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Sample records for bam area earthquake

  1. Crisis Management Aspects of Bam Catastrophic Earthquake: Review Article

    PubMed Central

    Sadeghi-Bazargani, Homayoun; Azami-Aghdash, Saber; Kazemi, Abdolhassan; Ziapour, Behrad

    2015-01-01

    Background: Bam earthquake was the most catastrophic natural disasters in recent years. The aim of this study was to review different aspects of crisis management during and after the catastrophic earthquake in Bam City, Iran. Methods: Data needed for this systematic review were collected through searching PubMed, EMBASE and SID databases, for the period from 2003 to 2011. Keywords included earthquake, Iran and Bam earthquake. The data were summarized and were analyzed using Content Analysis. Results: Out of 422 articles, 25 articles were included in the study. Crisis Management aspects and existing pitfalls were classified into seven categories including planning and organization, human resource management, management of logistics, international humanitarian aids, field performance of the military and security forces, health and medical service provision, and information management. Positive aspects and major pitfalls of crisis management have been introduced in all the mentioned categories. Conclusion: The available evidence indicated poor crisis management during Bam earthquake that resulted in aggravating the losses as well as diminishing the effect of interventions. Thus, concerning the importance of different aspects of the crisis management and the high prevalence of disasters in Iran, the observed vulnerability in disaster management process should be addressed. PMID:26000241

  2. The 2003 Bam (Iran) earthquake: Rupture of a blind strike-slip fault

    NASA Technical Reports Server (NTRS)

    Talebian, M.; Fielding, E. J.; Funning, G. J.; Ghorashi, M.; Jackson, J.; Nazari, H.; Parsons, B.; Priestley, K.; Rosen, P. A.; Walker, R.; Wright, T. J.

    2004-01-01

    A magnitude 6.5 earthquake devastated the town of Bam in southeast Iran on 26 December 2003. Surface displacements and decorrelation effects, mapped using Envisat radar data, reveal that over 2 m of slip occurred at depth on a fault that had not previously been identified. It is common for earthquakes to occur on blind faults which, despite their name, usually produce long-term surface effects by which their existence may be recognised. However, in this case there is a complete absence of morphological features associated with the seismogenic fault that destroyed Bam.

  3. General Health Among Parents Who Lost Their Children in the Bam Earthquake

    PubMed Central

    Rashidinejad, Masoumeh; Dehghan, Mahlagha; Tirgari, Batool; Rafiei, Hossein; Iranmanesh, Sedigheh

    2015-01-01

    Aim: Bam earthquake and its profound tragedy of thousands killed has caused emotional and psychological trauma for tens of thousands of people who have survived. This study aimed to investigate general health of parents who lose their children in Bam earthquake 10 years after the earthquake. Method: General health of 166 parents who lost their children in Bam earthquake was assessed using a translated version of General Health Questionnarie-28 items. Results: The mean score of GHQ was 25.63 ± 15.28. Among all domains, the higher mean score belonged to the category of “anxiety/insomnia” and the lower one belonged to the category of “severe depression. The results revealed significant correlation between total GHQ mean score and gender as well as educational level (0.003) Conclusion: Providing reflective narrative environments in which survivors can express their own experiences and feelings about earthquake, their loss and how they cope with it seems to be as an effective approach to identify their psychosocial situation and its influential factors. In such narrative environments special attention should be given to older participants, females and those who are single. PMID:26156934

  4. Outcomes of fasciotomy in patients with crush-induced acute kidney injury after Bam earthquake.

    PubMed

    Safari, Saeed; Najafi, Iraj; Hosseini, Mostafa; Sanadgol, Houshang; Sharifi, Ali; Alavi Moghadam, Mostafa; Abdulvand, Ali; Rashid Farrokhi, Farin; Borumand, Behrooz

    2011-01-01

    INTRODUCTION. Fasciotomy may increase the morbidity and mortality in patients with crush-induced acute kidney injury (AKI), by creating an open wound, increasing the risk of bleeding, coagulopathy, and potentially fatal sepsis. This study evaluates the outcomes of fasciotomy in these patients after Bam earthquake in Iran. MATERIALS AND METHODS. We reviewed medical records of victims of Bam earthquake complicated with crush-induced AKI. Demographic, biochemical, and clinical data of patients who underwent fasciotomy were evaluated and compared with other patients with AKI. RESULTS. Fasciotomy was performed for 70 of 200 patients with crush-induced AKI (35.0%). There were no significant differences regarding sex, age, time under the rubble, and muscle enzymes level between these patients and those without fasciotomy. They did not experience higher rates of disseminated intravascular coagulopathy, sepsis, adult respiratory distress syndrome, amputation, and dialysis session. Neither did they have a longer hospitalization period or higher death rate. CONCLUSIONS. This study showed that fasciotomy did not have any deteriorating effect on morbidity and mortality of patients with crush-induced AKI after Bam earthquake.

  5. Trends of Serum Electrolyte Changes in Crush syndrome patients of Bam Earthquake; a Cross sectional Study

    PubMed Central

    Safari, Saeed; Eshaghzade, Mehdi; Najafi, Iraj; Baratloo, Alireza; Hashemi, Behrooz; Forouzanfar, Mohammad Mehdi; Rahmati, Farhad

    2017-01-01

    Introduction: Electrolyte imbalances are very common among crushed earthquake victims but there is not enough data regarding their trend of changes. The present study was designed to evaluate the trend of changes in sodium, calcium, and phosphorus ions among crush syndrome patients. Methods: In this retrospective cross-sectional study, using the database of Bam earthquake victims, which was developed by Iranian Society of Nephrology following Bam earthquake, Iran, 2003, the 10-day trend of sodium, calcium, and phosphorus ions changes in > 15 years old crush syndrome patients was evaluated. Results: 118 patients with the mean age of 25.6 ± 6.9 years were studied (57.3 male). On the first day of admission, 52.5% (95% CI: 42.7 - 62.3) of the patients had hyponatremia, which reached 43.9% (95% CI: 28.5 - 59.3) on day 10. 100.0% of patients were hypocalcemic on admission and serum calcium level did not change dramatically during the 10 days of hospitalization. The prevalence of hyperphosphatemia on the first day was 90.5% (95% CI: 81.5 - 99.5) and on the 10th day of hospitalization 66.7% (95% CI: 48.5 - 84.8) of the patients were still affected. Conclusion: The results of the present study shows the 52.5% prevalence of hyponatremia, 100% hypocalcemia, and 90.5% hyperphosphatemia among crush syndrome patients of Bam earthquake victims on the first day of admission. Evaluation of 10-day trend shows a slow decreasing pattern of these imbalances as after 10 days, 43.9% still remain hyponatremic, 92.3% hypocalcemic, and 66.7% hypophosphatemic. PMID:28286814

  6. Rupture Process of the 2003 Bam, Iran, Earthquake: Did Shallow Asperities on a Fresh Fault Cause Extreme Ground Motions?

    NASA Astrophysics Data System (ADS)

    Miyake, H.; Koketsu, K.; Mostafaei, H.

    2004-12-01

    The Bam, Iran, earthquake on December 26, 2003 caused heavy damage to the city of Bam including the historic heritage of Arg-e-Bam. This Mw6.5 earthquake rupture created fresh faults 5 km westward away from the Bam fault. The Bam strong-motion station recorded 992 gal in the UD component and two directivity pulses in the horizontal components with a dominant frequency of 1 Hz. We inferred the rupture process of the 2003 Bam earthquake from strong motion data observed by BHRC, together with teleseismic data to constrain global features of the source. Waveform inversions using teleseismic data (e.g. Yamanaka, 2003; Yagi, 2003) have suggested the existence of a shallow asperity. Nakamura et al. (2004) estimated aftershock distribution with vertical dipping that superimposed the fresh faults, not the Bam fault. They proposed fault planes consisting N-S alignment with northward branches beneath the city of Bam. Our preliminary analyses show that two directivity pulses are created by northward rupture near the hypocenter and north-eastward rupture beneath the city. Recent earthquakes occurred on immature faults with shallow asperities have also generated localized extreme-strong motions (e.g., 2003 Miyagi-ken Hokubu, Japan, with Mw6.1; 2000 Tottori, Japan, with Mw6.6). Larger fracture energy is expected for shallow asperities on immature faults than those on mature faults. For example, the 2000 Tottori earthquake has several times larger fracture energy than expected by the scaling between seismic moment and fracture energy. When considering the energy budget, are radiated energy from the immature faults enough to generate the extreme ground motions? Detailed source process inversions might be able to answer this question.

  7. Role of dipstick in detection of haeme pigment due to rhabdomyolysis in victims of Bam earthquake.

    PubMed

    Amini, M; Sharifi, A; Najafi, I; Eghtesadi-Araghi, P; Rasouli, M R

    2010-09-01

    Avoiding life-threatening complications of rhabdomyolysis depends on early diagnosis and prompt management. The aim of this study was to evaluate the role of urinary dipstick test in the detection of haeme pigment in patients who were at risk of acute renal failure (ARF) due to rhabdomyolysis after suffering injury in the Bam earthquake. Serum creatine phosphokinase (CPK) level was used as the gold standard for prediction of ARF. ARF developed in 8 (10%) of 79 patients studied. We found no significant differences in the sensitivity, specificity and accuracy of dipstick urine and serum CPK tests for identifying patients who were at risk of ARF. However, dipstick urine test is an easy test that can be performed quickly at an earthquake site.

  8. 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

    PubMed Central

    Aflatoonian, Mohammad Reza; Sharifi, Iraj; Aflatoonian, Bahnaz; Shirzadi, Mohammad Reza; Gouya, Mohammad Mahdi; Kermanizadeh, Alireza

    2016-01-01

    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. PMID:27308286

  9. Surface Ruptures and Building Damage of the 2003 Bam, Iran, Earthquake Mapped by Satellite Synthetic Aperture Radar Interferometric Correlation

    NASA Technical Reports Server (NTRS)

    Fielding, Eric J.; Talebian, M.; Rosen, P. A.; Nazari, H.; Jackson, J. A.; Ghorashi, M.; Walker, R.

    2005-01-01

    We use the interferometric correlation from Envisat synthetic aperture radar (SAR) images to map the details of the surface ruptures related to the 26 December 2003 earthquake that devastated Bam, Iran. The main strike-slip fault rupture south of the city of Bam has a series of four segments with left steps shown by a narrow line of low correlation in the coseismic interferogram. This also has a clear expression in the field because of the net extension across the fault. Just south of the city limits, the surface strain becomes distributed over a width of about 500 m, probably because of a thicker layer of soft sedimentary material.

  10. Shallow Fault-zone Dilatancy Recovery after the 2003 Bam, Iran Earthquake from Eight Years of InSAR

    NASA Astrophysics Data System (ADS)

    Fielding, E. J.; Burgmann, R.; Lundgren, P.; Funning, G. J.

    2011-12-01

    The December 2003 Mw 6.6 earthquake that devastated Bam, Iran involved several meters of slip on a previously unknown fault beneath the city, but surface ruptures showed a maximum of 25 cm of offset. At shallow depths, the earthquake strain was distributed over a zone roughly 500-2000 m wide in a thick alluvial layer. The outstanding surface conditions for InSAR (interferometric synthetic aperture radar) and frequent coverage by Envisat ASAR provide an opportunity to map the coseismic and postseismic ground deformation and study the time history in the eight years since the earthquake using InSAR time series analysis. Postseismic deformation in the first three and a half years showed a clear pattern of subsidence over the main fault rupture, reflecting compaction of the fault zone material after the earthquake. Another pattern of postseismic deformation is consistent with afterslip on deeper parts of the fault zone. Compaction in the area of a compressional step-over in the fault may be due to poroelastic rebound, but the compaction in the straight fault segments is interpreted to be due to recovery of coseismic dilatancy. Simple modeling of the surface subsidence signal with volume changes in an elastic half space suggest that the compaction with a volume decrease of about 105 m3 occurred in the upper km of the fault zone over a length of about 4 km during the first 3.5 years after the earthquake, with a time function that can be approximated as log(t) where t is the time since the earthquake. The compaction of the shallow fault-zone is directly above the area of largest coseismic slip at depth. We infer that this part of the fault zone absorbed the upward-propagating coseismic rupture by distributed shear and damage in the unlithified or poorly lithified alluvial material that generated significant dilatancy. After the earthquake, compaction processes recovered this dilatancy. Distributed shearing of the shallow fault zone may resolve the paradox of shallow slip

  11. 20-Day Trend of Serum Potassium Changes in Bam Earthquake Victims with Crush Syndrome; a Cross-sectional Study

    PubMed Central

    Safari, Saeed; Najafi, Iraj; Hosseini, Mostafa; Baratloo, Alireza; Yousefifard, Mahmoud; Mohammadi, Hamidreza

    2017-01-01

    Introduction: Many of those who survive following an earthquake die in the next phase due to preventable and treatable medical conditions such as hyperkalemia. The present study aimed to evaluate the trend of potassium changes in crush syndrome patients of Bam earthquake. Methods: In this retrospective cross-sectional study, using the database of Bam earthquake victims, which were developed by Iranian Society of Nephrology following Bam earthquake, Iran, 2003, the 20-day trend of potassium changes in > 15 years old crush syndrome patients was evaluated. Results: 135 crush syndrome patients with the mean age of 29.9 ± 9.91 years were evaluated (56.3% male). Mean potassium concentration during the first 3 days of admission was 5.6 ± 1.3 mEq/L. On the day of admission, 43.1% (95% CI: 34.0 - 52.2) had normal potassium concentration, 3.4% (95% CI: 0.1 - 6.8) had hypokalemia, and 53.4% (44.3 - 62.6) had hyperkalemia. During 20-day follow-up, 62.3% (95% CI: 66.7-71.9) of the patients had normal potassium. While, 11.5% (95% CI: 9.7-13.3) had hypokalemia and 19.2% (95% CI: 17.0-21.5) had hyperkalemia. As the days of hospitalization increased, prevalence of hyperkalemia decreased while hypokalemia increased. On the 17th day 21.2% (95% CI: 2.2-39.9) had hypokalemia and 10.5% (95% CI: 0.1 – 24.7) had hyperkalemia. Conclusion: Findings of the present study showed that following urine alkalinization and fluid resuscitation, the prevalence of hyperkalemia reduced, but hypokalemia developed. It seems that the correction of serum potassium level should be accompanied by precise monitoring of intake and output of the patient and prescription of reasonable amount of intravenous fluid. PMID:28286812

  12. Toward a Better Nutritional Aiding in Disasters: Relying on Lessons Learned during the Bam Earthquake.

    PubMed

    Nekouie Moghadam, Mahmoud; Amiresmaieli, Mohammadreza; Hassibi, Mohammad; Doostan, Farideh; Khosravi, Sajad

    2017-03-27

    Introduction Examining various problems in the aftermath of disasters is very important to the disaster victims. Managing and coordinating food supply and its distribution among the victims is one of the most important problems after an earthquake. Therefore, the purpose of this study was to recognize problems and experiences in the field of nutritional aiding during an earthquake.

  13. St. Louis Area Earthquake Hazards Mapping Project

    USGS Publications Warehouse

    Williams, Robert A.; Steckel, Phyllis; Schweig, Eugene

    2007-01-01

    St. Louis has experienced minor earthquake damage at least 12 times in the past 200 years. Because of this history and its proximity to known active earthquake zones, the St. Louis Area Earthquake Hazards Mapping Project will produce digital maps that show variability of earthquake hazards in the St. Louis area. The maps will be available free via the internet. They can be customized by the user to show specific areas of interest, such as neighborhoods or transportation routes.

  14. Dissociative Reactions to the Bay Area Earthquake.

    ERIC Educational Resources Information Center

    Cardena, Etzel; Spiegel, David

    This study systematically evaluated the psychological reactions of a non-clinical population to the October 1989 Bay Area earthquake. Within a week of the earthquake, a checklist of anxiety and dissociative symptoms was administered to a representative sample of approximately 100 graduate students and faculty members from two different…

  15. BAM! Physical Activity

    MedlinePlus

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  16. BAM! Body and Mind

    MedlinePlus

    ... The CDC Cancel Submit Search The CDC BAM! Body and Mind Note: Javascript is disabled or is not supported ... please visit this page: About CDC.gov . BAM! Body and Mind Diseases Xpert Opinion Disease Dectectives Immune Platoon Learn ...

  17. Mapping of earthquakes vulnerability area in Papua

    NASA Astrophysics Data System (ADS)

    Muhammad Fawzy Ismullah, M.; Massinai, Muh. Altin

    2016-05-01

    Geohazard is a geological occurrence which may lead to a huge loss for human. A mitigation of these natural disasters is one important thing to be done properly in order to reduce the risks. One of the natural disasters that frequently occurs in the Papua Province is the earthquake. This study applies the principle of Geospatial and its application for mapping the earthquake-prone area in the Papua region. It uses earthquake data, which is recorded for 36 years (1973-2009), fault location map, and ground acceleration map of the area. The earthquakes and fault map are rearranged into an earthquake density map, as well as an earthquake depth density map and fault density map. The overlaid data of these three maps onto ground acceleration map are then (compiled) to obtain an earthquake unit map. Some districts area, such as Sarmi, Nabire, and Dogiyai, are identified by a high vulnerability index. In the other hand, Waropen, Puncak, Merauke, Asmat, Mappi, and Bouven Digoel area shows lower index. Finally, the vulnerability index in other places is detected as moderate.

  18. Understanding earthquake hazards in urban areas - Evansville Area Earthquake Hazards Mapping Project

    USGS Publications Warehouse

    Boyd, Oliver S.

    2012-01-01

    The region surrounding Evansville, Indiana, has experienced minor damage from earthquakes several times in the past 200 years. Because of this history and the proximity of Evansville to the Wabash Valley and New Madrid seismic zones, there is concern among nearby communities about hazards from earthquakes. Earthquakes currently cannot be predicted, but scientists can estimate how strongly the ground is likely to shake as a result of an earthquake and are able to design structures to withstand this estimated ground shaking. Earthquake-hazard maps provide one way of conveying such information and can help the region of Evansville prepare for future earthquakes and reduce earthquake-caused loss of life and financial and structural loss. The Evansville Area Earthquake Hazards Mapping Project (EAEHMP) has produced three types of hazard maps for the Evansville area: (1) probabilistic seismic-hazard maps show the ground motion that is expected to be exceeded with a given probability within a given period of time; (2) scenario ground-shaking maps show the expected shaking from two specific scenario earthquakes; (3) liquefaction-potential maps show how likely the strong ground shaking from the scenario earthquakes is to produce liquefaction. These maps complement the U.S. Geological Survey's National Seismic Hazard Maps but are more detailed regionally and take into account surficial geology, soil thickness, and soil stiffness; these elements greatly affect ground shaking.

  19. Earthquakes

    MedlinePlus

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

  20. Assessing the earthquake hazards in urban areas

    USGS Publications Warehouse

    Hays, W.W.; Gori, P.L.; Kockelman, W.J.

    1988-01-01

    Major urban areas in widely scattered geographic locations across the United States are a t varying degrees of risk from earthquakes. the locations of these urban areas include Charleston, South Carolina; Memphis Tennessee; St.Louis, Missouri; Salt Lake City, Utah; Seattle-Tacoma, Washington; Portland, Oregon; and Anchorage, Alaska; even Boston, Massachusetts, and Buffalo New York, have a history of large earthquakes. Cooperative research during the past decade has focused on assessing the nature and degree of the risk or seismic hazard i nthe broad geographic regions around each urban area. The strategy since the 1970's has been to bring together local, State, and Federal resources to solve the problem of assessing seismic risk. Successfl sooperative programs have been launched in the San Francisco Bay and Los Angeles regions in California and the Wasatch Front region in Utah. 

  1. Earthquakes.

    ERIC Educational Resources Information Center

    Pakiser, Louis C.

    One of a series of general interest publications on science topics, the booklet provides those interested in earthquakes with an introduction to the subject. Following a section presenting an historical look at the world's major earthquakes, the booklet discusses earthquake-prone geographic areas, the nature and workings of earthquakes, earthquake…

  2. Earthquake Hazard for Aswan High Dam Area

    NASA Astrophysics Data System (ADS)

    Ismail, Awad

    2016-04-01

    Earthquake activity and seismic hazard analysis are important components of the seismic aspects for very essential structures such as major dams. The Aswan High Dam (AHD) created the second man-made reservoir in the world (Lake Nasser) and is constructed near urban areas pose a high-risk potential for downstream life and property. The Dam area is one of the seismically active regions in Egypt and is occupied with several cross faults, which are dominant in the east-west and north-south. Epicenters were found to cluster around active faults in the northern part of Lake and AHD location. The space-time distribution and the relation of the seismicity with the lake water level fluctuations were studied. The Aswan seismicity separates into shallow and deep seismic zones, between 0 and 14 and 14 and 30 km, respectively. These two seismic zones behave differently over time, as indicated by the seismicity rate, lateral extent, b-value, and spatial clustering. It is characterized by earthquake swarm sequences showing activation of the clustering-events over time and space. The effect of the North African drought (1982 to present) is clearly seen in the reservoir water level. As it decreased and left the most active fault segments uncovered, the shallow activity was found to be more sensitive to rapid discharging than to the filling. This study indicates that geology, topography, lineations in seismicity, offsets in the faults, changes in fault trends and focal mechanisms are closely related. No relation was found between earthquake activity and both-ground water table fluctuations and water temperatures measured in wells located around the Kalabsha area. The peak ground acceleration is estimated in the dam site based on strong ground motion simulation. This seismic hazard analyses have indicated that AHD is stable with the present seismicity. The earthquake epicenters have recently took place approximately 5 km west of the AHD structure. This suggests that AHD dam must be

  3. BAM! Guide to Getting Along

    MedlinePlus

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  4. Earthquake Potential Areas Using Seismicity Catalog, Remote Sensing and GIS

    NASA Astrophysics Data System (ADS)

    Ahmad, Raed; Adris, Ahmad

    Abstract Satellite data (Landsat and Aster), Digital Elevation Model image 30 m resolution, Syrian Seismicity earthquake data, and various other land use cover maps were used as inputs to the study the earthquake prone areas. Important factors responsible for earthquake occurrence in the region, were identified and corresponding thematic data layers (past earthquake epicenters, faults, digital elevation model, and slope) were generated. In the first two layers the earthquake magnitudes and the distance to earthquake epicenters are also considered. The distance to the active fault and the length of fault have been considered in separate layers. The variation in terrain elevation and slope are also included in our model studies. For better estimation of earthquake potential areas the density distributions of earthquake epicenters and faults have been used in the model. A numerical rating scheme to identify the factors was developed for spatial data analysis using GIS. The resulting earthquake potential map delineates the area into different relative susceptibility classes: high, moderate, low and very low. The potential earthquake map was validated by correlating the obtained different classes with the local probability that produced using conventional analysis of Syrian seismicity catalog. Details of methodology showing a close agreement with the existing results will be presented.

  5. Susceptibility Status of Phlebotomus papatasi and P. sergenti (Diptera: Psychodidae) to DDT and Deltamethrin in a Focus of Cutaneous Leishmaniasis after Earthquake Strike in Bam, Iran

    PubMed Central

    Afshar, A Aghaei; Rassi, Y; Sharifi, I; Abai, MR; Oshaghi, MA; Yaghoobi-Ershadi, MR; Vatandoost, H

    2011-01-01

    Background: The cutaneous leishmaniasis (CL) has been occurred in Dehbakri County, located 46 km of Bam District, Kerman Province since 2004–2005. Phlebotomus papatasi is an important vector of zoonotic cutaneous leishmanisis (ZCL) as well as sand fly fever and P. sergenti is considered as main vector of anthroponotic cutaneous leishmaniasis (ACL) in Iran. There are several measures for vector control with emphasizing on insecticides. The objective of this study was to determine the baseline susceptibility of leishmaniasis vectors to the DDT and deltamethrin in an endemic focus of CL in southern Iran. Methods: Baseline susceptibility tests were carried out on field collected strains of P. papatasi and P. sergenti and tested with WHO impregnated papers with DDT 4.0% and deltamethrin 0.05% in the focus of disease in Dehbakri County during summer 2010. The values of LT50 and LT90 were determined using probit analysis and regression lines. Results: The LT50 value of DDT 4.0% and deltamethrin 0.05% against P. papatasi was 20.6 and 13.6 minutes respectively. The same data for P. sergenti were ranged between 21.8 and 17.7 minutes. Conclusion: The results of tests will provide a guideline for implementation of vector control using pesticides such as impregnated bed nets, indoor residual spraying and fogging. PMID:22808416

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

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

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

  7. Earthquakes

    USGS Publications Warehouse

    Shedlock, Kaye M.; Pakiser, Louis Charles

    1998-01-01

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

  8. Small Buildings in Earthquake Areas. Educational Building Digest 2.

    ERIC Educational Resources Information Center

    Mooij, D.

    This booklet is intended for builders and others who actually construct small buildings in earthquake areas and not for professionally qualified architects or engineers. In outline form with sketches the following topics are discussed: general construction and design principles; foundations; earth walls; brick, block, and stone walls; timber frame…

  9. The Bay Area Earthquake Cycle:A Paleoseismic Perspective

    NASA Astrophysics Data System (ADS)

    Schwartz, D. P.; Seitz, G.; Lienkaemper, J. J.; Dawson, T. E.; Hecker, S.; William, L.; Kelson, K.

    2001-12-01

    Stress changes produced by the 1906 San Francisco earthquake had a profound effect on Bay Area seismicity, dramatically reducing it in the 20th century. Whether the San Francisco Bay Region (SFBR) is still within, is just emerging from it, or is out of the 1906 stress shadow is an issue of strong debate with important implications for earthquake mechanics and seismic hazards. Historically the SFBR has not experienced one complete earthquake cycle--the interval immediately following, then leading up to and repeating, a 1906-type (multi-segment rupture, M7.9) San Andreas event. The historical record of earthquake occurrence in the SFBR appears to be complete at about M5.5 back to 1850 (Bakun, 1999), which is less than half a cycle. For large events (qualitatively placed at M*7) Toppozada and Borchardt (1998) suggest the record is complete back to 1776, which may represent about half a cycle. During this period only the southern Hayward fault (1868) and the San Andreas fault (1838?, 1906) have produced their expected large events. New paleoseismic data now provide, for the first time, a more complete view of the most recent pre-1906 SFBR earthquake cycle. Focused paleoseismic efforts under the Bay Area Paleoearthquake Experiment (BAPEX) have developed a chronology of the most recent large earthquakes (MRE) on major SFBR faults. The San Andreas (SA), northern Hayward (NH), southern Hayward (SH), Rodgers Creek (RC), and northern Calaveras (NC) faults provide clear paleoseismic evidence for large events post-1600 AD. The San Gregorio (SG) may have also produced a large earthquake after this date. The timing of the MREs, in years AD, follows. The age ranges are 2-sigma radiocarbon intervals; the dates in parentheses are 1-sigma. MRE ages are: a) SA 1600-1670 (1630-1660), NH 1640-1776 (1635-1776); SH 1635-1776 (1685-1676); RC 1670-1776 (1730-1776); NC 1670-1830?; and San Gregorio 1270-1776 but possibly 1640-1776 (1685-1776). Based on present radiocarbon dating, the NH

  10. Earthquakes

    MedlinePlus

    ... Thunderstorms & Lightning Tornadoes Tsunamis Volcanoes Wildfires Main Content Earthquakes Earthquakes are sudden rolling or shaking events caused ... at any time of the year. Before An Earthquake Look around places where you spend time. Identify ...

  11. Earthquakes, active faults, and geothermal areas in the imperial valley, california.

    PubMed

    Hill, D P; Mowinckel, P; Peake, L G

    1975-06-27

    A dense seismograph network in the Imperial Valley recorded a series of earthquake swarms along the Imperial and Brawley faults and a diffuse pattern of earthquakes along the San Jacinto fault. Two known geothermal areas are closely associated with these earthquake swarms. This seismicity pattern demonstrates that seismic slip is occurring along both the Imperial-Brawley and San Jacinto fault systems.

  12. Earthquakes.

    ERIC Educational Resources Information Center

    Walter, Edward J.

    1977-01-01

    Presents an analysis of the causes of earthquakes. Topics discussed include (1) geological and seismological factors that determine the effect of a particular earthquake on a given structure; (2) description of some large earthquakes such as the San Francisco quake; and (3) prediction of earthquakes. (HM)

  13. Observation of earthquake ground motion due to aftershocks of the 2016 Kumamoto earthquake in damaged areas

    NASA Astrophysics Data System (ADS)

    Yamanaka, Hiroaki; Chimoto, Kosuke; Miyake, Hiroe; Tsuno, Seiji; Yamada, Nobuyuki

    2016-12-01

    We have conducted observation of earthquake ground motion due to aftershocks of the 2016 Kumamoto earthquake at 26 temporary stations in damaged areas of Kumamoto city, Mashiki town, Nishihara village and Minami-Aso village (partly in Aso city) in Kumamoto prefecture, Japan. Continuous recordings of ground acceleration were acquired in a period of about 1 month after the occurrence of the main shock on April 16, 2016. This preliminary analysis of the observed records clearly indicates strong effects of local geological condition in the heavily damaged districts in Mashiki town and Nishihara village. Spectral ratios of the ground motions at the stations in the severely damaged districts to those at the reference sites are characterized by large amplitudes at periods of 0.5-1 s. Peak ground velocities and seismic intensities are also large at the sites. Seismic intensities at the stations in the damaged districts are larger by an intensity of one at the maximum than those at the stations with the minor damage. The ground motions at the stations in Kumamoto city are rich in later phases with long duration suggesting basin effects. However, site amplification effects could not clearly be identified at the stations in the Minami-Aso area from the results in the conventional spectral ratio approach.[Figure not available: see fulltext.

  14. Earthquakes

    ERIC Educational Resources Information Center

    Roper, Paul J.; Roper, Jere Gerard

    1974-01-01

    Describes the causes and effects of earthquakes, defines the meaning of magnitude (measured on the Richter Magnitude Scale) and intensity (measured on a modified Mercalli Intensity Scale) and discusses earthquake prediction and control. (JR)

  15. Earthquakes

    MedlinePlus

    ... and Cleanup Workers Hurricanes PSAs ASL Videos: Hurricanes Landslides & Mudslides Lightning Lightning Safety Tips First Aid Recommendations ... Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis Volcanoes Wildfires Winter Weather Earthquakes Language: ...

  16. Analysis of the relationship between landslides size distribution and earthquake source area

    NASA Astrophysics Data System (ADS)

    Valagussa, Andrea; Crosta, Giovanni B.; Frattini, Paolo; Xu, Chong

    2014-05-01

    The spatial distribution of earthquake induced landslides around the seismogenetic source has been analysed to better understand the triggering of landslides in seismic areas and to forecast the maximum distance at which an earthquake, with a certain magnitude, can induce landslides (e.g Keefer, 1984). However, when applying such approaches to old earthquakes (e.g 1929 Buller and 1968 Iningahua earthquakes New Zealand; Parker, 2013; 1976 Friuli earthquake, Italy) one should be concerned about the undersampling of smaller landslides which can be cancelled by erosion and landscape evolution. For this reason, it is important to characterize carefully the relationship between landslide area and number with distance from the source, but also the size distribution of landslides as a function of distance from the source. In this paper, we analyse the 2008 Wenchuan earthquake landslide inventory (Xu et al, 2013). The earthquake triggered more than 197,000 landslides of different type, including rock avalanches, rockfalls, translational and rotational slides, lateral spreads and derbies flows. First, we calculated the landslide intensity (number of landslides per unit area) and spatial density (landslide area per unit area) as a function of distance from the source area of the earthquake. Then, we developed magnitude frequency curves (MFC) for different distances from the source area. Comparing these curves, we can describe the relation between the distance and the frequency density of landslide in seismic area. Keefer D K (1984) Landslides caused by earthquakes. Geological Society of America Bulletin, 95(4), 406-421. Parker R N, (2013) Hillslope memory and spatial and temporal distributions of earthquake-induced landslides, Durham theses, Durham University. Xu, C., Xu, X., Yao, X., & Dai, F. (2013). Three (nearly) complete inventories of landslides triggered by the May 12, 2008 Wenchuan Mw 7.9 earthquake of China and their spatial distribution statistical analysis

  17. Pre- and Post-Earthquake Enrollment by Geographic Area.

    ERIC Educational Resources Information Center

    College of the Canyons, Santa Clarita, CA. Office of Institutional Development.

    On January 17, 1994, the Northridge earthquake caused major damage to the freeways leading into California's Santa Clarita Valley. For most of the spring semester, travel to and from the valley was difficult and time-consuming. To determine the effect of the earthquake on enrollment, College of the Canyons, in the Santa Clarita Valley, undertook a…

  18. Analysis of rupture area of aftershocks caused by twin earthquakes (Case study: 11 April 2012 earthquakes of Aceh-North Sumatra)

    SciTech Connect

    Diansari, Angga Vertika Purwana, Ibnu; Subakti, Hendri

    2015-04-24

    The 11 April 2012 earthquakes off-shore Aceh-North Sumatra are unique events for the history of Indonesian earthquake. It is unique because that they have similar magnitude, 8.5 Mw and 8.1 Mw; close to epicenter distance, similar strike-slip focal mechanism, and occuring in outer rise area. The purposes of this research are: (1) comparing area of earthquakes base on models and that of calculation, (2) fitting the shape and the area of earthquake rupture zones, (3) analyzing the relationship between rupture area and magnitude of the earthquakes. Rupture area of the earthquake fault are determined by using 4 different formulas, i.e. Utsu and Seki (1954), Wells and Coppersmith (1994), Ellsworth (2003), and Christophersen and Smith (2000). The earthquakes aftershock parameters are taken from PGN (PusatGempabumiNasional or National Earthquake Information Center) of BMKG (Indonesia Agency Meteorology Climatology and Geophysics). The aftershock epicenters are plotted by GMT’s software. After that, ellipse and rectangular models of aftershock spreading are made. The results show that: (1) rupture areas were calculated using magnitude relationship which are larger than the the aftershock distributions model, (2) the best fitting model for that earthquake aftershock distribution is rectangular associated with Utsu and Seki (1954) formula, (3) the larger the magnitude of the earthquake, the larger area of the fault.

  19. Evansville Area Earthquake Hazards Mapping Project (EAEHMP) - Progress Report, 2008

    USGS Publications Warehouse

    Boyd, Oliver S.; Haase, Jennifer L.; Moore, David W.

    2009-01-01

    Maps of surficial geology, deterministic and probabilistic seismic hazard, and liquefaction potential index have been prepared by various members of the Evansville Area Earthquake Hazard Mapping Project for seven quadrangles in the Evansville, Indiana, and Henderson, Kentucky, metropolitan areas. The surficial geologic maps feature 23 types of surficial geologic deposits, artificial fill, and undifferentiated bedrock outcrop and include alluvial and lake deposits of the Ohio River valley. Probabilistic and deterministic seismic hazard and liquefaction hazard mapping is made possible by drawing on a wealth of information including surficial geologic maps, water well logs, and in-situ testing profiles using the cone penetration test, standard penetration test, down-hole shear wave velocity tests, and seismic refraction tests. These data were compiled and collected with contributions from the Indiana Geological Survey, Kentucky Geological Survey, Illinois State Geological Survey, United States Geological Survey, and Purdue University. Hazard map products are in progress and are expected to be completed by the end of 2009, with a public roll out in early 2010. Preliminary results suggest that there is a 2 percent probability that peak ground accelerations of about 0.3 g will be exceeded in much of the study area within 50 years, which is similar to the 2002 USGS National Seismic Hazard Maps for a firm rock site value. Accelerations as high as 0.4-0.5 g may be exceeded along the edge of the Ohio River basin. Most of the region outside of the river basin has a low liquefaction potential index (LPI), where the probability that LPI is greater than 5 (that is, there is a high potential for liquefaction) for a M7.7 New Madrid type event is only 20-30 percent. Within the river basin, most of the region has high LPI, where the probability that LPI is greater than 5 for a New Madrid type event is 80-100 percent.

  20. Identification of Earthquake Induced Damage Areas Using Fourier Transform and SPOT HRVIR Pan Images

    PubMed Central

    Sertel, Elif

    2009-01-01

    A devastating earthquake with a magnitude of Mw 7.4 occurred on the North Anatolian Fault Zone (NAFZ) of Turkey on August 17, 1999 at 00:01:39 UTC (3:01 a.m. local time). The aim of this study is to propose a new approach to automatically identify earthquake induced damage areas which can provide valuable information to support emergency response and recovery assessment procedures. This research was conducted in the Adapazari inner city, covering a 3 × 3 km area, where 11,373 buildings collapsed as a result of the earthquake. SPOT high resolution visible infrared (HRVIR) Pan images obtained before (25 June 1999) and after (4 October 1999) the earthquake were used in the study. Five steps were employed to conduct the research and these are: (i) geometric and radiometric correction of satellite images, (ii) Fast Fourier Transform (FFT) of pre- and post-earthquake images and filtering the images in frequency domain, (iii) generating difference image using Inverse Fast Fourier Transform (IFFT) pre- and post- earthquake images, (iv) application of level slicing to difference image to identify the earthquake-induced damages, (v) accuracy assessment of the method using ground truth obtained from a 1/5,000 scale damage map. The total accuracy obtained in the research is 80.19 %, illustrating that the proposed method can be successfully used to automatically identify earthquake-induced damage areas. PMID:22573966

  1. Identification of Earthquake Induced Damage Areas Using Fourier Transform and SPOT HRVIR Pan Images.

    PubMed

    Sertel, Elif

    2009-01-01

    A devastating earthquake with a magnitude of Mw 7.4 occurred on the North Anatolian Fault Zone (NAFZ) of Turkey on August 17, 1999 at 00:01:39 UTC (3:01 a.m. local time). The aim of this study is to propose a new approach to automatically identify earthquake induced damage areas which can provide valuable information to support emergency response and recovery assessment procedures. This research was conducted in the Adapazari inner city, covering a 3 × 3 km area, where 11,373 buildings collapsed as a result of the earthquake. SPOT high resolution visible infrared (HRVIR) Pan images obtained before (25 June 1999) and after (4 October 1999) the earthquake were used in the study. Five steps were employed to conduct the research and these are: (i) geometric and radiometric correction of satellite images, (ii) Fast Fourier Transform (FFT) of pre- and post-earthquake images and filtering the images in frequency domain, (iii) generating difference image using Inverse Fast Fourier Transform (IFFT) pre- and post- earthquake images, (iv) application of level slicing to difference image to identify the earthquake-induced damages, (v) accuracy assessment of the method using ground truth obtained from a 1/5,000 scale damage map. The total accuracy obtained in the research is 80.19 %, illustrating that the proposed method can be successfully used to automatically identify earthquake-induced damage areas.

  2. Fault Mechanics and Post-seismic Deformation at Bam, SE Iran

    NASA Astrophysics Data System (ADS)

    Wimpenny, Sam; Copley, Alex; Ingleby, Tom

    2017-02-01

    The extent to which aseismic deformation relaxes co-seismic stress changes on a fault zone is fundamental to assessing the future seismic hazard following any earthquake, and in understanding the mechanical behaviour of faults. Here we use models of stress-driven afterslip and visco-elastic relaxation, in conjunction with post-seismic InSAR measurements, to show that there has been minimal release of co-seismic stress changes through post-seismic deformation following the 2003 Mw 6.6 Bam earthquake. Our analysis indicates the faults at Bam remain predominantly locked, suggesting that the co- plus inter-seismically accumulated elastic strain stored down-dip of the 2003 rupture patch may be released in a future Mw 6 earthquake. Our observations and models also provide an opportunity to probe the growth of topography at Bam. We find that, for our modelled afterslip distribution to be consistent with forming the sharp step in the local topography over repeated earthquake cycles, and also to be consistent with the geodetic observations, requires either (1) far-field tectonic loading equivalent to a 2-10 MPa deviatoric stress acting across the fault system, which suggests it supports stresses 60-100 times less than classical views of static fault strength, or (2) that the fault surface has some form of mechanical anisotropy, potentially related to corrugations on the fault plane, that controls the sense of slip.

  3. Earthquake!

    ERIC Educational Resources Information Center

    Hernandez, Hildo

    2000-01-01

    Examines the types of damage experienced by California State University at Northridge during the 1994 earthquake and what lessons were learned in handling this emergency are discussed. The problem of loose asbestos is addressed. (GR)

  4. Classification of magnitude 7 earthquakes which occurred after 1885 in Tokyo Metropolitan area

    NASA Astrophysics Data System (ADS)

    Ishibe, T.; Satake, K.; Shimazaki, K.; Nishiyama, A.

    2010-12-01

    Tokyo Metropolitan area is situated in tectonically complex region; both the Pacific (PAC) and Philippine Sea (PHS) plates are subducting from east and south, respectively, beneath the Kanto region. As a result, various types of earthquakes occur in this region; i.e., shallow crustal earthquakes, intraplate (slab) earthquakes within PHS, within PAC, and interplate earthquakes between continental plate and PHS, and between PHS and PAC. Among these, the largest earthquakes are Kanto earthquakes (M~8) occurring between the continental plate and PHS. The average recurrence interval is estimated to be 200 - 400 years (Earthq. Res. Comm., 2004), and hence, urgency of the next Kanto earthquake is thought to be low considering the lapse time (~87 yrs.) from the most recent Kanto earthquake in 1923. However, urgency of the other types of earthquakes with M~7 is high; Earthq. Res. Comm. (2004) calculated the probability of occurrence during the next 30 years as 70 %, based on the facts that five M~7 earthquakes (i.e., the 1894 Meiji-Tokyo, 1895 and 1921 Ibaraki-Ken-Nanbu, 1922 Uraga channel and 1987 Chiba-Ken Toho-Oki earthquakes) occurred since 1885. However, types of earthquakes are not well known especially for the 1894 Meiji-Tokyo and 1895 Ibaragi-Ken-Nanbu earthquakes due to low quality of data. Thus, it is important to classify these earthquakes into above-described intraplate or interplate earthquakes and to estimate their occurrence frequency. Ishibe et al. (2009a, 2009b) compiled previous studies and data for these five earthquakes. In this study, we report the preliminary result of focal depth and mechanism for the 1895 and 1921 Ibaraki-Ken-Nanbu earthquakes. The epicenter of the 1895 Ibaraki-Ken-Nanbu earthquake (M 7.2; Utsu, 1979) is discussed by various studies (e.g., Usami, 1973; Ishibashi, 1975; Katsumata, 1975; Utsu, 1979). However, few studies have discussed the hypocentral depth. The hypocentral depth is estimated to be 75 ~ 85 km using S-P time at Tokyo

  5. History of significant earthquakes in the Parkfield area

    USGS Publications Warehouse

    Bakun, W.H.

    1988-01-01

    Seismicity on the San Andreas fault near Parkfield occurs in a tectonic section that differs markedly from neighboring sections along the San Andreas to the northwest and to the southeast. Northwest of the Parkfield section, small shocks (magnitudes of less than 4) do occur frequently, but San Andreas movement occurs predominantly as aseismic fault creep; shocks of magnitude 6 and larger are unknown, and little, if any, strain is accumulating. In contrast, very few small earthquakes and no aseismic slip have been observed on the adjacent section to the southeast, the Cholame section, which is considered to be locked, in as much as it apparently ruptures exclusively in large earthquakes (magnitudes greater than 7), most recently during the great Fort Tejon earthquake of 1857. The Parkfield section is thus a transition zone between two sections having different modes of fault failure. In fact, the regularity of significant earthquakes at Parkfield since 1857 may be due to the nearly constant slip rate pattern on the adjoining fault sections. Until the magnitude 6.7 Coalinga earthquake on May 2, 1983, 40 kilmoeters northeast of Parkfield, the Parkfield section had been relatively free of stress changes due to nearby shocks; the effect of the Coalinga shock on the timing of the next Parkfield shock is not known. 

  6. Earthquake Rate Model 2 of the 2007 Working Group for California Earthquake Probabilities, Magnitude-Area Relationships

    USGS Publications Warehouse

    Stein, Ross S.

    2008-01-01

    The Working Group for California Earthquake Probabilities must transform fault lengths and their slip rates into earthquake moment-magnitudes. First, the down-dip coseismic fault dimension, W, must be inferred. We have chosen the Nazareth and Hauksson (2004) method, which uses the depth above which 99% of the background seismicity occurs to assign W. The product of the observed or inferred fault length, L, with the down-dip dimension, W, gives the fault area, A. We must then use a scaling relation to relate A to moment-magnitude, Mw. We assigned equal weight to the Ellsworth B (Working Group on California Earthquake Probabilities, 2003) and Hanks and Bakun (2007) equations. The former uses a single logarithmic relation fitted to the M=6.5 portion of data of Wells and Coppersmith (1994); the latter uses a bilinear relation with a slope change at M=6.65 (A=537 km2) and also was tested against a greatly expanded dataset for large continental transform earthquakes. We also present an alternative power law relation, which fits the newly expanded Hanks and Bakun (2007) data best, and captures the change in slope that Hanks and Bakun attribute to a transition from area- to length-scaling of earthquake slip. We have not opted to use the alternative relation for the current model. The selections and weights were developed by unanimous consensus of the Executive Committee of the Working Group, following an open meeting of scientists, a solicitation of outside opinions from additional scientists, and presentation of our approach to the Scientific Review Panel. The magnitude-area relations and their assigned weights are unchanged from that used in Working Group (2003).

  7. A STUDY ON EMERGENCYWATER DELIVERY IN WIDE-AREA EARTHQUAKE DISASTER - A CASE STUDY OF THE GREAT EAST JAPAN EARTHQUAKE DISASTER -

    NASA Astrophysics Data System (ADS)

    Ohnishi, Yoji; Kuwata, Yasuko

    The Great East Japan earthquake disaster caused water outage to 2. 25 million customers in all the eastern part of Japan. It was so-called "wide-area earthquake disaster". Japanwater supply authorities have improved disaster assistant system after the lessons learned from the Kobe earthquake. This study focuses on the emergency response capacity on water delivery in such a wide-area earthquake disaster reviewing the activity in assisting and assisted municipalities during the latest earthquake. The total of 355 water trucks dispatched is thought to be the maximum from the availablemunicipalities. It is turned out that the objective amount of 3 litters per person by the water delivery cannot be reached in the wide-area earthquake disaster.

  8. Detection of Interplate Earthquakes in the Source Area of the 2011 Tohoku Earthquake Using Extensive Seafloor Aftershock Observation Data

    NASA Astrophysics Data System (ADS)

    Nakatani, Y.; Mochizuki, K.; Shinohara, M.; Yamada, T.; Shiobara, H.; Hino, R.; Azuma, R.; Ito, Y.; Murai, Y.; Sato, T.; Uehira, K.; Shimbo, T.; Yakiwara, H.; Kodaira, S.; Machida, Y.; Hirata, K.; Tsushima, H.

    2015-12-01

    Previous studies on the source process of the 2011 Mw 9.0 Tohoku earthquake have revealed its large coseismic slip along a shallow plate interface to the Japan Trench axis. In order to further understand the complex rupture propagation along the plate interface, it is essential to elucidate recovery process of interplate coupling in the source area after the Tohoku earthquake. Estimating changes in b-values for interplate earthquakes before and after the Tohoku event is one of the available approaches to answer the above issue. To start with, we attempt to automatically detect and determine the location of interplate earthquakes using extensive seafloor aftershock observation data. We used mainly short-period pop-up type ocean bottom seismometers (OBSs) [Shinohara et al., 2011, 2012]. We applied a semblance-based method [Nakatani et al., 2015] to 23 OBSs deployed off Fukushima. A seismic tomography result [Matsubara and Obara, 2011] is used for calculation of P wave traveltimes between OBS stations and given grids along the plate interface. To confirm the validity of our method, we conducted synthetic tests by using a Ricker wavelet with several different sets of signal-to-noise (S/N) ratio and focal depths. As the results, semblance values of earthquakes with focal depths relative to the plate interface of 5 km are comparable to noise level, regardless of S/N ratio. On the other hand, earthquakes along the plate interface have significant peak semblance values. Therefore, our method is effective for detection of interplate earthquakes. We, then, applied the method to several waveforms of interplate events listed in the JMA (Japan Meteorological Agency) catalog and identified epicenters by backprojecting semblance values. We compared our resulted epicenters to those of Shinohara et al. (2011, 2012) which precisely relocated the JMA ones using P- and S-wave arrival times and maximum-likelihood estimate technique. The results show good coincidence between them. In

  9. Estimating soil erosion changes in the Wenchuan earthquake disaster area using geo-spatial information technology

    NASA Astrophysics Data System (ADS)

    Zhang, Bing; Jiao, Quanjun; Wu, Yanhong; Zhang, Wenjuan

    2009-05-01

    The secondary disasters induced by the Wenchuan earthquake of May 12, 2008, such as landslides, collapsing rocks, debris flows, floods, etc., have changed the local natural landscape tremendously and caused heavy soil erosion in the earthquake-hit areas. Using thematic mapper images taken before the earthquake and airborne images taken after the earthquake, we extracted information about the destroyed landscape by utilizing remote sensing and geographical information system techniques. Then, taking into account multi-year precipitation, vegetation cover, soil type, land use, and elevation data, we evaluated the soil erosion area and intensity using the revised universal soil loss equation. Results indicate that the soil erosion in earthquake-hit areas was exacerbated, with the severe erosion area increasing by 279.2 km2, or 1.9% of the total statistical area. Large amounts of soil and debris blocked streams and formed many barrier lakes over an area of more than 3.9 km2. It was evident from the spatial distribution of soil erosion areas that the intensity of soil erosion accelerated in the stream valley areas, especially in the valleys of the Min River and the Jian River.

  10. Frequency Spectrum Method-Based Stress Analysis for Oil Pipelines in Earthquake Disaster Areas

    PubMed Central

    Wu, Xiaonan; Lu, Hongfang; Huang, Kun; Wu, Shijuan; Qiao, Weibiao

    2015-01-01

    When a long distance oil pipeline crosses an earthquake disaster area, inertial force and strong ground motion can cause the pipeline stress to exceed the failure limit, resulting in bending and deformation failure. To date, researchers have performed limited safety analyses of oil pipelines in earthquake disaster areas that include stress analysis. Therefore, using the spectrum method and theory of one-dimensional beam units, CAESAR II is used to perform a dynamic earthquake analysis for an oil pipeline in the XX earthquake disaster area. This software is used to determine if the displacement and stress of the pipeline meet the standards when subjected to a strong earthquake. After performing the numerical analysis, the primary seismic action axial, longitudinal and horizontal displacement directions and the critical section of the pipeline can be located. Feasible project enhancement suggestions based on the analysis results are proposed. The designer is able to utilize this stress analysis method to perform an ultimate design for an oil pipeline in earthquake disaster areas; therefore, improving the safe operation of the pipeline. PMID:25692790

  11. Frequency spectrum method-based stress analysis for oil pipelines in earthquake disaster areas.

    PubMed

    Wu, Xiaonan; Lu, Hongfang; Huang, Kun; Wu, Shijuan; Qiao, Weibiao

    2015-01-01

    When a long distance oil pipeline crosses an earthquake disaster area, inertial force and strong ground motion can cause the pipeline stress to exceed the failure limit, resulting in bending and deformation failure. To date, researchers have performed limited safety analyses of oil pipelines in earthquake disaster areas that include stress analysis. Therefore, using the spectrum method and theory of one-dimensional beam units, CAESAR II is used to perform a dynamic earthquake analysis for an oil pipeline in the XX earthquake disaster area. This software is used to determine if the displacement and stress of the pipeline meet the standards when subjected to a strong earthquake. After performing the numerical analysis, the primary seismic action axial, longitudinal and horizontal displacement directions and the critical section of the pipeline can be located. Feasible project enhancement suggestions based on the analysis results are proposed. The designer is able to utilize this stress analysis method to perform an ultimate design for an oil pipeline in earthquake disaster areas; therefore, improving the safe operation of the pipeline.

  12. Earthquakes

    EPA Pesticide Factsheets

    Information on this page will help you understand environmental dangers related to earthquakes, what you can do to prepare and recover. It will also help you recognize possible environmental hazards and learn what you can do to protect you and your family

  13. Studies on `precarious rocks' in the epicentral area of the AD 1356 Basle earthquake, Switzerland

    NASA Astrophysics Data System (ADS)

    Schürch, Peter; Becker, Arnfried

    2005-11-01

    For the first time precarious rocks have been analysed in the epicentral area of the AD 1356 Basle earthquake in northern Switzerland. Several cliff sites in flat-lying, thickly bedded Upper Jurassic coral limestones in the Jura Mountains were investigated. Seven blocks are regarded as precarious with respect to earthquake strong ground motions. The age of these precarious rocks could not be determined directly as for instance by radiometric dating methods; however, based on slope degradation processes it can be concluded that the formation of these blocks predates the AD 1356 Basle earthquake. The acceleration required to topple a precarious rock from its pedestal is estimated using geometrical data for individual block sections and earthquake strong-motion records from stations on rock sites in the European Strong-Motion Database as input data for the computer program ROCKING V1.0 from the Seismological Laboratory, University of Nevada, Reno. The calculations indicate that toppling of a precarious rock largely depends on earthquake strength but also on the frequency spectrum of the signal. Although most investigated precarious rocks are surprisingly stable for ground motions similar to those expected to have occurred during the AD 1356 Basle earthquake, at least two blocks are clearly precariously balanced, with peak toppling accelerations lower than 0.3 g. Possible reasons why these blocks did not topple during the AD 1356 Basle earthquake include incomplete separation from their base, sliding of precarious rocks, their size, lower than assumed ground accelerations and/or duration of shaking.

  14. Moderate, strong and strongest earthquake-prone areas in the Caucasus, California and the Andes

    NASA Astrophysics Data System (ADS)

    Dzeboev, Boris; Gvishiani, Alexei

    2016-04-01

    We present this study on recognition of areas of possible occurrence of strong earthquakes. The study deals with the earthquake-prone areas in three regions with different geological and tectonic structures located in different parts of the world. The authors created a new method (FCAZ - Fuzzy Clustering and Zoning) for recognition of highly seismic areas, where epicenters of earthquakes with magnitude M≥M0 can occur. The magnitude threshold M0 depends on the seismic activity of the region. The objects of clustering are earthquake epicenters. The new method allows us to implement uniformly necessary clustering of the recognition objects respectively for moderate, strong and strongest events. Suggested approach consists of two steps: clustering of known earthquake epicenters by the original DPS (Discrete Perfect Sets) algorithm and delineating highly seismic zones around the recognized clusters by another original E2XT algorithm. By means of this method we detected the areas of possible occurrence of the epicenters of strong earthquakes in the Caucasus (M≥5), in California (M≥6.5) and in the mountain belt of the Andes (M≥7.75). The latter case relates to the possible areas of natural disaster occurence. Reliability of the results is confirmed by numerous control experiments, including individual and complete seismic history. Two strongest recent Chilean earthquakes occurred in 2014 and 2015 after the moment the results were published. Their epicenters belong to the zone recognized as high seismically hazardous. It is a strong independent argument which confirms the reliability of the results. The presented results integrate most recent outcomes of more than 40 years of research in pattern recognition and systems analysis for seismic zoning implemented in Russian Academy of Science. This research is supported by the Russian Science Foundation (project № 15-17-30020).

  15. Long-period building response to earthquakes in the San Francisco Bay Area

    USGS Publications Warehouse

    Olsen, A.H.; Aagaard, B.T.; Heaton, T.H.

    2008-01-01

    This article reports a study of modeled, long-period building responses to ground-motion simulations of earthquakes in the San Francisco Bay Area. The earthquakes include the 1989 magnitude 6.9 Loma Prieta earthquake, a magnitude 7.8 simulation of the 1906 San Francisco earthquake, and two hypothetical magnitude 7.8 northern San Andreas fault earthquakes with hypocenters north and south of San Francisco. We use the simulated ground motions to excite nonlinear models of 20-story, steel, welded moment-resisting frame (MRF) buildings. We consider MRF buildings designed with two different strengths and modeled with either ductile or brittle welds. Using peak interstory drift ratio (IDR) as a performance measure, the stiffer, higher strength building models outperform the equivalent more flexible, lower strength designs. The hypothetical magnitude 7.8 earthquake with hypocenter north of San Francisco produces the most severe ground motions. In this simulation, the responses of the more flexible, lower strength building model with brittle welds exceed an IDR of 2.5% (that is, threaten life safety) on 54% of the urban area, compared to 4.6% of the urban area for the stiffer, higher strength building with ductile welds. We also use the simulated ground motions to predict the maximum isolator displacement of base-isolated buildings with linear, single-degree-of-freedom (SDOF) models. For two existing 3-sec isolator systems near San Francisco, the design maximum displacement is 0.5 m, and our simulations predict isolator displacements for this type of system in excess of 0.5 m in many urban areas. This article demonstrates that a large, 1906-like earthquake could cause significant damage to long-period buildings in the San Francisco Bay Area.

  16. Predicting Ground Motion from Induced Earthquakes in Geothermal Areas

    NASA Astrophysics Data System (ADS)

    Douglas, J.; Edwards, B.; Convertito, V.; Sharma, N.; Tramelli, A.; Kraaijpoel, D.; Cabrera, B. M.; Maercklin, N.; Troise, C.

    2013-06-01

    Induced seismicity from anthropogenic sources can be a significant nuisance to a local population and in extreme cases lead to damage to vulnerable structures. One type of induced seismicity of particular recent concern, which, in some cases, can limit development of a potentially important clean energy source, is that associated with geothermal power production. A key requirement for the accurate assessment of seismic hazard (and risk) is a ground-motion prediction equation (GMPE) that predicts the level of earthquake shaking (in terms of, for example, peak ground acceleration) of an earthquake of a certain magnitude at a particular distance. Few such models currently exist in regard to geothermal-related seismicity, and consequently the evaluation of seismic hazard in the vicinity of geothermal power plants is associated with high uncertainty. Various ground-motion datasets of induced and natural seismicity (from Basel, Geysers, Hengill, Roswinkel, Soultz, and Voerendaal) were compiled and processed, and moment magnitudes for all events were recomputed homogeneously. These data are used to show that ground motions from induced and natural earthquakes cannot be statistically distinguished. Empirical GMPEs are derived from these data; and, although they have similar characteristics to recent GMPEs for natural and mining-related seismicity, the standard deviations are higher. To account for epistemic uncertainties, stochastic models subsequently are developed based on a single corner frequency and with parameters constrained by the available data. Predicted ground motions from these models are fitted with functional forms to obtain easy-to-use GMPEs. These are associated with standard deviations derived from the empirical data to characterize aleatory variability. As an example, we demonstrate the potential use of these models using data from Campi Flegrei.

  17. ABL and BAM Friction Analysis Comparison

    DOE PAGES

    Warner, Kirstin F.; Sandstrom, Mary M.; Brown, Geoffrey W.; ...

    2014-12-29

    Here, the Integrated Data Collection Analysis (IDCA) program has conducted a proficiency study for Small-Scale Safety and Thermal (SSST) testing of homemade explosives (HMEs). Described here is a comparison of the Alleghany Ballistic Laboratory (ABL) friction data and Bundesanstalt fur Materialforschung und -prufung (BAM) friction data for 19 HEM and military standard explosives.

  18. St. Louis Area Earthquake Hazards Mapping Project - A Progress Report-November 2008

    USGS Publications Warehouse

    Karadeniz, D.; Rogers, J.D.; Williams, R.A.; Cramer, C.H.; Bauer, R.A.; Hoffman, D.; Chung, J.; Hempen, G.L.; Steckel, P.H.; Boyd, O.L.; Watkins, C.M.; McCallister, N.S.; Schweig, E.

    2009-01-01

    St. Louis has experienced minor earthquake damage at least 12 times in the past 200 years. Because of this history and its proximity to known active earthquake zones, the St. Louis Area Earthquake Hazards Mapping Project (SLAEHMP) is producing digital maps that show variability of earthquake hazards, including liquefaction and ground shaking, in the St. Louis area. The maps will be available free via the internet. Although not site specific enough to indicate the hazard at a house-by-house resolution, they can be customized by the user to show specific areas of interest, such as neighborhoods or transportation routes. Earthquakes currently cannot be predicted, but scientists can estimate how strongly the ground is likely to shake as the result of an earthquake. Earthquake hazard maps provide one way of conveying such estimates. The U.S. Geological Survey (USGS), which produces earthquake hazard maps for the Nation, is working with local partners to develop detailed maps for urban areas vulnerable to strong ground shaking. These partners, which along with the USGS comprise the SLAEHMP, include the Missouri University of Science and Technology-Rolla (Missouri S&T), Missouri Department of Natural Resources (MDNR), Illinois State Geological Survey (ISGS), Saint Louis University, Missouri State Emergency Management Agency, and URS Corporation. Preliminary hazard maps covering a test portion of the 29-quadrangle St. Louis study area have been produced and are currently being evaluated by the SLAEHMP. A USGS Fact Sheet summarizing this project was produced and almost 1000 copies have been distributed at several public outreach meetings and field trips that have featured the SLAEHMP (Williams and others, 2007). In addition, a USGS website focusing on the SLAEHMP, which provides links to project results and relevant earthquake hazard information, can be found at: http://earthquake.usgs.gov/regional/ceus/urban_map/st_louis/index.php. This progress report summarizes the

  19. Map Showing Susceptibility to Earthquake-Induced Landsliding, San Juan Metropolitan Area, Puerto Rico

    USGS Publications Warehouse

    Santiago, Marilyn; Larsen, Matthew C.

    2001-01-01

    Analysis of slope angle and rock type using a geographic information system indicates that about 68 percent of the San Juan metropolitan area has low to no susceptibility to earthquake-induced landslides. This is at least partly due to the fact that 45 percent of the San Juan metropolitan area is constructed on slopes of 3 degrees or less, which are too gentle for landslides to occur. The areas with the highest susceptibility to earthquake-induced landslides account for 6 percent of the surface area. Almost one-quarter (24 percent) of the San Juan metropolitan area is moderately susceptible to earthquake-induced landslides. These areas are mainly in the southern portions of the San Juan metropolitan area, where housing development pressures are currently high because of land availability and the esthetics of greenery and hillside views. The combination of new development and moderate earthquake-induced landslide susceptibility indicate that the southern portions of the San Juan metropolitan area are be at greatest risk.

  20. Classification of M~7 earthquakes in Tokyo Metropolitan area since 1885 - The 1921 Ibaraki-ken Nambu and 1922 Uraga channel earthquakes

    NASA Astrophysics Data System (ADS)

    Ishibe, T.; Satake, K.; Shimazaki, K.; Murotani, S.; Nishiyama, A.

    2011-12-01

    S-P times, focal mechanism solutions from initial motion, and seismic intensity distribution show that the 1921 Ibaraki-ken Nambu earthquake (M 7.0) and the 1922 Uraga channel earthquake (M 6.8) both occurred within the subducting Philippine Sea plate beneath the Tokyo Metropolitan area. The Tokyo Metropolitan area is situated in a tectonically complex region; The Philippine Sea plate (PHS) subducts from south, while the Pacific plate (PAC) subducts from east below PHS. As a result, various types of earthquakes occur in this region. They are classified into: shallow crustal earthquakes, intraplate (slab) earthquakes within PHS, within PAC, and interplate earthquakes between continental plate and PHS, and between PHS and PAC. The probability of the large earthquakes with magnitude (M)~7 is high; Earthquake Research Committee calculated the probability of occurrence during the next 30 years as 70 %, based on the fact that five M~7 earthquakes (the 1894 Meiji Tokyo, 1895 and 1921 Ibaraki-ken Nambu, 1922 Uraga Channel, and 1987 Chiba-ken Toho-oki earthquakes) occurred since 1885. However, types of these earthquakes except for the 1987 earthquake are not well known due to low quality of data. It is important to classify these earthquakes into above-described intraplate or interplate earthquakes. The Ibaraki-ken Nambu earthquake occurred on 8 December, 1921 and caused damage such as fissures on road, tumble of gravestones especially in the northwestern Chiba and southwestern Ibaraki prefectures. The focal depth was estimated to be around 55 km using S-P times of old seismograms or JMA reports, suggesting that this earthquake was probably a slab earthquake within PHS. Seismic intensity distribution supports this result; seismic intensity anomalies characterizing the PAC slab earthquakes are not recognized. Furthermore, initial motion focal mechanisms using HASH algorithm (Hardebeck and Shearer, 2002) are strike-slip types, even if the uncertainty of hypocenter locations

  1. Chimney damage in the greater Seattle area from the Nisqually earthquake of 28 February 2001

    USGS Publications Warehouse

    Booth, D.B.; Wells, R.E.; Givler, R.W.

    2004-01-01

    Unreinforced brick chimneys in the greater Seattle area were damaged repeatedly in the Benioff zone earthquakes of 1949, 1965, and 2001. A survey of visible chimney damage after the 28 February 2001 Nisqually earthquake evaluated approximately 60,000 chimneys through block-by-block coverage of about 50 km2, identifying a total of 1556 damaged chimneys. Chimney damage was strongly clustered in certain areas, in particular in the neighborhood of West Seattle where prior damage was also noted and evaluated after the 1965 earthquake. Our results showed that damage produced by the 2001 earthquake did not obviously correspond to distance from the earthquake epicenter, soft soils, topography, or slope orientation. Chimney damage correlates well to instrumented strong-motion measurements and compiled resident-reported ground-shaking intensities, but it offers much finer spatial resolution than these other data sources. In general, most areas of greatest chimney damage coincide with best estimated locations of strands of the Seattle fault zone. The edge of that zone also coincides with areas where chimney damage dropped abruptly over only one or two blocks' distance. The association between shaking intensity and fault-zone structure suggests that abrupt changes in the depth to bedrock, edge effects at the margin of the Seattle basin, or localized trapping of seismic waves in the Seattle fault zone may be significant contributory factors in the distribution of chimney damage.

  2. Application and analysis of debris-flow early warning system in Wenchuan earthquake-affected area

    NASA Astrophysics Data System (ADS)

    Liu, D. L.; Zhang, S. J.; Yang, H. J.; Jiang, Y. H.; Leng, X. P.

    2015-09-01

    The activities of debris flow (DF) in the Wenchuan earthquake-affected area significantly increased after the earthquake on 12 May 2008. The safety of local people's lives and property has been and will continue to be threatened by DFs in a long term. To this end a physics-based early warning system (EWS) for DF forecasting was developed and applied in this earthquake area. This paper introduces an application of the system in the Wenchuan earthquake-affected area and analyzes the prediction results in comparison to the DF events triggered by the strong rainfall events reported by the local government. The prediction accuracy and efficiency was first compared with contribution-factors-based system currently adopted by the Weather Bureau of Sichuan Province using the storm on 17 August 2012 as a case study. The comparison shows that the failure prediction rate and false prediction rate of the new system is respectively 19 and 21 % lower than the system based on the contribution factors. Consequently, the prediction accuracy is obviously higher than the system based on the contribution factors with a higher operational efficiency. As invited by the Weather Bureau of Sichuan Province, authors have upgraded their prediction system of DF by using this new system before the monsoon of Wenchuan earthquake-affected area in 2013. Two prediction cases on 9 July of 2013 and 10 July of 2014 were chosen here to further demonstrate that the new EWS has a high stability, efficiency and prediction accuracy.

  3. Application and analysis of debris-flow early warning system in Wenchuan earthquake-affected area

    NASA Astrophysics Data System (ADS)

    Liu, D. L.; Zhang, S. J.; Yang, H. J.; Zhao, L. Q.; Jiang, Y. H.; Tang, D.; Leng, X. P.

    2016-02-01

    The activities of debris flow (DF) in the Wenchuan earthquake-affected area significantly increased after the earthquake on 12 May 2008. The safety of the lives and property of local people is threatened by DFs. A physics-based early warning system (EWS) for DF forecasting was developed and applied in this earthquake area. This paper introduces an application of the system in the Wenchuan earthquake-affected area and analyzes the prediction results via a comparison to the DF events triggered by the strong rainfall events reported by the local government. The prediction accuracy and efficiency was first compared with a contribution-factor-based system currently used by the weather bureau of Sichuan province. The storm on 17 August 2012 was used as a case study for this comparison. The comparison shows that the false negative rate and false positive rate of the new system is, respectively, 19 and 21 % lower than the system based on the contribution factors. Consequently, the prediction accuracy is obviously higher than the system based on the contribution factors with a higher operational efficiency. On the invitation of the weather bureau of Sichuan province, the authors upgraded their prediction system of DF by using this new system before the monsoon of Wenchuan earthquake-affected area in 2013. Two prediction cases on 9 July 2013 and 10 July 2014 were chosen to further demonstrate that the new EWS has high stability, efficiency, and prediction accuracy.

