struck the Ascension Island region on August 28. In southern California, aftershocks of the magnitude 7.6 earthquake on June 28, 1992, continued. One of these aftershocks caused damage and injuries, and at least one other aftershock caused additional damage. Earthquake-related fatalities were reportred in Kyrgzstan and Pakistan. 

  11. Evaluation of impact of earthquake on agriculture in Nepal based on remote sensing

    Science.gov (United States)

    Sekiyama, Ayako; Shimada, Sawahiko; Okazawa, Hiromu; Mihara, Machito; Kuo, Kuang Ting

    2016-07-01

    The big earthquake happening on April, 2015 killed over than 8000 people in Nepal. The effect of earthquake not only affected safety of local people but also agricultural field. Agricultural economy dominates income of local people. Therefore, restoration of agricultural areas are required for improving life of local people. However, lack of information about agricultural areas is main problem for local government to assess and restore damaged agricultural areas. Remote sensing was applied for accessing damaged agricultural field due to its advantages in observing responds of environment without temporal and spatial restriction. Accordingly, the objective of the study is to evaluate impact of earthquake on agriculture in Nepal based on remote sensing. The experimental procedure includes conducting the impact of earthquake on changes of total agricultural area, and analysis of response of greenness affected by earthquake in agricultural land. For conducting agricultural land changes, land use map was first created and classified into four categories: road, city, forest, and agricultural land. Changes before and after earthquake in total area of agricultural land were analyzed by GIS. Moreover, vegetation index was used as indicator for evaluating greenness responds in agricultural land and computed based on high-resolution satellite imagery such as World view-3. Finally, the conclusion of the study and suggestions will be made and provided for helping local government in Nepal restore agricultural areas.

  12. Response of Alum Rock springs to the October 30, 2007 Alum Rock earthquake and implications for the origin of increased discharge after earthquake

    Energy Technology Data Exchange (ETDEWEB)

    Rowland, Joel C [Los Alamos National Laboratory; Manga, Michael [UC BERKELEY

    2009-01-01

    The origin of increased stream flow and spring discharge following earthquakes have been the subject of controversy, in large part because there are many models to explain observations and few measurements suitable for distinguishing between hypotheses. On October 30, 2007 a magnitude 5.5 earthquake occurred near the Alum Rock springs, California, USA. Within a day we documented a several-fold increase in discharge. Over the following year, we have monitored a gradual return towards pre-earthquake properties, but for the largest springs there appears to be a permanent increase in the steady discharge at all the springs. The Alum Rock springs discharge waters that represent a mixture between modern ('shallow') meteoric water and old ('deep') connate waters expelled by regional transpression. After the earthquake, the increased discharge at the largest springs was accompanied by a small decrease in the fraction of connate water in the spring discharge. Combined with the rapid response, this implies that the increased discharge has a shallow origin. Increased discharge at these springs occurs for earthquakes that cause static volumetric expansion and those that cause contraction, supporting models in which dynamic strains are responsible for the subsurface changes that cause flow to increase. We show that models in which the permeability of the fracture system feeding the springs increases after the earthquake are in general consistent with the changes in discharge. The response of these springs to another earthquake will provide critical constraints on the changes that occur in the subsurface.

  13. Générateur de timing local pour l'acquisition des transformateurs rapides (LEIR, LINAC 3, LINAC 2, Ligne d'injection PSB)

    CERN Document Server

    Schnell, J D

    2006-01-01

    Dans le cadre des acquisitions des transformateurs rapides des deux LINACS, de la ligne d'injection PSB et de la machine LEIR, un nouveau hardware a été mis en opération [1]. Celui-ci assure la digitalisation des signaux analogiques et aussi de certains signaux de timing devant cadrer la mesure. Pour ce faire des ADC SIS3300 (SIS3320) et des DPRAM 80408 sont mis en service. Ces unités nécéssitent pour leur fonctionnement des horloges et des timings qui normalement sont intégralement fournis par l'équipement standard CO, notamment des CTRV et autres TG8. Suite à des problèmes d'approvisionnement, il existe des cas où l'on ne dispose pas (du moins pour le court terme) de suffisemment de ressources standard pour pourvoir au timing mentionné plus haut. Le tiroir qui fait l'objet de la présente description assure, avec certaines limitations, la génération des timings et autres horloges utilisées par les DPRAM 80408 et les ADC SIS3300.

  14. Photogrammetry-Based Head Digitization for Rapid and Accurate Localization of EEG Electrodes and MEG Fiducial Markers Using a Single Digital SLR Camera.

    Science.gov (United States)

    Clausner, Tommy; Dalal, Sarang S; Crespo-García, Maité

    2017-01-01

    The performance of EEG source reconstruction has benefited from the increasing use of advanced head modeling techniques that take advantage of MRI together with the precise positions of the recording electrodes. The prevailing technique for registering EEG electrode coordinates involves electromagnetic digitization. However, the procedure adds several minutes to experiment preparation and typical digitizers may not be accurate enough for optimal source reconstruction performance (Dalal et al., 2014). Here, we present a rapid, accurate, and cost-effective alternative method to register EEG electrode positions, using a single digital SLR camera, photogrammetry software, and computer vision techniques implemented in our open-source toolbox, janus3D. Our approach uses photogrammetry to construct 3D models from multiple photographs of the participant's head wearing the EEG electrode cap. Electrodes are detected automatically or semi-automatically using a template. The rigid facial features from these photo-based models are then surface-matched to MRI-based head reconstructions to facilitate coregistration to MRI space. This method yields a final electrode coregistration error of 0.8 mm, while a standard technique using an electromagnetic digitizer yielded an error of 6.1 mm. The technique furthermore reduces preparation time, and could be extended to a multi-camera array, which would make the procedure virtually instantaneous. In addition to EEG, the technique could likewise capture the position of the fiducial markers used in magnetoencephalography systems to register head position.

  15. USGS Earthquake Program GPS Use Case : Earthquake Early Warning

    Science.gov (United States)

    2015-03-12

    USGS GPS receiver use case. Item 1 - High Precision User (federal agency with Stafford Act hazard alert responsibilities for earthquakes, volcanoes and landslides nationwide). Item 2 - Description of Associated GPS Application(s): The USGS Eart...

  16. EARTHQUAKE-INDUCED DEFORMATION STRUCTURES AND RELATED TO EARTHQUAKE MAGNITUDES

    Directory of Open Access Journals (Sweden)

    Savaş TOPAL

    2003-02-01

    Full Text Available Earthquake-induced deformation structures which are called seismites may helpful to clasify the paleoseismic history of a location and to estimate the magnitudes of the potention earthquakes in the future. In this paper, seismites were investigated according to the types formed in deep and shallow lake sediments. Seismites are observed forms of sand dikes, introduced and fractured gravels and pillow structures in shallow lakes and pseudonodules, mushroom-like silts protruding laminites, mixed layers, disturbed varved lamination and loop bedding in deep lake sediments. Earthquake-induced deformation structures, by benefiting from previous studies, were ordered according to their formations and earthquake magnitudes. In this order, the lowest eartquake's record is loop bedding and the highest one is introduced and fractured gravels in lacustrine deposits.

  17. Localized infusions of the partial alpha 7 nicotinic receptor agonist SSR180711 evoke rapid and transient increases in prefrontal glutamate release

    DEFF Research Database (Denmark)

    Bortz, D M; Mikkelsen, J D; Bruno, J P

    2013-01-01

    that inhibited (threo-beta-benzyl-oxy-aspartate (TβOA), 100.0μM) or facilitated (ceftriaxalone, 200mg/kg, i.p.) excitatory amino acid transporters. TβOA slowed both the clearance (s) and rate of clearance (μM/s) by 10-fold, particularly at the mid-late stages of the return to baseline. Ceftriaxone reduced......The ability of local infusions of the alpha 7 nicotinic acetycholine receptor (α7 nAChR) partial agonist SSR180711 to evoke glutamate release in prefrontal cortex was determined in awake rats using a microelectrode array. Infusions of SSR180711 produced dose-dependent increases in glutamate levels...

