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Sample records for volcanoes earthquakes impact

  1. 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).

  2. This Dynamic Planet: World map of volcanoes, earthquakes, impact craters and plate tectonics

    Science.gov (United States)

    Simkin, Tom; Tilling, Robert I.; Vogt, Peter R.; Kirby, Stephen H.; Kimberly, Paul; Stewart, David B.

    2006-01-01

    Our Earth is a dynamic planet, as clearly illustrated on the main map by its topography, over 1500 volcanoes, 44,000 earthquakes, and 170 impact craters. These features largely reflect the movements of Earth's major tectonic plates and many smaller plates or fragments of plates (including microplates). Volcanic eruptions and earthquakes are awe-inspiring displays of the powerful forces of nature and can be extraordinarily destructive. On average, about 60 of Earth's 550 historically active volcanoes are in eruption each year. In 2004 alone, over 160 earthquakes were magnitude 6.0 or above, some of which caused casualties and substantial damage. This map shows many of the features that have shaped--and continue to change--our dynamic planet. Most new crust forms at ocean ridge crests, is carried slowly away by plate movement, and is ultimately recycled deep into the earth--causing earthquakes and volcanism along the boundaries between moving tectonic plates. Oceans are continually opening (e.g., Red Sea, Atlantic) or closing (e.g., Mediterranean). Because continental crust is thicker and less dense than thinner, younger oceanic crust, most does not sink deep enough to be recycled, and remains largely preserved on land. Consequently, most continental bedrock is far older than the oldest oceanic bedrock. (see back of map) The earthquakes and volcanoes that mark plate boundaries are clearly shown on this map, as are craters made by impacts of extraterrestrial objects that punctuate Earth's history, some causing catastrophic ecological changes. Over geologic time, continuing plate movements, together with relentless erosion and redeposition of material, mask or obliterate traces of earlier plate-tectonic or impact processes, making the older chapters of Earth's 4,500-million-year history increasingly difficult to read. The recent activity shown on this map provides only a present-day snapshot of Earth's long history, helping to illustrate how its present surface came to

  3. Earthquakes - Volcanoes (Causes and Forecast)

    Science.gov (United States)

    Tsiapas, E.

    2009-04-01

    EARTHQUAKES - VOLCANOES (CAUSES AND FORECAST) ELIAS TSIAPAS RESEARCHER NEA STYRA, EVIA,GREECE TEL.0302224041057 tsiapas@hol.gr The earthquakes are caused by large quantities of liquids (e.g. H2O, H2S, SO2, ect.) moving through lithosphere and pyrosphere (MOHO discontinuity) till they meet projections (mountains negative projections or projections coming from sinking lithosphere). The liquids are moved from West Eastward carried away by the pyrosphere because of differential speed of rotation of the pyrosphere by the lithosphere. With starting point an earthquake which was noticed at an area and from statistical studies, we know when, where and what rate an earthquake may be, which earthquake is caused by the same quantity of liquids, at the next east region. The forecast of an earthquake ceases to be valid if these components meet a crack in the lithosphere (e.g. limits of lithosphere plates) or a volcano crater. In this case the liquids come out into the atmosphere by the form of gasses carrying small quantities of lava with them (volcano explosion).

  4. EARTHQUAKES - VOLCANOES (Causes - Forecast - Counteraction)

    Science.gov (United States)

    Tsiapas, Elias

    2014-05-01

    Earthquakes and volcanoes are caused by: 1)Various liquid elements (e.g. H20, H2S, S02) which emerge from the pyrosphere and are trapped in the space between the solid crust and the pyrosphere (Moho discontinuity). 2)Protrusions of the solid crust at the Moho discontinuity (mountain range roots, sinking of the lithosphere's plates). 3)The differential movement of crust and pyrosphere. The crust misses one full rotation for approximately every 100 pyrosphere rotations, mostly because of the lunar pull. The above mentioned elements can be found in small quantities all over the Moho discontinuity, and they are constantly causing minor earthquakes and small volcanic eruptions. When large quantities of these elements (H20, H2S, SO2, etc) concentrate, they are carried away by the pyrosphere, moving from west to east under the crust. When this movement takes place under flat surfaces of the solid crust, it does not cause earthquakes. But when these elements come along a protrusion (a mountain root) they concentrate on its western side, displacing the pyrosphere until they fill the space created. Due to the differential movement of pyrosphere and solid crust, a vacuum is created on the eastern side of these protrusions and when the aforementioned liquids overfill this space, they explode, escaping to the east. At the point of their escape, these liquids are vaporized and compressed, their flow accelerates, their temperature rises due to fluid friction and they are ionized. On the Earth's surface, a powerful rumbling sound and electrical discharges in the atmosphere, caused by the movement of the gasses, are noticeable. When these elements escape, the space on the west side of the protrusion is violently taken up by the pyrosphere, which collides with the protrusion, causing a major earthquake, attenuation of the protrusions, cracks on the solid crust and damages to structures on the Earth's surface. It is easy to foresee when an earthquake will occur and how big it is

  5. Mechanical coupling between earthquakes, volcanos and landslides

    Science.gov (United States)

    Feigl, K. L.; Retina Team

    2003-04-01

    "The eruption began as a large earthquake that triggered a massive landslide that culminated in a violent lateral explosion" [Malone et al., USGS 1981]. The 1980 eruption of Mount St. Helens taught a very powerful lesson -- that one natural hazard can trigger another. For example, earthquakes have triggered landslides in Papua New Guinea. Similarly, eruptions of Vesuvius are mechanically coupled to earthquakes in the Appenines, just as an inflating magma chamber can trigger earthquakes near Hengill volcano in SW Iceland and on the Izu Peninsula in Japan. The Luzon earthquake may have triggered the eruption of Mount Pinatubo. In many of these cases, the second triggered event caused more damage than the initial one. If we can better understand the mechanical coupling underlying the temporal and spatial correlation of such events, we will improve our assessments of the hazards they pose. The RETINA project has been funded by the European Commission's 5th Framework to study couplings between three classes of natural hazards: earthquakes, landslides, and volcanoes. These three phenomena are linked to and by the stress field in the crust. If the stress increases enough, the material will fail catastrophically. For example, magma injection beneath a volcano can trigger an earthquake by increasing stress on a fault. Increasing shear stress on unconsolidated materials on steep slopes can trigger landslides. Such stress change triggers may also be tectonic (from plate driving forces), hydrological (from heavy rain), or volcanic (magmatic injection). Any of these events can perturb the stress field enough to trigger another event. Indeed, stress changes as small as 0.1 bar (0.01 MPa) suffice to trigger an earthquake. If the medium is close to failure, this small change can increase the Coulomb stress beyond the yield threshold, breaking the material. This quantity is the primary means we will use for describing mechanical coupling. In this paper, we will review several case

  6. Magma Supply System at Batur Volcano Inferred from Volcano-Tectonic Earthquakes and Their Focal Mechanism

    Directory of Open Access Journals (Sweden)

    Sri Hidayati

    2014-07-01

    Full Text Available DOI: 10.17014/ijog.v8i2.159The Volcano-Tectonic (VT earthquakes occurring during September - November 2009 were analyzed. The result shows that the epicentres aligning in NE- SW direction coincided with the weak zone of Batur Volcano Complex. The focal zone is located at the depth around 1.5 - 5.5 km beneath the summit. Migration of magma was detected by ground deformation measured by GPS and focal mechanism. Mechanism of VT earthquake shows mostly normal fault types during the swarm in November 2009.

  7. Volcanic Activities of Hakkoda Volcano after the 2011 Tohoku Earthquake

    Science.gov (United States)

    Yamamoto, M.; Miura, S.

    2014-12-01

    The 2011 Tohoku Earthquake of 11 March 2011 generated large deformation in and around the Japanese islands, and the large crustal deformation raises fear of further disasters including triggered volcanic activities. In this presentation, as an example of such potential triggered volcanic activities, we report the recent seismic activities of Hakkoda volcano, and discuss the relation to the movement of volcanic fluids. Hakkoda volcano is a group of stratovolcanoes at the northern end of Honshu Island, Japan. There are fumaroles and hot springs around the volcano, and phreatic eruptions from Jigoku-numa on the southwestern flank of Odake volcano, which is the highest peak of the volcanic group, were documented in its history. Since just after the occurrence of the Tohokui Earthquake, the seismicity around the volcano became higher, and the migration of hypocenters of volcano-tectonic (VT) earthquakes was observed.In addition to these VT earthquakes, long-period (LP) events started occurring beneath Odake at a depth of about 2-3 km since February, 2013, and subtle crustal deformation caused by deep inflation source was also detected by the GEONET GNSS network around the same time. The spectra of LP events are common between events irrespective of the magnitude of events, and they have several spectral peaks at 6-7 sec, 2-3 sec, 1 sec, and so on. These LP events sometimes occur like a swarm with an interval of several minutes. The characteristics of observed LP events at Hakkoda volcano are similar to those of LP events at other active volcanoes and hydrothermal area in the world, where abundant fluids exist. Our further analysis using far-field Rayleigh radiation pattern observed by NIED Hi-net stations reveals that the source of LP events is most likely to be a nearly vertical tensile crack whose strike is NE-SW direction. The strike is almost perpendicular to the direction of maximum extensional strain estimated from the geodetic analysis, and is almost parallel to

  8. Development of volcano monitoring technique using repeating earthquakes observed by the Volcano Observation Network of NIED

    Science.gov (United States)

    Kohno, Y.; Ueda, H.; Kimura, H.; Nagai, M.; Miyagi, Y.; Fujita, E.; Kozono, T.; Tanada, T.

    2012-12-01

    After the Grate East Japan Earthquake (M9.0) on March 11, 2011, the M6.4 earthquake occurred beneath Mt. Fuji on March 15, 2011. Although the hypocenter seemed to be very close to an assumed magma chamber of Fuji volcano, no anomalies in volcanic activity have been observed until August 2012. As an example, after the M6.1 earthquake occurred in 1998 at southwest of Iwate volcano, a change of seismic velocity structure (e.g. Nishimura et al., 2000) was observed as well as active seismicity and crustal deformation. It had affected waveforms of repeating earthquakes occurring at a plate subduction zone, that is, the waveform similarities were reduced just after the earthquake due to upwelling of magma. In this study, first we analyzed for Mt. Fuji where such changes are expected by the occurrence of the earthquake to try to develop a tool for monitoring active volcanoes using the Volcano Observation network (V-net) data. We used seismic waveform data of repeating earthquakes observed by short period seismometers of V-net and the High Sensitivity Seismograph Network Japan (Hi-net) stations near Fuji volcano after 2007. The seismic data were recorded with a sampling rate of 100 Hz, and we applied 4-8 Hz band pass filter to reduce noise. The repeating earthquakes occurred at the plate subduction zone and their catalog is compiled by Hi-net data (Kimura et al., 2006). We extracted repeating earthquake groups that include earthquakes before and after the M6.4 earthquake on March 15, 2011. A waveform of the first event of the group and waveforms of the other events are compared and calculated cross-correlation coefficients. We adjusted P wave arrivals of each event and calculate the coefficients and lag times of the latter part of the seismic waves with the time window of 1.25 s. We searched the best fit maximizing the cross-correlation coefficients with 0.1 s shift time at each time window. As a result we found three remarkable points at this time. [1] Comparing lag times

  9. Deep long-period earthquakes beneath Washington and Oregon volcanoes

    Science.gov (United States)

    Nichols, M.L.; Malone, S.D.; Moran, S.C.; Thelen, W.A.; Vidale, J.E.

    2011-01-01

    Deep long-period (DLP) earthquakes are an enigmatic type of seismicity occurring near or beneath volcanoes. They are commonly associated with the presence of magma, and found in some cases to correlate with eruptive activity. To more thoroughly understand and characterize DLP occurrence near volcanoes in Washington and Oregon, we systematically searched the Pacific Northwest Seismic Network (PNSN) triggered earthquake catalog for DLPs occurring between 1980 (when PNSN began collecting digital data) and October 2009. Through our analysis we identified 60 DLPs beneath six Cascade volcanic centers. No DLPs were associated with volcanic activity, including the 1980-1986 and 2004-2008 eruptions at Mount St. Helens. More than half of the events occurred near Mount Baker, where the background flux of magmatic gases is greatest among Washington and Oregon volcanoes. The six volcanoes with DLPs (counts in parentheses) are Mount Baker (31), Glacier Peak (9), Mount Rainier (9), Mount St. Helens (9), Three Sisters (1), and Crater Lake (1). No DLPs were identified beneath Mount Adams, Mount Hood, Mount Jefferson, or Newberry Volcano, although (except at Hood) that may be due in part to poorer network coverage. In cases where the DLPs do not occur directly beneath the volcanic edifice, the locations coincide with large structural faults that extend into the deep crust. Our observations suggest the occurrence of DLPs in these areas could represent fluid and/or magma transport along pre-existing tectonic structures in the middle crust. ?? 2010 Elsevier B.V.

  10. Earthquake impact scale

    Science.gov (United States)

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

    2011-01-01

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

  11. Catalog of earthquake hypocenters at Alaskan volcanoes: January 1 through December 31, 2011

    Science.gov (United States)

    Dixon, James P.; Stihler, Scott D.; Power, John A.; Searcy, Cheryl K.

    2012-01-01

    Between January 1 and December 31, 2011, the Alaska Volcano Observatory (AVO) located 4,364 earthquakes, of which 3,651 occurred within 20 kilometers of the 33 volcanoes with seismograph subnetworks. There was no significant seismic activity above background levels in 2011 at these instrumented volcanic centers. This catalog includes locations, magnitudes, and statistics of the earthquakes located in 2011 with the station parameters, velocity models, and other files used to locate these earthquakes.

  12. Delayed earthquake-volcano interactions at Campi Flegrei Caledra, Italy

    Science.gov (United States)

    Lupi, Matteo; Frehner, Marcel; Saenger, Erik H.; Tisato, Nicola; Weis, Philipp; Geiger, Sebastian; Chiodini, Giovanni; Driesner, Thomas

    2015-04-01

    coupled with increasing magmatic gas concentrations in fumarole discharges. The self-consistent mechanistic explanation of the time lag may have strong implications in the predictive aspects of volcanic hazard assessment in the Neapolitan region contributing to the understanding of unrest-related precursors of large dormant calderas. To date, clear triggering correlations could only be established for quasi-immediate earthquake-volcano interactions (i.e., from seconds to days) with the underlying mechanisms remaining elusive. Here we provide strong evidence for a much longer time window implying that earthquake-volcano interactions may be much more common processes than presently thought.

  13. Earthquake families in the seismicity of Popocatepetl volcano

    Energy Technology Data Exchange (ETDEWEB)

    Espindola, J. M [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico (Mexico); Zamora-Camacho, A [Posgrado en Ciencias de la Tierra, Universidad Nacional Autonoma de Mexico (Mexico); Jimenez, Z [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico (Mexico)

    2005-04-15

    Analysis of the seismicity of Popocatepetl volcano (Central Mexico) over the period September 1 to December 31, 1995, shows the existence of three earthquake families, with correlation coefficients better than 0.5 in all components of three stations. For two families the events have similar magnitudes and occur over a relatively long period of time. This suggests that they are of the asperity type. They occur up to a depth of 4 km below sea level underneath the volcano, and may be generated by the passage of magma through the upper volcanic conduits. [Spanish] El analisis de la sismicidad asociada al volcan Popocatepetl (Meseta Central, Mexico) en el periodo 1 de septiembre a 31 de diciembre de 1995 permitio la identificacion de 3 familias de temblores. El coeficiente de correlacion encontrado para todos los miembros de las familias es mayor de 0.5 en todas las componentes de 3 estaciones cercanas a los epicentros. Los eventos de dos de las familias son de similar magnitud y ocurren dentro de un periodo relativamente largo. Esto sugiere que sean generados por la accion de una misma aspereza. Los hipocentros de los eventos se localizan bajo el edificio volcanico a profundidades de hasta 4 km bajo el nivel del mar y fueron generados probablemente por el paso de magma a traves de los conductos volcanicos superiores.

  14. Catalog of earthquake hypocenters at Alaskan volcanoes: January 1 through December 31, 2009

    Science.gov (United States)

    Dixon, James P.; Stihler, Scott D.; Power, John A.; Searcy, Cheryl K.

    2010-01-01

    Between January 1 and December 31, 2009, the Alaska Volcano Observatory (AVO) located 8,829 earthquakes, of which 7,438 occurred within 20 kilometers of the 33 volcanoes with seismograph subnetworks. Monitoring highlights in 2009 include the eruption of Redoubt Volcano, as well as unrest at Okmok Caldera, Shishaldin Volcano, and Mount Veniaminof. Additionally severe seismograph subnetwork outages resulted in four volcanoes (Aniakchak, Fourpeaked, Korovin, and Veniaminof) being removed from the formal list of monitored volcanoes in late 2009. This catalog includes descriptions of: (1) locations of seismic instrumentation deployed during 2009; (2) earthquake detection, recording, analysis, and data archival systems; (3) seismic velocity models used for earthquake locations; (4) a summary of earthquakes located in 2009; and (5) an accompanying UNIX tar-file with a summary of earthquake origin times, hypocenters, magnitudes, phase arrival times, location quality statistics, daily station usage statistics, all files used to determine the earthquake locations in 2009, and a dataless SEED volume for the AVO seismograph network.

  15. Shallow earthquake inhibits unrest near Chiles-Cerro Negro volcanoes, Ecuador-Colombian border

    Science.gov (United States)

    Ebmeier, Susanna K.; Elliott, John R.; Nocquet, Jean-Mathieu; Biggs, Juliet; Mothes, Patricia; Jarrín, Paúl; Yépez, Marco; Aguaiza, Santiago; Lundgren, Paul; Samsonov, Sergey V.

    2016-09-01

    Magma movement or reservoir pressurisation can drive swarms of low-magnitude volcano-tectonic earthquakes, as well as occasional larger earthquakes (>M5) on local tectonic faults. Earthquakes >M5 near volcanoes are challenging to interpret in terms of evolving volcanic hazard, but are often associated with eruptions, and in some cases enhance the ascent of magma. We present geodetic observations from the first episode of unrest known to have occurred near Chiles and Cerro Negro de Mayasquer volcanoes on the Ecuador-Colombian border. A swarm of volcano-tectonic seismicity in October 2014 culminated in a Mw 5.6 earthquake south of the volcanoes. Satellite radar data spanning this earthquake detect displacements that are consistent with dextral oblique slip on a reverse fault at depths of 1.4-3.4 km within a SSW-NNE trending fault zone that last ruptured in 1886. GPS station measurements capture ∼20 days of uplift before the earthquake, probably originating from a pressure source ∼10-15 km south of Volcán Chiles, at depths exceeding 13 km. After the Mw 5.6 earthquake, uplift ceased and the rate of seismicity began to decrease. Potential mechanisms for this decline in activity include a decrease in the rate of movement of magma into the shallow crust, possibly caused by the restriction of fluid pathways. Our observations demonstrate that an earthquake triggered during volcanic unrest can inhibit magmatic processes, and have implications for the hazard interpretation of the interactions between earthquakes and volcanoes.

  16. Catalog of earthquake hypocenters at Alaskan volcanoes: January 1 through December 31, 2012

    Science.gov (United States)

    Dixon, James P.; Stihler, Scott D.; Power, John A.; Haney, Matthew M.; Parker, Tom; Searcy, Cheryl; Prejean, Stephanie

    2013-01-01

    Between January 1 and December 31, 2012, the Alaska Volcano Observatory located 4,787 earthquakes, of which 4,211 occurred within 20 kilometers of the 33 volcanoes monitored by a seismograph network. There was significant seismic activity at Iliamna, Kanaga, and Little Sitkin volcanoes in 2012. Instrumentation highlights for this year include the implementation of the Advanced National Seismic System Quake Monitoring System hardware and software in February 2012 and the continuation of the American Recovery and Reinvestment Act work in the summer of 2012. The operational highlight was the removal of Mount Wrangell from the list of monitored volcanoes. This catalog includes hypocenters, magnitudes, and statistics of the earthquakes located in 2012 with the station parameters, velocity models, and other files used to locate these earthquakes.

  17. Seismicity at Uturuncu Volcano, Bolivia: Volcano-Tectonic Earthquake Swarms Triggered by the 2010 Maule, Chile Earthquake and Non-Triggered Background Activity

    Science.gov (United States)

    Christensen, D. H.; Chartrand, Z. A.; Jay, J.; Pritchard, M. E.; West, M. E.; McNutt, S. R.

    2010-12-01

    We find that the 270 ky dormant Uturuncu Volcano in SW Bolivia exhibits relatively high rates of shallow, volcano-tectonic seismicity that is dominated by swarm-like activity. We also document that the 27 February 2010 Mw 8.8 Maule, Chile earthquake triggered an exceptionally high rate of seismicity in the seconds to days following the main event. Although dormant, Uturuncu is currently being studied due to its large-scale deformation rate of 1-2 cm/yr uplift as revealed by InSAR. As part of the NASA-funded Andivolc project to investigate seismicity of volcanoes in the central Andes, a seismic network of 15 stations (9 Mark Products L22 short period and 6 Guralp CMG40T intermediate period sensors) with an average spacing of about 10 km was installed at Uturuncu from April 2009 to April 2010. Volcano-tectonic earthquakes occur at an average rate of about 3-4 per day, and swarms of 5-60 events within a span of minutes to hours occur a few times per month. Most of these earthquakes are located close to the summit at depths near and above sea level. The largest swarm occurred on 28 September 2009 and consisted of 60 locatable events over a time span of 28 hours. The locations of volcano-tectonic earthquakes at Uturuncu are oriented in a NW-SE trend, which matches the dominant orientation of regional faults and suggests a relationship between the fault system at Uturuncu and the regional tectonics of the area; a NW-SE trending fault beneath Uturuncu may serve to localize stresses that are accumulating over the broad area of uplift. Based on automated locations, the maximum local magnitude of these events is approximately M = 4 and the average magnitude is approximately M = 2. An initial estimate of the b-value is about b = 1.2. The Mw 8.8 Maule earthquake on 27 February 2010 triggered hundreds of local volcano-tectonic events at Uturuncu. High-pass filtering of the long period surface waves reveals that the first triggered events occurred with the onset of the Rayleigh

  18. Detecting remotely triggered microseismicity around Changbaishan Volcano following nuclear explosions in North Korea and large distant earthquakes around the world

    Science.gov (United States)

    Liu, Guoming; Li, Chenyu; Peng, Zhigang; Li, Xuemei; Wu, Jing

    2017-05-01

    We conduct a systematic survey on locally triggered earthquakes by large distant earthquakes in Changbaishan Volcano, an active intraplate volcano on the border between China and North Korea. We examine waveforms of distant earthquakes recorded at broadband station Changbaishan (CBS) near the volcano with estimated dynamic stresses over 5 kPa between 2000 and 2016. Out of 26 selected distant earthquakes, three of them show positive evidence of triggering during large-amplitude surface waves. The earthquakes that had positive or possible evidences of triggering generated larger long-period surface waves, indicating that they are more efficient in triggering microseismicity. In addition, since 2006 North Korea has conducted five underground nuclear explosion (UNE) tests only 140 km away from Changbaishan Volcano. By systematically examining waveforms of these UNEs recorded at station CBS, we find that none of them have triggered microearthquakes in Changbaishan Volcano.

  19. Remote triggering of seismicity at Japanese volcanoes following the 2016 M7.3 Kumamoto earthquake

    Science.gov (United States)

    Enescu, Bogdan; Shimojo, Kengo; Opris, Anca; Yagi, Yuji

    2016-10-01

    The MJMA7.3 Kumamoto earthquake occurred on April 16, 2016, in the western part of Kyushu, at a depth of 12 km, on an active strike-slip fault. Here, we report on a relatively widespread activation of small remote earthquakes, which occurred as far as Hokkaido, detected by analyzing the continuous waveform data recorded at seismic stations all over Japan. Such relatively widespread remote seismicity activation, following a large inland earthquake, has not been reported before for Japan. Our analysis demonstrates that the remote events were triggered dynamically, by the passage of the surface waves from the Kumamoto earthquake. Most of the remotely triggered events in the Tohoku and Hokkaido regions, as well as close to Izu Peninsula, occur at or close to volcanoes, which suggests that the excitation of crustal fluids, by the passage of Rayleigh waves, played an important triggering role. Nevertheless, remote activation in other regions, like Noto Peninsula, occurred away from volcanoes. The relatively large-amplitude Love waves, enhanced by a source directivity effect during the Kumamoto earthquake, may have triggered seismicity on local active faults. The dynamic stresses in the areas where remote activation has been observed range from several kPa to tens of kPa, the thresholds being lower than in previous dynamic triggering cases for Japan; this might relate to a change in the crustal conditions following the 2011 M9.0 Tohoku-oki earthquake, in particular at volcanoes in NE Japan.[Figure not available: see fulltext.

  20. 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.

  1. Mechanism of the 1996-97 non-eruptive volcano-tectonic earthquake swarm at Iliamna Volcano, Alaska

    Science.gov (United States)

    Roman, D.C.; Power, J.A.

    2011-01-01

    A significant number of volcano-tectonic(VT) earthquake swarms, some of which are accompanied by ground deformation and/or volcanic gas emissions, do not culminate in an eruption.These swarms are often thought to represent stalled intrusions of magma into the mid- or shallow-level crust.Real-time assessment of the likelihood that a VTswarm will culminate in an eruption is one of the key challenges of volcano monitoring, and retrospective analysis of non-eruptive swarms provides an important framework for future assessments. Here we explore models for a non-eruptive VT earthquake swarm located beneath Iliamna Volcano, Alaska, in May 1996-June 1997 through calculation and inversion of fault-plane solutions for swarm and background periods, and through Coulomb stress modeling of faulting types and hypocenter locations observed during the swarm. Through a comparison of models of deep and shallow intrusions to swarm observations,we aim to test the hypothesis that the 1996-97 swarm represented a shallow intrusion, or "failed" eruption.Observations of the 1996-97 swarm are found to be consistent with several scenarios including both shallow and deep intrusion, most likely involving a relatively small volume of intruded magma and/or a low degree of magma pressurization corresponding to a relatively low likelihood of eruption. ?? 2011 Springer-Verlag.

  2. Micro-earthquake signal analysis and hypocenter determination around Lokon volcano complex

    Energy Technology Data Exchange (ETDEWEB)

    Firmansyah, Rizky, E-mail: rizkyfirmansyah@hotmail.com [Geophysical Engineering, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Bandung, 40132 (Indonesia); Nugraha, Andri Dian, E-mail: nugraha@gf.itb.ac.id [Global Geophysical Group, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Bandung, 40132 (Indonesia); Kristianto, E-mail: kris@vsi.esdm.go.id [Center for Volcanology and Geological Hazard Mitigation (CVGHM), Geological Agency, Bandung, 40122 (Indonesia)

    2015-04-24

    Mount Lokon is one of five active volcanoes which is located in the North Sulawesi region. Since June 26{sup th}, 2011, standby alert set by the Center for Volcanology and Geological Hazard Mitigation (CVGHM) for this mountain. The Mount Lokon volcano erupted on July 4{sup th}, 2011 and still continuously erupted until August 28{sup th}, 2011. Due to its high seismic activity, this study is focused to analysis of micro-earthquake signal and determine the micro-earthquake hypocenter location around the complex area of Lokon-Empung Volcano before eruption phase in 2011 (time periods of January, 2009 up to March, 2010). Determination of the hypocenter location was conducted with Geiger Adaptive Damping (GAD) method. We used initial model from previous study in Volcan de Colima, Mexico. The reason behind the model selection was based on the same characteristics that shared between Mount Lokon and Colima including andesitic stratovolcano and small-plinian explosions volcanian types. In this study, a picking events was limited to the volcano-tectonics of A and B types, hybrid, long-period that has a clear signal onset, and local tectonic with different maximum S – P time are not more than three seconds. As a result, we observed the micro-earthquakes occurred in the area north-west of Mount Lokon region.

  3. Micro-earthquake signal analysis and hypocenter determination around Lokon volcano complex

    Science.gov (United States)

    Firmansyah, Rizky; Nugraha, Andri Dian; Kristianto

    2015-04-01

    Mount Lokon is one of five active volcanoes which is located in the North Sulawesi region. Since June 26th, 2011, standby alert set by the Center for Volcanology and Geological Hazard Mitigation (CVGHM) for this mountain. The Mount Lokon volcano erupted on July 4th, 2011 and still continuously erupted until August 28th, 2011. Due to its high seismic activity, this study is focused to analysis of micro-earthquake signal and determine the micro-earthquake hypocenter location around the complex area of Lokon-Empung Volcano before eruption phase in 2011 (time periods of January, 2009 up to March, 2010). Determination of the hypocenter location was conducted with Geiger Adaptive Damping (GAD) method. We used initial model from previous study in Volcan de Colima, Mexico. The reason behind the model selection was based on the same characteristics that shared between Mount Lokon and Colima including andesitic stratovolcano and small-plinian explosions volcanian types. In this study, a picking events was limited to the volcano-tectonics of A and B types, hybrid, long-period that has a clear signal onset, and local tectonic with different maximum S - P time are not more than three seconds. As a result, we observed the micro-earthquakes occurred in the area north-west of Mount Lokon region.

  4. Distal Volcano-Tectonic Earthquakes (DVT's): Diagnosis and use in Eruption Forecasting

    Science.gov (United States)

    White, R. A.; Power, J. A.

    2001-12-01

    Volcano-tectonic earthquake swarms occurred 5-6 Km from the summit months prior to the catastrophic eruptions of Mt. Pinatubo (1991) and Nevado del Ruiz (1985). Similar earthquake swarms probably occurred beneath distal portions of Mt. St. Helens (1980), El Chichon (1982), and Soufriere Hills (1995-98) months to years prior the eruptions there. Thus these Distal Volcano-Tectonic (DVT) earthquakes were probably the longest-term precursors to those eruptions. Based on close correlation with observed volcanic activity, we show that DVT's result from magma intrusion. Although DVT's are brittle-failure earthquakes along faults, they are generally distinguishable from tectonic sequences by clustering features, most notably a slowly increasing to roughly constant moment release rate. Total seismic moments for DVT swarms appear constrained by magma viscosity, with the largest moments associated with basalts. DVT swarms occur from 30 Km from summits of volcanoes. Maximum depths increase roughly as the distance out to 10 km then gradually level off, as do depths to the brittle-ductile transition near active volcanoes. We interpret DVT's as resulting from injection of magmatic fluids into closed aquifers near the base of the brittle zone, over-pressurizing the aquifers out several to many kilometers horizontally. The over-pressure may trigger faulting in areas where the intruding magma increased the static stress. We show that the DVT moment rate is proportional to the fluid injection rate and is apparently delayed by only minutes to tens of minutes depending on distance, owing to the rapid hydraulic transmission of pore-pressures. Thus DVT earthquake swarms can provide early warning for major eruptions while possibly providing constraints in near-real time on magma viscosity, depth and ascent rate during intrusion.

  5. Hydrothermal response to a volcano-tectonic earthquake swarm, Lassen, California

    Science.gov (United States)

    Ingebritsen, Steven E.; Shelly, David R.; Hsieh, Paul A.; Clor, Laura; P.H. Seward,; Evans, William C.

    2015-01-01

    The increasing capability of seismic, geodetic, and hydrothermal observation networks allows recognition of volcanic unrest that could previously have gone undetected, creating an imperative to diagnose and interpret unrest episodes. A November 2014 earthquake swarm near Lassen Volcanic National Park, California, which included the largest earthquake in the area in more than 60 years, was accompanied by a rarely observed outburst of hydrothermal fluids. Although the earthquake swarm likely reflects upward migration of endogenous H2O-CO2 fluids in the source region, there is no evidence that such fluids emerged at the surface. Instead, shaking from the modest sized (moment magnitude 3.85) but proximal earthquake caused near-vent permeability increases that triggered increased outflow of hydrothermal fluids already present and equilibrated in a local hydrothermal aquifer. Long-term, multiparametric monitoring at Lassen and other well-instrumented volcanoes enhances interpretation of unrest and can provide a basis for detailed physical modeling.

  6. A Preliminary Study of the Types of Volcanic Earthquakes and Volcanic Activity at the Changbaishan Tianchi Volcano

    Institute of Scientific and Technical Information of China (English)

    Ming Yuehong; Su Wei; Fang Lihua

    2006-01-01

    Since 2002, a significant increase in seismicity, obvious ground deformation and geochemical anomalies have been observed in the Changbaishan Tianchi volcanic area. A series felt earthquakes occur near the caldera, causing great influence to society. In this paper, the types of volcanic earthquakes recorded by the temporal seismic network since 2002 have been classified by analyzing the spectrum, time-frequency characteristics and seismic waveforms at different stations. The risk of volcano eruptions was also estimated. Our results show that almost all earthquakes occurring in Tianchi volcano are volcanic-tectonic earthquakes. The low frequency seismic waveforms observed at a few stations may be caused by local mediums, and have no relation with long-period events. Although the level of seismicity increased obviously and earthquake swarms occurred more frequently than before, we considered that the magma activity is still in its early stage and the eruption risk of Changbaishan Tianchi volcano is still iow in the near future.

  7. A distal earthquake cluster concurrent with the 2006 explosive eruption of Augustine Volcano, Alaska

    Science.gov (United States)

    Fisher, M.A.; Ruppert, N.A.; White, R.A.; Wilson, F.H.; Comer, D.; Sliter, R.W.; Wong, F.L.

    2009-01-01

    Clustered earthquakes located 25??km northeast of Augustine Volcano began about 6??months before and ceased soon after the volcano's 2006 explosive eruption. This distal seismicity formed a dense cluster less than 5??km across, in map view, and located in depth between 11??km and 16??km. This seismicity was contemporaneous with sharply increased shallow earthquake activity directly below the volcano's vent. Focal mechanisms for five events within the distal cluster show strike-slip fault movement. Cluster seismicity best defines a plane when it is projected onto a northeast-southwest cross section, suggesting that the seismogenic fault strikes northwest. However, two major structural trends intersect near Augustine Volcano, making it difficult to put the seismogenic fault into a regional-geologic context. Specifically, interpretation of marine multichannel seismic-reflection (MCS) data shows reverse faults, directly above the seismicity cluster, that trend northeast, parallel to the regional geologic strike but perpendicular to the fault suggested by the clustered seismicity. The seismogenic fault could be a reactivated basement structure.

  8. Earthquake Monitoring and Study in the Jingpohu Volcano Cluster Area

    Institute of Scientific and Technical Information of China (English)

    Liu Zhi; Duan Yonghong; Xu Zhaofan; Yuan Qinxi; Yang Jian; Zhou Xuesong

    2008-01-01

    Seismicity in the Jingpohu volcanic area was investigated based on the seismic data recorded by the mobile seismic network consisting of 14 stations equipped with 24-bit broad-band 3- component seismographs around Crater Forest. Results show that there appears certain seismicity in Jingpohu and its adjacent areas with a low activity level and most of the recorded earthquakes are the volcanic-tectonic ones. The results of location indicate a dominant focal depth of 10km - 30km, most of the earthquakes are smaller than ML>2.0, and are concentrated in the area of "Crater Forest" and on the Dunhua-Mishan fault which runs through the volcanic area. At station No.2, which has better observation conditions, two types of events, likely associated to volcanism, were recorded; their waveform characteristics are somewhat similar to that of the long-period volcanic event and the volcanic tremor, but with different feature of frequencies.

  9. Earthquake prediction using extinct monogenetic volcanoes: A possible new research strategy

    Science.gov (United States)

    Szakács, Alexandru

    2011-04-01

    Volcanoes are extremely effective transmitters of matter, energy and information from the deep Earth towards its surface. Their capacities as information carriers are far to be fully exploited so far. Volcanic conduits can be viewed in general as rod-like or sheet-like vertical features with relatively homogenous composition and structure crosscutting geological structures of far more complexity and compositional heterogeneity. Information-carrying signals such as earthquake precursor signals originating deep below the Earth surface are transmitted with much less loss of information through homogenous vertically extended structures than through the horizontally segmented heterogeneous lithosphere or crust. Volcanic conduits can thus be viewed as upside-down "antennas" or waveguides which can be used as privileged pathways of any possible earthquake precursor signal. In particular, conduits of monogenetic volcanoes are promising transmitters of deep Earth information to be received and decoded at surface monitoring stations because the expected more homogenous nature of their rock-fill as compared to polygenetic volcanoes. Among monogenetic volcanoes those with dominantly effusive activity appear as the best candidates for privileged earthquake monitoring sites. In more details, effusive monogenetic volcanic conduits filled with rocks of primitive parental magma composition indicating direct ascent from sub-lithospheric magma-generating areas are the most suitable. Further selection criteria may include age of the volcanism considered and the presence of mantle xenoliths in surface volcanic products indicating direct and straightforward link between the deep lithospheric mantle and surface through the conduit. Innovative earthquake prediction research strategies can be based and developed on these grounds by considering conduits of selected extinct monogenetic volcanoes and deep trans-crustal fractures as privileged emplacement sites of seismic monitoring stations

  10. Improve earthquake hypocenter using adaptive simulated annealing inversion in regional tectonic, volcano tectonic, and geothermal observation

    Science.gov (United States)

    Ry, Rexha Verdhora; Nugraha, Andri Dian

    2015-04-01

    Observation of earthquakes is routinely used widely in tectonic activity observation, and also in local scale such as volcano tectonic and geothermal activity observation. It is necessary for determining the location of precise hypocenter which the process involves finding a hypocenter location that has minimum error between the observed and the calculated travel times. When solving this nonlinear inverse problem, simulated annealing inversion method can be applied to such global optimization problems, which the convergence of its solution is independent of the initial model. In this study, we developed own program codeby applying adaptive simulated annealing inversion in Matlab environment. We applied this method to determine earthquake hypocenter using several data cases which are regional tectonic, volcano tectonic, and geothermal field. The travel times were calculated using ray tracing shooting method. We then compared its results with the results using Geiger's method to analyze its reliability. Our results show hypocenter location has smaller RMS error compared to the Geiger's result that can be statistically associated with better solution. The hypocenter of earthquakes also well correlated with geological structure in the study area. Werecommend using adaptive simulated annealing inversion to relocate hypocenter location in purpose to get precise and accurate earthquake location.

  11. Improve earthquake hypocenter using adaptive simulated annealing inversion in regional tectonic, volcano tectonic, and geothermal observation

    Energy Technology Data Exchange (ETDEWEB)

    Ry, Rexha Verdhora, E-mail: rexha.vry@gmail.com [Master Program of Geophysical Engineering, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Jalan Ganesha No.10, Bandung 40132 (Indonesia); Nugraha, Andri Dian, E-mail: nugraha@gf.itb.ac.id [Global Geophysical Research Group, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Jalan Ganesha No.10, Bandung 40132 (Indonesia)

    2015-04-24

    Observation of earthquakes is routinely used widely in tectonic activity observation, and also in local scale such as volcano tectonic and geothermal activity observation. It is necessary for determining the location of precise hypocenter which the process involves finding a hypocenter location that has minimum error between the observed and the calculated travel times. When solving this nonlinear inverse problem, simulated annealing inversion method can be applied to such global optimization problems, which the convergence of its solution is independent of the initial model. In this study, we developed own program codeby applying adaptive simulated annealing inversion in Matlab environment. We applied this method to determine earthquake hypocenter using several data cases which are regional tectonic, volcano tectonic, and geothermal field. The travel times were calculated using ray tracing shooting method. We then compared its results with the results using Geiger’s method to analyze its reliability. Our results show hypocenter location has smaller RMS error compared to the Geiger’s result that can be statistically associated with better solution. The hypocenter of earthquakes also well correlated with geological structure in the study area. Werecommend using adaptive simulated annealing inversion to relocate hypocenter location in purpose to get precise and accurate earthquake location.

  12. Double-difference relocation of earthquakes at Uturuncu volcano, Bolivia, and Interior Alaska

    Science.gov (United States)

    Hutchinson, Laura

    In order to reliably interpret seismic patterns, we must have reliable earthquake locations. To improve our catalog locations, I incorporate cross-correlations into double-difference earthquake relocations to generate high precision relative locations. I perform relocations for two regions, one volcanic and one tectonic. At Uturuncu volcano, I incorporate a wealth of previous studies to present a picture of the processes at play. Seismic, gravity, InSAR, and electromagnetic studies all show that there is a magma body underlying the entire region, and chemical studies suggest that this magma body (the Altiplano-Puna Magma Body, or APMB) is the source of the large ignimbrite eruptions that have occurred in the past. The recent uplift has been modeled as a new batch of magma rising off the APMB, beginning the ascent as a diapir. My relocation results indicate that the seismicity aligns with the top of one of the imaged low velocities zones, which I interpret as a diapir beneath Uturuncu. The earthquakes mark the depth at which the crust is cool enough for brittle deformation. I also perform cross-correlations to determine families of similar events. These families are located around the summit of Uturuncu and display a radial pattern. This suggests that they are due to local volcanic stresses, such as inflation of the volcano, rather than regional stresses. In Interior Alaska, I study a region that is very seismically active, yet has no mapped Holocene faults. There are a series of seismic zones in the area, each comprised of NNE-striking seismic lineations. I perform earthquake relocations on 40 years worth of seismicity in order to refine and interpret fault planes. I additionally examine three earthquake sequences in the Minto Flats Seismic Zone (MFSZ). These earthquakes are large enough (≥M5) to produce an aftershock sequence to map out the rupture plane. I find that two of the three earthquakes occurred on WNW-striking planes, roughly perpendicular to the

  13. Volcano-tectonic earthquakes: A new tool for estimating intrusive volumes and forecasting eruptions

    Science.gov (United States)

    White, Randall A.; McCausland, Wendy

    2016-01-01

    We present data on 136 high-frequency earthquakes and swarms, termed volcano-tectonic (VT) seismicity, which preceded 111 eruptions at 83 volcanoes, plus data on VT swarms that preceded intrusions at 21 other volcanoes. We find that VT seismicity is usually the earliest reported seismic precursor for eruptions at volcanoes that have been dormant for decades or more, and precedes eruptions of all magma types from basaltic to rhyolitic and all explosivities from VEI 0 to ultraplinian VEI 6 at such previously long-dormant volcanoes. Because large eruptions occur most commonly during resumption of activity at long-dormant volcanoes, VT seismicity is an important precursor for the Earth's most dangerous eruptions. VT seismicity precedes all explosive eruptions of VEI ≥ 5 and most if not all VEI 4 eruptions in our data set. Surprisingly we find that the VT seismicity originates at distal locations on tectonic fault structures at distances of one or two to tens of kilometers laterally from the site of the eventual eruption, and rarely if ever starts beneath the eruption site itself. The distal VT swarms generally occur at depths almost equal to the horizontal distance of the swarm from the summit out to about 15 km distance, beyond which hypocenter depths level out. We summarize several important characteristics of this distal VT seismicity including: swarm-like nature, onset days to years prior to the beginning of magmatic eruptions, peaking of activity at the time of the initial eruption whether phreatic or magmatic, and large non-double couple component to focal mechanisms. Most importantly we show that the intruded magma volume can be simply estimated from the cumulative seismic moment of the VT seismicity from:

  14. Three-dimensional velocity structure of the Galeras volcano (Colombia) from passive local earthquake tomography

    Science.gov (United States)

    Vargas, Carlos Alberto; Torres, Roberto

    2015-08-01

    A three-dimensional estimation of the Vp, Vs and Vp/Vs ratio structure at Galeras volcano was conducted by means of passive local earthquake tomography. 14,150 volcano-tectonic events recorded by 58 stations in the seismological network established for monitoring the volcanic activity by the Colombian Geological Survey - Pasto Volcano Observatory between the years 1989 and 2015, were inverted by using the LOTOS code. The seismic events are associated with shear-stress fractures in solid rock as a response to pressure induced by magma flow. Tomography resolution tests suggest a depth of imaging that yield 10 km from the summit of the main crater, illuminating a large portion of the volcanic structure and the interaction of tectonic features like the Buesaco and Silvia-Pijao faults. Full catalog tomographic inversion, that represents the stacked image of the volcanic structure or the most permanent features underneath the volcano, shows vertical structures aligned with seismicity beneath the main crater. We hypothesize that these structures correspond to a system of ducts or fractures through which magma and fluid phases flow up from deeper levels toward the top and related with the intersection of the surface traces of the Silvia-Pijao and Buesaco faults.

  15. Magma fracture and hybrid earthquakes in the conduit of Augustine Volcano

    Science.gov (United States)

    Buurman, Helena; West, Michael E.

    2013-12-01

    exploit subtle but systematic shifts in seismic waveforms to examine a 2 h cluster of repeating hybrid volcanic earthquakes preceding the first magmatic explosions at Augustine Volcano in January 2006. We extract differential P wave traveltimes of <0.01 s to determine that the source locations migrated downward by approximately 35 m. Waveform characteristics, GPS observations, and visual reports of lava effusion at the summit suggest that the earthquakes were sourced by fracturing magma in the upper conduit. As the lava cooled and degassed at the surface, the conditions in the upper conduit changed causing the zone in which magma fracture could occur to move downward through the magma column. These changes may also have been the first indicators that the conduit was becoming choked, causing a buildup in pressure that resulted in the large magmatic explosions that followed 36 h later.

  16. Coseismic rupturing stopped by Aso volcano during the 2016 Mw 7.1 Kumamoto earthquake, Japan.

    Science.gov (United States)

    Lin, A; Satsukawa, T; Wang, M; Mohammadi Asl, Z; Fueta, R; Nakajima, F

    2016-11-18

    Field investigations and seismic data show that the 16 April 2016 moment magnitude (Mw) 7.1 Kumamoto earthquake produced a ~40-kilometer-long surface rupture zone along the northeast-southwest-striking Hinagu-Futagawa strike-slip fault zone and newly identified faults on the western side of Aso caldera, Kyushu Island, Japan. The coseismic surface ruptures cut Aso caldera, including two volcanic cones inside it, but terminate therein. The data show that northeastward propagation of coseismic rupturing terminated in Aso caldera because of the presence of magma beneath the Aso volcanic cluster. The seismogenic faults of the 2016 Kumamoto earthquake may require reassessment of the volcanic hazard in the vicinity of Aso volcano.

  17. Coseismic rupturing stopped by Aso volcano during the 2016 Mw 7.1 Kumamoto earthquake, Japan

    Science.gov (United States)

    Lin, A.; Satsukawa, T.; Wang, M.; Mohammadi Asl, Z.; Fueta, R.; Nakajima, F.

    2016-11-01

    Field investigations and seismic data show that the 16 April 2016 moment magnitude (Mw) 7.1 Kumamoto earthquake produced a ~40-kilometer-long surface rupture zone along the northeast-southwest-striking Hinagu-Futagawa strike-slip fault zone and newly identified faults on the western side of Aso caldera, Kyushu Island, Japan. The coseismic surface ruptures cut Aso caldera, including two volcanic cones inside it, but terminate therein. The data show that northeastward propagation of coseismic rupturing terminated in Aso caldera because of the presence of magma beneath the Aso volcanic cluster. The seismogenic faults of the 2016 Kumamoto earthquake may require reassessment of the volcanic hazard in the vicinity of Aso volcano.

  18. Communication between earthquake clusters separated by over 30 km supports simple volcano plumbing

    Science.gov (United States)

    Jonsdottir, K.; Jonasson, K.; Gudmundsson, M. T.; Hensch, M.; Hooper, A. J.; Holohan, E. P.; Sigmundsson, F.; Halldorsson, S. A.; Hognadottir, T.; Magnússon, E.; Pálsson, F.; Walter, T. R.; Ofeigsson, B.; Parks, M.; Roberts, M. J.; Hjorleifsdottir, V.; Cesca, S.; Guðmundsson, G.; Hreinsdottir, S.; Jarosch, A. H.; Dumont, S.; Fridriksdóttir, H. M.; Barsotti, S.; Einarsson, P.

    2015-12-01

    The subglacial Bárðarbunga volcano is composed of a large oval caldera (7x11 km) and fissures extending tens of kilometers away from the caldera along the rift zone, which marks the divergent plate boundary across Iceland. On August 16th, 2014 an intense seismic swarm started below the Bárðarbunga caldera and in the two weeks that followed a dyke migrated some 47 km laterally in the uppermost 6-10 km of the crust along the rift. The dyke propagation terminated in lava fields just north of Vatnajökull glacier, where a major (1.5 km3) six months long eruption took place. Intense earthquake activity in the caldera started in the period August 21-24 with over 70 M5 earthquakes accompanying slow caldera collapse, as verified by various geodetic measurements. The subsidence is likely due to magma withdrawal from a reservoir at depth beneath the caldera. During a five months period, October-February, the seismic activity was separated by over 30 km in two clusters; one along the caldera rims (due to piecewise caldera subsidence) and the other at the far end of the dyke (as a result of small shear movements). Here we present statistical analysis comparing the temporal behaviour of seismicity recorded in the two clusters. By comparing the earthquake rate in the dyke in temporal bins before and after caldera subsidence earthquakes to the rate away from these bins (background rate), we show that the number of dyke earthquakes was significantly higher (p earthquake (>M4.6) in the caldera. Increased dyke seismicity was also observed 0-3 hours following a large caldera earthquake. Elevated seismicity in the dyke before a large caldera earthquake may occur when a constriction in the dyke was reduced, followed by pressure drop in the chamber. Assuming that the large caldera earthquakes occurred when chamber pressure was lowest, the subsiding caldera piston may have caused temporary higher pressure in the dyke and thereby increased the likelihood of an earthquake. Our results

  19. Multi-disciplinary Hazard Reduction from Earthquakes and Volcanoes in Indonesia - International Research Cooperation Program

    Science.gov (United States)

    Kato, Teruyuki

    2010-05-01

    Indonesian and Japanese researchers started a three-year (2009-2011) multi-disciplinary cooperative research project as a part of "Science and Technology Research Partnership for Sustainable Development" supported by the Japanese government. The ultimate goal of this project is to reduce disaster from earthquakes, tsunamis and volcanoes by enhancing capability of forecasting hazards, reducing social vulnerability, and education and outreach activity of research outcomes. We plan to provide platform of collaboration among researchers in natural science, engineering and social sciences, as well as officials in national and local governments. Research activities are grouped into: (1) geological and geophysical surveys of past earthquakes, monitoring current crustal activity, and simulation of future ground motion or tsunamis, (2) short-term and long-term prediction of volcanic eruptions by monitoring Semeru, Guntur and other volcanoes, and development of their evaluation method, (3) studies to establish social infrastructure based on engineering technologies and hazard maps, (4) social, cultural and religious studies to reduce vulnerability of local communities, and (5) studies on education and outreach on disaster reduction and restoration of community. In addition, to coordinate these research activities and to utilize the research results, (6) application of the research and establishment of collaboration mechanism between researchers and the government officials is planned. In addition to mutual visits and collaborative field studies, it is planned to hold annual joint seminars (in Indonesia in 2009 and 2011, in Japan in 2010) that will be broadcasted through internet. Meetings with Joint Coordinating Committee, composed of representatives of relevant Indonesian ministries and institutions as well as project members, will be held annually to oversee the activities. The kick-off workshop was held in Bandung in April 2009 and the research plans from 22 different

  20. Special issue: Terrestrial fluids, earthquakes and volcanoes: The Hiroshi Wakita volume I

    Science.gov (United States)

    Perez, Nemesio M.; King, Chi-Yu; Gurrieri, Sergio; McGee, Kenneth A.

    2006-01-01

    Terrestrial Fluids, Earthquakes and Volcanoes: The Hiroshi Wakita Volume I is a special publication to honor Professor Hiroshi Wakita for his scientific contributions. This volume consists of 17 original papers dealing with various aspects of the role of terrestrial fluids in earthquake and volcanic processes, which reflect Prof. Wakita’s wide scope of research interests.Professor Wakita co-founded the Laboratory for Earthquake Chemistry in 1978 and served as its director from 1988 until his retirement from the university in 1997. He has made the laboratory a leading world center for studying earthquakes and volcanic activities by means of geochemical and hydrological methods. Together with his research team and a number of foreign guest researchers that he attracted, he has made many significant contributions in the above-mentioned scientific fields of interest. This achievement is a testimony to not only his scientific talent, but also his enthusiasm, his open mindedness, and his drive in obtaining both human and financial support.

  1. Development of an Earthquake Impact Scale

    Science.gov (United States)

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

    2009-12-01

    With the advent of the USGS Prompt Assessment of Global Earthquakes for Response (PAGER) system, domestic (U.S.) and international earthquake responders are reconsidering their automatic alert and activation levels as well as their response procedures. To help facilitate rapid and proportionate earthquake response, we propose and describe an Earthquake Impact Scale (EIS) founded on two alerting criteria. One, based on the estimated cost of damage, is most suitable for domestic events; the other, based on estimated ranges of fatalities, is more appropriate for most global events. Simple thresholds, derived from the systematic analysis of past earthquake impact and response levels, turn out to be quite effective in communicating predicted impact and response level of an event, characterized by alerts of green (little or no impact), yellow (regional impact and response), orange (national-scale impact and response), and red (major disaster, necessitating international response). Corresponding fatality thresholds for yellow, orange, and red alert levels are 1, 100, and 1000, respectively. For damage impact, yellow, orange, and red thresholds are triggered by estimated losses exceeding 1M, 10M, and $1B, respectively. The rationale for a dual approach to earthquake alerting stems from the recognition that relatively high fatalities, injuries, and homelessness dominate in countries where vernacular building practices typically lend themselves to high collapse and casualty rates, and it is these impacts that set prioritization for international response. In contrast, it is often financial and overall societal impacts that trigger the level of response in regions or countries where prevalent earthquake resistant construction practices greatly reduce building collapse and associated fatalities. Any newly devised alert protocols, whether financial or casualty based, must be intuitive and consistent with established lexicons and procedures. In this analysis, we make an attempt

  2. Napa Earthquake impact on water systems

    Science.gov (United States)

    Wang, J.

    2014-12-01

    South Napa earthquake occurred in Napa, California on August 24 at 3am, local time, and the magnitude is 6.0. The earthquake was the largest in SF Bay Area since the 1989 Loma Prieta earthquake. Economic loss topped $ 1 billion. Wine makers cleaning up and estimated the damage on tourism. Around 15,000 cases of lovely cabernet were pouring into the garden at the Hess Collection. Earthquake potentially raise water pollution risks, could cause water crisis. CA suffered water shortage recent years, and it could be helpful on how to prevent underground/surface water pollution from earthquake. This research gives a clear view on drinking water system in CA, pollution on river systems, as well as estimation on earthquake impact on water supply. The Sacramento-San Joaquin River delta (close to Napa), is the center of the state's water distribution system, delivering fresh water to more than 25 million residents and 3 million acres of farmland. Delta water conveyed through a network of levees is crucial to Southern California. The drought has significantly curtailed water export, and salt water intrusion reduced fresh water outflows. Strong shaking from a nearby earthquake can cause saturated, loose, sandy soils liquefaction, and could potentially damage major delta levee systems near Napa. Napa earthquake is a wake-up call for Southern California. It could potentially damage freshwater supply system.

  3. Oil the possible relationship between the Matsushiro earthquake swarm and the inactivity of Asama-yama Volcano

    Directory of Open Access Journals (Sweden)

    P. HÉDERVÀRI

    1975-05-01

    Full Text Available During the famous Matsushiro earthquake swarm more t h a n 700 000 (volcanic earthquakes were observed. At (he same time remarkable contortion of the ground also took place together with other strange geophysical phenomena. In the course of these events, volcano Asama-yama (one of the most active volcanoes of the world showed a perfect inactivity. This volcano is situated at a distance of about 30 km measured from Matsushiro, that is very near the site of the events. In the paper a causal relationship is suggested between the geophysical phenomena at .Matsushiro and the inactivity of Asama-yama. Two alternative possibilites are t r e a t e d briefly. The hypothetical character of these ideas is strongly emphasized by the author, however both possibilities appear to be physically real and can explain all the important geophysical events observed on the spot.

  4. Volcanoes

    Science.gov (United States)

    ... or more from a volcano. Before a Volcanic Eruption The following are things you can do to ... in case of an emergency. During a Volcanic Eruption Follow the evacuation order issued by authorities and ...

  5. Rupture process of the 2016 Kumamoto earthquake in relation to the thermal structure around Aso volcano

    Science.gov (United States)

    Yagi, Yuji; Okuwaki, Ryo; Enescu, Bogdan; Kasahara, Amato; Miyakawa, Ayumu; Otsubo, Makoto

    2016-07-01

    We constructed the rupture process model for the 2016 Kumamoto, Japan, earthquake from broadband teleseismic body waveforms (P-waves) by using a novel waveform inversion method that takes into account the uncertainty of Green's function. The estimated source parameters are: seismic moment = 5.1 × 1019 Nm (Mw = 7.1), fault length = 40 km, and fault width = 15 km. The mainshock rupture mainly propagated northeastward from the epicenter, for about 30 km, along an active strike-slip fault. The rupture propagation of the mainshock decelerated and terminated near the southwest side of the Aso volcano; the aftershock activity was low around the northeastern edge of the major slip area. Our results suggest that the rupture process of the mainshock and the distribution of aftershocks were influenced by the high-temperature area around the magma chamber of Mt. Aso.

  6. Bowie Lecture: High-Rate GPS: Earthquakes, Ice Sheets, and Volcanoes

    Science.gov (United States)

    Larson, K. M.

    2007-12-01

    Today GPS networks installed around the world are used to quantify long-term plate rates and the temporal and spatial complexities of crustal deformation at plate boundaries. Daily position precisions of several mm and long-term position rates of 0.1 mm/yr are routinely reported. These kinds of precisions are the outcome of 20 years of sustained development of observable models, a global tracking network, and an accurate terrestrial reference frame. But many geophysical problems require positioning at intervals much smaller than these standard "one-day" GPS results. The focus of this talk will be subdaily positioning applications, specifically using GPS to measure displacements during and after earthquakes, volcanic events, and ice-sheet kinematics. The methods I have used to analyze high-rate GPS data vary depending on the geophysical signal and the frequencies and amplitudes of the GPS error sources. For volcano applications, Kalman filtering can significantly reduce the errors due to multipath without suppressing the geophysical signal. I will discuss new volcano results using the 2007 Father's Day dike intrusion dataset from Kilauea. A second filtering application will focus on ice sheet measurements from Greenland, where surface melt linked to rising temperatures causes temporal variations in ice sheet speed. Finally I will discuss high-rate GPS as applied to seismology. Smoothing or averaging as shown for the previous cases is not a reasonable GPS analysis strategy for ground motions during an earthquake, and thus alternate multipath mitigation techniques must be used. Fortunately, the repetition of the GPS orbit can be used to develop empirical multipath corrections, significantly improving the precision of high-rate GPS solutions. I'll focus on the Tokachi-Oki dataset, discussing both measurements of the seismic signal and early postseismic deformation.

  7. Development of the teaching materials of the elementary school science related to a Volcano, an Earthquake, and a Life.

    Science.gov (United States)

    Sasaki, R.; Matsumoto, I.; Norimoto, S.; Kanagi, E.; Fujimoto, E.

    2014-12-01

    Importance of the learning about Volcano, Earthquake and Life is increasing since the disaster by the Tohoku-Earthquake and Tsunami at the 11th March 2011, in Japan. This research aims at the teaching-materials development of the science education of elementary school about natural disaster, disaster prevention, and life respect. We are carrying this research using the following three Methods. 1) We summarize the present student's knowledge and understanding about volcano, Earthquake and Life. 2) We summarize the state of the science teaching materials as disaster prevention, disaster reduction and life education. 3) We discuss about how depending on which the human beings to a natural disaster, and the state of the teaching materials which student study about the importance of a life. In this presentation we made preliminary report about developed teaching materials of Volcanoes of Mt. Sambe and Mt. Dai and the past earthquakes. According to above teaching materials, it found out It is important how a student is accompanied by realistic feelings.

  8. Initial phases of explosion earthquakes accompanying Vulcanian eruptions at Lokon-Empung volcano, Indonesia

    Science.gov (United States)

    Yamada, Taishi; Aoyama, Hiroshi; Nishimura, Takeshi; Yakiwara, Hiroshi; Nakamichi, Haruhisa; Oikawa, Jun; Iguchi, Masato; Hendrasto, Muhamad; Suparman, Yasa

    2016-11-01

    We examine the initial phases of explosion earthquakes accompanying Vulcanian eruptions at Lokon-Empung volcano in Indonesia to reveal the triggering process of explosive eruptions. In 2012-2013, 56 Vulcanian eruptions at Lokon-Empung were observed by our temporary observation network being comprised of four broadband seismometers and two infrasound microphones at 1.6-6.8 km from the active vent. The seismic records of each explosion earthquake share almost the same waveform characteristics of initial phases, consisting of a small compressional onset (P phase) and a subsequent large dilatational phase (D phase). Particle orbits of both phases show straight motion from beneath the active vent, which suggests that these phases are composed of a longitudinal body wave. For each explosion, the origin times of the P phase precedes 0.8-2.5 s before the occurrence of an explosion at the vent that are detected by infrasound data. Since the signal-to-noise ratio of the P phase is insufficient for a quantitative analysis, we analyze the D phase dominating the initial phases. Our analysis for the signals of 0.2-1.0 Hz shows the D phase are well explained by a cylindrical contraction source with a half-cosine shaped time function located at 1.0-1.3 km depth beneath the active vent. We also recognize that some explosions are followed by a prominent tremor that coincides with continuous ash emission (ET). The seismic amplitudes and intensity of the D phase of events in ET are larger than the explosions without accompanying tremor (EX). The frequency distribution of the time interval from the previous eruption is also different in the events in ET and EX. The implosion source in the initial phases of explosion earthquakes at several km beneath the active vent has been reported at Sakurajima volcano. Since our result shows considerable agreement with the previous works at Sakurajima, both Lokon-Empung and Sakurajima may share similar initial processes of Vulcanian eruptions.

  9. The Recent Seismicity At Vesuvius Volcano, Italy: Source Parameters and Spatial Clustering of Earthquakes

    Science.gov (United States)

    Saccorotti, G.; del Pezzo, E.; Ruggiero, L.

    This work describes the analysis of seismological data collected at Mt. Vesuvius since three years before the October 9, 1999, ML=3.6 earthquake till the end of 2000, and describes the pattern of seismic energy release focusing onto the spatial distribution of strain release and stress drop. Results indicate a twofold pattern of stress drop release, with high values (up to 100 bars) for earthquakes occurring close to the top of the carbonate basement which underlies the volcano at 2-3 km of depth, and low values (down to 0.1 bars) for the shallower events occurring inside the volcanic edifice. Inter- pretation favors a dynamic of the seismic phenomena in which aquifers play an impor- tant role for shallower events, whilst the pre-fractured carbonate basement may be the site of ruptures associated to the regional stress. We seek the July 1999 U April 2000 catalogue for the occurrence of similar earthquakes (multiplets). Out of almost 126000 independent event pairs, about 1300 are related by correlation coefficients greater than 0.75. These pairs of similar earthquakes are then grouped into 6 different families us- ing the Equivalence Class approach. For each family, we use interpolated correlation analyses to estimate the time shifts among the different members of the family with respect to a principal event selected as the master one. Least Usquares adjustment of arrival times provide consistency of these estimates throughout the different members of the cluster. This refined set of arrival times is then used to relocate events belong- ing to individual clusters using a non-linear, probabilistic technique acting on a 3-D heterogeneous earth structure. The high similarity of waveforms for events belonging to different families is associated to similar source location and mechanism, in turn suggesting repeated slip on the same fault. However, there is no regular relationship among the time of occurrence of individual earthquakes and their position on the fault

  10. Intermediate-Term Declines in Seismicity at Mt. Wrangell and Mt. Veniaminof Volcanoes, Alaska, Following the November 3, 2002 Mw 7.9 Denali Fault Earthquake

    Science.gov (United States)

    Sanchez, J. J.; McNutt, S. R.

    2003-12-01

    On November 3, 2002 a Mw 7.9 earthquake ruptured segments of the Denali Fault and adjacent faults in interior Alaska providing a unique opportunity to look for intermediate-term (days to weeks) responses of Alaskan volcanoes to shaking from a large regional earthquake. The Alaska Volcano Observatory (AVO) monitors 24 volcanoes with seismograph networks. We examined one station per volcano, generally the closest to the vent (typically within 5 km) unless noise, or other factors made the data unusable. Data were digitally filtered between 0.8 and 5 Hz to enhance the signal-to-noise ratio. Data for the period four weeks before to four weeks after the Mw 7.9 earthquake were then plotted at a standard scale used for AVO routine monitoring. Mt. Veniaminof volcano, which has had recent mild eruptions and a rate of ten earthquakes per day on station VNNF, suffered a drop in seismicity by a factor of two after the earthquake; this lasted for 15 days. Wrangell, the closest volcano to the epicenter, had a background rate of about 16 earthquakes per day. Data from station WANC could not be measured for 3 days after the Mw 7.9 earthquake because the large number and size of aftershocks impeded identification of local earthquakes. For the following 30 days, however, its seismicity rate dropped by a factor of two. Seismicity then remained low for an additional 4 months at Wrangell, whereas that at Veniaminof returned to normal within weeks. The seismicity at both Mt. Veniaminof and Mt. Wrangell is dominated by low-frequency volcanic events. The detection thresholds for both seismograph networks are low and stations VNNF and WANC operated normally during the time of our study, thus we infer that the changes in seismicity may be related to the earthquake. It is known that Wrangell increased its heat output after the Mw 9.2 Alaska earthquake of 1964 and again after the Ms 7.1 St.Elias earthquake of 1979. The other volcanoes showed no changes in seismicity that can be attributable to

  11. Moderate-magnitude earthquakes induced by magma reservoir inflation at Kīlauea Volcano, Hawai‘i

    Science.gov (United States)

    Wauthier, Christelle; Roman, Diana C.; Poland, Michael P.

    2013-01-01

    Although volcano-tectonic (VT) earthquakes often occur in response to magma intrusion, it is rare for them to have magnitudes larger than ~M4. On 24 May 2007, two shallow M4+ earthquakes occurred beneath the upper part of the east rift zone of Kīlauea Volcano, Hawai‘i. An integrated analysis of geodetic, seismic, and field data, together with Coulomb stress modeling, demonstrates that the earthquakes occurred due to strike-slip motion on pre-existing faults that bound Kīlauea Caldera to the southeast and that the pressurization of Kīlauea's summit magma system may have been sufficient to promote faulting. For the first time, we infer a plausible origin to generate rare moderate-magnitude VTs at Kīlauea by reactivation of suitably oriented pre-existing caldera-bounding faults. Rare moderate- to large-magnitude VTs at Kīlauea and other volcanoes can therefore result from reactivation of existing fault planes due to stresses induced by magmatic processes.

  12. Impact of the Christchurch earthquakes on hospital staff.

    Science.gov (United States)

    Tovaranonte, Pleayo; Cawood, Tom J

    2013-06-01

    On September 4, 2010 a major earthquake caused widespread damage, but no loss of life, to Christchurch city and surrounding areas. There were numerous aftershocks, including on February 22, 2011 which, in contrast, caused substantial loss of life and major damage to the city. The research aim was to assess how these two earthquakes affected the staff in the General Medicine Department at Christchurch Hospital. Problem To date there have been no published data assessing the impact of this type of natural disaster on hospital staff in Australasia. A questionnaire that examined seven domains (demographics, personal impact, psychological impact, emotional impact, impact on care for patients, work impact, and coping strategies) was handed out to General Medicine staff and students nine days after the September 2010 earthquake and 14 days after the February 2011 earthquake. Response rates were ≥ 99%. Sixty percent of responders were earthquakes, respectively. A fifth to a third of people had to find an alternative route of transport to get to work but only eight percent to 18% took time off work. Financial impact was more severe following the February earthquake, with 46% reporting damage of >NZ $1,000, compared with 15% following the September earthquake (P earthquake than the September earthquake (42% vs 69%, P earthquake but this rose to 53% after the February earthquake (12/53 vs 45/85, P earthquake but this dropped significantly to 15% following the February earthquake (27/53 vs 13/62, P earthquakes upon General Medicine hospital staff. The effect was widespread with minor financial impact during the first but much more during the second earthquake. Moderate psychological impact was experienced in both earthquakes. This data may be useful to help prepare plans for future natural disasters. .

  13. Volcanoes

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In the past thousand years,volcanoes have claimed more than 300,000 lives. Volcanology is ayoung and dangerous science that helps us against the power of the Earth itself.We live on a fiery planet. Nearly 2000 miles beneath our feet, the Earth's inner core reachestemperatures of 12,000 degrees Fahrenheit. Molten rock or magma, rises to the earth's surface. Acold, rigid crust fractured into some twenty plates. When magma breaks through crust it becomes

  14. Earthquake and volcano clustering via stress transfer at Yucca Mountain, Nevada

    Science.gov (United States)

    Parsons, T.; Thompson, G.A.; Cogbill, A.H.

    2006-01-01

    The proposed national high-level nuclear waste repository at Yucca Mountain is close to Quaternary cinder cones and faults with Quaternary slip. Volcano eruption and earthquake frequencies are low, with indications of spatial and temporal clustering, making probabilistic assessments difficult. In an effort to identify the most likely intrusion sites, we based a three-dimensional finite-element model on the expectation that faulting and basalt intrusions are sensitive to the magnitude and orientation of the least principal stress in extensional terranes. We found that in the absence of fault slip, variation in overburden pressure caused a stress state that preferentially favored intrusions at Crater Flat. However, when we allowed central Yucca Mountain faults to slip in the model, we found that magmatic clustering was not favored at Crater Flat or in the central Yucca Mountain block. Instead, we calculated that the stress field was most encouraging to intrusions near fault terminations, consistent with the location of the most recent volcanism at Yucca Mountain, the Lathrop Wells cone. We found this linked fault and magmatic system to be mutually reinforcing in the model in that Lathrop Wells feeder dike inflation favored renewed fault slip. ?? 2006 Geological Society of America.

