Living with earthquakes - development and usage of earthquake-resistant construction methods in European and Asian Antiquity

Science.gov (United States)

Kázmér, Miklós; Major, Balázs; Hariyadi, Agus; Pramumijoyo, Subagyo; Ditto Haryana, Yohanes

2010-05-01

Earthquakes are among the most horrible events of nature due to unexpected occurrence, for which no spiritual means are available for protection. The only way of preserving life and property is applying earthquake-resistant construction methods. Ancient Greek architects of public buildings applied steel clamps embedded in lead casing to hold together columns and masonry walls during frequent earthquakes in the Aegean region. Elastic steel provided strength, while plastic lead casing absorbed minor shifts of blocks without fracturing rigid stone. Romans invented concrete and built all sizes of buildings as a single, unflexible unit. Masonry surrounding and decorating concrete core of the wall did not bear load. Concrete resisted minor shaking, yielding only to forces higher than fracture limits. Roman building traditions survived the Dark Ages and 12th century Crusader castles erected in earthquake-prone Syria survive until today in reasonably good condition. Concrete and steel clamping persisted side-by-side in the Roman Empire. Concrete was used for cheap construction as compared to building of masonry. Applying lead-encased steel increased costs, and was avoided whenever possible. Columns of the various forums in Italian Pompeii mostly lack steel fittings despite situated in well-known earthquake-prone area. Whether frequent recurrence of earthquakes in the Naples region was known to inhabitants of Pompeii might be a matter of debate. Seemingly the shock of the AD 62 earthquake was not enough to apply well-known protective engineering methods throughout the reconstruction of the city before the AD 79 volcanic catastrophe. An independent engineering tradition developed on the island of Java (Indonesia). The mortar-less construction technique of 8-9th century Hindu masonry shrines around Yogyakarta would allow scattering of blocks during earthquakes. To prevent dilapidation an intricate mortise-and-tenon system was carved into adjacent faces of blocks. Only the

Simultaneous estimation of earthquake source parameters and ...

Indian Academy of Sciences (India)

moderate-size aftershocks (Mw 2.1–5.1) of the Mw 7.7 2001 Bhuj earthquake. The horizontal- ... claimed a death toll of 20,000 people. This earth- .... quake occurred west of Kachchh, with an epicenter at 24. ◦. N, 68 ..... for dominance of body waves for R ≤ 100 km ...... Bhuj earthquake sequence; J. Asian Earth Sci. 40.

Earthquakes, detecting and understanding them

International Nuclear Information System (INIS)

2008-05-01

The signatures at the surface of the Earth is continually changing on a geological timescale. The tectonic plates, which make up this surface, are moving in relation to each other. On human timescale, these movements are the result of earthquakes, which suddenly, release energy accumulated over a period of time. The vibrations they produce propagate through the interior of the Earth: these are seismic waves. However, other phenomena can generate seismic waves, such as volcanoes, quarry blasts, etc. The surf of the ocean waves on the coasts, the wind in the trees and human activity (industry and road traffic) all contribute to the 'seismic background noise'. Sensors are able to detect signals from events which are then discriminated, analyzed and located. Earthquakes and active volcanoes are not distributed randomly over the surface of the globe: they mainly coincide with mountain chains and ocean trenches and ridges. 'An earthquake results from the abrupt release of the energy accumulated by movements and rubbing of different plates'. The study of the propagation of seismic waves has allowed to determine the outline of the plates inside the Earth and has highlighted their movements. There are seven major plates which are colliding, diverging or sliding past each other. Each year the continents move several centimeters with respect to one another. This process, known as 'continental drift', was finally explained by plate tectonics. The initial hypothesis for this science dates from the beginning of the 20. century, but it was not confirmed until the 1960's. It explains that convection inside the Earth is the source of the forces required for these movements. This science, as well as explaining these great movements, has provided a coherent, unifying and quantitative framework, which unites the explanations for all the geophysical phenomena under one mechanism. (authors)

PageRank for low frequency earthquake detection

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Aguiar, A. C.; Beroza, G. C.

2013-12-01

We have analyzed Hi-Net seismic waveform data during the April 2006 tremor episode in the Nankai Trough in SW Japan using the autocorrelation approach of Brown et al. (2008), which detects low frequency earthquakes (LFEs) based on pair-wise waveform matching. We have generalized this to exploit the fact that waveforms may repeat multiple times, on more than just a pair-wise basis. We are working towards developing a sound statistical basis for event detection, but that is complicated by two factors. First, the statistical behavior of the autocorrelations varies between stations. Analyzing one station at a time assures that the detection threshold will only depend on the station being analyzed. Second, the positive detections do not satisfy "closure." That is, if window A correlates with window B, and window B correlates with window C, then window A and window C do not necessarily correlate with one another. We want to evaluate whether or not a linked set of windows are correlated due to chance. To do this, we map our problem on to one that has previously been solved for web search, and apply Google's PageRank algorithm. PageRank is the probability of a 'random surfer' to visit a particular web page; it assigns a ranking for a webpage based on the amount of links associated with that page. For windows of seismic data instead of webpages, the windows with high probabilities suggest likely LFE signals. Once identified, we stack the matched windows to improve the snr and use these stacks as template signals to find other LFEs within continuous data. We compare the results among stations and declare a detection if they are found in a statistically significant number of stations, based on multinomial statistics. We compare our detections using the single-station method to detections found by Shelly et al. (2007) for the April 2006 tremor sequence in Shikoku, Japan. We find strong similarity between the results, as well as many new detections that were not found using

GPS detection of ionospheric perturbation before the 13 February 2001, El Salvador earthquake

Science.gov (United States)

Plotkin, V. V.

A large earthquake of M6.6 occurred on 13 February 2001 at 14:22:05 UT in El Salvador. We detected ionospheric perturbation before this earthquake using GPS data received from CORS network. Systematic decreases of ionospheric total electron content during two days before the earthquake onset were observed at set of stations near the earthquake location and probably in region of about 1000 km from epicenter. This result is consistent with that of investigators, which studied these phenomena with several observational techniques. However it is possible, that such TEC changes are simultaneously accompanied by changes due to solar wind parameters and Kp -index.

GPS detection of ionospheric perturbation before the 13 February 2001, El Salvador earthquake

Directory of Open Access Journals (Sweden)

V. V. Plotkin

2003-01-01

Full Text Available A large earthquake of M6.6 occurred on 13 February 2001 at 14:22:05 UT in El Salvador. We detected ionospheric perturbation before this earthquake using GPS data received from CORS network. Systematic decreases of ionospheric total electron content during two days before the earthquake onset were observed at set of stations near the earthquake location and probably in region of about 1000 km from epicenter. This result is consistent with that of investigators, which studied these phenomena with several observational techniques. However it is possible, that such TEC changes are simultaneously accompanied by changes due to solar wind parameters and Kp -index.

Rapid and specific detection of Asian- and African-lineage Zika viruses.

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Chotiwan, Nunya; Brewster, Connie D; Magalhaes, Tereza; Weger-Lucarelli, James; Duggal, Nisha K; Rückert, Claudia; Nguyen, Chilinh; Garcia Luna, Selene M; Fauver, Joseph R; Andre, Barb; Gray, Meg; Black, William C; Kading, Rebekah C; Ebel, Gregory D; Kuan, Guillermina; Balmaseda, Angel; Jaenisch, Thomas; Marques, Ernesto T A; Brault, Aaron C; Harris, Eva; Foy, Brian D; Quackenbush, Sandra L; Perera, Rushika; Rovnak, Joel

2017-05-03

Understanding the dynamics of Zika virus transmission and formulating rational strategies for its control require precise diagnostic tools that are also appropriate for resource-poor environments. We have developed a rapid and sensitive loop-mediated isothermal amplification (LAMP) assay that distinguishes Zika viruses of Asian and African lineages. The assay does not detect chikungunya virus or flaviviruses such as dengue, yellow fever, or West Nile viruses. The assay conditions allowed direct detection of Zika virus RNA in cultured infected cells; in mosquitoes; in virus-spiked samples of human blood, plasma, saliva, urine, and semen; and in infected patient serum, plasma, and semen samples without the need for RNA isolation or reverse transcription. The assay offers rapid, specific, sensitive, and inexpensive detection of the Asian-lineage Zika virus strain that is currently circulating in the Western hemisphere, and can also detect the African-lineage Zika virus strain using separate, specific primers. Copyright © 2017, American Association for the Advancement of Science.

Rapid and specific detection of Asian- and African-lineage Zika viruses

Science.gov (United States)

Chotiwan, Nunya; Brewster, Connie D.; Magalhaes, Tereza; Weger-Lucarelli, James; Duggal, Nisha K.; Rückert, Claudia; Nguyen, Chilinh; Garcia Luna, Selene M.; Fauver, Joseph R.; Andre, Barb; Gray, Meg; Black, William C.; Kading, Rebekah C.; Ebel, Gregory D.; Kuan, Guillermina; Balmaseda, Angel; Jaenisch, Thomas; Marques, Ernesto T. A.; Brault, Aaron C.; Harris, Eva; Foy, Brian D.; Quackenbush, Sandra L.; Perera, Rushika; Rovnak, Joel

2017-01-01

Understanding the dynamics of Zika virus transmission and formulating rational strategies for its control require precise diagnostic tools that are also appropriate for resource-poor environments. We have developed a rapid and sensitive loop-mediated isothermal amplification (LAMP) assay that distinguishes Zika viruses of Asian and African lineages. The assay does not detect chikungunya virus or flaviviruses such as dengue, yellow fever, or West Nile viruses. The assay conditions allowed direct detection of Zika virus RNA in cultured infected cells; in mosquitoes; in virus-spiked samples of human blood, plasma, saliva, urine, and semen; and in infected patient serum, plasma, and semen samples without the need for RNA isolation or reverse transcription. The assay offers rapid, specific, sensitive, and inexpensive detection of the Asian-lineage Zika virus strain that is currently circulating in the Western hemisphere, and can also detect the African-lineage Zika virus strain using separate, specific primers. PMID:28469032

Crustal Deformation Caused by Earthquake Detected by InSAR Technique Using ALOS/PALSAR Data

Science.gov (United States)

Miyagi, Y.; Nishimura, Y.; Takahashi, H.; Shimada, M.

2007-12-01

The Japan Aerospace Exploration Agency (JAXA) launched the Advanced Land Observing Satellite (ALOS), which is commonly called 'Daichi' in Japanese, on 24th January 2006. This satellite has the Phased Array type L- band Synthetic Aperture Radar (PALSAR) following the mission of the Japanese Earth Resource Satellite-1 (JERS-1). The PALSAR is an advanced SAR sensor with up to 10 m of spatial resolution and variable off-nadir angle. The ALOS/PALSAR can determine the position and attitude with high accuracy by use of mounted dual frequency GPS system and high precision star trackers, and L-band SAR sensor is suitable to observe even heavily-vegetated area. Therefore it is expected much better coherent SAR images than the JERS-1 and the other previous C-band SAR satellites, and major step forward for InSAR (Interferometric SAR) technique. Actually, several outstanding results from InSAR measurements have been reported for the period after the launch. In 2007, two big earthquakes causing some damages on the periphery occurred in Japan. One is M6.7 Noto Peninsula earthquake on 25th March 2007, and the other is M6.8 off the Chuetsu region earthquake on 16th July 2007. Because both seismic faults inferred from these earthquakes are located at shallow depth beneath the bottom of the sea near the coast, obvious crustal deformation in a land area were detected by PALSAR data. In Japan, there is a dense nation-wide GPS network (GEONET) composed of more than 1200 GPS sites established and operated by Geographical Survey Institute and a lot of seismometers. Similarly GPS and seismometer could detect signals caused by the earthquakes, so these are noticeable cases from the standpoint of a comparison among various kinds of data. A remote sensing technique like the ALOS/PALSAR has advantage to observe and monitor a disaster occurred in a remote location where it is difficult to get and there has been little geophysical observation. In this presentation, we notice the case of

Protecting your family from earthquakes: The seven steps to earthquake safety

Science.gov (United States)

Developed by American Red Cross, Asian Pacific Fund

2007-01-01

This book is provided here because of the importance of preparing for earthquakes before they happen. Experts say it is very likely there will be a damaging San Francisco Bay Area earthquake in the next 30 years and that it will strike without warning. It may be hard to find the supplies and services we need after this earthquake. For example, hospitals may have more patients than they can treat, and grocery stores may be closed for weeks. You will need to provide for your family until help arrives. To keep our loved ones and our community safe, we must prepare now. Some of us come from places where earthquakes are also common. However, the dangers of earthquakes in our homelands may be very different than in the Bay Area. For example, many people in Asian countries die in major earthquakes when buildings collapse or from big sea waves called tsunami. In the Bay Area, the main danger is from objects inside buildings falling on people. Take action now to make sure your family will be safe in an earthquake. The first step is to read this book carefully and follow its advice. By making your home safer, you help make our community safer. Preparing for earthquakes is important, and together we can make sure our families and community are ready. English version p. 3-13 Chinese version p. 14-24 Vietnamese version p. 25-36 Korean version p. 37-48

Automatic Event Detection and Picking of P, S Seismic Phases for Earthquake Early Warning: A Case Study of the 2008 Wenchuan Earthquake

Science.gov (United States)

WANG, Z.; Zhao, B.

2015-12-01

We develop an automatic seismic phase arrival detection and picking algorithm for the impending earthquakes occurred with diverse focal mechanisms and depths. The polarization analysis of the three-component seismograms is utilized to distinguish between P and S waves through a sliding time window. When applying the short term average/long term average (STA/LTA) method to the polarized data, we also construct a new characteristics function that can sensitively reflect the changes of signals' amplitude and frequency, providing a better detection for the phase arrival. Then an improved combination method of the higher order statistics and the Akaike information criteria (AIC) picker is applied to the refined signal to lock on the arrival time with a higher degree of accuracy. We test our techniques to the aftershocks of the Ms8.0 Wenchuan earthquake, where hundreds of three-component acceleration records with magnitudes of 4.0 to 6.4 are treated. In comparison to the analyst picks, the results of the proposed detection algorithms are shown to perform well and can be applied from a single instrument within a network of stations for the large seismic events in the Earthquake Early Warning System (EEWS).

Stochastic output error vibration-based damage detection and assessment in structures under earthquake excitation

Science.gov (United States)

Sakellariou, J. S.; Fassois, S. D.

2006-11-01

A stochastic output error (OE) vibration-based methodology for damage detection and assessment (localization and quantification) in structures under earthquake excitation is introduced. The methodology is intended for assessing the state of a structure following potential damage occurrence by exploiting vibration signal measurements produced by low-level earthquake excitations. It is based upon (a) stochastic OE model identification, (b) statistical hypothesis testing procedures for damage detection, and (c) a geometric method (GM) for damage assessment. The methodology's advantages include the effective use of the non-stationary and limited duration earthquake excitation, the handling of stochastic uncertainties, the tackling of the damage localization and quantification subproblems, the use of "small" size, simple and partial (in both the spatial and frequency bandwidth senses) identified OE-type models, and the use of a minimal number of measured vibration signals. Its feasibility and effectiveness are assessed via Monte Carlo experiments employing a simple simulation model of a 6 storey building. It is demonstrated that damage levels of 5% and 20% reduction in a storey's stiffness characteristics may be properly detected and assessed using noise-corrupted vibration signals.

First detection of ammonia (NH3 in the Asian summer monsoon upper troposphere

Directory of Open Access Journals (Sweden)

M. Höpfner

2016-11-01

Full Text Available Ammonia (NH3 has been detected in the upper troposphere by the analysis of averaged MIPAS (Michelson Interferometer for Passive Atmospheric Sounding infrared limb-emission spectra. We have found enhanced amounts of NH3 within the region of the Asian summer monsoon at 12–15 km altitude. Three-monthly, 10° longitude  ×  10° latitude average profiles reaching maximum mixing ratios of around 30 pptv in this altitude range have been retrieved, with a vertical resolution of 3–8 km and estimated errors of about 5 pptv. These observations show that loss processes during transport from the boundary layer to the upper troposphere within the Asian monsoon do not deplete the air entirely of NH3. Thus, ammonia might contribute to the so-called Asian tropopause aerosol layer by the formation of ammonium aerosol particles. On a global scale, outside the monsoon area and during different seasons, we could not detect enhanced values of NH3 above the actual detection limit of about 3–5 pptv. This upper bound helps to constrain global model simulations.

Microearthquake detection at 2012 M4.9 Qiaojia earthquake source area , the north of the Xiaojiang Fault in Yunnan, China

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Li, Y.; Yang, H.; Zhou, S.; Yan, C.

2016-12-01

We perform a comprehensive analysis in Yunnan area based on continuous seismic data of 38 stations of Qiaojia Network in Xiaojiang Fault from 2012.3 to 2015.2. We use an effective method: Match and Locate (M&L, Zhang&Wen, 2015) to detect and locate microearthquakes to conduct our research. We first study dynamic triggering around the Xiaojiang Fault in Yunnan. The triggered earthquakes are identified as two impulsive seismic arrivals in 2Hz-highpass-filtered velocity seismograms during the passage of surface waves of large teleseismic earthquakes. We only find two earthquakes that may have triggered regional earthquakes through inspecting their spectrograms: Mexico Mw7.4 earthquake in 03/20/2012 and El Salvador Mw7.3 earthquake in 10/14/2014. To confirm the two earthquakes are triggered instead of coincidence, we use M&L to search if there are any repeating earthquakes. The result of the coefficients shows that it is a coincidence during the surface waves of El Salvador earthquake and whether 2012 Mexico have triggered earthquake is under discussion. We then visually inspect the 2-8Hz-bandpass-filterd velocity envelopes of these years to search for non-volcanic tremor. We haven't detected any signals similar to non-volcanic tremors yet. In the following months, we are going to study the 2012 M4.9 Qiaojia earthquake. It occurred only 30km west of the epicenter of the 2014 M6.5 Ludian earthquake. We use Match and Locate (M&L) technique to detect and relocate microearthquakes that occurred 2 days before and 3 days after the mainshock. Through this, we could obtain several times more events than listed in the catalogs provided by NEIC and reduce the magnitude of completeness Mc. We will also detect microearthquakes along Xiaojiang Fault using template earthquakes listed in the catalogs to learn more about fault shape and other properties of Xiaojiang Fault. Analyzing seismicity near Xiaojiang Fault systematically may cast insight on our understanding of the features of

Testing continuous earthquake detection and location in Alentejo (South Portugal) by waveform coherency analysis

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Matos, Catarina; Grigoli, Francesco; Cesca, Simone; Custódio, Susana

2015-04-01

In the last decade a permanent seismic network of 30 broadband stations, complemented by dense temporary deployments, covered Portugal. This extraordinary network coverage enables now the computation of a high-resolution image of the seismicity of Portugal, which in turn will shed light on the seismotectonics of Portugal. The large data volumes available cannot be analyzed by traditional time-consuming manual location procedures. In this presentation we show first results on the automatic detection and location of earthquakes occurred in a selected region in the south of Portugal Our main goal is to implement an automatic earthquake detection and location routine in order to have a tool to quickly process large data sets, while at the same time detecting low magnitude earthquakes (i.e., lowering the detection threshold). We present a modified version of the automatic seismic event location by waveform coherency analysis developed by Grigoli et al. (2013, 2014), designed to perform earthquake detections and locations in continuous data. The event detection is performed by continuously computing the short-term-average/long-term-average of two different characteristic functions (CFs). For the P phases we used a CF based on the vertical energy trace, while for S phases we used a CF based on the maximum eigenvalue of the instantaneous covariance matrix (Vidale 1991). Seismic event detection and location is obtained by performing waveform coherence analysis scanning different hypocentral coordinates. We apply this technique to earthquakes in the Alentejo region (South Portugal), taking advantage from a small aperture seismic network installed in the south of Portugal for two years (2010 - 2011) during the DOCTAR experiment. In addition to the good network coverage, the Alentejo region was chosen for its simple tectonic setting and also because the relationship between seismicity, tectonics and local lithospheric structure is intriguing and still poorly understood. Inside

Detection of Repeating Earthquakes within the Cascadia Subduction Zone Using 2013-2014 Cascadia Initiative Amphibious Network Data

Science.gov (United States)

Kenefic, L.; Morton, E.; Bilek, S.

2017-12-01

It is well known that subduction zones create the largest earthquakes in the world, like the magnitude 9.5 Chile earthquake in 1960, or the more recent 9.1 magnitude Japan earthquake in 2011, both of which are in the top five largest earthquakes ever recorded. However, off the coast of the Pacific Northwest region of the U.S., the Cascadia subduction zone (CSZ) remains relatively quiet and modern seismic instruments have not recorded earthquakes of this size in the CSZ. The last great earthquake, a magnitude 8.7-9.2, occurred in 1700 and is constrained by written reports of the resultant tsunami in Japan and dating a drowned forest in the U.S. Previous studies have suggested the margin is most likely segmented along-strike. However, variations in frictional conditions in the CSZ fault zone are not well known. Geodetic modeling indicates that the locked seismogenic zone is likely completely offshore, which may be too far from land seismometers to adequately detect related seismicity. Ocean bottom seismometers, as part of the Cascadia Initiative Amphibious Network, were installed directly above the inferred seismogenic zone, which we use to better detect small interplate seismicity. Using the subspace detection method, this study looks to find new seismogenic zone earthquakes. This subspace detection method uses multiple previously known event templates concurrently to scan through continuous seismic data. Template events that make up the subspace are chosen from events in existing catalogs that likely occurred along the plate interface. Corresponding waveforms are windowed on the nearby Cascadia Initiative ocean bottom seismometers and coastal land seismometers for scanning. Detections that are found by the scan are similar to the template waveforms based upon a predefined threshold. Detections are then visually examined to determine if an event is present. The presence of repeating event clusters can indicate persistent seismic patches, likely corresponding to

A study of earthquake-induced building detection by object oriented classification approach

Science.gov (United States)

Sabuncu, Asli; Damla Uca Avci, Zehra; Sunar, Filiz

2017-04-01

Among the natural hazards, earthquakes are the most destructive disasters and cause huge loss of lives, heavily infrastructure damages and great financial losses every year all around the world. According to the statistics about the earthquakes, more than a million earthquakes occur which is equal to two earthquakes per minute in the world. Natural disasters have brought more than 780.000 deaths approximately % 60 of all mortality is due to the earthquakes after 2001. A great earthquake took place at 38.75 N 43.36 E in the eastern part of Turkey in Van Province on On October 23th, 2011. 604 people died and about 4000 buildings seriously damaged and collapsed after this earthquake. In recent years, the use of object oriented classification approach based on different object features, such as spectral, textural, shape and spatial information, has gained importance and became widespread for the classification of high-resolution satellite images and orthophotos. The motivation of this study is to detect the collapsed buildings and debris areas after the earthquake by using very high-resolution satellite images and orthophotos with the object oriented classification and also see how well remote sensing technology was carried out in determining the collapsed buildings. In this study, two different land surfaces were selected as homogenous and heterogeneous case study areas. In the first step of application, multi-resolution segmentation was applied and optimum parameters were selected to obtain the objects in each area after testing different color/shape and compactness/smoothness values. In the next step, two different classification approaches, namely "supervised" and "unsupervised" approaches were applied and their classification performances were compared. Object-based Image Analysis (OBIA) was performed using e-Cognition software.

Real-Time Detection of Rupture Development: Earthquake Early Warning Using P Waves From Growing Ruptures

Science.gov (United States)

Kodera, Yuki

2018-01-01

Large earthquakes with long rupture durations emit P wave energy throughout the rupture period. Incorporating late-onset P waves into earthquake early warning (EEW) algorithms could contribute to robust predictions of strong ground motion. Here I describe a technique to detect in real time P waves from growing ruptures to improve the timeliness of an EEW algorithm based on seismic wavefield estimation. The proposed P wave detector, which employs a simple polarization analysis, successfully detected P waves from strong motion generation areas of the 2011 Mw 9.0 Tohoku-oki earthquake rupture. An analysis using 23 large (M ≥ 7) events from Japan confirmed that seismic intensity predictions based on the P wave detector significantly increased lead times without appreciably decreasing the prediction accuracy. P waves from growing ruptures, being one of the fastest carriers of information on ongoing rupture development, have the potential to improve the performance of EEW systems.

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.

National Earthquake Information Center Seismic Event Detections on Multiple Scales

Science.gov (United States)

Patton, J.; Yeck, W. L.; Benz, H.; Earle, P. S.; Soto-Cordero, L.; Johnson, C. E.

2017-12-01

The U.S. Geological Survey National Earthquake Information Center (NEIC) monitors seismicity on local, regional, and global scales using automatic picks from more than 2,000 near-real time seismic stations. This presents unique challenges in automated event detection due to the high variability in data quality, network geometries and density, and distance-dependent variability in observed seismic signals. To lower the overall detection threshold while minimizing false detection rates, NEIC has begun to test the incorporation of new detection and picking algorithms, including multiband (Lomax et al., 2012) and kurtosis (Baillard et al., 2014) pickers, and a new bayesian associator (Glass 3.0). The Glass 3.0 associator allows for simultaneous processing of variably scaled detection grids, each with a unique set of nucleation criteria (e.g., nucleation threshold, minimum associated picks, nucleation phases) to meet specific monitoring goals. We test the efficacy of these new tools on event detection in networks of various scales and geometries, compare our results with previous catalogs, and discuss lessons learned. For example, we find that on local and regional scales, rapid nucleation of small events may require event nucleation with both P and higher-amplitude secondary phases (e.g., S or Lg). We provide examples of the implementation of a scale-independent associator for an induced seismicity sequence (local-scale), a large aftershock sequence (regional-scale), and for monitoring global seismicity. Baillard, C., Crawford, W. C., Ballu, V., Hibert, C., & Mangeney, A. (2014). An automatic kurtosis-based P-and S-phase picker designed for local seismic networks. Bulletin of the Seismological Society of America, 104(1), 394-409. Lomax, A., Satriano, C., & Vassallo, M. (2012). Automatic picker developments and optimization: FilterPicker - a robust, broadband picker for real-time seismic monitoring and earthquake early-warning, Seism. Res. Lett. , 83, 531-540, doi: 10

Sismosima: A pioneer project for earthquake detection

International Nuclear Information System (INIS)

Echague, C. de

2015-01-01

Currently you can only study how earthquakes occur and minimizing their consequences, but in Sismosima are studied earthquakes for if possible issue a pre-alert. Geological and Mining Institute of Spain (IGME) launched this project that has already achieved in test the caves in which you installed meters an increase of carbon dioxide (CO 2 ) that match the shot earthquake. Now, it remains check if gas emission occurs simultaneously, before or after. If were before, a couple of minutes would be enough to give an early warning with which save lives and ensure facilities. (Author)

Earthquake effect on the geological environment

International Nuclear Information System (INIS)

Kawamura, Makoto

1999-01-01

Acceleration caused by the earthquake, changes in the water pressure, and the rock-mass strain were monitored for a series of 344 earthquakes from 1990 to 1998 at Kamaishi In Situ Test Site. The largest acceleration was registered to be 57.14 gal with the earthquake named 'North coast of Iwate Earthquake' (M4.4) occurred in June, 1996. Changes of the water pressure were recorded with 27 earthquakes; the largest change was -0.35 Kgt/cm 2 . The water-pressure change by earthquake was, however, usually smaller than that caused by rainfall in this area. No change in the electric conductivity or pH of ground water was detected before and after the earthquake throughout the entire period of monitoring. The rock-mass strain was measured with a extensometer whose detection limit was of the order of 10 -8 to 10 -9 degrees and the remaining strain of about 2.5x10 -9 degrees was detected following the 'Offshore Miyagi Earthquake' (M5.1) in October, 1997. (H. Baba)

Slow Earthquakes in the Alaska-Aleutian Subduction Zone Detected by Multiple Mini Seismic Arrays

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LI, B.; Ghosh, A.; Thurber, C. H.; Lanza, F.

2017-12-01

The Alaska-Aleutian subduction zone is one of the most seismically and volcanically active plate boundaries on earth. Compared to other subduction zones, the slow earthquakes, such as tectonic tremors (TTs) and low frequency earthquakes (LFEs), are relatively poorly studied due to the limited data availability and difficult logistics. The analysis of two-months of continuous data from a mini array deployed in 2012 shows abundant tremor and LFE activities under Unalaska Island that is heterogeneously distributed [Li & Ghosh, 2017]. To better study slow earthquakes and understand their physical characteristics in the study region, we deployed a hybrid array of arrays, consisting of three well-designed mini seismic arrays and five stand alone stations, in the Unalaska Island in 2014. They were operational for between one and two years. Using the beam back-projection method [Ghosh et al., 2009, 2012], we detect continuous tremor activities for over a year when all three arrays are running. The sources of tremors are located south of the Unalaska and Akutan Islands, at the eastern and down-dip edge of the rupture zone of the 1957 Mw 8.6 earthquake, and they are clustered in several patches, with a gap between the two major clusters. Tremors show multiple migration patterns with propagation in both along-strike and dip directions and a wide range of velocities. We also identify tens of LFE families and use them as templates to search for repeating LFE events with the matched-filter method. Hundreds to thousands of LFEs for each family are detected and their activities are spatiotemporally consistent with tremor activities. The array techniques are revealing a near-continuous tremor activity in this area with remarkable spatiotemporal details. It helps us to better recognize the physical properties of the transition zone, provides new insights into the slow earthquake activities in this area, and explores their relation with the local earthquakes and the potential slow

Multi-Parameter Observation and Detection of Pre-Earthquake Signals in Seismically Active Areas

Science.gov (United States)

Ouzounov, D.; Pulinets, S.; Parrot, M.; Liu, J. Y.; Hattori, K.; Kafatos, M.; Taylor, P.

2012-01-01

.9) in Taiwan and Japan. We have found anomalous behavior before all of these events with no false negatives. Calculated false alarm ratio for the for the same month over the entire period of analysis (2003-2009) is less than 10% and was d as the earthquakes. The commonalities in detecting atmospheric/ionospheric anomalies show that they may exist over both land and sea in regions of maximum stress (i.e., along plate boundaries) Our results indicate that the ISTF model could provide a capability to observe pre-earthquake atmospheric/ionospheric signals by combining this information into a common framework.

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.

Detection of collapsed buildings from lidar data due to the 2016 Kumamoto earthquake in Japan

Directory of Open Access Journals (Sweden)

L. Moya

2018-01-01

Full Text Available The 2016 Kumamoto earthquake sequence was triggered by an Mw 6.2 event at 21:26 on 14 April. Approximately 28 h later, at 01:25 on 16 April, an Mw 7.0 event (the mainshock followed. The epicenters of both events were located near the residential area of Mashiki and affected the region nearby. Due to very strong seismic ground motion, the earthquake produced extensive damage to buildings and infrastructure. In this paper, collapsed buildings were detected using a pair of digital surface models (DSMs, taken before and after the 16 April mainshock by airborne light detection and ranging (lidar flights. Different methods were evaluated to identify collapsed buildings from the DSMs. The change in average elevation within a building footprint was found to be the most important factor. Finally, the distribution of collapsed buildings in the study area was presented, and the result was consistent with that of a building damage survey performed after the earthquake.

Megathrust Earthquake Swarms Contemporaneous to Slow Slip and Non-Volcanic Tremor in Southern Mexico, Detected and Analyzed through a Template Matching Approach

Science.gov (United States)

Holtkamp, S.; Brudzinski, M. R.; Cabral-Cano, E.; Arciniega-Ceballos, A.

2012-12-01

An outstanding question in geophysics is the degree to which the newly discovered types of slow fault slip are related to their destructive cousin - the earthquake. Here, we utilize a local network along the Oaxacan segment of the Middle American subduction zone to investigate the potential relationship between slow slip, non-volcanic tremor (NVT), and earthquakes along the subduction megathrust. We have developed a multi-station "template matching" waveform cross correlation technique which is able to detect and locate events several orders of magnitude smaller than would be possible using more traditional techniques. Also, our template matching procedure is capable of consistently locate events which occur during periods of increased background activity (e.g., during productive NVT, loud cultural noise, or after larger earthquakes) because the multi-station detector is finely tuned to events with similar hypocentral location and focal mechanism. The local network in the Oaxaca region allows us to focus on documented megathrust earthquake swarms, which we focus on because slow slip is hypothesized to be the cause for earthquake swarms in some tectonic environments. We identify a productive earthquake swarm in July 2006 (~600 similar earthquakes detected), which occurred during a week-long episode of productive tremor and slow slip. Families of events in this sequence were also active during larger and longer slow slip events, which provides a potential link between slow slip in the transition zone and earthquakes at the downdip end of the seismogenic portion of the megathrust. Because template matching techniques only detect similar signals, detected waveforms can be stacked together to produce higher signal to noise ratios or cross correlated against each other to produce precise relative phase arrival times. We are using the refined signals to look for evidence of expansion or propagation of hypocenters during these earthquake swarms, which could be used as a

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

level of shaking intensity with empirical models of fatality losses calibrated on past earthquakes in each country. Non-seismic detections and macroseismic questionnaires collected online are combined to identify as many as possible of the felt earthquakes regardless their magnitude. Non seismic detections include Twitter earthquake detections, developed by the US Geological Survey, 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. All together, we estimate that the number of detected felt earthquakes is around 1 000 per year, compared with the 35 000 earthquakes annually reported by the EMSC! Felt events are already the subject of the web page "Latest significant earthquakes" on EMSC website (http://www.emsc-csem.org/Earthquake/significant_earthquakes.php) and of a dedicated Twitter service @LastQuake. We will present the identification process of the earthquakes that matter, the smartphone application itself (to be released in May) and its future evolutions.

OMG Earthquake! Can Twitter improve earthquake response?

Science.gov (United States)

Earle, P. S.; Guy, M.; Ostrum, C.; Horvath, S.; Buckmaster, R. A.

2009-12-01

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 its earthquake response products and the delivery of hazard information. The goal is to gather near real-time, earthquake-related messages (tweets) and provide geo-located earthquake detections and rough maps of the corresponding felt areas. Twitter and other social Internet technologies are providing the general public with anecdotal earthquake hazard information before scientific information has been published from authoritative sources. People local to an event often publish information within seconds via these technologies. In contrast, depending on the location of the earthquake, scientific alerts take between 2 to 20 minutes. Examining the tweets following the March 30, 2009, M4.3 Morgan Hill earthquake shows it is possible (in some cases) to rapidly detect and map the felt area of an earthquake using Twitter responses. Within a minute of the earthquake, the frequency of “earthquake” tweets rose above the background level of less than 1 per hour to about 150 per minute. Using the tweets submitted in the first minute, a rough map of the felt area can be obtained by plotting the tweet locations. Mapping the tweets from the first six minutes shows observations extending from Monterey to Sacramento, similar to the perceived shaking region mapped by the USGS “Did You Feel It” system. The tweets submitted after the earthquake also provided (very) short first-impression narratives from people who experienced the shaking. Accurately assessing the potential and robustness of a Twitter-based system is difficult because only tweets spanning the previous seven days can be searched, making a historical study impossible. We have, however, been archiving tweets for several months, and it is clear that significant limitations do exist. The main drawback is the lack of quantitative information

Object-Oriented Analysis of Satellite Images Using Artificial Neural Networks for Post-Earthquake Buildings Change Detection

Science.gov (United States)

Khodaverdi zahraee, N.; Rastiveis, H.

2017-09-01

Earthquake is one of the most divesting natural events that threaten human life during history. After the earthquake, having information about the damaged area, the amount and type of damage can be a great help in the relief and reconstruction for disaster managers. It is very important that these measures should be taken immediately after the earthquake because any negligence could be more criminal losses. The purpose of this paper is to propose and implement an automatic approach for mapping destructed buildings after an earthquake using pre- and post-event high resolution satellite images. In the proposed method after preprocessing, segmentation of both images is performed using multi-resolution segmentation technique. Then, the segmentation results are intersected with ArcGIS to obtain equal image objects on both images. After that, appropriate textural features, which make a better difference between changed or unchanged areas, are calculated for all the image objects. Finally, subtracting the extracted textural features from pre- and post-event images, obtained values are applied as an input feature vector in an artificial neural network for classifying the area into two classes of changed and unchanged areas. The proposed method was evaluated using WorldView2 satellite images, acquired before and after the 2010 Haiti earthquake. The reported overall accuracy of 93% proved the ability of the proposed method for post-earthquake buildings change detection.

Detecting cardiometabolic syndrome using World Health Organization public health action points for Asians and Pacific Islanders.

Science.gov (United States)

Grandinetti, Andrew; Kaholokula, Joseph K; Mau, Marjorie K; Chow, Dominic C

2010-01-01

To assess the screening characteristics of World Health Organization (WHO) body mass index action points for cardiometabolic syndrome (CMS) in Native Hawaiians and people of Asian ancestry (ie, Filipino and Japanese). Cross-sectional data were collected from 1,452 residents of a rural community of Hawai'i between 1997 and 2000, of which 1,198 were analyzed in this study. Ethnic ancestry was determined by self-report. Metabolic status was assessed using National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATPIII) criteria. Screening characteristics of WHO criteria for overweight and obesity were compared to WHO public health action points or to WHO West Pacific Regional Office (WPRO) cut-points. Among Asian-ancestry participants, WHO public health action points improved both sensitivity and specificity for detecting CMS. However, similar improvements were not observed for WPRO criteria for Native Hawaiians. Moreover, predictive values were high regardless of which criteria were utilized due to high CMS prevalence. WHO public health actions points for Asians provide a significant improvement in sensitivity in detection of CMS. However, predictive value, which varies greatly with disease prevalence, should be considered when deciding which criteria to apply.

Limitation of the Predominant-Period Estimator for Earthquake Early Warning and the Initial Rupture of Earthquakes

Science.gov (United States)

Yamada, T.; Ide, S.

2007-12-01

Earthquake early warning is an important and challenging issue for the reduction of the seismic damage, especially for the mitigation of human suffering. One of the most important problems in earthquake early warning systems is how immediately we can estimate the final size of an earthquake after we observe the ground motion. It is relevant to the problem whether the initial rupture of an earthquake has some information associated with its final size. Nakamura (1988) developed the Urgent Earthquake Detection and Alarm System (UrEDAS). It calculates the predominant period of the P wave (τp) and estimates the magnitude of an earthquake immediately after the P wave arrival from the value of τpmax, or the maximum value of τp. The similar approach has been adapted by other earthquake alarm systems (e.g., Allen and Kanamori (2003)). To investigate the characteristic of the parameter τp and the effect of the length of the time window (TW) in the τpmax calculation, we analyze the high-frequency recordings of earthquakes at very close distances in the Mponeng mine in South Africa. We find that values of τpmax have upper and lower limits. For larger earthquakes whose source durations are longer than TW, the values of τpmax have an upper limit which depends on TW. On the other hand, the values for smaller earthquakes have a lower limit which is proportional to the sampling interval. For intermediate earthquakes, the values of τpmax are close to their typical source durations. These two limits and the slope for intermediate earthquakes yield an artificial final size dependence of τpmax in a wide size range. The parameter τpmax is useful for detecting large earthquakes and broadcasting earthquake early warnings. However, its dependence on the final size of earthquakes does not suggest that the earthquake rupture is deterministic. This is because τpmax does not always have a direct relation to the physical quantities of an earthquake.

Earthquake Damage Assessment Using Objective Image Segmentation: A Case Study of 2010 Haiti Earthquake

Science.gov (United States)

Oommen, Thomas; Rebbapragada, Umaa; Cerminaro, Daniel

2012-01-01

In this study, we perform a case study on imagery from the Haiti earthquake that evaluates a novel object-based approach for characterizing earthquake induced surface effects of liquefaction against a traditional pixel based change technique. Our technique, which combines object-oriented change detection with discriminant/categorical functions, shows the power of distinguishing earthquake-induced surface effects from changes in buildings using the object properties concavity, convexity, orthogonality and rectangularity. Our results suggest that object-based analysis holds promise in automatically extracting earthquake-induced damages from high-resolution aerial/satellite imagery.

Geotechnical hazards from large earthquakes and heavy rainfalls

CERN Document Server

Kazama, Motoki; Lee, Wei

2017-01-01

This book is a collection of papers presented at the International Workshop on Geotechnical Natural Hazards held July 12–15, 2014, in Kitakyushu, Japan. The workshop was the sixth in the series of Japan–Taiwan Joint Workshops on Geotechnical Hazards from Large Earthquakes and Heavy Rainfalls, held under the auspices of the Asian Technical Committee No. 3 on Geotechnology for Natural Hazards of the International Society for Soil Mechanics and Geotechnical Engineering. It was co-organized by the Japanese Geotechnical Society and the Taiwanese Geotechnical Society. The contents of this book focus on geotechnical and natural hazard-related issues in Asia such as earthquakes, tsunami, rainfall-induced debris flows, slope failures, and landslides. The book contains the latest information and mitigation technology on earthquake- and rainfall-induced geotechnical natural hazards. By dissemination of the latest state-of-the-art research in the area, the information contained in this book will help researchers, des...

Spinal cord injury rehabilitation and pressure ulcer prevention after the 2005 South Asian Earthquake: a CBR case study from Pakistan.

Science.gov (United States)

Chishtie, Jawad; Chishtie, Farrukh; Yoshida, Karen; Balogh, Robert

2018-03-07

The 2005 South Asian earthquake led to large-scale injuries and disabilities in northern Pakistan, which were dealt with using various approaches. In this regard, a community-based rehabilitation approach was initiated in the Muzaffarabad district of Pakistan in early 2006, focused on preventing complications among persons with Spinal Cord Injury. This case study briefly describes its development, aims and service provision components, in addition to the distribution of injuries from the disaster. Pressure ulcer prevention education, its recall and decrease in prevalence over a year are presented as key outcomes and illuminate the process of implementing rehabilitation in this context. This case study presents findings from a larger internal program evaluation in 2010-11. The study design was cross-sectional, to elicit recall of education components and the resulting prevalence of pressure ulcers over the year, in 33 randomly selected persons with Spinal Cord Injury. Outcomes included retention of knowledge about pressure ulcer prevention, practices and reduction in the prevalence of pressure ulcers over the last year. We also conducted a narrative literature review on the types of injuries and complications in the Spinal Cord population from Northern Pakistan. Hospital cohort studies reported "spine" injuries at 5%, while persons with spinal cord injury were identified as the most underserved needing rehabilitation services after the quake. Results from the evaluation of prevention education revealed that all 33 respondents were trained in detection of pressure ulcers, while 32 recalled "danger signs" for which they would seek immediate help. All correctly recalled postural change timings, however, their actual practices differed. Twenty-seven respondents (82%) reported no pressure ulcers over the last year. The decrease in pressure ulcer prevalence over the last year in persons with spinal cord injury highlights the strengths of the community-based rehabilitation

Prospects of nuclear power development in Southeast and South Asian nations, and the impacts of Fukushima accident

International Nuclear Information System (INIS)

Kita, Tomohiko; Nakasugi, Hideo; Wada, Yuko

2011-01-01

The Accident at Fukushima Daiichi Nuclear Power Station, caused by the Great East Japan Earthquake followed by Tsunami on March 11, 2011, has brought about strong socio-political impacts internationally including to Asian countries. This report provides updated information on nuclear energy development program in Asian countries. It also touches on impacts caused by the Fukushima Accident in Asian countries that plan to introduce nuclear power as well as those plan to expand their nuclear power programs. The article focuses on following countries in the regions: Indonesia, Malaysia, Thailand, Vietnam; India, and Pakistan. (author)

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

crowd-to-agency system, but unlike them it is not based on declarative information (e.g. answers to a questionnaire) but on implicit data, clickstream observed on our website. We present first the main improvements of the method, improved detection of traffic surges, and a way to instantly map areas affected by severe damage or network disruptions. The second part describes how the derived information improves and fastens public earthquake information and, beyond seismology, what it can teach us on public behaviour when facing an earthquake. Finally, the discussion will focus on the future evolutions and how flash-sourcing could ultimately improve earthquake response.

Parallelization of the Coupled Earthquake Model

Science.gov (United States)

Block, Gary; Li, P. Peggy; Song, Yuhe T.

2007-01-01

This Web-based tsunami simulation system allows users to remotely run a model on JPL s supercomputers for a given undersea earthquake. At the time of this reporting, predicting tsunamis on the Internet has never happened before. This new code directly couples the earthquake model and the ocean model on parallel computers and improves simulation speed. Seismometers can only detect information from earthquakes; they cannot detect whether or not a tsunami may occur as a result of the earthquake. When earthquake-tsunami models are coupled with the improved computational speed of modern, high-performance computers and constrained by remotely sensed data, they are able to provide early warnings for those coastal regions at risk. The software is capable of testing NASA s satellite observations of tsunamis. It has been successfully tested for several historical tsunamis, has passed all alpha and beta testing, and is well documented for users.

Smartphone MEMS accelerometers and earthquake early warning

Science.gov (United States)

Kong, Q.; Allen, R. M.; Schreier, L.; Kwon, Y. W.

2015-12-01

The low cost MEMS accelerometers in the smartphones are attracting more and more attentions from the science community due to the vast number and potential applications in various areas. We are using the accelerometers inside the smartphones to detect the earthquakes. We did shake table tests to show these accelerometers are also suitable to record large shakings caused by earthquakes. We developed an android app - MyShake, which can even distinguish earthquake movements from daily human activities from the recordings recorded by the accelerometers in personal smartphones and upload trigger information/waveform to our server for further analysis. The data from these smartphones forms a unique datasets for seismological applications, such as earthquake early warning. In this talk I will layout the method we used to recognize earthquake-like movement from single smartphone, and the overview of the whole system that harness the information from a network of smartphones for rapid earthquake detection. This type of system can be easily deployed and scaled up around the global and provides additional insights of the earthquake hazards.

Red blood cell antigen genotype analysis for 9087 Asian, Asian American, and Native American blood donors.

Science.gov (United States)

Delaney, Meghan; Harris, Samantha; Haile, Askale; Johnsen, Jill; Teramura, Gayle; Nelson, Karen

2015-10-01

There has yet to be a comprehensive analysis of blood group antigen prevalence in Asian Americans and Native Americans. There may be ethnic differences in blood group frequencies that would result in clinically important mismatches through transfusion. Blood donors who self-identified as Asian or Native American were tested using a single-nucleotide polymorphism (SNP) DNA array (HEA BeadChip kit, Bioarray Solutions Ltd) that predicts expression of 38 human erythrocyte antigens (HEAs) and by serology for ABO, D, C, M, N, Jk(a) , and Jk(b) . The prevalence of blood group antigens was compared to published European prevalence. Discrepancies between SNP-predicted and serology-detected antigens were tallied. A total of 9087 blood donors were tested from nine Asian and Native American heritages. The predicted prevalence of selected antigens in the RHCE, JK, FY, MNS, LU, CO, and DO blood group systems were variable between Asian populations, but overall not significantly different than Europeans. Compared to European frequencies, Kell blood group allele frequencies were significantly different in the Chinese, Native American, Hawaiian/Pacific Islander, South Asian, and Southeast Asian heritage blood donors; Diego antigens Di(a) and Di(b) were different in donors of Native American and South Asian ancestries (p Asian and Native Americans donors. Several ethnic groups exhibited differences in HEA frequencies compared to Europeans. Genotype-serotype discrepancies were detected in all systems studied. © 2015 AABB.

Evaluation of Earthquake Detection Performance in Terms of Quality and Speed in SEISCOMP3 Using New Modules Qceval, Npeval and Sceval

Science.gov (United States)

Roessler, D.; Weber, B.; Ellguth, E.; Spazier, J.

2017-12-01

The geometry of seismic monitoring networks, site conditions and data availability as well as monitoring targets and strategies typically impose trade-offs between data quality, earthquake detection sensitivity, false detections and alert times. Network detection capabilities typically change with alteration of the seismic noise level by human activity or by varying weather and sea conditions. To give helpful information to operators and maintenance coordinators, gempa developed a range of tools to evaluate earthquake detection and network performance including qceval, npeval and sceval. qceval is a module which analyzes waveform quality parameters in real-time and deactivates and reactivates data streams based on waveform quality thresholds for automatic processing. For example, thresholds can be defined for latency, delay, timing quality, spikes and gaps count and rms. As changes in the automatic processing have a direct influence on detection quality and speed, another tool called "npeval" was designed to calculate in real-time the expected time needed to detect and locate earthquakes by evaluating the effective network geometry. The effective network geometry is derived from the configuration of stations participating in the detection. The detection times are shown as an additional layer on the map and updated in real-time as soon as the effective network geometry changes. Yet another new tool, "sceval", is an automatic module which classifies located seismic events (Origins) in real-time. sceval evaluates the spatial distribution of the stations contributing to an Origin. It confirms or rejects the status of Origins, adds comments or leaves the Origin unclassified. The comments are passed to an additional sceval plug-in where the end user can customize event types. This unique identification of real and fake events in earthquake catalogues allows to lower network detection thresholds. In real-time monitoring situations operators can limit the processing to

Machine-Learning Inspired Seismic Phase Detection for Aftershocks of the 2008 MW7.9 Wenchuan Earthquake

Science.gov (United States)

Zhu, L.; Li, Z.; Li, C.; Wang, B.; Chen, Z.; McClellan, J. H.; Peng, Z.

2017-12-01

Spatial-temporal evolution of aftershocks is important for illumination of earthquake physics and for rapid response of devastative earthquakes. To improve aftershock catalogs of the 2008 MW7.9 Wenchuan earthquake in Sichuan, China, Alibaba cloud and China Earthquake Administration jointly launched a seismological contest in May 2017 [Fang et al., 2017]. This abstract describes how we handle this problem in this competition. We first used Short-Term Average/Long-Term Average (STA/LTA) and Kurtosis function to obtain over 55000 candidate phase picks (P or S). Based on Signal to Noise Ratio (SNR), about 40000 phases (P or S) are selected. So far, these 40000 phases have a hit rate of 40% among the manually picks. The causes include that 1) there exist false picks (neither P nor S); 2) some P and S arrivals are mis-labeled. To improve our results, we correlate the 40000 phases over continuous waveforms to obtain the phases missed by during the first pass. This results in 120,000 events. After constructing an affinity matrix based on the cross-correlation for newly detected phases, subspace clustering methods [Vidal 2011] are applied to group those phases into separated subspaces. Initial results show good agreement between empirical and clustered labels of P phases. Half of the empirical S phases are clustered into the P phase cluster. This may be a combined effect of 1) mislabeling isolated P phases to S phases and 2) clustering errors due to a small incomplete sample pool. Phases that were falsely detected in the initial results can be also teased out. To better characterize P and S phases, our next step is to apply subspace clustering methods directly to the waveforms, instead of using the cross-correlation coefficients of detected phases. After that, supervised learning, e.g., a convolutional neural network, can be employed to improve the pick accuracy. Updated results will be presented at the meeting.

Alarm systems detect volcanic tremor and earthquake swarms during Redoubt eruption, 2009

Science.gov (United States)

Thompson, G.; West, M. E.

2009-12-01

We ran two alarm algorithms on real-time data from Redoubt volcano during the 2009 crisis. The first algorithm was designed to detect escalations in continuous seismicity (tremor). This is implemented within an application called IceWeb which computes reduced displacement, and produces plots of reduced displacement and spectrograms linked to the Alaska Volcano Observatory internal webpage every 10 minutes. Reduced displacement is a measure of the amplitude of volcanic tremor, and is computed by applying a geometrical spreading correction to a displacement seismogram. When the reduced displacement at multiple stations exceeds pre-defined thresholds and there has been a factor of 3 increase in reduced displacement over the previous hour, a tremor alarm is declared. The second algorithm was to designed to detect earthquake swarms. The mean and median event rates are computed every 5 minutes based on the last hour of data from a real-time event catalog. By comparing these with thresholds, three swarm alarm conditions can be declared: a new swarm, an escalation in a swarm, and the end of a swarm. The end of swarm alarm is important as it may mark a transition from swarm to continuous tremor. Alarms from both systems were dispatched using a generic alarm management system which implements a call-down list, allowing observatory scientists to be called in sequence until someone acknowledged the alarm via a confirmation web page. The results of this simple approach are encouraging. The tremor alarm algorithm detected 26 of the 27 explosive eruptions that occurred from 23 March - 4 April. The swarm alarm algorithm detected all five of the main volcanic earthquake swarm episodes which occurred during the Redoubt crisis on 26-27 February, 21-23 March, 26 March, 2-4 April and 3-7 May. The end-of-swarm alarms on 23 March and 4 April were particularly helpful as they were caused by transitions from swarm to tremor shortly preceding explosive eruptions; transitions which were

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

Development of a technique for long-term detection of precursors of strong earthquakes using high-resolution satellite images

Science.gov (United States)

Soto-Pinto, C. A.; Arellano-Baeza, A. A.; Ouzounov, D. P.

2012-12-01

Among a variety of processes involved in seismic activity, the principal process is the accumulation and relaxation of stress in the crust, which takes place at the depth of tens of kilometers. While the Earth's surface bears at most the indirect sings of the accumulation and relaxation of the crust stress, it has long been understood that there is a strong correspondence between the structure of the underlying crust and the landscape. We assume the structure of the lineaments reflects an internal structure of the Earth's crust, and the variation of the lineament number and arrangement reflects the changes in the stress patterns related to the seismic activity. Contrary to the existing assumptions that lineament structure changes only at the geological timescale, we have found that the much faster seismic activity strongly affects the system of lineaments extracted from the high-resolution multispectral satellite images. Previous studies have shown that accumulation of the stress in the crust previous to a strong earthquake is directly related to the number increment and preferential orientation of lineament configuration present in the satellite images of epicenter zones. This effect increases with the earthquake magnitude and can be observed approximately since one month before. To study in details this effect we have developed a software based on a series of algorithms for automatic detection of lineaments. It was found that the Hough transform implemented after the application of discontinuity detection mechanisms like Canny edge detector or directional filters is the most robust technique for detection and characterization of changes in the lineament patterns related to strong earthquakes, which can be used as a robust long-term precursor of earthquakes indicating regions of strong stress accumulation.