  4. Real-time earthquake shake, damage, and loss mapping for Istanbul metropolitan area

    NASA Astrophysics Data System (ADS)

    Zülfikar, A. Can; Fercan, N. Özge Zülfikar; Tunç, Süleyman; Erdik, Mustafa

    2017-01-01

    The past devastating earthquakes in densely populated urban centers, such as the 1994 Northridge; 1995 Kobe; 1999 series of Kocaeli, Düzce, and Athens; and 2011 Van-Erciş events, showed that substantial social and economic losses can be expected. Previous studies indicate that inadequate emergency response can increase the number of casualties by a maximum factor of 10, which suggests the need for research on rapid earthquake shaking damage and loss estimation. The reduction in casualties in urban areas immediately following an earthquake can be improved if the location and severity of damages can be rapidly assessed by information from rapid response systems. In this context, a research project (TUBITAK-109M734) titled "Real-time Information of Earthquake Shaking, Damage, and Losses for Target Cities of Thessaloniki and Istanbul" was conducted during 2011-2014 to establish the rapid estimation of ground motion shaking and related earthquake damages and casualties for the target cities. In the present study, application to Istanbul metropolitan area is presented. In order to fulfill this objective, earthquake hazard and risk assessment methodology known as Earthquake Loss Estimation Routine, which was developed for the Euro-Mediterranean region within the Network of Research Infrastructures for European Seismology EC-FP6 project, was used. The current application to the Istanbul metropolitan area provides real-time ground motion information obtained by strong motion stations distributed throughout the densely populated areas of the city. According to this ground motion information, building damage estimation is computed by using grid-based building inventory, and the related loss is then estimated. Through this application, the rapidly estimated information enables public and private emergency management authorities to take action and allocate and prioritize resources to minimize the casualties in urban areas during immediate post-earthquake periods. Moreover, it

  5. Areas of slip of recent earthquakes in the Mexican subduction zone

    NASA Astrophysics Data System (ADS)

    Hjorleifsdottir, V.; Sánchez-Reyes, H. S.; Singh, S.; Ji, C.; Iglesias, A.; Perez-Campos, X.

    2012-12-01

    The Mexican subduction zone is unusual: the width of the seismogenic zone is relatively narrow and a large portion of the co-seismic slip generally occurs below the coast, ~ 45 to 80 km from the trench. The earthquake recurrence interval is relatively short and almost the entire length of the zone has experienced a large (Mw≥7.4) earthquake in the last 100 years (Singh et al., 1981). In this study we present detailed analysis of the areas of significant slip during several recent (last 20 years) large earthquakes in the Mexican subduction zone. The most recent earthquake of 20 March 2012 (Mw7.4) occurred near the Guerrero/Oaxaca border. The slip was concentrated on the plate interface below land and the epicentral PGAs ranged between 0.2 and 0.7g. The updip portion of the plate interface had previously broken during the 25 Feb 1996 earthquake (Mw7.1), which was a slow earthquake and produced anomalously low PGAs (Iglesias et al., 2003). This indicates that in this region the area close to the trench is at least partially locked, with some earthquakes breaking the down-dip portion of the interface and others rupturing the up-dip portion. The Jalisco/Colima segment of the subduction zone seems to behave in a similar fashion. The 9 October 1995 (Mw 8.0) earthquake generated small accelerations relative to its size. The energy to moment ratio, E0/M0, is 4.2e-6 (Pérez-Campos, Singh and Beroza, 2003), a value similar to the Feb, 1996 earthquake. This value is low compared to other thrust events in the region. The earthquake also had the largest (Ms-Mw) disparity along the Mexican subduction zone, 7.4 vs 8.0. The event produced relatively large tsunami. On the contrary, the 3 June 1932 earthquake (Ms8.2, Mw8.0), that is believed to have broken the same segment of the subduction zone, appears to be "normal." Based on the available evidence, it may be concluded that the 1932 event broke a deeper patch of the plate interface relative to the 1995 event. The mode of rupture

  6. Challenges for Resuming Normal Life After Earthquake: A Qualitative Study on Rural Areas of Iran

    PubMed Central

    Alipour, Fardin; Khankeh, Hamid Reza; Fekrazad, Hussain; Kamali, Mohammad; Rafiey, Hassan; Sarrami Foroushani, Pooria; Rowell, Kevin; Ahmadi, Shokoufeh

    2014-01-01

    Background and objective: Growing evidence is indicating that some of disaster affected people face challenges to resume normal life several months after an earthquake. However, there is no sufficient in-depth understanding of complex process of resuming normal life after an earthquake in Iran, as one of the most disaster-prone countries in the world, and in rural areas as a particular setting. This study aimed to explore challenges of return to normalcy in rural earthquake-stricken areas of Iran. Methods: The study was conducted using qualitative content analysis method (Graneheim approach). Twenty people from the earthquake-stricken areas and seven qualified experts were selected via purposeful sampling .Data was collected through semi-structured interviews, focus group discussions, and field notes from August 2013 to January 2014. Data collection continued to the point of data saturation (no new information was provided by interviewees). Data saturation supported the sample size. Data analysis was based on qualitative content analysis principles. Results: “Social uncertainty and confusion” was the most prominent challenge of return to the normal life after earthquake, which was categorized into six concepts of social vulnerability, lack of comprehensive rehabilitation plan, incomplete reconstruction, ignorance of local social capital, waste of assets, and psychological problems. Conclusions: Findings showed that social uncertainty and confusion occurs as a result of negligence of some important social aspects in process of returning to the normal life. This issue, in turn, can greatly interrupt the normal developmental processes. Understanding the challenges of life recovery after disasters will help policy makers consider social rehabilitation as a key factor in facilitation of return to normal life process after earthquakes. Keywords: Disaster; earthquake; social rehabilitation; social uncertainty. PMID:25685625

  7. Geomorphic effects of the earthquake of March 27, 1964, in the Martin-Bering Rivers area, Alaska: Chapter B in The Alaska earthquake, March 27, 1964: regional effects

    USGS Publications Warehouse

    Tuthill, Samuel J.; Laird, Wilson M.

    1966-01-01

    The Alaska earthquake of March 27, 1964, caused widespread geomorphic changes in the Martin-Bering Rivers area-900 square miles of uninhabited mountains, alluvial flatlands, and marshes north of the Gulf of Alaska, and east of the Copper River. This area is at lat 60°30’ N. and long 144°22’ W., 32 miles east of Cordova, and approximately 130 miles east-southeast of the epicenter of the earthquake. The geomorphic effects observed were: (1) earthquake-induced ground fractures, (2) mudvent deposits, (3) “earthquake-fountain” craters, (4) subsidence, (5) mudcones, (6) avalanches, (7) subaqueous landslides, (8) turbidity changes in ice-basined lakes on the Martin River glacier, (9) filling of ice-walled sinkholes, (10) gravel-coated snow cones, (11) lake ice fractures, and (12) uplift accompanied the earthquake. In addition to geomorphic effects, the earthquake affected the animal populations of the area. These include migratory fish, terrestrial mollusks, fur-bearing animals, and man. The Alaska earthquake clearly delineated areas of alluvial fill, snow and rock avalanche corridors, and deltas of the deeper lakes as unsuitable for future construction.

  8. Source parameters of small and moderate earthquakes in the area of the 2009 L’Aquila earthquake sequence (central Italy)

    NASA Astrophysics Data System (ADS)

    D'Amico, Sebastiano; Orecchio, Barbara; Presti, Debora; Neri, Giancarlo; Wu, Wen-Nan; Sandu, Ilie; Zhu, Lupei; Herrmann, Robert B.

    The main goal of this study is to provide moment tensor solutions for small and moderate earthquakes of the 2009 L’Aquila seismic sequence (central Italy). The analysis was performed by using data coming from the permanent Italian seismic network run by the Istituto Nazionale di Geofisica e Vulcanologia (INGV) and the “Cut And Paste” (CAP) method based on broadband waveform inversion. Focal mechanisms, source depths and moment magnitudes are determined through a grid search technique. By allowing time shifts between synthetics and observed data the CAP method reduces dependence of the solution on the assumed velocity model and on earthquake location. We computed seismic moment tensors for 312 earthquakes having local magnitude in the range between 2.7 and 5.9. The CAP method has made possible to considerably expand the database of focal mechanisms from waveform analysis in the lowest magnitude range (i.e. in the neighborhood of magnitude 3) without overlooking the reliability of results. The obtained focal mechanisms generally show NW-SE striking focal planes in agreement with mapped faults in the region. Comparisons with the already published solutions and with seismological and geological information available allowed us to proper interpret the moment tensor solutions in the frame of the seismic sequence evolution and also to furnish additional information about less energetic seismic phases. Focal data were inverted to obtain the seismogenic stress in the study area. Results are compatible with the major tectonic domain. We also obtained a relation between moment and local magnitude suitable for the area and for the available magnitude range.

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

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

    The recent large earthquakes (M9.0 Tohoku, 03/2011; M7.0 Haiti, 01/2010; M6.7 L Aquila, 04/2008; and M7.9 Wenchuan 05/2008) have renewed interest in pre-anomalous seismic signals associated with them. Recent workshops (DEMETER 2006, 2011 and VESTO 2009 ) have shown that there were precursory atmospheric /ionospheric signals observed in space prior to these events. Our initial results indicate that no single pre-earthquake observation (seismic, magnetic field, electric field, thermal infrared [TIR], or GPS/TEC) can provide a consistent and successful global scale early warning. This is most likely due to complexity and chaotic nature of earthquakes and the limitation in existing ground (temporal/spatial) and global satellite observations. In this study we analyze preseismic temporal and spatial variations (gas/radon counting rate, atmospheric temperature and humidity change, long-wave radiation transitions and ionospheric electron density/plasma variations) which we propose occur before the onset of major earthquakes:. We propose an Integrated Space -- Terrestrial Framework (ISTF), as a different approach for revealing pre-earthquake phenomena in seismically active areas. ISTF is a sensor web of a coordinated observation infrastructure employing multiple sensors that are distributed on one or more platforms; data from satellite sensors (Terra, Aqua, POES, DEMETER and others) and ground observations, e.g., Global Positioning System, Total Electron Content (GPS/TEC). As a theoretical guide we use the Lithosphere-Atmosphere-Ionosphere Coupling (LAIC) model to explain the generation of multiple earthquake precursors. Using our methodology, we evaluated retrospectively the signals preceding the most devastated earthquakes during 2005-2011. We observed a correlation between both atmospheric and ionospheric anomalies preceding most of these earthquakes. The second phase of our validation include systematic retrospective analysis for more than 100 major earthquakes (M>5

  10. Using Earthquake Early Warning in the Bay Area Rapid Transit System (Invited)

    NASA Astrophysics Data System (ADS)

    McPartland, J.

    2013-12-01

    When a major earthquake occurs without warning, the public will have no choice but to REACT to the risks and dangers around them. If earthquake early warning (EEW) can be provided, the public will be able to PROACTIVELY take action to reduce risks and protect themselves and their areas of responsibility. The Bay Area Rapid Transit System (BART) is implementing an earthquake retrofit program designed to keep BART operational after a major seismic event. But a critical component of success depends on BART being able to prevent derailments caused by a major earthquake itself. At peak commute, BART runs 64 trains of 8-10 cars each with as many as 100 or more passengers per car and, most importantly, 40-45% of the trains are moving at top speed, ~70 mph. Were a major earthquake to strike at peak commute without warning, we expect many derailments that would result in mass casualties; the higher the speed- the greater the risk of derailments. To address this critical issue, in August 2012 BART implemented a system based on EEW to slow and stop trains before the earthquake shaking starts. When activated, train speeds drop at 3 mph per second reducing the risk both of derailments and casualties. A 70 mph train can be fully stopped within 25 seconds of early warning. In addition, if BART remains operational with few or no derailments, it can provide critical transportation support to the region for response, supply and evacuation until streets and highways can be reopened. Considerations like these, weighing the cost of casualties and damage against the perspective of mitigating disaster, can help to justify the cost of an EEW system to legislators and the public. The figures presented indicate that the aftermath of an earthquake may be overwhelmingly frightening if we don't act, but can be amazingly good for us if we do plan and act. And the good and bad news is: THE CHOICE IS OURS!

  11. Scenario earthquake hazards for the Long Valley Caldera-Mono Lake area, east-central California

    USGS Publications Warehouse

    Chen, Rui; Branum, David M.; Wills, Chris J.; Hill, David P.

    2014-01-01

    As part of the U.S. Geological Survey’s (USGS) multi-hazards project in the Long Valley Caldera-Mono Lake area, the California Geological Survey (CGS) developed several earthquake scenarios and evaluated potential seismic hazards, including ground shaking, surface fault rupture, liquefaction, and landslide hazards associated with these earthquake scenarios. The results of these analyses can be useful in estimating the extent of potential damage and economic losses because of potential earthquakes and in preparing emergency response plans. The Long Valley Caldera-Mono Lake area has numerous active faults. Five of these faults or fault zones are considered capable of producing magnitude ≥6.7 earthquakes according to the Uniform California Earthquake Rupture Forecast, Version 2 (UCERF 2) developed by the 2007 Working Group of California Earthquake Probabilities (WGCEP) and the USGS National Seismic Hazard Mapping (NSHM) Program. These five faults are the Fish Slough, Hartley Springs, Hilton Creek, Mono Lake, and Round Valley Faults. CGS developed earthquake scenarios for these five faults in the study area and for the White Mountains Fault to the east of the study area. Earthquake scenarios are intended to depict the potential consequences of significant earthquakes. They are not necessarily the largest or most damaging earthquakes possible. Earthquake scenarios are both large enough and likely enough that emergency planners should consider them in regional emergency response plans. Earthquake scenarios presented here are based on fault geometry and activity data developed by the WGCEP, and are consistent with the 2008 Update of the United States National Seismic Hazard Maps (NSHM).For the Hilton Creek Fault, two alternative scenarios were developed in addition to the NSHM scenario to account for different opinions in how far north the fault extends into the Long Valley Caldera. For each scenario, ground motions were calculated using the current standard practice

  12. Earthquakes Magnitude Predication Using Artificial Neural Network in Northern Red Sea Area

    NASA Astrophysics Data System (ADS)

    Alarifi, A. S.; Alarifi, N. S.

    2009-12-01

    Earthquakes are natural hazards that do not happen very often, however they may cause huge losses in life and property. Early preparation for these hazards is a key factor to reduce their damage and consequence. Since early ages, people tried to predicate earthquakes using simple observations such as strange or a typical animal behavior. In this paper, we study data collected from existing earthquake catalogue to give better forecasting for future earthquakes. The 16000 events cover a time span of 1970 to 2009, the magnitude range from greater than 0 to less than 7.2 while the depth range from greater than 0 to less than 100km. We propose a new artificial intelligent predication system based on artificial neural network, which can be used to predicate the magnitude of future earthquakes in northern Red Sea area including the Sinai Peninsula, the Gulf of Aqaba, and the Gulf of Suez. We propose a feed forward new neural network model with multi-hidden layers to predicate earthquakes occurrences and magnitudes in northern Red Sea area. Although there are similar model that have been published before in different areas, to our best knowledge this is the first neural network model to predicate earthquake in northern Red Sea area. Furthermore, we present other forecasting methods such as moving average over different interval, normally distributed random predicator, and uniformly distributed random predicator. In addition, we present different statistical methods and data fitting such as linear, quadratic, and cubic regression. We present a details performance analyses of the proposed methods for different evaluation metrics. The results show that neural network model provides higher forecast accuracy than other proposed methods. The results show that neural network achieves an average absolute error of 2.6% while an average absolute error of 3.8%, 7.3% and 6.17% for moving average, linear regression and cubic regression, respectively. In this work, we show an analysis

  13. Classification of M~7 earthquakes in Tokyo Metropolitan area since 1885 - The 1894 Meiji Tokyo and 1895 Ibaraki-ken Nambu earthquakes -

    NASA Astrophysics Data System (ADS)

    Murotani, S.; Ishibe, T.; Satake, K.; Shimazaki, K.

    2011-12-01

    S-P times on old seismograms and seismic intensity distributions indicate that the 1894 Meiji Tokyo earthquake (M7.0) occurred within the subducting Philippine Sea plate (PHS), while the 1895 Ibaraki-ken Nambu earthquake (M7.2) was deeper and occurred within the subducting Pacific plate (PAC). The Tokyo Metropolitan area is situated in a tectonically complex region; the PHS subducts from south, while the PAC subducts from east below PHS. Thus, various types of earthquakes occur in this region. They are classified into: shallow crustal earthquakes, intraplate (slab) earthquakes within PHS or PAC, and interplate earthquakes between continental plate and PHS, and between PHS and PAC. The probability of large earthquakes with magnitude (M)~7 is high; Earthquake Research Committee in Japan calculated the probability of occurrence during the next 30 years as 70 %, based on the fact that five M~7 earthquakes (the 1894 Meiji Tokyo, 1895 and 1921 Ibaraki-ken Nambu, 1922 Uraga Channel, and 1987 Chiba-ken Toho-oki earthquakes) occurred since 1885. However, types of these earthquakes except for the 1987 earthquake are not well known due to low quality of data. It is important to classify these earthquakes into above-described intraplate or interplate earthquakes. Seismometer observations started around 1880 in Japan. For both the 1894 and 1895 earthquakes, the disk-type seismograph had been used at the University of Tokyo and the drum-type seismograph had been used at Central Meteorological Observatory (CMO) stations of Tokyo and Utsunomiya. We digitized those records and restored those from Circular to Cartesian coordinates, although their instrumental responses are not known. Furthermore, because the arm of disk-type seismograph was triggered by the first motion of earthquake, the P-wave first motion might be missed. As a result, S-P times read from multiple instruments at the same location (e.g., University of Tokyo campus) are variable. The Meiji Tokyo earthquake occurred

  14. A seismologically consistent expression for the total area and volume of earthquake-triggered landsliding

    NASA Astrophysics Data System (ADS)

    Marc, Odin; Hovius, Niels; Meunier, Patrick; Gorum, Tolga; Uchida, Taro

    2016-04-01

    We present a new, seismologically consistent expression for the total area and volume of populations of earthquake-triggered landslides. This model builds on a set of scaling relationships between key parameters, such as landslide spatial density, seismic ground acceleration, fault length, earthquake source depth, and seismic moment. To assess the model we have assembled and normalized a catalog of landslide inventories for 40 shallow, continental earthquakes. Low landscape steepness causes systematic overprediction of the total area and volume of landslides. When this effect is accounted for, the model predicts the total landslide volume of 63% of 40 cases to within a factor 2 of the volume estimated from observations (R2=0.76). The prediction of total landslide area is also sensitive to the landscape steepness, but less so than the total volume, and it appears to be sensitive to controls on the landslide size-frequency distribution, and possibly the shaking duration. Some outliers are likely associated with exceptionally strong rock mass in the epicentral area, while others may be related to seismic source complexities ignored by the model. However, the close match between prediction and estimate for about two thirds of cases in our database suggests that rock mass strength is similar in many cases and that our simple seismic model is often adequate, despite the variety of lithologies and tectonic settings covered. This makes our expression suitable for integration into landscape evolution models and application to the anticipation or rapid assessment of secondary hazards associated with earthquakes.

  15. Earthquake scenario ground motions for the urban area of Evansville, Indiana

    USGS Publications Warehouse

    Haase, Jennifer S.; Nowack, Robert L.; Cramer, Chris H.; Boyd, Oliver S.; Bauer, Robert A.

    2011-01-01

    The Wabash Valley seismic zone and the New Madrid seismic zone are the closest large earthquake source zones to Evansville, Indiana. The New Madrid earthquakes of 1811-1812, over 180 kilometers (km) from Evansville, produced ground motions with a Modified Mercalli Intensity of VII near Evansville, the highest intensity observed in Indiana. Liquefaction evidence has been documented less than 40 km away from Evansville resulting from two large earthquakes in the past 12,000 years in the Wabash Valley. Two earthquake scenarios are described in this paper that demonstrate the expected ground motions for a 33×42-km region around Evansville based on a repeat earthquake from each of these source regions. We perform a one-dimensional analysis for a grid of sites that takes into account the amplification or deamplification of ground motion in the unconsolidated soil layer using a new three-dimensional model of seismic velocity and bedrock depth. There are significant differences in the calculated amplification from that expected for National Earthquake Hazard Reduction Program site class D conditions, with deamplification at many locations within the ancient bedrock valley underlying Evansville. Ground motions relative to the acceleration of gravity (g) in the Evansville area from a simulation of a magnitude (M) 7.7 New Madrid earthquake range from 0.15 to 0.25 g for peak ground acceleration, 0.14 to 0.7 g for 0.2-second (s) spectral acceleration, and 0.05 to 0.25 g for 1.0-s spectral acceleration. Ground motions from a M6.8 Wabash Valley earthquake centered 40 km northwest of the city produce ground motions that decrease with distance from 1.5 to 0.3 g for 0.2-s spectral acceleration when they reach the main part of Evansville, but then increase in amplitude from 0.3 to 0.6 g south of the city and the Ohio River. The densest urbanization in Evansville and Henderson, Ky., is within the area of preferential amplification at 1.0-s period for both scenarios, but the area

  16. St. Louis Area Earthquake Hazards Mapping Project - December 2008-June 2009 Progress Report

    USGS Publications Warehouse

    Williams, R.A.; Bauer, R.A.; Boyd, O.S.; Chung, J.; Cramer, C.H.; Gaunt, D.A.; Hempen, G.L.; Hoffman, D.; McCallister, N.S.; Prewett, J.L.; Rogers, J.D.; Steckel, P.J.; Watkins, C.M.

    2009-01-01

    This report summarizes the mission, the project background, the participants, and the progress of the St. Louis Area Earthquake Hazards Mapping Project (SLAEHMP) for the period from December 2008 through June 2009. During this period, the SLAEHMP held five conference calls and two face-to-face meetings in St. Louis, participated in several earthquake awareness public meetings, held one outreach field trip for the business and government community, collected and compiled new borehole and digital elevation data from partners, and published a project summary.

  17. St. Louis Area Earthquake Hazards Mapping Project - A PowerPoint Presentation

    USGS Publications Warehouse

    Williams, Robert A.

    2009-01-01

    This Open-File Report contains illustrative materials, in the form of PowerPoint slides, used for an oral presentation given at the Earthquake Insight St. Louis, Mo., field trip held on May 28, 2009. The presentation focused on summarizing the St. Louis Area Earthquake Hazards Mapping Project (SLAEHMP) justification, goals, achievements, and products, for an audience of business and public officials. The individual PowerPoint slides highlight, in an abbreviated format, the topics addressed; they are discussed below and are explained with additional text as appropriate.

  18. Post Earthquake Investigation Of The Mw7.8 Haida Gwaii, Canada, Rupture Area And Constraints On Earthquake Source Models

    NASA Astrophysics Data System (ADS)

    Haeussler, P. J.; Witter, R. C.; Wang, K.

    2013-12-01

    The October 28, 2012 Mw 7.8 Haida Gwaii, British Columbia, earthquake was the second largest historical earthquake recorded in Canada. Earthquake seismology and GPS geodesy shows this was an underthrusting event, in agreement with prior studies that indicated oblique underthrusting of the Haida Gwaii by the Pacific plate. Coseismic deformation is poorly constrained by geodesy, with only six GPS sites and two tide gauge stations anywhere near the rupture area. In order to better constrain the coseismic deformation, we measured the upper limit of sessile intertidal organisms at 26 sites relative to sea level. We dominantly measured the positions of bladder weed (fucus distichus - 617 observations) and the common acorn barnacle (Balanus balanoides - 686 observations). Physical conditions control the upper limit of sessile intertidal organisms, so we tried to find the quietest water conditions, with steep, but not overhanging faces, where slosh from wave motion was minimized. We focused on the western side of the islands as rupture models indicated that the greatest displacement was there. However, we were also looking for calm water sites in bays located as close as possible to the often tumultuous Pacific Ocean. In addition, we made 322 measurements of sea level that will be used to develop a precise tidal model and to evaluate the position of the organisms with respect to a common sea level datum. We anticipate the resolution of the method will be about 20-30 cm. The sites were focused on the western side of the Haida Gwaii from Wells Bay on the south up to Otard Bay to the north, with 5 transects across strike. We also collected data at the town of Masset, which lies outside of the deformation zone of the earthquake. We observed dried and desiccated bands of fucus and barnacles at two sites on the western coast of southern Moresby Island (Gowgia Bay and Wells Bay). Gowgia Bay had the strongest evidence of uplift with fucus that was dried out and apparently dead. A

  19. Earthquake Rate Model 2.2 of the 2007 Working Group for California Earthquake Probabilities, Appendix D: Magnitude-Area Relationships

    USGS Publications Warehouse

    Stein, Ross S.

    2007-01-01

    Summary To estimate the down-dip coseismic fault dimension, W, the Executive Committee has chosen the Nazareth and Hauksson (2004) method, which uses the 99% depth of background seismicity to assign W. For the predicted earthquake magnitude-fault area scaling used to estimate the maximum magnitude of an earthquake rupture from a fault's length, L, and W, the Committee has assigned equal weight to the Ellsworth B (Working Group on California Earthquake Probabilities, 2003) and Hanks and Bakun (2002) (as updated in 2007) equations. The former uses a single relation; the latter uses a bilinear relation which changes slope at M=6.65 (A=537 km2).

  20. Analysing post-earthquake landslide activity using multi-temporal landslide inventories near the epicentral area of the 2008 Wenchuan earthquake

    NASA Astrophysics Data System (ADS)

    Tang, Chenxiao; Van Westen, Cees J.; Tanyas, Hakan; Jetten, Victor G.

    2016-12-01

    Large earthquakes in mountainous regions may trigger thousands of landslides, some active for years. We analysed the changes in landslide activity near the epicentre of the 2008 Wenchuan earthquake by generating five landslide inventories for different years through stereoscopic digital visual image interpretation. From May 2008 to April 2015, 660 new landslides occurred outside the co-seismic landslide areas. In April 2015, the number of active landslides had gone down to 66, less than 1 % of the co-seismic landslides, but still much higher than the pre-earthquake levels. We expect that the landslide activity will continue to decay, but may be halted if extreme rainfall events occur.

  1. Earthquake hypocenter relocation using double difference method in East Java and surrounding areas

    SciTech Connect

    C, Aprilia Puspita; Nugraha, Andri Dian; Puspito, Nanang T

    2015-04-24

    Determination of precise hypocenter location is very important in order to provide information about subsurface fault plane and for seismic hazard analysis. In this study, we have relocated hypocenter earthquakes in Eastern part of Java and surrounding areas from local earthquake data catalog compiled by Meteorological, Climatological, and Geophysical Agency of Indonesia (MCGA) in time period 2009-2012 by using the double-difference method. The results show that after relocation processes, there are significantly changes in position and orientation of earthquake hypocenter which is correlated with the geological setting in this region. We observed indication of double seismic zone at depths of 70-120 km within the subducting slab in south of eastern part of Java region. Our results will provide useful information for advance seismological studies and seismic hazard analysis in this study.

  2. Earthquake hypocenter relocation using double difference method in East Java and surrounding areas

    NASA Astrophysics Data System (ADS)

    C, Aprilia Puspita; Nugraha, Andri Dian; Puspito, Nanang T.

    2015-04-01

    Determination of precise hypocenter location is very important in order to provide information about subsurface fault plane and for seismic hazard analysis. In this study, we have relocated hypocenter earthquakes in Eastern part of Java and surrounding areas from local earthquake data catalog compiled by Meteorological, Climatological, and Geophysical Agency of Indonesia (MCGA) in time period 2009-2012 by using the double-difference method. The results show that after relocation processes, there are significantly changes in position and orientation of earthquake hypocenter which is correlated with the geological setting in this region. We observed indication of double seismic zone at depths of 70-120 km within the subducting slab in south of eastern part of Java region. Our results will provide useful information for advance seismological studies and seismic hazard analysis in this study.

  3. Seismic hazard assessment and pattern recognition of earthquake prone areas in the Po Plain (Italy)

    NASA Astrophysics Data System (ADS)

    Gorshkov, Alexander; Peresan, Antonella; Soloviev, Alexander; Panza, Giuliano F.

    2014-05-01

    A systematic and quantitative assessment, capable of providing first-order consistent information about the sites where large earthquakes may occur, is crucial for the knowledgeable seismic hazard evaluation. The methodology for the pattern recognition of areas prone to large earthquakes is based on the morphostructural zoning method (MSZ), which employs topographic data and present-day tectonic structures for the mapping of earthquake-controlling structures (i.e. the nodes formed around lineaments intersections) and does not require the knowledge about past seismicity. The nodes are assumed to be characterized by a uniform set of topographic, geologic, and geophysical parameters; on the basis of such parameters the pattern recognition algorithm defines a classification rule to discriminate seismogenic and non-seismogenic nodes. This methodology has been successfully applied since the early 1970s in a number of regions worldwide, including California, where it permitted the identification of areas that have been subsequently struck by strong events and that previously were not considered prone to strong earthquakes. Recent studies on the Iberian Peninsula and the Rhone Valley, have demonstrated the applicability of MSZ to flat basins, with a relatively flat topography. In this study, the analysis is applied to the Po Plain (Northern Italy), an area characterized by a flat topography, to allow for the systematic identification of the nodes prone to earthquakes with magnitude larger or equal to M=5.0. The MSZ method differs from the standard morphostructural analysis where the term "lineament" is used to define the complex of alignments detectable on topographic maps or on satellite images. According to that definition the lineament is locally defined and the existence of the lineament does not depend on the surrounding areas. In MSZ, the primary element is the block - a relatively homogeneous area - while the lineament is a secondary element of the morphostructure

  4. Increases in seismicity rate in the Tokyo Metropolitan area after the 2011 Tohoku Earthquake

    NASA Astrophysics Data System (ADS)

    Ishibe, T.; Satake, K.; Sakai, S.; Shimazaki, K.; Tsuruoka, H.; Nakagawa, S.; Hirata, N.

    2013-12-01

    Abrupt increases in seismicity rate have been observed in the Kanto region, where the Tokyo Metropolitan area is located, after the 2011 off the Pacific coast of Tohoku earthquake (M9.0) on March 11, 2011. They are well explained by the static increases in the Coulomb Failure Function (ΔCFF) imparted by the gigantic thrusting while some other possible factors (e.g., dynamic stress changes, excess of fluid dehydration, post-seismic slip) may also contribute the rate changes. Because of various types of earthquakes with different focal mechanisms occur in the Kanto region, the receiver faults for the calculation of ΔCFF were assumed to be two nodal planes of small earthquakes before and after the Tohoku earthquake. The regions where seismicity rate increased after the Tohoku earthquake well correlate with concentration on positive ΔCFF (i.e., southwestern Ibaraki and northern Chiba prefectures where intermediate-depth earthquakes occur, and in the shallow crust of western Kanagawa, eastern Shizuoka, and southeastern Yamanashi including the Izu and Hakone regions). The seismicity rate has increased since March 11, 2011 with respect to the Epidemic Type Aftershock Sequence (ETAS) model (Ogata, 1988), suggesting that the rate increase was due to the stress increase by the Tohoku earthquake. Furthermore, the z-values immediately after the Tohoku earthquake show the minimum values during the recent 10 years, indicating significant increases in seismicity rate. At intermediate depth, abrupt increases in thrust faulting earthquakes are well consistent with the Coulomb stress increase. At shallow depth, the earthquakes with the T-axes of roughly NE-SW were activated probably due to the E-W extension of the overriding continental plate, and this is also well explained by the Coulomb stress increase. However, the activated seismicity in the Izu and Hakone regions rapidly decayed following the Omori-Utsu formula, while the increased rate of seismicity in the southwestern

  5. A study of earthquakes induced by water injection in the Changning salt mine area, SW China

    NASA Astrophysics Data System (ADS)

    Sun, Xiaolong; Yang, Pengtao; Zhang, Zhiwei

    2017-04-01

    The features of earthquakes induced by water injection in the Changning salt mine area of China were analyzed using the pore pressure diffusion method. The relationships between maximum magnitude, cumulative seismic moment, and cumulative water loss volume were investigated. Results show that increased seismic activities near the Changning salt mine in recent years are closely related to water injection during salt mining. High-pressure water injection over a long period of time caused water to diffuse into rock cracks, which increased pore pressure on faults and induced ruptures. Injection-induced earthquakes were located below the injection sites, mainly aligned NW-SE, with most occurring southeast of the mine area. Such a distribution indicates that seismic activities were affected by anticline structures in the Changning area. Based on pore pressure diffusion considerations, the diffusion coefficient was estimated to be ∼0.15 m2/s, with a slightly lower value west of the injection site than to the east. A semi-logarithmic linear relationship was found between cumulative seismic moment and cumulative water loss volume, while maximum magnitude increased with increasing volume of cumulative water loss. This study may provide reference material for analysis of injection-induced earthquakes and evaluation of the danger of earthquakes induced by water injection.

  6. A detailed seismic zonation model for shallow earthquakes in the broader Aegean area

    NASA Astrophysics Data System (ADS)

    Vamvakaris, D. A.; Papazachos, C. B.; Papaioannou, Ch. A.; Scordilis, E. M.; Karakaisis, G. F.

    2016-01-01

    In the present work we propose a new seismic zonation model of area type sources for the broader Aegean area, which can be readily used for seismic hazard assessment. The definition of this model is based not only on seismicity information but incorporates all available seismotectonic and neotectonic information for the study area, in an attempt to define zones which show not only a rather homogeneous seismicity release but also exhibit similar active faulting characteristics. For this reason, all available seismological information such as fault plane solutions and the corresponding kinematic axes have been incorporated in the analysis, as well as information about active tectonics, such as seismic and active faults. Moreover, various morphotectonic features (e.g. relief, coastline) were also considered. Finally, a revised seismic catalogue is employed and earthquake epicentres since historical times (550 BC-2008) are employed, in order to define areas of common seismotectonic characteristics, that could constitute a discrete seismic zone. A new revised model of 113 earthquake seismic zones of shallow earthquakes for the broader Aegean area is finally proposed. Using the proposed zonation model, a detailed study is performed for the catalogue completeness for the recent instrumental period.Using the defined completeness information, seismicity parameters (such as G-R values) for the 113 new seismic zones have been calculated, and their spatial distribution was also examined. The spatial variation of the obtained b values shows an excellent correlation with the geotectonic setting in the area, in good agreement with previous studies. Moreover, a quantitative estimation of seismicity is performed in terms of the mean return period, Tm, of large (M ≥ 6.0) earthquakes, as well as the most frequent maximum magnitude, Mt, for a typical time period (T = 50 yr), revealing significant spatial variations of seismicity levels within the study area. The new proposed

  7. Horizontal sliding of kilometre-scale hot spring area during the 2016 Kumamoto earthquake.

    PubMed

    Tsuji, Takeshi; Ishibashi, Jun'ichiro; Ishitsuka, Kazuya; Kamata, Ryuichi

    2017-02-20

    We report horizontal sliding of the kilometre-scale geologic block under the Aso hot springs (Uchinomaki area) caused by vibrations from the 2016 Kumamoto earthquake (Mw 7.0). Direct borehole observations demonstrate the sliding along the horizontal geological formation at ~50 m depth, which is where the shallowest hydrothermal reservoir developed. Owing to >1 m northwest movement of the geologic block, as shown by differential interferometric synthetic aperture radar (DInSAR), extensional open fissures were generated at the southeastern edge of the horizontal sliding block, and compressional deformation and spontaneous fluid emission from wells were observed at the northwestern edge of the block. The temporal and spatial variation of the hot spring supply during the earthquake can be explained by the horizontal sliding and borehole failures. Because there was no strain accumulation around the hot spring area prior to the earthquake and gravitational instability could be ignored, the horizontal sliding along the low-frictional formation was likely caused by seismic forces from the remote earthquake. The insights derived from our field-scale observations may assist further research into geologic block sliding in horizontal geological formations.

  8. Subducting seamounts control interplate coupling and seismic rupture in the 2014 Iquique earthquake area

    PubMed Central

    Geersen, Jacob; Ranero, César R.; Barckhausen, Udo; Reichert, Christian

    2015-01-01

    To date, the parameters that determine the rupture area of great subduction zone earthquakes remain contentious. On 1 April 2014, the Mw 8.1 Iquique earthquake ruptured a portion of the well-recognized northern Chile seismic gap but left large highly coupled areas un-ruptured. Marine seismic reflection and swath bathymetric data indicate that structural variations in the subducting Nazca Plate control regional-scale plate-coupling variations, and the limited extent of the 2014 earthquake. Several under-thrusting seamounts correlate to the southward and up-dip arrest of seismic rupture during the 2014 Iquique earthquake, thus supporting a causal link. By fracturing of the overriding plate, the subducting seamounts are likely further responsible for reduced plate-coupling in the shallow subduction zone and in a lowly coupled region around 20.5°S. Our data support that structural variations in the lower plate influence coupling and seismic rupture offshore Northern Chile, whereas the structure of the upper plate plays a minor role. PMID:26419949

  9. Subducting seamounts control interplate coupling and seismic rupture in the 2014 Iquique earthquake area.

    PubMed

    Geersen, Jacob; Ranero, César R; Barckhausen, Udo; Reichert, Christian

    2015-09-30

    To date, the parameters that determine the rupture area of great subduction zone earthquakes remain contentious. On 1 April 2014, the Mw 8.1 Iquique earthquake ruptured a portion of the well-recognized northern Chile seismic gap but left large highly coupled areas un-ruptured. Marine seismic reflection and swath bathymetric data indicate that structural variations in the subducting Nazca Plate control regional-scale plate-coupling variations, and the limited extent of the 2014 earthquake. Several under-thrusting seamounts correlate to the southward and up-dip arrest of seismic rupture during the 2014 Iquique earthquake, thus supporting a causal link. By fracturing of the overriding plate, the subducting seamounts are likely further responsible for reduced plate-coupling in the shallow subduction zone and in a lowly coupled region around 20.5°S. Our data support that structural variations in the lower plate influence coupling and seismic rupture offshore Northern Chile, whereas the structure of the upper plate plays a minor role.

  10. Horizontal sliding of kilometre-scale hot spring area during the 2016 Kumamoto earthquake

    PubMed Central

    Tsuji, Takeshi; Ishibashi, Jun’ichiro; Ishitsuka, Kazuya; Kamata, Ryuichi

    2017-01-01

    We report horizontal sliding of the kilometre-scale geologic block under the Aso hot springs (Uchinomaki area) caused by vibrations from the 2016 Kumamoto earthquake (Mw 7.0). Direct borehole observations demonstrate the sliding along the horizontal geological formation at ~50 m depth, which is where the shallowest hydrothermal reservoir developed. Owing to >1 m northwest movement of the geologic block, as shown by differential interferometric synthetic aperture radar (DInSAR), extensional open fissures were generated at the southeastern edge of the horizontal sliding block, and compressional deformation and spontaneous fluid emission from wells were observed at the northwestern edge of the block. The temporal and spatial variation of the hot spring supply during the earthquake can be explained by the horizontal sliding and borehole failures. Because there was no strain accumulation around the hot spring area prior to the earthquake and gravitational instability could be ignored, the horizontal sliding along the low-frictional formation was likely caused by seismic forces from the remote earthquake. The insights derived from our field-scale observations may assist further research into geologic block sliding in horizontal geological formations. PMID:28218298

  11. Horizontal sliding of kilometre-scale hot spring area during the 2016 Kumamoto earthquake

    NASA Astrophysics Data System (ADS)

    Tsuji, Takeshi; Ishibashi, Jun’Ichiro; Ishitsuka, Kazuya; Kamata, Ryuichi

    2017-02-01

    We report horizontal sliding of the kilometre-scale geologic block under the Aso hot springs (Uchinomaki area) caused by vibrations from the 2016 Kumamoto earthquake (Mw 7.0). Direct borehole observations demonstrate the sliding along the horizontal geological formation at ~50 m depth, which is where the shallowest hydrothermal reservoir developed. Owing to >1 m northwest movement of the geologic block, as shown by differential interferometric synthetic aperture radar (DInSAR), extensional open fissures were generated at the southeastern edge of the horizontal sliding block, and compressional deformation and spontaneous fluid emission from wells were observed at the northwestern edge of the block. The temporal and spatial variation of the hot spring supply during the earthquake can be explained by the horizontal sliding and borehole failures. Because there was no strain accumulation around the hot spring area prior to the earthquake and gravitational instability could be ignored, the horizontal sliding along the low-frictional formation was likely caused by seismic forces from the remote earthquake. The insights derived from our field-scale observations may assist further research into geologic block sliding in horizontal geological formations.

  12. Synergistic use of geospatial and in-situ data for earthquake hazard assessment in Vrancea area

    NASA Astrophysics Data System (ADS)

    Zoran, M. A.; Savastru, R. S.; Savastru, D. M.

    2016-08-01

    Space-time anomalies of Earth's emitted radiation: thermal infrared in spectral range measured from satellite months to weeks before the occurrence of earthquakes, radon in underground water and soil, etc., and electromagnetic anomalies are considered as pre-seismic signals. Satellite remote sensing provides spatially continuous information of the tectonic landscape but also contribute to the understanding of specific fault and information about stress transfer between fault systems from depth and to the surface as well as on released energy by earthquakes and other modes of deformation. This paper presents observations made using time series MODIS Terra/Aqua, NOAA-AVHRR, Landsat satellite data for derived multi-parameters land surface temperature (LST), outgoing long-wave radiation (OLR), and mean air temperature (AT) for some seismic events recorded in Vrancea active geotectonic region in Romania. For some analyzed earthquakes, starting with almost one week prior to a moderate or strong earthquake a transient thermal infrared rise in LST of several Celsius degrees (oC) and the increased OLR values higher than the normal function of the magnitude and focal depth, which disappeared after the main shock. Synergy of multisenzor and multitemporal satellite data with in-situ and GPS data and spatial analysis of magnitude-frequency distributions of Vrancea earthquakes provides more information on Vrancea area seismicity. Earthquake hazard assessment for Vrancea region in Romania must have different degrees of complexity, which consists of derived geospatial and in-situ geophysical/geodetic parameters monitoring, analysis, predictive modeling, and forecast-oriented as well as decision-making procedures.

  13. Expectable Earthquakes and their ground motions in the Van Norman Reservoirs Area

    USGS Publications Warehouse

    Wesson, R.L.; Page, R.A.; Boore, D.M.; Yerkes, R.F.

    1974-01-01

    The upper and lower Van Norman dams, in northwesternmost San Fernando Valley about 20 mi (32 km) northwest of downtown Los Angeles, were severely damaged during the 1971 San Fernando earthquake. An investigation of the geologic-seismologic setting of the Van Norman area indicates that an earthquake of at least M 7.7 may be expected in the Van Norman area. The expectable transitory effects in the Van Norman area of such an earthquake are as follows: peak horizontal acceleration of at least 1.15 g, peak velocity of displacement of 4.43 ft/sec (135 cm/sec), peak displacement of 2.3 ft (70 cm), and duration of shaking at accelerations greater than 0.05 g, 40 sec. A great earthquake (M 8+) on the San Andreas fault, 25 mi distant, also is expectable. Transitory effects in the Van Norman area from such an earthquake are estimated as follows: peak horizontal acceleration of 0.5 g, peak velocity of 1.97 ft/sec (60 cm/sec), displacement of 1.31 ft (40 cm), and duration of shaking at accelerations greater than 0.05 g, 80 sec. The permanent effects of the expectable local earthquake could include simultaneous fault movement at the lower damsite, the upper damsite, and the site proposed for a replacement dam halfway between the upper and lower dams. The maximum differential displacements due to such movements are estimated at 16.4 ft (5 m) at the lower damsite and about 9.6 ft (2.93 m) at the upper and proposed damsites. The 1971 San Fernando earthquake (M 6?) was accompanied by the most intense ground motions ever recorded instrumentally for a natural earthquake. At the lower Van Norman dam, horizontal accelerations exceeded 0.6 g, and shaking greater than 0.25 g lasted for about 13 see; at Pacoima dam, 6 mi (10 km) northeast of the lower dam, high-frequency peak horizontal accelerations of 1.25 g were recorded in two directions, and shaking greater than 0.25 g lasted for about 7 sec. Permanent effects of the earthquake include slope failures in the embankments of the upper

  14. Earthquake Facts

    MedlinePlus

    ... May 22, 1960. The earliest reported earthquake in California was felt in 1769 by the exploring expedition ... by wind or tides. Each year the southern California area has about 10,000 earthquakes . Most of ...

  15. [Experience of DMAT rescue activity by doctor-helicopter in Tohoku Area after the earthquake].

    PubMed

    Otsuka, Naomi; Yamashita, Ako; Kimura, Yoshinobu; Aimono, Mako; Kobayashi, Iwao; Nanba, Hitoshi; Watanabe, Akihiko; Sumita, Shinzou

    2012-07-01

    We operated rescue activities in Tohoku area after the earthquake of March 11th, 2011. From our hospital, a doctor-helicopter flew to the staging care unit at Hanamaki airport with two members of the disaster medical assistance team (DMAT), one of whom was an anesthesiologist. The helicopter carried ten patients by nine flight missions, who were the victims of tsunami after the earthquake. There were seven doctor-helicopters from all over Japan and did the missions based at Hanamaki airport. The missions was quite different from our usual job as an anesthesiologist, but we could transfer the patients safely by using some knowledge of stabilizing the unstable patients as flight doctors. We report the details of our activities by our doctor-helicopters in Tohoku area.

  16. Microzonation of Seismic Hazards and Estimation of Human Fatality for Scenario Earthquakes in Chianan Area, Taiwan

    NASA Astrophysics Data System (ADS)

    Liu, K. S.; Chiang, C. L.; Ho, T. T.; Tsai, Y. B.

    2015-12-01

    In this study, we assess seismic hazards in the 57 administration districts of Chianan area, Taiwan in the form of ShakeMaps as well as to estimate potential human fatalities from scenario earthquakes on the three Type I active faults in this area. As a result, it is noted that two regions with high MMI intensity greater than IX in the map of maximum ground motion. One is in the Chiayi area around Minsyong, Dalin and Meishan due to presence of the Meishan fault and large site amplification factors which can reach as high as 2.38 and 2.09 for PGA and PGV, respectively, in Minsyong. The other is in the Tainan area around Jiali, Madou, Siaying, Syuejia, Jiangjyun and Yanshuei due to a disastrous earthquake occurred near the border between Jiali and Madou with a magnitude of Mw 6.83 in 1862 and large site amplification factors which can reach as high as 2.89 and 2.97 for PGA and PGV, respectively, in Madou. In addition, the probabilities in 10, 30, and 50-year periods with seismic intensity exceeding MMII VIII in above areas are greater than 45%, 80% and 95%, respectively. Moreover, from the distribution of probabilities, high values of greater than 95% over a 10 year period with seismic intensity corresponding to CWBI V and MMI VI are found in central and northern Chiayi and northern Tainan. At last, from estimation of human fatalities for scenario earthquakes on three active faults in Chianan area, it is noted that the numbers of fatalities increase rapidly for people above age 45. Compared to the 1946 Hsinhua earthquake, the number of fatality estimated from the scenario earthquake on the Hsinhua active fault is significantly high. However, the higher number of fatality in this case is reasonable after considering the probably reasons. Hence, we urge local and the central governments to pay special attention on seismic hazard mitigation in this highly urbanized area with large number of old buildings.

  17. When it happens again: impact of future San Francisco Bay area earthquakes

    NASA Astrophysics Data System (ADS)

    Zoback, M.; Boatwright, J.; Kornfield, L.; Scawthorn, C.; Rojahn, C.

    2005-12-01

    San Francisco Bay area earthquakes, like major floods and hurricanes, have the potential for massive damage to dense urban population centers concentrated in vulnerable zones-along active faults, in coastal regions, and along major river arteries. The recent destruction of Hurricane Katrina does have precedent in the destruction following the 1906 "San Francisco" earthquake and fire in which more than 3000 people were killed and 225,000 were left homeless in San Francisco alone, a city of 400,000 at the time. Analysis of a comprehensive set of damage reports from the magnitude (M) 7.9 1906 earthquake indicates a region of ~ 18,000 km2 was subjected to shaking of Modified Mercalli Intensity of VIII or more - motions capable of damaging even modern, well-built structures; more than 60,000 km2 was subjected to shaking of Intensity VII or greater - the threshold for damage to masonry and poorly designed structures. By comparison, Katrina's hurricane force winds and intense rainfall impacted an area of ~100,000 km2 on the Gulf Coast. Thus, the anticipated effects of a future major Bay Area quake to lives, property, and infrastructure are comparable in scale to Katrina. Secondary hazards (levee failure and flooding in the case of Katrina and fire following the 1906 earthquake) greatly compounded the devastation in both disasters. A recent USGS-led study concluded there is a 62% chance of one or more damaging (M6.7 or greater) earthquakes striking the greater San Francisco Bay area over the next 30 years. The USGS prepared HAZUS loss estimates for the 10 most likely forecast earthquakes which range in size from a M6.7 event on a blind thrust to the largest anticipated event, a M7.9 repeat of the 1906 earthquake. The largest economic loss is expected for a repeat of the 1906 quake. Losses in the Bay region for this event are nearly double those predicted for a M6.9 rupture of the entire Hayward Fault in the East Bay. However, because of high density of population along the

  18. Three-dimensional ground-motion simulations of earthquakes for the Hanford area, Washington

    USGS Publications Warehouse

    Frankel, Arthur; Thorne, Paul; Rohay, Alan

    2014-01-01

    This report describes the results of ground-motion simulations of earthquakes using three-dimensional (3D) and one-dimensional (1D) crustal models conducted for the probabilistic seismic hazard assessment (PSHA) of the Hanford facility, Washington, under the Senior Seismic Hazard Analysis Committee (SSHAC) guidelines. The first portion of this report demonstrates that the 3D seismic velocity model for the area produces synthetic seismograms with characteristics (spectral response values, duration) that better match those of the observed recordings of local earthquakes, compared to a 1D model with horizontal layers. The second part of the report compares the response spectra of synthetics from 3D and 1D models for moment magnitude (M) 6.6–6.8 earthquakes on three nearby faults and for a dipping plane wave source meant to approximate regional S-waves from a Cascadia great earthquake. The 1D models are specific to each site used for the PSHA. The use of the 3D model produces spectral response accelerations at periods of 0.5–2.0 seconds as much as a factor of 4.5 greater than those from the 1D models for the crustal fault sources. The spectral accelerations of the 3D synthetics for the Cascadia plane-wave source are as much as a factor of 9 greater than those from the 1D models. The differences between the spectral accelerations for the 3D and 1D models are most pronounced for sites with thicker supra-basalt sediments and for stations with earthquakes on the Rattlesnake Hills fault and for the Cascadia plane-wave source.

  19. Spatiotemporal variations of seismicity before major earthquakes in the Japanese area and their relation with the epicentral locations.

    PubMed

    Sarlis, Nicholas V; Skordas, Efthimios S; Varotsos, Panayiotis A; Nagao, Toshiyasu; Kamogawa, Masashi; Uyeda, Seiya

    2015-01-27

    Using the Japan Meteorological Agency earthquake catalog, we investigate the seismicity variations before major earthquakes in the Japanese region. We apply natural time, the new time frame, for calculating the fluctuations, termed β, of a certain parameter of seismicity, termed κ1. In an earlier study, we found that β calculated for the entire Japanese region showed a minimum a few months before the shallow major earthquakes (magnitude larger than 7.6) that occurred in the region during the period from 1 January 1984 to 11 March 2011. In this study, by dividing the Japanese region into small areas, we carry out the β calculation on them. It was found that some small areas show β minimum almost simultaneously with the large area and such small areas clustered within a few hundred kilometers from the actual epicenter of the related main shocks. These results suggest that the present approach may help estimation of the epicentral location of forthcoming major earthquakes.

  20. Non-shear focal mechanisms of earthquakes at The Geysers, California and Hengill, Iceland, geothermal areas

    USGS Publications Warehouse

    Julian, B.R.; Miller, A.D.; Foulger, G.R.; ,

    1993-01-01

    Several thousand earthquakes were recorded in each area. We report an initial investigation of the focal mechanisms based on P-wave polarities. Distortion by complicated three-dimensional crustal structure was minimized using tomographically derived three-dimensional crustal models. Events with explosive and implosive source mechanisms, suggesting cavity opening and collapse, have been tentatively identified at The Geysers. The new data show that some of these events do not fit the model of tensile cracking accompanied by isotropic pore pressure decreases that was suggested in earlier studies, but that they may instead involve combination of explosive and shear processes. However, the confirmation of earthquakes dominated by explosive components supports the model that the event are caused by crack opening induced by thermal contraction of the heat source.

  1. The 1987 Whittier Narrows Earthquake in the Los Angeles Metropolitan Area, California

    NASA Astrophysics Data System (ADS)

    Hauksson, Egill; Jones, Lucile M.; Davis, Thomas L.; Hutton, L. Katherine; Brady, A. Gerald; Reasenberg, Paul A.; Michael, Andrew J.; Yerkes, Robert F.; Williams, Patrick; Reagor, Glen; Stover, Carl W.; Bent, Allison L.; Shakal, Anthony K.; Etheredge, Edwin; Porcella, Ronald L.; Bufe, Charles G.; Johnston, Malcolm J. S.; Cranswick, Edward

    1988-03-01

    The Whittier Narrows earthquake sequence (local magnitude, ML = 5.9), which caused over 358-million damage, indicates that assessments of earthquake hazards in the Los Angeles metropolitan area may be underestimated. The sequence ruptured a previously unidentified thrust fault that may be part of a large system of thrust faults that extends across the entire east-west length of the northern margin of the Los Angeles basin. Peak horizontal accelerations from the main shock, which were measured at ground level and in structures, were as high as 0.6g (where g is the acceleration of gravity at sea level) within 50 kilometers of the epicenter. The distribution of the modified Mercalli intensity VII reflects a broad north-south elongated zone of damage that is approximately centered on the main shock epicenter.

  2. The 1987 Whittier Narrows earthquake in the Los Angeles metropolitan area, California

    USGS Publications Warehouse

    Hauksson, E.; Jones, L.M.; Davis, T.L.; Hutton, L.K.; Brady, A.G.; Reasenberg, P.A.; Michael, A.J.; Yerkes, R.F.; Williams, Pat; Reagor, G.; Stover, C.W.; Bent, A.L.; Shakal, A.K.; Etheredge, E.; Porcella, R.L.; Bufe, C.G.; Johnston, M.J.S.; Cranswick, E.

    1988-01-01

    The Whittier Narrows earthquake sequence (local magnitude, ML=5.9), which caused over $358-million damage, indicates that assessments of earthquake hazards in the Los Angeles metropolitan area may be underestimated. The sequence ruptured a previously unidentified thrust fault that may be part of a large system of thrust faults that extends across the entire east-west length of the northern margin of the Los Angeles basin. Peak horizontal accelerations from the main shock, which were measured at ground level and in structures, were as high as 0.6g (where g is the acceleration of gravity at sea level) within 50 kilometers of the epicenter. The distribution of the modified Mercalli intensity VII reflects a broad north-south elongated zone of damage that is approximately centered on the main shock epicenter.

  3. Source processes of industrially-induced earthquakes at the Geysers geothermal area, California

    USGS Publications Warehouse

    Ross, A.; Foulger, G.R.; Julian, B.R.

    1999-01-01

    Microearthquake activity at The Geysers geothermal area, California, mirrors the steam production rate, suggesting that the earthquakes are industrially induced. A 15-station network of digital, three-component seismic stations was operated for one month in 1991, and 3,900 earthquakes were recorded. Highly-accurate moment tensors were derived for 30 of the best recorded earthquakes by tracing rays through tomographically derived 3-D VP and VP / VS structures, and inverting P-and S-wave polarities and amplitude ratios. The orientations of the P-and T-axes are very scattered, suggesting that there is no strong, systematic deviatoric stress field in the reservoir, which could explain why the earthquakes are not large. Most of the events had significant non-double-couple (non-DC) components in their source mechanisms with volumetric components up to ???30% of the total moment. Explosive and implosive sources were observed in approximately equal numbers, and must be caused by cavity creation (or expansion) and collapse. It is likely that there is a causal relationship between these processes and fluid reinjection and steam withdrawal. Compensated linear vector dipole (CLVD) components were up to 100% of the deviatoric component. Combinations of opening cracks and shear faults cannot explain all the observations, and rapid fluid flow may also be involved. The pattern of non-DC failure at The Geysers contrasts with that of the Hengill-Grensdalur area in Iceland, a largely unexploited water-dominated field in an extensional stress regime. These differences are poorly understood but may be linked to the contrasting regional stress regimes and the industrial exploitation at The Geysers.

  4. Quasi-static Slips Around the Source Areas of the 2003 Tokachi-oki (M8.0) and 2005 Miyagi-oki (M7.2) Earthquakes, Japan Estimated From Small Repeating Earthquakes

    NASA Astrophysics Data System (ADS)

    Uchida, N.; Matsuzawa, T.; Hirahara, S.; Igarashi, T.; Hasegawa, A.; Kasahara, M.

    2005-12-01

    We have estimated spatio-temporal distribution of interplate quasi-static slips around the source areas of the 2003 Tokachi-oki (M8.0) and 2005 Miyagi-oki (M7.2) earthquakes by using small repeating earthquakes. The small repeating earthquakes are thought to be caused by repeated rupture of small asperities surrounded by stable sliding areas on the fault. Here we estimated cumulative slips for small repeating earthquakes assuming that they were equal to the quasi-static slip histories in the surrounding areas on the plate boundaries (Igarashi et al., 2003; Uchida et al., 2003). The 2003 Tokachi-oki earthquake occurred on September 26, 2003 off the southeast of Hokkaido, Japan. The present analyses show that the slips in the areas around and to the east of the asperity of the earthquake were slow before the earthquake but that it was significantly accelerated after the earthquake. The slip rate acceleration to the east of the asperity probably triggered a M7.1 event which occurred on November 29, 2004 at the eastern edge of the accelerated area (about 100km east from the hypocenter of the Tokachi-oki earthquake). It seems that the quasi-static slip released the slip deficit in the locked area between the asperities of the 2003 Tokachi-oki and 1973 Nemuro-oki (M7.4) earthquakes. The 2005 Miyagi-oki earthquake occurred on August 16, 2005 in the anticipated source area for the recurrent _eMiyagi-oki earthquake_f. However, it was estimated that the earthquake did not destroyed the whole area of the asperity which caused the previous Miyagi-oki earthquake in 1978 (The Headquarters for Earthquake Research Promotion, 2005). Our result shows the quasi-static slips for the period of 20 years before the earthquake was almost constant to the west of the source area of the 2005 earthquake. The slips after the earthquake were not significant for the period of 15 days which suggests the plate boundary around the asperity for the earthquake is still locking.

  5. Multi-Scale Structure and Earthquake Properties in the San Jacinto Fault Zone Area

    NASA Astrophysics Data System (ADS)

    Ben-Zion, Y.

    2014-12-01

    I review multi-scale multi-signal seismological results on structure and earthquake properties within and around the San Jacinto Fault Zone (SJFZ) in southern California. The results are based on data of the southern California and ANZA networks covering scales from a few km to over 100 km, additional near-fault seismometers and linear arrays with instrument spacing 25-50 m that cross the SJFZ at several locations, and a dense rectangular array with >1100 vertical-component nodes separated by 10-30 m centered on the fault. The structural studies utilize earthquake data to image the seismogenic sections and ambient noise to image the shallower structures. The earthquake studies use waveform inversions and additional time domain and spectral methods. We observe pronounced damage regions with low seismic velocities and anomalous Vp/Vs ratios around the fault, and clear velocity contrasts across various sections. The damage zones and velocity contrasts produce fault zone trapped and head waves at various locations, along with time delays, anisotropy and other signals. The damage zones follow a flower-shape with depth; in places with velocity contrast they are offset to the stiffer side at depth as expected for bimaterial ruptures with persistent propagation direction. Analysis of PGV and PGA indicates clear persistent directivity at given fault sections and overall motion amplification within several km around the fault. Clear temporal changes of velocities, probably involving primarily the shallow material, are observed in response to seasonal, earthquake and other loadings. Full source tensor properties of M>4 earthquakes in the complex trifurcation area include statistically-robust small isotropic component, likely reflecting dynamic generation of rock damage in the source volumes. The dense fault zone instruments record seismic "noise" at frequencies >200 Hz that can be used for imaging and monitoring the shallow material with high space and time details, and

  6. Relationship between large slip area and static stress drop of aftershocks of inland earthquake :Example of the 2007 Noto Hanto earthquake

    NASA Astrophysics Data System (ADS)

    Urano, S.; Hiramatsu, Y.; Yamada, T.

    2013-12-01

    The 2007 Noto Hanto earthquake (MJMA 6.9; hereafter referred to the main shock) occurred at 0:41(UTC) on March 25, 2007 at a depth of 11km beneath the west coast of Noto Peninsula, central Japan. The dominant slip of the main shock was on a reverse fault with a right-lateral slip and the large slip area was distributed from hypocenter to the shallow part on the fault plane (Horikawa, 2008). The aftershocks are distributed not only in the small slip area but also in the large slip area (Hiramatsu et al., 2011). In this study, we estimate static stress drops of aftershocks on the fault plane of the main shock. We discuss the relationship between the static stress drops of the aftershocks and the large slip area of the main shock by investigating spatial pattern of the values of the static stress drops. We use the waveform data obtained by the group for the joint aftershock observations of the 2007 Noto Hanto Earthquake (Sakai et al., 2007). The sampling frequency of the waveform data is 100 Hz or 200 Hz. Focusing on similar aftershocks reported by Hiramatsu et al. (2011), we analyze static stress drops by using the method of empirical Green's function (EGF) (Hough, 1997) as follows. The smallest earthquake (MJMA≥2.0) of each group of similar earthquakes is set to the EGF earthquake, and the largest earthquake (MJMA≥2.5) is set to the target earthquake. We then deconvolve the waveform of an interested earthquake with that of the EGF earthquake at each station and obtain the spectral ratio of the sources that cancels the propagation effects (path and site effects). Following the procedure of Yamada et al. (2010), we finally estimate static stress drops for P- and S-waves from corner frequencies of the spectral ratio by using a model of Madariaga (1976). The estimated average value of static stress drop is 8.2×1.3 MPa (8.6×2.2 MPa for P-wave and 7.8×1.3 MPa for S-wave). These values are coincident approximately with the static stress drop of aftershocks of other

  7. Surface-seismic imaging for nehrp soil profile classifications and earthquake hazards in urban areas

    USGS Publications Warehouse

    Williams, R.A.; Stephenson, W.J.; Odum, J.K.

    1998-01-01

    We acquired high-resolution seismic-refraction data on the ground surface in selected areas of the San Fernando Valley (SFV) to help explain the earthquake damage patterns and the variation in ground motion caused by the 17 January 1994 magnitude 6.7 Northridge earthquake. We used these data to determine the compressional- and shear-wave velocities (Vp and Vs) at 20 aftershock recording sites to 30-m depth ( V??s30, and V??p30). Two other sites, located next to boreholes with downhole Vp and Vs data, show that we imaged very similar seismic-vefocity structures in the upper 40 m. Overall, high site response appears to be associated with tow Vs in the near surface, but there can be a wide rangepf site amplifications for a given NEHRP soil type. The data suggest that for the SFV, if the V??s30 is known, we can determine whether the earthquake ground motion will be amplified above a factor of 2 relative to a local rock site.

  8. Psychological distress in an earthquake-devastated area with pre-existing high rate of suicide.

    PubMed

    Tachibana, Akira; Kitamura, Hideaki; Shindo, Masanobu; Honma, Hiroko; Someya, Toshiyuki

    2014-10-30

    On 12 March 2011 an earthquake devastated the Matsunoyama and Matsudai districts of Tōkamachi City, Niigata, Japan. These areas had high pre-existing suicide rates, especially among the elderly. We investigated whether mental health status became worse among the sufferers 5 months after the earthquake, and what kind of factors were implicated in any changes. A 15-item questionnaire that tapped earthquake-related variables and the Kessler 10 Psychological Distress Scale to measure psychological distress were distributed to 1923 residents aged over 40 years. The mean age (S.D.) of the total 1731 respondents (male, 805; female, 926) was 68.2 (13.1) years. Of these, we assessed K10 scores from 1346 respondents. The mean scores (S.D.) for K10 and K6 (six selected items from the K10) were 5.8 (6.3) and 3.4 (3.9), respectively. Among the respondents, 9.1% and 3.2% obtained a score of K10 ≥15 and K6 ≥13, respectively. These scores showed slightly higher psychological distress, especially among the elderly, in comparison with existing community-based data. Categorical regression analysis revealed significant and relatively strong effects of initial psychological impact, decrease in sleep hours, advanced age, and decrease in interpersonal relationships within the community on the K10 score. The last item suggests the importance of socio-environmental factors in post-disaster mental health.

  9. P wave crustal velocity structure in the greater Mount Rainier area from local earthquake tomography

    USGS Publications Warehouse

    Moran, S.C.; Lees, J.M.; Malone, S.D.

    1999-01-01

    We present results from a local earthquake tomographic imaging experiment in the greater Mount Rainier area. We inverted P wave arrival times from local earthquakes recorded at permanent and temporary Pacific Northwest Seismograph Network seismographs between 1980 and 1996. We used a method similar to that described by Lees and Crosson [1989], modified to incorporate the parameter separation method for decoupling the hypocenter and velocity problems. In the upper 7 km of the resulting model there is good correlation between velocity anomalies and surface geology. Many focal mechanisms within the St. Helens seismic zone have nodal planes parallel to the epicentral trend as well as to a north-south trending low-velocity trough, leading us to speculate that the trough represents a zone of structural weakness in which a moderate (M 6.5-7.0) earthquake could occur. In contrast, the western Rainier seismic zone does not correlate in any simple way with anomaly patterns or focal mechanism fault planes, leading us to infer that it is less likely to experience a moderate earthquake. A ???10 km-wide low-velocity anomaly occurs 5 to 18 km beneath the summit of Mount Rainier, which we interpret to be a signal of a region composed of hot, fractured rock with possible small amounts of melt or fluid. No systematic velocity pattern is observed in association with the southern Washington Cascades conductor. A midcrustal anomaly parallels the Olympic-Wallowa lineament as well as several other geophysical trends, indicating that it may play an important role in regional tectonics. Copyright 1999 by the American Geophysical Union.

  10. Solar modulation of earthquake occurrence in areas penetrated by L of 2.0 populated by anomalous cosmic rays

    NASA Astrophysics Data System (ADS)

    Khachikyan, Galina; Inchin, Alexander; Toyshiev, Nursultan

    An analysis of data of global seismological catalog NEIC (National Earthquake Information Center of the U.S. Geological Survey) for 1973-2011 (182933 events with magnitude equal to 4.5 and more) has been carried out with taken into account the geometry of the main geomagnetic field as gives the International Geomagnetic Reference Field (IGRF-11) model. It is found that the greatest number of earthquakes occurs in seismic areas penetrated by the geomagnetic force lines L=1.0-1.1, and additionally, the L-shell distribution of earthquake counting rate is peaked at the L equal to 2.0-2.2, which are inhabited by the Anomalous Cosmic Rays (ACRs). It is revealed that occurrence of strong earthquakes (with magnitude 7.0 and more) in these areas is modulated by the 11 year solar cycle. Namely, during 1973-2011, twenty strong earthquakes occurred in regions where the L=2.0-2.2 are loaned into the earth’s crust and, surprisingly, all of these earthquakes occurred only at the declining phase of the 11 year solar cycles while were absent at the ascending phase. Solar modulation of earthquake occurrence may be explained at present in the frame of a modern idea that earthquake is triggered by the electric currents flowing into the global electric circuit (GEC), where the charged geomagnetic force lines play the role of conductors (field align currents). The operation of GEC depends on intensity of cosmic rays which provide ionization and conductivity of the air in the middle atmosphere. Since the ACRs are especially sensitive to solar modulation, and since they populate the L of 2.0, it may be expected that earthquake occurrence in the areas penetrated by L of 2.0 would be especially sensitive to solar modulation. Our results prove this expectation, but much work is required to study this problem in more details.

  11. Seafloor seismological/geodetic observations in the rupture area of the 2011 Tohoku-oki Earthquake

    NASA Astrophysics Data System (ADS)

    Hino, Ryota; Shinohara, Masanao; Ito, Yoshihiro

    2016-04-01

    A number of important aspects of the 2011 Tohoku-oki earthquake (Mw 9.0) were clarified by the seafloor seismological and geodetic observation above the rupture area of the earthquake. Besides the extraordinarily large coseismic displacements, various kinds of slow slip phenomena associated with intensive micro-seismicity on the plate boundary fault were identified by near field ocean bottom seismographs and seafloor geodetic observation networks. The Tohoku-oki earthquake was preceded by evident foreshock activity with a spatial expansion of this seismicity. The activity became significantly intense after the occurrence of the largest foreshock two days before the mainshock rupture. During the period, clear continuous seafloor deformation was identified caused by the aseismic slip following the largest foreshock. Another different type of aseismic slip event had occurred before this pre-imminent activity had started about a month before the largest foreshock happened. The observed increased seismicity associated with aseismic slip suggests that there must have been some chain reaction like interplay of seismic and interseismic slips before the large earthquake broke out. However, no evident deformation signals were observed indicating acceleration of fault slip immediately before the mainshock. Seafloor geodetic measurements reveals that the postseismic deformation around the rupture area of the Tohoku-oki earthquake shows complex spatial pattern and the complexity is mostly due to significant viscoelastic relaxation induced by the huge coseismic slip. The effects of viscoelastic deformation makes it difficult to identify the deformation associated with the after slip or regaining of interplate coupling and requires us to enhance the abilities of seafloor monitoring to detect the slip activities on the fault. We started an array of seismometer arrays observation including broad-band seismographs to detect and locate slow-slip events and low-frequency tremors

  12. Amylases StAmy23, StBAM1 and StBAM9 regulate cold-induced sweetening of potato tubers in distinct ways.

    PubMed

    Hou, Juan; Zhang, Huiling; Liu, Jun; Reid, Stephen; Liu, Tengfei; Xu, Shijing; Tian, Zhendong; Sonnewald, Uwe; Song, Botao; Xie, Conghua

    2017-03-28

    Cold-induced sweetening (CIS) in potato is detrimental to the quality of processed products. Conversion of starch to reducing sugars (RS) by amylases is considered one of the main pathways in CIS but is not well studied. The amylase genes StAmy23, StBAM1, and StBAM9 were studied for their functions in potato CIS. StAmy23 is localized in the cytoplasm, whereas StBAM1 and StBAM9 are targeted to the plastid stroma and starch granules, respectively. Genetic transformation of these amylases in potatoes by RNA interference showed that β-amylase activity could be decreased in cold-stored tubers by silencing of StBAM1 and collective silencing of StBAM1 and StBAM9. However, StBAM9 silencing did not decrease β-amylase activity. Silencing StBAM1 and StBAM9 caused starch accumulation and lower RS, which was more evident in simultaneously silenced lines, suggesting functional redundancy. Soluble starch content increased in RNAi-StBAM1 lines but decreased in RNAi-StBAM9 lines, suggesting that StBAM1 may regulate CIS by hydrolysing soluble starch and StBAM9 by directly acting on starch granules. Moreover, StBAM9 interacted with StBAM1 on the starch granules. StAmy23 silencing resulted in higher phytoglycogen and lower RS accumulation in cold-stored tubers, implying that StAmy23 regulates CIS by degrading cytosolic phytoglycogen. Our findings suggest that StAmy23, StBAM1, and StBAM9 function in potato CIS with varying levels of impact.