  15. Crustal CO2 liberation during the 2006 eruption and earthquake events at Merapi volcano, Indonesia

    Science.gov (United States)

    Troll, Valentin R.; Hilton, David R.; Jolis, Ester M.; Chadwick, Jane P.; Blythe, Lara S.; Deegan, Frances M.; Schwarzkopf, Lothar M.; Zimmer, Martin

    2012-06-01

    High-temperature volcanic gas is widely considered to originate from ascending, mantle-derived magma. In volcanic arc systems, crustal inputs to magmatic gases mainly occur via subducted sediments in the mantle source region. Our data from Merapi volcano, Indonesia imply, however, that during the April-October 2006 eruption significant quantities of CO2 were added from shallow crustal sources. We show that prior to the 2006 events, summit fumarole gas δ13C(CO2) is virtually constant (δ13C1994-2005 = -4.1 ± 0.3‰), but during the 2006 eruption and after the shallow Yogyakarta earthquake of late May, 2006 (M6.4; hypocentres at 10-15 km depth), carbon isotope ratios increased to -2.4 ± 0.2‰. This rise in δ13C is consistent with considerable addition of crustal CO2 and coincided with an increase in eruptive intensity by a factor of ˜3 to 5. We postulate that this shallow crustal volatile input supplemented the mantle-derived volatile flux at Merapi, intensifying and sustaining the 2006 eruption. Late-stage volatile additions from crustal contamination may thus provide a trigger for explosive eruptions independently of conventional magmatic processes.

  16. Stress controlled magma-earthquake interaction during unrest at Chiles-Cerro Negro Volcanoes (Ecuador-Colombian border)

    Science.gov (United States)

    Ebmeier, S. K.; Elliott, J. R.; Nocquet, J. M.; Biggs, J.; Mothes, P. A.; Lundgren, P.; Samsonov, S. V.; Jarrin, P.; Yepez, M.; Aguaiza, S.

    2015-12-01

    The movement of fluids beneath a volcano can cause deformation, and therefore changes to the subsurface stress field that manifest in swarms of low magnitude (Chiles-Cerro Negro volcanoes on the Ecuador-Colombian border. These volcanoes were previously considered to be historically inactive, but between 2013 and early 2015 there were three episodes of unrest characterised by VT swarms of increasing energy and duration. GPS measurements at two stations near Volcán Chiles show inflation over a time period of approximately twenty days prior to the 20th October, consistent with the intrusion of magma at half space depths >13 km. This inflation took place during a swarm of VT seismicity with thousands of low magnitude events per day and culminated in a M 5.6 earthquake on the 20th October, when inflation abruptly ceased. We measure coseismic displacements from the M 5.6 earthquake with data from three independent InSAR platforms and find that they are consistent with shallow slip of 1.2 m on an oblique reverse fault. This fault plane would have experienced positive Coulomb stress changes from some of the range of potential sources consistent with the inflation. Magmatic intrusion could therefore have contributed to the loading on the fault directly through stress changes caused by pressurisation, and indirectly through the decrease in effective friction coefficient due to elevated pore fluid pressure. The cessation of inflation immediately after the moderate earthquake suggests a link between the two events. We expect slip on the fault plane identified from the InSAR data to have resulted in compression in the shallow crust south of Volcán Chiles, above the source that had previously been inflating. This would have inhibited further ascent of magma. The Chiles-Cerro Nego unrest provides rare observations of interaction between magmatic intrusion and a moderate earthquake during volcanic unrest.

  17. The story of the Hawaiian Volcano Observatory -- A remarkable first 100 years of tracking eruptions and earthquakes

    Science.gov (United States)

    Babb, Janet L.; Kauahikaua, James P.; Tilling, Robert I.

    2011-01-01

    part of the USGS, the Nation’s premier Earth science agency. It currently operates under the direction of the USGS Volcano Science Center, which now supports five volcano observatories covering six U.S. areas—Hawaiʻi (HVO), Alaska and the Northern Mariana Islands (Alaska Volcano Observatory), Washington and Oregon (Cascades Volcano Observatory), California (California Volcano Observatory), and the Yellowstone region (Yellowstone Volcano Observatory). Although the National Park Service (NPS) managed HVO for only 12 years, HVO has enjoyed a close working relationship with Hawaiʻi Volcanoes National Park (named Hawaii National Park until 1961) since the park’s founding in 1916. Today, as in past years, the USGS and NPS work together to ensure the safety and education of park visitors. We are grateful to all park employees, particularly Superintendent Cindy Orlando and Chief Ranger Talmadge Magno and their predecessors, for their continuing support of HVO’s mission. HVO also works closely with the Hawaiʻi County Civil Defense. During volcanic and earthquake crises, we have appreciated the support of civil defense staff, especially that of Harry Kim and Quince Mento, who administered the agency during highly stressful episodes of Kīlauea's ongoing eruption. Our work in remote areas on Hawaiʻi’s active volcanoes is possible only with the able assistance of Hawaiʻi County and private pilots who have safely flown HVO staff to eruption sites through the decades. A special mahalo goes to David Okita, who has been HVO’s principal helicopter pilot for more than two decades. Many commercial and Civil Air Patrol pilots have also assisted HVO by reporting their observations during various eruptive events. Hawaiʻi’s news media—print, television, radio, and online sources—do an excellent job of distributing volcano and earthquake information to the public. Their assistance is invaluable to HVO, especially during times of crisis. HVO’s efforts to provide

  18. A one-dimensional seismic model for Uturuncu volcano, Bolivia, and its impact on full moment tensor inversions

    KAUST Repository

    Shen, Weisen

    2016-11-24

    Using receiver functions, Rayleigh wave phase velocity dispersion determined from ambient noise and teleseismic earthquakes, and Rayleigh wave horizontal to vertical ground motion amplitude ratios from earthquakes observed across the PLUTONS seismic array, we construct a one-dimensional (1-D) S-wave velocity (Vs) seismic model with uncertainties for Uturuncu volcano, Bolivia, located in the central Andes and overlying the eastward-subducting Nazca plate. We find a fast upper crustal lid placed upon a low-velocity zone (LVZ) in the mid-crust. By incorporating all three types of measurements with complimentary sensitivity, we also explore the average density and Vp/Vs (ratio of P-wave to S-wave velocity) structures beneath the young silicic volcanic field. We observe slightly higher Vp/Vs and a decrease in density near the LVZ, which implies a dacitic source of the partially molten magma body. We exploit the impact of the 1-D model on full moment tensor inversion for the two largest local earthquakes recorded (both magnitude ∼3), demonstrating that the 1-D model influences the waveform fits and the estimated source type for the full moment tensor. Our 1-D model can serve as a robust starting point for future efforts to determine a three-dimensional velocity model for Uturuncu volcano.

  19. Global Impacts of the 1600 Eruption of Peru's Huaynaputina Volcano

    Science.gov (United States)

    Verosub, Kenneth L.; Lippman, Jake

    2008-04-01

    The human impacts of the 1815 eruption of Tambora volcano in eastern Indonesia are well known. The sulfur injected into the stratosphere by that eruption produced a veil of sunlight-reflecting sulfate aerosols. The following year, often called the ``year without a summer,'' was marked by significant global cooling, resulting in crop failures, famine, and social unrest as well as by a broad array of climatic impacts [Oppenheimer, 2003]. Over the past 10,000 years, there have been many other volcanic eruptions of comparable (and greater) magnitude than Tambora, and at least some of these must have had similar effects. However, Tambora is the only major eruption whose global climatic and human impacts have been comprehensively documented.

  20. Automatic identification of rockfalls and volcano-tectonic earthquakes at the Piton de la Fournaise volcano using a Random Forest algorithm

    Science.gov (United States)

    Hibert, Clément; Provost, Floriane; Malet, Jean-Philippe; Maggi, Alessia; Stumpf, André; Ferrazzini, Valérie

    2017-06-01

    Monitoring the endogenous seismicity of volcanoes helps to forecast eruptions and prevent their related risks, and also provides critical information on the eruptive processes. Due the high number of events recorded during pre-eruptive periods by the seismic monitoring networks, cataloging each event can be complex and time-consuming if done by human operators. Automatic seismic signal processing methods are thus essential to build consistent catalogs based on objective criteria. We evaluated the performance of the ;Random Forests; (RF) machine-learning algorithm for classifying seismic signals recorded at the Piton de la Fournaise volcano, La Réunion Island (France). We focused on the discrimination of the dominant event types (rockfalls and volcano-tectonic earthquakes) using over 19,000 events covering two time periods: 2009-2011 and 2014-2015. We parametrized the seismic signals using 60 attributes that were then given to RF algorithm. When the RF classifier was given enough training samples, its sensitivity (rate of good identification) exceeded 99%, and its performance remained high (above 90%) even with few training samples. The sensitivity collapsed when using an RF classifier trained with data from 2009 to 2011 to classify data from 2014 to 2015 catalog, because the physical characteristics of the rockfalls and hence their seismic signals had evolved between the two time-periods. The main attribute families (waveform, spectrum, spectrogram or polarization) were all found to be useful for event discrimination. Our work validates the performance of the RF algorithm and suggests it could be implemented at other volcanic observatories to perform automatic, near real-time, classification of seismic events.

  1. Three-dimensional velocity structure and high-precision earthquake relocations at Augustine, Akutan, and Makushin Volcanoes, Alaska

    Science.gov (United States)

    Syracuse, E. M.; Thurber, C. H.; Power, J. A.; Prejean, S. G.

    2010-12-01

    Alaska contains over 100 volcanoes, 21 of which have been active within the past 20 years, including Augustine in Cook Inlet, and Akutan and Makushin in the central Aleutian arc. We incorporate 14-15 years of earthquake data from the Alaska Volcano Observatory (AVO) to obtain P-wave velocity structure and high-precision earthquake locations at each volcano. At Augustine, most relocated seismicity is beneath the summit at an average depth of 0.6 km. In the weeks leading to the 2006 eruption, seismicity shallowed and focused on a NW-SE line, suggestive of an inflating dike. Through August 2006, intermittent seismicity was observed at 1 to 4.5 km depth, pointing to an association with the transport of magma. Active-source data are also incorporated into the tomographic inversion, illuminating a high-velocity column beneath the summit, and elevated velocities on the south flank. The high-velocity column surrounds the observed deeper seismicity and is likely due to intruded volcanic material. The elevated velocities on the south flank are associated with uplifted zeolitzed sandstones. Akutan most recently erupted in 1992, before the seismic network was installed. Most seismicity is above 9 km depth, with 10% occurring between 14 to30 km depth. Seismicity is separated into two main groups that dip away from the caldera—one to the east and one to the west. The eastern group contains earthquakes from a swarm in early 1996 and the western group contains earthquakes from mid-1996 through the present that form rough lines radiating from the summit. Ongoing seismicity also occurs in a broader region beneath the caldera. Makushin most recently erupted in 1995, also prior to seismic monitoring by AVO. Relocations here show that most seismicity is at 3 to 13 km depth and either beneath the caldera or within one of two dipping clusters 20 km to the northeast. Additional seismicity occurs at up to 25 km depth beneath the summit, as well as scattered throughout the island at

  2. Velocity structure of the crust and upper mantle at the northern group of Kamchatka volcanoes (Based on the travel time of P-waves from volcanic earthquakes)

    Science.gov (United States)

    Slavina, L. B.; Pivovarova, N. B.; Senyukov, S. L.

    2012-12-01

    The results of a calculation of the P-wave ( V P ) velocity fields are presented on the basis of the method of the reversible wave and the TAU parameter characterizing the V P / V S ratio of seismic waves from the local volcanic earthquakes that occurred at the northern group of Kamchatka volcanoes in 2005-2007. The 3D velocity cross sections were constructed along the SW-NE-trending volcanic group from the Ploskii Tolbachik volcano in the southwest up to the Shiveluch volcano in the northeast. The change of velocity field in time and depth is found. The problems of relating these changes to volcanic activity is reviewed.

  3. FEASIBLE STUDY ON THE INTEGRATION SYSTEM FOR THE SPACE MONITORING OF MAJOR EARTHQUAKES AND VOLCANOES IN TERRESTRIAL LAND

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    With the rapid development of space technology, earth observation technology and sky observatory technolo-gy, they have played a more and more important part in monitoring and predicting of earthquakes and volcanoes in the terres-trial land. In recent years, the related agencies have done the experiments and researches on monitoring and predicting ofearthquakes and volcanoes in the forewarning period by means of many approaches, such as satellite thermal infrared re-mote sensing(TIRS), Global Positioning System(GPS), differential interferometric synthesis aperture radar (D-INSAR),astronomical time-latitude residual anomaly, and Geographic Information Systems(GIS), etc. A quite large number of re-search foundation has been built in the fundamental theories and application methods. The experiments and researcheshave shown that these technology is efficient methods for high frequency crust movement. If the existed separate scientificforces and results are possibly assembled together to form a more complete integration monitoring system with the combina-tion of space, sky observation, ground, deep geology and macro anomaly, it will come into a new stage of monitoring andpredicting of earthquakes and volcanic eruptions.

  4. Three-dimensional crustal movement and the activities of earthquakes, volcanoes and faults in Hainan Island, China

    Directory of Open Access Journals (Sweden)

    Yaxuan Hu

    2016-07-01

    Full Text Available Hainan Island is a seismic active region, where Qiongshan M7.5 earthquake occurred in 1605 and several seismic belts appeared in recent years, especially the NS trending seismic belt (NSB located in the northeast part of the island. Here is also a magmatic active region. The lava from about 100 volcanoes covered more than 4000 km2. The latest eruptions occurred on Ma'anling–Lei Huling volcanoes within 10,000 years. The neotectonic movement has been determined by geological method in the island and its adjacent areas. In the paper, the present-day 3D crustal movement is obtained by using Global Positioning System (GPS data observed from 2009 to 2014 and leveling observations measured in 1970s and 1990s respectively. The results show the horizontal movement is mainly along SEE direction relative to the Eurasian Plate. The velocities are between 4.01 and 6.70 mm/a. The tension rate near the NSB is less than 1 mm/a. The vertical movement shows the island uplifts as a whole with respect to the reference benchmark Xiuyinggang. The average uplifting rate is 2.4 mm/a. The rates are 2–3 mm/a in the northwest and 3–5mm/a in the northwest. It shows the deformation pattern of the southwest island is upward relative to the northeast, which is different from the result inferred from the coastal change and GPS. Haikou and its adjacent region present a subsidence in a long time. The southern part of the middle segment of the Wangwu-Wenjiao fault uplifts relative to the northern. Meanwhile, the western part uplifts relative to the eastern NSB. The vertical crustal motion and the two normal faults nearly correspond to the terrain. The NSB is located along the Puqiangang-Dazhibo fault, which is assessed as a segmented fault with a dip of 80°–90°and partly exposed. The 3D deformations and other studies reveal the present activities of earthquakes, volcanoes and the faults. The small earthquakes will still occur in the NS belt and the volcanoes are

  5. Stress perturbation given on the Mount Fuji Volcano Magma System caused by the Tohoku Megathrust Earthquake, Japan

    Science.gov (United States)

    Fujita, E.; Kozono, T.; Ozawa, T.; Ueda, H.; Kohno, Y.; Yoshioka, S.; Toda, N.; Kikuchi, A.; Ida, Y.

    2012-12-01

    Earthquake often triggers volcanic eruptions nearby, and its mechanism is widely discussed. The megathrust earthquake on March 11, 2011, in Tohoku, Japan, caused enormous crustal deformation over the mainland of Japan, and 20 volcanoes showed abnormal activities. In this presentation, we evaluate the perturbation given on Mount Fuji volcanic system. We applied the Finite-Element Method (FEM) to calculate both static and quasi-static stress changes. The Japanese main-land and the Mount Fuji region are modeled based on seismic tomography, as well as the effects of the topography. Our results changes indicate that the static stress change due to Tohoku earthquake is in the order of 0.01MPa. In addition, an induced Mw5.9 East-Shizuoka earthquake occurred four days after the major earthquake beneath the south flank of Mount Fuji. This seismic fault is estimated to be located above the magma reservoir in the mid-crust, based on the inversion of ground deformation data, and FEM result suggests the stress changes of 0.1-1MPa. We also consider the quasi-static model to evaluate the mechanism of time lag between earthquakes and volcanic eruption. We applied the visco-elastic (Maxwell) model to crustal structure. We must obtain strain velocity in each time step, which controls the response after. Our results shows that the differential stress around the main shock region will reduce to 78 % of the static stress change in 100 years, but will increase to 7% of the static stress change beneath the magma reservoir of Mount Fuji volcano. Our interest is in whether these disturbances are sufficient to excite the magma and trigger and eruption. Here we consider two kinds of processes leading to an eruption. The first one is the promotion of the promotion of bubbling due to depressurization, and the other is the stress changes in the surrounding rocks. We performed numerical simulations of depressurization bubbling by VERA code (Fujita et al., 2007, IUGG). We assume initial bubble

  6. Volcanic magma reservoir imaged as a low-density body beneath Aso volcano that terminated the 2016 Kumamoto earthquake rupture

    Science.gov (United States)

    Miyakawa, Ayumu; Sumita, Tatsuya; Okubo, Yasukuni; Okuwaki, Ryo; Otsubo, Makoto; Uesawa, Shimpei; Yagi, Yuji

    2016-12-01

    We resolve the density structure of a possible magma reservoir beneath Aso, an active volcano on Kyushu Island, Japan, by inverting gravity data. In the context of the resolved structure, we discuss the relationship between the fault rupture of the 2016 Kumamoto earthquake and Aso volcano. Low-density bodies were resolved beneath central Aso volcano using a three-dimensional inversion with an assumed density contrast of ±0.3 g/cm3. The resultant location of the southern low-density body is consistent with a magma reservoir reported in previous studies. No Kumamoto aftershocks occur in the southern low-density body; this aseismic anomaly may indicate a ductile feature due to high temperatures and/or the presence of partial melt. Comparisons of the location of the southern low-density body with rupture models of the mainshock, obtained from teleseismic waveform and InSAR data, suggest that the rupture terminus overlaps the southern low-density body. The ductile features of a magma reservoir could have terminated rupture propagation. On the other hand, a northern low-density body is resolved in the Asodani area, where evidence of current volcanic activity is scarce and aftershock activity is high. The northern low-density body might, therefore, be derived from a thick caldera fill in the Asodani area, or correspond to mush magma or a high-crystallinity magma reservoir that could be the remnant of an ancient intrusion.[Figure not available: see fulltext.

  7. The Impact of Earthquakes on the Domestic Stock Market

    NARCIS (Netherlands)

    Scholtens, Bert; Voorhorst, Yvonne

    2013-01-01

    How do financial markets respond to the impact of earthquakes? We investigate this for more than 100 earthquakes with fatalities in 21 countries from five continents in the period 1973-2011. Using an event study methodology we conclude that there are significant negative effects on stock market valu

  8. The Impact of Earthquakes on the Domestic Stock Market

    NARCIS (Netherlands)

    Scholtens, Bert; Voorhorst, Yvonne

    How do financial markets respond to the impact of earthquakes? We investigate this for more than 100 earthquakes with fatalities in 21 countries from five continents in the period 1973-2011. Using an event study methodology we conclude that there are significant negative effects on stock market

  9. Impact of the Wenchuan Earthquake on Tourism in Sichuan, China

    Institute of Scientific and Technical Information of China (English)

    YANG Weiqiong; CHEN Guojie; WANG Daojie

    2008-01-01

    An intensive earthquake, the Wenchuan Earthquake of 8.0 on the Richter scale, struck western Sichuan, China on May 12, 2008. The earthquake has tremendously affected all industries in the quake-hit areas, with no exception :of the local tourism. The study of the effect of the earthquake on tourism enriches the theory of tourism, and more importantly,it well serves as the foundation for policy making. The objective of this study is to outline for readers the empirical findings on the various ways that the earthquake affected the operations and viability of tourism in the quake-hit areas. This paper is mainly divided into 3 parts. The first part is to discuss the importance of tourism in the quake-hit areas. The second is to analyze the influencing factors of tourism.The third is to assess the impact of the earthquake on tourism in Sichuan in different seasons.

  10. Preliminary impact assessment of effusive eruptions at Etna volcano

    Science.gov (United States)

    Cappello, Annalisa; Michaud-Dubuy, Audrey; Branca, Stefano; De Beni, Emanuela; Del Negro, Ciro

    2016-04-01

    Lava flows are a recurring and widespread form of volcanic activity that threaten people and property around the world. The growing demographic congestion around volcanic structures increases the potential risks and costs that lava flows represent, and leads to a pressing need for faster and more accurate assessment of lava flow impact. To fully evaluate potential effects and losses that an effusive eruption may cause to society, property and environment, it is necessary to consider the hazard, the distribution of the exposed elements at stake and the associated vulnerability. Lava flow hazard assessment is at an advanced state, whereas comprehensive vulnerability assessment is lacking. Cataloguing and analyzing volcanic impacts provide insight on likely societal and physical vulnerabilities during future eruptions. Here we quantify the lava flow impact of two past main effusive eruptions of Etna volcano: the 1669, which is the biggest and destructive flank eruption to have occurred on Etna in historical time, and the 1981, lasting only 6 days, but characterized by an intense eruptive dynamics. Different elements at stake are considered, including population, hospitals, critical facilities, buildings of historic value, industrial infrastructures, gas and electricity networks, railways, roads, footways and finally land use. All these elements were combined with the 1669 and 1981 lava flow fields to quantify the social damage and economic loss.

  11. The Lushan earthquake and the giant panda: impacts and conservation.

    Science.gov (United States)

    Zhang, Zejun; Yuan, Shibin; Qi, Dunwu; Zhang, Mingchun

    2014-06-01

    Earthquakes not only result in a great loss of human life and property, but also have profound effects on the Earth's biodiversity. The Lushan earthquake occurred on 20 Apr 2013, with a magnitude of 7.0 and an intensity of 9.0 degrees. A distance of 17.0 km from its epicenter to the nearest distribution site of giant pandas recorded in the Third National Survey was determined. Making use of research on the Wenchuan earthquake (with a magnitude of 8.0), which occurred approximately 5 years ago, we briefly analyze the impacts of the Lushan earthquake on giant pandas and their habitat. An earthquake may interrupt ongoing behaviors of giant pandas and may also cause injury or death. In addition, an earthquake can damage conservation facilities for pandas, and result in further habitat fragmentation and degradation. However, from a historical point of view, the impacts of human activities on giant pandas and their habitat may, in fact, far outweigh those of natural disasters such as earthquakes. Measures taken to promote habitat restoration and conservation network reconstruction in earthquake-affected areas should be based on requirements of giant pandas, not those of humans. © 2013 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

  12. Swarms of similar long-period earthquakes in the mantle beneath Mauna Loa Volcano

    Science.gov (United States)

    Okubo, P.G.; Wolfe, C.J.

    2008-01-01

    We present analyses of two swarms of long-period (LP) earthquakes at > 30??km depth that accompanied the geodetically observed 2002-2005 Mauna Loa intrusion. The first LP earthquake swarm in 2002 consisted of 31 events that were precursory and preceded the start of Mauna Loa inflation; the second LP swarm of two thousand events occurred from 2004-2005. The rate of LP earthquakes slowed significantly coincident with the occurrence of the December 26, 2004 Mw 9.3 Sumatra earthquake, suggesting that the seismic waves from this great earthquake may have had a dynamic triggering effect on the behavior of Mauna Loa's deep magma system. Using waveform cross correlation and double difference relocation, we find that a large number of earthquakes in each swarm are weakly similar and can be classified into two families. The relocated hypocenters for each family collapse to compact point source regions almost directly beneath the Mauna Loa intrusion. We suggest that the observed waveform characteristics are compatible with each family being associated with the resonance of a single fluid filled vertical crack of fixed geometry, with differences in waveforms between events being produced by slight variations in the trigger mechanism. If these LP earthquakes are part of the primary magma system that fed the 2002-2005 intrusion, as indicated by the spatial and temporal associations between mantle seismicity and surface deformation, then our results raise the possibility that this magma system may be quite focused at these depths as opposed to being a diffuse network. It is likely that only a few locations of Mauna Loa's deep magma system met the geometric and fluid dynamic conditions for generating LP earthquakes that were large enough to be recorded at the surface, and that much of the deep magma transfer associated with the 2002-2005 intrusion occurred aseismically. ?? 2008 Elsevier B.V.

  13. The 2005 volcano-tectonic earthquake swarm in the Andaman Sea: Triggered by the 2004 great Sumatra-Andaman earthquake

    Digital Repository Service at National Institute of Oceanography (India)

    Kundu, B.; Legrand, D.; Gahalaut, K.; Gahalaut, V.K.; Mahesh, P.; KameshRaju, K.A.; Catherine, J.K.; Ambikapthy, A.; Chadha, R.K.

    environments (e.g Roman et al., 2004; Legrand et al., 2011; Wright et al., 2012). 8.4. Feed-back tectonic and volcanic responses The 2005 Andaman swarm is related to both tectonic and volcanic processes. The swarm probably occurred on the WAF and on the en... mechanisms of all the earthquakes are compatible with a unique stress tensor (Fig. 6). Thus the time evolution of the focal mechanism shows the feedback response of the tectonic behavior of this swarm (strike-slip focal mechanisms almost on the right...

  14. Estimating surface faulting impacts from the shakeout scenario earthquake

    Science.gov (United States)

    Treiman, J.A.; Pontib, D.J.

    2011-01-01

    An earthquake scenario, based on a kinematic rupture model, has been prepared for a Mw 7.8 earthquake on the southern San Andreas Fault. The rupture distribution, in the context of other historic large earthquakes, is judged reasonable for the purposes of this scenario. This model is used as the basis for generating a surface rupture map and for assessing potential direct impacts on lifelines and other infrastructure. Modeling the surface rupture involves identifying fault traces on which to place the rupture, assigning slip values to the fault traces, and characterizing the specific displacements that would occur to each lifeline impacted by the rupture. Different approaches were required to address variable slip distribution in response to a variety of fault patterns. Our results, involving judgment and experience, represent one plausible outcome and are not predictive because of the variable nature of surface rupture. ?? 2011, Earthquake Engineering Research Institute.

  15. Lahar at Kali Konto after the 2014 Eruption of Kelud Volcano, East Java: Impacts and Risk

    OpenAIRE

    2015-01-01

    Five days after the Kelud Volcano eruption of 13 February 2014, lahar occurred in several channels of the Volcano. Rainfall with intensity of 26 mm/hour mobilized pyroclastic material from the upper slopes of Kelud Volcano down the channel during 3.5 hour. Using this eruption as a case study, the aims of this paper are (1) to study the geomorphic impact of lahars and (2) to study future hazards and risks due to the potential of lahar source material and lahar repose area. To reach these two g...

  16. Short-term volcano-tectonic earthquake forecasts based on a moving mean recurrence time algorithm: the El Hierro seismo-volcanic crisis experience

    Science.gov (United States)

    García, Alicia; De la Cruz-Reyna, Servando; Marrero, José M.; Ortiz, Ramón

    2016-05-01

    Under certain conditions, volcano-tectonic (VT) earthquakes may pose significant hazards to people living in or near active volcanic regions, especially on volcanic islands; however, hazard arising from VT activity caused by localized volcanic sources is rarely addressed in the literature. The evolution of VT earthquakes resulting from a magmatic intrusion shows some orderly behaviour that may allow the occurrence and magnitude of major events to be forecast. Thus governmental decision makers can be supplied with warnings of the increased probability of larger-magnitude earthquakes on the short-term timescale. We present here a methodology for forecasting the occurrence of large-magnitude VT events during volcanic crises; it is based on a mean recurrence time (MRT) algorithm that translates the Gutenberg-Richter distribution parameter fluctuations into time windows of increased probability of a major VT earthquake. The MRT forecasting algorithm was developed after observing a repetitive pattern in the seismic swarm episodes occurring between July and November 2011 at El Hierro (Canary Islands). From then on, this methodology has been applied to the consecutive seismic crises registered at El Hierro, achieving a high success rate in the real-time forecasting, within 10-day time windows, of volcano-tectonic earthquakes.

  17. 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

    Uncertainties in rapid earthquake impact models are intrinsically large even when excluding potential indirect losses (fires, landslides, tsunami…). The reason is that they are based on several factors which are themselves difficult to constrain, such as the geographical distribution of shaking intensity, building type inventory and vulnerability functions. The difficulties can be illustrated by two boundary cases. For moderate (around M6) earthquakes, the size of potential damage zone and the epicentral location uncertainty share comparable dimension of about 10-15km. When such an earthquake strikes close to an urban area, like in 1999, in Athens (M5.9), earthquake location uncertainties alone can lead to dramatically different impact scenario. Furthermore, for moderate magnitude, the overall impact is often controlled by individual accidents, like in 2002 in Molise, Italy (M5.7), in Bingol, Turkey (M6.4) in 2003 or in Christchurch, New Zealand (M6.3) where respectively 23 out of 30, 84 out of 176 and 115 out of 185 of the causalities perished in a single building failure. Contrastingly, for major earthquakes (M>7), the point source approximation is not valid anymore, and impact assessment requires knowing exactly where the seismic rupture took place, whether it was unilateral, bilateral etc.… and this information is not readily available directly after the earthquake's occurrence. In-situ observations of actual impact provided by eyewitnesses can dramatically reduce impact models uncertainties. We will present the overall strategy developed at the EMSC which comprises of crowdsourcing and flashsourcing techniques, the development of citizen operated seismic networks, and the use of social networks to engage with eyewitnesses within minutes of an earthquake occurrence. For instance, testimonies are collected through online questionnaires available in 32 languages and automatically processed in maps of effects. Geo-located pictures are collected and then

  18. Earthquake relocations and InSAR time series analysis of the June 12th 2011 eruption of Nabro Volcano, Eritrea

    Science.gov (United States)

    Hamlyn, J.; Keir, D.; Hammond, J. O.; Wright, T. J.; Neuberg, J.; Kibreab, A.; Ogubazghi, G.; Goitom, B.

    2012-12-01

    Nabro volcano sits on the Danakil block next to the Afar triangle, nested between the Somalian, Arabian and Nubian plates. It is the largest and most central volcano within the ~110-km-long, SSW-NNE trending Nabro Volcanic Range (NVR) which extends from the Afar depression to the Red Sea. On the 12th June 2011, Nabro volcano suddenly erupted after being inactive for 10, 000 years. The resulting ash cloud rose 15 km, it reached the stratosphere and forced aircraft to re-route. The eruption also caused a 17 km long lava flow and ranks as one of the largest SO2 eruptions since the Mt. Pinatubo (1991) event. In response, a network of 8 seismometers were located around the active vent and were recording by the 31st August. Also, satellites with InSAR acquisition capabilities were tasked to the region including TerraSAR-X, Cosmo-SkyMed and Envisat. We processed the seismic signals detected by the array and those arriving at a regional seismic station (located in the north west) to provide accurate earthquake locations for the period September-October, 2011. We used Hypoinverse-2000 to provide preliminary locations for events, which were then relocated using HypoDD. Absolute error after Hypoinverse-2000 processing was, on average, approximately ±2 and ±4 km in the horizontal and the vertical directions, respectively. These errors were reduced to a relative error of ±20 and ±30 m in the horizontal and vertical directions, respectively, using HypoDD. Investigation of the parameters controlling the relocation was completed, in order to monitor bias that they caused in the final positioning of the hypocentres. The hypocentres produced have a very small relative depth error (~±30m), and show columns and clusters of activity as well as areas devoid of events. The majority of the seismic events are located at the active vent and within Nabro caldera, with fewer events located on the flanks. There also appears to be a smaller cluster of events to the south-west of Nabro

  19. Laboratory simulations of fluid/gas induced micro-earthquakes: application to volcano seismology.

    Directory of Open Access Journals (Sweden)

    Philip Michael Benson

    2014-11-01

    Full Text Available Understanding different seismic signals recorded in active volcanic regions allows geoscientists to derive insight into the processes that generate them. A key type is known as Low Frequency or Long Period (LP event, generally understood to be generated by different fluid types resonating in cracks and faults. The physical mechanisms of these signals have been linked to either resonance/turbulence within fluids, or as a result of fluids ‘sloshing’ due to a mixture of gas and fluid being present in the system. Less well understood, however, is the effect of the fluid type (phase on the measured signal. To explore this, we designed an experiment in which we generated a precisely controlled liquid to gas transition in a closed system by inducing rapid decompression of fluid-filled fault zones in a sample of basalt from Mt. Etna Volcano, Italy. We find that fluid phase transition is accompanied by a marked frequency shift in the accompanying microseismic dataset that can be compared to volcano seismic data. Moreover, our induced seismic activity occurs at pressure conditions equivalent to hydrostatic depths of 200 to 750 meters. This is consistent with recently measured dominant frequencies of LP events and with numerous models.

  20. Low-frequency earthquakes at the Torfajökull volcano, south Iceland

    Science.gov (United States)

    Soosalu, Heidi; Lippitsch, Regina; Einarsson, Páll

    2006-05-01

    Torfajökull is a large rhyolitic volcanic edifice with a 12-km-diameter caldera and abundant high-temperature geothermal activity. It is located in the neovolcanic zone in south Iceland, at the junction of the eastern rift zone and a transform zone with the intraplate volcanic flank zone of south Iceland. The latest eruption at Torfajökull occurred about 500 years ago. Torfajökull is a source of persistent small-scale seismicity, where two types of earthquakes occur. High-frequency events are concentrated in the western part of the caldera and low-frequency events cluster in the south. Small low-frequency earthquakes have been observed at Torfajökull since the installation of a local analogue seismograph station in 1985. They typically occur in swarms; up to 300 earthquakes per day have been observed. The low-frequency events have a frequency content of about 1-3 Hz, and are difficult to locate, because of the emergent nature of their phases. The 160 events located during the years 1994-2000 using the permanent Icelandic seismic network cluster in the southern part of the Torfajökull caldera. A closer study of low-frequency events was carried out between May and October 2002, with a dense network of twenty Güralp 6TD broadband seismometers in the Torfajökull area. No distinct swarm activity was observed during this period, but small low-frequency events occurred almost on a daily basis. About 330 low-frequency events were detected during the study period. They are located in the southern part of the caldera, between two small glaciers. Areas of intensive geothermal activity surround the cluster of low-frequency events. It is argued that these earthquakes are associated with active magma in the south part of the Torfajökull caldera, possibly a rising cryptodome.

  1. Seismic Study of the Velocity Structure and Earthquake FocalMechanisms beneath the Krafla Central Volcano, NE Iceland

    Science.gov (United States)

    Martens, H. R.; Schuler, J.; Greenfield, T. S.; White, R. S.; Roecker, S. W.; Brandsdottir, B.; Stock, J. M.; Tarasewicz, J.; Pugh, D. J.

    2015-12-01

    We investigated the seismic velocity structure of the Krafla central volcano, NE Iceland, and its shallow geothermal fields. In our 3D tomographic inversions, we used passive seismic data recorded between 2009-2012 from a temporary local network as well as active seismic legacy data to constrain the velocity models. We find high P-wave velocities (Vp) underneath regions of elevated topographic relief as well as two low-Vp anomalies that coincide spatially with two attenuating bodies outlined from S-wave shadows during the Krafla rifting episode of 1974-1985. Within the Krafla geothermal reservoir, which is developed for energy production, we imaged a shallow low-Vp/Vs zone overlying a deeper high-Vp/Vs zone and interpreted them as steam- and brine-bearing formations, respectively. Previously undertaken borehole measurements support our findings. A prominent low-Vp/Vs anomaly underlies these zones at rock depths greater than 1.5 km, where a super-heated zone within felsic overlies rhyolitic within the geothermal melt. Calculations systems show that of the most earthquake focal events are mechanisms consistent double-couple source models with only a few clear non-shear source models.

  2. Earthquake relocations and InSAR analysis following the June 12th 2011 eruption of Nabro volcano, Afar

    Science.gov (United States)

    Hamlyn, Joanna; Wright, Tim; Keir, Derek; Neuberg, Jurgen; Grandin, Raphael; Goitom, Berhe; Hammond, James; Kibreab, Alem; Ogubazghi, Ghebrebrhan; Pagli, Carolina; Sansosti, Eugenio

    2014-05-01

    Nabro volcano sits on the southern part of Danakil block to the east of the Afar depression, on the Arabian plate. On the 12th June 2011, Nabro volcano suddenly erupted after being inactive for 10,000 years. The eruption caused a 17-km-long lava flow, a 15-km-high ash cloud, and ranks as one of the largest emissions of SO2 since the Mt. Pinatubo (1991) event. This eruption creates an important opportunity to use seismicity and surface deformation measurements to understand the subsurface magmatic system and deformation of a hazardous, off axis caldera during continental rupture. We installed a network of 8 seismometers around Nabro caldera which began recording on the 31st August and tasked SAR acquisitions from TerraSAR-X (TSX) and Cosmo-SkyMed (CSK) satellites. The SAR images used for this study post date the eruption. We used TSX stripmap mode images from ascending and descending orbits. Using a small baseline approach, we used 25 images acquired between the 1st July 2011 to the 5th October 2012 on descending orbit 046, to create 34 interferograms. We complemented these with 19 images from ascending orbit 130 spanning the 6th July 2011 to the 10th October 2012 from ascending orbit 130, which we used to create 21 interferograms. We produced a velocity ratemap and timeseries using π-RATE showing subsidence of up to 25cm/yr centred on Nabro. We used a Monte-Carlo hybrid downhill simplex technique to invert the dataset and found the best fitting solution as a mogi source at 6.9 ±1.1 km depth, and located at a 13.35 (lat) and 41.69 (long). The time dependence observed is consistent with a viscoelastic relaxation around the magma chamber, following depletion. Concurrent with the TSX acquisitions, CSK imaged the volcano on a descending track between 26th June 2011 and 18th July 2012 within the ASI project SAR4Volcanoes, and 64 images were used to produce 171 interferograms which were inverted to form a timeseries using a SBAS approach. This dataset has an overall

  3. Impact analytical models for earthquake-induced pounding simulation

    Institute of Scientific and Technical Information of China (English)

    Kun YE; Li LI

    2009-01-01

    Structural pounding under earthquake has been recently extensively investigated using various impact analytical models. In this paper, a brief review on the commonly used impact analytical models is conducted.Based on this review, the formula used to determine the damping constant related to the impact spring stiffness,coefficient of restitution, and relative approaching velocity in the Hertz model with nonlinear damping is found to be incorrect. To correct this error, a more accurate approximating formula for the damping constant is theoretically derived 5~nd numerically verified. At the same time, a modified Kelvin impact model, which can reasonably account for the physical nature of pounding and conveniently implemented in the earthquake-induced pounding simulation of structural engineering is proposed.

  4. Long-term impact of earthquakes on sleep quality.

    Directory of Open Access Journals (Sweden)

    Daniela Tempesta

    Full Text Available PURPOSE: We investigated the impact of the 6.3 magnitude 2009 L'Aquila (Italy earthquake on standardized self-report measures of sleep quality (Pittsburgh Sleep Quality Index, PSQI and frequency of disruptive nocturnal behaviours (Pittsburgh Sleep Quality Index-Addendum, PSQI-A two years after the natural disaster. METHODS: Self-reported sleep quality was assessed in 665 L'Aquila citizens exposed to the earthquake compared with a different sample (n = 754 of L'Aquila citizens tested 24 months before the earthquake. In addition, sleep quality and disruptive nocturnal behaviours (DNB of people exposed to the traumatic experience were compared with people that in the same period lived in different areas ranging between 40 and 115 km from the earthquake epicenter (n = 3574. RESULTS: The comparison between L'Aquila citizens before and after the earthquake showed a significant deterioration of sleep quality after the exposure to the trauma. In addition, two years after the earthquake L'Aquila citizens showed the highest PSQI scores and the highest incidence of DNB compared to subjects living in the surroundings. Interestingly, above-the-threshold PSQI scores were found in the participants living within 70 km from the epicenter, while trauma-related DNBs were found in people living in a range of 40 km. Multiple regressions confirmed that proximity to the epicenter is predictive of sleep disturbances and DNB, also suggesting a possible mediating effect of depression on PSQI scores. CONCLUSIONS: The psychological effects of an earthquake may be much more pervasive and long-lasting of its building destruction, lasting for years and involving a much larger population. A reduced sleep quality and an increased frequency of DNB after two years may be a risk factor for the development of depression and posttraumatic stress disorder.

  5. Evidence for high fluid/melt content beneath Krakatau volcano (Indonesia) from local earthquake tomography

    Science.gov (United States)

    Jaxybulatov, Kairly; Koulakov, Ivan; Seht, Malte Ibs-von; Klinge, Klaus; Reichert, Christian; Dahren, Börje; Troll, Valentin R.

    2011-09-01

    Within the KRAKMON project for multiparameter monitoring of Anak Krakatau volcano (Indonesia), a network of temporary stations was installed on the islands of the Krakatau complex as well as in the surrounding areas of the Sunda Strait, Sumatra and Java. The network was operated from June 2005 until January 2006. More than 700 local events were recorded during this experiment, and travel times from these events were used to perform a tomographic inversion for P and S velocities and for the Vp/Vs ratio. In this study, special attention was paid to the validation of the computed model based on different tests, such as inversion of independent data subsets and synthetic modeling. Although the network configuration and the distribution of the events are not favorable for high-quality tomographic imaging, we have obtained some important and robust features which give information about sources of volcanic activity in the Krakatau complex. The most interesting feature of this study is a zone of high Vp/Vs ratio beneath the Krakatau complex. At depths down to 4 km depth we observe anticorrelation of higher P- and lower S-velocities that leads to Vp/Vs ratio higher than 2. This is a probable indicator of the presence of partially molten and/or with high fluid content material with a composition corresponding to deeper layers. It is important that the anomaly of high Vp/Vs ratio beneath the Krakatau complex appears to be separated in two parts at a depth of 5-6 km. This fits to results of geobarometric analysis that presume the existence of several levels of magma chambers beneath Anak Krakatau.

  6. Relative relocation of earthquakes without a predefined velocity model: an example from a peculiar seismic cluster on Katla volcano's south-flank (Iceland)

    CERN Document Server

    Sgattoni, Giulia; Einarsson, Páll; Lucchi, Federico

    2016-01-01

    Relative relocation methods are commonly used to precisely relocate earthquake clusters consisting of similar waveforms. Repeating waveforms are often recorded at volcanoes, where, however, the crust structure is expected to contain strong heterogeneities and therefore the 1D velocity model assumption that is made in most location strategies is not likely to describe reality. A peculiar cluster of repeating low-frequency seismic events was recorded on the south flank of Katla volcano (Iceland) from 2011. As the hypocentres are located at the rim of the glacier, the seismicity may be due to volcanic or glacial processes. Information on the size and shape of the cluster may help constraining the source process. The extreme similarity of waveforms points to a very small spatial distribution of hypocentres. In order to extract meaningful information about size and shape of the cluster, we minimize uncertainty by optimizing the cross-correlation measurements and relative-relocation process. With a synthetic test w...

  7. Impact of the earth's oscillations on the earthquakes

    CERN Document Server

    Guglielmi, A

    2012-01-01

    In this work we have discovered that the global seismic activity undergoes a modulation with the period of 54 min. We assume that the modulation is caused by the fundamental spheroidal oscillations of the Earth 0S2. The hidden 54-min periodicity of earthquakes was revealed by analyzing of earthquake catalogs using the method of epoch superposition and the spectral method. Initially we discovered some signs of the impact of 0S2 oscillations on the earthquakes accidentally when searching for an antipodal effect of the strong earthquakes. Subsequently we found independent evidence in favor of our hypothesis when analyzing human impact on the seismic activity. Namely, along with the spectral peak of the seismicity at the frequency of 0.277 mHz (which is clearly of anthropogenic origin) we found a more powerful peak at the frequency of 0.309 mHz, i.e. on the period of 54 min, which coincides with the period of the fundamental mode of eigen spheroidal oscillations of the Earth.

  8. Volcanic gas impacts on vegetation at Turrialba Volcano, Costa Rica

    Science.gov (United States)

    Teasdale, R.; Jenkins, M.; Pushnik, J.; Houpis, J. L.; Brown, D. L.

    2010-12-01

    Turrialba volcano is an active composite stratovolcano that is located approximately 40 km east of San Jose, Costa Rica. Seismic activity and degassing have increased since 2005, and gas compositions reflect further increased activity since 2007 peaking in January 2010 with a phreatic eruption. Gas fumes dispersed by trade winds toward the west, northwest, and southwest flanks of Turrialba volcano have caused significant vegetation kill zones, in areas important to local agriculture, including dairy pastures and potato fields, wildlife and human populations. In addition to extensive vegetative degradation is the potential for soil and water contamination and soil erosion. Summit fumarole temperatures have been measured over 200 degrees C and gas emissions are dominated by SO2; gas and vapor plumes reach up to 2 km (fumaroles and gases are measured regularly by OVSICORI-UNA). A recent network of passive air sampling, monitoring of water temperatures of hydrothermal systems, and soil pH measurements coupled with measurement of the physiological status of surrounding plants using gas exchange and fluorescence measurements to: (1) identify physiological correlations between leaf-level gas exchange and chlorophyll fluorescence measurements of plants under long term stress induced by the volcanic gas emissions, and (2) use measurements in tandem with remotely sensed reflectance-derived fluorescence ratio indices to track natural photo inhibition caused by volcanic gas emissions, for use in monitoring plant stress and photosynthetic function. Results may prove helpful in developing potential land management strategies to maintain the biological health of the area.

  9. Long Period (LP) volcanic earthquake source location at Merapi volcano by using dense array technics

    Science.gov (United States)

    Metaxian, Jean Philippe; Budi Santoso, Agus; Laurin, Antoine; Subandriyo, Subandriyo; Widyoyudo, Wiku; Arshab, Ghofar

    2015-04-01

    Since 2010, Merapi shows unusual activity compared to last decades. Powerful phreatic explosions are observed; some of them are preceded by LP signals. In the literature, LP seismicity is thought to be originated within the fluid, and therefore to be representative of the pressurization state of the volcano plumbing system. Another model suggests that LP events are caused by slow, quasi-brittle, low stress-drop failure driven by transient upper-edifice deformations. Knowledge of the spatial distribution of LP events is fundamental for better understanding the physical processes occurring in the conduit, as well as for the monitoring and the improvement of eruption forecasting. LP events recorded at Merapi have a spectral content dominated by frequencies between 0.8 and 3 Hz. To locate the source of these events, we installed a seismic antenna composed of 4 broadband CMG-6TD Güralp stations. This network has an aperture of 300 m. It is located on the site of Pasarbubar, between 500 and 800 m from the crater rim. Two multi-parameter stations (seismic, tiltmeter, S-P) located in the same area, equipped with broadband CMG-40T Güralp sensors may also be used to complete the data of the antenna. The source of LP events is located by using different approaches. In the first one, we used a method based on the measurement of the time delays between the early beginnings of LP events for each array receiver. The observed differences of time delays obtained for each pair of receivers are compared to theoretical values calculated from the travel times computed between grid nodes, which are positioned in the structure, and each receiver. In a second approach, we estimate the slowness vector by using MUSIC algorithm applied to 3-components data. From the slowness vector, we deduce the back-azimuth and the incident angle, which give an estimation of LP source depth in the conduit. This work is part of the Domerapi project funded by French Agence Nationale de la Recherche (https

  10. Calibration and validation of earthquake catastrophe models. Case study: Impact Forecasting Earthquake Model for Algeria

    Science.gov (United States)

    Trendafiloski, G.; Gaspa Rebull, O.; Ewing, C.; Podlaha, A.; Magee, B.

    2012-04-01

    Calibration and validation are crucial steps in the production of the catastrophe models for the insurance industry in order to assure the model's reliability and to quantify its uncertainty. Calibration is needed in all components of model development including hazard and vulnerability. Validation is required to ensure that the losses calculated by the model match those observed in past events and which could happen in future. Impact Forecasting, the catastrophe modelling development centre of excellence within Aon Benfield, has recently launched its earthquake model for Algeria as a part of the earthquake model for the Maghreb region. The earthquake model went through a detailed calibration process including: (1) the seismic intensity attenuation model by use of macroseismic observations and maps from past earthquakes in Algeria; (2) calculation of the country-specific vulnerability modifiers by use of past damage observations in the country. The use of Benouar, 1994 ground motion prediction relationship was proven as the most appropriate for our model. Calculation of the regional vulnerability modifiers for the country led to 10% to 40% larger vulnerability indexes for different building types compared to average European indexes. The country specific damage models also included aggregate damage models for residential, commercial and industrial properties considering the description of the buildings stock given by World Housing Encyclopaedia and the local rebuilding cost factors equal to 10% for damage grade 1, 20% for damage grade 2, 35% for damage grade 3, 75% for damage grade 4 and 100% for damage grade 5. The damage grades comply with the European Macroseismic Scale (EMS-1998). The model was validated by use of "as-if" historical scenario simulations of three past earthquake events in Algeria M6.8 2003 Boumerdes, M7.3 1980 El-Asnam and M7.3 1856 Djidjelli earthquake. The calculated return periods of the losses for client market portfolio align with the

  11. Analysis on Global Earthquake and Volcano Activity in Recent Years%近年来全球地震与火山活动分析

    Institute of Scientific and Technical Information of China (English)

    洪汉净

    2011-01-01

    The eruption of Unzen Volcano of Japan in 1900 and eruption of Pinatubo volcano of Philippine in 1991 resulted in the active in the west margin of Philippine Sea Plate, and then the global seismic and volcanism come into a new stage. Great earthquakes (M≥8) are mostly in southern hemisphere, includes Sumatra Mw 9.1, 2004, and Chile Mw 8. 8, 2010. Volcano active has similar regime, both of 2 eruptions with VEI≥5 occurred in southern hemisphere. Tohoku earthquake in 2011 induced most expensive catastrophes, and effected the global seismic regime. Based on the comparison of patterns of earthquake distribution, the earthquake at Japan Arc may not overthrow the present regime of global earthquake activity.%1990年日本云仙岳火山和1991年菲律宾皮那图博火山喷发,引发了菲律宾海板块西缘的活动.全球板块运动以及相应的地震、火山活动进入一个新的阶段,特大地震活动以南半球为主,发生了2004年苏门答腊Mw 9.1大震(Mw是矩震级),2010年智利Mw 8.8级大地震.火山活动也有类似表现,两个VEI≥5(VEI是火山爆发指数)的喷发都发生在南半球.2011年日本仙台东发生Mw 9.1级大震造成巨大的灾难,也影响了世界地震活动的格局.考虑到1933年日本三陆大震后的图像.日本弧大震可能没有完全改变全球活动格局.

  12. Impact of the 2016 Ecuador Earthquake on Zika Virus Cases.

    Science.gov (United States)

    Vasquez, Diego; Palacio, Ana; Nuñez, Jose; Briones, Wladimir; Beier, John C; Pareja, Denisse C; Tamariz, Leonardo

    2017-07-01

    To evaluate the impact of the April 2016 7.8-magnitude earthquake in Ecuador on the incidence of Zika virus (ZIKV) cases. We used the national public health surveillance system for reportable transmissible conditions and included suspected and laboratory-confirmed ZIKV cases. We compared the number of cases before and after the earthquake in areas closer to and farther from the epicenter. From January to July 2016, 2234 patients suspected of having ZIKV infection were reported in both affected and control areas. A total of 1110 patients had a reverse transcription-polymerase chain reaction assay, and 159 were positive for ZIKV. The cumulative incidence of ZIKV in the affected area was 11.1 per 100 000 after the earthquake. The odds ratio of having ZIKV infection in those living in the affected area was 8.0 (95% CI = 4.4, 14.6; P < .01) compared with the control area and adjusted for age, gender, province population, and number of government health care facilities. A spike in ZIKV cases occurred after the earthquake. Patients in the area closest to the epicenter had a delay in seeking care.

  13. Hazard map for volcanic ballistic impacts at El Chichón volcano (Mexico)

    Science.gov (United States)

    Alatorre-Ibarguengoitia, Miguel; Ramos-Hernández, Silvia; Jiménez-Aguilar, Julio

    2014-05-01

    The 1982 eruption of El Chichón Volcano in southeastern Mexico had a strong social and environmental impact. The eruption resulted in the worst volcanic disaster in the recorded history of Mexico, causing about 2,000 casualties, displacing thousands, and producing severe economic losses. Even when some villages were relocated after the 1982 eruption, many people still live and work in the vicinities of the volcano and may be affected in the case of a new eruption. The hazard map of El Chichón volcano (Macías et al., 2008) comprises pyroclastic flows, pyroclastic surges, lahars and ash fall but not ballistic projectiles, which represent an important threat to people, infrastructure and vegetation in the case of an eruption. In fact, the fatalities reported in the first stage of the 1982 eruption were caused by roof collapse induced by ashfall and lithic ballistic projectiles. In this study, a general methodology to delimit the hazard zones for volcanic ballistic projectiles during volcanic eruptions is applied to El Chichón volcano. Different scenarios are defined based on the past activity of the volcano and parameterized by considering the maximum kinetic energy associated with ballistic projectiles ejected during previous eruptions. A ballistic model is used to reconstruct the "launching" kinetic energy of the projectiles observed in the field. The maximum ranges expected for the ballistics in the different explosive scenarios defined for El Chichón volcano are presented in a ballistic hazard map which complements the published hazard map. These maps assist the responsible authorities to plan the definition and mitigation of restricted areas during volcanic crises.

  14. The 2011 Tohoku earthquake : the impact on the energy sector

    OpenAIRE

    Azevedo Neto, Guilherme Maria Ferraz de

    2013-01-01

    The purpose of this paper is to study the impact caused by the Tohoku 2011 earthquake, within the energy sector across the World. In order to measure results, a couple of methodologies that resorted to abnormal returns were undertaken and multiple significance tests were made to verify statistical relevancy on the findings. It has been possible to observe a positive reaction on the “Nuclear Energy” companies, as well as a negative impact on the “Renewable Energy” group, with the most prominen...

  15. Hazard information management, interagency coordination, and impacts of the 2005-2006 eruption of Augustine Volcano: Chapter 28 in The 2006 eruption of Augustine Volcano, Alaska

    Science.gov (United States)

    Neal, Christina A.; Murray, Thomas L.; Power, John A.; Adleman, Jennifer N.; Whitmore, Paul M.; Osiensky, Jeffery M.; Power, John A.; Coombs, Michelle L.; Freymueller, Jeffrey T.

    2010-01-01

    Dissemination of volcano-hazard information in coordination with other Federal, State, and local agencies is a primary responsibility of the Alaska Volcano Observatory (AVO). During the 2005-6 eruption of Augustine Volcano in Alaska, AVO used existing interagency relationships and written protocols to provide hazard guidance before, during, and after eruptive events. The 2005-6 eruption was notable because of the potential for volcanogenic tsunami, which required establishment of a new procedure for alerts of possible landslide-induced tsunami in Cook Inlet. Despite repeated ash-cloud generating explosions and far-traveled ash clouds, impacts from the event were relatively minor. Primary economic losses occurred when air carriers chose to avoid flights into potentially unsafe conditions. Post-eruption evaluations by agencies involved in the response indicated weaknesses in information centralization and availability of specific information regarding ash fall hazards in real time.

  16. Asia-Pacific Region Global Earthquake and Volcanic Eruption Risk Management (G-EVER) project and a next-generation real-time volcano hazard assessment system

    Science.gov (United States)

    Takarada, S.

    2012-12-01

    The first Workshop of Asia-Pacific Region Global Earthquake and Volcanic Eruption Risk Management (G-EVER1) was held in Tsukuba, Ibaraki Prefecture, Japan from February 23 to 24, 2012. The workshop focused on the formulation of strategies to reduce the risks of disasters worldwide caused by the occurrence of earthquakes, tsunamis, and volcanic eruptions. More than 150 participants attended the workshop. During the workshop, the G-EVER1 accord was approved by the participants. The Accord consists of 10 recommendations like enhancing collaboration, sharing of resources, and making information about the risks of earthquakes and volcanic eruptions freely available and understandable. The G-EVER Hub website (http://g-ever.org) was established to promote the exchange of information and knowledge among the Asia-Pacific countries. Several G-EVER Working Groups and Task Forces were proposed. One of the working groups was tasked to make the next-generation real-time volcano hazard assessment system. The next-generation volcano hazard assessment system is useful for volcanic eruption prediction, risk assessment, and evacuation at various eruption stages. The assessment system is planned to be developed based on volcanic eruption scenario datasets, volcanic eruption database, and numerical simulations. Defining volcanic eruption scenarios based on precursor phenomena leading up to major eruptions of active volcanoes is quite important for the future prediction of volcanic eruptions. Compiling volcanic eruption scenarios after a major eruption is also important. A high quality volcanic eruption database, which contains compilations of eruption dates, volumes, and styles, is important for the next-generation volcano hazard assessment system. The volcanic eruption database is developed based on past eruption results, which only represent a subset of possible future scenarios. Hence, different distributions from the previous deposits are mainly observed due to the differences in

  17. Strategies for rapid global earthquake impact estimation: the Prompt Assessment of Global Earthquakes for Response (PAGER) system

    Science.gov (United States)

    Jaiswal, Kishor; Wald, D.J.

    2013-01-01

    This chapter summarizes the state-of-the-art for rapid earthquake impact estimation. It details the needs and challenges associated with quick estimation of earthquake losses following global earthquakes, and provides a brief literature review of various approaches that have been used in the past. With this background, the chapter introduces the operational earthquake loss estimation system developed by the U.S. Geological Survey (USGS) known as PAGER (for Prompt Assessment of Global Earthquakes for Response). It also details some of the ongoing developments of PAGER’s loss estimation models to better supplement the operational empirical models, and to produce value-added web content for a variety of PAGER users.

  18. Lahar at Kali Konto after the 2014 Eruption of Kelud Volcano, East Java: Impacts and Risk

    Directory of Open Access Journals (Sweden)

    Suprapto Dibyosaputro

    2015-08-01

    Full Text Available Five days after the Kelud Volcano eruption of 13 February 2014, lahar occurred in several channels of the Volcano. Rainfall with intensity of 26 mm/hour mobilized pyroclastic material from the upper slopes of Kelud Volcano down the channel during 3.5 hour. Using this eruption as a case study, the aims of this paper are (1 to study the geomorphic impact of lahars and (2 to study future hazards and risks due to the potential of lahar source material and lahar repose area. To reach these two goals, we use both primary and secondary data. The primary data comprises an integration of remote sensing, GIS approach, and fieldwork control, in order to investigate the geomorphic impacts of lahars. Secondary data were collected through interviews and statistical approach in villages, in order to determine their perception to the risk of lahar. Morphogenic processes such as riverbank erosion, channel-widening and riverbed downcutting took an important role in generating the impact of lahar in Kali Konto. The medial and distal areas were affected more largely affected than the proximal area. This major impacts have been river widening and buried crop field inside of the channel. This result allowed us to provide recommendation to population living along those areas at risk, in order to be prepared against the eventuality of potentially large and destructive lahars.

  19. Earthquake

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    正A serious earthquake happened in Wenchuan, Sichuan. Over 60,000 people died in the earhtquake, millins of people lost their homes. After the earthquake, people showed their love in different ways. Some gave food, medicine and everything necessary, some gave money,

  20. 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

  1. The economic costs of natural disasters globally from 1900-2015: historical and normalised floods, storms, earthquakes, volcanoes, bushfires, drought and other disasters

    Science.gov (United States)

    Daniell, James; Wenzel, Friedemann; Schaefer, Andreas

    2016-04-01

    For the first time, a breakdown of natural disaster losses from 1900-2015 based on over 30,000 event economic losses globally is given based on increased analysis within the CATDAT Damaging Natural Disaster databases. Using country-CPI and GDP deflator adjustments, over 7 trillion (2015-adjusted) in losses have occurred; over 40% due to flood/rainfall, 26% due to earthquake, 19% due to storm effects, 12% due to drought, 2% due to wildfire and under 1% due to volcano. Using construction cost indices, higher percentages of flood losses are seen. Depending on how the adjustment of dollars are made to 2015 terms (CPI vs. construction cost indices), between 6.5 and 14.0 trillion USD (2015-adjusted) of natural disaster losses have been seen from 1900-2015 globally. Significant reductions in economic losses have been seen in China and Japan from 1950 onwards. An AAL of around 200 billion in the last 16 years has been seen equating to around 0.25% of Global GDP or around 0.1% of Net Capital Stock per year. Normalised losses have also been calculated to examine the trends in vulnerability through time for economic losses. The normalisation methodology globally using the exposure databases within CATDAT that were undertaken previously in papers for the earthquake and volcano databases, are used for this study. The original event year losses are adjusted directly by capital stock change, very high losses are observed with respect to floods over time (however with improved flood control structures). This shows clear trends in the improvement of building stock towards natural disasters and a decreasing trend in most perils for most countries.

  2. Joint analysis of geodetic and earthquake fault-plane solution data to constrain magmatic sources: A case study from Kīlauea Volcano

    Science.gov (United States)

    Wauthier, Christelle; Roman, Diana C.; Poland, Michael P.

    2016-12-01

    A joint analysis of geodetic and seismic datasets from Kīlauea Volcano during a period of magmatic unrest in 2006 demonstrates the effectiveness of this combination for testing and constraining models of magma dynamics for a complex, multi-source system. At the end of 2003, Kīlauea's summit began a four-year-long period of inflation due to a surge in magma supply to the volcano. In 2006, for the first time since 1982, Kīlauea's Southwest Rift Zone (SWRZ) also experienced inflation. To investigate the characteristics of active magma sources and the nature of their interactions with faults in the SWRZ during 2006, we integrate, through Coulomb stress modeling, contemporary geodetic data from InSAR and GPS with a new catalogue of double-couple fault-plane solutions for volcano-tectonic earthquakes. We define two periods of inflation during 2006 based on the rate of deformation measured in daily GPS data, spanning February to 15 March 2006 (Period 1) and 16 March to 30 September 2006 (Period 2). InSAR data for these two periods are inverted to determine the position, change in size, and shape of inflation sources in each period. Our new models are consistent with microseismic activity from each period. They suggest that, during Period 1, deformation in the SWRZ can be explained by pressurization of magma in a spherical reservoir beneath the south caldera, and that, during Period 2, magma was also aseismically intruded farther to the southwest into the SWRZ along a sub-horizontal plane. Our Coulomb stress analysis shows that the microseismicity recorded in the SWRZ is induced by overpressurization of the south caldera reservoir, and not by magma intrusion into the SWRZ. This study highlights the importance of a joint analysis of independent geophysical datasets to fully constrain the nature of magma accumulation.

  3. Joint analysis of geodetic and earthquake fault-plane solution data to constrain magmatic sources: A case study from Kīlauea Volcano

    Science.gov (United States)

    Wauthier, Christelle; Roman, Diana C.; Poland, Michael

    2016-01-01

    A joint analysis of geodetic and seismic datasets from Kīlauea Volcano during a period of magmatic unrest in 2006 demonstrates the effectiveness of this combination for testing and constraining models of magma dynamics for a complex, multi-source system. At the end of 2003, Kīlauea's summit began a four-year-long period of inflation due to a surge in magma supply to the volcano. In 2006, for the first time since 1982, Kīlauea's Southwest Rift Zone (SWRZ) also experienced inflation. To investigate the characteristics of active magma sources and the nature of their interactions with faults in the SWRZ during 2006, we integrate, through Coulomb stress modeling, contemporary geodetic data from InSAR and GPS with a new catalogue of double-couple fault-plane solutions for volcano-tectonic earthquakes. We define two periods of inflation during 2006 based on the rate of deformation measured in daily GPS data, spanning February to 15 March 2006 (Period 1) and 16 March to 30 September 2006 (Period 2). InSAR data for these two periods are inverted to determine the position, change in size, and shape of inflation sources in each period. Our new models are consistent with microseismic activity from each period. They suggest that, during Period 1, deformation in the SWRZ can be explained by pressurization of magma in a spherical reservoir beneath the south caldera, and that, during Period 2, magma was also aseismically intruded farther to the southwest into the SWRZ along a sub-horizontal plane. Our Coulomb stress analysis shows that the microseismicity recorded in the SWRZ is induced by overpressurization of the south caldera reservoir, and not by magma intrusion into the SWRZ. This study highlights the importance of a joint analysis of independent geophysical datasets to fully constrain the nature of magma accumulation.

  4. Hazard map for volcanic ballistic impacts at Popocatépetl volcano (Mexico)

    Science.gov (United States)

    Alatorre-Ibargüengoitia, Miguel A.; Delgado-Granados, Hugo; Dingwell, Donald B.

    2012-11-01

    During volcanic explosions, volcanic ballistic projectiles (VBP) are frequently ejected. These projectiles represent a threat to people, infrastructure, vegetation, and aircraft due to their high temperatures and impact velocities. In order to protect people adequately, it is necessary to delimit the projectiles' maximum range within well-defined explosion scenarios likely to occur in a particular volcano. In this study, a general methodology to delimit the hazard zones for VBP during volcanic eruptions is applied to Popocatépetl volcano. Three explosion scenarios with different intensities have been defined based on the past activity of the volcano and parameterized by considering the maximum kinetic energy associated with VBP ejected during previous eruptions. A ballistic model is used to reconstruct the "launching" kinetic energy of VBP observed in the field. In the case of Vulcanian eruptions, the most common type of activity at Popocatépetl, the ballistic model was used in concert with an eruptive model to correlate ballistic range with initial pressure and gas content, parameters that can be estimated by monitoring techniques. The results are validated with field data and video observations of different Vulcanian eruptions at Popocatépetl. For each scenario, the ballistic model is used to calculate the maximum range of VBP under optimum "launching" conditions: ballistic diameter, ejection angle, topography, and wind velocity. Our results are presented in the form of a VBP hazard map with topographic profiles that depict the likely maximum ranges of VBP under explosion scenarios defined specifically for Popocatépetl volcano. The hazard zones shown on the map allow the responsible authorities to plan the definition and mitigation of restricted areas during volcanic crises.

  5. Catalog of earthquake hypocenters for Augustine, Redoubt, Iliamna, and Mount Spurr volcanoes, Alaska: January 1, 1991 - December 31, 1993

    Science.gov (United States)

    Jolly, Arthur D.; Power, John A.; Stihler, Scott D.; Rao, Lalitha N.; Davidson, Gail; Paskievitch, John F.; Estes, Steve; Lahr, John C.

    1996-01-01

    The Alaska Volcano Observatory (AVO), a cooperative program of the U.S. Geological Survey, the Geophysical Institute of the University of Alaska, Fairbanks, and the Alaska Division of Geological and Geophysical Surveys, has maintained a program of seismic monitoring at potentially active volcanoes in the Cook Inlet region since 1988. The principal objectives of this program include the seismic surveillance of the Cook Inlet volcanoes and the investigation of seismic processes associated with active volcanism. This catalog reflects the status and evolution of the seismic monitoring program, and presents the basic seismic data for the time interval January 1, 1991, to December 31, 1993. For an interpretation of these data the reader should refer to several recent articles on volcano related seismicity in the Cook Inlet region (e.g. Jolly and others, 1994; Power and others, 1995; and McNutt and others, 1995). A similar catalog covers the period from October 12, 1989 to December 31, 1991 (Power and others 1993).

  6. The impact of soil suction variation on earthquake intensity indices

    Directory of Open Access Journals (Sweden)

    Biglari Mahnoosh

    2016-01-01

    Full Text Available Soil properties can completely change the ground motion characteristics as they travel from the bedrock to the surface because, soil as a low-pass filter, may amplify or deamplify seismic motions in some frequencies on the wave travelling path. Recent studies about the advanced unsaturated soil mechanics clearly shows that dynamic properties of soils, including small-strain shear modulus (Gmax, shear modulus reduction (G/Gmax, and damping ratio (D curves are affected by changes in the soil suction level. The current study present nonlinear time-dependent analysis of three different unsaturated soils available in the literature with different ranges of nonlinear behaviour that earlier have been studied on unsaturated dynamic models. Since, the earthquake intensity parameters can be used to describe the damage potential of an earthquake, the focus of this paper is to evaluate the impact of the suction variation on the engineering ground motion parameters, including peak values of strong motion, Vmax/Amax, root-mean-square acceleration, Arias intensity, characteristic intensity, cumulative absolute velocity, acceleration spectrum intensity, effective design acceleration, A95 parameter and predominant period separately under the near-field and the far-field seismicity categories.

  7. Comparative study of the amplification of ground motion using seismic noise and recent earthquakes adjacent to the Cerro Prieto volcano, Baja California

    Science.gov (United States)

    Vega, F. D.; Vidal-Villegas, A.

    2009-12-01

    We have chosen an area of approximately 79 km2, centered around the Cerro Prieto volcano, in the Mexicalli valley, Baja California, based on elevated registered acceleration data. The GEO station, located in the Cerro Prieto geothermal field has registered seismic accelerations on the order of 492 gales. The local residents near the study area have reported feeling numerous smaller magnitude earthquakes, compared to those of the nearby populated city of Mexicalli. Does there exist an amplified seismic signal in the area? If so, what is the cause of the amplification? The objective of our study is to answer these questions and determine the subsurface (0-50 m) structure in 4 specific sites. To obtain these answers, we registered seismic noise samples using short period seismometers (1 s), intermediate (5 s) and 16 bit recorders, along a linear profile which crosses the volcano with an 18 degree NE orientation. Furthermore, we analyzed ground-motion data (from 2004-2006), obtained from 24-bit accelerographs. Using both types of data (noise and accelegraphs) we calculated the H/V spectral ratios, and the relative ratios between both sites. To determine the subsurface structure, we used a unidimensional model of the H/V ratios, based on the methodology used by Huerta-Lopez et al., 2005. The H/V spectral ratios from the seismic noise adjacent to the volcano display amplitude of 1 in the frequency range (0.8 - 30 Hz). In contrast, the amplitude in the volcano crater (159 m.a.s.l.) was 6 in the frequency range (0.8 - 3 Hz). The average H/V relative ratio of the crater and the adjacent sites is 4, with frequencies between 0.8 and 1.2 Hz. The S-wave H/V ratios for the VCP acceleration station (110 m.a.s.l.), are near 8, with frequencies between 1 and 2. The H/V spectral ratios from the seismic noise for the geothermal field display amplitude of 4 for frequencies between 0.8 and 1.3 Hz, while the results from the S wave display amplitudes of 5 between 1.5 and 3 Hz. In the

  8. The impact of persistent volcanic degassing on vegetation: A case study at Turrialba volcano, Costa Rica

    Science.gov (United States)

    Tortini, R.; van Manen, S. M.; Parkes, B. R. B.; Carn, S. A.