  18. Application of a Novel and Automated Branched DNA in Situ Hybridization Method for the Rapid and Sensitive Localization of mRNA Molecules in Plant Tissues

    Directory of Open Access Journals (Sweden)

    Andrew J. Bowling

    2014-04-01

    Full Text Available Premise of the study: A novel branched DNA detection technology, RNAscope in situ hybridization (ISH, originally developed for use on human clinical and animal tissues, was adapted for use in plant tissue in an attempt to overcome some of the limitations associated with traditional ISH assays. Methods and Results: Zea mays leaf tissue was formaldehyde fixed and paraffin embedded (FFPE and then probed with the RNAscope ISH assay for two endogenous genes, phosphoenolpyruvate carboxylase (PEPC and phosphoenolpyruvate carboxykinase (PEPCK. Results from both manual and automated methods showed tissue- and cell-specific mRNA localization patterns expected from these well-studied genes. Conclusions: RNAscope ISH is a sensitive method that generates high-quality, easily interpretable results from FFPE plant tissues. Automation of the RNAscope method on the Ventana Discovery Ultra platform allows significant advantages for repeatability, reduction in variability, and flexibility of workflow processes.

  19. Application of a novel and automated branched DNA in situ hybridization method for the rapid and sensitive localization of mRNA molecules in plant tissues.

    Science.gov (United States)

    Bowling, Andrew J; Pence, Heather E; Church, Jeffrey B

    2014-04-01

    A novel branched DNA detection technology, RNAscope in situ hybridization (ISH), originally developed for use on human clinical and animal tissues, was adapted for use in plant tissue in an attempt to overcome some of the limitations associated with traditional ISH assays. • Zea mays leaf tissue was formaldehyde fixed and paraffin embedded (FFPE) and then probed with the RNAscope ISH assay for two endogenous genes, phosphoenolpyruvate carboxylase (PEPC) and phosphoenolpyruvate carboxykinase (PEPCK). Results from both manual and automated methods showed tissue- and cell-specific mRNA localization patterns expected from these well-studied genes. • RNAscope ISH is a sensitive method that generates high-quality, easily interpretable results from FFPE plant tissues. Automation of the RNAscope method on the Ventana Discovery Ultra platform allows significant advantages for repeatability, reduction in variability, and flexibility of workflow processes.

  20. Determination of soil properties from earthquake data

    Science.gov (United States)

    Huerta Lopez, Carlos Isidro

    2002-08-01

    Soil damping and site (system) dominant vibration frequency estimations were obtained by means of the Random Decrement Method (RDM) using numerically simulated time series of soil model responses upon random excitations and real earthquake records. Highly reliable estimations were obtained when the system response was dominated by a distinctive or preferential vibration mode. Different damping mechanisms did not play a significant role in the variability of damping estimations; however, the excitation type did. The damping estimations were highly dependent on how well the Randomdec signature was defined. The alternate methods to measure the decay of the Randomdec signature may produce large variability in the damping estimations. The most consistent and reliable estimations were obtained using the average of the decay every half-cycle of the Randomdec signature. Hurley's method consistently underestimated the damping values by an average of 50%. The frequency estimations were highly consistent when the Randomdec signature is well defined. Horizontal-to-vertical (H/V) spectral ratios were used to characterize local sediment response, and 1-D wave propagation modeling was used to estimate soil properties and theoretical amplification factors of shallow marine sediment layers in an experimental site in the Gulf of Mexico (GOM). Relative to the vertical spectral amplitude, the horizontal spectral amplitudes increased by an order of magnitude at 0.35 Hz, and by at least two orders of magnitude at 1.9 Hz. A 50-m-thick soil system parameterized as three solid layers resting over a half-space with a water layer at the top produced theoretical H/V spectral ratios largely consistent with the observed H/V spectral ratios. The modeling results were consistent with both earthquake and background noise records. The use of background noise offers the advantage of better defining the spectral characteristics of the signal when, during the averaging process, a large ensemble is

  1. Earthquake sources and seismic hazard in Southeastern Sicily

    Directory of Open Access Journals (Sweden)

    R. Rigano

    2001-06-01

    Full Text Available A study of some earthquakes (M > 5.3 affecting Southeastern Sicily was performed to define their seismic sources and to estimate seismic hazard in the region. An analysis of historical reports allowed us to reassess intensities of the 1542, 1693, 1818, 1848 and 1990 earthquakes by using the new European Macroseismic Scale ’98. The new intensity data were used to define parameters and the orientation of seismic sources. The sources obtained were compared with the ones computed using the MCS intensities retrieved from the Catalogue of Strong Italian Earthquakes. The adopted procedure gives results that are statistically significant, but both the epicentre location and source azimuth, in some cases, are strongly affected by the azimuthal gap in the intensity distribution. This is evident mainly for the 1693 January earthquakes. For these earthquakes the macroseismic data uncertainty gives significantly different solutions, and does not allow the events to be associated with known active faults. By handling the new estimated intensity data and using the site seismic histories, the seismic hazard for some localities was calculated. The highest probability of occurrence, for destructive events (I = 10, was obtained in the area between Catania, Lentini and Augusta, suggesting that the seismogenic sources are located near the Ionian coast.

  2. An Overview of Soil Models for Earthquake Response Analysis

    Directory of Open Access Journals (Sweden)

    Halida Yunita

    2015-01-01

    Full Text Available Earthquakes can damage thousands of buildings and infrastructure as well as cause the loss of thousands of lives. During an earthquake, the damage to buildings is mostly caused by the effect of local soil conditions. Depending on the soil type, the earthquake waves propagating from the epicenter to the ground surface will result in various behaviors of the soil. Several studies have been conducted to accurately obtain the soil response during an earthquake. The soil model used must be able to characterize the stress-strain behavior of the soil during the earthquake. This paper compares equivalent linear and nonlinear soil model responses. Analysis was performed on two soil types, Site Class D and Site Class E. An equivalent linear soil model leads to a constant value of shear modulus, while in a nonlinear soil model, the shear modulus changes constantly,depending on the stress level, and shows inelastic behavior. The results from a comparison of both soil models are displayed in the form of maximum acceleration profiles and stress-strain curves.

  3. People’s perspectives and expectations on preparedness against earthquakes: Tehran case study

    Science.gov (United States)

    Jahangiri, Katayoun; Izadkhah, Yasamin O; Montazeri, Ali; Hosseini, Mahmood

    2010-01-01

    information during the aftermath of an earthquake, Discussion: A participatory approach to earthquake-preparedness planning is recommended. This would ensure that program planners use methods, tools, media, and educational materials that are compatible with the culture, needs, and skills of the local communities. Conclusions: The findings of this study also reveal methods and tools that the local community considers to be most effective for earthquake-preparedness planning and management. The development of an earthquake-resistance and a safe community requires a high level of collaboration between broadcasting organizations, seismologists, experts in the disaster- preparedness field, as well as the local community. This will allow for timely planning, development, and dissemination of essential information to all stakeholders including the local communities. PMID:21483203

  4. Historical Review of Tsunamigenic Earthquakes on the Jalisco Coast

    Science.gov (United States)

    Castillo, R.; Ramirez-Herrera, M.

