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Sample records for bam area earthquake

  1. Seismicity anomalies of the 2003 Bam, Iran earthquake

    NASA Astrophysics Data System (ADS)

    Ashtari Jafari, Mohammad

    2012-08-01

    The Bam earthquake occurred in an area without any historically recorded major earthquake. Based on active tectonics and CMT solutions the area is under the influence of shortening and right-lateral strike-slip faulting. Seismicity is of a shallow crustal type which is mainly distributed within the Koohbanan-Golbaf, Lakarkooh-Shahdad-Gowk fault systems and the terminal sections of Zagros. In order to detect temporal seismicity anomalies before this earthquake we compiled a catalog from the ISC events and then analyzed it for the magnitude of completeness. After declustering this catalog, changes in seismicity were assessed by the z-value test. The temporal variations indicate a relative decrease in z-value before the Bam earthquake. Additional to seismic quiescence and decrease in b-value before the main shock there are pieces of evidence corresponding to increase in triggered background seismicity after this earthquake.

  2. 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

  3. Revisiting blood transfusion preparedness: experience from the Bam earthquake response.

    PubMed

    Abolghasemi, Hassan; Radfar, Mohammad H; Tabatabaee, Morteza; Hosseini-Divkolayee, Nasim S; Burkle, Frederick M

    2008-01-01

    Blood transfusion plays a critical role in the provision of medical care for disasters due to man-made and natural hazards. Although the short-term increase in blood donations following national disasters is well-documented, some aspects of blood transfusion during disasters remain under study. The 2003 earthquake in Bam, Iran resulted in the death of >29,000 people and injured 23,000. In total, 108,985 blood units were donated, but only 21,347 units (23%) actually were distributed to hospitals around the country. Kerman Province, the site of the disaster, received 1,231 (1.3%) of the donated units in the first four days after the disaster. The Bam experience revealed crucial missteps in the development of a post-event strategy for blood product management, and led to the development of a detailed disaster preparedness and response plan that addresses issues of donation, distribution, communication, transportation, and coordination. The current plan requires the Iranian Blood Transfusion Organization to convene a disaster task force immediately as the main coordinator of all disaster preparedness and response activities. PMID:19189607

  4. The devastation of Bam: an overview of health issues 1 month after the earthquake.

    PubMed

    Akbari, M E; Farshad, A A; Asadi-Lari, M

    2004-09-01

    The appalling earthquake in the ancient city of Bam on December 27th 2003 was one of the worst disasters since the last century in Iran. Further to the chilling statistics of human loss, essential services including water supply, power, telephone, health care services, main roads, and the city's only airport were crippled. From the 'public health' and 'health emergency' perspectives, the initial priorities were to minimise avoidable further mortality and morbidity. This required prompt evacuation of the injured, defining catchment areas, establishment of efficient systems for disease control, organising a disaster management plan, out patient management, co-ordination of international aid, and re-organising the current PHC network in the district. The second stage, each department planning health delivery for the subsequent year, was rapidly initiated. This paper discusses these strategies, which were designed specifically for Bam but are likely useful in similar situations. PMID:15313593

  5. The perspective of psychosocial support a decade after Bam earthquake: achievements and challenges.

    PubMed

    Farhoudian, Ali; Hajebi, Ahmad; Bahramnejad, Ali; Katz, Craig L

    2013-09-01

    The 2003 Bam earthquake was one of the most catastrophic disasters to have struck Iran. This article summarizes the short-term and long-term psychological, social, and economic impacts of the Bam earthquake on survivors across a decade since its occurrence. Identification and definition of capability as well as recognizing the nature and extent of personal and social capabilities in a community are priceless in preventing disasters and reducing their consequent destruction. PMID:23954054

  6. 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.

  7. Simulation of 2003 Bam (Iran) earthquake using empirical Green's function method via very small and near-fault events

    NASA Astrophysics Data System (ADS)