    2017-07-01

    Although the impacts of large volcanic eruptions on the global environment have been frequently studied, the impacts of lower tropospheric emissions from persistently degassing volcanoes remain poorly understood. Gas emissions from persistent degassing exceed those from sporadic eruptive activity, and can have significant long-term (years to decades) effects on local and regional scales, both on humans and the environment. Here, we exploit a variety of high temporal and high spatial resolution satellite-based time series and complementary ground-based measurements of element deposition and surveys of species richness, to enable a comprehensive spatio-temporal assessment of sulfur dioxide (SO2) emissions and their associated impacts on vegetation at Turrialba volcano (Costa Rica) from 2000 to 2013. We observe increased emissions of SO2 coincident with a decline in vegetation health downwind of the vents, in accordance with the prevalent wind direction at Turrialba. We also find that satellite-derived vegetation indices at various spatial resolutions are able to accurately define the vegetation kill zone, the extent of which is independently confirmed by ground-based sampling, and monitor its expansion over time. In addition, ecological impacts in terms of vegetation composition and diversity and physiological damage to vegetation, all spatially correspond to fumigation by Turrialba's plume. This study shows that analyzing and relating satellite observations to conditions and impacts on the ground can provide an increased understanding of volcanic degassing, its impacts in terms of the long-term vegetation response and the potential of satellite-based monitoring to inform hazard management strategies related to land use.

  9. The human impact of volcanoes: a historical review of events 1900-2009 and systematic literature review.

    Science.gov (United States)

    Doocy, Shannon; Daniels, Amy; Dooling, Shayna; Gorokhovich, Yuri

    2013-01-01

    Introduction. More than 500 million people live within the potential exposure range of a volcano. The risk of catastrophic losses in future eruptions is significant given population growth, proximities of major cities to volcanoes, and the possibility of larger eruptions. The objectives of this review are to describe the impact of volcanoes on the human population, in terms of mortality, injury, and displacement and, to the extent possible, identify risk factors associated with these outcomes. This is one of five reviews on the human impact of natural disasters. Methods. Data on the impact of volcanoes were compiled using two methods, a historical review of volcano events from 1900 to 2009 from multiple databases and a systematic literature review of publications ending in October 2012. Analysis included descriptive statistics and bivariate tests for associations between volcano mortality and characteristics using STATA 11. Findings. There were a total of 91,789 deaths (range: 81,703-102,372), 14,068 injuries (range 11,541-17,922), and 4.72 million people affected by volcanic events between 1900 and 2008. Inconsistent reporting suggests this is an underestimate, particularly in terms of numbers injured and affected. The primary causes of mortality in recent volcanic eruptions were ash asphyxiation, thermal injuries from pyroclastic flow, and trauma. Mortality was concentrated with the ten deadliest eruptions accounting for more than 80% of deaths; 84% of fatalities occurred in four locations (the Island of Martinique (France), Colombia, Indonesia, and Guatemala). Conclusions. Changes in land use practices and population growth provide a background for increasing risk; in conjunction with increasing urbanization in at risk areas, this poses a challenge for future volcano preparedness and mitigation efforts.

  10. Magma source beneath the Bezymianny volcano and its interconnection with Klyuchevskoy inferred from local earthquake seismic tomography

    Science.gov (United States)

    Ivanov, A. I.; Koulakov, I. Yu.; West, M.; Jakovlev, A. V.; Gordeev, E. I.; Senyukov, S.; Chebrov, V. N.

    2016-09-01

    We present a new 3D model of P and S wave velocities and Vp/Vs ratio to 20 km depth beneath the active Klyuchevskoy and Bezymianny volcanoes (Kamchatka, Russia). In this study, we use travel time data from local seismicity recorded by temporary stations of the PIRE experiment from October 24 to December 15, 2009 and permanent stations operated by the Kamchatkan Branch of Geophysical Survey (KBGS). The calculations were performed using the LOTOS code (Koulakov, 2009). The resolution limitations were explored using a series of synthetic tests with checkerboard patterns in the horizontal and vertical sections. At shallow depths, the resulting Vp and Vs anomalies tend to alternate on opposite sides of the lineation connecting the most active volcanic centers of the Klyuchevskoy Volcanic Group (KVG). This prominent lineation suggests the presence of a large fault zone passing throughout the KVG, consistent with regional tectonics. We suggest that this fault zone weakens the crust creating a natural pathway for magmas to reach the upper crust. Beneath Bezymianny volcano we observe a shallow anomaly of high Vp/Vs ratio extending to 5-6 km depth. Beneath Klyuchevskoy another high Vp/Vs anomaly is observed, at deeper depths of 7 and 15 km. These findings are consistent with the regional-scale model of Koulakov et al. (2013a) and provide some explanation for how very different eruption styles can be maintained at two volcanoes in close proximity over numerous eruption cycles.

  11. Charles Darwin's earthquake reports

    Science.gov (United States)

    Galiev, Shamil

    2010-05-01

    problems which began to discuss only during the last time. Earthquakes often precede volcanic eruptions. According to Darwin, the earthquake-induced shock may be a common mechanism of the simultaneous eruptions of the volcanoes separated by long distances. In particular, Darwin wrote that ‘… the elevation of many hundred square miles of territory near Concepcion is part of the same phenomenon, with that splashing up, if I may so call it, of volcanic matter through the orifices in the Cordillera at the moment of the shock;…'. According to Darwin the crust is a system where fractured zones, and zones of seismic and volcanic activities interact. Darwin formulated the task of considering together the processes studied now as seismology and volcanology. However the difficulties are such that the study of interactions between earthquakes and volcanoes began only recently and his works on this had relatively little impact on the development of geosciences. In this report, we discuss how the latest data on seismic and volcanic events support the Darwin's observations and ideas about the 1835 Chilean earthquake. The material from researchspace. auckland. ac. nz/handle/2292/4474 is used. We show how modern mechanical tests from impact engineering and simple experiments with weakly-cohesive materials also support his observations and ideas. On the other hand, we developed the mathematical theory of the earthquake-induced catastrophic wave phenomena. This theory allow to explain the most important aspects the Darwin's earthquake reports. This is achieved through the simplification of fundamental governing equations of considering problems to strongly-nonlinear wave equations. Solutions of these equations are constructed with the help of analytic and numerical techniques. The solutions can model different strongly-nonlinear wave phenomena which generate in a variety of physical context. A comparison with relevant experimental observations is also presented.

  12. Impacts of the 2010 Haitian earthquake in the diaspora: findings from Little Haiti, Miami, FL.

    Science.gov (United States)

    Kobetz, Erin; Menard, Janelle; Kish, Jonathan; Bishop, Ian; Hazan, Gabrielle; Nicolas, Guerda

    2013-04-01

    In January 2010, a massive earthquake struck Haiti resulting in unprecedented damage. Little attention, however, has focused on the earthquake's mental health impact in the Haitian diaspora community. As part of an established community-based participatory research initiative in Little Haiti, the predominately Haitian neighborhood in Miami, FL, USA, community health workers conducted surveys with neighborhood residents about earthquake-related losses, coping strategies, and depressive/traumatic symptomology. Findings reveal the earthquake strongly impacted the diaspora community and highlights prominent coping strategies. Following the earthquake, only a small percentage of participants self-reported engaging in any negative health behaviors. Instead, a majority relied on their social networks for support. This study contributes to the discourse on designing culturally-responsive mental health initiatives for the Haitian diaspora and the ability of existing community-academic partnerships to rapidly adapt to community needs.

  13. Joint relative location of earthquakes without a predefined velocity model: an example from a peculiar seismic cluster on Katla volcano's south-flank (Iceland)

    Science.gov (United States)

    Sgattoni, G.; Gudmundsson, Ó.; Einarsson, P.; Lucchi, F.

    2016-09-01

    Relative location methods are commonly used to precisely locate earthquake clusters consisting of similar waveforms. Repeating waveforms are often recorded at volcanoes, where, however, the crust structure is expected to contain strong heterogeneities and therefore the 1D velocity model assumption that is made in most location strategies is not likely to describe reality. A peculiar cluster of repeating low-frequency seismic events was recorded on the south flank of Katla volcano (Iceland) from 2011. As the hypocentres are located at the rim of the glacier, the seismicity may be due to volcanic or glacial processes. Information on the size and shape of the cluster may help constraining the source process. The extreme similarity of waveforms points to a very small spatial distribution of hypocentres. In order to extract meaningful information about size and shape of the cluster, we minimize uncertainty by optimizing the cross-correlation measurements and relative-location process. With a synthetic test we determine the best parameters for differential-time measurements and estimate their uncertainties, specifically for each waveform. We design a location strategy to work without a predefined velocity model, by formulating and inverting the problem to seek changes in both location and slowness, thus accounting for azimuth, take-off angles and velocity deviations from a 1D model. We solve the inversion explicitly in order to propagate data errors through the calculation. With this approach we are able to resolve a source volume few tens of meters wide in horizontal directions and around 100 meters in depth. There is no suggestion that the hypocentres lie on a single fault plane and the depth distribution indicates that their source is unlikely to be related to glacial processes as the ice thickness is not expected to exceed few tens of meters in the source area. Our method is designed for a very small source region, allowing us to assume a constant slowness for the

  14. Joint relative location of earthquakes without a pre-defined velocity model: an example from a peculiar seismic cluster on Katla volcano's south-flank (Iceland)

    Science.gov (United States)

    Sgattoni, G.; Gudmundsson, Ó.; Einarsson, P.; Lucchi, F.

    2016-11-01

    Relative location methods are commonly used to precisely locate earthquake clusters consisting of similar waveforms. Repeating waveforms are often recorded at volcanoes, where, however, the crust structure is expected to contain strong heterogeneities and therefore the 1-D velocity model assumption that is made in most location strategies is not likely to describe reality. A peculiar cluster of repeating low-frequency seismic events was recorded on the south flank of Katla volcano (Iceland) from 2011. As the hypocentres are located at the rim of the glacier, the seismicity may be due to volcanic or glacial processes. Information on the size and shape of the cluster may help constraining the source process. The extreme similarity of waveforms points to a very small spatial distribution of hypocentres. In order to extract meaningful information about size and shape of the cluster, we minimize uncertainty by optimizing the cross-correlation measurements and relative-location process. With a synthetic test we determine the best parameters for differential-time measurements and estimate their uncertainties, specifically for each waveform. We design a location strategy to work without a pre-defined velocity model, by formulating and inverting the problem to seek changes in both location and slowness, thus accounting for azimuth, take-off angles and velocity deviations from a 1-D model. We solve the inversion explicitly in order to propagate data errors through the calculation. With this approach we are able to resolve a source volume few tens of metres wide in horizontal directions and around 100 metres in depth. There is no suggestion that the hypocentres lie on a single fault plane and the depth distribution indicates that their source is unlikely to be related to glacial processes as the ice thickness is not expected to exceed few tens of metres in the source area. Our method is designed for a very small source region, allowing us to assume a constant slowness for the

  15. Investigation of earthquake mechanisms and their impact on certain basic concepts in earthquake engineering and seismology

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In this paper, mantle circulation flow, continental drift, earthquake origin and other mechanical principles are examined as they apply to earthquake engineering, seismology and dynamics of fluid saturated porous medium. The relationship of mantle flow to earthquakes is examined and clarified, and a new model, different from Haskell's, is proposed for the earthquake mechanism. The proposed new model is based on the discovery that two pairs of jump stress and jump velocity will start to act from the fault plane. Records obtained directly from recent earthquakes nearby and right on the fault break show a very large velocity impulse, which verify, indirectly, the new mechanism proposed by the author. Further, at least two physical parameters that characterize the seismic intensity must be specified, because according to the discontinuous (jump) wave theory, at the earthquake source, the stress jump and the velocity jump of particle motion should act simultaneously when a sudden break occurs. The third key parameter is shown to be the break (fracture) propagation speed together with the break plane area. This parameter influences the form of the unloading time function at the source. The maximum seismic stress in and displacement of a building are estimated for two unfavorable combinations of the building and its base ground in terms of their relative rigidity. Finally, it is shown that Bjot's theory of wave propagation in fluid saturated porous media is valid only when fluid flow cannot occur.

  16. Impact of Earthquake Demolition Debris on the Quality of Groundwater

    Directory of Open Access Journals (Sweden)

    M. S. Benmenni

    2010-01-01

    Full Text Available Problem statement: Debris from construction or demolition/deconstruction processes have no significant impact on the environment as they are res-usable and inert. This has been also long admitted for solid waste generated by the demolition of damaged cities following violent earthquakes. Approach: This study is a contribution to the assessment of actual impact on the quality of groundwater of buried demolition debris from the city of Boumerdes, in the North of Algeria 5 years after the May 21st 2003 earthquake hit the region. The public discharge of Boumerdes city has been used as a temporary landfill. It is located about 5 km downtown of Boumerdes at the Tidjelabine site which is marly-calcareous formation. Leachate from the landfill was directly rejected in the receiving environment, where the soil is marly-calcareous type with cracks giving a variable permeability (10-2 m sec-1 to nearly 10-6 m sec-1 that facilitates infiltration of potential pollutants to the groundwater. The slope character (from 5-10% of the field contributes to pollutants movement and may accentuate water quality deterioration. Three domestic wells (designated S1, S2 and S3 were selected in the vicinity of the landfill and served as piezometers. Leachate samples were taken from the landfill and evaluated. Results: Leachate analysis indicated organic matter with relatively high COD (1136 mg L-1 O2 and BOD5 (200 mg L-1 O2; whereas the pH yielded 7.65 thus indicating fermentation phase of the landfill. Heavy metal contents were beyond national standard limits except for Pb with 0.51 mg L-1 which is slightly higher than limit value of 0.5 mg L-1. More than five years after the creation of this landfill and despite its predominant C&D nature, these results showed that it was following a typical urban wastes decomposition scheme. Same analysis carried on water samples drawn from the piezometers yielded following results: acidic pH (6.88, acceptable values of target heavy metals

  17. Triggering of volcanic eruptions by large earthquakes

    Science.gov (United States)

    Nishimura, Takeshi

    2017-08-01

    When a large earthquake occurs near an active volcano, there is often concern that volcanic eruptions may be triggered by the earthquake. In this study, recently accumulated, reliable data were analyzed to quantitatively evaluate the probability of the occurrence of new eruptions of volcanoes located near the epicenters of large earthquakes. For volcanoes located within 200 km of large earthquakes of magnitude 7.5 or greater, the eruption occurrence probability increases by approximately 50% for 5 years after the earthquake origin time. However, no significant increase in the occurrence probability of new eruptions was observed at distant volcanoes or for smaller earthquakes. The present results strongly suggest that new eruptions are likely triggered by static stress changes and/or strong ground motions caused by nearby large earthquakes. This is not similar to the previously presented evidence that volcanic earthquakes at distant volcanoes are remotely triggered by surface waves generated by large earthquakes.

  18. Damage Proxy Map from InSAR Coherence Applied to February 2011 M6.3 Christchurch Earthquake, 2011 M9.0 Tohoku-oki Earthquake, and 2011 Kirishima Volcano Eruption

    Science.gov (United States)

    Yun, S.; Agram, P. S.; Fielding, E. J.; Simons, M.; Webb, F.; Tanaka, A.; Lundgren, P.; Owen, S. E.; Rosen, P. A.; Hensley, S.

    2011-12-01

    Under ARIA (Advanced Rapid Imaging and Analysis) project at JPL and Caltech, we developed a prototype algorithm to detect surface property change caused by natural or man-made damage using InSAR coherence change. The algorithm was tested on building demolition and construction sites in downtown Pasadena, California. The developed algorithm performed significantly better, producing 150 % higher signal-to-noise ratio, than a standard coherence change detection method. We applied the algorithm to February 2011 M6.3 Christchurch earthquake in New Zealand, 2011 M9.0 Tohoku-oki earthquake in Japan, and 2011 Kirishima volcano eruption in Kyushu, Japan, using ALOS PALSAR data. In Christchurch area we detected three different types of damage: liquefaction, building collapse, and landslide. The detected liquefaction damage is extensive in the eastern suburbs of Christchurch, showing Bexley as one of the most significantly affected areas as was reported in the media. Some places show sharp boundaries of liquefaction damage, indicating different type of ground materials that might have been formed by the meandering Avon River in the past. Well reported damaged buildings such as Christchurch Cathedral, Canterbury TV building, Pyne Gould building, and Cathedral of the Blessed Sacrament were detected by the algorithm. A landslide in Redcliffs was also clearly detected. These detected damage sites were confirmed with Google earth images provided by GeoEye. Larger-scale damage pattern also agrees well with the ground truth damage assessment map indicated with polygonal zones of 3 different damage levels, compiled by the government of New Zealand. The damage proxy map of Sendai area in Japan shows man-made structure damage due to the tsunami caused by the M9.0 Tohoku-oki earthquake. Long temporal baseline (~2.7 years) and volume scattering caused significant decorrelation in the farmlands and bush forest along the coastline. The 2011 Kirishima volcano eruption caused a lot of ash

  19. The Economic Impact of Merapi Volcano Eruption in Livestock Farming Systems

    Directory of Open Access Journals (Sweden)

    Atien Priyanti

    2011-12-01

    Full Text Available Merapi volcano eruption has impact significantly to the most of surrounding farming areas, including livestock, which belongs to rural peoples as the main sources of income. Estimated loss of economic values of resources amounted to IDR 5821 billion, covering among others: salak pondok, farm animals (dairy, beef cattle, buffaloes, sheep, goats and poultry and food crops (maize and rice field business. The areas mostly hit by the eruption include the districts of Boyolali, Klaten and Magelang of Central Java, and District of Sleman in DIY. Livestock sub sector of the economy in these areas suffers losses in terms of death of animals, sold and unsold animals, fodder crops, and reduced of milk production. It has been estimated that these losses have reached IDR 88,320 billion. Rehabilitation and reconstruction programs are necessary for both short and longer terms efforts to recover people livelihood which derived particularly from livestock farming.

  20. New Perspectives on the Climatic Impact of the 1600 Eruption of Huaynaputina Volcano, Peru

    Science.gov (United States)

    Verosub, K. L.; Lippman, J.

    2007-05-01

    A critical test of the new understanding of volcanic aerosols developed since 1982 is to determine if it can predict the effects of larger eruptions than those that have occurred since El Chichon. To do that, requires detailed information about the effects of specific large eruptions. We have been investigating the human and climatic impacts of the 1600 eruption of Huaynaputina volcano in Peru. The estimated Volcanic Explosivity Index for this eruption is 6, which is comparable to that of the 1815 eruption of Tambora volcano in Indonesia, which produced global cooling and led to crop failures, famine and social unrest. On the basis of tree-ring data, Briffa et al. (1998) suggested that the most severe short-term Northern Hemisphere cooling event of the past 600 years occurred in 1601, the year following the Huaynaputina eruption. In order gain a better understanding of the nature and extent of this cooling, we have been collecting annual time series that provide information about climatic conditions during time intervals that bracket the Huaynaputina eruption. Among the time series that we have examined (or plan to examine) are ice conditions in the harbors of Tallinn, Estonia, and Riga, Latvia and in Lake Suwa in Japan: cherry blossom blooming (sakura) dates from Kyoto, Japan; records of agricultural production from China and Russia; tithe records from the Spanish colonial empire; dates of the beginning of the wine harvest in France and the rye harvest in Sweden; prices of agricultural commodities in Europe; and river flows from the Nile and the Colorado. Often, in the records we have examined, 1601 shows up as one of the coldest years, if not the coldest year. In addition, the worst famines in Russian history took place between 1601 and 1603, which eventually led to the overthrow of Tsar Boris Gudonov. Thus, there is considerable evidence that the climatic impacts of the Huaynaputina eruption were comparable to those from the Tambora eruption. This result is

  1. Earthquake effect on volcano and the geological structure in central java using tomography travel time method and relocation hypocenter by grid search method

    Science.gov (United States)

    Suharsono; Nurdian, S. W.; Palupi, I. R.

    2016-11-01

    Relocating hypocenter is a way to improve the velocity model of the subsurface. One of the method is Grid Search. To perform the distribution of the velocity in subsurface by tomography method, it is used the result of relocating hypocenter to be a reference for subsurface analysis in volcanic and major structural patterns, such as in Central Java. The main data of this study is the earthquake data recorded from 1952 to 2012 with the P wave number is 9162, the number of events is 2426 were recorded by 30 stations located in the vicinity of Central Java. Grid search method has some advantages they are: it can relocate the hypocenter more accurate because this method is dividing space lattice model into blocks, and each grid block can only be occupied by one point hypocenter. Tomography technique is done by travel time data that has had relocated with inversion pseudo bending method. Grid search relocated method show that the hypocenter's depth is shallower than before and the direction is to the south, the hypocenter distribution is modeled into the subduction zone between the continent of Eurasia with the Indo-Australian with an average angle of 14 °. The tomography results show the low velocity value is contained under volcanoes with value of -8% to -10%, then the pattern of the main fault structure in Central Java can be description by the results of tomography at high velocity that is from 8% to 10% with the direction is northwest and northeast-southwest.

  2. Translating Volcano Hazards Research in the Cascades Into Community Preparedness

    Science.gov (United States)

    Ewert, J. W.; Driedger, C. L.

    2015-12-01

    Research by the science community into volcanic histories and physical processes at Cascade volcanoes in the states of Washington, Oregon, and California has been ongoing for over a century. Eruptions in the 20th century at Lassen Peak and Mount St. Helen demonstrated the active nature of Cascade volcanoes; the 1980 eruption of Mount St. Helens was a defining moment in modern volcanology. The first modern volcano hazards assessments were produced by the USGS for some Cascade volcanoes in the 1960s. A rich scientific literature exists, much of which addresses hazards at these active volcanoes. That said community awareness, planning, and preparation for eruptions generally do not occur as a result of a hazard analyses published in scientific papers, but by direct communication with scientists. Relative to other natural hazards, volcanic eruptions (or large earthquakes, or tsunami) are outside common experience, and the public and many public officials are often surprised to learn of the impacts volcanic eruptions could have on their communities. In the 1980s, the USGS recognized that effective hazard communication and preparedness is a multi-faceted, long-term undertaking and began working with federal, state, and local stakeholders to build awareness and foster community action about volcano hazards. Activities included forming volcano-specific workgroups to develop coordination plans for volcano emergencies; a concerted public outreach campaign; curriculum development and teacher training; technical training for emergency managers and first responders; and development of hazard information that is accessible to non-specialists. Outcomes include broader ownership of volcano hazards as evidenced by bi-national exchanges of emergency managers, community planners, and first responders; development by stakeholders of websites focused on volcano hazards mitigation; and execution of table-top and functional exercises, including evacuation drills by local communities.

  3. Insights into the origins of drumbeat earthquakes, periodic low frequency seismicity, and plug degradation from multi-instrument monitoring at Tungurahua volcano, Ecuador, April 2015

    Science.gov (United States)

    Bell, Andrew; Hernandez, Stephen; Gaunt, Elizabeth; Mothes, Patricia; Hidalgo, Silvana; Ruiz, Mario

    2016-04-01

    Highly-periodic repeating 'drumbeat' earthquakes have been reported from several andesitic and dacitic volcanoes. Physical models for the origin of drumbeat earthquakes incorporate, to different extents, the incremental upward movement of viscous magma. However, the roles played by stick-slip friction, brittle failure, and fluid flow, and the relations between drumbeat earthquakes and other low-frequency seismic signals, remain controversial. Here we report the results of analysis of three weeks of geophysical data recorded during an unrest episode at Tungurahua, an andesitic stratovolcano in Ecuador, during April 2015, by the monitoring network of the Instituto Geofisico of Ecuador. Combined seismic, geodetic, infrasound, and gas monitoring has provided new insights into the origins of periodic low-frequency seismic signals, conduit processes, and the nature of current unrest. Over the three-week period, the relative seismic amplitude (RSAM) correlated closely with short-term deformation rates and gas fluxes. However, the characteristics of the seismic signals, as recorded at a short-period station closest to the summit crater, changed considerably with time. Initially high RSAM and gas fluxes, with modest ash emissions, were associated with continuous and 'pulsed' tremor signals (amplitude modulated, with 30-100 second periods). As activity levels decreased over several days, tremor episodes became increasingly intermittent, and short-lived bursts of low-frequency earthquakes with quasiperiodic inter-event times were observed. Following one day of quiescence, the onset of pronounced low frequency drumbeat earthquakes signalled the resumption of elevated unrest, initially with mean inter-event times of 32 seconds, and later increasing to 74 seconds and longer, with periodicity progressively breaking down over several days. A reduction in RSAM was then followed by one week of persistent, quasiperiodic, longer-duration emergent low-frequency pulses, including

  4. Impact of the Great Eastern Japan Earthquake on transplant renal function in Iwaki city, Fukushima.

    Science.gov (United States)

    Shimmura, H; Kawaguchi, H; Tokiwa, M; Tanabe, K

    2014-01-01

    Tokiwa-kai group is a urologic and dialysis institution complex located in Iwaki city, Fukushima, Japan, and has performed renal transplantation since 1997. Although water is mandatory for renal transplant recipients, the water supply did not work for approximately a month after the earthquake in Iwaki city. Moreover, after the Fukushima Daiichi nuclear accident struck Iwaki city, there was a critical shortage of food and medical supplies, including immunosuppressant drugs. Therefore, we investigated the impact of the Great Eastern Japan Earthquake on transplant renal function. We followed 30 patients who underwent renal transplantation before the Great Eastern Japan Earthquake. There were 19 males and 11 females with a mean age of 47 years. All recipients were not injured by the earthquake or the tsunami. Of the 30 recipients, 1 lost his renal graft at 12 months after the earthquake, and 1 has deterioration of graft function with a serum creatinine level of 5.5 mg/dL. Their creatinine levels before the earthquake were 2.79 mg/dL and 3.78 mg/dL, respectively. The other recipients have good graft function with a mean creatinine level of 1.5 mg/dL. All recipients did not experience any rejection episode after the earthquake. The shortage of water and food after the Great Eastern Japan Earthquake exacerbated the renal graft function, especially in the recipients with the lower graft function. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Analysis of the Earthquake Impact towards water-based fire extinguishing system

    Science.gov (United States)

    Lee, J.; Hur, M.; Lee, K.

    2015-09-01

    Recently, extinguishing system installed in the building when the earthquake occurred at a separate performance requirements. Before the building collapsed during the earthquake, as a function to maintain a fire extinguishing. In particular, the automatic sprinkler fire extinguishing equipment, such as after a massive earthquake without damage to piping also must maintain confidentiality. In this study, an experiment installed in the building during the earthquake, the water-based fire extinguishing saw grasp the impact of the pipe. Experimental structures for water-based fire extinguishing seismic construction step by step, and then applied to the seismic experiment, the building appears in the extinguishing of the earthquake response of the pipe was measured. Construction of acceleration caused by vibration being added to the size and the size of the displacement is measured and compared with the data response of the pipe from the table, thereby extinguishing water piping need to enhance the seismic analysis. Define the seismic design category (SDC) for the four groups in the building structure with seismic criteria (KBC2009) designed according to the importance of the group and earthquake seismic intensity. The event of a real earthquake seismic analysis of Category A and Category B for the seismic design of buildings, the current fire-fighting facilities could have also determined that the seismic performance. In the case of seismic design categories C and D are installed in buildings to preserve the function of extinguishing the required level of seismic retrofit design is determined.

  6. Evaluation of impact of earthquake on agriculture in Nepal based on remote sensing

    Science.gov (United States)

    Sekiyama, Ayako; Shimada, Sawahiko; Okazawa, Hiromu; Mihara, Machito; Kuo, Kuang Ting

    2016-07-01

    The big earthquake happening on April, 2015 killed over than 8000 people in Nepal. The effect of earthquake not only affected safety of local people but also agricultural field. Agricultural economy dominates income of local people. Therefore, restoration of agricultural areas are required for improving life of local people. However, lack of information about agricultural areas is main problem for local government to assess and restore damaged agricultural areas. Remote sensing was applied for accessing damaged agricultural field due to its advantages in observing responds of environment without temporal and spatial restriction. Accordingly, the objective of the study is to evaluate impact of earthquake on agriculture in Nepal based on remote sensing. The experimental procedure includes conducting the impact of earthquake on changes of total agricultural area, and analysis of response of greenness affected by earthquake in agricultural land. For conducting agricultural land changes, land use map was first created and classified into four categories: road, city, forest, and agricultural land. Changes before and after earthquake in total area of agricultural land were analyzed by GIS. Moreover, vegetation index was used as indicator for evaluating greenness responds in agricultural land and computed based on high-resolution satellite imagery such as World view-3. Finally, the conclusion of the study and suggestions will be made and provided for helping local government in Nepal restore agricultural areas.

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

    Science.gov (United States)

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

    2014-12-01

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

  8. The impact of Kelud Volcano eruption to food security case study: Ngantang district, Malang Regencys

    Science.gov (United States)

    Rachmawati, Turniningtyas Ayu; Hidayat, Ar Rohman Taufiq; Wahyuningtyas, Loetvi; Rachmansyah, Arief

    2017-07-01

    Kelud volcano is one of the active volcanoes in Indonesia. Kelud volcano is located among Malang, Kediri and Blitar Regency. The last eruption occurred on February, 2014. Ngantang District, Malang Regency was the worst affected area with severe infrastructure damage including clean water, roads, and bridges, causing temporary isolation. This led to disturbance in food security that consists of aspects of food availability, food access and food utilization. Food security is a condition related to the supply of food, and individuals' access to it. This research focuses on achieving household food security by analyzing 1) disaster prone area of Kelud Volcano at Ngantang District after eruption 2014; and 2) food security that consists of the assessment of food availability, food access and food utilization at Ngantang District. This research finds that: 1) Pandansari village and Ngantru village are the worst prone area villages; and 2) The food security analysis shows that Pandansari Village is higly insecure of food security.

  9. The 1989-1990 eruption of Redoubt Volcano, Alaska: impacts on aircraft operations

    Science.gov (United States)

    Casadevall, T.J.

    1994-01-01

    The December 1989-June 1990 eruption of Redoubt Volcano affected commercial and military air operations in the vicinity of Anchorage, Alaska. These effects were due to the direct impact of volcanic ash on jet aircraft, as well as to the rerouting and cancellations of flight operations owing to eruptive activity. Between December and February, five commercial jetliners were damaged from ash encounters. The most serious incident took place on December 15, 1989 when a Boeing 747-400 aircraft temporarily lost power of all four engines after encountering an ash cloud as the airplane descended for a landing in Anchorage. While there were no injuries to passengers, the damage to engines, avionics, and aircraft structure from this encounter is estimated at $80 million. Four additional encounters between jet aircraft and Redoubt ash clouds occurred in the Anchorage area on December 15 and 16, 1989 and February 21, 1990; none resulted in engine failure. Two additional encounters took place on December 17, 1989 when jet airliners encountered the Redoubt cloud over west Texas. At the time of these encounters, the cloud was up to 55 hours old and had traveled in excess of 2,900 nautical miles (5,300 km). Following the December 15 encounters, Anchorage International Airport remained open, however, most airline companies canceled operations for up to several days. As communications between Federal agencies and airlines improved, and as a better understanding of the nature and behavior of ash-rich eruption clouds was achieved, most airlines resumed normal service by early January 1990. The resulting loss of revenue at Anchorage International Airport during several months following the eruption is estimated to total $2.6 million. The impact on general aviation and military operations consisted mostly of cancellation and rerouting of flights. ?? 1994.

  10. Impact of intensity and loss assessment following the great Wenchuan Earthquake

    Institute of Scientific and Technical Information of China (English)

    Yuan Yifan

    2008-01-01

    The great Wenchuan Earthquake occurred on May 12, 2008 in the Sichuan Province of China, and had a magnitude of 8.0. It is the most serious earthquake disaster in China since the great Tangshan Earthquake (M=7.8, July 28, 1976). According to official reports, there were 69,225 deaths, 379,640 injuries and 17,939 missing as of Aug. 11, 2008. The China Earthquake Administration quickly sent hundreds of experts to the field immediately after the event, to investigate the damage and assess the economic losses. This paper emphasizes the impact of seismic intensity and presents a preliminary loss assessment. A brief description of the geological features of the affected region is provided, followed by a summary of the earthquake damage. An isoseismal map is developed that shows that the high intensity region is distributed like a belt around the seimogenic fault, and that the epicentral intensity reached XI (Chinese Intensity Scale, similar to the Modified Mercalli Scale). The direct economic loss resulting from the earthquake is 692 billions RMB (about 100 billions US$).

  11. Modeling the reactive halogen plume from Ambrym volcano and its impact on the troposphere with the CCATT-BRAMS mesoscale model

    OpenAIRE

    Jourdain, L.; T. J. Roberts; M. Pirre; Josse, B.

    2015-01-01

    Ambrym volcano (Vanuatu, Southwest Pacific) is one of the largest sources of continuous volcanic emissions worldwide. As well as releasing SO2 that is oxidized to sulfate, volcanic plumes in the troposphere are shown to undergo reactive halogen chemistry whose atmospheric impacts have been little explored to date. Here, two-way nested simulations were performed with the regional scale model CCATT-BRAMS to test our understanding of the volcano plume chemical...

  12. Social impacts of earthquakes caused by gas extraction in the Province of Groningen, The Netherlands

    NARCIS (Netherlands)

    van den Voort, Nick; Vanclay, Frank

    2015-01-01

    Gas extraction from the Groningen gasfield in the northern Netherlands has led to localized earthquakes which are projected to become more severe. The social impacts experienced by local residents include: damage to property; declining house prices; concerns about the chance of dykes breaking; feeli

  13. Earthquake Impact on Miami Haitian Americans: The Role of Family/Social Connectedness

    Science.gov (United States)

    Allen, Andrea; Marcelin, Louis Herns; Schmitz, Susan; Hausmann, Vicky; Shultz, James M.

    2012-01-01

    Individuals who are indirectly exposed to disasters may be affected psychologically. The impact of the 2010 Haiti earthquake reverberated throughout the Haitian American community in Miami, Florida. Many within the community held strong transnational family and friendship bonds to their homeland. We examined associations between indicators of…

  14. Earthquake Impact on Miami Haitian Americans: The Role of Family/Social Connectedness

    Science.gov (United States)

    Allen, Andrea; Marcelin, Louis Herns; Schmitz, Susan; Hausmann, Vicky; Shultz, James M.

    2012-01-01

    Individuals who are indirectly exposed to disasters may be affected psychologically. The impact of the 2010 Haiti earthquake reverberated throughout the Haitian American community in Miami, Florida. Many within the community held strong transnational family and friendship bonds to their homeland. We examined associations between indicators of…

  15. Social impacts of earthquakes caused by gas extraction in the Province of Groningen, The Netherlands

    NARCIS (Netherlands)

    van den Voort, Nick; Vanclay, Frank

    2015-01-01

    Gas extraction from the Groningen gasfield in the northern Netherlands has led to localized earthquakes which are projected to become more severe. The social impacts experienced by local residents include: damage to property; declining house prices; concerns about the chance of dykes breaking; feeli

  16. Pakistan’s Earthquake and Tsunami Hazards Potential Impact on Infrastructure

    Directory of Open Access Journals (Sweden)

    GEORGE PARARAS-CARAYANNIS

    2011-06-01

    Full Text Available Interaction of the Indian, Arabian and Eurasian tectonic plates has resulted in the formation of major active fault systems in South Asia. Compression along the tectonic boundaries results in thrust or reverse type of faulting and zones of crustal deformation characterized by high seismic activity and continuing Orogenesis. The more intense seismic activity occurs near regions of thrust faulting which is developing at the Himalayan foothills. In northern Pakistan, the Hindu Kush Mountains converge with the Karakoram Range to form a part of the Himalayan mountain system. Northern, western as well as southern Pakistan, Kashmir and northern India and Afghanistan are along such zones of high seismic activity. In Pakistan, most of the earthquakes occur in the north and western regions along the boundary of the Indian tectonic plate with the Iranian and Afghan micro-plates. The active zone extends from the Makran region in the southwest to the Hazara-Kashmir syntaxial bend in the north. Southwest Pakistan is vulnerable to both earthquake and tsunami hazards. In 2005, earthquakes devastated northern Pakistan and Kashmir and severely affected the cities of Muzaffarabad, Islamadad and Rawalpindi, causing severe destruction to the infrastructure of the northern region. A major earthquake along an extensive transform fault system in 1935 destroyed the city Quetta and the adjoining region. A major earthquake along the northern Arabian sea in 1945 generated a very destructive tsunami along the coasts of Baluchistan and Sindh Provinces. The region near Karachi is vulnerable as it is located near four major faults where destructive earthquakes and tsunamis have occurred in the past. Given Pakistan’s vulnerability and extensive infrastructure development in recent years, the present study reviews briefly the earthquake and tsunami risk factors and assesses the impact that such disasters can have on the country’s critical infrastructure - which includes

  17. Impacting earthquake science and geoscience education: Educational programming to earthquake relocation

    Science.gov (United States)

    Carrick, Tina Louise

    This dissertation is comprised of four studies: three related to research on geoscience education and another seismological study of the South Island of New Zealand. The geoscience education research is grounded in 10 years of data collection and its implications for best practices for recruitment and retention of underrepresented minority students into higher education in the geosciences. The seismological component contains results from the relocation of earthquakes from the 2009 Dusky Sound Mw 7.8 event, South Island, New Zealand. In recent years, many have cited a major concern that U.S. is not producing enough STEM graduates to fit the forecasted economic need. This situation is exacerbated by the fact that underrepresented minorities are becoming a growing portion of the population, and people in these groups enter STEM careers at rates much smaller than their proportion of the populations. Among the STEM disciplines the Geosciences are the worst at attracting young people from underrepresented minorities. This dissertation reports on results the Pathways program at the University of Texas at El Paso Pathways which sought to create a geoscience recruitment and training network in El Paso, Texas to increase the number of Hispanic Americans students to attain higher degrees and increase the awareness of the geosciences from 2002-2012. Two elements of the program were a summer program for high school students and an undergraduate research program conducted during the academic year, called PREP. Data collected from pre- and post-surveys from the summer program showed statistically significant positive changes in attitudes towards the geosciences. Longitudinal data shows a strong positive correlation of the program with retention of participants in the geoscience pipeline. Results from the undergraduate research program show that it produced far more women and minority geoscience professionals than national norms. Combination of the institutional data, focus

  18. Assessment of impact of strong earthquakes to the global economy by example of Thoku event

    Science.gov (United States)

    Tatiana, Skufina; Peter, Skuf'in; Sergey, Baranov; Vera, Samarina; Taisiya, Shatalova

    2016-04-01

    We examine the economic consequences of strong earthquakes by example of M9 Tahoku one that occurred on March 11, 2011 close to the northeast shore of Japanese coast Honshu. This earthquake became the strongest in the whole history of the seismological observations in this part of the planet. The generated tsunami killed more than 15,700 people, damaged 332,395 buildings and 2,126 roads. The total economic loss in Japan was estimated at 309 billion. The catastrophe in Japan also impacted global economy. To estimate its impact, we used regional and global stock indexes, production indexes, stock prices of the main Japanese, European and US companies, import and export dynamics, as well as the data provided by the custom of Japan. We also demonstrated that the catastrophe substantially affected the markets and on the short run in some indicators it even exceeded the effect of the global financial crisis of 2008. The last strong earthquake occurred in Nepal (25.04.2015, M7.8) and Chile (16.09.2015, M8.3), both actualized the research of cost assessments of the overall economic impact of seismic hazard. We concluded that it is necessary to treat strong earthquakes as one very important factor that affects the world economy depending on their location. The research was supported by Russian Foundation for Basic Research (Project 16-06-00056A).

  19. The impact of the Canterbury earthquakes on successful school leaving for adolescents.

    Science.gov (United States)

    Beaglehole, Ben; Bell, Caroline; Frampton, Christopher; Moor, Stephanie

    2017-02-01

    To examine the impact of the Canterbury earthquakes on the important adolescent transition period of school leaving. Local and national data on school leaving age, attainment of National Certificate of Educational Achievement (NCEA) standards, and school rolls (total registered students for schools) were examined to clarify long-term trends and delineate these from any impacts of the Canterbury earthquakes.  Results: Despite concerns about negative impacts, there was no evidence for increased school disengagement or poorer academic performance by students as a consequence of the earthquakes. Although there may have been negative effects for a minority, the possibility of post-disaster growth and resilience being the norm for the majority meant that negative effects on school leaving were not observed following the earthquakes. A range of post-disaster responses may have mitigated adverse effects on the adolescent population. Implications for Public Health: Overall long-term negative effects are unlikely for the affected adolescent population. The results also indicate that similar populations exposed to disasters in other settings are likely to do well in the presence of a comprehensive post-disaster response. © 2016 The Authors.

  20. Exploring hotspots of pneumococcal pneumonia and potential impacts of ejecta dust exposure following the Christchurch earthquakes.

    Science.gov (United States)

    Pearson, Amber L; Kingham, Simon; Mitchell, Peter; Apparicio, Philippe

    2013-12-01

    The etiology of pneumococcal pneumonia (PP) is well-known. Yet, some events may increase its incidence. Natural disasters may worsen air quality, a risk factor for PP. We investigated spatial/spatio-temporal clustering of PP pre- and post-earthquakes in Christchurch, New Zealand. The earthquakes resulted in deaths, widespread damage and liquefaction ejecta (a source of air-borne dust). We tested for clusters and associations with ejecta, using 97 cases (diagnosed 10/2008-12/2011), adjusted for age and area-level deprivation. The strongest evidence to support the potential role of ejecta in clusters of PP cases was the: (1) geographic shift in the spatio-temporal cluster after deprivation adjustment to match the post-earthquake clusters and; (2) increased relative risk in the fully-adjusted post-earthquake compared to the pre-earthquake cluster. The application of spatial statistics to study PP and ejecta are novel. Further studies to assess the long-term impacts of ejecta inhalation are recommended particularly in Christchurch, where seismic activity continues.

  1. Volcano Preparedness

    Science.gov (United States)

    ... You might feel better to learn that an ‘active’ volcano is one that has erupted in the past ... miles away. If you live near a known volcano, active or dormant, following these tips will help you ...

  2. Impact of the January-February 1980 earthquake sequence on various structures at the Lawrence Livermore National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Murray, R.C.; Nelson, T.A.; Coats, D.W.; Ng, D.S.; Weaver, H.J.

    1981-02-04

    On January 24, 1980, California's Livermore Valley was rocked by a moderate earthquake that caused some damage to the Lawrence Livermore National Laboratory (LLNL). The earthquake, which measured 5.5 on the Richter scale and was centered about 20 km (12 mi) northwest of the Laboratory, produced estimated peak horizontal ground acceleration at LLNL of between 0.15 and 0.3 g. The earthquake was part of a sequence that included two sharp aftershocks (magnitudes 5.2 and 4.2) within 1.5 minutes of the initial event. A second earthquake (magnitude 5.8) struck on January 26, and several lesser earthquakes occurred during the next few weeks. This paper describes the damage impact of the January 24 earthquake, including: background information on LLNL, discussion of pre-earthquake seismic safety philosophy, and description of the impact of the January 24 earthquake, including a description of the seismic setting of the Laboratory, a discussion of the ground motion, and a summary of damage. This paper also describes a data gathering and reduction effort at LLNL in the aftermath of the January earthquakes.

  3. The impact of the Canterbury earthquakes on prescribing for mental health.

    Science.gov (United States)

    Beaglehole, Ben; Bell, Caroline; Frampton, Christopher; Hamilton, Greg; McKean, Andrew

    2015-08-01

    The aim of this study is to evaluate the impact of the Canterbury earthquakes on the mental health of the local population by examining prescribing patterns of psychotropic medication. Dispensing data from community pharmacies for antidepressants, antipsychotics, anxiolytics and sedatives/hypnotics are routinely recorded in a national database. The close relationship between prescribing and dispensing provides the opportunity to assess prescribing trends for Canterbury compared to national data and therefore examines the longitudinal impact of the earthquakes on prescribing patterns. Short-term increases in the use of anxiolytics and sedatives/hypnotics were observed after the most devastating February 2011 earthquake, but this effect was not sustained. There were no observable effects of the earthquakes on antidepressant or antipsychotic dispensing. Short-term increases in dispensing were only observed for the classes of anxiolytics and sedatives/hypnotics. No sustained changes in dispensing occurred. These findings suggest that long-term detrimental effects on the mental health of the Canterbury population were either not present or have not resulted in increased prescribing of psychotropic medication. © The Royal Australian and New Zealand College of Psychiatrists 2015.

  4. Causes, Dynamics and Impacts of Lahar Mass Flows due to the April 2015 Eruption of Calbuco Volcano, Chile

    Science.gov (United States)

    Dussaillant, Alejandro; Russell, Andy; Meier, Claudio; Rivera, Andres; Mella, Mauricio; Garrido, Natalia; Hernandez, Jorge; Napoleoni, Felipe; Gonzalez, Cristian

    2016-04-01

    Calbuco is a 2015m high, glacier capped, stratovolcano in the heavily populated Los Lagos region of southern Chile with a history of large volcanic eruptions in 1893-95, 1906-7, 1911-12, 1917, 1932, 1945, 1961 and 1972. Calbuco volcano experienced a powerful 90 minute eruption at 18:04h on 22 April, 2015 followed by additional major eruptions at 01:00h and 13:10h on 23 & 30 April, respectively, resulting in the evacuation of 6500 people and the imposition of a 20 km radius exclusion zone. Pyroclastic flows descended into several river catchments radiating from the volcano with lahars travelling distances of up to 14 km, reaching populated areas. We present findings from detailed field observations from April and July 2015, and January 2016, regarding the causes, dynamics and impacts of lahars generated by the April 2015 eruption, supported by satellite imagery, LiDAR and detailed rtkGPS & TLS surveys, as well as sediment sampling. Pyroclastic flows melted glacier ice and snow generating the largest lahars in the Rio Este and Rio Blanco Sur on the southern flanks of the volcano. Lahar deposits in the Rio Blanco Norte were buried by pyroclastic flow deposits with measured temperatures of up to 282°C three months after emplacement. Lahar erosional impacts included bedrock erosion, alluvial channel incision, erosion of surficial deposits and the felling of large areas of forest. Depositional landforms included boulder run-ups on the outsides of channel bends, boulder clusters and large woody debris jams. Lahars deposited up to 8m of sediment within distal reaches. Deposits on the southern flanks of Calbuco indicate the passage of multiple pulses of contrasting rheology. Lahar occurrence and magnitude was controlled by the pre-eruption distribution of snow and ice on the volcano. Pre-existing lahar channels controlled flows to lower piedmont zones where routing was determined by palaeo-lahar geomorphology. Ongoing erosion of proximal pyroclastic flow and lahar deposits

  5. Social impacts of earthquakes caused by gas extraction in the Province of Groningen, The Netherlands

    Energy Technology Data Exchange (ETDEWEB)

    Voort, Nick van der, E-mail: nickvdvoort@gmail.com; Vanclay, Frank, E-mail: frank.vanclay@rug.nl

    2015-01-15

    Gas extraction from the Groningen gasfield in the northern Netherlands has led to localised earthquakes which are projected to become more severe. The social impacts experienced by local residents include: damage to property; declining house prices; concerns about the chance of dykes breaking; feelings of anxiety and insecurity; health issues; and anger. These social and emotional impacts are exacerbated by the increasing distrust Groningen people have towards the national government and the gas company, NAM, a partnership between Shell and ExxonMobil. The earthquakes have reopened discussions about the distribution of benefits from gas production and the extent to which benefits are retained locally. Mitigation of the impacts is attempted, but the lack of trust decreases the effectiveness of the mitigation measures. The extent of this experience of previously-unforeseen, unanticipated impacts suggests that a new social and environmental impact assessment needs to be undertaken, and a new Social Impact Management Plan (SIMP) and Impacts and Benefits Agreement (IBA) developed, so that the project can regain its legitimacy and social licence to operate. In addition to conventional gas, this paper has wider relevance for unconventional gas developments, for example shale gas extraction by hydraulic fracturing methods (fracking). - Highlights: • Gas production in Groningen has caused over 1000 earthquakes. • The induced seismicity has caused many social impacts. • Impacts include building damage, reduced house prices, fear and health issues. • Mitigation measures attempted to date are inadequate. • Distrust towards the national government and operator hinders mitigation efforts. • Gas production in Groningen has lost its social licence to operate.

  6. 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

  7. March 2011 earthquake, tsunami and Fukushima nuclear accident impacts on Japanese agri-food sector

    OpenAIRE

    Bachev, Hrabrin

    2015-01-01

    The paper presents findings of a large study on socio-economic impacts of the March 2011 earthquake, tsunami and Fukushima nuclear disaster on the Japanese agriculture and food sector. It contains fourteen parts: introduction with the framework of analysis; a brief description of events and their overall social, economic and environmental effects; assessments on affected farms and agricultural resources; progress and challenges of restoration of agricultural communities, lands, infrastructure...

  8. Physical and chemical changes of water in the deep interior of the Earth-Decrepitation-style mud -volcano-earthquake-A bright lamp to shed light on the mysteries of the deep interior of the Earth

    Institute of Scientific and Technical Information of China (English)

    ZENG Mingguo

    2010-01-01

    The 2008-05-12 Wenchuan mud-volcano-earthquake was accompanied with eruption of a huge volume of gas and stone, revealing that earthquakes generally result from instant reverse phase explosion of supercritical water (SCW) at the supercritical point. In the deep parts of the crust and mantle there still exists a large amount of supercritical water equivalent in order of magnitude to that of the Earth's hydrosphere. Soft fluids which exist in the MOHO at the top of the upper mantle are the so-called deep supercritical fluids (SCWD). Supercritical water (SCW) has n×103 times strong capability to dissolve gas. Its viscosity is extremely low and its diffusivity is extremely strong. Therefore, it can naturally migrate toward a region with relatively negative pressure. In the steep break zone of the MOHO at the 57-65 km depth beneath the earthquake belt, due to mutation of overburden pressure, SCWD can automatically separate out CaSiO3 and other inorganic salts, evolving into the SCW (H2O-CO2-CH4O system. In going upwards to the 10-20-km depth of the crust SCW will be accumulated as an earthquake-pregnant reservoir in the broken terrain. The phase-transition heat of SCW is estimated at 606.62 kJ/kg and the reverse phasing kinetic energy is 2350.8 kJ/kg. When automatic exhaust at the time of decompression reaches the critical pressure (Pc), the instant explosion reverse phase will be normal-state air water. It will release a huge volume of energy and high-kinetic-energy gas which has been expanded by a factor of 1000, leading to the breaking of the country rocks overlying the earthquake-pregnant reservoir, thus giving rise to a Ms 8.0 earthquake. As a result, there were formed eruptive and air-driven (pneumatic) debris flows whose volumatric flow rate reaches n×1014 m3/s, and their force greatly exceeds the power of INT explosive of the same equivalent value.

  9. The psychological impact of a dual-disaster caused by earthquakes and radioactive contamination in Ichinoseki after the Great East Japan Earthquake.

    Science.gov (United States)

    Niitsu, Tomihisa; Takaoka, Kota; Uemura, Saho; Kono, Akiko; Saito, Akihiko; Kawakami, Norito; Nakazato, Michiko; Shimizu, Eiji

    2014-05-20

    The psychological impact of dual-disasters (earthquakes and a nuclear accident), on affected communities is unknown. This study investigated the impact of a dual-disaster (earthquakes and radioactive contamination) on the prevalence of psychological distress in a landlocked city within the Tohoku area, Japan. A cross-sectional mail-in survey with a random sample of inhabitants from Ichinoseki city was conducted eleven months after the disasters, and data from 902 respondents were analyzed by logistic regression models, with multiple imputation methodology. The K6 was used to determine psychological distress. The estimated prevalence of psychological distress was 48.0 percent. House damage due to earthquakes and anxiety about radioactive contamination were significantly associated with psychological distress (p radioactive contamination was not significant. Being female, middle-to-low educational status and unemployed were additional risk factors for psychological distress. This dual-disaster was associated with a moderate prevalence of psychological distress in the area. The impact of the earthquake and radioactive contamination appeared additive.

  10. Impact of average household income and damage exposure on post-earthquake distress and functioning: A community study following the February 2011 Christchurch earthquake.

    Science.gov (United States)

    Dorahy, Martin J; Rowlands, Amy; Renouf, Charlotte; Hanna, Donncha; Britt, Eileen; Carter, Janet D

    2015-08-01

    Post-traumatic stress, depression and anxiety symptoms are common outcomes following earthquakes, and may persist for months and years. This study systematically examined the impact of neighbourhood damage exposure and average household income on psychological distress and functioning in 600 residents of Christchurch, New Zealand, 4-6 months after the fatal February, 2011 earthquake. Participants were from highly affected and relatively unaffected suburbs in low, medium and high average household income areas. The assessment battery included the Acute Stress Disorder Scale, the depression module of the Patient Health Questionnaire (PHQ-9), and the Generalized Anxiety Disorder Scale (GAD-7), along with single item measures of substance use, earthquake damage and impact, and disruptions in daily life and relationship functioning. Controlling for age, gender and social isolation, participants from low income areas were more likely to meet diagnostic cut-offs for depression and anxiety, and have more severe anxiety symptoms. Higher probabilities of acute stress, depression and anxiety diagnoses were evident in affected versus unaffected areas, and those in affected areas had more severe acute stress, depression and anxiety symptoms. An interaction between income and earthquake effect was found for depression, with those from the low and medium income affected suburbs more depressed. Those from low income areas were more likely, post-earthquake, to start psychiatric medication and increase smoking. There was a uniform increase in alcohol use across participants. Those from the low income affected suburb had greater general and relationship disruption post-quake. Average household income and damage exposure made unique contributions to earthquake-related distress and dysfunction.

  11. Environmental risk evaluation to minimize impacts within the area affected by the Wenchuan earthquake.

    Science.gov (United States)

    Du, Pengfei; Chen, Jining; Chen, Chao; Liu, Yi; Liu, Jianguo; Wang, Hongtao; Zhang, Xiaojian

    2012-03-01

    Earthquakes can be devastating to built infrastructure and the natural environment, as evidenced by the March 2011, M=9.0 earthquake, and subsequent tsunami, in Japan. As seen in the Japanese event, environmental damage caused by secondary disasters (tsunami, leakage from a nuclear reactor) can equal or exceed the impacts of the primary event. In order to develop an environmental assessment system to examine secondary disasters, a comprehensive environmental impact evaluation was conducted after the Wenchuan earthquake that occurred on 12 May 2008 in the Sichuan Province, China. This evaluation focused on several key environmental elements such as wastewater, drinking water, soil, solid waste, radiation, and ecosystem-level effects. As part of this assessment, an analysis of root causes and potential solutions was conducted for key issues such as population relocation and resettlement in temporary dwellings, recovery of environmental protection functions, industrial development strategies and production recovery. Methods for post-quake environmental assessment were developed, utilizing GIS-based techniques for spatial evaluation of primary and secondary disaster patterns. The goal of this exercise was the development of effective assessment methods that can be rapidly applied in a post-disaster situation to reduce and mitigate damage caused by secondary disasters, and facilitate the recovery of impaired environmental management structure and function.

  12. Environmental impact of the landslides caused by the 12 May 2008, Wenchuan, China earthquake

    Science.gov (United States)

    Highland, Lynn; Sun, Ping; Edited by Margottini, Claudio; Canuti, Paolo; Sassa, Kyoji

    2013-01-01

    The magnitude 7.9 (Mw) Wenchuan, China, earthquake of May 12, 2008 caused at least 88,000 deaths of which one third are estimated to be due to the more than 56,000 earthquake-induced landslides. The affected area is mountainous, featuring densely-vegetated, steep slopes through which narrowly confined rivers and streams flow. Numerous types of landslides occurred in the area, including rock avalanches, rock falls, translational and rotational slides, lateral spreads and debris flows. Some landslides mobilized hundreds of million cubic meters of material, often resulting in the damming of rivers and streams, impacting river ecosystems and morphology. Through an extensive search of both Chinese- and English-language publications we provide a summary of pertinent research on environmental effects, emphasizing key findings. Environmental effects caused by landslides include the alteration of agriculture, changes to natural ecosystems, changes in river morphology due to landslide dams and other effects such as sedimentation and flooding. Damage by landslides to the giant panda reserve infrastructure and habitat, was severe, threatening the survival of one of the world’s rarest species. The Panda reserves are of national significance to China, and to the vital tourism economy of the region. One of the major impacts to both the natural and built environment is the complete relocation of some human populations and infrastructure to new areas, resulting in the abandonment of towns and other areas that were damaged by the earthquake and landslides. The landslide effects have affected the biodiversity of the affected area, and it has been hypothesized that strict forest preservation measures taken in the years preceding the earthquake resulted in a reduction of the environmental damage to the area.

  13. Preliminary volcano-hazard assessment for Iliamna Volcano, Alaska

    Science.gov (United States)

    Waythomas, Christopher F.; Miller, Thomas P.

    1999-01-01

    Iliamna Volcano is a 3,053-meter-high, ice- and snow-covered stratovolcano in the southwestern Cook Inlet region about 225 kilometers southwest of Anchorage and about 100 kilometers northwest of Homer. Historical eruptions of Iliamna Volcano have not been positively documented; however, the volcano regularly emits steam and gas, and small, shallow earthquakes are often detected beneath the summit area. The most recent eruptions of the volcano occurred about 300 years ago, and possibly as recently as 90-140 years ago. Prehistoric eruptions have generated plumes of volcanic ash, pyroclastic flows, and lahars that extended to the volcano flanks and beyond. Rock avalanches from the summit area have occurred numerous times in the past. These avalanches flowed several kilometers down the flanks and at least two large avalanches transformed to cohesive lahars. The number and distribution of known volcanic ash deposits from Iliamna Volcano indicate that volcanic ash clouds from prehistoric eruptions were significantly less voluminous and probably less common relative to ash clouds generated by eruptions of other Cook Inlet volcanoes. Plumes of volcanic ash from Iliamna Volcano would be a major hazard to jet aircraft using Anchorage International Airport and other local airports, and depending on wind direction, could drift at least as far as the Kenai Peninsula and beyond. Ashfall from future eruptions could disrupt oil and gas operations and shipping activities in Cook Inlet. Because Iliamna Volcano has not erupted for several hundred years, a future eruption could involve significant amounts of ice and snow that could lead to the formation of large lahars and downstream flooding. The greatest hazards in order of importance are described below and shown on plate 1.

  14. Vanishing Volcano

    Institute of Scientific and Technical Information of China (English)

    杨树仁

    1995-01-01

    Mauna Loa, the world’s largest active volcano,is sinking into the Pacific Ocean——and it’s taking the main island of Hawaii with it! The problem:The mighty volcano has gained too much weight, says Peter Lipman of the U. S. Geological Survey.

  15. Impact of volcanic processes on the cryospheric system of the Peteroa Volcano, Andes of southern Mendoza, Argentina

    Science.gov (United States)

    Liaudat, Dario Trombotto; Penas, Pablo; Aloy, Gustavo

    2014-03-01

    Soil temperatures of the active Volcanic Complex Peteroa situated in the Cordillera Principal between Chile and Argentina at 35°15‧ S and 70°35‧ W (approximately) were monitored in the area, and local geomorphology (periglacial geomorphology, presence of permafrost, and cryoforms) was studied. The present contribution also resulted in a comparison of two consecutive analyses of the volcano peak carried out with special thermocameras (AGEMA TVH 550, FUR P660) in order to study the thermal range of different hot and cold sites selected in 2009. The thermocameras were used ascending by foot and also during flights with a Cessna 180. A night expedition to the volcanic avalanche caldera, at up to 3900 m asl (approximately), completed the monitoring activity of 2010. Hot zones were associated to present volcanism and cold zones to the presence of glacier ice and shadowy slopes with possible presence of permafrost. Identifying and mapping uncovered and covered ice was possible with the help of monitoring and geomorphological interpretation related to the upper englacement, which is severely affected by volcanism. Glaciers are retreating toward the north or approaching the rims of the volcanic avalanche caldera leaving islands of ice associated with superficial permafrost. The cryogenic area with slope permafrost was identified through active protalus and sedimentary cryogenic slopes. Craters have undergone considerable thermal changes in comparison to the year 2009; and new, much more vigorous fumaroles have appeared in hot areas detected in 2009 following a tendency toward the west. New subaquatic heat columns that appeared in crater 3, crater walls, and glaciated areas vanished, supplying cold water and thus contributing to the formation of a new lake in crater 4. A possible post-seismic shift of the volcanic activity may provide geodynamical evidence of the changes registered in other areas after the earthquake of 27 February 2010.

  16. Impact of Short-term Changes In Earthquake Hazard on Risk In Christchurch, New Zealand

    Science.gov (United States)

    Nyst, M.

    2012-12-01

    The recent Mw 7.1, 4 September 2010 Darfield, and Mw 6.2, 22 February 2011 Christchurch, New Zealand earthquakes and the following aftershock activity completely changed the existing view on earthquake hazard of the Christchurch area. Not only have several faults been added to the New Zealand fault database, the main shocks were also followed by significant increases in seismicity due to high aftershock activity throughout the Christchurch region that is still on-going. Probabilistic seismic hazard assessment (PSHA) models take into account a stochastic event set, the full range of possible events that can cause damage or loss at a particular location. This allows insurance companies to look at their risk profiles via average annual losses (AAL) and loss-exceedance curves. The loss-exceedance curve is derived from the full suite of seismic events that could impact the insured exposure and plots the probability of exceeding a particular loss level over a certain period. Insurers manage their risk by focusing on a certain return period exceedance benchmark, typically between the 100 and 250 year return period loss level, and then reserve the amount of money needed to account for that return period loss level, their so called capacity. This component of risk management is not too sensitive to short-term changes in risk due to aftershock seismicity, as it is mostly dominated by longer-return period, larger magnitude, more damaging events. However, because the secondairy uncertainties are taken into account when calculating the exceedance probability, even the longer return period losses can still experience significant impact from the inclusion of time-dependent earthquake behavior. AAL is calculated by summing the product of the expected loss level and the annual rate for all events in the event set that cause damage or loss at a particular location. This relatively simple metric is an important factor in setting the annual premiums. By annualizing the expected losses

  17. Lessons learned from the 12 May 2008 Wenchuan earthquake: Impact on industry

    Science.gov (United States)

    Krausmann, E.; Cruz, A. M.; Affeltranger, B.

    2009-04-01

    polluting a river also necessitated the evacuation of 6,000 residents. The main cause of worker death and injury was the collapse of warehouses, office and manufacturing buildings. This concerned mostly concrete structures with insufficient confinement or poor reinforcement that could not withstand the earthquake loads. The falling debris resulted in equipment damage and loss, as well as pipe severing and crushing in buildings housing machinery. This was brought about either by direct debris impact or by support failure inside buildings. Pipes were also severed, bent or crushed outside of structures when connected tanks were displaced or buildings collapsed, although in many cases anchoring proved to be effective in avoiding displacement. Pipe support concrete columns in the open generally performed well. In some sites soil-liquefaction induced damage was evident, highlighting the need to consider potential site effects when selecting the location for a facility.

  18. Impact of the 11 March, 2011, Tohoku earthquake and tsunami on the chemical industry

    Science.gov (United States)

    Krausmann, E.; Cruz, A. M.

    2012-04-01

    An earthquake of magnitude 9.0 occurred off the Pacific coast of Tohoku, Japan, on March 11, 2011, at 14:46:23 Japan Standard Time (5:46:23 UTC). It generated a tsunami 130 km off the coast of Miyagi Prefecture in northeast Japan, which inundated over 400 km2 of land. The death toll has reached >15,800 according to the Japan National Policy Agency with over 3,700 still missing as of 26 October 2011. Significant damage to or complete collapse of houses also resulted. The earthquake generated strong ground motion; nevertheless most damage was caused by the tsunami, which is a tribute to the effectiveness of Japan's earthquake damage reduction measures in saving lives and property. Nonetheless, the direct losses amount to more than 200 billion US dollars (not counting the costs of the accident at the Fukushima nuclear power plant). The earthquake and tsunami had a significant impact on all types of industry, and in particular on the petrochemical and chemical industry in the affected areas, resulting in hazardous-materials releases, fires and explosions and forcing businesses to interrupt production. These so-called Natech accidents pose an immediate or even long-term threat to the population and the environment, and can also interrupt the supply chain. Overall, the earthquake and tsunami took over 30% of Japan's oil production offline, and two refineries are still not or only partially in operation to repair the damage caused by the fires and explosions. The fire-fighting efforts could only be started 4 days after the disaster due to the absence of personnel that had been evacuated and because of the continuing tsunami alerts. In one of the affected refineries the fires could only be extinguished 10 days after the disasters. Many petrochemical and chemical companies reported problems either due to damage to facilities or because of power outages. In fact, in facilities that suffered no or only minor damage the resuming of operations was hampered by continuous

  19. Dante's volcano

    Science.gov (United States)

    1994-09-01

    This video contains two segments: one a 0:01:50 spot and the other a 0:08:21 feature. Dante 2, an eight-legged walking machine, is shown during field trials as it explores the inner depths of an active volcano at Mount Spurr, Alaska. A NASA sponsored team at Carnegie Mellon University built Dante to withstand earth's harshest conditions, to deliver a science payload to the interior of a volcano, and to report on its journey to the floor of a volcano. Remotely controlled from 80-miles away, the robot explored the inner depths of the volcano and information from onboard video cameras and sensors was relayed via satellite to scientists in Anchorage. There, using a computer generated image, controllers tracked the robot's movement. Ultimately the robot team hopes to apply the technology to future planetary missions.

  20. What Are Volcano Hazards?

    Science.gov (United States)

    ... Sheet 002-97 Revised March 2008 What Are Volcano Hazards? Volcanoes give rise to numerous geologic and ... as far as 15 miles from the volcano. Volcano Landslides A landslide or debris avalanche is a ...

  1. Geology of Kilauea volcano

    Energy Technology Data Exchange (ETDEWEB)

    Moore, R.B. (Geological Survey, Denver, CO (United States). Federal Center); Trusdell, F.A. (Geological Survey, Hawaii National Park, HI (United States). Hawaiian Volcano Observatory)

    1993-08-01

    This paper summarizes studies of the structure, stratigraphy, petrology, drill holes, eruption frequency, and volcanic and seismic hazards of Kilauea volcano. All the volcano is discussed, but the focus is on its lower east rift zone (LERZ) because active exploration for geothermal energy is concentrated in that area. Kilauea probably has several separate hydrothermal-convection systems that develop in response to the dynamic behavior of the volcano and the influx of abundant meteoric water. Important features of some of these hydrothermal-convection systems are known through studies of surface geology and drill holes. Observations of eruptions during the past two centuries, detailed geologic mapping, radiocarbon dating, and paleomagnetic secular-variation studies indicate that Kilauea has erupted frequently from its summit and two radial rift zones during Quaternary time. Petrologic studies have established that Kilauea erupts only tholeiitic basalt. Extensive ash deposits at Kilauea's summit and on its LERZ record locally violent, but temporary, disruptions of local hydrothermal-convection systems during the interaction of water or steam with magma. Recent drill holes on the LERZ provide data on the temperatures of the hydrothermal-convection systems, intensity of dike intrusion, porosity and permeability, and an increasing amount of hydrothermal alteration with depth. The prehistoric and historic record of volcanic and seismic activity indicates that magma will continue to be supplied to deep and shallow reservoirs beneath Kilauea's summit and rift zones and that the volcano will be affected by eruptions and earthquakes for many thousands of years. 71 refs., 2 figs.

  2. 4D volcano gravimetry

    Science.gov (United States)

    Battaglia, Maurizio; Gottsmann, J.; Carbone, D.; Fernandez, J.

    2008-01-01

    Time-dependent gravimetric measurements can detect subsurface processes long before magma flow leads to earthquakes or other eruption precursors. The ability of gravity measurements to detect subsurface mass flow is greatly enhanced if gravity measurements are analyzed and modeled with ground-deformation data. Obtaining the maximum information from microgravity studies requires careful evaluation of the layout of network benchmarks, the gravity environmental signal, and the coupling between gravity changes and crustal deformation. When changes in the system under study are fast (hours to weeks), as in hydrothermal systems and restless volcanoes, continuous gravity observations at selected sites can help to capture many details of the dynamics of the intrusive sources. Despite the instrumental effects, mainly caused by atmospheric temperature, results from monitoring at Mt. Etna volcano show that continuous measurements are a powerful tool for monitoring and studying volcanoes.Several analytical and numerical mathematical models can beused to fit gravity and deformation data. Analytical models offer a closed-form description of the volcanic source. In principle, this allows one to readily infer the relative importance of the source parameters. In active volcanic sites such as Long Valley caldera (California, U.S.A.) and Campi Flegrei (Italy), careful use of analytical models and high-quality data sets has produced good results. However, the simplifications that make analytical models tractable might result in misleading volcanological inter-pretations, particularly when the real crust surrounding the source is far from the homogeneous/ isotropic assumption. Using numerical models allows consideration of more realistic descriptions of the sources and of the crust where they are located (e.g., vertical and lateral mechanical discontinuities, complex source geometries, and topography). Applications at Teide volcano (Tenerife) and Campi Flegrei demonstrate the

  3. Earthquake impact on settlements: the role of urban and structural morphology

    Science.gov (United States)

    Bostenaru Dan, M.; Armas, I.