  13. a Goes-W Satellite Thermal Infrared Survey (2006-2014) Over South Western us Earthquake Prone Area: Preliminary Results on 24 August 2014 Napa Earthquake (M=6)

    NASA Astrophysics Data System (ADS)

    Tramutoli, V.; Genzano, N.; Coviello, I.; Filizzola, C.; Lisi, M.; Paciello, R.; Pergola, N.; Satriano, V.

    2014-12-01

    The RST (Robust Satellite Technique) methodology has been widely applied to tens of earthquakes occurred in different continents (Europe, Asia, America and Africa), in various geo-tectonic settings (compressive, extensional and transcurrent) and with a wide range of magnitudes (from 4.0 to 7.9) trying to identify anomalous fluctuations of the Earth's emitted TIR (Thermal InfraRed) radiation in possible relation with earthquake occurrence discriminating them from those variations due to other causes. An extended study is presented in the AGU2014 NH008 session by Tramutoli et al. which is devoted to verify to which extent Significant (space-time persistent, non-spurious) Sequences of TIR Anomalies (SSTAs) appear within prefixed space-time windows around earthquakes of magnitude M>4 occurred on 6 years (2006-2011) over South Western US seismic area. Results of such a study (with a rate of false positive of 35%) give an idea on the possible relevance of RST based TIR surveys in the framework of an operational, multi-parametric system for time-Dependent Assessment of Seismic Hazard (t-DASH). In this paper all the data available from the new GOES-W satellite (in orbit in between 2010 and 2014) have been analysed by the same way in the case of the earthquake occurred on 24 August 2014 (M=6) over Napa valley (California). The results presented in this paper, even if still preliminary, seem to confirm the significance of RST based TIR survey in a t-DASH perspective. It should however mentioned, that such an approach (even if not devoted to be used for short-term Earthquake Forecast outside a multiparametric t-DASH system), when compared with whatever traditional OEF (Operational Earthquake Forecast) method (like the one abandoned ten years ago in US but recently re-proposed for Italy) seems already to gives forecast reliabilities of orders of magnitude greater.

  14. Robust Satellite Techniques (RST) for monitoring earthquake prone areas by satellite TIR observations: The case of 1999 Chi-Chi earthquake (Taiwan)

    NASA Astrophysics Data System (ADS)

    Genzano, N.; Filizzola, C.; Paciello, R.; Pergola, N.; Tramutoli, V.

    2015-12-01

    For more than 13 years a multi-temporal data-analysis method, named Robust Satellite Techniques (RST), has been being applied to satellite Thermal InfraRed (TIR) monitoring of seismically active regions. It gives a clear definition of a TIR anomaly within a validation/confutation scheme devoted to verify if detected anomalies can be associated or not to the time and location of the occurrence of major earthquakes. In this scheme, the confutation part (i.e. verifying if similar anomalies do not occur in the absence of a significant seismic activity) assumes a role even much important than the usual validation component devoted to verify the presence of anomalous signal transients before (or in association with) specific seismic events. Since 2001, RST approach has been being used to study tens of earthquakes with a wide range of magnitudes (from 4.0 to 7.9) occurred in different continents and in various geo-tectonic settings. In this paper such a long term experience is exploited in order to give a quantitative definition of a significant sequence of TIR anomalies (SSTA) in terms of the required space-time continuity constraints (persistence), identifying also the different typologies of known spurious sequences of TIR anomalies that have to be excluded from the following validation steps. On the same basis, taking also into account for the physical models proposed for justifying the existence of a correlation between TIR anomalies and earthquakes occurrence, specific validation rules (in line with the ones used by the Collaboratory for the Study of Earthquake Predictability - CSEP - Project) have been defined to drive the validation process. In this work, such an approach is applied for the first time to a long-term dataset of night-time GMS-5/VISSR (Geostationary Meteorological Satellite/Visible and Infrared Spin-Scan Radiometer) TIR measurements, comparing SSTAs and earthquakes with M > 4 which occurred in a wide area around Taiwan, in the month of September of

  15. Seismic Disaster Mitigation in Urban Area by using Building Vibration Observation of Weak Earthquake Ground Motion: an Approach of the IT Kyoshin Seismometer for Buildings

    NASA Astrophysics Data System (ADS)

    Takano, K.; Ito, T.

    2010-12-01

    There are a lot of buildings which is not experienced severe earthquakes in urban area. In Hanshin-Awaji (Kobe) Earthquake, it was presumed that 80 percent or more of the person was dead immediately after the earthquake by building collapse. Also in Haiti, a lot of buildings deprived of the life of persons. In order to prevent the earthquake damage of urban area, it is the most effective to make the building earthquake-proof. However, there are still a lot of buildings not made earthquake-proof in Japan though 15 years passed since Kobe Earthquake. In order to promote making of the building earthquake-proof, various approaches such as visualization of seismic hazard, education of disaster prevention and legal system for promotion are needed. We have developed the IT Kyoshin(strong motion) Seismometer for Building which is the observation system of the usual weak earthquake ground motion by installing a lot of acceleration sensors in building, and have been setting it up in some buildings of the University of Tokyo. We have also developed the visualization tool that can reproduce the building vibration during earthquake from the observed data. By this tool, we can successfully show where is more shaking in the building or what is the feature of building vibration easily. Such information contributes to not only promotion of making building earthquake-proof but also promotion of disaster prevention action such as fixation of bookshelf, making the safety area in building, etc. In addition, we proposed a concrete technique of the health investigation of buildings by using weak earthquake ground motion. Because there are 20 to 30 felt earthquakes in year in Tokyo area, it is possible to observe these building vibrations by using weak earthquake ground motions. In addition, we have developed the high sensitive ITK sensor which can observe from the microtremor to the felt earthquake in the place without the felt earthquake either.

  16. Some characteristics of the earthquake swarms in the lake Awan area, Egypt

    NASA Astrophysics Data System (ADS)

    Hassoup, A.

    2003-04-01

    The earthquake swarms beneath the northern part of the Lake Aswan are located along a tectonic fault with hypocentral distribution from 3 to 30 km depths in the crust. This seismicity is separated into shallow and deep seismic zones. Shallow events have focal depths of less than 10 km. Deep events extend from 10 to 30 km. A 3-dimensional P-waves velocity analysis demonstrates that the deep events are distributed within a high velocity anomaly. The temporal seismicity sequence (1982-1999) is correlated with seasonal variation of the water level using spectral analysis. The results show phase shifts of 1.3 months for the shallow and 3 months for the deep seismicity. The fractal evolution of the spatial hypocentral- distribution (DS) is examined. DS is determined using the correlation dimension, in tandem with b values of the maximum likelihood method. Both are obtained in a set of discrete time windows moving through the catalogue of events with magnitude range MD (2.3 < MD < 4.6). DS ranges between 0.85 and 1.15 with a mean value of 0.95, whereas b-value ranges from 0.7 to 1.6 with a mean value 0.88. The correlation between DS and b is not evident here. However, these two parameters are remarkably decreased prior to the occurrence of the larger earthquake (MD d 3.9) in the Aswan catalogue. In addition the annual variation histogram for energy released by earthquakes (E) in the lake Aswan area is obtained. It shows concentration of E in the earlier part of the catalogue. Key words: Seismicity characteristics, tectonic setting, and Lake Aswan area.

  17. A cross section of the Los Angeles Area: Seismically active fold and thrust belt, The 1987 Whittier Narrows earthquake, and earthquake hazard

    NASA Astrophysics Data System (ADS)

    Davis, Thomas L.; Namson, Jay; Yerkes, Robert F.

    1989-07-01

    Retrodeformable cross sections across the Los Angeles area interpret the Pliocene to Quaternary deformation to be a developing basement-involved fold and thrust belt. The fold and thrust belt is seismically active as evidenced by the 1987 Whittier Narrows earthquake (ML = 5.9) and the 1971 San Fernando earthquake (MW = 6.6). The structural geology of the Los Angeles area is dominated by three major compressional uplift trends: (1) the Palos Verdes anticlinorium and western shelf, (2) the Santa Monica Mountains anticlinorium, and (3) the Verdugo Mountains-San Rafael Hills and the San Gabriel Mountains. These trends result from major thrust ramps off a detachment(s) at 10-15 km depth. Thrusts of the Verdugo Mountains-San Rafael Hills and the San Gabriel Mountains reach the surface; the other two uplifts are associated with blind thrusts. Compressional seismicity is concentrated along these thrust ramps. The 1987 Whittier Narrows earthquake probably occurred on the Elysian Park thrust which underlies the Santa Monica Mountains anticlinorium. The thrust interpretation accounts for the geometry of the anticlinorium, the seismological characteristics of the earthquake, and the geometry of coseismic uplift. The earthquake and aftershocks occurred within a structurally complex, narrow zone of Miocene and Pliocene northwest trending faults that cross the anticlinorium at a high angle. These northwest trending faults are interpreted to be reactivated faults now behaving as tears in the Elysian Park thrust and not the result of active right-lateral deformation extending into the Whittier Narrows area. Our analysis suggests the Whittier Narrows earthquake sequence occurred within a structurally weakened zone along the Elysian Park thrust. We also suggest that the Whittier fault is not an important Quaternary structure and may not be seismogenic. The regional cross section is a nonunique solution, and other possible solutions are considered. Multiple solutions arise from the

  18. The EP-3E vs. the BAMS UAS: An Operating and Support Cost Comparison

    DTIC Science & Technology

    2012-09-01

    thesis is to reexamine, compare and analyze the Operating and Support ( O &S) costs for both the EP-3E ISR aircraft with the Broad Area Maritime...capability. This comparison includes all costs from initial system deployment through the end of the platforms’ service life. This thesis uses the revised O &S...typical O &S comparison, this thesis modifies the existing BAMS O &S costs to account for the additional costs of bandwidth, ground station support

  19. Initiation processes for run-off generated debris flows in the Wenchuan earthquake area of China

    NASA Astrophysics Data System (ADS)

    Hu, W.; Dong, X. J.; Xu, Q.; Wang, G. H.; van Asch, T. W. J.; Hicher, P. Y.

    2016-01-01

    The frequency of huge debris flows greatly increased in the epicenter area of the Wenchuan earthquake. Field investigation revealed that runoff during rainstorm played a major role in generating debris flows on the loose deposits, left by coseismic debris avalanches. However, the mechanisms of these runoff-generated debris flows are not well understood due to the complexity of the initiation processes. To better understand the initiation mechanisms, we simulated and monitored the initiation process in laboratory flume test, with the help of a 3D laser scanner. We found that run-off incision caused an accumulation of material down slope. This failed as shallow slides when saturated, transforming the process into debris in a second stage. After this initial phase, the debris flow volume increased rapidly by a chain of subsequent cascading processes starting with collapses of the side walls, damming and breaching, leading to a rapid widening of the erosion channel. In terms of erosion amount, the subsequent mechanisms were much more important than the initial one. The damming and breaching were found to be the main reasons for the huge magnitude of the debris flows in the post-earthquake area. It was also found that the tested material was susceptible to excess pore pressure and liquefaction in undrained triaxial, which may be a reason for the fluidization in the flume tests.

  20. The 2016 Kumamoto-Oita earthquake sequence: aftershock seismicity gap and dynamic triggering in volcanic areas

    NASA Astrophysics Data System (ADS)

    Uchide, Takahiko; Horikawa, Haruo; Nakai, Misato; Matsushita, Reiken; Shigematsu, Norio; Ando, Ryosuke; Imanishi, Kazutoshi

    2016-11-01

    The 2016 Kumamoto-Oita earthquake sequence involving three large events ( M w ≥ 6) in the central Kyushu Island, southwest Japan, activated seismicities in two volcanic areas with unusual and puzzling spatial gaps after the largest earthquake ( M w 7.0) of April 16, 2016. We attempt to reveal the seismic process during the sequence by following seismological data analyses. Our hypocenter relocation result implies that the large events ruptured different faults of a complex fault system. A slip inversion analysis of the largest event indicates a large slip in the seismicity gap (Aso gap) in the caldera of Mt. Aso, which probably released accumulated stress and resulted in little aftershock production. We identified that the largest event dynamically triggered a mid-M6 event at Yufuin (80 km northeast of the epicenter), which is consistent with existence of the 20-km long zone where seismicity was activated and surface offset was observed. These findings will help us study the contribution of the identified complexity in fault geometries and the geotherm in the volcanic areas to the revealed seismic process and consequently improve our understanding of the seismo-volcano tectonics.[Figure not available: see fulltext.

  1. A postseismic process in the area of the Simushir 11/2006 Earthquake recovered by the GRACE data

    NASA Astrophysics Data System (ADS)

    Mikhailov, V. O.; Timoshkina, E. P.; Diament, M.

    2016-11-01

    The GRACE data make it possible to detect the areas where the earthquakes initiate postseismic creep in regions much larger than the focal area. This information is important for estimation of the seismic potential and position of the locked segments in the subduction zones.

  2. Pre-earthquake assessment and recovery planning for the regional transportation system in the San Francisco Bay area

    SciTech Connect

    Perkins, J.B.

    1995-12-31

    In May 1995, ABAG began a cooperative project with Caltrans District 4 to perform a vulnerability analysis of the regional transportation system in the San Francisco Bay Area. This assessment will be used for pre-earthquake planning to speed the recovery process for the transportation system, including both freeways and local roads. The project is using geographic information system (GIS) technology and computer simulation models to assist in the vulnerability analyses, assessment of hazard mitigation strategies, and pre-earthquake planning activities. It is expected that this project will result in improving post-earthquake short-term emergency response as well as in shortening the time for long-term recovery. In addition, this innovative and timely approach should be applicable to other large metropolitan areas of the state, as well as to other metropolitan areas in the nation.

  3. Association of earthquakes and faults in the San Francisco Bay area using Bayesian inference

    USGS Publications Warehouse

    Wesson, R.L.; Bakun, W.H.; Perkins, D.M.

    2003-01-01

    Bayesian inference provides a method to use seismic intensity data or instrumental locations, together with geologic and seismologic data, to make quantitative estimates of the probabilities that specific past earthquakes are associated with specific faults. Probability density functions are constructed for the location of each earthquake, and these are combined with prior probabilities through Bayes' theorem to estimate the probability that an earthquake is associated with a specific fault. Results using this method are presented here for large, preinstrumental, historical earthquakes and for recent earthquakes with instrumental locations in the San Francisco Bay region. The probabilities for individual earthquakes can be summed to construct a probabilistic frequency-magnitude relationship for a fault segment. Other applications of the technique include the estimation of the probability of background earthquakes, that is, earthquakes not associated with known or considered faults, and the estimation of the fraction of the total seismic moment associated with earthquakes less than the characteristic magnitude. Results for the San Francisco Bay region suggest that potentially damaging earthquakes with magnitudes less than the characteristic magnitudes should be expected. Comparisons of earthquake locations and the surface traces of active faults as determined from geologic data show significant disparities, indicating that a complete understanding of the relationship between earthquakes and faults remains elusive.

  4. Evaluation of the Vegetation Coverage Resilience in Areas Damaged by the Wenchuan Earthquake Based on MODIS-EVI Data.

    PubMed

    Liu, Xiaofu; Jiang, Weiguo; Li, Jing; Wang, Wenjie

    2017-01-28

    The concept of resilience was integrated into post-earthquake ecological restoration assessments in 10 counties heavily impacted by the 2008 Wenchuan earthquake. Ecological resilience was defined as the time interval required for the vegetation coverage to recover to pre-earthquake levels in damaged areas. MODIS-EVI data from May to August in 2000 to 2016 were used to calculate the ecological resilience by fitting the curve of recovery rate (RR) versus time. The following conclusions were reached: (1) An area of 424.1 km² sustained vegetation damage. (2) The vegetation recovery was found to be linear based on the statistical analysis of the most common components of the damaged areas; consequently, linear fitting was used to estimate the resilience. (3) In terms of vegetation coverage, 44.2% of the damaged areas have already recovered. The vast majority of damaged areas are predicted to achieve vegetation recovery by 2022, but 5.3% of the damaged areas will not recover within this time period and have no resilience. (4) The management of damaged areas near roads, rivers and mining operations, especially at elevations of 2000-2500 m, slopes greater than 30°, and precipitation levels greater than 1200 mm, should be prioritized in the future. (5) The innovations of this study include the method used to extract earthquake-related vegetation damage and the prediction of vegetation succession based on resilience.

  5. Evaluation of the Vegetation Coverage Resilience in Areas Damaged by the Wenchuan Earthquake Based on MODIS-EVI Data

    PubMed Central

    Liu, Xiaofu; Jiang, Weiguo; Li, Jing; Wang, Wenjie

    2017-01-01

    The concept of resilience was integrated into post-earthquake ecological restoration assessments in 10 counties heavily impacted by the 2008 Wenchuan earthquake. Ecological resilience was defined as the time interval required for the vegetation coverage to recover to pre-earthquake levels in damaged areas. MODIS-EVI data from May to August in 2000 to 2016 were used to calculate the ecological resilience by fitting the curve of recovery rate (RR) versus time. The following conclusions were reached: (1) An area of 424.1 km2 sustained vegetation damage. (2) The vegetation recovery was found to be linear based on the statistical analysis of the most common components of the damaged areas; consequently, linear fitting was used to estimate the resilience. (3) In terms of vegetation coverage, 44.2% of the damaged areas have already recovered. The vast majority of damaged areas are predicted to achieve vegetation recovery by 2022, but 5.3% of the damaged areas will not recover within this time period and have no resilience. (4) The management of damaged areas near roads, rivers and mining operations, especially at elevations of 2000–2500 m, slopes greater than 30°, and precipitation levels greater than 1200 mm, should be prioritized in the future. (5) The innovations of this study include the method used to extract earthquake-related vegetation damage and the prediction of vegetation succession based on resilience. PMID:28134856

  6. Variability in Ground Motions in the San Francisco Bay Urban Area from Large Earthquakes on the San Andreas Fault

    NASA Astrophysics Data System (ADS)

    Aagaard, B. T.

    2006-12-01

    I use 3-D numerical simulations of kinematic earthquake ruptures to characterize the expected long period (T > 2.0 s) strong ground motions in the San Francisco Bay urban area from large earthquakes on the San Andreas fault. The earthquakes include the 1906 M7.9 San Francisco earthquake and hypothetical variations of the 1906 event with different hypocenters, slip distributions, and rupture speeds. The simulations use finite-elements to discretize a 250 km by 110 km by 45 km volume centered around the San Francisco Bay metropolitan area. Using the USGS 3-D geologic model and corresponding velocity model, the simulations incorporate the 3-D geologic structure, including the nonplanar geometry of the faults, the variation in material properties associated with different rock types and depth, and topography and bathymetry. The simulations suggest that much of the currently urbanized area around San Francisco Bay could be subjected to significantly stronger ground motions in the next large earthquake on the northern San Andreas fault compared with the motions in the simulation of the 1906 event. A hypocenter north of the 1906 hypocenter, which was directly off the coast of San Francisco, increases the rupture directivity for the city of San Francisco and cities around the southern half of the bay, raising the MMI one unit over much of the urban area. Alternatively, if instead of having less than average slip along the San Francisco peninsula as in the 1906 earthquake, this portion of the rupture has greater than average slip, the peninsula is subjected to significantly stronger shaking. In addition to these large-scale effects, some smaller scale effects, such as locally intense shaking in the Cupertino and Santa Rosa areas due to sedimentary basins, are present in all of the scenarios. These results corroborate previous studies that show that variations in rupture directivity and slip have a strong influence on the distribution of ground shaking in areas with complex

  7. The Structure of a BamA-BamD Fusion Illuminates the Architecture of the β-Barrel Assembly Machine Core.

    PubMed

    Bergal, Hans Thor; Hopkins, Alex Hunt; Metzner, Sandra Ines; Sousa, Marcelo Carlos

    2016-02-02

    The β-barrel assembly machine (BAM) mediates folding and insertion of integral β-barrel outer membrane proteins (OMPs) in Gram-negative bacteria. Of the five BAM subunits, only BamA and BamD are essential for cell viability. Here we present the crystal structure of a fusion between BamA POTRA4-5 and BamD from Rhodothermus marinus. The POTRA5 domain binds BamD between its tetratricopeptide repeats 3 and 4. The interface structural elements are conserved in the Escherichia coli proteins, which allowed structure validation by mutagenesis and disulfide crosslinking in E. coli. Furthermore, the interface is consistent with previously reported mutations that impair BamA-BamD binding. The structure serves as a linchpin to generate a BAM model where POTRA domains and BamD form an elongated periplasmic ring adjacent to the membrane with a central cavity approximately 30 × 60 Å wide. We propose that nascent OMPs bind this periplasmic ring prior to insertion and folding by BAM.

  8. Intensity-duration threshold of rainfall-triggered debris flows in the Wenchuan Earthquake affected area, China

    NASA Astrophysics Data System (ADS)

    Guo, Xiaojun; Cui, Peng; Li, Yong; Ma, Li; Ge, Yonggang; Mahoney, William B.

    2016-01-01

    The Ms 8.0 Wenchuan Earthquake has greatly altered the rainfall threshold for debris flows in the affected areas. This study explores the local intensity-duration (I-D) relationship based on 252 post-earthquake debris flows. It was found that I = 5.25 D-0.76 accounts for more than 98% of the debris flow occurrences with rainfall duration between 1 and 135 h; therefore the curve defines the threshold for debris flows in the study area. This gives much lower thresholds than those proposed by the previous studies, suggesting that the earthquake has greatly decreased the thresholds in the past years. Moreover, the rainfall thresholds appear to increase annually in the period of 2008-2013, and present a logarithmic increasing tendency, indicating that the thresholds will recover in the future decades.

  9. The 'terrifying' Seattle/Olympia earthquake: a learning experience for area hospitals about disaster plans.

    PubMed

    2001-04-01

    A 6.8-magnitude earthquake that struck the Seattle/Olympia area about an hour before lunchtime on Wednesday, February 28, caused an estimated $2 billion in damage but resulted in only one death. The quake was centered near Washington's state capital, Olympia, about 50 miles from Seattle. Scientists attribute the relatively small amount of damage to the fact that the quake was a deep one centered about 30 miles below the earth's surface. Experts also credit modern building codes, which require new buildings to be quake-resistant, and the retrofitting of older buildings to resist quakes for the lack of damage and casualties (less than 400 injuries). Hospitals in the region escaped serious damage and emergency rooms received relatively few casualties. However, in carrying out disaster plans, security and safety officials uncovered a number of problems that could have had serious impact in another emergency situation.

  10. Non-double-couple earthquake mechanisms at the Geysers geothermal area, California

    USGS Publications Warehouse

    Ross, A.; Foulger, G.R.; Julian, B.R.

    1996-01-01

    Inverting P- and S-wave polarities and P:SH amplitude ratios using linear programming methods suggests that about 20% of earthquakes at The Geysers geothermal area have significantly non-double-couple focal mechanisms, with explosive volumetric components as large as 33% of the seismic moment. This conclusion contrasts with those of earlier studies, which interpreted data in terms of double couples. The non-double-couple mechanisms are consistent with combined shear and tensile faulting, possibly caused by industrial water injection. Implosive mechanisms, which might be expected because of rapid steam withdrawal, have not been found. Significant compensated-linear-vector-dipole (CLVD) components in some mechanisms may indicate rapid fluid flow accompanying crack opening. Copyright 1996 by the American Geophysical Union.

  11. Developing fragility functions for the areas affected by the 2009 Samoa earthquake and tsunami

    NASA Astrophysics Data System (ADS)

    Gokon, H.; Koshimura, S.; Imai, K.; Matsuoka, M.; Namegaya, Y.; Nishimura, Y.

    2014-12-01

    Fragility functions in terms of flow depth, flow velocity and hydrodynamic force are developed to evaluate structural vulnerability in the areas affected by the 2009 Samoa earthquake and tsunami. First, numerical simulations of tsunami propagation and inundation are conducted to reproduce the features of tsunami inundation. To validate the results, flow depths measured in field surveys and waveforms measured by Deep-ocean Assessment and Reporting of Tsunamis (DART) gauges are utilized. Next, building damage is investigated by visually interpreting changes between pre- and post-tsunami high-resolution satellite images. Finally, the data related to tsunami features and building damage are integrated using Geographic Information System (GIS), and tsunami fragility functions are developed based on the statistical analyses. From the developed fragility functions, we quantitatively understood the vulnerability of a coastal region in American Samoa characterized by steep terrains and ria coasts.

  12. Predicted Liquefaction in the Greater Oakland and Northern Santa Clara Valley Areas for a Repeat of the 1868 Hayward Earthquake

    NASA Astrophysics Data System (ADS)

    Holzer, T. L.; Noce, T. E.; Bennett, M. J.

    2008-12-01

    Probabilities of surface manifestations of liquefaction due to a repeat of the 1868 (M6.7-7.0) earthquake on the southern segment of the Hayward Fault were calculated for two areas along the margin of San Francisco Bay, California: greater Oakland and the northern Santa Clara Valley. Liquefaction is predicted to be more common in the greater Oakland area than in the northern Santa Clara Valley owing to the presence of 57 km2 of susceptible sandy artificial fill. Most of the fills were placed into San Francisco Bay during the first half of the 20th century to build military bases, port facilities, and shoreline communities like Alameda and Bay Farm Island. Probabilities of liquefaction in the area underlain by this sandy artificial fill range from 0.2 to ~0.5 for a M7.0 earthquake, and decrease to 0.1 to ~0.4 for a M6.7 earthquake. In the greater Oakland area, liquefaction probabilities generally are less than 0.05 for Holocene alluvial fan deposits, which underlie most of the remaining flat-lying urban area. In the northern Santa Clara Valley for a M7.0 earthquake on the Hayward Fault and an assumed water-table depth of 1.5 m (the historically shallowest water level), liquefaction probabilities range from 0.1 to 0.2 along Coyote and Guadalupe Creeks, but are less than 0.05 elsewhere. For a M6.7 earthquake, probabilities are greater than 0.1 along Coyote Creek but decrease along Guadalupe Creek to less than 0.1. Areas with high probabilities in the Santa Clara Valley are underlain by latest Holocene alluvial fan levee deposits where liquefaction and lateral spreading occurred during large earthquakes in 1868 and 1906. The liquefaction scenario maps were created with ArcGIS ModelBuilder. Peak ground accelerations first were computed with the new Boore and Atkinson NGA attenuation relation (2008, Earthquake Spectra, 24:1, p. 99-138), using VS30 to account for local site response. Spatial liquefaction probabilities were then estimated using the predicted ground motions

  13. Fault zone controlled seafloor methane seepage in the rupture area of the 2010 Maule earthquake, Central Chile

    NASA Astrophysics Data System (ADS)

    Geersen, Jacob; Scholz, Florian; Linke, Peter; Schmidt, Mark; Lange, Dietrich; Behrmann, Jan H.; Völker, David; Hensen, Christian

    2016-11-01

    Seafloor seepage of hydrocarbon-bearing fluids has been identified in a number of marine fore arcs. However, temporal variations in seep activity and the structural and tectonic parameters that control the seepage often remain poorly constrained. Subduction zone earthquakes, for example, are often discussed to trigger seafloor seepage but causal links that go beyond theoretical considerations have not yet been fully established. This is mainly due to the inaccessibility of offshore epicentral areas, the infrequent occurrence of large earthquakes, and challenges associated with offshore monitoring of seepage over large areas and sufficient time periods. Here we report visual, geochemical, geophysical, and modeling results and observations from the Concepción Methane Seep Area (offshore Central Chile) located in the rupture area of the 2010 Mw. 8.8 Maule earthquake. High methane concentrations in the oceanic water column and a shallow subbottom depth of sulfate penetration indicate active methane seepage. The stable carbon isotope signature of the methane and hydrocarbon composition of the released gas indicate a mixture of shallow-sourced biogenic gas and a deeper sourced thermogenic component. Pristine fissures and fractures observed at the seafloor together with seismically imaged large faults in the marine fore arc may represent effective pathways for methane migration. Upper plate fault activity with hydraulic fracturing and dilation is in line with increased normal Coulomb stress during large plate-boundary earthquakes, as exemplarily modeled for the 2010 earthquake. On a global perspective our results point out the possible role of recurring large subduction zone earthquakes in driving hydrocarbon seepage from marine fore arcs over long timescales.

  14. Long-period ocean-bottom motions in the source areas of large subduction earthquakes

    PubMed Central

    Nakamura, Takeshi; Takenaka, Hiroshi; Okamoto, Taro; Ohori, Michihiro; Tsuboi, Seiji

    2015-01-01

    Long-period ground motions in plain and basin areas on land can cause large-scale, severe damage to structures and buildings and have been widely investigated for disaster prevention and mitigation. However, such motions in ocean-bottom areas are poorly studied because of their relative insignificance in uninhabited areas and the lack of ocean-bottom strong-motion data. Here, we report on evidence for the development of long-period (10–20 s) motions using deep ocean-bottom data. The waveforms and spectrograms demonstrate prolonged and amplified motions that are inconsistent with attenuation patterns of ground motions on land. Simulated waveforms reproducing observed ocean-bottom data demonstrate substantial contributions of thick low-velocity sediment layers to development of these motions. This development, which could affect magnitude estimates and finite fault slip modelling because of its critical period ranges on their estimations, may be common in the source areas of subduction earthquakes where thick, low-velocity sediment layers are present. PMID:26617193

  15. Long-period ocean-bottom motions in the source areas of large subduction earthquakes.

    PubMed

    Nakamura, Takeshi; Takenaka, Hiroshi; Okamoto, Taro; Ohori, Michihiro; Tsuboi, Seiji

    2015-11-30

    Long-period ground motions in plain and basin areas on land can cause large-scale, severe damage to structures and buildings and have been widely investigated for disaster prevention and mitigation. However, such motions in ocean-bottom areas are poorly studied because of their relative insignificance in uninhabited areas and the lack of ocean-bottom strong-motion data. Here, we report on evidence for the development of long-period (10-20 s) motions using deep ocean-bottom data. The waveforms and spectrograms demonstrate prolonged and amplified motions that are inconsistent with attenuation patterns of ground motions on land. Simulated waveforms reproducing observed ocean-bottom data demonstrate substantial contributions of thick low-velocity sediment layers to development of these motions. This development, which could affect magnitude estimates and finite fault slip modelling because of its critical period ranges on their estimations, may be common in the source areas of subduction earthquakes where thick, low-velocity sediment layers are present.

  16. Long-period ocean-bottom motions in the source areas of large subduction earthquakes

    NASA Astrophysics Data System (ADS)

    Nakamura, Takeshi; Takenaka, Hiroshi; Okamoto, Taro; Ohori, Michihiro; Tsuboi, Seiji

    2015-11-01

    Long-period ground motions in plain and basin areas on land can cause large-scale, severe damage to structures and buildings and have been widely investigated for disaster prevention and mitigation. However, such motions in ocean-bottom areas are poorly studied because of their relative insignificance in uninhabited areas and the lack of ocean-bottom strong-motion data. Here, we report on evidence for the development of long-period (10-20 s) motions using deep ocean-bottom data. The waveforms and spectrograms demonstrate prolonged and amplified motions that are inconsistent with attenuation patterns of ground motions on land. Simulated waveforms reproducing observed ocean-bottom data demonstrate substantial contributions of thick low-velocity sediment layers to development of these motions. This development, which could affect magnitude estimates and finite fault slip modelling because of its critical period ranges on their estimations, may be common in the source areas of subduction earthquakes where thick, low-velocity sediment layers are present.

  17. Reconnaissance engineering geology of the Metlakatla area, Annette Island, Alaska, with emphasis on evaluation of earthquakes and other geologic hazards

    USGS Publications Warehouse

    Yehle, Lynn A.

    1977-01-01

    A program to study the engineering geology of most larger Alaska coastal communities and to evaluate their earthquake and other geologic hazards was started following the 1964 Alaska earthquake; this report about the Metlakatla area, Annette Island, is a product of that program. Field-study methods were of a reconnaissance nature, and thus the interpretations in the report are tentative. Landscape of the Metlakatla Peninsula, on which the city of Metlakatla is located, is characterized by a muskeg-covered terrane of very low relief. In contrast, most of the rest of Annette Island is composed of mountainous terrane with steep valleys and numerous lakes. During the Pleistocene Epoch the Metlakatla area was presumably covered by ice several times; glaciers smoothed the present Metlakatla Peninsula and deeply eroded valleys on the rest. of Annette Island. The last major deglaciation was completed probably before 10,000 years ago. Rebound of the earth's crust, believed to be related to glacial melting, has caused land emergence at Metlakatla of at least 50 ft (15 m) and probably more than 200 ft (61 m) relative to present sea level. Bedrock in the Metlakatla area is composed chiefly of hard metamorphic rocks: greenschist and greenstone with minor hornfels and schist. Strike and dip of beds are generally variable and minor offsets are common. Bedrock is of late Paleozoic to early Mesozoic age. Six types of surficial geologic materials of Quaternary age were recognized: firm diamicton, emerged shore, modern shore and delta, and alluvial deposits, very soft muskeg and other organic deposits, and firm to soft artificial fill. A combination map unit is composed of bedrock or diamicton. Geologic structure in southeastern Alaska is complex because, since at least early Paleozoic time, there have been several cycles of tectonic deformation that affected different parts of the region. Southeastern Alaska is transected by numerous faults and possible faults that attest to major

  18. Statistical analysis of seismicity rate change in the Tokyo Metropolitan area due to the 2011 Tohoku Earthquake

    NASA Astrophysics Data System (ADS)

    Ishibe, T.; Sakai, S.; Shimazaki, K.; Satake, K.; Tsuruoka, H.; Nakagawa, S.; Hirata, N.

    2012-12-01

    We examined a relationship between the Coulomb Failure Function (ΔCFF) due to the Tohoku earthquake (March 11, 2011; MJMA 9.0) and the seismicity rate change in Tokyo Metropolitan area following March 2011. Because of large variation in focal mechanism in the Kanto region, the receiver faults for the ΔCFF were assumed to be two nodal planes of small (M ≥ 2.0) earthquakes which occurred before and after the Tohoku earthquake. The seismicity rate changes, particularly the rate increase, are well explained by ΔCFF due to the gigantic thrusting, while some other possible factors (e.g., dynamic stress changes, excess of fluid dehydration) may also contribute the rate changes. Among 30,746 previous events provided by the National Research Institute for Earth Science and Disaster Prevention (M ≥ 2.0, July 1979 - July 2003), we used as receiver faults, almost 16,000 events indicate significant increase in ΔCFF, while about 8,000 events show significant decrease. Positive ΔCFF predicts seismicity rate increase in southwestern Ibaraki and northern Chiba prefectures where intermediate-depth earthquakes occur, and in shallow crust of the Izu-Oshima and Hakone regions. In these regions, seismicity rates significantly increased after the Tohoku earthquake. The seismicity has increased since March 2011 with respect to the Epidemic Type of Aftershock Sequence (ETAS) model (Ogata, 1988), indicating that the rate change was due to the stress increase by the Tohoku earthquake. The activated seismicity in the Izu and Hakone regions rapidly decayed following the Omori-Utsu formula, while the increased rate of seismicity in the southwestern Ibaraki and northern Chiba prefectures is still continuing. We also calculated ΔCFF due to the 2011 Tohoku earthquake for the focal mechanism solutions of earthquakes between April 2008 and October 2011 recorded on the Metropolitan Seismic Observation network (MeSO-net). The ΔCFF values for the earthquakes after March 2011 show more

  19. The large earthquake of 8 August 1303 in Crete: seismic scenario and tsunami in the Mediterranean area

    NASA Astrophysics Data System (ADS)

    Guidoboni, Emanuela; Comastri, Alberto

    By conducting a historical review of this large seismic event in the Mediterranean, it has been possible to identify both the epicentral area and the area in which its effects were principally felt. Ever since the nineteenth century, the seismological tradition has offered a variety of partial interpretations of the earthquake, depending on whether the main sources used were Arabic, Greek or Latin texts. Our systematic research has involved the analysis not only of Arab, Byzantine and Italian chronicle sources, but also and in particular of a large number of never previously used official and public authority documents, preserved in Venice in the State Archive, in the Marciana National Library and in the Library of the Museo Civico Correr. As a result, it has been possible to establish not only chronological parameters for the earthquake (they were previously uncertain) but also its overall effects (epicentral area in Crete, Imax XI MCS). Sources containing information in 41 affected localities and areas were identified. The earthquake also gave rise to a large tsunami, which scholars have seen as having certain interesting elements in common with that of 21 July 365, whose epicentre was also in Crete. As regards methodology, this research made it clear that knowledge of large historical earthquakes in the Mediterranean is dependent upon developing specialised research and going beyond the territorial limits of current national catalogues.

  20. Prominent reflector beneath around the segmentation boundary between Tonankai-Nankai earthquake area

    NASA Astrophysics Data System (ADS)

    Nakanishi, A.; Shimomura, N.; Fujie, G.; Kodaira, S.; Obana, K.; Takahashi, T.; Yamamoto, Y.; Yamashita, M.; Takahashi, N.; Kaneda, Y.; Mochizuki, K.; Kato, A.; Iidaka, T.; Kurashimo, E.; Shinohara, M.; Takeda, T.; Shiomi, K.

    2013-12-01

    In the Nankai Trough subduction seismogenic zone, the Nankai and Tonankai earthquakes had often occurred simultaneously, and caused a great event. In most cases, first break of such large events of Nankai Trough usually begins from southwest off the Kii Peninsula so far. The idea of split Philippine Sea plate between the Kii Peninsula and the Shikoku Island, which explains seismicity, tectonic background, receiver function image and historical plate motion, was previously suggested. Moreover, between the Kii Peninsula and the Shikoku Island, there is a gap of deep low-frequency events observed in the belt-like zone along the strike of the subducting Philippine Sea plate. In 2010 and 2011, we conducted the large-scale high-resolution wide-angle and reflection (MCS) seismic study, and long-term observation from off Shikoku and Kii Peninsula. Marine active source seismic data have been acquired along grid two-dimensional profiles having the total length of ~800km/year. A three-dimensional seismic tomography using active and passive seismic data observed both land and ocean bottom stations have been also performed. From those data, we found a possible prominent reflector imaged in the offshore side in the Kii channel at the depth of ~18km. The velocity just beneath the reflector cannot be determined due to the lack of ray paths. Based of the amplitude information, we interpret the reflector as the forearc Moho based on the velocity gap (from ~6.4km/s to ~7.4km/s). However, the reflector is shallower than the forearc Moho of other area along the Nankai Trough. Similar reflectors are recognized along other seismic profiles around the Kii channel. In this presentation, we will show the result of structure analysis to understand the peculiar structure including the prominent reflector around the Kii channel. Relation between the structure and the existence of the segmentation of the Nankai megathrust earthquake or seismic gap of the deep low-frequency events will be also

  1. Characteristics of Physician Outflow from Disaster Areas following the Great East Japan Earthquake

    PubMed Central

    Inoue, Kazuo; Matsumoto, Masatoshi

    2017-01-01

    Objective The shortage of physicians after a major disaster is a crucial issue. We aimed to evaluate the characteristics of physicians who left affected areas following the accident at Fukushima Daiichi Nuclear Power Plant caused by the Great East Japan Earthquake on March 11, 2011. Methods Using data from a physician census conducted in 2010 (pre-disaster) and 2012 (post-disaster), we evaluated changes in the number of physicians in affected areas. We then calculated the odds ratios and 95% confidence intervals using a logistic regression model to evaluate the association between physician characteristics and outflow. We also conducted stratified analyses based on physician characteristics. Results The number of physicians decreased in Fukushima Prefecture (–5.3%) and increased in Miyagi Prefecture (2.8%). The decrease in Fukushima and increase in Miyagi were evident even after taking the prefecture’s population change into account (change in physician to population ratios: –1.9% and 3.2%, respectively). Compared with physicians who lived in areas >100 km from the nuclear power plant, physicians living 20–50 km and 50–100 km were, respectively, 3.9 times (95% confidence interval, 2.6–5.7) and 2.6 times (95% confidence interval, 1.7–3.8) more likely to migrate to distant areas. In the stratified analysis, younger physicians and those earlier in their careers had higher odds ratios for outflow than other physicians (P for interaction = 0.02 and <0.01, respectively). Conclusions The risk of outflow was greater among younger and early-career physicians in areas around the power plant. Political support may be necessary to recruit and retain such physicians, who will be responsible for future community health in the disaster area. PMID:28046089

  2. Triggered surface slips in the Coachella Valley area associated with the 1992 Joshua Tree and Landers, California, Earthquakes

    USGS Publications Warehouse

    Rymer, M.J.

    2000-01-01

    The Coachella Valley area was strongly shaken by the 1992 Joshua Tree (23 April) and Landers (28 June) earthquakes, and both events caused triggered slip on active faults within the area. Triggered slip associated with the Joshua Tree earthquake was on a newly recognized fault, the East Wide Canyon fault, near the southwestern edge of the Little San Bernardino Mountains. Slip associated with the Landers earthquake formed along the San Andreas fault in the southeastern Coachella Valley. Surface fractures formed along the East Wide Canyon fault in association with the Joshua Tree earthquake. The fractures extended discontinuously over a 1.5-km stretch of the fault, near its southern end. Sense of slip was consistently right-oblique, west side down, similar to the long-term style of faulting. Measured offset values were small, with right-lateral and vertical components of slip ranging from 1 to 6 mm and 1 to 4 mm, respectively. This is the first documented historic slip on the East Wide Canyon fault, which was first mapped only months before the Joshua Tree earthquake. Surface slip associated with the Joshua Tree earthquake most likely developed as triggered slip given its 5 km distance from the Joshua Tree epicenter and aftershocks. As revealed in a trench investigation, slip formed in an area with only a thin (<3 m thick) veneer of alluvium in contrast to earlier documented triggered slip events in this region, all in the deep basins of the Salton Trough. A paleoseismic trench study in an area of 1992 surface slip revealed evidence of two and possibly three surface faulting events on the East Wide Canyon fault during the late Quaternary, probably latest Pleistocene (first event) and mid- to late Holocene (second two events). About two months after the Joshua Tree earthquake, the Landers earthquake then triggered slip on many faults, including the San Andreas fault in the southeastern Coachella Valley. Surface fractures associated with this event formed discontinuous

  3. Bam and Bgcn in Drosophila germline stem cell differentiation.

    PubMed

    Perinthottathil, Sreejith; Kim, Changsoo

    2011-01-01

    The female Drosophila reproductive organ, the ovary, has provided researchers with an incisive genetic system with which principle regulation of stem cell maintenance and differentiation has been delineated. An environmental niche regulates a stem cell's asymmetric self-renewal division that produces a daughter stem cell and a differentiated daughter cell, which further differentiate into eggs. A number of extrinsic and intrinsic factors have been identified that are required either for stem cell maintenance or differentiation. Bam/Bgcn complex plays a pivotal role in promoting stem cell differentiation. Recent papers suggest that Bam/Bgcn complex regulates translation of important maintenance factors and is also involved in the regulation of microRNA-dependent translational repression. Here, we focus on Bam and Bgcn repression of stem cell maintenance factors in the differentiation of germline stem cells (GSCs).

  4. Attenuation tomography in the rupture area of the 2010 M8.8 Maule, Chile, earthquake

    NASA Astrophysics Data System (ADS)

    Heather-Smith, Helen; Rietbrock, Andreas

    2016-04-01

    In recent years several seismological studies have developed a detailed image of the megathrust interface between the subducting Nazca plate and and the overriding South American plate in the rupture area of the 2010 M8.8 Maule, Chile, earthquake. Hicks et al. (2014) have published a high resolution 3D seismic tomography model and characterised the different regimes acting along the interface based on their seismic properties. A more detailed study by Moreno et al. (2014) showed that the seismic Vp/Vs ratio and inter-seismic locking determined from GPS measurements are correlated. Together these observations open up the possibility to map the rupture potential of possible future earthquakes, although the underlying processes are yet not fully understood and a more in depth analysis of other physical properties is needed. 3D seismic attenuation structure as well as seismic stress-drop distribution based on the aftershock seismicity are providing independent data sets to better constrain the physical processes acting along the subduction zone interface. As seismic attenuation is particularly sensitive to fluid saturation it opens up the possibility to study more directly the influence of fluids on aftershock activity as compared to standard velocity tomography studies. Based on our event catalogue of approximately 30,000 aftershocks we are currently selecting the most appropriate data set for the staggered 3D attenuation tomography. The inverted attenuation model will then be used to calculate seismic stress drop values for the complete aftershock catalogue. We will present our preliminary 3D attenuation model together with our stress drop estimates and compare our finding to the 3D velocity structure and slip distribution.

  5. Relocation of two earthquakes in the Southwest Indian Ridge area combining land seismic stations' with OBSs' data

    NASA Astrophysics Data System (ADS)

    Luo, Wei; Zhao, Minghui; Zhang, Jiazheng; Tao, Chunhui; Qiu, Xuelin; Ren, Yu

    2016-12-01

    Two earthquakes were recorded by 20 ocean bottom seismometers (OBS) deployed in the Southwest Indian Ridge (SWIR) area during a three-dimensional seismic survey in 2010. Their magnitudes (both M b = 4.4) and hypocenters have been determined by National Earthquake Information Center (NEIC) only using land seismic stations onset times. After the frequency analysis and the band-pass filtering of the OBSs' data, 7 and 13 P-phase onset times from OBSs were successfully picked for these two events, respectively. Then these two events were relocated by HYPOSAT program with onset times together from OBSs and land seismic stations using different velocity models. These relocation experiments confirm both the importance of adding OBSs' onset data and the need to apply a local oceanic velocity model for the location of these two events happened on the SWIR. This research has accumulated a wealth of experience for earthquakes observation and research using OBSs in the ocean.

  6. [Carbon source metabolic diversity of soil microbial community under different climate types in the area affected by Wenchuan earthquake].

    PubMed

    Zhang, Guang-Shuai; Lin, Yong-Ming; Ma, Rui-Feng; Deng, Hao-Jun; Du, Kun; Wu, Cheng-Zhen; Hong, Wei

    2015-02-01

    The MS8.0 Wenchuan earthquake in 2008 led to huge damage to land covers in northwest Sichuan, one of the critical fragile eco-regions in China which can be divided into Semi-arid dry hot climate zone (SDHC) and Subtropical humid monsoon climate zone (SHMC). Using the method of Bilog-ECO-microplate technique, this paper aimed to determine the functional diversity of soil microbial community in the earthquake-affected areas which can be divided into undamaged area (U), recover area (R) and damaged area without recovery (D) under different climate types, in order to provide scientific basis for ecological recovery. The results indicated that the average-well-color-development (AWCD) in undamaged area and recovery area showed SDHC > SHMC, which was contrary to the AWCD in the damaged area without recovery. The AWCD of damaged area without recovery was the lowest in both climate zones. The number of carbon source utilization types of soil microbial in SHMC zone was significantly higher than that in SDHC zone. The carbon source utilization types in both climate zones presented a trend of recover area > undamaged area > damaged area without recovery. The carbon source metabolic diversity characteristic of soil microbial community was significantly different in different climate zones. The diversity index and evenness index both showed a ranking of undamaged area > recover area > damaged area without recovery. In addition, the recovery area had the highest richness index. The soil microbial carbon sources metabolism characteristic was affected by soil nutrient, aboveground vegetation biomass and vegetation coverage to some extent. In conclusion, earthquake and its secondary disasters influenced the carbon source metabolic diversity characteristic of soil microbial community mainly through the change of aboveground vegetation and soil environmental factors.

  7. Monitoring of Ecological Restoration at the Central Quake-Hit Areas of Wenchuan Earthquake Using RS & GIS Remote Sensing

    NASA Astrophysics Data System (ADS)

    Zhang, Q.

    2014-12-01

    The 2008 Sichuan earthquake, occurred on 12 May 2008 with a magnitude of 8.0 and the center at Wenchuan (31.021°N, 103.367°E), has not only caused a large number of human casualties and property loss, but also severely damaged the ecological system in its surrounding 10 counties, threatening the local ecological safety. As part of the post-disaster reconstruction services, a systematic monitoring of the ecological restoration at the central quake-hit areas has been made based on RS & GIS remote sensing. In this paper we selected the Dujiangyan area for analysis. The reason to select this region is because that Dujiangyan area is about 40 km from the epicenter, and as a region in the subtropical monsoon climate zone, it has a well developed forest ecosystem in the northern part before the earth quake. The coverage of grassland in this region is relatively less. Since the ecological restoration after the earthquake is a long term process, the restoration for different vegetation types has different characteristics. From the analysis of the spatiotemporal change of land-use and vegetation cover in Dujiangyan area from the post-earthquake in 2008 to 2013, we found: (1) During the earthquake, the major vegetation type destroyed is the woodland, which accounts for 99.34% of the destroyed area, and the next are arable land and grassland. (2) The ecological restoration started from the grassland and gradually transited to shrub. In two years after the earthquake, the most significant increase in both area of coverage and magnitude is the grassland, and by 2013, the area of grassland decreased slightly, and instead the area of shrub increased, demonstrating a transition trend from the grassland to the shrub. (3) From the map of vegetation cover, we can see these change occurs mainly in the northern mountain area, while the change of land use mainly occurred in the southern part of the city. These changes can be linked clearly with the earthquake disaster and the post

  8. The tsunami source area of the 2003 Tokachi-oki earthquake estimated from tsunami travel times and its relationship to the 1952 Tokachi-oki earthquake

    USGS Publications Warehouse

    Hirata, K.; Tanioka, Y.; Satake, K.; Yamaki, S.; Geist, E.L.

    2004-01-01

    We estimate the tsunami source area of the 2003 Tokachi-oki earthquake (Mw 8.0) from observed tsunami travel times at 17 Japanese tide gauge stations. The estimated tsunami source area (???1.4 ?? 104 km2) coincides with the western-half of the ocean-bottom deformation area (???2.52 ?? 104 km2) of the 1952 Tokachi-oki earthquake (Mw 8.1), previously inferred from tsunami waveform inversion. This suggests that the 2003 event ruptured only the western-half of the 1952 rupture extent. Geographical distribution of the maximum tsunami heights in 2003 differs significantly from that of the 1952 tsunami, supporting this hypothesis. Analysis of first-peak tsunami travel times indicates that a major uplift of the ocean-bottom occurred approximately 30 km to the NNW of the mainshock epicenter, just above a major asperity inferred from seismic waveform inversion. Copyright ?? The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS); The Seismological Society of Japan; The Volcanological Society of Japan; The Geodetic Society of Japan; The Japanese Society for Planetary Sciences.

  9. Probabilistic Rockfall Hazard Analysis in the area affect by the Christchurch Earthquakes, New Zealand

    NASA Astrophysics Data System (ADS)

    Frattini, P.; Lari, S.; Agliardi, F.; Crosta, G. B.; Salzmann, H.

    2012-04-01

    To limit damages to human lives and property in case of natural disasters, land planning and zonation, as well as the design of countermeasures, are fundamental tools, requiring however a rigorous quantitative risk analysis. As a consequence of the 3rd September 2010 (Mw 7.1) Darfield Earthquake, and the 22nd February (Mw 6.2), the 16th April 2011 (Mw 5.3) and the 13th June, 2011 (Mw 6.2) aftershock events, about 6000 rockfalls were triggered in the Port Hills of Christchurch, New Zealand. Five people were killed by falling rocks in the area, and several hundred homes were damaged or evacuated. In this work, we present a probabilistic rockfall hazard analysis for a small area located in the south-eastern slope of Richmond Hill (0.6 km2, Sumner, Christchurch, NZ). For the analysis, we adopted a new methodology (Probabilistic Rockfall Hazard Analysis, PRHA), which allows to quantify the exceedance probability for a given slope location of being affected by a rockfall event with a specific level of kinetic energy, integrating the contribution of different rockfall magnitude (volume) scenarios. The methodology requires the calculation of onset annual frequency, rockfall runout, and spatially-varying kinetic energy. Onset annual frequencies for different magnitude scenarios were derived from frequency-magnitude relationship adapted from the literature. The probability distribution of kinetic energy for a given slope location and volume scenario was obtained by rockfall runout modeling of non-interacting blocks through the 3D Hy-Stone simulation code. The reference simulation was calibrated by back-analysis of rockfall events occurred during the earthquake. For each rockfall magnitude scenario, 20 rockfall trajectories have been simulated for each source cell using stochastically variable values of restitution parameters. Finally, probabilistic analysis integrating over six rockfall magnitude scenarios (ranging from 0.001 m3 to 1000 m3) was carried out to produce

  10. Effects of the earthquake of March 27, 1964 in the Copper River Basin area, Alaska: Chapter E in The Alaska earthquake, March 27, 1964: regional effects

    USGS Publications Warehouse

    Ferrians, Oscar J.

    1966-01-01

    The Copper River Basin area is in south-central Alaska and covers 17,800 square miles. It includes most of the Copper River Basin and parts of the surrounding Alaska Range and the Talkeetna, Chugach, and Wrangell Mountains. On March 27, 1964, shortly after 5:36 p.m. Alaska standard time, a great earthquake having a Richter magnitude of about 8.5 struck south-central Alaska. Computations by the U.S. Coast and Geodetic Survey place the epicenter of the main shock at lat 61.1° N. and long 147.7° W., and the hypocenter, or actual point of origin, from 20 to 50 kilometers below the surface. The epicenter is near the western shore of Unakwik Inlet in northern Prince William Sound; it is 30 miles from the closest point within the area of study and 180 miles from the farthest point. Releveling data obtained in 1964 after the earthquake indicates that broad areas of south-central Alaska were warped by uplift and subsidence. The configuration of these areas generally parallels the trend of the major tectonic elements of the region. Presumably a large part of this change took place during and immediately after the 1964 earthquake. The water level in several wells in the area lowered appreciably, and the water in many became turbid; generally, however, within a few days after the earthquake the water level returned to normal and the suspended sediment settled out. Newspaper reports that the Copper River was completely dammed and Tazlina Lake drained proved erroneous. The ice on most lakes was cracked, especially around the margins of the lakes where floating ice broke free from the ice frozen to the shore. Ice on Tazlina, Klutina, and Tonsina Lakes was intensely fractured by waves generated by sublacustrine landslides off the fronts of deltas. These waves stranded large blocks of ice above water level along the shores. River ice was generally cracked in the southern half of the area and was locally cracked in the northern half. In the area of study, the majority of the

  11. FCaZm intelligent recognition system for locating areas prone to strong earthquakes in the Andean and Caucasian mountain belts

    NASA Astrophysics Data System (ADS)

    Gvishiani, A. D.; Dzeboev, B. A.; Agayan, S. M.

    2016-07-01

    The fuzzy clustering and zoning method (FCAZm) of systems analysis is suggested for recognizing the areas of the probable generation of the epicenters of significant, strong, and the strongest earthquakes. FCAZm is a modified version of the previous FCAZ algorithmic system, which is advanced by the creation of the blocks of artificial intelligence that develop the system-forming algorithms. FCAZm has been applied for recognizing areas where the epicenters of the strongest ( M ≥ 73/4) earthquakes within the Andes mountain belt in the South America and significant earthquakes ( M ≥ 5) in the Caucasus can emerge. The reliability of the obtained results was assessed by the seismic-history type control experiments. The recognized highly seismic zones were compared with the ones previously recognized by the EPA method and by the initial version of the FCAZ system. The modified FCAZm system enabled us to pass from simple pattern recognition in the problem of recognizing the locations of the probable emergence of strong earthquakes to systems analysis. In particular, using FCAZm we managed to uniquely recognize a subsystem of highly seismically active zones from the nonempty complement using the exact boundary.

  12. Relationship between isoseismal area and magnitude of historical earthquakes in Greece by a hybrid fuzzy neural network method

    NASA Astrophysics Data System (ADS)

    Tselentis, G.-A.; Sokos, E.

    2012-01-01

    In this paper we suggest the use of diffusion-neural-networks, (neural networks with intrinsic fuzzy logic abilities) to assess the relationship between isoseismal area and earthquake magnitude for the region of Greece. It is of particular importance to study historical earthquakes for which we often have macroseismic information in the form of isoseisms but it is statistically incomplete to assess magnitudes from an isoseismal area or to train conventional artificial neural networks for magnitude estimation. Fuzzy relationships are developed and used to train a feed forward neural network with a back propagation algorithm to obtain the final relationships. Seismic intensity data from 24 earthquakes in Greece have been used. Special attention is being paid to the incompleteness and contradictory patterns in scanty historical earthquake records. The results show that the proposed processing model is very effective, better than applying classical artificial neural networks since the magnitude macroseismic intensity target function has a strong nonlinearity and in most cases the macroseismic datasets are very small.

  13. Structural Aspects of the Iquique Area With Possible Influence on the Mw 8.2, 2014, Pisagua Earthquake

    NASA Astrophysics Data System (ADS)

    Sobiesiak, M.; Schaller, T.; Meneses, G.; Goetze, H. J.; Satriano, C.; Poiata, N.; Ruiz, S.; Comte, D.; Bernard, P.; Vilotte, J. P.; Métois, M.; Olcay, M.; Tassera, C.; Campos, J. A.

    2014-12-01

    The Mw 8.2, 2014, Pisagua earthquake in Northern Chile did not come as a complete surprise as it was anticipated that in the "near future" a large earthquake could happen in the North Chile seismic gap. Whether the gap would rupture in a single M~9 event or in several M 7-8 events has been subject of debate. Now it is clear that the Pisagua earthquake ruptured the shallower part of one segment of the North Chilean seismogenic subduction interface and leaves the questions why the new rupture started here and what could be a future scenario for the failure of the seismic gaps' residuals. To identify seismogenic structures which define areas where large events might nucleate, asperities develop or segment boundaries form, we need large catalogues of accurately located seismic events in all magnitude ranges. Therefore, we apply a new method to automatically detect and locate seismic events based on the backprojection algorithm and multi-band kurtosis signal representation (see also abstracts Satriano et al. and Poiata et al.) using the data basis of the Iquique Local Network and the Integrated Plate Boundary Observatory in North Chile. Precise earthquake locations, seismicity rate changes and spatial b-value distributions can then refer to material boundaries, and distinguish between locked and creeping sections, which lead to the sites where actual deformation also on small scales is taking place.While seismicity distribution and its temporal changes help to identify the outlines of seismogenic structures, congruent gravity isostatic residual anomalies and modeled density distributions tell us something about the physical nature of earthquake nucleation zones and asperities. We present new results from density modeling on narrow profiles over the entire Pisagua earthquake rupture plane revealing dense bodies which we suggest have influenced the start of the main shock rupture as well as its propagation by linking spatial background and aftershock distributions.

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

    NASA Astrophysics Data System (ADS)

    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

  15. Ionospheric anomalies possibly associated with M > 6.0 earthquakes in the Japan area during 1998-2010 and the 2011 Off the Pacific Coast of Tohoku Earthquake (Mw9.0)

    NASA Astrophysics Data System (ADS)

    Ichikawa, T.; Hattori, K.; Kon, S.; Hirooka, S.; Liu, J. G.

    2011-12-01

    In this paper, we examine pre-earthquake ionospheric anomalies in time series and perform a statistical test by using total electron content (TEC) derived from global ionosphere maps (GIM) around the Japan area for the first time. The normalized GIM-TEC (GIM-TEC*), which is computed based on 15 days backward running mean of GIM-TEC, have been investigated for minimizing possible confounding effects of consecutive earthquakes and identify the abnormal signals. Meanwhile, to reduce the effect of strong geomagnetic activities such as geomagnetic storms, the criterion for removing the GIM-TEC data have been adapted; that is when Dst index exceeds -60 nT. Temporal variations of GIM-TEC* for large and destructive earthquakes in Japan have been studied; which are the 2004 mid-Niigata Prefecture Earthquake (M6.8), its aftershock (M6.1), the 2007 offshore mid-Niigata Earthquake (M6.8), and the 2008 Iwate-Miyagi Nairiku Earthquake (M7.2). Although there are some positive and negative TEC anomalies before and after the four earthquakes, there is a tendency that positive TEC anomalies appear 1-5 days before all the above earthquakes even during the quiet geomagnetic condition. Superposed epoch analyses have been performed for the statistical analysis of TEC anomalies associated with M>6.0 earthquakes during the 12-year period of May 1998-May 2010. The statistical result indicates the significance of the positive TEC anomalies 1-5 days before earthquakes within 1000 km from the epicenter around Japan. The results of the 20110311 Tohoku Earthquake (M9.0) (GPS-TEC, GIM-TEC, and TEC Tomography) will be presented.

  16. Backscatter Mossbauer Spectrometer (BaMS) for extraterrestrial applications

    NASA Astrophysics Data System (ADS)

    Agresti, D. G.; Shelfer, T. D.; Pimperl, M. M.; Wills, E. L.; Shen, M. H.; Morris, R. V.

    1993-06-01

    Mossbauer spectroscopy is a nuclear gamma resonance technique particularly well suited to the study of materials that contain iron (Fe-57). It can provide information on the oxidation state of iron as well as the type and proportion of iron-containing mineral species in a sample of interest. Iron Mossbauer spectroscopy (FeMS) has been applied to samples believed to have come from Mars (SNC meteorites) and has been helpful in refining the choice among putative Martian surface materials by suggesting a likely nanophase component of the Martian regolity. FeMS spectrum of a Martial analogue material (Hawaiian palagonite) is shown; it is dominated by ferric-bearing phases and shows evidence of a nanophase component. FeMS has also been applied to lunar materials. It can be used to measure the maturity of lunar surface material and has been proposed as a prospector for lunar ilmenite, an oxygen resource mineral. Several years ago we suggested a backscatter Mossbauer spectrometer (BaMS) for a Mars rover mission. Backscatter design was selected as most appropriate for in-situ application because no sample preparation is required. Since that time, we have continued to develop the BaMS instrument in anticipation that it would eventually find a home on a NASA planetary mission. Gooding proposed BaMS as a geochemistry instrument on MESUR. More recently, an LPI workshop has recommended that BaMS be included in a three-instrument payload on the next (1996?) lunar lander.

  17. Backscatter Mossbauer Spectrometer (BaMS) for extraterrestrial applications

    NASA Technical Reports Server (NTRS)

    Agresti, D. G.; Shelfer, T. D.; Pimperl, M. M.; Wills, E. L.; Shen, M. H.; Morris, R. V.

    1993-01-01

    Mossbauer spectroscopy is a nuclear gamma resonance technique particularly well suited to the study of materials that contain iron (Fe-57). It can provide information on the oxidation state of iron as well as the type and proportion of iron-containing mineral species in a sample of interest. Iron Mossbauer spectroscopy (FeMS) has been applied to samples believed to have come from Mars (SNC meteorites) and has been helpful in refining the choice among putative Martian surface materials by suggesting a likely nanophase component of the Martian regolity. FeMS spectrum of a Martial analogue material (Hawaiian palagonite) is shown; it is dominated by ferric-bearing phases and shows evidence of a nanophase component. FeMS has also been applied to lunar materials. It can be used to measure the maturity of lunar surface material and has been proposed as a prospector for lunar ilmenite, an oxygen resource mineral. Several years ago we suggested a backscatter Mossbauer spectrometer (BaMS) for a Mars rover mission. Backscatter design was selected as most appropriate for in-situ application because no sample preparation is required. Since that time, we have continued to develop the BaMS instrument in anticipation that it would eventually find a home on a NASA planetary mission. Gooding proposed BaMS as a geochemistry instrument on MESUR. More recently, an LPI workshop has recommended that BaMS be included in a three-instrument payload on the next (1996?) lunar lander.

  18. Deep Earthquakes.

    ERIC Educational Resources Information Center

    Frohlich, Cliff

    1989-01-01

    Summarizes research to find the nature of deep earthquakes occurring hundreds of kilometers down in the earth's mantle. Describes further research problems in this area. Presents several illustrations and four references. (YP)

  19. Site responses based on ambient vibrations and earthquake data: a case study from the meizoseismal area of the 2001 Bhuj earthquake

    NASA Astrophysics Data System (ADS)

    Natarajan, Thulasiraman; Rajendran, Kusala

    2016-08-01

    The 2001 Mw 7.6 earthquake sourced in the Kachchh rift of northwest India led to extensive damage in the city of Bhuj, located ~70 km southwest of its epicenter. The building stock of this densely populated city was a mix of modern, single, and multistoried structures as well as traditional and non-engineered abodes, most of which were not designed to withstand severe shaking effects. Although there was extensive liquefaction and ground failure in the meizoseismal area, they were not observed in Bhuj, but the damage was severe here. In this study, we apply horizontal to vertical spectral ratio method to ambient vibrations (HVSR-AV) to obtain fundamental resonance frequency (f0) and H/V peak amplitude (A0) to examine if site response had any significant role in the observed damage. The patterns of H/V curves as well as spatial distributions of f0 (0.6-1.4 Hz) and A0 (1.5-4.4) suggest absence of any strong impedance contrast within the subsurface. Similar results obtained for ambient vibrations and earthquake signals suggest the efficacy of the HVSR-AV method as most useful for regions of low-level seismicity. The weathered sandstone that is generally exposed in the city represents the resonating layer whose thickness is approximately estimated as ~66-155 m, based on 1D assumption. The current set of available data precludes any quantitative modeling, but our preliminary inference is that site effects were not significant during the 2001 earthquake damage observed in Bhuj.

  20. Modeling of strong ground motion during the 1992 Cairo earthquake in the urban area northern Greater of Cairo, Egypt

    NASA Astrophysics Data System (ADS)

    Omar, Khaled; Attia, Mohsen; Fergany, El Sayed; Hassoup, Awad; Elkhashab, Hussein

    2013-06-01

    The 1992 Cairo earthquake originated from Dahshour seismic zone at an epicentral distance of about 25 km southwest of Cairo. Regardless of its relatively moderate magnitude (Mb = 5.8), it caused extensive property damage besides injuries and loss of lives. The significant damage of this earthquake was probably associated with amplification of seismic waves due to local site effects. Liquefaction was observed at many sites near the epicenter. There are no records of strong ground motion at the damaged area during this earthquake. The main shock was recorded only by the local Kattamya station (KEG) constructed in limestone rock site at about 46-48 km east of Cairo. In the present work, the strong ground motion during 1992 Cairo earthquake was analyzed and the possible causes of damage and structural failure were discussed. The study area is located at the southern part of Cairo city, holding heavy population and many public structures and strategic buildings. The ground motion parameters in terms of peak ground acceleration (PGA), peak ground velocity (PGV), and pseudo-spectral acceleration (PSA) were estimated for each site in the study area and in the KEG site. The site-dependent spectral models together with the stochastic technique were applied for this purpose, using the Fourier amplitude spectrum (FAS) source scaling, attenuation model, and the site amplification functions. The peak ground acceleration of the studied area, comprising 89 sites in northern great of Cairo (Qalyoub city) was calculated. The calculated peak ground acceleration values indicate the sites of high values of peak ground acceleration which are also characterized by high ground motion amplification factors. The ground motion, which is presented in this study, is highly amplified by the soil layer covering the area. Otherwise, the surface layer must be totally removed before construction of the buildings to avoid its large amplification to the ground motion.

  1. Workshop on evaluation of earthquake hazards and risk in the Puget Sound and Portland areas

    SciTech Connect

    Hays, W.W.; Kitzmiller, C.

    1988-01-01

    Three tasks were undertaken in the forum provided by the workshop: (1) assessing the present state-of-knowledge of earthquake hazards in Washington and Oregon including scientific, engineering, and hazard-reduction components; (2) determining the need for additional scientific, engineering, and societal response information to implement an effective earthquake-hazard reduction program; and (3) developing a strategy for implementing programs to reduce potential earthquake losses and to foster preparedness and mitigation. Thirty-five papers were given at the workshop and each of these has been abstracted for the U.S. Department of Energy's Energy Data Base (EDB). In addition, the volume includes a glossary of technical terms used in earthquake engineering in Appendix A.

  2. The 2014 M 6.0 South Napa Earthquake in the Context of the Earthquake Cycle in the San Francisco Bay Area

    NASA Astrophysics Data System (ADS)

    Jaume, S. C.