    2013-05-01

    This study aims to discuss, interpret and map in a GIS database, historical data gathered from archives, scientific reports and newspapers, of earthquakes generated along the Jalisco and Colima coasts, to achieve a better understanding of epicenters location and the distribution of earthquake damage. Emphasis is placed on earthquakes that caused or may have caused tsunamis. This coastal area runs parallel to the Rivera's plate subduction, along an active convergent margin. The tectonic setting favors the generation of earthquakes with magnitude Ms≥6.5, causing damages locally and regionally. At least five tsunamis (23/02/1875, 03/06/1932, 22/06/1932, 19/06/1995 and 22/01/2003) have originated locally, two of them of great intensity. Historical data are available since the 16th century, but are scarce since this coast had few populated places. Early chronicles from 16th century described populated villages at Bahía de Banderas, Tomatlán and Barra de Navidad, though in the 18th century the western pacific coast of Jalisco (Nueva Galicia) was almost deserted. Between the 18th century and first half of the 20th century, this section of the Pacific coast experienced a slow occupation process, accelerated over the course of the last fifty years. Historical data analysis and GIS database are necessary in order to answer the questions on: 1) which ones were the most intense earthquakes and tsunamis that originated in the area, and 2) what kind of information is available for each one. This information is relevant to earthquake and tsunami hazard assessment and vulnerability of this area.

  5. Earthquake Early Warning and Public Policy: Opportunities and Challenges

    Science.gov (United States)

    Goltz, J. D.; Bourque, L.; Tierney, K.; Riopelle, D.; Shoaf, K.; Seligson, H.; Flores, P.

    2003-12-01

    Development of an earthquake early warning capability and pilot project were objectives of TriNet, a 5-year (1997-2001) FEMA-funded project to develop a state-of-the-art digital seismic network in southern California. In parallel with research to assemble a protocol for rapid analysis of earthquake data and transmission of a signal by TriNet scientists and engineers, the public policy, communication and educational issues inherent in implementation of an earthquake early warning system were addressed by TriNet's outreach component. These studies included: 1) a survey that identified potential users of an earthquake early warning system and how an earthquake early warning might be used in responding to an event, 2) a review of warning systems and communication issues associated with other natural hazards and how lessons learned might be applied to an alerting system for earthquakes, 3) an analysis of organization, management and public policy issues that must be addressed if a broad-based warning system is to be developed and 4) a plan to provide earthquake early warnings to a small number of organizations in southern California as an experimental prototype. These studies provided needed insights into the social and cultural environment in which this new technology will be introduced, an environment with opportunities to enhance our response capabilities but also an environment with significant barriers to overcome to achieve a system that can be sustained and supported. In this presentation we will address the main public policy issues that were subjects of analysis in these studies. They include a discussion of the possible division of functions among organizations likely to be the principle partners in the management of an earthquake early warning system. Drawing on lessons learned from warning systems for other hazards, we will review the potential impacts of false alarms and missed events on warning system credibility, the acceptability of fully automated

  6. Earthquake Risk Reduction to Istanbul Natural Gas Distribution Network

    Science.gov (United States)

    Zulfikar, Can; Kariptas, Cagatay; Biyikoglu, Hikmet; Ozarpa, Cevat

    2017-04-01

    Earthquake Risk Reduction to Istanbul Natural Gas Distribution Network Istanbul Natural Gas Distribution Corporation (IGDAS) is one of the end users of the Istanbul Earthquake Early Warning (EEW) signal. IGDAS, the primary natural gas provider in Istanbul, operates an extensive system 9,867km of gas lines with 750 district regulators and 474,000 service boxes. The natural gas comes to Istanbul city borders with 70bar in 30inch diameter steel pipeline. The gas pressure is reduced to 20bar in RMS stations and distributed to district regulators inside the city. 110 of 750 district regulators are instrumented with strong motion accelerometers in order to cut gas flow during an earthquake event in the case of ground motion parameters exceeds the certain threshold levels. Also, state of-the-art protection systems automatically cut natural gas flow when breaks in the gas pipelines are detected. IGDAS uses a sophisticated SCADA (supervisory control and data acquisition) system to monitor the state-of-health of its pipeline network. This system provides real-time information about quantities related to pipeline monitoring, including input-output pressure, drawing information, positions of station and RTU (remote terminal unit) gates, slum shut mechanism status at 750 district regulator sites. IGDAS Real-time Earthquake Risk Reduction algorithm follows 4 stages as below: 1) Real-time ground motion data transmitted from 110 IGDAS and 110 KOERI (Kandilli Observatory and Earthquake Research Institute) acceleration stations to the IGDAS Scada Center and KOERI data center. 2) During an earthquake event EEW information is sent from IGDAS Scada Center to the IGDAS stations. 3) Automatic Shut-Off is applied at IGDAS district regulators, and calculated parameters are sent from stations to the IGDAS Scada Center and KOERI. 4) Integrated building and gas pipeline damage maps are prepared immediately after the earthquake event. The today's technology allows to rapidly estimate the

  7. The Early Warning System(EWS) as First Stage to Generate and Develop Shake Map for Bucharest to Deep Vrancea Earthquakes

    Science.gov (United States)

    Marmureanu, G.; Ionescu, C.; Marmureanu, A.; Grecu, B.; Cioflan, C.

    2007-12-01

    EWS made by NIEP is the first European system for real-time early detection and warning of the seismic waves in case of strong deep earthquakes. EWS uses the time interval (28-32 seconds) between the moment when earthquake is detected by the borehole and surface local accelerometers network installed in the epicenter area (Vrancea) and the arrival time of the seismic waves in the protected area, to deliver timely integrated information in order to enable actions to be taken before a main destructive shaking takes place. Early warning system is viewed as part of an real-time information system that provide rapid information, about an earthquake impeding hazard, to the public and disaster relief organizations before (early warning) and after a strong earthquake (shake map).This product is fitting in with other new product on way of National Institute for Earth Physics, that is, the shake map which is a representation of ground shaking produced by an event and it will be generated automatically following large Vrancea earthquakes. Bucharest City is located in the central part of the Moesian platform (age: Precambrian and Paleozoic) in the Romanian Plain, at about 140 km far from Vrancea area. Above a Cretaceous and a Miocene deposit (with the bottom at roundly 1,400 m of depth), a Pliocene shallow water deposit (~ 700m thick) was settled. The surface geology consists mainly of Quaternary alluvial deposits. Later loess covered these deposits and the two rivers crossing the city (Dambovita and Colentina) carved the present landscape. During the last century Bucharest suffered heavy damage and casualties due to 1940 (Mw = 7.7) and 1977 (Mw = 7.4) Vrancea earthquakes. For example, 32 high tall buildings collapsed and more then 1500 people died during the 1977 event. The innovation with comparable or related systems worldwide is that NIEP will use the EWS to generate a virtual shake map for Bucharest (140 km away of epicentre) immediately after the magnitude is estimated

  8. Earthquake in Haiti

    DEFF Research Database (Denmark)

    Holm, Isak Winkel

    2012-01-01

    In the vocabulary of modern disaster research, Heinrich von Kleist's seminal short story "The Earthquake in Chile" from 1806 is a tale of disaster vulnerability. The story is not just about a natural disaster destroying the innocent city of Santiago but also about the ensuing social disaster...... orchestrated by the citizens of Santiago themselves. Three cognitive schemes play a role for the way Kleist – and his fictional characters – imagine the vulnerability of human society: the theodicy, the sublime, and the state of exception. These three symbolic forms are part of the surprisingly small...... and surprisingly stable repertoire of cultural concepts and images that, for several centuries now, govern the way we think about disasters and the way we act when they strike. The task of a cultural disaster research, the essay suggests, is to study the deep grammar of our common imagination of disaster surfacing...