    2015-10-01

    This study is aimed to create an alternative to the classical GIS representation of the impact of earthquake hazards on urban areas. To accomplish this, the traditional map was revised, so that it can cope with contemporary innovative ways of planning, namely strategic planning. As in the theory of fractals, the building dimension and the urban neighbourhood dimension are addressed as different geographic scales between which lessons for decisions can be learned through regression. The interaction between the two scales is useful when looking for alternatives, for the completion of a GIS analysis, and in choosing the landmarks, which, in the case of hazards, become strategic elements in strategic planning. A methodology to innovate mapping as a digital means for analysing and visualising the impact of hazards is proposed. This method relies on concepts from various geography, urban planning, structural engineering and architecture approaches related to disaster management. The method has been tested at the building scale for the N-S Boulevard in Bucharest, Romania, called Magheru. At the urban scale, an incident database has been created, in which the case study for the building level can be mapped. The paper presented is part of a larger research work, which addresses decision making using the framework shown here. The main value of the paper is in proposing a conceptual framework to deconstruct the map for digital earthquake disaster impact analysis and representation. The originality of the concept consists in the representation of elements at different scales considered to be of different levels of importance in the urban tissue, according to the analysis to be performed on them.

  4. Impact of the Great East Japan Earthquake on Regional Obstetrical Care in Miyagi Prefecture.

    Science.gov (United States)

    Sugawara, Junichi; Hoshiai, Tetsuro; Sato, Kazuyo; Tokunaga, Hideki; Nishigori, Hidekazu; Arai, Takanari; Okamura, Kunihiro; Yaegashi, Nobuo

    2016-06-01

    The authors report the results of surveys on the emergency transport or evacuation status of obstetric patients conducted in Miyagi prefecture, one of the major disaster areas of the Great East Japan Earthquake and tsunami. The surveys examined the damages to maternity institutions, evacuation status and transport of pregnant women, and prehospital childbirths and were conducted in 50 maternity institutions and 12 fire departments in Miyagi. Two coastal institutions were destroyed completely, and four institutions were destroyed partially by the tsunami, forcing them to stop medical services. In the two-month period after the disaster, 217 pregnant women received hospital transport or gave birth after evacuation. Satisfactory perinatal outcomes were maintained. Emergency obstetric transport increased to approximately 1.4 fold the number before the disaster. Twenty-three women had prehospital childbirths, indicating a marked increase to approximately three times the number of the previous year. In the acute phase of the tsunami disaster, maternity institutions were damaged severely and perinatal transport was not possible; as a result, pregnant women inevitably gave birth in unplanned institutions, and the number of prehospital births was increased extremely. To obtain satisfactory obstetric outcomes, it is necessary to construct a future disaster management system and to re-recognize pregnant women as people with special needs in disaster situations. Sugawara J , Hoshiai T , Sato K , Tokunaga H , Nishigori H , Arai T , Okamura K , Yaegashi N . Impact of the Great East Japan Earthquake on regional obstetrical care in Miyagi Prefecture. Prehosp Disaster Med. 2016;31(3):255- 258.

  5. The Impact of a Natural Disaster: Under- and Postgraduate Nursing Education Following the Canterbury, New Zealand, Earthquake Experiences

    Science.gov (United States)

    Richardson, S. K.; Richardson, A.; Trip, H.; Tabakakis, K.; Josland, H.; Maskill, V.; Dolan, B.; Hickmott, B.; Houston, G.; Cowan, L.; McKay, L.

    2015-01-01

    While natural disasters have been reported internationally in relation to the injury burden, role of rescuers and responders, there is little known about the impact on education in adult professional populations. A 7.1 magnitude earthquake affected the Canterbury region of New Zealand on 4 September 2010 followed by more than 13,000 aftershocks in…

  6. No Major Economic Aftershocks The tragic earthquake shouldn't have much impact on the economy-but problems remain

    Institute of Scientific and Technical Information of China (English)

    BRADLEY GARDNER

    2008-01-01

    @@ While rescue workers and emergency service crews continue sifting through the rubble caused by the devastating earthquake in Sichuan Province last month, financial institutions have been busy figuring out the financial implications of economy, and what can be done to manage the impact.

  7. Technical-Information Products for a National Volcano Early Warning System

    Science.gov (United States)

    Guffanti, Marianne; Brantley, Steven R.; Cervelli, Peter F.; Nye, Christopher J.; Serafino, George N.; Siebert, Lee; Venezky, Dina Y.; Wald, Lisa

    2007-01-01

    Introduction Technical outreach - distinct from general-interest and K-12 educational outreach - for volcanic hazards is aimed at providing usable scientific information about potential or ongoing volcanic activity to public officials, businesses, and individuals in support of their response, preparedness, and mitigation efforts. Within the context of a National Volcano Early Warning System (NVEWS) (Ewert et al., 2005), technical outreach is a critical process, transferring the benefits of enhanced monitoring and hazards research to key constituents who have to initiate actions or make policy decisions to lessen the hazardous impact of volcanic activity. This report discusses recommendations of the Technical-Information Products Working Group convened in 2006 as part of the NVEWS planning process. The basic charge to the Working Group was to identify a web-based, volcanological 'product line' for NVEWS to meet the specific hazard-information needs of technical users. Members of the Working Group were: *Marianne Guffanti (Chair), USGS, Reston VA *Steve Brantley, USGS, Hawaiian Volcano Observatory HI *Peter Cervelli, USGS, Alaska Volcano Observatory, Anchorage AK *Chris Nye, Division of Geological and Geophysical Surveys and Alaska Volcano Observatory, Fairbanks AK *George Serafino, National Oceanic and Atmospheric Administration, Camp Springs MD *Lee Siebert, Smithsonian Institution, Washington DC *Dina Venezky, USGS, Volcano Hazards Team, Menlo Park CA *Lisa Wald, USGS, Earthquake Hazards Program, Golden CO

  8. Electrophysiological evidence of personal experiences in the great Sichuan earthquake impacting on selective attention

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Event-related brain potentials(ERPs) were measured when 24 Chinese subjects performed the earthquake color-matching Stroop task.All of them have experienced the great Sichuan earthquake(5.12),with 12 subjects in each of Chengdu city and Chongqing city(different earthquake experiences) groups.The behavioral data showed that the earthquake Stroop task yielded robust the earthquake interference effect as indexed by longer RT for earthquake-related(Related) words than earthquake-unrelated(Unrelated) words only in the Chengdu group.Scalp ERP analysis also revealed the neurophysiological substrate of the interference effect:a greater positivity(P350-450) in Related words as compared to Unrelated words was found between 350 and 450 ms post-stimulus over fronto-central scalp regions in the Chengdu group,while the interference effect was not found in the Chongqing group.The P350-450 might reflect an earthquake experience interference,but also attention enhancing,effect of earthquake-related words.Dipole source analysis of the difference wave(Related-Unrelated) showed that a generator was localized in the parahippocampal gyrus,which was possibly associated with flashbulb memory(personal earthquake experience).The results indicated that different personal earthquake experiences might be critical in engaging the neural mechanisms that underlie the modulation of selective attention.

  9. THE GEOLOGIC RISK IN THE LAKE KIVU BASIN AREA PRODUCTED BY EARTHQUAKES. Case of the February 3th 2008 earthquake. By: L.M.Bagalwa(1), F.Lukaya(1), M.Burume(2), J.Moeyerson(3) (1): Goma Volcano Observatory, D.R.Congo (2): Naturals Sciences Research Center

    Science.gov (United States)

    Bagalwa Rukeza, Montfort

    2010-05-01

    The eastern Democratic Republic of Congo is prone to earthquakes of magnitude greater than or equal to 4 on the Richter scale. The western edge of Lake Kivu, the most populated part of the region is no exception to the solicitation of these earthquakes. Since 1997, the western basin of Lake Kivu is experiencing intense seismicity, several earthquakes of great intensity, magnitude greater than or equal to 4 develop major destructive phenomena. These include the 1997 earthquake (M = 4.7) 2000 (M = 4.6 and 5.4), 2002 (M = 4.9, 5.2, 6.1 and 24 October 2002 M = 6.2) of February 3rd 2008 (M = 6). Earthquakes of Kalehe on October 24th 2002 and Birava, February 3rd 2008 have resulted deformations of soil, human and material damage. This latest natural disaster ever known in the south-western basin of Lake Kivu has attracted our scientific curiosity we go there to inquire into its causes and consequences in this region. The basin of Lake Kivu is affected by transform faults emerging (MUKONKI & CHOROWICZ, 1980, quoted by K.S.KAVOTHA & ali, 1990) that delimit the Rift were intersecting at the level of Lake Kivu. We Consider the seismicity, volcanism and uplift of the basin of Lake Kivu as a sign of fracturing under way to delimit a plate tectonics formed (Wong and Von Herzen, 1974, quoted by KSKAVOTHA et al, 1990). The physiography of Lake Kivu is dominated by the fault which borders the western shore and one which intersects the island of Idjwi. The telemetry data of Goma Volcano Observatory added to those of the seismographic station of Lwiro have always revealed a pattern of epicenters clearer in Lake Kivu. In correlation with the faults of the region, earthquakes affect mainly the western edge of Lake Kivu and the island of Idjwi with increasing density from north to south (K.S.KAVOTHA et al, 1990). The great earthquake of Lake Kivu basin on February 03rd 2008, of magnitude 6 on the Richter scale occurred at 07 hours 34 minutes 12 seconds GMT, about 20 km north of Bukavu

  10. Quantifying the humanitarian and economic impact of earthquakes on South American capital cities (Invited)

    Science.gov (United States)

    Zoback, M. L.; Cabrera, C.; Pomonis, A.; Baca, A.; Brunner, I.; Cheung, G.; Chen, A.; Nagel, B.; Carrasco, S.

    2009-12-01

    By 2000, an estimated 80% of South America’s population lived in urban areas (Veblen et al., The Physical Geography of South America, Oxford University Press, 2007). A significant fraction of those urban dwellers resides in the capital cities which are major economic centers and act as magnets for rural poor and refugees. This population concentration includes many residents living in extreme poverty in substandard and informal housing, often on the margins of these capital cities and sometimes on steep slopes, greatly compounding the vulnerability to natural hazards. We are analyzing the humanitarian and economic risk for six of the seismically most-at-risk South American capitals along the northern and western plate boundaries of South America: Caracas, Venezuela; Bogotá, Colombia; Quito, Ecuador; Lima, Perú; La Paz, Bolivia; and Santiago, Chile. Impacts are provided in the form of expected losses for a specific “likely” scenario earthquake and in a probabilistic format using exceedance probability curves (probability of exceeding a given loss in different return periods). Impacts to be quantified include: total economic losses, potential fatalities, potential serious injuries, and the number of displaced households. Probabilistic seismic hazard was developed in collaboration with numerous South American experts and includes subduction interface, intraslab, background crustal and, where available, active fault sources. A significant challenge for this study is to accurately account for the exposure and vulnerability of populations living in the informal, shanty areas. Combining analysis of aerial imagery and on-the-ground reconnaissance, we define between 20-30 “inventory districts” of relatively uniform construction styles within each capital. Statistical distributions of the different construction types and their characteristics (height, occupancy, year built, average value) are estimated for each district. In addition, working with local graduate

  11. The 2008 Eruption of Chaitén Volcano, Chile and National Volcano-Monitoring Programs in the U.S. and Chile

    Science.gov (United States)

    Ewert, J. W.; Lara, L. E.; Moreno, H.

    2008-12-01

    Chaitén volcano, southern Chile, began erupting on 2 May 2008. The eruption produced 3 Plinian eruption pulses between May 2 and 8. Between Plinian phases the volcano emitted a constant column of ash to approximately 10 km, gradually diminishing to approximately 3 km by the end of June. The eruption of Chaitén was remarkable on several counts--it was the first rhyolite eruption on the planet since Novarupta (Katmai) erupted in 1912, and Chaitén had apparently lain dormant for approximately 9300 years. Though Chaitén is located in a generally sparsely populated region, the eruption had widespread impacts. More than 5000 people had to be quickly evacuated from proximal areas and aviation in southern South America was disrupted for weeks. Within 10 days secondary lahars had overrun much of the town of Chaitén complicating the prospects of the townspeople to return to their homes. Prior to the eruption onset, the nearest real-time seismic station was 300 km distant, and earthquakes were not felt by local citizens until approximately 30 hours before the eruption onset. No other signs of unrest were noted. Owing to the lack of near-field monitoring, and the nighttime eruption onset, there was initial confusion about which volcano was erupting: Chaitén or nearby Michinmahuida. Lack of monitoring systems at Chaitén meant that warning time for the public at risk was extremely short, and owing to the nature of the eruption and the physical geography of the area, it was very difficult to install monitoring instruments to track its progress after the eruption started. The lack of geophysical monitoring also means that an important data set on precursory behavior for silicic systems was not collected. With more than 120 Pleistocene to Holocene-age volcanoes within its continental territory, Chile is one of the more volcanically active countries in the world. The eruption of Chaitén has catalyzed the creation of a new program within the Servicio Nacional de Geología y

  12. Regional radiative impact of volcanic aerosol from the 2009 eruption of Redoubt volcano

    Directory of Open Access Journals (Sweden)

    C. L. Young

    2011-09-01

    Full Text Available High northern latitude eruptions have the potential to release volcanic aerosol into the Arctic environment, perturbing the Arctic's climate system. In this study, we present assessments of shortwave (SW, longwave (LW and net direct aerosol radiative forcings (DARFs and atmospheric heating/cooling rates caused by volcanic aerosol from the 2009 eruption of Redoubt Volcano by performing radiative transfer modeling constrained by NASA A-Train satellite data. The Ozone Monitoring Instrument (OMI, the Moderate Resolution Imaging Spectroradiometer (MODIS, and the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT model for volcanic ash were used to characterize aerosol across the region. A representative range of aerosol optical depths (AODs at 550 nm were obtained from MODIS, and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO was used to determine the altitude and thickness of the plumes. The optical properties of volcanic aerosol were calculated using a compositionally resolved microphysical model developed for both ash and sulfates. Two compositions of volcanic aerosol were considered in order to examine a fresh, ash rich plume and an older, ash poor plume. Optical models were incorporated into a modified version of the Santa Barbara Disort Atmospheric Radiative Transfer (SBDART model. Radiative transfer calculations were made for a range of surface albedos and solar zenith angles (SZA representative of the region. We find that the total DARF caused by a fresh, thin plume (~2.5–7 km at an AOD (550 nm range of 0.16–0.58 and SZA = 55° is –46 W m−2AOD−1 at the top of the atmosphere (TOA, 110 W m−2AOD−1 in the aerosol layer, and – 150 W m−2AOD−1 at the surface over seawater. However, the total DARF for the same plume over snow and at the same SZA at TOA, in the layer, and at the surface is 170, 170, and −2 W m−2

  13. Electrophysiological evidence of personal experiences in the great Sichuan earthquake impacting on selective attention

    Institute of Scientific and Technical Information of China (English)

    QIU Jiang; LI Hong; ZHANG QingLin; HUANG LiHui; GUO YaQiao; TU Shen; WANG Ting; WEI DongTao

    2009-01-01

    Event-related brain potentials (ERPs) were measured when 24 Chinese subjects performed the earth quake color-matching Stroop task. All of them have experienced the great Sichuan earthquake (5.12),with 12 subjects in each of Chengdu city and Chongqing city (different earthquake experiences) groups.The behavioral data showed that the earthquake Stroop task yielded robust the earthquake interference effect as indexed by longer RT for earthquake-related (Related) words than earthquake-unrelated (Unrelated) words only in the Chengdu group. Scalp ERP analysis also revealed the neurophysiological substrate of the interference effect: a greater positivity (P350--450) in Related words as compared to Unrelated words was found between 350 and 450 ms post-stimulus over fronto-central scalp regions in the Chengdu group, while the interference effect was not found in the Chongqing group. The P35H50 might reflect an earthquake experience interference, but also attention enhancing, effect of earthquake-related words. Dipole source analysis of the difference wave (Related-Unrelated) showed that a generator was localized in the parahippocampsl gyrus, which was possibly associated with flashbulb memory (personal earthquake experience). The results indicated that different personal earthquake experiences might be critical in engaging the neural mechanisms that underlie the modulation of selective attention.

  14. Public Release of Estimated Impact-Based Earthquake Alerts - An Update to the U.S. Geological Survey PAGER System

    Science.gov (United States)

    Wald, D. J.; Jaiswal, K. S.; Marano, K.; Hearne, M.; Earle, P. S.; So, E.; Garcia, D.; Hayes, G. P.; Mathias, S.; Applegate, D.; Bausch, D.

    2010-12-01

    The U.S. Geological Survey (USGS) has begun publicly releasing earthquake alerts for significant earthquakes around the globe based on estimates of potential casualties and economic losses. These estimates should significantly enhance the utility of the USGS Prompt Assessment of Global Earthquakes for Response (PAGER) system that has been providing estimated ShakeMaps and computing population exposures to specific shaking intensities since 2007. Quantifying earthquake impacts and communicating loss estimates (and their uncertainties) to the public has been the culmination of several important new and evolving components of the system. First, the operational PAGER system now relies on empirically-based loss models that account for estimated shaking hazard, population exposure, and employ country-specific fatality and economic loss functions derived using analyses of losses due to recent and past earthquakes. In some countries, our empirical loss models are informed in part by PAGER’s semi-empirical and analytical loss models, and building exposure and vulnerability data sets, all of which are being developed in parallel to the empirical approach. Second, human and economic loss information is now portrayed as a supplement to existing intensity/exposure content on both PAGER summary alert (available via cell phone/email) messages and web pages. Loss calculations also include estimates of the economic impact with respect to the country’s gross domestic product. Third, in order to facilitate rapid and appropriate earthquake responses based on our probable loss estimates, in early 2010 we proposed a four-level Earthquake Impact Scale (EIS). Instead of simply issuing median estimates for losses—which can be easily misunderstood and misused—this scale provides ranges of losses from which potential responders can gauge expected overall impact from strong shaking. EIS is based on two complementary criteria: the estimated cost of damage, which is most suitable for U

  15. Volcano seismology

    Science.gov (United States)

    Chouet, B.

    2003-01-01

    A fundamental goal of volcano seismology is to understand active magmatic systems, to characterize the configuration of such systems, and to determine the extent and evolution of source regions of magmatic energy. Such understanding is critical to our assessment of eruptive behavior and its hazardous impacts. With the emergence of portable broadband seismic instrumentation, availability of digital networks with wide dynamic range, and development of new powerful analysis techniques, rapid progress is being made toward a synthesis of high-quality seismic data to develop a coherent model of eruption mechanics. Examples of recent advances are: (1) high-resolution tomography to image subsurface volcanic structures at scales of a few hundred meters; (2) use of small-aperture seismic antennas to map the spatio-temporal properties of long-period (LP) seismicity; (3) moment tensor inversions of very-long-period (VLP) data to derive the source geometry and mass-transport budget of magmatic fluids; (4) spectral analyses of LP events to determine the acoustic properties of magmatic and associated hydrothermal fluids; and (5) experimental modeling of the source dynamics of volcanic tremor. These promising advances provide new insights into the mechanical properties of volcanic fluids and subvolcanic mass-transport dynamics. As new seismic methods refine our understanding of seismic sources, and geochemical methods better constrain mass balance and magma behavior, we face new challenges in elucidating the physico-chemical processes that cause volcanic unrest and its seismic and gas-discharge manifestations. Much work remains to be done toward a synthesis of seismological, geochemical, and petrological observations into an integrated model of volcanic behavior. Future important goals must include: (1) interpreting the key types of magma movement, degassing and boiling events that produce characteristic seismic phenomena; (2) characterizing multiphase fluids in subvolcanic

  16. THE EARTHQUAKE AND TSUNAMI OF JULY 21, 365 AD IN THE EASTERN MEDITERRANEAN SEA - Review of Impact on the Ancient World - Assessment of Recurrence and Future Impact

    Directory of Open Access Journals (Sweden)

    George Pararas-Carayannis

    2011-01-01

    Full Text Available There is ample evidence indicating that on July 21, 365 AD a great earthquake near the west coast of the Island of Crete generated a mega-tsunami, which was responsible for extensive destruction throughout the Eastern Mediterranean, but particularly on Peloponnesus, the Greek Islands, Sicily, Libya, Cyprus, Palestine and Egypt. It is believed that the combined catastrophic impacts of the earthquake and tsunami were significant catalysts in furthering the declination of the Roman Empire and contributing to its subsequent final division between the East Roman and the West (Byzantine empires in 395 A.D. In view of subsequent earthquakes and tsunamis in the region and the high probability that a similar great disaster will occur again, the present study reviews and summarizes the seismo-tectonic and kinematic characteristics of the Aegean and Anatolian micro-plates, their interaction with the African and Eurasian tectonic plates and examines and evaluates the historical records pertaining to this 4th Century AD disaster as to the destructive impact it had on the ancient world. Additionally, the study reconciles the impact described in historical and recent records with results obtained by numerical modeling studies, provides a rough estimate of the recurrence frequency of great tsunamigenic earthquakes in the Eastern Mediterranean region and assesses what the future impact may be in view of great increases in population densities along coastal areas.

  17. Characteristics of Hawaiian volcanoes

    Science.gov (United States)

    Poland, Michael P.; Takahashi, T. Jane; Landowski, Claire M.

    2014-01-01

    Founded in 1912 at the edge of the caldera of Kīlauea Volcano, HVO was the vision of Thomas A. Jaggar, Jr., a geologist from the Massachusetts Institute of Technology, whose studies of natural disasters around the world had convinced him that systematic, continuous observations of seismic and volcanic activity were needed to better understand—and potentially predict—earthquakes and volcanic eruptions. Jaggar summarized the aim of HVO by stating that “the work should be humanitarian” and have the goals of developing “prediction and methods of protecting life and property on the basis of sound scientific achievement.” These goals align well with those of the USGS, whose mission is to serve the Nation by providing reliable scientific information to describe and understand the Earth; minimize loss of life and property from natural disasters; manage natural resources; and enhance and protect our quality of life.

  18. Impact of the 2008 Wenchuan earthquake in China on subsequent long-term debris flow activities in the epicentral area

    Science.gov (United States)

    Zhang, S.; Zhang, L. M.

    2017-01-01

    The 2008 Wenchuan earthquake triggered the largest number of landslides among the recent strong earthquake events around the world. The loose landslide materials were retained on steep terrains and deep gullies. In the period from 2008 to 2015, numerous debris flows occurred during rainstorms along the Provincial Road 303 (PR303) near the epicentre of the earthquake, causing serious damage to the reconstructed highway. Approximately 5.24 × 106 m3 of debris-flow sediment was deposited shortly after the earthquake. This paper evaluates the evolution of the debris flows that occurred after the Wenchuan earthquake, which helps understand long-term landscape evolution and cascading effects in regions impacted by mega earthquakes. With the aid of a GIS platform combined with field investigations, we continuously tracked movements of the loose deposit materials in all the debris flow gullies along an 18 km reach of PR303 and the characteristics of the regional debris flows during several storms in the past seven years. This paper presents five important aspects of the evolution of debris flows: (1) supply of debris flow materials; (2) triggering rainfall; (3) initiation mechanisms and types of debris flows; (4) runout characteristics; and (5) elevated riverbed due to the deposited materials from the debris flows. The hillslope soil deposits gradually evolved into channel deposits and the solid materials in the channels moved towards the ravine mouth. Accordingly, channelized debris flows became dominant gradually. Due to the decreasing source material volume and changes in debris flow characteristics, the triggering rainfall tends to increase from 30 mm h- 1 in 2008 to 64 mm h- 1 in 2013, and the runout distance tends to decrease over time. The runout materials blocked the river and elevated the riverbed by at least 30 m in parts of the study area. The changes in the post-seismic debris flow activity can be categorized into three stages, i.e., active, unstable, and

  19. Impact of volcanic fluoride and SO/sub 7/ emissions from moderated activity volcanoes on the surrounding vegetation

    Energy Technology Data Exchange (ETDEWEB)

    Garrec, J.P.; Plebin, R.; Faivre-Pierret, R.X.

    1984-01-01

    Studies in the regions of the volcanoes Etna (Italy) and Masaya (Nicaragua) show that the continuous emissions of gaseous pollutants (HF and SO/sub 2/) from moderated activity volcanoes causes a chronic pollution in the surrounding vegetation with certain economical and ecological consequences. Reciprocally the measure of the pollutants in the plants growing in volcanic regions may be a simple and fast method to investigate some characteristics of the volcanic plume: for example, intensity of the emissions of gas, direction and extent of the plume. 12 references.

  20. An Approach for the Response of Buildings Subjected to Impact Load after Soft-Story Failure due to Earthquake Excitation

    Directory of Open Access Journals (Sweden)

    Wojciech Migda

    2013-01-01

    Full Text Available The soft-story failure is one of the most typical types of damage observed in buildings during earthquakes. The failure of an intermediate soft story of a structure results in large impact loading acting on the lower floors due to the fall of the upper stories. The aim of the present paper is to study the behavior of the structural members exposed to such extreme load conditions occurring under ground motion excitation. Special attention is paid to investigate the influence of the degradation of horizontal stiffness of columns on the response of the building during earthquake. The results of the study show that the stiffness degradation of building columns, due to impact caused by the fall of the upper stories, may have a considerable influence on the structural response. Moreover, the results clearly indicate that the time of impact plays a substantial role in the overall behavior of the building suffering from the soft-story failure. It has been shown that the structural response may be increased significantly if impact takes place when the building is in the range of its peak deformations during the earthquake, especially when the structure is just approaching the extreme position.

  1. Santorini Volcano

    Science.gov (United States)

    Druitt, T.H.; Edwards, L.; Mellors, R.M.; Pyle, D.M.; Sparks, R.S.J.; Lanphere, M.; Davies, M.; Barreirio, B.

    1999-01-01

    Santorini is one of the most spectacular caldera volcanoes in the world. It has been the focus of significant scientific and scholastic interest because of the great Bronze Age explosive eruption that buried the Minoan town of Akrotiri. Santorini is still active. It has been dormant since 1950, but there have been several substantial historic eruptions. Because of this potential risk to life, both for the indigenous population and for the large number of tourists who visit it, Santorini has been designated one of five European Laboratory Volcanoes by the European Commission. Santorini has long fascinated geologists, with some important early work on volcanoes being conducted there. Since 1980, research groups at Cambridge University, and later at the University of Bristol and Blaise Pascal University in Clermont-Ferrand, have collected a large amount of data on the stratigraphy, geochemistry, geochronology and petrology of the volcanics. The volcanic field has been remapped at a scale of 1:10 000. A remarkable picture of cyclic volcanic activity and magmatic evolution has emerged from this work. Much of this work has remained unpublished until now. This Memoir synthesizes for the first time all the data from the Cambridge/Bristol/Clermont groups, and integrates published data from other research groups. It provides the latest interpretation of the tectonic and magmatic evolution of Santorini. It is accompanied by the new 1:10 000 full-colour geological map of the island.

  2. Socio-economic and environmental impacts of Match 2011 earthquake, tsunami and Fukushima nuclear accident in Japan

    OpenAIRE

    Bachev, Hrabrin

    2014-01-01

    On March 11, 2011 the strongest recorded in Japan earthquake occurred which triggered a powerful tsunami and caused a nuclear accident in the Fukushima Daichi Nuclear Plant Station. The triple 2011 disaster has had immense impacts on people life, health and property, social infrastructure and economy, agri-food chains, natural and institutional environment, etc. in North-eastern Japan and beyond Due to the scale of the disasters and the number of affected agents, the effects’ multiplicities,...

  3. Impact of the great east Japan earthquake on the body mass index of preschool children: a nationwide nursery school survey.

    Science.gov (United States)

    Yokomichi, Hiroshi; Zheng, Wei; Matsubara, Hiroko; Ishikuro, Mami; Kikuya, Masahiro; Isojima, Tsuyoshi; Yokoya, Susumu; Tanaka, Toshiaki; Kato, Noriko; Chida, Shoichi; Ono, Atsushi; Hosoya, Mitsuaki; Tanaka, Soichiro; Kuriyama, Shinichi; Kure, Shigeo; Yamagata, Zentaro

    2016-04-07

    To evaluate the impact of the 2011 great east Japan earthquake on body mass index (BMI) of preschool children. Retrospective cohort study and ecological study. Affected prefectures (Fukushima, Miyagi and Iwate) and unaffected prefectures in northeast Japan. The cohort study assessed 2033 and 1707 boys and 1909 and 1658 girls in 3 affected prefectures and unaffected prefectures, respectively, all aged 3-4 years at the time of the earthquake. The ecological study examined random samples of schoolchildren from the affected prefectures. The cohort study compared postdisaster changes in BMIs and the prevalence of overweight and obese children. The ecological study evaluated postdisaster changes in the prevalence of overweight children. 1 month after the earthquake, significantly increased BMIs were observed among girls (+0.087 kg/m(2) vs unaffected prefectures) in Fukushima and among boys and girls (+0.165 and +0.124 kg/m(2), respectively vs unaffected prefectures) in Iwate. 19 months after the earthquake, significantly increased BMIs were detected among boys and girls (+0.137 and +0.200 kg/m(2), respectively vs unaffected prefectures) in Fukushima, whereas significantly decreased BMIs were observed among boys and girls (-0.218 and -0.082 kg/m(2), respectively vs unaffected prefectures) in Miyagi. 1 month after the earthquake, Fukushima, Miyagi and Iwate had a slightly increased prevalence of overweight boys, whereas Fukushima had a slightly decreased prevalence of overweight girls, compared with the unaffected prefectures. The ecological study detected increases in the prevalence of overweight boys and girls in Fukushima who were 6-11 and 6-10 years of age, respectively. These results suggest that in the affected prefectures, preschool children gained weight immediately after the earthquake. The long-term impact of the earthquake on early childhood growth was more variable among the affected prefectures, possibly as a result of different speeds of

  4. Impact of the great east Japan earthquake on the body mass index of preschool children: a nationwide nursery school survey

    Science.gov (United States)

    Yokomichi, Hiroshi; Zheng, Wei; Matsubara, Hiroko; Ishikuro, Mami; Kikuya, Masahiro; Isojima, Tsuyoshi; Yokoya, Susumu; Tanaka, Toshiaki; Kato, Noriko; Chida, Shoichi; Ono, Atsushi; Hosoya, Mitsuaki; Tanaka, Soichiro; Kuriyama, Shinichi; Kure, Shigeo; Yamagata, Zentaro

    2016-01-01

    Objective To evaluate the impact of the 2011 great east Japan earthquake on body mass index (BMI) of preschool children. Design Retrospective cohort study and ecological study. Setting Affected prefectures (Fukushima, Miyagi and Iwate) and unaffected prefectures in northeast Japan. Participants The cohort study assessed 2033 and 1707 boys and 1909 and 1658 girls in 3 affected prefectures and unaffected prefectures, respectively, all aged 3–4 years at the time of the earthquake. The ecological study examined random samples of schoolchildren from the affected prefectures. Primary and secondary outcome measures The cohort study compared postdisaster changes in BMIs and the prevalence of overweight and obese children. The ecological study evaluated postdisaster changes in the prevalence of overweight children. Results 1 month after the earthquake, significantly increased BMIs were observed among girls (+0.087 kg/m2 vs unaffected prefectures) in Fukushima and among boys and girls (+0.165 and +0.124 kg/m2, respectively vs unaffected prefectures) in Iwate. 19 months after the earthquake, significantly increased BMIs were detected among boys and girls (+0.137 and +0.200 kg/m2, respectively vs unaffected prefectures) in Fukushima, whereas significantly decreased BMIs were observed among boys and girls (−0.218 and −0.082 kg/m2, respectively vs unaffected prefectures) in Miyagi. 1 month after the earthquake, Fukushima, Miyagi and Iwate had a slightly increased prevalence of overweight boys, whereas Fukushima had a slightly decreased prevalence of overweight girls, compared with the unaffected prefectures. The ecological study detected increases in the prevalence of overweight boys and girls in Fukushima who were 6–11 and 6–10 years of age, respectively. Conclusions These results suggest that in the affected prefectures, preschool children gained weight immediately after the earthquake. The long-term impact of the earthquake on early childhood

  5. Ecological and genetic impact of the 2011 Tohoku Earthquake Tsunami on intertidal mud snails

    Science.gov (United States)

    Miura, Osamu; Kanaya, Gen; Nakai, Shizuko; Itoh, Hajime; Chiba, Satoshi; Makino, Wataru; Nishimura, Tomohiro; Kojima, Shigeaki; Urabe, Jotaro

    2017-01-01

    Natural disturbances often destroy local populations and can considerably affect the genetic properties of these populations. The 2011 Tohoku Earthquake Tsunami greatly damaged local populations of various coastal organisms, including the mud snail Batillaria attramentaria, which was an abundant macroinvertebrate on the tidal flats in the Tohoku region. To evaluate the impact of the tsunami on the ecology and population genetic properties of these snails, we monitored the density, shell size, and microsatellite DNA variation of B. attramentaria for more than ten years (2005–2015) throughout the disturbance event. We found that the density of snails declined immediately after the tsunami. Bayesian inference of the genetically effective population size (Ne) demonstrated that the Ne declined by 60–99% at the study sites exposed to the tsunami. However, we found that their genetic diversity was not significantly reduced after the tsunami. The maintenance of genetic diversity is essential for long-term survival of local populations, and thus, the observed genetic robustness could play a key role in the persistence of snail populations in this region which has been devastated by similar tsunamis every 500–800 years. Our findings have significant implications for understanding the sustainability of populations damaged by natural disturbances. PMID:28281698

  6. Transboundary Impacts of the 2010 Haiti Earthquake Disaster: Focus on Legal Dilemmas in South Florida

    Directory of Open Access Journals (Sweden)

    Alka Sapat

    2013-04-01

    Full Text Available Catastrophic disasters affect not just the areas/regions and countries where they strike, but also have transboundary effects and repercussions on neighboring countries, which often serve as receiving areas for displaced survivors. South Florida, for example, served as a receiving area for earthquake survivors after the 2010 Haiti earthquake. To understand the transboundary sociolegal impacts on host communities, we draw theoretical insights from research on transboundary crises and interviewed key members of school districts, city and county governments, non-profit organizations, relief task forces, the Haitian-American diaspora, and local government agencies. We also looked at relevant plans/policies modified by governmental and non-governmental institutions in response to the legal issues that arose. The findings highlight the manner in which street-level workers in state and non-state organizations deal with legal complexities and ramifications, along with the role played by the Haitian-American diaspora actors and their networks. Los desastres por catástrofes no afectan solo a las áreas/regiones y países a los que golpean, sino que también tienen efectos transfronterizos y repercuten en los países vecinos, que a menudo sirven como áreas de recepción para los sobrevivientes desplazados. El sur de Florida, por ejemplo, sirvió como área de acogida para los supervivientes del terremoto de Haiti de 2010. Para entender el impacto sociojurídico a nivel transfronterizo en las comunidades de acogida, se trazan nuevas percepciones teóricas a partir de la investigación de crisis transfronterizas, y mediante entrevistas a miembros clave de distritos escolares, gobiernos de ciudades y condados, organizaciones sin ánimos de lucro, grupos de trabajo de auxilio, la diáspora haitiano-estadounidense, y agencias del gobierno local. También se estudian los planes/políticas relevantes, modificados por las instituciones gubernamentales y no

  7. The impact of ocular trauma during the Nepal earthquake in 2015.

    Science.gov (United States)

    Pradhan, E; Limbu, B; Thakali, S; Jain, N S; Gurung, R; Ruit, S

    2017-03-28

    Nepal was struck by a massive earthquake on the 25th April 2015 and major aftershock on the 12th of May 2015, resulting in widespread devastation with a death toll in the thousands. The burden of ocular trauma resulting from the recent earthquakes in Nepal has not been described thus far. The aim of this study was to determine the types of ocular injuries sustained in the earthquake in Nepal and its management in Tilganga Institute of Ophthalmology (TIO) in Gaushala, Kathmandu. This is a hospital-based retrospective study of patients presenting to TIO following repeated earthquake. Variables that were recorded included patients' presenting symptoms and time to presentation, visual acuities at presentation and at follow-up, diagnosis of ocular injury and surgery performed. There were 59 cases of earthquake victims visiting TIO, Gaushala, Kathmandu from April 2015 to July 2015, with 64 affected eyes due to 5 cases of bilateral involvement. The majority of patients were from the district Sindhupalchowk (14 cases, 23.7%), which was the epicenter of the main earthquake. The average duration between the earthquake and presentation was 13 · 9 days (range 1-120 days). Closed globe injury was most frequent (23 cases), followed by open globe injuries (8 cases). While 24 patients (38%) initially presented with a visual acuity earthquake-related ocular trauma will facilitate planning for service provision in the event of a future earthquake in Nepal, or in countries, which are similarly at risk of having natural disasters.

  8. Lahar-hazard zonation for San Miguel volcano, El Salvador

    Science.gov (United States)

    Major, J.J.; Schilling, S.P.; Pullinger, C.R.; Escobar, C.D.; Chesner, C.A.; Howell, M.M.

    2001-01-01

    San Miguel volcano, also known as Chaparrastique, is one of many volcanoes along the volcanic arc in El Salvador. The volcano, located in the eastern part of the country, rises to an altitude of about 2130 meters and towers above the communities of San Miguel, El Transito, San Rafael Oriente, and San Jorge. In addition to the larger communities that surround the volcano, several smaller communities and coffee plantations are located on or around the flanks of the volcano, and the PanAmerican and coastal highways cross the lowermost northern and southern flanks of the volcano. The population density around San Miguel volcano coupled with the proximity of major transportation routes increases the risk that even small volcano-related events, like landslides or eruptions, may have significant impact on people and infrastructure. San Miguel volcano is one of the most active volcanoes in El Salvador; it has erupted at least 29 times since 1699. Historical eruptions of the volcano consisted mainly of relatively quiescent emplacement of lava flows or minor explosions that generated modest tephra falls (erupted fragments of microscopic ash to meter sized blocks that are dispersed into the atmosphere and fall to the ground). Little is known, however, about prehistoric eruptions of the volcano. Chemical analyses of prehistoric lava flows and thin tephra falls from San Miguel volcano indicate that the volcano is composed dominantly of basalt (rock having silica content

  9. The threat of silent earthquakes

    Science.gov (United States)

    Cervelli, Peter

    2004-01-01

    Not all earthquakes shake the ground. The so-called silent types are forcing scientists to rethink their understanding of the way quake-prone faults behave. In rare instances, silent earthquakes that occur along the flakes of seaside volcanoes may cascade into monstrous landslides that crash into the sea and trigger towering tsunamis. Silent earthquakes that take place within fault zones created by one tectonic plate diving under another may increase the chance of ground-shaking shocks. In other locations, however, silent slip may decrease the likelihood of destructive quakes, because they release stress along faults that might otherwise seem ready to snap.

  10. Inherited structures impact on co-seismic surface deformation pattern during the 2013 Balochistan, Pakistan, earthquake

    Science.gov (United States)

    Vallage, Amaury; Klinger, Yann; Grandin, Raphael; Delorme, Arthur; Pierrot-Deseilligny, Marc

    2016-04-01

    The understanding of earthquake processes and the interaction of earthquake rupture with Earth's free surface relies on the resolution of the observations. Recent and detailed post-earthquake measurements bring new insights on shallow mechanical behavior of rupture processes as it becomes possible to measure and locate surficial deformation distribution. The 2013 Mw 7.7 Balochistan earthquake, Pakistan, offers a nice opportunity to comprehend where and why surficial deformation might differs from at-depth localized slip. This earthquake ruptured the Hoshab fault over 200 km; the motion was mainly left lateral with a small and discontinuous vertical component in the southern part of the rupture. Using images with the finest resolution currently available, we measured the surface displacement amplitude and its orientation at the ground surface (including the numerous tensile cracks). We combined these measurements with the 1:500 scale ground rupture map to focus on the behavior of the frontal rupture in the area where deformation distributes. Comparison with orientations of inherited tectonic structures, visible in older rocks formation surrounding the actual 2013 rupture, shows the control exercised by such structures on co-seismic rupture distribution. Such observation raises the question on how pre-existing tectonic structures in a medium, mapped in several seismically active places around the globe; can control the co-seismic distribution of the deformation during earthquakes.

  11. Identification and impacts of earthquakes on the Roman Town of Patras- Archaeological evidence

    Science.gov (United States)

    Stamati, Alexandra-Venetia; Stiros, Stathis

    2015-04-01

    In this paper we examine the interactions between earthquakes and inhabitation history of the town of Patras (NW Peloponnese, Greece), flourishing during the Roman period. Instrumental seismicity data and the seismic history of the last two centuries indicate that the wider area is among the most seismically active parts of Europe. But surprisingly, for older periods no historical evidence of ancient earthquakes exists. If this absence of evidence of ancient earthquakes is indicative of a real absence of earthquakes, this may be important for different disciplines. For Seismology, it may perhaps indicate clusters of seismicity separated by intervals of quiescence, each at least several thousand years long. It may also indicate that the inhabitation history of Patras town was not interrupted by major natural catastrophic events, and some destruction observed in ancient remains can be assigned to anthropogenic effects. In order to contribute in the solution of this problem, we made a systematic Archaeoseismological investigation of Patras and examined for the first time several hundreds of reports of archaeological excavations that have been made during period of reconstruction of the city (1972-2004). Among these, about 100 reports provide evidence of destruction layers, some of which satisfy the criteria for identification of earthquakes from archaeological data. A further correlation of this evidence in space and time was made, and permitted to identify with certainty a few major seismic events which marked the history of Roman Patras (1st-6th century AD). In spite of their catastrophic effects, these earthquakes have not led to the abandonment of the ancient town (inhabitation hiatus), but have certainly left their marks in the urban and perhaps social and economic history of this Roman town. Some certain uniformity in the frequency of earthquakes in Patras was also inferred.

  12. Impact of the Great East Japan Earthquake on acute myocardial infarction in Fukushima prefecture.

    Science.gov (United States)

    Yamaki, Takayoshi; Nakazato, Kazuhiko; Kijima, Mikihiro; Maruyama, Yukio; Takeishi, Yasuchika

    2014-06-01

    The incidence of cardiovascular disease (CVD) reportedly increases following a huge disaster. On March 11, 2011, the Great East Japan Earthquake hit a large area of eastern Japan. In Fukushima prefecture, many people suffered from the consequences of the earthquake, the subsequent tsunami, and especially the Fukushima Daiichi Nuclear Power Plant accident. We assessed whether the incidence of acute myocardial infarction (AMI) increased after the earthquake. We enrolled AMI patients admitted to 36 hospitals in Fukushima prefecture between March 11, 2009, and March 10, 2013 (n = 3068). We compared the incidence of AMI after the earthquake for more than 3 months and 1 year with that in the control years. The incidence of Fukushima's annual AMI patients (per 100 000 persons) in 2011 was similar to that of previous years (n = 38.9 [2011] vs 37.2 [2009] and 38.5 [2010], P = .581). However, a significantly higher incidence of AMI was found in the Iwaki district after the disaster that corresponded to the 1-year period of observation (n = 38.7 [2011] vs 27.3 [2009] and 32.8 [2010], P = .045). The Great East Japan Earthquake affected the incidence of AMI only in limited areas of Fukushima prefecture.

  13. The impact of degassing on the oxidation state of basaltic magmas: A case study of Kīlauea volcano

    Science.gov (United States)

    Moussallam, Yves; Edmonds, Marie; Scaillet, Bruno; Peters, Nial; Gennaro, Emanuela; Sides, Issy; Oppenheimer, Clive

    2016-09-01

    Volcanic emissions link the oxidation state of the Earth's mantle to the composition of the atmosphere. Whether the oxidation state of an ascending magma follows a redox buffer - hence preserving mantle conditions - or deviates as a consequence of degassing remains under debate. Thus, further progress is required before erupted basalts can be used to infer the redox state of the upper mantle or the composition of their co-emitted gases to the atmosphere. Here we present the results of X-ray absorption near-edge structure (XANES) spectroscopy at the iron K-edge carried out for a series of melt inclusions and matrix glasses from ejecta associated with three eruptions of Kīlauea volcano (Hawai'i). We show that the oxidation state of these melts is strongly correlated with their volatile content, particularly in respect of water and sulfur contents. We argue that sulfur degassing has played a major role in the observed reduction of iron in the melt, while the degassing of H2O and CO2 appears to have had a negligible effect on the melt oxidation state under the conditions investigated. Using gas-melt equilibrium degassing models, we relate the oxidation state of the melt to the composition of the gases emitted at Kīlauea. Our measurements and modelling yield a lower constraint on the oxygen fugacity of the mantle source beneath Kīlauea volcano, which we infer to be near the nickel nickel-oxide (NNO) buffer. Our findings should be widely applicable to other basaltic systems and we predict that the oxidation state of the mantle underneath most hotspot volcanoes is more oxidised than that of the associated lavas. We also suggest that whether the oxidation states of a basalt (in particular MORB) reflects that of its source, is primarily determined by the extent of sulfur degassing.

  14. Slow slip event at Kilauea Volcano

    Science.gov (United States)

    Poland, Michael P.; Miklius, Asta; Wilson, J. David; Okubo, Paul G.; Montgomery-Brown, Emily; Segall, Paul; Brooks, Benjamin; Foster, James; Wolfe, Cecily; Syracuse, Ellen; Thurbe, Clifford

    2010-01-01

    Early in the morning of 1 February 2010 (UTC; early afternoon 31 January 2010 local time), continuous Global Positioning System (GPS) and tilt instruments detected a slow slip event (SSE) on the south flank of Kilauea volcano, Hawaii. The SSE lasted at least 36 hours and resulted in a maximum of about 3 centimeters of seaward displacement. About 10 hours after the start of the slip, a flurry of small earthquakes began (Figure 1) in an area of the south flank recognized as having been seismically active during past SSEs [Wolfe et al., 2007], suggesting that the February earthquakes were triggered by stress associated with slip [Segall et al., 2006].

  15. What is the impact of the August 24, 2016 Amatrice earthquake on the seismic hazard assessment in central Italy?

    Directory of Open Access Journals (Sweden)

    Maura Murru

    2016-11-01

    Full Text Available The recent Amatrice strong event (Mw6.0 occurred on August 24, 2016 in Central Apennines (Italy in a seismic gap zone, motivated us to study and provide better understanding of the seismic hazard assessment in the macro area defined as “Central Italy”. The area affected by the sequence is placed between the Mw6.0 1997 Colfiorito sequence to the north (Umbria-Marche region the Campotosto area hit by the 2009 L’Aquila sequence Mw6.3 (Abruzzo region to the south. The Amatrice earthquake occurred while there was an ongoing effort to update the 2004 seismic hazard map (MPS04 for the Italian territory, requested in 2015 by the Italian Civil Protection Agency to the Center for Seismic Hazard (CPS of the Istituto Nazionale di Geofisica e Vulcanologia INGV. Therefore, in this study we brought to our attention new earthquake source data and recently developed ground-motion prediction equations (GMPEs. Our aim was to validate whether the seismic hazard assessment in this area has changed with respect to 2004, year in which the MPS04 map was released. In order to understand the impact of the recent earthquakes on the seismic hazard assessment in central Italy we compared the annual seismic rates calculated using a smoothed seismicity approach over two different periods; the Parametric Catalog of the Historical Italian earthquakes (CPTI15 from 1871 to 2003 and the historical and instrumental catalogs from 1871 up to 31 August 2016. Results are presented also in terms of peak ground acceleration (PGA, using the recent ground-motion prediction equations (GMPEs at Amatrice, interested by the 2016 sequence.

  16. Italian Volcano Supersites

    Science.gov (United States)

    Puglisi, G.

    2011-12-01

    Volcanic eruptions are among the geohazards that may have a substantial economic and social impact, even at worldwide scale. Large populated regions are prone to volcanic hazards worldwide. Even local phenomena may affect largely populated areas and in some cases even megacities, producing severe economic losses. On a regional or global perspective, large volcanic eruptions may affect the climate for years with potentially huge economic impacts, but even relatively small eruptions may inject large amounts of volcanic ash in the atmosphere and severely affect air traffic over entire continents. One of main challenges of the volcanological community is to continuously monitor and understand the internal processes leading to an eruption, in order to give substantial contributions to the risk reduction. Italian active volcanoes constitute natural laboratories and ideal sites where to apply the cutting-edge volcano observation systems, implement new monitoring systems and to test and improve the most advanced models and methods for investigate the volcanic processes. That's because of the long tradition of volcanological studies resulting into long-term data sets, both in-situ and from satellite systems, among the most complete and accurate worldwide, and the large spectrum of the threatening volcanic phenomena producing high local/regional/continental risks. This contribution aims at presenting the compound monitoring systems operating on the Italian active volcanoes, the main improvements achieved during the recent studies direct toward volcanic hazard forecast and risk reductions and the guidelines for a wide coordinated project aimed at applying the ideas of the GEO Supersites Initiative at Mt. Etna and Campi Flegrei / Vesuvius areas.

  17. "Mediterranean volcanoes vs. chain volcanoes in the Carpathians"

    Science.gov (United States)

    Chivarean, Radu

    2017-04-01

    Volcanoes have always represent an attractive subject for students. Europe has a small number of volcanoes and Romania has none active ones. The curricula is poor in the study of volcanoes. We want to make a parallel between the Mediterranean active volcanoes and the old extinct ones in the Oriental Carpathians. We made an comparison of the two regions in what concerns their genesis, space and time distribution, the specific relief and the impact in the landscape, consequences of their activities, etc… The most of the Mediterranean volcanoes are in Italy, in the peninsula in Napoli's area - Vezuviu, Campi Flegrei, Puzzoli, volcanic islands in Tirenian Sea - Ischia, Aeolian Islands, Sicily - Etna and Pantelleria Island. Santorini is located in Aegean Sea - Greece. Between Sicily and Tunisia there are 13 underwater volcanoes. The island called Vulcano, it has an active volcano, and it is the origin of the word. Every volcano in the world is named after this island, just north of Sicily. Vulcano is the southernmost of the 7 main Aeolian Islands, all volcanic in origin, which together form a small island arc. The cause of the volcanoes appears to be a combination of an old subduction event and tectonic fault lines. They can be considered as the origin of the science of volcanology. The volcanism of the Carpathian region is part of the extensive volcanic activity in the Mediterranean and surrounding regions. The Carpathian Neogene/Quaternary volcanic arc is naturally subdivided into six geographically distinct segments: Oas, Gutai, Tibles, Calimani, Gurghiu and Harghita. It is located roughly between the Carpathian thrust-and-fold arc to the east and the Transylvanian Basin to the west. It formed as a result of the convergence between two plate fragments, the Transylvanian micro-plate and the Eurasian plate. Volcanic edifices are typical medium-sized andesitic composite volcanoes, some of them attaining the caldera stage, complicated by submittal or peripheral domes

  18. Impacts of earthquake on atoll in Nansha Islands, South China Sea

    Science.gov (United States)

    Guo, Lei; Zhan, Wenhuan; Xiong, Lijia; Chen, Wujin; Yao, Yantao; Li, Jian

    2016-04-01

    Coral reef is a kind of rock soil masses. It is a special marine geotechnical medium, which are made up of the reef coral debris undergo very long geological age. Atoll is the predominant type of coral reefs in South China Sea. In recent years, there are more and more construction projects on the reef flat in Nansha Islands, South China Sea. Therefore, it is very important to estimate the stability of coral reefs, especially the atolls. According to the geological structure characters of atoll in Nansha Islands, a model of reef body is presented in this paper to study the influence of earthquake. Meanwhile, Geostudio, which is a popular geotechnical engineering simulation software, is used to stimulate the stress and deformation situation of reef body under different six kinds of earthquake intensity. The factor of safety can be calculated by the limit equilibrium method. And the possible scenario of earthquake-induced landslides and sliding scale can be defined through the Newmark sliding block method. The stress distribution and deformation behavior are studied. The main relations between atoll and earthquake are analyzed as follows: (1) the safety factor of reef slope exceeds 1.993 under self-gravity state; (2) It may cause slope's instability and bring slumping when the safety factor is less than one. The factor of safety decreases with increased earthquake intensity and it may fluctuate around a particular value when earthquake intensity continues to increase; (3) The smaller shallow landslide as new developed part of the reef is subject to collapse under earthquake action and the bigger slope of reef is more stable. The results show that it is feasible to evaluate the stability of coral reef by using geotechnical engineering simulation method, which can help to provide some information for construction on coral reefs in South China Sea. In the meantime,the authers wish to thank the National Natural Science Foundation of China (NO.41376063)and the National

  19. The velocity structure of crust and upper mantle in the Wudalianchi volcano area inferred from the receiver function

    Institute of Scientific and Technical Information of China (English)

    贺传松; 王椿镛; 吴建平

    2003-01-01

    The Wudalianchi volcano is a modern volcano erupted since the Holocene. Its frequent occurrence of the small earthquake is considered to be indicator of active dormancy volcano. The S wave velocity structure is inferred from the receiver function for the crust and upper mantle of the Wudalianchi volcano area. The results show that the low velocity structure of S wave is widely distributed underneath the volcano area and part of the low-velocity-zone located at shallow depth in the Wudalianchi volcano area. The low velocity structure is related to the seismicity. The Moho interface is not clear underneath the volcano area, which may be regard to be an necessary condition for the lava upwelling. Therefore, we infer that the Wudalianchi volcano has the deep structural condition for the volcano activity and may be alive again.

  20. The great Lisbon earthquake and tsunami of 1755: lessons from the recent Sumatra earthquakes and possible link to Plato's Atlantis

    Science.gov (United States)

    Gutscher, M.-A.

    2006-05-01

    Great earthquakes and tsunami can have a tremendous societal impact. The Lisbon earthquake and tsunami of 1755 caused tens of thousands of deaths in Portugal, Spain and NW Morocco. Felt as far as Hamburg and the Azores islands, its magnitude is estimated to be 8.5 9. However, because of the complex tectonics in Southern Iberia, the fault that produced the earthquake has not yet been clearly identified. Recently acquired data from the Gulf of Cadiz area (tomography, seismic profiles, high-resolution bathymetry, sampled active mud volcanoes) provide strong evidence for an active east dipping subduction zone beneath Gibraltar. Eleven out of 12 of the strongest earthquakes (M>8.5) of the past 100 years occurred along subduction zone megathrusts (including the December 2004 and March 2005 Sumatra earthquakes). Thus, it appears likely that the 1755 earthquake and tsunami were generated in a similar fashion, along the shallow east-dipping subduction fault plane. This implies that the Cadiz subduction zone is locked (like the Cascadia and Nankai/Japan subduction zones), with great earthquakes occurring over long return periods. Indeed, the regional paleoseismic record (contained in deep-water turbidites and shallow lagoon deposits) suggests great earthquakes off South West Iberia every 1500 2000 years. Tsunami deposits indicate an earlier great earthquake struck SW Iberia around 200 BC, as noted by Roman records from Cadiz. A written record of even older events may also exist. According to Plato's dialogues The Critias and The Timaeus, Atlantis was destroyed by ‘strong earthquakes and floods … in a single day and night’ at a date given as 11,600 BP. A 1 m thick turbidite deposit, containing coarse grained sediments from underwater avalanches, has been dated at 12,000 BP and may correspond to the destructive earthquake and tsunami described by Plato. The effects on a paleo-island (Spartel) in the straits of Gibraltar would have been devastating, if inhabited, and may

  1. Acute stress-related psychological impact in children following devastating natural disaster, the Sikkim earthquake (2011, India

    Directory of Open Access Journals (Sweden)

    Rakesh Mondal

    2013-01-01

    Full Text Available Background: Psychological stress following natural disaster is common. Despite several earthquakes in India, data on evaluation of acute stress among the child victims in the early postdisaster period is scarce. Immediately following a devastating earthquake (6.9 Richter at Sikkim on September, 18 2011, many children attended North Bengal Medical College, the nearest government tertiary care institution, with unusual stress symptoms. Objective: Evaluation of acute stress symptoms in children in the immediate postearthquake period. Materials and Methods: This was a cross-sectional study done over 4 weeks and includes all the children from 1 to 12 years presenting with unusual physical or behavioral symptoms. Those with major injuries requiring admission were excluded. They were divided into two age groups. For older children (8-12 years the 8-item Children Impact of Event Scale (CIES was used for screening of stress. Unusual symptoms were recorded in younger children (1-8 years as CIES is not validated < 8 years. Result: A total of 84 children (2.66% out of 3154 had stress symptoms. Maximum attendance was noted in first 3 days (65.47% and declined gradually. In children ≥ 8 years, 48.78% had psychological stress, which was statistically significant on CIES scores without any gender predilection. Static posturing (41.86%, sleeplessness (32.55%, anorexia (9.30%, recurrent vomiting (13.95%, excessive crying (13.95%, or night-awakenings (4.65% were found in younger children ( n = 43 and three required admission. Conclusion: This study represent the first Indian data showing statistically significant psychological impact in older children (8-12 years and various forms of physical stress symptoms in young children (1-8 years following earthquake.

  2. Volcano Monitoring Using Google Earth

    Science.gov (United States)

    Bailey, J. E.; Dehn, J.; Webley, P.; Skoog, R.

    2006-12-01

    At the Alaska Volcano Observatory (AVO), Google Earth is being used as a visualization tool for operational satellite monitoring of the region's volcanoes. Through the abilities of the Keyhole Markup Language (KML) utilized by Google Earth, different datasets have been integrated into this virtual globe browser. Examples include the ability to browse thermal satellite image overlays with dynamic control, to look for signs of volcanic activity. Webcams can also be viewed interactively through the Google Earth interface to confirm current activity. Other applications include monitoring the location and status of instrumentation; near real-time plotting of earthquake hypocenters; mapping of new volcanic deposits; and animated models of ash plumes within Google Earth, created by a combination of ash dispersion modeling and 3D visualization packages. The globe also provides an ideal interface for displaying near real-time information on detected thermal anomalies or "hotspot"; pixels in satellite images with elevated brightness temperatures relative to the background temperature. The Geophysical Institute at the University of Alaska collects AVHRR (Advanced Very High Resolution Radiometer) and MODIS (Moderate Resolution Imaging Spectroradiometer) through its own receiving station. The automated processing that follows includes application of algorithms that search for hotspots close to volcano location, flagging those that meet certain criteria. Further automated routines generate folders of KML placemarkers, which are linked to Google Earth through the network link function. Downloadable KML files have been created to provide links to various data products for different volcanoes and past eruptions, and to demonstrate examples of the monitoring tools developed. These KML files will be made accessible through a new website that will become publicly available in December 2006.

  3. Providing Hands on Experiences to Museum Visitors to Explore and Learn about Earthquakes and their Impacts in the Pacific Northwest

    Science.gov (United States)

    Olds, S. E.; Schiffman, C. R.; Butler, R. F.; Farley, M.; Frankel, S.; Hunter, N.; Lillie, R. J.

    2013-12-01

    Over the past ten years, UNAVCO has developed a suite of learning materials for formal undergraduate and grades 6-12 classroom environments, integrating GPS data from the EarthScope Plate Boundary Observatory (PBO) to explore Earth science processes. To make complex Earth processes accessible to general audiences, UNAVCO has designed a multi-component visiting museum exhibit that explores the tectonic setting of the United States Pacific Northwest, hazards of living on a plate boundary, and the technologies being used to study the plate motion and in the future, help communities become more resilient to the impacts of earthquakes. This exhibit was installed in Fall 2013 at the Oregon State University (OSU) Hatfield Marine Science Center (HMSC) in Newport, Oregon. Through multiple hands-on elements, visitors to the HMSC exhibit explore and experience the build up and release of strain in the region, along with some of the technologies used to measure these changes. In one component, visitors compress a model of the Pacific Northwest to feel the build up of strain in the landscape and observe the movement of land over time. Supporting panels connect this movement to the measurements currently being observed by the network of PBO and other GPS stations in the Pacific Northwest. In another component, visitors learn about the recurrence interval for earthquakes at the Juan De Fuca - North America plate boundary by turning a handle to slowly move and compress plates until a simulated earthquake occurs. A related component explores how an earthquake early warning system (EEWS) of the future might combine seismic data collected by both seismometers and real time GPS to allow people and communities time to prepare for oncoming ground shaking and tsunami after an earthquake. Several technologies are also highlighted throughout the exhibit, including information panels that compare the accuracy of high precision GPS with smartphone technologies. Additionally, models of a full

  4. Spatial analysis of the impacts of the Chaitén volcano eruption (Chile) in three fluvial systems

    Science.gov (United States)

    Ulloa, H.; Iroumé, A.; Picco, L.; Mohr, C. H.; Mazzorana, B.; Lenzi, M. A.; Mao, L.

    2016-08-01

    The eruption of the Chaitén volcano in May 2008 generated morphological and ecological disturbances in adjacent river basins, and the magnitude of these disturbances depended on the type of dominant volcanic process affecting each of them. The aim of this study is to analyse the morphological changes in different periods in river segments of the Blanco, El Amarillo and Rayas river basins located near the Chaitén volcano. These basins suffered disturbances of different intensity and spatial distribution caused by tephra fall, dome collapses and pyroclastic density currents that damaged hillslope forests, widened channels and destroyed island and floodplain vegetation. Changes continued to occur in the fluvial systems in the years following the eruption, as a consequence of the geomorphic processes indirectly induced by the eruption. Channel changes were analyzed by comparing remote images of pre and post-eruption conditions. Two periods were considered: the first from 2008 to 2009-2010 associated with the explosive and effusive phases of the eruption and the second that correspond to the post-eruption stage from 2009-2010 to 2013. Following the first phases channel segments widened 91% (38 m/yr), 6% (7 m/yr) and 7% (22 m/yr) for Blanco, Rayas and El Amarillo Rivers, respectively, compared to pre-eruption condition. In the second period, channel segments additionally widened 42% (8 m/yr), 2% (2 m/yr) and 5% (4 m/yr) for Blanco, Rayas and El Amarillo Rivers, respectively. In the Blanco River 62 and 82% of the islands disappeared in the first and second period, respectively, which is 6-8 times higher than in the El Amarillo approximately twice the Rayas. Sinuosity increased after the eruption only in the Blanco River but the three study channels showed a high braiding intensity mainly during the first post-eruption period. The major disturbances occurred during the eruptive and effusive phases of Chaitén volcano, and the intensity of these disturbances reflects the

  5. Seismic Hazards at Kilauea and Mauna LOA Volcanoes, Hawaii

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Fred W.

    1994-04-22

    A significant seismic hazard exists in south Hawaii from large tectonic earthquakes that can reach magnitude 8 and intensity XII. This paper quantifies the hazard by estimating the horizontal peak ground acceleration (PGA) in south Hawaii which occurs with a 90% probability of not being exceeded during exposure times from 10 to 250 years. The largest earthquakes occur beneath active, unbuttressed and mobile flanks of volcanoes in their shield building stage.

  6. Global Volcano Locations Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NGDC maintains a database of over 1,500 volcano locations obtained from the Smithsonian Institution Global Volcanism Program, Volcanoes of the World publication. The...

  7. Use of remote imagery to analyse spatial impacts of the Chaitén volcano eruption (Chile) in fluvial systems

    Science.gov (United States)

    Ulloa, Héctor; Iroumé, Andrés; Picco, Lorenzo; Mao, Luca; Lenzi, Mario

    2015-04-01

    The processes associated with the 2008 eruption of the Chaitén Volcano (south of Chile) generated morphological, ecological, and social disturbances. These disturbances were changes in the channel widths, vegetated islands and riparian forests. Changes in the river systems continued to occur years after the eruption due to hydrological processes induced indirectly by the volcanic eruption. This study analyzes the morphological changes in a river segment of three basins (Blanco, El Amarillo and Rayas) located near the Chaiten volcano, through an analysis of a sequence of remote images. The three watersheds were subjected to different disturbance intensities, depending on the type of dominant volcanic processes. In addition, changes were analysed by comparing two study periods, the first associated to the effusive and explosive period of the eruption, and the second after this period. In the first period mean channel widths increased by 91% (38 m/year), 6% (7 m/year) and 3% (11 m/year) for the Blanco, El Amarillo and Rayas rivers, respectively. In the second period, the variations of the mean channel widths were 19% (4 m/year), 2% (2 m/year) and 4% (5 m/year) for same rivers. On the other hand, the number of islands decreased annually by 15 and 16% on the Blanco River, 4 and 3%, in the El Amarillo River and 9 and 12% in the Rayas, in the first and second periods, respectively. The magnitude of active channel changes reflects the scale of the dominant volcanic processes in each watershed. While in the second study period strong changes continue to occur mainly at the level of the islands. This research is being developed within the framework of Project FONDECYT 1141064.

  8. Bidirectional feedback observed between a magmatic intrusion and shallow earthquake

    Science.gov (United States)

    Ebmeier, Susanna; Elliott, John; Nocquet, Jean-Mathieu; Biggs, Juliet; Mothes, Patricia; Jarrín, Paúl; Yépez, Marco; Aguaiza, Santiago; Lundgren, Paul; Samsonov, Sergey

    2016-04-01

    Moderate volcano-tectonic earthquakes (M 5-6) during volcanic unrest are unusual, and tend to be associated with major stress perturbations to the crust, occurring during episodes of rifting or the onset of volcanic eruptions. The feedback from such events may be positive, easing magma ascent and eruption, or, as we demonstrate here, negative, hindering any further magma movement. We present measurements of deformation at Chiles-Cerro Negro volcanoes on the Ecuador-Colombian border. There was previously no record of historical activity at either volcano, but between 2013 and early 2015 there were three episodes of unrest characterised by swarms of volcano-tectonic earthquakes of increasing energy and duration and thought to be associated with the hydrothermal system. In October 2014, magmatic processes not only caused many thousands of small earthquakes per day, but culminated in a Mw 5.6 earthquake located on a system of active tectonic faults that last ruptured in 1868. We find that inflation of a mid-crustal magmatic source ~10 km south of the volcanoes ceased abruptly at the time of the earthquake, after which time the rate of seismicity also began a gradual decline. The Chiles-Cerro Negro unrest is therefore an interesting example of magma ascent triggering a moderate earthquake on a tectonic fault and subsequently being inhibited by co-seismic stress changes. This is an important observation for the interpretation of moderate earthquakes during volcanic unrest in terms of evolving hazard.

  9. A Scientific Excursion: Volcanoes.

    Science.gov (United States)

    Olds, Henry, Jr.

    1983-01-01

    Reviews an educationally valuable and reasonably well-designed simulation of volcanic activity in an imaginary land. VOLCANOES creates an excellent context for learning information about volcanoes and for developing skills and practicing methods needed to study behavior of volcanoes. (Author/JN)

  10. Three-dimensional shallow velocity structure beneath Taal Volcano, Philippines

    Science.gov (United States)

    You, Shuei-Huei; Konstantinou, Konstantinos I.; Gung, Yuancheng; Lin, Cheng-Horng

    2017-07-01

    Based on its numerous historical explosive eruptions and high potential hazards to nearby population of millions, Taal Volcano is one of the most dangerous "Decade Volcanoes" in the world. To provide better investigation on local seismicity and seismic structure beneath Taal Volcano, we deployed a temporary seismic network consisting of eight stations from March 2008 to March 2010. In the preliminary data processing stage, three periods showing linear time-drifting of internal clock were clearly identified from noise-derived empirical Green's functions. The time-drifting errors were corrected prior to further data analyses. By using VELEST, 2274 local earthquakes were manually picked and located. Two major earthquake groups are noticed, with one lying beneath the western shore of Taal Lake showing a linear feature, and the other spreading around the eastern flank of Taal Volcano Island at shallower depths. We performed seismic tomography to image the 3D structure beneath Taal Volcano using the LOTOS algorithm. Some interesting features are revealed from the tomographic results, including a solidified magma conduit below the northwestern corner of Taal Volcano Island, indicated by high Vp, Vs, and low Vp/Vs ratio, and a large potential hydrothermal reservoir beneath the center of Taal Volcano Island, suggested by low Vs and high Vp/Vs ratio. Furthermore, combining earthquake distributions and tomographic images, we suggest potential existence of a hydrothermal reservoir beneath the southwestern corner of Taal Lake, and a fluid conduit extending to the northwest. These seismic features have never been proposed in previous studies, implying that new hydrothermal activity might be formed in places away from the historical craters on Taal Volcano Island.

  11. Impact of Mood Spectrum Spirituality and Mysticism Symptoms on Suicidality in Earthquake Survivors with PTSD.

    Science.gov (United States)

    Carmassi, Claudia; Stratta, P; Calderani, E; Bertelloni, C A; Menichini, M; Massimetti, E; Rossi, A; Dell'Osso, L

    2016-04-01

    The aim of the present study was to explore the correlations between Spirituality/Mysticism/Psychoticism symptoms and suicidality in young adult survivors of the L'Aquila earthquake. The sample included 475 subjects recruited among high school seniors who had experienced the April 6, 2009, earthquake. Assessments included: Trauma and Loss Spectrum-Self Report and Mood Spectrum-Self Report (MOODS-SR). Mysticism/Spirituality dimension and suicidality were evaluated by means of some specific items of the MOOD-SR. The Spirituality/Mysticism/Psychoticism MOODS-SR factor score was significantly higher among subjects with PTSD diagnosis with respect to those without. Similarly, subjects with suicidal ideation, as well as those who committed a suicide attempt, reported significantly higher scores than those without.