An attempt of using straight-line information for building damage detection based only on post-earthquake optical imagery

International Nuclear Information System (INIS)

Dong, Laigen; Ye, Yuanxin; Shan, Jie

2014-01-01

It is important to grasp damage information in stricken areas after an earthquake in order to perform quick rescue and recovery activities. Recent research into remote sensing techniques has shown significant ability to generate quality damage information. The methods based on only post-earthquake data are widely researched especially because there are no pre-earthquake reference data in many cities of the world. This paper addresses a method for detection of damaged buildings using only post-event satellite imagery so that scientists and researchers can take advantage of the ability of helicopters and airplanes to fly over the damage faster. Statistical information of line segments extracted from post-event satellite imagery, such as mean length (ML) and weighted tilt angel standard deviation (WTASD), are used for discriminating the damaged and undamaged buildings

Ionospheric detection of tsunami earthquakes: observation, modeling and ideas for future early warning

Science.gov (United States)

Occhipinti, G.; Manta, F.; Rolland, L.; Watada, S.; Makela, J. J.; Hill, E.; Astafieva, E.; Lognonne, P. H.

2017-12-01

Detection of ionospheric anomalies following the Sumatra and Tohoku earthquakes (e.g., Occhipinti 2015) demonstrated that ionosphere is sensitive to earthquake and tsunami propagation: ground and oceanic vertical displacement induces acoustic-gravity waves propagating within the neutral atmosphere and detectable in the ionosphere. Observations supported by modelling proved that ionospheric anomalies related to tsunamis are deterministic and reproducible by numerical modeling via the ocean/neutral-atmosphere/ionosphere coupling mechanism (Occhipinti et al., 2008). To prove that the tsunami signature in the ionosphere is routinely detected we show here perturbations of total electron content (TEC) measured by GPS and following tsunamigenic earthquakes from 2004 to 2011 (Rolland et al. 2010, Occhipinti et al., 2013), nominally, Sumatra (26 December, 2004 and 12 September, 2007), Chile (14 November, 2007), Samoa (29 September, 2009) and the recent Tohoku-Oki (11 Mars, 2011). Based on the observations close to the epicenter, mainly performed by GPS networks located in Sumatra, Chile and Japan, we highlight the TEC perturbation observed within the first 8 min after the seismic rupture. This perturbation contains information about the ground displacement, as well as the consequent sea surface displacement resulting in the tsunami. In addition to GNSS-TEC observations close to the epicenter, new exciting measurements in the far-field were performed by airglow measurement in Hawaii show the propagation of the internal gravity waves induced by the Tohoku tsunami (Occhipinti et al., 2011). This revolutionary imaging technique is today supported by two new observations of moderate tsunamis: Queen Charlotte (M: 7.7, 27 October, 2013) and Chile (M: 8.2, 16 September 2015). We finally detail here our recent work (Manta et al., 2017) on the case of tsunami alert failure following the Mw7.8 Mentawai event (25 October, 2010), and its twin tsunami alert response following the Mw7

The EM Earthquake Precursor

Science.gov (United States)

Jones, K. B., II; Saxton, P. T.

2013-12-01

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 the 1989 Loma Prieta Earthquake, American earthquake investigators predetermined magnetometer use and a minimum earthquake magnitude necessary for EM detection. This action was set in motion, due to the extensive damage incurred and public outrage concerning earthquake forecasting; however, the magnetometers employed, grounded or buried, are completely subject to static and electric fields and have yet to correlate to an identifiable precursor. Secondly, there is neither a networked array for finding any epicentral locations, nor have there been any attempts to find even one. This methodology needs dismissal, because it is overly complicated, subject to continuous change, and provides no response time. As for the minimum magnitude threshold, which was set at M5, this is simply higher than what modern technological advances have gained. Detection can now be achieved at approximately M1, which greatly improves forecasting chances. A propagating precursor has now been detected in both the field and laboratory. Field antenna testing conducted outside the NE Texas town of Timpson in February, 2013, detected three strong EM sources along with numerous weaker signals. The antenna had mobility, and observations were noted for recurrence, duration, and frequency response. Next, two

Auto Correlation Analysis of Coda Waves from Local Earthquakes for Detecting Temporal Changes in Shallow Subsurface Structures: the 2011 Tohoku-Oki, Japan Earthquake

Science.gov (United States)

Nakahara, Hisashi

2015-02-01

For monitoring temporal changes in subsurface structures I propose to use auto correlation functions of coda waves from local earthquakes recorded at surface receivers, which probably contain more body waves than surface waves. Use of coda waves requires earthquakes resulting in decreased time resolution for monitoring. Nonetheless, it may be possible to monitor subsurface structures in sufficient time resolutions in regions with high seismicity. In studying the 2011 Tohoku-Oki, Japan earthquake (Mw 9.0), for which velocity changes have been previously reported, I try to validate the method. KiK-net stations in northern Honshu are used in this analysis. For each moderate earthquake normalized auto correlation functions of surface records are stacked with respect to time windows in the S-wave coda. Aligning the stacked, normalized auto correlation functions with time, I search for changes in phases arrival times. The phases at lag times of <1 s are studied because changes at shallow depths are focused. Temporal variations in the arrival times are measured at the stations based on the stretching method. Clear phase delays are found to be associated with the mainshock and to gradually recover with time. The amounts of the phase delays are 10 % on average with the maximum of about 50 % at some stations. The deconvolution analysis using surface and subsurface records at the same stations is conducted for validation. The results show the phase delays from the deconvolution analysis are slightly smaller than those from the auto correlation analysis, which implies that the phases on the auto correlations are caused by larger velocity changes at shallower depths. The auto correlation analysis seems to have an accuracy of about several percent, which is much larger than methods using earthquake doublets and borehole array data. So this analysis might be applicable in detecting larger changes. In spite of these disadvantages, this analysis is still attractive because it can

Tremors behind the power outlet - where earthquakes appear on our monthly bill

Science.gov (United States)

Baisch, Stefan

2013-04-01

The world's appetite for energy has significantly increased over the last decades, not least due to the rapid growth of Asian economies. In parallel, the Fukushima shock raised widespread concerns against nuclear power generation and an increasing desire for clean energy technologies. To solve the conflict of higher demands, limited resources and a growing level of green consciousness, both up-scaling of conventional and development of renewable energy technologies are required. This is where the phenomenon of man-made earthquakes appears on the radar screen. Several of our energy production technologies have the potential to cause small, moderate, or sometimes even larger magnitude earthquakes. There is a general awareness that coal mining activities can produce moderate sized earthquakes. Similarly, long-term production from hydrocarbon reservoirs can lead to subsurface deformations accompanied by even larger magnitude earthquakes. Even the "renewables" are not necessarily earthquake-free. Several of the largest man-made earthquakes have been caused by water impoundment for hydropower plants. On a much smaller scale, micro earthquakes can occur in enhanced geothermal systems (EGS). Although still in its infancy, the EGS technology has an enormous potential to supply base load electricity, and its technical feasibility for a large scale application is currently being investigated in about a dozen pilot projects. The principal concept of heat extraction by circulating water through a subsurface reservoir is fairly simple, the technical implementation of EGS, however, exhibits several challenges not all of which are yet being solved. As the hydraulic conductivity at depth is usually extremely low at EGS sites, a technical stimulation of hydraulic pathways is required for creating an artificial heat exchanger. By injecting fluid under high pressure into the subsurface, tectonic stress on existing fractures can be released and the associated shearing of the fractures

Electrostatically actuated resonant switches for earthquake detection

KAUST Repository

Ramini, Abdallah H.; Masri, Karim M.; Younis, Mohammad I.

2013-01-01

action can be functionalized for useful functionalities, such as shutting off gas pipelines in the case of earthquakes, or can be used to activate a network of sensors for seismic activity recording in health monitoring applications. By placing a

Apparatus for isolating electric generators or like other facilities upon occurrence of earthquakes

International Nuclear Information System (INIS)

Toshimitsu, Satoru.

1983-01-01

Purpose: To prevent, upon occurrence of failures in a facility with poor earthquake-proof performance, undesired secondary effects caused by the above failures from prevailing on other facilities with excellent earthquake-proof performance. Constitution: An isolation valve is disposed at the midway of pipeways communicating facilities of different earthquake-proof performances. When the occurrence of earthquake and the magnitude thereof are detected and judged by an earthquake detection and control device, the isolation valve between the facility of excellent earthquake-proof performance and the facility of poor earthquake-proof performance is opened. Consequently, if the facility of poor earthquake-proof performance is failed, no fluid is issued from the facility of the excellent earthquake-proof performance to thereby improve the earthquake safety. (Kawakami, Y.)

Evaluation of 0 ≤ M ≤ 8 earthquake data sets in African – Asian region during 1966–2015

Directory of Open Access Journals (Sweden)

Theophilus Aanuoluwa Adagunodo

2018-04-01

Full Text Available This article evaluates the occurrence of 0 ≤ M ≤ 8 earthquake data sets for the period of 50 years (that is, January 1, 1966 to December 31, 2015 in African and Western Asia region. It is bounded by latitude 40° S to 40° N and longitude 30° W to 60° E with the focal depth of 0–700 km. Seventy seven thousand, six hundred and ninety-six data points were presented for the analysis. The data used were extracted from earthquake catalog of Advanced National Seismic system via http://quake.geo.berkeley.edu/cnss/, an official website of the Northern California Earthquake Data Centre, USA. Each datum comprised the earthquake occurrence date, time of the earthquake occurrence, epicenter’s coordinates, focal depth and magnitude. The Gutenberg-Richter’s relationship being the longest observed empirical relationship in seismology, analysis of variance and time series were used to analyze the seismicity of the study area. Annual distributions of earthquake occurrence based on magnitude variations with the limit 0 ≤ M ≤ 8 were presented. The two constants a and b in the Gutenberg-Richter’s equation, magnitude of completeness (MC adjusted R-Square and F-value for the period of 1966–1975, 1976–1985, 1986–1995, 1996–2005, 2006–2015, and the entire period of investigation ranging from 1966 to 2015 were determined so as to investigate the variations of these parameters on earthquake occurrence over time. The histograms of earthquake occurrence against magnitude of earthquakes for the selected years (1966–1975, 1976–1985, 1986–1995, 1996–2005, 2006–2015, and 1966–2015, and the decadal frequency distributions of earthquake occurrence were also plotted. The focal depth occurrence for each magnitude bins (0–0.9, 1–1.9, 2–2.9, 3–3.9, 4–4.9, 5–5.9, 6–6.9, 7–7.9, 8–8.9 were grouped into shallow, intermediate, and deep depths ranging from 0 to 70, 71 to 300, and 301 to 700 km as being used in seismology. The

Detecting earthquakes over a seismic network using single-station similarity measures

Science.gov (United States)

Bergen, Karianne J.; Beroza, Gregory C.

2018-06-01

New blind waveform-similarity-based detection methods, such as Fingerprint and Similarity Thresholding (FAST), have shown promise for detecting weak signals in long-duration, continuous waveform data. While blind detectors are capable of identifying similar or repeating waveforms without templates, they can also be susceptible to false detections due to local correlated noise. In this work, we present a set of three new methods that allow us to extend single-station similarity-based detection over a seismic network; event-pair extraction, pairwise pseudo-association, and event resolution complete a post-processing pipeline that combines single-station similarity measures (e.g. FAST sparse similarity matrix) from each station in a network into a list of candidate events. The core technique, pairwise pseudo-association, leverages the pairwise structure of event detections in its network detection model, which allows it to identify events observed at multiple stations in the network without modeling the expected moveout. Though our approach is general, we apply it to extend FAST over a sparse seismic network. We demonstrate that our network-based extension of FAST is both sensitive and maintains a low false detection rate. As a test case, we apply our approach to 2 weeks of continuous waveform data from five stations during the foreshock sequence prior to the 2014 Mw 8.2 Iquique earthquake. Our method identifies nearly five times as many events as the local seismicity catalogue (including 95 per cent of the catalogue events), and less than 1 per cent of these candidate events are false detections.

Young Asian Dutch constructing Asianness: Understanding the role of Asian popular culture

OpenAIRE

Kartosen, R.A.

2016-01-01

This doctoral thesis is about young Asian Dutch, panethnic Asian identities and identifications, and Asian/Asian Dutch popular culture. It addresses several pressing questions, including: why do young Asian Dutch, who were born and/or raised in the Netherlands, identify as Asian and construct Asian identities? What is the content or meaning of these Asian identities and identifications young Asian Dutch imagine? And how do these relate to young Asian Dutch’ Dutch and homeland identities and i...

Flash sourcing, or rapid detection and characterization of earthquake effects through website traffic analysis

Directory of Open Access Journals (Sweden)

Laurent Frobert

2011-06-01

Full Text Available

This study presents the latest developments of an approach called ‘flash sourcing’, which provides information on the effects of an earthquake within minutes of its occurrence. Information is derived from an analysis of the website traffic surges of the European–Mediterranean Seismological Centre website after felt earthquakes. These surges are caused by eyewitnesses to a felt earthquake, who are the first who are informed of, and hence the first concerned by, an earthquake occurrence. Flash sourcing maps the felt area, and at least in some circumstances, the regions affected by severe damage or network disruption. We illustrate how the flash-sourced information improves and speeds up the delivery of public earthquake information, and beyond seismology, we consider what it can teach us about public responses when experiencing an earthquake. Future developments should improve the description of the earthquake effects and potentially contribute to the improvement of the efficiency of earthquake responses by filling the information gap after the occurrence of an earthquake.

Ionospheric anomalies detected by ionosonde and possibly related to crustal earthquakes in Greece

Science.gov (United States)

Perrone, Loredana; De Santis, Angelo; Abbattista, Cristoforo; Alfonsi, Lucilla; Amoruso, Leonardo; Carbone, Marianna; Cesaroni, Claudio; Cianchini, Gianfranco; De Franceschi, Giorgiana; De Santis, Anna; Di Giovambattista, Rita; Marchetti, Dedalo; Pavòn-Carrasco, Francisco J.; Piscini, Alessandro; Spogli, Luca; Santoro, Francesca

2018-03-01

Ionosonde data and crustal earthquakes with magnitude M ≥ 6.0 observed in Greece during the 2003-2015 period were examined to check if the relationships obtained earlier between precursory ionospheric anomalies and earthquakes in Japan and central Italy are also valid for Greek earthquakes. The ionospheric anomalies are identified on the observed variations of the sporadic E-layer parameters (h'Es, foEs) and foF2 at the ionospheric station of Athens. The corresponding empirical relationships between the seismo-ionospheric disturbances and the earthquake magnitude and the epicentral distance are obtained and found to be similar to those previously published for other case studies. The large lead times found for the ionospheric anomalies occurrence may confirm a rather long earthquake preparation period. The possibility of using the relationships obtained for earthquake prediction is finally discussed.

Ionospheric anomalies detected by ionosonde and possibly related to crustal earthquakes in Greece

Directory of Open Access Journals (Sweden)

L. Perrone

2018-03-01

Full Text Available Ionosonde data and crustal earthquakes with magnitude M ≥ 6.0 observed in Greece during the 2003–2015 period were examined to check if the relationships obtained earlier between precursory ionospheric anomalies and earthquakes in Japan and central Italy are also valid for Greek earthquakes. The ionospheric anomalies are identified on the observed variations of the sporadic E-layer parameters (h′Es, foEs and foF2 at the ionospheric station of Athens. The corresponding empirical relationships between the seismo-ionospheric disturbances and the earthquake magnitude and the epicentral distance are obtained and found to be similar to those previously published for other case studies. The large lead times found for the ionospheric anomalies occurrence may confirm a rather long earthquake preparation period. The possibility of using the relationships obtained for earthquake prediction is finally discussed.

Young Asian Dutch constructing Asianness: Understanding the role of Asian popular culture

NARCIS (Netherlands)

Kartosen, R.A.

2016-01-01

This doctoral thesis is about young Asian Dutch, panethnic Asian identities and identifications, and Asian/Asian Dutch popular culture. It addresses several pressing questions, including: why do young Asian Dutch, who were born and/or raised in the Netherlands, identify as Asian and construct Asian

e-Science on Earthquake Disaster Mitigation by EUAsiaGrid

Science.gov (United States)

Yen, Eric; Lin, Simon; Chen, Hsin-Yen; Chao, Li; Huang, Bor-Shoh; Liang, Wen-Tzong

2010-05-01

Although earthquake is not predictable at this moment, with the aid of accurate seismic wave propagation analysis, we could simulate the potential hazards at all distances from possible fault sources by understanding the source rupture process during large earthquakes. With the integration of strong ground-motion sensor network, earthquake data center and seismic wave propagation analysis over gLite e-Science Infrastructure, we could explore much better knowledge on the impact and vulnerability of potential earthquake hazards. On the other hand, this application also demonstrated the e-Science way to investigate unknown earth structure. Regional integration of earthquake sensor networks could aid in fast event reporting and accurate event data collection. Federation of earthquake data center entails consolidation and sharing of seismology and geology knowledge. Capability building of seismic wave propagation analysis implies the predictability of potential hazard impacts. With gLite infrastructure and EUAsiaGrid collaboration framework, earth scientists from Taiwan, Vietnam, Philippine, Thailand are working together to alleviate potential seismic threats by making use of Grid technologies and also to support seismology researches by e-Science. A cross continental e-infrastructure, based on EGEE and EUAsiaGrid, is established for seismic wave forward simulation and risk estimation. Both the computing challenge on seismic wave analysis among 5 European and Asian partners, and the data challenge for data center federation had been exercised and verified. Seismogram-on-Demand service is also developed for the automatic generation of seismogram on any sensor point to a specific epicenter. To ease the access to all the services based on users workflow and retain the maximal flexibility, a Seismology Science Gateway integating data, computation, workflow, services and user communities would be implemented based on typical use cases. In the future, extension of the

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

Fossil rocks of slow earthquake detected by thermal diffusion length

Science.gov (United States)

Hashimoto, Yoshitaka; Morita, Kiyohiko; Okubo, Makoto; Hamada, Yohei; Lin, Weiren; Hirose, Takehiro; Kitamura, Manami

2016-04-01

Fault motion has been estimated by diffusion pattern of frictional heating recorded in geology (e.g., Fulton et al., 2012). The same record in deeper subduction plate interface can be observed from micro-faults in an exhumed accretionary complex. In this study, we focused on a micro-fault within the Cretaceous Shimanto Belt, SW Japan to estimate fault motion from the frictional heating diffusion pattern. A carbonaceous material concentrated layer (CMCL) with ~2m of thickness is observed in study area. Some micro-faults cut the CMCL. Thickness of a fault is about 3.7mm. Injection veins and dilatant fractures were observed in thin sections, suggesting that the high fluid pressure was existed. Samples with 10cm long were collected to measure distribution of vitrinite reflectance (Ro) as a function of distance from the center of micro-fault. Ro of host rock was ~1.0%. Diffusion pattern was detected decreasing in Ro from ~1.2%-~1.1%. Characteristic diffusion distance is ~4-~9cm. We conducted grid search to find the optimal frictional heat generation per unit area per second (Q (J/m^2/s), the product of friction coefficient, normal stress and slip velocity) and slip duration (t(s)) to fit the diffusion pattern. Thermal diffusivity (0.98*10^8m^2/s) and thermal conductivity (2.0 w/mK) were measured. In the result, 2000-2500J/m^2/s of Q and 63000-126000s of t were estimated. Moment magnitudes (M0) of slow earthquakes (slow EQs) follow a scaling law with slip duration and its dimension is different from that for normal earthquakes (normal EQ) (Ide et al., 2007). The slip duration estimated in this study (~10^4-~10^5s) consistent with 4-5 of M0, never fit to the scaling law for normal EQ. Heat generation can be inverted from 4-5 of M0, corresponding with ~10^8-~10^11J, which is consistent with rupture area of 10^5-10^8m2 in this study. The comparisons in heat generation and slip duration between geological measurements and geophysical remote observations give us the

Development of electrochemical biosensor for detection of pathogenic microorganism in Asian dust events.

Science.gov (United States)

Yoo, Min-Sang; Shin, Minguk; Kim, Younghun; Jang, Min; Choi, Yoon-E; Park, Si Jae; Choi, Jonghoon; Lee, Jinyoung; Park, Chulhwan

2017-05-01

We developed a single-walled carbon nanotubes (SWCNTs)-based electrochemical biosensor for the detection of Bacillus subtilis, one of the microorganisms observed in Asian dust events, which causes respiratory diseases such as asthma and pneumonia. SWCNTs plays the role of a transducer in biological antigen/antibody reaction for the electrical signal while 1-pyrenebutanoic acid succinimidyl ester (1-PBSE) and ant-B. subtilis were performed as a chemical linker and an acceptor, respectively, for the adhesion of target microorganism in the developed biosensor. The detection range (10 2 -10 10  CFU/mL) and the detection limit (10 2  CFU/mL) of the developed biosensor were identified while the response time was 10 min. The amount of target B. subtilis was the highest in the specificity test of the developed biosensor, compared with the other tested microorganisms (Staphylococcus aureus, Flavobacterium psychrolimnae, and Aquabacterium commune). In addition, target B. subtilis detected by the developed biosensor was observed by scanning electron microscope (SEM) analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

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.

Radon anomalies prior to earthquakes (2). Atmospheric radon anomaly observed before the Hyogoken-Nanbu earthquake

International Nuclear Information System (INIS)

Ishikawa, Tetsuo; Tokonami, Shinji; Yasuoka, Yumi; Shinogi, Masaki; Nagahama, Hiroyuki; Omori, Yasutaka; Kawada, Yusuke

2008-01-01

Before the 1995 Hyogoken-Nanbu earthquake, various geochemical precursors were observed in the aftershock area: chloride ion concentration, groundwater discharge rate, groundwater radon concentration and so on. Kobe Pharmaceutical University (KPU) is located about 25 km northeast from the epicenter and within the aftershock area. Atmospheric radon concentration had been continuously measured from 1984 at KPU, using a flow-type ionization chamber. The radon concentration data were analyzed using the smoothed residual values which represent the daily minimum of radon concentration with the exclusion of normalized seasonal variation. The radon concentration (smoothed residual values) demonstrated an upward trend about two months before the Hyogoken-Nanbu earthquake. The trend can be well fitted to a log-periodic model related to earthquake fault dynamics. As a result of model fitting, a critical point was calculated to be between 13 and 27 January 1995, which was in good agreement with the occurrence date of earthquake (17 January 1995). The mechanism of radon anomaly before earthquakes is not fully understood. However, it might be possible to detect atmospheric radon anomaly as a precursor before a large earthquake, if (1) the measurement is conducted near the earthquake fault, (2) the monitoring station is located on granite (radon-rich) areas, and (3) the measurement is conducted for more than several years before the earthquake to obtain background data. (author)

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...

Time series of GNSS-derived ionospheric maps to detect anomalies as possible precursors of high magnitude earthquakes

Science.gov (United States)

Barbarella, M.; De Giglio, M.; Galeandro, A.; Mancini, F.

2012-04-01

The modification of some atmospheric physical properties prior to a high magnitude earthquake has been recently debated within the Lithosphere-Atmosphere-Ionosphere (LAI) Coupling model. Among this variety of phenomena the ionization of air at the higher level of the atmosphere, called ionosphere, is investigated in this work. Such a ionization occurrences could be caused by possible leaking of gases from earth crust and their presence was detected around the time of high magnitude earthquakes by several authors. However, the spatial scale and temporal domain over which such a disturbances come into evidence is still a controversial item. Even thought the ionospheric activity could be investigated by different methodologies (satellite or terrestrial measurements), we selected the production of ionospheric maps by the analysis of GNSS (Global Navigation Satellite Data) data as possible way to detect anomalies prior of a seismic event over a wide area around the epicentre. It is well known that, in the GNSS sciences, the ionospheric activity could be probed by the analysis of refraction phenomena occurred on the dual frequency signals along the satellite to receiver path. The analysis of refraction phenomena affecting data acquired by the GNSS permanent trackers is able to produce daily to hourly maps representing the spatial distribution of the ionospheric Total Electron Content (TEC) as an index of the ionization degree in the upper atmosphere. The presence of large ionospheric anomalies could be therefore interpreted in the LAI Coupling model like a precursor signal of a strong earthquake, especially when the appearance of other different precursors (thermal anomalies and/or gas fluxes) could be detected. In this work, a six-month long series of ionospheric maps produced from GNSS data collected by a network of 49 GPS permanent stations distributed within an area around the city of L'Aquila (Abruzzi, Italy), where an earthquake (M = 6.3) occurred on April 6, 2009

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

Opto-mechanical lab-on-fibre seismic sensors detected the Norcia earthquake.

Science.gov (United States)

Pisco, Marco; Bruno, Francesco Antonio; Galluzzo, Danilo; Nardone, Lucia; Gruca, Grzegorz; Rijnveld, Niek; Bianco, Francesca; Cutolo, Antonello; Cusano, Andrea

2018-04-27

We have designed and developed lab-on-fibre seismic sensors containing a micro-opto-mechanical cavity on the fibre tip. The mechanical cavity is designed as a double cantilever suspended on the fibre end facet and connected to a proof mass to tune its response. Ground acceleration leads to displacement of the cavity length, which in turn can be remotely detected using an interferometric interrogation technique. After the sensors characterization, an experimental validation was conducted at the Italian National Institute of Geophysics and Volcanology (INGV), which is responsible for seismic surveillance over the Italian country. The fabricated sensors have been continuously used for long periods to demonstrate their effectiveness as seismic accelerometer sensors. During the tests, fibre optic seismic accelerometers clearly detected the seismic sequence that culminated in the severe Mw6.5 Norcia earthquake that struck central Italy on October 30, 2016. The seismic data provided by the optical sensors were analysed by specialists at the INGV. The wave traces were compared with state-of-the-art traditional sensors typically incorporated into the INGV seismic networks. The comparison verifies the high fidelity of the optical sensors in seismic wave detection, indicating their suitability for a novel class of seismic sensors to be employed in practical scenarios.

Auto correlation analysis of coda waves from local earthquakes for detecting temporal changes in shallow subsurface structures - The 2011 Tohoku-Oki, Japan, earthquake -

Science.gov (United States)

Nakahara, H.

2013-12-01

For monitoring temporal changes in subsurface structures, I propose to use auto correlation functions of coda waves from local earthquakes recorded at surface receivers, which probably contain more body waves than surface waves. Because the use of coda waves requires earthquakes, time resolution for monitoring decreases. But at regions with high seismicity, it may be possible to monitor subsurface structures in sufficient time resolutions. Studying the 2011 Tohoku-Oki (Mw 9.0), Japan, earthquake for which velocity changes have been already reported by previous studies, I try to validate the method. KiK-net stations in northern Honshu are used in the analysis. For each moderate earthquake, normalized auto correlation functions of surface records are stacked with respect to time windows in S-wave coda. Aligning the stacked normalized auto correlation functions with time, I search for changes in arrival times of phases. The phases at lag times of less than 1s are studied because changes at shallow depths are focused. Based on the stretching method, temporal variations in the arrival times are measured at the stations. Clear phase delays are found to be associated with the mainshock and to gradually recover with time. Amounts of the phase delays are in the order of 10% on average with the maximum of about 50% at some stations. For validation, the deconvolution analysis using surface and subsurface records at the same stations are conducted. The results show that the phase delays from the deconvolution analysis are slightly smaller than those from the auto correlation analysis, which implies that the phases on the auto correlations are caused by larger velocity changes at shallower depths. The auto correlation analysis seems to have an accuracy of about several percents, which is much larger than methods using earthquake doublets and borehole array data. So this analysis might be applicable to detect larger changes. In spite of these disadvantages, this analysis is

Crowd-Sourced Global Earthquake Early Warning

Science.gov (United States)

Minson, S. E.; Brooks, B. A.; Glennie, C. L.; Murray, J. R.; Langbein, J. O.; Owen, S. E.; Iannucci, B. A.; Hauser, D. L.

2014-12-01

Although earthquake early warning (EEW) has shown great promise for reducing loss of life and property, it has only been implemented in a few regions due, in part, to the prohibitive cost of building the required dense seismic and geodetic networks. However, many cars and consumer smartphones, tablets, laptops, and similar devices contain low-cost versions of the same sensors used for earthquake monitoring. If a workable EEW system could be implemented based on either crowd-sourced observations from consumer devices or very inexpensive networks of instruments built from consumer-quality sensors, EEW coverage could potentially be expanded worldwide. Controlled tests of several accelerometers and global navigation satellite system (GNSS) receivers typically found in consumer devices show that, while they are significantly noisier than scientific-grade instruments, they are still accurate enough to capture displacements from moderate and large magnitude earthquakes. The accuracy of these sensors varies greatly depending on the type of data collected. Raw coarse acquisition (C/A) code GPS data are relatively noisy. These observations have a surface displacement detection threshold approaching ~1 m and would thus only be useful in large Mw 8+ earthquakes. However, incorporating either satellite-based differential corrections or using a Kalman filter to combine the raw GNSS data with low-cost acceleration data (such as from a smartphone) decreases the noise dramatically. These approaches allow detection thresholds as low as 5 cm, potentially enabling accurate warnings for earthquakes as small as Mw 6.5. Simulated performance tests show that, with data contributed from only a very small fraction of the population, a crowd-sourced EEW system would be capable of warning San Francisco and San Jose of a Mw 7 rupture on California's Hayward fault and could have accurately issued both earthquake and tsunami warnings for the 2011 Mw 9 Tohoku-oki, Japan earthquake.

a Collaborative Cyberinfrastructure for Earthquake Seismology

Science.gov (United States)

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

2013-12-01

One of the challenges in real time seismology is the prediction of earthquake's impact. It is particularly true for moderate earthquake (around magnitude 6) located close to urbanised areas, where the slightest uncertainty in event location, depth, magnitude estimates, and/or misevaluation of propagation characteristics, site effects and buildings vulnerability can dramatically change impact scenario. The Euro-Med Seismological Centre (EMSC) has developed a cyberinfrastructure to collect observations from eyewitnesses in order to provide in-situ constraints on actual damages. This cyberinfrastructure takes benefit of the natural convergence of earthquake's eyewitnesses on EMSC website (www.emsc-csem.org), the second global earthquake information website within tens of seconds of the occurrence of a felt event. It includes classical crowdsourcing tools such as online questionnaires available in 39 languages, and tools to collect geolocated pics. It also comprises information derived from the real time analysis of the traffic on EMSC website, a method named flashsourcing; In case of a felt earthquake, eyewitnesses reach EMSC website within tens of seconds to find out the cause of the shaking they have just been through. By analysing their geographical origin through their IP address, we automatically detect felt earthquakes and in some cases map the damaged areas through the loss of Internet visitors. We recently implemented a Quake Catcher Network (QCN) server in collaboration with Stanford University and the USGS, to collect ground motion records performed by volunteers and are also involved in a project to detect earthquakes from ground motions sensors from smartphones. Strategies have been developed for several social media (Facebook, Twitter...) not only to distribute earthquake information, but also to engage with the Citizens and optimise data collection. A smartphone application is currently under development. We will present an overview of this

The HayWired Earthquake Scenario—Earthquake Hazards

Science.gov (United States)

Detweiler, Shane T.; Wein, Anne M.

2017-04-24

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

[Earthquakes--a historical review, environmental and health effects, and health care measures].

Science.gov (United States)

Nola, Iskra Alexandra; Doko Jelinić, Jagoda; Žuškin, Eugenija; Kratohvil, Mladen

2013-06-01

Earthquakes are natural disasters that can occur at any time, regardless of the location. Their frequency is higher in the Circum-Pacific and Mediterranean/Trans-Asian seismic belt. A number of sophisticated methods define their magnitude using the Richter scale and intensity using the Mercani-Cancani-Sieberg scale. Recorded data show a number of devastating earthquakes that have killed many people and changed the environment dramatically. Croatia is located in a seismically active area, which has endured a series of historical earthquakes, among which several occurred in the Zagreb area. The consequences of an earthquake depend mostly on the population density and seismic resistance of buildings in the affected area. Environmental consequences often include air, water, and soil pollution. The effects of this kind of pollution can have long-term health effects. The most dramatic health consequences result from the demolition of buildings. Therefore, quick and efficient aid depends on well-organized health professionals as well as on the readiness of the civil defence, fire department, and Mountain Rescue Service members. Good coordination among these services can save many lives Public health interventions must include effective control measures in the environment as secondary prevention methods for health problems caused by unfavourable environmental factors. The identification and control of long-term hazards can reduce chronic health effects. The reduction of earthquake-induced damages includes setting priorities in building seismically safe buildings.

Shallow moonquakes - How they compare with earthquakes

Science.gov (United States)

Nakamura, Y.

1980-01-01

Of three types of moonquakes strong enough to be detectable at large distances - deep moonquakes, meteoroid impacts and shallow moonquakes - only shallow moonquakes are similar in nature to earthquakes. A comparison of various characteristics of moonquakes with those of earthquakes indeed shows a remarkable similarity between shallow moonquakes and intraplate earthquakes: (1) their occurrences are not controlled by tides; (2) they appear to occur in locations where there is evidence of structural weaknesses; (3) the relative abundances of small and large quakes (b-values) are similar, suggesting similar mechanisms; and (4) even the levels of activity may be close. The shallow moonquakes may be quite comparable in nature to intraplate earthquakes, and they may be of similar origin.

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.

AIRBORNE LIGHT DETECTION AND RANGING (LIDAR DERIVED DEFORMATION FROM THE MW 6.0 24 AUGUST, 2014 SOUTH NAPA EARTHQUAKE ESTIMATED BY TWO AND THREE DIMENSIONAL POINT CLOUD CHANGE DETECTION TECHNIQUES

Directory of Open Access Journals (Sweden)

A. W. Lyda

2016-06-01

Full Text Available Remote sensing via LiDAR (Light Detection And Ranging has proven extremely useful in both Earth science and hazard related studies. Surveys taken before and after an earthquake for example, can provide decimeter-level, 3D near-field estimates of land deformation that offer better spatial coverage of the near field rupture zone than other geodetic methods (e.g., InSAR, GNSS, or alignment array. In this study, we compare and contrast estimates of deformation obtained from different pre and post-event airborne laser scanning (ALS data sets of the 2014 South Napa Earthquake using two change detection algorithms, Iterative Control Point (ICP and Particle Image Velocimetry (PIV. The ICP algorithm is a closest point based registration algorithm that can iteratively acquire three dimensional deformations from airborne LiDAR data sets. By employing a newly proposed partition scheme, “moving window,” to handle the large spatial scale point cloud over the earthquake rupture area, the ICP process applies a rigid registration of data sets within an overlapped window to enhance the change detection results of the local, spatially varying surface deformation near-fault. The other algorithm, PIV, is a well-established, two dimensional image co-registration and correlation technique developed in fluid mechanics research and later applied to geotechnical studies. Adapted here for an earthquake with little vertical movement, the 3D point cloud is interpolated into a 2D DTM image and horizontal deformation is determined by assessing the cross-correlation of interrogation areas within the images to find the most likely deformation between two areas. Both the PIV process and the ICP algorithm are further benefited by a presented, novel use of urban geodetic markers. Analogous to the persistent scatterer technique employed with differential radar observations, this new LiDAR application exploits a classified point cloud dataset to assist the change detection

The results of the pilot project in Georgia to install a network of electromagnetic radiation before the earthquake

Science.gov (United States)

Machavariani, Kakhaber; Khazaradze, Giorgi; Turazashvili, Ioseb; Kachakhidze, Nino; Kachakhidze, Manana; Gogoberidze, Vitali

2016-04-01

The world's scientific literature recently published many very important and interesting works of VLF / LF electromagnetic emissions, which is observed in the process of earthquake preparation. This works reliable earthquake prediction in terms of trends. Because, Georgia is located in Trans Asian earthquake zone, VLF / LF electromagnetic emissions network are essential. In this regard, it was possible to take first steps. It is true that our university has Shota Rustaveli National Science Foundation № DI / 21 / 9-140 / 13 grant, which included the installation of a receiver in Georgia, but failed due to lack of funds to buy this device. However, European friends helped us (Prof. Dr. PF Biagi and Prof. Dr. Aydın BÜYÜKSARAÇ) and made possible the installation of a receiver. Turkish scientists expedition in Georgia was organized in August 2015. They brought with them VLF / LF electromagnetic emissions receiver and together with Georgian scientists install near Tbilisi. The station was named GEO-TUR. It should be noted that Georgia was involved in the work of the European network. It is possible to completely control the earthquake in Georgia in terms of electromagnetic radiation. This enables scientists to obtain the relevant information not only on the territory of our country, but also on seismically active European countries as well. In order to maintain and develop our country in this new direction, it is necessary to keep independent group of scientists who will learn electromagnetic radiation ahead of an earthquake in Georgia. At this stage, we need to remedy this shortcoming, it is necessary and appropriate specialists to Georgia to engage in a joint international research. The work is carried out in the frame of grant (DI/21/9-140/13 „Pilot project of before earthquake detected Very Low Frequency/Low Frequency electromagnetic emission network installation in Georgia") by financial support of Shota Rustaveli National Science Foundation.

25 April 2015 Gorkha Earthquake in Nepal Himalaya (Part 2)

Science.gov (United States)

Rao, N. Purnachandra; Burgmann, Roland; Mugnier, Jean-Louis; Gahalaut, Vineet; Pandey, Anand

2017-06-01

The response from the geosciences community working on Himalaya in general, and the 2015 Nepal earthquakes in specific, was overwhelming, and after a rigorous review process, thirteen papers were selected and published in Part-1. We are still left with a few good papers which are being brought out as Part-2 of the special issue. In the opening article Jean-Louis Mugnier and colleagues attempt to provide a structural geological perspective of the 25 April 2015 Gorkha earthquake and highlight the role of segmentation in generating the Himalayan mega-thrusts. They could infer segmentation by stable barriers in the HT that define barrier-type earthquake families. In yet another interesting piece of work, Pandey and colleagues map the crustal structure across the earthquake volume using Receiver function approach and infer a 5-km thick low velocity layer that connects to the MHT ramp. They are also able to correlate the rupture termination with the highest point of coseismic uplift. The last paper by Shen et al. highlights the usefulness of INSAR technique in mapping the coseismic slip distribution applied to the 25 April 2015 Gorkha earthquake. They infer low stress drop and corner frequency which coupled with hybrid modeling explain the low level of slip heterogeneity and frequency of ground motion. We compliment the journal of Asian Earth Sciences for bringing out the two volumes and do hope that these efforts have made a distinct impact on furthering our understanding of seismogenesis in Himalaya using the very latest data sets.

Sensitivity to Regional Earthquake Triggering and Magnitude-Frequency Characteristics of Microseismicity Detected via Matched-Filter Analysis, Central Southern Alps, New Zealand

Science.gov (United States)

Boese, C. M.; Townend, J.; Chamberlain, C. J.; Warren-Smith, E.

2016-12-01

Microseismicity recorded since 2008 by the Southern Alps Microseismicity Borehole Array (SAMBA) and other predominantly short-period seismic networks deployed in the central Southern Alps, New Zealand, reveals distinctive patterns of triggering in response to regional seismicity (magnitudes larger than 5, epicentral distances of 100-500 km). Using matched-filter detection methods implemented in the EQcorrscan package (Chamberlain et al., in prep.), we analyze microseismicity occurring in several geographically distinct swarms in order to examine the responses of specific microearthquake sources to earthquakes of different sizes occurring at different distances and azimuths. The swarms exhibit complex responses to regional seismicity which reveal that microearthquake triggering in these cases involves a combination of extrinsic factors (related to the dynamic stresses produced by the regional earthquake) and intrinsic factors (controlled by the local state of stress and possibly by hydrogeological processes). We find also that the microearthquakes detected by individual templates have Gutenberg-Richter magnitude-frequency characteristics. Since the detected events, by design, have very similar hypocentres and focal mechanisms, the observed scaling pertains to a restricted set of fault planes.

Real-Time Earthquake Monitoring with Spatio-Temporal Fields

Science.gov (United States)

Whittier, J. C.; Nittel, S.; Subasinghe, I.

2017-10-01

With live streaming sensors and sensor networks, increasingly large numbers of individual sensors are deployed in physical space. Sensor data streams are a fundamentally novel mechanism to deliver observations to information systems. They enable us to represent spatio-temporal continuous phenomena such as radiation accidents, toxic plumes, or earthquakes almost as instantaneously as they happen in the real world. Sensor data streams discretely sample an earthquake, while the earthquake is continuous over space and time. Programmers attempting to integrate many streams to analyze earthquake activity and scope need to write code to integrate potentially very large sets of asynchronously sampled, concurrent streams in tedious application code. In previous work, we proposed the field stream data model (Liang et al., 2016) for data stream engines. Abstracting the stream of an individual sensor as a temporal field, the field represents the Earth's movement at the sensor position as continuous. This simplifies analysis across many sensors significantly. In this paper, we undertake a feasibility study of using the field stream model and the open source Data Stream Engine (DSE) Apache Spark(Apache Spark, 2017) to implement a real-time earthquake event detection with a subset of the 250 GPS sensor data streams of the Southern California Integrated GPS Network (SCIGN). The field-based real-time stream queries compute maximum displacement values over the latest query window of each stream, and related spatially neighboring streams to identify earthquake events and their extent. Further, we correlated the detected events with an USGS earthquake event feed. The query results are visualized in real-time.

Toward standardization of slow earthquake catalog -Development of database website-

Science.gov (United States)

Kano, M.; Aso, N.; Annoura, S.; Arai, R.; Ito, Y.; Kamaya, N.; Maury, J.; Nakamura, M.; Nishimura, T.; Obana, K.; Sugioka, H.; Takagi, R.; Takahashi, T.; Takeo, A.; Yamashita, Y.; Matsuzawa, T.; Ide, S.; Obara, K.

2017-12-01

Slow earthquakes have now been widely discovered in the world based on the recent development of geodetic and seismic observations. Many researchers detect a wide frequency range of slow earthquakes including low frequency tremors, low frequency earthquakes, very low frequency earthquakes and slow slip events by using various methods. Catalogs of the detected slow earthquakes are open to us in different formats by each referring paper or through a website (e.g., Wech 2010; Idehara et al. 2014). However, we need to download catalogs from different sources, to deal with unformatted catalogs and to understand the characteristics of different catalogs, which may be somewhat complex especially for those who are not familiar with slow earthquakes. In order to standardize slow earthquake catalogs and to make such a complicated work easier, Scientific Research on Innovative Areas "Science of Slow Earthquakes" has been developing a slow earthquake catalog website. In the website, we can plot locations of various slow earthquakes via the Google Maps by compiling a variety of slow earthquake catalogs including slow slip events. This enables us to clearly visualize spatial relations among slow earthquakes at a glance and to compare the regional activities of slow earthquakes or the locations of different catalogs. In addition, we can download catalogs in the unified format and refer the information on each catalog on the single website. Such standardization will make it more convenient for users to utilize the previous achievements and to promote research on slow earthquakes, which eventually leads to collaborations with researchers in various fields and further understanding of the mechanisms, environmental conditions, and underlying physics of slow earthquakes. Furthermore, we expect that the website has a leading role in the international standardization of slow earthquake catalogs. We report the overview of the website and the progress of construction. Acknowledgment: This

Field Detection of Microcracks to Define the Nucleation Stage of Earthquake Occurrence

Directory of Open Access Journals (Sweden)

Y. Fujinawa

2013-01-01

Full Text Available Main shocks of natural earthquakes are known to be accompanied by preshocks which evolve following the modified Ohmori’s law in average over many samples. Individual preshock activity, however, is far less systematic for predictive purposes. On the other hand, the microcracks in laboratory rock experiments are always preceded to final rupture. And, previous investigations of field acoustic emissions showed that the activity increases prominently before and after the main shock. But there is no detection of any phenomena to identify the nucleation stage. Here we show that a special underground electric field measurement could detect microcracks. Pulse-like variations were classified into three groups (A, B, C by frequency. The B-type is suggested to define the nucleation period: activity increases sharply following the modified Omori’s law before the main shock and there is no activity afterward. The B-type is subgrouped into three types possibly corresponding to crack-rupture modes. The variations are supposed to be induced by crack occurrence through electrokinetic effects in the elastic-porous medium. The detection distance is suggested to be several orders larger than that of the acoustic emission due to the effective smallness of dissipation rate, and the waveform can be used to infer the rupture mode.

Remotely Triggered Earthquakes Recorded by EarthScope's Transportable Array and Regional Seismic Networks: A Case Study Of Four Large Earthquakes

Science.gov (United States)

Velasco, A. A.; Cerda, I.; Linville, L.; Kilb, D. L.; Pankow, K. L.

2013-05-01

Changes in field stress required to trigger earthquakes have been classified in two basic ways: static and dynamic triggering. Static triggering occurs when an earthquake that releases accumulated strain along a fault stress loads a nearby fault. Dynamic triggering occurs when an earthquake is induced by the passing of seismic waves from a large mainshock located at least two or more fault lengths from the epicenter of the main shock. We investigate details of dynamic triggering using data collected from EarthScope's USArray and regional seismic networks located in the United States. Triggered events are identified using an optimized automated detector based on the ratio of short term to long term average (Antelope software). Following the automated processing, the flagged waveforms are individually analyzed, in both the time and frequency domains, to determine if the increased detection rates correspond to local earthquakes (i.e., potentially remotely triggered aftershocks). Here, we show results using this automated schema applied to data from four large, but characteristically different, earthquakes -- Chile (Mw 8.8 2010), Tokoku-Oki (Mw 9.0 2011), Baja California (Mw 7.2 2010) and Wells Nevada (Mw 6.0 2008). For each of our four mainshocks, the number of detections within the 10 hour time windows span a large range (1 to over 200) and statistically >20% of the waveforms show evidence of anomalous signals following the mainshock. The results will help provide for a better understanding of the physical mechanisms involved in dynamic earthquake triggering and will help identify zones in the continental U.S. that may be more susceptible to dynamic earthquake triggering.

Epidemiology of prostate cancer in Asian countries.

Science.gov (United States)

Kimura, Takahiro; Egawa, Shin

2018-06-01

The incidence of prostate cancer has been increasing worldwide in recent years. The GLOBOCAN project showed that prostate cancer was the second most frequently diagnosed cancer and the fifth leading cause of cancer mortality among men worldwide in 2012. This trend has been growing even in Asian countries, where the incidence had previously been low. However, the accuracy of data about incidence and mortality as a result of prostate cancer in some Asian countries is limited. The cause of this increasing trend is multifactorial. One possible explanation is changes in lifestyles due to more Westernized diets. The incidence is also statistically biased by the wide implementation of early detection systems and the accuracy of national cancer registration systems, which are still immature in most Asian countries. Mortality rate decreases in Australia, New Zealand and Japan since the 1990s are possibly due to the improvements in treatment and/or early detection efforts employed. However, this rate is increasing in the majority of other Asian countries. Studies of latent and incidental prostate cancer provide less biased information. The prevalence of latent and incidental prostate cancer in contemporary Japan and Korea is similar to those in Western countries, suggesting the influence of lifestyle changes on carcinogenesis. Many studies reported evidence of both congenital and acquired risk factors for carcinogenesis of prostate cancer. Recent changes in the acquired risk factors might be associated with the increasing occurrence of prostate cancer in Asian countries. This trend could continue, especially in developing Asian countries. © 2018 The Japanese Urological Association.

The contribution of the Global Change Observatory Central Asia to seismic hazard and risk assessment in the Central Asian region

Science.gov (United States)

Parolai, S.; Bindi, D.; Haberland, C. A.; Pittore, M.; Pilz, M.; Rosenau, M.; Schurr, B.; Wieland, M.; Yuan, X.

2012-12-01

Central Asia has one of the world's highest levels of earthquake hazard, owing to its exceptionally high deformation rates. Moreover, vulnerability to natural disasters in general is increasing, due to rising populations and a growing dependence on complex lifelines and technology. Therefore, there is an urgent need to undertake seismic hazard and risk assessment in this region, while at the same time improving upon existing methodologies, including the consideration of temporal variability in the seismic hazard, and in structural and social vulnerability. Over the last few years, the German Research Center for Geosciences (GFZ), in collaboration with local partners, has initiated a number of scientific activities within the framework of the Global Change Observatory Central Asia (GCO-CA). The work is divided into projects with specific concerns: - The installation and maintenance of the Central-Asian Real-time Earthquake MOnitoring Network (CAREMON) and the setup of a permanent wireless mesh network for structural health monitoring in Bishkek. - The TIPAGE and TIPTIMON projects focus on the geodynamics of the Tien-Shan, Pamir and Hindu Kush region, the deepest and most active intra-continental subduction zone in the world. The work covers time scales from millions of years to short-term snapshots based on geophysical measurements of seismotectonic activity and of the physical properties of the crust and upper mantle, as well as their coupling with other surface processes (e.g., landslides). - Existing risk analysis methods assume time-independent earthquake hazard and risk, although temporal changes are likely to occur due to, for example, co- and post-seismic changes in the regional stress field. We therefore aim to develop systematic time-dependent hazard and risk analysis methods in order to undertake the temporal quantification of earthquake activity (PROGRESS). - To improve seismic hazard assessment for better loss estimation, detailed site effects studies

The Rhetorical Making of the Asian/Asian American Face: Reading and Writing Asian Eyelids

OpenAIRE

Sano-Franchini, Jennifer

2013-01-01

In The Rhetorical Making of the Asian/Asian American Face: Reading and Writing Asian Eyelids, I examine representations of East Asian blepharoplasty in online video in order to gain a sense of how cultural values change over time. Drawing on scholarship in and around rhetorical theory, cultural rhetorics, Asian American rhetoric, cultural studies, Asian American studies, and postcolonial theory alongside qualitative data analysis of approximately fifty videos and the numerous viewer comments ...

From Tornadoes to Earthquakes: Forecast Verification for Binary Events Applied to the 1999 Chi-Chi, Taiwan,Earthquake

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Chien-Chih Chen

2006-01-01

Full Text Available Forecast verification procedures for statistical events with binary outcomes typically rely on the use of contingency tables and Relative Operating Characteristic (ROC diagrams. Originally developed for the statistical evaluation of tornado forecasts on a county-by-county basis, these methods can be adapted to the evaluation of competing earthquake forecasts. Here we apply these methods retrospectively to two forecasts for the M 7.3 1999 Chi-Chi, Taiwan, earthquake. We show that a previously proposed forecast method that is based on evaluating changes in seismic intensity on a regional basis is superior to a forecast based only on the magnitude of seismic intensity in the same region. Our results confirm earlier suggestions that the earthquake preparation process for events such as the Chi-Chi earthquake involves anomalous activation or quiescence, and that signatures of these processes can be detected in seismicity data using appropriate methods.

The Need for More Earthquake Science in Southeast Asia

Science.gov (United States)

Sieh, K.

2015-12-01

Many regions within SE Asia have as great a density of active seismic structures as does the western US - Sumatra, Myanmar, Bangladesh, New Guinea and the Philippines come first to mind. Much of Earth's release of seismic energy in the current millennium has, in fact, come from these regions, with great losses of life and livelihoods. Unfortunately, the scientific progress upon which seismic-risk reduction in SE Asia ultimately depends has been and continues to be slow. Last year at AGU, for example, I counted 57 talks about the M6 Napa earthquake. In contrast, I can't recall hearing any talk on a SE Asian M6 earthquake at any venue in the past many years. In fact, even M7+ earthquakes often go unstudied. Not uncommonly, the region's earthquake scientists face high financial and political impediments to conducting earthquake research. Their slow speed in the development of scientific knowledge doesn't bode well for speedy progress in the science of seismic hazards, the sine qua non for substantially reducing seismic risk. There are two basic necessities for the region to evolve significantly from the current state of affairs. Both involve the development of regional infrastructure: 1) Data: Robust and accessible geophysical monitoring systems would need to be installed, maintained and utilized by the region's earth scientists and their results shared internationally. Concomitantly, geological mapping (sensu lato) would need to be undertaken. 2) People: The training, employment, and enduring support of a new, young, international corps of earth scientists would need to accelerate markedly. The United States could play an important role in achieving the goal of significant seismic risk reduction in the most seismically active countries of SE Asia by taking the lead in establishing a coalition to robustly fund a multi-decadal program that supports scientists and their research institutions to work alongside local expertise.

VLF/LF Radio Sounding of Ionospheric Perturbations Associated with Earthquakes

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Masashi Hayakawa

2007-07-01

Full Text Available It is recently recognized that the ionosphere is very sensitive to seismic effects,and the detection of ionospheric perturbations associated with earthquakes, seems to bevery promising for short-term earthquake prediction. We have proposed a possible use ofVLF/LF (very low frequency (3-30 kHz /low frequency (30-300 kHz radio sounding ofthe seismo-ionospheric perturbations. A brief history of the use of subionospheric VLF/LFpropagation for the short-term earthquake prediction is given, followed by a significantfinding of ionospheric perturbation for the Kobe earthquake in 1995. After showingprevious VLF/LF results, we present the latest VLF/LF findings; One is the statisticalcorrelation of the ionospheric perturbation with earthquakes and the second is a case studyfor the Sumatra earthquake in December, 2004, indicating the spatical scale and dynamicsof ionospheric perturbation for this earthquake.

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.

Articulating Asianness: Young Asian Dutch and non-homeland Asian popular media

NARCIS (Netherlands)

Kartosen, R.A.; Tan, E.S.H.