    Riahi, Ali; Sadeghi, Hossein; Hosseini, Sayyed Keivan

    2015-06-01

    The 2003 Bam, Iran, earthquake (Mw = 6.6) was recorded by the BAM accelerometer station. Since the causative fault was located just below the city, the accelerometer recorded the main shock, a foreshock and several local aftershocks. To study the scenario of rupturing, we simulated all components of the observed main shock waveform via the empirical Green's function method. 28 selected aftershocks and the single foreshock are used to simulate the main shock in the frequency range of 0.5-5 Hz. Since the events were very close to the station, some small events may not have similar path effects to the main shock. Therefore, it is essential to employ some appropriate changes to the waveforms to alleviate path difference effects. The starting point of the rupture is identified in the centre of the strong motion generation area and is located approximately 5 km south of the BAM station and in depth of about 7 km. The horizontal simulated components imply that the main shock was located west of the BAM station. In contrast, significant variation in the ratio of amplitudes in EW and NS components may be used to discuss the possibility of dissimilarity in the focal mechanism of the small events. Most aftershocks with similar mechanisms to the main shock, that is similar EW/NS maximum amplitude ratio, have capacity to simulate certain peaks of their horizontal components. However, some small events with different mechanisms are only able to simulate the peaks of up to one horizontal component. Some changes were applied to the empirical Green's function method to incorporate two small events by using a combined fault model. While the two aftershocks have different mechanisms, some combinations may improve simulations. The rupture initiating point at the middle of the fault plane and improved simulations by combination of two fault surfaces with different focal mechanisms may suggest a bilateral rupture and combination of two focal mechanisms for the main shock of the Bam

  8. The prevalence of complicated grief among Bam earthquake survivors in Iran.

    PubMed

    Ghaffari-Nejad, Alireza; Ahmadi-Mousavi, Mohammadreza; Gandomkar, Mohsen; Reihani-Kermani, Hamed

    2007-10-01

    Earthquake is a natural disaster, which causes many psychological problems in survivors. Complicated grief is one of these sequelae. A devastating earthquake with a magnitude of 6.3 on the Richter scale destroyed the city of Bam in Kerman Province, Iran. Twenty-six thousand people were killed. Many of the survivors should have developed psychological problems in the aftermath of the disaster. In this study, we examined the prevalence of complicated grief and its correlation with the demographic factors and some suggested contributing variables. In this cross-sectional study, 400 persons were selected by stratified multistage area sampling. The survivors were interviewed in their temporary residential camp. After evaluating their demographic data, they were evaluated with the inventory of complicated grief. The cut-off point was set to 25. The mean+/-SD age of the participants was 37.8+/-12.7 years. Complicated grief was detected in 304 (76%) of the respondents. Score of complicated grief was higher among women and in those with lower educational levels. Presence in the city during the earthquake, observing burial of corpses, destruction of residential homes during the earthquake, residential problem after the catastrophe, and loss of at least one of the first relatives during previous earthquakes were variables which were correlated with complicated grief. Existence of complicated grief in more than two-thirds of respondents requires more attention of mental health services. Rebuilding of homes and solving the residential problems of survivors are the factors, which could help survivors to find their mental health within a shorter period. PMID:17903061

  9. 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

  10. Being Under the Umbrella of Persistent Grief: Experiences of Survivors of Bam Earthquake.

    PubMed

    Tirgari, Batool; Azzizadeh Forouzi, Mansooreh; Malakian, Lila

    2016-05-01

    The loss of a loved one is a highly stressful event that nearly everyone experiences. Multiple losses can leave relatives feeling overwhelmed or stuck in their grief, a phenomenon commonly referred to as bereavement overload. This study aimed to elucidate the meaning of prolonged grief from the viewpoint of the survivors of the Bam earthquake (Iran, December 2003) 11 years after the earthquake in south eastern Iran. Family members who lost loved ones in the Bam earthquake were considered potential participants. A total of 12 survivors participated in this study. The interviews were analyzed with Ricoeur's phenomenological hermeneutic method. The meaning of prolonged grief was comprehensively understood as "being under the umbrella of persistent grief." This can be divided into four themes: experiencing a divine and painful destiny, experiencing heartbreaking goodbye with loved ones, losing all hopes and dreams, and being in a state of fragile peace. The results in this study suggest survivors of the Bam earthquake grief can be moderated by adequate crisis-related coping resources such as social, cultural, and religious supports. These supports are clearly important to survivors' post-earthquake recovery. PMID:27172233

  11. Shallow fault-zone dilatancy recovery after the 2003 Bam earthquake in Iran.

    PubMed

    Fielding, Eric J; Lundgren, Paul R; Bürgmann, Roland; Funning, Gareth J

    2009-03-01

    Earthquakes radiate from slip on discrete faults, but also commonly involve distributed deformation within a broader fault zone, especially near the surface. Variations in rock strain during an earthquake are caused by heterogeneity in the elastic stress before the earthquake, by variable material properties and geometry of the fault zones, and by dynamic processes during the rupture. Stress changes due to the earthquake slip, both dynamic and static, have long been thought to cause dilatancy in the fault zone that recovers after the earthquake. Decreases in the velocity of seismic waves passing through the fault zone due to coseismic dilatancy have been observed followed by postseismic seismic velocity increases during healing. Dilatancy and its recovery have not previously been observed geodetically. Here we use interferometric analysis of synthetic aperture radar images to measure postseismic surface deformation after the 2003 Bam, Iran, earthquake and show reversal of coseismic dilatancy in the shallow fault zone that causes subsidence of the surface. This compaction of the fault zone is directly above the patch of greatest coseismic slip at depth. The dilatancy and compaction probably reflects distributed shear and damage to the material during the earthquake that heals afterwards. Coseismic and postseismic deformation spread through a fault zone volume may resolve the paradox of shallow slip deficits for some strike-slip fault ruptures. PMID:19262670