  12. Coping with disaster: general practitioners' perspectives on the impact of the canterbury earthquakes.

    Science.gov (United States)

    Johal, Sarb; Mounsey, Zoe; Tuohy, Robyn; Johnston, David

    2014-04-02

    Aim - To explore the challenges for general practitioners (GPs) following the 2010/2011 Canterbury earthquakes and describe how these were met. Methods - Qualitative study using semi-structured interviews with eight GPs from the Christchurch area exploring their experiences. Results - The interviews revealed that the GPs faced a range of challenges both in the immediate aftermath of the earthquakes and in the following months. These included dealing with an increased and changed workload, and managing personal concerns. The GPs reflected on their coping behaviour and how their professional practice had changed as a result. Conclusions - All GPs reported significant increases in workload raising questions about the need for coordination of locum support. GPs often found themselves working outside their area of accustomed expertise especially in relation to patients needing financial aid. GPs identified a number of coping behaviours though some only in hindsight. Greater awareness of self-care strategies would benefit GPs responding to disasters.

  13. Seismicity at Fuego, Pacaya, Izalco, and San Cristobal Volcanoes, Central America, 1973-1974

    Science.gov (United States)

    McNutt, S.R.; Harlow, D.H.

    1983-01-01

    Seismic data collected at four volcanoes in Central America during 1973 and 1974 indicate three sources of seismicity: regional earthquakes with hypocentral distances greater than 80 km, earthquakes within 40 km of each volcano, and seismic activity originating at the volcanoes due to eruptive processes. Regional earthquakes generated by the underthrusting and subduction of the Cocos Plate beneath the Caribbean Plate are the most prominent seismic feature in Central America. Earthquakes in the vicinity of the volcanoes occur on faults that appear to be related to volcano formation. Faulting near Fuego and Pacaya volcanoes in Guatemala is more complex due to motion on a major E-W striking transform plate boundary 40 km north of the volcanoes. Volcanic activity produces different kinds of seismic signatures. Shallow tectonic or A-type events originate on nearby faults and occur both singly and in swarms. There are typically from 0 to 6 A-type events per day with b value of about 1.3. At very shallow depths beneath Pacaya, Izalco, and San Cristobal large numbers of low-frequency or B-type events are recorded with predominant frequencies between 2.5 and 4.5 Hz and with b values of 1.7 to 2.9. The relative number of B-type events appears to be related to the eruptive states of the volcanoes; the more active volcanoes have higher levels of seismicity. At Fuego Volcano, however, low-frequency events have unusually long codas and appear to be similar to tremor. High-amplitude volcanic tremor is recorded at Fuego, Pacaya, and San Cristobal during eruptive periods. Large explosion earthquakes at Fuego are well recorded at five stations and yield information on near-surface seismic wave velocities (??=3.0??0.2 km/sec.). ?? 1983 Intern. Association of Volcanology and Chemistry of the Earth's Interior.

  14. The impact evaluation of soil liquefaction on low-rise building in the Meinong earthquake

    Science.gov (United States)

    Lu, Chih-Chieh; Hwang, Jin-Hung; Hsu, Shang-Yi

    2017-08-01

    This paper presents major preliminary observations on the liquefaction-induced damages in the Meinong earthquake ( M L = 6.4). The severe damages to buildings centered on Huian and Sanmin Streets in Tainan City where the places were reclaimed fish or farm ponds with poor construction quality from many decades ago. To better understand the effect due to the soil liquefaction at these sites, the information provided by the in situ 13 Standard Penetration Test boreholes and 5 Cone Penetration Test soundings accompanying with the PGAs derived from the near seismographs was used to conduct the soil liquefaction evaluation by the Seed method (Seed et al. in J Geotech Eng ASCE 111(12):1425-1445, 1985) when subject to the Meinong earthquake. The liquefaction potential index (LPI) was then evaluated accordingly. From the results, it was found that the estimated damage severity was not consistent to the field conditions if the local site effect was not taken into account. To better reflect the site response in such sites, the sites' PGAs in the PGA contour map were multiplied by 1.5 times to quantify the amplification effects due to the soft geological condition. In addition, the PGAs based on other simple approaches were evaluated as well for comparison. Besides, the effects of fines content and magnitude scaling factor were also discussed in this paper. After that, several common simplified methods were also used to calculate the LPI when subject to the Meinong earthquake in order to evaluate the applicability of these simplified methods.

  15. A multi-scale risk assessment for tephra fallout and airborne concentration from multiple Icelandic volcanoes - Part 2: Vulnerability and impact

    Science.gov (United States)

    Scaini, C.; Biass, S.; Galderisi, A.; Bonadonna, C.; Folch, A.; Smith, K.; Höskuldsson, A.

    2014-08-01

    We perform a multi-scale impact assessment of tephra fallout and dispersal from explosive volcanic activity in Iceland. A companion paper (Biass et al., 2014; "A multi-scale risk assessment of tephra fallout and airborne concentration from multiple Icelandic volcanoes - Part I: hazard assessment") introduces a multi-scale probabilistic assessment of tephra hazard based on selected eruptive scenarios at four Icelandic volcanoes (Hekla, Askja, Eyjafjallajökull and Katla) and presents probabilistic hazard maps for tephra accumulation in Iceland and tephra dispersal across Europe. Here, we present the associated vulnerability and impact assessment that describes the importance of single features at national and European levels and considers several vulnerability indicators for tephra dispersal and deposition. At the national scale, we focus on physical, systemic and economic vulnerability of Iceland to tephra fallout, whereas at the European scale we focus on the systemic vulnerability of the air traffic system to tephra dispersal. This is the first vulnerability and impact assessment analysis of this type and, although it does not include all the aspects of physical and systemic vulnerability, it allows for identifying areas on which further specific analysis should be performed. Results include vulnerability maps for Iceland and European airspace and allow for the qualitative identification of the impacts at both scales in the case of an eruption occurring. Maps produced at the national scale show that tephra accumulation associated with all eruptive scenarios considered can disrupt the main electricity network, in particular in relation to an eruption of Askja. Results also show that several power plants would be affected if an eruption occurred at Hekla, Askja or Katla, causing a substantial systemic impact due to their importance for the Icelandic economy. Moreover, the Askja and Katla eruptive scenarios considered could have substantial impacts on agricultural

  16. Impact of the 2011 earthquake on marriages, births and the secondary sex ratio in Japan.

    Science.gov (United States)

    Hamamatsu, Yuri; Inoue, Yosuke; Watanabe, Chiho; Umezaki, Masahiro

    2014-11-01

    On 11th March 2011 a magnitude nine earthquake struck the Tohoku region of Japan. The earthquake resulted in a large tsunami and an accident at the Fukushima Nuclear Power Plant. Previous studies have suggested that demographic indices relating to reproduction and marriage change after such massive disasters (e.g. large earthquakes). The present study investigated whether the number of births, number of marriages and the secondary sex ratio (SSR) changed after the East Japan Earthquake. The monthly number of births (males and females, separately) and marriages in each prefecture in Japan from January 1997 to June 2012 were obtained from the Demographic Survey of Japan. An analysis was performed for three different geographic boundary units: the disaster-stricken area, the non-disaster-stricken area and the whole of Japan. In each unit, the numbers of births and marriages in a given month during the post-disaster period were predicted based on a regression equation estimated by the numbers of births and marriages in that month during the pre-disaster period. The numbers of observed monthly births and marriages during the post-disaster period were compared with the predicted figures. Differences between the observed and predicted numbers were determined by referring to the 95% confidence limits for the predicted mean number. The observed probability of a male birth in a given month during the post-disaster period was compared with a 95% confidence interval of a binominal distribution. In all three boundary units, the number of births was significantly lower than the predicted number by about 3-8% from nine months after the disaster, while the number of marriages in October 2011 was significantly lower than the predicted number by about 25-28%. In October 2011, the SSR in the whole of Japan had decreased from 104.8 (the predicted SSR) to 102.9. The number of births and marriages and the SSR decreased in Japan after the East Japan Earthquake irrespective of locality.

  17. Alaska volcanoes guidebook for teachers

    Science.gov (United States)

    Adleman, Jennifer N.

    2011-01-01

    Alaska’s volcanoes, like its abundant glaciers, charismatic wildlife, and wild expanses inspire and ignite scientific curiosity and generate an ever-growing source of questions for students in Alaska and throughout the world. Alaska is home to more than 140 volcanoes, which have been active over the last 2 million years. About 90 of these volcanoes have been active within the last 10,000 years and more than 50 of these have been active since about 1700. The volcanoes in Alaska make up well over three-quarters of volcanoes in the United States that have erupted in the last 200 years. In fact, Alaska’s volcanoes erupt so frequently that it is almost guaranteed that an Alaskan will experience a volcanic eruption in his or her lifetime, and it is likely they will experience more than one. It is hard to imagine a better place for students to explore active volcanism and to understand volcanic hazards, phenomena, and global impacts. Previously developed teachers’ guidebooks with an emphasis on the volcanoes in Hawaii Volcanoes National Park (Mattox, 1994) and Mount Rainier National Park in the Cascade Range (Driedger and others, 2005) provide place-based resources and activities for use in other volcanic regions in the United States. Along the lines of this tradition, this guidebook serves to provide locally relevant and useful resources and activities for the exploration of numerous and truly unique volcanic landscapes in Alaska. This guidebook provides supplemental teaching materials to be used by Alaskan students who will be inspired to become educated and prepared for inevitable future volcanic activity in Alaska. The lessons and activities in this guidebook are meant to supplement and enhance existing science content already being taught in grade levels 6–12. Correlations with Alaska State Science Standards and Grade Level Expectations adopted by the Alaska State Department of Education and Early Development (2006) for grades six through eleven are listed at

  18. Spreading and collapse of big basaltic volcanoes

    Science.gov (United States)

    Puglisi, Giuseppe; Bonforte, Alessandro; Guglielmino, Francesco; Peltier, Aline; Poland, Michael

    2016-04-01

    Among the different types of volcanoes, basaltic ones usually form the most voluminous edifices. Because volcanoes are growing on a pre-existing landscape, the geologic and structural framework of the basement (and earlier volcanic landforms) influences the stress regime, seismicity, and volcanic activity. Conversely, the masses of these volcanoes introduce a morphological anomaly that affects neighboring areas. Growth of a volcano disturbs the tectonic framework of the region, clamps and unclamps existing faults (some of which may be reactivated by the new stress field), and deforms the substratum. A volcano's weight on its basement can trigger edifice spreading and collapse that can affect populated areas even at significant distance. Volcano instability can also be driven by slow tectonic deformation and magmatic intrusion. The manifestations of instability span a range of temporal and spatial scales, ranging from slow creep on individual faults to large earthquakes affecting a broad area. In the frame of MED-SVU project, our work aims to investigate the relation between basement setting and volcanic activity and stability at three Supersite volcanoes: Etna (Sicily, Italy), Kilauea (Island of Hawaii, USA) and Piton de la Fournaise (La Reunion Island, France). These volcanoes host frequent eruptive activity (effusive and explosive) and share common features indicating lateral spreading and collapse, yet they are characterized by different morphologies, dimensions, and tectonic frameworks. For instance, the basaltic ocean island volcanoes of Kilauea and Piton de la Fournaise are near the active ends of long hotspot chains while Mt. Etna has developed at junction along a convergent margin between the African and Eurasian plates and a passive margin separating the oceanic Ionian crust from the African continental crust. Magma supply and plate velocity also differ in the three settings, as to the sizes of the edifices and the extents of their rift zones. These

  19. The seismicity of Marapi volcano, West Sumatra.

    Science.gov (United States)

    D'Auria, L.

    2009-04-01

    Marapi is one of the active volcanoes in West Sumatra. It is a stratovolcano with an edifice that is elongated in the ENE-WSW direction. Its elevation is about 2,900 m a.s.l. The summit area is characterized by a caldera that contains some active craters aligned along the ENE-WSW direction. The Marapi volcano is an attractive region for tourists and hosts many small communities its surrounding areas. The recent history of Mt. Marapi is characterized by explosive activity at the summit craters. No lava flows have passed the rim of the summit caldera in recent times. The last eruption occurred on August 5, 2004, and consisted of moderate explosive activity from the central crater. In 1975 an eruption with magmatic and phreatic explosive phases and mudflows and lahars occurred that caused fatalities in the surrounding areas. Since 1980 other eruptions have occurred at Marapi volcano. Even if the explosive intensities of those eruptions have been small to moderate, in some cases, there were fatalities. A cooperation project started between Italy and Indonesia (COVIN) for the monitoring of volcanoes in West Sumatra. In the context of this project a monitoring centre has been set up at the Bukittinggi Observatory and a seismological monitoring system for Marapi volcano has been realized. This system is based on a broadband seismic network including 4 three-component stations. The data acquired by the broadband network of Marapi volcano are continuous recordings of the seismic signals starting from 19/10/2006. Volcano-Tectonic and Long Period events of Marapi volcano together with regional and teleseismic earthquakes are recorded. Several events of high magnitude located at short distances from the network were also recorded such as on March 6, 2007, when two events of Magnitudes Mw 6.4 and 6.3 were recorded with the epicentres near the Marapi volcano. During the following days, there was a sequence of hundreds of aftershocks. The preliminary analysis of the seismicity of

  20. Imaging magma plumbing beneath Askja volcano, Iceland

    Science.gov (United States)

    Greenfield, Tim; White, Robert S.

    2015-04-01

    Volcanoes during repose periods are not commonly monitored by dense instrumentation networks and so activity during periods of unrest is difficult to put in context. We have operated a dense seismic network of 3-component, broadband instruments around Askja, a large central volcano in the Northern Volcanic Zone, Iceland, since 2006. Askja last erupted in 1961, with a relatively small basaltic lava flow. Since 1975 the central caldera has been subsiding and there has been no indication of volcanic activity. Despite this, Askja has been one of the more seismically active volcanoes in Iceland. The majority of these events are due to an extensive geothermal area within the caldera and tectonically induced earthquakes to the northeast which are not related to the magma plumbing system. More intriguing are the less numerous deeper earthquakes at 12-24km depth, situated in three distinct areas within the volcanic system. These earthquakes often show a frequency content which is lower than the shallower activity, but they still show strong P and S wave arrivals indicative of brittle failure, despite their location being well below the brittle-ductile boundary, which, in Askja is ~7km bsl. These earthquakes indicate the presence of melt moving or degassing at depth while the volcano is not inflating, as only high strain rates or increased pore fluid pressures would cause brittle fracture in what is normally an aseismic region in the ductile zone. The lower frequency content must be the result of a slower source time function as earthquakes which are both high frequency and low frequency come from the same cluster, thereby discounting a highly attenuating lower crust. To image the plumbing system beneath Askja, local and regional earthquakes have been used as sources to solve for the velocity structure beneath the volcano. Travel-time tables were created using a finite difference technique and the residuals were used to solve simultaneously for both the earthquake locations

  1. The effects of spatially varying earthquake impacts on mood and anxiety symptom treatments among long-term Christchurch residents following the 2010/11 Canterbury earthquakes, New Zealand.

    Science.gov (United States)

    Hogg, Daniel; Kingham, Simon; Wilson, Thomas M; Ardagh, Michael

    2016-09-01

    This study investigates the effects of disruptions to different community environments, community resilience and cumulated felt earthquake intensities on yearly mood and anxiety symptom treatments from the New Zealand Ministry of Health's administrative databases between September 2009 and August 2012. The sample includes 172,284 long-term residents from different Christchurch communities. Living in a better physical environment was associated with lower mood and anxiety treatment rates after the beginning of the Canterbury earthquake sequence whereas an inverse effect could be found for social community environment and community resilience. These results may be confounded by pre-existing patterns, as well as intensified treatment-seeking behaviour and intervention programmes in severely affected areas. Nevertheless, the findings indicate that adverse mental health outcomes can be found in communities with worse physical but stronger social environments or community resilience post-disaster. Also, they do not necessarily follow felt intensities since cumulative earthquake intensity did not show a significant effect.

  2. Urban Security Initiative: Earthquake impacts on the urban ``system of systems``

    Energy Technology Data Exchange (ETDEWEB)

    Maheshwari, S.; Jones, E.; Rasmussen, S.

    1999-06-01

    This paper is a discussion of how to address the problems of disasters in a large city, a project titled Urban Security Initiative undertaken by the Los Alamos National Laboratory. The paper first discusses the need to address the problems of disasters in large cities and ten provides a framework that is suitable to address this problem. The paper then provides an overview of the module of the project that deals with assessment of earthquake damage on urban infrastructure in large cities and an internet-based approach for consensus building leading to better coordination in the post-disaster period. Finally, the paper discusses the future direction of the project.

  3. Impact of tephra falls on Andean communities: The influences of eruption size and weather conditions during the 1999-2001 activity of Tungurahua volcano, Ecuador

    Science.gov (United States)

    Le Pennec, Jean-Luc; Ruiz, Gorki A.; Ramón, Patricio; Palacios, Enrique; Mothes, Patricia; Yepes, Hugo

    2012-03-01

    Repeated ash fall events have occurred during the 1999-ongoing eruption of Tungurahua volcano, Ecuador, notably during the late 1999 and August 2001 eruptive phases. While the eruptive styles were similar, these two phases had different impacts on nearby rural and urban Andean populations: ash falls in late 1999 had limited effects on human health and farming, whereas the 2001 phase resulted in medical problems, death of animals in livestock, and damages to houses and crops. Here we investigate the origin of this difference by estimating the size of the August 2001 event (VEI, magnitude, intensity), and by comparing monitoring information of the 1999 and 2001 phases (duration, explosion rate, column height, SO2 output rate). The results show that both phases ranked at VEI 3, although the longer 1999 phase was likely larger than the 2001 phase. Mass magnitude (M) and intensity (I) indexes calculated for the 2001 phase reach M ≈ 2.7 and I ≈ 6.5 when based on ash fall layer data, but increase to M ≈ 3.2 and I ≈ 7.0 when ballistic products are included. We investigated the influence of rain fall and wind flow regimes on ash dispersion, sedimentation and remobilization. The analysis indicates that the harmful effect of the 2001 phase resulted from unfavorable conditions that combined volcanological and seasonal origins, including: a) a low elevation of the ash plume above rural regions owed to a usually bent-over column, b) ash sedimentation in a narrow area west of the volcano under sub-steady wind directions, c) anticipated ash settling by frequent rain flushing of low intensity, and d) formation of a wet cohesive ash coating on buildings and harvests. Conversely, the stronger 1999 phase injected a large amount of ash at higher elevation in the dry season; the ash was widely disseminated across the whole Ecuadorian territory and beyond, and was frequently removed by rain and winds. In summary, our study illustrates the influences of eruption size and weather

  4. Defeating Earthquakes

    Science.gov (United States)

    Stein, R. S.

    2012-12-01

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

  5. Spectral analysis of dike-induced earthquakes in Afar, Ethiopia

    Science.gov (United States)

    Tepp, Gabrielle; Ebinger, Cynthia J.; Yun, Sang-Ho

    2016-04-01

    Shallow dike intrusions may be accompanied by fault slip above the dikes, a superposition which complicates seismic and geodetic data analyses. The diverse volcano-tectonic and low-frequency local earthquakes accompanying the 2005-2010 large-volume dike intrusions in the Dabbahu-Manda Hararo rift (Afar), some with fault displacements of up to 3 m at the surface, provide an opportunity to examine the relations among the earthquakes, dike intrusions, and surface ruptures. We apply the frequency index (FI) method to characterize the spectra of swarm earthquakes from six of the dikes. These earthquakes often have broad spectra with multiple peaks, making the usual peak frequency classification method unreliable. Our results show a general bimodal character with high FI earthquakes associated with deeper dikes (top > 3 km subsurface) and low FI earthquakes associated with shallow dikes, indicating that shallow dikes result in earthquakes with more low-frequency content and larger-amplitude surface waves. Low FI earthquakes are more common during dike emplacement, suggesting that interactions between the dike and faults may lead to lower FI. Taken together, likely source processes for low FI earthquakes are shallow hypocenters (<3 km) possibly with surface rupture, slow rupture velocities, and interactions with dike fluids. Strong site effects also heavily influence the earthquake spectral content. Additionally, our results suggest a continuum of spectral responses, implying either that impulsive volcano-tectonic earthquakes and the unusual, emergent earthquakes have similar source processes or that simple spectral analyses, such as FI, cannot distinguish different source processes.

  6. New DSM-5 PTSD guilt and shame symptoms among Italian earthquake survivors: Impact on maladaptive behaviors.

    Science.gov (United States)

    Carmassi, Claudia; Bertelloni, Carlo Antonio; Gesi, Camilla; Conversano, Ciro; Stratta, Paolo; Massimetti, Gabriele; Rossi, Alessandro; Dell'Osso, Liliana

    2017-05-01

    Important changes were introduced concerning posttraumatic-stress disorder (PTSD) by the DSM-5 recognizing the role of negative emotions such as guilt and shame, but little evidence is yet available on their prevalence in population assessed by means of DSM-5 criteria. In this study we explored the rates of guilt and shame DSM-5 PTSD diagnostic symptoms among Italian survivors to a massive earthquake and their possible correlation with PTSD and maladaptive behaviors. 869 residents of the town of L'Aquila exposed to the earthquake of April 6th, 2009 were investigated by the Trauma and Loss Spectrum-Self Report (TALS-SR) with particular attention to guilt and shame feelings. DSM-5 symptomatological PTSD was reported by 41.7% of survivors, further 11.6% endorsed at least one guilt/shame symptoms, with significantly higher rates of endorsement were in PTSD respect to No-PTSD subjects, and in the subgroup with at least one maladaptive behavior respect to those with none. There was a significant main effects of PTSD and at least one guilt/shame symptom on TALS-SR symptomatological domains. Mean TALS-SR Maladaptive coping domain score appeared significantly higher in the subgroup with at least one guilt/shame symptom. Further study are needed to investigate guilt and shame feelings in survivors to a natural disaster. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  7. Volcanoes: Nature's Caldrons Challenge Geochemists.

    Science.gov (United States)

    Zurer, Pamela S.

    1984-01-01

    Reviews various topics and research studies on the geology of volcanoes. Areas examined include volcanoes and weather, plate margins, origins of magma, magma evolution, United States Geological Survey (USGS) volcano hazards program, USGS volcano observatories, volcanic gases, potassium-argon dating activities, and volcano monitoring strategies.…

  8. If ionospheric and geomagnetic disturbances observed before strong earthquakes may result from simultaneous impact of space weather on all geospheres including solid earth

    Science.gov (United States)

    Khachikyan, Galina

    2016-07-01

    It is revealed in previous decades that ionospheric disturbances precede strong earthquakes, thus, the ionospheric precursors of strong earthquakes are now under developing [Pulinets and Boyarchuk, 2004]. Simultaneously, it is revealed that strong earthquakes may be preceded by geomagnetic disturbances as well, as a result, the geomagnetic variations, for example, in the ULF band, are considered now as precursory signals [Fraser-Smith, 1990, doi/10.1029/GL017i009p01465]. At the same time, there is currently no reliable theory nor for ionospheric or to magnetic precursors of earthquakes. Moreover, several researches have reexamined some of above results and concluded that observed magnetic disturbances before strong earthquakes could be generated by other sources, such as global magnetic activity [e.g. Campbell, 2009, doi/10.1029/2008JA013932], and that ionospheric anomalies can also be an effect of the increase of the global magnetic activity [e. g. Masci and Thomas, 2015, doi:10.1002/2015RS005734]. Taking into account such conclusions, one may suggest that the observed ionospheric and geomagnetic disturbances before strong earthquakes might be due to simultaneous influence of a space weather on the complicated surrounding system including the solid earth. This report presents some statistical results to prove such suggestion. In particular, it is shown [Khachikyan et al., 2012, doi:10.4236/ijg.2012.35109] that maximal possible earthquake magnitude (seismic potential) can be determined, in first approximation, on the base of geomagnetic Z-component measured in the Geocentric Solar Magnetosphere (GSM) coordinate system, in which the space weather impact on the earth's environment, due to reconnection of the solar wind magnetic field with the earth's magnetic field, is more ordered.

  9. Seismic unrest at Katla Volcano- southern Iceland

    Science.gov (United States)

    jeddi, zeinab; Tryggvason, Ari; Gudmundsson, Olafur; Bödvarsson, Reynir; SIL Seismology Group

    2014-05-01

    in seismicity arising from magma movement in the crust are characteristic properties of almost all active volcanoes. Meanwhile the study of the seismicity and propagation of elastic waves through the earth have the potential to give us important information about the internal structure of volcanoes. As very little is known of the 3D structure of Katla volcano and in order to define the 3D velocity structure and the geometry of the possible magma chamber, both P and S-wave travel time data from the most active period of seismicity (July-November 2011) are inverted simultaneously for both hypocenter locations and 3D velocity structure by using Local Earthquake Tomography (LET).

  10. Volcano seismology from around the world: Case studies from Mount Pinatubo (Philippines) Galeras (Colombia), Mount Wrangell and Mount Veniaminof (Alaska)

    Science.gov (United States)

    Sanchez-Aguilar, John Jairo

    A compilation of research papers in volcano seismology is presented: (1) to study the configuration of magma systems beneath volcanoes, (2) to describe unexpected effects of the shaking from a regional earthquake on volcanic systems, and (3) to integrate seismicity investigations into a conceptual model for the magma system of a volcano. This work was undertaken because much research in volcano seismology is needed to help in hazard assessment. The possible configuration of magma systems beneath Mount Pinatubo, Philippines, and Galeras Volcano, Colombia, is studied with b-value mapping. We suggest models for earthquake-volcanoes interactions by studying the declines in local seismicity at Mt. Wrangell and Mt. Veniaminof, Alaska, following the 3 November 2002 Denali Fault Earthquake (DFE). Finally, a model for the magmatic-hydrothermal system beneath Mt. Veniaminof is proposed by deriving a velocity model and relocating the earthquakes, and by studying the temporal changes of frequencies and attenuation (Q) at the source of long-period (LP) events. Results from b-value mapping confirm that volcanoes are characterized by localized zones of high b-values, and also indicate that the internal structure of volcanoes is variable. Analyses of the background seismicity at Mt. Veniaminof suggest that earthquakes result from locally-induced stresses and that LP events may represent the response of a shallow hydrothermal system to heat input from below. The study of declines in seismicity at Mt. Wrangell and Mt. Veniaminof volcanoes following the DFE indicates that the dynamic shaking from regional shocks can physically damage a volcano and together with the static stress changes can affect the local seismicity for extended periods. We conclude that the use of simple methods allows a better understanding of the seismicity at volcanoes in Alaska, but most importantly in developing countries where the small number of seismograph stations puts challenging limitations for research.

  11. Field guides for excursions to the Nevado del Ruiz Volcano and to the Romeral Fault System (Colombia, in the frame of the Neotectonics of arc-continent collision concepts

    Directory of Open Access Journals (Sweden)

    Borrero Carlos

    2011-06-01

    Full Text Available Central Cordillera of Colombia near to the Nevado del Ruiz volcano, is a seismically active area above the subducting slab of the Nazca plate and deforming upper crust of the Andes. Buildings in the region require strengthening against the effects of both types of hazards: earthquakes and volcanoes. During these trips, we will discuss the 13
    November, 1985, Nevado del Ruiz Volcano eruption that destroyed the Armero city with about 22,000 deceases, as well the 25 January, 1999, Armenia earthquake (M 6.2 that killed about 2000 people and injured 4000 largely as the result of older, poorly 3 constructed buildings. The economic impact of the quake on the region was significant with about 8000 coffee farms either completely or partially destroyed and over 13,000 structures either partially damaged or completely destroyed.
    Both phenomena are associated to a large-transversal structure termed Caldas tear, which is controlling strong motion earthquakes and the Quaternary volcanism of the northern Andes.

  12. Foci of Volcanoes

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, I.

    1974-01-01

    One may assume a center of volcanic activities beneath the edifice of an active volcano, which is here called the focus of the volcano. Sometimes it may be a ''magma reservoir''. Its depth may differ with types of magma and change with time. In this paper, foci of volcanoes are discussed from the viewpoints of four items: (1) Geomagnetic changes related with volcanic activities; (2) Crustal deformations related with volcanic activities; (3) Magma transfer through volcanoes; and (4) Subsurface structure of calderas.

  13. Impact on Risk of Data-Constrained Inferences of the Variability of the Recurrence of Ground-Rupturing Earthquakes

    Science.gov (United States)

    Fitzenz, D. D.; Nyst, M.

    2015-12-01

    The concept of the time-dependence of the occurrence of large events on a given geologic structure emerged from the elastic rebound theory of Reid (1910). Models were developed or chosen to account for it. For the most part, those models need the long-term recurrence time, a measure of the allowed short-term variability of the recurrence time (e.g., the coefficient of variation CoV), and are applied in conjunction with the time since the last event whenever possible. Geologic estimates of the long-term have been used for a long time. CoV values, on the other hand, were first assigned usually through a logic-tree approach featuring a preferred value and one or two alternative values. Later-on a generic CoV value was determined on a global dataset (Elssworth et al 1999). It is only recently that earthquake timing data at a site have become numerous and high resolution enough to warrant data-constrained estimates of CoV. Whereas a logic-tree approach, meant to formulate epistemic uncertainties, leads to different (weighted) estimates of risk metrics, an approach in which the model parameters (such as CoV) are constrained by earthquake data presents a different view of risk uncertainty. Indeed, when the data are not informative, the resulting hazard rate curve vs. time since last event is flat. As information becomes integrated in the model, if the fault indeed exhibits a time-dependent behavior, the hazard rate curve shows variability with elapsed time. In terms of risk, a flat hazard rate translates into a time-independent view of risk whereas a time-varying hazard rate results in short-term variations in risk estimates. In this view, the hazard rate at a given time does not have an uncertainty associated to it (in the same way that a probability density function does not have an uncertainty associated to it). Its value integrates all the uncertainties coming from model and data. This approach allows a seamless update of risk metrics as new earthquake data becomes

  14. After the Earthquake: Impacts of Seismic Snow and Ice Redistribution in Langtang Valley, Nepal, on Glacier Mass Balances and Hydrological Regimes

    Science.gov (United States)

    Shea, J. M.; Ragettli, S.; Immerzeel, W.; Pellicciotti, F.; Miles, E. S.; Steiner, J. F.; Buri, P.; Kraaijenbrink, P. D. A.

    2015-12-01

    The magnitude 7.8 Gorkha Earthquake that struck Nepal on 25 April 2015 resulted in a catastrophic loss of life and property, and had major impacts in high mountain areas. The earthquake resulted in a number of massive ice avalanches in Langtang Valley that destroyed entire villages and killed over 300 people. We first conduct a remote sensing analysis of the entire catchment, and attempt to quantify the volumes of snow and ice redistributed through high-resolution optical imagery, thermal imagery, and DEM differencing. Where data are available we examine the impact on the surface mass balances of four major glaciers (Lirung, Shalbachaum, Langtang and Langshisha). Finally, we use the physically-based and fully distributed TOPKAPI model to simulate the impacts of the co-seismic snow and ice redistribution on the hydrology of the Langtang River.

  15. Darwin's triggering mechanism of volcano eruptions

    Science.gov (United States)

    Galiev, Shamil

    2010-05-01

    Charles Darwin wrote that ‘… the elevation of many hundred square miles of territory near Concepcion is part of the same phenomenon, with that splashing up, if I may so call it, of volcanic matter through the orifices in the Cordillera at the moment of the shock;…' and ‘…a power, I may remark, which acts in paroxysmal upheavals like that of Concepcion, and in great volcanic eruptions,…'. Darwin reports that ‘…several of the great chimneys in the Cordillera of central Chile commenced a fresh period of activity ….' In particular, Darwin reported on four-simultaneous large eruptions from the following volcanoes: Robinson Crusoe, Minchinmavida, Cerro Yanteles and Peteroa (we cite the Darwin's sentences following his The Voyage of the Beagle and researchspace. auckland. ac. nz/handle/2292/4474). Let us consider these eruptions taking into account the volcano shape and the conduit. Three of the volcanoes (Minchinmavida (2404 m), Cerro Yanteles (2050 m), and Peteroa (3603 m)) are stratovolcanos and are formed of symmetrical cones with steep sides. Robinson Crusoe (922 m) is a shield volcano and is formed of a cone with gently sloping sides. They are not very active. We may surmise, that their vents had a sealing plug (vent fill) in 1835. All these volcanoes are conical. These common features are important for Darwin's triggering model, which is discussed below. The vent fill material, usually, has high level of porosity and a very low tensile strength and can easily be fragmented by tension waves. The action of a severe earthquake on the volcano base may be compared with a nuclear blast explosion of the base. It is known, that after a underground nuclear explosion the vertical motion and the surface fractures in a tope of mountains were observed. The same is related to the propagation of waves in conical elements. After the explosive load of the base. the tip may break and fly off at high velocity. Analogous phenomenon may be generated as a result of a

  16. 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

  17. Earthquake engineering in Peru

    Science.gov (United States)

    Vargas, N.J

    1983-01-01

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

  18. Modeling the reactive halogen plume from Ambrym volcano and its impact on the troposphere with the CCATT-BRAMS mesoscale model

    Directory of Open Access Journals (Sweden)

    L. Jourdain

    2015-12-01

    Full Text Available Ambrym volcano (Vanuatu, Southwest Pacific is one of the largest sources of continuous volcanic emissions worldwide. As well as releasing SO2 that is oxidized to sulfate, volcanic plumes in the troposphere are shown to undergo reactive halogen chemistry whose atmospheric impacts have been little explored to date. Here, two-way nested simulations were performed with the regional scale model CCATT-BRAMS to test our understanding of the volcano plume chemical processing and to assess the impact of Ambrym on atmospheric chemistry at local and regional scales. We focus on an episode of extreme passive degassing that occurred in early 2005 and for which airborne DOAS measurements of SO2 and BrO columns, in the near downwind plume, have been reported. The model was developed to include reactive halogen chemistry and a volcanic emission source specific to this extreme degassing event. SO2 simulated columns show very good quantitative agreement with the DOAS observations as well as with OMI data, suggesting that the plume direction as well as its dilution are well represented. Simulations are presented with and without a high-temperature initialization that includes radicals formed by high temperature partial oxidation of magmatic gases by ambient air. When included high-temperature chemistry initialization, the model is able to capture the observed BrO/SO2 trend with distance from the vent in the near downwind plume. However, the maximum of BrO columns enhancement is still underestimated by a factor 3. The model identifies total in-plume depletion of ozone (15 ppbv as a limiting factor to the partitioning of reactive bromine into BrO, of particular importance in this very strong plume at low background ozone conditions. Impacts of Ambrym in the Southwest Pacific region were also evaluated. As the plume disperses regionally, reactive halogen chemistry continues on sulfate aerosols produced by SO2 oxidation and promotes BrCl formation. Ozone depletion is

  19. Economic impact of explosive volcanic eruptions: A simulation-based assessment model applied to Campania region volcanoes

    Science.gov (United States)

    Zuccaro, Giulio; Leone, Mattia Federico; Del Cogliano, Davide; Sgroi, Angelo

    2013-10-01

    PLINIVS Study Centre of University of Naples Federico II has developed a methodology that aims to estimate, in probabilistic terms, the direct and the indirect economic impacts of a Sub-Plinian I or Strombolian type eruption of Vesuvius. The economic model has been implemented as a complementary tool of the Volcanic Impact Simulation Model, a tool developed at PLINIVS Center available to the Italian Civil Protection Department (DPC) decision makers to quantify the potential losses consequent to a possible eruption of Vesuvius or Campi Flegrei. Along the expected time history of the eruptive event all the possible "direct costs" and the "factors" (indirect costs) impacting the economic growth in the event area have been identified. Each cost factor is built up through a specific algorithm that is fed by various providers, in order to run software that will estimate the global amount of economic damage from a volcanic event. The model does not include the economic evaluation of intangibles (e.g. human casualties), while the evaluation of damage to the local cultural heritage (historical buildings, archeological sites, monuments, etc.), is linked to the economic impact on tourism, estimated into indirect costs. The architecture of the model is based on a simulation logic, which allows an evaluation of different economic impact scenarios through input changes, allowing the model to be used as a tool to support the decision making process.

  20. Field Geological Exploration of the Ashikule Volcano Group in Western Kunlun Mountains

    Institute of Scientific and Technical Information of China (English)

    Xu Jiandong; Zhao Bo; Zhang Liuyi; Chen Zhengquan

    2012-01-01

    From May 4 to May 30, 2011, a field exploration of the Ashikule basin in the Western Kunlun Mountains area was conducted by a research team from the Institute of Geology, China Earthquake Administration and Earthquake Administration of Xinjiang Uygur Autonomous Region. This work is financially supported by the special fund for China earthquake research project " The Comprehensive Scientific Exploration of the Ms7.3 Yutian Earthquake in 2008 and the Ashikule Volcano Group". Through detailed field survey on geological and geomorphological features of the Ashikule volcano group, which is one of the highest altitude volcanic plateaus (about 5000m) in the world, we have determined the total number of volcanoes, the eruption type and structural parameters, and approximate active history of the volcano group. Our studies have provided field evidence for resolving past controversies such as the authenticity of the news report about the eruption event on May 27, 1951, the eruption pattern of the Daheishan volcano, and the reality of the Gaotaishan volcano.

  1. Seismic vulnerability of dwellings at Sete Cidades Volcano (S. Miguel Island, Azores

    Directory of Open Access Journals (Sweden)

    A. Gomes

    2006-01-01

    Full Text Available Since the settlement of S. Miguel Island (Azores, in the XV century, several earthquakes caused important human losses and severe damages on the island. Sete Cidades Volcano area, located in the westernmost part of the island, was attained by strong seismic crises of tectonic and volcanic origin and major events reached a maximum historical intensity of IX (European Macroseismic Scale 1998 in this zone. Aiming to evaluate the impact of a future major earthquakes, a field survey was carried out in ten parishes of Ponta Delgada County, located on the flanks of Sete Cidades volcano and inside it is caldera. A total of 7019 buildings were identified, being 4351 recognized as dwellings. The total number of inhabitants in the studied area is 11429. In this work, dwellings were classified according to their vulnerability to earthquakes (Classes A to F, using the structure types table of the EMS-98, adapted to the types of constructions made in the Azores. It was concluded that 76% (3306 of the houses belong to Class A, and 17% (740 to Class B, which are the classes of higher vulnerability. If the area is affected by a seismic event with intensity IX it is estimated, that 57% (2480 to 77% (3350 of the dwellings will partially or totally collapse and 15% (652 to 25% (1088 will need to be rehabilitated. In this scenario, considering the average of inhabitants per house for each parish, 82% (9372 to 92% (10515 of the population will be affected. The number of deaths, injured and dislodged people will pose severe problems to the civil protection authorities and will cause social and economic disruption in the entire archipelago.

  2. Seismic vulnerability of dwellings at Sete Cidades Volcano (S. Miguel Island, Azores)

    Science.gov (United States)

    Gomes, A.; Gaspar, J. L.; Queiroz, G.

    2006-01-01

    Since the settlement of S. Miguel Island (Azores), in the XV century, several earthquakes caused important human losses and severe damages on the island. Sete Cidades Volcano area, located in the westernmost part of the island, was attained by strong seismic crises of tectonic and volcanic origin and major events reached a maximum historical intensity of IX (European Macroseismic Scale 1998) in this zone. Aiming to evaluate the impact of a future major earthquakes, a field survey was carried out in ten parishes of Ponta Delgada County, located on the flanks of Sete Cidades volcano and inside it is caldera. A total of 7019 buildings were identified, being 4351 recognized as dwellings. The total number of inhabitants in the studied area is 11429. In this work, dwellings were classified according to their vulnerability to earthquakes (Classes A to F), using the structure types table of the EMS-98, adapted to the types of constructions made in the Azores. It was concluded that 76% (3306) of the houses belong to Class A, and 17% (740) to Class B, which are the classes of higher vulnerability. If the area is affected by a seismic event with intensity IX it is estimated, that 57% (2480) to 77% (3350) of the dwellings will partially or totally collapse and 15% (652) to 25% (1088) will need to be rehabilitated. In this scenario, considering the average of inhabitants per house for each parish, 82% (9372) to 92% (10515) of the population will be affected. The number of deaths, injured and dislodged people will pose severe problems to the civil protection authorities and will cause social and economic disruption in the entire archipelago.

  3. Three-axial Fiber Bragg Grating Strain Sensor for Volcano Monitoring

    Science.gov (United States)

    Giacomelli, Umberto; Beverini, Nicolò; Carbone, Daniele; Carelli, Giorgio; Francesconi, Francesco; Gambino, Salvatore; Maccioni, Enrico; Morganti, Mauro; Orazi, Massimo; Peluso, Rosario; Sorrentino, Fiodor

    2017-04-01

    Fiber optic and FBGs sensors have attained a large diffusion in the last years as cost-effective monitoring and diagnostic devices in civil engineering. However, in spite of their potential impact, these instruments have found very limited application in geophysics. In order to study earthquakes and volcanoes, the measurement of crustal deformation is of crucial importance. Stress and strain behaviour is among the best indicators of changes in the activity of volcanoes .. Deep bore-hole dilatometers and strainmeters have been employed for volcano monitoring. These instruments are very sensitive and reliable, but are not cost-effective and their installation requires a large effort. Fiber optic based devices offer low cost, small size, wide frequency band, easier deployment and even the possibility of creating a local network with several sensors linked in an array. We present the realization, installation and first results of a shallow-borehole (8,5 meters depth) three-axial Fiber Bragg Grating (FBG) strain sensor prototype. This sensor has been developed in the framework of the MED-SUV project and installed on Etna volcano, in the facilities of the Serra La Nave astrophysical observatory. The installation siteis about 7 Km South-West of the summit craters, at an elevation of about 1740 m. The main goal of our work is the realization of a three-axial device having a high resolution and accuracy in static and dynamic strain measurements, with special attention to the trade-off among resolution, cost and power consumption. The sensor structure and its read-out system are innovative and offer practical advantages in comparison with traditional strain meters. Here we present data collected during the first five months of operation. In particular, the very clear signals recorded in the occurrence of the Central Italy seismic event of October 30th demonstrate the performances of our device.

  4. Nowcasting Earthquakes

    Science.gov (United States)

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

    2016-12-01

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

  5. Earthquake Facts

    Science.gov (United States)

    Jump to Navigation Earthquake Facts The largest recorded earthquake in the United States was a magnitude 9.2 that struck Prince William Sound, ... we know, there is no such thing as "earthquake weather" . Statistically, there is an equal distribution of ...

  6. Nowcasting earthquakes

    Science.gov (United States)

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

    2016-11-01

    Nowcasting is a term originating from economics and finance. It refers to the process of determining the uncertain state of the economy or markets at the current time by indirect means. We apply this idea to seismically active regions, where the goal is to determine the current state of the fault system and its current level of progress through the earthquake cycle. In our implementation of this idea, we use the global catalog of earthquakes, using "small" earthquakes to determine the level of hazard from "large" earthquakes in the region. Our method does not involve any model other than the idea of an earthquake cycle. Rather, we define a specific region and a specific large earthquake magnitude of interest, ensuring that we have enough data to span at least 20 or more large earthquake cycles in the region. We then compute the earthquake potential score (EPS) which is defined as the cumulative probability distribution P(n < n(t)) for the current count n(t) for the small earthquakes in the region. From the count of small earthquakes since the last large earthquake, we determine the value of EPS = P(n < n(t)). EPS is therefore the current level of hazard and assigns a number between 0% and 100% to every region so defined, thus providing a unique measure. Physically, the EPS corresponds to an estimate of the level of progress through the earthquake cycle in the defined region at the current time.

  7. ACTIVITY AND Vp/Vs RATIO OF VOLCANO-TECTONIC SEISMIC SWARM ZONES AT NEVADO DEL RUIZ VOLCANO, COLOMBIA

    Directory of Open Access Journals (Sweden)

    Londoño B. John Makario

    2010-06-01

    Full Text Available An analysis of the seismic activity for volcano-tectonic earthquake (VT swarms zones at Nevado del Ruiz Volcano (NRV was carried out for the interval 1985- 2002, which is the most seismic active period at NRV until now (2010. The swarm-like seismicity of NRV was frequently concentrated in very well defined clusters around the volcano. The seismic swarm zone located at the active crater was the most active during the entire time. The seismic swarm zone located to the west of the volcano suggested some relationship with the volcanic crises. It was active before and after the two eruptions occurred in November 1985 and September 1989. It is believed that this seismic activity may be used as a monitoring tool of volcanic activity. For each seismic swarm zone the Vp/Vs ratio was also calculated by grouping of earthquakes and stations. It was found that each seismic swarm zone had a distinct Vp/Vs ratio with respect to the others, except for the crater and west swarm zones, which had the same value. The average Vp/Vs ratios for the seismic swarm zones located at the active crater and to the west of the volcano are about 6-7% lower than that for the north swarm zone, and about 3% lower than that for the south swarm zone. We suggest that the reduction of the Vp/Vs ratio is due to degassing phenomena inside the central and western earthquake swarm zones, or due to the presence of microcracks inside the volcano. This supposition is in agreement with other studies of geophysics, geochemistry and drilling surveys carried out at NRV.

  8. Impact of Uncertainty on Loss Estimates for a Repeat of the 1908 Messina-Reggio Calabria Earthquake in Southern Italy

    Science.gov (United States)

    Franco, Guillermo; Shen-Tu, BingMing; Goretti, Agostino; Bazzurro, Paolo; Valensise, Gianluca

    2008-07-01

    Increasing sophistication in the insurance and reinsurance market is stimulating the move towards catastrophe models that offer a greater degree of flexibility in the definition of model parameters and model assumptions. This study explores the impact of uncertainty in the input parameters on the loss estimates by departing from the exclusive usage of mean values to establish the earthquake event mechanism, the ground motion fields, or the damageability of the building stock. Here the potential losses due to a repeat of the 1908 Messina-Reggio Calabria event are calculated using different plausible alternatives found in the literature that encompass 12 event scenarios, 2 different ground motion prediction equations, and 16 combinations of damage functions for the building stock, a total of 384 loss scenarios. These results constitute the basis for a sensitivity analysis of the different assumptions on the loss estimates that allows the model user to estimate the impact of the uncertainty on input parameters and the potential spread of the model results. For the event under scrutiny, average losses would amount today to about 9.000 to 10.000 million Euros. The uncertainty in the model parameters is reflected in the high coefficient of variation of this loss, reaching approximately 45%. The choice of ground motion prediction equations and vulnerability functions of the building stock contribute the most to the uncertainty in loss estimates. This indicates that the application of non-local-specific information has a great impact on the spread of potential catastrophic losses. In order to close this uncertainty gap, more exhaustive documentation practices in insurance portfolios will have to go hand in hand with greater flexibility in the model input parameters.

  9. Far-Field Tsunami Impact in the North Atlantic Basin from Large Scale Flank Collapses of the Cumbre Vieja Volcano, La Palma

    Science.gov (United States)

    Tehranirad, Babak; Harris, Jeffrey C.; Grilli, Annette R.; Grilli, Stephan T.; Abadie, Stéphane; Kirby, James T.; Shi, Fengyan

    2015-12-01

    In their pioneering work, Ward and Day suggested that a large scale flank collapse of the Cumbre Vieja Volcano (CVV) on La Palma (Canary Islands) could trigger a mega-tsunami throughout the North Atlantic Ocean basin, causing major coastal impact in the far-field. While more recent studies indicate that near-field waves from such a collapse would be more moderate than originally predicted by Ward and Day [Løvholt et al. (J Geophy Res 113:C09026, 2008); Abadie et al. (J Geophy Res 117:C05030, 2012)], these would still be formidable and devastate the Canary Island, while causing major impact in the far-field at many locations along the western European, African, and the US east coasts. Abadie et al. (J Geophy Res 117:C05030, 2012) simulated tsunami generation and near-field tsunami impact from a few CVV subaerial slide scenarios, with volumes ranging from 20 to 450 km^3; the latter representing the most extreme scenario proposed by Ward and Day. They modeled tsunami generation, i.e., the tsunami source, using THETIS, a 3D Navier-Stokes (NS) multi-fluid VOF model, in which slide material was considered as a nearly inviscid heavy fluid. Near-field tsunami impact was then simulated for each source using FUNWAVE-TVD, a dispersive and fully nonlinear long wave Boussinesq model [ Shi et al. (Ocean Modell 43-44:36-51, 2012); Kirby et al. (Ocean Modeling, 62:39-55, 2013)]. Here, using FUNWAVE-TVD for a series of nested grids of increasingly fine resolution, we model and analyze far-field tsunami impact from two of Abadie et al.'s extreme CVV flank collapse scenarios: (i) that deemed the most "credible worst case scenario" based on a slope stability analysis, with a 80 km^3 volume; and (ii) the most extreme scenario, similar to Ward and Day's, with a 450 km^3 volume. Simulations are performed using a one-way coupling scheme in between two given levels of nested grids. Based on the simulation results, the overall tsunami impact is first assessed in terms of maximum surface

  10. Discussion on Earthquake Forecasting and Early Warning

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiaodong; Jiang Haikun; Li Mingxiao

    2008-01-01

    Through analysis of natural and social attributes of earthquake forecasting,the relationship between the natural and social attributes of earthquake forecasting (early warning) has been discussed.Regarding the natural attributes of earthquake forecasting,it only attempts to forecast the magnitude,location and occurrence time of future earthquake based on the aualysis of observational data and relevant theories and taking into consideration the present understanding of seismogeny and earthquake generation.It need not consider the consequences an earthquake forecast involves,and its purpose is to check out the level of scientific understanding of earthquakes.In respect of the social aspect of earthquake forecasting,people also focus on the consequence that the forecasting involves,in addition to its natural aspect,such as the uncertainty of earthquake prediction itself,the impact of earthquake prediction,and the earthquake resistant capability of structures (buildings),lifeline works,etc.In a word,it highlights the risk of earthquake forecasting and tries to mitigate the earthquake hazard as much as possible.In this paper,the authors also discuss the scientific and social challenges faced in earthquake prediction and analyze preliminarily the meanings and content of earthquake early warning.

  11. Ionospheric GPS TEC Anomalies and M >= 5.9 Earthquakes in Indonesia during 1993 - 2002

    Directory of Open Access Journals (Sweden)

    Sarmoko Saroso

    2008-01-01

    Full Text Available Indonesia is one of the most seismically active regions in the world, containing numerous active volcanoes and subject to frequent earthquakes with epicenters distributed along the same regions as volcanoes. In this paper, a case study is carried out to investigate pre-earthquake ionospheric anomalies in total electron content (TEC during the Sulawesi earthquakes of 1993 - 2002, and the Sumatra-Andaman earthquake of 26 December 2004, the largest earthquake in the world since 1964. It is found that the ionospheric TECs remarkably decrease within 2 - 7 days before the earthquakes, and for the very powerful Sumatra-Andaman earthquake, the anomalies extend up to about 1600 km from the epicenter.

  12. Volcano Monitoring Using Google Earth

    Science.gov (United States)

    Cameron, W.; Dehn, J.; Bailey, J. E.; Webley, P.

    2009-12-01

    At the Alaska Volcano Observatory (AVO), remote sensing is an important component of its daily monitoring of volcanoes. AVO’s remote sensing group (AVORS) primarily utilizes three satellite datasets; Advanced Very High Resolution Radiometer (AVHRR) data, from the National Oceanic and Atmospheric Administration’s (NOAA) Polar Orbiting Satellites (POES), Moderate Resolution Imaging Spectroradiometer (MODIS) data from the National Aeronautics and Space Administration’s (NASA) Terra and Aqua satellites, and NOAA’s Geostationary Operational Environmental Satellites (GOES) data. AVHRR and MODIS data are collected by receiving stations operated by the Geographic Information Network of Alaska (GINA) at the University of Alaska’s Geophysical Institute. An additional AVHRR data feed is supplied by NOAA’s Gilmore Creek satellite tracking station. GOES data are provided by the Naval Research Laboratory (NRL), Monterey Bay. The ability to visualize these images and their derived products is critical for the timely analysis of the data. To this end, AVORS has developed javascript web interfaces that allow the user to view images and metadata. These work well for internal analysts to quickly access a given dataset, but they do not provide an integrated view of all the data. To do this AVORS has integrated its datasets with Keyhole Markup Language (KML) allowing them to be viewed by a number of virtual globes or other geobrowsers that support this code. Examples of AVORS’ use of KML include the ability to browse thermal satellite image overlays to look for signs of volcanic activity. Webcams can also be viewed interactively through KML to confirm current activity. Other applications include monitoring the location and status of instrumentation; near real-time plotting of earthquake hypocenters; mapping of new volcanic deposits using polygons; and animated models of ash plumes, created by a combination of ash dispersion modeling and 3D visualization packages.

  13. Geoheritage value of the UNESCO site at Leon Viejo and Momotombo volcano, Nicaragua

    Science.gov (United States)

    van Wyk de Vries, Benjamin; Navarro, Martha; Espinoza, Eveling; Delgado, Hugo

    2017-04-01

    The Momotombo volcano has a special place in the history of Nicaragua. It is perfectly visible from the Capital, Managua, and from the major city of Leon. The old capital "Leon Viejo", founded in 1524 was abandoned in 1610, after a series of earthquakes and some major eruptions from Momotombo. The site was subsequently covered by Momotombo ash. A major geothermal power plant stands at the base of the volcano. Momotombo had been dormant for a hundred years, but had maintained high fumarole temperatures (900°C), indicating magma had been close to the surface for decades. In recent years, seismic activity has increased around the volcano. In December 2015, after a short ash eruption phase the volcano erupted lava, then a string of Vulcanian explosions. The volcano is now in a phase of small Vulcanian explosions and degassing. The Leon Viejo World Heritage site is at risk to mainly ash fall from the volcano, but the abandonment of the old city was primarily due to earthquakes. Additional risks come from high rainfall during hurricanes. There is an obvious link between the cultural site (inscribed under UNESCO cultural criteria) and the geological environment. First, the reactivation of Momotombo volcano makes it more important to revise the hazard of the site. At the same time, Leon Viejo can provide a portal for outreach related to the volcano and for geological risk in general. To maximise this, we provide a geosite inventory of the main features of Momotombo, and it's environs, that can be used as the first base for such studies. The volcano was visited by many adventure tourists before the 2015/2016 eruption, but is out of bounds at present. Alternative routes, around the volcano could be made, to adapt to the new situation and to show to visitors more of the geodiversity of this fascinating volcano-tectonic and cultural area.

  14. Analysis of the impact of fault mechanism radiation patterns on macroseismic fields in the epicentral area of 1998 and 2004 Krn Mountains earthquakes (NW Slovenia).

    Science.gov (United States)

    Gosar, Andrej

    2014-01-01

    Two moderate magnitude (Mw = 5.6 and 5.2) earthquakes in Krn Mountains occurred in 1998 and 2004 which had maximum intensity VII-VIII and VI-VII EMS-98, respectively. Comparison of both macroseismic fields showed unexpected differences in the epicentral area which cannot be explained by site effects. Considerably, different distribution of the highest intensities can be noticed with respect to the strike of the seismogenic fault and in some localities even higher intensities have been estimated for the smaller earthquake. Although hypocentres of both earthquakes were only 2 km apart and were located on the same seismogenic Ravne fault, their focal mechanisms showed a slight difference: almost pure dextral strike-slip for the first event and a strike-slip with small reverse component on a steep fault plane for the second one. Seismotectonically the difference is explained as an active growth of the Ravne fault at its NW end. The radiation patterns of both events were studied to explain their possible impact on the observed variations in macroseismic fields and damage distribution. Radiation amplitude lobes were computed for three orthogonal directions: radial P, SV, and SH. The highest intensities of both earthquakes were systematically observed in directions of four (1998) or two (2004) large amplitude lobes in SH component (which corresponds mainly to Love waves), which have significantly different orientation for both events. On the other hand, radial P direction, which is almost purely symmetrical for the strike-slip mechanism of 1998 event, showed for the 2004 event that its small reverse component of movement has resulted in a very pronounced amplitude lobe in SW direction where two settlements are located which expressed higher intensities in the case of the 2004 event with respect to the 1998 one. Although both macroseismic fields are very complex due to influences of multiple earthquakes, retrofitting activity after 1998, site effects, and sparse

  15. Instability of Hawaiian volcanoes: Chapter 4 in Characteristics of Hawaiian volcanoes

    Science.gov (United States)

    Denlinger, Roger P.; Morgan, Julia K.; Poland, Michael P.; Takahashi, T. Jane; Landowski, Claire M.

    2014-01-01

    Hawaiian volcanoes build long rift zones and some of the largest volcanic edifices on Earth. For the active volcanoes on the Island of Hawai‘i, the growth of these rift zones is upward and seaward and occurs through a repetitive process of decades-long buildup of a magma-system head along the rift zones, followed by rapid large-scale displacement of the seaward flank in seconds to minutes. This large-scale flank movement, which may be rapid enough to generate a large earthquake and tsunami, always causes subsidence along the coast, opening of the rift zone, and collapse of the magma-system head. If magma continues to flow into the conduit and out into the rift system, then the cycle of growth and collapse begins again. This pattern characterizes currently active Kīlauea Volcano, where periods of upward and seaward growth along rift zones were punctuated by large (>10 m) and rapid flank displacements in 1823, 1868, 1924, and 1975. At the much larger Mauna Loa volcano, rapid flank movements have occurred only twice in the past 200 years, in 1868 and 1951.

  16. Impact of the Great East Japan Earthquake on Hotel Industry in Pacific Tohoku Prefectures ---From Spatio-Temporal Dependence of Hotel Availability---

    Science.gov (United States)

    Sato, A.

    This paper investigates the impact of the Great Japan Earthquake(and subsequent tsunami turmoil) on socio-economic activities by using data on hotel opportunities collected from an electronic hotel booking service. A method to estimate both primary and secondary regional effects of a natural disaster on human behavior is proposed. It is confirmed that temporal variation in the regional share of available hotels before and after a natural disaster may be an indicator to measure the socio-economic impact at each district.

  17. Impact of the Great East Japan Earthquake on Hotel Industry in Pacific Tohoku Prefectures: From spatio-temporal dependence of hotel availability

    CERN Document Server

    Sato, Aki-Hiro

    2012-01-01

    This paper investigates the impact of the Great Japan Earthquake (and subsequent tsunami turmoil) on socio-economic activities by using data on hotel opportunities collected from an electronic hotel booking service. A method to estimate both primary and secondary regional effects of a natural disaster on human behavior is proposed. It is confirmed that temporal variation in the regional share of available hotels before and after a natural disaster may be an indicator to measure the socio-economic impact at each district.

  18. Google Mapplets for Earthquakes and Volcanic Activity

    Science.gov (United States)

    Haefner, S. A.; Venezky, D. Y.

    2007-12-01

    The USGS Earthquake and Volcano Hazards Programs monitor, assess, and issue warnings of natural hazards. Users can access our hazards information through our web pages, RSS feeds, and now through USGS Mapplets. Mapplets allow third party data layers to be added on top of Google Maps (http://maps.google.com - My Maps tab). Mapplets are created by parsing a GeoRSS feed, which involves searching through an XML file for location data and plotting the associated information on a map. The new Mapplets allow users to view both real-time earthquakes and current volcanic activity on the same map for the first time. In addition, the USGS Mapplets have been added to Google's extensive collection of Mapplets, allowing users to add the types of information they want to see on their own customized maps. The Earthquake Mapplet plots the past week of earthquakes around the world, showing the location, time and magnitude. The Volcano Mapplet displays the latest U.S. volcano updates, including the current level of both ground-based and aviation hazards. Join us to discuss how Mapplets are made and how they can be used to create your own customized map.

  19. Volcanoes - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer includes Holocene volcanoes, which are those thought to be active in the last 10,000 years, that are within an extended area of the northern...

  20. Italian active volcanoes

    Institute of Scientific and Technical Information of China (English)

    RobertoSantacroce; RenawCristofolini; LuigiLaVolpe; GiovanniOrsi; MauroRosi

    2003-01-01

    The eruptive histories, styles of activity and general modes of operation of the main active Italian volcanoes,Etna, Vulcano, Stromboli, Vesuvio, Campi Flegrei and Ischia, are described in a short summary.

  1. 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.

  2. Acute stress-related psychological impact in children following devastating natural disaster, the Sikkim earthquake (2011), India

    National Research Council Canada - National Science Library

    Rakesh Mondal; Sumantra Sarkar; Indira Banerjee; Avijit Hazra; Debabrata Majumder; Tapas Sabui; Sudip Dutta; Abhisek Saren; Partha Pan

    2013-01-01

    Background: Psychological stress following natural disaster is common. Despite several earthquakes in India, data on evaluation of acute stress among the child victims in the early postdisaster period is scarce...

  3. Acute stress-related psychological impact in children following devastating natural disaster, the Sikkim earthquake (2011), India

    National Research Council Canada - National Science Library

    Mondal, Rakesh; Sarkar, Sumantra; Banerjee, Indira; Hazra, Avijit; Majumder, Debabrata; Sabui, Tapas; Dutta, Sudip; Saren, Abhisek; Pan, Partha

    2013-01-01

    Psychological stress following natural disaster is common. Despite several earthquakes in India, data on evaluation of acute stress among the child victims in the early postdisaster period is scarce...

  4. Brief Communication: On the source characteristics and impacts of the magnitude 7.2 Bohol earthquake, Philippines

    Science.gov (United States)

    Lagmay, A. M. F.; Eco, R.

    2014-10-01

    A devastating earthquake struck Bohol, Philippines, on 15 October 2013. The earthquake originated at 12 km depth from an unmapped reverse fault, which manifested on the surface for several kilometers and with maximum vertical displacement of 3 m. The earthquake resulted in 222 fatalities with damage to infrastructure estimated at USD 52.06 million. Widespread landslides and sinkholes formed in the predominantly limestone region during the earthquake. These remain a significant threat to communities as destabilized hillside slopes, landslide-dammed rivers and incipient sinkholes are still vulnerable to collapse, triggered possibly by aftershocks and heavy rains in the upcoming months of November and December. The most recent fatal temblor originated from a previously unmapped fault, herein referred to as the Inabanga Fault. Like the hidden or previously unmapped faults responsible for the 2012 Negros and 2013 Bohol earthquakes, there may be more unidentified faults that need to be mapped through field and geophysical methods. This is necessary to mitigate the possible damaging effects of future earthquakes in the Philippines.

  5. The impact of major earthquakes on the psychological functioning of medical students: a Christchurch, New Zealand study.

    Science.gov (United States)

    Carter, Frances A; Bell, Caroline J; Ali, Anthony N; McKenzie, Janice; Wilkinson, Timothy J

    2014-07-18

    No previous studies have systematically assessed the psychological functioning of medical students following a major disaster. To describe the psychological functioning of medical students following the earthquakes in Canterbury, New Zealand, and identify predictors of adverse psychological functioning. 7 months following the most severe earthquake, medical students completed the Depression, Anxiety and Stress Scale (DASS), the Post-Traumatic Stress Disorder Checklist, the Eysenck Personality Questionnaire, the Connor Davidson Resilience Scale, the Work and Adjustment Scale, and Likert scales assessing psychological functioning at worst and currently. A substantial minority of medical students reported moderate-extreme difficulties on the DASS subscales 7 months following the most severe earthquake (Depression =12%; Anxiety =9%; Stress =10%). Multiple linear modelling produced a model that predicted 27% of the variance in total scores on the DASS. Variables contributing significantly to the model were: year of medical course, presence of mental health problems prior to the earthquakes, not being New Zealand European, and being higher on retrospectively rated neuroticism prior to the earthquakes. Around 10% of medical students experienced moderate-extreme psychological difficulties 7 months following the most severe earthquake on 22 February 2011. Specific groups at high risk for ongoing psychological symptomatology were able to be identified.

  6. Global Volcano Model

    Science.gov (United States)

    Sparks, R. S. J.; Loughlin, S. C.; Cottrell, E.; Valentine, G.; Newhall, C.; Jolly, G.; Papale, P.; Takarada, S.; Crosweller, S.; Nayembil, M.; Arora, B.; Lowndes, J.; Connor, C.; Eichelberger, J.; Nadim, F.; Smolka, A.; Michel, G.; Muir-Wood, R.; Horwell, C.

    2012-04-01

    Over 600 million people live close enough to active volcanoes to be affected when they erupt. Volcanic eruptions cause loss of life, significant economic losses and severe disruption to people's lives, as highlighted by the recent eruption of Mount Merapi in Indonesia. The eruption of Eyjafjallajökull, Iceland in 2010 illustrated the potential of even small eruptions to have major impact on the modern world through disruption of complex critical infrastructure and business. The effects in the developing world on economic growth and development can be severe. There is evidence that large eruptions can cause a change in the earth's climate for several years afterwards. Aside from meteor impact and possibly an extreme solar event, very large magnitude explosive volcanic eruptions may be the only natural hazard that could cause a global catastrophe. GVM is a growing international collaboration that aims to create a sustainable, accessible information platform on volcanic hazard and risk. We are designing and developing an integrated database system of volcanic hazards, vulnerability and exposure with internationally agreed metadata standards. GVM will establish methodologies for analysis of the data (eg vulnerability indices) to inform risk assessment, develop complementary hazards models and create relevant hazards and risk assessment tools. GVM will develop the capability to anticipate future volcanism and its consequences. NERC is funding the start-up of this initiative for three years from November 2011. GVM builds directly on the VOGRIPA project started as part of the GRIP (Global Risk Identification Programme) in 2004 under the auspices of the World Bank and UN. Major international initiatives and partners such as the Smithsonian Institution - Global Volcanism Program, State University of New York at Buffalo - VHub, Earth Observatory of Singapore - WOVOdat and many others underpin GVM.

  7. A Preliminary Study of Seismicity at Ceboruco, Volcano, Nayarit, Mexico

    Science.gov (United States)

    Sanchez, J. J.; Nunez-Cornu, F. J.; Suarez-Plascencia, C.; Trejo-Gomez, E.

    2007-12-01

    Ceboruco Volcano is located northwestern of Tepic-Zacoalco graben (Jalisco, Mexico). Its volcanic activity can be divided in four eruptive cycles differentiated by their volcano explosivity index (VEI) and chemical variations as well. As a result of andesitic effusive activity, during the first cycle the "paleo-Ceboruco" edifice was constructed. The end of this cycle is defined by a plinian eruption (VEI is estimated between 3 and 4) which occurred some 1020 years ago and formed the external caldera. During the second cycle an andesitic dome extruded in the interior of the caldera. The dome, called Dos Equis, collapsed and formed the internal caldera. The third cycle is represented by andesitic lava flows which partially cover the northern and south-southwestern part of the edifice. The last cycle is represented by historic andesitic lava flows located in the southwestern flank of the volcano. In February 2003 as part of an agreement with Nayarit Civil Defense a seismic station was installed in the SW flank of the volcano. The station is equipped with a Marslite (lennartz) digitizer with a 3DLe 1Hz. seismic sensor. Detection system is based on a STA/LTA recording algorithm. More than 2000 small earthquakes have been attributed to various local sources, and some of this earthquakes are possibly located beneath Ceboruco volcano. A preliminary classification separates high frequency and low frequency seismic events. The sources of high frequency earthquakes appear to be distributed as evidenced from waveforms variety and changing S-P arrivals separations. The low frequency seismic events also show varying signatures and some of them exhibit extended coda, including some monochromatic character.

  8. Expert elicitation for a national-level volcano hazard model

    Science.gov (United States)

    Bebbington, Mark; Stirling, Mark; Cronin, Shane; Wang, Ting; Jolly, Gill

    2016-04-01

    The quantification of volcanic hazard at national level is a vital pre-requisite to placing volcanic risk on a platform that permits meaningful comparison with other hazards such as earthquakes. New Zealand has up to a dozen dangerous volcanoes, with the usual mixed degrees of knowledge concerning their temporal and spatial eruptive history. Information on the 'size' of the eruptions, be it in terms of VEI, volume or duration, is sketchy at best. These limitations and the need for a uniform approach lend themselves to a subjective hazard analysis via expert elicitation. Approximately 20 New Zealand volcanologists provided estimates for the size of the next eruption from each volcano and, conditional on this, its location, timing and duration. Opinions were likewise elicited from a control group of statisticians, seismologists and (geo)chemists, all of whom had at least heard the term 'volcano'. The opinions were combined via the Cooke classical method. We will report on the preliminary results from the exercise.

  9. Hawaiian Volcano Observatory seismic data, January to March 2009

    Science.gov (United States)

    Nakata, Jennifer S.; Okubo, Paul G.

    2010-01-01

    This U.S. Geological Survey (USGS), Hawaiian Volcano Observatory (HVO) summary presents seismic data gathered during January–March 2009. The seismic summary offers earthquake hypocenters without interpretation as a source of preliminary data and is complete in that most data for events of M≥1.5 are included. All latitude and longitude references in this report are stated in Old Hawaiian Datum.

  10. Mauna Loa--history, hazards and risk of living with the world's largest volcano

    Science.gov (United States)

    Trusdell, Frank A.

    2012-01-01

    Mauna Loa on the Island Hawaiʻi is the world’s largest volcano. People residing on its flanks face many hazards that come with living on or near an active volcano, including lava flows, explosive eruptions, volcanic smog, damaging earthquakes, and local tsunami (giant seawaves). The County of Hawaiʻi (Island of Hawaiʻi) is the fastest growing County in the State of Hawaii. Its expanding population and increasing development mean that risk from volcano hazards will continue to grow. U.S. Geological Survey (USGS) scientists at the Hawaiian Volcano Observatory (HVO) closely monitor and study Mauna Loa Volcano to enable timely warning of hazardous activity and help protect lives and property.

  11. USGS SAFRR Tsunami Scenario: Potential Impacts to the U.S. West Coast from a Plausible M9 Earthquake near the Alaska Peninsula

    Science.gov (United States)

    Ross, S.; Jones, L. M.; Wilson, R. I.; Bahng, B.; Barberopoulou, A.; Borrero, J. C.; Brosnan, D.; Bwarie, J. T.; Geist, E. L.; Johnson, L. A.; Hansen, R. A.; Kirby, S. H.; Knight, E.; Knight, W. R.; Long, K.; Lynett, P. J.; Miller, K. M.; Mortensen, C. E.; Nicolsky, D.; Oglesby, D. D.; Perry, S. C.; Porter, K. A.; Real, C. R.; Ryan, K. J.; Suleimani, E. N.; Thio, H. K.; Titov, V. V.; Wein, A. M.; Whitmore, P.; Wood, N. J.