2013-01-01

This study explores Asian Dutch young people’s ethnic-cultural identification in relation to their media consumption, and specifically their consumption of popular media from Asian countries other than their country of origin. A survey was conducted among 486 Asian Dutch (18-35 years old). In

Satellite detection of carbon monoxide emission prior to the Gujarat earthquake of 26 January 2001

Energy Technology Data Exchange (ETDEWEB)

Singh, Ramesh P., E-mail: rsingh@chapman.edu [Department of Physics, Computational Science and Engineering, Schmid College of Science, Chapman University, One University Drive, Orange CA 92866 (United States); Senthil Kumar, J.; Zlotnicki, Jacques [Observatoire de Physique du Globe de Clermont-Ferrand, OPGC-CNRS, Campus des Cuzeaux, 24, av. des Landais, 63177 Aubiere Cedex (France); Kafatos, Menas [Department of Physics, Computational Science and Engineering, Schmid College of Science, Chapman University, One University Drive, Orange CA 92866 (United States)

2010-04-15

NOAA AVHRR images have clearly shown anomalous changes in land surface temperature associated with earthquakes in the past two decades. Soon after the Gujarat earthquake of January 26, 2001, an anomalous increase in land surface temperature was inferred from MODIS satellite data a few days prior to the main earthquake event. The cause of such an anomalous change in surface temperature prior to the earthquake is attributed to many probable phenomena, but no definite cause has been identified. In the present study, changes of a complementary nature were found of land surface temperature associated with the emission of CO from the epicentral region. The observed changes on land and atmosphere associated with the Gujarat earthquake of 26 January, 2001, show the existence of strong coupling between land, atmosphere and ionosphere.

Ethnopsychopharmacology considerations for Asians and Asian Americans.

Science.gov (United States)

Wong, Felicia K; Pi, Edmond H

2012-03-01

Asians comprise more than 60% of the world's population and are the fastest growing minority group in the United States. Today's psychiatrist must learn to recognize and appreciate the unique factors that influence mental health outcomes in this group. Asian Americans are affected by psychiatric disorders at similar rates as non-Asians, but are significantly underrepresented in psychiatric clinics. When Asians and Asian Americans do present for psychiatric treatment, they often do so with higher severity of illness, and variable levels of compliance. Studies over the past three decades have suggested that pharmacokinetic and pharmacodynamic profiles of various psychotropic medications may be different in Asians, leading to differences in dosage requirements and side-effect profiles. These variations appear to be largely determined by genetic predisposition, but are also influenced by other factors such as environment, social support, cultural perceptions, and physicians' prescribing habits. In this paper, we provide an overview of biological and socio-cultural issues as they relate to psychopharmacology in Asians and Asian Americans, with the hope that a better understanding of these issues will lead to improved mental health care delivery to this population both in the United States, as well as in Asian countries. Copyright © 2012 Elsevier B.V. All rights reserved.

A Deterministic Approach to Earthquake Prediction

Directory of Open Access Journals (Sweden)

Vittorio Sgrigna

2012-01-01

Full Text Available The paper aims at giving suggestions for a deterministic approach to investigate possible earthquake prediction and warning. A fundamental contribution can come by observations and physical modeling of earthquake precursors aiming at seeing in perspective the phenomenon earthquake within the framework of a unified theory able to explain the causes of its genesis, and the dynamics, rheology, and microphysics of its preparation, occurrence, postseismic relaxation, and interseismic phases. Studies based on combined ground and space observations of earthquake precursors are essential to address the issue. Unfortunately, up to now, what is lacking is the demonstration of a causal relationship (with explained physical processes and looking for a correlation between data gathered simultaneously and continuously by space observations and ground-based measurements. In doing this, modern and/or new methods and technologies have to be adopted to try to solve the problem. Coordinated space- and ground-based observations imply available test sites on the Earth surface to correlate ground data, collected by appropriate networks of instruments, with space ones detected on board of Low-Earth-Orbit (LEO satellites. Moreover, a new strong theoretical scientific effort is necessary to try to understand the physics of the earthquake.

Earthquakes

Science.gov (United States)

An earthquake happens when two blocks of the earth suddenly slip past one another. Earthquakes strike suddenly, violently, and without warning at any time of the day or night. If an earthquake occurs in a populated area, it may cause ...

The Challenge of Centennial Earthquakes to Improve Modern Earthquake Engineering

International Nuclear Information System (INIS)

Saragoni, G. Rodolfo

2008-01-01

The recent commemoration of the centennial of the San Francisco and Valparaiso 1906 earthquakes has given the opportunity to reanalyze their damages from modern earthquake engineering perspective. These two earthquakes plus Messina Reggio Calabria 1908 had a strong impact in the birth and developing of earthquake engineering. The study of the seismic performance of some up today existing buildings, that survive centennial earthquakes, represent a challenge to better understand the limitations of our in use earthquake design methods. Only Valparaiso 1906 earthquake, of the three considered centennial earthquakes, has been repeated again as the Central Chile, 1985, Ms = 7.8 earthquake. In this paper a comparative study of the damage produced by 1906 and 1985 Valparaiso earthquakes is done in the neighborhood of Valparaiso harbor. In this study the only three centennial buildings of 3 stories that survived both earthquakes almost undamaged were identified. Since for 1985 earthquake accelerogram at El Almendral soil conditions as well as in rock were recoded, the vulnerability analysis of these building is done considering instrumental measurements of the demand. The study concludes that good performance of these buildings in the epicentral zone of large earthquakes can not be well explained by modern earthquake engineering methods. Therefore, it is recommended to use in the future of more suitable instrumental parameters, such as the destructiveness potential factor, to describe earthquake demand

Earthquake prediction

International Nuclear Information System (INIS)

Ward, P.L.

1978-01-01

The state of the art of earthquake prediction is summarized, the possible responses to such prediction are examined, and some needs in the present prediction program and in research related to use of this new technology are reviewed. Three basic aspects of earthquake prediction are discussed: location of the areas where large earthquakes are most likely to occur, observation within these areas of measurable changes (earthquake precursors) and determination of the area and time over which the earthquake will occur, and development of models of the earthquake source in order to interpret the precursors reliably. 6 figures

Radon anomalies prior to earthquakes (1). Review of previous studies

International Nuclear Information System (INIS)

Ishikawa, Tetsuo; Tokonami, Shinji; Yasuoka, Yumi; Shinogi, Masaki; Nagahama, Hiroyuki; Omori, Yasutaka; Kawada, Yusuke

2008-01-01

The relationship between radon anomalies and earthquakes has been studied for more than 30 years. However, most of the studies dealt with radon in soil gas or in groundwater. Before the 1995 Hyogoken-Nanbu earthquake, an anomalous increase of atmospheric radon was observed at Kobe Pharmaceutical University. The increase was well fitted with a mathematical model related to earthquake fault dynamics. This paper reports the significance of this observation, reviewing previous studies on radon anomaly before earthquakes. Groundwater/soil radon measurements for earthquake prediction began in 1970's in Japan as well as foreign countries. One of the most famous studies in Japan is groundwater radon anomaly before the 1978 Izu-Oshima-kinkai earthquake. We have recognized the significance of radon in earthquake prediction research, but recently its limitation was also pointed out. Some researchers are looking for a better indicator for precursors; simultaneous measurements of radon and other gases are new trials in recent studies. Contrary to soil/groundwater radon, we have not paid much attention to atmospheric radon before earthquakes. However, it might be possible to detect precursors in atmospheric radon before a large earthquake. In the next issues, we will discuss the details of the anomalous atmospheric radon data observed before the Hyogoken-Nanbu earthquake. (author)

Coping with earthquakes induced by fluid injection

Science.gov (United States)

McGarr, Arthur F.; Bekins, Barbara; Burkardt, Nina; Dewey, James W.; Earle, Paul S.; Ellsworth, William L.; Ge, Shemin; Hickman, Stephen H.; Holland, Austin F.; Majer, Ernest; Rubinstein, Justin L.; Sheehan, Anne

2015-01-01

Large areas of the United States long considered geologically stable with little or no detected seismicity have recently become seismically active. The increase in earthquake activity began in the mid-continent starting in 2001 (1) and has continued to rise. In 2014, the rate of occurrence of earthquakes with magnitudes (M) of 3 and greater in Oklahoma exceeded that in California (see the figure). This elevated activity includes larger earthquakes, several with M > 5, that have caused significant damage (2, 3). To a large extent, the increasing rate of earthquakes in the mid-continent is due to fluid-injection activities used in modern energy production (1, 4, 5). We explore potential avenues for mitigating effects of induced seismicity. Although the United States is our focus here, Canada, China, the UK, and others confront similar problems associated with oil and gas production, whereas quakes induced by geothermal activities affect Switzerland, Germany, and others.

Abundant aftershock sequence of the 2015 Mw7.5 Hindu Kush intermediate-depth earthquake

Science.gov (United States)

Li, Chenyu; Peng, Zhigang; Yao, Dongdong; Guo, Hao; Zhan, Zhongwen; Zhang, Haijiang

2018-05-01

The 2015 Mw7.5 Hindu Kush earthquake occurred at a depth of 213 km beneath the Hindu Kush region of Afghanistan. While many early aftershocks were missing from the global earthquake catalogues, this sequence was recorded continuously by eight broad-band stations within 500 km. Here we use a waveform matching technique to systematically detect earthquakes around the main shock. More than 3000 events are detected within 35 d after the main shock, as compared with 42 listed in the Advanced National Seismic System catalogue (or 196 in the International Seismological Centre catalogue). The aftershock sequence generally follows the Omori's law with a decay constant p = 0.92. We also apply the recently developed double-pair double-difference technique to relocate all detected aftershocks. Most of them are located to the west of the hypocentre of the main shock, consistent with the westward propagation of the main-shock rupture. The aftershocks outline a nearly vertical southward dipping plane, which matches well with one of the nodal planes of the main shock. We conclude that the aftershock sequence of this intermediate-depth earthquake shares many similarities with those for shallow earthquakes and infer that there are some common mechanisms responsible for shallow and intermediate-depth earthquakes.

From Multi-Sensors Observations Towards Cross-Disciplinary Study of Pre-Earthquake Signals. What have We Learned from the Tohoku Earthquake?

Science.gov (United States)

Ouzounov, D.; Pulinets, S.; Papadopoulos, G.; Kunitsyn, V.; Nesterov, I.; Hayakawa, M.; Mogi, K.; Hattori, K.; Kafatos, M.; Taylor, P.

2012-01-01

The lessons we have learned from the Great Tohoku EQ (Japan, 2011) how this knowledge will affect our future observation and analysis is the main focus of this presentation.We present multi-sensors observations and multidisciplinary research in our investigation of phenomena preceding major earthquakes. These observations revealed the existence of atmospheric and ionospheric phenomena occurring prior to theM9.0 Tohoku earthquake of March 11, 2011, which indicates s new evidence of a distinct coupling between the lithosphere and atmosphere/ionosphere, as related to underlying tectonic activity. Similar results have been reported before the catastrophic events in Chile (M8.8, 2010), Italy (M6.3, 2009) and Sumatra (M9.3, 2004). For the Tohoku earthquake, our analysis shows a synergy between several independent observations characterizing the state of the lithosphere /atmosphere coupling several days before the onset of the earthquakes, namely: (i) Foreshock sequence change (rate, space and time); (ii) Outgoing Long wave Radiation (OLR) measured at the top of the atmosphere; and (iii) Anomalous variations of ionospheric parameters revealed by multi-sensors observations. We are presenting a cross-disciplinary analysis of the observed pre-earthquake anomalies and will discuss current research in the detection of these signals in Japan. We expect that our analysis will shed light on the underlying physics of pre-earthquake signals associated with some of the largest earthquake events

Ionospheric precursors to large earthquakes: A case study of the 2011 Japanese Tohoku Earthquake

Science.gov (United States)

Carter, B. A.; Kellerman, A. C.; Kane, T. A.; Dyson, P. L.; Norman, R.; Zhang, K.

2013-09-01

Researchers have reported ionospheric electron distribution abnormalities, such as electron density enhancements and/or depletions, that they claimed were related to forthcoming earthquakes. In this study, the Tohoku earthquake is examined using ionosonde data to establish whether any otherwise unexplained ionospheric anomalies were detected in the days and hours prior to the event. As the choices for the ionospheric baseline are generally different between previous works, three separate baselines for the peak plasma frequency of the F2 layer, foF2, are employed here; the running 30-day median (commonly used in other works), the International Reference Ionosphere (IRI) model and the Thermosphere Ionosphere Electrodynamic General Circulation Model (TIE-GCM). It is demonstrated that the classification of an ionospheric perturbation is heavily reliant on the baseline used, with the 30-day median, the IRI and the TIE-GCM generally underestimating, approximately describing and overestimating the measured foF2, respectively, in the 1-month period leading up to the earthquake. A detailed analysis of the ionospheric variability in the 3 days before the earthquake is then undertaken, where a simultaneous increase in foF2 and the Es layer peak plasma frequency, foEs, relative to the 30-day median was observed within 1 h before the earthquake. A statistical search for similar simultaneous foF2 and foEs increases in 6 years of data revealed that this feature has been observed on many other occasions without related seismic activity. Therefore, it is concluded that one cannot confidently use this type of ionospheric perturbation to predict an impending earthquake. It is suggested that in order to achieve significant progress in our understanding of seismo-ionospheric coupling, better account must be taken of other known sources of ionospheric variability in addition to solar and geomagnetic activity, such as the thermospheric coupling.

Implications of fault constitutive properties for earthquake prediction.

Science.gov (United States)

Dieterich, J H; Kilgore, B

1996-04-30

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 Dc, 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 Dc apply to faults in nature. However, scaling of Dc 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.

Automatic recognition of damaged town buildings caused by earthquake using remote sensing information: Taking the 2001 Bhuj, India, earthquake and the 1976 Tangshan, China, earthquake as examples

Science.gov (United States)

Liu, Jia-Hang; Shan, Xin-Jian; Yin, Jing-Yuan

2004-11-01

In the high-resolution images, the undamaged buildings generally show a natural textural feature, while the damaged or semi-damaged buildings always exhibit some low-grayscale blocks because of their coarsely damaged sections. If we use a proper threshold to classify the grayscale of image, some independent holes will appear in the damaged regions. By using such statistical information as the number of holes in every region, or the ratio between the area of holes and that of the region, etc, the damaged buildings can be separated from the undamaged, thus automatic detection of damaged buildings can be realized. Based on these characteristics, a new method to automatically detect the damage buildings by using regional structure and statistical information of texture is presented in the paper. In order to test its validity, 1-m-resolution iKonos merged image of the 2001 Bhuj earthquake and grayscale aerial photos of the 1976 Tangshan earthquake are selected as two examples to automatically detect the damaged buildings. Satisfied results are obtained.

Atmospheric gravity wave detection following the 2011 Tohoku earthquakes combining COSMIC occultation and GPS observations

Science.gov (United States)

Yan, X.; Tao, Y.; Xia, C.; Qi, Y.; Zuo, X.

2017-12-01

Several studies have reported the earthquake-induced atmospheric gravity waves detected by some new technologies such as airglow (Makela et al., 2011), GOCE (Garcia et al., 2013), GRACE (Yang et al., 2014), F3/C radio occultation sounding (Coïsson et al., 2015). In this work, we collected all occultation events on 11 March, and selected four events to analyze at last. The original and filtered podTEC is represented as function of the altitude of the impact parameter and UT of the four events. Then, the travel time diagrams of filtered podTEC derived from the events were analyzed. The occultation signal from one event (marked as No.73) is consistent with the previous results reported by Coïsson. 2015, which is corresponds to the ionospheric signal induced from tsunami gravity wave. What is noticeable, in this work, is that three occultation events of No.403, 77 and 118 revealed a disturbance of atmospheric gravity wave with velocity 300m/s, preceding the tsunami. It would probably be correspond to the gravity waves caused by seismic rupture but not tsunami. In addition, it can be seen that the perturbation height of occultation observation TEC is concentrated at 200-400km, corresponding ionosphere F region. The signals detected above are compared with GPS measurements of TEC from GEONET and IGS. From GPS data, traveling ionospheric disturbances were observed spreading out from the epicenter as a quasi-circular propagation pattern with the time. Exactly, we observed an acoustic wave coupled with Rayleigh wave starting from the epicenter with a speed of 3.0km/s and a superimposed acoustic-gravity wave moving with a speed of 800m/s. The acoustic-gravity wave generated at the epicenter and gradually attenuated 800km away, then it is replaced by a gravity wave coupled with the tsunami that moves with a speed of between 100 and 300m/s. It is necessary to confirm the propagation process of the waves if we attempt to evaluate the use of ionospheric seismology as a

Demonstration of the Cascadia G‐FAST geodetic earthquake early warning system for the Nisqually, Washington, earthquake

Science.gov (United States)

Crowell, Brendan; Schmidt, David; Bodin, Paul; Vidale, John; Gomberg, Joan S.; Hartog, Renate; Kress, Victor; Melbourne, Tim; Santillian, Marcelo; Minson, Sarah E.; Jamison, Dylan

2016-01-01

A prototype earthquake early warning (EEW) system is currently in development in the Pacific Northwest. We have taken a two‐stage approach to EEW: (1) detection and initial characterization using strong‐motion data with the Earthquake Alarm Systems (ElarmS) seismic early warning package and (2) the triggering of geodetic modeling modules using Global Navigation Satellite Systems data that help provide robust estimates of large‐magnitude earthquakes. In this article we demonstrate the performance of the latter, the Geodetic First Approximation of Size and Time (G‐FAST) geodetic early warning system, using simulated displacements for the 2001Mw 6.8 Nisqually earthquake. We test the timing and performance of the two G‐FAST source characterization modules, peak ground displacement scaling, and Centroid Moment Tensor‐driven finite‐fault‐slip modeling under ideal, latent, noisy, and incomplete data conditions. We show good agreement between source parameters computed by G‐FAST with previously published and postprocessed seismic and geodetic results for all test cases and modeling modules, and we discuss the challenges with integration into the U.S. Geological Survey’s ShakeAlert EEW system.

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.

Electromagnetic Signals and Earthquakes 2.0: Increasing Signals and Reducing Noise

Science.gov (United States)

Dunson, J. C.; Bleier, T.; Heraud, J. A.; Muller, S.; Lindholm, C.; Christman, L.; King, R.; Lemon, J.

2013-12-01

QuakeFinder has an international network of 150+ Magnetometers and air conductivity instruments located in California, Peru, Chile, Taiwan, and Greece. Since 2000, QuakeFinder has been collecting electromagnetic data and applying simple algorithms to identify and characterize electromagnetic signals that occur in the few weeks prior to earthquakes greater than M4.5. In this presentation, we show refinements to several aspects of our signal identification techniques that enhance detection of pre-earthquake patterns. Our magnetometers have been improved to show longer pulses, and we are now using second generation algorithms that have been refined to detect the proper shape of the earthquake-generated pulses and to allow individual site adjustments. Independent lightning strike data has also now been included to mask out lightning based on amplitude and distance from a given instrument site. Direction of arrival (Azimuth) algorithms have been added to identify patterns of pulse clustering that occur prior to nearby earthquakes. Likewise, positive and negative air ion concentration detection has been improved by building better enclosures, using stainless screens to eliminate insects and some dirt sources, conformal coating PC boards to reduce moisture contamination, and filtering out contaminated data segments based on relative humidity measurements at each site. Infra Red data from the western GOES satellite has been time-filtered, cloud-filtered, and compared to 3 year averages of each pixel's output (by seasonal month) to arrive at a relevant comparison baseline for each night's temperature/cooling slope. All these efforts have helped improve the detection of multiple, nearly simultaneous, electromagnetic signals due to earthquake preparation processes, while reducing false positive indications due to environmental noise sources.

Signals of ENPEMF Used in Earthquake Prediction

Science.gov (United States)

Hao, G.; Dong, H.; Zeng, Z.; Wu, G.; Zabrodin, S. M.

2012-12-01

The signals of Earth's natural pulse electromagnetic field (ENPEMF) is a combination of the abnormal crustal magnetic field pulse affected by the earthquake, the induced field of earth's endogenous magnetic field, the induced magnetic field of the exogenous variation magnetic field, geomagnetic pulsation disturbance and other energy coupling process between sun and earth. As an instantaneous disturbance of the variation field of natural geomagnetism, ENPEMF can be used to predict earthquakes. This theory was introduced by A.A Vorobyov, who expressed a hypothesis that pulses can arise not only in the atmosphere but within the Earth's crust due to processes of tectonic-to-electric energy conversion (Vorobyov, 1970; Vorobyov, 1979). The global field time scale of ENPEMF signals has specific stability. Although the wave curves may not overlap completely at different regions, the smoothed diurnal ENPEMF patterns always exhibit the same trend per month. The feature is a good reference for observing the abnormalities of the Earth's natural magnetic field in a specific region. The frequencies of the ENPEMF signals generally locate in kilo Hz range, where frequencies within 5-25 kilo Hz range can be applied to monitor earthquakes. In Wuhan, the best observation frequency is 14.5 kilo Hz. Two special devices are placed in accordance with the S-N and W-E direction. Dramatic variation from the comparison between the pulses waveform obtained from the instruments and the normal reference envelope diagram should indicate high possibility of earthquake. The proposed detection method of earthquake based on ENPEMF can improve the geodynamic monitoring effect and can enrich earthquake prediction methods. We suggest the prospective further researches are about on the exact sources composition of ENPEMF signals, the distinction between noise and useful signals, and the effect of the Earth's gravity tide and solid tidal wave. This method may also provide a promising application in

Effects of Huge Earthquakes on Earth Rotation and the length of Day

Directory of Open Access Journals (Sweden)

Changyi Xu

2013-01-01

Full Text Available We calculated the co-seismic Earth rotation changes for several typical great earthquakes since 1960 based on Dahlen¡¦s analytical expression of Earth inertia moment change, the excitation functions of polar motion and, variation in the length of a day (ΔLOD. Then, we derived a mathematical relation between polar motion and earthquake parameters, to prove that the amplitude of polar motion is independent of longitude. Because the analytical expression of Dahlen¡¦s theory is useful to theoretically estimate rotation changes by earthquakes having different seismic parameters, we show results for polar motion and ΔLOD for various types of earthquakes in a comprehensive manner. The modeled results show that the seismic effect on the Earth¡¦s rotation decreases gradually with increased latitude if other parameters are unchanged. The Earth¡¦s rotational change is symmetrical for a 45° dip angle and the maximum changes appear at the equator and poles. Earthquakes at a medium dip angle and low latitudes produce large rotation changes. As an example, we calculate the polar motion and ΔLOD caused by the 2011 Tohoku-Oki Earthquake using two different fault models. Results show that a fine slip fault model is useful to compute co-seismic Earth rotation change. The obtained results indicate Dahlen¡¦s method gives good approximations for computation of co-seismic rotation changes, but there are some differences if one considers detailed fault slip distributions. Finally we analyze and discuss the co-seismic Earth rotation change signal using GRACE data, showing that such a signal is hard to be detected at present, but it might be detected under some conditions. Numerical results of this study will serve as a good indicator to check if satellite observations such as GRACE can detect a seismic rotation change when a great earthquake occur.

Earthquake precursory events around epicenters and local active faults; the cases of two inland earthquakes in Iran

Science.gov (United States)

Valizadeh Alvan, H.; Mansor, S.; Haydari Azad, F.

2012-12-01

source and propagation of seismic waves. In many cases, active faults are capable of buildup and sudden release of tectonic stress. Hence, monitoring the active fault systems near epicentral regions of past earthquakes would be a necessity. In this paper, we try to detect possible anomalies in SLHF and AT during two moderate earthquakes of 6 - 6.5 M in Iran and explain the relationships between the seismic activities prior to these earthquake and active faulting in the area. Our analysis shows abnormal SLHF 5~10 days before these earthquakes. Meaningful anomalous concentrations usually occurred in the epicentral area. On the other hand, spatial distributions of these variations were in accordance with the local active faults. It is concluded that the anomalous increase in SLHF shows great potential in providing early warning of a disastrous earthquake, provided that there is a better understanding of the background noise due to the seasonal effects and climatic factors involved. Changes in near surface air temperature along nearby active faults, one or two weeks before the earthquakes, although not as significant as SLHF changes, can be considered as another earthquake indicator.

Earthquake Culture: A Significant Element in Earthquake Disaster Risk Assessment and Earthquake Disaster Risk Management

OpenAIRE

Ibrion, Mihaela

2018-01-01

This book chapter brings to attention the dramatic impact of large earthquake disasters on local communities and society and highlights the necessity of building and enhancing the earthquake culture. Iran was considered as a research case study and fifteen large earthquake disasters in Iran were investigated and analyzed over more than a century-time period. It was found that the earthquake culture in Iran was and is still conditioned by many factors or parameters which are not integrated and...

Disaster mitigation science for Earthquakes and Tsunamis -For resilience society against natural disasters-

Science.gov (United States)

Kaneda, Y.; Takahashi, N.; Hori, T.; Kawaguchi, K.; Isouchi, C.; Fujisawa, K.

2017-12-01

Destructive natural disasters such as earthquakes and tsunamis have occurred frequently in the world. For instance, 2004 Sumatra Earthquake in Indonesia, 2008 Wenchuan Earthquake in China, 2010 Chile Earthquake and 2011 Tohoku Earthquake in Japan etc., these earthquakes generated very severe damages. For the reduction and mitigation of damages by destructive natural disasters, early detection of natural disasters and speedy and proper evacuations are indispensable. And hardware and software developments/preparations for reduction and mitigation of natural disasters are quite important. In Japan, DONET as the real time monitoring system on the ocean floor is developed and deployed around the Nankai trough seismogenic zone southwestern Japan. So, the early detection of earthquakes and tsunamis around the Nankai trough seismogenic zone will be expected by DONET. The integration of the real time data and advanced simulation researches will lead to reduce damages, however, in the resilience society, the resilience methods will be required after disasters. Actually, methods on restorations and revivals are necessary after natural disasters. We would like to propose natural disaster mitigation science for early detections, evacuations and restorations against destructive natural disasters. This means the resilience society. In natural disaster mitigation science, there are lots of research fields such as natural science, engineering, medical treatment, social science and literature/art etc. Especially, natural science, engineering and medical treatment are fundamental research fields for natural disaster mitigation, but social sciences such as sociology, geography and psychology etc. are very important research fields for restorations after natural disasters. Finally, to realize and progress disaster mitigation science, human resource cultivation is indispensable. We already carried out disaster mitigation science under `new disaster mitigation research project on Mega

Automatic earthquake detection and classification with continuous hidden Markov models: a possible tool for monitoring Las Canadas caldera in Tenerife

Energy Technology Data Exchange (ETDEWEB)

Beyreuther, Moritz; Wassermann, Joachim [Department of Earth and Environmental Sciences (Geophys. Observatory), Ludwig Maximilians Universitaet Muenchen, D-80333 (Germany); Carniel, Roberto [Dipartimento di Georisorse e Territorio Universitat Degli Studi di Udine, I-33100 (Italy)], E-mail: roberto.carniel@uniud.it

2008-10-01

A possible interaction of (volcano-) tectonic earthquakes with the continuous seismic noise recorded in the volcanic island of Tenerife was recently suggested, but existing catalogues seem to be far from being self consistent, calling for the development of automatic detection and classification algorithms. In this work we propose the adoption of a methodology based on Hidden Markov Models (HMMs), widely used already in other fields, such as speech classification.

Rapid earthquake magnitude determination for Vrancea early warning system

International Nuclear Information System (INIS)

Marmureanu, Alexandru

2009-01-01

Due to the huge amount of recorded data, an automatic procedure was developed and used to test different methods to rapidly evaluate earthquake magnitude from the first seconds of the P wave. In order to test all the algorithms involved in detection and rapid earthquake magnitude estimation, several tests were performed, in order to avoid false alarms. A special detection algorithm was developed, that is based on the classical STA/LTA algorithm and tuned for early warning purpose. A method to rapidly estimate magnitude in 4 seconds from detection of P wave in the epicenter is proposed. The method was tested on al recorded data, and the magnitude error determination is acceptable taking into account that it is computed from only 3 stations in a very short time interval. (author)

The case study on elemental analyses of Asian dust particles by using an analytical scanning electron microscope

International Nuclear Information System (INIS)

Takeuchi, Jo; Masaki, Kazushige; Emoto, Yuji

2009-01-01

The individual particle analyses of suspended particulate matter (SPM: particles less than 10 μm in size) collected on tape filters during April 17-18, 2006, in Kawasaki, Japan, were carried out. The chemical elements present in aerosol particles were investigated by using a scanning electron microscope with an energy-dispersive X-ray spectrometer. The fraction of chemical elements detected in the particles collected on April 18, 2006, except for S, was in good agreement with that in Asian dust particles from the Loess Plateau, China. S was not detected in Asian dust particles but was detected in the particles collected on April 18, 2006. Therefore, it was concluded that the particles collected in April 18, 2006, in Kawasaki were Asian dust particles transported from the Asian continent, and the absorption of SO 2 or the coagulation of sulfate occurred during the transportation of Asian dust particles. (author)

Earthquakes and Earthquake Engineering. LC Science Tracer Bullet.

Science.gov (United States)

Buydos, John F., Comp.

An earthquake is a shaking of the ground resulting from a disturbance in the earth's interior. Seismology is the (1) study of earthquakes; (2) origin, propagation, and energy of seismic phenomena; (3) prediction of these phenomena; and (4) investigation of the structure of the earth. Earthquake engineering or engineering seismology includes the…

Neural network based tomographic approach to detect earthquake-related ionospheric anomalies

Directory of Open Access Journals (Sweden)

S. Hirooka

2011-08-01

Full Text Available A tomographic approach is used to investigate the fine structure of electron density in the ionosphere. In the present paper, the Residual Minimization Training Neural Network (RMTNN method is selected as the ionospheric tomography with which to investigate the detailed structure that may be associated with earthquakes. The 2007 Southern Sumatra earthquake (M = 8.5 was selected because significant decreases in the Total Electron Content (TEC have been confirmed by GPS and global ionosphere map (GIM analyses. The results of the RMTNN approach are consistent with those of TEC approaches. With respect to the analyzed earthquake, we observed significant decreases at heights of 250–400 km, especially at 330 km. However, the height that yields the maximum electron density does not change. In the obtained structures, the regions of decrease are located on the southwest and southeast sides of the Integrated Electron Content (IEC (altitudes in the range of 400–550 km and on the southern side of the IEC (altitudes in the range of 250–400 km. The global tendency is that the decreased region expands to the east with increasing altitude and concentrates in the Southern hemisphere over the epicenter. These results indicate that the RMTNN method is applicable to the estimation of ionospheric electron density.

Efficient blind search for similar-waveform earthquakes in years of continuous seismic data

Science.gov (United States)

Yoon, C. E.; Bergen, K.; Rong, K.; Elezabi, H.; Bailis, P.; Levis, P.; Beroza, G. C.

2017-12-01

Cross-correlating an earthquake waveform template with continuous seismic data has proven to be a sensitive, discriminating detector of small events missing from earthquake catalogs, but a key limitation of this approach is that it requires advance knowledge of the earthquake signals we wish to detect. To overcome this limitation, we can perform a blind search for events with similar waveforms, comparing waveforms from all possible times within the continuous data (Brown et al., 2008). However, the runtime for naive blind search scales quadratically with the duration of continuous data, making it impractical to process years of continuous data. The Fingerprint And Similarity Thresholding (FAST) detection method (Yoon et al., 2015) enables a comprehensive blind search for similar-waveform earthquakes in a fast, scalable manner by adapting data-mining techniques originally developed for audio and image search within massive databases. FAST converts seismic waveforms into compact "fingerprints", which are efficiently organized and searched within a database. In this way, FAST avoids the unnecessary comparison of dissimilar waveforms. To date, the longest duration of continuous data used for event detection with FAST was 3 months at a single station near Guy-Greenbrier, Arkansas, which revealed microearthquakes closely correlated with stages of hydraulic fracturing (Yoon et al., 2017). In this presentation we introduce an optimized, parallel version of the FAST software with improvements to the fingerprinting algorithm and the ability to detect events using continuous data from a network of stations (Bergen et al., 2016). We demonstrate its ability to detect low-magnitude earthquakes within several years of continuous data at locations of interest in California.

Subclinical infection of a young captive Asian elephant with elephant endotheliotropic herpesvirus 1.

Science.gov (United States)

Azab, Walid; Damiani, Armando Mario; Ochs, Andreas; Osterrieder, Nikolaus

2018-02-01

Elephant endotheliotropic herpesviruses (EEHVs) are a continuous threat for young Asian elephants. We report a laboratory-confirmed infection of a 5-year-old female Asian elephant (AZ_2016) in the Berlin Zoologischer Garten. Initially, high EEHV-1 loads were detected in trunk swabs obtained from the young elephant during routine screening. The animal showed no clinical signs except for slight irritability. EEHV-1 was continuously shed for almost one year, with fluctuations in viral load from time to time. Our investigations highlight the continuous threat of EEHV-1 to young captive Asian elephants and stress the importance of routine monitoring of captive elephants to allow early detection of infection.

Biomarker responses of mussels exposed to earthquake disturbances

Science.gov (United States)

Chandurvelan, Rathishri; Marsden, Islay D.; Glover, Chris N.; Gaw, Sally

2016-12-01

The green-lipped mussel, Perna canaliculus is recognised as a bioindicator of coastal contamination in New Zealand (NZ). Mussels (shell length 60-80 mm) were collected from three intertidal areas of Canterbury in the South Island of NZ prior to extreme earthquake disturbances on 22nd February 2011, and 9 months later in October 2011. Trace elements, including arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), nickel (Ni), and zinc (Zn), were measured in the gills, digestive gland, foot and mantle. Metal levels in tissues were site specific, and mostly unaffected by earthquake disturbances. Physiological biomarkers were negatively affected by earthquake disturbances and mussels from the Port of Lyttelton had higher negative scope for growth post-earthquake. Metallothionein-like protein in the digestive gland correlated with metal content of tissues, as did catalase activity in the gill and lipid peroxidation values for the digestive gland. This research demonstrates that physiological and other biomarkers are effective at detecting the effects of multiple stressors following seismic disturbances.

Analog earthquakes

International Nuclear Information System (INIS)

Hofmann, R.B.

1995-01-01

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

Profile: Asian Americans

Science.gov (United States)

... and Data > Minority Population Profiles > Asian American Profile: Asian Americans Asian American Profile (Map of the US with the top 10 states displaying the largest Asian American population according to the Census Bureau) CA - ...

The mtDNA haplogroup P of modern Asian cattle: A genetic legacy of Asian aurochs?

Science.gov (United States)

Noda, Aoi; Yonesaka, Riku; Sasazaki, Shinji

2018-01-01

Background Aurochs (Bos primigenius) were distributed throughout large parts of Eurasia and Northern Africa during the late Pleistocene and the early Holocene, and all modern cattle are derived from the aurochs. Although the mtDNA haplogroups of most modern cattle belong to haplogroups T and I, several additional haplogroups (P, Q, R, C and E) have been identified in modern cattle and aurochs. Haplogroup P was the most common haplogroup in European aurochs, but so far, it has been identified in only three of >3,000 submitted haplotypes of modern Asian cattle. Methodology We sequenced the complete mtDNA D-loop region of 181 Japanese Shorthorn cattle and analyzed these together with representative bovine mtDNA sequences. The haplotype P of Japanese Shorthorn cattle was analyzed along with that of 36 previously published European aurochs and three modern Asian cattle sequences using the hypervariable 410 bp of the D-loop region. Conclusions We detected the mtDNA haplogroup P in Japanese Shorthorn cattle with an extremely high frequency (83/181). Phylogenetic networks revealed two main clusters, designated as Pa for haplogroup P in European aurochs and Pc in modern Asian cattle. We also report the genetic diversity of haplogroup P compared with the sequences of extinct aurochs. No shared haplotypes are observed between the European aurochs and the modern Asian cattle. This finding suggests the possibility of local and secondary introgression events of haplogroup P in northeast Asian cattle, and will contribute to a better understanding of its origin and genetic diversity. PMID:29304129

The mtDNA haplogroup P of modern Asian cattle: A genetic legacy of Asian aurochs?

Science.gov (United States)

Noda, Aoi; Yonesaka, Riku; Sasazaki, Shinji; Mannen, Hideyuki

2018-01-01

Aurochs (Bos primigenius) were distributed throughout large parts of Eurasia and Northern Africa during the late Pleistocene and the early Holocene, and all modern cattle are derived from the aurochs. Although the mtDNA haplogroups of most modern cattle belong to haplogroups T and I, several additional haplogroups (P, Q, R, C and E) have been identified in modern cattle and aurochs. Haplogroup P was the most common haplogroup in European aurochs, but so far, it has been identified in only three of >3,000 submitted haplotypes of modern Asian cattle. We sequenced the complete mtDNA D-loop region of 181 Japanese Shorthorn cattle and analyzed these together with representative bovine mtDNA sequences. The haplotype P of Japanese Shorthorn cattle was analyzed along with that of 36 previously published European aurochs and three modern Asian cattle sequences using the hypervariable 410 bp of the D-loop region. We detected the mtDNA haplogroup P in Japanese Shorthorn cattle with an extremely high frequency (83/181). Phylogenetic networks revealed two main clusters, designated as Pa for haplogroup P in European aurochs and Pc in modern Asian cattle. We also report the genetic diversity of haplogroup P compared with the sequences of extinct aurochs. No shared haplotypes are observed between the European aurochs and the modern Asian cattle. This finding suggests the possibility of local and secondary introgression events of haplogroup P in northeast Asian cattle, and will contribute to a better understanding of its origin and genetic diversity.

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.

Feasibility of Twitter Based Earthquake Characterization From Analysis of 32 Million Tweets: There's Got to be a Pony in Here Somewhere!

Science.gov (United States)

Earle, P. S.; Guy, M. R.; Smoczyk, G. M.; Horvath, S. R.; Jessica, T. S.; Bausch, D. B.

2014-12-01

The U.S. Geological Survey (USGS) operates a real-time system that detects earthquakes using only data from Twitter—a service for sending and reading public text-based messages of up to 140 characters. The detector algorithm scans for significant increases in tweets containing the word "earthquake" in several languages and sends internal alerts with the detection time, representative tweet texts, and the location of the population center where most of the tweets originated. It has been running in real-time for over two years and finds, on average, two or three felt events per day, with a false detection rate of 9%. The main benefit of the tweet-based detections is speed, with most detections occurring between 20 and 120 seconds after the earthquake origin time. This is considerably faster than seismic detections in poorly instrumented regions of the world. The detections have reasonable coverage of populated areas globally. The number of Twitter-based 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-based detections are generally caused by widely felt events in populated urban areas that are of more immediate interest than those with no human impact. We will present a technical overview of the system and investigate the potential for rapid characterization of earthquake damage and effects using the 32 million "earthquake" tweets that the system has so far amassed. Initial results show potential for a correlation between characteristic responses and shaking level. For example, tweets containing the word "terremoto" were common following the MMI VII shaking produced by the April 1, 2014 M8.2 Iquique, Chile earthquake whereas a widely-tweeted deep-focus M5.2 north of Santiago, Chile on April 4, 2014 produced MMI VI shaking and almost exclusively "temblor" tweets. We are also investigating the use of other

A review on remotely sensed land surface temperature anomaly as an earthquake precursor

Science.gov (United States)

Bhardwaj, Anshuman; Singh, Shaktiman; Sam, Lydia; Joshi, P. K.; Bhardwaj, Akanksha; Martín-Torres, F. Javier; Kumar, Rajesh

2017-12-01

The low predictability of earthquakes and the high uncertainty associated with their forecasts make earthquakes one of the worst natural calamities, capable of causing instant loss of life and property. Here, we discuss the studies reporting the observed anomalies in the satellite-derived Land Surface Temperature (LST) before an earthquake. We compile the conclusions of these studies and evaluate the use of remotely sensed LST anomalies as precursors of earthquakes. The arrival times and the amplitudes of the anomalies vary widely, thus making it difficult to consider them as universal markers to issue earthquake warnings. Based on the randomness in the observations of these precursors, we support employing a global-scale monitoring system to detect statistically robust anomalous geophysical signals prior to earthquakes before considering them as definite precursors.

Use of high resolution satellite images for monitoring of earthquakes and volcano activity.

Science.gov (United States)

Arellano-Baeza, Alonso A.

Our studies have shown that the strain energy accumulation deep in the Earth's crust that precedes a strong earthquake can be detected by applying a lineament extraction technique to the high-resolution multispectral satellite images. A lineament is a straight or a somewhat curved feature in a satellite image, which it is possible to detect by a special processing of images based on directional filtering and or Hough transform. We analyzed tens of earthquakes occurred in the Pacific coast of the South America with the Richter scale magnitude ˜4.5, using ASTER/TERRA multispectral satellite images for detection and analysis of changes in the system of lineaments previous to a strong earthquake. All events were located in the regions with small seasonal variations and limited vegetation to facilitate the tracking of features associated with the seismic activity only. It was found that the number and orientation of lineaments changed significantly about one month before an earthquake approximately, and a few months later the system returns to its initial state. This effect increases with the earthquake magnitude. It also was shown that the behavior of lineaments associated to the volcano seismic activity is opposite to that obtained previously for earthquakes. This discrepancy can be explained assuming that in the last case the main reason of earthquakes is compression and accumulation of strength in the Earth's crust due to subduction of tectonic plates, whereas in the first case we deal with the inflation of a volcano edifice due to elevation of pressure and magma intrusion. The results obtained made it possible to include this research as a part of scientific program of Chilean Remote Sensing Satellite mission to be launched in 2010.

Social Media as Seismic Networks for the Earthquake Damage Assessment

Science.gov (United States)

Meletti, C.; Cresci, S.; La Polla, M. N.; Marchetti, A.; Tesconi, M.

2014-12-01

The growing popularity of online platforms, based on user-generated content, is gradually creating a digital world that mirrors the physical world. In the paradigm of crowdsensing, the crowd becomes a distributed network of sensors that allows us to understand real life events at a quasi-real-time rate. The SoS-Social Sensing project [http://socialsensing.it/] exploits the opportunistic crowdsensing, involving users in the sensing process in a minimal way, for social media emergency management purposes in order to obtain a very fast, but still reliable, detection of emergency dimension to face. First of all we designed and implemented a decision support system for the detection and the damage assessment of earthquakes. Our system exploits the messages shared in real-time on Twitter. In the detection phase, data mining and natural language processing techniques are firstly adopted to select meaningful and comprehensive sets of tweets. Then we applied a burst detection algorithm in order to promptly identify outbreaking seismic events. Using georeferenced tweets and reported locality names, a rough epicentral determination is also possible. The results, compared to Italian INGV official reports, show that the system is able to detect, within seconds, events of a magnitude in the region of 3.5 with a precision of 75% and a recall of 81,82%. We then focused our attention on damage assessment phase. We investigated the possibility to exploit social media data to estimate earthquake intensity. We designed a set of predictive linear models and evaluated their ability to map the intensity of worldwide earthquakes. The models build on a dataset of almost 5 million tweets exploited to compute our earthquake features, and more than 7,000 globally distributed earthquakes data, acquired in a semi-automatic way from USGS, serving as ground truth. We extracted 45 distinct features falling into four categories: profile, tweet, time and linguistic. We run diagnostic tests and

Iranian earthquakes, a uniform catalog with moment magnitudes

Science.gov (United States)

Karimiparidari, Sepideh; Zaré, Mehdi; Memarian, Hossein; Kijko, Andrzej

2013-07-01

A uniform earthquake catalog is an essential tool in any seismic hazard analysis. In this study, an earthquake catalog of Iran and adjacent areas was compiled, using international and national databanks. The following priorities were applied in selecting magnitude and earthquake location: (a) local catalogs were given higher priority for establishing the location of an earthquake and (b) global catalogs were preferred for determining earthquake magnitudes. Earthquakes that have occurred within the bounds between 23-42° N and 42-65° E, with a magnitude range of M W 3.5-7.9, from the third millennium BC until April 2010 were included. In an effort to avoid the "boundary effect," since the newly compiled catalog will be mainly used for seismic hazard assessment, the study area includes the areas adjacent to Iran. The standardization of the catalog in terms of magnitude was achieved by the conversion of all types of magnitude into moment magnitude, M W, by using the orthogonal regression technique. In the newly compiled catalog, all aftershocks were detected, based on the procedure described by Gardner and Knopoff (Bull Seismol Soc Am 64:1363-1367, 1974). The seismicity parameters were calculated for the six main tectonic seismic zones of Iran, i.e., the Zagros Mountain Range, the Alborz Mountain Range, Central Iran, Kope Dagh, Azerbaijan, and Makran.

Development of a hybrid earthquake early warning system based on single sensor technique

International Nuclear Information System (INIS)

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

2012-01-01

There are two methods to earthquake early warning system: the method based on a network of seismic stations and the single-sensor method. Both have advantages and drawbacks. The current systems rely on high density seismic networks. Attempts at implementing techniques based on the single-station principle encounter difficulties in the identification of earthquake in noise. The noise may be very diverse, from stationary to impulsive. It seems a promising line of research to develop hybrid warning systems with single-sensors being incorporated in the overall early warning network. This will permit using all advantages and will help reduce the radius of the hazardous zone where no earthquake warning can be produced. The main problems are highlighted and the solutions of these are discussed. The system is implemented to include three detection processes in parallel. The first is based on the study of the co-occurrence matrix of the signal wavelet transform. The second consists in using the method of a change point in a random process and signal detection in a moving time window. The third uses artificial neural networks. Further, applying a decision rule out the final earthquake detection is carried out and estimate its reliability. (author)

Performance of HEPA filters at LLNL following the 1980 and 1989 earthquakes

International Nuclear Information System (INIS)

Bergman, W.; Elliott, J.; Wilson, K.

1995-01-01

The Lawrence Livermore National Laboratory has experienced two significant earthquakes for which data is available to assess the ability of HEPA filters to withstand seismic conditions. A 5.9 magnitude earthquake with an epicenter 10 miles from LLNL struck on January 24, l980. Estimates of the peak ground accelerations ranged from 0.2 to 0.3 g. A 7.0 magnitude earthquake with an epicenter about 50 miles from LLNL struck on October 17, 1989. Measurements of the ground accelerations at LLNL averaged 0.1 g. The results from the in-place filter tests obtained after each of the earthquakes were compiled and studied to determine if the earthquakes had caused filter leakage. Our study showed that only the 1980 earthquake resulted in a small increase in the number of HEPA filters developing leaks. In the 12 months following the 1980 and 1989 earthquakes, the in-place filter tests showed 8.0% and 4.1% of all filters respectively developed leaks. The average percentage of filters developing leaks from 1980 to 1993 was 3.3%+/-1.7%. The increase in the filter leaks is significant for the 1980 earthquake, but not for the 1989 earthquake. No contamination was detected following the earthquakes that would suggest transient releases from the filtration system

Performance of HEPA filters at LLNL following the 1980 and 1989 earthquakes

Energy Technology Data Exchange (ETDEWEB)

Bergman, W.; Elliott, J.; Wilson, K. [Lawrence Livermore National Laboratory, CA (United States)

1995-02-01

The Lawrence Livermore National Laboratory has experienced two significant earthquakes for which data is available to assess the ability of HEPA filters to withstand seismic conditions. A 5.9 magnitude earthquake with an epicenter 10 miles from LLNL struck on January 24, l980. Estimates of the peak ground accelerations ranged from 0.2 to 0.3 g. A 7.0 magnitude earthquake with an epicenter about 50 miles from LLNL struck on October 17, 1989. Measurements of the ground accelerations at LLNL averaged 0.1 g. The results from the in-place filter tests obtained after each of the earthquakes were compiled and studied to determine if the earthquakes had caused filter leakage. Our study showed that only the 1980 earthquake resulted in a small increase in the number of HEPA filters developing leaks. In the 12 months following the 1980 and 1989 earthquakes, the in-place filter tests showed 8.0% and 4.1% of all filters respectively developed leaks. The average percentage of filters developing leaks from 1980 to 1993 was 3.3%+/-1.7%. The increase in the filter leaks is significant for the 1980 earthquake, but not for the 1989 earthquake. No contamination was detected following the earthquakes that would suggest transient releases from the filtration system.

Turkish Compulsory Earthquake Insurance and "Istanbul Earthquake

Science.gov (United States)

Durukal, E.; Sesetyan, K.; Erdik, M.

2009-04-01

The city of Istanbul will likely experience substantial direct and indirect losses as a result of a future large (M=7+) earthquake with an annual probability of occurrence of about 2%. This paper dwells on the expected building losses in terms of probable maximum and average annualized losses and discusses the results from the perspective of the compulsory earthquake insurance scheme operational in the country. The TCIP system is essentially designed to operate in Turkey with sufficient penetration to enable the accumulation of funds in the pool. Today, with only 20% national penetration, and about approximately one-half of all policies in highly earthquake prone areas (one-third in Istanbul) the system exhibits signs of adverse selection, inadequate premium structure and insufficient funding. Our findings indicate that the national compulsory earthquake insurance pool in Turkey will face difficulties in covering incurring building losses in Istanbul in the occurrence of a large earthquake. The annualized earthquake losses in Istanbul are between 140-300 million. Even if we assume that the deductible is raised to 15%, the earthquake losses that need to be paid after a large earthquake in Istanbul will be at about 2.5 Billion, somewhat above the current capacity of the TCIP. Thus, a modification to the system for the insured in Istanbul (or Marmara region) is necessary. This may mean an increase in the premia and deductible rates, purchase of larger re-insurance covers and development of a claim processing system. Also, to avoid adverse selection, the penetration rates elsewhere in Turkey need to be increased substantially. A better model would be introduction of parametric insurance for Istanbul. By such a model the losses will not be indemnified, however will be directly calculated on the basis of indexed ground motion levels and damages. The immediate improvement of a parametric insurance model over the existing one will be the elimination of the claim processing

Earthquake potential revealed by tidal influence on earthquake size-frequency statistics

Science.gov (United States)

Ide, Satoshi; Yabe, Suguru; Tanaka, Yoshiyuki

2016-11-01

The possibility that tidal stress can trigger earthquakes is long debated. In particular, a clear causal relationship between small earthquakes and the phase of tidal stress is elusive. However, tectonic tremors deep within subduction zones are highly sensitive to tidal stress levels, with tremor rate increasing at an exponential rate with rising tidal stress. Thus, slow deformation and the possibility of earthquakes at subduction plate boundaries may be enhanced during periods of large tidal stress. Here we calculate the tidal stress history, and specifically the amplitude of tidal stress, on a fault plane in the two weeks before large earthquakes globally, based on data from the global, Japanese, and Californian earthquake catalogues. We find that very large earthquakes, including the 2004 Sumatran, 2010 Maule earthquake in Chile and the 2011 Tohoku-Oki earthquake in Japan, tend to occur near the time of maximum tidal stress amplitude. This tendency is not obvious for small earthquakes. However, we also find that the fraction of large earthquakes increases (the b-value of the Gutenberg-Richter relation decreases) as the amplitude of tidal shear stress increases. The relationship is also reasonable, considering the well-known relationship between stress and the b-value. This suggests that the probability of a tiny rock failure expanding to a gigantic rupture increases with increasing tidal stress levels. We conclude that large earthquakes are more probable during periods of high tidal stress.

Preliminary earthquake locations in the Kenai Peninsula recorded by the MOOS Array and their relationship to structure in the 1964 great earthquake zone

Science.gov (United States)

Li, J.; Abers, G. A.; Christensen, D. H.; Kim, Y.; Calkins, J. A.

2011-12-01

Earthquakes in subduction zones are mostly generated at the interface between the subducting and overlying plates. In 2006-2009, the MOOS (Multidisciplinary Observations Of Subduction) seismic array was deployed around the Kenai Peninsula, Alaska, consisting of 34 broadband seismometers recording for 1-3 years. This region spans the eastern end of the Aleutian megathrust that ruptured in the 1964 Mw 9.2 great earthquake, the second largest recorded earthquake, and ongoing seismicity is abundant. Here, we report an initial analysis of seismicity recorded by MOOS, in the context of preliminary imaging. There were 16,462 events detected in one year from initial STA/LTA signal detections and subsequent event associations from the MOOS Array. We manually reviewed them to eliminate distant earthquakes and noise, leaving 11,879 local earthquakes. To refine this catalog, an adaptive auto-regressive onset estimation algorithm was applied, doubling the original dataset and producing 20,659 P picks and 22,999 S picks for one month (September 2007). Inspection shows that this approach lead to almost negligible false alarms and many more events than hand picking. Within the well-sampled part of the array, roughly 200 km by 300 km, we locate 250% more earthquakes for one month than the permanent network catalog, or 10 earthquakes per day on this patch of the megathrust. Although the preliminary locations of earthquakes still show some scatter, we can see a concentration of events in a ~20-km-wide belt, part of which can be interpreted as seismogenic thrust zone. In conjunction with the seismicity study, we are imaging the plate interface with receiver functions. The main seismicity zone corresponds to the top of a low-velocity layer imaged in receiver functions, nominally attributed to the top of the downgoing plate. As we refine velocity models and apply relative relocation algorithms, we expect to improve the precision of the locations substantially. When combined with image

Superconducting Gravimeters Detect Gravity Fluctuations Induced by Mw 5.7 Earthquake Along South Pacific Rise Few Hours Before the 2011 Mw 9.0 Tohoku-Oki Earthquake

Directory of Open Access Journals (Sweden)

Keliang Zhang Jin Ma

2014-01-01

Full Text Available Gravity changes sometimes appear before a big earthquake. To determine the possible sources is important for recognizing the mechanism and further geodynamic studies. During the first two hours on March 11 before the Mw 9.0 Tohoku-Oki earthquake, the non-tidal gravity time series of superconducting gravimeters worldwide showed low-frequency (< 0.10 Hz fluctuations with amplitude of ~1 to 4 × 10-8 ms-2 lasting ~10 - 20 minutes. Through comparing global seismicity with the arrival times of seismic waves, we find that the fluctuations were induced by the Mw 5.7 earthquake that occurred at 0:14:54.68 at (53.27°S, 118.18°W along the eastern South Pacific Rise. Several body waves such as P, S are clearly recorded in the station with ~400 km distance to the hypocenter. The fluctuations are in response to the waves that propagate with a velocity of about 4 km s-1. Their amplitudes are proportional to the inverse of the epicentral distances even though the fluctuations of European sites were overlapped with waves associated with a smaller, i.e., Mw 2.6, event in Europe during this period. That is, the Mw 5.7 earthquake induced remarkable gravity fluctuations over long distances at stations all over the world. As such, the foreshocks with larger magnitudes occurred before the Mw 9.0 earthquake would have more significant influence on the gravity recordings and the seismic-wave induced component should be removed during the analysis of anomalies prior to a great earthquake in future studies.