  12. The severity of cutaneous leishmaniasis before and after the earthquake in Bam, southeastern Iran.

    PubMed

    Sharifi, Iraj; Aflatoonian, Mohammad Reza; Aflatoonian, Behnaz; Kermanizadeh, Alireza

    2015-12-01

    Cutaneous leishmaniasis (CL) is a major disease with significant public health concerns in Iran. The objective of this study was to compare the severity of CL among the patients before and after the earthquake in the city and suburbs of Bam, southeastern Iran. This study was carried out as a descriptive-analytical manner by house-to-house visits in 2010 in Bam, southeastern Kerman province of Iran, where a massive earthquake has recently occurred. Overall, 1,481 individuals were selected as a cluster random sampling. Suspected lesions were detected by direct smear preparation and X(2) test was used for statistical significance at P < 0.05. Overall, 1,481 individuals (mean age; 25.7 ± 17.6 years) consisting of 51.4 % males and 48.6 % females were randomly selected. 549 individuals showed history of CL; 23.4 % belonged to before and 13.7 % belonged to after the earthquake. When the overall severity in terms of location, number, size and duration of lesions was considered, the lesions were less severe in the time period after the earthquake (P < 0.05) than those before the earthquake. Cutaneous leishmaniasis is currently considered as a growing public health concern worldwide, mainly due to creation of various risk factors particularly after a major natural disaster. Possibly the establishment of the CL health clinic to serve patients and to coordinate various activities had a major role in planning control strategies and thus reduction in severity of the CL disease. PMID:26688645

  13. 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. PMID:21218726

  14. Source Process of the 2003 Bam, Iran, Earthquake inferred from Joint Inversion of Teleseismic and Strong Motion Data

    NASA Astrophysics Data System (ADS)

    Poiata, N.; Miyake, H.; Koketsu, K.; Hikima, K.

    2009-04-01

    We attempt to determine precise fault geometry and source process of the December 26, 2003 Bam earthquake from southeast Iran, and answer the question why a moderate event (Mw 6.5) resulted in such a large disaster. Previous studies showed that the earthquake was caused by a subsurface rupture on previously unknown strike-slip fault. A remarkable record obtained at the strong-motion station inside the city of Bam and 5 km from the epicenter shows the PGA value of 988 gal in the UD component and two pulses with a dominant frequency of 1 Hz in the horizontal components. It was inferred that the large PGA value recorded at Bam station and the proportion of damage provoked by this event might be explained by the combination of the forward rupture directivity effect towards the city of Bam and a large speed of the rupture front over the fault (Bouchon et al., 2005). Although, there have been proposed several fault models of this event from geodetic data (Talebian et al., 2004; Wang et al., 2004; Fielding et al., 2005) and aftershock analysis (Nakamura et al., 2005), they are varying significantly in there location and some of them propose existence of the fault branching towards the north, beneath the city of Bam. We inverted teleseismic and strong motion data to determine the precise fault configuration and rupture process of the 2003 Bam earthquake. It is expected that the combination of this two different datasets will offer a more stable image of the source area, while each of the teleseismic and strong motion data carries information on different period ranges of the process at the source. To infer the general rupture process, we first analyzed teleseismic dataset. We applied the moment tensor analysis as well as the source inversion method developed by Kikuchi and Kanamori (1982, 1991) and Kikuchi et al. (2003) to 23 P- and 17 SH- far-field displacement waveforms from IRIS-DMC database. The hypocenter location was assumed to be at 29.050N, 58.365E and the initial

  15. 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

  16. 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.