    2012-12-01

    The U.S. Geological Survey's Science Application for Risk Reduction (SAFRR) project, in collaboration with the California Geological Survey, the California Emergency Management Agency, the National Oceanic and Atmospheric Administration, and other agencies and institutions are developing a Tsunami Scenario to describe in detail the impacts of a tsunami generated by a hypothetical, but realistic, M9 earthquake near the Alaska Peninsula. The overarching objective of SAFRR and its predecessor, the Multi-Hazards Demonstration Project, is to help communities reduce losses from natural disasters. As requested by emergency managers and other community partners, a primary approach has been comprehensive, scientifically credible scenarios that start with a model of a geologic event and extend through estimates of damage, casualties, and societal consequences. The first product was the ShakeOut scenario, addressing a hypothetical earthquake on the southern San Andreas fault, that spawned the successful Great California ShakeOut, an annual event and the nation's largest emergency preparedness exercise. That was followed by the ARkStorm scenario, which addresses California winter storms that surpass hurricanes in their destructive potential. Some of the Tsunami Scenario's goals include developing advanced models of currents and inundation for the event; spurring research related to Alaskan earthquake sources; engaging the port and harbor decision makers; understanding the economic impacts to local, regional and national economy in both the short and long term; understanding the ecological, environmental, and societal impacts of coastal inundation; and creating enhanced communication products for decision-making before, during, and after a tsunami event. The state of California, through CGS and Cal EMA, is using the Tsunami Scenario as an opportunity to evaluate policies regarding tsunami impact. The scenario will serve as a long-lasting resource to teach preparedness and

  12. Cook Inlet and Kenai Peninsula, Alaska ESI: VOLCANOS (Volcano Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains the locations of volcanos in Cook Inlet and Kenai Peninsula, Alaska. Vector points in the data set represent the location of the volcanos....

  13. 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…

  14. 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…

  15. Analog earthquakes

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-09-01

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

  16. Environmental monitoring of El Hierro Island submarine volcano, by combining low and high resolution satellite imagery

    Science.gov (United States)

    Eugenio, F.; Martin, J.; Marcello, J.; Fraile-Nuez, E.

    2014-06-01

    El Hierro Island, located at the Canary Islands Archipelago in the Atlantic coast of North Africa, has been rocked by thousands of tremors and earthquakes since July 2011. Finally, an underwater volcanic eruption started 300 m below sea level on October 10, 2011. Since then, regular multidisciplinary monitoring has been carried out in order to quantify the environmental impacts caused by the submarine eruption. Thanks to this natural tracer release, multisensorial satellite imagery obtained from MODIS and MERIS sensors have been processed to monitor the volcano activity and to provide information on the concentration of biological, chemical and physical marine parameters. Specifically, low resolution satellite estimations of optimal diffuse attenuation coefficient (Kd) and chlorophyll-a (Chl-a) concentration under these abnormal conditions have been assessed. These remote sensing data have played a fundamental role during field campaigns guiding the oceanographic vessel to the appropriate sampling areas. In addition, to analyze El Hierro submarine volcano area, WorldView-2 high resolution satellite spectral bands were atmospherically and deglinted processed prior to obtain a high-resolution optimal diffuse attenuation coefficient model. This novel algorithm was developed using a matchup data set with MERIS and MODIS data, in situ transmittances measurements and a seawater radiative transfer model. Multisensor and multitemporal imagery processed from satellite remote sensing sensors have demonstrated to be a powerful tool for monitoring the submarine volcanic activities, such as discolored seawater, floating material and volcanic plume, having shown the capabilities to improve the understanding of submarine volcanic processes.

  17. Are the elderly more vulnerable to psychological impact of natural disaster? A population-based survey of adult survivors of the 2008 Sichuan earthquake.

    Science.gov (United States)

    Jia, Zhaobao; Tian, Wenhua; Liu, Weizhi; Cao, Yang; Yan, Jin; Shun, Zhisheng

    2010-03-30

    The association between ages and psychological impact of natural disasters has not been well characterized. A population-based study was conducted 15 months after the 2008 Sichuan earthquake to assess whether elderly survivors were more likely to develop posttraumatic stress disorder (PTSD) and general psychiatric morbidity. A population-based survey of 327 survivors (152 elders, 175 younger adults) was conducted in severely affected areas by the earthquake, using a multi-stage systematic sampling design. Compared with the younger adult survivors, the elderly were more likely to have symptoms of PTSD (22.5% vs. 8.0%, p = 0.001) and general psychiatric morbidity (42.0% vs. 25.4%, p = 0.003). Risk factors, such as being elderly, having been in serious danger, having lost family members, and having felt guilt concerning one's death or injury were significantly associated with developing PTSD; being elderly, having family members or friends seriously injured, and having felt guilt concerning one's death or injury were significantly associated with developing general psychiatric morbidity. Utilization of mental health services is strongly associated with the decreased risk for developing both of the symptoms. Compared with the younger adults, the elderly survivors were more likely to develop PTSD and general psychiatric morbidity. More mental health services should be distributed to the elderly and groups at particular risk, to ensure their smooth mental health reconstruction after the earthquake.

  18. Are the elderly more vulnerable to psychological impact of natural disaster? A population-based survey of adult survivors of the 2008 Sichuan earthquake

    Directory of Open Access Journals (Sweden)

    Yan Jin

    2010-03-01

    Full Text Available Abstract Background The association between ages and psychological impact of natural disasters has not been well characterized. A population-based study was conducted 15 months after the 2008 Sichuan earthquake to assess whether elderly survivors were more likely to develop posttraumatic stress disorder (PTSD and general psychiatric morbidity. Methods A population-based survey of 327 survivors (152 elders, 175 younger adults was conducted in severely affected areas by the earthquake, using a multi-stage systematic sampling design. Results Compared with the younger adult survivors, the elderly were more likely to have symptoms of PTSD (22.5% vs. 8.0%, p = 0.001 and general psychiatric morbidity (42.0% vs. 25.4%, p = 0.003. Risk factors, such as being elderly, having been in serious danger, having lost family members, and having felt guilt concerning one's death or injury were significantly associated with developing PTSD; being elderly, having family members or friends seriously injured, and having felt guilt concerning one's death or injury were significantly associated with developing general psychiatric morbidity. Utilization of mental health services is strongly associated with the decreased risk for developing both of the symptoms. Conclusion Compared with the younger adults, the elderly survivors were more likely to develop PTSD and general psychiatric morbidity. More mental health services should be distributed to the elderly and groups at particular risk, to ensure their smooth mental health reconstruction after the earthquake.

  19. Satellite relay telemetry in the surveillance of active volcanoes and major fault zones

    Science.gov (United States)

    Eaton, J. P.; Ward, P. L.

    1972-01-01

    A review was made of efforts to develop a dense telemetered microearthquake network to study earthquake mechanics along the San Andreas fault and the strain mechanics of the Kilauea Volcano. The principle elements and objectives of the ERTS-A proposal are outlined. Some of the aspects of the earthquake network and the results obtained from it as well as some promising experiments in computerized record processing are discussed.

  20. Volcanoes: Coming Up from Under.

    Science.gov (United States)

    Science and Children, 1980

    1980-01-01

    Provides specific information about the eruption of Mt. St. Helens in March 1980. Also discusses how volcanoes are formed and how they are monitored. Words associated with volcanoes are listed and defined. (CS)

  1. Assessing Impacts of Typhoons and the Chi-Chi Earthquake on Chenyulan Watershed Landscape Pattern in Central Taiwan Using Landscape Metrics

    Science.gov (United States)

    Lin, Yu-Pin; Chang, Tsun-Kuo; Wu, Chen-Fa; Chiang, Te-Chih; Lin, Shin-Hwei

    2006-07-01

    The Chi-Chi earthquake (ML = 7.3) occurred in the central part of Taiwan on September 21, 1999. After the earthquake, typhoons Xangsane and Toraji produced heavy rainfall that fell across the eastern and central parts of Taiwan on November 2000 and July 2001. This study uses remote sensing data, landscape metrics, multivariate statistical analysis, and spatial autocorrelation to assess how earthquake and typhoons affect landscape patterns. It addresses variations of the Chenyulan watershed in Nantou County, near the earthquake’s epicenter and crossed by Typhoon Toraji. The subsequent disturbances have gradually changed landscape of the Chenyulan watershed. Disturbances of various types, sizes, and intensities, following various tracks, have various effects on the landscape patterns and variations of the Chenyulan watershed. The landscape metrics that are obtained by multivariate statistical analyses showed that the disturbances produced variously fragmented patches, interspersed with other patches and isolated from patches of the same type across the entire Chenyulan watershed. The disturbances also affected the isolation, size, and shape-complexity of patches at the landscape and class levels. The disturbances at the class level more strongly affected spatial variations in the landscape as well as patterns of grasslands and bare land, than variations in the watershed farmland and forest. Moreover, the earthquake with high magnitude was a starter to create these landscape variations in space in the Chenyulan watershed. The cumulative impacts of the disturbances on the watershed landscape pattern had existed, especially landslides and grassland in the study area, but were not always evident in space and time in landscape and other class levels.

  2. Examining Communities at Risk: Physical and Socioeconomic Impacts of an Earthquake Scenario on the Hayward Fault (The HayWired Scenario)

    Science.gov (United States)

    Dinitz, L.; Wein, A. M.; Johnson, L. A.; Jones, J. L.

    2015-12-01

    This research led by the U.S. Geological Survey aims to inform and stimulate the development of plans and policies in disaster management and hazard mitigation that will help improve the capacity of residents, businesses and communities to rebound from disasters. As was evidenced in the 1994 Northridge earthquake, "ghost towns" emerged in neighborhoods with high concentrations of damaged rental housing. Also, rental properties that served predominantly lower income households had more difficulty financing repairs which led to blight and other long-term community recovery challenges. Our approach is to develop a framework for identifying and spatially analyzing communities at risk of long-term displacement and recovery challenges for an earthquake scenario. The HayWired scenario postulates a M7.05 earthquake on the Hayward Fault in the San Francisco Bay Area with surface fault rupture, liquefaction, landslides, and fires, as well as subsequent aftershocks. The analytical framework relies on the literature and prior disaster experience to identify and systematically combine physical and socioeconomic impacts of the earthquake sequence with pre-existing socioeconomic conditions to identify areas where housing and building damage, lifeline service disruption, and socioeconomic challenges intersect and can potentially lead to long-term displacements of people, businesses, and jobs. Hazus analyses estimate $46 billion in building damage from the HayWired main shock, which increases by 10-25% due to aftershocks. Heavy damage to large apartment buildings exceeds many other housing types, and preliminary analyses identify neighborhoods where these damage concentrations also intersect with concentrations of low income households. Also, in some counties, the estimated population displaced from severely damaged housing far exceeds the number of vacant housing units, which means residents may be forced to move well away from former neighborhoods and even outside the region

  3. Subdiffusion of volcanic earthquakes

    CERN Document Server

    Abe, Sumiyoshi

    2016-01-01

    A comparative study is performed on volcanic seismicities at Mt.Eyjafjallajokull in Iceland and Mt. Etna in Sicily, Italy, from the viewpoint of science of complex systems, and the discovery of remarkable similarities between them regarding their exotic spatio-temporal properties is reported. In both of the volcanic seismicities as point processes, the jump probability distributions of earthquakes are found to obey the exponential law, whereas the waiting-time distributions follow the power law. In particular, a careful analysis is made about the finite size effects on the waiting-time distributions, and accordingly, the previously reported results for Mt. Etna [S. Abe and N. Suzuki, EPL 110, 59001 (2015)] are reinterpreted. It is shown that spreads of the volcanic earthquakes are subdiffusive at both of the volcanoes. The aging phenomenon is observed in the "event-time-averaged" mean-squared displacements of the hypocenters. A comment is also made on presence/absence of long term memories in the context of t...

  4. Tracking a closing volcanic system using repeating earthquakes

    Science.gov (United States)

    Buurman, H.; West, M. E.; Grapenthin, R.

    2011-12-01

    Repeating, volcano-tectonic (VT) earthquakes were recorded at the end of the explosive phase of the 2009 eruption of Redoubt Volcano, Alaska. The events cluster into several families which exhibit cross-correlation values greater than 0.8 and are distributed between 0-10 km below the edifice. The earthquake magnitudes decline gradually with time, and the events also appear to shallow as the sequence progresses. This activity continued for over 2 months and accompanied steady dome growth, which halted around the same time that the last of the repeating VTs were recorded. The repetitive nature of these earthquakes, their relatively deep locations and their occurrence following 3 weeks of major explosive eruptions suggest that they are related to changes around the conduit system and/or the magma storage area as the last of the magma was removed from the mid-crustal storage area. Geodetic data indicate that the deflation of the edifice, which had been continuous throughout the explosive activity, ceased coincident with the onset of the repeating VT earthquakes. We use evidence from earthquake relocations and earthquake focal mechanisms to investigate the source for the repeating VT earthquakes. We propose a model in which the repeating earthquakes are closely related to the adjustment of the conduit system and mid crustal storage area in response to the last of the ascending magma.

  5. The first Long Period earthquake detected in the background seismicity at Mt. Vesuvius

    Directory of Open Access Journals (Sweden)

    Paola Cusano

    2013-11-01

    Full Text Available The typical earthquakes occurring at Mt. Vesuvius are Volcano-Tectonic. On July 20, 2003, an unusual earthquake with low and narrow frequency content was detected. The seismograms presented an emergent onset and a nearly monochromatic spectrum at all stations of the Osservatorio Vesuviano (Istituto Nazionale di Geofisica e Vulcanologia seismic network. The event was located at about 4 km b.s.l. close to the crater axis and an equivalent duration magnitude of 0.6 was estimated. The nature of this event was investigated by comparing its features with those of two typical Volcano-Tectonic earthquakes occurred inside the same source volume. We compared the spectral content calculating the spectrograms and the coda patterns using the Hilbert Transform. A Seismic Moment Tensor inversion was performed on the low frequency earthquake. The focal mechanisms for the two Volcano-Tectonic earthquakes were estimated with a classical technique and resulted compatible with the stress field acting on the volcano. Taking into account the clear differences with the typical Volcano-Tectonic events as well as the peculiarities retrieved from our analyses (monochromatic, low frequency spectral content, and sustained coda and also some geochemical observations, we classify the unusual low frequency seismic event detected at Mt. Vesuvius as Long Period earthquake and propose that its origin could be linked to a pressure drop in the deep hydrothermal system.

  6. Hawaii's volcanoes revealed

    Science.gov (United States)

    Eakins, Barry W.; Robinson, Joel E.; Kanamatsu, Toshiya; Naka, Jiro; Smith, John R.; Takahashi, Eiichi; Clague, David A.

    2003-01-01

    Hawaiian volcanoes typically evolve in four stages as volcanism waxes and wanes: (1) early alkalic, when volcanism originates on the deep sea floor; (2) shield, when roughly 95 percent of a volcano's volume is emplaced; (3) post-shield alkalic, when small-volume eruptions build scattered cones that thinly cap the shield-stage lavas; and (4) rejuvenated, when lavas of distinct chemistry erupt following a lengthy period of erosion and volcanic quiescence. During the early alkalic and shield stages, two or more elongate rift zones may develop as flanks of the volcano separate. Mantle-derived magma rises through a vertical conduit and is temporarily stored in a shallow summit reservoir from which magma may erupt within the summit region or be injected laterally into the rift zones. The ongoing activity at Kilauea's Pu?u ?O?o cone that began in January 1983 is one such rift-zone eruption. The rift zones commonly extend deep underwater, producing submarine eruptions of bulbous pillow lava. Once a volcano has grown above sea level, subaerial eruptions produce lava flows of jagged, clinkery ?a?a or smooth, ropy pahoehoe. If the flows reach the ocean they are rapidly quenched by seawater and shatter, producing a steep blanket of unstable volcanic sediment that mantles the upper submarine slopes. Above sea level then, the volcanoes develop the classic shield profile of gentle lava-flow slopes, whereas below sea level slopes are substantially steeper. While the volcanoes grow rapidly during the shield stage, they may also collapse catastrophically, generating giant landslides and tsunami, or fail more gradually, forming slumps. Deformation and seismicity along Kilauea's south flank indicate that slumping is occurring there today. Loading of the underlying Pacific Plate by the growing volcanic edifices causes subsidence, forming deep basins at the base of the volcanoes. Once volcanism wanes and lava flows no longer reach the ocean, the volcano continues to submerge, while

  7. First oceanographic expedition to survey the impact of the Sumatra earthquake and the tsunami of 26 December 2004

    Digital Repository Service at National Institute of Oceanography (India)

    Murthy, K.S.R.

    from 16th January to 21st February 2005, within few weeks of the Great Sumatra earthquake and Tsunami event that has caused extensive damage both to the physiography and probably to the environment of the Andaman and Nicobar region. Multi...

  8. Evaluation of the impact of the 2010 pyroclastic density currents at Merapi volcano from high-resolution satellite imagery, field investigations and numerical simulations

    Science.gov (United States)

    Charbonnier, S. J.; Germa, A.; Connor, C. B.; Gertisser, R.; Preece, K.; Komorowski, J.-C.; Lavigne, F.; Dixon, T.; Connor, L.

    2013-07-01

    The 2010 pyroclastic density currents (PDC) at Merapi have presented a rare opportunity to collect a uniquely detailed dataset of the source, extent, lateral variations and impact of various PDC deposits on a densely populated area. Using traditional volcanological field-based methods and a multi-temporal dataset of high-resolution satellite imagery, a total of 23 PDC events have been recognized, including 5 main channeled flows, 15 overbank flows derived from overspill and re-channelization of the main PDCs into adjacent tributaries and two main surge events. The 2010 PDC deposits covered an area of ~ 22.3 km2, unequally distributed between valley-filling (6.9%), overbank (22.4%) and surge and associated fallout deposits (71.7%). Their total estimated non-DRE volume is ~ 36.3 × 106 m3, with 50.2% of this volume accounting for valley-filling deposits, 39.3% for overbank deposits and 10.5% for surge and associated fallout deposits. More than 70% of the total volume was deposited during the third eruptive phase (4-5 November), and only 16.6%, 11.5% and 0.9% during the first (26-29 October), second (30 October - 3 November) and fourth phase (6-23 November), respectively. The internal architecture and lithofacies variations of the 2010 PDC deposits were investigated using data collected from 30 stratigraphic sections measured after one rainy season of erosion. The results show that complex, local-scale variations in flow dynamics and deposit architectures are apparent and that the major factors controlling the propagation of the main flows and their potential hazards for overbanking were driven by: (1) the rapid emplacement of several voluminous PDCs, associated with the steady infilling of the receiving landscape after the two first phases of the eruption; (2) longitudinal changes in channel capacity following increased sinuosity in the valley and decreased containment space; and (3) the effects of varying source mechanisms (gravitational dome collapse, vertical or

  9. Santa Maria Volcano, Guatemala

    Science.gov (United States)

    2002-01-01

    The eruption of Santa Maria volcano in 1902 was one of the largest eruptions of the 20th century, forming a large crater on the mountain's southwest flank. Since 1922, a lava-dome complex, Santiaguito, has been forming in the 1902 crater. Growth of the dome has produced pyroclastic flows as recently as the 2001-they can be identified in this image. The city of Quezaltenango (approximately 90,000 people in 1989) sits below the 3772 m summit. The volcano is considered dangerous because of the possibility of a dome collapse such as one that occurred in 1929, which killed about 5000 people. A second hazard results from the flow of volcanic debris into rivers south of Santiaguito, which can lead to catastrophic flooding and mud flows. More information on this volcano can be found at web sites maintained by the Smithsonian Institution, Volcano World, and Michigan Tech University. ISS004-ESC-7999 was taken 17 February 2002 from the International Space Station using a digital camera. The image is provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Searching and viewing of additional images taken by astronauts and cosmonauts is available at the NASA-JSC Gateway to

  10. Anatomy of a volcano

    NARCIS (Netherlands)

    Wassink, J.

    2011-01-01

    The Icelandic volcano Eyjafjallajökull caused major disruption in European airspace last year. According to his co-author, Freysteinn Sigmundsson, the reconstruction published in Nature six months later by aerospace engineering researcher, Dr Andy Hooper, opens up a new direction in volcanology. “W

  11. Global Earthquake and Volcanic Eruption Economic losses and costs from 1900-2014: 115 years of the CATDAT database - Trends, Normalisation and Visualisation

    Science.gov (United States)

    Daniell, James; Skapski, Jens-Udo; Vervaeck, Armand; Wenzel, Friedemann; Schaefer, Andreas

    2015-04-01

    Over the past 12 years, an in-depth database has been constructed for socio-economic losses from earthquakes and volcanoes. The effects of earthquakes and volcanic eruptions have been documented in many databases, however, many errors and incorrect details are often encountered. To combat this, the database was formed with socioeconomic checks of GDP, capital stock, population and other elements, as well as providing upper and lower bounds to each available event loss. The definition of economic losses within the CATDAT Damaging Earthquakes Database (Daniell et al., 2011a) as of v6.1 has now been redefined to provide three options of natural disaster loss pricing, including reconstruction cost, replacement cost and actual loss, in order to better define the impact of historical disasters. Similarly for volcanoes as for earthquakes, a reassessment has been undertaken looking at the historical net and gross capital stock and GDP at the time of the event, including the depreciated stock, in order to calculate the actual loss. A normalisation has then been undertaken using updated population, GDP and capital stock. The difference between depreciated and gross capital can be removed from the historical loss estimates which have been all calculated without taking depreciation of the building stock into account. The culmination of time series from 1900-2014 of net and gross capital stock, GDP, direct economic loss data, use of detailed studies of infrastructure age, and existing damage surveys, has allowed the first estimate of this nature. The death tolls in earthquakes from 1900-2014 are presented in various forms, showing around 2.32 million deaths due to earthquakes (with a range of 2.18 to 2.63 million) and around 59% due to masonry buildings and 28% from secondary effects. For the death tolls from the volcanic eruption database, 98000 deaths with a range from around 83000 to 107000 is seen from 1900-2014. The application of VSL life costing from death and injury

  12. A series of transient slip events on Kilauea volcano, Hawaii.

    Science.gov (United States)

    Desmarais, E. K.; Segall, P.; Miklius, A.; Cervelli, P.

    2005-12-01

    Deformation on Kilauea volcano, Hawaii is monitored by a network of continuously recording GPS stations, among other methds. Since its installation in 1996, the GPS network has detected four spatially coherent accelerations on Kilauea's south flank that are not caused by either intrusions or earthquakes. These events, each lasting several hours to two days, occurred in September 1998, November 2000, July 2003, and January 2005. Previously, Cervelli et al., (Nature, 2002) interpreted the 2000 event as a silent earthquake due to slip on a sub-horizontal fault beneath Kilauea's south flank. We inverted the cumulative displacements ( less than 2 cm) using a simulated annealing algorithm for each event and found similarly sized, near horizontal, uniform slip source locations for all four events at depths of ~6 km. The estimated slip magnitudes are between 9 and 15 cm, with the upper block moving seaward. The 2005 event is the largest detected to date. Volcano-tectonic (VT) earthquakes on the south flank of Kilauea are typically restricted to the volume between the East Rift Zone and the Hilina and Poliokeawe Palis. Seismicity in this volume increased significantly during the silent events at depths of 5-10 km. However, all of the VT earthquakes were small ( less than M3) and their cumulative moment does not account for the moment released during the silent slip events. We are currently examining seismic waveform data for evidence of other signals, such as non-volcanic tremor, that might be associated with the slip events. To determine the exact onset and duration of the silent earthquakes, we invert for slip as a function of time directly from raw GPS phase and pseudorange observations. The November 2000 silent earthquake was preceded 9 days earlier by nearly 1 m of rainfall, which was speculated in Cervelli et al., (Nature, 2002) to have reduced fault stability through surface loading or pore pressure increase. In contrast, both the 2003 and 2005 events occurred

  13. Catalogue of Icelandic Volcanoes

    Science.gov (United States)

    Ilyinskaya, Evgenia; Larsen, Gudrun; Gudmundsson, Magnus T.; Vogfjord, Kristin; Pagneux, Emmanuel; Oddsson, Bjorn; Barsotti, Sara; Karlsdottir, Sigrun

    2016-04-01

    The Catalogue of Icelandic Volcanoes is a newly developed open-access web resource in English intended to serve as an official source of information about active volcanoes in Iceland and their characteristics. The Catalogue forms a part of an integrated volcanic risk assessment project in Iceland GOSVÁ (commenced in 2012), as well as being part of the effort of FUTUREVOLC (2012-2016) on establishing an Icelandic volcano supersite. Volcanic activity in Iceland occurs on volcanic systems that usually comprise a central volcano and fissure swarm. Over 30 systems have been active during the Holocene (the time since the end of the last glaciation - approximately the last 11,500 years). In the last 50 years, over 20 eruptions have occurred in Iceland displaying very varied activity in terms of eruption styles, eruptive environments, eruptive products and the distribution lava and tephra. Although basaltic eruptions are most common, the majority of eruptions are explosive, not the least due to magma-water interaction in ice-covered volcanoes. Extensive research has taken place on Icelandic volcanism, and the results reported in numerous scientific papers and other publications. In 2010, the International Civil Aviation Organisation (ICAO) funded a 3 year project to collate the current state of knowledge and create a comprehensive catalogue readily available to decision makers, stakeholders and the general public. The work on the Catalogue began in 2011, and was then further supported by the Icelandic government and the EU through the FP7 project FUTUREVOLC. The Catalogue of Icelandic Volcanoes is a collaboration of the Icelandic Meteorological Office (the state volcano observatory), the Institute of Earth Sciences at the University of Iceland, and the Civil Protection Department of the National Commissioner of the Iceland Police, with contributions from a large number of specialists in Iceland and elsewhere. The Catalogue is built up of chapters with texts and various

  14. Microtremor study of Gunung Anyar mud volcano, Surabaya, East Java

    Science.gov (United States)

    Syaifuddin, Firman; Bahri, Ayi Syaeful; Lestari, Wien; Pandu, Juan

    2016-05-01

    The existence of mud volcano system in East Java is known from the ancient period, especially in Surabaya. Gunung Anyar mud volcano is one of the mud volcano system manifestation was appeared close to the residence. Because of this phenomenon we have to learn about the impact of this mud volcano manifestation to the neighbourhood. The microtremor study was conducted to evaluate the possible influence effect of the mud volcano to the environment and get more information about the subsurface condition in this area. Microtremor is one of the geophysical methods which measure the natural tremor or vibration of the earth, the dominant frequency of the tremor represent thickness of the soft sediment layer overlay above the bed rock or harder rock layer beneath our feet. In this study 90 stations was measured to record the natural tremor. The result from this study shows the direct influenced area of this small mud volcano system is close to 50m from the centre of the mud volcano and bed rock of this area is range between 66 to 140 meter.

  15. Earthquake Hazards Program: Earthquake Scenarios

    Data.gov (United States)

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

  16. Liquefaction-fluidization induced land subsidence: impact of the 2011 Tohoku earthquake on reclaimed land around Tokyo bay area, Japan

    OpenAIRE

    A. Kagawa; Furuno, K; Kusuda, T.; Sakai, Y.; Yoshida, T.; Kazaoka, O.

    2015-01-01

    The 2011 Tohoku earthquake caused major liquefaction-induced, ground deformation of the reclaimed land surrounding Tokyo Bay. In this area, liquefaction was visibly manifest by sand boils, ejection of sandy water, land subsidence and floating underground tanks. The level measurements show a correspondence between the degree of liquefaction-fluidization and the amount of subsidence. The strata most susceptible to liquefaction are hydraulically emplaced dredged fill and artifi...

  17. Impact of sea-level rise on earthquake and landslide triggering offshore the Alentejo margin (SW Iberia)

    Science.gov (United States)

    Neves, M. C.; Roque, C.; Luttrell, K. M.; Vázquez, J. T.; Alonso, B.

    2016-12-01

    Earthquakes and submarine landslides are recurrent and widespread manifestations of fault activity offshore SW Iberia. The present work tests the effects of sea-level rise on offshore fault systems using Coulomb stress change calculations across the Alentejo margin. Large-scale faults capable of generating large earthquakes and tsunamis in the region, especially NE-SW trending thrusts and WNW-ESE trending dextral strike-slip faults imaged at basement depths, are either blocked or unaffected by flexural effects related to sea-level changes. Large-magnitude earthquakes occurring along these structures may, therefore, be less frequent during periods of sea-level rise. In contrast, sea-level rise promotes shallow fault ruptures within the sedimentary sequence along the continental slope and upper rise within distances of <100 km from the coast. The results suggest that the occurrence of continental slope failures may either increase (if triggered by shallow fault ruptures) or decrease (if triggered by deep fault ruptures) as a result of sea-level rise. Moreover, observations of slope failures affecting the area of the Sines contourite drift highlight the role of sediment properties as preconditioning factors in this region.

  18. PAGER - Prompt Assessment of Global Earthquakes for Response

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — PAGER (Prompt Assessment of Global Earthquakes for Response) is an automated system that estimates the impact of significant earthquakes around the world, informing...

  19. Intense Seismic Activity at Chiles and Cerro Negro Volcanoes on the Colombia-Ecuador Border

    Science.gov (United States)

    Torres, R. A.; Cadena, O.; Gomez, D.; Ruiz, M. C.; Prejean, S. G.; Lyons, J. J.; White, R. A.

    2015-12-01

    The region of Chiles and Cerro Negro volcanoes, located on the Colombian-Ecuadorian border, has experienced an ongoing seismic swarm beginning in Aug. 2013. Based on concern for local residents and authorities, a cooperative broadband monitoring network was installed by the Servicio Geológico Colombiano in Colombia and the Instituto Geofísico of the Escuela Politécnica Nacional in Ecuador. Since November 2013 more than 538,000 earthquakes were recorded; although since May 2015 the seismicity has decreased significantly to an average of 70 events per day. Three large earthquake swarms with increasing energy occurred in Aug.-Oct. 2013, March-May 2014, and Sept.-Dec. 2014. By the end of 2014, roughly 400 earthquakes greater than M 3 had occurred with a maximum rate of 8000 earthquakes per day. The largest earthquake was a 5.6 ML on Oct. 20, 2014. This event produced an InSAR coseismic deformation of ~23 cm (S. Ebmeier, personal communication). Most events are typical brittle failure volcano-tectonic (VT) earthquakes that are located in a cluster beneath the southern flank of Chiles volcano, with depths between 1.5 and 10 km. Although the great majority of earthquakes are VT, some low-frequency (LF, ~0.5 Hz) and very-low-frequency (VLF) events have occurred. Particle motion analysis suggests that the VLF source migrated with time. While a VLF on Oct. 15, 2014 was located south of Chiles volcano, near the InSAR source, the VLF registered on Feb. 14, 2015 was likely located very close to Chiles Volcano. We infer that magma intrusion and resulting fluid exsolution at depths greater than 5 km are driving seismicity in the Chiles-Cerro Negro region. However earthquakes are failing in a manner consistent with regional tectonics. Relative relocations reveal a structure consistent with mapped regional faults. Thus seismicity is likely controlled by an interaction of magmatic and tectonic processes. Because the regional stress field is highly compressional and the volcanoes

  20. Multi-parametric investigation of the volcano-hydrothermal system at Tatun Volcano Group, Northern Taiwan

    Directory of Open Access Journals (Sweden)

    S. Rontogianni

    2012-07-01

    Full Text Available The Tatun Volcano Group (TVG is located in northern Taiwan near the capital Taipei. In this study we selected and analyzed almost four years (2004–2007 of its seismic activity. The seismic network established around TVG initially consisted of eight three-component seismic stations with this number increasing to twelve by 2007. Local seismicity mainly involved high frequency (HF earthquakes occurring as isolated events or as part of spasmodic bursts. Mixed and low frequency (LF events were observed during the same period but more rarely. During the analysis we estimated duration magnitudes for the HF earthquakes and used a probabilistic non-linear method to accurately locate all these events. The complex frequencies of LF events were also analyzed with the Sompi method indicating fluid compositions consistent with a misty or dusty gas. We juxtaposed these results with geochemical/temperature anomalies extracted from fumarole gas and rainfall levels covering a similar period. This comparison is interpreted in the context of a model proposed earlier for the volcano-hydrothermal system of TVG where fluids and magmatic gases ascend from a magma body that lies at around 7–8 km depth. Most HF earthquakes occur as a response to stresses induced by fluid circulation within a dense network of cracks pervading the upper crust at TVG. The largest (ML ~ 3.1 HF event that occurred on 24 April 2006 at a depth of 5–6 km had source characteristics compatible with that of a tensile crack. It was followed by an enrichment in magmatic components of the fumarole gases as well as a fumarole temperature increase, and provides evidence for ascending fluids from a magma body into the shallow hydrothermal system. This detailed analysis and previous physical volcanology observations at TVG suggest that the region is volcanically active and that measures to mitigate potential hazards have to be considered by the local authorities.

  1. New Hypocenter Relocation Results From Volcano-Tectonic Events (1995-2006) at Popocatepetl Volcano, Mexico

    Science.gov (United States)

    Berger, P.; Nava, F. A.; Valdes-Gonzalez, C.

    2008-12-01

    Popocatepetl, one of the most active strato-volcanoes in Mexico, started a fumarolic and seismic reactivation in December 1994. New hypocenter relocation results have been calculated for some 1,800 volcano-tectonic (VT) events recorded by the seismic network operating at Popocatepetl during 1995-2006, and previously located by the National Center for Disasters Prevention (CENAPRED). We used two location programs to determine hypocenter relocation. One is a recently developed genetic algorithm program, Disloca, which adjusts the differences in arrival times between the recording seismic stations. The second is HypoDD, which uses the double difference earthquake location algorithm. Disloca allowed evaluation of station corrections, plus location of non-clustered hypocenters, while HypoDD refined the locations of clustered ones. Thus, for a given velocity model, hypocenters of clustered events varied slightly depending on the location program. For both programs, four different crustal velocity models were used, two of which include a low velocity zone (LVZ) below 6 km depth. This LVZ represents the presence of magma, which has been suggested to exist at this depth. The spatial distribution of the relocated hypocenters varies from one model to another, but a carefully considered combination of features common to the four distributions, allows a new characterization of the VT activity at Popocatepetl. The distribution of the relocated hypocenters found in this study differs from that of former investigations at Popocatépetl, and gives new insights into the volcano's structures. Hypocenters occur mainly above 10 km depth, with a horizontal range of about 5 km. Features of the spatial distribution allow a tentative interpretation of several internal volcanic structures. Chief among these are branched dike complexes and different sized zones free of volcano-tectonic events, which are in turn surrounded by zones of magma-rock interaction, as indicated by the presence of

  2. Catalogue of Icelandic volcanoes

    Science.gov (United States)

    Ilyinskaya, Evgenia; Larsen, Gudrun; Vogfjörd, Kristin; Tumi Gudmundsson, Magnus; Jonsson, Trausti; Oddsson, Björn; Reynisson, Vidir; Barsotti, Sara; Karlsdottir, Sigrun

    2015-04-01

    Volcanic activity in Iceland occurs on volcanic systems that usually comprise a central volcano and fissure swarm. Over 30 systems have been active during the Holocene. In the last 100 years, over 30 eruptions have occurred displaying very varied activity in terms of eruption styles, eruptive environments, eruptive products and their distribution. Although basaltic eruptions are most common, the majority of eruptions are explosive, not the least due to magma-water interaction in ice-covered volcanoes. Extensive research has taken place on Icelandic volcanism, and the results reported in scientific papers and other publications. In 2010, the International Civil Aviation Organisation funded a 3 year project to collate the current state of knowledge and create a comprehensive catalogue readily available to decision makers, stakeholders and the general public. The work on the Catalogue began in 2011, and was then further supported by the Icelandic government and the EU. The Catalogue forms a part of an integrated volcanic risk assessment project in Iceland (commenced in 2012), and the EU FP7 project FUTUREVOLC (2012-2016), establishing an Icelandic volcano Supersite. The Catalogue is a collaborative effort between the Icelandic Meteorological Office (the state volcano observatory), the Institute of Earth Sciences at the University of Iceland, and the Icelandic Civil Protection, with contributions from a large number of specialists in Iceland and elsewhere. The catalogue is scheduled for opening in the first half of 2015 and once completed, it will be an official publication intended to serve as an accurate and up to date source of information about active volcanoes in Iceland and their characteristics. The Catalogue is an open web resource in English and is composed of individual chapters on each of the volcanic systems. The chapters include information on the geology and structure of the volcano; the eruption history, pattern and products; the known precursory signals

  3. Volcano-hazard zonation for San Vicente volcano, El Salvador

    Science.gov (United States)

    Major, J.J.; Schilling, S.P.; Pullinger, C.R.; Escobar, C.D.; Howell, M.M.

    2001-01-01

    San Vicente volcano, also known as Chichontepec, is one of many volcanoes along the volcanic arc in El Salvador. This composite volcano, located about 50 kilometers east of the capital city San Salvador, has a volume of about 130 cubic kilometers, rises to an altitude of about 2180 meters, and towers above major communities such as San Vicente, Tepetitan, Guadalupe, Zacatecoluca, and Tecoluca. In addition to the larger communities that surround the volcano, several smaller communities and coffee plantations are located on or around the flanks of the volcano, and major transportation routes are located near the lowermost southern and eastern flanks of the volcano. The population density and proximity around San Vicente volcano, as well as the proximity of major transportation routes, increase the risk that even small landslides or eruptions, likely to occur again, can have serious societal consequences. The eruptive history of San Vicente volcano is not well known, and there is no definitive record of historical eruptive activity. The last significant eruption occurred more than 1700 years ago, and perhaps long before permanent human habitation of the area. Nevertheless, this volcano has a very long history of repeated, and sometimes violent, eruptions, and at least once a large section of the volcano collapsed in a massive landslide. The oldest rocks associated with a volcanic center at San Vicente are more than 2 million years old. The volcano is composed of remnants of multiple eruptive centers that have migrated roughly eastward with time. Future eruptions of this volcano will pose substantial risk to surrounding communities.

  4. 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

  5. Monitoring eruption activity using temporal stress changes at Mount Ontake volcano

    Science.gov (United States)

    Terakawa, Toshiko; Kato, Aitaro; Yamanaka, Yoshiko; Maeda, Yuta; Horikawa, Shinichiro; Matsuhiro, Kenjiro; Okuda, Takashi

    2016-01-01

    Volcanic activity is often accompanied by many small earthquakes. Earthquake focal mechanisms represent the fault orientation and slip direction, which are influenced by the stress field. Focal mechanisms of volcano-tectonic earthquakes provide information on the state of volcanoes via stresses. Here we demonstrate that quantitative evaluation of temporal stress changes beneath Mt. Ontake, Japan, using the misfit angles of focal mechanism solutions to the regional stress field, is effective for eruption monitoring. The moving average of misfit angles indicates that during the precursory period the local stress field beneath Mt. Ontake was deviated from the regional stress field, presumably by stress perturbations caused by the inflation of magmatic/hydrothermal fluids, which was removed immediately after the expulsion of volcanic ejecta. The deviation of the local stress field can be an indicator of increases in volcanic activity. The proposed method may contribute to the mitigation of volcanic hazards. PMID:26892716

  6. Monitoring eruption activity using temporal stress changes at Mount Ontake volcano.

    Science.gov (United States)

    Terakawa, Toshiko; Kato, Aitaro; Yamanaka, Yoshiko; Maeda, Yuta; Horikawa, Shinichiro; Matsuhiro, Kenjiro; Okuda, Takashi

    2016-02-19

    Volcanic activity is often accompanied by many small earthquakes. Earthquake focal mechanisms represent the fault orientation and slip direction, which are influenced by the stress field. Focal mechanisms of volcano-tectonic earthquakes provide information on the state of volcanoes via stresses. Here we demonstrate that quantitative evaluation of temporal stress changes beneath Mt. Ontake, Japan, using the misfit angles of focal mechanism solutions to the regional stress field, is effective for eruption monitoring. The moving average of misfit angles indicates that during the precursory period the local stress field beneath Mt. Ontake was deviated from the regional stress field, presumably by stress perturbations caused by the inflation of magmatic/hydrothermal fluids, which was removed immediately after the expulsion of volcanic ejecta. The deviation of the local stress field can be an indicator of increases in volcanic activity. The proposed method may contribute to the mitigation of volcanic hazards.

  7. Study of Seismic Activity at Ceboruco Volcano, Mexico

    Science.gov (United States)

    Nunez-Cornu, F. J.; Escudero, C. R.; Rodríguez Ayala, N. A.; Suarez-Plascencia, C.

    2013-12-01

    Many societies and their economies endure the disastrous consequences of destructive volcanic eruptions. The Ceboruco stratovolcano (2,280 m.a.s.l.) is located in Nayarit, Mexico, at the west of the Mexican volcanic belt and towards the Sierra de San Pedro southeast, which is a key communication point for coast of Jalisco and Nayarit and the northwest of Mexico. It last eruptive activity was in 1875, and during the following five years it presents superficial activity such as vapor emissions, ash falls and riodacitic composition lava flows along the southeast side. Although surface activity has been restricted to fumaroles near the summit, Ceboruco exhibits regular seismic unrest characterized by both low frequency seismic events and volcano-tectonic earthquakes. From March 2003 until July 2008 a three-component short-period seismograph Marslite station with a Lennartz 3D (1Hz) was deployed in the south flank (CEBN) and within 2 km from the summit to monitoring the seismic activity at the volcano. The LF seismicity recorded was classified using waveform characteristics and digital analysis. We obtained four groups: impulsive arrivals, extended coda, bobbin form, and wave package amplitude modulation earthquakes. The extended coda is the group with more earthquakes and present durations of 50 seconds. Using the moving particle technique, we read the P and S wave arrival times and estimate azimuth arrivals. A P-wave velocity of 3.0 km/s was used to locate the earthquakes, most of the hypocenters are below the volcanic edifice within a circular perimeter of 5 km of radius and its depths are calculated relative to the CEBN elevation as follows. The impulsive arrivals earthquakes present hypocenters between 0 and 1 km while the other groups between 0 and 4 km. Results suggest fluid activity inside the volcanic building that could be related to fumes on the volcano. We conclude that the Ceboruco volcano is active. Therefore, it should be continuously monitored due to the

  8. Interactive Volcano Studies and Education Using Virtual Globes

    Science.gov (United States)

    Dehn, J.; Bailey, J. E.; Webley, P.

    2006-12-01

    Internet-based virtual globe programs such as Google Earth provide a spatial context for visualization of monitoring and geophysical data sets. At the Alaska Volcano Observatory, Google Earth is being used to integrate satellite imagery, modeling of volcanic eruption clouds and seismic data sets to build new monitoring and reporting tools. However, one of the most useful information sources for environmental monitoring is under utilized. Local populations, who have lived near volcanoes for decades are perhaps one of the best gauges for changes in activity. Much of the history of the volcanoes is only recorded through local legend. By utilizing the high level of internet connectivity in Alaska, and the interest of secondary education in environmental science and monitoring, it is proposed to build a network of observation nodes around local schools in Alaska and along the Aleutian Chain. A series of interactive web pages with observations on a volcano's condition, be it glow at night, puffs of ash, discolored snow, earthquakes, sounds, and even current weather conditions can be recorded, and the users will be able to see their reports in near real time. The database will create a KMZ file on the fly for upload into the virtual globe software. Past observations and legends could be entered to help put a volcano's long-term activity in perspective. Beyond the benefit to researchers and emergency managers, students and teachers in the rural areas will be involved in volcano monitoring, and gain an understanding of the processes and hazard mitigation efforts in their community. K-12 students will be exposed to the science, and encouraged to participate in projects at the university. Infrastructure at the university can be used by local teachers to augment their science programs, hopefully encouraging students to continue their education at the university level.

  9. A Study of the Source Processes of Colima Volcano Explosions

    Science.gov (United States)

    Nunez-Cornu, F. J.; Vargas-Bracamontes, D.; Sanchez, J. J.; Suarez-Plascencia, C.

    2007-12-01

    Colima volcano, considered as Mexico's most active volcano, has presented several intermittent effusive and explosive phases in recent years. During 2005, a sequence of explosive events with VEI less than or equal to 3 occurred. This activity presented the most intense explosions since the seismic network was deployed. Many of the explosive events were recorded by the digital three-component seismic stations operated by the University of Guadalajara and Jalisco State Civil Defense. These signals were recorded not only by stations located on the volcanic edifice, but also by stations on the northern coast of Jalisco (MCUJ, BSSJ) and Ceboruco Volcano at 184, 182 and 200 km distance, respectively. A study of these signals will be presented. Each explosion was preceded by a seismic event. Nevertheless, the located earthquakes preceding the explosions did not show a common source under the volcano structure, which suggests the existence of a complex structure with possibly more than one conduit, this is also confirmed from a first motion analysis for station F03J, located 12 km at north of the volcano. From analysis of the first ten seconds of the seismic signal on F03J using different representations of the seismic signals, such as waveforms, spectra, time-frequency and time-scale analysis, it is suggested that the source processes are non-stationary, implying that for the case of this period, a general model of the source process of the Colima volcano explosions can not be formulated. The size of the events is evaluated using different criteria. A clear relation between the magnitude of the seismic signals and the amplitude of the sonic and infrasonic waves was not observed.

  10. Dense Local Seismic Network at Villarrica Volcano (Southern Chile)

    Science.gov (United States)

    Mora-Stock, C.; Thorwart, M.; Dzieran, L.; Rabbel, W.

    2013-12-01

    Villarrica volcano is one of the most active volcanoes in the Southern Andes. It has been presenting constant fumarole activity and seismicity since its last eruption in 1984-85. A local network was installed at Villarrica volcano (Southern Chile) during the first two weeks of March, 2012. In total, 75 DSS-Cube short-period stations (30 3-Component, 45 1-Component) were deployed at and around the volcano area, covering approx. 63 km x 55 km. The average station spacing is 1.5 km for stations inside the perimeter of the volcanic edifice, and 5km outside this perimeter. The network recorded ca. 94 volcano tectonic (VT) events located SSW, SSE and North of the crater, with clear P- and S-wave arrivals. Many others, ca.73 events, could be classified as 'hybrid' events (HB), which present high frequencies at the beginning of the signal, and a sharp and notorious S-wave at the crater stations, but a strong scattering, lower frequency content, and elongated coda on the stations along the volcanic edifice. This strong scattering effect is probably caused by the heterogeneous ash layers on the edifice structure. Few long period events (LP), with main frequencies between 2-4 Hz, were observed. From the tectonic regional events, three sets of events can be distinguished. One coming from the southern end of the focal plane of the Maule earthquake (2010), with S-P wave travel time difference of ca. 30 s or more. Another closer group with S-P wave travel time difference between 10 s and 20 s, and the last group with S-P wave travel time difference of 10 s or less. A cross-correlation analysis to the travel times of the regional events and a teleseismic event from Argentina was applied in order to determine the average velocity structure of the volcano, and obtained an average P-wave velocity of 3.6 km/s for the volcanic edifice inside a radius of 6.5 km, and 4.1 km/s for the surrounding area outside this radius. This model serves as a starting point for local earthquake

  11. Seismicity study of volcano-tectonic in and around Tangkuban Parahu active volcano in West Java region, Indonesia

    Science.gov (United States)

    Ry, Rexha V.; Priyono, A.; Nugraha, A. D.; Basuki, A.

    2016-05-01

    Tangkuban Parahu is one of the active volcano in Indonesia located about 15 km northern part of Bandung city. The objective of this study is to investigate the seismic activity in the time periods of January 2013 to December 2013. First, we identified seismic events induced by volcano-tectonic activities. These micro-earthquake events were identified as having difference of P-wave and S-wave arrival times less than three seconds. Then, we constrained its location of hypocenter to locate the source of the activities. Hypocenter determination was performed using adaptive simulated annealing method. Using these results, seismic tomographic inversions were conducted to image the three-dimensional velocity structure of Vp, Vs, and the Vp/Vs ratio. In this study, 278 micro-earthquake events have been identified and located. Distribution of hypocenters around Tangkuban Parahu volcano forms an alignment structure and may be related to the stress induced by magma below, also movement of shallow magma below Domas Crater. Our preliminary tomographic inversion results indicate the presences of low Vp, high Vs, and low Vp/Vs ratio that associate to accumulated young volcanic eruption products and hot material zones.

  12. Pairing the Volcano

    CERN Document Server

    Ionica, Sorina

    2011-01-01

    Isogeny volcanoes are graphs whose vertices are elliptic curves and whose edges are $\\ell$-isogenies. Algorithms allowing to travel on these graphs were developed by Kohel in his thesis (1996) and later on, by Fouquet and Morain (2001). However, up to now, no method was known, to predict, before taking a step on the volcano, the direction of this step. Hence, in Kohel's and Fouquet-Morain algorithms, many steps are taken before choosing the right direction. In particular, ascending or horizontal isogenies are usually found using a trial-and-error approach. In this paper, we propose an alternative method that efficiently finds all points $P$ of order $\\ell$ such that the subgroup generated by $P$ is the kernel of an horizontal or an ascending isogeny. In many cases, our method is faster than previous methods. This is an extended version of a paper published in the proceedings of ANTS 2010. In addition, we treat the case of 2-isogeny volcanoes and we derive from the group structure of the curve and the pairing ...

  13. Evolution of deformation and stress changes during the caldera collapse and dyking at Bárdarbunga, 2014-2015: Implication for triggering of seismicity at nearby Tungnafellsjökull volcano

    Science.gov (United States)

    Parks, Michelle Maree; Heimisson, Elías Rafn; Sigmundsson, Freysteinn; Hooper, Andrew; Vogfjörd, Kristín S.; Árnadóttir, Thóra; Ófeigsson, Benedikt; Hreinsdóttir, Sigrún; Hjartardóttir, Ásta Rut; Einarsson, Páll; Gudmundsson, Magnús Tumi; Högnadóttir, Thórdis; Jónsdóttir, Kristín; Hensch, Martin; Bagnardi, Marco; Dumont, Stéphanie; Drouin, Vincent; Spaans, Karsten; Ólafsdóttir, Rósa

    2017-03-01

    Stress transfer associated with an earthquake, which may result in the seismic triggering of aftershocks (earthquake-earthquake interactions) and/or increased volcanic activity (earthquake-volcano interactions), is a well-documented phenomenon. However limited studies have been undertaken concerning volcanic triggering of activity at neighbouring volcanoes (volcano-volcano interactions). Here we present new deformation and stress modelling results utilising a wealth of diverse geodetic observations acquired during the 2014-2015 unrest and eruption within the Bárdarbunga volcanic system. These comprise a combination of InSAR, GPS, LiDAR, radar profiling and optical satellite measurements. We find a strong correlation between the locations of increased seismicity at nearby Tungnafellsjökull volcano and regions of increased tensile and Coulomb stress changes. Our results suggest that stress transfer during this major event has resulted in earthquake triggering at the neighbouring Tungnafellsjökull volcano by unclamping faults within the associated fissure swarm. This work has immediate application to volcano monitoring; to distinguish the difference between stress transfer and new intrusive activity.

  14. Seismic instrumentation plan for the Hawaiian Volcano Observatory

    Science.gov (United States)

    Thelen, Weston A.

    2014-01-01

    The seismic network operated by the U.S. Geological Survey’s Hawaiian Volcano Observatory (HVO) is the main source of authoritative data for reporting earthquakes in the State of Hawaii, including those that occur on the State’s six active volcanoes (Kīlauea, Mauna Loa, Hualālai, Mauna Kea, Haleakalā, Lō‘ihi). Of these volcanoes, Kīlauea and Mauna Loa are considered “very high threat” in a report on the rationale for a National Volcanic Early Warning System (NVEWS) (Ewert and others, 2005). This seismic instrumentation plan assesses the current state of HVO’s seismic network with respect to the State’s active volcanoes and calculates the number of stations that are needed to upgrade the current network to provide a seismic early warning capability for forecasting volcanic activity. Further, the report provides proposed priorities for upgrading the seismic network and a cost assessment for both the installation costs and maintenance costs of the improved network that are required to fully realize the potential of the early warning system.

  15. Liquefaction-fluidization induced land subsidence: impact of the 2011 Tohoku earthquake on reclaimed land around Tokyo bay area, Japan

    Science.gov (United States)

    Kagawa, A.; Furuno, K.; Kusuda, T.; Sakai, Y.; Yoshida, T.; Kazaoka, O.

    2015-11-01

    The 2011 Tohoku earthquake caused major liquefaction-induced, ground deformation of the reclaimed land surrounding Tokyo Bay. In this area, liquefaction was visibly manifest by sand boils, ejection of sandy water, land subsidence and floating underground tanks. The level measurements show a correspondence between the degree of liquefaction-fluidization and the amount of subsidence. The strata most susceptible to liquefaction are hydraulically emplaced dredged fill and artificial strata on thick uncompacted Holocene deposits. On the other hand, the phenomena of seismic isolation coursed by liquefaction had saved the single-family houses from collapse.

  16. Characteristics of the Seismicity in the San Martin Tuxtla volcano area, Veracruz, Mexico

    Science.gov (United States)

    Espindola, J.; Zamora-Camacho, A.; Godinez, M.

    2012-12-01

    San Martin Tuxtla volcano (18.572N, 95.169W, 1650 masl) is a large volcano rising in the midst of the Tuxtla volcanic field in the State of Veracruz, eastern México. The last eruption of this volcano occurred in 1793 and produced thick ash fall deposits in its vicinity. Due to increasing population in the area, the volcano poses a significant risk. To determine the seismic characteristics of the area and evaluate their possible relationship with the volcano we installed a network of three seismic stations in its surroundings. The array has recorded the seismic activity from 2007 to 2011. We present the results of the analysis of the records of this period, which in general show that the seismicity in the area is relatively low both in frequency and magnitude: only 51 events of magnitude (Mc) less than 2.5 were observed and located. Most of the earthquakes are typical volcano tectonic events occurring at shallow depths (<< 12 km) around the volcano. This low level of seismicity is probably a characteristic of the area and not of the particular period studied, as has been observed in other areas of basaltic volcanism, and could be used to establish any unusual seismicity that could be related to impending volcanic activity.

  17. Earthquake engineering research: 1982

    Science.gov (United States)

    The Committee on Earthquake Engineering Research addressed two questions: What progress has research produced in earthquake engineering and which elements of the problem should future earthquake engineering pursue. It examined and reported in separate chapters of the report: Applications of Past Research, Assessment of Earthquake Hazard, Earthquake Ground Motion, Soil Mechanics and Earth Structures, Analytical and Experimental Structural Dynamics, Earthquake Design of Structures, Seismic Interaction of Structures and Fluids, Social and Economic Aspects, Earthquake Engineering Education, Research in Japan.

  18. In Brief: Underwater volcano gets real-time monitoring

    Science.gov (United States)

    Zielinski, Sarah

    2007-05-01

    A real-time underwater earthquake monitoring system was installed on the top of Kick'em Jenny, an underwater volcano located off the north coast of Grenada, on 6 May. The Real Time Offshore Seismic Station (RTOSS) consists of an ocean-bottom seismometer connected by a stretchy hose to a buoy on the ocean surface. The buoy is powered by solar panels and transmits seismic data by high-frequency radio to an observatory in Sauteurs, Grenada. The RTOSS research team, led by scientists from the Woods Hole Oceanographic Institution, is coordinating with the Grenadian National Disaster Management Agency and the Seismic Unit of the University of the West Indies to incorporate the RTOSS data into existing regional monitoring. Kick'em Jenny, the only `live' submarine volcano in the West Indies, last erupted in 2001.

  19. Earthquake location determination using data from DOMERAPI and BMKG seismic networks: A preliminary result of DOMERAPI project

    Science.gov (United States)

    Ramdhan, Mohamad; Nugraha, Andri Dian; Widiyantoro, Sri; Métaxian, Jean-Philippe; Valencia, Ayunda Aulia

    2015-04-01

    DOMERAPI project has been conducted to comprehensively study the internal structure of Merapi volcano, especially about deep structural features beneath the volcano. DOMERAPI earthquake monitoring network consists of 46 broad-band seismometers installed around the Merapi volcano. Earthquake hypocenter determination is a very important step for further studies, such as hypocenter relocation and seismic tomographic imaging. Ray paths from earthquake events occurring outside the Merapi region can be utilized to delineate the deep magma structure. Earthquakes occurring outside the DOMERAPI seismic network will produce an azimuthal gap greater than 1800. Owing to this situation the stations from BMKG seismic network can be used jointly to minimize the azimuthal gap. We identified earthquake events manually and carefully, and then picked arrival times of P and S waves. The data from the DOMERAPI seismic network were combined with the BMKG data catalogue to determine earthquake events outside the Merapi region. For future work, we will also use the BPPTKG (Center for Research and Development of Geological Disaster Technology) data catalogue in order to study shallow structures beneath the Merapi volcano. The application of all data catalogues will provide good information as input for further advanced studies and volcano hazards mitigation.

  20. Earthquake location determination using data from DOMERAPI and BMKG seismic networks: A preliminary result of DOMERAPI project

    Energy Technology Data Exchange (ETDEWEB)

    Ramdhan, Mohamad [Study Program of Earth Science, Institut Teknologi Bandung, Jl. Ganesa 10, Bandung, 40132 (Indonesia); Agency for Meteorology, Climatology and Geophysics of Indonesia (BMKG) Jl. Angkasa 1 No. 2 Kemayoran, Jakarta Pusat, 10720 (Indonesia); Nugraha, Andri Dian; Widiyantoro, Sri [Global Geophysics Research Group, Faculty of Mining and Petroleum Engineering, Institut TeknologiBandung, Jl. Ganesa 10, Bandung, 40132 (Indonesia); Métaxian, Jean-Philippe [Institut de Recherche pour le Développement (IRD) (France); Valencia, Ayunda Aulia, E-mail: mohamad.ramdhan@bmkg.go.id [Study Program of Geophysical Engineering, Institut Teknologi Bandung, Jl. Ganesa 10, Bandung, 40132 (Indonesia)

    2015-04-24

    DOMERAPI project has been conducted to comprehensively study the internal structure of Merapi volcano, especially about deep structural features beneath the volcano. DOMERAPI earthquake monitoring network consists of 46 broad-band seismometers installed around the Merapi volcano. Earthquake hypocenter determination is a very important step for further studies, such as hypocenter relocation and seismic tomographic imaging. Ray paths from earthquake events occurring outside the Merapi region can be utilized to delineate the deep magma structure. Earthquakes occurring outside the DOMERAPI seismic network will produce an azimuthal gap greater than 180{sup 0}. Owing to this situation the stations from BMKG seismic network can be used jointly to minimize the azimuthal gap. We identified earthquake events manually and carefully, and then picked arrival times of P and S waves. The data from the DOMERAPI seismic network were combined with the BMKG data catalogue to determine earthquake events outside the Merapi region. For future work, we will also use the BPPTKG (Center for Research and Development of Geological Disaster Technology) data catalogue in order to study shallow structures beneath the Merapi volcano. The application of all data catalogues will provide good information as input for further advanced studies and volcano hazards mitigation.

  1. Ambulance Dispatches From Unaffected Areas After the Great East Japan Earthquake: Impact on Emergency Care in the Unaffected Areas.

    Science.gov (United States)

    Hagihara, Akihito; Onozuka, Daisuke; Nagata, Takashi; Abe, Takeru; Hasegawa, Manabu; Nabeshima, Yoshihiro

    2015-12-01

    Although dispatching ambulance crews from unaffected areas to a disaster zone is inevitable when a major disaster occurs, the effect on emergency care in the unaffected areas has not been studied. We evaluated whether dispatching ambulance crews from unaffected prefectures to those damaged by the Great East Japan Earthquake was associated with reduced resuscitation outcomes in out-of-hospital cardiac arrest (OHCA) cases in the unaffected areas. We used the Box-Jenkins transfer function model to assess the relationship between ambulance crew dispatches and return of spontaneous circulation (ROSC) before hospital arrival or 1-month survival after the cardiac event. In a model whose output was the rate of ROSC before hospital arrival, dispatching 1000 ambulance crews was associated with a 0.474% decrease in the rate of ROSC after the dispatch in the prefectures (p=0.023). In a model whose output was the rate of 1-month survival, dispatching 1000 ambulance crews was associated with a 0.502% decrease in the rate of 1-month survival after the dispatch in the prefectures (p=0.011). The dispatch of ambulances from unaffected prefectures to earthquake-stricken areas was associated with a subsequent decrease in the ROSC and 1-month survival rates in OHCA cases in the unaffected prefectures.

  2. [Factors associated with the psychological impact of the Great East Japan earthquake on high school students 1 year and 4 months after the disaster].

    Science.gov (United States)

    Funakoshi, Shunichi; Ohno, Takashi; Kodaka, Akira; Okuyama, Junko; Honda, Nami; Inoue, Takao; Sato, Yuki; Miyajima, Maki; Tomita, Hiroaki; Denda, Kenzou; Matsuoka, Hiroo

    2014-01-01

    The purpose of this study was to investigate factors associated with the psychological impact of the Great East Japan Earthquake on high school students 1 year and 4 months after the disaster, and clarify support needs of the students. In the outreach program for students of three high schools in coastal areas of southern Miyagi Prefecture, Japan, 1,973 students were surveyed after obtaining informed consent for participation. Questionnaires included: the Quick Inventory of Depressive Symptomatology (QIDS-J), Self-rating Anxiety Scale (SAS), Impact of Event Scale-revised (IES-R), and Connor-Davidson Resilience Scale (CD-RISC10). All scores were compared using SPSS 20.0 J between school grades, locations of the schools, and extent of damage due to the Great East Japan Earthquake. Our analysis showed a significant positive correlation between school grades and the level of anxiety. PTSR scores, but not anxiety nor depressive scores, of students whose lives have suffered extensive damage were significantly higher than those of students who have not. Students of high schools which have suffered extensive damage and use temporary buildings showed significantly higher levels of depression and anxiety, and significantly lower resilience, compared to students of high schools which were not damaged. Although previous findings demonstrated that younger children have a higher risk of being influenced by disasters, symptoms related to PTSR and depression were found frequently in the high school students as well. Among the high school students, our analysis showed a positive correlation between the level of anxiety and school grades, probably because the disaster has affected an influential and pivotal point in their lives.

  3. Volcano deformation and subdaily GPS products

    Science.gov (United States)

    Grapenthin, Ronni

    Volcanic unrest is often accompanied by hours to months of deformation of the ground that is measurable with high-precision GPS. Although GPS receivers are capable of near continuous operation, positions are generally estimated for daily intervals, which I use to infer characteristics of a volcano’s plumbing system. However, GPS based volcano geodesy will not be useful in early warning scenarios unless positions are estimated at high rates and in real time. Visualization and analysis of dynamic and static deformation during the 2011 Tohokuoki earthquake in Japan motivates the application of high-rate GPS from a GPS seismology perspective. I give examples of dynamic seismic signals and their evolution to the final static offset in 30 s and 1 s intervals, which demonstrates the enhancement of subtle rupture dynamics through increased temporal resolution. This stresses the importance of processing data at recording intervals to minimize signal loss. Deformation during the 2009 eruption of Redoubt Volcano, Alaska, suggested net deflation by 0.05 km³ in three distinct phases. Mid-crustal aseismic precursory inflation began in May 2008 and was detected by a single continuous GPS station about 28 km NE of Redoubt. Deflation during the explosive and effusive phases was sourced from a vertical ellipsoidal reservoir at about 7-11.5 km. From this I infer a model for the temporal evolution of a complex plumbing system of at least 2 sources during the eruption. Using subdaily GPS positioning solutions I demonstrate that plumes can be detected and localized by utilizing information on phase residuals. The GPS network at Bezymianny Volcano, Kamchatka, records network wide subsidence at rapid rates between 8 and 12 mm/yr from 2005-2010. I hypothesize this to be caused by continuous deflation of a ˜30 km deep sill under Kluchevskoy Volcano. Interestingly, 1-2 explosive events per year cause little to no deformation at any site other than the summit site closest to the vent. I

  4. Earthquake swarms in South America

    Science.gov (United States)

    Holtkamp, S. G.; Pritchard, M. E.; Lohman, R. B.

    2011-10-01

    We searched for earthquake swarms in South America between 1973 and 2009 using the global Preliminary Determination of Epicenters (PDE) catalogue. Seismicity rates vary greatly over the South American continent, so we employ a manual search approach that aims to be insensitive to spatial and temporal scales or to the number of earthquakes in a potential swarm. We identify 29 possible swarms involving 5-180 earthquakes each (with total swarm moment magnitudes between 4.7 and 6.9) within a range of tectonic and volcanic locations. Some of the earthquake swarms on the subduction megathrust occur as foreshocks and delineate the limits of main shock rupture propagation for large earthquakes, including the 2010 Mw 8.8 Maule, Chile and 2007 Mw 8.1 Pisco, Peru earthquakes. Also, subduction megathrust swarms commonly occur at the location of subduction of aseismic ridges, including areas of long-standing seismic gaps in Peru and Ecuador. The magnitude-frequency relationship of swarms we observe appears to agree with previously determined magnitude-frequency scaling for swarms in Japan. We examine geodetic data covering five of the swarms to search for an aseismic component. Only two of these swarms (at Copiapó, Chile, in 2006 and near Ticsani Volcano, Peru, in 2005) have suitable satellite-based Interferometric Synthetic Aperture Radar (InSAR) observations. We invert the InSAR geodetic signal and find that the ground deformation associated with these swarms does not require a significant component of aseismic fault slip or magmatic intrusion. Three swarms in the vicinity of the volcanic arc in southern Peru appear to be triggered by the Mw= 8.5 2001 Peru earthquake, but predicted static Coulomb stress changes due to the main shock were very small at the swarm locations, suggesting that dynamic triggering processes may have had a role in their occurrence. Although we identified few swarms in volcanic regions, we suggest that particularly large volcanic swarms (those that

  5. The impact of the underground fluid in the process of earthquake preparation and occurrence:a review%地下流体对地震孕育发生过程的影响研究综述

    Institute of Scientific and Technical Information of China (English)

    缪淼; 朱守彪

    2012-01-01

    Underground fluid plays an important role in the earthquake preparation and occurrence. This paper reviews the research results about impact of underground fluid on earthquakes, and mainly introduces the physical mechanisms of fluid-induced earthquakes, such as increasing in pore pressure, fluid expansion due to thermal effect and softening effect of rock. Also it introduces some typical models of fluid-induced-earthquakes including earthquake pump,fault-valve, dilation-diffusion mode. Finally existing problems are pointed out and works need doing in the future is suggested. These results provide us new angles of view for further research of earthquake prediction and interaction between fluid and earthquakes.%地下流体对地震的孕育、发生过程起着重要作用.本文简述了近年来国内外关于地下流体影响地震的研究进展,对流体诱发地震的物理机制进行了深入介绍,主要有孔隙压的增加对有效应力的降低、流体受热膨胀扩容以及对岩石的润滑和软化作用;同时介绍了一些典型的流体触发地震模式,包括地震泵、断层阀、膨胀—扩散模式等,并讨论了目前存在的主要问题及今后研究的方向.这些研究成果将对我们认识地下流体与地震的相互作用及地震预测等提供一定的参考.

  6. Magma plumbing system and seismicity of an active mid-ocean ridge volcano

    Science.gov (United States)

    Schmid, Florian; Schlindwein, Vera; Koulakov, Ivan; Plötz, Aline; Scholz, John-Robert

    2017-02-01

    At mid-ocean ridges volcanism generally decreases with spreading rate but surprisingly massive volcanic centres occur at the slowest spreading ridges. These volcanoes can host unexpectedly strong earthquakes and vigorous, explosive submarine eruptions. Our understanding of the geodynamic processes forming these volcanic centres is still incomplete due to a lack of geophysical data and the difficulty to capture their rare phases of magmatic activity. We present a local earthquake tomographic image of the magma plumbing system beneath the Segment 8 volcano at the ultraslow-spreading Southwest Indian Ridge. The tomography shows a confined domain of partial melt under the volcano. We infer that from there melt is horizontally transported to a neighbouring ridge segment at 35 km distance where microearthquake swarms and intrusion tremor occur that suggest ongoing magmatic activity. Teleseismic earthquakes around the Segment 8 volcano, prior to our study, indicate that the current magmatic spreading episode may already have lasted over a decade and hence its temporal extent greatly exceeds the frequent short-lived spreading episodes at faster opening mid-ocean ridges.

  7. Magma plumbing system and seismicity of an active mid-ocean ridge volcano.

    Science.gov (United States)

    Schmid, Florian; Schlindwein, Vera; Koulakov, Ivan; Plötz, Aline; Scholz, John-Robert

    2017-02-20

    At mid-ocean ridges volcanism generally decreases with spreading rate but surprisingly massive volcanic centres occur at the slowest spreading ridges. These volcanoes can host unexpectedly strong earthquakes and vigorous, explosive submarine eruptions. Our understanding of the geodynamic processes forming these volcanic centres is still incomplete due to a lack of geophysical data and the difficulty to capture their rare phases of magmatic activity. We present a local earthquake tomographic image of the magma plumbing system beneath the Segment 8 volcano at the ultraslow-spreading Southwest Indian Ridge. The tomography shows a confined domain of partial melt under the volcano. We infer that from there melt is horizontally transported to a neighbouring ridge segment at 35 km distance where microearthquake swarms and intrusion tremor occur that suggest ongoing magmatic activity. Teleseismic earthquakes around the Segment 8 volcano, prior to our study, indicate that the current magmatic spreading episode may already have lasted over a decade and hence its temporal extent greatly exceeds the frequent short-lived spreading episodes at faster opening mid-ocean ridges.