Large earthquake rates from geologic, geodetic, and seismological perspectives

Science.gov (United States)

Jackson, D. D.

2017-12-01

Earthquake rate and recurrence information comes primarily from geology, geodesy, and seismology. Geology gives the longest temporal perspective, but it reveals only surface deformation, relatable to earthquakes only with many assumptions. Geodesy is also limited to surface observations, but it detects evidence of the processes leading to earthquakes, again subject to important assumptions. Seismology reveals actual earthquakes, but its history is too short to capture important properties of very large ones. Unfortunately, the ranges of these observation types barely overlap, so that integrating them into a consistent picture adequate to infer future prospects requires a great deal of trust. Perhaps the most important boundary is the temporal one at the beginning of the instrumental seismic era, about a century ago. We have virtually no seismological or geodetic information on large earthquakes before then, and little geological information after. Virtually all-modern forecasts of large earthquakes assume some form of equivalence between tectonic- and seismic moment rates as functions of location, time, and magnitude threshold. That assumption links geology, geodesy, and seismology, but it invokes a host of other assumptions and incurs very significant uncertainties. Questions include temporal behavior of seismic and tectonic moment rates; shape of the earthquake magnitude distribution; upper magnitude limit; scaling between rupture length, width, and displacement; depth dependence of stress coupling; value of crustal rigidity; and relation between faults at depth and their surface fault traces, to name just a few. In this report I'll estimate the quantitative implications for estimating large earthquake rate. Global studies like the GEAR1 project suggest that surface deformation from geology and geodesy best show the geography of very large, rare earthquakes in the long term, while seismological observations of small earthquakes best forecasts moderate earthquakes

Earthquake-induced water-level fluctuations at Yucca Mountain, Nevada, June 1992

International Nuclear Information System (INIS)

O'Brien, G.M.

1993-01-01

This report presents earthquake-induced water-level and fluid-pressure data for wells in the Yucca Mountain area, Nevada, during June 1992. Three earthquakes occurred which caused significant water-level and fluid-pressure responses in wells. Wells USW H-5 and USW H-6 are continuously monitored to detect short-term responses caused by earthquakes. Two wells, monitored hourly, had significant, longer-term responses in water level following the earthquakes. On June 28, 1992, a 7.5-magnitude earthquake occurred near Landers, California causing an estimated maximum water-level change of 90 centimeters in well USW H-5. Three hours later a 6.6-magnitude earthquake occurred near Big Bear Lake, California; the maximum water-level fluctuation was 20 centimeters in well USW H-5. A 5.6-magnitude earthquake occurred at Little Skull Mountain, Nevada, on June 29, approximately 23 kilometers from Yucca Mountain. The maximum estimated short-term water-level fluctuation from the Little Skull Mountain earthquake was 40 centimeters in well USW H-5. The water level in well UE-25p number-sign 1, monitored hourly, decreased approximately 50 centimeters over 3 days following the Little Skull Mountain earthquake. The water level in UE-25p number-sign 1 returned to pre-earthquake levels in approximately 6 months. The water level in the lower interval of well USW H-3 increased 28 centimeters following the Little Skull Mountain earthquake. The Landers and Little Skull Mountain earthquakes caused responses in 17 intervals of 14 hourly monitored wells, however, most responses were small and of short duration. For several days following the major earthquakes, many smaller magnitude aftershocks occurred causing measurable responses in the continuously monitored wells

Cultural Patterns of South Asian and Southeast Asian Americans.

Science.gov (United States)

Mathews, Rachel

2000-01-01

An overview of South Asian and Southeast Asian Americans is discussed to aid teachers in understanding behaviors exhibited by Asian students. Culture influences in the following areas are explored: family relationships, respect for age, social interaction, communication style, family expectations, humility, school situations, decision making, and…

Earthquake, GIS and multimedia. The 1883 Casamicciola earthquake

Directory of Open Access Journals (Sweden)

M. Rebuffat

1995-06-01

Full Text Available A series of multimedia monographs concerning the main seismic events that have affected the Italian territory are in the process of being produced for the Documental Integrated Multimedia Project (DIMP started by the Italian National Seismic Survey (NSS. The purpose of the project is to reconstruct the historical record of earthquakes and promote an earthquake public education. Producing the monographs. developed in ARC INFO and working in UNIX. involved designing a special filing and management methodology to integrate heterogeneous information (images, papers, cartographies, etc.. This paper describes the possibilities of a GIS (Geographic Information System in the filing and management of documental information. As an example we present the first monograph on the 1883 Casamicciola earthquake. on the island of Ischia (Campania, Italy. This earthquake is particularly interesting for the following reasons: I historical-cultural context (first destructive seismic event after the unification of Italy; 2 its features (volcanic earthquake; 3 the socioeconomic consequences caused at such an important seaside resort.

Earthquakes in Switzerland and surrounding regions during 2007

Energy Technology Data Exchange (ETDEWEB)

Baer, M.; Deichmann, N.; Clinton, J.; Husen, S.; Faeh, D.; Giardini, D.; Kaestli, P.; Kradolfer, U.; Wiemer, S

2008-12-15

This report of the Swiss Seismological Service summarizes the seismic activity in Switzerland and surrounding regions during 2007. During this period, 531 earthquakes and 92 quarry blasts were detected and located in the region under consideration. Of these earthquakes, 30 are aftershocks of the stimulation of a proposed geothermal reservoir beneath the city of Basel in December of 2006. With 20 events with {mu}{sub {iota}} {>=} 2.5, four of which were artificially induced, the seismic activity in the year 2007 was far below the average over the previous 32 years. (author)

Earthquakes in Switzerland and surrounding regions during 2007

International Nuclear Information System (INIS)

Baer, M.; Deichmann, N.; Clinton, J.; Husen, S.; Faeh, D.; Giardini, D.; Kaestli, P.; Kradolfer, U.; Wiemer, S.

2008-01-01

This report of the Swiss Seismological Service summarizes the seismic activity in Switzerland and surrounding regions during 2007. During this period, 531 earthquakes and 92 quarry blasts were detected and located in the region under consideration. Of these earthquakes, 30 are aftershocks of the stimulation of a proposed geothermal reservoir beneath the city of Basel in December of 2006. With 20 events with Μ ι ≥ 2.5, four of which were artificially induced, the seismic activity in the year 2007 was far below the average over the previous 32 years. (author)

Environmental Health assessment 200 Days after Earthquake-Affected Region in East Azerbaijan Earthquake, North-Western of Iran, 2012

Directory of Open Access Journals (Sweden)

Alihossein Zeinalzadeh

2017-04-01

Full Text Available Evaluating of health status and explore the challenges of health problems that threaten human life following disasters and major earthquakes providing windows of opportunities for health care providers in future planning of disasters. The main purpose of this report was to survey the environmental sanitation statues after 200 days of the affected populations in earthquakes of East Azerbaijan, northwestern of Iran, 2012. The survey was carried out in earthquake zones 200 days after the occurrence of the earthquake. A single stage cluster sampling from among 95 villages damaged in the earthquake of 2012 East Azerbaijan of three towns Ahar, Varzeghan and Heris were selected. The data were collected with questionnaire, site visits and evaluation of water and sanitation. In a twin Earthquake, East Azerbaijan province that 399 villages of Ahar, Varzeghan, Heris, Tabriz and Kaleibar cities were affected and 356 (89.2 % villages were destroyed between 30-100%.  Evaluation of water and sanitation infrastructure after 200 days, shown that only half of these villages consumed healthy water with high coverage and adequate. Half of the villages in 200 days after the earthquake were covered safe drinking water (treated drinking water. The bacteriological quality of drinking-water supply of the affected area was assessed in randomly collected 146 samples from this region and ten (6.8% reported as unsuitable. Solid waste management facilities in residents have not been acceptable that affect public health. Solid waste disposal was done by district residents (cooperation rural residents 68.4%, 36.8% and 76.3% in Ahar, Varzeghan and Heris, respectively. Overall, the impact of infectious and communicable diseases after Earthquake was reported 42.1% (16 villages in the Varzeghan. The lack of geographical view with a focus in mountainous and rural areas, partial support and dispersion of earthquake-stricken people in affected villages and lack of participatory need

Earthquake Early Warning Systems

OpenAIRE

Pei-Yang Lin

2011-01-01

Because of Taiwan’s unique geographical environment, earthquake disasters occur frequently in Taiwan. The Central Weather Bureau collated earthquake data from between 1901 and 2006 (Central Weather Bureau, 2007) and found that 97 earthquakes had occurred, of which, 52 resulted in casualties. The 921 Chichi Earthquake had the most profound impact. Because earthquakes have instant destructive power and current scientific technologies cannot provide precise early warnings in advance, earthquake ...

Correlation between Earthquakes and AE Monitoring of Historical Buildings in Seismic Areas

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Giuseppe Lacidogna

2015-12-01

Full Text Available In this contribution a new method for evaluating seismic risk in regional areas based on the acoustic emission (AE technique is proposed. Most earthquakes have precursors, i.e., phenomena of changes in the Earth’s physical-chemical properties that take place prior to an earthquake. Acoustic emissions in materials and earthquakes in the Earth’s crust, despite the fact that they take place on very different scales, are very similar phenomena; both are caused by a release of elastic energy from a source located in a medium. For the AE monitoring, two important constructions of Italian cultural heritage are considered: the chapel of the “Sacred Mountain of Varallo” and the “Asinelli Tower” of Bologna. They were monitored during earthquake sequences in their relative areas. By using the Grassberger-Procaccia algorithm, a statistical method of analysis was developed that detects AEs as earthquake precursors or aftershocks. Under certain conditions it was observed that AEs precede earthquakes. These considerations reinforce the idea that the AE monitoring can be considered an effective tool for earthquake risk evaluation.

Generation and characterization of antibodies against Asian elephant (Elephas maximus IgG, IgM, and IgA.

Directory of Open Access Journals (Sweden)

Alan F Humphreys

Full Text Available Asian elephant (Elephas maximus immunity is poorly characterized and understood. This gap in knowledge is particularly concerning as Asian elephants are an endangered species threatened by a newly discovered herpesvirus known as elephant endotheliotropic herpesvirus (EEHV, which is the leading cause of death for captive Asian elephants born after 1980 in North America. While reliable diagnostic assays have been developed to detect EEHV DNA, serological assays to evaluate elephant anti-EEHV antibody responses are lacking and will be needed for surveillance and epidemiological studies and also for evaluating potential treatments or vaccines against lethal EEHV infection. Previous studies have shown that Asian elephants produce IgG in serum, but they failed to detect IgM and IgA, further hampering development of informative serological assays for this species. To begin to address this issue, we determined the constant region genomic sequence of Asian elephant IgM and obtained some limited protein sequence information for putative serum IgA. The information was used to generate or identify specific commercial antisera reactive against IgM and IgA isotypes. In addition, we generated a monoclonal antibody against Asian elephant IgG. These three reagents were used to demonstrate that all three immunoglobulin isotypes are found in Asian elephant serum and milk and to detect antibody responses following tetanus toxoid booster vaccination or antibodies against a putative EEHV structural protein. The results indicate that these new reagents will be useful for developing sensitive and specific assays to detect and characterize elephant antibody responses for any pathogen or vaccine, including EEHV.

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.

Ground water and earthquakes

Energy Technology Data Exchange (ETDEWEB)

Ts' ai, T H

1977-11-01

Chinese folk wisdom has long seen a relationship between ground water and earthquakes. Before an earthquake there is often an unusual change in the ground water level and volume of flow. Changes in the amount of particulate matter in ground water as well as changes in color, bubbling, gas emission, and noises and geysers are also often observed before earthquakes. Analysis of these features can help predict earthquakes. Other factors unrelated to earthquakes can cause some of these changes, too. As a first step it is necessary to find sites which are sensitive to changes in ground stress to be used as sensor points for predicting earthquakes. The necessary features are described. Recording of seismic waves of earthquake aftershocks is also an important part of earthquake predictions.

A new perspective on the generation of the 2016 M6.4 Meilung earthquake, southwestern Taiwan

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Wang, Z.

2017-12-01

In order to investigate the likely generation mechanism of the 2016 M6.4 Meilung earthquake, a large number of high-quality travel times from P- and S-wave source-receiver pairs are used jointly in this study to invert three-dimensional (3-D) seismic velocity (Vp, Vs) and Poisson's ratio structures at high resolution. We also calculated crack density, saturate fracture, and bulk-sound velocity from our inverted Vp, Vs, and s models. In this way, multi-geophysical parameter imaging revealed that the 2016 Meilung earthquake occurred along a distinctive edge portion exhibiting high-to-low variations in these parameters in both horizontal and vertical directions across the hypocenter. We consider that a slow velocity and high-Poisson ratio body that has high-crack density and somewhat high-saturate fracture anomalies above the hypocenter under the coastal plain represents fluids contained in the young fold-and-thrust belt relative to the passive Asian continental margin in southwestern Taiwan. Intriguing, a continuous low Vp and Vs zone with high Poisson ratio, crack density and saturate fracture anomalies across the Laonung and Chishan faults is also clearly imaged in the northwestern upper crust beneath the coastal plain and western foothills as far as the southeastern lower crust under the central range. We therefore propose that this southeastern extending weakened zone was mainly the result of a fluid intrusion either from the young fold-and-thrust belt associated with the passive Asian continental margin in the shallow crust or the subducted Eurasian continental (EC) plate in the lower crust and uppermost mantle. We suggest that fluid intrusion into the upper Oligocene to Pleistocene shallow marine and clastic shelf units of the Eurasian continental crust and/or the relatively thin uppermost part of the transitional Pleistocene-Holocene foreland due to the subduction of the EC plate along the deformation front played a key role in earthquake generation in

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).

Analytical Methods for Mycotoxin Detection in Southeast Asian Nations (ASEAN).

Science.gov (United States)

Lim, Chee Wei; Chung, Gerald; Chan, Sheot Harn

2017-10-03

Aflatoxins B 1 (AFB 1 ) and B₂ (AFB₂) and G 1 and G₂ remain the top mycotoxins routinely analyzed and monitored by Association of Southeast Asian Nations (ASEAN) national laboratories primarily for food safety regulation in the major food commodities, nuts and spices. LC tandem fluorescence detection (LC–fluorescence) represents a current mainstream analytical method, with a progressive migration to a primary method by LC tandem MS (MS/MS) for the next half decade. Annual proficiency testing (PT) is conducted by ASEAN Food Reference Laboratories (AFRLs) for mycotoxin testing as part of capability building in national laboratories, with the scope of PT materials spanning from naturally mycotoxin-contaminated spices and nuts in the early 2010s to the recent contamination of corn flour in 2017 for total aflatoxin assay development. The merits of the mainstream LC–fluorescence method are witnessed by a significant improvement ( P < 0.05) in PT z -score passing rates (≤2) from 11.8 to 79.2% for AFB 1 , 23.5 to 83.3% for AFB₂, and 23.5 to 79.2% for total aflatoxins in the last 5 years. This paper discusses the journey of ASEAN national laboratories in analytical testing through AFRLs, and the progressive collective adoption of a multimycotoxin LC-MS/MS method aided by an isotopic dilution assay as a future primary method for safer food commodities.

Possible deep fault slip preceding the 2004 Parkfield earthquake, inferred from detailed observations of tectonic tremor

Science.gov (United States)

Shelly, David R.

2009-01-01

Earthquake predictability depends, in part, on the degree to which sudden slip is preceded by slow aseismic slip. Recently, observations of deep tremor have enabled inferences of deep slow slip even when detection by other means is not possible, but these data are limited to certain areas and mostly the last decade. The region near Parkfield, California, provides a unique convergence of several years of high-quality tremor data bracketing a moderate earthquake, the 2004 magnitude 6.0 event. Here, I present detailed observations of tectonic tremor from mid-2001 through 2008 that indicate deep fault slip both before and after the Parkfield earthquake that cannot be detected with surface geodetic instruments. While there is no obvious short-term precursor, I find unidirectional tremor migration accompanied by elevated tremor rates in the 3 months prior to the earthquake, which suggests accelerated creep on the fault ∼16 km beneath the eventual earthquake hypocenter.

Sismosima: A pioneer project for earthquake detection; Sismosima: un proyecto pionero para la deteccion de Terremotos

Energy Technology Data Exchange (ETDEWEB)

Echague, C. de

2015-07-01

Currently you can only study how earthquakes occur and minimizing their consequences, but in Sismosima are studied earthquakes for if possible issue a pre-alert. Geological and Mining Institute of Spain (IGME) launched this project that has already achieved in test the caves in which you installed meters an increase of carbon dioxide (CO{sub 2}) that match the shot earthquake. Now, it remains check if gas emission occurs simultaneously, before or after. If were before, a couple of minutes would be enough to give an early warning with which save lives and ensure facilities. (Author)

The Mw=8.8 Maule earthquake aftershock sequence, event catalog and locations

Science.gov (United States)

Meltzer, A.; Benz, H.; Brown, L.; Russo, R. M.; Beck, S. L.; Roecker, S. W.

2011-12-01

The aftershock sequence of the Mw=8.8 Maule earthquake off the coast of Chile in February 2010 is one of the most well-recorded aftershock sequences from a great megathrust earthquake. Immediately following the Maule earthquake, teams of geophysicists from Chile, France, Germany, Great Britain and the United States coordinated resources to capture aftershocks and other seismic signals associated with this significant earthquake. In total, 91 broadband, 48 short period, and 25 accelerometers stations were deployed above the rupture zone of the main shock from 33-38.5°S and from the coast to the Andean range front. In order to integrate these data into a unified catalog, the USGS National Earthquake Information Center develop procedures to use their real-time seismic monitoring system (Bulletin Hydra) to detect, associate, location and compute earthquake source parameters from these stations. As a first step in the process, the USGS has built a seismic catalog of all M3.5 or larger earthquakes for the time period of the main aftershock deployment from March 2010-October 2010. The catalog includes earthquake locations, magnitudes (Ml, Mb, Mb_BB, Ms, Ms_BB, Ms_VX, Mc), associated phase readings and regional moment tensor solutions for most of the M4 or larger events. Also included in the catalog are teleseismic phases and amplitude measures and body-wave MT and CMT solutions for the larger events, typically M5.5 and larger. Tuning of automated detection and association parameters should allow a complete catalog of events to approximately M2.5 or larger for that dataset of more than 164 stations. We characterize the aftershock sequence in terms of magnitude, frequency, and location over time. Using the catalog locations and travel times as a starting point we use double difference techniques to investigate relative locations and earthquake clustering. In addition, phase data from candidate ground truth events and modeling of surface waves can be used to calibrate the

High resolution measurement of earthquake impacts on rock slope stability and damage using pre- and post-earthquake terrestrial laser scans

Science.gov (United States)

Hutchinson, Lauren; Stead, Doug; Rosser, Nick

2017-04-01

Understanding the behaviour of rock slopes in response to earthquake shaking is instrumental in response and relief efforts following large earthquakes as well as to ongoing risk management in earthquake affected areas. Assessment of the effects of seismic shaking on rock slope kinematics requires detailed surveys of the pre- and post-earthquake condition of the slope; however, at present, there is a lack of high resolution monitoring data from pre- and post-earthquake to facilitate characterization of seismically induced slope damage and validate models used to back-analyze rock slope behaviour during and following earthquake shaking. Therefore, there is a need for additional research where pre- and post- earthquake monitoring data is available. This paper presents the results of a direct comparison between terrestrial laser scans (TLS) collected in 2014, the year prior to the 2015 earthquake sequence, with that collected 18 months after the earthquakes and two monsoon cycles. The two datasets were collected using Riegl VZ-1000 and VZ-4000 full waveform laser scanners with high resolution (c. 0.1 m point spacing as a minimum). The scans cover the full landslide affected slope from the toe to the crest. The slope is located in Sindhupalchok District, Central Nepal which experienced some of the highest co-seismic and post-seismic landslide intensities across Nepal due to the proximity to the epicenters (<20 km) of both of the main aftershocks on April 26, 2015 (M 6.7) and May 12, 2015 (M7.3). During the 2015 earthquakes and subsequent 2015 and 2016 monsoons, the slope experienced rockfall and debris flows which are evident in satellite imagery and field photographs. Fracturing of the rock mass associated with the seismic shaking is also evident at scales not accessible through satellite and field observations. The results of change detection between the TLS datasets with an emphasis on quantification of seismically-induced slope damage is presented. Patterns in the

Legal analysis of citizen lawsuit toward management of the 2006 Yogyakarta earthquake

Science.gov (United States)

Suprihadi, Bambang

2017-07-01

The Asian Disaster Reduction Center informed that on 27 May 2006 at 5:54 AM Local time or 26 May 2006 at 10:54:00 PM UTC, an M6.3 earthquake has struck the very highly populated region of Yogyakarta. The death estimated between 5,775 and 6,234 and the number of injured was between 46,000 and 53,000. Invitation letters were sent to Indonesia Agency for Meteorology Climatology and Geophysics (BMKG) and to 18 government institutions for attending the session at the Yogyakarta Court on 4 December 2006. Such case was a lawsuit proposed by 46 citizens and registered as number 73/PDT.G/ 2006/PN-Yk and the researcher attended court-session on behalf of the BMKG. Research is conducted to provide legal analysis of citizen lawsuit toward management of the 2006 Yogyakarta earthquake. Data was collected by examining the process of court sessions and mediation between Parties involved which then analysed using the relevant articles of Indonesian Civil Procedural Law. Legal analysis proposed by the researcher indicates that State Court (Pengadilan Negeri) held an `absolute competence' because such case shall not be settled by State Administrative Court (Pengadilan Tata Usaha Negara), however Yogyakarta District Court didn't hold a `relative competence' because such case shall be settled by the Central Jakarta District Court. Such case was not continued due to successful mediation between the two Parties. The 2006 Yogyakarta earthquake alerts BMKG as the earthquake information provider to work properly in accordance with the standard operating procedure to avoid citizen lawsuit that might be proposed in the near future.

Sampling Methods for Detection and Monitoring of the Asian Citrus Psyllid (Hemiptera: Psyllidae).

Science.gov (United States)

Monzo, C; Arevalo, H A; Jones, M M; Vanaclocha, P; Croxton, S D; Qureshi, J A; Stansly, P A

2015-06-01

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama is a key pest of citrus due to its role as vector of citrus greening disease or "huanglongbing." ACP monitoring is considered an indispensable tool for management of vector and disease. In the present study, datasets collected between 2009 and 2013 from 245 citrus blocks were used to evaluate precision, sensitivity for detection, and efficiency of five sampling methods. The number of samples needed to reach a 0.25 standard error-mean ratio was estimated using Taylor's power law and used to compare precision among sampling methods. Comparison of detection sensitivity and time expenditure (cost) between stem-tap and other sampling methodologies conducted consecutively at the same location were also assessed. Stem-tap sampling was the most efficient sampling method when ACP densities were moderate to high and served as the basis for comparison with all other methods. Protocols that grouped trees near randomly selected locations across the block were more efficient than sampling trees at random across the block. Sweep net sampling was similar to stem-taps in number of captures per sampled unit, but less precise at any ACP density. Yellow sticky traps were 14 times more sensitive than stem-taps but much more time consuming and thus less efficient except at very low population densities. Visual sampling was efficient for detecting and monitoring ACP at low densities. Suction sampling was time consuming and taxing but the most sensitive of all methods for detection of sparse populations. This information can be used to optimize ACP monitoring efforts. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Regional dependence in earthquake early warning and real time seismology

International Nuclear Information System (INIS)

Caprio, M.

2013-01-01

An effective earthquake prediction method is still a Chimera. What we can do at the moment, after the occurrence of a seismic event, is to provide the maximum available information as soon as possible. This can help in reducing the impact of the quake on population or and better organize the rescue operations in case of post-event actions. This study strives to improve the evaluation of earthquake parameters shortly after the occurrence of a major earthquake, and the characterization of regional dependencies in Real-Time Seismology. The recent earthquake experience from Tohoku (M 9.0, 11.03.2011) showed how an efficient EEW systems can inform numerous people and thus potentially reduce the economic and human losses by distributing warning messages several seconds before the arrival of seismic waves. In the case of devastating earthquakes, usually, in the first minutes to days after the main shock, the common communications channels can be overloaded or broken. In such cases, a precise knowledge of the macroseismic intensity distribution will represent a decisive contribution in help management and in the valuation of losses. In this work, I focused on improving the adaptability of EEW systems (chapters 1 and 2) and in deriving a global relationship for converting peak ground motion into macroseismic intensity and vice versa (chapter 3). For EEW applications, in chapter 1 we present an evolutionary approach for magnitude estimation for earthquake early warning based on real-time inversion of displacement spectra. The Spectrum Inversion (SI) method estimates magnitude and its uncertainty by inferring the shape of the entire displacement spectral curve based on the part of the spectra constrained by available data. Our method can be applied in any region without the need for calibration. SI magnitude and uncertainty estimates are updated each second following the initial P detection and potentially stabilize within 10 seconds from the initial earthquake detection

Regional dependence in earthquake early warning and real time seismology

Energy Technology Data Exchange (ETDEWEB)

Caprio, M.

2013-07-01

An effective earthquake prediction method is still a Chimera. What we can do at the moment, after the occurrence of a seismic event, is to provide the maximum available information as soon as possible. This can help in reducing the impact of the quake on population or and better organize the rescue operations in case of post-event actions. This study strives to improve the evaluation of earthquake parameters shortly after the occurrence of a major earthquake, and the characterization of regional dependencies in Real-Time Seismology. The recent earthquake experience from Tohoku (M 9.0, 11.03.2011) showed how an efficient EEW systems can inform numerous people and thus potentially reduce the economic and human losses by distributing warning messages several seconds before the arrival of seismic waves. In the case of devastating earthquakes, usually, in the first minutes to days after the main shock, the common communications channels can be overloaded or broken. In such cases, a precise knowledge of the macroseismic intensity distribution will represent a decisive contribution in help management and in the valuation of losses. In this work, I focused on improving the adaptability of EEW systems (chapters 1 and 2) and in deriving a global relationship for converting peak ground motion into macroseismic intensity and vice versa (chapter 3). For EEW applications, in chapter 1 we present an evolutionary approach for magnitude estimation for earthquake early warning based on real-time inversion of displacement spectra. The Spectrum Inversion (SI) method estimates magnitude and its uncertainty by inferring the shape of the entire displacement spectral curve based on the part of the spectra constrained by available data. Our method can be applied in any region without the need for calibration. SI magnitude and uncertainty estimates are updated each second following the initial P detection and potentially stabilize within 10 seconds from the initial earthquake detection

Multi-layered population structure in Island Southeast Asians

Science.gov (United States)

Mörseburg, Alexander; Pagani, Luca; Ricaut, Francois-Xavier; Yngvadottir, Bryndis; Harney, Eadaoin; Castillo, Cristina; Hoogervorst, Tom; Antao, Tiago; Kusuma, Pradiptajati; Brucato, Nicolas; Cardona, Alexia; Pierron, Denis; Letellier, Thierry; Wee, Joseph; Abdullah, Syafiq; Metspalu, Mait; Kivisild, Toomas

2016-01-01

The history of human settlement in Southeast Asia has been complex and involved several distinct dispersal events. Here, we report the analyses of 1825 individuals from Southeast Asia including new genome-wide genotype data for 146 individuals from three Mainland Southeast Asian (Burmese, Malay and Vietnamese) and four Island Southeast Asian (Dusun, Filipino, Kankanaey and Murut) populations. While confirming the presence of previously recognised major ancestry components in the Southeast Asian population structure, we highlight the Kankanaey Igorots from the highlands of the Philippine Mountain Province as likely the closest living representatives of the source population that may have given rise to the Austronesian expansion. This conclusion rests on independent evidence from various analyses of autosomal data and uniparental markers. Given the extensive presence of trade goods, cultural and linguistic evidence of Indian influence in Southeast Asia starting from 2.5 kya, we also detect traces of a South Asian signature in different populations in the region dating to the last couple of thousand years. PMID:27302840

The 5th Conference on Asian Trends in Prostate Cancer Hormone Therapy.

Science.gov (United States)

Akaza, Hideyuki; Moore, Malcolm A; Chang, Shu-Jen; Cheng, Christopher; Choi, Han Yong; Esuvaranathan, Kesavan; Hinotsu, Shiro; Hong, Sung-Joon; Kim, Choung-Soo; Kim, Wun-Jae; Murai, Masaru; Naito, Seiji; Soebadi, Doddy; Song, Jae-Mann; Umbas, Rainy; Usami, Michiyuki; Xia, Shujie; Yang, Chi-Rei

2007-01-01

The Conference on Asian Trends in Prostate Cancer Hormone Therapy is an annual forum for Asian urologists now in its 5th year. The 2006 conference, held in Bali, Indonesia, was attended by 27 leading urologic oncologists from China, Indonesia, Japan, Korea, Singapore, and Taiwan and featured a packed program of presentations and discussions on a wide range of topics such as relationships among clinicians and the newly opened Asia Regional Office for Cancer Control of the International Union Against Cancer (UICC), detection rates of prostate cancer by biopsy in each of the 6 Asian countries, and favored treatment modalities for hormone-refractory prostate cancer (HRPC) in each country. The first session of the conference kicked off with a keynote lecture entitled "Activities of the UICC ARO". UICC's new office will be the nerve center for its activities in the Asia region. Along with the Asian Pacific Organization for Cancer Prevention (APOCP), UICC aims to shift the focus of attention to cancer control. As such APOCP's long-running publication the APJCP is to be re-launched as the Asian Pacific Journal of Cancer Control. Although UICC is primarily concerned with cancer, several risk factors for cancer are common also to other non-communicable diseases such as diabetes and heart disease, and an important strategy is to implement measures to control these various pathologic conditions as a whole. Apart from contributing to an Asian prostate cancer registry the UICC-ARO will provide training courses, working groups, and assistance in collecting and processing data. The keynote lecture was followed by a roundtable discussion on possible ways in which clinicians from each Asian country can work with UICC. A number of suggestions were put forth including better registration, epidemiology research, possible implementation of UICC prostate cancer guidelines, early detection and screening, and roles of diet and phytotherapy. The underlying reasons for the large but

Foreshocks, aftershocks, and earthquake probabilities: Accounting for the landers earthquake

Science.gov (United States)

Jones, Lucile M.

1994-01-01

The equation to determine the probability that an earthquake occurring near a major fault will be a foreshock to a mainshock on that fault is modified to include the case of aftershocks to a previous earthquake occurring near the fault. The addition of aftershocks to the background seismicity makes its less probable that an earthquake will be a foreshock, because nonforeshocks have become more common. As the aftershocks decay with time, the probability that an earthquake will be a foreshock increases. However, fault interactions between the first mainshock and the major fault can increase the long-term probability of a characteristic earthquake on that fault, which will, in turn, increase the probability that an event is a foreshock, compensating for the decrease caused by the aftershocks.

Earthquake forecasting and warning

Energy Technology Data Exchange (ETDEWEB)

Rikitake, T.

1983-01-01

This review briefly describes two other books on the same subject either written or partially written by Rikitake. In this book, the status of earthquake prediction efforts in Japan, China, the Soviet Union, and the United States are updated. An overview of some of the organizational, legal, and societal aspects of earthquake prediction in these countries is presented, and scientific findings of precursory phenomena are included. A summary of circumstances surrounding the 1975 Haicheng earthquake, the 1978 Tangshan earthquake, and the 1976 Songpan-Pingwu earthquake (all magnitudes = 7.0) in China and the 1978 Izu-Oshima earthquake in Japan is presented. This book fails to comprehensively summarize recent advances in earthquake prediction research.

Report on Disaster Medical Operations with Acupuncture/Massage Therapy after the Great East Japan Earthquake

Directory of Open Access Journals (Sweden)

Shin Takayama

2012-01-01

Full Text Available The Great East Japan Earthquake inflicted immense damage over a wide area of eastern Japan with the consequent tsunami. Department of Traditional Asian Medicine, Tohoku University, started providing medical assistance to the disaster-stricken regions mainly employing traditional Asian therapies. We visited seven evacuation centers in Miyagi and Fukushima Prefecture and provided acupuncture/massage therapy. While massage therapy was performed manually, filiform needles and press tack needles were used to administer acupuncture. In total, 553 people were treated (mean age, 54.0 years; 206 men, 347 women. Assessment by interview showed that the most common complaint was shoulder/back stiffness. The rate of therapy satisfaction was 92.3%. Many people answered that they experienced not only physical but also psychological relief. At the time of the disaster, acupuncture/massage therapy, which has both mental and physical soothing effects, may be a therapeutic approach that can be effectively used in combination with Western medical practices.

Ionospheric earthquake precursors

International Nuclear Information System (INIS)

Bulachenko, A.L.; Oraevskij, V.N.; Pokhotelov, O.A.; Sorokin, V.N.; Strakhov, V.N.; Chmyrev, V.M.

1996-01-01

Results of experimental study on ionospheric earthquake precursors, program development on processes in the earthquake focus and physical mechanisms of formation of various type precursors are considered. Composition of experimental cosmic system for earthquake precursors monitoring is determined. 36 refs., 5 figs

The key role of eyewitnesses in rapid earthquake impact assessment

Science.gov (United States)

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

2014-05-01

published after validation. Quake Catcher Networks (QCN) where a cheap USB MEMS motion sensors transform a PC in a seismic station are being deployed in Thessaloniki and Patras (Greece) in collaboration with Stanford University and the USGS. Flashsourcing is also used which is the analysis in real time of traffic surges observed on EMSC's earthquake information website; these surges are caused by the natural convergence of eyewitnesses who rush to the Internet to investigate the cause of the shaking that they have just felt. Within 5 minutes and independently of any seismic data, this detects felt earthquakes, maps the felt area and can detect the presence of damage. We will also explain the roles of social networks in optimising data collection and how citizen involvement has changed our earthquake information services.

Long Period Earthquakes Beneath California's Young and Restless Volcanoes

Science.gov (United States)

Pitt, A. M.; Dawson, P. B.; Shelly, D. R.; Hill, D. P.; Mangan, M.

2013-12-01

The newly established USGS California Volcano Observatory has the broad responsibility of monitoring and assessing hazards at California's potentially threatening volcanoes, most notably Mount Shasta, Medicine Lake, Clear Lake Volcanic Field, and Lassen Volcanic Center in northern California; and Long Valley Caldera, Mammoth Mountain, and Mono-Inyo Craters in east-central California. Volcanic eruptions occur in California about as frequently as the largest San Andreas Fault Zone earthquakes-more than ten eruptions have occurred in the last 1,000 years, most recently at Lassen Peak (1666 C.E. and 1914-1917 C.E.) and Mono-Inyo Craters (c. 1700 C.E.). The Long Valley region (Long Valley caldera and Mammoth Mountain) underwent several episodes of heightened unrest over the last three decades, including intense swarms of volcano-tectonic (VT) earthquakes, rapid caldera uplift, and hazardous CO2 emissions. Both Medicine Lake and Lassen are subsiding at appreciable rates, and along with Clear Lake, Long Valley Caldera, and Mammoth Mountain, sporadically experience long period (LP) earthquakes related to migration of magmatic or hydrothermal fluids. Worldwide, the last two decades have shown the importance of tracking LP earthquakes beneath young volcanic systems, as they often provide indication of impending unrest or eruption. Herein we document the occurrence of LP earthquakes at several of California's young volcanoes, updating a previous study published in Pitt et al., 2002, SRL. All events were detected and located using data from stations within the Northern California Seismic Network (NCSN). Event detection was spatially and temporally uneven across the NCSN in the 1980s and 1990s, but additional stations, adoption of the Earthworm processing system, and heightened vigilance by seismologists have improved the catalog over the last decade. LP earthquakes are now relatively well-recorded under Lassen (~150 events since 2000), Clear Lake (~60 events), Mammoth Mountain

Evaluation of earthquake vibration on aseismic design of nuclear power plant judging from recent earthquakes

International Nuclear Information System (INIS)

Dan, Kazuo

2006-01-01

The Regulatory Guide for Aseismic Design of Nuclear Reactor Facilities was revised on 19 th September, 2006. Six factors for evaluation of earthquake vibration are considered on the basis of the recent earthquakes. They are 1) evaluation of earthquake vibration by method using fault model, 2) investigation and approval of active fault, 3) direct hit earthquake, 4) assumption of the short active fault as the hypocentral fault, 5) locality of the earthquake and the earthquake vibration and 6) remaining risk. A guiding principle of revision required new evaluation method of earthquake vibration using fault model, and evaluation of probability of earthquake vibration. The remaining risk means the facilities and people get into danger when stronger earthquake than the design occurred, accordingly, the scattering has to be considered at evaluation of earthquake vibration. The earthquake belt of Hyogo-Nanbu earthquake and strong vibration pulse in 1995, relation between length of surface earthquake fault and hypocentral fault, and distribution of seismic intensity of off Kushiro in 1993 are shown. (S.Y.)

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.

Automatic analysis of the 2015 Gorkha earthquake aftershock sequence.

Science.gov (United States)

Baillard, C.; Lyon-Caen, H.; Bollinger, L.; Rietbrock, A.; Letort, J.; Adhikari, L. B.

2016-12-01

The Mw 7.8 Gorkha earthquake, that partially ruptured the Main Himalayan Thrust North of Kathmandu on the 25th April 2015, was the largest and most catastrophic earthquake striking Nepal since the great M8.4 1934 earthquake. This mainshock was followed by multiple aftershocks, among them, two notable events that occurred on the 12th May with magnitudes of 7.3 Mw and 6.3 Mw. Due to these recent events it became essential for the authorities and for the scientific community to better evaluate the seismic risk in the region through a detailed analysis of the earthquake catalog, amongst others, the spatio-temporal distribution of the Gorkha aftershock sequence. Here we complement this first study by doing a microseismic study using seismic data coming from the eastern part of the Nepalese Seismological Center network associated to one broadband station in Everest. Our primary goal is to deliver an accurate catalog of the aftershock sequence. Due to the exceptional number of events detected we performed an automatic picking/locating procedure which can be splitted in 4 steps: 1) Coarse picking of the onsets using a classical STA/LTA picker, 2) phase association of picked onsets to detect and declare seismic events, 3) Kurtosis pick refinement around theoretical arrival times to increase picking and location accuracy and, 4) local magnitude calculation based amplitude of waveforms. This procedure is time efficient ( 1 sec/event), reduces considerably the location uncertainties ( 2 to 5 km errors) and increases the number of events detected compared to manual processing. Indeed, the automatic detection rate is 10 times higher than the manual detection rate. By comparing to the USGS catalog we were able to give a new attenuation law to compute local magnitudes in the region. A detailed analysis of the seismicity shows a clear migration toward the east of the region and a sudden decrease of seismicity 100 km east of Kathmandu which may reveal the presence of a tectonic

Temporal Variation of Tectonic Tremor Activity Associated with Nearby Earthquakes

Science.gov (United States)

Chao, K.; Van der Lee, S.; Hsu, Y. J.; Pu, H. C.

2017-12-01

Tectonic tremor and slow slip events, located downdip from the seismogenic zone, hold the key to recurring patterns of typical earthquakes. Several findings of slow aseismic slip during the prenucletion processes of nearby earthquakes have provided new insight into the study of stress transform of slow earthquakes in fault zones prior to megathrust earthquakes. However, how tectonic tremor is associated with the occurrence of nearby earthquakes remains unclear. To enhance our understanding of the stress interaction between tremor and earthquakes, we developed an algorithm for the automatic detection and location of tectonic tremor in the collisional tectonic environment in Taiwan. Our analysis of a three-year data set indicates a short-term increase in the tremor rate starting at 19 days before the 2010 ML6.4 Jiashian main shock (Chao et al., JGR, 2017). Around the time when the tremor rate began to rise, one GPS station recorded a flip in its direction of motion. We hypothesize that tremor is driven by a slow-slip event that preceded the occurrence of the shallower nearby main shock, even though the inferred slip is too small to be observed by all GPS stations. To better quantify what the necessary condition for tremor to response to nearby earthquakes is, we obtained a 13-year ambient tremor catalog from 2004 to 2016 in the same region. We examine the spatiotemporal relationship between tremor and 37 ML>=5.0 (seven events with ML>=6.0) nearby earthquakes located within 0.5 degrees to the active tremor sources. The findings from this study can enhance our understanding of the interaction among tremor, slow slip, and nearby earthquakes in the high seismic hazard regions.

Romanian earthquakes analysis using BURAR seismic array

International Nuclear Information System (INIS)

Borleanu, Felix; Rogozea, Maria; Nica, Daniela; Popescu, Emilia; Popa, Mihaela; Radulian, Mircea

2008-01-01

Bucovina seismic array (BURAR) is a medium-aperture array, installed in 2002 in the northern part of Romania (47.61480 N latitude, 25.21680 E longitude, 1150 m altitude), as a result of the cooperation between Air Force Technical Applications Center, USA and National Institute for Earth Physics, Romania. The array consists of ten elements, located in boreholes and distributed over a 5 x 5 km 2 area; nine with short-period vertical sensors and one with a broadband three-component sensor. Since the new station has been operating the earthquake survey of Romania's territory has been significantly improved. Data recorded by BURAR during 01.01.2005 - 12.31.2005 time interval are first processed and analyzed, in order to establish the array detection capability of the local earthquakes, occurred in different Romanian seismic zones. Subsequently a spectral ratios technique was applied in order to determine the calibration relationships for magnitude, using only the information gathered by BURAR station. The spectral ratios are computed relatively to a reference event, considered as representative for each seismic zone. This method has the advantage to eliminate the path effects. The new calibration procedure is tested for the case of Vrancea intermediate-depth earthquakes and proved to be very efficient in constraining the size of these earthquakes. (authors)

Very low frequency earthquakes (VLFEs) detected during episodic tremor and slip (ETS) events in Cascadia using a match filter method indicate repeating events

Science.gov (United States)

Hutchison, A. A.; Ghosh, A.

2016-12-01

Very low frequency earthquakes (VLFEs) occur in transitional zones of faults, releasing seismic energy in the 0.02-0.05 Hz frequency band over a 90 s duration and typically have magntitudes within the range of Mw 3.0-4.0. VLFEs can occur down-dip of the seismogenic zone, where they can transfer stress up-dip potentially bringing the locked zone closer to a critical failure stress. VLFEs also occur up-dip of the seismogenic zone in a region along the plate interface that can rupture coseismically during large megathrust events, such as the 2011 Tohoku-Oki earthquake [Ide et al., 2011]. VLFEs were first detected in Cascadia during the 2011 episodic tremor and slip (ETS) event, occurring coincidentally with tremor [Ghosh et al., 2015]. However, during the 2014 ETS event, VLFEs were spatially and temporally asynchronous with tremor activity [Hutchison and Ghosh, 2016]. Such contrasting behaviors remind us that the mechanics behind such events remain elusive, yet they are responsible for the largest portion of the moment release during an ETS event. Here, we apply a match filter method using known VLFEs as template events to detect additional VLFEs. Using a grid-search centroid moment tensor inversion method, we invert stacks of the resulting match filter detections to ensure moment tensor solutions are similar to that of the respective template events. Our ability to successfully employ a match filter method to VLFE detection in Cascadia intrinsically indicates that these events can be repeating, implying that the same asperities are likely responsible for generating multiple VLFEs.

Resilience of aging populations after devastating earthquake event and its determinants - A case study of the Chi-Chi earthquake in Taiwan

Science.gov (United States)

Hung, Chih-Hsuan; Hung, Hung-Chih

2016-04-01

1.Background Major portions of urban areas in Asia are highly exposed and vulnerable to devastating earthquakes. Many studies identify ways to reduce earthquake risk by concentrating more on building resilience for the particularly vulnerable populations. By 2020, as the United Nations' warning, many Asian countries would become 'super-aged societies', such as Taiwan. However, local authorities rarely use resilience approach to frame earthquake disaster risk management and land use strategies. The empirically-based research about the resilience of aging populations has also received relatively little attention. Thus, a challenge arisen for decision-makers is how to enhance resilience of aging populations within the context of risk reduction. This study aims to improve the understanding of the resilience of aging populations and its changes over time in the aftermath of a destructive earthquake at the local level. A novel methodology is proposed to assess the resilience of aging populations and to characterize their changes of spatial distribution patterns, as well as to examine their determinants. 2.Methods and data An indicator-based assessment framework is constructed with the goal of identifying composite indicators (including before, during and after a disaster) that could serve as proxies for attributes of the resilience of aging populations. Using the recovery process of the Chi-Chi earthquake struck central Taiwan in 1999 as a case study, we applied a method combined a geographical information system (GIS)-based spatial statistics technique and cluster analysis to test the extent of which the resilience of aging populations is spatially autocorrelated throughout the central Taiwan, and to explain why clustering of resilient areas occurs in specific locations. Furthermore, to scrutinize the affecting factors of resilience, we develop an aging population resilience model (APRM) based on existing resilience theory. Using the APRM, we applied a multivariate

Intra-day response of foreign exchange markets after the Tohoku-Oki earthquake

Science.gov (United States)

Nakano, Shuhei; Hirata, Yoshito; Iwayama, Koji; Aihara, Kazuyuki

2015-02-01

Although an economy is influenced by a natural disaster, the market response to the disaster during the first 24 hours is not clearly understood. Here we show that an earthquake quickly causes temporal changes in a foreign exchange market by examining the case of the Tohoku-Oki earthquake. Recurrence plots and statistical change point detection independently show that the United States dollar-Japanese yen market responded to the earthquake activity without delay and with the delay of about 2 minutes, respectively. These findings support that the efficient market hypothesis nearly holds now in the time scale of minutes.

Source characteristics and geological implications of the January 2016 induced earthquake swarm near Crooked Lake, Alberta

Science.gov (United States)

Wang, Ruijia; Gu, Yu Jeffrey; Schultz, Ryan; Zhang, Miao; Kim, Ahyi

2017-08-01

On 2016 January 12, an intraplate earthquake with an initial reported local magnitude (ML) of 4.8 shook the town of Fox Creek, Alberta. While there were no reported damages, this earthquake was widely felt by the local residents and suspected to be induced by the nearby hydraulic-fracturing (HF) operations. In this study, we determine the earthquake source parameters using moment tensor inversions, and then detect and locate the associated swarm using a waveform cross-correlation based method. The broad-band seismic recordings from regional arrays suggest a moment magnitude (M) 4.1 for this event, which is the largest in Alberta in the past decade. Similar to other recent M ∼ 3 earthquakes near Fox Creek, the 2016 January 12 earthquake exhibits a dominant strike-slip (strike = 184°) mechanism with limited non-double-couple components (∼22 per cent). This resolved focal mechanism, which is also supported by forward modelling and P-wave first motion analysis, indicates an NE-SW oriented compressional axis consistent with the maximum compressive horizontal stress orientations delineated from borehole breakouts. Further detection analysis on industry-contributed recordings unveils 1108 smaller events within 3 km radius of the epicentre of the main event, showing a close spatial-temporal relation to a nearby HF well. The majority of the detected events are located above the basement, comparable to the injection depth (3.5 km) on the Duvernay shale Formation. The spatial distribution of this earthquake cluster further suggests that (1) the source of the sequence is an N-S-striking fault system and (2) these earthquakes were induced by an HF well close to but different from the well that triggered a previous (January 2015) earthquake swarm. Reactivation of pre-existing, N-S oriented faults analogous to the Pine Creek fault zone, which was reported by earlier studies of active source seismic and aeromagnetic data, are likely responsible for the occurrence of the

Results of the Regional Earthquake Likelihood Models (RELM) test of earthquake forecasts in California.

Science.gov (United States)

Lee, Ya-Ting; Turcotte, Donald L; Holliday, James R; Sachs, Michael K; Rundle, John B; Chen, Chien-Chih; Tiampo, Kristy F

2011-10-04

The Regional Earthquake Likelihood Models (RELM) test of earthquake forecasts in California was the first competitive evaluation of forecasts of future earthquake occurrence. Participants submitted expected probabilities of occurrence of M ≥ 4.95 earthquakes in 0.1° × 0.1° cells for the period 1 January 1, 2006, to December 31, 2010. Probabilities were submitted for 7,682 cells in California and adjacent regions. During this period, 31 M ≥ 4.95 earthquakes occurred in the test region. These earthquakes occurred in 22 test cells. This seismic activity was dominated by earthquakes associated with the M = 7.2, April 4, 2010, El Mayor-Cucapah earthquake in northern Mexico. This earthquake occurred in the test region, and 16 of the other 30 earthquakes in the test region could be associated with it. Nine complete forecasts were submitted by six participants. In this paper, we present the forecasts in a way that allows the reader to evaluate which forecast is the most "successful" in terms of the locations of future earthquakes. We conclude that the RELM test was a success and suggest ways in which the results can be used to improve future forecasts.

Step-wise changes in glacier flow speed coincide with calving and glacial earthquakes at Helheim Glacier, Greenland

DEFF Research Database (Denmark)

Nettles, M.; Larsen, T. B.; Elósegui, P.

2008-01-01

Geodetic observations show several large, sudden increases in flow speed at Helheim Glacier, one of Greenland's largest outlet glaciers, during summer, 2007. These step-like accelerations, detected along the length of the glacier, coincide with teleseismically detected glacial earthquakes and major...... iceberg calving events. No coseismic offset in the position of the glacier surface is observed; instead, modest tsunamis associated with the glacial earthquakes implicate glacier calving in the seismogenic process. Our results link changes in glacier velocity directly to calving-front behavior...... at Greenland's largest outlet glaciers, on timescales as short as minutes to hours, and clarify the mechanism by which glacial earthquakes occur. Citation: Nettles, M., et al. (2008), Step-wise changes in glacier flow speed coincide with calving and glacial earthquakes at Helheim Glacier, Greenland....

Uganda's participation in CTBT activities and earthquake monitoring

International Nuclear Information System (INIS)

Tugume, F.A.

2002-01-01

Earthquake occurrence in Uganda is mostly related to East Africa Rift System. The country's western border lies within the Western branch of this system while the Eastern branch is only 200 km from its eastern border. The two tectonic features contribute to seismicity in Uganda. These are the Aswar shear zone running from Nimule at the border of Uganda and Sudan, to Mount Elgon on the Eastern border and Katonga fault break which cuts across the country from the foot hills of mount Rwenzori to the Western side of Lake Victoria. This unique tectonic setting makes Uganda one of most seismically active countries on the African continet as exemplified by some destructive earthquakes that have hit the country. For this reason the Government of uganda is in the process of setting up an earthquake monitoring system, the National Seismological Network, with efficient detectability, efficient data transmission and processing facilities so that earthquakes in Uganda can be properly assessed and seismic hazard studies of the country cunducted. The objectives of the said network, the seismic developments for the last two decades and its current satus are described

Earthquakes in Switzerland and surrounding regions during 2006

Energy Technology Data Exchange (ETDEWEB)

Baer, M.; Deichmann, N.; Braunmiller, J.; Clinton, J.; Husen, S.; Faeh, D.; Giardini, D.; Kaestli, P.; Kradolfer, U.; Wiemer, S

2007-12-15

This report of the Swiss Seismological Service summarizes the seismic activity in Switzerland and surrounding regions during 2006. During this period, 572 earthquakes and 91 quarry blasts were detected and located in the region under consideration. Of these earthquakes, two occurred in conjunction with the construction of the new Gotthard railway tunnel and 165 were induced artificially by the stimulation of a proposed geothermal reservoir beneath the city of Basel. With 20 events with {mu}{sub {iota}} {>=} 2.5, five of which were artificially induced, the seismic activity in the year 2006 was far below the average over the previous 31 years. Nevertheless, six events were felt by the public, most prominently the strongest of the induced Basel events ({mu}{sub {iota}} 3.4), which caused some non-structural building damage. Noteworthy are also the two earthquakes near Cortaillod ({mu}{sub {iota}} 3.2), on the shore of Lake Neuchatel, and in Val Mora ({mu}{sub {iota}} 3.5), between the Engadin and Val Muestair, as well as the 42 aftershocks of the {mu}{sub {iota}} 4.9 Vallorcine earthquake, between Martigny and Chamonix, of September 2005. (author)

Earthquakes in Switzerland and surrounding regions during 2006

International Nuclear Information System (INIS)

Baer, M.; Deichmann, N.; Braunmiller, J.; Clinton, J.; Husen, S.; Faeh, D.; Giardini, D.; Kaestli, P.; Kradolfer, U.; Wiemer, S.

2007-01-01

This report of the Swiss Seismological Service summarizes the seismic activity in Switzerland and surrounding regions during 2006. During this period, 572 earthquakes and 91 quarry blasts were detected and located in the region under consideration. Of these earthquakes, two occurred in conjunction with the construction of the new Gotthard railway tunnel and 165 were induced artificially by the stimulation of a proposed geothermal reservoir beneath the city of Basel. With 20 events with Μ ι ≥ 2.5, five of which were artificially induced, the seismic activity in the year 2006 was far below the average over the previous 31 years. Nevertheless, six events were felt by the public, most prominently the strongest of the induced Basel events (Μ ι 3.4), which caused some non-structural building damage. Noteworthy are also the two earthquakes near Cortaillod (Μ ι 3.2), on the shore of Lake Neuchatel, and in Val Mora (Μ ι 3.5), between the Engadin and Val Muestair, as well as the 42 aftershocks of the Μ ι 4.9 Vallorcine earthquake, between Martigny and Chamonix, of September 2005. (author)

Earthquakes, September-October 1986

Science.gov (United States)

Person, W.J.

1987-01-01

There was one great earthquake (8.0 and above) during this reporting period in the South Pacific in the Kermadec Islands. There were no major earthquakes (7.0-7.9) but earthquake-related deaths were reported in Greece and in El Salvador. There were no destrcutive earthquakes in the United States.

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.

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

Stress Regime in the Nepalese Himalaya from Recent Earthquakes.