  17. A hybrid method for simulating near-source, broadband seismograms: Application to the 2003 Bam earthquake (Mw 6.5)

    NASA Astrophysics Data System (ADS)

    Nicknam, Ahmad; Eslamian, Yasser

    2010-05-01

    The main objective of this article is to simulate the three components of near-source ground shaking recorded at Bam station, close to the causative fault, during the destructive the 2003 Bam earthquake, where were strongly influenced by rupture directivity effect. A hybrid technique composed of the theoretical Green's function, finite element and finite difference method proposed by Spudich et al. (1987, 2003) (COMPSYN) and a ω2-based finite-fault approach proposed by Beresnev and Atkinson (1998a) (FINSIM) are used for generating seismograms at low and high frequencies respectively. A Genetic algorithm technique is developed for minimizing the differences between the recorded and simulated data incorporating parameters within a predefined upper/lower bound's values previously estimated for main shock by other investigators. Two different faulting models, consist of a straight line segment and a straight line segment followed by a slightly north-eastward branch, are used. The simulated three component seismograms at Bam station, in terms of elastic response spectra, are validated by comparing the simulated time series with those of the observed data. Moreover, the pulses involved in the recorded time series due to the rupture directivity are estimated and compared with those of the observed data. A sensitivity analysis is performed for recognizing the influence of model parameter changes, such as focal mechanism (strike, dip and rake), rise-time, rupture velocity and hypocenter location on the simulated seismograms. Relatively good match of the simulated and observed time series, particularly the two faulting models, confirm the potentiality of the proposed technique and the suitability of seismological model parameters used. This technique can be used for specific site hazard analysis of the Bam region and linear/nonlinear dynamic analysis of structures where were damaged during the Bam earthquake particularly for retrofitting the well known international adobe

  18. Cutaneous Leishmaniasis in Bam: A Comparative Evaluation of Pre- and Post-Earthquake Years (1999–2008)

    PubMed Central

    Sharifi, I; Nakhaei, N; Aflatoonian, MR; Parizi, M Hakimi; Fekri, AR; Safizadeh, H; Shirzadi, MR; Gooya, MM; Khamesipour, A; Nadim, A

    2011-01-01

    Background: The recent devastating earthquake of December 26 in Bam, 2003 created various risk factors; caused a sharp increase in incidence of anthroponotic cutaneous leishmaniasis (ACL) cases and reached to an epidemic proportion. The objective of this study was to evaluate the status of ACL cases five years before the earthquake compared to the cases occurred five years after the earthquake (1999–2008). Methods: Status of disease was assessed retrospectively for the five years before the earthquake and prospectively for the five years after the earthquake. Identification was confirmed by smear and polymerase chain reaction (PCR). Results: The mean annual incidence of ACL for the period from 1999 to 2003 was 1.9 per 1000 comparing to post earthquake period, which was 7.6 per 1000. Most of the infection was in individuals of <20 years, more frequently in females before the earthquake, whilst in contrast, there was a progressive rise in the number of cases, significantly in male individuals of >20 years (P< 0.0001) in post earthquake era. The anatomical distribution of lesions considerably changed during the two periods. Most of the cases were limited to three zones within the city prior to the earthquake, whereas it was spread throughout different zones after the earthquake. PCR indicated that the CL was due to Leishmania tropica in the city. Conclusion: The results strongly suggest that in natural disasters such as earthquakes various precipitating factors in favor of disease will be created, which in turn provide a suitable condition for propagation of the vector and the transmission of the parasite. PMID:23113072

  19. Source Fault of the Dec.26, 2003 Bam Earthquake (Mw6.5) in Southeastern Iran Inferred From Aftershock Observation Data by Temporal High-Sensitive-Seismograph Network

    NASA Astrophysics Data System (ADS)

    Suzuki, S.; Matsushima, T.; Ito, Y.; Hosseini, S. K.; Nakamura, T.; Arash, J.; Sadeghi, H.; Maleki, M.; Aghda, F.

    2004-05-01

    The Bam earthquake occurred in southeastern Iran at 05:26 A.M.(local time) on December 26, 2003 (epicenter: 29.010N, 58.266E, Mo=6.6x10**18Nm, Mw=6.5; ref.1). The earthquake had strike-slip mechanism (strike=175, dip=85, slip=153; ref.2) and source parameters (focal depth=4km, fault dimension=20kmx15km, Dmax=1.0m, stress drop=3.7MPa; ref.2). The earthquake struck the ancient city of Bam and killed more than 40,000 people. It shows that one third of about 120,000 in population in and around Bam city were killed. The main reason of such a big damage may be caused by weak adobe and brick houses; even so, the damage was too much big. We, therefore, are researching other cause of such a big damage. Taking instruments from Japan for this aim we installed 9 high sensitive seismographs and one accelerograph in and around Bam city on February 6-8, 2004. And we observed aftershocks and continue during one month. Reading P and S arriving times of about 100 aftershocks occurring from February 6 to 10, we determined those preliminary hypocenters and magnitudes. Those epicenters (errors<500m) distribute mainly from northeastern Bam city to south direction with about 20km length. It means that the fault of the main shock passed just under eastern half of Bam city where most of houses and buildings were heavily damaged. This fault is about 4 km away west from Bam fault which is presented in geological map (ref.3). A north-south vertical cross-section of the hypocentral distribution (maybe errors < 1km) shows that most of their depths are shallower than 14km and a seismic gap exists in the laterally middle part of their distribution and shallower than 6 km in depth. The shallow seismic gap may correspond to a main fracture zone as shown in the slip distribution figure proposed by Yamanaka (ref.2). This main fracture occurring shallower than about 6 km in depth must be one of causes of the big damage in Bam. (Reference) ref1:USGS,http://neic.usgs.gov/neis/FM/, ref 2: ERI, U. Tokyo