  9. Dynamics of Earthquake Faults

    CERN Document Server

    Carlson, J M; Shaw, B E

    1993-01-01

    We present an overview of our ongoing studies of the rich dynamical behavior of the uniform, deterministic Burridge--Knopoff model of an earthquake fault. We discuss the behavior of the model in the context of current questions in seismology. Some of the topics considered include: (1) basic properties of the model, such as the magnitude vs. frequency distribution and the distinction between small and large events; (2) dynamics of individual events, including dynamical selection of rupture propagation speeds; (3) generalizations of the model to more realistic, higher dimensional models; (4) studies of predictability, in which artificial catalogs generated by the model are used to test and determine the limitations of pattern recognition algorithms used in seismology.

  10. Status of Public Earthquake Early Warning in the U.S

    Science.gov (United States)

    Given, D. D.

    2013-12-01

    system's effectiveness. We have developed an internet-based UserDisplay application and a smartphone app based on Google Cloud Messaging. In addition, USGS has applied for authorization to alert over FEMA's Integrated Pubic Alert and Warning System. We are also working with private companies to develop alert distribution channels and end user implementation capabilities. Finally, because policy makers, institutional users, and the public must be educated about the system, social scientists and communicators are determining how to communicate the alerts most effectively. Progress is also being made in several related areas. Real-time GPS position data is becoming available on a large scale and algorithms are being developed to use these data to rapidly characterize the fault rupture as it propagates. New, advanced seismological and geodetic algorithms for the Cascadia megathrust and San Andreas fault are being developed. We are exploring public-private partnerships to develop commercial EEW applications. And Federal, State and local agencies are working out their roles and responsibilities in building, operating and educating users about the system. There is much more to be done and funding the creation and operation of this new capability is a challenge in the current budget climate. However, our goal is to build an EEW system before the next big earthquake rather than in its aftermath.

  11. Better to light a candle than curse the darkness: illuminating spatial localization and temporal dynamics of rapid microbial growth in the rhizosphere

    Directory of Open Access Journals (Sweden)

    Patrick M Herron

    2013-09-01

    Full Text Available The rhizosphere is a hotbed of microbial activity in ecosystems, fueled by carbon compounds from plant roots. Basic questions about the location and dynamics of plant-spurred microbial growth in the rhizosphere are difficult to answer with standard, destructive soil assays mixing a multitude of microbe-scale microenvironments in a single, often sieved, sample. Soil microbial biosensors designed with the luxCDABE reporter genes fused to a promoter of interest enable continuous imaging of the microbial perception of (and response to environmental conditions in soil. We used the common soil bacterium Pseudomonas putida KT2440 as host to plasmid pZKH2 containing a fusion between the strong constituitive promoter nptII and luxCDABE (coding for light-emitting proteins from Vibrio fischeri. Experiments in liquid media demonstrated that high light production by KT2440/pZKH2 was associated with rapid microbial growth supported by high carbon availability. We applied the biosensors in microcosms filled with non-sterile soil in which corn (Zea mays L., black poplar (Populus nigra L. or tomato (Solanum lycopersicum L. was growing. We detected minimal light production from microbiosensors in the bulk soil, but biosensors reported continuously from around roots for as long as six days. For corn, peaks of luminescence were detected 1-4 and 20-35 mm along the root axis behind growing root tips, with the location of maximum light production moving farther back from the tip as root growth rate increased. For poplar, luminescence around mature roots increased and decreased on a coordinated diel rhythm, but was not bright near root tips. For tomato, luminescence was dynamic, but did not exhibit a diel rhythm, appearing in acropetal waves along roots. KT2440/pZKH2 revealed that root tips are not always the only, or even the dominant, hotspots for rhizosphere microbial growth, and carbon availability is highly variable in space and time around roots.

  12. Source mechanisms of the 2004 Baladeh (Iran) earthquake sequence from Iranian broadband and short-period data and seismotectonic implications

    DEFF Research Database (Denmark)

    Donner, S.; Rössler, Dirk; Krüger, F.

    -SSW oriented shortening. On 28th of May 2004 the Mw 6.3 Baladeh earthquake hit the north-central Alborz Mountains. It is one of the rare and large events in this region in modern time and thus a seldom chance to study earthquake mechanisms and the local ongoing deformation processes. It also demonstrated...

  13. POTENTIAL DEFICIENCIES IN EDUCATION, INSTRUMENTATION, AND WARNINGS FOR LOCALLY GENERATED TSUNAMIS

    Directory of Open Access Journals (Sweden)

    Daniel A. Walker

    2010-01-01

    Full Text Available A review of historical data for Hawaii reveals that significant tsunamis have been reported for only four of twenty-six potentially tsunamigenic earthquakes from 1868 through 2009 with magnitudes of 6.0 or greater. During the same time period, three significant tsunamis have been reported for substantially smaller earthquakes. This historical perspective, the fact that the last significant local tsunami occurred in 1975, and an understandable preoccupation with tsunamis generated around the margins of the Pacific, all combine to suggest apparent deficiencies in: (1 personal awareness of what to do in the event of a possible local tsunami; (2 the distribution of instrumentation capable of providing rapid confirmation that a local tsunami has been generated; and (3 the subsequent issuance of timely warnings for local tsunamis. With these deficiencies, far more lives may be lost in Hawaii due to local tsunamis than will result from tsunamis that have originated along the margins of the Pacific. Similar deficiencies may exist in other areas of the world threatened by local tsunamis.

  14. Size dependent rupture growth at the scale of real earthquake

    Science.gov (United States)

    Colombelli, Simona; Festa, Gaetano; Zollo, Aldo

    2017-04-01

    time evolution of Pd between small and large earthquakes, with very rapid time variations for small-to-moderate events, and a smoother evolution of the curve for the large events, even at the very beginning of the rupture process. Our observations, along with previous laboratory rupture experiments, support the evidence for a characterizing size of the earthquake nucleation zone, which plays a key role in the following rupture evolution, affecting the fate of the earthquake in terms of final rupture extent. Using the Iwate-Miyagi sequence data, we investigated how to quickly measure the initial slope variation of the recorded signals, in order to rapidly distinguish a small event from a large earthquake. The proposed approach could be used in real-time, in the context of Earthquake Early Warning Applications, to quickly infer the expected size of the ongoing event and possibly activate the issuance of a warning.

  15. Surgery under extreme conditions in the aftermath of the 2010 Haiti earthquake: the importance of regional anesthesia.