Science.gov (United States)

Pant, M.; Karplus, M. S.; Velasco, A. A.; Nabelek, J.; Kuna, V. M.; Ghosh, A.; Mendoza, M.; Adhikari, L. B.; Sapkota, S. N.; Klemperer, S. L.; Patlan, E.

2017-12-01

The two recent earthquakes, April 25, 2015 Mw 7.8 (Gorkha earthquake) and May 12, 2015 Mw 7.2, at the Indo-Eurasian plate margin killed thousands of people and caused billion dollars of property loss. In response to these events, we deployed a dense array of seismometers to record the aftershocks along Gorkha earthquake rupture area. Our network NAMASTE (Nepal Array Measuring Aftershock Seismicity Trailing Earthquake) included 45 different seismic stations (16 short period, 25 broadband, and 4 strong motion sensors) covering a large area from north-central Nepal to south of the Main Frontal Thrust at a spacing of 20 km. The instruments recorded aftershocks from June 2015 to May 2016. We used time domain short term average (STA) and long term average (LTA) algorithms (1/10s and 4/40s) respectively to detect the arrivals and then developed an earthquake catalog containing 9300 aftershocks. We are manually picking the P-wave first motion arrival polarity to develop a catalog of focal mechanisms for the larger magnitude (>M3.0) events with adequate (>10) arrivals. We hope to characterize the seismicity and stress mechanisms of the complex fault geometries in the Nepalese Himalaya and to address the geophysical processes controlling seismic cycles in the Indo-Eurasian plate margin.

Impact of earthquake-induced tsunamis on public health

Science.gov (United States)

Mavroulis, Spyridon; Mavrouli, Maria; Lekkas, Efthymios; Tsakris, Athanassios

2017-04-01

Tsunamis are caused by rapid sea floor displacement during earthquakes, landslides and large explosive eruptions in marine environment setting. Massive amounts of sea water in the form of devastating surface waves travelling hundreds of kilometers per hour have the potential to cause extensive damage to coastal infrastructures, considerable loss of life and injury and emergence of infectious diseases (ID). This study involved an extensive and systematic literature review of 50 research publications related to public health impact of the three most devastating tsunamis of the last 12 years induced by great earthquakes, namely the 2004 Sumatra-Andaman earthquake (moment magnitude Mw 9.2), the 2009 Samoa earthquake (Mw 8.1) and the 2011 Tōhoku (Japan) earthquake (Mw 9.0) in the Indian, Western Pacific and South Pacific Oceans respectively. The inclusion criteria were literature type comprising journal articles and official reports, natural disaster type including tsunamis induced only by earthquakes, population type including humans, and outcome measure characterized by disease incidence increase. The potential post-tsunami ID are classified into 11 groups including respiratory, pulmonary, wound-related, water-borne, skin, vector-borne, eye, fecal-oral, food-borne, fungal and mite-borne ID. Respiratory infections were detected after all the above mentioned tsunamis. Wound-related, skin and water-borne ID were observed after the 2004 and 2011 tsunamis, while vector-borne, fecal-oral and eye ID were observed only after the 2004 tsunami and pulmonary, food-borne and mite-borne ID were diagnosed only after the 2011 tsunami. Based on available age and genre data, it is concluded that the most vulnerable population groups are males, children (age ≤ 15 years) and adults (age ≥ 65 years). Tetanus and pneumonia are the deadliest post-tsunami ID. The detected risk factors include (1) lowest socioeconomic conditions, poorly constructed buildings and lack of prevention

Megathrust earthquakes in Central Chile: What is next after the Maule 2010 earthquake?

Science.gov (United States)

Madariaga, R.

2013-05-01

The 27 February 2010 Maule earthquake occurred in a well identified gap in the Chilean subduction zone. The event has now been studied in detail using both far-field, near field seismic and geodetic data, we will review this information gathered so far. The event broke a region that was much longer along strike than the gap left over from the 1835 Concepcion earthquake, sometimes called the Darwin earthquake because he was in the area when the earthquake occurred and made many observations. Recent studies of contemporary documents by Udias et al indicate that the area broken by the Maule earthquake in 2010 had previously broken by a similar earthquake in 1751, but several events in the magnitude 8 range occurred in the area principally in 1835 already mentioned and, more recently on 1 December 1928 to the North and on 21 May 1960 (1 1/2 days before the big Chilean earthquake of 1960). Currently the area of the 2010 earthquake and the region immediately to the North is undergoing a very large increase in seismicity with numerous clusters of seismicity that move along the plate interface. Examination of the seismicity of Chile of the 18th and 19th century show that the region immediately to the North of the 2010 earthquake broke in a very large megathrust event in July 1730. this is the largest known earthquake in central Chile. The region where this event occurred has broken in many occasions with M 8 range earthquakes in 1822, 1880, 1906, 1971 and 1985. Is it preparing for a new very large megathrust event? The 1906 earthquake of Mw 8.3 filled the central part of the gap but it has broken again on several occasions in 1971, 1973 and 1985. The main question is whether the 1906 earthquake relieved enough stresses from the 1730 rupture zone. Geodetic data shows that most of the region that broke in 1730 is currently almost fully locked from the northern end of the Maule earthquake at 34.5°S to 30°S, near the southern end of the of the Mw 8.5 Atacama earthquake of 11

Changes in groundwater chemistry before two consecutive earthquakes in Iceland

KAUST Repository

Skelton, Alasdair

2014-09-21

Groundwater chemistry has been observed to change before earthquakes and is proposed as a precursor signal. Such changes include variations in radon count rates1, 2, concentrations of dissolved elements3, 4, 5 and stable isotope ratios4, 5. Changes in seismic wave velocities6, water levels in boreholes7, micro-seismicity8 and shear wave splitting9 are also thought to precede earthquakes. Precursor activity has been attributed to expansion of rock volume7, 10, 11. However, most studies of precursory phenomena lack sufficient data to rule out other explanations unrelated to earthquakes12. For example, reproducibility of a precursor signal has seldom been shown and few precursors have been evaluated statistically. Here we analyse the stable isotope ratios and dissolved element concentrations of groundwater taken from a borehole in northern Iceland between 2008 and 2013. We find that the chemistry of the groundwater changed four to six months before two greater than magnitude 5 earthquakes that occurred in October 2012 and April 2013. Statistical analyses indicate that the changes in groundwater chemistry were associated with the earthquakes. We suggest that the changes were caused by crustal dilation associated with stress build-up before each earthquake, which caused different groundwater components to mix. Although the changes we detect are specific for the site in Iceland, we infer that similar processes may be active elsewhere, and that groundwater chemistry is a promising target for future studies on the predictability of earthquakes.

Changes in groundwater chemistry before two consecutive earthquakes in Iceland

KAUST Repository

Skelton, Alasdair; André n, Margareta; Kristmannsdó ttir, Hrefna; Stockmann, Gabrielle; Mö rth, Carl-Magnus; Sveinbjö rnsdó ttir, Á rny; Jonsson, Sigurjon; Sturkell, Erik; Guð rú nardó ttir, Helga Rakel; Hjartarson, Hreinn; Siegmund, Heike; Kockum, Ingrid

2014-01-01

Groundwater chemistry has been observed to change before earthquakes and is proposed as a precursor signal. Such changes include variations in radon count rates1, 2, concentrations of dissolved elements3, 4, 5 and stable isotope ratios4, 5. Changes in seismic wave velocities6, water levels in boreholes7, micro-seismicity8 and shear wave splitting9 are also thought to precede earthquakes. Precursor activity has been attributed to expansion of rock volume7, 10, 11. However, most studies of precursory phenomena lack sufficient data to rule out other explanations unrelated to earthquakes12. For example, reproducibility of a precursor signal has seldom been shown and few precursors have been evaluated statistically. Here we analyse the stable isotope ratios and dissolved element concentrations of groundwater taken from a borehole in northern Iceland between 2008 and 2013. We find that the chemistry of the groundwater changed four to six months before two greater than magnitude 5 earthquakes that occurred in October 2012 and April 2013. Statistical analyses indicate that the changes in groundwater chemistry were associated with the earthquakes. We suggest that the changes were caused by crustal dilation associated with stress build-up before each earthquake, which caused different groundwater components to mix. Although the changes we detect are specific for the site in Iceland, we infer that similar processes may be active elsewhere, and that groundwater chemistry is a promising target for future studies on the predictability of earthquakes.

Tidal triggering of earthquakes suggests poroelastic behavior on the San Andreas Fault

International Nuclear Information System (INIS)

Delorey, Andrew A.; Elst, Nicholas J. van der; Johnson, Paul Allan

2016-01-01

Tidal triggering of earthquakes is hypothesized to provide quantitative information regarding the fault's stress state, poroelastic properties, and may be significant for our understanding of seismic hazard. To date, studies of regional or global earthquake catalogs have had only modest successes in identifying tidal triggering. We posit that the smallest events that may provide additional evidence of triggering go unidentified and thus we developed a technique to improve the identification of very small magnitude events. We identify events applying a method known as inter-station seismic coherence where we prioritize detection and discrimination over characterization. Here we show tidal triggering of earthquakes on the San Andreas Fault. We find the complex interaction of semi-diurnal and fortnightly tidal periods exposes both stress threshold and critical state behavior. Lastly, our findings reveal earthquake nucleation processes and pore pressure conditions – properties of faults that are difficult to measure, yet extremely important for characterizing earthquake physics and seismic hazards.

Tidal triggering of earthquakes suggests poroelastic behavior on the San Andreas Fault

Science.gov (United States)

Delorey, Andrew; Van Der Elst, Nicholas; Johnson, Paul

2017-01-01

Tidal triggering of earthquakes is hypothesized to provide quantitative information regarding the fault's stress state, poroelastic properties, and may be significant for our understanding of seismic hazard. To date, studies of regional or global earthquake catalogs have had only modest successes in identifying tidal triggering. We posit that the smallest events that may provide additional evidence of triggering go unidentified and thus we developed a technique to improve the identification of very small magnitude events. We identify events applying a method known as inter-station seismic coherence where we prioritize detection and discrimination over characterization. Here we show tidal triggering of earthquakes on the San Andreas Fault. We find the complex interaction of semi-diurnal and fortnightly tidal periods exposes both stress threshold and critical state behavior. Our findings reveal earthquake nucleation processes and pore pressure conditions – properties of faults that are difficult to measure, yet extremely important for characterizing earthquake physics and seismic hazards.

Beyond 'Asian Values': Rationales For Australian-Japan Cooperation In Asian Regionalism

OpenAIRE

Go Ito

2010-01-01

In the past, the experience of the ‘East Asian Miracle’ and the sufferings from the ‘East Asian Meltdown’ were the impetus to generate and develop East Asian regional identity. The situation, however, is changing drastically. The future of East Asia regionalism has become amorphous because of complicated new trends. Japan, one of the important actors that constitute triangular relationships in East Asia, has been encouraging development of East Asian regionalism in the economic arena. Austral...

Extreme value statistics and thermodynamics of earthquakes. Large earthquakes

Energy Technology Data Exchange (ETDEWEB)

Lavenda, B. [Camerino Univ., Camerino, MC (Italy); Cipollone, E. [ENEA, Centro Ricerche Casaccia, S. Maria di Galeria, RM (Italy). National Centre for Research on Thermodynamics

2000-06-01

A compound Poisson process is used to derive a new shape parameter which can be used to discriminate between large earthquakes and aftershocks sequences. Sample exceedance distributions of large earthquakes are fitted to the Pareto tail and the actual distribution of the maximum to the Frechet distribution, while the sample distribution of aftershocks are fitted to a Beta distribution and the distribution of the minimum to the Weibull distribution for the smallest value. The transition between initial sample distributions and asymptotic extreme value distributions show that self-similar power laws are transformed into non scaling exponential distributions so that neither self-similarity nor the Gutenberg-Richter law can be considered universal. The energy-magnitude transformation converts the Frechet distribution into the Gumbel distribution, originally proposed by Epstein and Lomnitz, and not the Gompertz distribution as in the Lomnitz-Adler and Lomnitz generalization of the Gutenberg-Richter law. Numerical comparison is made with the Lomnitz-Adler and Lomnitz analysis using the same catalogue of Chinese earthquakes. An analogy is drawn between large earthquakes and high energy particle physics. A generalized equation of state is used to transform the Gamma density into the order-statistic Frechet distribution. Earthquake temperature and volume are determined as functions of the energy. Large insurance claims based on the Pareto distribution, which does not have a right endpoint, show why there cannot be a maximum earthquake energy.

The GIS and analysis of earthquake damage distribution of the 1303 Hongtong M=8 earthquake

Science.gov (United States)

Gao, Meng-Tan; Jin, Xue-Shen; An, Wei-Ping; Lü, Xiao-Jian

2004-07-01

The geography information system of the 1303 Hongton M=8 earthquake has been established. Using the spatial analysis function of GIS, the spatial distribution characteristics of damage and isoseismal of the earthquake are studies. By comparing with the standard earthquake intensity attenuation relationship, the abnormal damage distribution of the earthquake is found, so the relationship of the abnormal distribution with tectonics, site condition and basin are analyzed. In this paper, the influence on the ground motion generated by earthquake source and the underground structures near source also are studied. The influence on seismic zonation, anti-earthquake design, earthquake prediction and earthquake emergency responding produced by the abnormal density distribution are discussed.

Earthquakes, November-December 1977

Science.gov (United States)

Person, W.J.

1978-01-01

Two major earthquakes occurred in the last 2 months of the year. A magnitude 7.0 earthquake struck San Juan Province, Argentina, on November 23, causing fatalities and damage. The second major earthquake was a magnitude 7.0 in the Bonin Islands region, an unpopulated area. On December 19, Iran experienced a destructive earthquake, which killed over 500.

Earthquake Triggering in the September 2017 Mexican Earthquake Sequence

Science.gov (United States)

Fielding, E. J.; Gombert, B.; Duputel, Z.; Huang, M. H.; Liang, C.; Bekaert, D. P.; Moore, A. W.; Liu, Z.; Ampuero, J. P.

2017-12-01

Southern Mexico was struck by four earthquakes with Mw > 6 and numerous smaller earthquakes in September 2017, starting with the 8 September Mw 8.2 Tehuantepec earthquake beneath the Gulf of Tehuantepec offshore Chiapas and Oaxaca. We study whether this M8.2 earthquake triggered the three subsequent large M>6 quakes in southern Mexico to improve understanding of earthquake interactions and time-dependent risk. All four large earthquakes were extensional despite the the subduction of the Cocos plate. The traditional definition of aftershocks: likely an aftershock if it occurs within two rupture lengths of the main shock soon afterwards. Two Mw 6.1 earthquakes, one half an hour after the M8.2 beneath the Tehuantepec gulf and one on 23 September near Ixtepec in Oaxaca, both fit as traditional aftershocks, within 200 km of the main rupture. The 19 September Mw 7.1 Puebla earthquake was 600 km away from the M8.2 shock, outside the standard aftershock zone. Geodetic measurements from interferometric analysis of synthetic aperture radar (InSAR) and time-series analysis of GPS station data constrain finite fault total slip models for the M8.2, M7.1, and M6.1 Ixtepec earthquakes. The early M6.1 aftershock was too close in time and space to the M8.2 to measure with InSAR or GPS. We analyzed InSAR data from Copernicus Sentinel-1A and -1B satellites and JAXA ALOS-2 satellite. Our preliminary geodetic slip model for the M8.2 quake shows significant slip extended > 150 km NW from the hypocenter, longer than slip in the v1 finite-fault model (FFM) from teleseismic waveforms posted by G. Hayes at USGS NEIC. Our slip model for the M7.1 earthquake is similar to the v2 NEIC FFM. Interferograms for the M6.1 Ixtepec quake confirm the shallow depth in the upper-plate crust and show centroid is about 30 km SW of the NEIC epicenter, a significant NEIC location bias, but consistent with cluster relocations (E. Bergman, pers. comm.) and with Mexican SSN location. Coulomb static stress

Evidence for strong Holocene earthquake(s) in the Wabash Valley seismic zone

International Nuclear Information System (INIS)

Obermeier, S.

1991-01-01

Many small and slightly damaging earthquakes have taken place in the region of the lower Wabash River Valley of Indiana and Illinois during the 200 years of historic record. Seismologists have long suspected the Wabash Valley seismic zone to be capable of producing earthquakes much stronger than the largest of record (m b 5.8). The seismic zone contains the poorly defined Wabash Valley fault zone and also appears to contain other vaguely defined faults at depths from which the strongest earthquakes presently originate. Faults near the surface are generally covered with thick alluvium in lowlands and a veneer of loess in uplands, which make direct observations of faults difficult. Partly because of this difficulty, a search for paleoliquefaction features was begun in 1990. Conclusions of the study are as follows: (1) an earthquake much stronger than any historic earthquake struck the lower Wabash Valley between 1,500 and 7,500 years ago; (2) the epicentral region of the prehistoric strong earthquake was the Wabash Valley seismic zone; (3) apparent sites have been located where 1811-12 earthquake accelerations can be bracketed

Spectrum of breast cancer in Asian women.

Science.gov (United States)

Agarwal, Gaurav; Pradeep, P V; Aggarwal, Vivek; Yip, Cheng-Har; Cheung, Polly S Y

2007-05-01

Breast cancer is the leading cause of cancer-related deaths in Asia, and in recent years is emerging as the commonest female malignancy in the developing Asian countries, overtaking cancer of the uterine cervix. There have been no studies objectively comparing data and facts relating to breast cancer in the developed, newly developed, and developing Asian countries thus far. This multi-national collaborative study retrospectively compared the demographic, clinical, pathological and outcomes data in breast cancer patients managed at participating breast cancer centers in India, Malaysia and Hong Kong. Data, including those on the availability of breast screening, treatment facilities and outcomes from other major cancer centers and cancer registries of these countries and from other Asian countries were also reviewed. Despite an increasing trend, the incidence of breast cancer is lower, yet the cause-specific mortality is significantly higher in developing Asian countries compared with developed countries in Asia and the rest of the world. Patients are about one decade younger in developing countries than their counterparts in developed nations. The proportions of young patients (women and the clinical picture are different from those of average patients managed elsewhere in the world. Owing to lack of awareness, lack of funding, lack of infrastructure, and low priority in public health schemes, breast cancer screening and early detection have not caught up in these under-privileged societies. The inadequacies of health care infrastructures and standards, sociocultural barriers, economic realities, illiteracy, and the differences in the clinical and pathological attributes of this disease in Asian women compared with the rest of the world together result in a different spectrum of the disease. Better socioeconomic conditions, health awareness, and availability of breast cancer screening in developed Asian countries seem to be the major causes of a favorable clinical

NATURAL HAZARD ASSESSMENT OF SW MYANMAR - A CONTRIBUTION OF REMOTE SENSING AND GIS METHODS TO THE DETECTION OF AREAS VULNERABLE TO EARTHQUAKES AND TSUNAMI / CYCLONE FLOODING

Directory of Open Access Journals (Sweden)

George Pararas-Carayannis

2009-01-01

Full Text Available Myanmar, formerly Burma, is vulnerable to several natural hazards, such as earthquakes, cyclones, floods, tsunamis and landslides. The present study focuses on geomorphologic and geologic investigations of the south-western region of the country, based on satellite data (Shuttle Radar Topography Mission-SRTM, MODIS and LANDSAT. The main objective is to detect areas vulnerable to inundation by tsunami waves and cyclone surges. Since the region is also vulnerable to earthquake hazards, it is also important to identify seismotectonic patterns, the location of major active faults, and local site conditions that may enhance ground motions and earthquake intensities. As illustrated by this study, linear, topographic features related to subsurface tectonic features become clearly visible on SRTM-derived morphometric maps and on LANDSAT imagery. The GIS integrated evaluation of LANDSAT and SRTM data helps identify areas most susceptible to flooding and inundation by tsunamis and storm surges. Additionally, land elevation maps help identify sites greater than 10 m in elevation height, that would be suitable for the building of protective tsunami/cyclone shelters.

Structural factors controlling inter-plate coupling and earthquake rupture process

Science.gov (United States)

Kodaira, S.

2007-05-01

Recent availability of a large number of ocean bottom seismographs (OBSs), a large volume of air-gun array and a long streamer cable for academics provide several new findings of lithospheric scale structures in subduction seismogenic zones. JAMSTEC has acquired long-offset seismic data using a super-densely deploy OBS (i.e. 1 - 5 km spacing OBSs along 100 - 500 km long profiles) in the Nankai seismogeinc zone, SW. Japan, since 1999. Long-offset multichannel seismic (MCS) data by a two-ship experiment, as well as conventional 2D MCS data, have been also acquired at a part of the profiles. Some of those profiles have been designed as combined onshore - offshore profiles for imaging a land-ocean transition zone. One of the most striking findings is an image of several scales of subducted seamounts/ridges in the Nankai trough seismogenic zone. We detected the subducted seamount/ridges, which are 50 - 100 km wide, distributing from near trough axis to ~ 40 km deep beneath the Japanese island. From a point of seismogenic process, an important aspect is that those structures are strongly correlated with slip zones of magnitude 8-class earthquakes, i.e.; subducted seamounts/ridge control the rupture propagations. Moreover, the most recent seismic study crossing the segmentation boundary between M=8 class earthquakes detected a high seismic velocity body forming a strongly coupled patch at the segmentation boundary. The numerical simulation incorporating all those structures explained the historic rupture patterns, and shows the occurrence of a giant earthquake along the entire Nankai trough, a distance of over 600 km long (Mw=8.7). The growth processes of a rupture revealed from the simulation are; 1) prior to the giant earthquake, a small slow event (or earthquake) occurs near the segmentation boundary, 2) this accelerates a very slow slip (slower than the plate convergent rate), at the strong patch, which reduces a degree of coupling, 3) then a rupture easily propagates

The 1985 central chile earthquake: a repeat of previous great earthquakes in the region?

Science.gov (United States)

Comte, D; Eisenberg, A; Lorca, E; Pardo, M; Ponce, L; Saragoni, R; Singh, S K; Suárez, G

1986-07-25

A great earthquake (surface-wave magnitude, 7.8) occurred along the coast of central Chile on 3 March 1985, causing heavy damage to coastal towns. Intense foreshock activity near the epicenter of the main shock occurred for 11 days before the earthquake. The aftershocks of the 1985 earthquake define a rupture area of 170 by 110 square kilometers. The earthquake was forecast on the basis of the nearly constant repeat time (83 +/- 9 years) of great earthquakes in this region. An analysis of previous earthquakes suggests that the rupture lengths of great shocks in the region vary by a factor of about 3. The nearly constant repeat time and variable rupture lengths cannot be reconciled with time- or slip-predictable models of earthquake recurrence. The great earthquakes in the region seem to involve a variable rupture mode and yet, for unknown reasons, remain periodic. Historical data suggest that the region south of the 1985 rupture zone should now be considered a gap of high seismic potential that may rupture in a great earthquake in the next few tens of years.

A comparison of classical and intelligent methods to detect potential thermal anomalies before the 11 August 2012 Varzeghan, Iran, earthquake (Mw = 6.4)

Science.gov (United States)

Akhoondzadeh, M.

2013-04-01

In this paper, a number of classical and intelligent methods, including interquartile, autoregressive integrated moving average (ARIMA), artificial neural network (ANN) and support vector machine (SVM), have been proposed to quantify potential thermal anomalies around the time of the 11 August 2012 Varzeghan, Iran, earthquake (Mw = 6.4). The duration of the data set, which is comprised of Aqua-MODIS land surface temperature (LST) night-time snapshot images, is 62 days. In order to quantify variations of LST data obtained from satellite images, the air temperature (AT) data derived from the meteorological station close to the earthquake epicenter has been taken into account. For the models examined here, results indicate the following: (i) ARIMA models, which are the most widely used in the time series community for short-term forecasting, are quickly and easily implemented, and can efficiently act through linear solutions. (ii) A multilayer perceptron (MLP) feed-forward neural network can be a suitable non-parametric method to detect the anomalous changes of a non-linear time series such as variations of LST. (iii) Since SVMs are often used due to their many advantages for classification and regression tasks, it can be shown that, if the difference between the predicted value using the SVM method and the observed value exceeds the pre-defined threshold value, then the observed value could be regarded as an anomaly. (iv) ANN and SVM methods could be powerful tools in modeling complex phenomena such as earthquake precursor time series where we may not know what the underlying data generating process is. There is good agreement in the results obtained from the different methods for quantifying potential anomalies in a given LST time series. This paper indicates that the detection of the potential thermal anomalies derive credibility from the overall efficiencies and potentialities of the four integrated methods.

Revisiting Slow Slip Events Occurrence in Boso Peninsula, Japan, Combining GPS Data and Repeating Earthquakes Analysis

Science.gov (United States)

Gardonio, B.; Marsan, D.; Socquet, A.; Bouchon, M.; Jara, J.; Sun, Q.; Cotte, N.; Campillo, M.

2018-02-01

Slow slip events (SSEs) regularly occur near the Boso Peninsula, central Japan. Their time of recurrence has been decreasing from 6.4 to 2.2 years from 1996 to 2014. It is important to better constrain the slip history of this area, especially as models show that the recurrence intervals could become shorter prior to the occurrence of a large interplate earthquake nearby. We analyze the seismic waveforms of more than 2,900 events (M≥1.0) taking place in the Boso Peninsula, Japan, from 1 April 2004 to 4 November 2015, calculating the correlation and the coherence between each pair of events in order to define groups of repeating earthquakes. The cumulative number of repeating earthquakes suggests the existence of two slow slip events that have escaped detection so far. Small transient displacements observed in the time series of nearby GPS stations confirm these results. The detection scheme coupling repeating earthquakes and GPS analysis allow to detect small SSEs that were not seen before by classical methods. This work brings new information on the diversity of SSEs and demonstrates that the SSEs in Boso area present a more complex history than previously considered.

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.

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.

Precursory changes in seismic velocity for the spectrum of earthquake failure modes

Science.gov (United States)

Scuderi, M.M.; Marone, C.; Tinti, E.; Di Stefano, G.; Collettini, C.

2016-01-01

Temporal changes in seismic velocity during the earthquake cycle have the potential to illuminate physical processes associated with fault weakening and connections between the range of fault slip behaviors including slow earthquakes, tremor and low frequency earthquakes1. Laboratory and theoretical studies predict changes in seismic velocity prior to earthquake failure2, however tectonic faults fail in a spectrum of modes and little is known about precursors for those modes3. Here we show that precursory changes of wave speed occur in laboratory faults for the complete spectrum of failure modes observed for tectonic faults. We systematically altered the stiffness of the loading system to reproduce the transition from slow to fast stick-slip and monitored ultrasonic wave speed during frictional sliding. We find systematic variations of elastic properties during the seismic cycle for both slow and fast earthquakes indicating similar physical mechanisms during rupture nucleation. Our data show that accelerated fault creep causes reduction of seismic velocity and elastic moduli during the preparatory phase preceding failure, which suggests that real time monitoring of active faults may be a means to detect earthquake precursors. PMID:27597879

Using Dynamic Fourier Analysis to Discriminate Between Seismic Signals from Natural Earthquakes and Mining Explosions

Directory of Open Access Journals (Sweden)

Maria C. Mariani

2017-08-01

Full Text Available A sequence of intraplate earthquakes occurred in Arizona at the same location where miningexplosions were carried out in previous years. The explosions and some of the earthquakes generatedvery similar seismic signals. In this study Dynamic Fourier Analysis is used for discriminating signalsoriginating from natural earthquakes and mining explosions. Frequency analysis of seismogramsrecorded at regional distances shows that compared with the mining explosions the earthquake signalshave larger amplitudes in the frequency interval ~ 6 to 8 Hz and significantly smaller amplitudes inthe frequency interval ~ 2 to 4 Hz. This type of analysis permits identifying characteristics in theseismograms frequency yielding to detect potentially risky seismic events.

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...

Earthquake hazard evaluation for Switzerland

International Nuclear Information System (INIS)

Ruettener, E.

1995-01-01

Earthquake hazard analysis is of considerable importance for Switzerland, a country with moderate seismic activity but high economic values at risk. The evaluation of earthquake hazard, i.e. the determination of return periods versus ground motion parameters, requires a description of earthquake occurrences in space and time. In this study the seismic hazard for major cities in Switzerland is determined. The seismic hazard analysis is based on historic earthquake records as well as instrumental data. The historic earthquake data show considerable uncertainties concerning epicenter location and epicentral intensity. A specific concept is required, therefore, which permits the description of the uncertainties of each individual earthquake. This is achieved by probability distributions for earthquake size and location. Historical considerations, which indicate changes in public earthquake awareness at various times (mainly due to large historical earthquakes), as well as statistical tests have been used to identify time periods of complete earthquake reporting as a function of intensity. As a result, the catalog is judged to be complete since 1878 for all earthquakes with epicentral intensities greater than IV, since 1750 for intensities greater than VI, since 1600 for intensities greater than VIII, and since 1300 for intensities greater than IX. Instrumental data provide accurate information about the depth distribution of earthquakes in Switzerland. In the Alps, focal depths are restricted to the uppermost 15 km of the crust, whereas below the northern Alpine foreland earthquakes are distributed throughout the entire crust (30 km). This depth distribution is considered in the final hazard analysis by probability distributions. (author) figs., tabs., refs

Earthquake Clusters and Spatio-temporal Migration of earthquakes in Northeastern Tibetan Plateau: a Finite Element Modeling

Science.gov (United States)

Sun, Y.; Luo, G.

2017-12-01

Seismicity in a region is usually characterized by earthquake clusters and earthquake migration along its major fault zones. However, we do not fully understand why and how earthquake clusters and spatio-temporal migration of earthquakes occur. The northeastern Tibetan Plateau is a good example for us to investigate these problems. In this study, we construct and use a three-dimensional viscoelastoplastic finite-element model to simulate earthquake cycles and spatio-temporal migration of earthquakes along major fault zones in northeastern Tibetan Plateau. We calculate stress evolution and fault interactions, and explore effects of topographic loading and viscosity of middle-lower crust and upper mantle on model results. Model results show that earthquakes and fault interactions increase Coulomb stress on the neighboring faults or segments, accelerating the future earthquakes in this region. Thus, earthquakes occur sequentially in a short time, leading to regional earthquake clusters. Through long-term evolution, stresses on some seismogenic faults, which are far apart, may almost simultaneously reach the critical state of fault failure, probably also leading to regional earthquake clusters and earthquake migration. Based on our model synthetic seismic catalog and paleoseismic data, we analyze probability of earthquake migration between major faults in northeastern Tibetan Plateau. We find that following the 1920 M 8.5 Haiyuan earthquake and the 1927 M 8.0 Gulang earthquake, the next big event (M≥7) in northeastern Tibetan Plateau would be most likely to occur on the Haiyuan fault.

SalanderMaps: A rapid overview about felt earthquakes through data mining of web-accesses

Science.gov (United States)

Kradolfer, Urs

2013-04-01

While seismological observatories detect and locate earthquakes based on measurements of the ground motion, they neither know a priori whether an earthquake has been felt by the public nor is it known, where it has been felt. Such information is usually gathered by evaluating feedback reported by the public through on-line forms on the web. However, after a felt earthquake in Switzerland, many people visit the webpages of the Swiss Seismological Service (SED) at the ETH Zurich and each such visit leaves traces in the logfiles on our web-servers. Data mining techniques, applied to these logfiles and mining publicly available data bases on the internet open possibilities to obtain previously unknown information about our virtual visitors. In order to provide precise information to authorities and the media, it would be desirable to rapidly know from which locations these web-accesses origin. The method 'Salander' (Seismic Activitiy Linked to Area codes - Nimble Detection of Earthquake Rumbles) will be introduced and it will be explained, how the IP-addresses (each computer or router directly connected to the internet has a unique IP-address; an example would be 129.132.53.5) of a sufficient amount of our virtual visitors were linked to their geographical area. This allows us to unprecedentedly quickly know whether and where an earthquake was felt in Switzerland. It will also be explained, why the method Salander is superior to commercial so-called geolocation products. The corresponding products of the Salander method, animated SalanderMaps, which are routinely generated after each earthquake with a magnitude of M>2 in Switzerland (http://www.seismo.ethz.ch/prod/salandermaps/, available after March 2013), demonstrate how the wavefield of earthquakes propagates through Switzerland and where it was felt. Often, such information is available within less than 60 seconds after origin time, and we always get a clear picture within already five minutes after origin time

Perception of earthquake risk in Taiwan: effects of gender and past earthquake experience.

Science.gov (United States)

Kung, Yi-Wen; Chen, Sue-Huei

2012-09-01

This study explored how individuals in Taiwan perceive the risk of earthquake and the relationship of past earthquake experience and gender to risk perception. Participants (n= 1,405), including earthquake survivors and those in the general population without prior direct earthquake exposure, were selected and interviewed through a computer-assisted telephone interviewing procedure using a random sampling and stratification method covering all 24 regions of Taiwan. A factor analysis of the interview data yielded a two-factor structure of risk perception in regard to earthquake. The first factor, "personal impact," encompassed perception of threat and fear related to earthquakes. The second factor, "controllability," encompassed a sense of efficacy of self-protection in regard to earthquakes. The findings indicated prior earthquake survivors and females reported higher scores on the personal impact factor than males and those with no prior direct earthquake experience, although there were no group differences on the controllability factor. The findings support that risk perception has multiple components, and suggest that past experience (survivor status) and gender (female) affect the perception of risk. Exploration of potential contributions of other demographic factors such as age, education, and marital status to personal impact, especially for females and survivors, is discussed. Future research on and intervention program with regard to risk perception are suggested accordingly. © 2012 Society for Risk Analysis.

Localizing Submarine Earthquakes by Listening to the Water Reverberations

Science.gov (United States)

Castillo, J.; Zhan, Z.; Wu, W.

2017-12-01

Mid-Ocean Ridge (MOR) earthquakes generally occur far from any land based station and are of moderate magnitude, making it complicated to detect and in most cases, locate accurately. This limits our understanding of how MOR normal and transform faults move and the manner in which they slip. Different from continental events, seismic records from earthquakes occurring beneath the ocean floor show complex reverberations caused by P-wave energy trapped in the water column that are highly dependent of the source location and the efficiency to which energy propagated to the near-source surface. These later arrivals are commonly considered to be only a nuisance as they might sometimes interfere with the primary arrivals. However, in this study, we take advantage of the wavefield's high sensitivity to small changes in the seafloor topography and the present-day availability of worldwide multi-beam bathymetry to relocate submarine earthquakes by modeling these water column reverberations in teleseismic signals. Using a three-dimensional hybrid method for modeling body wave arrivals, we demonstrate that an accurate hypocentral location of a submarine earthquake (<5 km) can be achieved if the structural complexities near the source region are appropriately accounted for. This presents a novel way of studying earthquake source properties and will serve as a means to explore the influence of physical fault structure on the seismic behavior of transform faults.

Support vector machines for TEC seismo-ionospheric anomalies detection

Directory of Open Access Journals (Sweden)

M. Akhoondzadeh

2013-02-01

Full Text Available Using time series prediction methods, it is possible to pursue the behaviors of earthquake precursors in the future and to announce early warnings when the differences between the predicted value and the observed value exceed the predefined threshold value. Support Vector Machines (SVMs are widely used due to their many advantages for classification and regression tasks. This study is concerned with investigating the Total Electron Content (TEC time series by using a SVM to detect seismo-ionospheric anomalous variations induced by the three powerful earthquakes of Tohoku (11 March 2011, Haiti (12 January 2010 and Samoa (29 September 2009. The duration of TEC time series dataset is 49, 46 and 71 days, for Tohoku, Haiti and Samoa earthquakes, respectively, with each at time resolution of 2 h. In the case of Tohoku earthquake, the results show that the difference between the predicted value obtained from the SVM method and the observed value reaches the maximum value (i.e., 129.31 TECU at earthquake time in a period of high geomagnetic activities. The SVM method detected a considerable number of anomalous occurrences 1 and 2 days prior to the Haiti earthquake and also 1 and 5 days before the Samoa earthquake in a period of low geomagnetic activities. In order to show that the method is acting sensibly with regard to the results extracted during nonevent and event TEC data, i.e., to perform some null-hypothesis tests in which the methods would also be calibrated, the same period of data from the previous year of the Samoa earthquake date has been taken into the account. Further to this, in this study, the detected TEC anomalies using the SVM method were compared to the previous results (Akhoondzadeh and Saradjian, 2011; Akhoondzadeh, 2012 obtained from the mean, median, wavelet and Kalman filter methods. The SVM detected anomalies are similar to those detected using the previous methods. It can be concluded that SVM can be a suitable learning method

The earthquake problem in engineering design: generating earthquake design basis information

International Nuclear Information System (INIS)

Sharma, R.D.

1987-01-01

Designing earthquake resistant structures requires certain design inputs specific to the seismotectonic status of the region, in which a critical facility is to be located. Generating these inputs requires collection of earthquake related information using present day techniques in seismology and geology, and processing the collected information to integrate it to arrive at a consolidated picture of the seismotectonics of the region. The earthquake problem in engineering design has been outlined in the context of a seismic design of nuclear power plants vis a vis current state of the art techniques. The extent to which the accepted procedures of assessing seismic risk in the region and generating the design inputs have been adherred to determine to a great extent the safety of the structures against future earthquakes. The document is a step towards developing an aproach for generating these inputs, which form the earthquake design basis. (author)

Gas injection may have triggered earthquakes in the Cogdell oil field, Texas.

Science.gov (United States)

Gan, Wei; Frohlich, Cliff

2013-11-19

Between 1957 and 1982, water flooding was conducted to improve petroleum production in the Cogdell oil field north of Snyder, TX, and a contemporary analysis concluded this induced earthquakes that occurred between 1975 and 1982. The National Earthquake Information Center detected no further activity between 1983 and 2005, but between 2006 and 2011 reported 18 earthquakes having magnitudes 3 and greater. To investigate these earthquakes, we analyzed data recorded by six temporary seismograph stations deployed by the USArray program, and identified 93 well-recorded earthquakes occurring between March 2009 and December 2010. Relocation with a double-difference method shows that most earthquakes occurred within several northeast-southwest-trending linear clusters, with trends corresponding to nodal planes of regional focal mechanisms, possibly indicating the presence of previously unidentified faults. We have evaluated data concerning injection and extraction of oil, water, and gas in the Cogdell field. Water injection cannot explain the 2006-2011 earthquakes, especially as net volumes (injection minus extraction) are significantly less than in the 1957-1982 period. However, since 2004 significant volumes of gases including supercritical CO2 have been injected into the Cogdell field. The timing of gas injection suggests it may have contributed to triggering the recent seismic activity. If so, this represents an instance where gas injection has triggered earthquakes having magnitudes 3 and larger. Further modeling studies may help evaluate recent assertions suggesting significant risks accompany large-scale carbon capture and storage as a strategy for managing climate change.

Building Damage Extraction Triggered by Earthquake Using the Uav Imagery

Science.gov (United States)

Li, S.; Tang, H.

2018-04-01

When extracting building damage information, we can only determine whether the building is collapsed using the post-earthquake satellite images. Even the satellite images have the sub-meter resolution, the identification of slightly damaged buildings is still a challenge. As the complementary data to satellite images, the UAV images have unique advantages, such as stronger flexibility and higher resolution. In this paper, according to the spectral feature of UAV images and the morphological feature of the reconstructed point clouds, the building damage was classified into four levels: basically intact buildings, slightly damaged buildings, partially collapsed buildings and totally collapsed buildings, and give the rules of damage grades. In particular, the slightly damaged buildings are determined using the detected roof-holes. In order to verify the approach, we conduct experimental simulations in the cases of Wenchuan and Ya'an earthquakes. By analyzing the post-earthquake UAV images of the two earthquakes, the building damage was classified into four levels, and the quantitative statistics of the damaged buildings is given in the experiments.

Osteoporosis and Asian American Women

Science.gov (United States)

... and Asian American Women Osteoporosis and Asian American Women Asian American women are at high risk for ... medications. Are There Any Special Issues for Asian Women Regarding Bone Health? Recent studies indicate a number ...

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.

Reactivation of slow-moving landslides by earthquakes, kinematics measurements and mechanical implications

Science.gov (United States)

Lacroix, Pascal; Perfettini, Hugo; Berthier, Etienne; Taipe, Edu; Guillier, Bertrand

2015-04-01

Major earthquakes in mountainous areas often trigger landslides. The impact of earthquakes on slow-moving landslides is however not well constrained due to few co-seismic measurements of landslide motion. We document the first time-series of a landslide reactivation by an earthquake (Mw6.0, distance 20 km), using continuous GPS measurements over the Maca landslide (Peru). Our survey shows a coseismic response of the landslide of about 2 cm, followed by a relaxation period of 5 weeks during which postseismic slip is three times greater than the coseismic displacement itself. Our results confirm the coseismic activation of landslides and provide the first observation of a post seismic displacement. Finally, a multi-temporal survey using images from the very high resolution Pléiades optical satellite, allowed us to detect 9 active slow-moving landslides over the whole valley. Their pattern of motion show they have been reactivated by the same earthquake. We analyze this small but comprehensive database of landslides reactivated by the earthquake. We find that the landslide motion due to the earthquake is function of the shaking intensity, suggesting a friction at the basal interface dependent on the earthquake solicitation. These various observations are consistent with a mechanical model where slip on the landslide basal interface is governed by rate and state friction, analogous to the mechanics of creeping tectonic faults.

Earthquake Source Parameters Inferred from T-Wave Observations

Science.gov (United States)

Perrot, J.; Dziak, R.; Lau, T. A.; Matsumoto, H.; Goslin, J.

2004-12-01

The seismicity of the North Atlantic Ocean has been recorded by two networks of autonomous hydrophones moored within the SOFAR channel on the flanks of the Mid-Atlantic Ridge (MAR). In February 1999, a consortium of U.S. investigators (NSF and NOAA) deployed a 6-element hydrophone array for long-term monitoring of MAR seismicity between 15o-35oN south of the Azores. In May 2002, an international collaboration of French, Portuguese, and U.S. researchers deployed a 6-element hydrophone array north of the Azores Plateau from 40o-50oN. The northern network (referred to as SIRENA) was recovered in September 2003. The low attenuation properties of the SOFAR channel for earthquake T-wave propagation results in a detection threshold reduction from a magnitude completeness level (Mc) of ˜ 4.7 for MAR events recorded by the land-based seismic networks to Mc=3.0 using hydrophone arrays. Detailed focal depth and mechanism information, however, remain elusive due to the complexities of seismo-acoustic propagation paths. Nonetheless, recent analyses (Dziak, 2001; Park and Odom, 2001) indicate fault parameter information is contained within the T-wave signal packet. We investigate this relationship further by comparing an earthquake's T-wave duration and acoustic energy to seismic magnitude (NEIC) and radiation pattern (for events M>5) from the Harvard moment-tensor catalog. First results show earthquake energy is well represented by the acoustic energy of the T-waves, however T-wave codas are significantly influenced by acoustic propagation effects and do not allow a direct determination of the seismic magnitude of the earthquakes. Second, there appears to be a correlation between T-wave acoustic energy, azimuth from earthquake source to the hydrophone, and the radiation pattern of the earthquake's SH waves. These preliminary results indicate there is a relationship between the T-wave observations and earthquake source parameters, allowing for additional insights into T

Sun, Moon and Earthquakes

Science.gov (United States)

Kolvankar, V. G.

2013-12-01

During a study conducted to find the effect of Earth tides on the occurrence of earthquakes, for small areas [typically 1000km X1000km] of high-seismicity regions, it was noticed that the Sun's position in terms of universal time [GMT] shows links to the sum of EMD [longitude of earthquake location - longitude of Moon's foot print on earth] and SEM [Sun-Earth-Moon angle]. This paper provides the details of this relationship after studying earthquake data for over forty high-seismicity regions of the world. It was found that over 98% of the earthquakes for these different regions, examined for the period 1973-2008, show a direct relationship between the Sun's position [GMT] and [EMD+SEM]. As the time changes from 00-24 hours, the factor [EMD+SEM] changes through 360 degree, and plotting these two variables for earthquakes from different small regions reveals a simple 45 degree straight-line relationship between them. This relationship was tested for all earthquakes and earthquake sequences for magnitude 2.0 and above. This study conclusively proves how Sun and the Moon govern all earthquakes. Fig. 12 [A+B]. The left-hand figure provides a 24-hour plot for forty consecutive days including the main event (00:58:23 on 26.12.2004, Lat.+3.30, Long+95.980, Mb 9.0, EQ count 376). The right-hand figure provides an earthquake plot for (EMD+SEM) vs GMT timings for the same data. All the 376 events including the main event faithfully follow the straight-line curve.

Awareness and understanding of earthquake hazards at school

Science.gov (United States)

Saraò, Angela; Peruzza, Laura; Barnaba, Carla; Bragato, Pier Luigi

2014-05-01

selected students as communicators so that they can transfer simple educational messages on the seismic risk reduction to other students and/or to the whole community. The experiment is taking place in North East Italy, an area on which OGS detect earthquakes for seismological study and seismic alarm purposes. Teachers and students participating in the project are expected to present their achieved experience during a public event, at University of Udine (Italy).

The performance review of EEWS(Earthquake Early Warning System) about Gyeongju earthquakes with Ml 5.1 and Ml 5.8 in Korea

Science.gov (United States)

Park, Jung-Ho; Chi, Heon-Cheol; Lim, In-Seub; Seong, Yun-Jeong; Park, Jihwan

2017-04-01

EEW(Earthquake Early Warning) service to the public has been officially operated by KMA (Korea Meteorological Administration) from 2015 in Korea. For the KMA's official EEW service, KIGAM has adopted ElarmS from UC Berkeley BSL and modified local magnitude relation, 1-D travel time curves and association procedures with real time waveform from about 201 seismic stations of KMA, KIGAM, KINS and KEPRI. There were two moderate size earthquakes with magnitude Ml 5.1 and Ml 5.8 close to Gyeongju city located at the southeastern part of Korea on Sep. 12. 2016. We have checked the performance of EEWS(Earthquake Early Warning System) named as TrigDB by KIGAM reviewing of these two Gyeongju earthquakes. The nearest station to epicenters of two earthquakes Ml 5.1(35.7697 N, 129.1904 E) and Ml 5.8(35.7632 N, 129.1898 E) was MKL which detected P phases in about 2.1 and 3.6 seconds after the origin times respectively. The first events were issued in 6.3 and 7.0 seconds from each origin time. Because of the unstable results on the early steps due to very few stations and unexpected automated analysis, KMA has the policy to wait for more 20 seconds for confirming the reliability. For these events KMA published EEW alarms in about 26 seconds after origin times with M 5.3 and M 5.9 respectively.

Awareness and Use of South Asian Tobacco Products Among South Asians in New Jersey.

Science.gov (United States)

Hrywna, Mary; Jane Lewis, M; Mukherjea, Arnab; Banerjee, Smita C; Steinberg, Michael B; Delnevo, Cristine D

2016-12-01

South Asians are the third largest Asian group in the US and among the fastest growing racial groups in New Jersey. Tobacco consumption among South Asians is characterized by several smoked and smokeless tobacco products indigenous to the Indian subcontinent. However, there is a paucity of research on tobacco use behaviors among South Asians in the US. The goal of this study was to examine the awareness and use of South Asian tobacco products such as bidis, gutkha, paan, paan masala, and zarda as well as other potentially carcinogenic products such as supari, their context of use, and their cultural significance among South Asians living in the US. Eight focus groups were conducted with South Asian adults living in Central New Jersey. Overall, participants were aware of a wide variety of foreign and American tobacco products with older South Asians identifying a greater variety of indigenous products compared to younger South Asians. Hookah was consistently recognized as popular among the younger generation while products such as paan or paan masala were more commonly identified with elders. Use of tobacco-related products such as paan and supari were described as common at social gatherings or after meals. In addition, light or social users of South Asian tobacco products, including products not consistently defined as tobacco, may not report tobacco use on a survey. Better understanding of the use of these products among South Asians and how some may classify tobacco usage can inform future research and public health interventions in these communities.

Strategic rehabilitation of the earthquake affected microhydropower plants in Nepal

Science.gov (United States)

Baidar, B.; Koirala, R.; Neopane, H. P.; Shrestha, M. V.; Thapa, B.

2016-11-01

Most people in the rural areas of Nepal rely on Micro-hydro Power Plants (MHPs) for their energy sources. With around four decade experiences in design and development of MHPs, Nepalese techno-entrepreneurs have gained wider reputation in the South Asian region and the beyond. However with the lack of competences in developing Francis turbines, majority of the MHPs are equipped with either Pelton of Cross Flow turbine, even though Francis units are suitable. With the devastating earthquake of a 7.6 magnitude that struck in the Gorkha district on Saturday, 25 April 2015, about 76 km northwest of the capital city Kathmandu, and the aftershocks followed claimed more than 8000 lives. It did not leave hydropower plants either. Many big plants have been affected and hundreds of MHPs were damaged, needing short to long term rehabilitation. The preliminary assessment of the 61 affected MHPs in the 6 earthquake affected districts shows more than 50% sites are suitable for Francis turbine. Hence the strategic rehabilitation plan has been developed in the present paper for the affected plants considering issues like geographical shift, dislocation of people and also with the focus on replacing the old turbine with Francis turbine in the suitable sites. The similar strategy can also be implemented in other developing countries with such situations.

Prevalence and diversity of gastrointestinal helminths in free-ranging Asian house shrew (Suncus murinus) in Bangladesh.

Science.gov (United States)

Rahman, Mizanur; Islam, Shariful; Masuduzzaman, Md; Alam, Mahabub; Chawdhury, Mohammad Nizam Uddin; Ferdous, Jinnat; Islam, Md Nurul; Hassan, Mohammad Mahmudul; Hossain, Mohammad Alamgir; Islam, Ariful

2018-04-01

Asian house shrew ( Suncus murinus ), a widely distributed small mammal in the South Asian region, can carry helminths of zoonotic importance. The aim of the study was to know the prevalence and diversity of gastrointestinal (GI) helminths in free-ranging Asian house shrew ( S. murinus ) in Bangladesh. A total of 86 Asian house shrews were captured from forest areas and other habitats of Bangladesh in 2015. Gross examination of the whole GI tract was performed for gross helminth detection, and coproscopy was done for identification of specific eggs or larvae. The overall prevalence of GI helminth was 77.9% (67/86), with six species including nematodes (3), cestodes (2), and trematodes (1). Of the detected helminths, the dominant parasitic group was from the genus Hymenolepis spp.(59%), followed by Strongyloides spp.(17%), Capillaria spp. (10%), Physaloptera spp. (3%), and Echinostoma spp.(3%). The finding shows that the presence of potential zoonotic parasites (Hymenolepis spp. and Capillaria spp.) in Asian house shrew is ubiquitous in all types of habitat (forest land, cropland and dwelling) in Bangladesh. Therefore, further investigation is crucial to examine their role in the transmission of human helminthiasis.

Earthquake engineering development before and after the March 4, 1977, Vrancea, Romania earthquake

International Nuclear Information System (INIS)

Georgescu, E.-S.

2002-01-01

At 25 years since the of the Vrancea earthquake of March, 4th 1977, we can analyze in an open and critical way its impact on the evolution of earthquake engineering codes and protection policies in Romania. The earthquake (M G-R = 7.2; M w = 7.5), produced 1,570 casualties and more than 11,300 injured persons (90% of the victims in Bucharest), seismic losses were estimated at more then USD 2 billions. The 1977 earthquake represented a significant episode of XXth century in seismic zones of Romania and neighboring countries. The INCERC seismic record of March 4, 1977 put, for the first time, in evidence the spectral content of long period seismic motions of Vrancea earthquakes, the duration, the number of cycles and values of actual accelerations, with important effects of overloading upon flexible structures. The seismic coefficients k s , the spectral curve (the dynamic coefficient β r ) and the seismic zonation map, the requirements in the antiseismic design norms were drastically, changed while the microzonation maps of the time ceased to be used, and the specific Vrancea earthquake recurrence was reconsidered based on hazard studies Thus, the paper emphasises: - the existing engineering knowledge, earthquake code and zoning maps requirements until 1977 as well as seismology and structural lessons since 1977; - recent aspects of implementing of the Earthquake Code P.100/1992 and harmonization with Eurocodes, in conjunction with the specific of urban and rural seismic risk and enforcing policies on strengthening of existing buildings; - a strategic view of disaster prevention, using earthquake scenarios and loss assessments, insurance, earthquake education and training; - the need of a closer transfer of knowledge between seismologists, engineers and officials in charge with disaster prevention public policies. (author)

Differences in Characteristics and Outcomes Between Asian and Non-Asian Patients in the TIAregistry.org.

Science.gov (United States)

Hoshino, Takao; Uchiyama, Shinichiro; Wong, Lawrence K S; Sissani, Leila; Albers, Gregory W; Bornstein, Natan M; Caplan, Louis R; Donnan, Geoffrey A; Ferro, José M; Hennerici, Michael G; Labreuche, Julien; Lavallée, Philippa C; Molina, Carlos; Rothwell, Peter M; Steg, Philippe Gabriel; Touboul, Pierre-Jean; Vicaut, Éric; Amarenco, Pierre

2017-07-01

This study provides the contemporary causes and prognosis of transient ischemic attack (TIA) and minor stroke in Asians and the direct comparisons with non-Asians. The TIAregistry.org enrolled 4789 patients (1149 Asians and 3640 non-Asians) with a TIA or minor ischemic stroke within 7 days of onset. Every participating facility had systems dedicated to urgent intervention of TIA/stroke patients by specialists. The primary outcome was a composite of cardiovascular death, nonfatal stroke, and nonfatal acute coronary syndrome. Approximately 80% of patients were evaluated within 24 hours of symptom onset. At 1 year, there were no differences in the rates of composite cardiovascular events (6.8% versus 6.0%; P =0.38) and stroke (6.0% versus 4.8%; P =0.11) between Asians and non-Asians. Asians had a lower risk of cerebrovascular disease (stroke or TIA) than non-Asians (adjusted hazard ratio, 0.79; 95% confidence interval, 0.63-0.98; P =0.03); the difference was primarily driven by a lower rate of TIA in Asians (4.2% versus 8.3%; P <0.001). Moderately severe bleeding was more frequent in Asians (0.8% versus 0.3%; P =0.02). In multivariable analysis, multiple acute infarcts ( P =0.005) and alcohol consumption ( P =0.02) were independent predictors of stroke recurrence in Asians, whereas intracranial stenosis ( P <0.001), ABCD 2 score ( P <0.001), atrial fibrillation ( P =0.008), extracranial stenosis ( P =0.03), and previous stroke or TIA ( P =0.03) were independent predictors in non-Asians. The short-term stroke risk after a TIA or minor stroke was lower than expected when urgent evidence-based care was delivered, irrespective of race/ethnicity or region. However, the predictors of stroke were different for Asians and non-Asians. © 2017 American Heart Association, Inc.