    2014-12-01

    The 2014 M 6.0 South Napa earthquake is the second M ≥ 5.5 earthquake to occur in the San Francisco Bay region since the 1989 M 7.0 Loma Prieta earthquake. This poster will examine how this earthquake fits into the earthquake history of the Bay region, which has shown considerable variation in the rate of moderate (M 5.5-6.5) earthquakes. A number of models have been developed to explain these changes in moderate earthquake rates, including the Accelerating Moment Release model (e.g., Sykes and Jaumé, Nature, 1990; Bufe and Varnes, J. Geophys. Res., 1993) and the Stress Shadow model (e.g., Harris and Simpson, J. Geophys. Res., 1998). In addition, various groups have made projections of future earthquake activity in the San Francisco Bay region, including the Working Group on California Earthquake Probabilities (Field et al., USGS OFR, 2008) and Bebbington et al. (PAGEOPH, 2010), utilizing different physical models for earthquake occurrence. In my poster I will compare and contrast these different views of seismicity in the Bay region and where the 2014 South Napa earthquake fits into them. In particular, I will explore what these different models imply for future moderate earthquake occurrence and hazards thereof.

  3. Real-time earthquake alert system for the greater San Francisco Bay Area: a prototype design to address operational issues

    SciTech Connect

    Harben, P.E.; Jarpe, S.; Hunter, S.

    1996-12-10

    The purpose of the earthquake alert system (EAS) is to outrun the seismic energy released in a large earthquake using a geographically distributed network of strong motion sensors that telemeter data to a rapid CPU-processing station, which then issues an area-wide warning to a region before strong motion will occur. The warning times involved are short, from 0 to 30 seconds or so; consequently, most responses must be automated. The San Francisco Bay Area is particularly well suited for an EAS because (1) large earthquakes have relatively shallow hypocenters (10- to 20-kilometer depth), giving favorable ray-path geometries for larger warning times than deeper from earthquakes, and (2) the active faults are few in number and well characterized, which means far fewer geographically distributed strong motion sensors are (about 50 in this region). An EAS prototype is being implemented in the San Francisco Bay Area. The system consists of four distinct subsystems: (1) a distributed strong motion seismic network, (2) a central processing station, (3) a warning communications system and (4) user receiver and response systems. We have designed a simple, reliable, and inexpensive strong motion monitoring station that consists of a three-component Analog Devices ADXLO5 accelerometer sensing unit, a vertical component weak motion sensor for system testing, a 16-bit digitizer with multiplexing, and communication output ports for RS232 modem or radio telemetry. The unit is battery-powered and will be sited in fire stations. The prototype central computer analysis system consists of a PC dam-acquisition platform that pipes the incoming strong motion data via Ethernet to Unix-based workstations for dam processing. Simple real-time algorithms, particularly for magnitude estimation, are implemented to give estimates of the time since the earthquake`s onset its hypocenter location, its magnitude, and the reliability of the estimate. These parameters are calculated and transmitted

  4. Seismic moment tensors and regional stress in the area of the December 2013-January 2014, Matese earthquake sequence (Italy)

    NASA Astrophysics Data System (ADS)

    D'Amico, Sebastiano; Cammarata, Laura; Cangemi, Marianna; Cavallaro, Danilo; Di Martino, Roberto Maria; Firetto Carlino, Marco

    2014-12-01

    The main goal of this study is to provide moment tensor solutions for small and moderate earthquakes of the Matese seismic sequence in southern Italy for the period of December 2013-January 2014. We estimate the focal mechanisms of 31 earthquakes with local magnitudes related to the Matese earthquake seismic sequence (December 2013-January 2014) in Southern-Central Italy which are recorded by the broadband stations of the Italian National Seismic Network and the Mediterranean Very Broadband Seismographic Network (MedNet) run by the Istituto Nazionale di Geofisica e Vulcanologia (INGV). The solutions show that normal faulting is the prevailing style of seismic deformation in agreement with the local faults mapped out in the area. Comparisons with already published solutions and with seismological and geological information available allowed us to properly interpret the moment tensor solutions in the frame of the seismic sequence evolution and also to furnish additional information about less energetic seismic phases. Focal data were inverted to obtain the seismogenic stress in the study area. The results are compatible with the major tectonic domain of the area.

  5. Environmentally Friendly Solution to Ground Hazards in Design of Bridges in Earthquake Prone Areas Using Timber Piles

    NASA Astrophysics Data System (ADS)

    Sadeghi, H.

    2015-12-01

    Bridges are major elements of infrastructure in all societies. Their safety and continued serviceability guaranties the transportation and emergency access in urban and rural areas. However, these important structures are subject to earthquake induced damages in structure and foundations. The basic approach to the proper support of foundations are a) distribution of imposed loads to foundation in a way they can resist those loads without excessive settlement and failure; b) modification of foundation ground with various available methods; and c) combination of "a" and "b". The engineers has to face the task of designing the foundations meeting all safely and serviceability criteria but sometimes when there are numerous environmental and financial constrains, the use of some traditional methods become inevitable. This paper explains the application of timber piles to improve ground resistance to liquefaction and to secure the abutments of short to medium length bridges in an earthquake/liquefaction prone area in Bohol Island, Philippines. The limitations of using the common ground improvement methods (i.e., injection, dynamic compaction) because of either environmental or financial concerns along with the abundance of timber in the area made the engineers to use a network of timber piles behind the backwalls of the bridge abutments. The suggested timber pile network is simulated by numerical methods and its safety is examined. The results show that the compaction caused by driving of the piles and bearing capacity provided by timbers reduce the settlement and lateral movements due to service and earthquake induced loads.

  6. Recent Fault Activity in the 1886 Charleston, South Carolina Earthquake Epicentral Area and its Relation to Buried Structures

    NASA Astrophysics Data System (ADS)

    Pratt, T. L.; Shah, A. K.; Horton, J. W., Jr.; Chapman, M. C.; Beale, J.

    2014-12-01

    The 1886 Charleston, SC earthquake (M6.8-7.3) is the largest recorded earthquake to strike the U.S. east of the Appalachian Mountains. It occurred along the U.S. passive margin within an area of extensive Mesozoic rifting and beneath the ~800-m thick, subhorizontal Atlantic Coastal Plain (ACP) strata. The fault(s) that caused the 1886 earthquake remain the subject of debate. We examine reprocessed seismic reflection data in the epicentral area to discern faults cutting the Cretaceous and Cenozoic ACP strata, and relate them to deeper structures revealed by the seismic profiles and filtered aeromagnetic data. Faults are identified on the seismic profiles by sharp vertical displacements of strata, abrupt but small changes in dip, and folding of the ACP strata. Some of these faults dip steeply and locally displace deeper reflectors within the underlying South Georgia rift basin with minor displacement; in places they bound uplifted blocks of ACP strata. These observations and the lack of surface scarps during the 1886 earthquake suggest a component of strike-slip for the Cretaceous and Cenozoic displacements, whereas some modern focal mechanisms show thrust motion. A prominent magnetic anomaly high shows a NE-trending west edge in the epicentral area, and short-wavelength magnetic anomalies show disruptions aligned along NE trends. These latter disruptions appear to be related to the seismically imaged faults that offset ACP strata. One of the faults, previously interpreted by Chapman and Beale (2010), shows folding and perhaps faulting of ACP strata with ~50 m vertical displacement and is aligned along the NW edge of the magnetic high. The vertical uplift is nearly equal through the ACP section with little or no upward decrease across the fault, indicating the motion is primarily Cenozoic. The fault lies near Summerville about 35 km NW of Charleston, where 1886 ground deformation was focused. Another NE-trending fault, crossing beneath the Ashley River ~15 km NW of

  7. Earthquake Risk Management of Underground Lifelines in the Urban Area of Catania

    SciTech Connect

    Grasso, S.; Maugeri, M.

    2008-07-08

    Lifelines typically include the following five utility networks: potable water, sewage natural gas, electric power, telecommunication and transportation system. The response of lifeline systems, like gas and water networks, during a strong earthquake, can be conveniently evaluated with the estimated average number of ruptures per km of pipe. These ruptures may be caused either by fault ruptures crossing, or by permanent deformations of the soil mass (landslides, liquefaction), or by transient soil deformations caused by seismic wave propagation. The possible consequences of damaging earthquakes on transportation systems may be the reduction or the interruption of traffic flow, as well as the impact on the emergency response and on the recovery assistance. A critical element in the emergency management is the closure of roads due to fallen obstacles and debris of collapsed buildings.The earthquake-induced damage to buried pipes is expressed in terms of repair rate (RR), defined as the number of repairs divided by the pipe length (km) exposed to a particular level of seismic demand; this number is a function of the pipe material (and joint type), of the pipe diameter and of the ground shaking level, measured in terms of peak horizontal ground velocity (PGV) or permanent ground displacement (PGD). The development of damage algorithms for buried pipelines is primarily based on empirical evidence, tempered with engineering judgment and sometimes by analytical formulations.For the city of Catania, in the present work use has been made of the correlation between RR and peak horizontal ground velocity by American Lifelines Alliance (ALA, 2001), for the verifications of main buried pipelines. The performance of the main buried distribution networks has been evaluated for the Level I earthquake scenario (January 11, 1693 event I = XI, M 7.3) and for the Level II earthquake scenario (February 20, 1818 event I = IX, M 6.2).Seismic damage scenario of main gas pipelines and

  8. Earthquake Risk Management of Underground Lifelines in the Urban Area of Catania

    NASA Astrophysics Data System (ADS)

    Grasso, S.; Maugeri, M.

    2008-07-01

    Lifelines typically include the following five utility networks: potable water, sewage natural gas, electric power, telecommunication and transportation system. The response of lifeline systems, like gas and water networks, during a strong earthquake, can be conveniently evaluated with the estimated average number of ruptures per km of pipe. These ruptures may be caused either by fault ruptures crossing, or by permanent deformations of the soil mass (landslides, liquefaction), or by transient soil deformations caused by seismic wave propagation. The possible consequences of damaging earthquakes on transportation systems may be the reduction or the interruption of traffic flow, as well as the impact on the emergency response and on the recovery assistance. A critical element in the emergency management is the closure of roads due to fallen obstacles and debris of collapsed buildings. The earthquake-induced damage to buried pipes is expressed in terms of repair rate (RR), defined as the number of repairs divided by the pipe length (km) exposed to a particular level of seismic demand; this number is a function of the pipe material (and joint type), of the pipe diameter and of the ground shaking level, measured in terms of peak horizontal ground velocity (PGV) or permanent ground displacement (PGD). The development of damage algorithms for buried pipelines is primarily based on empirical evidence, tempered with engineering judgment and sometimes by analytical formulations. For the city of Catania, in the present work use has been made of the correlation between RR and peak horizontal ground velocity by American Lifelines Alliance (ALA, 2001), for the verifications of main buried pipelines. The performance of the main buried distribution networks has been evaluated for the Level I earthquake scenario (January 11, 1693 event I = XI, M 7.3) and for the Level II earthquake scenario (February 20, 1818 event I = IX, M 6.2). Seismic damage scenario of main gas pipelines and

  9. Geomorphic changes induced by the April-May 2015 earthquake sequence in the Pharak-Khumbu area (Nepal): preliminary assessments.

    NASA Astrophysics Data System (ADS)

    Fort, Monique

    2016-04-01

    Landsliding is a common process shaping mountain slopes. There are various potential landslide triggers (rainfall, bank erosion, earthquakes) and their effectiveness depends on their distribution, frequency and magnitude. In a Himalayan context, the effects of monsoon rainfall can be assessed every year whereas the unpredictability and low frequency of large earthquakes make their role in triggering slope instability more obscure. A 7.8 magnitude earthquake struck central Nepal (Gorkha District) on 25 April 2015 and was followed by many aftershocks exceeding magnitude 5, including another strong 7.3 magnitude earthquake on May 12, 2015 (Dolakha District). This seismic crisis provides an exceptional opportunity to assess the disruptions that earthquakes may cause in "regular" geomorphic systems controlled by rainfall. Here we present field observations carried out in the Pharak-Khumbu area (East Nepal, Dudh Kosi catchment) before and after the April-May 2015 earthquakes. The Pharak, a "middle mountains" (2000-4500 m) area, is affected by monsoon rains (3000 m/yr at 2500 m) and characterised by steep hillslopes, shaped by different geomorphic processes according to slope height and aspect, rock type and strength, inherited landforms, stream connectivity and current land use changes. This study focuses on the south of Lukla (Phakding District), and more specifically on the Khari Khola catchment and its surroundings. The area lies at the transition between the Higher Himalayan crystallines and the Lesser Himalayan meta-sediments. On the basis of our diachronic observations (March and November 2015), we surveyed and mapped new earthquake-induced slope instabilities such as rock falls, rockslides, landslides and debris flows and a combination of several of them. Interviews with local people also helped to assess the exact timing of some events. While the first M 7.8 earthquake produced significant impacts in the northern Khumbu area, the M 7.3 aftershock seems to have

  10. Large-scale mapping of landslides in the epicentral area Loma Prieta earthquake of October 17, 1989, Santa Cruz County

    SciTech Connect

    Spittler, T.E.; Sydnor, R.H.; Manson, M.W.; Levine, P.; McKittrick, M.M.

    1990-01-01

    The Loma Prieta earthquake of October 17, 1989 triggered landslides throughout the Santa Cruz Mountains in central California. The California Department of Conservation, Division of Mines and Geology (DMG) responded to a request for assistance from the County of Santa Cruz, Office of Emergency Services to evaluate the geologic hazard from major reactivated large landslides. DMG prepared a set of geologic maps showing the landslide features that resulted from the October 17 earthquake. The principal purpose of large-scale mapping of these landslides is: (1) to provide county officials with regional landslide information that can be used for timely recovery of damaged areas; (2) to identify disturbed ground which is potentially vulnerable to landslide movement during winter rains; (3) to provide county planning officials with timely geologic information that will be used for effective land-use decisions; (4) to document regional landslide features that may not otherwise be available for individual site reconstruction permits and for future development.

  11. Special Issue "Impact of Natural Hazards on Urban Areas and Infrastructure" in the Bulletin of Earthquake Engineering

    NASA Astrophysics Data System (ADS)

    Bostenaru Dan, M.

    2009-04-01

    This special issue includes selected papers on the topic of earthquake impact from the sessions held in 2004 in Nice, France and in 2005 in Vienna, Austria at the first and respectivelly the second European Geosciences Union General Assembly. Since its start in 1999, in the Hague, Netherlands, the hazard of earthquakes has been the most popular of the session. The respective calls in 2004 was for: Nature's forces including earthquakes, floods, landslides, high winds and volcanic eruptions can inflict losses to urban settlements and man-made structures such as infrastructure. In Europe, recent years have seen such significant losses from earthquakes in south and south-eastern Europe, floods in central Europe, and wind storms in western Europe. Meanwhile, significant progress has been made in understanding disasters. Several scientific fields contribute to a holistic approach in the evaluation of capacities, vulnerabilities and hazards, the main factors on mitigating urban disasters due to natural hazards. An important part of the session is devoted to assessment of earthquake shaking and loss scenarios, including both physical damage and human causalities. Early warning and rapid damage evaluation are of utmost importance for addressing the safety of many essential facilities, for emergency management of events and for disaster response. In case of earthquake occurrence strong motion networks, data processing and interpretation lead to preliminary estimation (scenarios) of geographical distribution of damages. Factual information on inflicted damage, like those obtained from shaking maps or aerial imagery permit a confrontation with simulation maps of damage in order to define a more accurate picture of the overall losses. Most recent developments towards quantitative and qualitative simulation of natural hazard impacts on urban areas, which provide decision-making support for urban disaster management, and success stories of and lessons learned from disaster

  12. Large and great earthquakes in the Shillong plateau-Assam valley area of Northeast India Region: Pop-up and transverse tectonics

    NASA Astrophysics Data System (ADS)

    Kayal, J. R.; Arefiev, S. S.; Baruah, Saurabh; Hazarika, D.; Gogoi, N.; Gautam, J. L.; Baruah, Santanu; Dorbath, C.; Tatevossian, R.

    2012-04-01

    The tectonic model of the Shillong plateau and Assam valley in the northeast India region, the source area for the 1897 great earthquake (Ms ~ 8.7) and for the four (1869, 1923, 1930 and 1943) large earthquakes (M. ≥ 7.0), is examined using the high precision data of a 20-station broadband seismic network. About 300 selected earthquakes M ≥ 3.0 recorded during 2001-2009 are analysed to study the seismicity and fault plane solutions. The dominating thrust/reverse faulting earthquakes in the western plateau may be explained by the proposed pop-up tectonics between two active boundary faults, the Oldham-Brahmaputra fault to the north and the Dapsi-Dauki thrust to the south, though the northern boundary fault is debated. The more intense normal and strike-slip faulting earthquakes in the eastern plateau (Mikir massif) and in the Assam valley, on the other hand, are well explained by transverse tectonics at the long and deep rooted Kopili fault that cuts across the Himalaya and caused the 2009 Bhutan earthquake (Mw 6.3). It is conjectured that the complex tectonics of the Shillong plateau and transverse tectonics at the Kopili fault make the region vulnerable for impending large earthquake(s).

  13. The role of occupational therapy in the recovery stage of disaster relief: a report from earthquake stricken areas in China.

    PubMed

    Lee, Hoe C

    2014-02-01

    Earthquakes and their destructive forces are unpredictable and difficult to prepare for. Unfortunately, another powerful earthquake of magnitude 7.2 had struck when this report was being prepared. The disabling events have long-term negative impacts on occupational performance of the individuals and communities being affected. Occupational therapy practitioners can use their professional expertise and power of engagement to restore life when individuals and communities are disrupted by natural disaster. The events of the Wenchuan Earthquake have raised awareness of the importance of rehabilitation services in remote areas of China and highlight the need to incorporate rehabilitation in response to the planning of future humanitarian catastrophes. With health agendas advancing rapidly in China, disaster rehabilitation cannot be left behind. Occupational therapists with their holistic, humanistic approach and scientific training can play an important role in restoring physical functions and enhancing occupation participation for survivors of the natural disasters. Active participation in and contribution to research and holistic management of disaster survivors should ensure the occupational therapy profession a seat at the table in future health policy and practice decisions on disaster management.

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

    USGS Publications Warehouse

    Jaiswal, Kishor; Wald, David J.

    2008-01-01

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

  15. PiSAR-L2 observation of agricultural area damaged by seawater during the Great East Japan Earthquake in 2011

    NASA Astrophysics Data System (ADS)

    Watanabe, Manabu; Kawano, Noriyuki; Naoki, Kazuhiro; Shimada, Masanobu

    2012-11-01

    On March 11, 2011, a massive earthquake occurred on the eastern coast of Japan. The magnitude 9.0 quake was the most powerful ever recorded in Japan. The height of the tsunami that followed the earthquake was estimated to be more than 10 m. The water reached a few kilometers inland and resulted in thousands of casualties as well as serious damage to buildings and agricultural areas along the coastline. Several PiSAR-L2 observations were carried out in these tsunamiaffected areas from April to September in 2012, and field experiments were performed in agricultural areas that had been damaged by seawater. The complex dielectric constant and the electrical conductivity of the soil were measured to estimate the soil's salinity. The imaginary part of the dielectric constant for a tsunami-damaged area 0.7 km from the coastline was shown to be 37.1 at 1 GHz, and the electric conductivity was shown to be 7.8 mS/cm. These values exceeded those from non-damaged inland areas. One of the full polarimetric parameters, co-polarization backscattering ratio (σ0HH/σ0VV) derived from PiSAR-L2 data, were examined and compared for damaged/non-damaged areas. The analysis indicates that the higher-salinity area was well detected by σ0HH/σ0VV. However, water areas and flat surfaces covered by gravel exhibit similar characteristics, and this may result in the false detection of salt-affected agricultural areas.

  16. Seismic tomography of the area of the 2010 Beni-Ilmane earthquake sequence, north-central Algeria.

    PubMed

    Abacha, Issam; Koulakov, Ivan; Semmane, Fethi; Yelles-Chaouche, Abd Karim

    2014-01-01

    The region of Beni-Ilmane (District of M'sila, north-central Algeria) was the site of an earthquake sequence that started on 14 May 2010. This sequence, which lasted several months, was triggered by conjugate E-W reverse and N-S dextral faulting. To image the crustal structure of these active faults, we used a set of 1406 well located aftershocks events and applied the local tomography software (LOTOS) algorithm, which includes absolute source location, optimization of the initial 1D velocity model, and iterative tomographic inversion for 3D seismic P- and S-wave velocities (and the Vp/Vs ratio), and source parameters. The patterns of P-wave low-velocity anomalies correspond to the alignments of faults determined from geological evidence, and the P-wave high-velocity anomalies may represent rigid blocks of the upper crust that are not deformed by regional stresses. The S-wave low-velocity anomalies coincide with the aftershock area, where relatively high values of Vp/Vs ratio (1.78) are observed compared with values in the surrounding areas (1.62-1.66). These high values may indicate high fluid contents in the aftershock area. These fluids could have been released from deeper levels by fault movements during earthquakes and migrated rapidly upwards. This hypothesis is supported by vertical sections across the study area show that the major Vp/Vs anomalies are located above the seismicity clusters.

  17. Evaluation of Seismicity Using Density Analysis of 2000-2015 Earthquakes in The West Coastal Zone of Anatolia (Turkey) And Its Correlation with Geothermal Areas

    NASA Astrophysics Data System (ADS)

    Bakak, Özde

    2016-10-01

    The purpose of the study is to evaluate the seismic activity using the density analysis methods (point density and Kernel density analysis) for 2000-2015 earthquake catalogue belonging to the study area surrounded by Qanakkale to the north, Fethiye to the south and Denizli (Buharkent) to the east, and also to apply its correlation with geothermal regions. The earthquake data, in total 6.675 earthquakes with M>3 magnitudes were obtained from DDA Catalogue of Prime Ministry Disaster & Emergency Management Authority (AFAD) official website. In this survey, data analysis and maps were prepared using ArcGIS (version_10.1) program. The analysis maps present (1) the intensity clustered earthquakes dominant in Sigacik and Gokova Gulfs, (2) regions which have high seismic risk were determined according to Buffer analysis for 2 km distance, (3) geothermal areas (21.4-153°C) in the west coastal zone of Anatolia were mapped, (4) regions the most affected by seismic activity for the last 15 years were detected from 2015 population data, and as latest (5) Seferihisar, Urla, Gulbahge, Demircili, Bodrum, and Datga provinces are identified as areas having high seismic activity for the last 15 years. Consequently, all analysis results were compared with the geothermal areas, and the review made that earthquake catalogue has not the relationship with hot regions and also these shocks triggered by active faults in this region using ArcGIS program. the author recommends that these regions should be investigated the earthquake sensitivity analysis in the near future.

  18. Neotectonics of the Dinarides-Pannonian Basin transition and possible earthquake sources in the Banja Luka epicentral area

    NASA Astrophysics Data System (ADS)

    Ustaszewski, Kamil; Herak, Marijan; Tomljenović, Bruno; Herak, Davorka; Matej, Srebrenka

    2014-12-01

    This study provides evidence for post-5 Ma shortening in the transition area between the Dinarides fold-and-thrust belt and the Pannonian Basin and reviews possible earthquake sources for the Banja Luka epicentral area (northern Bosnia and Herzegovina) where the strongest instrumentally recorded earthquake (ML 6.4) occurred on 27 October 1969. Geological, geomorphological and reflection seismic data provide evidence for a contractional reactivation of Late Palaeogene to Middle Miocene normal faults at slip rates below 0.1 mm/a. This reactivation postdates deposition of the youngest sediments in the Pannonian Basin of Pontian age (c. 5 Ma). Fault plane solutions for the main 1969 Banja Luka earthquake (ML 6.4) and its largest foreshock (ML 6.0) indicate reverse faulting along ESE-WNW-striking nodal planes and generally N-S trending pressure axes. The spatial distribution of epicentres and focal depths, analyses of the macroseismic field and fault-plane solutions for several smaller events suggest on-going shortening in the internal Dinarides. Seismic deformation of the upper crust is also associated with strike-slip faults, likely related to the NE-SW trending, sinistral Banja Luka fault. Possibly, this fault transfers contraction between adjacent segments of the Dinarides thrust system. The study area represents the seismically most active region of the Dinarides apart from the Adriatic Sea coast and the bend zone around Zagreb. We propose that on-going thrusting in the internal Dinarides thrust system takes up a portion of the current Adria-Europe convergence.

  19. Fault Interactions and Large Complex Earthquakes in the Los Angeles Area

    USGS Publications Warehouse

    Anderson, G.; Aagaard, B.; Hudnut, K.

    2003-01-01

    Faults in complex tectonic environments interact in various ways, including triggered rupture of one fault by another, that may increase seismic hazard in the surrounding region. We model static and dynamic fault interactions between the strike-slip and thrust fault systems in southern California. We find that rupture of the Sierra Madre-Cucamonga thrust fault system is unlikely to trigger rupture of the San Andreas or San Jacinto strike-slip faults. However, a large northern San Jacinto fault earthquake could trigger a cascading rupture of the Sierra Madre-Cucamonga system, potentially causing a moment magnitude 7.5 to 7.8 earthquake on the edge of the Los Angeles metropolitan region.

  20. Hadoop-BAM: directly manipulating next generation sequencing data in the cloud.

    PubMed

    Niemenmaa, Matti; Kallio, Aleksi; Schumacher, André; Klemelä, Petri; Korpelainen, Eija; Heljanko, Keijo

    2012-03-15

    Hadoop-BAM is a novel library for the scalable manipulation of aligned next-generation sequencing data in the Hadoop distributed computing framework. It acts as an integration layer between analysis applications and BAM files that are processed using Hadoop. Hadoop-BAM solves the issues related to BAM data access by presenting a convenient API for implementing map and reduce functions that can directly operate on BAM records. It builds on top of the Picard SAM JDK, so tools that rely on the Picard API are expected to be easily convertible to support large-scale distributed processing. In this article we demonstrate the use of Hadoop-BAM by building a coverage summarizing tool for the Chipster genome browser. Our results show that Hadoop offers good scalability, and one should avoid moving data in and out of Hadoop between analysis steps.

  1. Determination of the runoff threshold for triggering debris flows in the area affected by the Wenchuan Earthquake

    NASA Astrophysics Data System (ADS)

    Cui, P.; Guo, X. J.; Zhuang, J. Q.

    2014-07-01

    We constructed an experiment to determine the critical runoff discharge for debris flow initiation in Wenchuan Earthquake area. A single dimensionless discharge variable was integrated to incorporate influential parameters, including channel width, median particle diameter, and surface flow discharge. The results revealed that relationship with the debris flow density, slope and discharge required. Taking into account the behaviors of debris flow formation corresponding to different ranges of slopes, the critical runoff thresholds for debris flow initiation were calculated for three different scenarios. The thresholds were validated against actual debris flow events, and the use in this study is applicable.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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.

  4. Detailed crustal structure in the area of the southern Apennines-Calabrian Arc border from local earthquake tomography

    NASA Astrophysics Data System (ADS)

    Totaro, C.; Koulakov, I.; Orecchio, B.; Presti, D.

    2014-12-01

    We present a new seismic velocity model for the southern Apennines-Calabrian Arc border region with the aim to better define the crustal structures at the northern edge of the Ionian subduction zone. This sector also includes the Pollino Mts. area, where a seismic sequence of thousands of small to moderate earthquakes has been recorded between spring 2010 and 2013. In this sector a seismic gap was previously hypothesized by paleoseismological evidences associated with the lack of major earthquakes in historical catalogs. To perform the tomographic inversion we selected ca. 3600 earthquakes that have occurred in the last thirty years and recorded by permanent and temporary networks managed by INGV and Calabria University. Using for the first time the Local Tomography Software for passive tomography inversion (LOTOS hereinafter) to crustal analysis in southern Italy, we have computed the distribution of Vp, Vs, and the Vp/Vs ratio. The obtained velocity model, jointly evaluated with results of synthetic modeling, as well as with the hypocenter distribution and geological information, gives us new constraints on the geodynamical and structural knowledge of the study area. The comparison between the shallow tomography sections and surface geology shows good correlation between velocity patterns and the main geological features of the study area. In the upper crust a low-velocity anomaly of P- and S-waves is detectable beneath the Pollino Mts. area and seems to separate the Calabrian and southern Apennines domains, characterized by higher velocities. The distributions of high Vp/Vs ratio, representing strongly fractured rocks with likely high fluid content, clearly correlate with areas of significant seismicity. In the lower crust we detect a clear transition from high to low seismic velocities in correspondence with the Tyrrhenian coast of the study area, which may represent the transition from the thinner Tyrrhenian crust to the thicker one beneath Calabria. In this

  5. Asymmetric DNA recognition by the OkrAI endonuclease, an isoschizomer of BamHI

    SciTech Connect

    Vanamee, Éva Scheuring; Viadiu, Hector; Chan, Siu-Hong; Ummat, Ajay; Hartline, Adrian M.; Xu, Shuang-yong; Aggarwal, Aneel K.

    2011-11-18

    Restriction enzymes share little or no sequence homology with the exception of isoschizomers, or enzymes that recognize and cleave the same DNA sequence. We present here the structure of a BamHI isoschizomer, OkrAI, bound to the same DNA sequence (TATGGATCCATA) as that cocrystallized with BamHI. We show that OkrAI is a more minimal version of BamHI, lacking not only the N- and C-terminal helices but also an internal 310 helix and containing {beta}-strands that are shorter than those in BamHI. Despite these structural differences, OkrAI recognizes the DNA in a remarkably similar manner to BamHI, including asymmetric contacts via C-terminal 'arms' that appear to 'compete' for the minor groove. However, the arms are shorter than in BamHI. We observe similar DNA-binding affinities between OkrAI and BamHI but OkrAI has higher star activity (at 37 C) compared to BamHI. Together, the OkrAI and BamHI structures offer a rare opportunity to compare two restriction enzymes that work on exactly the same DNA substrate.

  6. Species-specificity of the BamA component of the bacterial outer membrane protein-assembly machinery.

    PubMed

    Volokhina, Elena B; Grijpstra, Jan; Beckers, Frank; Lindh, Erika; Robert, Viviane; Tommassen, Jan; Bos, Martine P

    2013-01-01

    The BamA protein is the key component of the Bam complex, the assembly machinery for outer membrane proteins (OMP) in gram-negative bacteria. We previously demonstrated that BamA recognizes its OMP substrates in a species-specific manner in vitro. In this work, we further studied species specificity in vivo by testing the functioning of BamA homologs of the proteobacteria Neisseria meningitidis, Neisseria gonorrhoeae, Bordetella pertussis, Burkholderia mallei, and Escherichia coli in E. coli and in N. meningitidis. We found that no BamA functioned in another species than the authentic one, except for N. gonorrhoeae BamA, which fully complemented a N. meningitidis bamA mutant. E. coli BamA was not assembled into the N. meningitidis outer membrane. In contrast, the N. meningitidis BamA protein was assembled into the outer membrane of E. coli to a significant extent and also associated with BamD, an essential accessory lipoprotein of the Bam complex.Various chimeras comprising swapped N-terminal periplasmic and C-terminal membrane-embedded domains of N. meningitidis and E. coli BamA proteins were also not functional in either host, although some of them were inserted in the OM suggesting that the two domains of BamA need to be compatible in order to function. Furthermore, conformational analysis of chimeric proteins provided evidence for a 16-stranded β-barrel conformation of the membrane-embedded domain of BamA.

  7. Effects of the March 1964 Alaska earthquake on the hydrology of the Anchorage area, Alaska: Chapter B in The Alaska earthquake, March 27, 1964: effects hydrologic regimen

    USGS Publications Warehouse

    Waller, Roger M.

    1966-01-01

    The Anchorage hydrologic system was greatly affected by the seismic shock. Immediate but temporary effects included increased stream discharge, seiche action on lakes, and fluctuations in ground-water levels. Generally, ground-water levels were residually lowered after the initial period of fluctuation. This lowering is attributed either to changes in the discharge zones offshore or to a change in the permeability of the aquifers by seismically induced strain. Water supplies were disrupted temporarily by snowslides on streams and by sanding or turbidity in wells. Salt-water encroachment to wells on Fire Island seems to have increased. The approximate 3.7-foot lowering of land level and the diminished artesian head may permit further salt-water encroachment. Increased pore pressure in the Pleistocene Bootlegger Cove Clay led to liquefaction in silt and sand lenses that contributed to the disastrous bluff landslides. Measurements after the earthquake indicate that most pore pressures are declining, whereas some remain high or are increasing. Subsidence in the area was caused principally by tectonic readjustment, but differential compaction within the Bootlegger Cove Clay contributed to subsidences estimated to be as much as 0.6 foot beneath Anchorage.

  8. Studying local earthquakes in the area Baltic-Bothnia Megashear using the data of the POLENET/LAPNET temporary array

    NASA Astrophysics Data System (ADS)

    Usoltseva, Olga; Kozlovskaya, Elena

    2016-07-01

    Earthquakes in areas within continental plates are still not completely understood, and progress on understanding intraplate seismicity is slow due to a short history of instrumental seismology and sparse regional seismic networks in seismically non-active areas. However, knowledge about position and depth of seismogenic structures in such areas is necessary in order to estimate seismic hazard for such critical facilities such as nuclear power plants and nuclear waste deposits. In the present paper we address the problem of seismicity in the intraplate area of northern Fennoscandia using the information on local events recorded by the POLENET/LAPNET (Polar Earth Observing Network) temporary seismic array during the International Polar Year 2007-2009. We relocate the seismic events using the program HYPOELLIPS (a computer program for determining local earthquake hypocentral parameters) and grid search method. We use the first arrivals of P waves of local events in order to calculate a 3-D tomographic P wave velocity model of the uppermost crust (down to 20 km) for a selected region inside the study area and show that the velocity heterogeneities in the upper crust correlate well with known tectonic units. We compare the position of the velocity heterogeneities with the seismogenic structures delineated by epicentres of relocated events and demonstrate that these structures generally do not correlate with the crustal units formed as a result of crustal evolution in the Archaean and Palaeoproterozoic. On the contrary, they correlate well with the postglacial faults located in the area of the Baltic-Bothnia Megashear (BBMS). Hypocentres of local events have depths down to 30 km. We also obtain the focal mechanism of a selected event with good data quality. The focal mechanism is of oblique type with strike-slip prevailing. Our results demonstrate that the Baltic-Bothnia Megashear is an important large-scale, reactivated tectonic structure that has to be taken into

  9. The most recent large earthquake on the Rodgers Creek fault, San Francisco bay area

    USGS Publications Warehouse

    Hecker, S.; Pantosti, D.; Schwartz, D.P.; Hamilton, J.C.; Reidy, L.M.; Powers, T.J.

    2005-01-01

    The Rodgers Creek fault (RCF) is a principal component of the San Andreas fault system north of San Francisco. No evidence appears in the historical record of a large earthquake on the RCF, implying that the most recent earthquake (MRE) occurred before 1824, when a Franciscan mission was built near the fault at Sonoma, and probably before 1776, when a mission and presidio were built in San Francisco. The first appearance of nonnative pollen in the stratigraphic record at the Triangle G Ranch study site on the south-central reach of the RCF confirms that the MRE occurred before local settlement and the beginning of livestock grazing. Chronological modeling of earthquake age using radiocarbon-dated charcoal from near the top of a faulted alluvial sequence at the site indicates that the MRE occurred no earlier than A.D. 1690 and most likely occurred after A.D. 1715. With these age constraints, we know that the elapsed time since the MRE on the RCF is more than 181 years and less than 315 years and is probably between 229 and 290 years. This elapsed time is similar to published recurrence-interval estimates of 131 to 370 years (preferred value of 230 years) and 136 to 345 years (mean of 205 years), calculated from geologic data and a regional earthquake model, respectively. Importantly, then, the elapsed time may have reached or exceeded the average recurrence time for the fault. The age of the MRE on the RCF is similar to the age of prehistoric surface rupture on the northern and southern sections of the Hayward fault to the south. This suggests possible rupture scenarios that involve simultaneous rupture of the Rodgers Creek and Hayward faults. A buried channel is offset 2.2 (+ 1.2, - 0.8) m along one side of a pressure ridge at the Triangle G Ranch site. This provides a minimum estimate of right-lateral slip during the MRE at this location. Total slip at the site may be similar to, but is probably greater than, the 2 (+ 0.3, - 0.2) m measured previously at the

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

    NASA Astrophysics Data System (ADS)

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

    2016-10-01

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

  11. Seismically induced environmental effects in costal areas : the 1783, 1905 and 1908 earthquakes in Calabria and Sicily, (Southern Italy).

    NASA Astrophysics Data System (ADS)

    Porfido, S.; Esposito, E.; Violante, C.; Sacchi, M.; Guerrieri, L.; Serva, L.; Sciarrotta, S.

    2009-04-01

    Calabria and Sicily's Coast, particularly in the Messina Strait, is one of the most seismically active areas of the Southern Italy. Since 1783, there have been seven earthquakes with magnitude ranging between 6.0 and 7.2 These earthquakes have produced wide damages on the MCS Intensities scale of X or greater. The high rate of seismic activity in the region is related to the complex geologic setting resulting in a number of different sources of potentially damaging earthquakes. All these earthquake induced numerous and spectacular coseismic environmental effects overall along the coast where the impact was particularly catastrophic. These earthquakes caused several changes in elevation, due to tectonic deformations, landslides and settlements (i.e along both sides of the Messina Straits, 1908 event), relevant landslides (the February6, 1783 event triggered in Scilla, along the cliff of the M. Pacì a huge rock avalanche estimate of 5 Mm3 in the areal zone and 3 Mm3 in the submarine zone (Bozzano et al 2006), that fell into the sea generating a disastrous tsunamis), ground fractures (in the Capo Vaticano promontory area, 1905 event; in Messina Reggio C., Villa S. Giovanni, 1908 event); liquefaction phenomena (in the area of Messina, Ganzirri and Reggio Calabria, 1908 event), and catastrophic tsunamis (five induced by the 1783 Calabrian seismic sequence, other two by 1905 and 1908 events, Graziani et al 2006). The run-up observed ranging from few cm to tens of m: the highest tsunami wave was about 16 m in Scilla (Feb. 6, 1783 tsunami), 13 m in Pellaro (1908 event) and 1,30 m along the Calabrian coast (1905 tsunami) . Portion of the coast were lost, most of them eroded by the tsunamis with a coastline retreat and flooded the shore for several hundred meters inland depositing a large amount of silt and fish, and in some case killing people (i.e 1500 in Scilla and 28 in Messina during the February 6, 1783 tsunami, Barbano 2008; Porfido et al.,2008). Finally, it is

  12. Spinal fractures resulting from the 1995 Great Hanshin Earthquake of the Kobe-Osaka area of Japan.

    PubMed

    Maruo, S; Matumoto, M

    1996-07-01

    One of the worst earthquakes hit the Hanshin area between Kobe and Osaka, in the early morning at 5:46 AM on January 17th 1995. The destructive force with MG 7.2 severely damaged buildings, houses, roads and railways, leaving 6500 dead, and 34,900 injured. Hyogo College of Medicine located in this area was also severely damaged, thus there was a major challenge to provide post-quake medical support. A post-quake investigation in this area was done by 50 affiliated hospitals. More than 15,000 victim-patients were treated at these hospitals during the first 3 days after the quake. Major injuries were spinal fractures, and other trunk fractures, including rib or pelvis fractures, but fractures of long bones were uncommon, because the quake hit this area in the early morning when most people were asleep. In this study, the mechanisms of these major injuries were analysed by direct interview soon after the quake, with 230 victim-patients who had 140 spinal fractures, and 100 with rib or pelvis fractures. Most of those who had a spinal fracture had either sat up or stood up on their 'Futon' mattresses without bed frames and were struck on their backs by falling furniture or ceilings. On the other hand, patients who had fractures of the ribs or the pelvis had been lying in the supine or lateral position and were hit on their chest or pelvis. This characteristic lifestyle pattern of the Japanese people to lie down on the floor directly beside furniture, resulted in these injuries. From these results, we will emphasize the following precautions:- If an earthquake occurs during sleeping hours at home, do not stand up or sit up. The best position is to crouch on the 'Futon' mattress.

  13. Estimating earthquake potential

    USGS Publications Warehouse

    Page, R.A.

    1980-01-01

    The hazards to life and property from earthquakes can be minimized in three ways. First, structures can be designed and built to resist the effects of earthquakes. Second, the location of structures and human activities can be chosen to avoid or to limit the use of areas known to be subject to serious earthquake hazards. Third, preparations for an earthquake in response to a prediction or warning can reduce the loss of life and damage to property as well as promote a rapid recovery from the disaster. The success of the first two strategies, earthquake engineering and land use planning, depends on being able to reliably estimate the earthquake potential. The key considerations in defining the potential of a region are the location, size, and character of future earthquakes and frequency of their occurrence. Both historic seismicity of the region and the geologic record are considered in evaluating earthquake potential. 

  14. Predicted liquefaction in the greater Oakland area and northern Santa Clara Valley during a repeat of the 1868 Hayward Fault (M6.7-7.0) earthquake

    USGS Publications Warehouse

    Holzer, Thomas L.; Noce, Thomas E.; Bennett, Michael J.

    2010-01-01

    Probabilities of surface manifestations of liquefaction due to a repeat of the 1868 (M6.7-7.0) earthquake on the southern segment of the Hayward Fault were calculated for two areas along the margin of San Francisco Bay, California: greater Oakland and the northern Santa Clara Valley. Liquefaction is predicted to be more common in the greater Oakland area than in the northern Santa Clara Valley owing to the presence of 57 km2 of susceptible sandy artificial fill. Most of the fills were placed into San Francisco Bay during the first half of the 20th century to build military bases, port facilities, and shoreline communities like Alameda and Bay Farm Island. Probabilities of liquefaction in the area underlain by this sandy artificial fill range from 0.2 to ~0.5 for a M7.0 earthquake, and decrease to 0.1 to ~0.4 for a M6.7 earthquake. In the greater Oakland area, liquefaction probabilities generally are less than 0.05 for Holocene alluvial fan deposits, which underlie most of the remaining flat-lying urban area. In the northern Santa Clara Valley for a M7.0 earthquake on the Hayward Fault and an assumed water-table depth of 1.5 m (the historically shallowest water level), liquefaction probabilities range from 0.1 to 0.2 along Coyote and Guadalupe Creeks, but are less than 0.05 elsewhere. For a M6.7 earthquake, probabilities are greater than 0.1 along Coyote Creek but decrease along Guadalupe Creek to less than 0.1. Areas with high probabilities in the Santa Clara Valley are underlain by young Holocene levee deposits along major drainages where liquefaction and lateral spreading occurred during large earthquakes in 1868 and 1906.

  15. Sam2bam: High-Performance Framework for NGS Data Preprocessing Tools

    PubMed Central

    Cheng, Yinhe; Tzeng, Tzy-Hwa Kathy

    2016-01-01

    This paper introduces a high-throughput software tool framework called sam2bam that enables users to significantly speed up pre-processing for next-generation sequencing data. The sam2bam is especially efficient on single-node multi-core large-memory systems. It can reduce the runtime of data pre-processing in marking duplicate reads on a single node system by 156–186x compared with de facto standard tools. The sam2bam consists of parallel software components that can fully utilize multiple processors, available memory, high-bandwidth storage, and hardware compression accelerators, if available. The sam2bam provides file format conversion between well-known genome file formats, from SAM to BAM, as a basic feature. Additional features such as analyzing, filtering, and converting input data are provided by using plug-in tools, e.g., duplicate marking, which can be attached to sam2bam at runtime. We demonstrated that sam2bam could significantly reduce the runtime of next generation sequencing (NGS) data pre-processing from about two hours to about one minute for a whole-exome data set on a 16-core single-node system using up to 130 GB of memory. The sam2bam could reduce the runtime of NGS data pre-processing from about 20 hours to about nine minutes for a whole-genome sequencing data set on the same system using up to 711 GB of memory. PMID:27861637

  16. Three dimensional images of geothermal systems: local earthquake P-wave velocity tomography at the Hengill and Krafla geothermal areas, Iceland, and The Geysers, California

    USGS Publications Warehouse

    Julian, B.R.; Prisk, A.; Foulger, G.R.; Evans, J.R.; ,

    1993-01-01

    Local earthquake tomography - the use of earthquake signals to form a 3-dimensional structural image - is now a mature geophysical analysis method, particularly suited to the study of geothermal reservoirs, which are often seismically active and severely laterally inhomogeneous. Studies have been conducted of the Hengill (Iceland), Krafla (Iceland) and The Geysers (California) geothermal areas. All three systems are exploited for electricity and/or heat production, and all are highly seismically active. Tomographic studies of volumes a few km in dimension were conducted for each area using the method of Thurber (1983).

  17. An investigation into the socioeconomic aspects of two major earthquakes in Iran.

    PubMed

    Amini Hosseini, Kambod; Hosseinioon, Solmaz; Pooyan, Zhila

    2013-07-01

    An evaluation of the socioeconomic consequences of earthquakes is an essential part of the development of risk reduction and disaster management plans. However, these variables are not normally addressed sufficiently after strong earthquakes; researchers and relevant stakeholders focus primarily on the physical damage and casualties. The importance of the socioeconomic consequences of seismic events became clearer in Iran after the Bam earthquake on 26 December 2003, as demonstrated by the formulation and approval of various laws and ordinances. This paper reviews the country's regulatory framework in the light of the socioeconomic aspects of two major and destructive earthquakes: in Manjil-Rudbar in 1990, and in Bam in 2003. The results take the form of recommendations and practical strategies for incorporating the socioeconomic dimensions of earthquakes in disaster risk management planning. The results presented here can be applied in other countries with similar conditions to those of Iran in order to improve public preparedness and risk reduction.

  18. β-amylase 1 (BAM1) degrades transitory starch to sustain proline biosynthesis during drought stress.

    PubMed

    Zanella, Martina; Borghi, Gian Luca; Pirone, Claudia; Thalmann, Matthias; Pazmino, Diana; Costa, Alex; Santelia, Diana; Trost, Paolo; Sparla, Francesca

    2016-03-01

    During photosynthesis of higher plants, absorbed light energy is converted into chemical energy that, in part, is accumulated in the form of transitory starch within chloroplasts. In the following night, transitory starch is mobilized to sustain the heterotrophic metabolism of the plant. β-amylases are glucan hydrolases that cleave α-1,4-glycosidic bonds of starch and release maltose units from the non-reducing end of the polysaccharide chain. In Arabidopsis, nocturnal degradation of transitory starch involves mainly β-amylase-3 (BAM3). A second β-amylase isoform, β-amylase-1 (BAM1), is involved in diurnal starch degradation in guard cells, a process that sustains stomata opening. However, BAM1 also contributes to diurnal starch turnover in mesophyll cells under osmotic stress. With the aim of dissecting the role of β-amylases in osmotic stress responses in Arabidopsis, mutant plants lacking either BAM1 or BAM3 were subject to a mild (150mM mannitol) and prolonged (up to one week) osmotic stress. We show here that leaves of osmotically-stressed bam1 plants accumulated more starch and fewer soluble sugars than both wild-type and bam3 plants during the day. Moreover, bam1 mutants were impaired in proline accumulation and suffered from stronger lipid peroxidation, compared with both wild-type and bam3 plants. Taken together, these data strongly suggest that carbon skeletons deriving from BAM1 diurnal degradation of transitory starch support the biosynthesis of proline required to face the osmotic stress. We propose the transitory-starch/proline interplay as an interesting trait to be tackled by breeding technologies aimingto improve drought tolerance in relevant crops.

  19. LLNL Small-Scale Friction sensitivity (BAM) Test

    SciTech Connect

    Simpson, L.R.; Foltz, M.F.

    1996-06-01

    Small-scale safety testing of explosives, propellants and other energetic materials, is done to determine their sensitivity to various stimuli including friction, static spark, and impact. Testing is done to discover potential handling problems for either newly synthesized materials of unknown behavior, or materials that have been stored for long periods of time. This report describes the existing {open_quotes}BAM{close_quotes} Small-Scale Friction Test, and the methods used to determine the friction sensitivity pertinent to handling energetic materials. The accumulated data for the materials tested is not listed here - that information is in a database. Included is, however, a short list of (1) materials that had an unusual response, and (2), a few {open_quotes}standard{close_quotes} materials representing the range of typical responses usually seen.

  20. Shallow earthquake swarms in southern Ryukyu area: manifestation of dynamics of fluid and/or magma plumbing system revealed by teleseismic and regional datasets

    NASA Astrophysics Data System (ADS)

    Špičák, Aleš; Vaněk, Jiří

    2016-06-01

    Earthquake swarm occurrence beneath volcanic domains is one of the indicators of current magmatic activity in the Earth's crust. Repeated occurrence of teleseismically recorded earthquake swarms has been observed in the lithospheric wedge of the southern Ryukyu area above the subducting slab of the Philippine Sea Plate. The swarms were analyzed using the EHB, ISC and JMA catalogs of hypocenter parameters. The swarm earthquakes are shallow (1-60 km), in the body-wave magnitude range up to 5.8. The swarms are distributed beneath the seafloor, parallel to the Ryukyu Trench along a belt connecting active subaerial volcanoes Io-Torishima north-east and Kueishantao west of the investigated area. Epicentral zones of the swarms often coincide with distinct elevations at the seafloor—seamounts and seamount ranges. The top of the subducting slab reaches a depth of about 100 km beneath the zones of earthquake swarm occurrence, which is an average depth of a slab beneath volcanoes in general. The repeated occurrence of relatively strong, teleseismically recorded earthquake swarms thus probably reflects fluid and/or magma migration in the plumbing system of the volcanic arc and points to brittle character of the lithospheric wedge at respective depths. In addition to the factual results, this study documents the high accuracy of hypocenter parameter determinations published by the International Seismological Centre and the usefulness of the EHB relocation procedure.

  1. Classifying β-Barrel Assembly Substrates by Manipulating Essential Bam Complex Members

    PubMed Central

    Mahoney, Tara F.; Ricci, Dante P.

    2016-01-01

    ABSTRACT The biogenesis of the outer membrane (OM) of Escherichia coli is a conserved and vital process. The assembly of integral β-barrel outer membrane proteins (OMPs), which represent a major component of the OM, depends on periplasmic chaperones and the heteropentameric β-barrel assembly machine (Bam complex) in the OM. However, not all OMPs are affected by null mutations in the same chaperones or nonessential Bam complex members, suggesting there are categories of substrates with divergent requirements for efficient assembly. We have previously demonstrated two classes of substrates, one comprising large, low-abundance, and difficult-to-assemble substrates that are heavily dependent on SurA and also Skp and FkpA, and the other comprising relatively simple and abundant substrates that are not as dependent on SurA but are strongly dependent on BamB for assembly. Here, we describe novel mutations in bamD that lower levels of BamD 10-fold and >25-fold without altering the sequence of the mature protein. We utilized these mutations, as well as a previously characterized mutation that lowers wild-type BamA levels, to reveal a third class of substrates. These mutations preferentially cause a marked decrease in the levels of multimeric proteins. This susceptibility of multimers to lowered quantities of Bam machines in the cell may indicate that multiple Bam complexes are needed to efficiently assemble multimeric proteins into the OM. IMPORTANCE The outer membrane (OM) of Gram-negative bacteria, such as Escherichia coli, serves as a selective permeability barrier that prevents the uptake of toxic molecules and antibiotics. Integral β-barrel proteins (OMPs) are assembled by the β-barrel assembly machine (Bam), components of which are conserved in mitochondria, chloroplasts, and all Gram-negative bacteria, including many clinically relevant pathogenic species. Bam is essential for OM biogenesis and accommodates a diverse array of client proteins; however, a

  2. Hadoop-BAM: directly manipulating next generation sequencing data in the cloud

    PubMed Central

    Niemenmaa, Matti; Kallio, Aleksi; Schumacher, André; Klemelä, Petri; Korpelainen, Eija; Heljanko, Keijo

    2012-01-01

    Summary: Hadoop-BAM is a novel library for the scalable manipulation of aligned next-generation sequencing data in the Hadoop distributed computing framework. It acts as an integration layer between analysis applications and BAM files that are processed using Hadoop. Hadoop-BAM solves the issues related to BAM data access by presenting a convenient API for implementing map and reduce functions that can directly operate on BAM records. It builds on top of the Picard SAM JDK, so tools that rely on the Picard API are expected to be easily convertible to support large-scale distributed processing. In this article we demonstrate the use of Hadoop-BAM by building a coverage summarizing tool for the Chipster genome browser. Our results show that Hadoop offers good scalability, and one should avoid moving data in and out of Hadoop between analysis steps. Availability: Available under the open-source MIT license at http://sourceforge.net/projects/hadoop-bam/ Contact: matti.niemenmaa@aalto.fi Supplementary information: Supplementary material is available at Bioinformatics online. PMID:22302568

  3. Methods to Characterize Folding and Function of BamA Crosslink Mutants

    PubMed Central

    Kuszak, Adam J.; Noinaj, Nicholas; Buchanan, Susan K.

    2016-01-01

    Summary The utility of protein engineering, both the mutation and deletion of specific amino acids, to investigate protein structure and function has been demonstrated time and time again, and inter- and intra-molecular interactions within the BAM complex and its individual components are no exception. Extensive efforts have probed conserved and unique amino acid sequences of the Bam proteins to define their functional roles. This chapter will summarize efforts as applied to the disulfide crosslink mutants of BamA and describe experimental methods used in our studies to determine that lateral opening of the barrel domain is required for function. PMID:26427681

  4. Propagation mechanisms of incident tsunami wave in Jiangsu coastal area, caused by eastern Japan earthquake on March 11, 2011

    NASA Astrophysics Data System (ADS)

    Yuan, Chun-guang; Wang, Yi-gang; Huang, Hui-ming; Chen, Cheng; Chen, Da-ke

    2016-03-01

    At 13:46 on March 11, 2011 (Beijing time), an earthquake of Mw=9.0 occurred in Japan. By comparing the tsunami data from Guanhekou marine station with other tsunami wave observation gathered from southeast coastal area of China, it was evident that, only in Guanhekou, the position of the maximum wave height appeared in the middle part rather than in the front of the tsunami wave train. A numerical model of tsunami propagation based on 2-D nonlinear shallow water equations was built to study the impact range and main causes of the special tsunami waveform discovered in Jiangsu coastal area. The results showed that nearly three-quarters of the Jiangsu coastal area, mainly comprised the part north of the radial sand ridges, reached its maximum tsunami wave height in the middle part of the wave train. The main cause of the special waveform was the special underwater topography condition of the Yellow Sea and the East China Sea area, which influenced the tsunami propagation and waveform significantly. Although land boundary reflection brought an effect on the position of the maximum wave height to a certain extent, as the limits of the incident waveform and distances between the observation points and shore, it was not the dominant influence factor of the special waveform. Coriolis force's impact on the tsunami waves was so weak that it was not the main cause for the special phenomenon in Jiangsu coastal area. The study reminds us that the most destructive wave might not appear in the first one in tsunami wave train.

  5. Earthquakes of the Holocene.

    USGS Publications Warehouse

    Schwartz, D.P.

    1987-01-01

    Areas in which significant new data and insights have been obtained are: 1) fault slip rates; 2) earthquake recurrence models; 3) fault segmentation; 4) dating past earthquakes; 5) paleoseismicity in the E and central US; 6) folds and earthquakes, and 7) future earthquake behavior. Summarizes important trends in each of these research areas based on information published between June 1982 and June 1986 and preprints of papers in press. The bibliography for this period contains mainly referred publications in journals and books.-from Author

  6. Improving the RST Approach for Earthquake Prone Areas Monitoring: Results of Correlation Analysis among Significant Sequences of TIR Anomalies and Earthquakes (M>4) occurred in Italy during 2004-2014

    NASA Astrophysics Data System (ADS)

    Tramutoli, V.; Coviello, I.; Filizzola, C.; Genzano, N.; Lisi, M.; Paciello, R.; Pergola, N.

    2015-12-01

    Looking toward the assessment of a multi-parametric system for dynamically updating seismic hazard estimates and earthquake short term (from days to weeks) forecast, a preliminary step is to identify those parameters (chemical, physical, biological, etc.) whose anomalous variations can be, to some extent, associated to the complex process of preparation of a big earthquake. Among the different parameters, the fluctuations of Earth's thermally emitted radiation, as measured by sensors on board of satellite system operating in the Thermal Infra-Red (TIR) spectral range, have been proposed since long time as potential earthquake precursors. Since 2001, a general approach called Robust Satellite Techniques (RST) has been used to discriminate anomalous thermal signals, possibly associated to seismic activity from normal fluctuations of Earth's thermal emission related to other causes (e.g. meteorological) independent on the earthquake occurrence. Thanks to its full exportability on different satellite packages, RST has been implemented on TIR images acquired by polar (e.g. NOAA-AVHRR, EOS-MODIS) and geostationary (e.g. MSG-SEVIRI, NOAA-GOES/W, GMS-5/VISSR) satellite sensors, in order to verify the presence (or absence) of TIR anomalies in presence (absence) of earthquakes (with M>4) in different seismogenic areas around the world (e.g. Italy, Turkey, Greece, California, Taiwan, etc.).In this paper, a refined RST (Robust Satellite Techniques) data analysis approach and RETIRA (Robust Estimator of TIR Anomalies) index were used to identify Significant Sequences of TIR Anomalies (SSTAs) during eleven years (from May 2004 to December 2014) of TIR satellite records, collected over Italy by the geostationary satellite sensor MSG-SEVIRI. On the basis of specific validation rules (mainly based on physical models and results obtained by applying RST approach to several earthquakes all around the world) the level of space-time correlation among SSTAs and earthquakes (with M≥4

  7. Post-traumatic psychological changes among survivors of the Lushan earthquake living in the most affected areas.

    PubMed

    Tang, Bihan; Kang, Peng; Liu, Xu; Liu, Yuan; Liu, Zhipeng; Wang, Bowen; Lv, Yipeng; Zhang, Lulu

    2014-12-15

    The primary objective of our study was to investigate both the negative and positive psychological changes following the Lushan earthquake, and to explore the factors associated with psychological changes. Multi-stage random sampling was used to select respondents from Lushan County, Sichuan Province, China. A simplified Chinese version of the short form of Changes in Outlook Questionnaire (CiOQ-S) was used to assess psychological changes in earthquake survivors. Descriptive statistics, t-tests, ANOVA and stepwise linear regression analysis were used for data analysis. A total of 4972 respondents were investigated in the cross-sectional study. The mean scores of the positive and negative psychological changes were 26.61 and 8.12, respectively. The factors associated with positive psychological changes included ethnic minority, high level of education, high household income, not injured in the earthquake, not trapped during the earthquake, and having experienced the Wenchuan earthquake. The factors associated with negative psychological changes included female gender, ethnic minority, low household income, history of diseases, injured during the earthquake, and trapped during the earthquake. The current analysis helps expand our knowledge of the negative and positive psychological changes that may occur following an earthquake experience.

  8. The population in China’s earthquake-prone areas has increased by over 32 million along with rapid urbanization

    NASA Astrophysics Data System (ADS)

    He, Chunyang; Huang, Qingxu; Dou, Yinyin; Tu, Wei; Liu, Jifu

    2016-07-01

    Accurate assessments of the population exposed to seismic hazard are crucial in seismic risk mapping. Recent rapid urbanization in China has resulted in substantial changes in the size and structure of the population exposed to seismic hazard. Using the latest population census data and seismic maps, this work investigated spatiotemporal changes in the exposure of the population in the most seismically hazardous areas (MSHAs) in China from 1990 to 2010. In the context of rapid urbanization and massive rural-to-urban migration, nearly one-tenth of the Chinese population in 2010 lived in MSHAs. From 1990 to 2010, the MSHA population increased by 32.53 million at a significantly higher rate of change (33.6%) than the national average rate (17.7%). The elderly population in MSHAs increased by 81.4%, which is much higher than the group’s national growth rate of 58.9%. Greater attention should be paid to the demographic changes in earthquake-prone areas in China.

  9. Rainfall intensity-duration threshold and erosion competence of debris flows in four areas affected by the 2008 Wenchuan earthquake

    NASA Astrophysics Data System (ADS)

    Ma, Chao; Wang, Yujie; Hu, Kaiheng; Du, Cui; Yang, Wentao

    2017-04-01

    Debris flows in the Wenchuan seismic region have caused human casualties and severe damage to local infrastructure. Consequently, the triggering rainfall threshold and erosion capability of post-quake debris flows has become an important research topic worldwide. In this study, we analyze five years of rainstorms and debris flow data from four typical earthquake-hit regions in order to examine the local rainfall intensity-duration (I-D) thresholds and debris supply conditions. It was found that debris flow events in the four seismic areas exhibited different I-D thresholds, related to local mean annual hourly precipitation and debris flow supply conditions. The I-D thresholds, normalized by mean annual maximum hourly rainfall, illustrate that post-quake rainfall thresholds were reduced by at least 30% compared to pre-quake levels. Regression analysis revealed a clear linear relationship between the debris supply condition and the empirical coefficient, α, of the I-D equation. This means that rainfall thresholds of post-quake debris flows in different areas are distinctive and are strongly affected by sediment volume. Different relationships between the entrainment rate and the debris volume per watershed area and its product with the channel gradient illustrate that stream sediments in Yingxiu and Dujiangyan are more eroded, and that local debris flows might persist over a shorter time than in Qingping and Beichuan in the future. Finally, debris flows in the studied area exhibit no tendency of reduction in erosion competence entrainment rate, as found in Taiwan, which might be indicative of a higher entrainment rate persisting for a longer time.

  10. biobambam: tools for read pair collation based algorithms on BAM files

    PubMed Central

    2014-01-01

    Background Sequence alignment data is often ordered by coordinate (id of the reference sequence plus position on the sequence where the fragment was mapped) when stored in BAM files, as this simplifies the extraction of variants between the mapped data and the reference or of variants within the mapped data. In this order paired reads are usually separated in the file, which complicates some other applications like duplicate marking or conversion to the FastQ format which require to access the full information of the pairs. Results In this paper we introduce biobambam, a set of tools based on the efficient collation of alignments in BAM files by read name. The employed collation algorithm avoids time and space consuming sorting of alignments by read name where this is possible without using more than a specified amount of main memory. Using this algorithm tasks like duplicate marking in BAM files and conversion of BAM files to the FastQ format can be performed very efficiently with limited resources. We also make the collation algorithm available in the form of an API for other projects. This API is part of the libmaus package. Conclusions In comparison with previous approaches to problems involving the collation of alignments by read name like the BAM to FastQ or duplication marking utilities our approach can often perform an equivalent task more efficiently in terms of the required main memory and run-time. Our BAM to FastQ conversion is faster than all widely known alternatives including Picard and bamUtil. Our duplicate marking is about as fast as the closest competitor bamUtil for small data sets and faster than all known alternatives on large and complex data sets.

  11. Structure of BamA, an essential factor in outer membrane protein biogenesis.

    PubMed

    Albrecht, Reinhard; Schütz, Monika; Oberhettinger, Philipp; Faulstich, Michaela; Bermejo, Ivan; Rudel, Thomas; Diederichs, Kay; Zeth, Kornelius

    2014-06-01

    Outer membrane protein (OMP) biogenesis is an essential process for maintaining the bacterial cell envelope and involves the β-barrel assembly machinery (BAM) for OMP recognition, folding and assembly. In Escherichia coli this function is orchestrated by five proteins: the integral outer membrane protein BamA of the Omp85 superfamily and four associated lipoproteins. To unravel the mechanism underlying OMP folding and insertion, the structure of the E. coli BamA β-barrel and P5 domain was determined at 3 Å resolution. These data add information beyond that provided in the recently published crystal structures of BamA from Haemophilus ducreyi and Neisseria gonorrhoeae and are a valuable basis for the interpretation of pertinent functional studies. In an `open' conformation, E. coli BamA displays a significant degree of flexibility between P5 and the barrel domain, which is indicative of a multi-state function in substrate transfer. E. coli BamA is characterized by a discontinuous β-barrel with impaired β1-β16 strand interactions denoted by only two connecting hydrogen bonds and a disordered C-terminus. The 16-stranded barrel surrounds a large cavity which implies a function in OMP substrate binding and partial folding. These findings strongly support a mechanism of OMP biogenesis in which substrates are partially folded inside the barrel cavity and are subsequently released laterally into the lipid bilayer.

  12. Seismic structure beneath the Gulf of Aqaba and adjacent areas based on the tomographic inversion of regional earthquake data

    NASA Astrophysics Data System (ADS)

    El Khrepy, Sami; Koulakov, Ivan; Al-Arifi, Nassir; Petrunin, Alexey G.

    2016-06-01

    We present the first 3-D model of seismic P and S velocities in the crust and uppermost mantle beneath the Gulf of Aqaba and surrounding areas based on the results of passive travel time tomography. The tomographic inversion was performed based on travel time data from ˜ 9000 regional earthquakes provided by the Egyptian National Seismological Network (ENSN), and this was complemented with data from the International Seismological Centre (ISC). The resulting P and S velocity patterns were generally consistent with each other at all depths. Beneath the northern part of the Red Sea, we observed a strong high-velocity anomaly with abrupt limits that coincide with the coastal lines. This finding may indicate the oceanic nature of the crust in the Red Sea, and it does not support the concept of gradual stretching of the continental crust. According to our results, in the middle and lower crust, the seismic anomalies beneath the Gulf of Aqaba seem to delineate a sinistral shift (˜ 100 km) in the opposite flanks of the fault zone, which is consistent with other estimates of the left-lateral displacement in the southern part of the Dead Sea Transform fault. However, no displacement structures were visible in the uppermost lithospheric mantle.

  13. Improving Geological Map of Soil Covered Area in Yogyakarta Region by Using FTIR and ASTER Image, Response to 2006 Earthquake

    NASA Astrophysics Data System (ADS)

    Barianto, D. H.; Setijadji, L. D.; Watanabe, K.

    2007-05-01

    Yogyakarta region is located in the southeastern part of Central Java, Indonesia, that mostly covered by product of Quaternary deposits of Merapi volcano and was entirely mapped as single geologic unit (i.e. the Young Volcanic Deposits of Merapi Volcano). This simplicity will be affected for making detail hazard map regarding to last divesting earthquake. The problem for tropical region with highly weathered is make soil covered almost the entire surface and difficult to distinguish kinds of parent/ origin rock. However the research on soil in relation to the spread of lithology in this region is rarely conducted. Geologists are challenged to improve the existing geological map by using the recent data and methods especially in soil covered area in this case by using FTIR and ASTER image. At least 50 samples of various rocks and soils were taken for FTIR which is combining with ASTER Image to create new border of geological units for improving Geological Map especially on Quaternary unit. Soil distribution related to parent rock can be recognize such as Tertiary units of tuffaceous limestone of Sentolo Fm, volcanic breccia of Nglanggran Fm, diorite from Godean and Gendol, more detailed of Quaternary Merapi's sediments and new unit as black clay from Gantiwarno which all have different physical properties. Each soils distribution and border is delineated by using satellite image from ASTER. Hopefully this research will be able to support other research which is need more accurate sedimentary unit border in Yogyakarta region.

  14. Evidence for late Holocene relative sea-level fall from reconnaissance stratigraphical studies in an area of earthquake-subsided intertidal deposits, Isla Chiloé, southern Chile

    USGS Publications Warehouse

    Frostick, L.E.; Steel, R.J.; Bartsch-Winkler, S.; Schmoll, H.R.

    1993-01-01

    indeterminable.Dead forests still mark some locations that subsided into the intertidal zone during the 1960 earthquake, particularly at Río Pudeto and southern coastal Chiloé. There is little evidence of post-1960 growth in any of these subsided areas. Tree-ring counts and tree-diameter measurements provide evidence that these trees survived the 1837 earthquake, and probably survived the 1737 earthquake, strongly suggesting that these earthquakes were of smaller magnitude than the 1960 event, or that the epicentre locations were further removed than the 1960 epicentre from Isla Chiloé, and that earthquake-induced relative sea-level changes differed from those occurring in 1960.

  15. Crustal Fluid Distribution in the Source Area of the 2008 Iwate-Miyagi Nairiku Earthquake, NE Japan Inferred from Seismic Tomography

    NASA Astrophysics Data System (ADS)

    Okada, T.

    2014-12-01

    Seismic tomography is an important tool for detecting the distibution of magma and other crustal fluids. In this presentation, we show the results of seismic tomography, in an area that includes the Naruko volcano and the 2008 Iwate-Miyagi Nairiku earthquake, using data from a dense temporary seismic network, and discuss the crustal fluid distribution related to the volcanic and seismic activity. The seismic velocity structure is complex within the crust and we found distinct seismic low-velocity zones (LVZs). In the shallow crust, the LVZ is located beneath each volcano (Naruko, Onikobe, and Kurikoma) in the focal area of the 2008 Iwate-Miyagi Nairiku Earthquake.In the middle to deep crust (10-20 km), a distinct LVZ beneath the volcanic front can be observed. This LVZ seems to be continuously distributed in the NNE-SSW direction, from the Yakeishi to the Naruko volcano. The lateral extent of the LVZ in the NNE-SSW direction is almost the same as the lateral extent of the aftershock area of the 2008 Iwate-Miyagi Nairiku earthquake. Some low-V areas in the upper crust have high Vp/Vs areas. The aseismic low-V and high-Vp/Vs areas just beneath the volcanoes could correspond to an area with molten magma. We also found some low-V and high Vp/Vs areas with seismicity in the upper crust. Possible reason for this low-V and relatively high-Vp/Vs area could be the presence of overpressurized fluid. For a misoriented compressional inversion fault, reduction of fault strength by overpressurized fluid along the fault is a possible cause for reactivation (Sibson 1990; Sibson 2009). The fault plane of the 2008 Iwate-Miyagi Nairiku earthquake is thought to be as compressional inversion fault (Sibson, 2009). Compressional inversion fault is the reverse fault along the pre-existing "normal" fault. The complex distribution of the aftershock alignment (i.e. fault) has been spatially correlated with the distribution of the LVZ. This suggests that the fluid path distribution could have

  16. Earthquake history of Oregon

    USGS Publications Warehouse

    von Hake, C. A.