    Science.gov (United States)

    Missair, Andres; Gebhard, Ralf; Pierre, Edgar; Cooper, Lebron; Lubarsky, David; Frohock, Jeffery; Pretto, Ernesto A

    2010-01-01

    The 12 January 2010 earthquake that struck Port-au-Prince, Haiti caused >200,000 deaths, thousands of injuries requiring immediate surgical interventions, and 1.5 million internally displaced survivors. The earthquake destroyed or disabled most medical facilities in the city, seriously hampering the ability to deliver immediate life- and limb-saving surgical care. A Project Medishare/University of Miami Miller School of Medicine trauma team deployed to Haiti from Miami within 24 hours of the earthquake. The team began work at a pre-existing tent facility in the United Nations (UN) compound based at the airport, where they encountered 225 critically injured patients. However, non-sterile conditions, no means to administer oxygen, the lack of surgical equipment and supplies, and no anesthetics precluded the immediate delivery of general anesthesia. Despite these limitations, resuscitative care was administered, and during the first 72 hours following the event, some amputations were performed with local anesthesia. Because of these austere conditions, an anesthesiologist, experienced and equipped to administer regional block anesthesia, was dispatched three days later to perform anesthesia for limb amputations, debridements, and wound care using single shot block anesthesia until a better equipped tent facility was established. After four weeks, the relief effort evolved into a 250-bed, multi-specialty trauma/intensive care center staffed with >200 medical, nursing, and administrative staff. Within that timeframe, the facility and its staff completed 1,000 surgeries, including spine and pediatric neurological procedures, without major complications. This experience suggests that when local emergency medical resources are completely destroyed or seriously disabled, a surgical team staffed and equipped to provide regional nerve block anesthesia and acute pain management can be dispatched rapidly to serve as a bridge to more advanced field surgical and intensive care

  16. Quantifying slip balance in the earthquake cycle: Coseismic slip model constrained by interseismic coupling

    KAUST Repository

    Wang, Lifeng

    2015-11-11

    The long-term slip on faults has to follow, on average, the plate motion, while slip deficit is accumulated over shorter time scales (e.g., between the large earthquakes). Accumulated slip deficits eventually have to be released by earthquakes and aseismic processes. In this study, we propose a new inversion approach for coseismic slip, taking interseismic slip deficit as prior information. We assume a linear correlation between coseismic slip and interseismic slip deficit, and invert for the coefficients that link the coseismic displacements to the required strain accumulation time and seismic release level of the earthquake. We apply our approach to the 2011 M9 Tohoku-Oki earthquake and the 2004 M6 Parkfield earthquake. Under the assumption that the largest slip almost fully releases the local strain (as indicated by borehole measurements, Lin et al., 2013), our results suggest that the strain accumulated along the Tohoku-Oki earthquake segment has been almost fully released during the 2011 M9 rupture. The remaining slip deficit can be attributed to the postseismic processes. Similar conclusions can be drawn for the 2004 M6 Parkfield earthquake. We also estimate the required time of strain accumulation for the 2004 M6 Parkfield earthquake to be ~25 years (confidence interval of [17, 43] years), consistent with the observed average recurrence time of ~22 years for M6 earthquakes in Parkfield. For the Tohoku-Oki earthquake, we estimate the recurrence time of~500-700 years. This new inversion approach for evaluating slip balance can be generally applied to any earthquake for which dense geodetic measurements are available.

  17. Effect of Stress Interaction on the Probability of Occurrence of Characteristic Earthquakes in Southern Apennines

    Science.gov (United States)

    Console, R.; Catalli, F.; Leggeri, M.; Colangelo, A.

    2006-12-01

    It is commonly accepted that neighboring faults can interact, affecting the probability of occurrence of future earthquakes. A large earthquake can change the static stress on surrounding faults up to several hundred kms promoting their rupture, and activating aftershock sequences. In several cases a clear correlation has been noted between the pattern of positive Coulomb stress change and the increase of the local occurrence rate density, both in normal and in strike fault systems. In this study we compute the effect of stress change due to previous historical earthquakes on the probability of occurrence of future earthquakes on neighboring faults. Following the methodology developed in the last decade (e.g. Parsons et al., JGR 2004) we start from the estimate of the probability of occurrence in the next 30 years for a characteristic earthquake on known seismogenic structures, based on a time-dependent renewal model. Then, a physical model for the Coulomb stress change caused by previous earthquakes on these structures is applied. The influence of this stress change on the occurrence rate of characteristic earthquakes is computed taking into account both a permanent (clock advance) and a temporary (state-and- rate) perturbation. We apply the method so developed to the computation of earthquake hazard of the main seismogenic structures recognized in the Southern Apennines region, for which both historical and paleoseismological data are available. This study provides the opportunity of reviewing the problems to be faced in connection with the estimate of the parameters of a renewal model in case of characteristic earthquakes characterized by return times that are longer than the time spanned by the available catalogues, and the concept of characteristic earthquake itself. The results show that the estimated effect of earthquake interaction in this region is small compared with the uncertainties affecting the statistical model used for the basic time

  18. Behavior of Columns During Earthquakes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The behavior of columns during earthquakes is very important since column failures may lead to additional structural failures and result in total building collapses....

  19. Sociological aspects of earthquake prediction

    Science.gov (United States)

    Spall, H.

    1979-01-01

    Henry Spall talked recently with Denis Mileti who is in the Department of Sociology, Colorado State University, Fort Collins, Colo. Dr. Mileti is a sociologst involved with research programs that study the socioeconomic impact of earthquake prediction. 

  20. Earthquake Early Warning with Seismogeodesy: Detection, Location, and Magnitude Estimation

    Science.gov (United States)

    Goldberg, D.; Bock, Y.; Melgar, D.

    2016-12-01

    Earthquake early warning is critical to reducing injuries and casualties in case of a large magnitude earthquake. The system must rely on near-source data to minimize the time between event onset and issuance of a warning. Early warning systems typically use seismic instruments (seismometers and accelerometers), but these instruments experience difficulty maintaining reliable data in the near-source region and undergo magnitude saturation for large events. Global Navigation Satellite System (GNSS) instruments capture the long period motions and have been shown to produce robust estimates of the true size of the earthquake source. However, GNSS is often overlooked in this context in part because it is not precise enough to record the first seismic wave arrivals (P-wave detection), an important consideration for issuing an early warning. GNSS instruments are becoming integrated into early warning, but are not yet fully exploited. Our approach involves the combination of direct measurements from collocated GNSS and accelerometer stations to estimate broadband coseismic displacement and velocity waveforms [Bock et al., 2011], a method known as seismogeodesy. We present the prototype seismogeodetic early warning system developed at Scripps and demonstrate that the seismogeodetic dataset can be used for P-wave detection, hypocenter location, and shaking onset determination. We discuss uncertainties in each of these estimates and include discussion of the sensitivity of our estimates as a function of the azimuthal distribution of monitoring stations. The seismogeodetic combination has previously been shown to be immune to magnitude saturation [Crowell et al., 2013; Melgar et al., 2015]. Rapid magnitude estimation is an important product in earthquake early warning, and is the critical metric in current tsunami hazard warnings. Using the seismogeodetic approach, we refine earthquake magnitude scaling using P-wave amplitudes (Pd) and peak ground displacements (PGD) for a

  1. Non-local competition drives both rapid divergence and prolonged stasis in a model of speciation in populations with degenerate resource consumption

    Directory of Open Access Journals (Sweden)

    Atamas Nicholas

    2012-12-01

    Full Text Available Abstract The theory of speciation is dominated by adaptationist thinking, with less attention to mechanisms that do not affect species adaptation. Degeneracy – the imperfect specificity of interactions between diverse elements of biological systems and their environments – is key to the adaptability of populations. A mathematical model was explored in which population and resource were distributed one-dimensionally according to trait value. Resource consumption was degenerate – neither strictly location-specific nor location-independent. As a result, the competition for resources among the elements of the population was non-local. Two modeling approaches, a modified differential-integral Verhulstian equation and a cellular automata model, showed similar results: narrower degeneracy led to divergent dynamics with suppression of intermediate forms, whereas broader degeneracy led to suppression of diversifying forms, resulting in population stasis with increasing phenotypic homogeneity. Such behaviors did not increase overall adaptation because they continued after the model populations achieved maximal resource consumption rates, suggesting that degeneracy-driven distributed competition for resources rather than selective pressure toward more efficient resource exploitation was the driving force. The solutions were stable in the presence of limited environmental stochastic variability or heritable phenotypic variability. A conclusion was made that both dynamic diversification and static homogeneity of populations may be outcomes of the same process – distributed competition for resource not affecting the overall adaptation – with the difference between them defined by the spread of trait degeneracy in a given environment. Thus, biological degeneracy is a driving force of both speciation and stasis in biology, which, by themselves, are not necessarily adaptive in nature.