The music of earthquakes and Earthquake Quartet #1

Science.gov (United States)

Michael, Andrew J.

2013-01-01

Earthquake Quartet #1, my composition for voice, trombone, cello, and seismograms, is the intersection of listening to earthquakes as a seismologist and performing music as a trombonist. Along the way, I realized there is a close relationship between what I do as a scientist and what I do as a musician. A musician controls the source of the sound and the path it travels through their instrument in order to make sound waves that we hear as music. An earthquake is the source of waves that travel along a path through the earth until reaching us as shaking. It is almost as if the earth is a musician and people, including seismologists, are metaphorically listening and trying to understand what the music means.

Observations of an ionospheric perturbation arising from the Coalinga earthquake of May 2, 1983

International Nuclear Information System (INIS)

Wolcott, J.H.; Simons, D.J.; Lee, D.D.; Nelson, R.A.

1984-01-01

An ionospheric perturbation that was produced by the Coalinga earthquake of May 2, 1983, was detected by a network of high-frequency radio links in northern California. The ionospheric refraction regions of all five HF propagation paths, at distances between 160 and 285 km (horizontal range) from the epicenter, were affected by a ground-motion-induced acoustic pulse that propagated to ionospheric heights. The acoustic pulse was produced by the earthquake-induced seismic waves rather than the vertical ground motion above the epicenter. These observations appear to be the first ionospheric disturbances to be reported this close to an earthquake epicenter

Feasibility study of earthquake early warning (EEW) in Hawaii

Science.gov (United States)

Thelen, Weston A.; Hotovec-Ellis, Alicia J.; Bodin, Paul

2016-09-30

The effects of earthquake shaking on the population and infrastructure across the State of Hawaii could be catastrophic, and the high seismic hazard in the region emphasizes the likelihood of such an event. Earthquake early warning (EEW) has the potential to give several seconds of warning before strong shaking starts, and thus reduce loss of life and damage to property. The two approaches to EEW are (1) a network approach (such as ShakeAlert or ElarmS) where the regional seismic network is used to detect the earthquake and distribute the alarm and (2) a local approach where a critical facility has a single seismometer (or small array) and a warning system on the premises.The network approach, also referred to here as ShakeAlert or ElarmS, uses the closest stations within a regional seismic network to detect and characterize an earthquake. Most parameters used for a network approach require observations on multiple stations (typically 3 or 4), which slows down the alarm time slightly, but the alarms are generally more reliable than with single-station EEW approaches. The network approach also benefits from having stations closer to the source of any potentially damaging earthquake, so that alarms can be sent ahead to anyone who subscribes to receive the notification. Thus, a fully implemented ShakeAlert system can provide seconds of warning for both critical facilities and general populations ahead of damaging earthquake shaking.The cost to implement and maintain a fully operational ShakeAlert system is high compared to a local approach or single-station solution, but the benefits of a ShakeAlert system would be felt statewide—the warning times for strong shaking are potentially longer for most sources at most locations.The local approach, referred to herein as “single station,” uses measurements from a single seismometer to assess whether strong earthquake shaking can be expected. Because of the reliance on a single station, false alarms are more common than

Toward real-time regional earthquake simulation of Taiwan earthquakes

Science.gov (United States)

Lee, S.; Liu, Q.; Tromp, J.; Komatitsch, D.; Liang, W.; Huang, B.

2013-12-01

We developed a Real-time Online earthquake Simulation system (ROS) to simulate regional earthquakes in Taiwan. The ROS uses a centroid moment tensor solution of seismic events from a Real-time Moment Tensor monitoring system (RMT), which provides all the point source parameters including the event origin time, hypocentral location, moment magnitude and focal mechanism within 2 minutes after the occurrence of an earthquake. Then, all of the source parameters are automatically forwarded to the ROS to perform an earthquake simulation, which is based on a spectral-element method (SEM). We have improved SEM mesh quality by introducing a thin high-resolution mesh layer near the surface to accommodate steep and rapidly varying topography. The mesh for the shallow sedimentary basin is adjusted to reflect its complex geometry and sharp lateral velocity contrasts. The grid resolution at the surface is about 545 m, which is sufficient to resolve topography and tomography data for simulations accurate up to 1.0 Hz. The ROS is also an infrastructural service, making online earthquake simulation feasible. Users can conduct their own earthquake simulation by providing a set of source parameters through the ROS webpage. For visualization, a ShakeMovie and ShakeMap are produced during the simulation. The time needed for one event is roughly 3 minutes for a 70 sec ground motion simulation. The ROS is operated online at the Institute of Earth Sciences, Academia Sinica (http://ros.earth.sinica.edu.tw/). Our long-term goal for the ROS system is to contribute to public earth science outreach and to realize seismic ground motion prediction in real-time.

Latitude-Time Total Electron Content Anomalies as Precursors to Japan's Large Earthquakes Associated with Principal Component Analysis

Directory of Open Access Journals (Sweden)

Jyh-Woei Lin

2011-01-01

Full Text Available The goal of this study is to determine whether principal component analysis (PCA can be used to process latitude-time ionospheric TEC data on a monthly basis to identify earthquake associated TEC anomalies. PCA is applied to latitude-time (mean-of-a-month ionospheric total electron content (TEC records collected from the Japan GEONET network to detect TEC anomalies associated with 18 earthquakes in Japan (M≥6.0 from 2000 to 2005. According to the results, PCA was able to discriminate clear TEC anomalies in the months when all 18 earthquakes occurred. After reviewing months when no M≥6.0 earthquakes occurred but geomagnetic storm activity was present, it is possible that the maximal principal eigenvalues PCA returned for these 18 earthquakes indicate earthquake associated TEC anomalies. Previously PCA has been used to discriminate earthquake-associated TEC anomalies recognized by other researchers, who found that statistical association between large earthquakes and TEC anomalies could be established in the 5 days before earthquake nucleation; however, since PCA uses the characteristics of principal eigenvalues to determine earthquake related TEC anomalies, it is possible to show that such anomalies existed earlier than this 5-day statistical window.

Geophysical Anomalies and Earthquake Prediction

Science.gov (United States)

Jackson, D. D.

2008-12-01

Finding anomalies is easy. Predicting earthquakes convincingly from such anomalies is far from easy. Why? Why have so many beautiful geophysical abnormalities not led to successful prediction strategies? What is earthquake prediction? By my definition it is convincing information that an earthquake of specified size is temporarily much more likely than usual in a specific region for a specified time interval. We know a lot about normal earthquake behavior, including locations where earthquake rates are higher than elsewhere, with estimable rates and size distributions. We know that earthquakes have power law size distributions over large areas, that they cluster in time and space, and that aftershocks follow with power-law dependence on time. These relationships justify prudent protective measures and scientific investigation. Earthquake prediction would justify exceptional temporary measures well beyond those normal prudent actions. Convincing earthquake prediction would result from methods that have demonstrated many successes with few false alarms. Predicting earthquakes convincingly is difficult for several profound reasons. First, earthquakes start in tiny volumes at inaccessible depth. The power law size dependence means that tiny unobservable ones are frequent almost everywhere and occasionally grow to larger size. Thus prediction of important earthquakes is not about nucleation, but about identifying the conditions for growth. Second, earthquakes are complex. They derive their energy from stress, which is perniciously hard to estimate or model because it is nearly singular at the margins of cracks and faults. Physical properties vary from place to place, so the preparatory processes certainly vary as well. Thus establishing the needed track record for validation is very difficult, especially for large events with immense interval times in any one location. Third, the anomalies are generally complex as well. Electromagnetic anomalies in particular require

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.

Evolution in the lineament patterns associated to strong earthquakes revealed by satellite observations

Science.gov (United States)

Soto-Pinto, C. A.; Arellano-Baeza, A. A.; Ouzounov, D. P.

2011-12-01

We study the temporal evolution of the stress patterns in the crust by using high-resolution (10-300 m) satellite images from MODIS and ASTER satellite sensors. We are able to detect some changes in density and orientation of lineaments preceding earthquake events. A lineament is generally defined as a straight or a somewhat curved feature in the landscape visible in a satellite image as an aligned sequence of pixels of a contrasting intensity compared to the background. The system of lineaments extracted from the satellite images is not identical to the geological lineaments; nevertheless, it generally reflects the structure of the faults and fractures in the Earth's crust. Our analysis has shown that the system of lineaments is very dynamical, and the significant number of lineaments appeared approximately one month before an earthquake, while one month after the earthquake the lineament configuration returned to its initial state. These features were not observed in the test areas that are free of any seismic activity in that period (null hypothesis). We have designed a computational prototype capable to detect lineament evolution and to utilize both ASTER and MODIS satellite L1/L2. We will demonstrate the first successful test results for several Mw> 5 earthquakes in Chile, Peru, China, and California (USA).

Slow Earthquake Hunters: A New Citizen Science Project to Identify and Catalog Slow Slip Events in Geodetic Data

Science.gov (United States)

Bartlow, N. M.

2017-12-01

Slow Earthquake Hunters is a new citizen science project to detect, catalog, and monitor slow slip events. Slow slip events, also called "slow earthquakes", occur when faults slip too slowly to generate significant seismic radiation. They typically take between a few days and over a year to occur, and are most often found on subduction zone plate interfaces. While not dangerous in and of themselves, recent evidence suggests that monitoring slow slip events is important for earthquake hazards, as slow slip events have been known to trigger damaging "regular" earthquakes. Slow slip events, because they do not radiate seismically, are detected with a variety of methods, most commonly continuous geodetic Global Positioning System (GPS) stations. There is now a wealth of GPS data in some regions that experience slow slip events, but a reliable automated method to detect them in GPS data remains elusive. This project aims to recruit human users to view GPS time series data, with some post-processing to highlight slow slip signals, and flag slow slip events for further analysis by the scientific team. Slow Earthquake Hunters will begin with data from the Cascadia subduction zone, where geodetically detectable slow slip events with a duration of at least a few days recur at regular intervals. The project will then expand to other areas with slow slip events or other transient geodetic signals, including other subduction zones, and areas with strike-slip faults. This project has not yet rolled out to the public, and is in a beta testing phase. This presentation will show results from an initial pilot group of student participants at the University of Missouri, and solicit feedback for the future of Slow Earthquake Hunters.

Where was the 1898 Mare Island Earthquake? Insights from the 2014 South Napa Earthquake

Science.gov (United States)

Hough, S. E.

2014-12-01

The 2014 South Napa earthquake provides an opportunity to reconsider the Mare Island earthquake of 31 March 1898, which caused severe damage to buildings at a Navy yard on the island. Revising archival accounts of the 1898 earthquake, I estimate a lower intensity magnitude, 5.8, than the value in the current Uniform California Earthquake Rupture Forecast (UCERF) catalog (6.4). However, I note that intensity magnitude can differ from Mw by upwards of half a unit depending on stress drop, which for a historical earthquake is unknowable. In the aftermath of the 2014 earthquake, there has been speculation that apparently severe effects on Mare Island in 1898 were due to the vulnerability of local structures. No surface rupture has ever been identified from the 1898 event, which is commonly associated with the Hayward-Rodgers Creek fault system, some 10 km west of Mare Island (e.g., Parsons et al., 2003). Reconsideration of detailed archival accounts of the 1898 earthquake, together with a comparison of the intensity distributions for the two earthquakes, points to genuinely severe, likely near-field ground motions on Mare Island. The 2014 earthquake did cause significant damage to older brick buildings on Mare Island, but the level of damage does not match the severity of documented damage in 1898. The high intensity files for the two earthquakes are more over spatially shifted, with the centroid of the 2014 distribution near the town of Napa and that of the 1898 distribution near Mare Island, east of the Hayward-Rodgers Creek system. I conclude that the 1898 Mare Island earthquake was centered on or near Mare Island, possibly involving rupture of one or both strands of the Franklin fault, a low-slip-rate fault sub-parallel to the Rodgers Creek fault to the west and the West Napa fault to the east. I estimate Mw5.8 assuming an average stress drop; data are also consistent with Mw6.4 if stress drop was a factor of ≈3 lower than average for California earthquakes. I

Earthquakes, May-June 1991

Science.gov (United States)

Person, W.J.

1992-01-01

One major earthquake occurred during this reporting period. This was a magntidue 7.1 in Indonesia (Minahassa Peninsula) on June 20. Earthquake-related deaths were reported in the Western Caucasus (Georgia, USSR) on May 3 and June 15. One earthquake-related death was also reported El Salvador on June 21. 

Long Period Source Characteristics of Great Earthquakes: diagnosing complexity

Science.gov (United States)

Rivera, L. A.; Kanamori, H.

2013-12-01

With the commonly used centroid moment tensor inversions, just one number represents the long period size of the event, the seismic moment Mo (or corresponding Mw). However, several recent studies have clearly demonstrated that this is not satisfactory, at least for some earthquakes. For example, for the 2004 Sumatra-Andaman Is. Earthquake, the amplitudes of long-period normal modes indicated that the effective seismic moment increases from 4.0x1022 to 7.1x1022 N-m as the period increases from 300 to 1000 sec. For the 2009 Samoa Is. earthquake (Mw=8.1), the moment tensor was found to be strongly dependent on frequency because the source of this earthquake consists of at least 2 distinct events with very different mechanisms. It is possible that other large and great earthquakes may have similar complex characteristics, but with the standard moment tensor inversion with a single frequency band, we may not notice this easily. Here we investigate the possible frequency dependence of the moment tensor of large earthquakes by performing W phase inversions using teleseismic data and equally spaced narrow overlapping frequency bands. We investigate frequencies from 2.6 to 3.8 mHz. We focus on the variation with frequency of the scalar moment, the amount of non double couple and the focal mechanism. We apply this technique to 30 major events in the period 1994-2013 and use the results to detect source complexity. We class them in three groups according to the variability of the source parameters with frequency: Simple, Complex and Intermediate events and we discuss the correlation of the result of this approach with independent observations of source complexity.

Modeling, Forecasting and Mitigating Extreme Earthquakes

Science.gov (United States)

Ismail-Zadeh, A.; Le Mouel, J.; Soloviev, A.

2012-12-01

Recent earthquake disasters highlighted the importance of multi- and trans-disciplinary studies of earthquake risk. A major component of earthquake disaster risk analysis is hazards research, which should cover not only a traditional assessment of ground shaking, but also studies of geodetic, paleoseismic, geomagnetic, hydrological, deep drilling and other geophysical and geological observations together with comprehensive modeling of earthquakes and forecasting extreme events. Extreme earthquakes (large magnitude and rare events) are manifestations of complex behavior of the lithosphere structured as a hierarchical system of blocks of different sizes. Understanding of physics and dynamics of the extreme events comes from observations, measurements and modeling. A quantitative approach to simulate earthquakes in models of fault dynamics will be presented. The models reproduce basic features of the observed seismicity (e.g., the frequency-magnitude relationship, clustering of earthquakes, occurrence of extreme seismic events). They provide a link between geodynamic processes and seismicity, allow studying extreme events, influence of fault network properties on seismic patterns and seismic cycles, and assist, in a broader sense, in earthquake forecast modeling. Some aspects of predictability of large earthquakes (how well can large earthquakes be predicted today?) will be also discussed along with possibilities in mitigation of earthquake disasters (e.g., on 'inverse' forensic investigations of earthquake disasters).

The Asian crisis contagion: A dynamic correlation approach analysis

Directory of Open Access Journals (Sweden)

Essaadi Essahbi

2009-01-01

Full Text Available In this paper we are testing for contagion caused by the Thai baht collapse of July 1997. In line with earlier work, shift-contagion is defined as a structural change within the international propagation mechanisms of financial shocks. We adopt Bai and Perron's (1998 structural break approach in order to detect the endogenous break points of the pair-wise time-varying correlations between Thailand and seven Asian stock market returns. Our approach enables us to solve the misspecification problem of the crisis window. Our results illustrate the existence of shift-contagion in the Asian crisis caused by the crisis in Thailand.

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

Earthquake Catalogue of the Caucasus

Science.gov (United States)

Godoladze, T.; Gok, R.; Tvaradze, N.; Tumanova, N.; Gunia, I.; Onur, T.

2016-12-01

The Caucasus has a documented historical catalog stretching back to the beginning of the Christian era. Most of the largest historical earthquakes prior to the 19th century are assumed to have occurred on active faults of the Greater Caucasus. Important earthquakes include the Samtskhe earthquake of 1283 (Ms˜7.0, Io=9); Lechkhumi-Svaneti earthquake of 1350 (Ms˜7.0, Io=9); and the Alaverdi earthquake of 1742 (Ms˜6.8, Io=9). Two significant historical earthquakes that may have occurred within the Javakheti plateau in the Lesser Caucasus are the Tmogvi earthquake of 1088 (Ms˜6.5, Io=9) and the Akhalkalaki earthquake of 1899 (Ms˜6.3, Io =8-9). Large earthquakes that occurred in the Caucasus within the period of instrumental observation are: Gori 1920; Tabatskuri 1940; Chkhalta 1963; Racha earthquake of 1991 (Ms=7.0), is the largest event ever recorded in the region; Barisakho earthquake of 1992 (M=6.5); Spitak earthquake of 1988 (Ms=6.9, 100 km south of Tbilisi), which killed over 50,000 people in Armenia. Recently, permanent broadband stations have been deployed across the region as part of the various national networks (Georgia (˜25 stations), Azerbaijan (˜35 stations), Armenia (˜14 stations)). The data from the last 10 years of observation provides an opportunity to perform modern, fundamental scientific investigations. In order to improve seismic data quality a catalog of all instrumentally recorded earthquakes has been compiled by the IES (Institute of Earth Sciences/NSMC, Ilia State University) in the framework of regional joint project (Armenia, Azerbaijan, Georgia, Turkey, USA) "Probabilistic Seismic Hazard Assessment (PSHA) in the Caucasus. The catalogue consists of more then 80,000 events. First arrivals of each earthquake of Mw>=4.0 have been carefully examined. To reduce calculation errors, we corrected arrivals from the seismic records. We improved locations of the events and recalculate Moment magnitudes in order to obtain unified magnitude

Impact of earthquakes and their secondary environmental effects on public health

Science.gov (United States)

Mavroulis, Spyridon; Mavrouli, Maria; Lekkas, Efthymios; Tsakris, Athanassios

2017-04-01

Earthquakes are among the most impressive geological processes with destructive effects on humans, nature and infrastructures. Secondary earthquake environmental effects (EEE) are induced by the ground shaking and are classified into ground cracks, slope movements, dust clouds, liquefactions, hydrological anomalies, tsunamis, trees shaking and jumping stones. Infectious diseases (ID) emerging during the post-earthquake period are considered as secondary earthquake effects on public health. This study involved an extensive and systematic literature review of 121 research publications related to the public health impact of 28 earthquakes from 1980 to 2015 with moment magnitude (Mw) from 6.1 to 9.2 and their secondary EEE including landslides, liquefaction and tsunamis generated in various tectonic environments (extensional, transform, compressional) around the world (21 events in Asia, 5 in America and one each in Oceania and Europe). The inclusion criteria were the literature type comprising journal articles and official reports, the natural disaster type including earthquakes and their secondary EEE (landslides, liquefaction, tsunamis), the population type including humans and the outcome measures characterized by disease incidence increase. The potential post-earthquake ID are classified into 14 groups including respiratory (detected after 15 of 28 earthquakes, 53.57%), water-borne (15, 53.57%), skin (8, 28.57%), vector-borne (8, 28.57%) wound-related (6, 21.43%), blood-borne (4, 14.29%), pulmonary (4, 14.29%), fecal-oral (3, 10.71%), food-borne (3, 10.71%), fungal (3, 10.71%), parasitic (3, 10.71%), eye (1, 3.57%), mite-borne (1, 3.57%) and soil-borne (1, 3.57%) infections. Based on age and genre data available for 15 earthquakes, the most vulnerable population groups are males, young children (age ≤ 10 years) and adults (age ≥ 65 years). Cholera, pneumonia and tetanus are the deadliest post-earthquake ID. The risk factors leading not only to disease

Coseismic Deformation of Chi-Chi Earthquake as Detected by Differential Synthetic Aperture Radar Interferometry and GPS Data

Directory of Open Access Journals (Sweden)

Chia-Sheng Hsieh Tian-Yuan Shih

2006-01-01

Full Text Available A rupture in the Chelungpu fault caused an Mw 7.6 earthquake on 21 September 1999 near Chi-Chi in central Taiwan. This earthquake was the most destructive experienced in Taiwan for the past century along this fault. In this study, we examined the earthquake-induced surface deformation pattern using differential synthetic aperture radar interferometry (D-InSAR combined with global positioning system (GPS data regarding the footwall of the Chelungpu fault. Six synthetic aperture radar (SAR scenes, approximately 100 × 100 km each, recorded by the European Remote Sensing Satellite 2 (ERS-2, spanning the rupture area, were selected for study. The data were used to generate a high-resolution, wide-area map of displacements in flat or semi-flat areas. Interferograms show radar line contours indicating line-of-sight (LOS changes corresponding to surface displacements caused by earthquake ruptures. These results were compared to synthetic interferograms generated from GPS data. Displacements shown by GPS data were interpolated onto wide-area maps and transformed to coincide with the radar LOS direction. The resulting coseismic displacement contour map showed a lobed pattern consistent with the precise GPSbased displacement field. Highly accurate vertical displacement was determined using D-InSAR data using the coordinate transform method, while GPS data was effective in showing the horizontal component. Thus, this study confirmed the effectiveness of the D-InSAR method for determining the coseismic deformation caused by the Chi-Chi earthquake at the footwall of the Chelungpu fault.

Asian Adolescents with Excess Weight are at Higher Risk for Insulin Resistance than Non-Asian Peers.

Science.gov (United States)

Elsamadony, Ahmed; Yates, Kathy F; Sweat, Victoria; Yau, Po Lai; Mangone, Alex; Joseph, Adriana; Fierman, Arthur; Convit, Antonio

2017-11-01

The purpose of this study was to evaluate whether Asian American adolescents have higher metabolic risk from excess weight than non-Asians. Seven hundred thirty-three students, aged 14 to 19 years old, completed a school-based health screening. The 427 Asian and 306 non-Asian students were overall equivalent on age, sex, and family income. Height, weight, waist circumference, percent body fat, and blood pressure were measured. Fasting triglycerides, high- and low-density lipoproteins, glucose, and insulin levels were measured. Asian and non-Asians in lean or overweight/obesity groups were contrasted on the five factors that make up the metabolic syndrome. Asian adolescents carrying excess weight had significantly higher insulin resistance (IR), triglyceride levels, and waist-height ratios (W/H), despite a significantly lower overall BMI than corresponding non-Asians. Similarly, Asians had a stronger relationship between W/H and the degree of IR than non-Asian counterparts; 35% and 18% of the variances were explained (R 2  = 0.35, R 2  = 0.18) respectively, resulting in a significant W/H by racial group interaction (F change [1,236] = 11.56, P Asians have higher IR and triglyceride levels from excess weight than their non-Asian counterparts. One-size-fits-all public health policies targeting youth should be reconsidered and attention paid to Asian adolescents, including those with mild degrees of excess weight. © 2017 The Obesity Society.

Quantifying 10 years of improved earthquake-monitoring performance in the Caribbean region

Science.gov (United States)

McNamara, Daniel E.; Hillebrandt-Andrade, Christa; Saurel, Jean-Marie; Huerfano-Moreno, V.; Lynch, Lloyd

2015-01-01

Over 75 tsunamis have been documented in the Caribbean and adjacent regions during the past 500 years. Since 1500, at least 4484 people are reported to have perished in these killer waves. Hundreds of thousands are currently threatened along the Caribbean coastlines. Were a great tsunamigenic earthquake to occur in the Caribbean region today, the effects would potentially be catastrophic due to an increasingly vulnerable region that has seen significant population increases in the past 40–50 years and currently hosts an estimated 500,000 daily beach visitors from North America and Europe, a majority of whom are not likely aware of tsunami and earthquake hazards. Following the magnitude 9.1 Sumatra–Andaman Islands earthquake of 26 December 2004, the United Nations Educational, Scientific and Cultural Organization (UNESCO) Intergovernmental Coordination Group (ICG) for the Tsunami and other Coastal Hazards Early Warning System for the Caribbean and Adjacent Regions (CARIBE‐EWS) was established and developed minimum performance standards for the detection and analysis of earthquakes. In this study, we model earthquake‐magnitude detection threshold and P‐wave detection time and demonstrate that the requirements established by the UNESCO ICG CARIBE‐EWS are met with 100% of the network operating. We demonstrate that earthquake‐monitoring performance in the Caribbean Sea region has improved significantly in the past decade as the number of real‐time seismic stations available to the National Oceanic and Atmospheric Administration tsunami warning centers have increased. We also identify weaknesses in the current international network and provide guidance for selecting the optimal distribution of seismic stations contributed from existing real‐time broadband national networks in the region.

Cancer screening promotion among medically underserved Asian American women: integration of research and practice.

Science.gov (United States)

Yu, Mei-yu; Seetoo, Amy D; Hong, Oi Saeng; Song, Lixin; Raizade, Rekha; Weller, Adelwisa L Agas

2002-01-01

Mammography and Pap smear tests are known to be effective early detection measures for breast and cervical cancers, respectively, but Asian Americans are reluctant to make visits for routine preventive care. Quantitative and qualitative research conducted by the Healthy Asian Americans Project (HAAP) between 1996 and 1999 indicated that Asian residents in southeastern Michigan, like the general Asian population in the US, underutilized early cancer screening programs due to cultural, psychosocial, linguistic, and economic barriers. This article reports how the HAAP's research findings guided the Michigan Breast and Cervical Cancer Control Program (BCCCP) promotion (conducted from 2000 to 2001 among medically underserved Asian women residing in southeastern Michigan), and how evaluation of the HAAP's BCCCP promotion will direct future research and health promotion programs. The article presents strategies used to improve access to cancer screening programs for diverse Asian sub-groups as well as outcomes of the 2-year HAAP's BCCCP promotion among the target population. Discussion regarding lessons and experiences gained from integration of research and practice has implications on design and implementation of the cancer screening promotion for the rapidly increasing Asian American population as well as other medically underserved minority populations in the US.

Use of high resolution satellite images for tracking of changes in the lineament structure, caused by earthquakes

OpenAIRE

Arellano-Baeza, A. A.; Garcia, R. V.; Trejo-Soto, M.

2007-01-01

Over the last decades strong efforts have been made to apply new spaceborn technologies to the study and possible forecast of strong earthquakes. In this study we use ASTER/TERRA multispectral satellite images for detection and analysis of changes in the system of lineaments previous to a strong earthquake. A lineament is a straight or a somewhat curved feature in an image, which it is possible to detect by a special processing of images based on directional filtering and or Hough transform. ...

Towards an Earthquake and Tsunami Early Warning in the Caribbean

Science.gov (United States)

Huerfano Moreno, V. A.; Vanacore, E. A.

2017-12-01

The Caribbean region (CR) has a documented history of large damaging earthquakes and tsunamis that have affected coastal areas, including the events of Jamaica in 1692, Virgin Islands in 1867, Puerto Rico in 1918, the Dominican Republic in 1946 and Haiti in 2010. There is clear evidence that tsunamis have been triggered by large earthquakes that deformed the ocean floor around the Caribbean Plate boundary. The CR is monitored jointly by national/regional/local seismic, geodetic and sea level networks. All monitoring institutions are participating in the UNESCO ICG/Caribe EWS, the purpose of this initiative is to minimize loss of life and destruction of property, and to mitigate against catastrophic economic impacts via promoting local research, real time (RT) earthquake, geodetic and sea level data sharing and improving warning capabilities and enhancing education and outreach strategies. Currently more than, 100 broad-band seismic, 65 sea levels and 50 GPS high rate stations are available in real or near real-time. These real-time streams are used by Local/Regional or Worldwide detection and warning institutions to provide earthquake source parameters in a timely manner. Currently, any Caribbean event detected to have a magnitude greater than 4.5 is evaluated, and sea level is measured, by the TWC for tsumanigenic potential. The regional cooperation is motivated both by research interests as well as geodetic, seismic and tsunami hazard monitoring and warning. It will allow the imaging of the tectonic structure of the Caribbean region to a high resolution which will consequently permit further understanding of the seismic source properties for moderate and large events and the application of this knowledge to procedures of civil protection. To reach its goals, the virtual network has been designed following the highest technical standards: BB sensors, 24 bits A/D converters with 140 dB dynamic range, real-time telemetry. Here we will discuss the state of the PR

Natural Time and Nowcasting Earthquakes: Are Large Global Earthquakes Temporally Clustered?

Science.gov (United States)

Luginbuhl, Molly; Rundle, John B.; Turcotte, Donald L.

2018-02-01

The objective of this paper is to analyze the temporal clustering of large global earthquakes with respect to natural time, or interevent count, as opposed to regular clock time. To do this, we use two techniques: (1) nowcasting, a new method of statistically classifying seismicity and seismic risk, and (2) time series analysis of interevent counts. We chose the sequences of M_{λ } ≥ 7.0 and M_{λ } ≥ 8.0 earthquakes from the global centroid moment tensor (CMT) catalog from 2004 to 2016 for analysis. A significant number of these earthquakes will be aftershocks of the largest events, but no satisfactory method of declustering the aftershocks in clock time is available. A major advantage of using natural time is that it eliminates the need for declustering aftershocks. The event count we utilize is the number of small earthquakes that occur between large earthquakes. The small earthquake magnitude is chosen to be as small as possible, such that the catalog is still complete based on the Gutenberg-Richter statistics. For the CMT catalog, starting in 2004, we found the completeness magnitude to be M_{σ } ≥ 5.1. For the nowcasting method, the cumulative probability distribution of these interevent counts is obtained. We quantify the distribution using the exponent, β, of the best fitting Weibull distribution; β = 1 for a random (exponential) distribution. We considered 197 earthquakes with M_{λ } ≥ 7.0 and found β = 0.83 ± 0.08. We considered 15 earthquakes with M_{λ } ≥ 8.0, but this number was considered too small to generate a meaningful distribution. For comparison, we generated synthetic catalogs of earthquakes that occur randomly with the Gutenberg-Richter frequency-magnitude statistics. We considered a synthetic catalog of 1.97 × 10^5 M_{λ } ≥ 7.0 earthquakes and found β = 0.99 ± 0.01. The random catalog converted to natural time was also random. We then generated 1.5 × 10^4 synthetic catalogs with 197 M_{λ } ≥ 7.0 in each catalog and

Earthquake hazard assessment and small earthquakes

International Nuclear Information System (INIS)

Reiter, L.

1987-01-01

The significance of small earthquakes and their treatment in nuclear power plant seismic hazard assessment is an issue which has received increased attention over the past few years. In probabilistic studies, sensitivity studies showed that the choice of the lower bound magnitude used in hazard calculations can have a larger than expected effect on the calculated hazard. Of particular interest is the fact that some of the difference in seismic hazard calculations between the Lawrence Livermore National Laboratory (LLNL) and Electric Power Research Institute (EPRI) studies can be attributed to this choice. The LLNL study assumed a lower bound magnitude of 3.75 while the EPRI study assumed a lower bound magnitude of 5.0. The magnitudes used were assumed to be body wave magnitudes or their equivalents. In deterministic studies recent ground motion recordings of small to moderate earthquakes at or near nuclear power plants have shown that the high frequencies of design response spectra may be exceeded. These exceedances became important issues in the licensing of the Summer and Perry nuclear power plants. At various times in the past particular concerns have been raised with respect to the hazard and damage potential of small to moderate earthquakes occurring at very shallow depths. In this paper a closer look is taken at these issues. Emphasis is given to the impact of lower bound magnitude on probabilistic hazard calculations and the historical record of damage from small to moderate earthquakes. Limited recommendations are made as to how these issues should be viewed

Extreme value distribution of earthquake magnitude

Science.gov (United States)

Zi, Jun Gan; Tung, C. C.

1983-07-01

Probability distribution of maximum earthquake magnitude is first derived for an unspecified probability distribution of earthquake magnitude. A model for energy release of large earthquakes, similar to that of Adler-Lomnitz and Lomnitz, is introduced from which the probability distribution of earthquake magnitude is obtained. An extensive set of world data for shallow earthquakes, covering the period from 1904 to 1980, is used to determine the parameters of the probability distribution of maximum earthquake magnitude. Because of the special form of probability distribution of earthquake magnitude, a simple iterative scheme is devised to facilitate the estimation of these parameters by the method of least-squares. The agreement between the empirical and derived probability distributions of maximum earthquake magnitude is excellent.

Multiple-Threshold Event Detection and Other Enhancements to the Virtual Seismologist (VS) Earthquake Early Warning Algorithm

Science.gov (United States)

Fischer, M.; Caprio, M.; Cua, G. B.; Heaton, T. H.; Clinton, J. F.; Wiemer, S.

2009-12-01

The Virtual Seismologist (VS) algorithm is a Bayesian approach to earthquake early warning (EEW) being implemented by the Swiss Seismological Service at ETH Zurich. The application of Bayes’ theorem in earthquake early warning states that the most probable source estimate at any given time is a combination of contributions from a likelihood function that evolves in response to incoming data from the on-going earthquake, and selected prior information, which can include factors such as network topology, the Gutenberg-Richter relationship or previously observed seismicity. The VS algorithm was one of three EEW algorithms involved in the California Integrated Seismic Network (CISN) real-time EEW testing and performance evaluation effort. Its compelling real-time performance in California over the last three years has led to its inclusion in the new USGS-funded effort to develop key components of CISN ShakeAlert, a prototype EEW system that could potentially be implemented in California. A significant portion of VS code development was supported by the SAFER EEW project in Europe. We discuss recent enhancements to the VS EEW algorithm. We developed and continue to test a multiple-threshold event detection scheme, which uses different association / location approaches depending on the peak amplitudes associated with an incoming P pick. With this scheme, an event with sufficiently high initial amplitudes can be declared on the basis of a single station, maximizing warning times for damaging events for which EEW is most relevant. Smaller, non-damaging events, which will have lower initial amplitudes, will require more picks to be declared an event to reduce false alarms. This transforms the VS codes from a regional EEW approach reliant on traditional location estimation (and it requirement of at least 4 picks as implemented by the Binder Earthworm phase associator) to a hybrid on-site/regional approach capable of providing a continuously evolving stream of EEW

Asian longhorned beetle (ALB) Anoplophora gabripennis: advancements in the eradication program

Science.gov (United States)

Christine Markham; Joe Gittleman; Tom Denholm; Clint. McFarland

2011-01-01

Current detections of Asian longhorned beetle (ALB): August 1996--Brooklyn, NY, later detected on Long Island and in other parts of New York City; July 1998--Chicago, IL; October 2002--Jersey City, NJ; August 2004--Carteret, NJ; August 2008--Worcester, MA. Declared eradication of ALB infestations: April 2008--Chicago, IL, and Jersey City, NJ. Currently regulated for...

Historic Eastern Canadian earthquakes

International Nuclear Information System (INIS)

Asmis, G.J.K.; Atchinson, R.J.

1981-01-01

Nuclear power plants licensed in Canada have been designed to resist earthquakes: not all plants, however, have been explicitly designed to the same level of earthquake induced forces. Understanding the nature of strong ground motion near the source of the earthquake is still very tentative. This paper reviews historical and scientific accounts of the three strongest earthquakes - St. Lawrence (1925), Temiskaming (1935), Cornwall (1944) - that have occurred in Canada in 'modern' times, field studies of near-field strong ground motion records and their resultant damage or non-damage to industrial facilities, and numerical modelling of earthquake sources and resultant wave propagation to produce accelerograms consistent with the above historical record and field studies. It is concluded that for future construction of NPP's near-field strong motion must be explicitly considered in design

Real-Time Integration of Positioning and Accelerometer Data for Early Earthquake Warning on Canada's West Coast

Science.gov (United States)

Biffard, B.; Rosenberger, A.; Pirenne, B.; Valenzuela, M.; MacArthur, M.

2017-12-01

Ocean Networks Canada (ONC) operates ocean and coastal observatories on all three of Canada's coasts, and more particularly across the Cascadia subduction zone. The data are acquired, parsed, calibrated and archived by ONC's data management system (Oceans 2.0), with real-time event detection, reaction and access capabilities. As such, ONC is in a unique position to develop early warning systems for earthquakes, near- and far-field tsunamis and other events. ONC is leading the development of a system to alert southwestern British Columbia of an impending Cascadia subduction zone earthquake on behalf of the provincial government and with the support of the Canadian Federal Government. Similarly to other early earthquake warning systems, an array of accelerometers is used to detect the initial earthquake p-waves. This can provide 5-60 seconds of warning to subscribers who can then take action, such as stopping trains and surgeries, closing valves, taking cover, etc. To maximize the detection capability and the time available to react to a notification, instruments are placed both underwater and on land on Vancouver Island. A novel feature of ONC's system is, for land-based sites, the combination of real-time satellite positioning (GNSS) and accelerometer data in the calculations to improve earthquake intensity estimates. This results in higher accuracy, dynamic range and responsiveness than either type of sensor is capable of alone. P-wave detections and displacement data are sent from remote stations to a data centre that must calculate epicentre locations and magnitude. The latter are then delivered to subscribers with client software that, given their position, will calculate arrival time and intensity. All of this must occur with very high standards for latency, reliability and accuracy.

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.

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…

Excel, Earthquakes, and Moneyball: exploring Cascadia earthquake probabilities using spreadsheets and baseball analogies

Science.gov (United States)

Campbell, M. R.; Salditch, L.; Brooks, E. M.; Stein, S.; Spencer, B. D.

2017-12-01

Much recent media attention focuses on Cascadia's earthquake hazard. A widely cited magazine article starts "An earthquake will destroy a sizable portion of the coastal Northwest. The question is when." Stories include statements like "a massive earthquake is overdue", "in the next 50 years, there is a 1-in-10 chance a "really big one" will erupt," or "the odds of the big Cascadia earthquake happening in the next fifty years are roughly one in three." These lead students to ask where the quoted probabilities come from and what they mean. These probability estimates involve two primary choices: what data are used to describe when past earthquakes happened and what models are used to forecast when future earthquakes will happen. The data come from a 10,000-year record of large paleoearthquakes compiled from subsidence data on land and turbidites, offshore deposits recording submarine slope failure. Earthquakes seem to have happened in clusters of four or five events, separated by gaps. Earthquakes within a cluster occur more frequently and regularly than in the full record. Hence the next earthquake is more likely if we assume that we are in the recent cluster that started about 1700 years ago, than if we assume the cluster is over. Students can explore how changing assumptions drastically changes probability estimates using easy-to-write and display spreadsheets, like those shown below. Insight can also come from baseball analogies. The cluster issue is like deciding whether to assume that a hitter's performance in the next game is better described by his lifetime record, or by the past few games, since he may be hitting unusually well or in a slump. The other big choice is whether to assume that the probability of an earthquake is constant with time, or is small immediately after one occurs and then grows with time. This is like whether to assume that a player's performance is the same from year to year, or changes over their career. Thus saying "the chance of

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.

Toward real-time regional earthquake simulation II: Real-time Online earthquake Simulation (ROS) of Taiwan earthquakes

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Lee, Shiann-Jong; Liu, Qinya; Tromp, Jeroen; Komatitsch, Dimitri; Liang, Wen-Tzong; Huang, Bor-Shouh

2014-06-01

We developed a Real-time Online earthquake Simulation system (ROS) to simulate regional earthquakes in Taiwan. The ROS uses a centroid moment tensor solution of seismic events from a Real-time Moment Tensor monitoring system (RMT), which provides all the point source parameters including the event origin time, hypocentral location, moment magnitude and focal mechanism within 2 min after the occurrence of an earthquake. Then, all of the source parameters are automatically forwarded to the ROS to perform an earthquake simulation, which is based on a spectral-element method (SEM). A new island-wide, high resolution SEM mesh model is developed for the whole Taiwan in this study. We have improved SEM mesh quality by introducing a thin high-resolution mesh layer near the surface to accommodate steep and rapidly varying topography. The mesh for the shallow sedimentary basin is adjusted to reflect its complex geometry and sharp lateral velocity contrasts. The grid resolution at the surface is about 545 m, which is sufficient to resolve topography and tomography data for simulations accurate up to 1.0 Hz. The ROS is also an infrastructural service, making online earthquake simulation feasible. Users can conduct their own earthquake simulation by providing a set of source parameters through the ROS webpage. For visualization, a ShakeMovie and ShakeMap are produced during the simulation. The time needed for one event is roughly 3 min for a 70 s ground motion simulation. The ROS is operated online at the Institute of Earth Sciences, Academia Sinica (http://ros.earth.sinica.edu.tw/). Our long-term goal for the ROS system is to contribute to public earth science outreach and to realize seismic ground motion prediction in real-time.

Sedimentary Signatures of Submarine Earthquakes: Deciphering the Extent of Sediment Remobilization from the 2011 Tohoku Earthquake and Tsunami and 2010 Haiti Earthquake

Science.gov (United States)

McHugh, C. M.; Seeber, L.; Moernaut, J.; Strasser, M.; Kanamatsu, T.; Ikehara, K.; Bopp, R.; Mustaque, S.; Usami, K.; Schwestermann, T.; Kioka, A.; Moore, L. M.

2017-12-01

The 2004 Sumatra-Andaman Mw9.3 and the 2011 Tohoku (Japan) Mw9.0 earthquakes and tsunamis were huge geological events with major societal consequences. Both were along subduction boundaries and ruptured portions of these boundaries that had been deemed incapable of such events. Submarine strike-slip earthquakes, such as the 2010 Mw7.0 in Haiti, are smaller but may be closer to population centers and can be similarly catastrophic. Both classes of earthquakes remobilize sediment and leave distinct signatures in the geologic record by a wide range of processes that depends on both environment and earthquake characteristics. Understanding them has the potential of greatly expanding the record of past earthquakes, which is critical for geohazard analysis. Recent events offer precious ground truth about the earthquakes and short-lived radioisotopes offer invaluable tools to identify sediments they remobilized. In the 2011 Mw9 Japan earthquake they document the spatial extent of remobilized sediment from water depths of 626m in the forearc slope to trench depths of 8000m. Subbottom profiles, multibeam bathymetry and 40 piston cores collected by the R/V Natsushima and R/V Sonne expeditions to the Japan Trench document multiple turbidites and high-density flows. Core tops enriched in xs210Pb,137Cs and 134Cs reveal sediment deposited by the 2011 Tohoku earthquake and tsunami. The thickest deposits (2m) were documented on a mid-slope terrace and trench (4000-8000m). Sediment was deposited on some terraces (600-3000m), but shed from the steep forearc slope (3000-4000m). The 2010 Haiti mainshock ruptured along the southern flank of Canal du Sud and triggered multiple nearshore sediment failures, generated turbidity currents and stirred fine sediment into suspension throughout this basin. A tsunami was modeled to stem from both sediment failures and tectonics. Remobilized sediment was tracked with short-lived radioisotopes from the nearshore, slope, in fault basins including the

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

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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.

Spectral characteristics of the P codas of eurasian earthquakes and explosions

International Nuclear Information System (INIS)

Evernden, J.F.

1977-01-01

Spectral analysis of ''infinite velocity sum'' subarray beams at LASA for the P codas of 36 explosions and 23 earthquakes indicates the presence of 6 to 9 Hz energy well above noise level for large explosions and earthquakes. A discriminant (D), based on use of the full spectral bandwidth from 0.4 to 9 Hz, successfully discriminates all Eurasian explosions and shallow-focus earthquakes. The basic character and contrast in spectral composition of the source spectra of earthquakes and explosions is discussed. It is pointed out that the discriminant (D), when use is made of signals recorded in the range 60 0 to 90 0 , is as or more successful in discriminating events of near m/sub b/ 4.0 as those at and above m/sub b/ 6.0, and the basis for this success is clarified. It is suggested that proper use of P coda spectral discriminants appears capable of achieving identification essentially at the detection threshold of a network, while circumventing such problems as refined depths of focus, mixed events, etc

Perinatal outcomes among Asian-white interracial couples.

Science.gov (United States)

Nystrom, Michael J; Caughey, Aaron B; Lyell, Deirdre J; Druzin, Maurice L; El-Sayed, Yasser Y

2008-10-01

To investigate whether perinatal outcomes among interracial Asian-white couples are different than among Asian-Asian and white-white couples. This was a retrospective study of Asian, white, and Asian-white couples delivered at the Lucile Packard Children's Hospital from 2000-2005. Asian-white couples were subdivided into white-mother/Asian-father or Asian-mother/white-father. Perinatal outcomes included gestational diabetes, hypertensive disorders of pregnancy, preterm delivery, birth weight >4000 g and interracial Asian-white couples.

Current Update in Asian Rhinoplasty

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Clyde H. Ishii, MD, FACS

2014-04-01

Full Text Available Summary: There has been a tremendous growth of cosmetic surgery among Asians worldwide. Rhinoplasty is second only to blepharoplasty in terms of popularity among Asians regarding cosmetic surgical procedures. Most Asians seek to improve their appearance while maintaining the essential features of their ethnicity. There are considerable ethnic nasal and facial variations in this population alone. Successful rhinoplasty in Asians must take into account underlying anatomic differences between Asians and whites. Due to ethnic variations, cultural differences, and occasional language barriers, careful preoperative counseling is necessary to align the patient’s expectations with the limitations of the procedure. This article will review the many facets of Asian rhinoplasty as it is practiced today.

HYDROACOUSTIC OBSERVATIONS OF WEAK EARTHQUAKES IN SHALLOW WATERS OF THE SOUTHERN KURIL ISLANDS

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Alexander S. Borisov

2012-01-01

Full Text Available Results of hydroacoustic observations of signals from weak earthquakes in natural conditions in the region of the Southern Kuril Islands are presented. Some earthquakes were registered by the the Yuzhno-Kurilsk Seismic Station, other were only recorded by hydrophone stations. The observations were specific as seismic signals were recorded in shallow waters, i.e. in high noise level conditions. Hydrophones were installed in Lake Lagunnoe (Kunashir and Khromovaya Bay (Shikotan. Our analysis of hydroacoustic records received from the hydrophone stations revealed no evident precursory response of the geological medium to weak distant events. This means that neither before the period of earthquake preparation nor during the earthquake preparation period, any geoacoustic emission was not detected. It is shown that despite the unfavourable noise level conditions, even distant weak earthquakes can be confidently registered by hydrophone stations, and pending application of proper signal processing techniques, it can be possible to determine arrival times of seismic waves and to measure parameters of seismic waves. It is also established that the frequency spectrum of acoustic signals from the weak earthquakes recordable by the hydrophone stations is continuous and of noise type in the frequency range up to 90–100 Hz. It is revealed that in some cases, weak earthquakes and microearthquakes may be forerun by low frequency signals.

The 2008 Wenchuan Earthquake and the Rise and Fall of Earthquake Prediction in China

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Chen, Q.; Wang, K.

2009-12-01

Regardless of the future potential of earthquake prediction, it is presently impractical to rely on it to mitigate earthquake disasters. The practical approach is to strengthen the resilience of our built environment to earthquakes based on hazard assessment. But this was not common understanding in China when the M 7.9 Wenchuan earthquake struck the Sichuan Province on 12 May 2008, claiming over 80,000 lives. In China, earthquake prediction is a government-sanctioned and law-regulated measure of disaster prevention. A sudden boom of the earthquake prediction program in 1966-1976 coincided with a succession of nine M > 7 damaging earthquakes in the densely populated region of the country and the political chaos of the Cultural Revolution. It climaxed with the prediction of the 1975 Haicheng earthquake, which was due mainly to an unusually pronounced foreshock sequence and the extraordinary readiness of some local officials to issue imminent warning and evacuation order. The Haicheng prediction was a success in practice and yielded useful lessons, but the experience cannot be applied to most other earthquakes and cultural environments. Since the disastrous Tangshan earthquake in 1976 that killed over 240,000 people, there have been two opposite trends in China: decreasing confidence in prediction and increasing emphasis on regulating construction design for earthquake resilience. In 1976, most of the seismic intensity XI areas of Tangshan were literally razed to the ground, but in 2008, many buildings in the intensity XI areas of Wenchuan did not collapse. Prediction did not save life in either of these events; the difference was made by construction standards. For regular buildings, there was no seismic design in Tangshan to resist any earthquake shaking in 1976, but limited seismic design was required for the Wenchuan area in 2008. Although the construction standards were later recognized to be too low, those buildings that met the standards suffered much less

1/f and the Earthquake Problem: Scaling constraints that facilitate operational earthquake forecasting

Science.gov (United States)

yoder, M. R.; Rundle, J. B.; Turcotte, D. L.

2012-12-01

The difficulty of forecasting earthquakes can fundamentally be attributed to the self-similar, or "1/f", nature of seismic sequences. Specifically, the rate of occurrence of earthquakes is inversely proportional to their magnitude m, or more accurately to their scalar moment M. With respect to this "1/f problem," it can be argued that catalog selection (or equivalently, determining catalog constraints) constitutes the most significant challenge to seismicity based earthquake forecasting. Here, we address and introduce a potential solution to this most daunting problem. Specifically, we introduce a framework to constrain, or partition, an earthquake catalog (a study region) in order to resolve local seismicity. In particular, we combine Gutenberg-Richter (GR), rupture length, and Omori scaling with various empirical measurements to relate the size (spatial and temporal extents) of a study area (or bins within a study area) to the local earthquake magnitude potential - the magnitude of earthquake the region is expected to experience. From this, we introduce a new type of time dependent hazard map for which the tuning parameter space is nearly fully constrained. In a similar fashion, by combining various scaling relations and also by incorporating finite extents (rupture length, area, and duration) as constraints, we develop a method to estimate the Omori (temporal) and spatial aftershock decay parameters as a function of the parent earthquake's magnitude m. From this formulation, we develop an ETAS type model that overcomes many point-source limitations of contemporary ETAS. These models demonstrate promise with respect to earthquake forecasting applications. Moreover, the methods employed suggest a general framework whereby earthquake and other complex-system, 1/f type, problems can be constrained from scaling relations and finite extents.; Record-breaking hazard map of southern California, 2012-08-06. "Warm" colors indicate local acceleration (elevated hazard

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

International Nuclear Information System (INIS)

Rodriguez, Jenna; Ustin, Susan; Sandoval-Solis, Samuel; O'Geen, Anthony Toby

2016-01-01

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

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.

Post-earthquake building safety inspection: Lessons from the Canterbury, New Zealand, earthquakes

Science.gov (United States)

Marshall, J.; Jaiswal, Kishor; Gould, N.; Turner, F.; Lizundia, B.; Barnes, J.

2013-01-01

The authors discuss some of the unique aspects and lessons of the New Zealand post-earthquake building safety inspection program that was implemented following the Canterbury earthquake sequence of 2010–2011. The post-event safety assessment program was one of the largest and longest programs undertaken in recent times anywhere in the world. The effort engaged hundreds of engineering professionals throughout the country, and also sought expertise from outside, to perform post-earthquake structural safety inspections of more than 100,000 buildings in the city of Christchurch and the surrounding suburbs. While the building safety inspection procedure implemented was analogous to the ATC 20 program in the United States, many modifications were proposed and implemented in order to assess the large number of buildings that were subjected to strong and variable shaking during a period of two years. This note discusses some of the key aspects of the post-earthquake building safety inspection program and summarizes important lessons that can improve future earthquake response.

Extreme value statistics and thermodynamics of earthquakes: large earthquakes

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B. H. Lavenda

2000-06-01

Full Text Available A compound Poisson process is used to derive a new shape parameter which can be used to discriminate between large earthquakes and aftershock sequences. Sample exceedance distributions of large earthquakes are fitted to the Pareto tail and the actual distribution of the maximum to the Fréchet distribution, while the sample distribution of aftershocks are fitted to a Beta distribution and the distribution of the minimum to the Weibull distribution for the smallest value. The transition between initial sample distributions and asymptotic extreme value distributions shows that self-similar power laws are transformed into nonscaling exponential distributions so that neither self-similarity nor the Gutenberg-Richter law can be considered universal. The energy-magnitude transformation converts the Fréchet distribution into the Gumbel distribution, originally proposed by Epstein and Lomnitz, and not the Gompertz distribution as in the Lomnitz-Adler and Lomnitz generalization of the Gutenberg-Richter law. Numerical comparison is made with the Lomnitz-Adler and Lomnitz analysis using the same Catalogue of Chinese Earthquakes. An analogy is drawn between large earthquakes and high energy particle physics. A generalized equation of state is used to transform the Gamma density into the order-statistic Fréchet distribution. Earthquaketemperature and volume are determined as functions of the energy. Large insurance claims based on the Pareto distribution, which does not have a right endpoint, show why there cannot be a maximum earthquake energy.