    1976-01-01

    Although situated between two States (California and Washington) that have has many violent earthquakes, Oregon is noticeably less active seismically. the greatest damage experienced resulted from a major shock near Olympia, Wash., in 1949. During the short history record available (since 1841), 34 earthquakes of intensity V, Modified Mercalli Scale, or greater have centered within Oregon or near its borders. Only 13 of the earthquakes had an intensity above V, and many of the shocks were local. However, a 1936 earthquake in the eastern Oregon-Washington region caused extensive damage and was felt over an area of 272,000 square kilometers. 

  17. Reactivated faulting near Cushing, Oklahoma: Increased potential for a triggered earthquake in an area of United States strategic infrastructure

    USGS Publications Warehouse

    McNamara, Daniel E.; Hayes, Gavin; Benz, Harley M.; Williams, Robert; McMahon, Nicole D; Aster, R.C.; Holland, Austin F.; Sickbert, T; Herrmann, Robert B.; Briggs, Richard; Smoczyk, Gregory M.; Bergman, Eric; Earle, Paul S.

    2015-01-01

    In October 2014 two moderate-sized earthquakes (Mw 4.0 and 4.3) struck south of Cushing, Oklahoma, below the largest crude oil storage facility in the world. Combined analysis of the spatial distribution of earthquakes and regional moment tensor focal mechanisms indicate reactivation of a subsurface unnamed and unmapped left-lateral strike-slip fault. Coulomb failure stress change calculations using the relocated seismicity and slip distribution determined from regional moment tensors, allow for the possibility that the Wilzetta-Whitetail fault zone south of Cushing, Oklahoma, could produce a large, damaging earthquake comparable to the 2011 Prague event. Resultant very strong shaking levels (MMI VII) in the epicentral region present the possibility of this potential earthquake causing moderate to heavy damage to national strategic infrastructure and local communities.

  18. Reactivated faulting near Cushing, Oklahoma: Increased potential for a triggered earthquake in an area of United States strategic infrastructure

    NASA Astrophysics Data System (ADS)

    McNamara, D. E.; Hayes, G. P.; Benz, H. M.; Williams, R. A.; McMahon, N. D.; Aster, R. C.; Holland, A.; Sickbert, T.; Herrmann, R.; Briggs, R.; Smoczyk, G.; Bergman, E.; Earle, P.

    2015-10-01

    In October 2014 two moderate-sized earthquakes (Mw 4.0 and 4.3) struck south of Cushing, Oklahoma, below the largest crude oil storage facility in the world. Combined analysis of the spatial distribution of earthquakes and regional moment tensor focal mechanisms indicate reactivation of a subsurface unnamed and unmapped left-lateral strike-slip fault. Coulomb failure stress change calculations using the relocated seismicity and slip distribution determined from regional moment tensors, allow for the possibility that the Wilzetta-Whitetail fault zone south of Cushing, Oklahoma, could produce a large, damaging earthquake comparable to the 2011 Prague event. Resultant very strong shaking levels (MMI VII) in the epicentral region present the possibility of this potential earthquake causing moderate to heavy damage to national strategic infrastructure and local communities.

  19. Uncertainty of earthquake losses due to model uncertainty of input ground motions in the Los Angeles area

    USGS Publications Warehouse

    Cao, T.; Petersen, M.D.

    2006-01-01

    In a recent study we used the Monte Carlo simulation method to evaluate the ground-motion uncertainty of the 2002 update of the California probabilistic seismic hazard model. The resulting ground-motion distribution is used in this article to evaluate the contribution of the hazard model to the uncertainty in earthquake loss ratio, the ratio of the expected loss to the total value of a structure. We use the Hazards U.S. (HAZUS) methodology for loss estimation because it is a widely used and publicly available risk model and intended for regional studies by public agencies and for use by governmental decision makers. We found that the loss ratio uncertainty depends not only on the ground-motion uncertainty but also on the mean ground-motion level. The ground-motion uncertainty, as measured by the coefficient of variation (COV), is amplified when converting to the loss ratio uncertainty because loss increases concavely with ground motion. By comparing the ground-motion uncertainty with the corresponding loss ratio uncertainty for the structural damage of light wood-frame buildings in Los Angeles area, we show that the COV of loss ratio is almost twice the COV of ground motion with a return period of 475 years around the San Andreas fault and other major faults in the area. The loss ratio for the 2475-year ground-motion maps is about a factor of three higher than for the 475-year maps. However, the uncertainties in ground motion and loss ratio for the longer return periods are lower than for the shorter return periods because the uncertainty parameters in the hazard logic tree are independent of the return period, but the mean ground motion increases with return period.

  20. Earthquake history of Oklahoma

    USGS Publications Warehouse

    von Hake, C. A.

    1976-01-01

    The strongest and most widely felt earthquake in Oklahoma occured on April 9, 1952. The intensity VII (Modified Mercalli Scale) tremor was felt over 362,000 sqaure kilometres. A second intensity VII earthquake, felt over a very small area, occurred in October 1956. In addition, 15 other shocks, intensity V or VI, have originated within Oklahoma. 

  1. Catalytically-inactive beta-amylase BAM4 required for starch breakdown in Arabidopsis leaves is a starch-binding-protein.

    PubMed

    Li, Jing; Francisco, Perigio; Zhou, Wenxu; Edner, Christoph; Steup, Martin; Ritte, Gerhard; Bond, Charles S; Smith, Steven M

    2009-09-01

    Of the four chloroplast beta-amylase (BAM) proteins identified in Arabidopsis, BAM3 and BAM4 were previously shown to play the major roles in leaf starch breakdown, although BAM4 apparently lacks key active site residues and beta-amylase activity. Here we tested multiple BAM4 proteins with different N-terminal sequences with a range of glucan substrates and assay methods, but detected no alpha-1,4-glucan hydrolase activity. BAM4 did not affect BAM1, BAM2 or BAM3 activity even when added in 10-fold excess, nor the BAM3-catalysed release of maltose from isolated starch granules in the presence of glucan water dikinase. However, BAM4 binds to amylopectin and to amylose-Sepharose whereas BAM2 has very low beta-amylase activity and poor glucan binding. The low activity of BAM2 may be explained by poor glucan binding but absence of BAM4 activity is not. These results suggest that BAM4 facilitates starch breakdown by a mechanism involving direct interaction with starch or other alpha-1,4-glucan.

  2. Winnetka deformation zone: Surface expression of coactive slip on a blind fault during the Northridge earthquake sequence, California. Evidence that coactive faulting occurred in the Canoga Park, Winnetka, and Northridge areas during the 17 January 1994, Northridge, California earthquake

    SciTech Connect

    Cruikshank, K.M.; Johnson, A.M.; Fleming, R.W.; Jones, R.L.

    1996-12-31

    Measurements of normalized length changes of streets over an area of 9 km{sup 2} in San Fernando Valley of Los Angeles, California, define a distinctive strain pattern that may well reflect blind faulting during the 1994 Northridge earthquake. Strain magnitudes are about 3 {times} 10{sup {minus}4}, locally 10{sup {minus}3}. They define a deformation zone trending diagonally from near Canoga Park in the southwest, through Winnetka, to near Northridge in the northeast. The deformation zone is about 4.5 km long and 1 km wide. The northwestern two-thirds of the zone is a belt of extension of streets, and the southeastern one-third is a belt of shortening of streets. On the northwest and southeast sides of the deformation zone the magnitude of the strains is too small to measure, less than 10{sup {minus}4}. Complete states of strain measured in the northeastern half of the deformation zone show that the directions of principal strains are parallel and normal to the walls of the zone, so the zone is not a strike-slip zone. The magnitudes of strains measured in the northeastern part of the Winnetka area were large enough to fracture concrete and soils, and the area of larger strains correlates with the area of greater damage to such roads and sidewalks. All parts of the pattern suggest a blind fault at depth, most likely a reverse fault dipping northwest but possibly a normal fault dipping southeast. The magnitudes of the strains in the Winnetka area are consistent with the strains produced at the ground surface by a blind fault plane extending to depth on the order of 2 km and a net slip on the order of 1 m, within a distance of about 100 to 500 m of the ground surface. The pattern of damage in the San Fernando Valley suggests a fault segment much longer than the 4.5 km defined by survey data in the Winnetka area. The blind fault segment may extend several kilometers in both directions beyond the Winnetka area. This study of the Winnetka area further supports

  3. Fragility analysis of flood protection structures in earthquake and flood prone areas around Cologne, Germany for multi-hazard risk assessment

    NASA Astrophysics Data System (ADS)

    Tyagunov, Sergey; Vorogushyn, Sergiy; Munoz Jimenez, Cristina; Parolai, Stefano; Fleming, Kevin; Merz, Bruno; Zschau, Jochen

    2013-04-01

    The work presents a methodology for fragility analyses of fluvial earthen dikes in earthquake and flood prone areas. Fragility estimates are being integrated into the multi-hazard (earthquake-flood) risk analysis being undertaken within the framework of the EU FP7 project MATRIX (New Multi-Hazard and Multi-Risk Assessment Methods for Europe) for the city of Cologne, Germany. Scenarios of probable cascading events due to the earthquake-triggered failure of flood protection dikes and the subsequent inundation of surroundings are analyzed for the area between the gauges Andernach and Düsseldorf along the Rhine River. Along this river stretch, urban areas are partly protected by earthen dikes, which may be prone to failure during exceptional floods and/or earthquakes. The seismic fragility of the dikes is considered in terms of liquefaction potential (factor of safety), estimated by the use of the simplified procedure of Seed and Idriss. It is assumed that initiation of liquefaction at any point throughout the earthen dikes' body corresponds to the failure of the dike and, therefore, this should be taken into account for the flood risk calculations. The estimated damage potential of such structures is presented as a two-dimensional surface (as a function of seismic hazard and water level). Uncertainties in geometrical and geotechnical dike parameters are considered within the framework of Monte Carlo simulations. Taking into consideration the spatial configuration of the existing flood protection system within the area under consideration, seismic hazard curves (in terms of PGA) are calculated for sites along the river segment of interest at intervals of 1 km. The obtained estimates are used to calculate the flood risk when considering the temporal coincidence of seismic and flood events. Changes in flood risk for the considered hazard cascade scenarios are quantified and compared to the single-hazard scenarios.

  4. Reconnaissance engineering geology of the Haines area, Alaska, with emphasis on evaluation of earthquake and other geologic hazards

    USGS Publications Warehouse

    Lemke, Richard Walter; Yehle, Lynn A.

    1972-01-01

    The Alaska earthquake of March 27, 1964, brought into sharp focus the need for engineering geologic studies in urban areas. Study of the Haines area constitutes an integral part of an overall program to evaluate earthquake and other geologic hazards in most of the larger Alaska coastal communities. The evaluations of geologic hazards that follow, although based only upon reconnaissance studies and, therefore, subject to revision, will provide broad guidelines useful in city and land-use planning. It is hoped that the knowledge gained will result in new facilities being built in the best possible geologic environments and being designed so as to minimize future loss of life and property damage. Haines, which is in the northern part of southeastern Alaska approximately 75 miles northwest of Juneau, had a population, of about 700 people in 1970. It is built at the northern end of the Chilkat Peninsula and lies within the Coast Mountains of the Pacific Mountain system. The climate is predominantly marine and is characterized by mild winters and cool summers. The mapped area described in this report comprises about 17 square miles of land; deep fiords constitute most of the remaining mapped area that is evaluated in this study. The Haines area was covered by glacier ice at least once and probably several times during the Pleistocene Epoch. The presence of emergent marine deposits, several hundred feet above sea level, demonstrates that the land has been uplifted relative to sea level since the last major deglaciation of the region about 10,000 years ago. The rate of relative uplift of the land at Haines during the past 39 years is 2.26 cm per year. Most or all of this uplift appears to be due to rebound as a result of deglaciation. Both bedrock and surficial deposits are present in the area. Metamorphic and igneous rocks constitute the exposed bedrock. The metamorphic rocks consist of metabasalt of Mesozoic age and pyroxenite of probable early middle Cretaceous age. The

  5. Seismic Strong Motion Array Project (SSMAP) to Record Future Large Earthquakes in the Nicoya Peninsula area, Costa Rica

    NASA Astrophysics Data System (ADS)

    Simila, G.; Lafromboise, E.; McNally, K.; Quintereo, R.; Segura, J.

    2007-12-01

    The seismic strong motion array project (SSMAP) for the Nicoya Peninsula in northwestern Costa Rica is composed of 10 - 13 sites including Geotech A900/A800 accelerographs (three-component), Ref-Teks (three- component velocity), and Kinemetric Episensors. The main objectives of the array are to: 1) record and locate strong subduction zone mainshocks [and foreshocks, "early aftershocks", and preshocks] in Nicoya Peninsula, at the entrance of the Nicoya Gulf, and in the Papagayo Gulf regions of Costa Rica, and 2) record and locate any moderate to strong upper plate earthquakes triggered by a large subduction zone earthquake in the above regions. Our digital accelerograph array has been deployed as part of our ongoing research on large earthquakes in conjunction with the Earthquake and Volcano Observatory (OVSICORI) at the Universidad Nacional in Costa Rica. The country wide seismographic network has been operating continuously since the 1980's, with the first earthquake bulletin published more than 20 years ago, in 1984. The recording of seismicity and strong motion data for large earthquakes along the Middle America Trench (MAT) has been a major research project priority over these years, and this network spans nearly half the time of a "repeat cycle" (~ 50 years) for large (Ms ~ 7.5- 7.7) earthquakes beneath the Nicoya Peninsula, with the last event in 1950. Our long time co- collaborators include the seismology group OVSICORI, with coordination for this project by Dr. Ronnie Quintero and Mr. Juan Segura. The major goal of our project is to contribute unique scientific information pertaining to a large subduction zone earthquake and its related seismic activity when the next large earthquake occurs in Nicoya. We are now collecting a database of strong motion records for moderate sized events to document this last stage prior to the next large earthquake. A recent event (08/18/06; M=4.3) located 20 km northwest of Samara was recorded by two stations (Playa Carrillo

  6. Earthquakes; January-February, 1979

    USGS Publications Warehouse

    Person, W.J.

    1979-01-01

    The first major earthquake (magnitude 7.0 to 7.9) of the year struck in southeastern Alaska in a sparsely populated area on February 28. On January 16, Iran experienced the first destructive earthquake of the year causing a number of casualties and considerable damage. Peru was hit by a destructive earthquake on February 16 that left casualties and damage. A number of earthquakes were experienced in parts of the Untied States, but only minor damage was reported. 

  7. Earthquake activity in Oklahoma

    SciTech Connect

    Luza, K.V.; Lawson, J.E. Jr. )

    1989-08-01

    Oklahoma is one of the most seismically active areas in the southern Mid-Continent. From 1897 to 1988, over 700 earthquakes are known to have occurred in Oklahoma. The earliest documented Oklahoma earthquake took place on December 2, 1897, near Jefferson, in Grant County. The largest known Oklahoma earthquake happened near El Reno on April 9, 1952. This magnitude 5.5 (mb) earthquake was felt from Austin, Texas, to Des Moines, Iowa, and covered a felt area of approximately 362,000 km{sup 2}. Prior to 1962, all earthquakes in Oklahoma (59) were either known from historical accounts or from seismograph stations outside the state. Over half of these events were located in Canadian County. In late 1961, the first seismographs were installed in Oklahoma. From 1962 through 1976, 70 additional earthquakes were added to the earthquake database. In 1977, a statewide network of seven semipermanent and three radio-telemetry seismograph stations were installed. The additional stations have improved earthquake detection and location in the state of Oklahoma. From 1977 to 1988, over 570 additional earthquakes were located in Oklahoma, mostly of magnitudes less than 2.5. Most of these events occurred on the eastern margin of the Anadarko basin along a zone 135 km long by 40 km wide that extends from Canadian County to the southern edge of Garvin County. Another general area of earthquake activity lies along and north of the Ouachita Mountains in the Arkoma basin. A few earthquakes have occurred in the shelves that border the Arkoma and Anadarko basins.

  8. The bamA gene for anaerobic ring fission is widely distributed in the environment

    PubMed Central

    Porter, Abigail W.; Young, Lily Y.

    2013-01-01

    Benzoyl-CoA is the signature central metabolite associated with the anaerobic metabolism of a diverse range of compounds such as humic acid, lignin, amino acids, and industrial chemicals. Aromatic chemicals with different upstream degradation pathways all funnel into the downstream benzoyl-CoA pathway. Different genes encoding enzymes of the benzoyl-CoA pathway could be used as biomarkers for the anaerobic benzoyl-CoA pathway, however, the ring opening hydrolase, encoded by the bamA gene, is ideal because it is detected under a range of respiratory conditions, including under denitrifying, iron-reducing, sulfate-reducing, and fermentative conditions. This work evaluated DNA samples from six diverse environments for the presence of the bamA gene, and had positive results for every sample. Individual bamA gene clones from these sites were compared to published genome sequences. The clone sequences were distributed amongst the genome sequences, although there were clone sequences from two of the analyzed sites that formed a unique clade. Clone sequences were then grouped by site and analyzed with a functional operational taxonomic unit based clustering program to compare the bamA gene diversity of these sites to that of several locations reported in the literature. The results showed that the sequence diversity of the sites separated into two clusters, but there was no clear trend that could be related to the site characteristics. Interestingly, two pristine freshwater sites formed a subgroup within one of the larger clusters. Thus far the bamA gene has only been examined within the context of contaminated environments, however, this study demonstrates that the bamA gene is also detected in uncontaminated sites. The widespread presence of the bamA gene in diverse environments suggests that the anaerobic benzoyl-CoA pathway plays an important role in the global carbon cycle that has thus far been understudied. PMID:24133487

  9. 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).

    PubMed

    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

  10. Vertical Seismic Profiling at riser drilling site in the rupture area of the 1944 Tonankai Earthquake, Japan (Invited)

    NASA Astrophysics Data System (ADS)

    Hino, R.; Kinoshita, M.; Araki, E.; Byrne, T. B.; McNeill, L. C.; Saffer, D. M.; Eguchi, N. O.; Takahashi, K.; Toczko, S.

    2009-12-01

    A series of scientific drilling expeditions is in operation in the Nankai Trough to reveal the faulting mechanism of the magathrust earthquakes, through clarifying composition, fine structure, mechanical behavior, and environmental variables of the seismogenic faults. In the studied area, extensive seismic surveys for site characterization have been made to image detailed geometry of the fault complex in the accretionary prism as well as Vp distribution around the faults. Although these previous surveys provided invaluable information for understanding seismotectonic processes in this subduction zone, more complete knowledge is needed to be acquired to predict dynamic behavior of the faults, such as geometrical irregularities in short wavelength, Vs and seismic attenuation which are sensitive to fluid distribution in and around fault zones. It is expected that estimation of these parameters would be improved considerably by a seismic exploration using a vertical array of seismographs installed in a deep borehole (VSP: vertical seismic profiling). In July 2009, we made a VSP at one of the drilling sites located just above the rupture area of the 1994 Tonankai Earthquake (M 8.1), during the IODP Exp.319. The well site of our VSP was made by the riser drilling of D/V Chikyu. The seismic array, lowered from Chikyu into the hole, was composed of a three-component accelerometer and vertical separation of the array elements was 15.12 m. The VSP was composed of offset VSP and zero-offset VSP. In the offset VSP, a tuned airgun array towed by R/V Kairei was shot along one straight line (walk-away VSP) and another circular line (walk-around VSP) and seismic signals were recorded by an array consisting of 16 elements installed from 907 to 1,135 m in depth from seafloor. The object of the walk-away VSP is to obtain fine image of the faults using reflection arrivals with less attenuation. It is also expected to obtain spatial variation of Vs from arrival time tomography of

  11. Distribution of similar earthquakes in aftershocks of inland earthquakes

    NASA Astrophysics Data System (ADS)

    Hayashi, M.; Hiramatsu, Y.; Aftershock Observations Of 2007 Noto Hanto, G.

    2010-12-01

    Frictional properties control the slip behavior on a fault surface such as seismic slip and aseismic slip. Asperity, as a seismic slip area, is characterized by a strong coupling in the interseismic period and large coseismic slip. On the other hand, steady slip or afterslip occurs in an aseismic slip area around the asperity. If an afterslip area includes small asperities, a repeating rupture of single asperity can generate similar earthquakes due to the stress accumulation caused by the afterslip. We here investigate a detail distribution of similar earthquakes in the aftershocks of the 2007 Noto Hanto earthquake (Mjma 6.9) and the 2000 Western Tottori earthquake (Mjma 7.3), inland large earthquakes in Japan. We use the data obtained by the group for the aftershock observations of the 2007 Noto Hanto Earthquake and by the group for the aftershock observations of the 2000 Western Tottori earthquake. First, we select pairs of aftershocks whose cross correlation coefficients in 10 s time window of band-pass filtered waveforms of 1~4 Hz are greater than 0.95 at more than 5 stations and divide those into groups by a link of the cross correlation coefficients. Second, we reexamine the arrival times of P and S waves and the maximum amplitude for earthquakes of each group and apply the double-difference method (Waldhouser and Ellsworth, 2000) to relocate them. As a result of the analysis, we find 24 groups of similar earthquakes in the aftershocks on the source fault of the 2007 Noto Hanto Earthquake and 86 groups of similar earthquakes in the aftershocks on the source fault of the 2000 Western Tottori Earthquake. Most of them are distributed around or outside the asperity of the main shock. Geodetic studies reported that postseismic deformation was detected for the both earthquakes (Sagiya et al., 2002; Hashimoto et al., 2008). The source area of similar earthquakes seems to correspond to the afterslip area. These features suggest that the similar earthquakes observed

  12. Seismic Strong Motion Array Project (SSMAP) to Record Future Large Earthquakes in the Nicoya Peninsula area, Costa Rica

    NASA Astrophysics Data System (ADS)

    Simila, G.; McNally, K.; Quintero, R.; Segura, J.

    2006-12-01

    The seismic strong motion array project (SSMAP) for the Nicoya Peninsula in northwestern Costa Rica is composed of 10 13 sites including Geotech A900/A800 accelerographs (three-component), Ref-Teks (three- component velocity), and Kinemetric Episensors. The main objectives of the array are to: 1) record and locate strong subduction zone mainshocks [and foreshocks, "early aftershocks", and preshocks] in Nicoya Peninsula, at the entrance of the Nicoya Gulf, and in the Papagayo Gulf regions of Costa Rica, and 2) record and locate any moderate to strong upper plate earthquakes triggered by a large subduction zone earthquake in the above regions. Our digital accelerograph array has been deployed as part of our ongoing research on large earthquakes in conjunction with the Earthquake and Volcano Observatory (OVSICORI) at the Universidad Nacional in Costa Rica. The country wide seismographic network has been operating continuously since the 1980's, with the first earthquake bulletin published more than 20 years ago, in 1984. The recording of seismicity and strong motion data for large earthquakes along the Middle America Trench (MAT) has been a major research project priority over these years, and this network spans nearly half the time of a "repeat cycle" (50 years) for large (Ms 7.5- 7.7) earthquakes beneath the Nicoya Peninsula, with the last event in 1950. Our long time co-collaborators include the seismology group OVSICORI, with coordination for this project by Dr. Ronnie Quintero and Mr. Juan Segura. Numerous international investigators are also studying this region with GPS and seismic stations (US, Japan, Germany, Switzerland, etc.). Also, there are various strong motion instruments operated by local engineers, for building purposes and mainly concentrated in the population centers of the Central Valley. The major goal of our project is to contribute unique scientific information pertaining to a large subduction zone earthquake and its related seismic activity when

  13. A seismological study of shallow weak earthquakes in the urban area of Hamburg city, Germany, and its possible relation to salt dissolution

    NASA Astrophysics Data System (ADS)

    Dahm, Torsten; Heimann, Sebastian; Bialowons, Wilhelm

    2010-05-01

    In the night from 8/9 April 2009, shortly after midnight on Maundy Thursday before Easter, several people in Gross-Flottbek, Hamburg, felt unusual strong ground shocks so that some of them left their houses in fear of earthquake shaking. Police and Fire Brigade received phone calls of worried residents, and few days later Internet pages were published where people reported their observations. On 21 April 2009 at about 8 p.m. local time a second micro-earthquake was felt. Damage to buildings or infrastructure did not occur to our knowledge. The Institute of Geophysics, University of Hamburg, installed from 22 April to 17 May 2009 three temporal seismic stations in the epicentral area. Seismological data from two close-by stations at the Deutsches Elektron-Synchrotron (DESY) in about 1 km and the Geophysical Institute in about 7 km distance were collected and integrated to the temporal network. The events occurred above the roof of the shallow Othmarschen Langenfelde salt diapir (OLD), in an area known for active sinkhole formation and previous historic ground shaking events. The analysis of the seismological data recovers that three shallow micro-earthquakes occurred from 8 to 21 April at a depth of about 100m, the largest one with a moment magnitude of about MW 0.6. Depth location of such shallow events is difficult with standard methods, and is here constrained by waveform modeling of surface waves. Earthquakes occurring in soft sediments within the uppermost 100 m are a rare phenomena and cannot be explained by standard models. Rupture process in soft sediments differ from those on faults in more competent rock. We discuss the rupture and source mechanism of the earthquakes in the context of previous historic shocks and existing sinkhole and deformation data. Although the event was so weak, the rupture duration was unusual long and possibly 0.3 s. Three possible models for the generation of repeated micro-earthquakes in Gross Flottbek are developed and discussed

  14. Genotypic Characterization of Human Immunodeficiency Virus Type 1 Derived from Antiretroviral Drug-Treated Individuals Residing in Earthquake-Affected Areas in Nepal.

    PubMed

    Negi, Bharat Singh; Kotaki, Tomohiro; Joshi, Sunil Kumar; Bastola, Anup; Nakazawa, Minato; Kameoka, Masanori

    2017-04-10

    Molecular epidemiological data on human immunodeficiency virus type 1 (HIV-1) are limited in Nepal and have not been available in areas affected by the April 2015 earthquake. Therefore, we conducted a genotypic study on HIV-1 genes derived from individuals on antiretroviral therapy residing in 14 districts in Nepal highly affected by the earthquake. HIV-1 genomic fragments were amplified from 40 blood samples of HIV treatment-failure individuals, and a sequencing analysis was performed on these genes. In the 40 samples, 29 protease, 32 reverse transcriptase, 25 gag, and 21 env genes were sequenced. HIV-1 subtyping revealed that subtype C (84.2%, 32/38) was the major subtype prevalent in the region, while CRF01_AE (7.9%, 3/38) and other recombinant forms (7.9%, 3/38) were also detected. In addition, major drug resistance mutations were identified in 21.9% (7/32) of samples, indicating the possible emergence of HIV-1 drug resistance in earthquake-affected areas in Nepal.

  15. Aminobacter MSH1-Mineralisation of BAM in Sand-Filters Depends on Biological Diversity

    PubMed Central

    Ekelund, Flemming; Harder, Christoffer Bugge; Knudsen, Berith Elkær; Aamand, Jens

    2015-01-01

    BAM (2,6-dichlorobenzamide) is a metabolite of the pesticide dichlobenil. Naturally occurring bacteria that can utilize BAM are rare. Often the compound cannot be degraded before it reaches the groundwater and therefore it poses a serious threat to drinking water supplies. The bacterial strain Aminobacter MSH1 is a BAM degrader and therefore a potential candidate to be amended to sand filters in waterworks to remediate BAM polluted drinking water. A common problem in bioremediation is that bacteria artificially introduced into new diverse environments often thrive poorly, which is even more unfortunate because biologically diverse environments may ensure a more complete decomposition. To test the bioaugmentative potential of MSH1, we used a serial dilution approach to construct microcosms with different biological diversity. Subsequently, we amended Aminobacter MSH1 to the microcosms in two final concentrations; i.e. 105 cells mL-1 and 107 cells mL-1. We anticipated that BAM degradation would be most efficient at “intermediate diversities” as low diversity would counteract decomposition because of incomplete decomposition of metabolites and high diversity would be detrimental because of eradication of Aminobacter MSH1. This hypothesis was only confirmed when Aminobacter MSH1 was amended in concentrations of 105 cells mL-1.Our findings suggest that Aminobacter MSH1 is a very promising bioremediator at several diversity levels. PMID:26076202

  16. Relationship between characteristics of gravity and magnetic anomalies and the earthquakes in the Longmenshan range and adjacent areas

    NASA Astrophysics Data System (ADS)

    Zhang, Jisheng; Gao, Rui; Zeng, Lingsen; Li, Qiusheng; Guan, Ye; He, Rizheng; Wang, Haiyan; Lu, Zhanwu

    2010-08-01

    The 2008 Wenchuan earthquake and aftershocks occurred along the northeast-trending Longmenshan fault zone in the eastern margin of the Tibetan plateau. The Tibetan plateau has the strongest negative Bouguer gravity anomaly zone in China and is surrounded by the great gravity horizontal gradient belt. The horizontal gradient belt of the observed gravity anomaly in the Longmenshan area is a part of this giant gravity gradient belt. The Longmenshan fault zone is located to the east of this belt. The horizontal gradient belt of the residual gravity anomaly, obtained by removing large effects of sedimentary basin and variations in the crustal thickness, well matches the Longmenshan fault zone. But this belt is located to the east of the horizontal gradient belt of the observed gravity anomalies. The deviation of the two horizontal gradient belts increases from the southwest to the northeast with a maximum of about 40-50 km. A significant difference in density exists in the lower crust and the uppermost mantle between the Songpan-Ganzê block and the Sichuan basin block. The Songpan-Ganzê block is less dense than the Sichuan basin block in the lower crust as well as in the uppermost mantle. The boundary between the two blocks is located to the west of the Wenchuan-Maoxian, Yinxiu-Beichuan, and Anxian-Guanxian faults approximately. The fault plane crosses the lower crust and uppermost mantle. The rigid Sichuan basin block acts as a resistant for the pushing from the Songpan-Ganzê block. Far-field effects of the collision between the Indian and Eurasian plates, might lead to thrust of some brittle layers in the upper crust along the detachment, in the middle crust of the Songpan-Ganzê block. When movement on a large and deep crustal mega-thrust occurs, earthquakes strike the Longmen Shan margin of the Tibetan Plateau. In the Guanxian-Beichuan segment in the southern Longmenshan fault zone, push from the Songpan-Ganzê block is perpendicular to the density boundary

  17. Surface Fractures Formed in the Potrero Canyon, Tapo Canyon, and McBean Parkway Areas in Association with the 1994 Northridge, California Earthquake

    USGS Publications Warehouse

    Rymer, Michael J.; Treiman, Jerome A.; Powers, Thomas J.; Fumal, Thomas E.; Schwartz, David P.; Hamilton, John C.; Cinti, Francesca R.

    2001-01-01

    INTRODUCTION The magnitude 6.7 (M6.7) Northridge earthquake of 17 January 1994 strongly shook the Los Angeles urban region, resulting in 33 direct deaths, more than 20,000 people forced out of their homes, and an estimated $20 billion in damage (Hall, 1994). The earthquake was caused by slip on a previously unrecognized south-dipping fault buried beneath the San Fernando Valley. Slip on the fault propagated from a depth of about 19 km to about 8 km below the ground surface (USGS and SCEC, 1994). Although there was no surface faulting associated with the causative fault, surface fractures did develop along at least one fault (Mission Wells fault) and also in areas without recognized faults (Hart and others, 1995; Hecker and others, 1995a, 1995b; Rymer and others, 1995; Treiman, 1995). The term 'surface fractures' is used herein to describe ground breakage that is not associated with primary faulting or with triggered, secondary, surface faulting on a deep seismogenic fault. This report describes fault- and nonfault-related surface fractures that occurred at three sites, Potrero Canyon, Tapo Canyon, and the McBean Parkway area, 22 to 28 km north-northwest of the main shock (Fig. 1). Investigation of these sites documents far reaching effects of even moderately large earthquakes. Study of such effects has become increasingly important with further urbanization and development. Hecker and others (1995a, 1995b) documented the distribution of surface deformation associated with the Northridge earthquake in the Granada Hills area. The search for surface faulting and surface fracturing was initiated within hours of the earthquake. Both ground and airborne searches were made of the region. After fresh surface fractures were found in Potrero Canyon, aerial photographs were taken of the area (including the McBean Parkway site) by I.K. Curtis, on 21 January 1994, at scales of about 1:2,000 and 1:6,000. These aerial photographs were studied under high magnification to

  18. REVIEW ARTICLE: A comparison of site response techniques using earthquake data and ambient seismic noise analysis in the large urban areas of Santiago de Chile

    NASA Astrophysics Data System (ADS)

    Pilz, Marco; Parolai, Stefano; Leyton, Felipe; Campos, Jaime; Zschau, Jochen

    2009-08-01

    Situated in an active tectonic region, Santiago de Chile, the country's capital with more than six million inhabitants, faces tremendous earthquake risk. Macroseismic data for the 1985 Valparaiso event show large variations in the distribution of damage to buildings within short distances, indicating strong effects of local sediments on ground motion. Therefore, a temporary seismic network was installed in the urban area for recording earthquake activity and a study was carried out aiming to estimate site amplification derived from horizontal-to-vertical (H/V) spectral ratios from earthquake data (EHV) and ambient noise (NHV), as well as using the standard spectral ratio (SSR) technique with a nearby reference station located on igneous rock. The results lead to the following conclusions: (1) The analysis of earthquake data shows significant dependence on the local geological structure with respect to amplitude and duration. (2) An amplification of ground motion at frequencies higher than the fundamental one can be found. This amplification would not be found when looking at NHV ratios alone. (3) The analysis of NHV spectral ratios shows that they can only provide a lower bound in amplitude for site amplification. (4) P-wave site responses always show lower amplitudes than those derived by S waves, and sometimes even fail to provide some frequencies of amplification. (5) No variability in terms of time and amplitude is observed in the analysis of the H/V ratio of noise. (6) Due to the geological conditions in some parts of the investigated area, the fundamental resonance frequency of a site is difficult to estimate following standard criteria proposed by the SESAME consortium, suggesting that these are too restrictive under certain circumstances.

  19. BAMS2 Workspace: a comprehensive and versatile neuroinformatic platform for collating and processing neuroanatomical connections

    PubMed Central

    Bota, Mihail; Talpalaru, Ştefan; Hintiryan, Houri; Dong, Hong-Wei; Swanson, Larry W.

    2014-01-01

    We present in this paper a novel neuroinformatic platform, the BAMS2 Workspace (http://brancusi1.usc.edu), designed for storing and processing information about gray matter region axonal connections. This de novo constructed module allows registered users to directly collate their data by using a simple and versatile visual interface. It also allows construction and analysis of sets of connections associated with gray matter region nomenclatures from any designated species. The Workspace includes a set of tools allowing the display of data in matrix and networks formats, and the uploading of processed information in visual, PDF, CSV, and Excel formats. Finally, the Workspace can be accessed anonymously by third party systems to create individualized connectivity networks. All features of the BAMS2 Workspace are described in detail, and are demonstrated with connectivity reports collated in BAMS and associated with the rat sensory-motor cortex, medial frontal cortex, and amygdalar regions. PMID:24668342

  20. Microstructure and magnetism in barium strontium titanate (BSTO)-barium hexaferrite (BaM) multilayers

    SciTech Connect

    Frey, N.A.; Heindl, R.; Srinath, S.; Srikanth, H. . E-mail: sharihar@cas.usf.edu; Dudney, N.J.

    2005-08-11

    High quality multilayers of barium ferrite (BaM) and barium strontium titanate (BSTO) were grown in optimized conditions on thermally oxidized Si(1 0 0) and Al{sub 2}O{sub 3} substrates using magnetron sputtering. As-grown films were amorphous and different annealing procedures were explored to stabilize crystalline phases. BSTO and BaM phases were identified using X-ray diffraction and cross-sectional scanning electron micrographs showed sharp interfaces between BSTO and BaM layers. Magnetic hysteresis loops obtained at various temperatures and field orientations showed a large coercivity ({approx}2500 Oe) consistent with the hard magnetic hexaferrite component. Hysteresis loops also revealed the distinct influence of magnetocrystalline and shape anisotropies at different temperature ranges.

  1. Earthquake history of Mississippi

    USGS Publications Warehouse

    von Hake, C. A.

    1974-01-01

    Since its admission into the Union in 1817, Mississippi has had only four earthquakes of intensity V or greater within its borders. Although the number of earthquakes known to have been centered within Mississippi's boundaries is small, the State has been affected by numerous shocks located in neighboring States. In 1811 and 1812, a series of great earthquakes near the New Madrid Missouri area was felt in Mississippi as far south as the gulf coast. The New Madrid series caused the banks of the Mississippi River to cave in as far as Vicksburg, mroe than 300 miles from the epicentral region. As a result of this great earthquake series, the northwest corner of Mississippi is in seismic risk zone 3, the highest risk zone. Expect for the new Madrid series, effects in Mississippi from earthquakes located outside of the State have been less than intensity V. 

  2. Defeating Earthquakes

    NASA Astrophysics Data System (ADS)

    Stein, R. S.

    2012-12-01

    our actions. Using these global datasets will help to make the model as uniform as possible. The model must be built by scientists in the affected countries with GEM's support, augmented by their insights and data. The model will launch in 2014; to succeed it must be open, international, independent, and continuously tested. But the mission of GEM is not just the likelihood of ground shaking, but also gaging the economic and social consequences of earthquakes, which greatly amplify the losses. For example, should the municipality of Istanbul retrofit schools, or increase its insurance reserves and recovery capacity? Should a homeowner in a high-risk area move or strengthen her building? This is why GEM is a public-private partnership. GEM's fourteen public sponsors and eight non-governmental organization members are standing for the developing world. To extend GEM into the financial world, we draw upon the expertise of companies. GEM's ten private sponsors have endorsed the acquisition of public knowledge over private gain. In a competitive world, this is a courageous act. GEM is but one link in a chain of preparedness: from earth science and engineering research, through groups like GEM, to mitigation, retrofit or relocate decisions, building codes and insurance, and finally to prepared hospitals, schools, and homes. But it is a link that our community can make strong.

  3. Passivity of memristor-based BAM neural networks with different memductance and uncertain delays.

    PubMed

    Anbuvithya, R; Mathiyalagan, K; Sakthivel, R; Prakash, P

    2016-08-01

    This paper addresses the passivity problem for a class of memristor-based bidirectional associate memory (BAM) neural networks with uncertain time-varying delays. In particular, the proposed memristive BAM neural networks is formulated with two different types of memductance functions. By constructing proper Lyapunov-Krasovskii functional and using differential inclusions theory, a new set of sufficient condition is obtained in terms of linear matrix inequalities which guarantee the passivity criteria for the considered neural networks. Finally, two numerical examples are given to illustrate the effectiveness of the proposed theoretical results.

  4. Seismic imaging beneath an InSAR anomaly in eastern Washington State: Shallow faulting associated with an earthquake swarm in a low-hazard area

    USGS Publications Warehouse

    Stephenson, William J.; Odum, Jackson K.; Wicks, Chuck; Pratt, Thomas L.; Blakely, Richard J.

    2016-01-01

    In 2001, a rare swarm of small, shallow earthquakes beneath the city of Spokane, Washington, caused ground shaking as well as audible booms over a five‐month period. Subsequent Interferometric Synthetic Aperture Radar (InSAR) data analysis revealed an area of surface uplift in the vicinity of the earthquake swarm. To investigate the potential faults that may have caused both the earthquakes and the topographic uplift, we collected ∼3  km of high‐resolution seismic‐reflection profiles to image the upper‐source region of the swarm. The two profiles reveal a complex deformational pattern within Quaternary alluvial, fluvial, and flood deposits, underlain by Tertiary basalts and basin sediments. At least 100 m of arching on a basalt surface in the upper 500 m is interpreted from both the seismic profiles and magnetic modeling. Two west‐dipping faults deform Quaternary sediments and project to the surface near the location of the Spokane fault defined from modeling of the InSAR data.

  5. Earthquakes; March-April 1975

    USGS Publications Warehouse

    Person, W.J.

    1975-01-01

    There were no major earthquakes (magnitude 7.0-7.9) in March or April; however, there were earthquake fatalities in Chile, Iran, and Venezuela and approximately 35 earthquake-related injuries were reported around the world. In the United States a magnitude 6.0 earthquake struck the Idaho-Utah border region. Damage was estimated at about a million dollars. The shock was felt over a wide area and was the largest to hit the continental Untied States since the San Fernando earthquake of February 1971. 

  6. Using 2,6-dichlorobenzamide (BAM) degrading Aminobacter sp. MSH1 in flow through biofilters--initial adhesion and BAM degradation potentials.

    PubMed

    Albers, Christian Nyrop; Jacobsen, Ole Stig; Aamand, Jens

    2014-01-01

    Micropollutants in groundwater are given significant attention by water companies and authorities due to an increasing awareness that they might be present even above the legal threshold values. As part of our investigations of the possibility to remove the common groundwater pollutant 2,6-dichlorobenzamide (BAM) by introducing the efficient BAM degrader Aminobacter sp. MSH1 into biologically active sand filters, we investigated if the strain adheres to filters containing various filter materials and if the initial adherence and subsequent degradation of BAM could be optimized. We found that most of the inoculated MSH1 cells adhered fast and that parameters like pH and ionic strength had only a minor influence on the adhesion despite huge influence on cell surface hydrophobicity. At the given growth protocol, the MSH1 strain apparently developed a subpopulation that had lost its ability to adhere to the filter materials, which was supported by attempted reinoculation of non-adhered cells. Analysis by quantitative PCR showed that most cells adhered in the top of the filters and that some of these were lost from the filters during initial operation, while insignificant losses occurred after 1 day of operation. The inoculated filters were found to degrade 2.7 μg/L BAM to below 0.1 μg/L at a 1.1-h residence time with insignificant formation of known degradation products. In conclusion, most filter materials and water types should be feasible for inoculation with the MSH1 strain, while more research into degradation at low concentrations and temperatures is needed before this technology is ready for use at actual waterworks.

  7. 3D seismic velocity structure in the rupture area of the 2014 M8.2 Iquique earthquake in Northern Chile

    NASA Astrophysics Data System (ADS)

    Woollam, Jack; Fuenzallida, Amaya; Garth, Tom; Rietbrock, Andreas; Ruiz, Sergio; Tavera, Hernando

    2016-04-01

    Seismic velocity tomography is one of the key tools in Earth sciences to image the physical properties of the subsurface. In recent years significant advances have been made to image the Chilean subductions zone, especially in the area of the 2010 M8.8 Maule earthquake (e.g. Hicks et al., 2014), providing much needed physical constraints for earthquakes source inversions and rupture models. In 2014 the M8.2 Iquique earthquake struck the northern part of the Chilean subduction zone in close proximity to the Peruvian boarder. The pre- and aftershock sequence of this major earthquake was recorded by a densified seismological network in Northern Chile and Southern Peru, which provides an excellent data set to study in depth the 3D velocity structure along the subduction megathrust. Based on an automatic event catalogue of nearly 10,000 events spanning the time period March to May 2014 we selected approximately 450 events for a staggered 3D inversion approach. Events are selected to guarantee an even ray coverage through the inversion volume. We only select events with a minimum GAP of 200 to improve depth estimates and therefore increase resolution in the marine forearc. Additionally, we investigate secondary arrivals between the P- and S-wave arrival to improve depth location. Up to now we have processed about 450 events, from which about 150 with at least 30 P- and S-wave observations have been selected for the subsequent 3D tomography. Overall the data quality is very high, which allows arrival time estimates better than 0.05s on average. We will show results from the 1D, 2D, and preliminary 3D inversions and discuss the results together with the obtained seismicity distribution.

  8. The 1868 Hayward Earthquake Alliance: A Case Study - Using an Earthquake Anniversary to Promote Earthquake Preparedness

    NASA Astrophysics Data System (ADS)

    Brocher, T. M.; Garcia, S.; Aagaard, B. T.; Boatwright, J. J.; Dawson, T.; Hellweg, M.; Knudsen, K. L.; Perkins, J.; Schwartz, D. P.; Stoffer, P. W.; Zoback, M.

    2008-12-01

    Last October 21st marked the 140th anniversary of the M6.8 1868 Hayward Earthquake, the last damaging earthquake on the southern Hayward Fault. This anniversary was used to help publicize the seismic hazards associated with the fault because: (1) the past five such earthquakes on the Hayward Fault occurred about 140 years apart on average, and (2) the Hayward-Rodgers Creek Fault system is the most likely (with a 31 percent probability) fault in the Bay Area to produce a M6.7 or greater earthquake in the next 30 years. To promote earthquake awareness and preparedness, over 140 public and private agencies and companies and many individual joined the public-private nonprofit 1868 Hayward Earthquake Alliance (1868alliance.org). The Alliance sponsored many activities including a public commemoration at Mission San Jose in Fremont, which survived the 1868 earthquake. This event was followed by an earthquake drill at Bay Area schools involving more than 70,000 students. The anniversary prompted the Silver Sentinel, an earthquake response exercise based on the scenario of an earthquake on the Hayward Fault conducted by Bay Area County Offices of Emergency Services. 60 other public and private agencies also participated in this exercise. The California Seismic Safety Commission and KPIX (CBS affiliate) produced professional videos designed forschool classrooms promoting Drop, Cover, and Hold On. Starting in October 2007, the Alliance and the U.S. Geological Survey held a sequence of press conferences to announce the release of new research on the Hayward Fault as well as new loss estimates for a Hayward Fault earthquake. These included: (1) a ShakeMap for the 1868 Hayward earthquake, (2) a report by the U. S. Bureau of Labor Statistics forecasting the number of employees, employers, and wages predicted to be within areas most strongly shaken by a Hayward Fault earthquake, (3) new estimates of the losses associated with a Hayward Fault earthquake, (4) new ground motion

  9. Stress-based aftershock forecasts made within 24 h postmain shock: Expected north San Francisco Bay area seismicity changes after the 2014 M = 6.0 West Napa earthquake

    NASA Astrophysics Data System (ADS)

    Parsons, Tom; Segou, Margaret; Sevilgen, Volkan; Milner, Kevin; Field, Edward; Toda, Shinji; Stein, Ross S.

    2014-12-01

    We calculate stress changes resulting from the M = 6.0 West Napa earthquake on north San Francisco Bay area faults. The earthquake ruptured within a series of long faults that pose significant hazard to the Bay area, and we are thus concerned with potential increases in the probability of a large earthquake through stress transfer. We conduct this exercise as a prospective test because the skill of stress-based aftershock forecasting methodology is inconclusive. We apply three methods: (1) generalized mapping of regional Coulomb stress change, (2) stress changes resolved on Uniform California Earthquake Rupture Forecast faults, and (3) a mapped rate/state aftershock forecast. All calculations were completed within 24 h after the main shock and were made without benefit of known aftershocks, which will be used to evaluative the prospective forecast. All methods suggest that we should expect heightened seismicity on parts of the southern Rodgers Creek, northern Hayward, and Green Valley faults.

  10. Stress-based aftershock forecasts made within 24h post mainshock: Expected north San Francisco Bay area seismicity changes after the 2014M=6.0 West Napa earthquake

    USGS Publications Warehouse

    Parsons, Thomas E.; Segou, Margaret; Sevilgen, Volkan; Milner, Kevin; Field, Ned; Toda, Shinji; Stein, Ross S.

    2014-01-01

    We calculate stress changes resulting from the M= 6.0 West Napa earthquake on north San Francisco Bay area faults. The earthquake ruptured within a series of long faults that pose significant hazard to the Bay area, and we are thus concerned with potential increases in the probability of a large earthquake through stress transfer. We conduct this exercise as a prospective test because the skill of stress-based aftershock forecasting methodology is inconclusive. We apply three methods: (1) generalized mapping of regional Coulomb stress change, (2) stress changes resolved on Uniform California Earthquake Rupture Forecast faults, and (3) a mapped rate/state aftershock forecast. All calculations were completed within 24 h after the main shock and were made without benefit of known aftershocks, which will be used to evaluative the prospective forecast. All methods suggest that we should expect heightened seismicity on parts of the southern Rodgers Creek, northern Hayward, and Green Valley faults.

  11. Spatio-temporal earthquake risk assessment for the Lisbon Metropolitan Area - A contribution to improving standard methods of population exposure and vulnerability analysis

    NASA Astrophysics Data System (ADS)

    Freire, Sérgio; Aubrecht, Christoph

    2010-05-01

    The recent 7.0 M earthquake that caused severe damage and destruction in parts of Haiti struck close to 5 PM (local time), at a moment when many people were not in their residences, instead being in their workplaces, schools, or churches. Community vulnerability assessment to seismic hazard relying solely on the location and density of resident-based census population, as is commonly the case, would grossly misrepresent the real situation. In particular in the context of global (climate) change, risk analysis is a research field increasingly gaining in importance whereas risk is usually defined as a function of hazard probability and vulnerability. Assessment and mapping of human vulnerability has however generally been lagging behind hazard analysis efforts. Central to the concept of vulnerability is the issue of human exposure. Analysis of exposure is often spatially tied to administrative units or reference objects such as buildings, spanning scales from the regional level to local studies for small areas. Due to human activities and mobility, the spatial distribution of population is time-dependent, especially in metropolitan areas. Accurately estimating population exposure is a key component of catastrophe loss modeling, one element of effective risk analysis and emergency management. Therefore, accounting for the spatio-temporal dynamics of human vulnerability correlates with recent recommendations to improve vulnerability analyses. Earthquakes are the prototype for a major disaster, being low-probability, rapid-onset, high-consequence events. Lisbon, Portugal, is subject to a high risk of earthquake, which can strike at any day and time, as confirmed by modern history (e.g. December 2009). The recently-approved Special Emergency and Civil Protection Plan (PEERS) is based on a Seismic Intensity map, and only contemplates resident population from the census as proxy for human exposure. In the present work we map and analyze the spatio-temporal distribution of

  12. Proceedings of Conference XVIII: a workshop on "Continuing actions to reduce losses from earthquakes in the Mississippi Valley area," 24-26 May, 1982, St. Louis, Missouri

    USGS Publications Warehouse

    Gori, Paula L.; Hays, Walter W.; Kitzmiller, Carla

    1983-01-01

    payoff and trre lowest cost and effort requirements. These action plans, which identify steps that can be undertaken immediately to reduce losses from earthquakes in each of the seven States in the Mississippi Valley area, are contained in this report. The draft 5-year plan for the Central United States, prepared in the Knoxville workshop, was the starting point of the small group discussions in the St. Louis workshop which lead to the action plans contained in this report. For completeness, the draft 5-year plan for the Central United States is reproduced as Appendix B.

  13. Spatially heterogeneous stress field in the source area of the 2011 Mw 6.6 Fukushima-Hamadori earthquake, NE Japan, probably caused by static stress change

    NASA Astrophysics Data System (ADS)

    Yoshida, Keisuke; Hasegawa, Akira; Okada, Tomomi

    2015-05-01

    In order to know whether principal stress orientations in the source area rotated after the 2011 April 11 Mw 6.6 Fukushima-Hamadori earthquake in NE Japan, we investigated detailed spatial distributions of stress orientations for both the pre- and post-main shock periods using a large amount of focal mechanism data. We applied stress tensor inversions to focal mechanism data from Japan's National Research Institute for Earth Science and Disaster Prevention's F-net broadband seismic network and the Japan Meteorological Agency (JMA). The σ3-axes estimated for the pre-main shock period are predominantly oriented WSW-ENE, and are relatively homogeneously in space. In contrast, the orientations of the σ3-axes show a significantly heterogeneous distribution in space for the post-main shock period. In the northern subarea of the focal region, the σ3-axes are oriented NW-SE. In the east and west portions of the central subarea, they are oriented NNW-SSE and WNW-ESE, respectively, almost perpendicular to each other. In the southern subarea, the σ3-axes are oriented WSW-ENE. On the whole, the σ3-axis orientations show concentric circle-like distribution surrounding the large slip area of the Mw Mw 6.6 main shock rupture. The change of principal stress axis orientations after the earthquake is not significant because of the sparse data set for the pre-main shock period. We calculated static stress changes from the Mw 6.6 main shock and three Mw > 5.5 earthquakes to compare with the observed stress axis orientations in the post-main shock period. The σ3-axis orientations of the calculated total static stress change show a concentric circle-like distribution surrounding the large slip area of the main shock, similar to that noted above. This observation strongly suggests that the spatially heterogeneous stress orientations in the post-main shock period were caused by the static stress change from the Mw 6.6 main shock and other large earthquakes. In order to estimate the

  14. Forecasting Earthquakes

    NASA Technical Reports Server (NTRS)

    1994-01-01

    In this video there are scenes of damage from the Northridge Earthquake and interviews with Dr. Andrea Donnelan, Geophysics at JPL, and Dr. Jim Dolan, earthquake geologist from Cal. Tech. The interviews discuss earthquake forecasting by tracking changes in the earth's crust using antenna receiving signals from a series of satellites called the Global Positioning System (GPS).

  15. Nowcasting earthquakes

    NASA Astrophysics Data System (ADS)

    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.

  16. Hidden Earthquakes.

    ERIC Educational Resources Information Center

    Stein, Ross S.; Yeats, Robert S.

    1989-01-01

    Points out that large earthquakes can take place not only on faults that cut the earth's surface but also on blind faults under folded terrain. Describes four examples of fold earthquakes. Discusses the fold earthquakes using several diagrams and pictures. (YP)

  17. In silico analysis and recombinant expression of BamA protein as a universal vaccine against Escherichia coli in mice.

    PubMed

    Guan, Qingfeng; Wang, Xiao; Wang, Xiumin; Teng, Da; Wang, Jianhua

    2016-06-01

    Colibacillosis, caused by pathogenic Escherichia coli, is a common disease in animals and human worldwide with extensive losses in breeding industry and with millions of people death annually. There is thus an urgent need for the development of universal vaccines against colibacillosis. In this study, the BamA protein was analyzed in silico for sequence homology, physicochemical properties, allergenic prediction, and epitopes prediction. The BamA protein (containing 286 amino acids) clusters in E. coli were retrieved in UniProtKB database, in which 81.7 % sequences were identical (Uniref entry A7ZHR7), and sequences with 94.82 % identity were above 93.4 %. Moreover, BamA was highly conserved among Salmonella and Shigella and has no allergenicity to mice and human. The epitopes of BamA were located principally in periplasm and extracellular domain. Surf_Ag_VNR domain (at position 448-810 aa) of BamA was expressed, purified, and then used for immunization of mice. Titers of the rBamA sera were 1:736,000 and 1:152,000 against rBamA and E. coli and over 1:27,000 against Salmonella and Shigella. Opsonophagocytosis result revealed that the rBamA sera strengthened the phagocytic activity of neutrophils against E. coli. The survival rate of mice vaccinated with rBamA and PBS was 80 and 20 %, respectively. These data indicated that BamA could serve as a promising universal vaccine candidate for the development of a protective subunit vaccine against bacterial infection. Thus, the above protocol would provide more feasible technical clues and choices for available control of pathogenic E. coli, Salmonella, and Shigella.

  18. [Effects of empathy on fund-raising activities on behalf of victims of the 2011 Great East Japan Earthquake, focusinig on the residents in the South Kanto area].

    PubMed

    Yamamoto, Youichi; Yoo, Seonyoung; Matsui, Yutaka

    2015-02-01

    Fund-raising activities on behalf of victims of the 2011 Great East Japan Earthquake during the year after the earthquake were investigated in residents of the South Kanto area (N = 749), which is adjacent to the disaster area. The percentage of people that raised funds was 67.4%. We investigated the effects of the following on fundraising activities: demographic variables (sex, age, and educational background), trait empathy (empathic concern, perspective taking, and personal distress), former experience with fund-raising activities, effects of similarity to victims (e.g., experienced inconveniences because of the disaster, or had problems returning home), and psychological closeness to victims (e.g, have family members or acquaintances that suffered from the disaster, or that once lived in the disaster area). The results indicated that fund-raising activities were affected by former experience with fund-raising, similarity to victims, psychological closeness to victims, empathic concern, and being female. The relationship between fund-raising activities for victims and empathy are discussed.

  19. Prototype Earthquake Early Warning System for Areas of Highest Seismic Risk in the Western U.S.

    NASA Astrophysics Data System (ADS)

    Bock, Y.; Geng, J.; Goldberg, D.; Saunders, J. K.; Haase, J. S.; Squibb, M. B.; Melgar, D.; Crowell, B. W.; Clayton, R. W.; Yu, E.; Walls, C. P.; Mann, D.; Mencin, D.; Mattioli, G. S.

    2015-12-01

    We report on a prototype earthquake early warning system for the Western U.S. based on GNSS (GPS+GLONASS) observations, and where available collocated GNSS and accelerometer data (seismogeodesy). We estimate with latency of 2-3 seconds GNSS displacement waveforms from more than 120 stations, focusing on the southern segment of the San Andreas fault, the Hayward and Rodgers Creek faults and Cascadia. The displacements are estimated using precise point positioning with ambiguity resolution (PPP-AR), which provides for efficient processing of hundreds of "clients" within the region of interest with respect to a reference frame well outside the expected zone of deformation. The GNSS displacements are useful for alleviating magnitude saturation concerns, rapid earthquake magnitude estimation using peak ground displacements, CMT solutions and finite fault slip models. However, GNSS alone is insufficient for strict earthquake early warning (i.e., P wave detection). Therefore, we employ a self-contained seismogeodetic technique, where collocations of GNSS and accelerometer instruments are available, to estimate real-time displacement and velocity waveforms using PPP-AR with accelerometers (PPP-ARA). Using the velocity waveforms we can detect the P wave arrival for earthquakes of interest (>M 5.5), estimate a hypocenter, S wave propagation, and earthquake magnitude using Pd scaling relationships within seconds. Currently we are gearing up to receive observatory-grade accelerometer data from the CISN. We have deployed 25 inexpensive MEMS accelerometers at existing GNSS stations. The SIO Geodetic Modules that control the flow of the GNSS and accelerometer data are being upgraded with in situ PPP-ARA and P wave picking. In situ processing allows us to use the data at the highest sampling rate of the GNSS receiver (10 Hz or higher), in combination with the 100 Hz accelerometer data. Adding the GLONASS data allows for increased precision in the vertical, an important factor in P

  20. WGCEP Historical California Earthquake Catalog

    USGS Publications Warehouse

    Felzer, Karen R.; Cao, Tianqing

    2008-01-01

    This appendix provides an earthquake catalog for California and the surrounding area. Our goal is to provide a listing for all known M > 5.5 earthquakes that occurred from 1850-1932 and all known M > 4.0 earthquakes that occurred from 1932-2006 within the region of 31.0 to 43.0 degrees North and -126.0 to -114.0 degrees West. Some pre-1932 earthquakes 4 5, before the Northern California network was online. Some earthquakes from 1900-1932, and particularly from 1910-1932 are also based on instrumental readings, but the quality of the instrumental record and the resulting analysis are much less precise than for later listings. A partial exception is for some of the largest earthquakes, such as the San Francisco earthquake of April 18, 1906, for which global teleseismic records (Wald et al. 1993) and geodetic measurements (Thatcher et al. 1906) have been used to help determine magnitudes.

  1. 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)

    PubMed Central

    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

  2. OMG Earthquake! Can Twitter improve earthquake response?

    NASA Astrophysics Data System (ADS)

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

    2009-12-01

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

  3. Cutaneous leishmaniasis in primary school children in the south-eastern Iranian city of Bam, 1994-95.

    PubMed Central

    Sharifi, I.; Fekri, A. R.; Aflatonian, M. R.; Nadim, A.; Nikian, Y.; Kamesipour, A.

    1998-01-01

    Between August 1994 and July 1995, 11,517 primary school children aged 6-11 years in the south-eastern Iranian city of Bam, comprising 5560 (48.3%) girls and 5957 (51.7%) boys, were examined for the presence of active lesions or scars of cutaneous leishmaniasis (CL). There was a trend towards increasing prevalence with age, the prevalence being 10.7% in 6-year-old and 20% in > or = 11-year-old children. Overall, 1.3% of the children had active lesions and 14.3% had scars. There was no significant difference between the sexes in the prevalence of active lesions and/or scars. Of the children examined, 54 (0.5%) had leishmaniasis recidivans: 19 girls (35.2%) and 35 boys (64.8%). The number of active lesions or scars per child ranged from 1 to 10. The majority (82.3%) had 1 lesion, 12.4% had 2 lesions, and 5.3% had > or = 3. The average number of lesions was 1.08 (1.03 in girls and 1.18 in boys). The face was the part of the body most commonly involved (63.6%), followed by the hands (20.9%), legs (12.8%) and other parts of the body (2.7%). Examination of isolates from 14 children revealed that in 13 (92.9%) the causal organism was Leishmania tropica and in the other (7.1%) L. major. The survey indicates that the geographical distribution of CL is far wider than previously thought. It also shows that Bam is a suitable areas for a vaccine field trial. PMID:9744249

  4. Focal mechanisms of micro-earthquakes in the Dobrá Voda seismoactive area in the Malé Karpaty Mts. (Little Carpathians), Slovakia

    NASA Astrophysics Data System (ADS)

    Fojtíková, Lucia; Vavryčuk, Václav; Cipciar, Andrej; Madarás Malé, Ján

    2010-09-01

    We have analyzed 44 micro-earthquakes with magnitudes between 1.2 and 3.4, which occurred in the Dobrá Voda area, Slovakia, in the period 2001-2009. The epicentres of the micro-earthquakes form a cluster elongated in the ENE-WSW direction. This direction coincides with the orientation of the main fault systems in the area: Dobrá Voda and Brezová faults. The depths of the hypocentres vary from 1 km to 14 km. Three different methods were used to calculate the focal mechanisms: (a) a method using the polarities of Pg and Pn waves, (b) the P-wave amplitude inversion of moment tensors, and (c) the waveform inversion of moment tensors. The majority of the analyzed micro-earthquakes have a left-lateral strike-slip focal mechanism with weak normal or reverse components. The full moment tensors comprise significant non-double-couple (non-DC) components. The non-DC components are partly numerical errors of the inversion but might be also of a physical origin. The most accurate values of the non-DC components are obtained from the P-wave amplitude inversion. For this inversion, the isotropic component (ISO) and the compensated linear vector dipole component (CLVD) are mostly positive and well correlated. This might indicate tensile faulting. Adopting the model of tensile faulting, we estimated the mean ratio of P to S wave velocities in the focal area from the values of ISO and CLVD, vP/ vS = 1.5-1.6. The three different datasets of the focal mechanisms have been inverted for the present-day tectonic stress in the Dobrá Voda area. The slip shear stress component criterion was applied in the stress inversion. The results of the three inversions are well-consistent and point to a high reliability and good accuracy of the inverted stress. The orientations of the principal stresses are (azimuth/plunge): σ1 = 210-220°/5-25°, σ2 = 70-105°/55-75°, and σ3 = 305-315°/15-25°, and the shape ratio is R = 0.45-0.60. The azimuth is measured clockwise from the north and the

  5. The 1946 Unimak Tsunami Earthquake Area: revised tectonic structure in reprocessed seismic images and a suspect near field tsunami source

    USGS Publications Warehouse

    Miller, John J.; von Huene, Roland; Ryan, Holly F.

    2014-01-01

    In 1946 at Unimak Pass, Alaska, a tsunami destroyed the lighthouse at Scotch Cap, Unimak Island, took 159 lives on the Hawaiian Islands, damaged island coastal facilities across the south Pacific, and destroyed a hut in Antarctica. The tsunami magnitude of 9.3 is comparable to the magnitude 9.1 tsunami that devastated the Tohoku coast of Japan in 2011. Both causative earthquake epicenters occurred in shallow reaches of the subduction zone. Contractile tectonism along the Alaska margin presumably generated the far-field tsunami by producing a seafloor elevation change. However, the Scotch Cap lighthouse was destroyed by a near-field tsunami that was probably generated by a coeval large undersea landslide, yet bathymetric surveys showed no fresh large landslide scar. We investigated this problem by reprocessing five seismic lines, presented here as high-resolution graphic images, both uninterpreted and interpreted, and available for the reader to download. In addition, the processed seismic data for each line are available for download as seismic industry-standard SEG-Y files. One line, processed through prestack depth migration, crosses a 10 × 15 kilometer and 800-meter-high hill presumed previously to be basement, but that instead is composed of stratified rock superimposed on the slope sediment. This image and multibeam bathymetry illustrate a slide block that could have sourced the 1946 near-field tsunami because it is positioned within a distance determined by the time between earthquake shaking and the tsunami arrival at Scotch Cap and is consistent with the local extent of high runup of 42 meters along the adjacent Alaskan coast. The Unimak/Scotch Cap margin is structurally similar to the 2011 Tohoku tsunamigenic margin where a large landslide at the trench, coeval with the Tohoku earthquake, has been documented. Further study can improve our understanding of tsunami sources along Alaska’s erosional margins.

  6. The most-probable-number enumeration of dichlobenil and 2,6-dichlorobenzamide (BAM) degrading microbes in Finnish aquifers.

    PubMed

    Pukkila, Veera; Gustafsson, Juhani; Tuominen, Jari; Aallonen, Anri; Kontro, Merja H

    2009-09-01

    In groundwater subsurface deposits and a topsoil from five aquifers having 2,6-dichlorobenzamide (BAM) in water, we determined the most-probable-number (MPN) of 2,6-dichlorobenzonitrile (dichlobenil) and metabolite BAM degrading microorganisms. Dichlobenil and BAM were combined nitrogen sources in the MPN tubes, which were scored positive at concentrations <75% after 1 month incubation. Aerobic and anaerobic microbes degrading dichlobenil and BAM were common in samples in low numbers of 3.6-210 MPN g dw(-1). Additional degradation occurred in high MPN dilutions of some samples, the microbial numbers being 0.11-120 x 10(5) MPN g dw(-1). The strains were isolated from low and high dilutions of one deposit, and degradation in pure cultures was confirmed by HPLC. According to the 16S rDNA sequencing, strains were from genera Zoogloea, Pseudomonas, Xanthomonas, Rhodococcus, Nocardioides, Sphingomonas, and Ralstonia. Dichlobenil (45.5 +/- 18.3%) and BAM (37.6 +/- 14%) degradation was low in the MPN tubes. Despite of microbial BAM degradation activity in subsurface deposits, BAM was measured from groundwater.

  7. High-resolution seismic reflection surveys and modeling across an area of high damage from the 1994 Northridge earthquake, Sherman Oaks, California

    USGS Publications Warehouse

    Stephenson, William J.; Williams, Robert A.; Odum, Jack K.; Worley, David M.

    2000-01-01

    Approximately 3.6 km of P-wave seismic-reflection data were acquired along two orthogonal profiles in Sherman Oaks, California to determine whether shallow (less than 1-km depth) geologic structures contributed to the dramatic localized damage resulting from the 1994 Northridge earthquake. Both lines, one along Matilija Avenue and one along Milbank Street, crossed areas of both high and low damage. We believe these data reveal a geologic structure in the upper 600 m that contributed to the increased earthquake ground shaking in the high-damage areas south of and along the Los Angeles River. Of interest in these data is a reflection interpreted to be from bedrock that can be traced to the north along the Matilija Avenue profile. This reflecting interface, dipping northward at 15°–22°, may be an important impedance boundary because it is the lower boundary of a wedge of overlying low-velocity sediments. The wedge thins and terminates in the area where we interpret down-warped reflections as evidence of a shallow subbasin. The low-velocity subbasin sediments (Vs of 200 m/sec Vp of 500 m/sec) may be up to 150 m thick beneath the channelized Los Angeles River. The area across the subbasin experienced greater earthquake damage from possible geometric focusing effects. Three-dimensional basin effects may be responsible for the variable damage pattern, but from these seismic profiles it is not possible to determine the regional structural trends. Two-dimensional elastic and SH-mode finite-difference modeling of the imaged structural geometry along Matilija Avenue suggests that a peak horizontal-velocity amplification factor of two-and-over can be explained in the high-damage area above the shallow subbasin and sediment wedge. Amplification factors up to 5 were previously observed in aftershock data, at frequencies of 2 to 6 Hz. Amplification in the elastic simulation at the Santa Monica Mountains range-front on the southern end of the Matilija profile, with the

  8. Effects of the earthquake of March 27, 1964, in the Homer area, Alaska, with a section on beach changes on Homer Spit: Chapter D in The Alaska earthquake, March 27, 1964: effects on communities

    USGS Publications Warehouse

    Waller, Roger M.; Stanley, Kirk W.