  8. Ruiz Volcano: Preliminary report

    Science.gov (United States)

    Ruiz Volcano, Colombia (4.88°N, 75.32°W). All times are local (= GMT -5 hours).An explosive eruption on November 13, 1985, melted ice and snow in the summit area, generating lahars that flowed tens of kilometers down flank river valleys, killing more than 20,000 people. This is history's fourth largest single-eruption death toll, behind only Tambora in 1815 (92,000), Krakatau in 1883 (36,000), and Mount Pelée in May 1902 (28,000). The following briefly summarizes the very preliminary and inevitably conflicting information that had been received by press time.

  9. Earthquake risk assessment for Istanbul metropolitan area

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The impact of earthquakes in urban centers prone to disastrous earthquakes necessitates the analysis of associated risk for rational formulation of contingency plans and mitigation strategies. In urban centers, the seismic risk is best quantified and portrayed through the preparation of "Earthquake Damage and Loss Scenarios." The components of such scenarios are the assessment of the hazard, inventories and the vulnerabilities of elements at risk. For the development of the earthquake risk scenario in Istanbul, two independent approaches, one based on intensities and the second on spectral displacements, are utilized. This paper will present the important features of a comprehensive study, highlight the methodology, discuss the results and provide insights to future developments.

  10. 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.

  11. Connecting slow earthquakes to huge earthquakes

    Science.gov (United States)

    Obara, Kazushige; Kato, Aitaro

    2016-07-01

    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 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.

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

    Science.gov (United States)

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

    2011-01-01

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

  13. Assessing the Mental Health Impact of the 2011 Great Japan Earthquake, Tsunami, and Radiation Disaster on Elementary and Middle School Children in the Fukushima Prefecture of Japan.

    Science.gov (United States)

    Lieber, Mark

    2017-01-01

    On March 11, 2011, a magnitude 9.0 earthquake occurred off of Japan's Pacific coast, which was followed by huge tsunamis that destroyed many coastal cities in the area. Due to the earthquake and subsequent tsunami, malfunctions occurred at the Fukushima Daiichi (Fukushima I) nuclear power plant, resulting in the release of radioactive material in the region. While recent studies have investigated the effects of these events on the mental health of adults in the region, no studies have yet been performed investigating similar effects among children. This study aims to fill that gap by: 1) assessing the mental health of elementary and middle school children living within the Fukushima prefecture of Japan, and 2) identifying risk and protective factors that are associated with the children's mental health scores. These factors were quantified using an original demographics survey, the Strengths and Difficulties Questionnaire (SDQ), and the Impact of Event Scale-Revised (IES-R), the latter two of which have been previously validated in a Japanese setting. The surveys were distributed to approximately 3,650 elementary and middle school students during the months of February and March, 2012. The data suggests that those children who had been relocated to the city of Koriyama had significantly higher SDQ scores than those children who were native to Koriyama (p < .05) as well as a control group that lived outside of the Fukushima prefecture (p < .01). Using a multivariate regression, we also found that younger age and parental trauma were significantly correlated with higher SDQ scores (p < .001), while gender, displacement from one's home, and exposure to violence were not. These results suggest that, among children affected by natural disasters, younger children and those with parents suffering from trauma-related distress are particularly vulnerable to the onset of pediatric mental disturbances.

  14. Impact of the Japan earthquake disaster with massive Tsunami on emergency coronary intervention and in-hospital mortality in patients with acute ST-elevation myocardial infarction.

    Science.gov (United States)

    Itoh, Tomonori; Nakajima, Satoshi; Tanaka, Fumitaka; Nishiyama, Osamu; Matsumoto, Tatsuya; Endo, Hiroshi; Sakai, Toshiaki; Nakamura, Motoyuki; Morino, Yoshihiro

    2014-09-01

    The aims of this study were to evaluate reperfusion rate, therapeutic time course and in-hospital mortality pre- and post-Japan earthquake disaster, comparing patients with ST-elevation myocardial infarction (STEMI) treated in the inland area or the Tsunami-stricken area of Iwate prefecture. Subjects were 386 consecutive STEMI patients admitted to the four percutaneous coronary intervention (PCI) centers in Iwate prefecture in 2010 and 2011. Patients were divided into two groups: those treated in the inland or Tsunami-stricken area. We compared clinical characteristics, time course and in-hospital mortality in both years in the two groups. PCI was performed in 310 patients (80.3%). Door-to-balloon (D2B) time in the Tsunami-stricken area in 2011 was significantly shorter than in 2010 in patients treated with PCI. However, the rate of PCI performed in the Tsunami-stricken area in March-April 2011 was significantly lower than that in March-April 2010 (41.2% vs 85.7%; p=0.03). In-hospital mortality increased three-fold from 7.1% in March-April 2010 to 23.5% in March-April 2011 in the Tsunami-stricken area. Standardized mortality ratio (SMR) in March-April 2011 in the Tsunami-stricken area was significantly higher than the control SMR (SMR 4.72: 95% confidence interval (CI): 1.77-12.6: p=0.007). The rate of PCI decreased and in-hospital mortality increased immediately after the Japan earthquake disaster in the Tsunami-stricken area. Disorder in hospitals and in the distribution systems after the disaster impacted the clinical care and outcome of STEMI patients. © The European Society of Cardiology 2014.

  15. Impact of the Great East Japan Earthquake and tsunami on health, medical care and public health systems in Iwate Prefecture, Japan, 2011

    Directory of Open Access Journals (Sweden)

    Masaru Nohara

    2011-12-01

    Full Text Available Problem: The Great East Japan Earthquake was one of the largest earthquakes ever recorded in global history. The damage was spread over a wide area, with the worst-hit areas being Iwate, Miyagi and Fukushima prefectures. In this paper we report on the damage and the impact of the damage to describe the health consequences among disaster victims in Iwate Prefecture.Context: In Iwate Prefecture the tsunami claimed 4659 lives, with 1633 people missing. In addition to electricity, water and gas being cut off following the disaster, communication functions were paralysed and there was a lack of gasoline.Action: Medical and public health teams from Iwate Prefecture and around the country, including many different specialists, engaged in a variety of public health activities mainly at evacuation centres, including medical and mental health care and activities to prevent infectious diseases.Outcome: Given the many fatalities, there were relatively few patients who required medical treatment for major injuries. However, there were significant medical needs in the subacute and chronic phases of care in evacuation centres, with great demand for medical treatment and public health assistance, measures to counteract infection and mental health care.Discussion: By referring to past experiences of national and international large-scale disasters, it was possible to respond effectively to the health-related challenges. However, there are still challenges concerning how to share information and coordinate overall activities among multiple public health response teams. Further examination will be required to ensure better preparedness in response to future disasters.

  16. Assessing the Mental Health Impact of the 2011 Great Japan Earthquake, Tsunami, and Radiation Disaster on Elementary and Middle School Children in the Fukushima Prefecture of Japan

    Science.gov (United States)

    2017-01-01

    Background On March 11, 2011, a magnitude 9.0 earthquake occurred off of Japan’s Pacific coast, which was followed by huge tsunamis that destroyed many coastal cities in the area. Due to the earthquake and subsequent tsunami, malfunctions occurred at the Fukushima Daiichi (Fukushima I) nuclear power plant, resulting in the release of radioactive material in the region. While recent studies have investigated the effects of these events on the mental health of adults in the region, no studies have yet been performed investigating similar effects among children. Methods and Findings This study aims to fill that gap by: 1) assessing the mental health of elementary and middle school children living within the Fukushima prefecture of Japan, and 2) identifying risk and protective factors that are associated with the children’s mental health scores. These factors were quantified using an original demographics survey, the Strengths and Difficulties Questionnaire (SDQ), and the Impact of Event Scale–Revised (IES-R), the latter two of which have been previously validated in a Japanese setting. The surveys were distributed to approximately 3,650 elementary and middle school students during the months of February and March, 2012. The data suggests that those children who had been relocated to the city of Koriyama had significantly higher SDQ scores than those children who were native to Koriyama (p < .05) as well as a control group that lived outside of the Fukushima prefecture (p < .01). Using a multivariate regression, we also found that younger age and parental trauma were significantly correlated with higher SDQ scores (p < .001), while gender, displacement from one’s home, and exposure to violence were not. Conclusions These results suggest that, among children affected by natural disasters, younger children and those with parents suffering from trauma-related distress are particularly vulnerable to the onset of pediatric mental disturbances. PMID:28099497

  17. New insights into Kilauea's volcano dynamics brought by large-scale relative relocation of microearthquakes

    Science.gov (United States)

    Got, J.-L.; Okubo, P.

    2003-01-01

    We investigated the microseismicity recorded in an active volcano to infer information concerning the volcano structure and long-term dynamics, by using relative relocations and focal mechanisms of microearthquakes. There were 32,000 earthquakes of the Mauna Loa and Kilauea volcanoes recorded by more than eight stations of the Hawaiian Volcano Observatory seismic network between 1988 and 1999. We studied 17,000 of these events and relocated more than 70%, with an accuracy ranging from 10 to 500 m. About 75% of these relocated events are located in the vicinity of subhorizontal decollement planes, at a depth of 8-11 km. However, the striking features revealed by these relocation results are steep southeast dipping fault planes working as reverse faults, clearly located below the decollement plane and which intersect it. If this decollement plane coincides with the pre-Mauna Loa seafloor, as hypothesized by numerous authors, such reverse faults rupture the pre-Mauna Loa oceanic crust. The weight of the volcano and pressure in the magma storage system are possible causes of these ruptures, fully compatible with the local stress tensor computed by Gillard et al. [1996]. Reverse faults are suspected of producing scarps revealed by kilometer-long horizontal slip-perpendicular lineations along the decollement surface and therefore large-scale roughness, asperities, and normal stress variations. These are capable of generating stick-slip, large-magnitude earthquakes, the spatial microseismic pattern observed in the south flank of Kilauea volcano, and Hilina-type instabilities. Rupture intersecting the decollement surface, causing its large-scale roughness, may be an important parameter controlling the growth of Hawaiian volcanoes.

  18. Update earthquake risk assessment in Cairo, Egypt

    Science.gov (United States)

    Badawy, Ahmed; Korrat, Ibrahim; El-Hadidy, Mahmoud; Gaber, Hanan

    2016-12-01

    The Cairo earthquake (12 October 1992; m b = 5.8) is still and after 25 years one of the most painful events and is dug into the Egyptians memory. This is not due to the strength of the earthquake but due to the accompanied losses and damages (561 dead; 10,000 injured and 3000 families lost their homes). Nowadays, the most frequent and important question that should rise is "what if this earthquake is repeated today." In this study, we simulate the same size earthquake (12 October 1992) ground motion shaking and the consequent social-economic impacts in terms of losses and damages. Seismic hazard, earthquake catalogs, soil types, demographics, and building inventories were integrated into HAZUS-MH to produce a sound earthquake risk assessment for Cairo including economic and social losses. Generally, the earthquake risk assessment clearly indicates that "the losses and damages may be increased twice or three times" in Cairo compared to the 1992 earthquake. The earthquake risk profile reveals that five districts (Al-Sahel, El Basateen, Dar El-Salam, Gharb, and Madinat Nasr sharq) lie in high seismic risks, and three districts (Manshiyat Naser, El-Waily, and Wassat (center)) are in low seismic risk level. Moreover, the building damage estimations reflect that Gharb is the highest vulnerable district. The analysis shows that the Cairo urban area faces high risk. Deteriorating buildings and infrastructure make the city particularly vulnerable to earthquake risks. For instance, more than 90 % of the estimated buildings damages are concentrated within the most densely populated (El Basateen, Dar El-Salam, Gharb, and Madinat Nasr Gharb) districts. Moreover, about 75 % of casualties are in the same districts. Actually, an earthquake risk assessment for Cairo represents a crucial application of the HAZUS earthquake loss estimation model for risk management. Finally, for mitigation, risk reduction, and to improve the seismic performance of structures and assure life safety

  19. Update earthquake risk assessment in Cairo, Egypt

    Science.gov (United States)

    Badawy, Ahmed; Korrat, Ibrahim; El-Hadidy, Mahmoud; Gaber, Hanan

    2017-07-01

    The Cairo earthquake (12 October 1992; m b = 5.8) is still and after 25 years one of the most painful events and is dug into the Egyptians memory. This is not due to the strength of the earthquake but due to the accompanied losses and damages (561 dead; 10,000 injured and 3000 families lost their homes). Nowadays, the most frequent and important question that should rise is "what if this earthquake is repeated today." In this study, we simulate the same size earthquake (12 October 1992) ground motion shaking and the consequent social-economic impacts in terms of losses and damages. Seismic hazard, earthquake catalogs, soil types, demographics, and building inventories were integrated into HAZUS-MH to produce a sound earthquake risk assessment for Cairo including economic and social losses. Generally, the earthquake risk assessment clearly indicates that "the losses and damages may be increased twice or three times" in Cairo compared to the 1992 earthquake. The earthquake risk profile reveals that five districts (Al-Sahel, El Basateen, Dar El-Salam, Gharb, and Madinat Nasr sharq) lie in high seismic risks, and three districts (Manshiyat Naser, El-Waily, and Wassat (center)) are in low seismic risk level. Moreover, the building damage estimations reflect that Gharb is the highest vulnerable district. The analysis shows that the Cairo urban area faces high risk. Deteriorating buildings and infrastructure make the city particularly vulnerable to earthquake risks. For instance, more than 90 % of the estimated buildings damages are concentrated within the most densely populated (El Basateen, Dar El-Salam, Gharb, and Madinat Nasr Gharb) districts. Moreover, about 75 % of casualties are in the same districts. Actually, an earthquake risk assessment for Cairo represents a crucial application of the HAZUS earthquake loss estimation model for risk management. Finally, for mitigation, risk reduction, and to improve the seismic performance of structures and assure life safety

  20. Is Earthquake Triggering Driven by Small Earthquakes?

    CERN Document Server

    Helmstetter, A

    2002-01-01

    Using a catalog of seismicity for Southern California, we measure how the number of triggered earthquakes increases with the earthquake magnitude. The trade-off between this scaling and the distribution of earthquake magnitudes controls the relative role of small compared to large earthquakes. We show that seismicity triggering is driven by the smallest earthquakes, which trigger fewer aftershocks than larger earthquakes, but which are much more numerous. We propose that the non-trivial scaling of the number of aftershocks emerges from the fractal spatial distribution of aftershocks.

  1. Elementary analysis of data from Tianchi Volcano

    Institute of Scientific and Technical Information of China (English)

    LIU Guo-ming; ZHANG Heng-rong; KONG Qing-jun; WU Cheng-zhi; GUO Feng; ZHANG Chao-fan

    2004-01-01

    Tianchi Volcano is the largest potential erupticve volcano in China. Analyzing these data on seismic monitoring, deformation observation and water chemistry investigation gained from the Tianchi Volcano Observatory (TVO), the authors consider that the Tianchi Volcano is in going into a new flourishing time.

  2. Predictable earthquakes?

    Science.gov (United States)

    Martini, D.

    2002-12-01

    acceleration) and global number of earthquake for this period from published literature which give us a great picture about the dynamical geophysical phenomena. Methodology: The computing of linear correlation coefficients gives us a chance to quantitatively characterise the relation among the data series, if we suppose a linear dependence in the first step. The correlation coefficients among the Earth's rotational acceleration and Z-orbit acceleration (perpendicular to the ecliptic plane) and the global number of the earthquakes were compared. The results clearly demonstrate the common feature of both the Earth's rotation and Earth's Z-acceleration around the Sun and also between the Earth's rotational acceleration and the earthquake number. This fact might means a strong relation among these phenomena. The mentioned rather strong correlation (r = 0.75) and the 29 year period (Saturn's synodic period) was clearly shown in the counted cross correlation function, which gives the dynamical characteristic of correlation, of Earth's orbital- (Z-direction) and rotational acceleration. This basic period (29 year) was also obvious in the earthquake number data sets with clear common features in time. Conclusion: The Core, which involves the secular variation of the Earth's magnetic field, is the only sufficiently mobile part of the Earth with a sufficient mass to modify the rotation which probably effects on the global time distribution of the earthquakes. Therefore it might means that the secular variation of the earthquakes is inseparable from the changes in Earth's magnetic field, i.e. the interior process of the Earth's core belongs to the dynamical state of the solar system. Therefore if the described idea is real the global distribution of the earthquakes in time is predictable.

  3. A smartphone application for earthquakes that matter!

    Science.gov (United States)

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

    2014-05-01

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

  4. The impact of rapid recharge events on the evolution of magma chambers: Case studies of Santorini Volcano (Greece) and Volcan Quizapu (Chile)

    Science.gov (United States)

    Degruyter, Wim; Huber, Christian; Bachmann, Olivier; Cooper, Kari; Kent, Adam

    2016-04-01

    Magma reservoirs in the crust are thought to be dominantly formed by episodic recharge events at rates that are much larger than the long-term average magma inflow rates. Hence, a better understanding of the evolution of a magma reservoir requires elucidating the mass change, pressurization, heating, deformation and the potential for an eruption associated with different recharge scenarios. Most importantly, the bifurcation in behavior between a recharge event that leads to eruption and one that will grow the chamber requires quantification for better volcanic hazard assessment. We use a numerical model to determine the change in pressure, temperature and volume of a magma chamber as it is exposed to a recharge event. The model is applied to the well-studied volcanic systems of Santorini Volcano (Greece) and Volcan Quizapu (Chile). We establish the rates and the duration of magma recharge events that will lead to an eruption. In doing so, we demonstrate the importance of the state of the magma chamber prior to the recharge event, i.e. its size and exsolved volatile content, on the subsequent evolution of the reservoir. In the case of Santorini, the model successfully reproduces the main features of the Minoan eruption and Nea Kameni activity, providing volume estimates for the active part of the current subvolcanic reservoir as well as information regarding the presence of exsolved volatiles. For Quizapu, we suggest that the change in eruptive style, from an effusive outpouring of lava in 1846-1847 to an explosive Plinian eruption in 1932, was controlled by a shift in the state of the magma chamber induced by the first eruption. These case studies show that thermo-mechanical models offer a new framework to integrate the historic eruption record with geodetic measurements and provide a context to understand the past, present and future of active volcanic centers.

  5. Mount Rainier active cascade volcano

    Science.gov (United States)

    1994-01-01

    Mount Rainier is one of about two dozen active or recently active volcanoes in the Cascade Range, an arc of volcanoes in the northwestern United States and Canada. The volcano is located about 35 kilometers southeast of the Seattle-Tacoma metropolitan area, which has a population of more than 2.5 million. This metropolitan area is the high technology industrial center of the Pacific Northwest and one of the commercial aircraft manufacturing centers of the United States. The rivers draining the volcano empty into Puget Sound, which has two major shipping ports, and into the Columbia River, a major shipping lane and home to approximately a million people in southwestern Washington and northwestern Oregon. Mount Rainier is an active volcano. It last erupted approximately 150 years ago, and numerous large floods and debris flows have been generated on its slopes during this century. More than 100,000 people live on the extensive mudflow deposits that have filled the rivers and valleys draining the volcano during the past 10,000 years. A major volcanic eruption or debris flow could kill thousands of residents and cripple the economy of the Pacific Northwest. Despite the potential for such danger, Mount Rainier has received little study. Most of the geologic work on Mount Rainier was done more than two decades ago. Fundamental topics such as the development, history, and stability of the volcano are poorly understood.

  6. Mount Rainier active cascade volcano

    Science.gov (United States)

    Mount Rainier is one of about two dozen active or recently active volcanoes in the Cascade Range, an arc of volcanoes in the northwestern United States and Canada. The volcano is located about 35 kilometers southeast of the Seattle-Tacoma metropolitan area, which has a population of more than 2.5 million. This metropolitan area is the high technology industrial center of the Pacific Northwest and one of the commercial aircraft manufacturing centers of the United States. The rivers draining the volcano empty into Puget Sound, which has two major shipping ports, and into the Columbia River, a major shipping lane and home to approximately a million people in southwestern Washington and northwestern Oregon. Mount Rainier is an active volcano. It last erupted approximately 150 years ago, and numerous large floods and debris flows have been generated on its slopes during this century. More than 100,000 people live on the extensive mudflow deposits that have filled the rivers and valleys draining the volcano during the past 10,000 years. A major volcanic eruption or debris flow could kill thousands of residents and cripple the economy of the Pacific Northwest. Despite the potential for such danger, Mount Rainier has received little study. Most of the geologic work on Mount Rainier was done more than two decades ago. Fundamental topics such as the development, history, and stability of the volcano are poorly understood.

  7. A comparison of the medium-term impact and recovery of the Pakistan floods and the Haiti earthquake: objective and subjective measures.

    Science.gov (United States)

    Weiss, William M; Kirsch, Thomas D; Doocy, Shannon; Perrin, Paul

    2014-06-01

    The 2010 Haiti earthquake and Pakistan floods were similar in their massive human impact. Although the specific events were very different, the humanitarian response to disasters is supposed to achieve the same ends. This paper contrasts the disaster effects and aims to contrast the medium-term response. In January 2011, similarly structured population-based surveys were carried out in the most affected areas using stratified cluster designs (80×20 in Pakistan and 60×20 in Haiti) with probability proportional to size sampling. Displacement persisted in Haiti and Pakistan at 53% and 39% of households, respectively. In Pakistan, 95% of households reported damage to their homes and loss of income or livelihoods, and in Haiti, the rates were 93% and 85%, respectively. Frequency of displacement, and income or livelihood loss, were significantly higher in Pakistan, whereas disaster-related deaths or injuries were significantly more prevalent in Haiti. Given the rise in disaster frequency and costs, and the volatility of humanitarian funding streams as a result of the recent global financial crisis, it is increasingly important to measure the impact of humanitarian response against the goal of a return to normalcy.

  8. Soufriere Hills Volcano

    Science.gov (United States)

    2002-01-01

    In this ASTER image of Soufriere Hills Volcano on Montserrat in the Caribbean, continued eruptive activity is evident by the extensive smoke and ash plume streaming towards the west-southwest. Significant eruptive activity began in 1995, forcing the authorities to evacuate more than 7,000 of the island's original population of 11,000. The primary risk now is to the northern part of the island and to the airport. Small rockfalls and pyroclastic flows (ash, rock and hot gases) are common at this time due to continued growth of the dome at the volcano's summit.This image was acquired on October 29, 2002 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. Science team leader; Bjorn Eng of JPL is the project manager. The Terra mission is part of NASA

  9. The tsunami's impact on mortality in a town severely damaged by the 2011 Great East Japan Earthquake.

    Science.gov (United States)

    Nagata, Satoko; Teramoto, Chie; Okamoto, Reiko; Koide, Keiko; Nishida, Masumi; Suzuki, Ruriko; Nomura, Michie; Tada, Toshiko; Kishi, Emiko; Sakai, Yoko; Jojima, Noriko; Kusano, Emiko; Iwamoto, Saori; Saito, Miki; Murashima, Sachiyo

    2014-07-01

    This study identifies the relationship between tsunami damage and mortality through a demographic pyramid of a town severely damaged by the tsunami following the Great East Japan Earthquake of 11 March 2011. It uses cross-sectional data collection. Volunteers visited all households, including shelters, and asked residents about the whereabouts of family members and neighbours. The information was collated with lists of evacuees and the dead to confirm the whereabouts of all residents about 50 days after the disaster. Demographic pyramids for the whole population based on pre- and post-disaster data were drawn. In all, 1,412 (8.8 per cent) were dead or missing, 60.2 per cent of whom were aged 65 and over and 37.5 per cent aged 75 and over, suggesting that the very old should be located beyond the reach of tsunamis. The mortality rate of children was lower than that in other studies, which may indicate the efficacy of disaster evacuation drills. © 2014 The Author(s). Disasters © Overseas Development Institute, 2014.

  10. 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.

  11. El Quindio Colombia Earthquake, January 25, 1999

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The El Quindio earthquake was one of the most destructive natural disasters to have occurred in Colombia in recent years. Long lasting economic and social impacts...

  12. Precursors to dyke-fed eruptions at basaltic volcanoes: insights from patterns of volcano-tectonic seismicity at Kilauea volcano, Hawaii

    Science.gov (United States)

    Bell, Andrew F.; Kilburn, Christopher R. J.

    2012-03-01

    To investigate the physical controls on volcano-tectonic (VT) precursors to eruptions and intrusions at basaltic volcanoes, we have analyzed the spatial and temporal patterns of VT earthquakes associated with 34 eruptions and 23 dyke intrusions that occurred between 1960 and 1983 at Kilauea, in Hawaii. Eighteen of the 57 magmatic events were preceded by an acceleration of the mean rate of VT earthquakes located close to the main shallow magma reservoir. Using a maximum-likelihood technique and the Bayesian Information Criterion for model preference, we demonstrate that an exponential acceleration is preferred over a power-law acceleration for all sequences. These sequences evolve over time-scales of weeks to months and are consistent with theoretical models for the approach to volcanic eruptions based on the growth of a population of fractures in response to an excess magma pressure. Among the remaining 40 magmatic events, we found a significant correlation between swarms of VT earthquakes located in the mobile south-flank of Kilauea and eruptions and intrusions. The behaviour of these swarms suggests that at least some of the magmatic events are triggered by transient episodes of elevated rates of aseismic flank movement, which could explain why many eruptions and intrusions are not preceded by longer-term precursory signals. In none of the 57 cases could a precursory sequence be used to distinguish between the approach to an eruption or an intrusion, so that, even when a precursory sequence is recognized, there remains an empirical chance of about 40% (24 intrusions from 57 magmatic events) of issuing a false alarm for an imminent eruption.

  13. Mud Volcanoes as Exploration Targets on Mars

    Science.gov (United States)

    Allen, Carlton C.; Oehler, Dorothy Z.

    2010-01-01

    Tens of thousands of high-albedo mounds occur across the southern part of the Acidalia impact basin on Mars. These structures have geologic, physical, mineralogic, and morphologic characteristics consistent with an origin from a sedimentary process similar to terrestrial mud volcanism. The potential for mud volcanism in the Northern Plains of Mars has been recognized for some time, with candidate mud volcanoes reported from Utopia, Isidis, northern Borealis, Scandia, and the Chryse-Acidalia region. We have proposed that the profusion of mounds in Acidalia is a consequence of this basin's unique geologic setting as the depocenter for the tune fraction of sediments delivered by the outflow channels from the highlands.

  14. 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.

  15. Seismicity patterns during a period of inflation at Sierra Negra volcano, Galápagos Ocean Island Chain

    Science.gov (United States)

    Davidge, Lindsey; Ebinger, Cynthia; Ruiz, Mario; Tepp, Gabrielle; Amelung, Falk; Geist, Dennis; Coté, Dustin; Anzieta, Juan

    2017-03-01

    Basaltic shield volcanoes of the western Galápagos islands are among the most rapidly deforming volcanoes worldwide, but little was known of the internal structure and brittle deformation processes accompanying inflation and deflation cycles. A 15-station broadband seismic array was deployed on and surrounding Sierra Negra volcano, Galápagos from July 2009 through June 2011 to characterize seismic strain patterns during an inter-eruption inflation period and to evaluate single and layered magma chamber models for ocean island volcanoes. We compare precise earthquake locations determined from a 3D velocity model and from a double difference cluster method. Using first-motion of P-arrivals, we determine focal mechanisms for 8 of the largest earthquakes (ML ≤ 1.5) located within the array. Most of the 2382 earthquakes detected by the array occurred beneath the broad (∼9 km-wide) Sierra Negra caldera, at depths from surface to about 8 km below sea level. Although outside our array, frequent and larger magnitude (ML ≤ 3.4) earthquakes occurred at Alcedo and Fernandina volcano, and in a spatial cluster beneath the shallow marine platform between Fernandina and Sierra Negra volcanoes. The time-space relations and focal mechanism solutions from a 4-day long period of intense seismicity June 4-9, 2010 along the southeastern flank of Sierra Negra suggests that the upward-migrating earthquake swarm occurred during a small volume intrusion at depths 5-8 km subsurface, but there was no detectable signal in InSAR data to further constrain geometry and volume. Focal mechanisms of earthquakes beneath the steep intra-caldera faults and along the ring fault system are reverse and strike-slip. These new seismicity data integrated with tomographic, geodetic, and petrological models indicate a stratified magmatic plumbing system: a shallow sill beneath the large caldera that is supplied by magma from a large volume deeper feeding system. The large amplitude inter

  16. Volcanoes in Eruption - Set 1

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The word volcano is used to refer to the opening from which molten rock and gas issue from Earth's interior onto the surface, and also to the cone, hill, or mountain...

  17. Volcanoes in Eruption - Set 2

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The word volcano is used to refer to the opening from which molten rock and gas issue from Earth's interior onto the surface, and also to the cone, hill, or mountain...

  18. USGS Volcano Notification Service (VNS)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Website provides a subscription service to receive an email when changes occur in the activity levels for monitored U.S. volcanoes and/or when information releases...

  19. Large-N in Volcano Settings: Volcanosri

    Science.gov (United States)

    Lees, J. M.; Song, W.; Xing, G.; Vick, S.; Phillips, D.

    2014-12-01

    We seek a paradigm shift in the approach we take on volcano monitoring where the compromise from high fidelity to large numbers of sensors is used to increase coverage and resolution. Accessibility, danger and the risk of equipment loss requires that we develop systems that are independent and inexpensive. Furthermore, rather than simply record data on hard disk for later analysis we desire a system that will work autonomously, capitalizing on wireless technology and in field network analysis. To this end we are currently producing a low cost seismic array which will incorporate, at the very basic level, seismological tools for first cut analysis of a volcano in crises mode. At the advanced end we expect to perform tomographic inversions in the network in near real time. Geophone (4 Hz) sensors connected to a low cost recording system will be installed on an active volcano where triggering earthquake location and velocity analysis will take place independent of human interaction. Stations are designed to be inexpensive and possibly disposable. In one of the first implementations the seismic nodes consist of an Arduino Due processor board with an attached Seismic Shield. The Arduino Due processor board contains an Atmel SAM3X8E ARM Cortex-M3 CPU. This 32 bit 84 MHz processor can filter and perform coarse seismic event detection on a 1600 sample signal in fewer than 200 milliseconds. The Seismic Shield contains a GPS module, 900 MHz high power mesh network radio, SD card, seismic amplifier, and 24 bit ADC. External sensors can be attached to either this 24-bit ADC or to the internal multichannel 12 bit ADC contained on the Arduino Due processor board. This allows the node to support attachment of multiple sensors. By utilizing a high-speed 32 bit processor complex signal processing tasks can be performed simultaneously on multiple sensors. Using a 10 W solar panel, second system being developed can run autonomously and collect data on 3 channels at 100Hz for 6 months

  20. Spatial variations of sea level along the coast of Thailand: Impacts of extreme land subsidence, earthquakes and the seasonal monsoon

    Science.gov (United States)

    Saramul, Suriyan; Ezer, Tal

    2014-11-01

    The study addresses two important issues associated with sea level along the coasts of Thailand: first, the fast sea level rise and its spatial variation, and second, the monsoonal-driven seasonal variations in sea level. Tide gauge data that are more extensive than in past studies were obtained from several different local and global sources, and relative sea level rise (RSLR) rates were obtained from two different methods, linear regressions and non-linear Empirical Mode Decomposition/Hilbert-Huang Transform (EMD/HHT) analysis. The results show extremely large spatial variations in RSLR, with rates varying from ~ 1 mm y-1 to ~ 20 mm y-1; the maximum RSLR is found in the upper Gulf of Thailand (GOT) near Bangkok, where local land subsidence due to groundwater extraction dominates the trend. Furthermore, there are indications that RSLR rates increased significantly in all locations after the 2004 Sumatra-Andaman Earthquake and the Indian Ocean tsunami that followed, so that recent RSLR rates seem to have less spatial differences than in the past, but with high rates of ~ 20-30 mm y-1 almost everywhere. The seasonal sea level cycle was found to be very different between stations in the GOT, which have minimum sea level in June-July, and stations in the Andaman Sea, which have minimum sea level in February. The seasonal sea-level variations in the GOT are driven mostly by large-scale wind-driven set-up/set-down processes associated with the seasonal monsoon and have amplitudes about ten times larger than either typical steric changes at those latitudes or astronomical annual tides.

  1. Large historical eruptions at subaerial mud volcanoes, Italy

    Directory of Open Access Journals (Sweden)

    M. Manga

    2012-11-01

    Full Text Available Active mud volcanoes in the northern Apennines, Italy, currently have gentle eruptions. There are, however, historical accounts of violent eruptions and outbursts. Evidence for large past eruptions is also recorded by large decimeter rock clasts preserved in erupted mud. We measured the rheological properties of mud currently being erupted in order to evaluate the conditions needed to transport such large clasts to the surface. The mud is well-characterized by the Herschel-Bulkley model, with yield stresses between 4 and 8 Pa. Yield stresses of this magnitude can support the weight of particles with diameters up to several mm. At present, particles larger than this size are not being carried to the surface. The transport of larger clasts to the surface requires ascent speeds greater than their settling speed in the mud. We use a model for the settling of particles and rheological parameters from laboratory measurements to show that the eruption of large clasts requires ascent velocities > 1 m s−1, at least three orders of magnitude greater than during the present, comparatively quiescent, activity. After regional earthquakes on 20 May and 29 May 2012, discharge also increased at locations where the stress changes produced by the earthquakes would have unclamped feeder dikes below the mud volcanoes. The magnitude of increased discharge, however, is less than that inferred from the large clasts. Both historical accounts and erupted deposits are consistent in recording episodic large eruptions.

  2. GLACIERS OF THE KORYAK VOLCANO

    Directory of Open Access Journals (Sweden)

    T. M. Manevich

    2012-01-01

    Full Text Available The paper presents main glaciological characteristics of present-day glaciers located on the Koryaksky volcano. The results of fieldwork (2008–2009 and high-resolution satellite image analysis let us to specify and complete information on modern glacial complex of Koryaksky volcano. Now there are seven glaciers with total area 8.36 km2. Three of them advance, two are in stationary state and one degrades. Moreover, the paper describes the new crater glacier.

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

    Directory of Open Access Journals (Sweden)

    Daniel C. Bowden

    2011-06-01

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

  4. Slope instability induced by volcano-tectonics as an additional source of hazard in active volcanic areas: the case of Ischia island (Italy)

    Science.gov (United States)

    Della Seta, Marta; Marotta, Enrica; Orsi, Giovanni; de Vita, Sandro; Sansivero, Fabio; Fredi, Paola

    2012-01-01

    Ischia is an active volcanic island in the Gulf of Naples whose history has been dominated by a caldera-forming eruption (ca. 55 ka) and resurgence phenomena that have affected the caldera floor and generated a net uplift of about 900 m since 33 ka. The results of new geomorphological, stratigraphical and textural investigations of the products of gravitational movements triggered by volcano-tectonic events have been combined with the information arising from a reinterpretation of historical chronicles on natural phenomena such as earthquakes, ground deformation, gravitational movements and volcanic eruptions. The combined interpretation of all these data shows that gravitational movements, coeval to volcanic activity and uplift events related to the long-lasting resurgence, have affected the highly fractured marginal portions of the most uplifted Mt. Epomeo blocks. Such movements, mostly occurring since 3 ka, include debris avalanches; large debris flows (lahars); smaller mass movements (rock falls, slumps, debris and rock slides, and small debris flows); and deep-seated gravitational slope deformation. The occurrence of submarine deposits linked with subaerial deposits of the most voluminous mass movements clearly shows that the debris avalanches impacted on the sea. The obtained results corroborate the hypothesis that the behaviour of the Ischia volcano is based on an intimate interplay among magmatism, resurgence dynamics, fault generation, seismicity, slope oversteepening and instability, and eruptions. They also highlight that volcano-tectonically triggered mass movements are a potentially hazardous phenomena that have to be taken into account in any attempt to assess volcanic and related hazards at Ischia. Furthermore, the largest mass movements could also flow into the sea, generating tsunami waves that could impact on the island's coast as well as on the neighbouring and densely inhabited coast of the Neapolitan area.

  5. Seismic evidence for a crustal magma reservoir beneath the upper east rift zoneof Kilauea volcano, Hawaii

    Science.gov (United States)

    Lin, Guoqing; Amelung, Falk; Lavallee, Yan; Okubo, Paul G.

    2014-01-01

    An anomalous body with low Vp (compressional wave velocity), low Vs (shear wave velocity), and high Vp/Vs anomalies is observed at 8–11 km depth beneath the upper east rift zone of Kilauea volcano in Hawaii by simultaneous inversion of seismic velocity structure and earthquake locations. We interpret this body to be a crustal magma reservoir beneath the volcanic pile, similar to those widely recognized beneath mid-ocean ridge volcanoes. Combined seismic velocity and petrophysical models suggest the presence of 10% melt in a cumulate magma mush. This reservoir could have supplied the magma that intruded into the deep section of the east rift zone and caused its rapid expansion following the 1975 M7.2 Kalapana earthquake.

  6. Geophysical data collection using an interactive personal computer system. Part 1. ; Experimental monitoring of Suwanosejima volcano

    Energy Technology Data Exchange (ETDEWEB)

    Iguchi, M. (Kyoto Univerdity, Kyoto (Japan). Disaster Prevention Reserach Institute)

    1991-10-15

    In the article, a computer-communication system was developed in order to collect geophysical data from remote volcanos via a public telephpne network. This system is composed of a host presonal computer at an observatory and several personal computers as terminals at remote stations. Each terminal acquires geophysical data, such as seismic, intrasonic, and ground deformation date. These gara are stored in the terminals temporarily, and transmitted to the host computer upon command from host computer. Experimental monitoring was conducted between Sakurajima Volcanological Observatory and several statins in the Satsunan Islands and southern Kyushu. The seismic and eruptive activities of Suwanosejima volcano were monitored by this system. Consequently, earthquakes and air-shocks accompanied by the explosive activity were observed. B-type earthquakes occurred prio to the relatively prolonged eruptive activity. Intermittent occurrences of volcanic tremors were also clearly recognized from the change in mean amplitubes of seismic waves. 7 refs., 10 figs., 2 tabs.

  7. Hurricane Sandy and earthquakes

    OpenAIRE

    MAVASHEV BORIS; MAVASHEV IGOR

    2013-01-01

    Submit for consideration the connection between formation of a hurricane Sandy and earthquakes. As a rule, weather anomalies precede and accompany earthquakes. The hurricane Sandy emerged 2 days prior to strong earthquakes that occurred in the area. And the trajectory of the hurricane Sandy matched the epicenter of the earthquakes. Possibility of early prediction of natural disasters will minimize the moral and material damage.

  8. Mahukona: The missing Hawaiian volcano

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M.O.; Muenow, D.W. (Univ. of Hawaii, Honolulu (USA)); Kurz, M.D. (Woods Hole Oceanographic Institution, MA (USA))

    1990-11-01

    New bathymetric and geochemical data indicate that a seamount west of the island of Hawaii, Mahukona, is a Hawaiian shield volcano. Mahukona has weakly alkalic lavas that are geochemically distinct. They have high {sup 3}He/{sup 4}He ratios (12-21 times atmosphere), and high H{sub 2}O and Cl contents, which are indicative of the early state of development of Hawaiian volcanoes. The He and Sr isotopic values for Mahukona lavas are intermediate between those for lavas from Loihi and Manuna Loa volcanoes and may be indicative of a temporal evolution of Hawaiian magmas. Mahukona volcano became extinct at about 500 ka, perhaps before reaching sea level. It fills the previously assumed gap in the parallel chains of volcanoes forming the southern segment of the Hawaiian hotspot chain. The paired sequence of volcanoes was probably caused by the bifurcation of the Hawaiian mantle plume during its ascent, creating two primary areas of melting 30 to 40 km apart that have persisted for at least the past 4 m.y.

  9. Dynamic behavior of Kilauea Volcano and its relation to hydrothermal systems and geothermal energy

    Science.gov (United States)

    Kauhikaua, Jim; Moore, R.B.; ,

    1993-01-01

    Exploitation of hydrothermal systems on active basaltic volcanoes poses some unique questions about the role of volcanism and hydrothermal system evolution. Volcanic activity creates and maintains hydrothermal systems while earthquakes create permeable fractures that, at least temporarily, enhance circulation. Magma and water, possibly hydrothermal water, can interact violently to produce explosive eruptions. Finally, we speculate on whether volcanic behavior can be affected by high rates of heat extraction.

  10. Analysis of Distribution of Volcanoes around the Korean Peninsula and the Potential Effects on Korea

    Science.gov (United States)

    Choi, Eun-kyeong; Kim, Sung-wook

    2017-04-01

    Since the scale and disaster characteristics of volcanic eruptions are determined by their geological features, it is important not only to grasp the current states of the volcanoes in neighboring countries around the Korean Peninsula, but also to analyze the tectonic settings, tectonic regions, geological features, volcanic types, and eruption histories of these volcanoes. Volcanic data were based on the volcano information registered with the Global Volcanism Program at the Smithsonian Institute. We created a database of 289 volcanoes around Korea, Japan, China, Taiwan, and the Kamchatka area in Russia, and then identified a high-risk group of 29 volcanoes that are highly likely to affect the region, based on conditions such as volcanic activity, types of rock at risk of eruption, distance from Seoul, and volcanoes having Plinian eruption history with volcanic explosivity index (VEI) of 4 or more. We selected 29 hazardous volcanoes, including Baekdusan, Ulleungdo, and 27 Japanese volcanoes that can cause widespread ashfall on the Korean peninsula by potentially explosive eruptions. In addition, we identified ten volcanoes that should be given the highest priority, through an analysis of data available in literature, such as volcanic ash dispersion results from previous Japanese eruptions, the definition of a large-scale volcano used by Japan's Cabinet Office, and examination of cumulative magma layer volumes from Japan's quaternary volcanoes. We expect that predicting the extent of the spread of ash caused by this hazardous activity and analyzing its impact on the Korean peninsula will be help to predict volcanic ash damage as well as provide direction for hazard mitigation research. Acknowledgements This research was supported by a grant [MPSS-NH-2015-81] through the Disaster and Safety Management Institute funded by Ministry of Public Safety and Security of Korean government.

  11. Losses Associated with Secondary Effects in Earthquakes

    Directory of Open Access Journals (Sweden)

    James E. Daniell

    2017-06-01

    Full Text Available The number of earthquakes with high damage and high losses has been limited to around 100 events since 1900. Looking at historical losses from 1900 onward, we see that around 100 key earthquakes (or around 1% of damaging earthquakes have caused around 93% of fatalities globally. What is indeed interesting about this statistic is that within these events, secondary effects have played a major role, causing around 40% of economic losses and fatalities as compared to shaking effects. Disaggregation of secondary effect economic losses and fatalities demonstrating the relative influence of historical losses from direct earthquake shaking in comparison to tsunami, fire, landslides, liquefaction, fault rupture, and other type losses is important if we are to understand the key causes post-earthquake. The trends and major event impacts of secondary effects are explored in terms of their historic impact as well as looking to improved ways to disaggregate them through two case studies of the Tohoku 2011 event for earthquake, tsunami, liquefaction, fire, and the nuclear impact; as well as the Chilean 1960 earthquake and tsunami event.

  12. Strongly gliding harmonic tremor during the 2009 eruption of Redoubt Volcano

    Science.gov (United States)

    Hotovec, Alicia J.; Prejean, Stephanie G.; Vidale, John E.; Gomberg, Joan S.

    2013-01-01

    During the 2009 eruption of Redoubt Volcano, Alaska, gliding harmonic tremor occurred prominently before six nearly consecutive explosions during the second half of the eruptive sequence. The fundamental frequency repeatedly glided upward from < 1 Hz to as high as 30 Hz in less than 10 min, followed by a relative seismic quiescence of 10 to 60 s immediately prior to explosion. High frequency (5 to 20 Hz) gliding returned during the extrusive phase, and lasted for 20 min to 3 h at a time. Although harmonic tremor is not uncommon at volcanoes, tremor at such high frequencies is a rare observation. These frequencies approach or exceed the plausible upper limits of many models that have been suggested for volcanic tremor. We also analyzed the behavior of a swarm of repeating earthquakes that immediately preceded the first instance of pre-explosion gliding harmonic tremor. We find that these earthquakes share several traits with upward gliding harmonic tremor, and favor the explanation that the gliding harmonic tremor at Redoubt Volcano is created by the superposition of increasingly frequent and regular, repeating stick–slip earthquakes through the Dirac comb effect.

  13. Magnitude 8.1 Earthquake off the Solomon Islands

    Science.gov (United States)

    2007-01-01

    On April 1, 2007, a magnitude 8.1 earthquake rattled the Solomon Islands, 2,145 kilometers (1,330 miles) northeast of Brisbane, Australia. Centered less than ten kilometers beneath the Earth's surface, the earthquake displaced enough water in the ocean above to trigger a small tsunami. Though officials were still assessing damage to remote island communities on April 3, Reuters reported that the earthquake and the tsunami killed an estimated 22 people and left as many as 5,409 homeless. The most serious damage occurred on the island of Gizo, northwest of the earthquake epicenter, where the tsunami damaged the hospital, schools, and hundreds of houses, said Reuters. This image, captured by the Landsat-7 satellite, shows the location of the earthquake epicenter in relation to the nearest islands in the Solomon Island group. Gizo is beyond the left edge of the image, but its triangular fringing coral reefs are shown in the upper left corner. Though dense rain forest hides volcanic features from view, the very shape of the islands testifies to the geologic activity of the region. The circular Kolombangara Island is the tip of a dormant volcano, and other circular volcanic peaks are visible in the image. The image also shows that the Solomon Islands run on a northwest-southeast axis parallel to the edge of the Pacific plate, the section of the Earth's crust that carries the Pacific Ocean and its islands. The earthquake occurred along the plate boundary, where the Australia/Woodlark/Solomon Sea plates slide beneath the denser Pacific plate. Friction between the sinking (subducting) plates and the overriding Pacific plate led to the large earthquake on April 1, said the United States Geological Survey (USGS) summary of the earthquake. Large earthquakes are common in the region, though the section of the plate that produced the April 1 earthquake had not caused any quakes of magnitude 7 or larger since the early 20th century, said the USGS.

  14. Why did we lose the 59 climbers in 2014 Ontake Volcano Eruption?

    Science.gov (United States)

    Kimata, F.

    2015-12-01

    The first historical eruption at Ontake volcano, central Japan was in 1979, and it was a phreatic eruption. Until then, most Japanese volcanologists understood that Ontake is a dormant or an extinct volcano. Re-examination of active volcanoes was done after the eruption.After the first historical eruption in 1979, two small eruptions are repeated in 1991 and 2007. Through the three eruptions, nobody has got injured. The last eruption on September 27, 2014, we lost 65 people included missing. Because it was fine weekend and there were many climbers on the summit. The eruption was almost at lunchtime. Clearly, casualties by tsunamis are inhabitants along the coastlines, and casualties by eruption are visitors not inhabitants around the volcano. Basically, visitors have small information of Ontake volcano. After the accident, one mountain guide tells us that we never have long broken such as lunch around the summit, because an active creator is close, and they are afraid of the volcano gas accidents. All casualties by eruption were lost their lives in the area of 1.0 km distance from the 2014 creators. In 2004 Sumatra Earthquake Tsunami, we could not recognize the tsunami inspiration between the habitants in Banda Aceh, Sumatra. They have no idea of tsunami, and they called "Rising Sea" never"Tsunami". As the result, they lost many habitants close to the coast. In 2011 Tohoku Earthquake Tsunami, when habitants felt strong shaking close to coast, they understood the tsunami coming. 0ver 50 % habitants decide to evacuate from the coast. However, 20-30 % habitants believe in themselves no tsunami attacking for them. As a result we lost many habitants. Additionally, the tsunami height was higher than broadcasting one by JMA. According to the results of the questionnaire survey in climbers or bereaved families of the eruption day on Ontake volcano (Shinano Mainich Newspaper, 2015), 39 % of them were climbing no understand of "Ontake active volcano". Moreover, only 10

  15. Mud Volcanoes Formation And Occurrence

    Science.gov (United States)

    Guliyev, I. S.

    2007-12-01

    Mud volcanoes are natural phenomena, which occur throughout the globe. They are found at a greater or lesser scale in Azerbaijan, Turkmenistan, Georgia, on the Kerch and Taman peninsulas, on Sakhalin Island, in West Kuban, Italy, Romania, Iran, Pakistan, India, Burma, China, Japan, Indonesia, Malaysia, New Zealand, Mexico, Colombia, Trinidad and Tobago, Venezuela and Ecuador. Mud volcanoes are most well-developed in Eastern Azerbaijan, where more than 30% of all the volcanoes in the world are concentrated. More than 300 mud volcanoes have already been recognized here onshore or offshore, 220 of which lie within an area of 16,000 km2. Many of these mud volcanoes are particularly large (up to 400 m high). The volcanoes of the South Caspian form permanent or temporary islands, and numerous submarine banks. Many hypotheses have been developed regarding the origin of mud volcanoes. Some of those hypotheses will be examined in the present paper. Model of spontaneous excitation-decompaction (proposed by Ivanov and Guliev, 1988, 2002). It is supposed that one of major factors of the movement of sedimentary masses and formation of hydrocarbon deposits are phase transitions in sedimentary basin. At phase transitions there are abnormal changes of physical and chemical parameters of rocks. Abnormal (high and negative) pressure takes place. This process is called as excitation of the underground environment with periodicity from several tens to several hundreds, or thousand years. The relationship between mud volcanism and the generation of hydrocarbons, particularly methane, is considered to be a critical factor in mud volcano formation. At high flow rates the gas and sediment develops into a pseudo-liquid state and as flow increases the mass reaches the "so-called hover velocity" where mass transport begins. The mass of fluid moves as a quasi-uniform viscous mass through the sediment pile in a piston like manner until expelled from the surface as a "catastrophic eruption

  16. Ceboruco Volcano Seismicity Study using a 3D Single Digital Station

    Science.gov (United States)

    Rodriguez-Uribe, M. C.; Nunez-Cornu, F. J.; Nava Pichardo, F. A.; Suarez-Plascencia, C.; Escudero Ayala, C. R.

    2011-12-01

    The Ceboruco stratovolcano (2,280 m.a.s.l.) is located in Nayarit, Mexico, at the west of the Mexican volcanic belt and towards the Sierra de San Pedro southeast. It last eruptive activity was in 1875, and during the following five years it presents superficial activity such as vapor emissions, ash falls and riodacític composition lava flows along the southeast side. We use data recorded from March 2003 to July 2008 at the CEBN triaxial short period digital station located at the southwest side of the volcano. Our final data set consist of 139 volcanic earthquakes. We classified them according waveform characteristics of the east-west horizontal component. We obtained four groups: impulsive arrivals, extended coda, bobbin form, and wave package amplitude modulation earthquakes. The extended coda is the group with more earthquakes and present durations of 50 seconds. Using the moving particle technique, we read the P and S wave arrival times and estimate azimuth arrivals. A P-wave velocity of 3.0 km/s was used to locate the earthquakes, the hypocenters are below the volcanic building within a circular perimeter of 5 km of radius and its depths are calculated relative to the CEBN elevation as follows. The impulsive arrivals earthquakes present hypocenters between 0 and 1 km while the other groups between 0 and 4 km. The epicenters show similar directions as the tectonic structures of the area (Tepic-Zacoalco Graben and regional faults). Results suggest fluid activity inside the volcanic building that could be related to fumes on the volcano. We conclude that the Ceboruco volcano is active. Therefore, it should be continuously monitored due to the risk that represent to the surrounding communities and economic activities.

  17. Tohoku earthquake: a surprise?

    CERN Document Server

    Kagan, Yan Y

    2011-01-01

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

  18. Numerical earthquake simulations for seismic hazard assessment

    Science.gov (United States)

    Ismail-Zadeh, Alik; Sokolov, Vladimir; Soloviev, Alexander

    2017-04-01

    A comprehensive seismic hazard assessment can contribute to earthquake preparedness and preventive measures aimed to reduce impacts of earthquakes, especially in the view of growing population and increasing vulnerability and exposure. Realistic earthquake simulations coupled with a seismic hazard analysis can provide better assessments of potential ground shaking due to large earthquakes. We present a model of block-and-fault dynamics, which simulates earthquakes in response to lithosphere movements and allows for studying the influence of fault network properties on seismic patterns. Using case studies (e.g., the Tibet-Himalayan region and the Caucasian region), we analyse the model's performance in terms of reproduction of basic features of the observed seismicity, such as the frequency-magnitude relationship, clustering of earthquakes, occurrences of large events, fault slip rates, and earthquake mechanisms. We examine a new approach to probabilistic seismic hazard assessment, which is based on instrumentally recorded, historical and simulated earthquakes. Based on predicted and observed peak ground acceleration values, we show that the hazard level associated with large events significantly increases if the long record of simulated seismicity is considered in the hazard assessment.

  19. A Review of Impact of Bam Earthquake on Cutaneous Leishmaniasis and Status: Epidemic of Old Foci, Emergence of New Foci and Changes in Features of the Disease

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Aflatoonian

    2016-01-01

    Full Text Available Background: Global findings indicate that incidence rate of cutaneous leishmaniasis (CL has significantly in­creased during the past decade, as documented in many countries. This review was aimed to evaluate the trend of CL cases in terms of demographic and clinical characteristics during a decade after the earthquake (2003–2012 com­pared to the corresponding period before the earthquake in Bam (1993–2003.Methods: Direct smear preparations along with different intrinsic methods were used for detection and identification of the causative agents.Results: Overall, 20999 cases of CL have occurred during the last 20 years (1993–2012, 6731 cases before and 14268 cases after the earthquake (P< 0.001.Conclusions: Following a major earthquake, several risk factors could activate epidemics of cutaneous leishmaniasis in old foci and induce emerging foci in new areas.

  20. Hunting remnants of maar-diatreme-volcanoes

    Science.gov (United States)

    Kroner, Corinna; Kämpf, Horst; Matthes, Heidrun; Jahr, Thomas; Markwart, David; Hermann, Tobias; Mrlina, Jan

    2010-05-01

    In the area of the Rostock-Leipzig-Regensburg fault zone (Germany) several centres of seismic activity are found with seismicity manifesting itself in swarm earthquakes. The occurrence of these earthquakes is globally linked to ascending magma and magmatic fluids. Information is scarce regarding the depth and geometry of the magmatic source, dynamics in the sub-Moho/lower crust region and fluid-tectonic processes in the upper crust in this area. From studies of maar structures located in the seismic active section of the fault zone magma-tectonic phenomena can be reconstructed. For this purpose two relicts of maar volcanoes of different age within a distance of 60 km are investigated by geophysical surveys. Both structures are located in a distance of a few 10 km from recent swarm earthquake centres. The diatreme structure near Ebersbrunn/W-Saxony which is probably of tertiary age is known for several years, the late Quaternary, volcanic palaeo-lake near Mýtina close to the Czech-German border was only recently discovered. Both structures are characterized by distinct gravimetric and magnetic anomalies of about -2 mGal and several 100 nT resp. indicating steeply dipping structures as well as electrical conductivity anomalies. The magnetic total field anomaly of the Ebersbrunn structure has an uncommon rugged appearance. The hypothesis of an origin related to a redistribution of material with high magnetic susceptibility values and saponification of magnetic minerals due to melt water run-off after the last glacial period could not be confirmed. Thus the heterogeneous anomaly character appears to be mainly associated with the degree of weathering of the volcanic material within the diatreme with depth. From 3D gravimetric and magnetic modelling information is gained on geometry and structural composition. Drilling results were used as additional boundary conditions. In both cases modelling reveals an inner zone of significantly reduced density and increased

  1. Space Radar Image of Kilauea Volcano, Hawaii

    Science.gov (United States)

    1994-01-01

    This is a deformation map of the south flank of Kilauea volcano on the big island of Hawaii, centered at 19.5 degrees north latitude and 155.25 degrees west longitude. The map was created by combining interferometric radar data -- that is data acquired on different passes of the space shuttle which are then overlayed to obtain elevation information -- acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar during its first flight in April 1994 and its second flight in October 1994. The area shown is approximately 40 kilometers by 80 kilometers (25 miles by 50 miles). North is toward the upper left of the image. The colors indicate the displacement of the surface in the direction that the radar instrument was pointed (toward the right of the image) in the six months between images. The analysis of ground movement is preliminary, but appears consistent with the motions detected by the Global Positioning System ground receivers that have been used over the past five years. The south flank of the Kilauea volcano is among the most rapidly deforming terrains on Earth. Several regions show motions over the six-month time period. Most obvious is at the base of Hilina Pali, where 10 centimeters (4 inches) or more of crustal deformation can be seen in a concentrated area near the coastline. On a more localized scale, the currently active Pu'u O'o summit also shows about 10 centimeters (4 inches) of change near the vent area. Finally, there are indications of additional movement along the upper southwest rift zone, just below the Kilauea caldera in the image. Deformation of the south flank is believed to be the result of movements along faults deep beneath the surface of the volcano, as well as injections of magma, or molten rock, into the volcano's 'plumbing' system. Detection of ground motions from space has proven to be a unique capability of imaging radar technology. Scientists hope to use deformation data acquired by SIR-C/X-SAR and future imaging

  2. Spatial and Temporal Distributions and Types of Impacts of Earthquake Disasters on Transportation from 1831 BC to 1980 AD in China%公元前1831年-公元1980年中国地震灾害对交通影响的时空分布及其类型

    Institute of Scientific and Technical Information of China (English)

    任慧子; 曹小曙

    2011-01-01

    Earthquake disasters have significant effects on traffic.With the development of economy and tech-nology,the ability of people to deal with natural disasters is gradually enhanced.The vulnerability of the trans-portation system after earthquake disasters and the"lifeline"role that transportation system plays prompt people to pay more attention to the impacts of earthquake disasters on traffic.The research on earthquake disasters and traffic and other related issues are concentrated in earthquake engineering fields,namely from the perspective of traffic engineering construction to study the earthquake resistant behavior of the traffic system.There are rela-tively few studies from the perspective of human geography on the impacts of earthquake disasters on traffic based on the historical earthquake data.China has more detailed historical earthquake materials and data than any other countries in the world.China has not only a great deal of historical earthquake data,but also a large number of modern earthquake assembly data.On the basis of comprehensively coordinating the earthquake di-saster data from 1831 BC to 1980 AD,and using the GIS technology,this article discusses the characteristics of China's earthquake disasters in time and space,and their influences.The earthquakes in China are imbalanced in spatial and temporal distributions.In the Yuan Dynasty,the earthquakes were concentrated in Shanxi,Henan and Shaanxi.Earthquakes in Southwest China and Taiwan increased in the Ming and Qing dynasties,and those in the Republic of China and during 1949-1980 occurred mainly in Southwest China,Northwest China and Tai-wan.Traffic impacts by earthquake disasters were also concentrated in Northwest and Southwest China,especial-ly in Yunnan,Sichuan and Xinjiang.The earthquakes with high intensities had significant influences on the trans-portation system of Xinjiang.And in Sichuan and Yunnan provinces,the earthquakes with low intensity also had great influences on the

  3. Remote Sensing of Active Volcanoes

    Science.gov (United States)

    Francis, Peter; Rothery, David

    The synoptic coverage offered by satellites provides unparalleled opportunities for monitoring active volcanoes, and opens new avenues of scientific inquiry. Thermal infrared radiation can be used to monitor levels of activity, which is useful for automated eruption detection and for studying the emplacement of lava flows. Satellite radars can observe volcanoes through clouds or at night, and provide high-resolution topographic data. In favorable conditions, radar inteferometery can be used to measure ground deformation associated with eruptive activity on a centimetric scale. Clouds from explosive eruptions present a pressing hazard to aviation; therefore, techniques are being developed to assess eruption cloud height and to discriminate between ash and meterological clouds. The multitude of sensors to be launched on future generations of space platforms promises to greatly enhance volcanological studies, but a satellite dedicated to volcanology is needed to meet requirements of aviation safety and volcano monitoring.

  4. Mount Rainier: A decade volcano

    Science.gov (United States)

    Swanson, Donald A.; Malone, Stephen D.; Samora, Barbara A.

    Mount Rainier, the highest (4392 m) volcano in the Cascade Range, towers over a population of more than 2.5 million in the Seattle-Tacoma metropolitan area, and its drainage system via the Columbia River potentially affects another 500,000 residents of southwestern Washington and northwestern Oregon (Figure 1). Mount Rainier is the most hazardous volcano in the Cascades in terms of its potential for magma-water interaction and sector collapse. Major eruptions, or debris flows even without eruption, pose significant dangers and economic threats to the region. Despite such hazard and risk, Mount Rainier has received little study; such important topics as its petrologic and geochemical character, its proximal eruptive history, its susceptibility to major edifice failure, and its development over time have been barely investigated. This situation may soon change because of Mount Rainier's recent designation as a “Decade Volcano.”

  5. Infrasound Monitoring of the Volcanic Activities of Japanese Volcanoes in Korea

    Science.gov (United States)

    Lee, H. I.; Che, I. Y.; Shin, J. S.

    2015-12-01

    Since 1999 when our first infrasound array station(CHNAR) has been installed at Cheolwon, Korea Institute of Geoscience and Mineral Resources(KIGAM) is continuously observing infrasound signals with an infrasound array network, named KIN(Korean Infrasound Network). This network is comprised of eight seismo-acoustic array stations(BRDAR, YPDAR, KMPAR, CHNAR, YAGAR, KSGAR, ULDAR, TJIAR). The aperture size of the smallest array is 300m and the largest is about 1.4km. The number of infrasound sensors are between 4(TJIAR) and 18(YAGAR), and 1~5 seismometers are collocated with infrasound sensors. Many interesting infrasound signals associated with different type of sources, such as blasting, large earthquake, bolide, volcanic explosion are detected by KIN in the past 15 years. We have analyzed the infrasound signals possibly associated with the japanese volcanic explosions with reference to volcanic activity report published by Japanese Meteorological Agency. Analysis results of many events, for example, Asama volcano explosion in 2004 and Shinmoe volcano in 2011, are well matched with the official report. In some cases, however, corresponding infrasound signals are not identified. By comparison of the infrasound signals from different volcanoes, we also found that the characteristics of signals are distinguishing. It may imply that the specific volcano has its own unique fingerprint in terms of infrasound signal. It might be investigated by long-term infrasound monitoring for a specific volcano as a ground truth generating repetitive infrasound signal.

  6. Systematic radon survey over active volcanoes

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, J.L.; Monnin, M.; Garcia Vindas, J.R. [Centre National de la Recherche Cientifique, Montpellier (France). Lab. GBE; Ricard, L.P.; Staudacher, T. [Observatoire Volcanologique Du Pitou de la Fournaise, La Plaine des Cafres (France)

    1999-08-01

    Data obtained since 1993 on Costa Rica volcanos are presented and radon anomalies recorded before the eruption of the Irazu volcano (December 8, 1994) are discussed. The Piton de la Fournaise volcano is inactive since mid 1992. The influence of the external parameters on the radon behaviour is studied and the type of perturbations induced on short-term measurements are individuate.

  7. InSAR Analysis of the 2011 Hawthorne (Nevada) Earthquake Swarm: Implications of Earthquake Migration and Stress Transfer

    Science.gov (United States)

    Zha, X.; Dai, Z.; Lu, Z.

    2015-12-01

    earthquake may trigger the subsequence one. Because no abnormal volcano activity was observed during the 2011 Hawthorne earthquake swarm, we can rule out the volcano activity to induce these events. However, the groundwater change and mining in the epicentral zone may contribute to the 2011 Hawthorne earthquake.

  8. Earthquake vulnerability evaluation Faizabad district of Kermanshah

    Directory of Open Access Journals (Sweden)

    Saba Naderi

    2014-07-01

    Full Text Available This paper as examplehas been studied Faizabad district of Kermanshah and to reach its main purpose, which is reducing the damagecaused by the earthquake on the Faizabad district is been providedand in subsidiary purposes part the research is tried identify factors influence in vulnerability earthquakes,pay to provide the factors required; All these factors havean impact on reducing earthquake vulnerability. This data using geological data, soil texture, getting satelliteimages and layering over Arc Gis software identified and for long term periods donepredict using relation kernel PSHA also. In determining the level ofenvironmental risk is to use software crisis. Finally, by recognizing the riskzone, solutions for Faizabad district offered.

  9. Seismicity controlled by resistivity structure: the 2016 Kumamoto earthquakes, Kyushu Island, Japan

    Science.gov (United States)

    Aizawa, Koki; Asaue, Hisafumi; Koike, Katsuaki; Takakura, Shinichi; Utsugi, Mitsuru; Inoue, Hiroyuki; Yoshimura, Ryokei; Yamazaki, Ken'ichi; Komatsu, Shintaro; Uyeshima, Makoto; Koyama, Takao; Kanda, Wataru; Shiotani, Taro; Matsushima, Nobuo; Hata, Maki; Yoshinaga, Tohru; Uchida, Kazunari; Tsukashima, Yuko; Shito, Azusa; Fujita, Shiori; Wakabayashi, Asuma; Tsukamoto, Kaori; Matsushima, Takeshi; Miyazaki, Masahiro; Kondo, Kentaro; Takashima, Kanade; Hashimoto, Takeshi; Tamura, Makoto; Matsumoto, Satoshi; Yamashita, Yusuke; Nakamoto, Manami; Shimizu, Hiroshi

    2017-01-01

    The M JMA 7.3 Kumamoto earthquake that occurred at 1:25 JST on April 16, 2016, not only triggered aftershocks in the vicinity of the epicenter, but also triggered earthquakes that were 50-100 km away from the epicenter of the main shock. The active seismicity can be divided into three regions: (1) the vicinity of the main faults, (2) the northern region of Aso volcano (50 km northeast of the mainshock epicenter), and (3) the regions around three volcanoes, Yufu, Tsurumi, and Garan (100 km northeast of the mainshock epicenter). Notably, the zones between these regions are distinctively seismically inactive. The electric resistivity structure estimated from one-dimensional analysis of the 247 broadband (0.005-3000 s) magnetotelluric and telluric observation sites clearly shows that the earthquakes occurred in resistive regions adjacent to conductive zones or resistive-conductive transition zones. In contrast, seismicity is quite low in electrically conductive zones, which are interpreted as regions of connected fluids. We suggest that the series of the earthquakes was induced by a local accumulated stress and/or fluid supply from conductive zones. Because the relationship between the earthquakes and the resistivity structure is consistent with previous studies, seismic hazard assessment generally can be improved by taking into account the resistivity structure. Following on from the 2016 Kumamoto earthquake series, we suggest that there are two zones that have a relatively high potential of earthquake generation along the western extension of the MTL. [Figure not available: see fulltext.

  10. Impacts of Social Network on Therapeutic Community Participation: A Follow-up Survey of Data Gathered after Ya'an Earthquake.

    Directory of Open Access Journals (Sweden)

    Zhichao Li

    2015-01-01

    Full Text Available In recent years, natural disasters and the accompanying health risks have become more frequent, and rehabilitation work has become an important part of government performance. On one hand, social networks play an important role in participants' therapeutic community participation and physical & mental recovery. On the other hand, therapeutic communities with widespread participation can also contribute to community recovery after disaster.This paper described a field study in an earthquake-stricken area of Ya'an. A set of 3-stage follow-up data was obtained concerning with the villagers' participation in therapeutic community, social network status, demographic background, and other factors. The Hierarchical linear Model (HLM method was used to investigate the determinants of social network on therapeutic community participation.First, social networks have significantly impacts on the annual changes of therapeutic community participation. Second, there were obvious differences in education between groups mobilized by the self-organization and local government. However, they all exerted the mobilization force through the acquaintance networks. Third, local cadre networks of villagers could negatively influence the activities of self-organized therapeutic community, while with positively influence in government-organized therapeutic activities.This paper suggests that relevant government departments need to focus more on the reconstruction and cultivation of villagers' social network and social capital in the process of post-disaster recovery. These findings contribute to better understandings of how social networks influence therapeutic community participation, and what role local government can play in post-disaster recovery and public health improvement after natural disasters.

  11. Tohoku-Oki Earthquake Tsunami Runup and Inundation Data for Sites Around the Island of Hawaiʻi

    Science.gov (United States)

    Trusdell, Frank A.; Chadderton, Amy; Hinchliffe, Graham; Hara, Andrew; Patenge, Brent; Weber, Tom

    2012-01-01

    At 0546 U.t.c. March 11, 2011, a Mw 9.0 ("great") earthquake occurred near the northeast coast of Honshu Island, Japan, generating a large tsunami that devastated the east coast of Japan and impacted many far-flung coastal sites around the Pacific Basin. After the earthquake, the Pacific Tsunami Warning Center issued a tsunami alert for the State of Hawaii, followed by a tsunami-warning notice from the local State Civil Defense on March 10, 2011 (Japan is 19 hours ahead of Hawaii). After the waves passed the islands, U.S. Geological Survey (USGS) scientists from the Hawaiian Volcano Observatory (HVO) measured inundation (maximum inland distance of flooding), runup (elevation at maximum extent of inundation) and took photographs in coastal areas around the Island of Hawaiʻi. Although the damage in West Hawaiʻi is well documented, HVO's mapping revealed that East Hawaiʻi coastlines were also impacted by the tsunami. The intent of this report is to provide runup and inundation data for sites around the Island of Hawaiʻi.

  12. Short-term seismic quiescence immediately preceding explosions during the 2011 eruption of Telica Volcano, Nicaragua

    Science.gov (United States)

    Rodgers, M.; Roman, D. C.; Geirsson, H.; La Femina, P. C.; Muñoz, A.; Tenorio, V.