Recurrent slow slip event likely hastened by the 2011 Tohoku earthquake

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Hirose, Hitoshi; Kimura, Hisanori; Enescu, Bogdan; Aoi, Shin

2012-01-01

Slow slip events (SSEs) are another mode of fault deformation than the fast faulting of regular earthquakes. Such transient episodes have been observed at plate boundaries in a number of subduction zones around the globe. The SSEs near the Boso Peninsula, central Japan, are among the most documented SSEs, with the longest repeating history, of almost 30 y, and have a recurrence interval of 5 to 7 y. A remarkable characteristic of the slow slip episodes is the accompanying earthquake swarm activity. Our stable, long-term seismic observations enable us to detect SSEs using the recorded earthquake catalog, by considering an earthquake swarm as a proxy for a slow slip episode. Six recurrent episodes are identified in this way since 1982. The average duration of the SSE interoccurrence interval is 68 mo; however, there are significant fluctuations from this mean. While a regular cycle can be explained using a simple physical model, the mechanisms that are responsible for the observed fluctuations are poorly known. Here we show that the latest SSE in the Boso Peninsula was likely hastened by the stress transfer from the March 11, 2011 great Tohoku earthquake. Moreover, a similar mechanism accounts for the delay of an SSE in 1990 by a nearby earthquake. The low stress buildups and drops during the SSE cycle can explain the strong sensitivity of these SSEs to stress transfer from external sources. PMID:22949688

Countermeasures to earthquakes in nuclear plants

International Nuclear Information System (INIS)

Sato, Kazuhide

1979-01-01

The contribution of atomic energy to mankind is unmeasured, but the danger of radioactivity is a special thing. Therefore in the design of nuclear power plants, the safety has been regarded as important, and in Japan where earthquakes occur frequently, the countermeasures to earthquakes have been incorporated in the examination of safety naturally. The radioactive substances handled in nuclear power stations and spent fuel reprocessing plants are briefly explained. The occurrence of earthquakes cannot be predicted effectively, and the disaster due to earthquakes is apt to be remarkably large. In nuclear plants, the prevention of damage in the facilities and the maintenance of the functions are required at the time of earthquakes. Regarding the location of nuclear plants, the history of earthquakes, the possible magnitude of earthquakes, the properties of ground and the position of nuclear plants should be examined. After the place of installation has been decided, the earthquake used for design is selected, evaluating live faults and determining the standard earthquakes. As the fundamentals of aseismatic design, the classification according to importance, the earthquakes for design corresponding to the classes of importance, the combination of loads and allowable stress are explained. (Kako, I.)

Rapid Estimates of Rupture Extent for Large Earthquakes Using Aftershocks

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Polet, J.; Thio, H. K.; Kremer, M.

2009-12-01

The spatial distribution of aftershocks is closely linked to the rupture extent of the mainshock that preceded them and a rapid analysis of aftershock patterns therefore has potential for use in near real-time estimates of earthquake impact. The correlation between aftershocks and slip distribution has frequently been used to estimate the fault dimensions of large historic earthquakes for which no, or insufficient, waveform data is available. With the advent of earthquake inversions that use seismic waveforms and geodetic data to constrain the slip distribution, the study of aftershocks has recently been largely focused on enhancing our understanding of the underlying mechanisms in a broader earthquake mechanics/dynamics framework. However, in a near real-time earthquake monitoring environment, in which aftershocks of large earthquakes are routinely detected and located, these data may also be effective in determining a fast estimate of the mainshock rupture area, which would aid in the rapid assessment of the impact of the earthquake. We have analyzed a considerable number of large recent earthquakes and their aftershock sequences and have developed an effective algorithm that determines the rupture extent of a mainshock from its aftershock distribution, in a fully automatic manner. The algorithm automatically removes outliers by spatial binning, and subsequently determines the best fitting “strike” of the rupture and its length by projecting the aftershock epicenters onto a set of lines that cross the mainshock epicenter with incremental azimuths. For strike-slip or large dip-slip events, for which the surface projection of the rupture is recti-linear, the calculated strike correlates well with the strike of the fault and the corresponding length, determined from the distribution of aftershocks projected onto the line, agrees well with the rupture length. In the case of a smaller dip-slip rupture with an aspect ratio closer to 1, the procedure gives a measure

Barriers for breast cancer screening among Asian women: a mini literature review.

Science.gov (United States)

Parsa, Parisa; Kandiah, Mirnalini; Abdul Rahman, H; Zulkefli, Na Mohd

2006-01-01

Breast cancer is the most commonly diagnosed cancer among Asian women. Breast cancer is detected in advanced stages and among younger age group women in Asia. The delay in presentation is attributed mainly to the social-cultural perception of the disease, poverty, and the strong influence of traditional medicine. Many of Asian women are not aware of the importance of regular screening. Cultural attitudes toward breast cancer screening tests, modesty, lack of encouragement by family members and physicians are the major inhibitors to women's participation in breast cancer screening. Health education using media and community health programs to create awareness of the advantages of earlier presentation and diagnosis of breast cancer in Asian women can motivate participation in breast cancer screening programs.

Do earthquakes exhibit self-organized criticality?

International Nuclear Information System (INIS)

Yang Xiaosong; Ma Jin; Du Shuming

2004-01-01

If earthquakes are phenomena of self-organized criticality (SOC), statistical characteristics of the earthquake time series should be invariant after the sequence of events in an earthquake catalog are randomly rearranged. In this Letter we argue that earthquakes are unlikely phenomena of SOC because our analysis of the Southern California Earthquake Catalog shows that the first-return-time probability P M (T) is apparently changed after the time series is rearranged. This suggests that the SOC theory should not be used to oppose the efforts of earthquake prediction

Prevalence and diversity of gastrointestinal helminths in free-ranging Asian house shrew (Suncus murinus in Bangladesh

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Mizanur Rahman

2018-04-01

Full Text Available Background and Aim: Asian house shrew (Suncus murinus, a widely distributed small mammal in the South Asian region, can carry helminths of zoonotic importance. The aim of the study was to know the prevalence and diversity of gastrointestinal (GI helminths in free-ranging Asian house shrew (S. murinus in Bangladesh. Materials and Methods: A total of 86 Asian house shrews were captured from forest areas and other habitats of Bangladesh in 2015. Gross examination of the whole GI tract was performed for gross helminth detection, and coproscopy was done for identification of specific eggs or larvae. Results: The overall prevalence of GI helminth was 77.9% (67/86, with six species including nematodes (3, cestodes (2, and trematodes (1. Of the detected helminths, the dominant parasitic group was from the genus Hymenolepis spp. (59%, followed by Strongyloides spp. (17%, Capillaria spp. (10%, Physaloptera spp. (3%, and Echinostoma spp. (3%. Conclusion: The finding shows that the presence of potential zoonotic parasites (Hymenolepis spp. and Capillaria spp. in Asian house shrew is ubiquitous in all types of habitat (forest land, cropland and dwelling in Bangladesh. Therefore, further investigation is crucial to examine their role in the transmission of human helminthiasis.

Prevalence and diversity of gastrointestinal helminths in free-ranging Asian house shrew (Suncus murinus) in Bangladesh

Science.gov (United States)

Rahman, Mizanur; Islam, Shariful; Masuduzzaman, Md.; Alam, Mahabub; Chawdhury, Mohammad Nizam Uddin; Ferdous, Jinnat; Islam, Md. Nurul; Hassan, Mohammad Mahmudul; Hossain, Mohammad Alamgir; Islam, Ariful

2018-01-01

Background and Aim Asian house shrew (Suncus murinus), a widely distributed small mammal in the South Asian region, can carry helminths of zoonotic importance. The aim of the study was to know the prevalence and diversity of gastrointestinal (GI) helminths in free-ranging Asian house shrew (S. murinus) in Bangladesh. Materials and Methods A total of 86 Asian house shrews were captured from forest areas and other habitats of Bangladesh in 2015. Gross examination of the whole GI tract was performed for gross helminth detection, and coproscopy was done for identification of specific eggs or larvae. Results The overall prevalence of GI helminth was 77.9% (67/86), with six species including nematodes (3), cestodes (2), and trematodes (1). Of the detected helminths, the dominant parasitic group was from the genus Hymenolepis spp.(59%), followed by Strongyloides spp.(17%), Capillaria spp. (10%), Physaloptera spp. (3%), and Echinostoma spp.(3%). Conclusion The finding shows that the presence of potential zoonotic parasites (Hymenolepis spp. and Capillaria spp.) in Asian house shrew is ubiquitous in all types of habitat (forest land, cropland and dwelling) in Bangladesh. Therefore, further investigation is crucial to examine their role in the transmission of human helminthiasis. PMID:29805224

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

2018-01-01

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

Characterization of the Virginia earthquake effects and source parameters from website traffic analysis

Science.gov (United States)

Bossu, R.; Lefebvre, S.; Mazet-Roux, G.; Roussel, F.

2012-12-01

This paper presents an after the fact study of the Virginia earthquake of 2011 August 23 using only the traffic observed on the EMSC website within minutes of its occurrence. Although the EMSC real time information services remain poorly identified in the US, a traffic surge was observed immediately after the earthquake's occurrence. Such surges, known as flashcrowd and commonly observed on our website after felt events within the Euro-Med region are caused by eyewitnesses looking for information about the shaking they have just felt. EMSC developed an approach named flashsourcing to map the felt area, and in some circumstances, the regions affected by severe damage or network disruption. The felt area is mapped simply by locating the Internet Protocol (IP) addresses of the visitors to the website during these surges while the existence of network disruption is detected by the instantaneous loss at the time of earthquake's occurrence of existing Internet sessions originating from the impacted area. For the Virginia earthquake, which was felt at large distances, the effects of the waves propagation are clearly observed. We show that the visits to our website are triggered by the P waves arrival: the first visitors from a given locality reach our website 90s after their location was shaken by the P waves. From a processing point of view, eyewitnesses can then be considered as ground motion detectors. By doing so, the epicentral location is determined through a simple dedicated location algorithm within 2 min of the earthquake's occurrence and 30 km accuracy. The magnitude can be estimated in similar time frame by using existing empirical relationships between the surface of the felt area and the magnitude. Concerning the effects of the earthquake, we check whether one can discriminate localities affected by strong shaking from web traffic analysis. This is actually the case. Localities affected by strong level of shaking exhibit higher ratio of visitors to the number

Overestimation of the earthquake hazard along the Himalaya: constraints in bracketing of medieval earthquakes from paleoseismic studies

Science.gov (United States)

Arora, Shreya; Malik, Javed N.

2017-12-01

The Himalaya is one of the most seismically active regions of the world. The occurrence of several large magnitude earthquakes viz. 1905 Kangra earthquake (Mw 7.8), 1934 Bihar-Nepal earthquake (Mw 8.2), 1950 Assam earthquake (Mw 8.4), 2005 Kashmir (Mw 7.6), and 2015 Gorkha (Mw 7.8) are the testimony to ongoing tectonic activity. In the last few decades, tremendous efforts have been made along the Himalayan arc to understand the patterns of earthquake occurrences, size, extent, and return periods. Some of the large magnitude earthquakes produced surface rupture, while some remained blind. Furthermore, due to the incompleteness of the earthquake catalogue, a very few events can be correlated with medieval earthquakes. Based on the existing paleoseismic data certainly, there exists a complexity to precisely determine the extent of surface rupture of these earthquakes and also for those events, which occurred during historic times. In this paper, we have compiled the paleo-seismological data and recalibrated the radiocarbon ages from the trenches excavated by previous workers along the entire Himalaya and compared earthquake scenario with the past. Our studies suggest that there were multiple earthquake events with overlapping surface ruptures in small patches with an average rupture length of 300 km limiting Mw 7.8-8.0 for the Himalayan arc, rather than two or three giant earthquakes rupturing the whole front. It has been identified that the large magnitude Himalayan earthquakes, such as 1905 Kangra, 1934 Bihar-Nepal, and 1950 Assam, that have occurred within a time frame of 45 years. Now, if these events are dated, there is a high possibility that within the range of ±50 years, they may be considered as the remnant of one giant earthquake rupturing the entire Himalayan arc. Therefore, leading to an overestimation of seismic hazard scenario in Himalaya.

Stress triggering of the Lushan M7. 0 earthquake by the Wenchuan Ms8. 0 earthquake

Directory of Open Access Journals (Sweden)

Wu Jianchao

2013-08-01

Full Text Available The Wenchuan Ms8. 0 earthquake and the Lushan M7. 0 earthquake occurred in the north and south segments of the Longmenshan nappe tectonic belt, respectively. Based on the focal mechanism and finite fault model of the Wenchuan Ms8. 0 earthquake, we calculated the coulomb failure stress change. The inverted coulomb stress changes based on the Nishimura and Chenji models both show that the Lushan M7. 0 earthquake occurred in the increased area of coulomb failure stress induced by the Wenchuan Ms8. 0 earthquake. The coulomb failure stress increased by approximately 0. 135 – 0. 152 bar in the source of the Lushan M7. 0 earthquake, which is far more than the stress triggering threshold. Therefore, the Lushan M7. 0 earthquake was most likely triggered by the coulomb failure stress change.

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...

Seismic swarm associated with the 2008 eruption of Kasatochi Volcano, Alaska: earthquake locations and source parameters

Science.gov (United States)

Ruppert, Natalia G.; Prejean, Stephanie G.; Hansen, Roger A.

2011-01-01

An energetic seismic swarm accompanied an eruption of Kasatochi Volcano in the central Aleutian volcanic arc in August of 2008. In retrospect, the first earthquakes in the swarm were detected about 1 month prior to the eruption onset. Activity in the swarm quickly intensified less than 48 h prior to the first large explosion and subsequently subsided with decline of eruptive activity. The largest earthquake measured as moment magnitude 5.8, and a dozen additional earthquakes were larger than magnitude 4. The swarm exhibited both tectonic and volcanic characteristics. Its shear failure earthquake features were b value = 0.9, most earthquakes with impulsive P and S arrivals and higher-frequency content, and earthquake faulting parameters consistent with regional tectonic stresses. Its volcanic or fluid-influenced seismicity features were volcanic tremor, large CLVD components in moment tensor solutions, and increasing magnitudes with time. Earthquake location tests suggest that the earthquakes occurred in a distributed volume elongated in the NS direction either directly under the volcano or within 5-10 km south of it. Following the MW 5.8 event, earthquakes occurred in a new crustal volume slightly east and north of the previous earthquakes. The central Aleutian Arc is a tectonically active region with seismicity occurring in the crusts of the Pacific and North American plates in addition to interplate events. We postulate that the Kasatochi seismic swarm was a manifestation of the complex interaction of tectonic and magmatic processes in the Earth's crust. Although magmatic intrusion triggered the earthquakes in the swarm, the earthquakes failed in context of the regional stress field.

Active tectonics and earthquake potential of the Myanmar region

Science.gov (United States)

Wang, Yu; Sieh, Kerry; Tun, Soe Thura; Lai, Kuang-Yin; Myint, Than

2014-04-01

This paper describes geomorphologic evidence for the principal neotectonic features of Myanmar and its immediate surroundings. We combine this evidence with published structural, geodetic, and seismic data to present an overview of the active tectonic architecture of the region and its seismic potential. Three tectonic systems accommodate oblique collision of the Indian plate with Southeast Asia and extrusion of Asian territory around the eastern syntaxis of the Himalayan mountain range. Subduction and collision associated with the Sunda megathrust beneath and within the Indoburman range and Naga Hills accommodate most of the shortening across the transpressional plate boundary. The Sagaing fault system is the predominant locus of dextral motion associated with the northward translation of India. Left-lateral faults of the northern Shan Plateau, northern Laos, Thailand, and southern China facilitate extrusion of rocks around the eastern syntaxis of the Himalaya. All of these systems have produced major earthquakes within recorded history and continue to present major seismic hazards in the region.

Monitoring of soil radon by SSNTD in Eastern India in search of possible earthquake precursor.

Science.gov (United States)

Deb, Argha; Gazi, Mahasin; Ghosh, Jayita; Chowdhury, Saheli; Barman, Chiranjib

2018-04-01

The present paper deals with monitoring soil radon-222 concentration at two different locations, designated Site A and Site B, 200 m apart at Jadavpur University campus, Kolkata, India, with a view to find possible precursors for the earthquakes that occurred within a few hundred kilometers from the monitoring site. The solid state nuclear track detector CR-39 has been used for detection of radon gas coming out from soil. Radon-222 time series at both locations during the period August 2012-December 2013 have been analysed. Distinct anomalies in the soil radon time series have been observed for seven earthquakes of magnitude greater than 4.0 M that occurred during this time. Of these, radon anomalies for two earthquakes have been observed at both locations A and B. Absence of anomalies for some other earthquakes has been discussed, and the observations have been compared with some earthquake precursor models. Copyright © 2018. Published by Elsevier Ltd.

History of Asian American psychology.

Science.gov (United States)

Leong, Frederick T L; Okazaki, Sumie

2009-10-01

An overview of the history of Asian American psychology is provided by reviewing the context for the development of the field as well as the early founding of the Asian American Psychological Association (AAPA). The presidents of AAPA as well as key events and conferences are noted. The involvement of AAPA leaders in national mental health policies and activities are reviewed. The substantive areas of Asian American psychology and the education and training of Asian American psychologists are also discussed. The article ends with some comments about the future of Asian American psychology. Copyright 2009 APA, all rights reserved.

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.

Thoracic Injuries in earthquake-related versus non-earthquake-related trauma patients: differentiation via Multi-detector Computed Tomography

Science.gov (United States)

Dong, Zhi-hui; Yang, Zhi-gang; Chen, Tian-wu; Chu, Zhi-gang; Deng, Wen; Shao, Heng

2011-01-01

PURPOSE: Massive earthquakes are harmful to humankind. This study of a historical cohort aimed to investigate the difference between earthquake-related crush thoracic traumas and thoracic traumas unrelated to earthquakes using a multi-detector Computed Tomography (CT). METHODS: We retrospectively compared an earthquake-exposed cohort of 215 thoracic trauma crush victims of the Sichuan earthquake to a cohort of 215 non-earthquake-related thoracic trauma patients, focusing on the lesions and coexisting injuries to the thoracic cage and the pulmonary parenchyma and pleura using a multi-detector CT. RESULTS: The incidence of rib fracture was elevated in the earthquake-exposed cohort (143 vs. 66 patients in the non-earthquake-exposed cohort, Risk Ratio (RR) = 2.2; pchest (45/143 vs. 11/66 patients, RR = 1.9; ptraumas resulting from the earthquake were life threatening with a high incidence of bony thoracic fractures. The ribs were frequently involved in bilateral and severe types of fractures, which were accompanied by non-rib fractures, pulmonary parenchymal and pleural injuries. PMID:21789386

Priorities and approaches to investigating Asian youth health: perspectives of young Asian New Zealanders.

Science.gov (United States)

Wong, Agnes; Peiris-John, Roshini; Sobrun-Maharaj, Amritha; Ameratunga, Shanthi

2015-12-01

The proportion of young people in New Zealand identifying with Asian ethnicities has increased considerably. Despite some prevalent health concerns, Asian youth are less likely than non-Asian peers to seek help. As preparatory research towards a more nuanced approach to service delivery and public policy, this qualitative study aimed to identify young Asian New Zealanders' perspectives on best approaches to investigate health issues of priority concern to them. Three semi-structured focus group discussions were conducted with 15 Asian youth leaders aged 18-24 years. Using an inductive approach for thematic analysis, key themes were identified and analysed. Study participants considered ethno-cultural identity, racism and challenges in integration to play significant roles influencing the health of Asian youth (especially mental health) and their access to health services. While emphasising the importance of engaging young Asians in research and service development so that their needs and aspirations are met, participants also highlighted the need for approaches that are cognisant of the cultural, contextual and intergenerational dimensions of issues involved in promoting youth participation. Research that engages Asian youth as key agents using methods that are sensitive to their cultural and sociological contexts can inform more responsive health services and public policy. This is of particular relevance in primary health care where culturally competent services can mitigate risks of unmet health needs and social isolation.

Consideration for standard earthquake vibration (1). The Niigataken Chuetsu-oki Earthquake in 2007

International Nuclear Information System (INIS)

Ishibashi, Katsuhiko

2007-01-01

Outline of new guideline of quakeproof design standard of nuclear power plant and the standard earthquake vibration are explained. The improvement points of new guideline are discussed on the basis of Kashiwazaki-Kariwa Nuclear Power Plant incidents. The fundamental limits of new guideline are pointed. Placement of the quakeproof design standard of nuclear power plant, JEAG4601 of Japan Electric Association, new guideline, standard earthquake vibration of new guideline, the Niigataken Chuetsu-oki Earthquake in 2007 and damage of Kashiwazaki-Kariwa Nuclear Power Plant are discussed. The safety criteria of safety review system, organization, standard and guideline should be improved on the basis of this earthquake and nuclear plant accident. The general knowledge, 'a nuclear power plant is not constructed in the area expected large earthquake', has to be realized. Preconditions of all nuclear power plants should not cause damage to anything. (S.Y.)

Intensity earthquake scenario (scenario event - a damaging earthquake with higher probability of occurrence) for the city of Sofia

Science.gov (United States)

Aleksandrova, Irena; Simeonova, Stela; Solakov, Dimcho; Popova, Maria

2014-05-01

Among the many kinds of natural and man-made disasters, earthquakes dominate with regard to their social and economical impact on the urban environment. Global seismic risk to earthquakes are increasing steadily as urbanization and development occupy more areas that a prone to effects of strong earthquakes. Additionally, the uncontrolled growth of mega cities in highly seismic areas around the world is often associated with the construction of seismically unsafe buildings and infrastructures, and undertaken with an insufficient knowledge of the regional seismicity peculiarities and seismic hazard. The assessment of seismic hazard and generation of earthquake scenarios is the first link in the prevention chain and the first step in the evaluation of the seismic risk. The earthquake 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. The city of Sofia is the capital of Bulgaria. It is situated in the centre of the Sofia area that is the most populated (the population is of more than 1.2 mil. inhabitants), industrial and cultural region of Bulgaria that faces considerable earthquake risk. The available historical documents prove the occurrence of destructive earthquakes during the 15th-18th centuries in the Sofia zone. In 19th century the city of Sofia has experienced two strong earthquakes: the 1818 earthquake with epicentral intensity I0=8-9 MSK and the 1858 earthquake with I0=9-10 MSK. During the 20th century the strongest event occurred in the vicinity of the city of Sofia is the 1917 earthquake with MS=5.3 (I0=7-8 MSK). Almost a century later (95 years) an earthquake of moment magnitude 5.6 (I0=7-8 MSK) hit the city of Sofia, on May 22nd, 2012. In the present study as a deterministic scenario event is considered a damaging earthquake with higher probability of occurrence that could affect the city with intensity less than or equal to VIII

Evolution of Asian Interior Arid-Zone Biota: Evidence from the Diversification of Asian Zygophyllum (Zygophyllaceae)

Science.gov (United States)

Li, Hong-Lei; Yu, Sheng-Xiang; Zhang, Lin-Jing; Wang, Wei

2015-01-01

The Asian interior arid zone is the largest desert landform system in the Northern Hemisphere, and has high biodiversity. Little is currently known about the evolutionary history of its biota. In this study, we used Zygophyllum, an important and characteristic component of the Asian interior arid zone, to provide new insights into the evolution of this biota. By greatly enlarged taxon sampling, we present the phylogenetic analysis of Asian Zygophyllum based on two plastid and one nuclear markers. Our phylogenetic analyses indicate that Asian Zygophyllum and Sarcozygium form a clade and Sarcozygium is further embedded within the shrub subclade. An integration of phylogenetic, biogeographic, and molecular dating methods indicates that Zygophyllum successfully colonized the Asian interior from Africa in the early Oligocene, and Asian Zygophyllum became differentiated in the early Miocene and underwent a burst of diversification in the late Miocene associated with the expansion of Asian interior arid lands due to orogenetic and climatic changes. Combining diversification patterns of other important components of the Asian interior arid zone, we propose a multi-stage evolution model for this biota: the late Eocene–early Oligocene origin, the early Miocene expansion, and the middle-late Miocene rapid expansion to the whole Asian interior arid zone. This study also demonstrates that, for Zygophyllum and perhaps other arid-adapted organisms, arid biomes are evolutionary cradles of diversity. PMID:26393796

Earthquake recurrence models fail when earthquakes fail to reset the stress field

Science.gov (United States)

Tormann, Thessa; Wiemer, Stefan; Hardebeck, Jeanne L.

2012-01-01

Parkfield's regularly occurring M6 mainshocks, about every 25 years, have over two decades stoked seismologists' hopes to successfully predict an earthquake of significant size. However, with the longest known inter-event time of 38 years, the latest M6 in the series (28 Sep 2004) did not conform to any of the applied forecast models, questioning once more the predictability of earthquakes in general. Our study investigates the spatial pattern of b-values along the Parkfield segment through the seismic cycle and documents a stably stressed structure. The forecasted rate of M6 earthquakes based on Parkfield's microseismicity b-values corresponds well to observed rates. We interpret the observed b-value stability in terms of the evolution of the stress field in that area: the M6 Parkfield earthquakes do not fully unload the stress on the fault, explaining why time recurrent models fail. We present the 1989 M6.9 Loma Prieta earthquake as counter example, which did release a significant portion of the stress along its fault segment and yields a substantial change in b-values.

Cascading hazards: Understanding triggering relations between wet tropical cyclones, landslides, and earthquakes

Science.gov (United States)

Wdowinski, S.; Peng, Z.; Ferrier, K.; Lin, C. H.; Hsu, Y. J.; Shyu, J. B. H.

2017-12-01

Earthquakes, landslides, and tropical cyclones are extreme hazards that pose significant threats to human life and property. Some of the couplings between these hazards are well known. For example, sudden, widespread landsliding can be triggered by large earthquakes and by extreme rainfall events like tropical cyclones. Recent studies have also shown that earthquakes can be triggered by erosional unloading over 100-year timescales. In a NASA supported project, titled "Cascading hazards: Understanding triggering relations between wet tropical cyclones, landslides, and earthquake", we study triggering relations between these hazard types. The project focuses on such triggering relations in Taiwan, which is subjected to very wet tropical storms, landslides, and earthquakes. One example for such triggering relations is the 2009 Morakot typhoon, which was the wettest recorded typhoon in Taiwan (2850 mm of rain in 100 hours). The typhoon caused widespread flooding and triggered more than 20,000 landslides, including the devastating Hsiaolin landslide. Six months later, the same area was hit by the 2010 M=6.4 Jiashian earthquake near Kaohsiung city, which added to the infrastructure damage induced by the typhoon and the landslides. Preliminary analysis of temporal relations between main-shock earthquakes and the six wettest typhoons in Taiwan's past 50 years reveals similar temporal relations between M≥5 events and wet typhoons. Future work in the project will include remote sensing analysis of landsliding, seismic and geodetic monitoring of landslides, detection of microseismicity and tremor activities, and mechanical modeling of crustal stress changes due to surface unloading.

The results of the Seismic Alert System of Mexico SASMEX, during the earthquakes of 7 and 19 of September 2017

Science.gov (United States)

Espinosa Aranda, J. M., Sr.; Cuellar Martinez, A.

2017-12-01

The Seismic Alert System of Mexico, SASMEX began in 1991, is integrated by the seismic alert system of Mexico City and the seismic alert system of Oaxaca. SASMEX has 97 seismic sensors which are distributed in the seismic regions of the Pacific coast and the South of the Trans-Mexican Volcanic Belt of states of Jalisco, Colima, Michoacán, Guerrero, Oaxaca and Puebla. The alert dissemination covers the cities of: Acapulco, Chilpancingo, Morelia, Puebla, Oaxaca, Toluca and Mexico City, reaching the earthquake warnings to more than 25 millions of people. SASMEX has detected correctly more than 5600 earthquakes and warned 156. Mexico City has different alert dissemination systems like several Radio and Tv commercial broadcasters, dedicated radio receivers, EAS-SAME-SARMEX radio receivers and more tha 6700 public loud speakers. The other cities have only some of those systems. The Mw 8.2 Chiapas earthquake on September 7, despite the epicentral distance far of the first seismic detections (more than 180 km) and the low amplitudes of the P waves, the earthquake warning time gave more than 90 seconds to Mexico City before the arrivals of S waves with minor damages to the city in contrast with high damages in towns in the coast. This earthquake offered an opportunity to show the developments and lacks to reduce the risk, such as the need to increase the seismic detection coverage and the earthquake warning dissemination in towns with high seismic vulnerability. The Mw 7.1 Morelos earthquake on September 19 caused thousands of damages and hundreds of deaths and injuries in Mexico City, this earthquake is the second with the most damages after the Mw 8.1 Michoacán earthquake of September 19 on 1985. The earthquake early warning gave 11 seconds after the arrivals of S waves, however the activation occurred few seconds after the P waves arrives to Mexico City, and due to the seismic focus was near to the city, the P waves were felt for the people. The Accelerographic Network

Observation of Asian dust properties by using multi-wavelength LIDAR system at anmyeon island, Korea

International Nuclear Information System (INIS)

Choi, Sung Chul; Ko, Do Kyeoung; Lee, Jong Min; Kim, Young Joon; Noh, Young Min

2004-01-01

The Asian dust affect climate both directly and indirectly because they act as effective ice nuclei and forms ice cloud. However, little is known about spatial distribution and trajectory because few measurement data are available in the free troposphere over East Asia, where a large amount of Asian dust are transported form desert regions in Asian continent. LIDAR system is an effective tool for remotely measuring the vertical distribution of aerosol optical properties. For measurement of Asian dust optical properties, a multi-wavelength LIDAR system developed by the Advanced Environment Monitoring Research Center (ADEMRC), Gwangju Institute Science and Technology (GIST), Korea. This paper presents the results of ground-based multi-wavelength LIDAR measurements of the Asian dust aerosol over Anmyeon Island (36.40N, 126.10E) during the spring of 2004. To discriminate between Asian dust and cloud, depolarization ratio is useful for the detection of these particles and the LIDAR ratio. Also, we discuss the relationship between LIDAR ratio and other optical properties from LIDAR measurement, i.e., the depolarization ratio, aerosol extinction coefficient and LIDAR ratio

Defining obesity cut-off points for migrant South Asians.

Directory of Open Access Journals (Sweden)

Laura J Gray

Full Text Available Body mass index (BMI and waist circumference (WC are used to define cardiovascular and type 2 diabetes risk. We aimed to derive appropriate BMI and WC obesity cut-off points in a migrant South Asian population.4688 White Europeans and 1333 South Asians resident in the UK aged 40-75 years inclusive were screened for type 2 diabetes. Principal components analysis was used to derive a glycaemia, lipid, and a blood pressure factor. Regression models for each factor, adjusted for age and stratified by sex, were used to identify BMI and WC cut-off points in South Asians that correspond to those defined for White Europeans.For South Asian males, derived BMI obesity cut-off points equivalent to 30.0 kg/m(2 in White Europeans were 22.6 kg/m(2 (95% Confidence Interval (95% CI 20.7 kg/m(2 to 24.5 kg/m(2 for the glycaemia factor, 26.0 kg/m(2 (95% CI 24.7 kg/m(2 to 27.3 kg/m(2 for the lipid factor, and 28.4 kg/m(2 (95% CI 26.5 kg/m(2 to 30.4 kg/m(2 for the blood pressure factor. For WC, derived cut-off points for South Asian males equivalent to 102 cm in White Europeans were 83.8 cm (95% CI 79.3 cm to 88.2 cm for the glycaemia factor, 91.4 cm (95% CI 86.9 cm to 95.8 cm for the lipid factor, and 99.3 cm (95% CI 93.3 cm to 105.2 cm for the blood pressure factor. Lower ethnicity cut-off points were seen for females for both BMI and WC.Substantially lower obesity cut-off points are needed in South Asians to detect an equivalent level of dysglycemia and dyslipidemia as observed in White Europeans. South Asian ethnicity could be considered as a similar level of risk as obesity (in White Europeans for the development of type 2 diabetes.

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.

The CATDAT damaging earthquakes database

Science.gov (United States)

Daniell, J. E.; Khazai, B.; Wenzel, F.; Vervaeck, A.

2011-08-01

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 reinsurance field.

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

Insight into the Earthquake Risk Information Seeking Behavior of the Victims: Evidence from Songyuan, China

Directory of Open Access Journals (Sweden)

Shasha Li

2017-03-01

Full Text Available Efficient risk communication is a vital way to reduce the vulnerability of individuals when facing emergency risks, especially regarding earthquakes. Efficient risk communication aims at improving the supply of risk information and fulfilling the need for risk information by individuals. Therefore, an investigation into individual-level information seeking behavior within earthquake risk contexts is very important for improved earthquake risk communication. However, at present there are very few studies that have explored the behavior of individuals seeking earthquake risk information. Under the guidance of the Risk Information Seeking and Processing model as well as relevant practical findings using the structural equation model, this study attempts to explore the main determinants of an individual’s earthquake risk information seeking behavior, and to validate the mediator effect of information need during the seeking process. A questionnaire-based survey of 918 valid respondents in Songyuan, China, who had been hit by a small earthquake swarm, was used to provide practical evidence for this study. Results indicated that information need played a noteworthy role in the earthquake risk information seeking process, and was detected both as an immediate predictor and as a mediator. Informational subjective norms drive the seeking behavior on earthquake risk information through both direct and indirect approaches. Perceived information gathering capacity, negative affective responses and risk perception have an indirect effect on earthquake risk information seeking behavior via information need. The implications for theory and practice regarding risk communication are discussed and concluded.

The Asian methanol market

International Nuclear Information System (INIS)

Nagase, Hideki

1995-01-01

For the purpose of this presentation, Asia has been broadly defined as a total of 15 countries, namely Japan, Korea, Taiwan, China, Hong Kong, the Philippines, Thailand, Malaysia, Singapore, Indonesia, Myanmar, India, Vietnam, Australia and New Zealand. In 1994 and the first half of 1995, the methanol industry and its derivative industries experienced hard time, because of extraordinarily high methanol prices. In spite of this circumstance, methanol demand in Asian countries has been growing steadily and remarkably, following Asian high economic growth. Most of this growth in demand has been and will continue to be met by outside supply. However, even with increased import of methanol from outside of Asia, as a result of this growth, Asian trade volume will be much larger in the coming years. Asian countries must turn their collective attention to making logistics and transportation for methanol and its derivatives more efficient in the Asian region to make better use of existing supply resources. The author reviews current economic growth as his main topic, and explains the forecast of the growth of methanol demand and supply in Asian countries in the near future

Comparison of aftershock sequences between 1975 Haicheng earthquake and 1976 Tangshan earthquake

Science.gov (United States)

Liu, B.

2017-12-01

The 1975 ML 7.3 Haicheng earthquake and the 1976 ML 7.8 Tangshan earthquake occurred in the same tectonic unit. There are significant differences in spatial-temporal distribution, number of aftershocks and time duration for the aftershock sequence followed by these two main shocks. As we all know, aftershocks could be triggered by the regional seismicity change derived from the main shock, which was caused by the Coulomb stress perturbation. Based on the rate- and state- dependent friction law, we quantitative estimated the possible aftershock time duration with a combination of seismicity data, and compared the results from different approaches. The results indicate that, aftershock time durations from the Tangshan main shock is several times of that form the Haicheng main shock. This can be explained by the significant relationship between aftershock time duration and earthquake nucleation history, normal stressand shear stress loading rateon the fault. In fact the obvious difference of earthquake nucleation history from these two main shocks is the foreshocks. 1975 Haicheng earthquake has clear and long foreshocks, while 1976 Tangshan earthquake did not have clear foreshocks. In that case, abundant foreshocks may mean a long and active nucleation process that may have changed (weakened) the rocks in the source regions, so they should have a shorter aftershock sequences for the reason that stress in weak rocks decay faster.

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.

Validating of Atmospheric Signals Associated with some of the Major Earthquakes in Asia (2003-2009)

Science.gov (United States)

Ouzounov, D. P.; Pulinets, S.; Liu, J. Y.; Hattori, K.; Oarritm N,; Taylor, P. T.

2010-01-01

The recent catastrophic earthquake in Haiti (January 2010) has provided and renewed interest in the important question of the existence of precursory signals related to strong earthquakes. Latest studies (VESTO workshop in Japan 2009) have shown that there were precursory atmospheric signals observed on the ground and in space associated with several recent earthquakes. The major question, still widely debated in the scientific community is whether such signals systematically precede major earthquakes. To address this problem we have started to validate the anomalous atmospheric signals during the occurrence of large earthquakes. Our approach is based on integration analysis of several physical and environmental parameters (thermal infrared radiation, electron concentration in the ionosphere, Radon/ion activities, air temperature and seismicity) that were found to be associated with earthquakes. We performed hind-cast detection over three different regions with high seismicity Taiwan, Japan and Kamchatka for the period of 2003-2009. We are using existing thermal satellite data (Aqua and POES); in situ atmospheric data (NOAA/NCEP); and ionospheric variability data (GPS/TEC and DEMETER). The first part of this validation included 42 major earthquakes (M greater than 5.9): 10 events in Taiwan, 15 events in Japan, 15 events in Kamchatka and four most recent events for M8.0 Wenchuan earthquake (May 2008) in China and M7.9 Samoa earthquakes (Sep 2009). Our initial results suggest a systematic appearance of atmospheric anomalies near the epicentral area, 1 to 5 days prior to the largest earthquakes, that could be explained by a coupling process between the observed physical parameters, and the earthquake preparation processes.

Tradable Earthquake Certificates

NARCIS (Netherlands)

Woerdman, Edwin; Dulleman, Minne

2018-01-01

This article presents a market-based idea to compensate for earthquake damage caused by the extraction of natural gas and applies it to the case of Groningen in the Netherlands. Earthquake certificates give homeowners a right to yearly compensation for both property damage and degradation of living

Seismomagnetic models for earthquakes in the eastern part of Izu Peninsula, Central Japan

Directory of Open Access Journals (Sweden)

Y. Ishikawa

1997-06-01

Full Text Available Seismomagnetic changes accompanied by four damaging earthquakes are explained by the piezomagnetic effect observed in the eastern part of Izu Peninsula, Central Japan. Most of the data were obtained by repeat surveys. Although these data suffered electric railway noise, significant magnetic changes were detected at points close to earthquake faults. Coseismic changes can be well interpreted by piezomagnetic models in the case of the 1978 Near Izu-Oshima (M 7.0 and the 1980 East Off Izu Peninsula (M 6.7 earthquakes. A large total intensity change up to 5 nT was observed at a survey point almost above the epicenter of the 1976 Kawazu (M 5.4 earthquake. This change is not explained by a single fault model; a 2-segment fault is suggested. Remarkable precursory and coseismic changes in the total force intensity were observed at KWZ station along with the 1978 Higashi-Izu (M 4.9 earthquake. KWZ station is located very close to a buried subsidiary fault of the M 7.0 Near Izu-Oshima earthquake, which moved aseismically at the time of the M 7.0 quake. The precursory magnetic change to the M 4.9 quake is ascribed to aseismic faulting of this buried fault, while the coseismic rebound to enlargement of the slipping surface at the time of M 4.9 quake. This implies that we observed the formation process of the earthquake nucleation zone via the magnetic field.

South Asian high and Asian-Pacific-American climate teleconnection

Science.gov (United States)

Zhang, Peiqun; Song, Yang; Kousky, Vernon E.

2005-11-01

Growing evidence indicates that the Asian monsoon plays an important role in affecting the weather and climate outside of Asia. However, this active role of the monsoon has not been demonstrated as thoroughly as has the variability of the monsoon caused by various impacting factors such as sea surface temperature and land surface. This study investigates the relationship between the Asian monsoon and the climate anomalies in the Asian-Pacific-American (APA) sector. A hypothesis is tested that the variability of the upper-tropospheric South Asian high (SAH), which is closely associated with the overall heating of the large-scale Asian monsoon, is linked to changes in the subtropical western Pacific high (SWPH), the mid-Pacific trough, and the Mexican high. The changes in these circulation systems cause variability in surface temperature and precipitation in the APA region. A stronger SAH is accompanied by a stronger and more extensive SWPH. The enlargement of the SWPH weakens the mid-Pacific trough. As a result, the southern portion of the Mexican high becomes stronger. These changes are associated with changes in atmospheric teleconnections, precipitation, and surface temperature throughout the APA region. When the SAH is stronger, precipitation increases in southern Asia, decreases over the Pacific Ocean, and increases over the Central America. Precipitation also increases over Australia and central Africa and decreases in the Mediterranean region. While the signals in surface temperature are weak over the tropical land portion, they are apparent in the mid latitudes and over the eastern Pacific Ocean.

What Can Sounds Tell Us About Earthquake Interactions?

Science.gov (United States)

Aiken, C.; Peng, Z.

2012-12-01

It is important not only for seismologists but also for educators to effectively convey information about earthquakes and the influences earthquakes can have on each other. Recent studies using auditory display [e.g. Kilb et al., 2012; Peng et al. 2012] have depicted catastrophic earthquakes and the effects large earthquakes can have on other parts of the world. Auditory display of earthquakes, which combines static images with time-compressed sound of recorded seismic data, is a new approach to disseminating information to a general audience about earthquakes and earthquake interactions. Earthquake interactions are influential to understanding the underlying physics of earthquakes and other seismic phenomena such as tremors in addition to their source characteristics (e.g. frequency contents, amplitudes). Earthquake interactions can include, for example, a large, shallow earthquake followed by increased seismicity around the mainshock rupture (i.e. aftershocks) or even a large earthquake triggering earthquakes or tremors several hundreds to thousands of kilometers away [Hill and Prejean, 2007; Peng and Gomberg, 2010]. We use standard tools like MATLAB, QuickTime Pro, and Python to produce animations that illustrate earthquake interactions. Our efforts are focused on producing animations that depict cross-section (side) views of tremors triggered along the San Andreas Fault by distant earthquakes, as well as map (bird's eye) views of mainshock-aftershock sequences such as the 2011/08/23 Mw5.8 Virginia earthquake sequence. These examples of earthquake interactions include sonifying earthquake and tremor catalogs as musical notes (e.g. piano keys) as well as audifying seismic data using time-compression. Our overall goal is to use auditory display to invigorate a general interest in earthquake seismology that leads to the understanding of how earthquakes occur, how earthquakes influence one another as well as tremors, and what the musical properties of these

Real-Time Data Processing Systems and Products at the Alaska Earthquake Information Center

Science.gov (United States)

Ruppert, N. A.; Hansen, R. A.

2007-05-01

The Alaska Earthquake Information Center (AEIC) receives data from over 400 seismic sites located within the state boundaries and the surrounding regions and serves as a regional data center. In 2007, the AEIC reported ~20,000 seismic events, with the largest event of M6.6 in Andreanof Islands. The real-time earthquake detection and data processing systems at AEIC are based on the Antelope system from BRTT, Inc. This modular and extensible processing platform allows an integrated system complete from data acquisition to catalog production. Multiple additional modules constructed with the Antelope toolbox have been developed to fit particular needs of the AEIC. The real-time earthquake locations and magnitudes are determined within 2-5 minutes of the event occurrence. AEIC maintains a 24/7 seismologist-on-duty schedule. Earthquake alarms are based on the real- time earthquake detections. Significant events are reviewed by the seismologist on duty within 30 minutes of the occurrence with information releases issued for significant events. This information is disseminated immediately via the AEIC website, ANSS website via QDDS submissions, through e-mail, cell phone and pager notifications, via fax broadcasts and recorded voice-mail messages. In addition, automatic regional moment tensors are determined for events with M>=4.0. This information is posted on the public website. ShakeMaps are being calculated in real-time with the information currently accessible via a password-protected website. AEIC is designing an alarm system targeted for the critical lifeline operations in Alaska. AEIC maintains an extensive computer network to provide adequate support for data processing and archival. For real-time processing, AEIC operates two identical, interoperable computer systems in parallel.

Masculine Norms, Avoidant Coping, Asian Values and Depression among Asian American Men.

Science.gov (United States)

Iwamoto, Derek Kenji; Liao, Liang; Liu, William Ming

2010-01-01

Contrary to the "model minority" myth, growing research indicates that the rates of mental health problems among Asian Americans may be higher than initially assumed. This study seeks to add to the scant knowledge regarding the mental health of Asian American men by examining the role of masculine norms, coping and cultural values in predicting depression among this population (N=149). Results reveal that Asian American men who used avoidant coping strategies and endorsed the masculine norm Dominance reported higher levels of depressive symptoms. In contrast, endorsing Winning masculine norms was associated to lower levels of depressive symptoms. Findings suggest that adherence to masculine norms and avoidant coping strategies play a salient role in the mental health of Asian American men.

Masculine Norms, Avoidant Coping, Asian Values and Depression among Asian American Men

Science.gov (United States)

Iwamoto, Derek Kenji; Liao, Liang; Liu, William Ming

2010-01-01

Contrary to the “model minority” myth, growing research indicates that the rates of mental health problems among Asian Americans may be higher than initially assumed. This study seeks to add to the scant knowledge regarding the mental health of Asian American men by examining the role of masculine norms, coping and cultural values in predicting depression among this population (N=149). Results reveal that Asian American men who used avoidant coping strategies and endorsed the masculine norm Dominance reported higher levels of depressive symptoms. In contrast, endorsing Winning masculine norms was associated to lower levels of depressive symptoms. Findings suggest that adherence to masculine norms and avoidant coping strategies play a salient role in the mental health of Asian American men. PMID:20657794

Nowcasting Earthquakes and Tsunamis

Science.gov (United States)

Rundle, J. B.; Turcotte, D. L.

2017-12-01

The term "nowcasting" refers to the estimation of the current uncertain state of a dynamical system, whereas "forecasting" is a calculation of probabilities of future state(s). Nowcasting is a term that originated in economics and finance, referring to the process of determining the uncertain state of the economy or market indicators such as GDP at the current time by indirect means. We have applied this idea to seismically active regions, where the goal is to determine the current state of a system of faults, and its current level of progress through the earthquake cycle (http://onlinelibrary.wiley.com/doi/10.1002/2016EA000185/full). Advantages of our nowcasting method over forecasting models include: 1) Nowcasting is simply data analysis and does not involve a model having parameters that must be fit to data; 2) We use only earthquake catalog data which generally has known errors and characteristics; and 3) We use area-based analysis rather than fault-based analysis, meaning that the methods work equally well on land and in subduction zones. To use the nowcast method to estimate how far the fault system has progressed through the "cycle" of large recurring earthquakes, we use the global catalog of earthquakes, using "small" earthquakes to determine the level of hazard from "large" earthquakes in the region. We select a "small" region in which the nowcast is to be made, and compute the statistics of a much larger region around the small region. The statistics of the large region are then applied to the small region. For an application, we can define a small region around major global cities, for example a "small" circle of radius 150 km and a depth of 100 km, as well as a "large" earthquake magnitude, for example M6.0. The region of influence of such earthquakes is roughly 150 km radius x 100 km depth, which is the reason these values were selected. We can then compute and rank the seismic risk of the world's major cities in terms of their relative seismic risk

Roles of Radon-222 and other natural radionuclides in earthquake prediction

International Nuclear Information System (INIS)

Smith, A.R.; Wollenberg, H.A.; Mosier, D.F.

1980-01-01

The concentration of 222 Rn in subsurface waters is one of the natural parameters being investigated to help develop the capability to predict destructive earthquakes. Since 1966, scientists in several nations have sought to link radon variations with ongoing seismic activity, primarily through the dilatancy model for earthquake occurrences. Within the range of these studies, alpha-, beta-, and gamma-radiation detection techniques have been used in both discrete-sampling and continiuous-monitoring programs. These measured techniques are reviewed in terms of instrumentation adapted to seismic-monitoring purposes. A recent Lawrence Berkeley Laboratory study conducted in central California incorporated discrete sampling of wells in the aftershock area of the 1975 Oroville earthquake and continuous monitoring of water radon in a well on the San Andreas Fault. The results presented show short-term radon variations that may be associated with aftershocks and diurnal changes that may reflect earth tidal forces

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.

Earthquake at 40 feet

Science.gov (United States)

Miller, G. J.

1976-01-01

The earthquake that struck the island of Guam on November 1, 1975, at 11:17 a.m had many unique aspects-not the least of which was the experience of an earthquake of 6.25 Richter magnitude while at 40 feet. My wife Bonnie, a fellow diver, Greg Guzman, and I were diving at Gabgab Beach in teh outer harbor of Apra Harbor, engaged in underwater phoyography when the earthquake struck. 

Earthquakes and economic growth

OpenAIRE

Fisker, Peter Simonsen

2012-01-01

This study explores the economic consequences of earthquakes. In particular, it is investigated how exposure to earthquakes affects economic growth both across and within countries. The key result of the empirical analysis is that while there are no observable effects at the country level, earthquake exposure significantly decreases 5-year economic growth at the local level. Areas at lower stages of economic development suffer harder in terms of economic growth than richer areas. In addition,...

"How Asian Am I?": Asian American Youth Cultures, Drug Use, and Ethnic Identity Construction

Science.gov (United States)

Hunt, Geoffrey; Moloney, Molly; Evans, Kristin

2011-01-01

This article analyzes the construction of ethnic identity in the narratives of 100 young Asian Americans in a dance club/rave scene. Authors examine how illicit drug use and other consuming practices shape their understanding of Asian American identities, finding three distinct patterns. The first presents a disjuncture between Asian American…

Retrospective stress-forecasting of earthquakes

Science.gov (United States)

Gao, Yuan; Crampin, Stuart

2015-04-01

Observations of changes in azimuthally varying shear-wave splitting (SWS) above swarms of small earthquakes monitor stress-induced changes to the stress-aligned vertical microcracks pervading the upper crust, lower crust, and uppermost ~400km of the mantle. (The microcracks are intergranular films of hydrolysed melt in the mantle.) Earthquakes release stress, and an appropriate amount of stress for the relevant magnitude must accumulate before each event. Iceland is on an extension of the Mid-Atlantic Ridge, where two transform zones, uniquely run onshore. These onshore transform zones provide semi-continuous swarms of small earthquakes, which are the only place worldwide where SWS can be routinely monitored. Elsewhere SWS must be monitored above temporally-active occasional swarms of small earthquakes, or in infrequent SKS and other teleseismic reflections from the mantle. Observations of changes in SWS time-delays are attributed to stress-induced changes in crack aspect-ratios allowing stress-accumulation and stress-relaxation to be identified. Monitoring SWS in SW Iceland in 1988, stress-accumulation before an impending earthquake was recognised and emails were exchanged between the University of Edinburgh (EU) and the Iceland Meteorological Office (IMO). On 10th November 1988, EU emailed IMO that a M5 earthquake could occur soon on a seismically-active fault plane where seismicity was still continuing following a M5.1 earthquake six-months earlier. Three-days later, IMO emailed EU that a M5 earthquake had just occurred on the specified fault-plane. We suggest this is a successful earthquake stress-forecast, where we refer to the procedure as stress-forecasting earthquakes as opposed to predicting or forecasting to emphasise the different formalism. Lack of funds has prevented us monitoring SWS on Iceland seismograms, however, we have identified similar characteristic behaviour of SWS time-delays above swarms of small earthquakes which have enabled us to

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

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).

Flashsourcing or Real-Time Mapping of Earthquake Effects from Instantaneous Analysis of the EMSC Website Traffic

Science.gov (United States)

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

2010-12-01

Earthquake response efforts are often hampered by the lack of timely and reliable information on the earthquake impact. Rapid detection of damaging events and production of actionable information for emergency response personnel within minutes of their occurrence are essential to mitigate the human impacts from earthquakes. Economically developed countries deploy dense real-time accelerometric networks in regions of high seismic hazard to constrain scenarios from in-situ data. A cheaper alternative, named flashsourcing, is based on implicit data derived from the analysis of the visits by eyewitnesses, the first informed persons, to websites offering real time earthquake information. We demonstrated in 2004 that widely felt earthquakes generate a surge of traffic, known as a flashcrowd, caused by people rushing websites such as the EMSC’s to find information about the shaking they have just felt. With detailed traffic analysis and metrics, widely felt earthquakes can be detected within one minute of the earthquake’s occurrence. In addition, the geographical area where the earthquake has been felt is automatically mapped within 5 minutes by statistically analysing the IP locations of the eyewitnesses, without using any seismological data. These results have been validated on more than 150 earthquakes by comparing the automatic felt maps with the felt area derived from macroseismic questionnaires. In practice, the felt maps are available before the first location is published by the EMSC. We have also demonstrated the capacity to rapidly detect and map areas of widespread damage by detecting when visitors suddenly end their sessions on the website en masse. This has been successfully applied to time and map the massive power failure which plunged a large part of Chile into darkness in March, 2010. If damage to power and communication lines cannot be discriminated from damage to buildings, the absence of sudden session closures precludes the possibility of heavy

Earthquake predictions using seismic velocity ratios

Science.gov (United States)

Sherburne, R. W.

1979-01-01

Since the beginning of modern seismology, seismologists have contemplated predicting earthquakes. The usefulness of earthquake predictions to the reduction of human and economic losses and the value of long-range earthquake prediction to planning is obvious. Not as clear are the long-range economic and social impacts of earthquake prediction to a speicifc area. The general consensus of opinion among scientists and government officials, however, is that the quest of earthquake prediction is a worthwhile goal and should be prusued with a sense of urgency. 

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.…

GROWTH AFTER THE ASIAN CRISIS: WHAT REMAINS OF THE EAST ASIAN MODEL?

OpenAIRE

JOMO K.S.

2001-01-01

This paper focuses on the prospects for sustained development in the four East Asian economies most adversely affected by the crises of 1997/98. These include all three second-tier South-East Asian newly industrializing countries (NICs) – Indonesia, Malaysia and Thailand – as well as the Republic of Korea, the most adversely affected of the first-generation newly industrialized economies (NIEs). The first section critically examines the East Asian model presented by the World Bank’s “East Asi...

Smoking prevalence increases following Canterbury earthquakes.