    1966-01-01

    The March 27, 1964, earthquake shook the Homer area for about 3 minutes. Land effects consisted of a 2- to 6-foot subsidence of the mainland and Homer Spit, one earthflow at the mouth of a canyon, several landslides on the Homer escarpment and along the sea bluffs, and minor fissuring of the ground, principally at the edges of bluffs and on Homer Spit. Hydrologic effects consisted of at least one and possibly two submarine landslides at the end of the spit, seiche waves in Kachemak Bay, ice breakage on Beluga Lake, sanding of wells, and a temporary loss of water in some wells. Seismic damage to the community was light in comparison with that of other communities closer to the epicenter. One submarine landslide, however, took out most of the harbor breakwater. The greatest damage was due to the subsidence of the spit, both tectonically (2–3 ft) and by differential compaction or lateral spreading (an additional 1–4 ft). Higher tides now flood much of the spit. The harbor and dock had to be replaced, and buildings on the end of the spit had to be elevated. Protection works for other buildings and the highway were needed. These works included application of fill to raise the highway and parts of the spit above high tides. Reconstruction costs and disaster loans totaled about $2½ million, but this amount includes added improvement costs over preexisting values. Homer Spit in particular and the Homer area in general rank as areas where precautions must be taken in selecting building sites. The hazards of landslides, earthflows, compaction and submarine slumping—all of which might be triggered by an earthquake—should be considered in site selection. In plan, Homer Spit resembles a scimitar with its curving blade pointed seaward. It is about 4 miles long and as much as 1,500 feet wide. The spit is composed largely of gravel intermixed with some sand. After the earthquake and the resulting tectonic subsidence and compaction, much of the spit was below high

  9. Crustal structure modelling for the northern part of the Aswan lake area using seismic waves generated by explosions and local earthquakes

    NASA Astrophysics Data System (ADS)

    Kebeasy, R. M.; Bayoumi, A. I.; Gharib, A. A.

    In this work, two types of seismic waves generated from explosions and local earthquakes were used as wave sources to model the crust and upper mantle structure of the Aswan area. Two reserved refraction profiles oriented N-S were carried out in the northern part of the Aswan Lake area across the E-W fault trends. Interpretation of seismic explosion data shows the crust beneath the Aswan reservoir area to be characterized by three major refractors below the sedimentary cover. P-and S-Wave velocities and depths of these layers respectively are; 5.3 and 3.0 km/s from the base of the Nubian sandstone to a depth of 4.7 km; 6.2 and 3.5 km/s to a depth of 16 km and 6.9 and 3.7 km/s for depths greater than 16 km. The uppermost mantle P velocity is 8.1 km/s which is deduced from the old Aswan Dam explosion, as a P mP phase. Near the reservoir area, the sediments comprise a single layer with Vp1 of 2.2. km/s and Vs1 of 1.25 kms/s with varying thickness from 250 m at the northern shot (Khor Kurkur) to 350 m at the southern shot (Garf Hussein) west of Gebel Marawa; along the Sinn El-Kaddab profile, however, it shows two different velocity layers having Vp2 of 2.2 km/s and Vp1 of 1.22 km/s for the layer and Vp2 of km/s and Vs2 of 1.98 km/s for the second with thickness of 250 m and 450 m, respectively. A remarkable slowing of Pg at Gebel Marawa is due to abundant faults and fractures. Local earthquake data indicate that the velocity variations in the Aswan crust similar to those deduced from the refraction explosion experiment. The P-wave ( P ∗) velocity of 6.9 km/s for the lower crust was extended to a depth of 30 km by introducing a P n velocity of 8.1 km/s for the upper mantle, this significantly improved the RMS residuals. The relative station correction derived from the velocity inversion of local earthquakes reflects the local variations in the crustal structure combined with local sedimentary inhomogeneities and variation in thickness.

  10. PtrBAM1, a β-amylase-coding gene of Poncirus trifoliata, is a CBF regulon member with function in cold tolerance by modulating soluble sugar levels.

    PubMed

    Peng, Ting; Zhu, Xiaofang; Duan, Nian; Liu, Ji-Hong

    2014-12-01

    β-Amylase (BAM) catalyses starch breakdown to generate maltose, which can be incorporated into sugar metabolism. However, the role of BAM genes in cold tolerance is less characterized. In this study, we report the isolation and functional characterization of a chloroplast-localizing BAM-encoding gene PtrBAM1 from Poncirus trifoliata. PtrBAM1 was induced by cold, dehydration and salt, but repressed by maltose. Overexpression of PtrBAM1 in tobacco (Nicotiana nudicaulis) increased BAM activity, promoted starch degradation and enhanced the contents of maltose and soluble sugars, whereas opposite changes were observed when PtrBAM1 homolog in lemon (Citrus lemon) was knocked down. The tobacco overexpressing lines exhibited enhanced tolerance to cold at chilling or freezing temperatures. Under cold stress, higher BAM activity and greater accumulation of maltose and soluble sugars were observed in the overexpressing lines when compared with the wild-type or empty vector transformants. Bioinformatics analysis demonstrated that PtrBAM1 promoter contained a CBF-recognizing element. Yeast one-hybrid assay demonstrated that PtrCBF could interact with the promoter fragment containing the element. Taken together, these results demonstrate that PtrBAM1 is a member of CBF regulon and plays an important role in cold tolerance by modulating the levels of soluble sugars acting as osmolytes or antioxidants.

  11. Deep electrical resistivity tomography along the tectonically active Middle Aterno Valley (2009 L'Aquila earthquake area, central Italy)

    NASA Astrophysics Data System (ADS)

    Pucci, Stefano; Civico, Riccardo; Villani, Fabio; Ricci, Tullio; Delcher, Eric; Finizola, Anthony; Sapia, Vincenzo; De Martini, Paolo Marco; Pantosti, Daniela; Barde-Cabusson, Stéphanie; Brothelande, Elodie; Gusset, Rachel; Mezon, Cécile; Orefice, Simone; Peltier, Aline; Poret, Matthieu; Torres, Liliana; Suski, Barbara

    2016-11-01

    Three 2-D Deep Electrical Resistivity Tomography (ERT) transects, up to 6.36 km long, were obtained across the Paganica-San Demetrio Basin, bounded by the 2009 L'Aquila Mw 6.1 normal-faulting earthquake causative fault (central Italy). The investigations allowed defining for the first time the shallow subsurface basin structure. The resistivity images, and their geological interpretation, show a dissected Mesozoic-Tertiary substratum buried under continental infill of mainly Quaternary age due to the long-term activity of the Paganica-San Demetrio normal faults system (PSDFS), ruling the most recent deformational phase. Our results indicate that the basin bottom deepens up to 600 m moving to the south, with the continental infill largely exceeding the known thickness of the Quaternary sequence. The causes of this increasing thickness can be: (1) the onset of the continental deposition in the southern sector took place before the Quaternary, (2) there was an early stage of the basin development driven by different fault systems that produced a depocentre in the southern sector not related to the present-day basin shape, or (3) the fault system slip rate in the southern sector was faster than in the northern sector. We were able to gain sights into the long-term PSDFS behaviour and evolution, by comparing throw rates at different timescales and discriminating the splays that lead deformation. Some fault splays exhibit large cumulative throws (>300 m) in coincidence with large displacement of the continental deposits sequence (>100 m), thus testifying a general persistence in time of their activity as leading splays of the fault system. We evaluate the long-term (3-2.5 Myr) cumulative and Quaternary throw rates of most of the leading splays to be 0.08-0.17 mm yr-1, indicating a substantial stability of the faults activity. Among them, an individual leading fault splay extends from Paganica to San Demetrio ne' Vestini as a result of a post-Early Pleistocene linkage of

  12. Enhanced Geothermal Systems in Urban Areas - Lessons Learned from the 2006 Basel ML3.4 Earthquake

    NASA Astrophysics Data System (ADS)

    Kraft, T.; Mai, P. M.; Wiemer, S.; Deichmann, N.; Ripperger, J.; Kästli, P.; Bachmann, C. E.; Fäh, D.; Woessner, J.; Giardini, D.

    2009-12-01

    We report on a recent deep-heat mining experiment carried out in 2006/2007 in the city of Basel (Switzerland). This pilot project was designed to produce renewable geothermal energy using the Enhanced Geothermal System (EGS) methodology. For developing the geothermal reservoir, a deep borehole was brought down to 5 km depth. Then, in December 2006, the deep-heat-mining project entered the first critical phase when the water injections started for generating micro-fracturing of the rock. These fractures increase the permeability of the host rock, needed for efficient heat exchange between the rock and the cold water; however, these fracture are also source of micro-seismicity - small earthquakes that are continuously recorded and monitored by dedicated local seismic networks. In this stimulation phase, the seismic activity increased rapidly above the usual background seismicity, and culminated in a widely felt ML 3.4 earthquake, which caused some damage in the city of Basel. Due to the higher-than-expected seismic activity, and the reaction of the population, the media, and the politicians, the experiment was stalled only 6 days after the stimulations began. Although the injected water was allowed to escape immediately after the mainshock and pressure at the wellhead dropped rapidly, the seismic activity declined only slowly, with three ML > 3 events occurring one to two months later. Although the EGS technology has been applied and studied at various sites since the 1970s, the physical processes and parameters that control injection-induced seismicity - in terms of earthquake rate, size distribution and maximum magnitude - are still poorly understood. Consequently, the seismic hazard and risk associated with the creation and operation of EGS are difficult to estimate. The very well monitored Basel seismic sequence provides an excellent opportunity to advance the understanding of the physics of EGS. The Swiss Seismological Service (SED) is investigating the Basel

  13. The Bam repeats of the mouse genome belong in several superfamilies the longest of which is over 9 kb in size.

    PubMed Central

    Meunier-Rotival, M; Bernardi, G

    1984-01-01

    Mouse DNA contains two equally abundant, homologous subfamilies of MspI 3.6 and 5 kb repeated fragments. The first subfamily corresponds to the previously described (1) Bam 4 kb repeats, the second one to Bam repeated fragments of higher molecular weight. These subfamilies account for the vast majority of long Bam repeats and are linked with contiguous short Bam 0.5 kb repeats. A minority of these composite Bam repeats extend, on the 0.5 kb side, into R repeats. In turn, a fraction of the composite Bam/R repeats extend further, for at least 3 kb, into other repeated sequences contiguous to the R repeats. The long Bam repeats belong, therefore, in at least three superfamilies of repeats, the longest one being over 9 kb in size. Some general properties of these superfamilies are discussed. Images PMID:6322110

  14. Symptoms of posttraumatic stress disorder, depression, and anxiety among junior high school students in worst-hit areas 3 years after the Wenchuan earthquake in China.

    PubMed

    Pan, Xiao; Liu, Weizhi; Deng, Guanghui; Liu, Taosheng; Yan, Jin; Tang, Yunxiang; Dong, Wei; Cui, Yi; Xu, Miao

    2015-03-01

    The aim of this study was to examine symptoms of posttraumatic stress disorder (PTSD), depression, and anxiety among junior high school students in worst-hit areas 3 years after the Wenchuan earthquake. Analyses were carried out on 373 of the 377 students enrolled. In addition to obtaining demographic characteristics, the Impact of Event Scale-Revised, the Zung Self-rating Depression Scale, the Zung Self-rating Anxiety Scale, and an Earthquake exposure screening scale were administered. It was found that 29.6%, 44.8%, and 37.6% of participants reported clinical symptoms of PTSD, depression, and anxiety, respectively. PTSD, depression, and anxiety were highly comorbid. Having witnessed someone being killed, family members being killed, close friends seriously injured or being killed, and felt scared remained as significant predictors for PTSD. Having witnessed someone seriously injured and felt scared remained as significant predictors for depression. Having witnessed someone seriously injured, witnessed someone being killed, and felt scared remained as significant predictors for anxiety.

  15. Earthquakes with non--double-couple mechanisms.

    PubMed

    Frohlich, C

    1994-05-06

    Seismological observations confirm that the pattern of seismic waves from some earthquakes cannot be produced by slip along a planar fault surface. More than one physical mechanism is required to explain the observed varieties of these non-double-couple earthquakes. The simplest explanation is that some earthquakes are complex, with stress released on two or more suitably oriented, nonparallel fault surfaces. However, some shallow earthquakes in volcanic and geothermal areas require other explanations. Current research focuses on whether fault complexity explains most observed non-double-couple earthquakes and to what extent ordinary earthquakes have non-double-couple components.

  16. Earthquakes in the United States

    USGS Publications Warehouse

    Stover, C.

    1977-01-01

    To supplement data in the report Preliminary Determination of Epicenters (PDE), the National earthquake Information Service (NEIS) also publishes a quarterly circular, Earthquakes in the United States. This provides information on the felt area of U.S earthquakes and their intensity. The main purpose is to describe the larger effects of these earthquakes so that they can be used in seismic risk studies, site evaluations for nuclear power plants, and answering inquiries by the general public.

  17. Investigations on antibody binding to a micro-cantilever coated with a BAM pesticide residue

    NASA Astrophysics Data System (ADS)

    Bache, Michael; Taboryski, Rafael; Schmid, Silvan; Aamand, Jens; Jakobsen, Mogens Havsteen

    2011-05-01

    The attachment of an antibody to an antigen-coated cantilever has been investigated by repeated experiments, using a cantilever-based detection system by Cantion A/S. The stress induced by the binding of a pesticide residue BAM (2,6 dichlorobenzamide) immobilized on a cantilever surface to anti-BAM antibody is measured using the CantiLab4© system from Cantion A/S with four gold-coated cantilevers and piezo resistive readout. The detection mechanism is in principle label-free, but fluorescent-marked antibodies have been used to subsequently verify the binding on the cantilever surface. The bending and increase in mass of each cantilever has also been investigated using a light interferometer and a Doppler Vibrometer. The system has been analyzed during repeated measurements to investigate whether the CantiLab4© system is a suited platform for a pesticide assay system.

  18. SeqLib: a C ++ API for rapid BAM manipulation, sequence alignment and sequence assembly.

    PubMed

    Wala, Jeremiah; Beroukhim, Rameen

    2017-03-01

    We present SeqLib, a C ++ API and command line tool that provides a rapid and user-friendly interface to BAM/SAM/CRAM files, global sequence alignment operations and sequence assembly. Four C libraries perform core operations in SeqLib: HTSlib for BAM access, BWA-MEM and BLAT for sequence alignment and Fermi for error correction and sequence assembly. Benchmarking indicates that SeqLib has lower CPU and memory requirements than leading C ++ sequence analysis APIs. We demonstrate an example of how minimal SeqLib code can extract, error-correct and assemble reads from a CRAM file and then align with BWA-MEM. SeqLib also provides additional capabilities, including chromosome-aware interval queries and read plotting. Command line tools are available for performing integrated error correction, micro-assemblies and alignment.

  19. Existence and global exponential stability of periodic solution of memristor-based BAM neural networks with time-varying delays.

    PubMed

    Li, Hongfei; Jiang, Haijun; Hu, Cheng

    2016-03-01

    In this paper, we investigate a class of memristor-based BAM neural networks with time-varying delays. Under the framework of Filippov solutions, boundedness and ultimate boundedness of solutions of memristor-based BAM neural networks are guaranteed by Chain rule and inequalities technique. Moreover, a new method involving Yoshizawa-like theorem is favorably employed to acquire the existence of periodic solution. By applying the theory of set-valued maps and functional differential inclusions, an available Lyapunov functional and some new testable algebraic criteria are derived for ensuring the uniqueness and global exponential stability of periodic solution of memristor-based BAM neural networks. The obtained results expand and complement some previous work on memristor-based BAM neural networks. Finally, a numerical example is provided to show the applicability and effectiveness of our theoretical results.

  20. Earthquake prediction; fact and fallacy

    USGS Publications Warehouse

    Hunter, R.N.

    1976-01-01

    Earthquake prediction is a young and growing area in the field of seismology. Only a few years ago, experts in seismology were declaring flatly that it was impossible. Now, some successes have been achieved and more are expected. Within a few years, earthquakes may be predicted as routinely as the weather, and possibly with greater accuracy. 

  1. The Damaging Effects of Earthquake Excitation on Concrete Cooling Towers

    SciTech Connect

    Abedi-Nik, Farhad; Sabouri-Ghomi, Saeid

    2008-07-08

    Reinforced concrete cooling towers of hyperbolic shell configuration find widespread application in utilities engaged in the production of electric power. In design of critical civil infrastructure of this type, it is imperative to consider all the possible loading conditions that the cooling tower may experience, an important loading condition in many countries is that of the earthquake excitation, whose influence on the integrity and stability of cooling towers is profound. Previous researches have shown that the columns supporting a cooling tower are sensitive to earthquake forces, as they are heavily loaded elements that do not possess high ductility, and understanding the behavior of columns under earthquake excitation is vital in structural design because they provide the load path for the self weight of the tower shell. This paper presents the results of a finite element investigation of a representative 'dry' cooling tower, using realistic horizontal and vertical acceleration data obtained from the recent and widely-reported Tabas, Naghan and Bam earthquakes in Iran. The results of both linear and nonlinear analyses are reported in the paper, the locations of plastic hinges within the supporting columns are identified and the ramifications of the plastic hinges on the stability of the cooling tower are assessed. It is concluded that for the (typical) cooling tower configuration analyzed, the columns that are instrumental in providing a load path are influenced greatly by earthquake loading, and for the earthquake data used in this study the representative cooling tower would be rendered unstable and would collapse under the earthquake forces considered.

  2. USDA FSIS, FDA BAM, AOAC, and ISO culture methods BD BBL CHROMagar Listeria Media.

    PubMed

    Ritter, Vicki; Kircher, Susan; Sturm, Krista; Warns, Patty; Dick, Nancy

    2009-01-01

    BBL CHROMagar Listeria Media (CL) was evaluated for detection of Listeria monocytogenes in raw ground beef, smoked salmon, lettuce, and Brie cheese. The recovery of L. monocytogenes on CL was compared to the U.S. Food and Drug Administration (FDA) Bacteriological Analytical Manual (BAM), U.S. Department of Agriculture (USDA) Food Safety and Inspection Service (FSIS), AOAC, and International Organization for Standardization (ISO) reference-plated media using the recommended pre-enrichments and selective enrichments. Of the 265 food samples tested, 140 were tested using BAM, USDA, or AOAC methods and 125 were tested using ISO methods. CL produced comparable results with the reference methods on all matrixes with a sensitivity of 99.3% and a specificity of 100%. No false negatives were found in testing the food matrixes. There was no statistical difference in recovery based on Chi-square analysis. Known isolates were evaluated, and CL had a sensitivity and specificity of 100%. The results of this study demonstrate that CL is an effective medium for the recovery and detection of L. monocytogenes in raw ground beef, smoked salmon, lettuce, and Brie cheese using FDA BAM, USDA FSIS, AOAC, and ISO culture methods.

  3. Thick barium hexaferrite (Ba-M) films prepared by electron-beam evaporation for microwave application

    NASA Astrophysics Data System (ADS)

    Wane, I.; Bessaudou, A.; Cosset, F.; Célérier, A.; Girault, C.; Decossas, J. L.; Vareille, J. C.

    2000-03-01

    Hexagonal ferrites such as barium or strontium hexaferrites have many existing and potential applications. Among these are microwave devices. In this paper we present the results of Ba-M thick ferrite films deposited on silicon (1 0 0) by electron-beam evaporation. To increase adhesion and reduce cracks, the films are also deposited on thin (#1 μm) metallic underlayers. The influence of deposition rate and post-deposition annealing on crystallographic structure, magnetic properties, morphology and chemical composition has been investigated. The deposition pressure was equal to 0.46 Pa and substrate temperature was kept at 200°C. The results show that, before annealing, the films do not crystallise under the bulk phase of BaFe 12O 19 (Ba-M) and magnetic measurements show no hysteresis curve. On the other hand, films annealed at 850°C for 2 h in oxygen atmosphere are magnetic and crystallise in the Ba-M phase. The coercive fields of these films range between 160 and 360 kA/m. The saturation magnetisation of the annealed films varies between 0.15 and 0.21 T. The EDX analysis shows that the Fe/Ba atomic ratio depends on the deposition rate. The SEM study shows homogeneous film surfaces and small grains size.

  4. Earthquake prediction

    NASA Technical Reports Server (NTRS)

    Turcotte, Donald L.

    1991-01-01

    The state of the art in earthquake prediction is discussed. Short-term prediction based on seismic precursors, changes in the ratio of compressional velocity to shear velocity, tilt and strain precursors, electromagnetic precursors, hydrologic phenomena, chemical monitors, and animal behavior is examined. Seismic hazard assessment is addressed, and the applications of dynamical systems to earthquake prediction are discussed.

  5. Earthquake Hazards.

    ERIC Educational Resources Information Center

    Donovan, Neville

    1979-01-01

    Provides a survey and a review of earthquake activity and global tectonics from the advancement of the theory of continental drift to the present. Topics include: an identification of the major seismic regions of the earth, seismic measurement techniques, seismic design criteria for buildings, and the prediction of earthquakes. (BT)

  6. Analog earthquakes

    SciTech Connect

    Hofmann, R.B.

    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.

  7. The nutritional status of young children and feeding practices two years after the Wenchuan Earthquake in the worst-affected areas in China.

    PubMed

    Sun, Jing; Huo, Junsheng; Zhao, Liyun; Fu, Ping; Wang, Jie; Huang, Jian; Wang, Lijuan; Song, Pengkun; Fang, Zheng; Chang, Suying; Yin, Shian; Zhang, Jian; Ma, Guansheng

    2013-01-01

    This study was carried out to investigate the nutritional status and feeding practices of young children in the worst-affected areas of China two years after the Wenchuan Earthquake. The sample consisted of 1,254 children 6-23 months of age living in four selected counties from the disaster-affected provinces of Sichuan, Shaanxi and Gansu. Length-for-age, weight-for-age, weight-for-length, and hemoglobin concentration were used to evaluate nutritional status. Interviews with selected children's caretakers collected basic demographic information, children's medical history, and child feeding practices. Stunting, underweight, and wasting prevalence rates in children 6-23 months of age were 10.8%, 4.9% and 2.8% respectively, and anemia prevalence was 52.2%. Only 12.3% of children had initiated breastfeeding within the first hour after birth. Overall, 90.9% of children had ever been breastfed, and 87% children 6-8 months of age had received solid, semi-solid or soft foods the day before the interview. The diets of 45% of children 6-23 months of age met the definition of minimum dietary diversity, and the diets of 39% of breastfed and 7.6% non- breastfed children 6-23 months of age met the criteria for minimum meal frequency. The results highlight that a substantial proportion of young children in the earthquake affected disaster areas continue to have various forms of malnutrition, with an especially high prevalence of anemia, and that most feeding practices are suboptimal. Further efforts should be made to enhance the nutritional status of these children. As part of this intervention, it may be necessary to improve child feeding practices.

  8. Earthquake Engineering Research Center: 25th anniversry edition

    NASA Astrophysics Data System (ADS)

    1993-10-01

    The Earthquake Engineering Research Center exists to conduct research and develop technical information in all areas pertaining to earthquake engineering, including strong ground motion and ground failure, response of natural and manmade structures to earthquakes, design of structures to resist earthquakes, development of new systems for earthquake protection, and development of architectural and public policy aspects of earthquake engineering. The annual report for 1992-93 presents information on: Current Research Programs; Contracts and Grants; Public Service Program; National Information Service for Earthquake Engineering; Core Administration; Committees of the Earthquake Engineering Research Center; Research Participants - Faculty; and Research Participants - Students.

  9. Efficacy of a low-dosage combination of butorphanol, azaperone, and medetomidine (BAM) to immobilize Rocky Mountain elk.

    PubMed

    Wolfe, Lisa L; Fisher, Mark C; Davis, Tracy R; Miller, Michael W

    2014-07-01

    We compared dosages of a combination of sedatives, which included butorphanol tartrate, azaperone tartrate, and medetomidine HCl (BAM) in captive adult Rocky Mountain elk (Cervus elaphus nelsoni). All three BAM dosages (low, medium, and high) effectively immobilized elk and produced an adequate level of sedation in all subjects. Induction times were similar among the three groups (mean ± SD: low=6.9 ± 1.1 min; medium=6.3 ± 0.9 min; high=4.7 ± 1.3 min). Most elk became hypoxemic regardless of BAM dosage, but hypoxemia tended to be most severe in the high-BAM group; regardless of BAM dosage, oxygen supplementation improved the percentage of oxygen saturation and stabilized the vital rates. Recovery after administration of antagonists (3 mg atipamezole/mg medetomidine and 2 mg/kg tolazoline) was comparable among groups (range of means=9 ± 1.5-11.7 ± 1 min). Based on the findings from clinical trials and field data from free-ranging elk immobilizations, we recommend low-dose BAM (2 mL dose; equivalent to 46 mg butorphanol, 30 mg azaperone, and 18 mg medetomidine) and supplemental oxygen for adult elk; immobilization should be antagonized using 3-5 mg atipamezole/mg medetomidine and 2 mg/kg tolazoline, with tolazoline injected about 5-10 min before atipamezole to smooth out recovery.

  10. Earthquake Mechanisms of the Mediterranean Area (EMMA) version 3: an improved tool for characterizing the tectonic deformation styles in the Mediterranean.

    NASA Astrophysics Data System (ADS)

    Vannucci, G.; Imprescia, P.; Gasperini, P.

    2009-04-01

    EMMA (Earthquake Mechanisms of the Mediterranean Area) database contains available literature data with the goal of making them more usable and available. EMMA is continuously improving by the addition of further focal mechanisms found in literature. At the present time, EMMA pre-release 3 includes more than 12700 focal solutions, about twice of previous official release 2.2 (Vannucci and Gasperini, 2004). They cover a time window from 1905 to 2006. In the new release, many added solutions are in areas not much covered or completely uncovered in the previous one (e.g. Bulgaria, Germany, Anatolia). As in the previous versions (Vannucci and Gasperini, 2003 and 2004), we have uniformed the different formats and notations of the data available from different sources and we have tried to solve misprints, inaccuracies and inconsistencies that might make the data unusable for other investigations. By an automatic procedure based on several criteria, we have chosen the "most representative" (best) solution when more than one is available for the same earthquake. Thanks to this, we have obtained about 6000 best solutions. The end user can use the best solution obtained with our procedure or he can change criteria. The database allows to make selections and to export data files suitable to be handled by graphic software and user generated scripts. In the new version, still MS-ACCESS based, we have added geographic information to the display of the focal solution, as well as we have integrated the hypocentral and magnitude data found on the original papers with those reported by regional and local catalogs and bulletins. In order to make EMMA more accessible, a web version is currently in progress. Through an internet connection it will be possible data selection and export, without installation and configuration problems found in the past. EMMA was already used in the past and will be (hopefully) useful in the future to better characterize the tectonic deformation styles (e

  11. Testing an earthquake prediction algorithm

    USGS Publications Warehouse

    Kossobokov, V.G.; Healy, J.H.; Dewey, J.W.

    1997-01-01

    A test to evaluate earthquake prediction algorithms is being applied to a Russian algorithm known as M8. The M8 algorithm makes intermediate term predictions for earthquakes to occur in a large circle, based on integral counts of transient seismicity in the circle. In a retroactive prediction for the period January 1, 1985 to July 1, 1991 the algorithm as configured for the forward test would have predicted eight of ten strong earthquakes in the test area. A null hypothesis, based on random assignment of predictions, predicts eight earthquakes in 2.87% of the trials. The forward test began July 1, 1991 and will run through December 31, 1997. As of July 1, 1995, the algorithm had forward predicted five out of nine earthquakes in the test area, which success ratio would have been achieved in 53% of random trials with the null hypothesis.

  12. The Loma Prieta, California, Earthquake of October 17, 1989: Earthquake Occurrence

    USGS Publications Warehouse

    Coordinated by Bakun, William H.; Prescott, William H.

    1993-01-01

    Professional Paper 1550 seeks to understand the M6.9 Loma Prieta earthquake itself. It examines how the fault that generated the earthquake ruptured, searches for and evaluates precursors that may have indicated an earthquake was coming, reviews forecasts of the earthquake, and describes the geology of the earthquake area and the crustal forces that affect this geology. Some significant findings were: * Slip during the earthquake occurred on 35 km of fault at depths ranging from 7 to 20 km. Maximum slip was approximately 2.3 m. The earthquake may not have released all of the strain stored in rocks next to the fault and indicates a potential for another damaging earthquake in the Santa Cruz Mountains in the near future may still exist. * The earthquake involved a large amount of uplift on a dipping fault plane. Pre-earthquake conventional wisdom was that large earthquakes in the Bay area occurred as horizontal displacements on predominantly vertical faults. * The fault segment that ruptured approximately coincided with a fault segment identified in 1988 as having a 30% probability of generating a M7 earthquake in the next 30 years. This was one of more than 20 relevant earthquake forecasts made in the 83 years before the earthquake. * Calculations show that the Loma Prieta earthquake changed stresses on nearby faults in the Bay area. In particular, the earthquake reduced stresses on the Hayward Fault which decreased the frequency of small earthquakes on it. * Geological and geophysical mapping indicate that, although the San Andreas Fault can be mapped as a through going fault in the epicentral region, the southwest dipping Loma Prieta rupture surface is a separate fault strand and one of several along this part of the San Andreas that may be capable of generating earthquakes.

  13. Gravity study through the Tualatin Mountains, Oregon: Understanding crustal structure and earthquake hazards in the Portland urban area

    USGS Publications Warehouse

    Blakely, R.J.; Beeson, M.H.; Cruikshank, K.; Wells, R.E.; Johnson, Aaron H.; Walsh, K.

    2004-01-01

    A high-resolution gravity survey through the Tualatin Mountains (Portland Nills) west of downtown Portland exhibits evidence of faults previously identified from surface geologic and aeromagnetic mapping. The gravity survey was conducted in 1996 along the 4.5-km length of a twin-bore tunnel, then under construction and now providing light-rail service between downtown Portland and communities west of the Portland Hills. Gravitational attraction gradually increases from west to east inside the tunnel, which reflects the tunnel's location between low-density sedimentary deposits of the Tualatin basin to the west and high-density, mostly concealed Eocene basalt to the east. Superimposed on this gradient are several steplike anomalies that we interpret as evidence for faulted contacts between rocks of contrasting density. The largest of these anomalies occurs beneath Sylvan Creek, where a fault had previously been mapped inside the tunnel. Another occurs 1200 m from the west portal, at the approximate intersection of the tunnel with an aeromagnetic anomaly associated with the Sylvan fault (formerly called the Oatfield fault). Lithologic cross sections based on these gravity data show that the steplike anomalies are consistent with steeply dipping reverse faults, although strike-slip displacements also may be important. Three gravity lows correspond with topographic lows directly overhead and may reflect zones of shearing. Several moderate earthquakes (M ??? 3.5) occurred near the present-day location of the tunnel in 1991, suggesting that some of these faults or other faults in the Portland Hills fault zone are seismically active.

  14. The relationship between the deep-level structure in crust and brewing of strong earthquakes in Xingtai area

    NASA Astrophysics Data System (ADS)

    Xiao, Lan-Xi; Zhu, Yuan-Qing; Zhang, Shao-Quan; Liu, Xu; Guo, Yu

    1999-11-01

    In this paper, crust medium is treated as Maxwell medium, and crust model includes hard inclusion, soft inclusion, deep-level fault. The stress concentration and its evolution with time are obtained by using three-dimensional finite element method and differential method. The conclusions are draw as follows: (1) The average stress concentration and maximum shear stress concentration caused by non-heterogeneous of crust are very high in hard inclusion and around the deep fault. With the time passing by, the concentration of average stress in the model gradually trends to uniform. At the same time, the concentration of maximum shear stress in hard inclusion increases gradually. This character is favorable to transfer shear strain energy from soft inclusion to hard inclusion. (2) When the upper mantle beneath the inclusion upheave at a certain velocity of 1 cm/a, the changes of average stress concentration with time become complex, and the boundary of the hard and soft inclusion become unconspicuous, but the maximum shear stress concentration increases much more in the hard inclusion with time at a higher velocity. This feature make for transformation of energy from the soft inclusion to the hard inclusion. (3) The changes of average stress concentration and maximum shear stress concentration with time around the deep-level fault result in further accumulation of maximum shear stress concentration and finally cause the deep-level fault instable and accelerated creep along fault direction. (4) The changes of vertical displacement on the surface of the model, which is caused by the accelerated creep of the deep-level fault, is similar to that of the observation data before Xingtai strong earthquake.

  15. Three Campaigns to Image the Earth's Interior Using Mermaids (Mobile Earthquake Recorder in Marine Areas by Indepen-dent Divers).

    NASA Astrophysics Data System (ADS)

    Pazmino, A.; Bonnieux, S.; Joubert, C.; Gonzales, N.; Hello, Y.; Nolet, G.

    2014-12-01

    Mermaids have been developed to improve seismic data coverage in the oceanic domain for imaging of the Earth's interior. Though housed in conventional Argo-type floats, hardware and software was developed to analyze acoustic signals and determine whether an earthquake has been recorded, and whether the Mermaid should to come up to the surface and transmit to the satellite. In contrast to the passive Argo floats, Mermaids are essentially floating computers that decide for themselves what to do. After testing in the Mediterranean and Indian Ocean and improving the concept for more than a year, we recently started two fully scientific experiments using Mermaids. In cooperation with Inocar, we deployed a fleet of 10 Mermaids in May 2014 around the Galapagos islands from the LAE Sirius to study the suspected mantle plume beneath these islands. We are interested in plumes because we do not understand very well how the mantle has retained an almost constant temperature for three or four billion years, an essential condition for life to develop. The depth of mantle plumes is an important unknown, because it may tell us how well the lower mantle is able to transmit heat into the upper mantle. A second experiment is taking place in the Ligurian Sea. This basin opened with a rifting phase in late Oligocene. The rifting phase of the Ligurian basin is followed by the Corsica - Sardinia block counterclockwise rotation, but the deeper causes of this are still poorly understood. Three Mermaids are deployed, and re-deployed after drifting too far west, to augment the P arrivals observed for 6 months with 5 OBS's during the 2008 Grosmarin campaign. The experience obtained with this first generation of Mermaids has led to the development of a new multidisciplinary float (Multimermaid), which is programmable, able to carry up to 8 sensors to a depth of 3000 m, and with a duration of at least five years.

  16. Effects of gravel on infiltration, runoff, and sediment yield in landslide deposit slope in Wenchuan earthquake area, China.

    PubMed

    Li, Tianyang; He, Binghui; Chen, Zhanpeng; Zhang, Yi; Liang, Chuan; Wang, Renxin

    2016-06-01

    Amounts of landslide deposits were triggered by the Wenchuan earthquake with magnitude 8.0 on May 12, 2008. The landslide deposits were composed of soil and rock fragments, which play important roles in hydrological and erosion processes in the steep slope of landslide deposits. The mixtures of soil and gravels are common in the top layers of landslide deposits, and its processes are obviously different with the soil without gravels. Based on the data of field investigation, a series of simulated scouring flow experiments with four proportion of gravel (0, 25, 33.3, and 50 %) and three scouring flow rates (4, 8, 12 L/min) under two steep slopes (67.5, 72.7 %) were conducted sequentially to know the effects of proportion of gravel on infiltration capacity, runoff generation, and sediment production in the steep slope of landslide deposit. Results indicated that gravel had promoted or reduced effects on infiltration capacity which could affect further the cumulative runoff volume and cumulative sediment mass increase or decrease. The cumulative infiltration volume in 25 % proportion of gravel was less than those in 0, 33.3, and 50 % proportion of gravel. The cumulative runoff volume was in an order of 25 > 0 > 33.3 > 50 % while cumulative sediment mass ranked as 25 > 33.3 > 0 > 50 % with different proportions of gravel. A significant power relationship was found between scouring time and cumulative runoff volume as well as cumulative sediment mass. The relationship between average soil and water loss rate and proportion of gravel was able to express by quadratic function, with a high degree of reliability. The results have important implications for soil and water conservation and modeling in landslide deposit but also provide useful information for the similar conditions.

  17. Pediatric Epidemic of Salmonella enterica Serovar Typhimurium in the Area of L’Aquila, Italy, Four Years after a Catastrophic Earthquake

    PubMed Central

    Nigro, Giovanni; Bottone, Gabriella; Maiorani, Daniela; Trombatore, Fabiana; Falasca, Silvana; Bruno, Gianfranco

    2016-01-01

    Background: A Salmonella enterica epidemic occurred in children of the area of L’Aquila (Central Italy, Abruzzo region) between June 2013 and October 2014, four years after the catastrophic earthquake of 6 April 2009. Methods: Clinical and laboratory data were collected from hospitalized and ambulatory children. Routine investigations for Salmonella infection were carried out on numerous alimentary matrices of animal origin and sampling sources for drinking water of the L’Aquila district, including pickup points of the two main aqueducts. Results: Salmonella infection occurred in 155 children (83 females: 53%), aged 1 to 15 years (mean 2.10). Of these, 44 children (28.4%) were hospitalized because of severe dehydration, electrolyte abnormalities, and fever resistant to oral antipyretic and antibiotic drugs. Three children (1.9%) were reinfected within four months after primary infection by the same Salmonella strain. Four children (2.6%), aged one to two years, were coinfected by rotavirus. A seven-year old child had a concomitant right hip joint arthritis. The isolated strains, as confirmed in about the half of cases or probable/possible in the remaining ones, were identified as S. enterica serovar Typhimurium [4,5:i:-], monophasic variant. Aterno river, bordering the L’Aquila district, was recognized as the main responsible source for the contamination of local crops and vegetables derived from polluted crops. Conclusions: The high rate of hospitalized children underlines the emergence of a highly pathogenic S. enterica strain probably subsequent to the contamination of the spring water sources after geological changes occurred during the catastrophic earthquake. PMID:27164121

  18. Charles Darwin's earthquake reports

    NASA Astrophysics Data System (ADS)

    Galiev, Shamil

    2010-05-01

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

  19. Earthquake Facts

    MedlinePlus

    ... the source of earthquakes. Moonquakes (“earthquakes” on the moon) do occur, but they happen less frequently and ... with the varying distance between the Earth and Moon. They also occur at great depth, about halfway ...

  20. Earthquake Analysis.

    ERIC Educational Resources Information Center

    Espinoza, Fernando

    2000-01-01

    Indicates the importance of the development of students' measurement and estimation skills. Analyzes earthquake data recorded at seismograph stations and explains how to read and modify the graphs. Presents an activity for student evaluation. (YDS)

  1. Photodynamic activity of BAM-SiPc, an unsymmetrical bisamino silicon(IV) phthalocyanine, in tumour-bearing nude mice

    PubMed Central

    Leung, S C H; Lo, P-C; Ng, D K P; Liu, W-K; Fung, K-P; Fong, W-P

    2008-01-01

    Background and purpose Ever since the discovery of photodynamic therapy, there has been a continuous search for more potent photosensitizers. Towards that end, we have synthesized a number of novel phthalocyanine derivatives. The unsymmetrical bisamino silicon(IV) phthalocyanine BAM-SiPc is one of the most potent compounds. In in vitro cell culture, it exhibits high phototoxicity against a number of cancer cell lines. Experimental approach In the present investigation, the in vivo effect of BAM-SiPc was studied in the tumour-bearing nude mice model. The biodistribution of BAM-SiPc was followed to evaluate its tumour selectivity and rate of clearance. The tumour volume in the hepatocarcinoma HepG2- and the colorectal adenocarcinoma HT29-bearing nude mice was measured after photodynamic therapy. The level of intrinsic toxicity induced was also investigated. Finally, the metabolism of BAM-SiPc in the ‘normal' WRL68 liver cells and the hepatocarcinoma HepG2 cells was compared. Key results The results not only showed significant tumour regression of HepG2 and growth inhibition of HT29 in the tumour-bearing nude mice, but also no apparent hepatic or cardiac injury with the protocol used. Histological analyses showed that apoptosis was induced in the solid tumour. BAM-SiPc could be metabolized by WRL68 liver cells but not by the hepatocarcinoma HepG2 cells. Unfortunately, BAM-SiPc did not show any specific targeting towards the tumour tissue. Conclusions and implications The efficiency of BAM-SiPc in inhibiting tumour growth makes it a good candidate for further evaluation. Enhancement of its uptake in tumour tissue by conjugation with biomolecules is currently under investigation. PMID:18332853

  2. Refinement Method for Residential Area Revision Using Remote Sensing Image and GIS Data in Earthquake Risk Assessment

    NASA Astrophysics Data System (ADS)

    Dou, A. X.; Yuan, X. X.; Wang, X. Q.; Li, Z. M.

    2016-06-01

    This paper proposes an automatic approach for residential areas revision by means of analysing the correlation between the residential area and the topographic and geographical factors. The approach consists of four major steps: the extracting of missing residential area from the remote sensing images with high resolution; the statistic analysing on the size changes of missing residential area in each grade of the elevation, slope, distance from the road and other impact factors; modelling of residential area modification in the urban and rural region; testing the methods using 100 counties data which are located in the middle part of China North-South Seismic Belt and comparing the result to the Land Use in map scale 1:100000. The experimental results present the accuracy of urban residents by 70% increased to 89.4%, rural residents by 47% up to 81.9%, rural residents from 8% increased to 78.5%. Therefore, there is available risk exposure information in a sparsely populated area because the spatial grid distributions of population and buildings are based on the residential areas. The proposed approach in this paper will improve the accuracy of the seismic risk assessment if it is applied to the national or the whole world.

  3. Catastrophic debris flows on 13 August 2010 in the Qingping area, southwestern China: The combined effects of a strong earthquake and subsequent rainstorms

    NASA Astrophysics Data System (ADS)

    Tang, C.; van Asch, T. W. J.; Chang, M.; Chen, G. Q.; Zhao, X. H.; Huang, X. C.

    2012-02-01

    In the Wenchuan area in SW China, an abundance of loose co-seismic landslide debris was present on the slopes after the Wenchuan earthquake, which in later years served as source material for rainfall-induced debris flows or shallow landslides. Slopes composed of Cambrian sandstones and siltstones intercalated with slates appeared to be most susceptible to co-seismic landsliding. A total of 20 debris flows are described in this paper; all were triggered by heavy rainfall on 13th of August 2010. Field reconnaissance and measurements, supported by aerial photo interpretation, were conducted to identify the locations and morphological characteristics of the debris flow gullies in order to obtain information about surface area and volume of landslides and the debris flows. The debris flows in the study area were initiated by two processes: a) run-off erosion on co-seismic landslide material, and concentrated erosion of landslide debris in steep channels; b) new landslides that transform into debris flows. The volume of debris flow deposits on individual fans varies by many orders of magnitude. The smallest deposit has a volume of from 5760 to 3.1 million m 3. A comparison of the measured volumes, deposited on the fan with the volumes of debris stored in the catchment shows the huge potential for future debris flow activity. Whilst there is a weakly significant positive correlation between these two volumes, no significant statistical correlation could be established between volumes of debris flow deposits and other morphometric parameters of the catchment. A catastrophic debris flow catchment (the Wenjia catchment) was selected as an extreme case to show in detail the mechanism of debris flow formation as a result of intensive erosion in loose material, which was deposited by a rock avalanche during the 2008 Earthquake event. Analyses of the meteorological conditions that triggered these debris flows show one day antecedent precipitation varying between 67.7 and 137

  4. Changes in rainfall thresholds for debris flow initiation and run-out on a local and regional scale in the Wenchuan earthquake area, SW China.

    NASA Astrophysics Data System (ADS)

    van Asch, Theo; Luna, Byron Quan; Tang, Chenxiao; van Westen, Cees; Alkema, Dinand; Fan, Xuanmei

    2013-04-01

    For the development of early warning systems for the initiation and run-out distances of debris flows, to avoid or mitigate intolerable risks, it is necessary to assess rainfall thresholds. However one must be aware that these thresholds can change. These changes can be ascribed to environmental and climate change as well as socio-economical changes. In the Wenchuan area in the Sichuan Province, SW China, changes in thresholds are related to a depletion of source materials for these debris flows. The intensive Earthquake of 2008 in the Wenchuan area generated many co-seismic landslides, which delivered a lot of loose source material. It caused a dramatic increase in debris flow occurrences in the subsequent years. A preliminary model was designed, with entrainment processes driven by run-off water as the main triggering mechanism, to describe the relationship between rain input and debris flow run-out with the intention to assess rainfall thresholds for the start of debris flows and critical run out distances. The model was calibrated on the depositional volumes of debris flow events which occurred in individual catchments in August 2011. The calibrated model was used to construct rainfall intensity -duration threshold curves. These curves describe the thresholds for a critical run-out distance, determined by the outlet of the catchment, which was considered as the limit beyond which elements at risk situated in the main river plain are threatened. The research is focused on the change in these thresholds curves after a range of consecutive debris flow triggering rain events. It appeared that for individual catchments the rate of change of these thresholds can vary dramatically which is related to the location of available loose erodible material in the catchment. The model is also applied on a regional scale in the Jingxiu area. A method was proposed to made a general estimate of the time duration to arrive at a debris flow frequency level before the earthquake

  5. Earthquake watch

    USGS Publications Warehouse

    Hill, M.

    1976-01-01

     When the time comes that earthquakes can be predicted accurately, what shall we do with the knowledge? This was the theme of a November 1975 conference on earthquake warning and response held in San Francisco called by Assistant Secretary of the Interior Jack W. Carlson. Invited were officials of State and local governments from Alaska, California, Hawaii, Idaho, Montana, Nevada, utah, Washington, and Wyoming and representatives of the news media. 

  6. The 1988 earthquake in soviet armenia: implications for earthquake preparedness.

    PubMed

    Noji, E K

    1989-09-01

    An earthquake registering 6.9 on the Richter scale hit the northern part of the Armenian Republic of the Soviet Union on 7 December 1988, resulting in thousands of deaths and injuries. The majority of these resulted from the collapse of inadequately designed and constructed buildings. Analysis of the effects of the Armenian earthquake on the population, as well as of the rescue and medical response, has strong implications for earthquake preparedness and response in other seismically vulnerable parts of the world. Specifically, this paper will recommend a number of important endeavours deemed necessary to improve medical planning, preparedness and response to earthquakes. Strengthening the self-reliance of the community in disaster preparedness is suggested as the best way to improve the effectiveness of relief operations. In earthquake-prone areas, training and education in basic first aid and methods of rescue should be an integral part of any community preparedness programme.

  7. Earthquake predictions using seismic velocity ratios

    USGS Publications Warehouse

    Sherburne, R. W.

    1979-01-01

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

  8. Liquefaction susceptibility assessment in fluvial plains using airborne lidar: the case of the 2012 Emilia earthquake sequence area (Italy)

    NASA Astrophysics Data System (ADS)

    Civico, R.; Brunori, C. A.; De Martini, P. M.; Pucci, S.; Cinti, F. R.; Pantosti, D.

    2015-11-01

    We report a case study from the Po River plain region (northern Italy), where significant liquefaction-related land and property damage occurred during the 2012 Emilia seismic sequence. We took advantage of a 1 m pixel lidar digital terrain model (DTM) and of the 2012 Emilia coseismic liquefaction data set to (a) perform a detailed geomorphological study of the Po River plain area and (b) quantitatively define the liquefaction susceptibility of the geomorphologic features that experienced different abundance of liquefaction. One main finding is that linear topographic highs of fluvial origin - together with crevasse splays, abandoned riverbeds and very young land reclamation areas - acted as a preferential location for the occurrence of liquefaction phenomena. Moreover, we quantitatively defined a hierarchy in terms of liquefaction susceptibility for an ideal fluvial environment. We observed that a very high liquefaction susceptibility is found in coincidence with fluvial landforms, a high-to-moderate liquefaction susceptibility within a buffer distance of 100 and 200 m from mapped fluvial landforms and a low liquefaction susceptibility outside fluvial landforms and relative buffer areas. Lidar data allowed a significant improvement in mapping with respect to conventionally available topographic data and/or aerial imagery. These results have significant implications for accurate hazard and risk assessment as well as for land-use planning. We propose a simple geomorphological approach for liquefaction susceptibility estimation. Our findings can be applied to areas beyond Emilia that are characterized by similar fluvial-dominated environments and prone to significant seismic hazard.

  9. Earthquake Scaling, Simulation and Forecasting

    NASA Astrophysics Data System (ADS)

    Sachs, Michael Karl

    Earthquakes are among the most devastating natural events faced by society. In 2011, just two events, the magnitude 6.3 earthquake in Christcurch New Zealand on February 22, and the magnitude 9.0 Tohoku earthquake off the coast of Japan on March 11, caused a combined total of $226 billion in economic losses. Over the last decade, 791,721 deaths were caused by earthquakes. Yet, despite their impact, our ability to accurately predict when earthquakes will occur is limited. This is due, in large part, to the fact that the fault systems that produce earthquakes are non-linear. The result being that very small differences in the systems now result in very big differences in the future, making forecasting difficult. In spite of this, there are patterns that exist in earthquake data. These patterns are often in the form of frequency-magnitude scaling relations that relate the number of smaller events observed to the number of larger events observed. In many cases these scaling relations show consistent behavior over a wide range of scales. This consistency forms the basis of most forecasting techniques. However, the utility of these scaling relations is limited by the size of the earthquake catalogs which, especially in the case of large events, are fairly small and limited to a few 100 years of events. In this dissertation I discuss three areas of earthquake science. The first is an overview of scaling behavior in a variety of complex systems, both models and natural systems. The focus of this area is to understand how this scaling behavior breaks down. The second is a description of the development and testing of an earthquake simulator called Virtual California designed to extend the observed catalog of earthquakes in California. This simulator uses novel techniques borrowed from statistical physics to enable the modeling of large fault systems over long periods of time. The third is an evaluation of existing earthquake forecasts, which focuses on the Regional

  10. California earthquake history

    USGS Publications Warehouse

    Toppozada, T.; Branum, D.

    2004-01-01

    This paper presents an overview of the advancement in our knowledge of California's earthquake history since ??? 1800, and especially during the last 30 years. We first review the basic statewide research on earthquake occurrences that was published from 1928 through 2002, to show how the current catalogs and their levels of completeness have evolved with time. Then we review some of the significant new results in specific regions of California, and some of what remains to be done. Since 1850, 167 potentially damaging earthquakes of M ??? 6 or larger have been identified in California and its border regions, indicating an average rate of 1.1 such events per year. Table I lists the earthquakes of M ??? 6 to 6.5 that were also destructive since 1812 in California and its border regions, indicating an average rate of one such event every ??? 5 years. Many of these occurred before 1932 when epicenters and magnitudes started to be determined routinely using seismographs in California. The number of these early earthquakes is probably incomplete in sparsely populated remote parts of California before ??? 1870. For example, 6 of the 7 pre-1873 events in table I are of M ??? 7, suggesting that other earthquakes of M 6.5 to 6.9 occurred but were not properly identified, or were not destructive. The epicenters and magnitudes (M) of the pre-instrumental earthquakes were determined from isoseismal maps that were based on the Modified Mercalli Intensity of shaking (MMI) at the communities that reported feeling the earthquakes. The epicenters were estimated to be in the regions of most intense shaking, and values of M were estimated from the extent of the areas shaken at various MMI levels. MMI VII or greater shaking is the threshold of damage to weak buildings. Certain areas in the regions of Los Angeles, San Francisco, and Eureka were each shaken repeatedly at MMI VII or greater at least six times since ??? 1812, as depicted by Toppozada and Branum (2002, fig. 19).

  11. Weight Gain in Survivors Living in Temporary Housing in the Tsunami-Stricken Area during the Recovery Phase following the Great East Japan Earthquake and Tsunami

    PubMed Central

    Yonekura, Yuki; Sasaki, Ryohei; Yokoyama, Yukari; Tanno, Kozo; Sakata, Kiyomi; Ogawa, Akira; Kobayashi, Seichiro; Yamamoto, Taro

    2016-01-01

    Introduction Survivors who lost their homes in the Great East Japan Earthquake and Tsunami were forced to live in difficult conditions in temporary housing several months after the disaster. Body weights of survivors living in temporary housing for a long period might increase due to changes in their life style and psychosocial state during the medium-term and long-term recovery phases. The aim of this study was to determine whether there were differences between body weight changes of people living in temporary housing and those not living in temporary housing in a tsunami-stricken area during the medium-term and long-term recovery phases. Materials and methods Health check-ups were performed about 7 months after the disaster (in 2011) and about 18 months after the disaster (in 2012) for people living in a tsunami-stricken area (n = 6,601, mean age = 62.3 y). We compared the changes in body weight in people living in temporary housing (TH group, n = 2,002) and those not living in temporary housing (NTH group, n = 4,599) using a multiple linear regression model. Results While there was no significant difference between body weights in the TH and NTH groups in the 2011 survey, there was a significant difference between the mean changes in body weight in both sexes. We found that the changes in body weight were significantly greater in the TH group than in the NTH group in both sexes. The partial regression coefficients of mean change in body weight were +0.52 kg (P-value < 0.001) in males in the TH group and +0.56 kg (P-value < 0.001) in females in the TH group (reference: NTH group). Conclusion Analysis after adjustment for life style, psychosocial factors and cardiovascular risk factors found that people living in temporary housing in the tsunami- stricken area had a significant increase in body weight. PMID:27907015

  12. A comprehensive analysis of earthquake damage patterns using high dimensional model representation feature selection

    NASA Astrophysics Data System (ADS)

    Taşkin Kaya, Gülşen

    2013-10-01

    Recently, earthquake damage assessment using satellite images has been a very popular ongoing research direction. Especially with the availability of very high resolution (VHR) satellite images, a quite detailed damage map based on building scale has been produced, and various studies have also been conducted in the literature. As the spatial resolution of satellite images increases, distinguishability of damage patterns becomes more cruel especially in case of using only the spectral information during classification. In order to overcome this difficulty, textural information needs to be involved to the classification to improve the visual quality and reliability of damage map. There are many kinds of textural information which can be derived from VHR satellite images depending on the algorithm used. However, extraction of textural information and evaluation of them have been generally a time consuming process especially for the large areas affected from the earthquake due to the size of VHR image. Therefore, in order to provide a quick damage map, the most useful features describing damage patterns needs to be known in advance as well as the redundant features. In this study, a very high resolution satellite image after Iran, Bam earthquake was used to identify the earthquake damage. Not only the spectral information, textural information was also used during the classification. For textural information, second order Haralick features were extracted from the panchromatic image for the area of interest using gray level co-occurrence matrix with different size of windows and directions. In addition to using spatial features in classification, the most useful features representing the damage characteristic were selected with a novel feature selection method based on high dimensional model representation (HDMR) giving sensitivity of each feature during classification. The method called HDMR was recently proposed as an efficient tool to capture the input

  13. Interpretation of earthquake-induced landslides triggered by the 12 May 2008, M7.9 Wenchuan earthquake in the Beichuan area, Sichuan Province, China using satellite imagery and Google Earth

    USGS Publications Warehouse

    Sato, H.P.; Harp, E.L.

    2009-01-01

    The 12 May 2008 M7.9 Wenchuan earthquake in the People's Republic of China represented a unique opportunity for the international community to use commonly available GIS (Geographic Information System) tools, like Google Earth (GE), to rapidly evaluate and assess landslide hazards triggered by the destructive earthquake and its aftershocks. In order to map earthquake-triggered landslides, we provide details on the applicability and limitations of publicly available 3-day-post- and pre-earthquake imagery provided by GE from the FORMOSAT-2 (formerly ROCSAT-2; Republic of China Satellite 2). We interpreted landslides on the 8-m-resolution FORMOSAT-2 image by GE; as a result, 257 large landslides were mapped with the highest concentration along the Beichuan fault. An estimated density of 0.3 landslides/km2 represents a minimum bound on density given the resolution of available imagery; higher resolution data would have identified more landslides. This is a preliminary study, and further study is needed to understand the landslide characteristics in detail. Although it is best to obtain landslide locations and measurements from satellite imagery having high resolution, it was found that GE is an effective and rapid reconnaissance tool. ?? 2009 Springer-Verlag.

  14. External effective radiation dose to workers in the restricted area of the Fukushima Daiichi Nuclear Power Plant during the third year after the Great East Japan Earthquake.

    PubMed

    Sakumi, Akira; Miyagawa, Ryu; Tamari, Yuki; Nawa, Kanabu; Sakura, Osamu; Nakagawa, Keiichi

    2016-03-01

    Since the Great East Japan Earthquake on 11 March 2011, Iitate Village has continued to be classified as a deliberate evacuation area, in which residents are estimated to receive an annual additional effective radiation dose of >20 mSv. Some companies still operate in Iitate Village, with a special permit from the Cabinet Office Team in Charge of Assisting the Lives of Disaster Victims. In this study, we measured the annual effective radiation dose to workers in Iitate Village from 15 January to 13 December 2013. The workers stayed in Iitate for 10 h and left the village for the remaining 14 h each working day. They worked for 5 days each week in Iitate Village, but stayed outside of the village for the remaining 2 days each week. We found that the effective radiation dose of 70% of the workers was <2 mSv, including natural radiation; the maximum dose was 3.6 mSv. We estimated the potential annual additional effective radiation dose if people returned full-time to Iitate. Our analysis supports the plan for people to return to their home village at the end of 2017.

  15. K2 red giant asteroseismology using Bayesian Asteroseismology data Modeling (BAM)

    NASA Astrophysics Data System (ADS)

    Zinn, Joel; Stello, Dennis; Pinsonneault, Marc H.

    2017-01-01

    The re-purposed Kepler mission, K2, boasts an impressive panoramic view of tens of thousands of red giants along the ecliptic, zooming in on clusters of various ages and metalliticies and probing Galactic sight lines inaccessible to the original Kepler field of view. However, its compromised pointing has introduced spurious features in stellar light curves and has reduced its photometric quality compared to that of the original Kepler mission. Enhanced data processing techniques above and beyond those used for Kepler are therefore required in order to translate observed K2 stellar light curves in to reliable fundamental parameters like surface gravity, radius, and mass with asteroseismology. I will present results from one such effort -- the Bayesian Asteroseismology data Modeling (BAM) pipeline. I will discuss the state of science with red giants in K2, with particular emphasis on a sample of red giants analyzed with the BAM. Implications for Galactic population studies using K2 red giants will be presented, with an eye toward completeness and contamination.

  16. StratBAM: A Discrete-Event Simulation Model to Support Strategic Hospital Bed Capacity Decisions.

    PubMed

    Devapriya, Priyantha; Strömblad, Christopher T B; Bailey, Matthew D; Frazier, Seth; Bulger, John; Kemberling, Sharon T; Wood, Kenneth E

    2015-10-01

    The ability to accurately measure and assess current and potential health care system capacities is an issue of local and national significance. Recent joint statements by the Institute of Medicine and the Agency for Healthcare Research and Quality have emphasized the need to apply industrial and systems engineering principles to improving health care quality and patient safety outcomes. To address this need, a decision support tool was developed for planning and budgeting of current and future bed capacity, and evaluating potential process improvement efforts. The Strategic Bed Analysis Model (StratBAM) is a discrete-event simulation model created after a thorough analysis of patient flow and data from Geisinger Health System's (GHS) electronic health records. Key inputs include: timing, quantity and category of patient arrivals and discharges; unit-level length of care; patient paths; and projected patient volume and length of stay. Key outputs include: admission wait time by arrival source and receiving unit, and occupancy rates. Electronic health records were used to estimate parameters for probability distributions and to build empirical distributions for unit-level length of care and for patient paths. Validation of the simulation model against GHS operational data confirmed its ability to model real-world data consistently and accurately. StratBAM was successfully used to evaluate the system impact of forecasted patient volumes and length of stay in terms of patient wait times, occupancy rates, and cost. The model is generalizable and can be appropriately scaled for larger and smaller health care settings.

  17. Deep earthquakes

    SciTech Connect

    Frohlich, C.

    1989-01-01

    Earthquakes are often recorded at depths as great as 650 kilometers or more. These deep events mark regions where plates of the earth's surface are consumed in the mantle. But the earthquakes themselves present a conundrum: the high pressures and temperatures at such depths should keep rock from fracturing suddenly and generating a tremor. This paper reviews the research on this problem. Almost all deep earthquakes conform to the pattern described by Wadati, namely, they generally occur at the edge of a deep ocean and define an inclined zone extending from near the surface to a depth of 600 kilometers of more, known as the Wadati-Benioff zone. Several scenarios are described that were proposed to explain the fracturing and slipping of rocks at this depth.

  18. Earthquake damage to transportation systems

    USGS Publications Warehouse

    McCullough, Heather

    1994-01-01

    Earthquakes represent one of the most destructive natural hazards known to man. A large magnitude earthquake near a populated area can affect residents over thousands of square kilometers and cause billions of dollars in property damage. Such an event can kill or injure thousands of residents and disrupt the socioeconomic environment for months, sometimes years. A serious result of a large-magnitude earthquake is the disruption of transportation systems, which limits post-disaster emergency response. Movement of emergency vehicles, such as police cars, fire trucks and ambulances, is often severely restricted. Damage to transportation systems is categorized below by cause including: ground failure, faulting, vibration damage, and tsunamis.

  19. Earthquakes, November-December 1977

    USGS Publications Warehouse

    Person, W.J.

    1978-01-01

    In the United States, the largest earthquake during this reporting period was a magntidue 6.6 in the Andreanof Islands, which are part of the Aleutian Islands chain, on November 4 that caused some minor damage. Northern California was struck by a magnitude 4.8 earthquake on November 22 causing moderate damage in the Willits area. This was the most damaging quake in the United States during the year. Two major earthquakes of magntidues 7.0 or above to 14 for the year. 

  20. The CATDAT damaging earthquakes database

    NASA Astrophysics Data System (ADS)

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

    2011-08-01

    The global CATDAT damaging earthquakes and secondary effects (tsunami, fire, landslides, liquefaction and fault rupture) database was developed to validate, remove discrepancies, and expand greatly upon existing global databases; and to better understand the trends in vulnerability, exposure, and possible future impacts of such historic earthquakes. Lack of consistency and errors in other earthquake loss databases frequently cited and used in analyses was a major shortcoming in the view of the authors which needed to be improved upon. Over 17 000 sources of information have been utilised, primarily in the last few years, to present data from over 12 200 damaging earthquakes historically, with over 7000 earthquakes since 1900 examined and validated before insertion into the database. Each validated earthquake includes seismological information, building damage, ranges of social losses to account for varying sources (deaths, injuries, homeless, and affected), and economic losses (direct, indirect, aid, and insured). Globally, a slightly increasing trend in economic damage due to earthquakes is not consistent with the greatly increasing exposure. The 1923 Great Kanto (214 billion USD damage; 2011 HNDECI-adjusted dollars) compared to the 2011 Tohoku (>300 billion USD at time of writing), 2008 Sichuan and 1995 Kobe earthquakes show the increasing concern for economic loss in urban areas as the trend should be expected to increase. Many economic and social loss values not reported in existing databases have been collected. Historical GDP (Gross Domestic Product), exchange rate, wage information, population, HDI (Human Development Index), and insurance information have been collected globally to form comparisons. This catalogue is the largest known cross-checked global historic damaging earthquake database and should have far-reaching consequences for earthquake loss estimation, socio-economic analysis, and the global reinsurance field.

  1. 2010 Chile Earthquake Aftershock Response

    NASA Astrophysics Data System (ADS)

    Barientos, Sergio

    2010-05-01

    The Mw=8.8 earthquake off the coast of Chile on 27 February 2010 is the 5th largest megathrust earthquake ever to be recorded and provides an unprecedented opportunity to advance our understanding of megathrust earthquakes and associated phenomena. The 2010 Chile earthquake ruptured the Concepcion-Constitucion segment of the Nazca/South America plate boundary, south of the Central Chile region and triggered a tsunami along the coast. Following the 2010 earthquake, a very energetic aftershock sequence is being observed in an area that is 600 km along strike from Valparaiso to 150 km south of Concepcion. Within the first three weeks there were over 260 aftershocks with magnitude 5.0 or greater and 18 with magnitude 6.0 or greater (NEIC, USGS). The Concepcion-Constitucion segment lies immediately north of the rupture zone associated with the great magnitude 9.5 Chile earthquake, and south of the 1906 and the 1985 Valparaiso earthquakes. The last great subduction earthquake in the region dates back to the February 1835 event described by Darwin (1871). Since 1835, part of the region was affected in the north by the Talca earthquake in December 1928, interpreted as a shallow dipping thrust event, and by the Chillan earthquake (Mw 7.9, January 1939), a slab-pull intermediate depth earthquake. For the last 30 years, geodetic studies in this area were consistent with a fully coupled elastic loading of the subduction interface at depth; this led to identify the area as a mature seismic gap with potential for an earthquake of magnitude of the order 8.5 or several earthquakes of lesser magnitude. What was less expected was the partial rupturing of the 1985 segment toward north. Today, the 2010 earthquake raises some disturbing questions: Why and how the rupture terminated where it did at the northern end? How did the 2010 earthquake load the adjacent segment to the north and did the 1985 earthquake only partially ruptured the plate interface leaving loaded asperities since

  2. Earthquakes in stable continental crust

    SciTech Connect

    Johnson, A.C.; Kanter, L.R. )

    1990-03-01

    Earthquakes can strike even in stable crust, well away from the familiar earthquake zones at the edges of tectonic plates, but their mere occurrence is both a source of concern in planning critical facilities such as nuclear power plants. The authors sought answers to two major questions: Just how much seismic activity does take place within the stable parts of continents And are there specific geologic features that make some areas of stable crust particularly susceptible to earthquakes They began by studying North America alone, but it soon became clear that the fairly short record of these rare events on a single continent would not provide enough data for reliable analysis. Hence, they decided to substitute space for time--to survey earthquake frequency and distribution in stable continental areas worldwide. This paper discusses their findings.

  3. Parametrizing Physics-Based Earthquake Simulations

    NASA Astrophysics Data System (ADS)

    Schultz, Kasey W.; Yoder, Mark R.; Wilson, John M.; Heien, Eric M.; Sachs, Michael K.; Rundle, John B.; Turcotte, Don L.

    2016-11-01

    Utilizing earthquake source parameter scaling relations, we formulate an extensible slip weakening friction law for quasi-static earthquake simulations. This algorithm is based on the method used to generate fault strengths for a recent earthquake simulator comparison study of the California fault system. Here we focus on the application of this algorithm in the Virtual Quake earthquake simulator. As a case study we probe the effects of the friction law's parameters on simulated earthquake rates for the UCERF3 California fault model, and present the resulting conditional probabilities for California earthquake scenarios. The new friction model significantly extends the moment magnitude range over which simulated earthquake rates match observed rates in California, as well as substantially improving the agreement between simulated and observed scaling relations for mean slip and total rupture area.

  4. Major Earthquakes of the Past Decade (2000-2010): A Comparative Review of Various Aspects of Management

    PubMed Central

    Kalantar Motamedi, Mohammad Hosein; Sagafinia, Masoud; Ebrahimi, Ali; Shams, Ehsan; Kalantar Motamedi, Mostafa

    2012-01-01

    Objectives: This article sought to review and compare data of major earthquakes of the past decade and their aftermath in order to compare the magnitude, death toll, type of injuries, management procedures, extent of destruction and effectiveness of relief efforts. Materials and Methods: A retrospective study of the various aspects of management and aftermath of 5 major earthquakes of the past decade (2000–2010) was undertaken. This included earthquakes occurring in Bam Iran, Sichuan China, Port-au-Prince Haiti, Kashmir Pakistan and Ica Peru. A literature search was done via computer of published articles (indexed in Pubmed). The issues assessed included: 1)Local magnitude,2)Type of building structure 3)Time of the earthquake (day/time/season), 4)Time to rescue, 5)Triage, Transfer, and Treatment 6) Distribution of casualties (dead/ injured), 7)Degree of city damage, 8)Degree of damage to health facilities, 9)Field hospital availability, 10)International aid, 11)Air transfer, 12) Telecommunication systems availability, 13) PTSD prevalence, 14) Most common injury and 15) Most common disease outbreak. Results: The Bam earthquake had the lowest (6.6 Richter’s) and the Sichuan earthquake had the greatest magnitude (8.0 Richter’s). Mortality in Haiti was 212,000 and it was the deadliest earthquake of the past decade. Collapse of heavy clay roofing structures was a major cause of death in Iran and Pakistan. Earthquakes occurring at night and nonworking days carried a high death toll. The time to rescue and treat was the lengthiest in Haiti (possibly contributing to the death to injured ratio). However, the worst dead to injured ratios were in Bam (51%) and in Pakistan (47%); the best ratio was in China (15%). Iran and Pakistan suffered the highest percentage of damage to the health facilities (90%). Field hospital availability, international aid and air transfer were important issues. Telecommunication systems were best in China and worst in Pakistan. PTSD

  5. Deformation from 1973 through 1991 in the epicentral area of the 1992 Landers, California, earthquake (M(sub S) = 7.5)

    NASA Astrophysics Data System (ADS)

    Savage, J. C.; Lisowski, M.; Murray, M.

    1993-11-01

    Deformation of a 50 x 60 km trilateration network that spans the epicenter of the 1992 Landers earthquake (M(sub s) = 7.5) was measured by seven surveys over the 19 years preceding the earthquake. Three moderate earthquakes (1979 Homestead Valley, M(sub s) = 5.6; 1986 North Palm Springs, M(sub s) = 6.0; and 1992 Joshua Tree, M(sub s) = 6.1) occurred within the network during those 19 years. Here we use geodetic and seismic data to construct a dislocation model for each of the three moderate earthquakes. Coseismic changes due to these three moderate earthquakes as predicted by the dislocation models are then removed from the trilateration data. The residual geodetic changes appear to be uniform in time. We take those changes to represent secular strain accumulation. This strain accumulation clearly shows right-lateral shear across the San Andreas fault but also suggests a northwest-southeast extension northeast of the eastern end of the 'Big Bend' of the San Andreas fault. The Landers earthquake ruptured along a north-northwest trend across this region of northwest-southeast extension.