  2. Modeling Seismic Cycles of Great Megathrust Earthquakes Across the Scales With Focus at Postseismic Phase

    Science.gov (United States)

    Sobolev, Stephan V.; Muldashev, Iskander A.

    2017-12-01

    Subduction is substantially multiscale process where the stresses are built by long-term tectonic motions, modified by sudden jerky deformations during earthquakes, and then restored by following multiple relaxation processes. Here we develop a cross-scale thermomechanical model aimed to simulate the subduction process from 1 min to million years' time scale. The model employs elasticity, nonlinear transient viscous rheology, and rate-and-state friction. It generates spontaneous earthquake sequences and by using an adaptive time step algorithm, recreates the deformation process as observed naturally during the seismic cycle and multiple seismic cycles. The model predicts that viscosity in the mantle wedge drops by more than three orders of magnitude during the great earthquake with a magnitude above 9. As a result, the surface velocities just an hour or day after the earthquake are controlled by viscoelastic relaxation in the several hundred km of mantle landward of the trench and not by the afterslip localized at the fault as is currently believed. Our model replicates centuries-long seismic cycles exhibited by the greatest earthquakes and is consistent with the postseismic surface displacements recorded after the Great Tohoku Earthquake. We demonstrate that there is no contradiction between extremely low mechanical coupling at the subduction megathrust in South Chile inferred from long-term geodynamic models and appearance of the largest earthquakes, like the Great Chile 1960 Earthquake.

  3. Global earthquake fatalities and population

    Science.gov (United States)

    Holzer, Thomas L.; Savage, James C.

    2013-01-01

    Modern global earthquake fatalities can be separated into two components: (1) fatalities from an approximately constant annual background rate that is independent of world population growth and (2) fatalities caused by earthquakes with large human death tolls, the frequency of which is dependent on world population. Earthquakes with death tolls greater than 100,000 (and 50,000) have increased with world population and obey a nonstationary Poisson distribution with rate proportional to population. We predict that the number of earthquakes with death tolls greater than 100,000 (50,000) will increase in the 21st century to 8.7±3.3 (20.5±4.3) from 4 (7) observed in the 20th century if world population reaches 10.1 billion in 2100. Combining fatalities caused by the background rate with fatalities caused by catastrophic earthquakes (>100,000 fatalities) indicates global fatalities in the 21st century will be 2.57±0.64 million if the average post-1900 death toll for catastrophic earthquakes (193,000) is assumed.

  4. @INGVterremoti: Tweeting the Automatic Detection of Earthquakes

    Science.gov (United States)

    Casarotti, E.; Amato, A.; Comunello, F.; Lauciani, V.; Nostro, C.; Polidoro, P.

    2014-12-01

    The use of social media is emerging as a powerful tool fordisseminating trusted information about earthquakes. Since 2009, theTwitter account @INGVterremoti provides constant and timely detailsabout M2+ seismic events detected by the Italian National SeismicNetwork, directly connected with the seismologists on duty at IstitutoNazionale di Geofisica e Vulcanologia (INGV). After the 2012 seismicsequence, the account has been awarded by a national prize as the"most useful Twitter account". Currently, it updates more than 110,000followers (one the first 50 Italian Twitter accounts for number offollowers). Nevertheless, since it provides only the manual revisionof seismic parameters, the timing (approximately between 10 and 20minutes after an event) has started to be under evaluation.Undeniably, mobile internet, social network sites and Twitter in particularrequire a more rapid and "real-time" reaction.During the last 18 months, INGV tested the tweeting of the automaticdetection of M3+ earthquakes, obtaining results reliable enough to bereleased openly 1 or 2 minutes after a seismic event. During the summerof 2014, INGV, with the collaboration of CORIS (Department ofCommunication and Social Research, Sapienza University of Rome),involved the followers of @INGVterremoti and citizens, carrying out aquali-quantitative study (through in-depth interviews and a websurvey) in order to evaluate the best format to deliver suchinformation. In this presentation we will illustrate the results of the reliability test and theanalysis of the survey.

  5. Tweeting Earthquakes using TensorFlow

    Science.gov (United States)

    Casarotti, E.; Comunello, F.; Magnoni, F.

    2016-12-01

    The use of social media is emerging as a powerful tool for disseminating trusted information about earthquakes. Since 2009, the Twitter account @INGVterremoti provides constant and timely details about M2+ seismic events detected by the Italian National Seismic Network, directly connected with the seismologists on duty at Istituto Nazionale di Geofisica e Vulcanologia (INGV). Currently, it updates more than 150,000 followers. Nevertheless, since it provides only the manual revision of seismic parameters, the timing (approximately between 10 and 20 minutes after an event) has started to be under evaluation. Undeniably, mobile internet, social network sites and Twitter in particular require a more rapid and "real-time" reaction. During the last 36 months, INGV tested the tweeting of the automatic detection of M3+ earthquakes, studying the reliability of the information both in term of seismological accuracy that from the point of view of communication and social research. A set of quality parameters (i.e. number of seismic stations, gap, relative error of the location) has been recognized to reduce false alarms and the uncertainty of the automatic detection. We present an experiment to further improve the reliability of this process using TensorFlow™ (an open source software library originally developed by researchers and engineers working on the Google Brain Team within Google's Machine Intelligence research organization).

  6. Combining multiple earthquake models in real time for earthquake early warning

    Science.gov (United States)

    Minson, Sarah E.; Wu, Stephen; Beck, James L; Heaton, Thomas H.

    2017-01-01

    The ultimate goal of earthquake early warning (EEW) is to provide local shaking information to users before the strong shaking from an earthquake reaches their location. This is accomplished by operating one or more real‐time analyses that attempt to predict shaking intensity, often by estimating the earthquake’s location and magnitude and then predicting the ground motion from that point source. Other EEW algorithms use finite rupture models or may directly estimate ground motion without first solving for an earthquake source. EEW performance could be improved if the information from these diverse and independent prediction models could be combined into one unified, ground‐motion prediction. In this article, we set the forecast shaking at each location as the common ground to combine all these predictions and introduce a Bayesian approach to creating better ground‐motion predictions. We also describe how this methodology could be used to build a new generation of EEW systems that provide optimal decisions customized for each user based on the user’s individual false‐alarm tolerance and the time necessary for that user to react.

  7. Tectonic tremor activity associated with teleseismic and nearby earthquakes

    Science.gov (United States)

    Chao, K.; Obara, K.; Peng, Z.; Pu, H. C.; Frank, W.; Prieto, G. A.; Wech, A.; Hsu, Y. J.; Yu, C.; Van der Lee, S.; Apley, D. W.