Science.gov (United States)

Erskine, Nick; Daley, Vivien; Stevenson, Sue; Rhodes, Bronwen; Beckert, Lutz

2013-01-01

A magnitude 7.1 earthquake hit Canterbury in September 2010. This earthquake and associated aftershocks took the lives of 185 people and drastically changed residents' living, working, and social conditions. To explore the impact of the earthquakes on smoking status and levels of tobacco consumption in the residents of Christchurch. Semistructured interviews were carried out in two city malls and the central bus exchange 15 months after the first earthquake. A total of 1001 people were interviewed. In August 2010, prior to any earthquake, 409 (41%) participants had never smoked, 273 (27%) were currently smoking, and 316 (32%) were ex-smokers. Since the September 2010 earthquake, 76 (24%) of the 316 ex-smokers had smoked at least one cigarette and 29 (38.2%) had smoked more than 100 cigarettes. Of the 273 participants who were current smokers in August 2010, 93 (34.1%) had increased consumption following the earthquake, 94 (34.4%) had not changed, and 86 (31.5%) had decreased their consumption. 53 (57%) of the 93 people whose consumption increased reported that the earthquake and subsequent lifestyle changes as a reason to increase smoking. 24% of ex-smokers resumed smoking following the earthquake, resulting in increased smoking prevalence. Tobacco consumption levels increased in around one-third of current smokers.

Initiation process of earthquakes and its implications for seismic hazard reduction strategy.

Science.gov (United States)

Kanamori, H

1996-04-30

For the average citizen and the public, "earthquake prediction" means "short-term prediction," a prediction of a specific earthquake on a relatively short time scale. Such prediction must specify the time, place, and magnitude of the earthquake in question with sufficiently high reliability. For this type of prediction, one must rely on some short-term precursors. Examinations of strain changes just before large earthquakes suggest that consistent detection of such precursory strain changes cannot be expected. Other precursory phenomena such as foreshocks and nonseismological anomalies do not occur consistently either. Thus, reliable short-term prediction would be very difficult. Although short-term predictions with large uncertainties could be useful for some areas if their social and economic environments can tolerate false alarms, such predictions would be impractical for most modern industrialized cities. A strategy for effective seismic hazard reduction is to take full advantage of the recent technical advancements in seismology, computers, and communication. In highly industrialized communities, rapid earthquake information is critically important for emergency services agencies, utilities, communications, financial companies, and media to make quick reports and damage estimates and to determine where emergency response is most needed. Long-term forecast, or prognosis, of earthquakes is important for development of realistic building codes, retrofitting existing structures, and land-use planning, but the distinction between short-term and long-term predictions needs to be clearly communicated to the public to avoid misunderstanding.

Cyclic migration of weak earthquakes between Lunigiana earthquake of October 10, 1995 and Reggio Emilia earthquake of October 15, 1996 (Northern Italy)

Science.gov (United States)

di Giovambattista, R.; Tyupkin, Yu

The cyclic migration of weak earthquakes (M 2.2) which occurred during the yearprior to the October 15, 1996 (M = 4.9) Reggio Emilia earthquake isdiscussed in this paper. The onset of this migration was associated with theoccurrence of the October 10, 1995 (M = 4.8) Lunigiana earthquakeabout 90 km southwest from the epicenter of the Reggio Emiliaearthquake. At least three series of earthquakes migrating from theepicentral area of the Lunigiana earthquake in the northeast direction wereobserved. The migration of earthquakes of the first series terminated at adistance of about 30 km from the epicenter of the Reggio Emiliaearthquake. The earthquake migration of the other two series halted atabout 10 km from the Reggio Emilia epicenter. The average rate ofearthquake migration was about 200-300 km/year, while the time ofrecurrence of the observed cycles varied from 68 to 178 days. Weakearthquakes migrated along the transversal fault zones and sometimesjumped from one fault to another. A correlation between the migratingearthquakes and tidal variations is analysed. We discuss the hypothesis thatthe analyzed area is in a state of stress approaching the limit of thelong-term durability of crustal rocks and that the observed cyclic migrationis a result of a combination of a more or less regular evolution of tectonicand tidal variations.

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

Recently our understanding of tectonic faulting has been shaken by the discoveries of seismic tremor, low frequency earthquakes, slow slip events, and other models of fault slip. These phenomenas represent models of failure that were thought to be non-existent and theoretically impossible only a few years ago. Slow earthquakes are seismic phenomena in which the rupture of geological faults in the earth's crust occurs gradually without creating strong tremors. Despite the growing number of observations of slow earthquakes their origin remains unresolved. Studies show that the duration of slow earthquakes ranges from a few seconds to a few hundred seconds. The regular earthquakes with which most people are familiar release a burst of built-up stress in seconds, slow earthquakes release energy in ways that do little damage. This study focus on the characteristics of the Mw5.6 earthquake occurred in Sofia seismic zone on May 22nd, 2012. The Sofia area is the most populated, industrial and cultural region of Bulgaria that faces considerable earthquake risk. The Sofia seismic zone is located in South-western Bulgaria - the area with pronounce tectonic activity and proved crustal movement. In 19th century the city of Sofia (situated in the centre of the Sofia seismic zone) has experienced two strong earthquakes with epicentral intensity of 10 MSK. During the 20th century the strongest event occurred in the vicinity of the city of Sofia is the 1917 earthquake with MS=5.3 (I0=7-8 MSK64).The 2012 quake occurs in an area characterized by a long quiescence (of 95 years) for moderate events. Moreover, a reduced number of small earthquakes have also been registered in the recent past. The Mw5.6 earthquake is largely felt on the territory of Bulgaria and neighbouring countries. No casualties and severe injuries have been reported. Mostly moderate damages were observed in the cities of Pernik and Sofia and their surroundings. These observations could be assumed indicative for a

Earthquake Early Warning: A Prospective User's Perspective (Invited)

Science.gov (United States)

Nishenko, S. P.; Savage, W. U.; Johnson, T.

2009-12-01

system, limiting the time available for an EEW-based response (i.e., slowing or stopping trains). While EEW systems are currently being tested in California, the societal benefits may be even more pronounced in other earthquake-prone parts of the United States. In the central and eastern United States, strong ground motions are felt over significantly larger areas than in California, enabling both a larger area and longer lead times for warnings ahead of the arrival of strong shaking. Because these regions are less resistant to earthquake shaking, such warnings may be even more important for safety and emergency response. However, in many areas a significant increase in the instrumentation density would be required for EEW to become a reality. Although the details of EEW systems are specific to earthquakes, the operation of sensor networks, real-time data analysis, and rapid notification to lifelines is an emerging technology that can be used for real-time detection and early warning of other types of natural and human-caused disasters and emergencies.

Racism and Asian American Student Leadership

Science.gov (United States)

Chung, Jennifer Y.

2014-01-01

This article provides a theoretical analysis and ethnographic account of Asian American student leadership in higher education. Existing literature highlights Asian and Asian American leadership styles as cultural differences. I shift the analysis from culture to racism in order to work toward a more socially just conception of Asian American…

The severity of an earthquake

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,

1997-01-01

The severity of an earthquake can be expressed in terms of both intensity and magnitude. However, the two terms are quite different, and they are often confused. Intensity is based on the observed effects of ground shaking on people, buildings, and natural features. It varies from place to place within the disturbed region depending on the location of the observer with respect to the earthquake epicenter. Magnitude is related to the amount of seismic energy released at the hypocenter of the earthquake. It is based on the amplitude of the earthquake waves recorded on instruments

Thoracic Injuries in earthquake-related versus non-earthquake-related trauma patients: differentiation via Multi-detector Computed Tomography

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Zhi-hui Dong

2011-01-01

Full Text Available PURPOSE: Massive earthquakes are harmful to humankind. This study of a historical cohort aimed to investigate the difference between earthquake-related crush thoracic traumas and thoracic traumas unrelated to earthquakes using a multi-detector Computed Tomography (CT. METHODS: We retrospectively compared an earthquake-exposed cohort of 215 thoracic trauma crush victims of the Sichuan earthquake to a cohort of 215 non-earthquake-related thoracic trauma patients, focusing on the lesions and coexisting injuries to the thoracic cage and the pulmonary parenchyma and pleura using a multi-detector CT. RESULTS: The incidence of rib fracture was elevated in the earthquake-exposed cohort (143 vs. 66 patients in the non-earthquake-exposed cohort, Risk Ratio (RR = 2.2; p<0.001. Among these patients, those with more than 3 fractured ribs (106/143 vs. 41/66 patients, RR=1.2; p<0.05 or flail chest (45/143 vs. 11/66 patients, RR=1.9; p<0.05 were more frequently seen in the earthquake cohort. Earthquake-related crush injuries more frequently resulted in bilateral rib fractures (66/143 vs. 18/66 patients, RR= 1.7; p<0.01. Additionally, the incidence of non-rib fracture was higher in the earthquake cohort (85 vs. 60 patients, RR= 1.4; p<0.01. Pulmonary parenchymal and pleural injuries were more frequently seen in earthquake-related crush injuries (117 vs. 80 patients, RR=1.5 for parenchymal and 146 vs. 74 patients, RR = 2.0 for pleural injuries; p<0.001. Non-rib fractures, pulmonary parenchymal and pleural injuries had significant positive correlation with rib fractures in these two cohorts. CONCLUSIONS: Thoracic crush traumas resulting from the earthquake were life threatening with a high incidence of bony thoracic fractures. The ribs were frequently involved in bilateral and severe types of fractures, which were accompanied by non-rib fractures, pulmonary parenchymal and pleural injuries.

An Integrated Monitoring System of Pre-earthquake Processes in Peloponnese, Greece

Science.gov (United States)

Karastathis, V. K.; Tsinganos, K.; Kafatos, M.; Eleftheriou, G.; Ouzounov, D.; Mouzakiotis, E.; Papadopoulos, G. A.; Voulgaris, N.; Bocchini, G. M.; Liakopoulos, S.; Aspiotis, T.; Gika, F.; Tselentis, A.; Moshou, A.; Psiloglou, B.

2017-12-01

One of the controversial issues in the contemporary seismology is the ability of radon accumulation monitoring to provide reliable earthquake forecasting. Although there are many examples in the literature showing radon increase before earthquakes, skepticism arises from instability of the measurements, false alarms, difficulties in interpretation caused by the weather influence (eg. rainfall) and difficulties on the consideration an irrefutable theoretical background of the phenomenon.We have developed and extensively tested a multi parameter network aimed for studying of the pre-earthquake processes and operating as a part of integrated monitoring system in the high seismicity area of the Western Hellenic Arc (SW Peloponnese, Greece). The prototype consists of four components: A real-time monitoring system of Radon accumulation. It consists of three gamma radiation detectors [NaI(Tl) scintillators] A nine-station seismic array to monitor the microseismicity in the offshore area of the Hellenic arc. The processing of the data is based on F-K and beam-forming techniques. Real-time weather monitoring systems for air temperature, relative humidity, precipitation and pressure. Thermal radiation emission from AVHRR/NOAA-18 polar orbit satellite observation. The project revolved around the idea of jointly studying the emission of Radon that has been proven in many cases as a reliable indicator of the possible time of an event, with the accurate location of the foreshock activity detected by the seismic array that can be a more reliable indicator of the possible position of an event. In parallel a satellite thermal anomaly detection technique has been used for monitoring of larger magnitude events (possible indicator for strong events M ≥5.0.). The first year of operations revealed a number of pre-seismic radon variation anomalies before several local earthquakes (M>3.6). The Radon increases systematically before the larger events.Details about the overall performance

Post-earthquake Distress and Development of Emotional Expertise in Young Adults

Directory of Open Access Journals (Sweden)

Francesca Pistoia

2018-05-01

Full Text Available After a natural disaster like an earthquake about 15% of the population experience a post-traumatic stress disorder (PTSD. However, even those without a diagnosis of PTSD can suffer from disorders of the affective sphere, including anxiety, depression and alteration of emotion recognition. The objective of this study was to investigate the neuropsychological and emotional profile of students living in the earthquake-affected areas of L’Aquila, Italy. A group of students living in L’Aquila at the time of the 2009 earthquake was recruited, and compared to a control group of students not living in any earthquake-affected areas. Participants were assessed by means of the Beck Depression Inventory (BDI scale, the State-Trait Anxiety Inventory (STAI, the Insomnia Severity Index (ISI, the Intolerance of Uncertainty Scale Short Form, the Uncertainty Response Scale (URS, the Anxiety Sensitivity Index 3 (ASI-3, and the Eysenck Personality Questionnaire-Revised Short Form (EPQ-RS. Participants also took part in two behavioral experiments aimed at evaluating their ability to recognize facial expressions (by means of the Ekman and Friesen Pictures of Facial Affect and to evaluate emotionally evocative scenes (by means of the International Affective Picture System (IAPS. Results showed that students living in the earthquake-affected areas had a general increase of anxiety and anticipation of threats. Moreover, students living in the earthquake-affected areas showed a significantly higher overall accuracy in recognizing facial expressions as compared to controls. No significant differences between the two groups were detected in the evaluation of emotionally evocative scenes. The novel result lies in the greater accuracy of earthquake victims in recognizing facial expressions, despite the lack of differences from controls in evaluating affective evocative scenes. The trauma exposure may have increased vigilance for threats in earthquake victims, leading

Earthquake prediction by Kina Method

International Nuclear Information System (INIS)

Kianoosh, H.; Keypour, H.; Naderzadeh, A.; Motlagh, H.F.

2005-01-01

Earthquake prediction has been one of the earliest desires of the man. Scientists have worked hard to predict earthquakes for a long time. The results of these efforts can generally be divided into two methods of prediction: 1) Statistical Method, and 2) Empirical Method. In the first method, earthquakes are predicted using statistics and probabilities, while the second method utilizes variety of precursors for earthquake prediction. The latter method is time consuming and more costly. However, the result of neither method has fully satisfied the man up to now. In this paper a new method entitled 'Kiana Method' is introduced for earthquake prediction. This method offers more accurate results yet lower cost comparing to other conventional methods. In Kiana method the electrical and magnetic precursors are measured in an area. Then, the time and the magnitude of an earthquake in the future is calculated using electrical, and in particular, electrical capacitors formulas. In this method, by daily measurement of electrical resistance in an area we make clear that the area is capable of earthquake occurrence in the future or not. If the result shows a positive sign, then the occurrence time and the magnitude can be estimated by the measured quantities. This paper explains the procedure and details of this prediction method. (authors)

Sense of Community and Depressive Symptoms among Older Earthquake Survivors Following the 2008 Earthquake in Chengdu China

Science.gov (United States)

Li, Yawen; Sun, Fei; He, Xusong; Chan, Kin Sun

2011-01-01

This study examined the impact of an earthquake as well as the role of sense of community as a protective factor against depressive symptoms among older Chinese adults who survived an 8.0 magnitude earthquake in 2008. A household survey of a random sample was conducted 3 months after the earthquake and 298 older earthquake survivors participated…

Negotiating Intra-Asian Games Networks: On Cultural Proximity, East Asian Games Design, and Chinese Farmers

Directory of Open Access Journals (Sweden)

Dean Chan

2006-01-01

Full Text Available A key feature of networked games in East Asia is the relationship between the adaptation of regional Asian aesthetic and narrative forms in game content, and the parallel growth in more regionally-focused marketing and distribution initiatives. This essay offers a contextual analysis of intra-Asian games networks, with reference to the production, marketing and circulation of Asian MMORPGs. My discussion locates these networks as part of broader discourses on regionalism, East Asian cultural production and Asian modernity. At the same time, I consider how these networks highlight structural asymmetry and uneven power relations within the region; and I examine the emergent use of gamer-workers known as Chinese farmers in the digital game-items trade.

Precisely locating the Klamath Falls, Oregon, earthquakes

Science.gov (United States)

Qamar, A.; Meagher, K.L.

1993-01-01

The Klamath Falls earthquakes on September 20, 1993, were the largest earthquakes centered in Oregon in more than 50 yrs. Only the magnitude 5.75 Milton-Freewater earthquake in 1936, which was centered near the Oregon-Washington border and felt in an area of about 190,000 sq km, compares in size with the recent Klamath Falls earthquakes. Although the 1993 earthquakes surprised many local residents, geologists have long recognized that strong earthquakes may occur along potentially active faults that pass through the Klamath Falls area. These faults are geologically related to similar faults in Oregon, Idaho, and Nevada that occasionally spawn strong earthquakes. 

A fluid-driven earthquake swarm on the margin of the Yellowstone caldera

Science.gov (United States)

Shelly, David R.; Hill, David P.; Massin, Frederick; Farrell, Jamie; Smith, Robert B.; Taira, Taka'aki

2013-01-01

Over the past several decades, the Yellowstone caldera has experienced frequent earthquake swarms and repeated cycles of uplift and subsidence, reflecting dynamic volcanic and tectonic processes. Here, we examine the detailed spatial-temporal evolution of the 2010 Madison Plateau swarm, which occurred near the northwest boundary of the Yellowstone caldera. To fully explore the evolution of the swarm, we integrated procedures for seismic waveform-based earthquake detection with precise double-difference relative relocation. Using cross-correlation of continuous seismic data and waveform templates constructed from cataloged events, we detected and precisely located 8710 earthquakes during the three-week swarm, nearly four times the number of events included in the standard catalog. This high-resolution analysis reveals distinct migration of earthquake activity over the course of the swarm. The swarm initiated abruptly on January 17, 2010 at about 10 km depth and expanded dramatically outward (both shallower and deeper) over time, primarily along a NNW-striking, ~55º ENE-dipping structure. To explain these characteristics, we hypothesize that the swarm was triggered by the rupture of a zone of confined high-pressure aqueous fluids into a pre-existing crustal fault system, prompting release of accumulated stress. The high-pressure fluid injection may have been accommodated by hybrid shear and dilatational failure, as is commonly observed in exhumed hydrothermally affected fault zones. This process has likely occurred repeatedly in Yellowstone as aqueous fluids exsolved from magma migrate into the brittle crust, and it may be a key element in the observed cycles of caldera uplift and subsidence.

An autocorrelation method to detect low frequency earthquakes within tremor

Science.gov (United States)

Brown, J.R.; Beroza, G.C.; Shelly, D.R.

2008-01-01

Recent studies have shown that deep tremor in the Nankai Trough under western Shikoku consists of a swarm of low frequency earthquakes (LFEs) that occur as slow shear slip on the down-dip extension of the primary seismogenic zone of the plate interface. The similarity of tremor in other locations suggests a similar mechanism, but the absence of cataloged low frequency earthquakes prevents a similar analysis. In this study, we develop a method for identifying LFEs within tremor. The method employs a matched-filter algorithm, similar to the technique used to infer that tremor in parts of Shikoku is comprised of LFEs; however, in this case we do not assume the origin times or locations of any LFEs a priori. We search for LFEs using the running autocorrelation of tremor waveforms for 6 Hi-Net stations in the vicinity of the tremor source. Time lags showing strong similarity in the autocorrelation represent either repeats, or near repeats, of LFEs within the tremor. We test the method on an hour of Hi-Net recordings of tremor and demonstrates that it extracts both known and previously unidentified LFEs. Once identified, we cross correlate waveforms to measure relative arrival times and locate the LFEs. The results are able to explain most of the tremor as a swarm of LFEs and the locations of newly identified events appear to fill a gap in the spatial distribution of known LFEs. This method should allow us to extend the analysis of Shelly et al. (2007a) to parts of the Nankai Trough in Shikoku that have sparse LFE coverage, and may also allow us to extend our analysis to other regions that experience deep tremor, but where LFEs have not yet been identified. Copyright 2008 by the American Geophysical Union.

The mechanism of earthquake

Science.gov (United States)

Lu, Kunquan; Cao, Zexian; Hou, Meiying; Jiang, Zehui; Shen, Rong; Wang, Qiang; Sun, Gang; Liu, Jixing

2018-03-01

The physical mechanism of earthquake remains a challenging issue to be clarified. Seismologists used to attribute shallow earthquake to the elastic rebound of crustal rocks. The seismic energy calculated following the elastic rebound theory and with the data of experimental results upon rocks, however, shows a large discrepancy with measurement — a fact that has been dubbed as “the heat flow paradox”. For the intermediate-focus and deep-focus earthquakes, both occurring in the region of the mantle, there is not reasonable explanation either. This paper will discuss the physical mechanism of earthquake from a new perspective, starting from the fact that both the crust and the mantle are discrete collective system of matters with slow dynamics, as well as from the basic principles of physics, especially some new concepts of condensed matter physics emerged in the recent years. (1) Stress distribution in earth’s crust: Without taking the tectonic force into account, according to the rheological principle of “everything flows”, the normal stress and transverse stress must be balanced due to the effect of gravitational pressure over a long period of time, thus no differential stress in the original crustal rocks is to be expected. The tectonic force is successively transferred and accumulated via stick-slip motions of rock blocks to squeeze the fault gouge and then exerted upon other rock blocks. The superposition of such additional lateral tectonic force and the original stress gives rise to the real-time stress in crustal rocks. The mechanical characteristics of fault gouge are different from rocks as it consists of granular matters. The elastic moduli of the fault gouges are much less than those of rocks, and they become larger with increasing pressure. This peculiarity of the fault gouge leads to a tectonic force increasing with depth in a nonlinear fashion. The distribution and variation of the tectonic stress in the crust are specified. (2) The

Turkish 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…

TOWARDS A MORE EFFICIENT DETECTION OF EARTHQUAKE INDUCED FAÇADE DAMAGES USING OBLIQUE UAV IMAGERY

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D. Duarte

2017-08-01

Full Text Available Urban search and rescue (USaR teams require a fast and thorough building damage assessment, to focus their rescue efforts accordingly. Unmanned aerial vehicles (UAV are able to capture relevant data in a short time frame and survey otherwise inaccessible areas after a disaster, and have thus been identified as useful when coupled with RGB cameras for façade damage detection. Existing literature focuses on the extraction of 3D and/or image features as cues for damage. However, little attention has been given to the efficiency of the proposed methods which hinders its use in an urban search and rescue context. The framework proposed in this paper aims at a more efficient façade damage detection using UAV multi-view imagery. This was achieved directing all damage classification computations only to the image regions containing the façades, hence discarding the irrelevant areas of the acquired images and consequently reducing the time needed for such task. To accomplish this, a three-step approach is proposed: i building extraction from the sparse point cloud computed from the nadir images collected in an initial flight; ii use of the latter as proxy for façade location in the oblique images captured in subsequent flights, and iii selection of the façade image regions to be fed to a damage classification routine. The results show that the proposed framework successfully reduces the extracted façade image regions to be assessed for damage 6 fold, hence increasing the efficiency of subsequent damage detection routines. The framework was tested on a set of UAV multi-view images over a neighborhood of the city of L’Aquila, Italy, affected in 2009 by an earthquake.

Large earthquakes and creeping faults

Science.gov (United States)

Harris, Ruth A.

2017-01-01

Faults are ubiquitous throughout the Earth's crust. The majority are silent for decades to centuries, until they suddenly rupture and produce earthquakes. With a focus on shallow continental active-tectonic regions, this paper reviews a subset of faults that have a different behavior. These unusual faults slowly creep for long periods of time and produce many small earthquakes. The presence of fault creep and the related microseismicity helps illuminate faults that might not otherwise be located in fine detail, but there is also the question of how creeping faults contribute to seismic hazard. It appears that well-recorded creeping fault earthquakes of up to magnitude 6.6 that have occurred in shallow continental regions produce similar fault-surface rupture areas and similar peak ground shaking as their locked fault counterparts of the same earthquake magnitude. The behavior of much larger earthquakes on shallow creeping continental faults is less well known, because there is a dearth of comprehensive observations. Computational simulations provide an opportunity to fill the gaps in our understanding, particularly of the dynamic processes that occur during large earthquake rupture and arrest.

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.

Instruction system upon occurrence of earthquakes

International Nuclear Information System (INIS)

Inagaki, Masakatsu; Morikawa, Matsuo; Suzuki, Satoshi; Fukushi, Naomi.

1987-01-01

Purpose: To enable rapid re-starting of a nuclear reactor after earthquakes by informing various properties of encountered earthquake to operators and properly displaying the state of damages in comparison with designed standard values of facilities. Constitution: Even in a case where the maximum accelerations due to the movements of earthquakes encountered exceed designed standard values, it may be considered such a case that equipments still remain intact depending on the wave components of the seismic movements and the vibration properties inherent to the equipments. Taking notice of the fact, the instruction device comprises a system that indicates the relationship between the seismic waveforms of earthquakes being encountered and the scram setting values, a system for indicating the comparison between the floor response spectrum of the seismic waveforms of the encountered earthquakes and the designed floor response spectrum used for the design of the equipments and a system for indicating those equipments requiring inspection after the earthquakes. Accordingly, it is possible to improve the operationability upon scram of a nuclear power plant undergoing earthquakes and improve the power saving and safety by clearly defining the inspection portion after the earthquakes. (Kawakami, Y.)

How fault geometry controls earthquake magnitude

Science.gov (United States)

Bletery, Q.; Thomas, A.; Karlstrom, L.; Rempel, A. W.; Sladen, A.; De Barros, L.

2016-12-01

Recent large megathrust earthquakes, such as the Mw9.3 Sumatra-Andaman earthquake in 2004 and the Mw9.0 Tohoku-Oki earthquake in 2011, astonished the scientific community. The first event occurred in a relatively low-convergence-rate subduction zone where events of its size were unexpected. The second event involved 60 m of shallow slip in a region thought to be aseismicaly creeping and hence incapable of hosting very large magnitude earthquakes. These earthquakes highlight gaps in our understanding of mega-earthquake rupture processes and the factors controlling their global distribution. Here we show that gradients in dip angle exert a primary control on mega-earthquake occurrence. We calculate the curvature along the major subduction zones of the world and show that past mega-earthquakes occurred on flat (low-curvature) interfaces. A simplified analytic model demonstrates that shear strength heterogeneity increases with curvature. Stress loading on flat megathrusts is more homogeneous and hence more likely to be released simultaneously over large areas than on highly-curved faults. Therefore, the absence of asperities on large faults might counter-intuitively be a source of higher hazard.

Detection of primary angle closure using anterior segment optical coherence tomography in Asian eyes.

Science.gov (United States)

Nolan, Winifred P; See, Jovina L; Chew, Paul T K; Friedman, David S; Smith, Scott D; Radhakrishnan, Sunita; Zheng, Ce; Foster, Paul J; Aung, Tin

2007-01-01

To evaluate noncontact anterior segment optical coherence technology (AS-OCT) as a qualitative method of imaging the anterior chamber angle and to determine its ability to detect primary angle closure when compared with gonioscopy in Asian subjects. Prospective observational case series. Two hundred three subjects were recruited from glaucoma clinics in Singapore with diagnoses of primary angle closure, primary open-angle glaucoma, ocular hypertension, or cataract. Both eyes (if eligible) of each patient were included in the study. Exclusion criteria were pseudophakia or previous glaucoma surgery. Images of the nasal, temporal, and inferior angles were obtained with AS-OCT in dark and then light conditions. Gonioscopic angle width was graded using the Spaeth classification for each quadrant in low lighting conditions. Angle closure was defined by AS-OCT as contact between the peripheral iris and angle wall anterior to the scleral spur and by gonioscopy as a Spaeth grade of 0 degree (posterior trabecular meshwork not visible). Comparison of the 2 methods in detecting angle closure was done by eye and by individual. Sensitivities and specificities of AS-OCT were calculated using gonioscopy as the reference standard. Complete data were available for 342 eyes of 200 patients. Of the patients, 70.9% had a clinical diagnosis of treated or untreated primary angle closure. Angle closure in > or =1 quadrants was detected by AS-OCT in 142 (71%) patients (228 [66.7%] eyes) and by gonioscopy in 99 (49.5%) patients (152 [44.4%] eyes). The inferior angle was closed more frequently than the nasal or temporal quadrants using both AS-OCT and gonioscopy. When performed under dark conditions, AS-OCT identified 98% of those subjects found to have angle closure on gonioscopy (95% confidence interval [CI], 92.2-99.6) and led to the characterization of 44.6% of those found to have open angles on gonioscopy to have angle closure as well. With gonioscopy as the reference standard

Earthquake casualty models within the USGS Prompt Assessment of Global Earthquakes for Response (PAGER) system

Science.gov (United States)

Jaiswal, Kishor; Wald, David J.; Earle, Paul S.; Porter, Keith A.; Hearne, Mike

2011-01-01

Since the launch of the USGS’s Prompt Assessment of Global Earthquakes for Response (PAGER) system in fall of 2007, the time needed for the U.S. Geological Survey (USGS) to determine and comprehend the scope of any major earthquake disaster anywhere in the world has been dramatically reduced to less than 30 min. PAGER alerts consist of estimated shaking hazard from the ShakeMap system, estimates of population exposure at various shaking intensities, and a list of the most severely shaken cities in the epicentral area. These estimates help government, scientific, and relief agencies to guide their responses in the immediate aftermath of a significant earthquake. To account for wide variability and uncertainty associated with inventory, structural vulnerability and casualty data, PAGER employs three different global earthquake fatality/loss computation models. This article describes the development of the models and demonstrates the loss estimation capability for earthquakes that have occurred since 2007. The empirical model relies on country-specific earthquake loss data from past earthquakes and makes use of calibrated casualty rates for future prediction. The semi-empirical and analytical models are engineering-based and rely on complex datasets including building inventories, time-dependent population distributions within different occupancies, the vulnerability of regional building stocks, and casualty rates given structural collapse.

Riding the Asian Wave....

Science.gov (United States)

Ward, Ben

1999-01-01

Discusses strategies U.S. universities are using to deal with declining enrollments by Asian students, brought on by the Asian financial crisis. Strategies include recruiting students from other countries. (Author/VWL)

Dense Ocean Floor Network for Earthquakes and Tsunamis; DONET/ DONET2, Part2 -Development and data application for the mega thrust earthquakes around the Nankai trough-

Science.gov (United States)

Kaneda, Y.; Kawaguchi, K.; Araki, E.; Matsumoto, H.; Nakamura, T.; Nakano, M.; Kamiya, S.; Ariyoshi, K.; Baba, T.; Ohori, M.; Hori, T.; Takahashi, N.; Kaneko, S.; Donet Research; Development Group

2010-12-01

Yoshiyuki Kaneda Katsuyoshi Kawaguchi*, Eiichiro Araki*, Shou Kaneko*, Hiroyuki Matsumoto*, Takeshi Nakamura*, Masaru Nakano*, Shinichirou Kamiya*, Keisuke Ariyoshi*, Toshitaka Baba*, Michihiro Ohori*, Narumi Takakahashi*, and Takane Hori** * Earthquake and Tsunami Research Project for Disaster Prevention, Leading Project , Japan Agency for Marine-Earth Science and Technology (JAMSTEC) **Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology (JAMSTEC) DONET (Dense Ocean Floor Network for Earthquakes and Tsunamis) is the real time monitoring system of the Tonankai seismogenic zones around the Nankai trough southwestern Japan. We were starting to develop DONET to perform real time monitoring of crustal activities over there and the advanced early warning system. DONET will provide important and useful data to understand the Nankai trough maga thrust earthquake seismogenic zones and to improve the accuracy of the earthquake recurrence cycle simulation. Details of DONET concept are as follows. 1) Redundancy, Extendable function and advanced maintenance system using the looped cable system, junction boxes and the ROV/AUV. DONET has 20 observatories and incorporated in a double land stations concept. Also, we are developed ROV for the 10km cable extensions and heavy weight operations. 2) Multi kinds of sensors to observe broad band phenomena such as long period tremors, very low frequency earthquakes and strong motions of mega thrust earthquakes over M8: Therefore, sensors such as a broadband seismometer, an accelerometer, a hydrophone, a precise pressure gauge, a differential pressure gauge and a thermometer are equipped with each observatory in DONET. 3) For speedy detections, evaluations and notifications of earthquakes and tsunamis: DONET system will be deployed around the Tonankai seismogenic zone. 4) Provide data of ocean floor crustal deformations derived from pressure sensors: Simultaneously, the development of data

Measuring the size of an earthquake

Science.gov (United States)

Spence, W.; Sipkin, S.A.; Choy, G.L.

1989-01-01

Earthquakes range broadly in size. A rock-burst in an Idaho silver mine may involve the fracture of 1 meter of rock; the 1965 Rat Island earthquake in the Aleutian arc involved a 650-kilometer length of the Earth's crust. Earthquakes can be even smaller and even larger. If an earthquake is felt or causes perceptible surface damage, then its intensity of shaking can be subjectively estimated. But many large earthquakes occur in oceanic areas or at great focal depths and are either simply not felt or their felt pattern does not really indicate their true size.

Earthquakes-Rattling the Earth's Plumbing System

Science.gov (United States)

Sneed, Michelle; Galloway, Devin L.; Cunningham, William L.

2003-01-01

Hydrogeologic responses to earthquakes have been known for decades, and have occurred both close to, and thousands of miles from earthquake epicenters. Water wells have become turbid, dry or begun flowing, discharge of springs and ground water to streams has increased and new springs have formed, and well and surface-water quality have become degraded as a result of earthquakes. Earthquakes affect our Earth’s intricate plumbing system—whether you live near the notoriously active San Andreas Fault in California, or far from active faults in Florida, an earthquake near or far can affect you and the water resources you depend on.

Real-time earthquake source imaging: An offline test for the 2011 Tohoku earthquake

Science.gov (United States)

Zhang, Yong; Wang, Rongjiang; Zschau, Jochen; Parolai, Stefano; Dahm, Torsten

2014-05-01

In recent decades, great efforts have been expended in real-time seismology aiming at earthquake and tsunami early warning. One of the most important issues is the real-time assessment of earthquake rupture processes using near-field seismogeodetic networks. Currently, earthquake early warning systems are mostly based on the rapid estimate of P-wave magnitude, which contains generally large uncertainties and the known saturation problem. In the case of the 2011 Mw9.0 Tohoku earthquake, JMA (Japan Meteorological Agency) released the first warning of the event with M7.2 after 25 s. The following updates of the magnitude even decreased to M6.3-6.6. Finally, the magnitude estimate stabilized at M8.1 after about two minutes. This led consequently to the underestimated tsunami heights. By using the newly developed Iterative Deconvolution and Stacking (IDS) method for automatic source imaging, we demonstrate an offline test for the real-time analysis of the strong-motion and GPS seismograms of the 2011 Tohoku earthquake. The results show that we had been theoretically able to image the complex rupture process of the 2011 Tohoku earthquake automatically soon after or even during the rupture process. In general, what had happened on the fault could be robustly imaged with a time delay of about 30 s by using either the strong-motion (KiK-net) or the GPS (GEONET) real-time data. This implies that the new real-time source imaging technique is helpful to reduce false and missing warnings, and therefore should play an important role in future tsunami early warning and earthquake rapid response systems.

Earthquake forewarning in the Cascadia region

Science.gov (United States)

Gomberg, Joan S.; Atwater, Brian F.; Beeler, Nicholas M.; Bodin, Paul; Davis, Earl; Frankel, Arthur; Hayes, Gavin P.; McConnell, Laura; Melbourne, Tim; Oppenheimer, David H.; Parrish, John G.; Roeloffs, Evelyn A.; Rogers, Gary D.; Sherrod, Brian; Vidale, John; Walsh, Timothy J.; Weaver, Craig S.; Whitmore, Paul M.

2015-08-10

This report, prepared for the National Earthquake Prediction Evaluation Council (NEPEC), is intended as a step toward improving communications about earthquake hazards between information providers and users who coordinate emergency-response activities in the Cascadia region of the Pacific Northwest. NEPEC charged a subcommittee of scientists with writing this report about forewarnings of increased probabilities of a damaging earthquake. We begin by clarifying some terminology; a “prediction” refers to a deterministic statement that a particular future earthquake will or will not occur. In contrast to the 0- or 100-percent likelihood of a deterministic prediction, a “forecast” describes the probability of an earthquake occurring, which may range from >0 to processes or conditions, which may include Increased rates of M>4 earthquakes on the plate interface north of the Mendocino region 

Links Between Earthquake Characteristics and Subducting Plate Heterogeneity in the 2016 Pedernales Ecuador Earthquake Rupture Zone

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Bai, L.; Mori, J. J.

2016-12-01

The collision between the Indian and Eurasian plates formed the Himalayas, the largest orogenic belt on the Earth. The entire region accommodates shallow earthquakes, while intermediate-depth earthquakes are concentrated at the eastern and western Himalayan syntaxis. Here we investigate the focal depths, fault plane solutions, and source rupture process for three earthquake sequences, which are located at the western, central and eastern regions of the Himalayan orogenic belt. The Pamir-Hindu Kush region is located at the western Himalayan syntaxis and is characterized by extreme shortening of the upper crust and strong interaction of various layers of the lithosphere. Many shallow earthquakes occur on the Main Pamir Thrust at focal depths shallower than 20 km, while intermediate-deep earthquakes are mostly located below 75 km. Large intermediate-depth earthquakes occur frequently at the western Himalayan syntaxis about every 10 years on average. The 2015 Nepal earthquake is located in the central Himalayas. It is a typical megathrust earthquake that occurred on the shallow portion of the Main Himalayan Thrust (MHT). Many of the aftershocks are located above the MHT and illuminate faulting structures in the hanging wall with dip angles that are steeper than the MHT. These observations provide new constraints on the collision and uplift processes for the Himalaya orogenic belt. The Indo-Burma region is located south of the eastern Himalayan syntaxis, where the strike of the plate boundary suddenly changes from nearly east-west at the Himalayas to nearly north-south at the Burma Arc. The Burma arc subduction zone is a typical oblique plate convergence zone. The eastern boundary is the north-south striking dextral Sagaing fault, which hosts many shallow earthquakes with focal depth less than 25 km. In contrast, intermediate-depth earthquakes along the subduction zone reflect east-west trending reverse faulting.

Collective properties of injection-induced earthquake sequences: 1. Model description and directivity bias

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Dempsey, David; Suckale, Jenny

2016-05-01

Induced seismicity is of increasing concern for oil and gas, geothermal, and carbon sequestration operations, with several M > 5 events triggered in recent years. Modeling plays an important role in understanding the causes of this seismicity and in constraining seismic hazard. Here we study the collective properties of induced earthquake sequences and the physics underpinning them. In this first paper of a two-part series, we focus on the directivity ratio, which quantifies whether fault rupture is dominated by one (unilateral) or two (bilateral) propagating fronts. In a second paper, we focus on the spatiotemporal and magnitude-frequency distributions of induced seismicity. We develop a model that couples a fracture mechanics description of 1-D fault rupture with fractal stress heterogeneity and the evolving pore pressure distribution around an injection well that triggers earthquakes. The extent of fault rupture is calculated from the equations of motion for two tips of an expanding crack centered at the earthquake hypocenter. Under tectonic loading conditions, our model exhibits a preference for unilateral rupture and a normal distribution of hypocenter locations, two features that are consistent with seismological observations. On the other hand, catalogs of induced events when injection occurs directly onto a fault exhibit a bias toward ruptures that propagate toward the injection well. This bias is due to relatively favorable conditions for rupture that exist within the high-pressure plume. The strength of the directivity bias depends on a number of factors including the style of pressure buildup, the proximity of the fault to failure and event magnitude. For injection off a fault that triggers earthquakes, the modeled directivity bias is small and may be too weak for practical detection. For two hypothetical injection scenarios, we estimate the number of earthquake observations required to detect directivity bias.

Earthquakes; May-June 1982

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Person, W.J.

1982-01-01

There were four major earthquakes (7.0-7.9) during this reporting period: two struck in Mexico, one in El Salvador, and one in teh Kuril Islands. Mexico, El Salvador, and China experienced fatalities from earthquakes.

Prevalence and psychosocial risk factors of PTSD: 18 months after Kashmir earthquake in Pakistan.

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Naeem, Farooq; Ayub, Muhammad; Masood, Khadija; Gul, Huma; Khalid, Mahwish; Farrukh, Ammara; Shaheen, Aisha; Waheed, Waquas; Chaudhry, Haroon Rasheed

2011-04-01

On average in a year 939 earthquakes of a magnitude between 5 and 8 on the Richter scale occur around the world. In earthquakes developing countries are prone to large-scale destruction because of poor structural quality of buildings, and preparedness for earthquakes. On 8th October 2005, a major earthquake hit the remote and mountainous region of northern Pakistan and Kashmir. We wanted to find out the rate of PTSD in a randomly selected sample of participants living in earthquake area and the correlates of the PTSD. The study was conducted 18 months after the earthquake. We selected a sample of men and women living in the houses and tents for interviews. Using well established instruments for PTSD and general psychiatric morbidity we gathered information from over 1200 people in face to face interviews. We gathered information about trauma exposure and loss as well. 55.2% women and 33.4% men suffered from PTSD. Living in a joint family was protective against the symptoms of PTSD. Dose of exposure to trauma was associated with the symptoms of PTSD. Living in a tent was associated with general psychiatric morbidity but not with PTSD. We used questionnaire instead of interviews to detect the symptoms of psychiatric disorders. The symptoms of PTSD are common 18 months after the earthquake and they are specifically associated with the dose of trauma exposure. This may have implications for rehabilitation of this population. Copyright © 2010 Elsevier B.V. All rights reserved.

Scrolling and Strolling, Asian Style

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Sterling, Joan

2012-01-01

In this article, the author describes a lesson on Asian cultures. Asian cultures demonstrate respect for nature through their art. Students learned how to use Asian brush techniques and designs to create scrolls. They also learned how to write Haiku, a three-line form of poetry that uses a pattern of syllables.

On the electric field transient anomaly observed at the time of the Kythira M=6.9 earthquake on January 2006

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M. R. Varley

2007-11-01

Full Text Available The study of the Earth's electromagnetic fields prior to the occurrence of strong seismic events has repeatedly revealed cases were transient anomalies, often deemed as possible earthquake precursors, were observed on electromagnetic field recordings of surface, atmosphere and near space carried out measurements. In an attempt to understand the nature of such signals several models have been proposed based upon the exhibited characteristics of the observed anomalies and different possible generation mechanisms, with electric earthquake precursors (EEP appearing to be the main candidates for short-term earthquake precursors. This paper discusses the detection of a ULF electric field transient anomaly and its identification as a possible electric earthquake precursor accompanying the Kythira M=6.9 earthquake occurred on the 8 January 2006.

Asian American Education: Identities, Racial Issues, and Languages. Research on the Education of Asian Pacific Americans

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Rong, Xue Lan, Ed.; Endo, Russell, Ed.

2011-01-01

Asian American Education--Asian American Identities, Racial Issues, and Languages presents groundbreaking research that critically challenges the invisibility, stereotyping, and common misunderstandings of Asian Americans by disrupting "customary" discourse and disputing "familiar" knowledge. The chapters in this anthology…

Radon observation for earthquake prediction

Energy Technology Data Exchange (ETDEWEB)

Wakita, Hiroshi [Tokyo Univ. (Japan)

1998-12-31

Systematic observation of groundwater radon for the purpose of earthquake prediction began in Japan in late 1973. Continuous observations are conducted at fixed stations using deep wells and springs. During the observation period, significant precursory changes including the 1978 Izu-Oshima-kinkai (M7.0) earthquake as well as numerous coseismic changes were observed. At the time of the 1995 Kobe (M7.2) earthquake, significant changes in chemical components, including radon dissolved in groundwater, were observed near the epicentral region. Precursory changes are presumably caused by permeability changes due to micro-fracturing in basement rock or migration of water from different sources during the preparation stage of earthquakes. Coseismic changes may be caused by seismic shaking and by changes in regional stress. Significant drops of radon concentration in groundwater have been observed after earthquakes at the KSM site. The occurrence of such drops appears to be time-dependent, and possibly reflects changes in the regional stress state of the observation area. The absence of radon drops seems to be correlated with periods of reduced regional seismic activity. Experience accumulated over the two past decades allows us to reach some conclusions: 1) changes in groundwater radon do occur prior to large earthquakes; 2) some sites are particularly sensitive to earthquake occurrence; and 3) the sensitivity changes over time. (author)

Detection of induced seismicity due to oil and gas extraction in the northern Gulf of Mexico, USA

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Fadugba, Oluwaseun Idowu

Drilling operations and extraction of oil and gas (O&G) may lead to subsurface slumping or compression of sediments due to reduced vertical principal stress which may lead to small earthquakes at the drilling site. O&G extraction is common in the northern Gulf of Mexico (NGM) and only thirty-five earthquakes of magnitudes between 2.3 and 6.0 have been recorded in the area from 1974 to the present. The purpose of this research is to detect more earthquakes using stacks of seismic data from the Transportable USArray (TA) from 2011 to 2013, and determine the spatiotemporal relationship between the detected earthquakes and O&G extraction. Five new small offshore earthquakes, that may be associated with the offshore O&G production, have been detected in the data. Spatial correlation of the epicenters with offshore drilling sites shows that the earthquakes may be due to the O&G extraction.

Vrancea earthquakes. Courses for specific actions to mitigate seismic risk

International Nuclear Information System (INIS)

Marmureanu, Gheorghe; Marmureanu, Alexandru

2005-01-01

Earthquakes in the Carpathian-Pannonian region are confined to the crust, except the Vrancea zone, where earthquakes with focal depth down to 200 Km occur. For example, the ruptured area migrated from 150 km to 180 km (November 10,1940, M w = 7.7) from 90 km to 110 km (March 4, 1977, M w 7.4), from 130 km to 150 km (August 30, 1986, M w = 7.1) and from 70 km to 90 km (May 30, 1990, M w = 6.9) depth. The depth interval between 110 km and 130 km remains not ruptured since 1802, October 26, when it was the strongest earthquake occurred in this part of Central Europe. The magnitude is assumed to be M w = 7.9 - 8.0 and this depth interval is a natural candidate for the next strong Vrancea event. While no country in the world is entirely safe, the lack of capacity to limit the impact of seismic hazards remains a major burden for all countries and while the world has witnessed an exponential increase in human and material losses due to natural disasters given by earthquakes, there is a need to reverse trends in seismic risk mitigation to future events. Main courses for specific actions to mitigate the seismic risk given by strong deep Vrancea earthquakes should be considered as key for development actions: - Early warning system for industrial facilities. Early warning is more than a technological instrument to detect, monitor and submit warnings. It should become part of a management information system for decision-making in the context of national institutional frameworks for disaster management and part of national and local strategies and programmers for risk mitigation; - Prediction program of Vrancea strong earthquakes of short and long term; - Hazard seismic map of Romania. The wrong assessment of the seismic hazard can lead to dramatic situations as those from Bucharest or Kobe. Before the 1977 Vrancea earthquake, the city of Bucharest was designed to intensity I = VII (MMI) and the real intensity was I = IX1/2-X (MMI); - Seismic microzonation of large populated

Possible precursors to the 2011 3/11 Japan earthquake:

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Hayakawa, M.; Hobara, Y.; Schekotov, A.; Rozhnoi, A.; Solovieva, M.

2012-04-01

The purpose of this paper is to present a possible precursor to the 2011 March 11 Japan earthquake. First of all, we present the results on subionospheric VLF/LF propagation anomaly (ionospheric perturbation) by means of Japan-Russia VLF network. It is found that the ionospheric perturbation is clearly detected on March 4, 5 and 6 on the propagation paths of NLK (Seattle, USA) to Japanese stations and on a path of JJI (Miyazaki, Kyushu) to Kamchatka. Next, we present the results on the ULF depression (horizontal component) on the same days, which is interpreted in terms of the absorption in the disturbed lower ionosphere of the downgoing magnetospheric Alfve'n waves. These two precursors are considered to be due to the same effect of the lower ionospheric perturbation about one week before the earthquake.

Earthquake number forecasts testing

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Kagan, Yan Y.

2017-10-01

We study the distributions of earthquake numbers in two global earthquake catalogues: Global Centroid-Moment Tensor and Preliminary Determinations of Epicenters. The properties of these distributions are especially required to develop the number test for our forecasts of future seismic activity rate, tested by the Collaboratory for Study of Earthquake Predictability (CSEP). A common assumption, as used in the CSEP tests, is that the numbers are described by the Poisson distribution. It is clear, however, that the Poisson assumption for the earthquake number distribution is incorrect, especially for the catalogues with a lower magnitude threshold. In contrast to the one-parameter Poisson distribution so widely used to describe earthquake occurrences, the negative-binomial distribution (NBD) has two parameters. The second parameter can be used to characterize the clustering or overdispersion of a process. We also introduce and study a more complex three-parameter beta negative-binomial distribution. We investigate the dependence of parameters for both Poisson and NBD distributions on the catalogue magnitude threshold and on temporal subdivision of catalogue duration. First, we study whether the Poisson law can be statistically rejected for various catalogue subdivisions. We find that for most cases of interest, the Poisson distribution can be shown to be rejected statistically at a high significance level in favour of the NBD. Thereafter, we investigate whether these distributions fit the observed distributions of seismicity. For this purpose, we study upper statistical moments of earthquake numbers (skewness and kurtosis) and compare them to the theoretical values for both distributions. Empirical values for the skewness and the kurtosis increase for the smaller magnitude threshold and increase with even greater intensity for small temporal subdivision of catalogues. The Poisson distribution for large rate values approaches the Gaussian law, therefore its skewness

Obesity and Asian Americans

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... and Data > Minority Population Profiles > Asian American > Obesity Obesity and Asian Americans Non-Hispanic whites are 60% ... youthonline . [Accessed 08/18/2017] HEALTH IMPACT OF OBESITY People who are overweight are more likely to ...

Glaucoma in Asian Populations

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... Involved News About Us Donate In This Section Glaucoma In Asian Populations email Send this article to ... lower than in their Asian counterparts. Normal Tension Glaucoma affects Japanese Japanese populations, however, have a substantially ...

Long-term change of activity of very low-frequency earthquakes in southwest Japan

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Baba, S.; Takeo, A.; Obara, K.; Kato, A.; Maeda, T.; Matsuzawa, T.

2017-12-01

On plate interface near seismogenic zone of megathrust earthquakes, various types of slow earthquakes were detected including non-volcanic tremors, slow slip events (SSEs) and very low-frequency earthquakes (VLFEs). VLFEs are classified into deep VLFEs, which occur in the downdip side of the seismogenic zone, and shallow VLFEs, occur in the updip side, i.e. several kilometers in depth in southwest Japan. As a member of slow earthquake family, VLFE activity is expected to be a proxy of inter-plate slipping because VLFEs have the same mechanisms as inter-plate slipping and are detected during Episodic tremor and slip (ETS). However, long-term change of the VLFE seismicity has not been well constrained compared to deep low-frequency tremor. We thus studied long-term changes in the activity of VLFEs in southwest Japan where ETS and long-term SSEs have been most intensive. We used continuous seismograms of F-net broadband seismometers operated by NIED from April 2004 to March 2017. After applying the band-pass filter with a frequency range of 0.02—0.05 Hz, we adopted the matched-filter technique in detecting VLFEs. We prepared templates by calculating synthetic waveforms for each hypocenter grid assuming typical focal mechanisms of VLFEs. The correlation coefficients between templates and continuous F-net seismograms were calculated at each grid every 1s in all components. The grid interval is 0.1 degree for both longitude and latitude. Each VLFE was detected as an event if the average of correlation coefficients exceeds the threshold. We defined the detection threshold as eight times as large as the median absolute deviation of the distribution. At grids in the Bungo channel, where long-term SSEs occurred frequently, the cumulative number of detected VLFEs increases rapidly in 2010 and 2014, which were modulated by stress loading from the long-term SSEs. At inland grids near the Bungo channel, the cumulative number increases steeply every half a year. This stepwise

Imaging 2015 Mw 7.8 Gorkha Earthquake and Its Aftershock Sequence Combining Multiple Calibrated Global Seismic Arrays

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LI, B.; Ghosh, A.

2016-12-01

The 2015 Mw 7.8 Gorkha earthquake provides a good opportunity to study the tectonics and earthquake hazards in the Himalayas, one of the most seismically active plate boundaries. Details of the seismicity patterns and associated structures in the Himalayas are poorly understood mainly due to limited instrumentation. Here, we apply a back-projection method to study the mainshock rupture and the following aftershock sequence using four large aperture global seismic arrays. All the arrays show eastward rupture propagation of about 130 km and reveal similar evolution of seismic energy radiation, with strong high-frequency energy burst about 50 km north of Kathmandu. Each single array, however, is typically limited by large azimuthal gap, low resolution, and artifacts due to unmodeled velocity structures. Therefore, we use a self-consistent empirical calibration method to combine four different arrays to image the Gorkha event. It greatly improves the resolution, can better track rupture and reveal details that cannot be resolved by any individual array. In addition, we also use the same arrays at teleseismic distances and apply a back-projection technique to detect and locate the aftershocks immediately following the Gorkha earthquake. We detect about 2.5 times the aftershocks recorded by the Advance National Seismic System comprehensive earthquake catalog during the 19 days following the mainshock. The aftershocks detected by the arrays show an east-west trend in general, with majority of the aftershocks located at the eastern part of the rupture patch and surrounding the rupture zone of the largest Mw 7.3 aftershock. Overall spatiotemporal aftershock pattern agrees well with global catalog, with our catalog showing more details relative to the standard global catalog. The improved aftershock catalog enables us to better study the aftershock dynamics, stress evolution in this region. Moreover, rapid and better imaging of aftershock distribution may aid rapid response

Stomach cancer incidence rates among Americans, Asian Americans and Native Asians from 1988 to 2011

Directory of Open Access Journals (Sweden)

Yeerae Kim

2015-02-01

Full Text Available Stomach cancer is the second most common cancer in Eastern Asia, accounting for approximately 50% of all new cases of stomach cancer worldwide. Our objective was to compare the stomach cancer incidence rates of Asian Americans in Los Angeles with those of native Asians to assess the etiology of stomach cancer from 1988 to 2011. To examine these differences, Asian Americans (Korean, Japanese, Chinese, and Filipino Americans living in Los Angeles, California, USA and native Asians (from Korea, Japan, China, and the Philippines were selected for this study. Using the Cancer Incidence in Five Continents database, stomach cancer incidence rates were examined. Data from the National Cancer Registry of Korea were used for native Koreans. Between native countries, the incidence rates in Japan, China, the Philippines, and the US declined over time, but the incidence in Korea has remained constant. The incidences among Asian immigrants were lower than those among native Asians. The incidence rates of males were approximately 2 times higher than those among females in Asian countries were. The effect of immigration on stomach cancer incidence suggests that lifestyle factors are a significant determinant of stomach cancer risk. However, the incidence in Korea remains the highest of these countries