  6. Earthquake engineering research: 1982

    NASA Astrophysics Data System (ADS)

    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.

  7. Earthquake Testing

    NASA Technical Reports Server (NTRS)

    1979-01-01

    During NASA's Apollo program, it was necessary to subject the mammoth Saturn V launch vehicle to extremely forceful vibrations to assure the moonbooster's structural integrity in flight. Marshall Space Flight Center assigned vibration testing to a contractor, the Scientific Services and Systems Group of Wyle Laboratories, Norco, California. Wyle-3S, as the group is known, built a large facility at Huntsville, Alabama, and equipped it with an enormously forceful shock and vibration system to simulate the liftoff stresses the Saturn V would encounter. Saturn V is no longer in service, but Wyle-3S has found spinoff utility for its vibration facility. It is now being used to simulate earthquake effects on various kinds of equipment, principally equipment intended for use in nuclear power generation. Government regulations require that such equipment demonstrate its ability to survive earthquake conditions. In upper left photo, Wyle3S is preparing to conduct an earthquake test on a 25ton diesel generator built by Atlas Polar Company, Ltd., Toronto, Canada, for emergency use in a Canadian nuclear power plant. Being readied for test in the lower left photo is a large circuit breaker to be used by Duke Power Company, Charlotte, North Carolina. Electro-hydraulic and electro-dynamic shakers in and around the pit simulate earthquake forces.

  8. Earthquake tectonics

    SciTech Connect

    Steward, R.F. )

    1991-02-01

    Earthquakes release a tremendous amount of energy into the subsurface in the form of seismic waves. The seismic wave energy of the San Francisco 1906 (M = 8.2) earthquake was equivalent to over 8 billion tons of TNT (3.3 {times} 10{sup 19} joules). Four basic wave types are propagated form seismic sources, two non-rotational and two rotational. As opposed to the non-rotational R and SH waves, the rotational compressional (RC) and rotational shear (RS) waves carry the bulk of the energy from a seismic source. RC wavefronts propagate in the subsurface and refract similarly to P waves, but are considerably slower. RC waves are critically refracted beneath the air surface interface at velocities less than the velocity of sound in air because they refract at the velocity of sound in air minus the retrograde particle velocity at the top of the wave. They propagate at tsunami waves in the open ocean, and produce loud sounds on land that are heard by humans and animals during earthquakes. The energy of the RS wave dwarfs that of the P, SH, and even the RC wave. The RS wave is the same as what is currently called the S wave in earthquake seismology, and produces both folding and strike-slip faulting at considerable distances from the epicenter. RC and RS waves, propagated during earthquakes from the Santa Ynez fault and a right-slip fault on trend with the Red Mountain fault, produced the Santa Ynez Mountains in California beginning in the middle Pliocene and continuing until the present.

  9. Earthquake damage to schools

    USGS Publications Warehouse

    McCullough, Heather

    1994-01-01

    These unusual slides show earthquake damage to school and university buildings around the world. They graphically illustrate the potential danger to our schools, and to the welfare of our children, that results from major earthquakes. The slides range from Algeria, where a collapsed school roof is held up only by students' desks; to Anchorage, Alaska, where an elementary school structure has split in half; to California and other areas, where school buildings have sustained damage to walls, roofs, and chimneys. Interestingly, all the United States earthquakes depicted in this set of slides occurred either on a holiday or before or after school hours, except the 1935 tremor in Helena, Montana, which occurred at 11:35 am. It undoubtedly would have caused casualties had the schools not been closed days earlier by Helena city officials because of a damaging foreshock. Students in Algeria, the People's Republic of China, Armenia, and other stricken countries were not so fortunate. This set of slides represents 17 destructive earthquakes that occurred in 9 countries, and covers more than a century--from 1886 to 1988. Two of the tremors, both of which occurred in the United States, were magnitude 8+ on the Richter Scale, and four were magnitude 7-7.9. The events represented by the slides (see table below) claimed more than a quarter of a million lives.

  10. Using focal mechanism solutions to correlate earthquakes with faults in the Lake Tahoe-Truckee area, California and Nevada, and to help design LiDAR surveys for active-fault reconnaissance

    NASA Astrophysics Data System (ADS)

    Cronin, V. S.; Lindsay, R. D.

    2011-12-01

    Geomorphic analysis of hillshade images produced from aerial LiDAR data has been successful in identifying youthful fault traces. For example, the recently discovered Polaris fault just northwest of Lake Tahoe, California/Nevada, was recognized using LiDAR data that had been acquired by local government to assist land-use planning. Subsequent trenching by consultants under contract to the US Army Corps of Engineers has demonstrated Holocene displacement. The Polaris fault is inferred to be capable of generating a magnitude 6.4-6.9 earthquake, based on its apparent length and offset characteristics (Hunter and others, 2011, BSSA 101[3], 1162-1181). Dingler and others (2009, GSA Bull 121[7/8], 1089-1107) describe paleoseismic or geomorphic evidence for late Neogene displacement along other faults in the area, including the West Tahoe-Dollar Point, Stateline-North Tahoe, and Incline Village faults. We have used the seismo-lineament analysis method (SLAM; Cronin and others, 2008, Env Eng Geol 14[3], 199-219) to establish a tentative spatial correlation between each of the previously mentioned faults, as well as with segments of the Dog Valley fault system, and one or more earthquake(s). The ~18 earthquakes we have tentatively correlated with faults in the Tahoe-Truckee area occurred between 1966 and 2008, with magnitudes between 3 and ~6. Given the focal mechanism solution for a well-located shallow-focus earthquake, the nodal planes can be projected to Earth's surface as represented by a DEM, plus-or-minus the vertical and horizontal uncertainty in the focal location, to yield two seismo-lineament swaths. The trace of the fault that generated the earthquake is likely to be found within one of the two swaths [1] if the fault surface is emergent, and [2] if the fault surface is approximately planar in the vicinity of the focus. Seismo-lineaments from several of the earthquakes studied overlap in a manner that suggests they are associated with the same fault. The surface

  11. Do buried-rupture earthquakes trigger less landslides than surface-rupture earthquakes for reverse faults?

    NASA Astrophysics Data System (ADS)

    Xu, Chong

    2014-07-01

    Gorum et al. (2013, Geomorphology 184, 127-138) carried out a study on inventory compilation and statistical analyses of landslides triggered by the 2010 Mw 7.0 Haiti earthquake. They revealed that spatial distribution patterns of these landslides were mainly controlled by complex rupture mechanism and topography. They also suggested that blind-rupture earthquakes trigger fewer landslides than surface-rupture earthquakes on thrust reverse faults. Although a few lines of evidence indicate that buried-rupture earthquakes might trigger fewer landslides than surface-rupture earthquakes on reverse faults, more careful comparisons and analyses indicate that it is not always true. Instead, some cases show that a buried-rupture earthquake can trigger a larger quantity of landslides that are distributed in a larger area, whereas surface-rupture earthquakes can trigger larger but a fewer landslides distributed in a smaller area.

  12. Earthquakes in Virginia and vicinity 1774 - 2004

    USGS Publications Warehouse

    Tarr, Arthur C.; Wheeler, Russell L.

    2006-01-01

    This map summarizes two and a third centuries of earthquake activity. The seismic history consists of letters, journals, diaries, and newspaper and scholarly articles that supplement seismograph recordings (seismograms) dating from the early twentieth century to the present. All of the pre-instrumental (historical) earthquakes were large enough to be felt by people or to cause shaking damage to buildings and their contents. Later, widespread use of seismographs meant that tremors too small or distant to be felt could be detected and accurately located. Earthquakes are a legitimate concern in Virginia and parts of adjacent States. Moderate earthquakes cause slight local damage somewhere in the map area about twice a decade on the average. Additionally, many buildings in the map area were constructed before earthquake protection was added to local building codes. The large map shows all historical and instrumentally located earthquakes from 1774 through 2004.

  13. Localization of intermediate-term earthquake prediction

    NASA Astrophysics Data System (ADS)

    Kossobokov, V. G.; Keilis-Borok, V. I.; Smith, S. W.

    1990-11-01

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

  14. Tidal triggering effect on earthquakes occurrence

    NASA Astrophysics Data System (ADS)

    Contadakis, M. E.; Arabelos, D.; Spatalas, S. D.

    2016-01-01

    In this review we present the investigation for the tidal triggering evidence on the earthquakes at various seismic areas of Greece. The result of our analysis using the HiCum method, indicate that the monthly variation of the frequencies of earthquake occurrence is in accordance with the period of the tidal lunar monthly (Mm) variations. The same happens with the corresponding diurnal and semi-diurnal variations of the frequencies of earthquake occurrence with the diurnal (K1), (O1) and semi-diurnal solar (S2) and semidiurnal lunar (M2) tidal variations. The confidence level of the Tidal-Earthquake frequency period compliance is very sensitive to the seismicity of the area and we call it Tidal - Earthquake frequency compliance parameter. We suggest that this parameter may be used in earthquake risk evaluation.

  15. Thioredoxin-regulated beta-amylase (BAM1) triggers diurnal starch degradation in guard cells, and in mesophyll cells under osmotic stress.

    PubMed

    Valerio, Concetta; Costa, Alex; Marri, Lucia; Issakidis-Bourguet, Emmanuelle; Pupillo, Paolo; Trost, Paolo; Sparla, Francesca

    2011-01-01

    BAM1 is a plastid-targeted β-amylase of Arabidopsis thaliana specifically activated by reducing conditions. Among eight different chloroplast thioredoxin isoforms, thioredoxin f1 was the most efficient redox mediator, followed by thioredoxins m1, m2, y1, y2, and m4. Plastid-localized NADPH-thioredoxin reductase (NTRC) was also able partially to restore the activity of oxidized BAM1. Promoter activity of BAM1 was studied by reporter gene expression (GUS and YFP) in Arabidopsis transgenic plants. In young (non-flowering) plants, BAM1 was expressed both in leaves and roots, but expression in leaves was mainly restricted to guard cells. Compared with wild-type plants, bam1 knockout mutants were characterized by having more starch in illuminated guard cells and reduced stomata opening, suggesting that thioredoxin-regulated BAM1 plays a role in diurnal starch degradation which sustains stomata opening. Besides guard cells, BAM1 appears in mesophyll cells of young plants as a result of a strongly induced gene expression under osmotic stress, which is paralleled by an increase in total β-amylase activity together with its redox-sensitive fraction. Osmotic stress impairs the rate of diurnal starch accumulation in leaves of wild-type plants, but has no effect on starch accumulation in bam1 mutants. It is proposed that thioredoxin-regulated BAM1 activates a starch degradation pathway in illuminated mesophyll cells upon osmotic stress, similar to the diurnal pathway of starch degradation in guard cells that is also dependent on thioredoxin-regulated BAM1.

  16. Earthquake technology fights crime

    USGS Publications Warehouse

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

    1996-01-01

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

  17. United States earthquakes, 1984

    SciTech Connect

    Stover, C.W.

    1988-01-01

    The report contains information for eartthquakes in the 50 states and Puerto Rico and the area near their shorelines. The data consist of earthquake locations (date, time, geographic coordinates, depth, and magnitudes), intensities, macroseismic information, and isoseismal and seismicity maps. Also, included are sections detailing the activity of seismic networks operated by universities and other government agencies and a list of results form strong-motion seismograph records.

  18. Spatiotemporal model for crustal deformation around the focal area of the 2008 Iwate-Miyagi Inland Earthquake, northeastern Japan, estimated by GPS and InSAR

    NASA Astrophysics Data System (ADS)

    Ohzono, M.; McCaffrey, R.; Ohta, Y.; Miura, S.; Iinuma, T.; Tachibana, K.; Sato, T.

    2009-12-01

    Applying the program tDEFNODE [McCaffrey, GRL09] to model elastic lithospheric block rotations and strains, and locking or coseismic slip on block-bounding faults, we model GPS and InSAR data of crustal deformation before and after the 2008 M7.2 Iwate-Miyagi Inland Earthquake (IMEQ). The epicenter of the IMEQ is located in a high strain rate zone along the Ou Backbone Range (OBR) in northeastern Japan, where volcanic front runs subparallel to the Japan Trench. Along eastern and western margin of the OBR, major inland active faults have been growing. In order to clarify detailed strain field around these active faults, Japan Nuclear Energy Safety Organization (JNES) installed 7 new continuous GPS sites with ~5 km spacing across the Dedana Fault (DF), which is a part of the eastern marginal active faults, in October 2007. Because the DF is located at only ~20 km northeast from the hypocenter of the IMEQ, the detailed coseismic and postseismic crustal deformation was obtained at these GPS sites [Ohta et al., EPS08; Iinuma et al., GRL09]. Takada et al. [EPS09] also estimated coseismic faults from InSAR with pixel-offset method. These studies, however, handled each data independently. We unify both GPS and InSAR data to model crustal deformation over inter-, co-, and post-seismic period using tDEFNODE. This code interprets geodetic timeseries data by assuming elastic block rotation, transient phenomena such as slow slip, and coseismic slip, on the block boundary faults. We use timeseries data obtained by continuous GPS networks conducted by JNES, Tohoku University, Geographical Survey Institute (GSI), National Astronomical Observatory (NAO), and IGS from 2006 to June 2009, together with a temporal network for postseismic deformation installed by Japanese University Consortium for GPS Research (JUNCO). InSAR data is obtained by analyzing images of ALOS/PALSAR mission. We presumed three blocks in the study area divided by two boundary faults. We expressed the time

  19. Fault tectonics and earthquake hazards in parts of southern California. [penninsular ranges, Garlock fault, Salton Trough area, and western Mojave Desert

    NASA Technical Reports Server (NTRS)

    Merifield, P. M. (Principal Investigator); Lamar, D. L.; Gazley, C., Jr.; Lamar, J. V.; Stratton, R. H.

    1976-01-01

    The author has identified the following significant results. Four previously unknown faults were discovered in basement terrane of the Peninsular Ranges. These have been named the San Ysidro Creek fault, Thing Valley fault, Canyon City fault, and Warren Canyon fault. In addition fault gouge and breccia were recognized along the San Diego River fault. Study of features on Skylab imagery and review of geologic and seismic data suggest that the risk of a damaging earthquake is greater along the northwestern portion of the Elsinore fault than along the southeastern portion. Physiographic indicators of active faulting along the Garlock fault identifiable in Skylab imagery include scarps, linear ridges, shutter ridges, faceted ridges, linear valleys, undrained depressions and offset drainage. The following previously unrecognized fault segments are postulated for the Salton Trough Area: (1) An extension of a previously known fault in the San Andreas fault set located southeast of the Salton Sea; (2) An extension of the active San Jacinto fault zone along a tonal change in cultivated fields across Mexicali Valley ( the tonal change may represent different soil conditions along opposite sides of a fault). For the Skylab and LANDSAT images studied, pseudocolor transformations offer no advantages over the original images in the recognition of faults in Skylab and LANDSAT images. Alluvial deposits of different ages, a marble unit and iron oxide gossans of the Mojave Mining District are more readily differentiated on images prepared from ratios of individual bands of the S-192 multispectral scanner data. The San Andreas fault was also made more distinct in the 8/2 and 9/2 band ratios by enhancement of vegetation differences on opposite sides of the fault. Preliminary analysis indicates a significant earth resources potential for the discrimination of soil and rock types, including mineral alteration zones. This application should be actively pursued.

  20. Structural Analysis of Recent and Active Faults and Regional State of Stress in the Epicentral Area of the 1978 Thessaloniki Earthquakes (northern Greece)

    NASA Astrophysics Data System (ADS)

    Mercier, Jacques-Louis; Carey-Gailhardis, Evelyne; Mouyaris, Nicolas; Simeakis, Konstantinos; Roundoyannis, Theodora; Anghelidhis, Christos

    1983-12-01

    During spring and summer 1978, Macedonia (Greece) suffered damaging seismic activity. During the two main shocks which occurred on May 23 (Mb = 5.7) and June 20 (Mb = 6.1), seismic open cracks and faults were formed in the epicentral area, 25 km NNE from Thessaloniki. They have been mapped and their kinematics analyzed. These studies have shown that they result from the reactivation of existing faults of Pleistocene, Recent, and historical age and that the crust is stretching along a N-S to NNE-SSW direction in that part of the North Aegean. Principal stress directions have been computed from the slip vectors measured on recent neotectonic faults and seismic cracks and faults, this computation utilizing a simple mechanical model (homogeneous deformation through the addition of small and independent displacements of rigid blocks in a highly fractured body). A striking feature of this analysis is that the tensional directions σ3 deduced from seismic faulting and from recent neotectonic faulting are nearly the same. They are compatible with the regional tension axis deduced from focal mechanisms of North Aegean and with the focal mechanisms of the 1978 Thessaloniki main shocks. They are also compatible with in situ stress measurements in this region. Studies of superficial seismic faulting strongly support previous assumptions proposed from aftershock distribution: the 1978 Thessaloniki earthquakes resulted from reactivation of several different faults situated within the same NE dipping fault zone of Upper Eocene-Lower Oligocene age (and older) separating the Serbo-Macedonian Massif from the Peonias (East Vardar) zone.

  1. Alview: Portable Software for Viewing Sequence Reads in BAM Formatted Files.

    PubMed

    Finney, Richard P; Chen, Qing-Rong; Nguyen, Cu V; Hsu, Chih Hao; Yan, Chunhua; Hu, Ying; Abawi, Massih; Bian, Xiaopeng; Meerzaman, Daoud M

    2015-01-01

    The name Alview is a contraction of the term Alignment Viewer. Alview is a compiled to native architecture software tool for visualizing the alignment of sequencing data. Inputs are files of short-read sequences aligned to a reference genome in the SAM/BAM format and files containing reference genome data. Outputs are visualizations of these aligned short reads. Alview is written in portable C with optional graphical user interface (GUI) code written in C, C++, and Objective-C. The application can run in three different ways: as a web server, as a command line tool, or as a native, GUI program. Alview is compatible with Microsoft Windows, Linux, and Apple OS X. It is available as a web demo at https://cgwb.nci.nih.gov/cgi-bin/alview. The source code and Windows/Mac/Linux executables are available via https://github.com/NCIP/alview.

  2. NEIC; the National Earthquake Information Center

    USGS Publications Warehouse

    Masse, R.P.; Needham, R.E.

    1989-01-01

    At least 9,500 people were killed, 30,000 were injured and 100,000 were left homeless by this earthquake. According to some unconfirmed reports, the death toll from this earthquake may have been as high as 35,000. this earthquake is estimated to have seriously affected an area of 825,000 square kilometers, caused between 3 and 4 billion dollars in damage, and been felt by 20 million people. 

  3. Patterns of Seismicity Characterizing the Earthquake Cycle

    NASA Astrophysics Data System (ADS)

    Rundle, J. B.; Turcotte, D. L.; Yoder, M. R.; Holliday, J. R.; Schultz, K.; Wilson, J. M.; Donnellan, A.; Grant Ludwig, L.

    2015-12-01

    A number of methods to calculate probabilities of major earthquakes have recently been proposed. Most of these methods depend upon understanding patterns of small earthquakes preceding the large events. For example, the Natural Time Weibull method for earthquake forecasting (see www.openhazards.com) is based on the assumption that large earthquakes complete the Gutenberg-Richter scaling relation defined by the smallest earthquakes. Here we examine the scaling patterns of small earthquakes having magnitudes between cycles of large earthquakes. For example, in the region of California-Nevada between longitudes -130 to -114 degrees W, and latitudes 32 to 45 degrees North, we find 79 earthquakes having magnitudes M6 during the time interval 1933 - present, culminating with the most recent event, the M6.0 Napa, California earthquake of August 24, 2014. Thus we have 78 complete cycles of large earthquakes in this region. After compiling and stacking the smaller events occurring between the large events, we find a characteristic pattern of scaling for the smaller events. This pattern shows a scaling relation for the smallest earthquakes up to about 3earthquakes for 4.5earthquake having M~6.4. In addition, statistics indicate that departure of the successive earthquake cycles from their average pattern can be characterized by Coefficients of Variability and other measures. We discuss these ideas and apply them not only to California, but also to other seismically active areas in the world

  4. Geochemical challenge to earthquake prediction.

    PubMed

    Wakita, H

    1996-04-30

    The current status of geochemical and groundwater observations for earthquake prediction in Japan is described. The development of the observations is discussed in relation to the progress of the earthquake prediction program in Japan. Three major findings obtained from our recent studies are outlined. (i) Long-term radon observation data over 18 years at the SKE (Suikoen) well indicate that the anomalous radon change before the 1978 Izu-Oshima-kinkai earthquake can with high probability be attributed to precursory changes. (ii) It is proposed that certain sensitive wells exist which have the potential to detect precursory changes. (iii) The appearance and nonappearance of coseismic radon drops at the KSM (Kashima) well reflect changes in the regional stress state of an observation area. In addition, some preliminary results of chemical changes of groundwater prior to the 1995 Kobe (Hyogo-ken nanbu) earthquake are presented.

  5. Medical complications associated with earthquakes.

    PubMed

    Bartels, Susan A; VanRooyen, Michael J

    2012-02-25

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

  6. Darwin's earthquake.

    PubMed

    Lee, Richard V

    2010-07-01

    Charles Darwin experienced a major earthquake in the Concepción-Valdivia region of Chile 175 years ago, in February 1835. His observations dramatically illustrated the geologic principles of James Hutton and Charles Lyell which maintained that the surface of the earth was subject to alterations by natural events, such as earthquakes, volcanoes, and the erosive action of wind and water, operating over very long periods of time. Changes in the land created new environments and fostered adaptations in life forms that could lead to the formation of new species. Without the demonstration of the accumulation of multiple crustal events over time in Chile, the biologic implications of the specific species of birds and tortoises found in the Galapagos Islands and the formulation of the concept of natural selection might have remained dormant.

  7. Connecting slow earthquakes to huge earthquakes.

    PubMed

    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.

  8. Epitaxially grown BaM hexaferrite films having uniaxial axis in the film plane for self-biased devices

    PubMed Central

    Zhang, Xiaozhi; Meng, Siqin; Song, Dongsheng; Zhang, Yao; Yue, Zhenxing; Harris, Vincent G.

    2017-01-01

    Barium hexaferrite (BaM) films with in-plane c-axis orientation are promising and technically important materials for self-biased magnetic microwave devices. In this work, highly oriented BaM films with different thickness and an in-plane easy axis (c-axis) of magnetization were grown on a-plane single-crystal sapphire substrates by direct current magnetron sputtering. A procedure involving seed layers, layer-by-layer annealing was adopted to reduce the substrate-induced strains and allow for the growth of thick (~3.44 μm) films. The epitaxial growth of the BaM film on sapphire was revealed by high-resolution transmission electron microscopy with dislocations being observed at the film-substrate interface. The orientation was also verified by X-ray diffraction and more notably, polarized Raman scattering. The magnetic properties and ferromagnetic resonant frequencies were experimentally characterized by a vibrating sample magnetometry and a frequency-swept ferromagnetic resonant flip-chip technique, respectively. The micron-thick BaM films exhibited a large remanence ratio of 0.92 along in-plane easy axis and a small one of 0.09 for the in-plane hard axis loop measurement. The FMR frequency was 50.3 GHz at zero field and reached 57.9 GHz under a magnetic field of 3 kOe, indicating that the epitaxial BaM films with strong self-biased behaviors have good electromagnetic properties in millimeter-wave range. PMID:28276492

  9. Epitaxially grown BaM hexaferrite films having uniaxial axis in the film plane for self-biased devices

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaozhi; Meng, Siqin; Song, Dongsheng; Zhang, Yao; Yue, Zhenxing; Harris, Vincent G.

    2017-03-01

    Barium hexaferrite (BaM) films with in-plane c-axis orientation are promising and technically important materials for self-biased magnetic microwave devices. In this work, highly oriented BaM films with different thickness and an in-plane easy axis (c-axis) of magnetization were grown on a-plane single-crystal sapphire substrates by direct current magnetron sputtering. A procedure involving seed layers, layer-by-layer annealing was adopted to reduce the substrate-induced strains and allow for the growth of thick (~3.44 μm) films. The epitaxial growth of the BaM film on sapphire was revealed by high-resolution transmission electron microscopy with dislocations being observed at the film-substrate interface. The orientation was also verified by X-ray diffraction and more notably, polarized Raman scattering. The magnetic properties and ferromagnetic resonant frequencies were experimentally characterized by a vibrating sample magnetometry and a frequency-swept ferromagnetic resonant flip-chip technique, respectively. The micron-thick BaM films exhibited a large remanence ratio of 0.92 along in-plane easy axis and a small one of 0.09 for the in-plane hard axis loop measurement. The FMR frequency was 50.3 GHz at zero field and reached 57.9 GHz under a magnetic field of 3 kOe, indicating that the epitaxial BaM films with strong self-biased behaviors have good electromagnetic properties in millimeter-wave range.

  10. Earthquake and tsunami forecasts: Relation of slow slip events to subsequent earthquake rupture

    PubMed Central

    Dixon, Timothy H.; Jiang, Yan; Malservisi, Rocco; McCaffrey, Robert; Voss, Nicholas; Protti, Marino; Gonzalez, Victor

    2014-01-01

    The 5 September 2012 Mw 7.6 earthquake on the Costa Rica subduction plate boundary followed a 62-y interseismic period. High-precision GPS recorded numerous slow slip events (SSEs) in the decade leading up to the earthquake, both up-dip and down-dip of seismic rupture. Deeper SSEs were larger than shallower ones and, if characteristic of the interseismic period, release most locking down-dip of the earthquake, limiting down-dip rupture and earthquake magnitude. Shallower SSEs were smaller, accounting for some but not all interseismic locking. One SSE occurred several months before the earthquake, but changes in Mohr–Coulomb failure stress were probably too small to trigger the earthquake. Because many SSEs have occurred without subsequent rupture, their individual predictive value is limited, but taken together they released a significant amount of accumulated interseismic strain before the earthquake, effectively defining the area of subsequent seismic rupture (rupture did not occur where slow slip was common). Because earthquake magnitude depends on rupture area, this has important implications for earthquake hazard assessment. Specifically, if this behavior is representative of future earthquake cycles and other subduction zones, it implies that monitoring SSEs, including shallow up-dip events that lie offshore, could lead to accurate forecasts of earthquake magnitude and tsunami potential. PMID:25404327

  11. Earthquake and tsunami forecasts: relation of slow slip events to subsequent earthquake rupture.

    PubMed

    Dixon, Timothy H; Jiang, Yan; Malservisi, Rocco; McCaffrey, Robert; Voss, Nicholas; Protti, Marino; Gonzalez, Victor

    2014-12-02

    The 5 September 2012 M(w) 7.6 earthquake on the Costa Rica subduction plate boundary followed a 62-y interseismic period. High-precision GPS recorded numerous slow slip events (SSEs) in the decade leading up to the earthquake, both up-dip and down-dip of seismic rupture. Deeper SSEs were larger than shallower ones and, if characteristic of the interseismic period, release most locking down-dip of the earthquake, limiting down-dip rupture and earthquake magnitude. Shallower SSEs were smaller, accounting for some but not all interseismic locking. One SSE occurred several months before the earthquake, but changes in Mohr-Coulomb failure stress were probably too small to trigger the earthquake. Because many SSEs have occurred without subsequent rupture, their individual predictive value is limited, but taken together they released a significant amount of accumulated interseismic strain before the earthquake, effectively defining the area of subsequent seismic rupture (rupture did not occur where slow slip was common). Because earthquake magnitude depends on rupture area, this has important implications for earthquake hazard assessment. Specifically, if this behavior is representative of future earthquake cycles and other subduction zones, it implies that monitoring SSEs, including shallow up-dip events that lie offshore, could lead to accurate forecasts of earthquake magnitude and tsunami potential.

  12. Seismic reflection profiling around the hypocentral area of the 2003 Miyagi-ken Hokubu earthquake (Mj6.4): Reactivated thrust faulting of a Miocene normal fault.

    NASA Astrophysics Data System (ADS)

    Yokokura, T.; Yamaguchi, K.; Kano, N.; Yokota, T.; Tanaka, A.; Ohtaki, T.

    2004-12-01

    The 2003 Miyagi-ken Hokubu (northern Miyagi) earthquake occurred on July 26, which was preceded by the largest foreshock of Mj5.6 and was followed by the largest aftershock of Mj5.5. Although these earthquakes were not so large in magnitude, they caused large damages. The earthquakes occurred just beneath the Asahiyama hills, where exist the active Asahiyama flexure. Aftershock observations delineate a clear fault plane that extends toward the Sue hills in the east, not toward the Asahiyama hills. However neither surface ruptures nor active fault assocciated with the earthquakes were observed in this region. To clarify both the surface extension of the fault and geologic structure of this region, we conducted 17km-long seismic reflection profiling, using a 17.5-ton vibrator. Geologically, this region was subjected rapid EW extension in middle Miocene and thus produced rift basin was filled by the Matsushima-wan Group (syn-rift sediments) which was bounded by a normal fault, the Ishinomaki-wan fault, in the eastern side of the basin. The Matsushima-wan Group was unconformably overlain by the Shida Group (Miocene post-rift sediments). The Shida Group was unconformably overlain by the Pliocene and post-Pliocene sediments. Deformed Pliocene strata show thrust faulting, indicating EW compression after early Pliocene. Detailed data processing reveals that the seismic profile is essentially concordant with the structure inferred from surface geology. A west-dipping fault with about 50 degrees is found beneath the southeastern extension of the Sue hills where the Ishinomaki-wan fault was supposed to extend. The deeper part of the fault extends toward the earthquake fault plane determined by aftershocks and the shallower part shows a thrust-like structure, which indicate basin inversion using this fault. Thus the 2003 Miyagi-ken Hokubu earthquake occurred as reactivated thrust faulting of the Miocene normal fault bounding the eastern side of the rift basin.

  13. Vp structure in the largest slip area of the 2011 Tohoku-oki earthquake by airgun-ocean bottom seismometer surveys

    NASA Astrophysics Data System (ADS)

    Azuma, R.; Hino, R.; Ohta, Y.; Mochizuki, K.; Murai, Y.; Ito, Y.; Yakiwara, H.; Sato, T.; Shinohara, M.

    2015-12-01

    The huge coseismic slip during the 2011 Tohoku-oki earthquake concentrated beneath the lower inner slope of the middle Japan Trench (Miyagi region) and its amount sharply diminished along the trench within a hundred kilometers (e.g., Iinuma et al., 2012). The previous 2-D seismic study in the corresponding area found a notable Vp change in the hanging wall side of the megathrust (Azuma et al., in prep.). High-Vp body, corresponding to the rigid backstop block (Tsuru et al., 2002) was identified in the Miyagi, but was absent in the northern area. The spatial extent of the high-Vp anomaly almost coincides with the large slip zone and the correlation suggests that the heterogeneous structure in the overriding plate controlled the rupture process of the M-9 mainshock. To confirm the correlation between the seismic structure and coseismic slip distribution, we conducted a wide-angle survey in 2014 around the previous survey. In analysis, we operated a traveltime inversion for the first arrivals (Fujie et al., 2000) to obtain a rough model. Then, we made a trial-and-error adjustment of the structure model based on the travel time modeling with a 2D ray tracing (Zelt and Ellis, 1988). In the modeling, we tried to identify the location of the boundary between the backstop block and the low-Vp prism, because we assume the boundary (B/P boundary) to be correlated to the border of the high-slip zone during the 2011 event. The results showed sharp Vp transition from >3.7 km/s (backstop) to <3.4 km/s (prism) representing the B/P boundary. This feature agrees with the Vp variation or the along-trench distribution of the prism clarified by the previous studies. In the several observed record sections, there are clear shadow zone of the refracted arrivals from the backstop layer. The presence of the shadow indicates that a low Vp layer underlies the backstop, which is consistent with the previous reflection profiling made across the trench system. The low Vp prism is located

  14. Earthquakes and plate tectonics.

    USGS Publications Warehouse

    Spall, H.

    1982-01-01

    Earthquakes occur at the following three kinds of plate boundary: ocean ridges where the plates are pulled apart, margins where the plates scrape past one another, and margins where one plate is thrust under the other. Thus, we can predict the general regions on the earth's surface where we can expect large earthquakes in the future. We know that each year about 140 earthquakes of magnitude 6 or greater will occur within this area which is 10% of the earth's surface. But on a worldwide basis we cannot say with much accuracy when these events will occur. The reason is that the processes in plate tectonics have been going on for millions of years. Averaged over this interval, plate motions amount to several mm per year. But at any instant in geologic time, for example the year 1982, we do not know, exactly where we are in the worldwide cycle of strain build-up and strain release. Only by monitoring the stress and strain in small areas, for instance, the San Andreas fault, in great detail can we hope to predict when renewed activity in that part of the plate tectonics arena is likely to take place. -from Author

  15. LAT-independent Erk activation via Bam32-PLC-γ1-Pak1 complexes: GTPase-independent Pak1 activation.

    PubMed

    Rouquette-Jazdanian, Alexandre K; Sommers, Connie L; Kortum, Robert L; Morrison, Deborah K; Samelson, Lawrence E

    2012-10-26

    In T cells, the adaptor Bam32 is coupled to Erk activation downstream of the TCR by an unknown mechanism. We characterized in Jurkat cells and primary T lymphocytes a pathway dependent on Bam32-PLC-γ1-Pak1 complexes, in which Pak1 kinase activates Raf-1 and Mek-1, both upstream of Erk. In the Bam32-PLC-γ1-Pak1 complex, catalytically inactive PLC-γ1 is used as a scaffold linking Bam32 to Pak1. PLC-γ1(C-SH2) directly binds S141 of Bam32, preventing LAT-mediated activation of Ras by PLC-γ1. The Bam32-PLC-γ1 interaction enhances the binding of the SH3 domain of the phospholipase with Pak1. The PLC-γ1(SH3)-Pak1 interaction activates Pak1 independently of the small GTPases Rac1/Cdc42, previously described as being the only activators of Pak1 in T cells. Direct binding of the SH3 domain of PLC-γ1 to Pak1 dissociates inactive Pak1 homodimers, a mechanism required for Pak1 activation. We have thus uncovered a LAT/Ras-independent, Bam32-nucleated pathway that activates Erk signaling in T cells.

  16. Putting down roots in earthquake country-Your handbook for earthquakes in the Central United States

    USGS Publications Warehouse

    Contributors: Dart, Richard; McCarthy, Jill; McCallister, Natasha; Williams, Robert A.

    2011-01-01

    This handbook provides information to residents of the Central United States about the threat of earthquakes in that area, particularly along the New Madrid seismic zone, and explains how to prepare for, survive, and recover from such events. It explains the need for concern about earthquakes for those residents and describes what one can expect during and after an earthquake. Much is known about the threat of earthquakes in the Central United States, including where they are likely to occur and what can be done to reduce losses from future earthquakes, but not enough has been done to prepare for future earthquakes. The handbook describes such preparations that can be taken by individual residents before an earthquake to be safe and protect property.

  17. Streamflow and water well responses to earthquakes.

    PubMed

    Montgomery, David R; Manga, Michael

    2003-06-27

    Earthquake-induced crustal deformation and ground shaking can alter stream flow and water levels in wells through consolidation of surficial deposits, fracturing of solid rocks, aquifer deformation, and the clearing of fracture-filling material. Although local conditions affect the type and amplitude of response, a compilation of reported observations of hydrological response to earthquakes indicates that the maximum distance to which changes in stream flow and water levels in wells have been reported is related to earthquake magnitude. Detectable streamflow changes occur in areas within tens to hundreds of kilometers of the epicenter, whereas changes in groundwater levels in wells can occur hundreds to thousands of kilometers from earthquake epicenters.

  18. Thermoluminescence dating of Australian palaeo-earthquakes

    USGS Publications Warehouse

    Hutton, J.T.; Prescott, J.R.; Bowman, J.R.; Dunham, M.N.E.; Crone, A.J.; Machette, M.N.; Twidale, C.R.

    1994-01-01

    Thermoluminescence (TL) dating is a useful tool for determining the age of prehistoric earthquakes by dating deposits that are stratigraphically related to fault scarps that formed during the earthquakes. TL dating of aeolian sand in the area of the 1988 Tennant Creek, Northern Territory, earthquakes provides evidence that similar earthquakes have not ruptured the causative faults for at least 50 ka. Pilot TL measurements of deposits associated with the Roopena and Ash Ridge fault scarps near Whyalla on Eyre Peninsula, South Australia, suggest an age of 140 ka for the Quaternary deposits associated with the formation of the scarps. ?? 1994.

  19. Mega-earthquakes rupture flat megathrusts.

    PubMed

    Bletery, Quentin; Thomas, Amanda M; Rempel, Alan W; Karlstrom, Leif; Sladen, Anthony; De Barros, Louis

    2016-11-25

    The 2004 Sumatra-Andaman and 2011 Tohoku-Oki earthquakes highlighted gaps in our understanding of mega-earthquake rupture processes and the factors controlling their global distribution: A fast convergence rate and young buoyant lithosphere are not required to produce mega-earthquakes. We calculated the curvature along the major subduction zones of the world, showing that mega-earthquakes preferentially rupture flat (low-curvature) interfaces. A simplified analytic model demonstrates that heterogeneity in shear strength increases with curvature. Shear strength on flat megathrusts is more homogeneous, and hence more likely to be exceeded simultaneously over large areas, than on highly curved faults.

  20. Space-borne Observations of Atmospheric Pre-Earthquake Signals in Seismically Active Areas: Case Study for Greece 2008-2009

    NASA Technical Reports Server (NTRS)

    Ouzounov, D. P.; Pulinets, S. A.; Davidenko, D. A.; Kafatos, M.; Taylor, P. T.

    2013-01-01

    We are conducting theoretical studies and practical validation of atm osphere/ionosphere phenomena preceding major earthquakes. Our approach is based on monitoring of two physical parameters from space: outgoi ng long-wavelength radiation (OLR) on the top of the atmosphere and e lectron and electron density variations in the ionosphere via GPS Tot al Electron Content (GPS/TEC). We retrospectively analyzed the temporal and spatial variations of OLR an GPS/TEC parameters characterizing the state of the atmosphere and ionosphere several days before four m ajor earthquakes (M>6) in Greece for 2008-2009: M6.9 of 02.12.08, M6. 2 02.20.08; M6.4 of 06.08.08 and M6.4 of 07.01.09.We found anomalous behavior before all of these events (over land and sea) over regions o f maximum stress. We expect that our analysis reveal the underlying p hysics of pre-earthquake signals associated with some of the largest earthquakes in Greece.

  1. Earthquakes at North Atlantic passive margins

    SciTech Connect

    Gregersen, S. ); Basham, P.W. )

    1989-01-01

    The main focus of this volume is the earthquakes that occur at and near the continental margins on both sides of the North Atlantic. The book, which contains the proceedings of the NATO workshop on Causes and Effects of Earthquakes at Passive Margins and in Areas of Postglacial Rebound on Both Sides of the North Atlantic, draws together the fields of geophysics, geology and geodesy to address the stress and strain in the Earth's crust. The resulting earthquakes produced on ancient geological fault zones and the associated seismic hazards these pose to man are also addressed. Postglacial rebound in North America and Fennoscandia is a minor source of earthquakes today, during the interglacial period, but evidence is presented to suggest that the ice sheets suppressed earthquake strain while they were in place, and released this strain as a pulse of significant earthquakes after the ice melted about 9000 years ago.

  2. Oklahoma's recent earthquakes and saltwater disposal.

    PubMed

    Walsh, F Rall; Zoback, Mark D

    2015-06-01

    Over the past 5 years, parts of Oklahoma have experienced marked increases in the number of small- to moderate-sized earthquakes. In three study areas that encompass the vast majority of the recent seismicity, we show that the increases in seismicity follow 5- to 10-fold increases in the rates of saltwater disposal. Adjacent areas where there has been relatively little saltwater disposal have had comparatively few recent earthquakes. In the areas of seismic activity, the saltwater disposal principally comes from "produced" water, saline pore water that is coproduced with oil and then injected into deeper sedimentary formations. These formations appear to be in hydraulic communication with potentially active faults in crystalline basement, where nearly all the earthquakes are occurring. Although most of the recent earthquakes have posed little danger to the public, the possibility of triggering damaging earthquakes on potentially active basement faults cannot be discounted.

  3. Soviet prediction of a major earthquake

    USGS Publications Warehouse

    Simpson, D.W.

    1979-01-01

    On November 1, 1978, a magnitude 7 earthquake occurred north of the Pamir Mountains near the Tadjiskistan-Kirghizia border, 150 kilometers east of Garm in Soviet Central Asia. Although the earthquake was felt in Tashkent, Dushanbe, and the Fergana Valley, the epicentral area was uninhabited at that time of year, and no damage was reported. 

  4. Revisiting the 1872 Owens Valley, California, Earthquake

    USGS Publications Warehouse

    Hough, S.E.; Hutton, K.

    2008-01-01

    The 26 March 1872 Owens Valley earthquake is among the largest historical earthquakes in California. The felt area and maximum fault displacements have long been regarded as comparable to, if not greater than, those of the great San Andreas fault earthquakes of 1857 and 1906, but mapped surface ruptures of the latter two events were 2-3 times longer than that inferred for the 1872 rupture. The preferred magnitude estimate of the Owens Valley earthquake has thus been 7.4, based largely on the geological evidence. Reinterpreting macroseismic accounts of the Owens Valley earthquake, we infer generally lower intensity values than those estimated in earlier studies. Nonetheless, as recognized in the early twentieth century, the effects of this earthquake were still generally more dramatic at regional distances than the macroseismic effects from the 1906 earthquake, with light damage to masonry buildings at (nearest-fault) distances as large as 400 km. Macroseismic observations thus suggest a magnitude greater than that of the 1906 San Francisco earthquake, which appears to be at odds with geological observations. However, while the mapped rupture length of the Owens Valley earthquake is relatively low, the average slip was high. The surface rupture was also complex and extended over multiple fault segments. It was first mapped in detail over a century after the earthquake occurred, and recent evidence suggests it might have been longer than earlier studies indicated. Our preferred magnitude estimate is Mw 7.8-7.9, values that we show are consistent with the geological observations. The results of our study suggest that either the Owens Valley earthquake was larger than the 1906 San Francisco earthquake or that, by virtue of source properties and/or propagation effects, it produced systematically higher ground motions at regional distances. The latter possibility implies that some large earthquakes in California will generate significantly larger ground motions than San

  5. Update earthquake risk assessment in Cairo, Egypt

    NASA Astrophysics Data System (ADS)

    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

  6. Delayed increase in male suicide rates in tsunami disaster-stricken areas following the great east japan earthquake: a three-year follow-up study in Miyagi Prefecture.

    PubMed

    Orui, Masatsugu; Sato, Yasuhiro; Tazaki, Kanako; Kawamura, Ikuko; Harada, Shuichiro; Hayashi, Mizuho

    2015-01-01

    Devastating natural disasters and their aftermath are known to cause psychological distress. However, little information is available regarding suicide rates following tsunami disasters that destroy regional social services and networks. The aim of the present study was to determine whether the tsunami disaster following the Great East Japan Earthquake in March 2011 has influenced suicide rates. The study period was from March 2009 to February 2014. Tsunami disaster-stricken areas were defined as the 16 municipalities facing the Pacific Ocean in Miyagi Prefecture. Inland areas were defined as other municipalities in Miyagi that were damaged by the earthquake. Suicide rates in the tsunami disaster-stricken areas were compared to national averages, using a time-series analysis and the Poisson distribution test. In tsunami disaster-stricken areas, male suicide rates were significantly lower than the national average during the initial post-disaster period and began to increase after two years. Likewise, male suicide rates in the inland areas decreased for seven months, and then increased to exceed the national average. In contrast, female post-disaster suicide rates did not change in both areas compared to the national average. Importantly, the male suicide rates in the inland areas started to increase earlier compared to the tsunami-stricken areas, which may reflect the relative deficiency of mental healthcare services in the inland areas. Considering the present status that many survivors from the tsunami disaster still live in temporary housing and face various challenges to rebuild their lives, we should continue intensive, long-term mental healthcare services in the tsunami-stricken areas.

  7. Building with Earthquakes in Mind

    NASA Astrophysics Data System (ADS)

    Mangieri, Nicholas

    2016-04-01

    Earthquakes are some of the most elusive and destructive disasters humans interact with on this planet. Engineering structures to withstand earthquake shaking is critical to ensure minimal loss of life and property. However, the majority of buildings today in non-traditional earthquake prone areas are not built to withstand this devastating force. Understanding basic earthquake engineering principles and the effect of limited resources helps students grasp the challenge that lies ahead. The solution can be found in retrofitting existing buildings with proper reinforcements and designs to deal with this deadly disaster. The students were challenged in this project to construct a basic structure, using limited resources, that could withstand a simulated tremor through the use of an earthquake shake table. Groups of students had to work together to creatively manage their resources and ideas to design the most feasible and realistic type of building. This activity provided a wealth of opportunities for the students to learn more about a type of disaster they do not experience in this part of the country. Due to the fact that most buildings in New York City were not designed to withstand earthquake shaking, the students were able to gain an appreciation for how difficult it would be to prepare every structure in the city for this type of event.

  8. Earthquake history of the United States

    USGS Publications Warehouse

    Coffman, Jerry L.; Von Hake, Carl A.; Stover, Carl W.; Coffman, Jerry L.; von Hake, Carl A.; Stover, Carl W.

    1982-01-01

    This publication is a history of the prominent earthquakes in the United States from historical times through 1970. It supersedes all previous editions with the same or similar titles (see page ii) and, in addition to updating earthquake listings through 1970, contains several additions and corrections to previous issues. It also brings together under a common cover earthquake data previously listed in two separate reports: Earthquake History of the United States, Part I, Stronger Earthquakes of the United States (Exclusive of California and Western Nevada) and Earthquake History of the United States, Part II, Stronger Earthquakes of California and Western Nevada. Another addition to this publication is the inclusion of a section describing earthquakes in the Puerto Rico region. For the purpose of listing and describing earthquakes, the United States has been divided into nine regions: (1) Northeastern Region, which includes New England and New York activity and observations of the principal earthquakes of eastern Canada; (2) Eastern Region, including the central Appalachian seismic region activity and the area near Charleston, S.C.; (3) Central Region, which consists of the area between the region just described and the Rocky Mountains; (4) Western Mountain Region, which includes all remaining states except those on the Pacific coast; (5) Washington and Oregon; (6) Alaska; (7) Hawaii; (8) Puerto Rico; and (9) California and Western Nevada. This arrangement has been made chiefly with reference to the natural seismic divisions. It also is a convenient arrangement because there are only three states where there is an important division of earthquake activity: In Tennessee, there are quite distinct areas at opposite ends of the state that fall into different regions. Only central and eastern Nevada are included in the Western Mountain Region, as the activity of the western part is closely associated with that of California. Some earthquake activity has occurred in the

  9. An evaluation of the seismic- window theory for earthquake prediction.

    USGS Publications Warehouse

    McNutt, M.; Heaton, T.H.

    1981-01-01

    Reports studies designed to determine whether earthquakes in the San Francisco Bay area respond to a fortnightly fluctuation in tidal amplitude. It does not appear that the tide is capable of triggering earthquakes, and in particular the seismic window theory fails as a relevant method of earthquake prediction. -J.Clayton

  10. Performance of lifelines during the January 17, 1994 Northridge earthquake

    SciTech Connect

    Eguchi, R.T.; Chung, R.M.

    1995-12-31

    The occurrence for the January 17, 1994 Northridge earthquake has provided a unique opportunity to study the earthquake performance of lifeline systems. This particular areas has experienced two major earthquake events in the last 25 years, each playing a significant role in changing the way in which one designs and constructs lifeline systems for earthquake. In 1971, the San Fernando earthquake shook apart many lifeline systems causing significant damage and service disruption to Los Angeles area residents and businesses. As a result of this earthquake, special investigations were initiated to better understand and design these systems to remain functional after moderate and major earthquakes. Because of these post-1971 efforts, significant damage to lifelines was minimized in the January event. In each new earthquake, however, new lessons are learned, and as a result of these lessons, changes in either design or operational procedures are made to reduce the effects in future events. In the Northridge earthquake, some of the most significant lessons include effects on electric power system components and older steel natural gas transmission pipelines. This paper attempts to identify where lessons from previous southern California earthquakes were useful in preparing for the Northridge earthquake. In addition, areas that deserve further research or analysis, as a result of new lessons learned from the Northridge earthquake, are identified.

  11. A smartphone application for earthquakes that matter!

    NASA Astrophysics Data System (ADS)

    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

  12. A Large Scale Automatic Earthquake Location Catalog in the San Jacinto Fault Zone Area Using An Improved Shear-Wave Detection Algorithm

    NASA Astrophysics Data System (ADS)

    White, M. C. A.; Ross, Z.; Vernon, F.; Ben-Zion, Y.

    2015-12-01

    UC San Diego's ANZA network began archiving event-triggered data in 1982. As a result of improved recording technology, continuous waveform data archives are available starting in 1998. This continuous dataset, from 1998-present, represents a wealth of potential insight into spatio-temporal seismicity patterns, earthquake physics and mechanics of the San Jacinto Fault Zone. However, the volume of data renders manual analysis costly. In order to investigate the characteristics of the data in space and time, an automatic earthquake location catalog is needed. To this end, we apply standard earthquake signal processing techniques to the continuous data to detect first-arriving P-waves in combination with a recently developed S-wave detection algorithm. The resulting dataset of arrival time observations are processed using a grid association algorithm to produce initial absolute locations which are refined using a location inversion method that accounts for 3-D velocity heterogeneities. Precise relative locations are then derived from the refined absolute locations using the HypoDD double-difference algorithm. Moment magnitudes for the events are estimated from multi-taper spectral analysis. A >650% increase in the S:P pick ratio is achieved using the updated S-wave detection algorithm, when compared to the currently available catalog for the ANZA network. The increased number of S-wave observations leads to improved earthquake location accuracy and reliability (ie. less false event detections). Various aspects of spatio-temporal seismicity patterns and size distributions are investigated. Updated results will be presented at the meeting.

  13. Degradation of trace concentrations of the persistent groundwater pollutant 2,6-dichlorobenzamide (BAM) in bioaugmented rapid sand filters.

    PubMed

    Albers, Christian Nyrop; Feld, Louise; Ellegaard-Jensen, Lea; Aamand, Jens

    2015-10-15

    Groundwater is an important drinking water resource. Yet, this resource is threatened by pollution from chemicals, such as pesticides and their degradation products. To investigate the potential for remediation of groundwater polluted by trace concentrations of the pesticide residue 2,6-dichlorobenzamide (BAM), we established a pilot waterworks including two sand filters. The waterworks treated groundwater polluted with 0.2 μg/L BAM at flow conditions typical for rapid sand filters. Bioaugmentation of the sand filter with a specific BAM-degrading bacterium (Aminobacter sp. MSH1) resulted in significant BAM degradation to concentrations below the legal threshold level (0.1 μg/L), and this without adverse effects on other sand filter processes such as ammonium and iron oxidation. However, efficient degradation for more than 2-3 weeks was difficult to maintain due to loss of MSH1-bacteria, especially during backwashing. By limiting backwash procedures, the period of degradation was prolonged, but bacteria (and hence degradation activity) were still lost with time. Protozoa were observed to grow in the filters to a density that contributed significantly to the general loss of bacteria from the filters. Additionally, the concentration of easily assimilable organic carbon (AOC) in the remediated water may have been too low to sustain a sufficient population of degrader bacteria in the filter. This study shows that scaling up is not trivial and shortcomings in transferring degradation rates obtained in batch experiments to a rapid sand filter system are discussed. Further optimization is necessary to obtain and control more temporally stable systems for water purification. However, for the first time outside the laboratory and at realistic conditions a potential for the biodegradation of recalcitrant micropollutants in bioaugmented rapid sand filters is shown.

  14. Low loss NiZn spinel ferrite-W-type hexaferrite composites from BaM addition for antenna applications

    NASA Astrophysics Data System (ADS)

    Zheng, Zongliang; Zhang, Huaiwu; Xiao, John Q.; Yang, Qinghui; Jia, Lijun

    2014-03-01

    A series of NiZn ferrite composites with various BaFe12O19 hexaferrite (BaM) additions (x) were successfully synthesized by the solid-state reaction method for their potential application as magneto-dielectric antenna substrate materials. XRD and energy-dispersive spectrum analyses reveal that a W-type hexagonal phase is formed when the mixture of NiZn ferrite and BaM are sintered at 1200 °C, and diphase composite ferrite that consists of NiZn spinel ferrite and BaW hexaferrite is finally obtained. The composites display much smaller grain size and a refined microstructure. With the increasing x, the initial permeability decreases from ˜84.5 to ˜15.5, while the cut-off frequency is dramatically improved from 75 to 570 MHz. BaM addition significantly inhibits the frequency dispersion of permittivity spectrum and stable permittivity ɛ‧ around 15 is observed for the doped samples from 1 MHz to 1 GHz, which is proved to be closely related to the refined grains according to Koops' theory. Besides, compared with the undoped NiZn ferrite, both the magnetic loss and dielectric loss are found to be reduced in the doped samples. Almost equal values of μ‧ and ɛ‧ is obtained in the sample with x = 30 wt%. Related magnetic and dielectric mechanisms are also discussed.

  15. Disclosing early steps of protein-primed genome replication of the Gram-positive tectivirus Bam35

    PubMed Central

    Berjón-Otero, Mónica; Villar, Laurentino; Salas, Margarita; Redrejo-Rodríguez, Modesto

    2016-01-01

    Protein-primed replication constitutes a generalized mechanism to initiate DNA or RNA synthesis in a number of linear genomes of viruses, linear plasmids and mobile elements. By this mechanism, a so-called terminal protein (TP) primes replication and becomes covalently linked to the genome ends. Bam35 belongs to a group of temperate tectiviruses infecting Gram-positive bacteria, predicted to replicate their genomes by a protein-primed mechanism. Here, we characterize Bam35 replication as an alternative model of protein-priming DNA replication. First, we analyze the role of the protein encoded by the ORF4 as the TP and characterize the replication mechanism of the viral genome (TP-DNA). Indeed, full-length Bam35 TP-DNA can be replicated using only the viral TP and DNA polymerase. We also show that DNA replication priming entails the TP deoxythymidylation at conserved tyrosine 194 and that this reaction is directed by the third base of the template strand. We have also identified the TP tyrosine 172 as an essential residue for the interaction with the viral DNA polymerase. Furthermore, the genetic information of the first nucleotides of the genome can be recovered by a novel single-nucleotide jumping-back mechanism. Given the similarities between genome inverted terminal repeats and the genes encoding the replication proteins, we propose that related tectivirus genomes can be replicated by a similar mechanism. PMID:27466389

  16. Identification of Deep Earthquakes

    DTIC Science & Technology

    2010-09-01

    develop a ground truth dataset of earthquakes at both normal crustal depths and earthquakes from subduction zones , below the overlying crust. Many...deep earthquakes (depths between about 50 and 300 km). These deep earthquakes are known to occur in the Asia-India continental collision zone ...and/or NIL, as these stations are within a few hundred km of the zone where deep earthquakes are known to occur. To date we have selected about 300

  17. Issues on the Japanese Earthquake Hazard Evaluation

    NASA Astrophysics Data System (ADS)

    Hashimoto, M.; Fukushima, Y.; Sagiya, T.

    2013-12-01

    The 2011 Great East Japan Earthquake forced the policy of counter-measurements to earthquake disasters, including earthquake hazard evaluations, to be changed in Japan. Before the March 11, Japanese earthquake hazard evaluation was based on the history of earthquakes that repeatedly occurs and the characteristic earthquake model. The source region of an earthquake was identified and its occurrence history was revealed. Then the conditional probability was estimated using the renewal model. However, the Japanese authorities changed the policy after the megathrust earthquake in 2011 such that the largest earthquake in a specific seismic zone should be assumed on the basis of available scientific knowledge. According to this policy, three important reports were issued during these two years. First, the Central Disaster Management Council issued a new estimate of damages by a hypothetical Mw9 earthquake along the Nankai trough during 2011 and 2012. The model predicts a 34 m high tsunami on the southern Shikoku coast and intensity 6 or higher on the JMA scale in most area of Southwest Japan as the maximum. Next, the Earthquake Research Council revised the long-term earthquake hazard evaluation of earthquakes along the Nankai trough in May 2013, which discarded the characteristic earthquake model and put much emphasis on the diversity of earthquakes. The so-called 'Tokai' earthquake was negated in this evaluation. Finally, another report by the CDMC concluded that, with the current knowledge, it is hard to predict the occurrence of large earthquakes along the Nankai trough using the present techniques, based on the diversity of earthquake phenomena. These reports created sensations throughout the country and local governments are struggling to prepare counter-measurements. These reports commented on large uncertainty in their evaluation near their ends, but are these messages transmitted properly to the public? Earthquake scientists, including authors, are involved in

  18. Mitochondrial-bacterial hybrids of BamA/Tob55 suggest variable requirements for the membrane integration of β-barrel proteins

    PubMed Central

    Pfitzner, Anna-Katharina; Steblau, Nadja; Ulrich, Thomas; Oberhettinger, Philipp; Autenrieth, Ingo B.; Schütz, Monika; Rapaport, Doron

    2016-01-01

    β-Barrel proteins are found in the outer membrane (OM) of Gram-negative bacteria, chloroplasts and mitochondria. The assembly of these proteins into the corresponding OM is facilitated by a dedicated protein complex that contains a central conserved β-barrel protein termed BamA in bacteria and Tob55/Sam50 in mitochondria. BamA and Tob55 consist of a membrane-integral C-terminal domain that forms a β-barrel pore and a soluble N-terminal portion comprised of one (in Tob55) or five (in BamA) polypeptide transport-associated (POTRA) domains. Currently the functional significance of this difference and whether the homology between BamA and Tob55 can allow them to replace each other are unclear. To address these issues we constructed hybrid Tob55/BamA proteins with differently configured N-terminal POTRA domains. We observed that constructs harboring a heterologous C-terminal domain could not functionally replace the bacterial BamA or the mitochondrial Tob55 demonstrating species-specific requirements. Interestingly, the various hybrid proteins in combination with the bacterial chaperones Skp or SurA supported to a variable extent the assembly of bacterial β-barrel proteins into the mitochondrial OM. Collectively, our findings suggest that the membrane assembly of various β-barrel proteins depends to a different extent on POTRA domains and periplasmic chaperones. PMID:27982054

  19. Field reconnaissance of the 2007 Niigata-Chuetsu Oki earthquake

    NASA Astrophysics Data System (ADS)

    Apostolakis, Georgios; Qu, Bing; Ecemis, Nurhan; Dogruel, Seda

    2007-12-01

    As part of the 2007 Tri-Center Field Mission to Japan, a reconnaissance team comprised of fourteen graduate students and three faculty members from three U.S. earthquake engineering research centers, namely, Multidisciplinary Center for Earthquake Engineering Research (MCEER), Mid-America Earthquake Center (MAE), and Pacific Earthquake Engineering Research Center (PEER), undertook a reconnaissance visit to the affected area shortly after the 2007 Niigata-Chuetsu Oki earthquake. This mission provided an opportunity to review the nature of the earthquake damage that occurred, as well as to assess the significance of the damage from an educational perspective. This paper reports on the seismological characteristics of the earthquake, preliminary findings of geotechnical and structural damage, and the causes of the observed failures or collapses. In addition, economic and socio-economic considerations and experiences to enhance earthquake resilience are presented.

  20. Stalking the next Parkfield earthquake

    SciTech Connect

    Kerr, R.A.

    1984-01-06

    The 30-kilometer section of the San Andreas fault midway between San Francisco and Los Angeles is the most well understood and most intensely monitored fault in the world. The geology of the area, its rock mechanics, the study of its past earthquakes, and prediction efforts for the next quake are described.

  1. Earthquakes triggered by fluid extraction

    USGS Publications Warehouse

    Segall, P.

    1989-01-01

    Seismicity is correlated in space and time with production from some oil and gas fields where pore pressures have declined by several tens of megapascals. Reverse faulting has occurred both above and below petroleum reservoirs, and normal faulting has occurred on the flanks of at least one reservoir. The theory of poroelasticity requires that fluid extraction locally alter the state of stress. Calculations with simple geometries predict stress perturbations that are consistent with observed earthquake locations and focal mechanisms. Measurements of surface displacement and strain, pore pressure, stress, and poroelastic rock properties in such areas could be used to test theoretical predictions and improve our understanding of earthquake mechanics. -Author

  2. Mineralization of the Common Groundwater Pollutant 2,6-Dichlorobenzamide (BAM) and its Metabolite 2,6-Dichlorobenzoic Acid (2,6-DCBA) in Sand Filter Units of Drinking Water Treatment Plants.

    PubMed

    Vandermaesen, Johanna; Horemans, Benjamin; Degryse, Julie; Boonen, Jos; Walravens, Eddy; Springael, Dirk

    2016-09-20

    The intrinsic capacity to mineralize the groundwater pollutant 2,6-dichlorobenzamide (BAM) and its metabolite 2,6-dichlorobenzoic acid (2,6-DCBA) was evaluated in samples from sand filters (SFs) of drinking water treatment plants (DWTPs). Whereas BAM mineralization occurred rarely and only in SFs exposed to BAM, 2,6-DCBA mineralization was common in SFs, including those treating uncontaminated water. Nevertheless, SFs treating BAM contaminated water showed the highest 2,6-DCBA mineralization rates. For comparison, 2,6-DCBA and BAM mineralization were determined in various topsoil samples. As in SF samples, BAM mineralization was rare, whereas 2,6-DCBA mineralization capacity appeared widespread, with high mineralization rates found especially in forest soils. Multivariate analysis showed that in both SF and soil samples, high 2,6-DCBA mineralization correlated with high organic carbon content. Adding a 2,6-DCBA degradation deficient mutant of the BAM mineralizing Aminobacter sp. MSH1 confirmed that 2,6-DCBA produced from BAM is rapidly mineralized by the endogenous microbial community in SFs showing intrinsic 2,6-DCBA mineralization. This study demonstrates that (i) 2,6-DCBA mineralization is widely established in SFs of DWTPs, allowing the mineralization of 2,6-DCBA produced during BAM degradation and (ii) the first metabolic step in BAM mineralization is rare in microbial communities, rather than its further degradation beyond 2,6-DCBA.

  3. Low stress drop earthquakes in the rupture zone of the 1992 Nicaragua tsunami earthquake

    NASA Astrophysics Data System (ADS)

    Bilek, Susan L.; Rotman, Holly M. M.; Phillips, W. Scott

    2016-10-01

    Tsunami earthquakes, events that generate larger than expected tsunami and are deficient in high-frequency seismic radiation, are rare but hazardous to coastal populations. One model for these events is shallow rupture through low-strength materials. We calculate seismic moment, corner frequency, and stress drop for 216 earthquakes (2.1 < Mw < 4.7, November 2005 to June 2006) within and external to the 1992 Nicaragua tsunami earthquake rupture zone to test the hypothesis that differences in fault zone properties defined the limits of the 1992 tsunami rupture zone and continue to produce spatial variations in earthquake source properties. Mean stress drop of events within the rupture area is 1.2 MPa, and 5.5 MPa for events just outside of the rupture zone, with similar magnitude earthquakes in each group. Our results demonstrate different source parameter characteristics for microseismicity in the region of a past tsunami earthquake.

  4. Possible occurrence of a giant interplate earthquake in northeast Japan greater than the 2011 Tohoku earthquake

    NASA Astrophysics Data System (ADS)

    Ohtani, M.; Hirahara, K.; Hori, T.; Hyodo, M.

    2012-12-01

    We supposed there occur M7-class earthquakes and the co-rupturing M8 earthquakes on the Pacific plate interface subducting beneath northeast Japan. Against our speculation, the 2011 Tohoku earthquake grew up to Mw9.0. We have so far constructed cycle models of this giant earthquake to understand why this grew up to Mw9.0. Next question is; is there any possibility that a much larger earthquake occurs in this region? In this study, we explore this possibility through quasi-dynamic earthquake cycle simulations. The 2011 Tohoku earthquake ruptured a large region of 200km x 500km. The rupture region includes a confined area with huge coseismic slip over 50 m in the shallow Off-Miyagi region close to the Japan Trench, and several M7 asperities in Off-Miyagi and Ibaraki regions which have been ruptured repeatedly at intervals of several ten years. The tsunami deposit surveys suggest this giant earthquake has the recurrence time of several hundred years. The afterslip occurs mainly in the deeper region of the coseismic slip region, except the Off-Miyagi region [Ozawa et al., 2012]. At Off-Kamaishi and Off-Fukushima regions located in the northern and southern sides of the Off-Miyagi region, we can find the local maximum of the afterslip. The Off-Kamaishi region did not produce much coseismic slip, and has not experienced historical large earthquakes. And no large afterslip extended to the northern region beyond Off-Kamaishi. Then, the Off-Kamaishi region is a kind of boundary between the 2011 Tohoku earthquake and its adjacent northern regions. In the northern region, there occurred the 1968 Off-Tokachi Mw8.3 earthquake, which has three M7 asperities with recurrence times of several ten years [Yamanaka & Kikuchi, 2004]. An aftershock of the 2011 Tohoku earthquake, which occurred 22 minutes after the main shock, is located at the southern asperity area. And there is a region close to the Japan Trench, where the 1897 Meiji-sanriku tsunami earthquake occurred. We performed

  5. Helena banks strike-slip(. ) fault and the relation to other Cenozoic faults along reactivated Triassic(. ) basin boundary fault zones in the Charleston, South Carolina, earthquake area - results from a marine high-resolution multichannel seismic-reflection survey

    SciTech Connect

    Behrendt, J.C.; Yuan, A.

    1985-01-01

    In 1981, the USGS conducted a high-resolution multichannel seismic (MCS) survey offshore of Charleston, South Carolina, to study the relation of Cenozoic faulting to future earthquake hazard. High-angle reverse displacement of Coastal Plain sedimentary rock indicating a linear increase with depth of 51 +/- 12 m/km is observed on the reflection profiles. This is similar to the Gants and Cooke faults in the meizoseismal area of the 1886 Charleston earthquake. The authors interpret these results to indicate that the stress field cannot have varied significantly in direction or in magnitude from Late Cretaceous time to Miocene or Pliocene time in the region. The HBF zone trends N 66/sup 0/ E; it comprises several 15- to 40-km-long segments that trend from N 68/sup 0/ E to N 77/sup 0/ E. The en-echelon pattern of the segments is compatible with left-lateral strike-slip and is thus consistent with the present northeast-trending maximum compressional stress field. The HBF zone appears to be an obliquely compressional reactivation of a tensional Triassic(.) fault zone bounding the Triassic(.) Kiawah Basin that has been identified on several MCS profiles. Similarly, the northeast-trending Gants reverse or strike-slip fault was probably reactivated from an old tensional fault bounding the Jedburg Triassic(.) basin in the 1886 meizoseismal area.

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

    NASA Astrophysics Data System (ADS)

    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

  7. Landslides and ridge-top failures associated with the epicentral area of the Loma Prieta earthquake of October 17, 1989 Santa Cruz County, California

    SciTech Connect

    Spittler, T.E.; Sydnor, R.H.

    1990-01-01

    Extensive landslides and ridge-top failures occurred in the epicentral are of the Loma Prieta earthquake. These failures have been subdivided into four categories: (1) small rockfalls, dry debris flows, minor slumps, wedge-failure landslides along highway cut-slopes, and sea cliff failures; (2) ridge-top fractures dominated by tensional separation; (3) crown scarps of incipient landslides on the axes of steeply-plunging, steed-sided spur ridges; and (4) remobilized portions of existing large-scale rotational landslide complexes. These failures are described in detail.

  8. Assessing the risk of earthquakes in the eastern United States

    SciTech Connect

    Not Available

    1981-09-01

    Although earthquakes in the U.S. are generally considered California's problem, a number of major earthquakes have struck the central and eastern United States. The last damaging earthquake in the eastern U.S. occurred in 1886, near Charleston, SC, killing 60 people and causing extensive damage in Charleston. During the winter of 1811-12, three major earthquakes occurred near New Madrid in southeastern Missouri. Because the area, at that time, was sparsely populated, casualties were not extensive, but the quakes caused damage and ground shaking over an area 20 times larger than that for the 1906 San Francisco earthquake. Because of these earthquakes and others, the potential for damaging earthquakes in the eastern U.S. is real, and this was the subject of a recent meeting of geologists, seismologists, and engineers in Knoxville, TN, in September 1981. The highlights of their discussions are presented in this article.

  9. Intraplate triggered earthquakes: Observations and interpretation

    USGS Publications Warehouse

    Hough, S.E.; Seeber, L.; Armbruster, J.G.