    2016-12-01

    Tectonic tremor is an extremely stress-sensitive seismic phenomenon located in the brittle-ductile transition section of a fault. To better understand the stress interaction between tremor and earthquake, we conduct the following studies: (1) search for triggered tremor globally, (2) examine ambient tremor activities associated with distant earthquakes, and (3) quantify the temporal variation of ambient tremor activity before and after nearby earthquakes. First, we developed a Matlab toolbox to enhance the searching of triggered tremor globally. We have discovered new tremor sources in the inland faults in Kyushu, Kanto, and Hokkaido in Japan, southern Chile, Ecuador, and central Colombia in South America, and in South Italy. Our findings suggest that tremor is more common than previously believed and indicate the potential existence of ambient tremor in the triggered tremor active regions. Second, we adapt the statistical analysis to examine whether the long-term ambient tremor rate may affect by the dynamic stress of teleseismic earthquakes. We analyzed the data in Nankai, Hokkaido, Cascadia, and Taiwan. Our preliminary results did not show an apparent increase of ambient tremor rate after the passing of surface waves. Third, we quantify temporal changes in ambient tremor activity before and after the occurrence of local earthquakes under the southern Central Range of Taiwan with magnitudes of >=5.5 from 2004 to 2016. For a particular case, we found a temporal variation of tremor rate before and after the 2010/03/04 Mw6.3 earthquake, located about 20 km away from the active tremor source. The long-term increase in the tremor rate after the earthquake could have been caused by an increase in static stress following the mainshock. For comparison, clear evidence from seismic and GPS observations indicate a short-term increase in the tremor rate a few weeks before the mainshock. The increase in the tremor rate before the mainshock could correlate with stress changes

  8. Dynamic Source Inversion of Intermediate Depth Earthquakes in Mexico

    Science.gov (United States)

    Yuto Sho Mirwald, Aron; Cruz-Atienza, Victor Manuel; Krishna Singh-Singh, Shri

    2017-04-01

    The source mechanisms of earthquakes at intermediate depth (50-300 km) are still under debate. Due to the high confining pressure at depths below 50 km, rocks ought to deform by ductile flow rather than brittle failure, which is the mechanism originating most earthquakes. Several source mechanisms have been proposed, but for neither of them conclusive evidence has been found. One of two viable mechanisms is Dehydration Embrittlement, where liberation of water lowers the effective pressure and enables brittle fracture. The other is Thermal Runaway, a highly localized ductile deformation (Prieto et. al., Tecto., 2012). In the Mexican subduction zone, intermediate depth earthquakes represent a real hazard in central Mexico due to their proximity to highly populated areas and the large accelerations induced on ground motion (Iglesias et. al., BSSA, 2002). To improve our understanding of these rupture processes, we use a recently introduced inversion method (Diaz-Mojica et. al., JGR, 2014) to analyze several intermediate depth earthquakes in Mexico. The method inverts strong motion seismograms to determine the dynamic source parameters based on a genetic algorithm. It has been successfully used for the M6.5 Zumpango earthquake that occurred at a depth of 62 km in the state of Guerrero, Mexico. For this event, high radiated energy, low radiation efficiency and low rupture velocity were determined. This indicates a highly dissipative rupture process, suggesting that Thermal Runaway could probably be the dominant source process. In this work we improved the inversion method by introducing a theoretical consideration for the nucleation process that minimizes the effects of rupture initiation and guarantees self-sustained rupture propagation (Galis et. al., GJInt., 2014). Preliminary results indicate that intermediate depth earthquakes in central Mexico may vary in their rupture process. For instance, for a M5.9 normal-faulting earthquake at 55 km depth that produced very

  9. Moving towards the operational seismogeodesy component of earthquake and tsunami early warning

    Science.gov (United States)

    Haase, J. S.; Bock, Y.; Geng, J.; Melgar, D.; Crowell, B. W.; Squibb, M. B.

    2013-12-01

    A robust technique for rapid estimation of extended earthquake source properties from seismogeodetic (combined seismic acceleration and GPS displacement) time series has been demonstrated for recent large events. By simulating the recording and analysis of GPS and seismic data in real time using Precise Point Positioning with Ambiguity Resolution (PPP-AR) we have determined the latency in creating a fast-Centroid Moment Tensor (fast-CMT) solution to be less than 3 minutes following the initiation of rupture for the 2011 M9.0 Tohoku-Oki tsunamigenic earthquake. This would have made an estimate of the ~290 km source length available in time to update an early warning of the impending tsunami with a better estimate of the wave height. Combining this information with wave gauge data, which could also be implemented in real time, provides improved estimates of tsunami run-up heights at coastal sites (see Melgar et al., 'Near-field tsunami models with rapid earthquake source inversions', this meeting). The fast-CMT method produces continuous updates of a static source inversion using many possible line source fault geometries to determine a rough estimate of the fault slip and area that does not rely on a priori assumptions about fault zone geometry. The key to this new capability is robust, fast, and accurate analysis of real-time 1Hz GPS data that incorporates the following advances: 1) a real time GPS service that produces satellite clocks and fractional cycle biases available for positioning individual sites within the San Andreas fault system and Cascadia subduction zone. This means cpu requirements increase linearly with the number of sites in PPP mode, increasing the feasibility of analyzing data from large dense networks in real time; 2) the tightly-coupled Kalman filter combination of GPS observations with local accelerometer data. This provides ambiguity resolution comparable in quality to a network solution and real-time precision of mitigate errors due to

  10. iOS and OS X Apps for Exploring Earthquake Activity

    Science.gov (United States)

    Ammon, C. J.

    2015-12-01

    The U.S. Geological Survey and many other agencies rapidly provide information following earthquakes. This timely information garners great public interest and provides a rich opportunity to engage students in discussion and analysis of earthquakes and tectonics. In this presentation I will describe a suite of iOS and Mac OS X apps that I use for teaching and that Penn State employs in outreach efforts in a small museum run by the College of Earth and Mineral Sciences. The iOS apps include a simple, global overview of earthquake activity, epicentral, designed for a quick review or event lookup. A more full-featured iPad app, epicentral-plus, includes a simple global overview along with views that allow a more detailed exploration of geographic regions of interest. In addition, epicentral-plus allows the user to monitor ground motions using seismic channel lists compatible with the IRIS web services. Some limited seismogram processing features are included to allow focus on appropriate signal bandwidths. A companion web site, which includes background material on earthquakes, and a blog that includes sample images and channel lists appropriate for monitoring earthquakes in regions of recent earthquake activity can be accessed through the a third panel in the app. I use epicentral-plus at the beginning of each earthquake seismology class to review recent earthquake activity and to stimulate students to formulate and to ask questions that lead to discussions of earthquake and tectonic processes. Less interactive OS X versions of the apps are used to display a global map of earthquake activity and seismograms in near real time in a small museum on the ground floor of the building hosting Penn State's Geoscience Department.

  11. The smart cluster method. Adaptive earthquake cluster identification and analysis in strong seismic regions

    Science.gov (United States)

    Schaefer, Andreas M.; Daniell, James E.; Wenzel, Friedemann

    2017-07-01

    Earthquake clustering is an essential part of almost any statistical analysis of spatial and temporal properties of seismic activity. The nature of earthquake clusters and subsequent declustering of earthquake catalogues plays a crucial role in determining the magnitude-dependent earthquake return period and its respective spatial variation for probabilistic seismic hazard assessment. This study introduces the Smart Cluster Method (SCM), a new methodology to identify earthquake clusters, which uses an adaptive point process for spatio-temporal cluster identification. It utilises the magnitude-dependent spatio-temporal earthquake density to adjust the search properties, subsequently analyses the identified clusters to determine directional variation and adjusts its search space with respect to directional properties. In the case of rapid subsequent ruptures like the 1992 Landers sequence or the 2010-2011 Darfield-Christchurch sequence, a reclassification procedure is applied to disassemble subsequent ruptures using near-field searches, nearest neighbour classification and temporal splitting. The method is capable of identifying and classifying earthquake clusters in space and time. It has been tested and validated using earthquake data from California and New Zealand. A total of more than 1500 clusters have been found in both regions since 1980 with M m i n = 2.0. Utilising the knowledge of cluster classification, the method has been adjusted to provide an earthquake declustering algorithm, which has been compared to existing methods. Its performance is comparable to established methodologies. The analysis of earthquake clustering statistics lead to various new and updated correlation functions, e.g. for ratios between mainshock and strongest aftershock and general aftershock activity metrics.