    2013-12-01

    Telica Volcano, Nicaragua, experienced a VEI 2 eruptive episode from March-June 2011. The eruption consisted of numerous small to moderate ash explosions, many of which were observed visually and recorded by a local broadband seismic network (the TESAND network). Seismicity at Telica during both background and eruptive periods is characterized by generally high and variable rates of low-magnitude volcano-seismic events. Explosions at Telica are also detected seismically and distinguished from volcanic earthquakes by the length of the seismic signal, their emergent nature and 'cigar-shaped' envelope, and broadband spectral content. During the month of May 2011, we identified 16 explosion events on a seismometer located 0.5 km from the crater vent, some of which correlate with visually observed explosions. From May 1-12, ten explosions are apparent in continuous seismic data. During this period, the rate of volcano-seismic events is relatively low (0-20 events/hour with an average of 4 events per hour). Prior to eight of the 10 explosions, there were no detected seismic events within one hour of the explosion. From May 13-31, seven explosions were identified in the continuous seismic data. During this period, the rate of volcano-seismic events is relatively high (0-48 events per hour, with an average of 18 events per hour). In the hour preceding all seven explosions, there were no detected volcano-seismic events. Visual inspection of the continuous seismic data confirms that a strong decrease in the number of volcano-seismic events immediately preceded most of the 2011 explosions at Telica Volcano. We suggest that the apparent short-term decrease in seismicity before explosions at Telica is related to a cycle of pressure buildup and release in the shallow magmatic-hydrothermal system, with an increase in pressure prior to the explosions both resulting from and reflecting constriction of gas pathways.

  13. Preliminary volcano-hazard assessment for Augustine Volcano, Alaska

    Science.gov (United States)

    Waythomas, Christopher F.; Waitt, Richard B.

    1998-01-01

    Augustine Volcano is a 1250-meter high stratovolcano in southwestern Cook Inlet about 280 kilometers southwest of Anchorage and within about 300 kilometers of more than half of the population of Alaska. Explosive eruptions have occurred six times since the early 1800s (1812, 1883, 1935, 1964-65, 1976, and 1986). The 1976 and 1986 eruptions began with an initial series of vent-clearing explosions and high vertical plumes of volcanic ash followed by pyroclastic flows, surges, and lahars on the volcano flanks. Unlike some prehistoric eruptions, a summit edifice collapse and debris avalanche did not occur in 1812, 1935, 1964-65, 1976, or 1986. However, early in the 1883 eruption, a portion of the volcano summit broke loose forming a debris avalanche that flowed to the sea. The avalanche initiated a small tsunami reported on the Kenai Peninsula at English Bay, 90 kilometers east of the volcano. Plumes of volcanic ash are a major hazard to jet aircraft using Anchorage International and other local airports. Ashfall from future eruptions could disrupt oil and gas operations and shipping activities in Cook Inlet. Eruptions similar to the historical and prehistoric eruptions are likely in Augustine's future.

  14. Earthquake Damage - General

    Data.gov (United States)

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

  15. Earthquake Notification Service

    Data.gov (United States)

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

  16. 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.

  17. Earthquakes in Southern California

    Data.gov (United States)

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

  18. Shallow magma accumulation at Kilauea Volcano, Hawai'i, revealed by microgravity surveys

    Science.gov (United States)

    Johnson, David J.; Eggers, Albert A.; Bagnardi, Marco; Battaglia, Maurizio; Poland, Michael P.; Miklius, Asta

    2010-01-01

    Using microgravity data collected at Kilauea Volcano, Hawai'i (United States), between November 1975 and January 2008, we document significant mass increase beneath the east margin of Halema'uma'u Crater, within Kilauea's summit caldera. Surprisingly, there was no sustained uplift accompanying the mass accumulation. We propose that the positive gravity residual in the absence of significant uplift is indicative of magma accumulation in void space (probably a network of interconnected cracks), which may have been created when magma withdrew from the summit in response to the 29 November 1975 M = 7.2 south flank earthquake. Subsequent refilling documented by gravity represents a gradual recovery from that earthquake. A new eruptive vent opened at the summit of Kilauea in 2008 within a few hundred meters of the positive gravity residual maximum, probably tapping the reservoir that had been accumulating magma since the 1975 earthquake.

  19. Shallow magma accumulation at Kīlauea Volcano, Hawai‘i, revealed by microgravity surveys

    Science.gov (United States)

    Johnson, Daniel J.; Eggers, Albert A.; Bagnardi, Marco; Battaglia, Maurizio; Poland, Michael P.; Miklius, Asta

    2010-01-01

    Using microgravity data collected at Kīlauea Volcano, Hawai‘i (United States), between November 1975 and January 2008, we document significant mass increase beneath the east margin of Halema‘uma‘u Crater, within Kīlauea's summit caldera. Surprisingly, there was no sustained uplift accompanying the mass accumulation. We propose that the positive gravity residual in the absence of significant uplift is indicative of magma accumulation in void space (probably a network of interconnected cracks), which may have been created when magma withdrew from the summit in response to the 29 November 1975 M = 7.2 south flank earthquake. Subsequent refilling documented by gravity represents a gradual recovery from that earthquake. A new eruptive vent opened at the summit of Kīlauea in 2008 within a few hundred meters of the positive gravity residual maximum, probably tapping the reservoir that had been accumulating magma since the 1975 earthquake.

  20. EARTHQUAKE SCALING PARADOX

    Institute of Scientific and Technical Information of China (English)

    WU ZHONG-LIANG

    2001-01-01

    Two measures of earthquakes, the seismic moment and the broadband radiated energy, show completely different scaling relations. For shallow earthquakes worldwide from January 1987 to December 1998, the frequency distribution of the seismic moment shows a clear kink between moderate and large earthquakes, as revealed by previous works. But the frequency distribution of the broadband radiated energy shows a single power law, a classical Gutenberg-Richter relation. This inconsistency raises a paradox in the self-organized criticality model of earthquakes.

  1. Risk-Free Volcano Observations Using an Unmanned Autonomous Helicopter: seismic observations near the active vent of Sakurajima volcano, Japan

    Science.gov (United States)

    Ohminato, T.; Kaneko, T.; Koyama, T.; Yasuda, A.; Watanabe, A.; Takeo, M.; Honda, Y.; Kajiwara, K.; Kanda, W.; Iguchi, M.; Yanagisawa, T.

    2010-12-01

    Observations in the vicinity of summit area of active volcanoes are important not only for understanding physical processes in the volcanic conduit but also for eruption prediction and volcanic hazards mitigation. It is, however, challenging to install observation sensors near active vents because of the danger of sudden eruptions. We need safe and efficient ways of installing sensors near the summit of active volcanoes. We have been developing an volcano observation system based on an unmanned autonomous vehicle (UAV) for risk-free volcano observations. Our UAV is an unmanned autonomous helicopter manufactured by Yamaha-Motor Co., Ltd. The UAV is 3.6m long and weighs 84kg with maximum payload of 10kg. The UAV can aviate autonomously along a previously programmed path within a meter accuracy using real-time kinematics differential GPS equipment. The maximum flight time and distance from the operator are 90 minutes and 5km, respectively. We have developed various types of volcano observation techniques adequate for the UAV, such as aeromagnetic survey, taking infrared and visible images from onboard high-resolution cameras, volcanic ash sampling in the vicinity of active vents. Recently, we have developed an earthquake observation module (EOM), which is exclusively designed for the UAV installation in the vicinity of active volcanic vent. In order to meet the various requirements for UAV installation, the EOM is very compact, light-weight (5-6kg), and is solar-powered. It is equipped with GPS for timing, a communication device using cellular-phone network, and triaxial accelerometers. Our first application of the EOM installation using the UAV is one of the most active volcanoes in Japan, Sakurajima volcano. Since 2006, explosive eruptions have been continuing at the reopened Showa crater at the eastern flank near the summit of Sakurajima. Entering the area within 2 km from the active craters is prohibited, and thus there were no observation station in the vicinity

  2. Self repair of impacts, higher energy impacts, and earthquake damage in critical targets such as infrastructure components made of polymers and concrete

    Science.gov (United States)

    Dry, Carolyn

    2007-04-01

    The goal of our research has been to develop self-repairing matrices with unique toughness and strength for infrastructure and vehicles. Our revolutionary approach involves the autonomous release of repair chemicals from within the matrix itself. The repair agents are contained in hollow, structural fibers or beads that are embedded within the matrix. Under stress, the matrix senses external environmental factors and reacts by releasing the repair agents from within the hollow vessels. This autonomous response occurs wherever and whenever cracking, debonding or other matrix damage transpires. Superior performance over the life of the matrix is achieved through this self-repairing mechanism. The advantages are safely executed trips, fewer repairs and eventually lighter bridges and vehicles. Research to assess and clarify the impact of the various factors involved in self-repair of matrix materials has been the focus of our work for several years. Our research has addressed the issues by correlating the impact of the various factors, such as 1) delivery vessel, shape/size, coating, chemicals released, release trigger and efficacy and impact on matrix properties 2) influence of end use such as the importance of speed and force of release (airplane skin repair) 3) impact of processing methods that involve heat and pressure on the repair vessels. Our self repairing system can: be processed at temperatures of 350F, repairs in less than 30 seconds, and does not damage the matrix by repair fiber insertion. Unique toughness and strength is developed at damaged areas and material interfaces. Findings are based on testing in compression after impact, compression, fatigue, flexural toughness and flexure modes. The presentation will focus on highlighting the issues that were resolved in creating autonomous, self-repairing structures and vehicles.

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

    Science.gov (United States)

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

    1996-01-01

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

  4. Visco-elastic stress triggering model of Tangshan earthquake sequence

    Institute of Scientific and Technical Information of China (English)

    WAN Yong-ge; SHEN Zheng-kang; ZENG Yue-hua; SHENG Shu-zhong; XU Xiao-feng

    2008-01-01

    We calculated the Coulomb failure stress change generated by the 1976 Tangshan earthquake that is projected onto the fault planes and slip directions of large subsequent aftershocks. Results of previous studies on the seismic failure distribution, crustal velocity and viscosity structures of the Tangshan earthquake are used as model constraints. Effects of the local pore fluid pressure and impact of soft medium near the fault are also considered. Our result shows that the subsequent Luanxian and Ninghe earthquakes occurred in the regions with a positive Coulomb failure stress produced by the Tangshan earthquake. To study the triggering effect of the Tangshan, Luanxian, and Ninghe earthquakes on the follow-up small earthquakes, we first evaluate the possible focal mechanisms of small earthquakes according to the regional stress field and co-seismic slip distributions derived from previous studies, assuming the amplitude of regional tectonic stress as 10 MPa. By projecting the stress changes generated by the above three earthquakes onto the possible fault planes and slip directions of small earthquakes, we find that the "butterfly" distribution pattern of increased Coulomb failure stress is consistent with the spatial distribution of follow-up earthquakes, and 95% of the aftershocks occurred in regions where Coulomb failure stresses increase, indicating that the former large earthquakes modulated occurrences of follow-up earthquakes in the Tangshan earthquake sequence. This result has some significance in rapid assessment of aftershock hazard after a large earthquake. If detailed failure distribution, seismogenic fault in the focal area and their slip features can be rapidly determined after a large earthquake, our algorithm can be used to predict the locations of large aftershocks.

  5. 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…

  6. Earthquake and Schools. [Videotape].

    Science.gov (United States)

    Federal Emergency Management Agency, Washington, DC.

    Designing schools to make them more earthquake resistant and protect children from the catastrophic collapse of the school building is discussed in this videotape. It reveals that 44 of the 50 U.S. states are vulnerable to earthquake, but most schools are structurally unprepared to take on the stresses that earthquakes exert. The cost to the…

  7. School Safety and Earthquakes.

    Science.gov (United States)

    Dwelley, Laura; Tucker, Brian; Fernandez, Jeanette

    1997-01-01

    A recent assessment of earthquake risk to Quito, Ecuador, concluded that many of its public schools are vulnerable to collapse during major earthquakes. A subsequent examination of 60 buildings identified 15 high-risk buildings. These schools were retrofitted to meet standards that would prevent injury even during Quito's largest earthquakes. US…

  8. The 2009 eruption of Redoubt Volcano, Alaska

    Science.gov (United States)

    Bull, Katharine F.; Cameron, Cheryl; Coombs, Michelle L.; Diefenbach, Angie; Lopez, Taryn; McNutt, Steve; Neal, Christina; Payne, Allison; Power, John A.; Schneider, David J.; Scott, William E.; Snedigar, Seth; Thompson, Glenn; Wallace, Kristi; Waythomas, Christopher F.; Webley, Peter; Werner, Cynthia A.; Schaefer, Janet R.

    2012-01-01

    Redoubt Volcano, an ice-covered stratovolcano on the west side of Cook Inlet, erupted in March 2009 after several months of escalating unrest. The 2009 eruption of Redoubt Volcano shares many similarities with eruptions documented most recently at Redoubt in 1966–68 and 1989–90. In each case, the eruptive phase lasted several months, consisted of multiple ashproducing explosions, produced andesitic lava and tephra, removed significant amounts of ice from the summit crater and Drift glacier, generated lahars that inundated the Drift River valley, and culminated with the extrusion of a lava dome in the summit crater. Prior to the 2009 explosive phase of the eruption, precursory seismicity lasted approximately six months with the fi rst weak tremor recorded on September 23, 2008. The first phreatic explosion was recorded on March 15, and the first magmatic explosion occurred seven days later, at 22:34 on March 22. The onset of magmatic explosions was preceded by a strong, shallow swarm of repetitive earthquakes that began about 04:00 on March 20, 2009, less than three days before an explosion. Nineteen major ash-producing explosions generated ash clouds that reached heights between 17,000 ft and 62,000 ft (5.2 and 18.9 km) ASL. During ash fall in Anchorage, the Ted Stevens International Airport was shut down for 20 hours, from ~17:00 on March 28 until 13:00 on March 29. On March 23 and April 4, lahars with fl ow depths to 10 m in the upper Drift River valley inundated parts of the Drift River Terminal (DRT). The explosive phase ended on April 4 with a dome collapse at 05:58. The April 4 ash cloud reached 50,000 ft (15.2 km) and moved swiftly to the southeast, depositing up to 2 mm of ash fall in Homer, Anchor Point, and Seldovia. At least two and possibly three lava domes grew and were destroyed by explosions prior to the final lava dome extrusion that began after the April 4 event. The fi nal lava dome ceased growth by July 1, 2009, with an estimated volume of 72

  9. Redefining Earthquakes and the Earthquake Machine

    Science.gov (United States)

    Hubenthal, Michael; Braile, Larry; Taber, John

    2008-01-01

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

  10. Redefining Earthquakes and the Earthquake Machine

    Science.gov (United States)

    Hubenthal, Michael; Braile, Larry; Taber, John

    2008-01-01

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

  11. Bayesian estimation of magma supply, storage, and eruption rates using a multiphysical volcano model: Kīlauea Volcano, 2000-2012

    Science.gov (United States)

    Anderson, Kyle R.; Poland, Michael P.

    2016-08-01

    Estimating rates of magma supply to the world's volcanoes remains one of the most fundamental aims of volcanology. Yet, supply rates can be difficult to estimate even at well-monitored volcanoes, in part because observations are noisy and are usually considered independently rather than as part of a holistic system. In this work we demonstrate a technique for probabilistically estimating time-variable rates of magma supply to a volcano through probabilistic constraint on storage and eruption rates. This approach utilizes Bayesian joint inversion of diverse datasets using predictions from a multiphysical volcano model, and independent prior information derived from previous geophysical, geochemical, and geological studies. The solution to the inverse problem takes the form of a probability density function which takes into account uncertainties in observations and prior information, and which we sample using a Markov chain Monte Carlo algorithm. Applying the technique to Kīlauea Volcano, we develop a model which relates magma flow rates with deformation of the volcano's surface, sulfur dioxide emission rates, lava flow field volumes, and composition of the volcano's basaltic magma. This model accounts for effects and processes mostly neglected in previous supply rate estimates at Kīlauea, including magma compressibility, loss of sulfur to the hydrothermal system, and potential magma storage in the volcano's deep rift zones. We jointly invert data and prior information to estimate rates of supply, storage, and eruption during three recent quasi-steady-state periods at the volcano. Results shed new light on the time-variability of magma supply to Kīlauea, which we find to have increased by 35-100% between 2001 and 2006 (from 0.11-0.17 to 0.18-0.28 km3/yr), before subsequently decreasing to 0.08-0.12 km3/yr by 2012. Changes in supply rate directly impact hazard at the volcano, and were largely responsible for an increase in eruption rate of 60-150% between 2001 and

  12. Bayesian estimation of magma supply, storage, and eruption rates using a multiphysical volcano model: Kīlauea Volcano, 2000–2012

    Science.gov (United States)

    Anderson, Kyle R.; Poland, Michael

    2016-01-01

    Estimating rates of magma supply to the world's volcanoes remains one of the most fundamental aims of volcanology. Yet, supply rates can be difficult to estimate even at well-monitored volcanoes, in part because observations are noisy and are usually considered independently rather than as part of a holistic system. In this work we demonstrate a technique for probabilistically estimating time-variable rates of magma supply to a volcano through probabilistic constraint on storage and eruption rates. This approach utilizes Bayesian joint inversion of diverse datasets using predictions from a multiphysical volcano model, and independent prior information derived from previous geophysical, geochemical, and geological studies. The solution to the inverse problem takes the form of a probability density function which takes into account uncertainties in observations and prior information, and which we sample using a Markov chain Monte Carlo algorithm. Applying the technique to Kīlauea Volcano, we develop a model which relates magma flow rates with deformation of the volcano's surface, sulfur dioxide emission rates, lava flow field volumes, and composition of the volcano's basaltic magma. This model accounts for effects and processes mostly neglected in previous supply rate estimates at Kīlauea, including magma compressibility, loss of sulfur to the hydrothermal system, and potential magma storage in the volcano's deep rift zones. We jointly invert data and prior information to estimate rates of supply, storage, and eruption during three recent quasi-steady-state periods at the volcano. Results shed new light on the time-variability of magma supply to Kīlauea, which we find to have increased by 35–100% between 2001 and 2006 (from 0.11–0.17 to 0.18–0.28 km3/yr), before subsequently decreasing to 0.08–0.12 km3/yr by 2012. Changes in supply rate directly impact hazard at the volcano, and were largely responsible for an increase in eruption rate of 60–150% between

  13. Elastic energy release in great earthquakes and eruptions

    Directory of Open Access Journals (Sweden)

    Agust eGudmundsson

    2014-05-01

    Full Text Available The sizes of earthquakes are measured using well-defined, measurable quantities such as seismic moment and released (transformed elastic energy. No similar measures exist for the sizes of volcanic eruptions, making it difficult to compare the energies released in earthquakes and eruptions. Here I provide a new measure of the elastic energy (the potential mechanical energy associated with magma chamber rupture and contraction (shrinkage during an eruption. For earthquakes and eruptions, elastic energy derives from two sources: (1 the strain energy stored in the volcano/fault zone before rupture, and (2 the external applied load (force, pressure, stress, displacement on the volcano/fault zone. From thermodynamic considerations it follows that the elastic energy released or transformed (dU during an eruption is directly proportional to the excess pressure (pe in the magma chamber at the time of rupture multiplied by the volume decrease (-dVc of the chamber, so that . This formula can be used as a basis for a new eruption magnitude scale, based on elastic energy released, which can be related to the moment-magnitude scale for earthquakes. For very large eruptions (>100 km3, the volume of the feeder-dike is negligible, so that the decrease in chamber volume during an eruption corresponds roughly to the associated volume of erupted materials , so that the elastic energy is . Using a typical excess pressures of 5 MPa, it is shown that the largest known eruptions on Earth, such as the explosive La Garita Caldera eruption (27-28 million years ago and largest single (effusive Colombia River basalt lava flows (15-16 million years ago, both of which have estimated volumes of about 5000 km3, released elastic energy of the order of 10EJ. For comparison, the seismic moment of the largest earthquake ever recorded, the M9.5 1960 Chile earthquake, is estimated at 100 ZJ and the associated elastic energy release at 10EJ.

  14. Mount Rainier, a decade volcano

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, S.C.; Hooper, P.R. (Washington State Univ., Pullman, WA (United States). Dept. of Geology); Eggers, A.E. (Univ. of Puget Sound, Tacoma, WA (United States). Dept. of Geology)

    1993-04-01

    Mount Rainier, recently designated as a decade volcano, is a 14,410 foot landmark which towers over the heavily populated southern Puget Sound Lowland of Washington State. It last erupted in the mid-1800's and is an obvious threat to this area, yet Rainier has received little detailed study. Previous work has divided Rainier into two distinct pre-glacial eruptive episodes and one post-glacial eruptive episode. In a pilot project, the authors analyzed 253 well-located samples from the volcano for 27 major and trace elements. Their objective is to test the value of chemical compositions as a tool in mapping the stratigraphy and understanding the eruptive history of the volcano which they regard as prerequisite to determining the petrogenesis and potential hazard of the volcano. The preliminary data demonstrates that variation between flows is significantly greater than intra-flow variation -- a necessary condition for stratigraphic use. Numerous flows or groups of flows can be distinguished chemically. It is also apparent from the small variation in Zr abundances and considerable variation in such ratios as Ba/Nb that fractional crystallization plays a subordinate role to some form of mixing process in the origin of the Mount Rainier lavas.

  15. Global volcanic earthquake swarm database and preliminary analysis of volcanic earthquake swarm duration

    Directory of Open Access Journals (Sweden)

    S. R. McNutt

    1996-06-01

    Full Text Available Global data from 1979 to 1989 pertaining to volcanic earthquake swarms have been compiled into a custom-designed relational database. The database is composed of three sections: 1 a section containing general information on volcanoes, 2 a section containing earthquake swarm data (such as dates of swarm occurrence and durations, and 3 a section containing eruption information. The most abundant and reliable parameter, duration of volcanic earthquake swarms, was chosen for preliminary analysis. The distribution of all swarm durations was found to have a geometric mean of 5.5 days. Precursory swarms were then separated from those not associated with eruptions. The geometric mean precursory swarm duration was 8 days whereas the geometric mean duration of swarms not associated with eruptive activity was 3.5 days. Two groups of precursory swarms are apparent when duration is compared with the eruption repose time. Swarms with durations shorter than 4 months showed no clear relationship with the eruption repose time. However, the second group, lasting longer than 4 months, showed a significant positive correlation with the log10 of the eruption repose period. The two groups suggest that different suites of physical processes are involved in the generation of volcanic earthquake swarms.

  16. Environmental impact of CO2, Rn, Hg degassing from the rupture zones produced by Wenchuan M s 8.0 earthquake in western Sichuan, China.

    Science.gov (United States)

    Zhou, Xiaocheng; Chen, Zhi; Cui, Yueju

    2016-10-01

    The concentrations and flux of CO2, (222)Radon (Rn), and gaseous elemental mercury (Hg) in soil gas were investigated based on the field measurements in June 2010 at ten sites along the seismic rupture zones produced by the May 12, 2008, Wenchuan M s 8.0 earthquake in order to assess the environmental impact of degassing of CO2, Rn and Hg. Soil gas concentrations of 344 sampling points were obtained. Seventy measurements of CO2, Rn and Hg flux by the static accumulation chamber method were performed. The results of risk assessment of CO2, Rn and Hg concentration in soil gas showed that (1) the concentration of CO2 in the epicenter of Wenchuan M s 8.0 earthquake and north end of seismic ruptures had low risk of asphyxia; (2) the concentrations of Rn in the north segment of seismic ruptures had high levels of radon, Maximum was up to level 4, according to Chinese code (GB 50325-2001); (3) the average geoaccumulation index I geo of soil Hg denoted the lack of soil contamination, and maximum values classified the soil gas as moderately to strongly polluted in the epicenter. The investigation of soil gas CO2, Rn and Hg degassing rate indicated that (1) the CO2 in soil gas was characterized by a mean [Formula: see text] of -20.4 ‰ and by a mean CO2 flux of 88.1 g m(-2) day(-1), which were in the range of the typical values for biologic CO2 degassing. The maximum of soil CO2 flux reached values of 399 g m(-2) day(-1) in the epicenter; (2) the soil Rn had higher exhalation in the north segment of seismic ruptures, the maximum reached value of 1976 m Bq m(-2) s(-1); (3) the soil Hg flux was lower, ranging from -2.5 to 18.7 n g m(-2) h(-1) and increased from south to north. The mean flux over the all profiles was 4.2 n g m(-2) h(-1). The total output of CO2 and Hg degassing estimated along seismic ruptures for a survey area of 18.17 km(2) were approximately 0.57 Mt year(-1) and 688.19 g year(-1). It is recommended that land-use planners should

  17. Operational earthquake forecasting can enhance earthquake preparedness

    Science.gov (United States)

    Jordan, T.H.; Marzocchi, W.; Michael, A.J.; Gerstenberger, M.C.

    2014-01-01

    We cannot yet predict large earthquakes in the short term with much reliability and skill, but the strong clustering exhibited in seismic sequences tells us that earthquake probabilities are not constant in time; they generally rise and fall over periods of days to years in correlation with nearby seismic activity. Operational earthquake forecasting (OEF) is the dissemination of authoritative information about these time‐dependent probabilities to help communities prepare for potentially destructive earthquakes. The goal of OEF is to inform the decisions that people and organizations must continually make to mitigate seismic risk and prepare for potentially destructive earthquakes on time scales from days to decades. To fulfill this role, OEF must provide a complete description of the seismic hazard—ground‐motion exceedance probabilities as well as short‐term rupture probabilities—in concert with the long‐term forecasts of probabilistic seismic‐hazard analysis (PSHA).

  18. Forecasting eruptions using pre-eruptive seismic patterns at Sinabung Volcano, Indonesia

    Science.gov (United States)

    McCausland, W. A.; White, R. A.; Hendrasto, M.; Gunawan, H.; Indrastuti, N.; Triastuti, H.; Suparman, Y.; Putra, A.

    2015-12-01

    Forecasting the size, timing and style of volcanic eruptions is of primary interest to observatories and civil authorities world-wide, yet most observatories only have access to long-term data at a very limited number of volcanoes under their jurisdiction. When extensive long-term data sets are available to responsible agencies, volcanic eruptive size, timing and style can usually be successfully forecast using current monitoring data and knowledge of precursory eruptive patterns, enabling the communication of timely forecasts to civil authorities. Experienced agencies, such as Indonesia's Center for Volcanology and Geologic Hazards Mitigation and the USAID-USGS Volcano Disaster Assistance Program, utilize extensive collective experiences with multiple monitoring streams over multiple eruption cycles and across volcano types to successfully forecast eruption size, style and onset, as well as changes in eruptive style and size within ongoing eruptions. The longest-term real-time monitoring parameter commonly available at volcanoes worldwide is seismic data. Seismic data is a direct measure of rate-dependent strain changes in the magmatic system from the deep magmatic input to shallow eruptive processes. Patterns of pre-eruptive earthquakes coupled with other available monitoring data and conceptual models of magma ascent enable short-term forecasting of eruption size, style, and onset. First order event locations, characterization of background seismicity, and changes in earthquake types and energy release are most important to successful eruption forecasting. This study demonstrates how this approach has been used to successfully forecast eruption onsets, changes in eruptive style, and to change alert levels and extend or contract evacuation zones during the ongoing eruption of Sinabung Volcano, Indonesia.

  19. 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

  20. Galactic Super-volcano in Action

    Science.gov (United States)

    2010-08-01

    A galactic "super-volcano" in the massive galaxy M87 is erupting and blasting gas outwards, as witnessed by NASA's Chandra X-ray Observatory and NSF's Very Large Array. The cosmic volcano is being driven by a giant black hole in the galaxy's center and preventing hundreds of millions of new stars from forming. Astronomers studying this black hole and its effects have been struck by the remarkable similarities between it and a volcano in Iceland that made headlines earlier this year. At a distance of about 50 million light years, M87 is relatively close to Earth and lies at the center of the Virgo cluster, which contains thousands of galaxies. M87's location, coupled with long observations over Chandra's lifetime, has made it an excellent subject for investigations of how a massive black hole impacts its environment. "Our results show in great detail that supermassive black holes have a surprisingly good control over the evolution of the galaxies in which they live," said Norbert Werner of the Kavli Institute for Particle Astrophysics and Cosmology at Stanford University and the SLAC National Accelerator Laboratory, who led one of two papers describing the study. "And it doesn't stop there. The black hole's reach extends ever farther into the entire cluster, similar to how one small volcano can affect practically an entire hemisphere on Earth." The cluster surrounding M87 is filled with hot gas glowing in X-ray light, which is detected by Chandra. As this gas cools, it can fall toward the galaxy's center where it should continue to cool even faster and form new stars. However, radio observations with the Very Large Array suggest that in M87 jets of very energetic particles produced by the black hole interrupt this process. These jets lift up the relatively cool gas near the center of the galaxy and produce shock waves in the galaxy's atmosphere because of their supersonic speed. The scientists involved in this research have found the interaction of this cosmic

  1. Volcano-related materials in concretes: a comprehensive review.

    Science.gov (United States)

    Cai, Gaochuang; Noguchi, Takafumi; Degée, Hervé; Zhao, Jun; Kitagaki, Ryoma

    2016-04-01

    Massive volcano-related materials (VRMs) erupted from volcanoes bring the impacts to natural environment and humanity health worldwide, which include generally volcanic ash (VA), volcanic pumice (VP), volcanic tuff (VT), etc. Considering the pozzolanic activities and mechanical characters of these materials, civil engineers propose to use them in low carbon/cement and environment-friendly concrete industries as supplementary cementitious materials (SCMs) or artificial/natural aggregates. The utilization of VRMs in concretes has attracted increasing and pressing attentions from research community. Through a literature review, this paper presents comprehensively the properties of VRMs and VRM concretes (VRMCs), including the physical and chemical properties of raw VRMs and VRMCs, and the fresh, microstructural and mechanical properties of VRMCs. Besides, considering environmental impacts and the development of long-term properties, the durability and stability properties of VRMCs also are summarized in this paper. The former focuses on the resistance properties of VRMCs when subjected to aggressive environmental impacts such as chloride, sulfate, seawater, and freezing-thawing. The latter mainly includes the fatigue, creep, heat-insulating, and expansion properties of VRMCs. This study will be helpful to promote the sustainability in concrete industries, protect natural environment, and reduce the impacts of volcano disaster. Based on this review, some main conclusions are discussed and important recommendations regarding future research on the application of VRMs in concrete industries are provided.

  2. Transportations Systems Modeling and Applications in Earthquake Engineering

    Science.gov (United States)

    2010-07-01

    earthquake (Japan) The 1995 Hanshin-Awaji earthquake ( wM 6.8) in the Osaka -Kobe area had an even greater impact on the transportation systems compared...with the Loma Prieta and Northridge earthquakes in the U.S. The span collapses of the elevated Osaka -Kobe expressway (Route 3) caused long- time...nation’s economy and society. The numerical case study focuses on the road network in the Memphis metropolitan area. The road network information

  3. Crustal deformation associated with the 2011 eruption of the Nabro volcano, Eritrea

    Science.gov (United States)

    Hamiel, Yariv; Baer, Gidon

    2016-11-01

    We investigate the crustal deformation associated with the 2011 eruption of the Nabro volcano, Afar, Eritrea. The Nabro volcano erupted on the night of 12 June 2011. A seismic sequence started 5 h before the onset of the volcanic eruption. It included 25 M > 3 earthquakes, of which one Mw 5.6 normal fault earthquake occurred on 12 June at about the same time as the onset of the eruption, and one Mw 5.6 strike-slip earthquake occurred at the end of the main sequence on 17 June. The deformation associated with the eruption and the seismic activity was resolved by Interferometric Synthetic Aperture Radar (InSAR) measurements of the TerraSAR-X and ENVISAT satellites. Interferograms were generated using ascending and descending track pairs. The Nabro caldera and the associated channel of magma flow are characterized by significant loss of coherence which limited our InSAR observations at the near field of the volcano. Therefore, detailed assessment of co- and post-eruptive seismicity and monitoring of post-eruptive deformation using continued InSAR observations were added to the co-eruptive analysis in order to better constrain the different magmatic and tectonic components and determine the final source model. We carried out tens of different inversion models. Our best-fit model includes a dike, a normal fault and a strike-slip fault, consistent with the mechanisms of the major earthquakes. Coulomb stress calculations based on our model are found to be in agreement with post-eruptive seismicity. Finally, the source mechanism and geometry of our model are found to be in accord with the major tectonic structures in this area.

  4. Strategies for the implementation of a European Volcano Observations Research Infrastructure

    Science.gov (United States)

    Puglisi, Giuseppe

    2015-04-01

    Active volcanic areas in Europe constitute a direct threat to millions of people on both the continent and adjacent islands. Furthermore, eruptions of "European" volcanoes in overseas territories, such as in the West Indies, an in the Indian and Pacific oceans, can have a much broader impacts, outside Europe. Volcano Observatories (VO), which undertake volcano monitoring under governmental mandate and Volcanological Research Institutions (VRI; such as university departments, laboratories, etc.) manage networks on European volcanoes consisting of thousands of stations or sites where volcanological parameters are either continuously or periodically measured. These sites are equipped with instruments for geophysical (seismic, geodetic, gravimetric, electromagnetic), geochemical (volcanic plumes, fumaroles, groundwater, rivers, soils), environmental observations (e.g. meteorological and air quality parameters), including prototype deployment. VOs and VRIs also operate laboratories for sample analysis (rocks, gases, isotopes, etc.), near-real time analysis of space-borne data (SAR, thermal imagery, SO2 and ash), as well as high-performance computing centres; all providing high-quality information on the current status of European volcanoes and the geodynamic background of the surrounding areas. This large and high-quality deployment of monitoring systems, focused on a specific geophysical target (volcanoes), together with the wide volcanological phenomena of European volcanoes (which cover all the known volcano types) represent a unique opportunity to fundamentally improve the knowledge base of volcano behaviour. The existing arrangement of national infrastructures (i.e. VO and VRI) appears to be too fragmented to be considered as a unique distributed infrastructure. Therefore, the main effort planned in the framework of the EPOS-PP proposal is focused on the creation of services aimed at providing an improved and more efficient access to the volcanological facilities

  5. Soufrière Hills eruption, Montserrat, 1995 - 1997: volcanic earthquake locations and fault plane solutions

    Science.gov (United States)

    Aspinall, W.P.; Miller, A.D.; Lynch, L.L.; Latchman, J.L.; Stewart, R.C.; White, R.A.; Power, J.A.

    1998-01-01

    A total of 9242 seismic events, recorded since the start of the eruption on Montserrat in July 1995, have been uniformly relocated with station travel-time corrections. Early seismicity was generally diffuse under southern Montserrat, and mostly restricted to depths less than 7 km. However, a NE-SW alignment of epicentres beneath the NE flank of the volcano emerged in one swarm of volcano-tectonic earthquakes (VTs) and later nests of VT hypocentres developed beneath the volcano and at a separated location, under St. George's Hill. The overall spatial distribution of hypocentres suggests a minimum depth of about 5 km for any substantial magma body. Activity associated with the opening of a conduit to the surface became increasingly shallow, with foci concentrated below the crater and, after dome building started in Fall 1995, VTs diminished and repetitive swarms of ‘hybrid’ seismic events became predominant. By late-1996, as magma effusion rates escalated, most seismic events were originating within a volume about 2 km diameter which extended up to the surface from only about 3 km depth - the diminution of shear failure earthquakes suggests the pathway for magma discharge had become effectively unconstricted. Individual and composite fault plane solutions have been determined for a few larger earthquakes. We postulate that localised extensional stress conditions near the linear VT activity, due to interaction with stresses in the overriding lithospheric plate, may encourage normal fault growth and promote sector weaknesses in the volcano.

  6. Earthquake Science: a New Start

    Institute of Scientific and Technical Information of China (English)

    Chen Yun-tai

    2009-01-01

    @@ Understanding the mechanisms which cause earthquakes and thus earthquake prediction, is inher-ently difficult in comparison to other physical phenom-ena. This is due to the inaccessibility of the Earth's inte-rior, the infrequency of large earthquakes, and the com-plexities of the physical processes involved. Conse-quently, in its broadest sense, earthquake science--the science of studying earthquake phenomena, is a com-prehensive and inter-disciplinary field. The disciplines involved in earthquake science include: traditional seismology, earthquake geodesy, earthquake geology, rock mechanics, complex system theory, and informa-tion and communication technologies related to earth-quake studies.

  7. Impact of the Great East Japan earthquake on out-of-hospital cardiac arrest with cardiac origin in non-disaster areas [corrected].

    Science.gov (United States)

    Kiyohara, Kosuke; Kitamura, Tetsuhisa; Iwami, Taku; Nishiyama, Chika; Kawamura, Takashi

    2015-02-01

    To examine changes in the incidence of out-of-hospital cardiac arrest (OHCA) with cardiac origin in the non-disaster areas of Japan before and after the Great East Japan Earthquake of 11 March 2011. The 35 prefectures in Japan with no dead or missing caused directly by the earthquake were defined as the non-disaster areas. Data of adult OHCA patients in the non-disaster areas from March 4 to 24 each year from 2005 to 2011 were obtained from the All-Japan Utstein Registry. Risk ratios (RRs) of OHCA incidence and 95% CIs were estimated for three specific weeks in 2011 (1 week before and 2 weeks after the earthquake) by applying multivariable Poisson regression model. Incidence in the corresponding periods of March 4-24 from 2005 to 2010 was set as the baseline risk. In the analyses from a total of 17,353 OHCA patients, the incidence statistically significantly increased in the first week after the earthquake in all adults (adjusted-RR=1.13, 95% CI=1.05 to 1.22, p=0.001) and in elderly women (adjusted-RR=1.23, 95% CI=1.11 to 1.37, pJapan Earthquake caused the increase of OHCA among elderly women even in the non-disaster areas. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  8. Aleutian Islands Coastal Resources Inventory and Environmental Sensitivity Maps: VOLCANOS (Volcano Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains point locations of active volcanoes as compiled by Motyka et al., 1993. Eighty-nine volcanoes with eruptive phases in the Quaternary are...

  9. The Hawaiian Volcano Observatory: a natural laboratory for studying basaltic volcanism: Chapter 1 in Characteristics of Hawaiian volcanoes

    Science.gov (United States)

    Tilling, Robert I.; Kauahikaua, James P.; Brantley, Steven R.; Neal, Christina A.; Poland, Michael P.; Takahashi, T. Jane; Landowski, Claire M.

    2014-01-01

    In the beginning of the 20th century, geologist Thomas A. Jaggar, Jr., argued that, to fully understand volcanic and associated hazards, the expeditionary mode of studying eruptions only after they occurred was inadequate. Instead, he fervently advocated the use of permanent observatories to record and measure volcanic phenomena—at and below the surface—before, during, and after eruptions to obtain the basic scientific information needed to protect people and property from volcanic hazards. With the crucial early help of American volcanologist Frank Alvord Perret and the Hawaiian business community, the Hawaiian Volcano Observatory (HVO) was established in 1912, and Jaggar’s vision became reality. From its inception, HVO’s mission has centered on several goals: (1) measuring and documenting the seismic, eruptive, and geodetic processes of active Hawaiian volcanoes (principally Kīlauea and Mauna Loa); (2) geological mapping and dating of deposits to reconstruct volcanic histories, understand island evolution, and determine eruptive frequencies and volcanic hazards; (3) systematically collecting eruptive products, including gases, for laboratory analysis; and (4) widely disseminating observatory-acquired data and analysis, reports, and hazard warnings to the global scientific community, emergency-management authorities, news media, and the public. The long-term focus on these goals by HVO scientists, in collaboration with investigators from many other organizations, continues to fulfill Jaggar’s career-long vision of reducing risks from volcanic and earthquake hazards across the globe.

  10. Modeling eruptions of Karymsky volcano

    OpenAIRE

    Ozerov, A.; Ispolatov, I.; Lees, J.

    2001-01-01

    A model is proposed to explain temporal patterns of activity in a class of periodically exploding Strombolian-type volcanos. These patterns include major events (explosions) which follow each other every 10-30 minutes and subsequent tremor with a typical period of 1 second. This two-periodic activity is thought to be caused by two distinct mechanisms of accumulation of the elastic energy in the moving magma column: compressibility of the magma in the lower conduit and viscoelastic response of...

  11. Observed inflation-deflation cycles at Popocatepetl volcano using tiltmeters and its possible correlation with regional seismic activity in Mexico

    Science.gov (United States)

    Contreras Ruiz Esparza, M. G., Sr.; Jimenez Velazquez, J. C., Sr.; Valdes Gonzalez, C. M., Sr.; Reyes Pimentel, T. A.; Galaviz Alonso, S. A.

    2014-12-01

    Popocatepetl, the smoking mountain, is a stratovolcano located in central Mexico with an elevation of 5450 masl. The active volcano, close to some of the largest urban centers in Mexico - 60 km and 30 km far from Mexico City and Puebla, respectively - poses a high hazard to an estimated population of 500 thousand people living in the vicinity of the edifice. Accordingly, in July 1994 the Popocatepetl Volcanological Observatory (POVO) was established. The observatory is operated and supported by the National Center for Disaster Prevention of Mexico (CENAPRED), and is equipped to fully monitor different aspects of the volcanic activity. Among the instruments deployed, we use in this investigation two tiltmometers and broad-band seismometers at two sites (Chipiquixtle and Encinos), which send the information gathered continuously to Mexico City.In this research, we study the characteristics of the tiltmeters signals minutes after the occurrence of certain earthquakes. The Popocatepetl volcano starts inflation-deflation cycles due to the ground motion generated by events located at certain regions. We present the analysis of the tiltmeters and seismic signals of all the earthquakes (Mw>5) occurred from January 2013 to June 2014, recorded at Chipiquixtle and Encinos stations. First, we measured the maximum tilt variation after each earthquake. Next, we apply a band-pass filter for different frequency ranges to the seismic signals of the two seismic stations, and estimated the total energy of the strong motion phase of the seismic record. Finally, we compared both measurements and observed that the maximum tilt variations were occurring when the maximum total energy of the seismic signals were in a specific frequency range. We also observed that the earthquake records that have the maximum total energy in that frequency range were the ones with a epicentral location south-east of the volcano. We conclude that our observations can be used set the ground for an early

  12. Active Deformation of Etna Volcano Combing IFSAR and GPS data

    Science.gov (United States)

    Lundgren, Paul

    1997-01-01

    The surface deformation of an active volcano is an important indicator of its eruptive state and its hazard potential. Mount Etna volcano in Sicily is a very active volcano with well documented eruption episodes.

  13. Earthquakes, Cities, and Lifelines: lessons integrating tectonics, society, and engineering in middle school Earth Science

    Science.gov (United States)

    Toke, N.; Johnson, A.; Nelson, K.

    2010-12-01

    Earthquakes are one of the most widely covered geologic processes by the media. As a result students, even at the middle school level, arrive in the classroom with preconceptions about the importance and hazards posed by earthquakes. Therefore earthquakes represent not only an attractive topic to engage students when introducing tectonics, but also a means to help students understand the relationships between geologic processes, society, and engineering solutions. Facilitating understanding of the fundamental connections between science and society is important for the preparation of future scientists and engineers as well as informed citizens. Here, we present a week-long lesson designed to be implemented in five one hour sessions with classes of ~30 students. It consists of two inquiry-based mapping investigations, motivational presentations, and short readings that describe fundamental models of plate tectonics, faults, and earthquakes. The readings also provide examples of engineering solutions such as the Alaskan oil pipeline which withstood multi-meter surface offset in the 2002 Denali Earthquake. The first inquiry-based investigation is a lesson on tectonic plates. Working in small groups, each group receives a different world map plotting both topography and one of the following data sets: GPS plate motion vectors, the locations and types of volcanoes, the location of types of earthquakes. Using these maps and an accompanying explanation of the data each group’s task is to map plate boundary locations. Each group then presents a ~10 minute summary of the type of data they used and their interpretation of the tectonic plates with a poster and their mapping results. Finally, the instructor will facilitate a class discussion about how the data types could be combined to understand more about plate boundaries. Using student interpretations of real data allows student misconceptions to become apparent. Throughout the exercise we record student preconceptions

  14. 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...

  15. Campgrounds in Hawaii Volcanoes National Park

    Data.gov (United States)

    National Park Service, Department of the Interior — This dataset provides campground locations in Hawaii Volcanoes National Park. Information about facilities, water availability, permit requirements and type of...

  16. Advances in seismic monitoring at Deception Island volcano (Antarctica since the International Polar Year

    Directory of Open Access Journals (Sweden)

    Enrique Carmona

    2014-06-01

    Full Text Available Deception Island is an active volcano located in the south Shetland Islands, Antarctica. It constitutes a natural laboratory to test geophysical instruments in extreme conditions, since they have to endure not only the Antarctic climate but also the volcanic environment. Deception is one of the most visited places in Antarctica, both by scientists and tourists, which emphasize the importance of volcano monitoring. Seismic monitoring has been going on since 1986 during austral summer surveys. The recorded data include volcano-tectonic earthquakes, long-period events and volcanic tremor, among others. The level of seismicity ranges from quiet periods to seismic crises (e.g. 1992-1993, 1999. Our group has been involved in volcano monitoring at Deception Island since 1994. Based on this experience, in recent years we have made the most of the opportunities of the International Polar Year 2007-2008 to introduce advances in seismic monitoring along four lines: (1 the improvement of the seismic network installed for seismic monitoring during the summer surveys; (2 the development and improvement of seismic arrays for the detection and characterization of seismo-volcanic signals; (3 the design of automated event recognition tools, to simplify the process of data interpretation; and (4 the deployment of permanent seismic stations. These advances help us to obtain more data of better quality, and therefore to improve our interpretation of the seismo-volcanic activity at Deception Island, which is a crucial step in terms of hazards assessment.

  17. Evaluation of landslide susceptibility of Sete Cidades Volcano (S. Miguel Island, Azores

    Directory of Open Access Journals (Sweden)

    A. Gomes

    2005-01-01

    Full Text Available Sete Cidades is an active central volcano with a summit caldera located in the westernmost part of S. Miguel Island (Azores. Since the settlement of the Island, in the 15th century, many landslide events occurred in this volcano, causing extensive damages in buildings and infrastructures. The study of historical records and the observation of new occurrences showed that landslides in the region have been triggered by heavy rainfall periods, earthquakes and erosion. In order to assess landslide susceptibility at Sete Cidades Volcano, landslide scars and associated deposits were mapped through aerial photographs and field surveys. The obtained data were inserted in a GIS to produce a landslide distribution map. It was concluded that the high density landslide areas are related with (1 major scarp faults, (2 the margin of fluvial channels, (3 the sea cliffs and (4 volcanic landforms, namely the caldera wall. About 73% of the mapped events took place in areas where pyroclastic deposits are the dominant lithology and more than 77% occurred where slopes are equal or higher than 20°. These two parameters were integrated and used to generate a preliminary susceptibility map. The incorporation of vulnerability data into the GIS allowed concluding that 30% of dwellings and most of the roads on Sete Cidades Volcano are located in areas where landslide susceptibility is high to very high. Such conclusion should be taken into account for emergency and land use planning.

  18. Earthquake Monitoring in Australia Using Satellite Radar Interferometry

    Institute of Scientific and Technical Information of China (English)

    Ge Lin-lin; E. Cheng; D. Polonska; C. Rizos; C. Collins; C. Smith

    2003-01-01

    Are there any earthquakes in Australia? Although most Australians are not as familiar with earthquakes as citizens in countries such as Japan, there are some quakes on the Australian continent every year. Differential Synthetic Aperture Radar Interferometry (DInSAR) has been widely used in recent years for monitoring crustal deformation due to earthquakes, volcanoes, underground mining, oil extraction,and so on. Hence the follow-on question is, can repeat-pass satellite DInSAR be used in Australian regions to monitor earthquakes? Nine ERS-1 and ERS-2 radar images of the Burakin region in Western Australia were used to form the InSAR pairs.Twenty-two InSAR pairs were formed and were used to study the temporal decorrelation characteristics in the Burakin area. It was found that good coherence could be maintained all over the full scene for a pair spanning 211 d. The repeat cycles of RADARSAT and ERS (all C-band SAR missions) are 24 and 35 drespectively, Furthermore it is easier to maintain good coherence in L-band SAR images (e.g. the JERS-1 mission has a 44 d repeat cycle). Therefore the authors are confident that repeat-pass differential InSAR can be used to monitor ground deformation due to earthquakes in the Burakin region.

  19. Faulting of local earthquakes in the Valley of Mexico Basin

    Science.gov (United States)

    Bello, D. I.; Quintanar, L.; Jimenez, Z.

    2012-12-01

    In this work we determine focal mechanisms and source parameters of relevant earthquakes (M > 2 occurred in the Valley of Mexico Basin during the past ten years. Data delineates four seismic zones: the first is located north of the Basin, the second in the Chichinautzin mountains range, the third in the Eastern part of Basin and the fourth in the area surrounding the volcano Popocatepetl; here earthquakes are associated with volcanic activity. Source mechanisms were obtained using a method of waveform modeling and joint inversion of polarities and amplitudes of P and S phases. Our results show mechanisms mainly of normal type, consistent with the faulting found across the Trans Mexican volcanic belt. Likewise, from the spectral analysis of signals, we observe an overestimation of the magnitude reported by the Mexican Seismological Service for the earthquakes analyzed. During July 2012, there was an earthquake swarm in the eastern part of Valley of Mexico damaging some constructions in the epicentral area. Our preliminary analysis indicates that most earthquakes of the swarm occurred at shallow depth (<1 km), which could be correlated with the surface cracks observed in the zone. The seismicity, as well the subsidence and faults in the area, is a factor that contributes significantly to increase seismic hazard in the area and should be considered by civil authorities.

  20. Reduction of earthquake disasters

    Institute of Scientific and Technical Information of China (English)

    陈顒; 陈祺福; 黄静; 徐文立

    2003-01-01

    The article summarizes the researches on mitigating earthquake disasters of the past four years in China. The studyof earthquake disasters′ quantification shows that the losses increase remarkably when population concentrates inurban area and social wealth increase. The article also summarizes some new trends of studying earthquake disas-ters′ mitigation, which are from seismic hazard to seismic risk, from engineering disaster to social disaster andintroduces the community-centered approach.

  1. Volcanic subsidence triggered by the 2011 Tohoku earthquake in Japan: Hot and weak material hypothesis

    Science.gov (United States)

    Takada, Youichiro; Fukushima, Yo

    2014-05-01

    With spaceborne interferometric synthetic aperture radar (InSAR) analysis, we found that the 2011 Mw 9.0 Tohoku earthquake in Japan (March 11, 2011) has triggered unprecedented subsidence of multiple volcanoes. Similar phenomenon has been reported for the 2010 Mw 8.8 Maule earthquake (Pritchard et al., 2013). We used SAR data acquired before and after the mainshock by ALOS (PALSAR). By removing long wave-length phase trend from InSAR images, we obtained the localized subsidence signals at five active volcanoes: Mt. Akitakoma, Mt. Kurikoma, Mt. Zao, Mt. Azuma, and Mt. Nasu. All of them belong to the volcanic front of Northeast Japan. The subsidence areas exhibit elliptic shape elongated in the North-South direction - perpendicular to the principal axis of the extensional stress change due to the Tohoku earthquake. Major axis of the ellipse reaches 15 - 20 km, and the amount of subsidence is up to 15 cm (Mt. Azuma). GPS data from two volcanoes also indicate surface subsidence consistent with the satellite radar observations. Furthermore, the GPS data show that the subsidence occurred immediately after the earthquake. A common feature of the five volcanoes is their high geothermal activity. The areas of high geothermal gradient and high thermal water temperature are in good agreement with the area of subsidence detected by InSAR. Also, the Late Cenozoic calderas cluster around the subsidence regions, which implies that hot plutonic bodies once intruded are still hot and highly deformable even now. According to numerical modelling, the observed subsidence can be explained by the co-seismic response of fluid-filled ellipsoid beneath each volcano. We confirmed that the surface subsidence is also caused by the ellipsoid filled with elastic body of low shear strength. We further checked that an ellipsoid is more effective to cause the subsidence than a sphere when the ellipsoid is elongated perpendicular to the tension axis of the imposed stress. References: Takada, Y. and

  2. Antarctic volcanoes: A remote but significant hazard

    Science.gov (United States)

    Geyer, Adelina; Martí, Alex; Folch, Arnau; Giralt, Santiago

    2017-04-01

    Ash emitted during explosive volcanic eruptions can be dispersed over massive areas of the globe, posing a threat to both human health and infrastructures, such as the air traffic. Some of the last eruptions occurred during this decade (e.g. 14/04/2010 - Eyjafjallajökull, Iceland; 24/05/2011-Grímsvötn, Iceland; 05/06/2011-Puyehue-Cordón Caulle, Chile) have strongly affected the air traffic in different areas of the world, leading to economic losses of billions of euros. From the tens of volcanoes located in Antarctica, at least nine are known to be active and five of them have reported volcanic activity in historical times. However, until now, no attention has been paid to the possible social, economical and environmental consequences of an eruption that would occur on high southern latitudes, perhaps because it is considered that its impacts would be minor or local, and mainly restricted to the practically inhabited Antarctic continent. We show here, as a case study and using climate models, how volcanic ash emitted during a regular eruption of one of the most active volcanoes in Antarctica, Deception Island (South Shetland Islands), could reach the African continent as well as Australia and South America. The volcanic cloud could strongly affect the air traffic not only in the region and at high southern latitudes, but also the flights connecting Africa, South America and Oceania. Results obtained are crucial to understand the patterns of volcanic ash distribution at high southern latitudes with obvious implications for tephrostratigraphical and chronological studies that provide valuable isochrones with which to synchronize palaeoclimate records. This research was partially funded by the MINECO grants VOLCLIMA (CGL2015-72629-EXP)and POSVOLDEC(CTM2016-79617-P)(AEI/FEDER, UE), the Ramón y Cajal research program (RYC-2012-11024) and the NEMOH European project (REA grant 34 agreement n° 289976).

  3. Newberry Volcano EGS Demonstration - Phase I Results

    Energy Technology Data Exchange (ETDEWEB)

    Osborn, William L. [AltaRock Energy, Inc., Seattle, WA (United States); Petty, Susan [AltaRock Energy, Inc., Seattle, WA (United States); Cladouhos, Trenton T. [AltaRock Energy, Inc., Seattle, WA (United States); Iovenitti, Joe [AltaRock Energy, Inc., Seattle, WA (United States); Nofziger, Laura [AltaRock Energy, Inc., Seattle, WA (United States); Callahan, Owen [AltaRock Energy, Inc., Seattle, WA (United States); Perry, Douglas S. [Davenport Newberry Holdings LLC, Stamford, CT (United States); Stern, Paul L. [PLS Environmental, LLC, Boulder, CO (United States)

    2011-10-23

    Phase I of the Newberry Volcano Enhanced Geothermal System (EGS) Demonstration included permitting, community outreach, seismic hazards analysis, initial microseismic array deployment and calibration, final MSA design, site characterization, and stimulation planning. The multi-disciplinary Phase I site characterization supports stimulation planning and regulatory permitting, as well as addressing public concerns including water usage and induced seismicity. A review of the project's water usage plan by an independent hydrology consultant found no expected impacts to local stakeholders, and recommended additional monitoring procedures. The IEA Protocol for Induced Seismicity Associated with Enhanced Geothermal Systems was applied to assess site conditions, properly inform stakeholders, and develop a comprehensive mitigation plan. Analysis of precision LiDAR elevation maps has concluded that there is no evidence of recent faulting near the target well. A borehole televiewer image log of the well bore revealed over three hundred fractures and predicted stress orientations. No natural, background seismicity has been identified in a review of historic data, or in more than seven months of seismic data recorded on an array of seven seismometers operating around the target well. A seismic hazards and induced seismicity risk assessment by an independent consultant concluded that the Demonstration would contribute no additional risk to residents of the nearest town of La Pine, Oregon. In Phase II of the demonstration, an existing deep hot well, NWG 55-29, will be stimulated using hydroshearing techniques to create an EGS reservoir. The Newberry Volcano EGS Demonstration is allowing geothermal industry and academic experts to develop, validate and enhance geoscience and engineering techniques, and other procedures essential to the expansion of EGS throughout the country. Successful development will demonstrate to the American public that EGS can play a significant role

  4. A new active volcano in the Tyrrhenian Sea?

    Directory of Open Access Journals (Sweden)

    M. Sedita

    2006-06-01

    Full Text Available A strong earthquake occurred in 2002 offshore from the northern coast of Sicily in the Southern Tyrrhenian Sea (Italy, and was followed by a series of hundreds of aftershocks. Communications through the fibre-optic cable between Palermo and Rome were interrupted a few hours after the occurrence of the main shock. After the required technical checks, the failure point was found a few kilometres away from the seismic sequence area. A few days later, a specialised cable ship reached the failure area. One side of the cable was completely burnt, while about three kilometres of cable was found locked. Tests on slices of cable showed that the temperature at which the cable was heated went well above 700oC. We can speculate that the earthquakes triggered off the emission of a submarine lava flow that buried, trapped and burnt the fibre-optic cable. The revising of the bathymetric survey made before the cable’s deployment allowed for the identification of a seamount in the vicinity of the rupture. This structure could represent the lava flow’s source volcano.

  5. The Characteristics of Earthquake Disasters and Countermeasures for Their Mitigation in Metropolitans

    Institute of Scientific and Technical Information of China (English)

    Gao Mengtan

    2003-01-01

    Metropolitans are a result of fast economic development in China. Many metropolitans have emerged in the eastern part of China. Earthquake disasters in metropolitans are more complicated and serious than those in a smaller city, and the impact of earthquake disaster on the economy and society is large. The characteristics of earthquake disasters and countermeasures to protect against and mitigate disaster in the metropolitan, as well as some key research fields in the earthquake disaster protection and mitigation, are discussed.

  6. Earthquakes trigger the loss of groundwater biodiversity

    Science.gov (United States)

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

    2014-09-01

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

  7. Earthquakes trigger the loss of groundwater biodiversity.

    Science.gov (United States)

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

    2014-09-03

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

  8. Earthquakes trigger the loss of groundwater biodiversity

    Science.gov (United States)

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

    2014-01-01

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

  9. Crustal structure below Popocat\\'epetl Volcano (Mexico) from analysis of Rayleigh waves

    CERN Document Server

    De Barros, Louis; Métaxian, J -P; Valdés-Gonzales, C; Lesage, Philippe

    2007-01-01

    An array of ten broadband stations was installed on the Popocat\\'epetl volcano (Mexico) for five months between October 2002 and February 2003. 26 regional and teleseismic earthquakes were selected and filtered in the frequency time domain to extract the fundamental mode of the Rayleigh wave. The average dispersion curve was obtained in two steps. Firstly, phase velocities were measured in the period range [2-50] s from the phase difference between pairs of stations, using Wiener filtering. Secondly, the average dispersion curve was calculated by combining observations from all events in order to reduce diffraction effects. The inversion of the mean phase velocity yielded a crustal model for the volcano which is consistent with previous models of the Mexican Volcanic Belt. The overall crustal structure beneath Popocat\\'epetl is therefore not different from the surrounding area, and the velocities in the lower crust are confirmed to be relatively low. Lateral variations of the structure were also investigated ...

  10. Prediction of earthquake-triggered landslide event sizes

    Science.gov (United States)

    Braun, Anika; Havenith, Hans-Balder; Schlögel, Romy

    2016-04-01

    Seismically induced landslides are a major environmental effect of earthquakes, which may significantly contribute to related losses. Moreover, in paleoseismology landslide event sizes are an important proxy for the estimation of the intensity and magnitude of past earthquakes and thus allowing us to improve seismic hazard assessment over longer terms. Not only earthquake intensity, but also factors such as the fault characteristics, topography, climatic conditions and the geological environment have a major impact on the intensity and spatial distribution of earthquake induced landslides. We present here a review of factors contributing to earthquake triggered slope failures based on an "event-by-event" classification approach. The objective of this analysis is to enable the short-term prediction of earthquake triggered landslide event sizes in terms of numbers and size of the affected area right after an earthquake event occurred. Five main factors, 'Intensity', 'Fault', 'Topographic energy', 'Climatic conditions' and 'Surface geology' were used to establish a relationship to the number and spatial extend of landslides triggered by an earthquake. The relative weight of these factors was extracted from published data for numerous past earthquakes; topographic inputs were checked in Google Earth and through geographic information systems. Based on well-documented recent earthquakes (e.g. Haiti 2010, Wenchuan 2008) and on older events for which reliable extensive information was available (e.g. Northridge 1994, Loma Prieta 1989, Guatemala 1976, Peru 1970) the combination and relative weight of the factors was calibrated. The calibrated factor combination was then applied to more than 20 earthquake events for which landslide distribution characteristics could be cross-checked. One of our main findings is that the 'Fault' factor, which is based on characteristics of the fault, the surface rupture and its location with respect to mountain areas, has the most important

  11. Seismic activity associated with the September 1977 deflation of the Krafla central volcano in NE-Iceland

    Energy Technology Data Exchange (ETDEWEB)

    Brandsdottir, Bryndis; Einarsson, Pall

    1979-01-01

    The September 1977 deflation event in the Krafla caldera was one of a series of such events that has been in progress since December 1975. The operation of portable seismographs in the active region and favorable location of the main seismic activity with respect to the permanent seismograph network in NE-Iceland allow a more detailed study of this deflation event than most of the other events. Continuous volcanic tremor appeared on the local seismographs shortly before 16 h on September 8, 1977. Deflation of the volcano began at the same time. A small basaltic eruption broke out on a 0.9 km long fissure near the northern rim of the caldera at about 18 h. Earthquake activity increased soon after the beginning of the tremor and the first earthquakes were located in the caldera region. The earthquake activity then migrated southwards along the Krafla fault swarm with a speed of about 0.5 m sec{sup -1}, and culminated shortly before midnight with 8 earthquakes larger than magnitude 3 that were located near the Namafjall geothermal area 8 km south of the center of the caldera. Shortly after the earthquake activity migrated into the Namafjall area small amounts of basaltic pumice were erupted through a 1138 m deep drill hole there. Depths of earthquakes were 0-6 km in the northern part of the hypocentral zone and 0-4 in the southern part. The first motion pattern of P-waves suggests dip-slip faulting on steeply dipping fault planes consistent with the extensive normal faulting observed on the surface throughout the epicentral zone. The magnitude-frequency relationship was nonlinear and changed during the earthquake sequence. The seismological data strongly support the interpretation that deflation of the Krafla volcano is associated with horizontal migration of magma from the caldera region and formation of dykes in the Krafla fault swarm.

  12. Research on Methods for Building Volcano Disaster Information System--taking Changbai Mountain as an example

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xuexia; BO Liqun; LU Xingchang

    2001-01-01

    Volcano eruption is one of the most serious geological disasters in the world. There are volcanoes in every territory on the earth, about a thousand in China, among which Changbai Mountain Volcano, Wudalianchi Volcano and Tengchong Volcano are the most latent catastrophic eruptive active volcanoes. The paper, following an instance of Changbai Mountain Volcano, expounds that monitoring, forecasting and estimating volcano disaster by building Volcano Disaster Information System (VDIS) is feasible to alleviate volcano disaster.

  13. The Christchurch earthquake stroke incidence study.

    Science.gov (United States)

    Wu, Teddy Y; Cheung, Jeanette; Cole, David; Fink, John N

    2014-03-01

    We examined the impact of major earthquakes on acute stroke admissions by a retrospective review of stroke admissions in the 6 weeks following the 4 September 2010 and 22 February 2011 earthquakes. The control period was the corresponding 6 weeks in the previous year. In the 6 weeks following the September 2010 earthquake there were 97 acute stroke admissions, with 79 (81.4%) ischaemic infarctions. This was similar to the 2009 control period which had 104 acute stroke admissions, of whom 80 (76.9%) had ischaemic infarction. In the 6 weeks following the February 2011 earthquake, there were 71 stroke admissions, and 61 (79.2%) were ischaemic infarction. This was less than the 96 strokes (72 [75%] ischaemic infarction) in the corresponding control period. None of the comparisons were statistically significant. There was also no difference in the rate of cardioembolic infarction from atrial fibrillation between the study periods. Patients admitted during the February 2011 earthquake period were less likely to be discharged directly home when compared to the control period (31.2% versus 46.9%, p=0.036). There was no observable trend in the number of weekly stroke admissions between the 2 weeks leading to and 6 weeks following the earthquakes. Our results suggest that severe psychological stress from earthquakes did not influence the subsequent short term risk of acute stroke, but the severity of the earthquake in February 2011 and associated civil structural damages may have influenced the pattern of discharge for stroke patients. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Volcanic hazards at Atitlan volcano, Guatemala

    Science.gov (United States)

    Haapala, J.M.; Escobar Wolf, R.; Vallance, James W.; Rose, William I.; Griswold, J.P.; Schilling, S.P.; Ewert, J.W.; Mota, M.

    2006-01-01

    Atitlan Volcano is in the Guatemalan Highlands, along a west-northwest trending chain of volcanoes parallel to the mid-American trench. The volcano perches on the southern rim of the Atitlan caldera, which contains Lake Atitlan. Since the major caldera-forming eruption 85 thousand years ago (ka), three stratovolcanoes--San Pedro, Toliman, and Atitlan--have formed in and around the caldera. Atitlan is the youngest and most active of the three volcanoes. Atitlan Volcano is a composite volcano, with a steep-sided, symmetrical cone comprising alternating layers of lava flows, volcanic ash, cinders, blocks, and bombs. Eruptions of Atitlan began more than 10 ka [1] and, since the arrival of the Spanish in the mid-1400's, eruptions have occurred in six eruptive clusters (1469, 1505, 1579, 1663, 1717, 1826-1856). Owing to its distance from population centers and the limited written record from 200 to 500 years ago, only an incomplete sample of the volcano's behavior is documented prior to the 1800's. The geologic record provides a more complete sample of the volcano's behavior since the 19th century. Geologic and historical data suggest that the intensity and pattern of activity at Atitlan Volcano is similar to that of Fuego Volcano, 44 km to the east, where active eruptions have been observed throughout the historical period. Because of Atitlan's moderately explosive nature and frequency of eruptions, there is a need for local and regional hazard planning and mitigation efforts. Tourism has flourished in the area; economic pressure has pushed agricultural activity higher up the slopes of Atitlan and closer to the source of possible future volcanic activity. This report summarizes the hazards posed by Atitlan Volcano in the event of renewed activity but does not imply that an eruption is imminent. However, the recognition of potential activity will facilitate hazard and emergency preparedness.

  15. Mechanism of High Frequency Shallow Earthquake Source in Mount Soputan, North Sulawesi

    Directory of Open Access Journals (Sweden)

    Yasa Suparman

    2014-06-01

    Full Text Available DOI: 10.17014/ijog.v6i3.122Moment tensor analysis had been conducted to understand the source mechanism of earthquakes in Soputan Volcano during October - November 2010 period. The record shows shallow earthquakes with frequency about 5 - 9 Hz. Polarity distribution of P-wave first onset indicates that the recorded earthquakes are predominated by earthquakes where almost at all stations have the same direction of P-wave first motions, and earthquakes with upward first motions.In this article, the source mechanism is described as the second derivative of moment tensor, approached with first motion amplitude inversion of P-wave at some seismic stations. The result of moment tensor decomposition are predominated by earthquakes with big percentage in ISO and CLVD component. Focal mechanism shows that the recorded earthquakes have the same strike in northeast-southwest direction with dip about 400 - 600. The sources of the high frequency shallow earthquakes are in the form of tensile-shear cracks or a combination between crack and tensile faulting.

  16. Mechanism of High Frequency Shallow Earthquake Source in Mount Soputan, North Sulawesi

    Directory of Open Access Journals (Sweden)

    Yasa Suparman

    2014-06-01

    Full Text Available DOI: 10.17014/ijog.v6i3.122Moment tensor analysis had been conducted to understand the source mechanism of earthquakes in Soputan Volcano during October - November 2010 period. The record shows shallow earthquakes with frequency about 5 - 9 Hz. Polarity distribution of P-wave first onset indicates that the recorded earthquakes are predominated by earthquakes where almost at all stations have the same direction of P-wave first motions, and earthquakes with upward first motions.In this article, the source mechanism is described as the second derivative of moment tensor, approached with first motion amplitude inversion of P-wave at some seismic stations. The result of moment tensor decomposition are predominated by earthquakes with big percentage in ISO and CLVD component. Focal mechanism shows that the recorded earthquakes have the same strike in northeast-southwest direction with dip about 400 - 600. The sources of the high frequency shallow earthquakes are in the form of tensile-shear cracks or a combination between crack and tensile faulting.

  17. From mantle to crust: Tomographic image of a mid-ocean ridge volcano

    Science.gov (United States)

    Schmid, Florian; Koulakov, Ivan; Schlindwein, Vera

    2016-04-01

    Volcanoes are an integral part of mid-ocean ridges. At ultraslow spreading ridges, volcanic centres receive more melt than is produced locally and hence are centres of very efficient magmatism. The cause of melt focussing and the structure of the underlying magma plumbing systems at these volcanic centres are still enigmatic. We present microearthquake data and local earthquake tomography results, based on a one-year deployment of ocean bottom seismometers from 2012 to 2013 on a volcanic centre at the ultraslow Southwest Indian Ridge. In the period 1996-2001, several tectono-magmatic earthquake swarms including unusually strong teleseismically recorded events indicated recent magmatic activity at the experiment site. The distribution of recorded microearthquakes reveals a prominent gap in seismicity of approx. 20 km diameter immediately beneath the volcano indicating elevated temperatures. Tomography results show distinct velocity anomalies in the area of the seismicity gap. An eminent circular low Vs anomaly was found at 4-6 km depth beneath the volcano, imaging a potential crustal magma chamber. Another anomaly of high Vp/Vs-ratios is located at the eastern rim of the seismicity gap, capped by a cluster of microearthquakes and underlain by another low Vs anomaly in the upper mantle. We propose anomalies of reduced seismic velocity to result from recent magmatic activity that is further manifested in elevated temperatures beneath the volcano. Clustering microearthquake foci might be associated with steep temperature gradients and thermal fracturing, where hot upwelling material is confronted with a cold, rigid crust. O