    2003-01-01

    We present evidence that at least two of the three 1811-1812 New Madrid, central United States, mainshocks and the 1886 Charleston, South Carolina, earthquake triggered earthquakes at regional distances. In addition to previously published evidence for triggered earthquakes in the northern Kentucky/southern Ohio region in 1812, we present evidence suggesting that triggered events might have occurred in the Wabash Valley, to the south of the New Madrid Seismic Zone, and near Charleston, South Carolina. We also discuss evidence that earthquakes might have been triggered in northern Kentucky within seconds of the passage of surface waves from the 23 January 1812 New Madrid mainshock. After the 1886 Charleston earthquake, accounts suggest that triggered events occurred near Moodus, Connecticut, and in southern Indiana. Notwithstanding the uncertainty associated with analysis of historical accounts, there is evidence that at least three out of the four known Mw 7 earthquakes in the central and eastern United States seem to have triggered earthquakes at distances beyond the typically assumed aftershock zone of 1-2 mainshock fault lengths. We explore the possibility that remotely triggered earthquakes might be common in low-strain-rate regions. We suggest that in a low-strain-rate environment, permanent, nonelastic deformation might play a more important role in stress accumulation than it does in interplate crust. Using a simple model incorporating elastic and anelastic strain release, we show that, for realistic parameter values, faults in intraplate crust remain close to their failure stress for a longer part of the earthquake cycle than do faults in high-strain-rate regions. Our results further suggest that remotely triggered earthquakes occur preferentially in regions of recent and/or future seismic activity, which suggests that faults are at a critical stress state in only some areas. Remotely triggered earthquakes may thus serve as beacons that identify regions of

  10. Earthquake friction

    NASA Astrophysics Data System (ADS)

    Mulargia, Francesco; Bizzarri, Andrea

    2016-12-01

    Laboratory friction slip experiments on rocks provide firm evidence that the static friction coefficient μ has values ∼0.7. This would imply large amounts of heat produced by seismically active faults, but no heat flow anomaly is observed, and mineralogic evidence of frictional heating is virtually absent. This stands for lower μ values ∼0.2, as also required by the observed orientation of faults with respect to the maximum compressive stress. We show that accounting for the thermal and mechanical energy balance of the system removes this inconsistence, implying a multi-stage strain release process. The first stage consists of a small and slow aseismic slip at high friction on pre-existent stress concentrators within the fault volume but angled with the main fault as Riedel cracks. This introduces a second stage dominated by frictional temperature increase inducing local pressurization of pore fluids around the slip patches, which is in turn followed by a third stage in which thermal diffusion extends the frictionally heated zones making them coalesce into a connected pressurized region oriented as the fault plane. Then, the system enters a state of equivalent low static friction in which it can undergo the fast elastic radiation slip prescribed by dislocation earthquake models.

  11. Impacts of the 1669 eruption and the 1693 earthquakes on the Etna Region (Eastern Sicily, Italy): An example of recovery and response of a small area to extreme events

    NASA Astrophysics Data System (ADS)

    Branca, Stefano; Azzaro, Raffaele; De Beni, Emanuela; Chester, David; Duncan, Angus

    2015-09-01

    In this paper we trace the impact of the 1669 eruption and the 1693 earthquakes in eastern Sicily, their effects on the people living in the Etna region and, more particularly, in the city of Catania and its hinterland. The former event was the largest historic eruption of Etna, having a flow field with an area of ca. 40 km2 and a maximum flow length of ca. 17 km, whereas the latter - occurring only 24 years later - killed between 11,000 and 20,000 of Catania's estimated 20-27,000 inhabitants, plus many more in smaller settlements. Using a combination of field-based research, contemporary accounts and archival sources, the authors are able to draw a number of conclusions. First, the 1669 eruption, although it did not kill or injure, was economically the most devastating of historical eruptions. Although it affected a limited area, inundation by lava meant that land was effectively sterilized for centuries and, in a pre-industrial agriculturally-based economy, recovery could not occur quickly without outside assistance from the State. Indeed some of the worst affected municipalities (i.e. Comuni) were only able to support populations that were much reduced in size. Secondly, much of the damage caused to buildings by volcanic earthquakes was effectively masked, because most of the settlements affected were quickly covered by lava flows. The vulnerability to volcanic earthquakes of traditionally constructed buildings has, however, remained a serious example of un-ameliorated risk exposure through to the present day. A third conclusion is that the 1693 earthquakes, although more serious with respect to the number of people and the area they affected in terms of mortality, morbidity and their immediate economic impact, saw a rapid and sustained recovery. This was due in part to the fact that, in contrast to lava flows, an earthquake does not sterilize land, but more significant was the reduction in population numbers which served both to release and concentrate funds

  12. Collaborative Comparison of Earthquake Simulators

    NASA Astrophysics Data System (ADS)

    Richards-Dinger, K.; Zielke, O.; Tullis, T. E.; Ward, S. N.; Kaneko, Y.; Shaw, B. E.; Lapusta, N.; Pollitz, F. F.; Morein, G.; Turcotte, D. L.; Robinson, R.; Dieterich, J. H.; Rundle, J. D.; Beeler, N. M.

    2008-12-01

    Earthquake simulators, i.e. computer models in which a series of earthquakes spontaneously occur, are important for understanding earthquake mechanics and earthquake predictability. However, to use earthquake simulators in hazard anaylsis they must show realistic behavior. It is difficult to determine how realistic simulator results are. This is in part because of the complexity of their behavior and the limited database of long sequences of natural earthquakes, especially large ones, against which to compare a simulator's behavior. Due to limits on memory and computation speed it is presently impossible to construct a simulator that simultaneously incorporates everything known about frictional behavior of rock, includes full elastodynamics, and utilizes both small enough elements to properly represent a continuum and enough elements to cover a large geographic area and represent many faults. Consequently, all simulators make compromises. A wide variety of simulators exist, each with different compromises. The effects on the simulator results of these compromises are not currently known. Our goal is to gain a better understanding of the validity of the results of earthquake simulators. This is a joint effort to compare the behavior of our nine independently devised earthquake simulators. We have defined and studied two simple problems. The first checks that each simulator accurately gives the stresses due to slip on a simple vertical strike-slip fault. All simulators satisfactorily passed this test. The second is a comparison of the behavior of a simple strike slip fault, with a simple bi-linear asymmetrically peaked initial stress distribution, and a constant loading rate. The fault constitutive properties have a fixed failure stress, higher than the peak in the initial stress, and a fixed dynamic sliding stress, although models utilizing rate and state friction only approximate this simple description. A series of earthquakes occur in the simulations and the

  13. Napa Earthquake impact on water systems

    NASA Astrophysics Data System (ADS)

    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.

  14. Tracking Earthquake Cascades

    NASA Astrophysics Data System (ADS)

    Jordan, T. H.

    2011-12-01

    In assessing their risk to society, earthquakes are best characterized as cascades that can propagate from the natural environment into the socio-economic (built) environment. Strong earthquakes rarely occur as isolated events; they usually cluster in foreshock-mainshock-aftershock sequences, seismic swarms, and extended sequences of large earthquakes that propagate along major fault systems. These cascades are regulated by stress-mediated interactions among faults driven by tectonic loading. Within these cascades, each large event can itself cause a chain reaction in which the primary effects of faulting and ground shaking induce secondary effects, including tsunami, landslides, liquefaction, and set off destructive processes within the built environment, such as fires and radiation leakage from nuclear plants. Recent earthquakes have demonstrated how the socio-economic effects of large earthquakes can reverberate for many years. To reduce earthquake risk and improve the resiliency of communities to earthquake damage, society depends on five geotechnologies for tracking earthquake cascades: long-term probabilistic seismic hazard analysis (PSHA), short-term (operational) earthquake forecasting, earthquake early warning, tsunami warning, and the rapid production of post-event information for response and recovery (see figure). In this presentation, I describe how recent advances in earthquake system science are leading to improvements in this geotechnology pipeline. In particular, I will highlight the role of earthquake simulations in predicting strong ground motions and their secondary effects before and during earthquake cascades

  15. Inhibition of Arabidopsis chloroplast β-amylase BAM3 by maltotriose suggests a mechanism for the control of transitory leaf starch mobilisation

    PubMed Central

    Li, Jing; Zhou, Wenxu; Francisco, Perigio; Wong, Russell; Zhang, Dongke

    2017-01-01

    Starch breakdown in leaves at night is tightly matched to the duration of the dark period, but the mechanism by which this regulation is achieved is unknown. In Arabidopsis chloroplasts, β-amylase BAM3 hydrolyses transitory starch, producing maltose and residual maltotriose. The aim of the current research was to investigate the regulatory and kinetic properties of BAM3. The BAM3 protein was expressed in Escherichia coli and first assayed using a model substrate. Enzyme activity was stimulated by treatment with dithiothreitol and was increased 40% by 2–10 μM Ca2+ but did not require Mg2+. In order to investigate substrate specificity and possible regulatory effects of glucans, we developed a GC-MS method to assay reaction products. BAM3 readily hydrolysed maltohexaose with a Km of 1.7 mM and Kcat of 4300 s-1 but activity was 3.4-fold lower with maltopentaose and was negligible with maltotetraose. With maltohexaose or amylopectin as substrates and using [UL-13C12]maltose in an isotopic dilution method, we discovered that BAM3 activity is inhibited by maltotriose at physiological (mM) concentrations, but not by maltose. In contrast, the extracellular β-amylase of barley is only weakly inhibited by maltotriose. Our results may explain the impaired starch breakdown in maltotriose-accumulating mutants such as dpe1 which lacks the chloroplast disproportionating enzyme (DPE1) metabolising maltotriose to glucose. We hypothesise that the rate of starch breakdown in leaves can be regulated by inhibition of BAM3 by maltotriose, the concentration of which is determined by DPE, which is in turn influenced by the stromal concentration of glucose. Since the plastid glucose transporter pGlcT catalyses facilitated diffusion between stroma and cytosol, changes in consumption of glucose in the cytosol are expected to lead to concomitant changes in plastid glucose and maltotriose, and hence compensatory changes in BAM3 activity. PMID:28225829

  16. Inhibition of Arabidopsis chloroplast β-amylase BAM3 by maltotriose suggests a mechanism for the control of transitory leaf starch mobilisation.

    PubMed

    Li, Jing; Zhou, Wenxu; Francisco, Perigio; Wong, Russell; Zhang, Dongke; Smith, Steven M

    2017-01-01

    Starch breakdown in leaves at night is tightly matched to the duration of the dark period, but the mechanism by which this regulation is achieved is unknown. In Arabidopsis chloroplasts, β-amylase BAM3 hydrolyses transitory starch, producing maltose and residual maltotriose. The aim of the current research was to investigate the regulatory and kinetic properties of BAM3. The BAM3 protein was expressed in Escherichia coli and first assayed using a model substrate. Enzyme activity was stimulated by treatment with dithiothreitol and was increased 40% by 2-10 μM Ca2+ but did not require Mg2+. In order to investigate substrate specificity and possible regulatory effects of glucans, we developed a GC-MS method to assay reaction products. BAM3 readily hydrolysed maltohexaose with a Km of 1.7 mM and Kcat of 4300 s-1 but activity was 3.4-fold lower with maltopentaose and was negligible with maltotetraose. With maltohexaose or amylopectin as substrates and using [UL-13C12]maltose in an isotopic dilution method, we discovered that BAM3 activity is inhibited by maltotriose at physiological (mM) concentrations, but not by maltose. In contrast, the extracellular β-amylase of barley is only weakly inhibited by maltotriose. Our results may explain the impaired starch breakdown in maltotriose-accumulating mutants such as dpe1 which lacks the chloroplast disproportionating enzyme (DPE1) metabolising maltotriose to glucose. We hypothesise that the rate of starch breakdown in leaves can be regulated by inhibition of BAM3 by maltotriose, the concentration of which is determined by DPE, which is in turn influenced by the stromal concentration of glucose. Since the plastid glucose transporter pGlcT catalyses facilitated diffusion between stroma and cytosol, changes in consumption of glucose in the cytosol are expected to lead to concomitant changes in plastid glucose and maltotriose, and hence compensatory changes in BAM3 activity.

  17. Self-Organized Earthquakes

    NASA Astrophysics Data System (ADS)

    Rundle, J. B.; Holliday, J. R.; Turcotte, D. L.; Klein, W.

    2011-12-01

    Self-Organized Criticality was proposed by the Per Bak et al. [1] as a means of explaining scaling laws observed in driven natural systems, usually in (slowly) driven threshold systems. The example used by Bak was a simple cellular automaton model of a sandpile, in which grains of sand were slowly dropped (randomly) onto a flat plate. After a period of time, during which the 'critical state' was approached, a series of self-similar avalanches would begin. Scaling exponents for the frequency-area statistics of the sandpile avalanches were found to be approximately 1, a value that characterizes 'flicker noise' in natural systems. SOC is associated with a critical point in the phase diagram of the system, and it was found that the usual 2-scaling field theory applies. A model related to SOC is the Self-Organized Spinodal (SOS), or intermittent criticality model. Here a slow but persistent driving force leads to quasi-periodic approach to, and retreat from, the classical limit of stability, or spinodal. Scaling exponents for this model can be related to Gutenberg-Richter and Omori exponents observed in earthquake systems. In contrast to SOC models, nucleation, both classical and non-classical types, is possible in SOS systems. Tunneling or nucleation rates can be computed from Langer-Klein-Landau-Ginzburg theories for comparison to observations. Nucleating droplets play a role similar to characteristic earthquake events. Simulations of these systems reveals much of the phenomenology associated with earthquakes and other types of "burst" dynamics. Whereas SOC is characterized by the full scaling spectrum of avalanches, SOS is characterized by both system-size events above the nominal frequency-size scaling curve, and scaling of small events. Applications to other systems including integrate-and-fire neural networks and financial crashes will be discussed. [1] P. Bak, C. Tang and K. Weisenfeld, Self-Organized Criticality, Phys. Rev. Lett., 59, 381 (1987).

  18. Earthquakes: hydrogeochemical precursors

    USGS Publications Warehouse

    Ingebritsen, Steven E.; Manga, Michael

    2014-01-01

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

  19. The size of earthquakes

    USGS Publications Warehouse

    Kanamori, H.

    1980-01-01

    How we should measure the size of an earthquake has been historically a very important, as well as a very difficult, seismological problem. For example, figure 1 shows the loss of life caused by earthquakes in recent times and clearly demonstrates that 1976 was the worst year for earthquake casualties in the 20th century. However, the damage caused by an earthquake is due not only to its physical size but also to other factors such as where and when it occurs; thus, figure 1 is not necessarily an accurate measure of the "size" of earthquakes in 1976. the point is that the physical process underlying an earthquake is highly complex; we therefore cannot express every detail of an earthquake by a simple straightforward parameter. Indeed, it would be very convenient if we could find a single number that represents the overall physical size of an earthquake. This was in fact the concept behind the Richter magnitude scale introduced in 1935. 

  20. Earthquakes for Kids

    MedlinePlus

    ... lab. Earthquake Animations A trench dug across a fault to learn about past earthquakes. Science Fair Projects ... History A scientist stands in front of a fault scarp in southern California. Damage to badly-constructed ...

  1. Speeding earthquake disaster relief

    USGS Publications Warehouse

    Mortensen, Carl; Donlin, Carolyn; Page, Robert A.; Ward, Peter

    1995-01-01

    In coping with recent multibillion-dollar earthquake disasters, scientists and emergency managers have found new ways to speed and improve relief efforts. This progress is founded on the rapid availability of earthquake information from seismograph networks.

  2. Earthquakes: Predicting the unpredictable?

    USGS Publications Warehouse

    Hough, S.E.

    2005-01-01

    The earthquake prediction pendulum has swung from optimism in the 1970s to rather extreme pessimism in the 1990s. Earlier work revealed evidence of possible earthquake precursors: physical changes in the planet that signal that a large earthquake is on the way. Some respected earthquake scientists argued that earthquakes are likewise fundamentally unpredictable. The fate of the Parkfield prediction experiment appeared to support their arguments: A moderate earthquake had been predicted along a specified segment of the central San Andreas fault within five years of 1988, but had failed to materialize on schedule. At some point, however, the pendulum began to swing back. Reputable scientists began using the "P-word" in not only polite company, but also at meetings and even in print. If the optimism regarding earthquake prediction can be attributed to any single cause, it might be scientists' burgeoning understanding of the earthquake cycle.

  3. Fault failure with moderate earthquakes

    USGS Publications Warehouse

    Johnston, M.J.S.; Linde, A.T.; Gladwin, M.T.; Borcherdt, R.D.

    1987-01-01

    High resolution strain and tilt recordings were made in the near-field of, and prior to, the May 1983 Coalinga earthquake (ML = 6.7, ?? = 51 km), the August 4, 1985, Kettleman Hills earthquake (ML = 5.5, ?? = 34 km), the April 1984 Morgan Hill earthquake (ML = 6.1, ?? = 55 km), the November 1984 Round Valley earthquake (ML = 5.8, ?? = 54 km), the January 14, 1978, Izu, Japan earthquake (ML = 7.0, ?? = 28 km), and several other smaller magnitude earthquakes. These recordings were made with near-surface instruments (resolution 10-8), with borehole dilatometers (resolution 10-10) and a 3-component borehole strainmeter (resolution 10-9). While observed coseismic offsets are generally in good agreement with expectations from elastic dislocation theory, and while post-seismic deformation continued, in some cases, with a moment comparable to that of the main shock, preseismic strain or tilt perturbations from hours to seconds (or less) before the main shock are not apparent above the present resolution. Precursory slip for these events, if any occurred, must have had a moment less than a few percent of that of the main event. To the extent that these records reflect general fault behavior, the strong constraint on the size and amount of slip triggering major rupture makes prediction of the onset times and final magnitudes of the rupture zones a difficult task unless the instruments are fortuitously installed near the rupture initiation point. These data are best explained by an inhomogeneous failure model for which various areas of the fault plane have either different stress-slip constitutive laws or spatially varying constitutive parameters. Other work on seismic waveform analysis and synthetic waveforms indicates that the rupturing process is inhomogeneous and controlled by points of higher strength. These models indicate that rupture initiation occurs at smaller regions of higher strength which, when broken, allow runaway catastrophic failure. ?? 1987.

  4. Izmit, Turkey 1999 Earthquake Interferogram

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This image is an interferogram that was created using pairs of images taken by Synthetic Aperture Radar (SAR). The images, acquired at two different times, have been combined to measure surface deformation or changes that may have occurred during the time between data acquisition. The images were collected by the European Space Agency's Remote Sensing satellite (ERS-2) on 13 August 1999 and 17 September 1999 and were combined to produce these image maps of the apparent surface deformation, or changes, during and after the 17 August 1999 Izmit, Turkey earthquake. This magnitude 7.6 earthquake was the largest in 60 years in Turkey and caused extensive damage and loss of life. Each of the color contours of the interferogram represents 28 mm (1.1 inches) of motion towards the satellite, or about 70 mm (2.8 inches) of horizontal motion. White areas are outside the SAR image or water of seas and lakes. The North Anatolian Fault that broke during the Izmit earthquake moved more than 2.5 meters (8.1 feet) to produce the pattern measured by the interferogram. Thin red lines show the locations of fault breaks mapped on the surface. The SAR interferogram shows that the deformation and fault slip extended west of the surface faults, underneath the Gulf of Izmit. Thick black lines mark the fault rupture inferred from the SAR data. Scientists are using the SAR interferometry along with other data collected on the ground to estimate the pattern of slip that occurred during the Izmit earthquake. This then used to improve computer models that predict how this deformation transferred stress to other faults and to the continuation of the North Anatolian Fault, which extends to the west past the large city of Istanbul. These models show that the Izmit earthquake further increased the already high probability of a major earthquake near Istanbul.

  5. Characterizing long-term radon concentration changes in a geothermal area for correlation with volcanic earthquakes and reservoir temperatures: A case study from Mt. Aso, southwestern Japan

    NASA Astrophysics Data System (ADS)

    Koike, Katsuaki; Yoshinaga, Tohru; Asaue, Hisafumi

    2014-04-01

    The purpose of this study is to characterize in detail the temporal changes in Rn (radon-222) concentration in soil gases near fumaroles and clarify its correlation with volcanic earthquakes and temperatures in two geothermal reservoirs. Mt. Aso crater in southwest Japan, which has two reservoirs on its western side estimated by magnetotelluric survey to be at about 2 km in depth, was selected for this study. For the long-term survey, the α scintillation counter method was used weekly for 12.5 years at the three hot springs within a 2-km range. Rn concentrations were calculated using the CRAS method, a calculation method that considers radioactive equilibrium or nonequilibrium state of the soil gas. Rn concentrations generally showed similar fluctuation patterns among the sites. CRAS was used as a new indicator for evaluating the age of the soil gas. This age corresponds to the elapsed time determined from the generation of Rn based on the measurement of the numbers of atoms of Rn and its daughter 218Po at the start of measurement. In comparing the Rn data with the history of earthquakes in the Aso caldera, volcanic seismicity was identified as a major controlling factor in the sudden increase and decrease in Rn concentration as a function of age. For more precise detections of change, Rn concentrations were measured continuously at one site by pumping soil gas from a borehole and using an ionization chamber over 2.5 years. Five chemical components (He, H2, N2, CH4, and CO2) were then measured by gas chromatography at 1-week intervals. Because Rn concentrations are affected strongly by atmospheric temperatures, the residual components were obtained by subtracting the trend of the components from the original data. Chemical component data were used to estimate the temperature and pressure in the reservoir at the site; temperatures ranged from 229 to 280 °C, (average 265 °C, average pressure 80 MPa). Residual Rn concentrations showed a clear correlation with

  6. Surface faulting and paleoseismic history of the 1932 Cedar Mountain earthquake area, west-central Nevada, and implications for modern tectonics of the Walker Lane

    USGS Publications Warehouse

    Bell, J.W.; DePolo, C.M.; Ramelli, A.R.; Sarna-Wojcicki, A. M.; Meyer, C.E.

    1999-01-01

    The 1932 Cedar Mountain earthquake (Ms 7.2) was one of the largest historical events in the Walker Lane region of western Nevada, and it produced a complicated strike-slip rupture pattern on multiple Quaternary faults distributed through three valleys. Primary, right-lateral surface ruptures occurred on north-striking faults in Monte Cristo Valley; small-scale lateral and normal offsets occurred in Stewart Valley; and secondary, normal faulting occurred on north-northeast-striking faults in the Gabbs Valley epicentral region. A reexamination of the surface ruptures provides new displacement and fault-zone data: maximum cumulative offset is estimated to be 2.7 m, and newly recognized faults extend the maximum width and end-to-end length of the rupture zone to 17 and 75 km, respectively. A detailed Quaternary allostratigraphic chronology based on regional alluvialgeomorphic relationships, tephrochronology, and radiocarbon dating provides a framework for interpreting the paleoseismic history of the fault zone. A late Wisconsinan alluvial-fan and piedmont unit containing a 32-36 ka tephra layer is a key stratigraphic datum for paleoseismic measurements. Exploratory trenching and radiocarbon dating of tectonic stratigraphy provide the first estimates for timing of late Quaternary faulting along the Cedar Mountain fault zone. Three trenches display evidence for six faulting events, including that in 1932, during the past 32-36 ka. Radiocarbon dating of organic soils interstratified with tectonically ponded silts establishes best-fit ages of the pre-1932 events at 4, 5,12,15, and 18 ka, each with ??2 ka uncertainties. On the basis of an estimated cumulative net slip of 6-12 m for the six faulting events, minimum and maximum late Quaternary slip rates are 0.2 and 0.7 mm/yr, respectively, and the preferred rate is 0.4-0.5 mm/yr. The average recurrence (interseismic) interval is 3600 yr. The relatively uniform thickness of the ponded deposits suggests that similar

  7. Anti-tumor immunity of BAM-SiPc-mediated vascular photodynamic therapy in a BALB/c mouse model

    PubMed Central

    Yeung, Hing-Yuen; Lo, Pui-Chi; Ng, Dennis K.P.; Fong, Wing-Ping

    2017-01-01

    In recent decades, accumulating evidence from both animal and clinical studies has suggested that a sufficiently activated immune system may strongly augment various types of cancer treatment, including photodynamic therapy (PDT). Through the generation of reactive oxygen species, PDT eradicates tumors by triggering localized tumor damage and inducing anti-tumor immunity. As the major component of anti-tumor immunity, the involvement of a cell-mediated immune response in PDT has been well investigated in the past decade, whereas the role of humoral immunity has remained relatively unexplored. In the present investigation, using the photosensitizer BAM-SiPc and the CT26 tumor-bearing BALB/c mouse model, it was demonstrated that both cell-mediated and humoral adaptive immune components could be involved in PDT. With a vascular PDT (VPDT) regimen, BAM-SiPc could eradicate the tumors of ∼70% of tumor-bearing mice and trigger an anti-tumor immune response that could last for more than 1 year. An elevation of Th2 cytokines was detected ex vivo after VPDT, indicating the potential involvement of a humoral response. An analysis of serum from the VPDT-cured mice also revealed elevated levels of tumor-specific antibodies. Moreover, this serum could effectively hinder tumor growth and protect the mice against further re-challenge in a T-cell-dependent manner. Taken together, these results show that the humoral components induced after BAM-SiPc-VPDT could assist the development of anti-tumor immunity. PMID:26388236

  8. Redefining Earthquakes and the Earthquake Machine

    ERIC Educational Resources Information Center

    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…

  9. Fast geodetic strain-rates in eastern Sicily (southern Italy): New insights into block tectonics and seismic potential in the area of the great 1693 earthquake

    NASA Astrophysics Data System (ADS)

    Mastrolembo Ventura, Brunella; Serpelloni, Enrico; Argnani, Andrea; Bonforte, Alessandro; Bürgmann, Roland; Anzidei, Marco; Baldi, Paolo; Puglisi, Giuseppe

    2014-10-01

    Along the ˜500 km long Sicily-Calabria segment of the Nubia-Eurasia plate boundary GPS data highlight a complex, and debated, kinematic pattern. We focus on eastern Sicily, where the style of crustal deformation rapidly changes in the space of few tens of kilometers. In southeastern Sicily, struck by the 1693 MW˜7.4 earthquake, GPS measurements highlight a steep velocity gradient, with ˜2.4 mm/yr of ˜N-S shortening in ˜10 km, changing to broader extension (˜3 mm/yr in ˜60 km) in northern Sicily and shortening in the southern Tyrrhenian Sea. GPS data and kinematic elastic block models highlight a complex fragmentation of the Sicilian domain into three tectonic blocks, which move independently from Nubia, describing an overall clockwise rotation of this crustal domain with respect to Eurasia. Shortening in southeastern Sicily is associated with a system of high-angle reverse faults resulting from tectonic inversion of extensional faults at the northern tip of the Hyblean plateau. Extension in northern Sicily occurs on a broader deformation belt, developed on the former Kumeta-Alcantara line, extending west of Mount Etna toward the southwestern Tyrrhenian Sea, accommodating the faster rotation of the northeastern Sicily block with respect to central Sicily. Although the seismic potential of inland faults is not negligible, our results strengthen the hypothesis that the Malta escarpment is the likely source of the large 1693 earthquake and tsunami. The observed kinematics appears only subordinately driven by the Nubia-Eurasia convergence and the dynamics of the Mediterranean subduction system is likely playing a major role in governing block motions and active tectonics in Sicily.

  10. Children's Ideas about Earthquakes

    ERIC Educational Resources Information Center

    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…

  11. Can We Predict Earthquakes?

    SciTech Connect

    Johnson, Paul

    2016-08-31

    The only thing we know for sure about earthquakes is that one will happen again very soon. Earthquakes pose a vital yet puzzling set of research questions that have confounded scientists for decades, but new ways of looking at seismic information and innovative laboratory experiments are offering tantalizing clues to what triggers earthquakes — and when.

  12. Earthquake and Schools. [Videotape].

    ERIC Educational Resources Information Center

    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…

  13. School Safety and Earthquakes.

    ERIC Educational Resources Information Center

    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…

  14. Real Earthquakes, Real Learning

    ERIC Educational Resources Information Center

    Schomburg, Aaron

    2003-01-01

    One teacher took her class on a year long earthquake expedition. The goal was to monitor the occurrences of real earthquakes during the year and mark their locations with push pins on a wall-sized world map in the hallway outside the science room. The purpose of the project was to create a detailed picture of the earthquakes that occurred…

  15. Can We Predict Earthquakes?

    ScienceCinema

    Johnson, Paul

    2016-09-09

    The only thing we know for sure about earthquakes is that one will happen again very soon. Earthquakes pose a vital yet puzzling set of research questions that have confounded scientists for decades, but new ways of looking at seismic information and innovative laboratory experiments are offering tantalizing clues to what triggers earthquakes — and when.

  16. Site amplification factors of whole Japan area estimated from spectral ratio of direct S-wave and their application to the real-time prediction of ground motion in Earthquake Early Warning

    NASA Astrophysics Data System (ADS)

    Ogiso, M.; Aoki, S.; Hoshiba, M.

    2014-12-01

    For applying the real-time prediction of ground motion proposed by Hoshiba (2013a, JGR) to Earthquake Early Warning, it is necessary to correct a site amplification factor in an observed waveform. In this study, we aim to estimate site amplification factors at whole area of Japan, and apply the real-time correction proposed by Hoshiba (2013b, BSSA) of site amplification factors to investigate their validity. To estimate site amplification factors, we used the spectral ratio of direct S-wave at two adjunct stations. We constructed a network with many pairs of stations, then solved the equations of the network in a least square sense. As a result, we successfully estimated site amplification factors almost whole of the Japan area, except a part of Hokkaido and Kyushu region, and Islands area. Next, we applied the real-time correction of site amplification factors in the observed waveforms of the 2011 off the Pacific coast of Tohoku Earthquake (Mw 9.0). Distribution of site-corrected seismic intensity calculated in time domain (Kunugi et al., 2008) showed clear distance-dependent relation of seismic intensity, which was not found in the distribution of non-corrected seismic intensity. Finally, we compared the two waveforms recorded in the Ishikari Plain, Hokkaido region, Japan, with correction of site amplification factors. The features of waveform in one station was well reproduced from the waveform of other station with the correction of site amplification factor. Although there are some subjects, e.g. nonlinear behavior of the ground with strong ground motion and azimuth dependency of site amplification factors which are not considered in this study, estimated site amplification factors in this study is effective in real-time prediction of ground motion.

  17. Characteristic ground motions of the 25th April 2015 Nepal earthquake (Mw 7.9) and its implications for the structural design codes for the border areas of India to Nepal

    NASA Astrophysics Data System (ADS)

    Sharma, Babita; Chingtham, Prasanta; Sharma, Varun; Kumar, Vikas; Mandal, H. S.; Mishra, O. P.

    2017-01-01

    The 25th April 2015 Nepal Earthquake was found associated with a series of aftershocks, and the mainshock rupture propagated predominantly towards SE direction where a major aftershock (Mw 7.3) rocked on 12th May 2015 to the east of the mainshock that enhanced the rate of occurrence of aftershocks in the affected region. We conducted a rigorous analysis of strong motion data to understand the characteristics of ground motion and their bearing on the structural design codes, responsible for the damage to the structures in the border area of India to Nepal. The effect of ground geology on the acceleration response spectra are also evaluated using main shock and its associated strong earthquakes. All the sites used in the present analysis are located on alluvium deposits showing a predominant period of 0.242 sec for horizontal components and at 0.193 sec for vertical components. Our results demonstrated that observed Peak Ground Acceleration (PGA) has prominent distribution in the border cities of UP and Bihar. PGA ranges from 3 to 80 cm/sec2 in the study region for the epicentral distance varying from 120 km to 495 km with respect to the source zone (mainshock). The Peak Ground Velocity (PGV) varies from 1 to 16 cm/sec while the Peak Ground Displacement (PGD) lies in between 1 cm and 20 cm for the same area. Our study shows that variation of PGD, PGV, and PGA are controlled and dictated by the geo-morphological constraints, besides the nature and extent of structural heterogeneities of the sub-surface geological formation materials. The obtained normalised spectral amplifications are compared with the Bureau of Indian Standard code for construction of buildings which shows that the current Indian building design code is within the structural limits proposed for the seismic forces at all periods for alluvium sites, suggesting that the structural heterogeneity has the strong role contributing towards the intrinsic attenuation in the seismic wave propagating medium. Our

  18. Threat of an earthquake right under the capital in Japan

    USGS Publications Warehouse

    Rikitake, T.

    1990-01-01

    Tokyo, Japan's capital, has been enjoying a seismically quiet period following the 1923 Kanto earthquake of magnitude 7.9 that killed more than 140,000 people. Such a quiet period seems likely to be a repetition of the 80-year quiescence after the great 1703 Genroku earthquake of magntidue 8.2 that occurred in an epicentral area adjacent to that of the 1923 Kanto earthquake. In 1784, seismic activity immediately under the capital area revived with occasional occurrence of magnitude 6 to 7 shocks. Earthquakes of this class tended to occur more frequently as time went on and they eventually culminated in the 1923 Kanto earthquake. As more than 60 years have passed since the Kanto earthquake, we may well expect another revival of activity immediately under the capital area

  19. Operational earthquake forecasting can enhance earthquake preparedness

    USGS Publications Warehouse

    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).

  20. Earthquake detection by new motion estimation algorithm in video processing

    NASA Astrophysics Data System (ADS)

    Hong, Chien-Shiang; Wang, Chuen-Ching; Tai, Shen-Chuan; Chen, Ji-Feng; Wang, Chung-Yao

    2011-01-01

    As increasing urbanization is taking place worldwide, earthquake hazards pose serious threats to lives and properties for urban areas. A practical earthquake prediction method appears to be far from realization. Generally, the traditional instruments for earthquake detection have the disadvantages of high cost and size. To solve these problems, this paper presents a new method which can detect earthquake intensity using video capture device. The main method is based on a new proposed motion vector algorithm with simple but effective methods to immediately calculate acceleration of a predefined target object. By estimating the motion vector variation, the movement distance of predefined target object can be computed, and therefore the earthquake amplitude can be defined. The effectiveness of the proposed scheme is demonstrated in a series of experimental simulations. It is shown that the scheme successfully detects the earthquake occurrence and identifies the earthquake amplitude from video streams.

  1. Remote monitoring of the earthquake cycle using satellite radar interferometry.

    PubMed

    Wright, Tim J

    2002-12-15

    The earthquake cycle is poorly understood. Earthquakes continue to occur on previously unrecognized faults. Earthquake prediction seems impossible. These remain the facts despite nearly 100 years of intensive study since the earthquake cycle was first conceptualized. Using data acquired from satellites in orbit 800 km above the Earth, a new technique, radar interferometry (InSAR), has the potential to solve these problems. For the first time, detailed maps of the warping of the Earth's surface during the earthquake cycle can be obtained with a spatial resolution of a few tens of metres and a precision of a few millimetres. InSAR does not need equipment on the ground or expensive field campaigns, so it can gather crucial data on earthquakes and the seismic cycle from some of the remotest areas of the planet. In this article, I review some of the remarkable observations of the earthquake cycle already made using radar interferometry and speculate on breakthroughs that are tantalizingly close.

  2. Earthquake Monitoring and Early Warning Systems in Taiwan (Invited)

    NASA Astrophysics Data System (ADS)

    Wu, Y.

    2010-12-01

    The Taiwan region is characterized by a high shortening rate and a strong seismic activity. The Central Weather Bureau (CWB) is responsible for the earthquake monitoring in Taiwan. The CWB seismic network consists of 71 real-time short-period seismic stations in Taiwan region for routinely earthquake monitoring and has recorded about 18,000 events each year in a roughly 400 km x 550 km region. There are 53 real-time broadband stations install for seismological research purposes and reporting moment tensor solution in Taiwan. With the implementation of a real-time strong-motion network by the CWB, earthquake rapid reporting and early warning systems have been developed in Taiwan. The network consists of 110 stations. For rapid reporting system, when a potentially felt earthquake occurs around the Taiwan area, the location, magnitude and shake map of seismic intensities can be automatically reported within about 40 to 60 sec. For large earthquakes, the shaking map and losses can be estimated within 2 min after the earthquake occurrence. For earthquake early warning system, earthquake information could be determined at about 15 to 20 sec after a large earthquake occurrence. Therefore, this system can provide early warning before the arrival of S-wave for metropolitan areas located 70 km away from the epicenter. Recently, onsite earthquake early warning device is developed using MEMS sensor. It focuses on that to offer early warning for areas close to the epicenter.

  3. Crowdsourced earthquake early warning.

    PubMed

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

    2015-04-01

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

  4. Crowdsourced earthquake early warning

    PubMed Central

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

    2015-01-01

    Earthquake early warning (EEW) can reduce harm to people and infrastructure from earthquakes and tsunamis, but it has not been implemented in most high earthquake-risk regions because of prohibitive cost. Common consumer devices such as smartphones contain low-cost versions of the sensors used in EEW. Although less accurate than scientific-grade instruments, these sensors are globally ubiquitous. Through controlled tests of consumer devices, simulation of an Mw (moment magnitude) 7 earthquake on California’s Hayward fault, and real data from the Mw 9 Tohoku-oki earthquake, we demonstrate that EEW could be achieved via crowdsourcing. PMID:26601167

  5. POST Earthquake Debris Management - AN Overview

    NASA Astrophysics Data System (ADS)

    Sarkar, Raju

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

  6. California Earthquake Residual Transportation Capability Study.

    DTIC Science & Technology

    1983-12-01

    through vi 0 Gardenia, Signal Hill and Huntington Beach to Newport Beach. The damaged area would extend from the San Fernando Valley to Oceanside. 0...Bernardino. Ocean service could come from San Diego via highway. Survivors in the San Fernando Valley would be supplied by distri- bution trucks that...1971 San Fernando earthquake, then fire, police and other emer- gency services can cope with the major problems. However, a massive earthquake that

  7. Earthquake forecasting and warning

    SciTech Connect

    Rikitake, T.

    1983-01-01

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

  8. Frog Swarms: Earthquake Precursors or False Alarms?

    PubMed Central

    Grant, Rachel A.; Conlan, Hilary

    2013-01-01

    Simple Summary Media reports linking unusual animal behaviour with earthquakes can potentially create false alarms and unnecessary anxiety among people that live in earthquake risk zones. Recently large frog swarms in China and elsewhere have been reported as earthquake precursors in the media. By examining international media reports of frog swarms since 1850 in comparison to earthquake data, it was concluded that frog swarms are naturally occurring dispersal behaviour of juveniles and are not associated with earthquakes. However, the media in seismic risk areas may be more likely to report frog swarms, and more likely to disseminate reports on frog swarms after earthquakes have occurred, leading to an apparent link between frog swarms and earthquakes. Abstract In short-term earthquake risk forecasting, the avoidance of false alarms is of utmost importance to preclude the possibility of unnecessary panic among populations in seismic hazard areas. Unusual animal behaviour prior to earthquakes has been reported for millennia but has rarely been scientifically documented. Recently large migrations or unusual behaviour of amphibians have been linked to large earthquakes, and media reports of large frog and toad migrations in areas of high seismic risk such as Greece and China have led to fears of a subsequent large earthquake. However, at certain times of year large migrations are part of the normal behavioural repertoire of amphibians. News reports of “frog swarms” from 1850 to the present day were examined for evidence that this behaviour is a precursor to large earthquakes. It was found that only two of 28 reported frog swarms preceded large earthquakes (Sichuan province, China in 2008 and 2010). All of the reported mass migrations of amphibians occurred in late spring, summer and autumn and appeared to relate to small juvenile anurans (frogs and toads). It was concluded that most reported “frog swarms” are actually normal behaviour, probably caused by

  9. Prediction of earthquake-triggered landslide event sizes

    NASA Astrophysics Data System (ADS)

    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

  10. Prediction model of earthquake with the identification of earthquake source polarity mechanism through the focal classification using ANFIS and PCA technique

    NASA Astrophysics Data System (ADS)

    Setyonegoro, W.

    2016-05-01

    Incidence of earthquake disaster has caused casualties and material in considerable amounts. This research has purposes to predictability the return period of earthquake with the identification of the mechanism of earthquake which in case study area in Sumatra. To predict earthquakes which training data of the historical earthquake is using ANFIS technique. In this technique the historical data set compiled into intervals of earthquake occurrence daily average in a year. Output to be obtained is a model return period earthquake events daily average in a year. Return period earthquake occurrence models that have been learning by ANFIS, then performed the polarity recognition through image recognition techniques on the focal sphere using principal component analysis PCA method. The results, model predicted a return period earthquake events for the average monthly return period showed a correlation coefficient 0.014562.

  11. A revised “earthquake report” questionaire

    USGS Publications Warehouse

    Stover, C.; Reagor, G.; Simon, R.

    1976-01-01

    The U.S geological Survey is responsible for conducting intensity and damage surveys following felt or destructive earthquakes in the United States. Shortly after a felt or damaging earthquake occurs, a canvass of the affected area is made. Specially developed questionnaires are mailed to volunteer observers located within the estimated felt area. These questionnaires, "Earthquake Reports," are filled out by the observers and returned to the Survey's National Earthquake Information Service, which is located in Colorado. They are then evaluated, and, based on answers to questions about physical effects seen or felt, each canvassed location is assigned to the various locations, they are plotted on an intensity distribution map. When all of the intensity data have been plotted, isoseismals can then be contoured through places where equal intensity was experienced. The completed isoseismal map yields a detailed picture of the earthquake, its effects, and its felt area. All of the data and maps are published quarterly in a U.S Geological Survey Circular series entitled "Earthquakes in the United States".  

  12. Investigation of atmospheric anomalies associated with Kashmir and Awaran Earthquakes

    NASA Astrophysics Data System (ADS)

    Mahmood, Irfan; Iqbal, Muhammad Farooq; Shahzad, Muhammad Imran; Qaiser, Saddam

    2017-02-01

    The earthquake precursors' anomalies at diverse elevation ranges over the seismogenic region and prior to the seismic events are perceived using Satellite Remote Sensing (SRS) techniques and reanalysis datasets. In the current research, seismic precursors are obtained by analyzing anomalies in Outgoing Longwave Radiation (OLR), Air Temperature (AT), and Relative Humidity (RH) before the two strong Mw>7 earthquakes in Pakistan occurred on 8th October 2005 in Azad Jammu Kashmir with Mw 7.6, and 24th September 2013 in Awaran, Balochistan with Mw 7.7. Multi-parameter data were computed based on multi-year background data for anomalies computation. Results indicate significant transient variations in observed parameters before the main event. Detailed analysis suggests presence of pre-seismic activities one to three weeks prior to the main earthquake event that vanishes after the event. These anomalies are due to increase in temperature after release of gases and physical and chemical interactions on earth surface before the earthquake. The parameter variations behavior for both Kashmir and Awaran earthquake events are similar to other earthquakes in different regions of the world. This study suggests that energy release is not concentrated to a single fault but instead is released along the fault zone. The influence of earthquake events on lightning were also investigated and it was concluded that there is a significant atmospheric lightning activity after the earthquake suggesting a strong possibility for an earthquake induced thunderstorm. This study is valuable for identifying earthquake precursors especially in earthquake prone areas.

  13. Hypothesis testing and earthquake prediction.

    PubMed

    Jackson, D D

    1996-04-30

    Requirements for testing include advance specification of the conditional rate density (probability per unit time, area, and magnitude) or, alternatively, probabilities for specified intervals of time, space, and magnitude. Here I consider testing fully specified hypotheses, with no parameter adjustments or arbitrary decisions allowed during the test period. Because it may take decades to validate prediction methods, it is worthwhile to formulate testable hypotheses carefully in advance. Earthquake prediction generally implies that the probability will be temporarily higher than normal. Such a statement requires knowledge of "normal behavior"--that is, it requires a null hypothesis. Hypotheses can be tested in three ways: (i) by comparing the number of actual earth-quakes to the number predicted, (ii) by comparing the likelihood score of actual earthquakes to the predicted distribution, and (iii) by comparing the likelihood ratio to that of a null hypothesis. The first two tests are purely self-consistency tests, while the third is a direct comparison of two hypotheses. Predictions made without a statement of probability are very difficult to test, and any test must be based on the ratio of earthquakes in and out of the forecast regions.

  14. Innovative methodology for the synthesis of Ba-M hexaferrite BaFe{sub 12}O{sub 19} nanoparticles

    SciTech Connect

    Ahmed, M.A.; Helmy, N.; El-Dek, S.I.

    2013-09-01

    Graphical abstract: Transmission electron microscope images for the BaFe12O19. - Highlights: • BaFe{sub 12}O{sub 19}nanoparticles were prepared in single-phase from organometallic precursors. • BaFe{sub 12}O{sub 19} possesses small size 65 nm, H{sub C} = 3695 Oe and M{sub s} = 58 emu/g. • This method of preparation could be extended in the synthesis of other metal oxide nanoparticles. - Abstract: In this piece of work, high quality and homogeneity, barium hexaferrite (BaM) BaFe{sub 12}O{sub 19} nanoparticles were prepared from organometallic precursors for the 1st time. This method is based on the formation of supramolecular crystal structure of Ba[Fe(H{sub 3}NCH{sub 2}CH{sub 2}NH{sub 3})]Cl{sub 7}·8H{sub 2}O. The crystal structure, morphology and magnetic properties of BaFe{sub 12}O{sub 19} at two different annealing temperatures namely 1000 °C and 1200 °C were investigated using X-ray diffraction, transmission electron microscope TEM and vibrating sample magnetometry (VSM). The results show that monophasic nanoparticles of hexaferrites were obtained. Nanoparticles of crystallite size 40–50 nm distinguished by narrow distribution and excellent homogeneity were obtained with superior magnetic properties which suggested single-domain particles of Ba-M hexaferrite.

  15. Seismicity prior to the 2016 Kumamoto earthquakes

    NASA Astrophysics Data System (ADS)

    Nanjo, Kazuyoshi Z.; Izutsu, Jun; Orihara, Yoshiaki; Furuse, Nobuhiro; Togo, Shoho; Nitta, Hidetoshi; Okada, Tomohiro; Tanaka, Rika; Kamogawa, Masashi; Nagao, Toshiyasu

    2016-11-01

    We report precursory seismic patterns prior to the 2016 Kumamoto earthquakes, as measured by four different methods based on changes in seismicity that can be used for earthquake forecasting: the b-value method, two methods of seismic quiescence evaluation, and an analysis of seismicity density in space and time. The spatial extent of precursory patterns differs from one method to the other and ranges from local scales (typically, asperity size) to regional scales (e.g., 2° × 3° around the source zone). The earthquakes were preceded by periods of pronounced anomalies, which lasted in yearly scales (1.5 years), or longer (>3 years). We demonstrate that a combination of multiple methods detected different signals prior to the Kumamoto earthquakes. This indicates great potential to reduce the hazard at possible future sites of earthquakes relative to long-term seismic hazard assessment. We also found that the seismic quiescence in a regional-scale area, detected by using the two methods of seismic quiescence evaluation, was a common precursor to the 2016 Kumamoto earthquakes and 2015 Off Satsuma Peninsula earthquake. The result allows us to interpret both events as the onset that occurred at a section along the tectonic line from the Okinawa Trough through the Beppu-Shimabara graben.[Figure not available: see fulltext.

  16. Non-Double-Couple Earthquakes 2. Observations

    USGS Publications Warehouse

    Miller, A.D.; Foulger, G.R.; Julian, B.R.

    1998-01-01

    Most studies assume that earthquakes have double-couple (DC) source mechanisms, corresponding to shear motion on planar faults. However, many well-recorded earthquakes have radiation patterns that depart radically from this model, indicating fundamentally different source processes. Seismic waves excited by advective processes, such as landslides and volcanic eruptions, are consistent with net forces rather than DCs. Some volcanic earthquakes also have single-force mechanisms, probably because of advection of magmatic fluids. Other volcanic earthquakes have mechanisms close to compensated linear vector dipoles and may be caused by magmatic intrusions. Shallow earthquakes in volcanic or geothermal areas and mines often have mechanisms with isotropic components, indicating volume changes of either explosive or implosive polarity. Such mechanisms are consistent with failure involving both shear and tensile faulting, which may be facilitated by high-pressure, high-temperature fluids. In mines, tunnels are cavities that may close. Deep-focus earthquakes occur within zones of polymorphic phase transformations in the upper mantle at depths where stick-slip instability cannot occur. Their mechanisms tend to be deviatoric (volume conserving), but non-DC, and their source processes are poorly understood. Automatic global moment tensor services routinely report statistically significant non-DC components for large earthquakes, but detailed reexamination of individual events is required to confirm such results.

  17. Smartphone MEMS accelerometers and earthquake early warning

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  18. New geological perspectives on earthquake recurrence models

    SciTech Connect

    Schwartz, D.P.

    1997-02-01

    In most areas of the world the record of historical seismicity is too short or uncertain to accurately characterize the future distribution of earthquakes of different sizes in time and space. Most faults have not ruptured once, let alone repeatedly. Ultimately, the ability to correctly forecast the magnitude, location, and probability of future earthquakes depends on how well one can quantify the past behavior of earthquake sources. Paleoseismological trenching of active faults, historical surface ruptures, liquefaction features, and shaking-induced ground deformation structures provides fundamental information on the past behavior of earthquake sources. These studies quantify (a) the timing of individual past earthquakes and fault slip rates, which lead to estimates of recurrence intervals and the development of recurrence models and (b) the amount of displacement during individual events, which allows estimates of the sizes of past earthquakes on a fault. When timing and slip per event are combined with information on fault zone geometry and structure, models that define individual rupture segments can be developed. Paleoseismicity data, in the form of timing and size of past events, provide a window into the driving mechanism of the earthquake engine--the cycle of stress build-up and release.

  19. Hypocenter Estimation of Induced Earthquakes in Groningen

    NASA Astrophysics Data System (ADS)

    Spetzler, Jesper; Dost, Bernard

    2017-01-01

    Induced earthquakes due to gas production have taken place in the province of Groningen in the North-East of the Netherlands since 1986. In the first years of seismicity, a sparse seismological network with large station distances from the seismogenic area in Groningen was used. The location of induced earthquakes was limited by the few and wide spread stations. Recently, the station network has been extended significantly and the location of induced earthquakes in Groningen has become routine work. Except for the depth estimation of the events. In the hypocenter method used for source location by the Royal Netherlands Meteorological Institute (KNMI), the depth of the induced earthquakes is by default set to 3 km which is the average depth of the gas-reservoir. Alternatively, a differential travel time for P-waves approach for source location is applied on recorded data from the extended network. The epicenter and depth of 87 induced earthquakes from 2014 to July 2016 have been estimated. The newly estimated epicentres are close to the induced earthquake locations from the current method applied by the KNMI. It is observed that most induced earthquakes take place at reservoir level. Several events in the same magnitude order are found near a brittle anhydrite layer in the overburden of mainly rock salt evaporites.

  20. Nonextensive models for earthquakes

    NASA Astrophysics Data System (ADS)

    Silva, R.; França, G. S.; Vilar, C. S.; Alcaniz, J. S.

    2006-02-01

    We have revisited the fragment-asperity interaction model recently introduced by Sotolongo-Costa and Posadas [Phy. Rev. Lett. 92, 048501 (2004)] by considering a different definition for mean values in the context of Tsallis nonextensive statistics and introducing a scale between the earthquake energy and the size of fragment γ∝r3 . The energy-distribution function (EDF) deduced in our approach is considerably different from the one obtained in the above reference. We have also tested the viability of this EDF with data from two different catalogs (in three different areas), namely, the NEIC and the Bulletin Seismic of the Revista Brasileira de Geofísica. Although both approaches provide very similar values for the nonextensive parameter q , other physical quantities, e.g., energy density, differ considerably by several orders of magnitude.

  1. Nonextensive models for earthquakes.

    PubMed

    Silva, R; França, G S; Vilar, C S; Alcaniz, J S

    2006-02-01

    We have revisited the fragment-asperity interaction model recently introduced by Sotolongo-Costa and Posadas [Phy. Rev. Lett. 92, 048501 (2004)] by considering a different definition for mean values in the context of Tsallis nonextensive statistics and introducing a scale between the earthquake energy and the size of fragment epsilon proportional to r3. The energy-distribution function (EDF) deduced in our approach is considerably different from the one obtained in the above reference. We have also tested the viability of this EDF with data from two different catalogs (in three different areas), namely, the NEIC and the Bulletin Seismic of the Revista Brasileira de Geofísica. Although both approaches provide very similar values for the nonextensive parameter , other physical quantities, e.g., energy density, differ considerably by several orders of magnitude.

  2. Research on earthquake prediction from infrared cloud images

    NASA Astrophysics Data System (ADS)

    Fan, Jing; Chen, Zhong; Yan, Liang; Gong, Jing; Wang, Dong

    2015-12-01

    In recent years, the occurrence of large earthquakes is frequent all over the word. In the face of the inevitable natural disasters, the prediction of the earthquake is particularly important to avoid more loss of life and property. Many achievements in the field of predict earthquake from remote sensing images have been obtained in the last few decades. But the traditional prediction methods presented do have the limitations of can't forecast epicenter location accurately and automatically. In order to solve the problem, a new predicting earthquakes method based on extract the texture and emergence frequency of the earthquake cloud is proposed in this paper. First, strengthen the infrared cloud images. Second, extract the texture feature vector of each pixel. Then, classified those pixels and converted to several small suspected area. Finally, tracking the suspected area and estimate the possible location. The inversion experiment of Ludian earthquake show that this approach can forecast the seismic center feasible and accurately.

  3. Are all major California cities seriously threatened by earthquakes?

    SciTech Connect

    Suen, C.J.

    1995-09-01

    This report discusses the seismic hazards associated with living in various urban areas of California, particularly the Fresno area. According to this assessment and other studies, the Fresno metropolitan area is relatively safe from the threat of a large destructive earthquake, due to its location away from major earthquake-prone fault zones. Unlike other major metropolitan areas in California such as San Francisco and Los Angeles, the Fresno area has no known active faults that are capable of causing destructive tremors. Several maps are included which indicate the location of earthquake epicenters and magnitudes in California from 1769 to the present.

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

    NASA Astrophysics Data System (ADS)

    Chen, Q.; Wang, K.

    2009-12-01

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

  5. Sichuan Earthquake in China

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Sichuan earthquake in China occurred on May 12, 2008, along faults within the mountains, but near and almost parallel the mountain front, northwest of the city of Chengdu. This major quake caused immediate and severe damage to many villages and cities in the area. Aftershocks pose a continuing danger, but another continuing hazard is the widespread occurrence of landslides that have formed new natural dams and consequently new lakes. These lakes are submerging roads and flooding previously developed lands. But an even greater concern is the possible rapid release of water as the lakes eventually overflow the new dams. The dams are generally composed of disintegrated rock debris that may easily erode, leading to greater release of water, which may then cause faster erosion and an even greater release of water. This possible 'positive feedback' between increasing erosion and increasing water release could result in catastrophic debris flows and/or flooding. The danger is well known to the Chinese earthquake response teams, which have been building spillways over some of the new natural dams.

    This ASTER image, acquired on June 1, 2008, shows two of the new large landslide dams and lakes upstream from the town of Chi-Kua-Kan at 32o12'N latitude and 104o50'E longitude. Vegetation is green, water is blue, and soil is grayish brown in this enhanced color view. New landslides appear bright off-white. The northern (top) lake is upstream from the southern lake. Close inspection shows a series of much smaller lakes in an elongated 'S' pattern along the original stream path. Note especially the large landslides that created the dams. Some other landslides in this area, such as the large one in the northeast corner of the image, occur only on the mountain slopes, so do not block streams, and do not form lakes.

  6. Missing great earthquakes

    USGS Publications Warehouse

    Hough, Susan E.

    2013-01-01

    The occurrence of three earthquakes with moment magnitude (Mw) greater than 8.8 and six earthquakes larger than Mw 8.5, since 2004, has raised interest in the long-term global rate of great earthquakes. Past studies have focused on the analysis of earthquakes since 1900, which roughly marks the start of the instrumental era in seismology. Before this time, the catalog is less complete and magnitude estimates are more uncertain. Yet substantial information is available for earthquakes before 1900, and the catalog of historical events is being used increasingly to improve hazard assessment. Here I consider the catalog of historical earthquakes and show that approximately half of all Mw ≥ 8.5 earthquakes are likely missing or underestimated in the 19th century. I further present a reconsideration of the felt effects of the 8 February 1843, Lesser Antilles earthquake, including a first thorough assessment of felt reports from the United States, and show it is an example of a known historical earthquake that was significantly larger than initially estimated. The results suggest that incorporation of best available catalogs of historical earthquakes will likely lead to a significant underestimation of seismic hazard and/or the maximum possible magnitude in many regions, including parts of the Caribbean.

  7. Continuing megathrust earthquake potential in Chile after the 2014 Iquique earthquake

    USGS Publications Warehouse

    Hayes, Gavin P.; Herman, Matthew W.; Barnhart, William D.; Furlong, Kevin P.; Riquelme, Sebástian; Benz, Harley M.; Bergman, Eric; Barrientos, Sergio; Earle, Paul S.; Samsonov, Sergey

    2014-01-01

    The seismic gap theory identifies regions of elevated hazard based on a lack of recent seismicity in comparison with other portions of a fault. It has successfully explained past earthquakes (see, for example, ref. 2) and is useful for qualitatively describing where large earthquakes might occur. A large earthquake had been expected in the subduction zone adjacent to northern Chile which had not ruptured in a megathrust earthquake since a M ~8.8 event in 1877. On 1 April 2014 a M 8.2 earthquake occurred within this seismic gap. Here we present an assessment of the seismotectonics of the March–April 2014 Iquique sequence, including analyses of earthquake relocations, moment tensors, finite fault models, moment deficit calculations and cumulative Coulomb stress transfer. This ensemble of information allows us to place the sequence within the context of regional seismicity and to identify areas of remaining and/or elevated hazard. Our results constrain the size and spatial extent of rupture, and indicate that this was not the earthquake that had been anticipated. Significant sections of the northern Chile subduction zone have not ruptured in almost 150 years, so it is likely that future megathrust earthquakes will occur to the south and potentially to the north of the 2014 Iquique sequence.

  8. Intermediate-term earthquake prediction.

    PubMed Central

    Keilis-Borok, V I

    1996-01-01

    An earthquake of magnitude M and linear source dimension L(M) is preceded within a few years by certain patterns of seismicity in the magnitude range down to about (M - 3) in an area of linear dimension about 5L-10L. Prediction algorithms based on such patterns may allow one to predict approximately 80% of strong earthquakes with alarms occupying altogether 20-30% of the time-space considered. An area of alarm can be narrowed down to 2L-3L when observations include lower magnitudes, down to about (M - 4). In spite of their limited accuracy, such predictions open a possibility to prevent considerable damage. The following findings may provide for further development of prediction methods: (i) long-range correlations in fault system dynamics and accordingly large size of the areas over which different observed fields could be averaged and analyzed jointly, (ii) specific symptoms of an approaching strong earthquake, (iii) the partial similarity of these symptoms worldwide, (iv) the fact that some of them are not Earth specific: we probably encountered in seismicity the symptoms of instability common for a wide class of nonlinear systems. Images Fig. 1 Fig. 2 Fig. 4 Fig. 5 PMID:11607660

  9. Intermediate-term earthquake prediction.

    PubMed

    Keilis-Borok, V I

    1996-04-30

    An earthquake of magnitude M and linear source dimension L(M) is preceded within a few years by certain patterns of seismicity in the magnitude range down to about (M - 3) in an area of linear dimension about 5L-10L. Prediction algorithms based on such patterns may allow one to predict approximately 80% of strong earthquakes with alarms occupying altogether 20-30% of the time-space considered. An area of alarm can be narrowed down to 2L-3L when observations include lower magnitudes, down to about (M - 4). In spite of their limited accuracy, such predictions open a possibility to prevent considerable damage. The following findings may provide for further development of prediction methods: (i) long-range correlations in fault system dynamics and accordingly large size of the areas over which different observed fields could be averaged and analyzed jointly, (ii) specific symptoms of an approaching strong earthquake, (iii) the partial similarity of these symptoms worldwide, (iv) the fact that some of them are not Earth specific: we probably encountered in seismicity the symptoms of instability common for a wide class of nonlinear systems.

  10. Prototype operational earthquake prediction system

    USGS Publications Warehouse

    Spall, Henry

    1986-01-01

    An objective if the U.S. Earthquake Hazards Reduction Act of 1977 is to introduce into all regions of the country that are subject to large and moderate earthquakes, systems for predicting earthquakes and assessing earthquake risk. In 1985, the USGS developed for the Secretary of the Interior a program for implementation of a prototype operational earthquake prediction system in southern California.

  11. Applicability of source scaling relations for crustal earthquakes to estimation of the ground motions of the 2016 Kumamoto earthquake

    NASA Astrophysics Data System (ADS)

    Irikura, Kojiro; Miyakoshi, Ken; Kamae, Katsuhiro; Yoshida, Kunikazu; Somei, Kazuhiro; Kurahashi, Susumu; Miyake, Hiroe

    2017-01-01

    A two-stage scaling relationship of the source parameters for crustal earthquakes in Japan has previously been constructed, in which source parameters obtained from the results of waveform inversion of strong motion data are combined with parameters estimated based on geological and geomorphological surveys. A three-stage scaling relationship was subsequently developed to extend scaling to crustal earthquakes with magnitudes greater than M w 7.4. The effectiveness of these scaling relationships was then examined based on the results of waveform inversion of 18 recent crustal earthquakes ( M w 5.4-6.9) that occurred in Japan since the 1995 Hyogo-ken Nanbu earthquake. The 2016 Kumamoto earthquake, with M w 7.0, was one of the largest earthquakes to occur since dense and accurate strong motion observation networks, such as K-NET and KiK-net, were deployed after the 1995 Hyogo-ken Nanbu earthquake. We examined the applicability of the scaling relationships of the source parameters of crustal earthquakes in Japan to the 2016 Kumamoto earthquake. The rupture area and asperity area were determined based on slip distributions obtained from waveform inversion of the 2016 Kumamoto earthquake observations. We found that the relationship between the rupture area and the seismic moment for the 2016 Kumamoto earthquake follows the second-stage scaling within one standard deviation ( σ = 0.14). The ratio of the asperity area to the rupture area for the 2016 Kumamoto earthquake is nearly the same as ratios previously obtained for crustal earthquakes. Furthermore, we simulated the ground motions of this earthquake using a characterized source model consisting of strong motion generation areas (SMGAs) based on the empirical Green's function (EGF) method. The locations and areas of the SMGAs were determined through comparison between the synthetic ground motions and observed motions. The sizes of the SMGAs were nearly coincident with the asperities with large slip. The synthetic

  12. Footprints of past earthquakes revealed in the afterslip of the 2010 Mw 7.8 Mentawai tsunami earthquake

    NASA Astrophysics Data System (ADS)

    Feng, Lujia; Barbot, Sylvain; Hill, Emma M.; Hermawan, Iwan; Banerjee, Paramesh; Natawidjaja, Danny H.

    2016-09-01

    The 2010 Mw 7.8 Mentawai tsunami earthquake marks one of the first tsunami earthquakes to have postseismic deformation observed by geodetic instruments. The Sumatran GPS Array has recorded the postseismic deformation following this event continuously for >5 years. The spatiotemporal evolution of the postseismic deformation is well explained by velocity-strengthening frictional sliding on the Sunda megathrust. Our results show that the 2010 afterslip progressed downdip relative to the 2010 coseismic rupture. The southeastern portion of the afterslip region overlaps the area that slipped during the main shock and afterslip of the 2007 Mw 8.4 Bengkulu earthquake, while the northwestern portion slipped an area without recent large earthquakes. By incorporating pre-earthquake stress conditions into quasi-dynamic models, we demonstrate that the preceding cumulative slip from the 2007 sequence might have caused a ˜0.1 MPa difference in pre-earthquake Coulomb stress between the southeastern and northwestern portions of the afterslip region.

  13. Geotechnical Extreme Events Reconnaissance Report on the Performance of Structures in Densely Urbanized Areas Affected by Surface Fault Rupture During the August 24, 2014 M6 South Napa Earthquake, California, USA.

    NASA Astrophysics Data System (ADS)

    Cohen-Waeber, J.; Lanzafame, R.; Bray, J.; Sitar, N.

    2014-12-01

    The August 24, 2014, M­w 6.0 South Napa earthquake is the largest seismic event to have occurred in the San Francisco Bay Region, California, USA, since the Mw 6.9 1989 Loma Prieta earthquake. The event epicenter occurred at the South end of the Napa Valley, California, principally rupturing northwest along parts of the active West Napa fault zone. Bound by two major fault zones to the East and West (Calaveras and Rogers Creek, respectively), the Napa Valley is filled with up to 170 m. of alluvial deposits and is considered to be moderately to very highly susceptible to liquefaction and has the potential for violent shaking. While damage due to strong ground shaking was significant, remarkably little damage due to liquefaction or landslide induced ground deformations was observed. This may be due to recent drought in the region. Instead, the South Napa earthquake is the first to produce significant surface rupture in this area since the Mw 7.9 1906 San Andreas event, and the first in Northern California to rupture through a densely urbanized environment. Clear expressions of surface fault rupture extended approximately 12 - 15 km northward from the epicenter and approximately 1-2 km southeast with a significant impact to infrastructure, including roads, lifelines and residential structures. The National Science Foundation funded Geotechnical Extreme Events Reconnaissance (GEER) Association presents here its observations on the performance of structures affected by surface fault rupture, in a densely populated residential neighborhood located approximately 10 km north of the epicenter. Based on the detailed mapping of 27 residential structures, a preliminary assessment of the quantitative descriptions of damage shows certain characteristic interactions between surface fault rupture and the overlying infrastructure: 48% of concrete slabs cracked up to 8 cm wide, 19% of structures shifted up to 11 cm off of their foundation and 44% of foundations cracked up to 3 cm

  14. Disturbances in equilibrium function after major earthquake

    NASA Astrophysics Data System (ADS)

    Honma, Motoyasu; Endo, Nobutaka; Osada, Yoshihisa; Kim, Yoshiharu; Kuriyama, Kenichi

    2012-10-01

    Major earthquakes were followed by a large number of aftershocks and significant outbreaks of dizziness occurred over a large area. However it is unclear why major earthquake causes dizziness. We conducted an intergroup trial on equilibrium dysfunction and psychological states associated with equilibrium dysfunction in individuals exposed to repetitive aftershocks versus those who were rarely exposed. Greater equilibrium dysfunction was observed in the aftershock-exposed group under conditions without visual compensation. Equilibrium dysfunction in the aftershock-exposed group appears to have arisen from disturbance of the inner ear, as well as individual vulnerability to state anxiety enhanced by repetitive exposure to aftershocks. We indicate potential effects of autonomic stress on equilibrium function after major earthquake. Our findings may contribute to risk management of psychological and physical health after major earthquakes with aftershocks, and allow development of a new empirical approach to disaster care after such events.

  15. Electromagnetic anomalies associated with 1995 Kobe earthquake

    NASA Astrophysics Data System (ADS)

    Nagao, T.; Enomoto, Y.; Fujinawa, Y.; Hata, M.; Hayakawa, M.; Huang, Q.; Izutsu, J.; Kushida, Y.; Maeda, K.; Oike, K.; Uyeda, S.; Yoshino, T.

    2002-07-01

    Occurrences of anomalous electro-magnetic phenomena at varied frequency ranges, covering ELF to VHF, have been reported in relation to the 17 January 1995 Kobe earthquake (M7.2), by several independent research groups. Prominent pre-seismic peaks, which could have been emitted from the focal area, were observed on 9-10 January in ELF, VLF, LF and HF ranges. Whether these changes were truly related to the earthquake is not certain, because atmospheric (thunderbolt discharge) activities also peaked on 9-10 January. The nomalous changes were markedly enhanced toward the catastrophe in agreement with many reports on unusual radio/TV noise. Anomalous transmission of man-made electromagnetic waves in VLF and VHF ranges was also detected from a few days before the earthquake, indicating the possibility that the ionosphere above the focal zone was disturbed at the final stage of the earthquake preparation process.

  16. Coping with earthquakes induced by fluid injection

    USGS Publications Warehouse

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

    2015-01-01

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

  17. Response to major earthquakes affecting Gemini twins

    NASA Astrophysics Data System (ADS)

    van der Hoeven, Michiel; Rogers, Rolando; Rippa, Mathew; Perez, Gabriel; Montes, Vanessa; Moreno, Cristian

    2016-07-01

    Both Gemini telescopes, in Hawaii and Chile, are located in highly seismic active areas. That means that the seismic protection is included in the structural design of the telescope, instruments and auxiliary structure. We will describe the specific design features to reduce permanent damage in case of major earthquakes. At this moment both telescopes have been affected by big earthquakes in 2006 and 2015 respectively. There is an opportunity to compare the original design to the effects that are caused by these earthquakes and analyze their effectiveness. The paper describes the way the telescopes responded to these events, the damage that was caused, how we recovered from it, the modifications we have done to avoid some of this damage in future occasions, and lessons learned to face this type of events. Finally we will cover on how we pretend to upgrade the limited monitoring tools we currently have in place to measure the impact of earthquakes.

  18. Safety and survival in an earthquake

    USGS Publications Warehouse

    ,

    1969-01-01

    Many earth scientists in this country and abroad are focusing their studies on the search for means of predicting impending earthquakes, but, as yet, an accurate prediction of the time and place of such an event cannot be made. From past experience, however, one can assume that earthquakes will continue to harass mankind and that they will occur most frequently in the areas where they have been relatively common in the past. In the United States, earthquakes can be expected to occur most frequently in the western states, particularly in Alaska, California, Washington, Oregon, Nevada, Utah, and Montana. The danger, however, is not confined to any one part of the country; major earthquakes have occurred at widely scattered locations.

  19. 1/f and the Earthquake Problem: Scaling constraints to facilitate operational earthquake forecasting

    NASA Astrophysics Data System (ADS)

    Yoder, M. R.; Rundle, J. B.; Glasscoe, M. T.

    2013-12-01

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