  12. Earthquake potential in California-Nevada implied by correlation of strain rate and seismicity

    Science.gov (United States)

    Zeng, Yuehua; Petersen, Mark D.; Shen, Zheng-Kang

    2018-01-01

    Rock mechanics studies and dynamic earthquake simulations show that patterns of seismicity evolve with time through (1) accumulation phase, (2) localization phase, and (3) rupture phase. We observe a similar pattern of changes in seismicity during the past century across California and Nevada. To quantify these changes, we correlate GPS strain rates with seismicity. Earthquakes of M > 6.5 are collocated with regions of highest strain rates. By contrast, smaller magnitude earthquakes of M ≥ 4 show clear spatiotemporal changes. From 1933 to the late 1980s, earthquakes of M ≥ 4 were more diffused and broadly distributed in both high and low strain rate regions (accumulation phase). From the late 1980s to 2016, earthquakes were more concentrated within the high strain rate areas focused on the major fault strands (localization phase). In the same time period, the rate of M > 6.5 events also increased significantly in the high strain rate areas. The strong correlation between current strain rate and the later period of seismicity indicates that seismicity is closely related to the strain rate. The spatial patterns suggest that before the late 1980s, the strain rate field was also broadly distributed because of the stress shadows from previous large earthquakes. As the deformation field evolved out of the shadow in the late 1980s, strain has refocused on the major fault systems and we are entering a period of increased risk for large earthquakes in California.

  13. Stress Concentration Phenomenon Before the 2011 M9.0 Tohoku-Oki Earthquake: its Implication for Earthquake Prediction

    Science.gov (United States)

    Zhang, Y. Q.; Xie, F. R.

    2014-12-01

    According to rock mechanics, there exists a stage of stress accumulation before final failure, this kind of stage also exists in the seismogenic process, but this kind of stage always hide behind the vast seismicity data . There are 5 large eartquakes (M>7.0) , generalized foreshocks, occurred in the source region of M9.0 Tohoku-Oki Earthquake from 2003 to 2011, and they formed a very narrow belt, which is nearly perpendicular to the strike of the Japan Trench. We performed temporal and spatial analysis to the stresses before and after the mainshock from static stress change and focal mechanism solutions. We derived a tectonic stress field model in the vicinity of the source area of the M9.0 North-eastern Japan Earthquake from modeling seismicity and analyzing earthquake focal mechanisms before and after the mainshock. The results show that the stress field in source region barely had any change before and after each large earthquake prior to the M9.0 mainshock. The stress state did not change in the places where are distant away from the rupture center of the M9.0 mainshock during its occurrence, with the azimuth of the maximum principal stress to be 290º, which is perpendicular to the strike of the Japan trench, and dip angle to be 19º. In comparison, the static stress has significant change in the central part of the source region after mainshock, with the occurrence of numerous normal fault type events. There exists an area with negative stress change in the source area of the M9.0 earthquake after the mainshock, with the P axis rotated from horizontal to vertical, which are responsible for numerous normal faulting events, where was dominated by thrust faulting prior to the mainshock. This pattern indicates a complete stress and strain release or locally stresses regime change. Our results provide a constrain to the stress accumulation- release pattern spatially and temporally for the source region of 2011 Tohoku-Oki earthquake. We suggested that the

  14. Response and recovery lessons from the 2010-2011 earthquake sequence in Canterbury, New Zealand

    Science.gov (United States)

    Pierepiekarz, Mark; Johnston, David; Berryman, Kelvin; Hare, John; Gomberg, Joan S.; Williams, Robert A.; Weaver, Craig S.

    2014-01-01

    The impacts and opportunities that result when low-probability moderate earthquakes strike an urban area similar to many throughout the US were vividly conveyed in a one-day workshop in which social and Earth scientists, public officials, engineers, and an emergency manager shared their experiences of the earthquake sequence that struck the city of Christchurch and surrounding Canterbury region of New Zealand in 2010-2011. Without question, the earthquake sequence has had unprecedented impacts in all spheres on New Zealand society, locally to nationally--10% of the country's population was directly impacted and losses total 8-10% of their GDP. The following paragraphs present a few lessons from Christchurch.

  15. Comparison of two large earthquakes: the 2008 Sichuan Earthquake and the 2011 East Japan Earthquake.

    Science.gov (United States)

    Otani, Yuki; Ando, Takayuki; Atobe, Kaori; Haiden, Akina; Kao, Sheng-Yuan; Saito, Kohei; Shimanuki, Marie; Yoshimoto, Norifumi; Fukunaga, Koichi

    2012-01-01

    Between August 15th and 19th, 2011, eight 5th-year medical students from the Keio University School of Medicine had the opportunity to visit the Peking University School of Medicine and hold a discussion session titled "What is the most effective way to educate people for survival in an acute disaster situation (before the mental health care stage)?" During the session, we discussed the following six points: basic information regarding the Sichuan Earthquake and the East Japan Earthquake, differences in preparedness for earthquakes, government actions, acceptance of medical rescue teams, earthquake-induced secondary effects, and media restrictions. Although comparison of the two earthquakes was not simple, we concluded that three major points should be emphasized to facilitate the most effective course of disaster planning and action. First, all relevant agencies should formulate emergency plans and should supply information regarding the emergency to the general public and health professionals on a normal basis. Second, each citizen should be educated and trained in how to minimize the risks from earthquake-induced secondary effects. Finally, the central government should establish a single headquarters responsible for command, control, and coordination during a natural disaster emergency and should centralize all powers in this single authority. We hope this discussion may be of some use in future natural disasters in China, Japan, and worldwide.

  16. Exponential decline of aftershocks of the M7.9 1868 great Kau earthquake, Hawaii, through the 20th century

    Science.gov (United States)

    Klein, F.W.; Wright, Tim

    2008-01-01

    The remarkable catalog of Hawaiian earthquakes going back to the 1820s is based on missionary diaries, newspaper accounts, and instrumental records and spans the great M7.9 Kau earthquake of April 1868 and its aftershock sequence. The earthquake record since 1868 defines a smooth curve complete to M5.2 of the declining rate into the 21st century, after five short volcanic swarms are removed. A single aftershock curve fits the earthquake record, even with numerous M6 and 7 main shocks and eruptions. The timing of some moderate earthquakes may be controlled by magmatic stresses, but their overall long-term rate reflects one of aftershocks of the Kau earthquake. The 1868 earthquake is, therefore, the largest and most controlling stress event in the 19th and 20th centuries. We fit both the modified Omori (power law) and stretched exponential (SE) functions to the earthquakes. We found that the modified Omori law is a good fit to the M ??? 5.2 earthquake rate for the first 10 years or so and the more rapidly declining SE function fits better thereafter, as supported by three statistical tests. The switch to exponential decay suggests that a possible change in aftershock physics may occur from rate and state fault friction, with no change in the stress rate, to viscoelastic stress relaxation. The 61-year exponential decay constant is at the upper end of the range of geodetic relaxation times seen after other global earthquakes. Modeling deformation in Hawaii is beyond the scope of this paper, but a simple interpretation of the decay suggests an effective viscosity of 1019 to 1020 Pa s pertains in the volcanic spreading of Hawaii's flanks. The rapid decline in earthquake rate poses questions for seismic hazard estimates in an area that is cited as one of the most hazardous in the United States.

  17. Localization of Living-Bodies Using Single-Frequency Multistatic Doppler Radar System

    Science.gov (United States)

    Miwa, Takashi; Ogiwara, Shun;