  20. Very High Resolution Optical Images for Detecting Co-seismic Surface Effects: the Cases of the 2005 Kashmir (Pakistan) and the 2003 Bam (Iran) Earthquakes

    NASA Astrophysics Data System (ADS)

    Chini, M.; Cinti, F. R.; Stramondo, S.

    2008-12-01

    Very High Resolution (VHR) satellite panchromatic image has revealed to be a reliable tool to detect surface effects of natural disasters. This is particularly true whereas the hit territory is a remote land and/or with logistic and security problems. Data from this kind of sensor have a potential for more exhaustive and accurate mapping of the environment with details of sub-meter ground resolution. We show two large earthquake case studies, the 2005 Mw 7.6 Kashmir and the 2003 Mw 6.6 Bam events, both producing significant surface effects as ruptures, landslides and building damages. In order to test the capability of VHR images to recognize and evaluate such features we used panchromatic QuickBird imagery (0.6 m spatial resolution) acquired before and after the events (kindly provided by DigitalGlobe). Concerning the Pakistan we focus on the Muzaffarabad and Balakot areas, both crossed by the earthquake fault and experiencing edifice collapses. Same sort of analysis is performed for the ancient town of Bam. We proceed with: 1. identification on the images of the main rupture trace and of major landslides; 2. generation of a detailed spatial distribution of damage and collapses through a single building automatic classification approach; 3. cross-comparison of the different surface effects. The QuickBird panchromatic images provide a view of the co-seismic features at large scale, revealing complex geometric pattern of the cracks and compressional deformation features. It is possible to detect the lateral sense of movement, and based on the sun shade projection in the images, we infer the facing of the scarp, thus the uplifted side. Regarding point two, if in one hand the use of QuickBird images leads to detect very small details, on the other hand buildings become rather complex structures. Furthermore they may be surrounded by scattering objects making less evident the contrast between the roofs and the ground, thus increasing the difficulties in the

  1. 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.

  2. The Emergence of Anthroponotic Cutaneous Leishmaniasis Following the Earthquake in Southern Villages of Bam District, Southeastern Iran, 2010

    PubMed Central

    Aflatoonian, Mohammad Reza; Sharifi, Iraj; Poursmaelian, Somayeh; Hakimi-Parizi, Maryam; Ziaali, Nasser

    2013-01-01

    Background: The objective of this study was to assess the epidemiological characteristics of a new emerging focus of cutaneous leishmaniasis (CL) in southern villages of Bam District, southeastern Iran, 2010. Methods: A house-to- house census survey of 5544 individuals were interviewed and physically examined for the presence of active lesions or scars. Diagnosis was confirmed by direct smears, cultures and identification by PCR. The data were entered into a computer and SPSS ver. 15. Results: Overall, 1.2% of the inhabitants were infected, 0.5% active and 0.7% scars and females were more significantly infected (1.7%) than males (0.8%), (P= 0.003). All age groups were equally affected. Most of the lesions were on the face and majority had single lesion. Most of the cases appeared from 2006 to 2008 during the CL epidemic in the city of Bam. PCR indicated L. tropica as the causative agent. Conclusion: The presence of non-immune individuals along with suitable ecological conditions could induce a new emerging focus of ACL in villages. PMID:23785690

  3. 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.

  4. 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 ...

  5. 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. 

  6. 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…

  7. 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

  8. Earthquake Risk Mitigation in the Tokyo Metropolitan area

    NASA Astrophysics Data System (ADS)

    Hirata, N.; Sakai, S.; Kasahara, K.; Nakagawa, S.; Nanjo, K.; Panayotopoulos, Y.; Tsuruoka, H.

    2010-12-01

    Seismic disaster risk mitigation in urban areas constitutes a challenge through collaboration of scientific, engineering, and social-science fields. Examples of collaborative efforts include research on detailed plate structure with identification of all significant faults, developing dense seismic networks; strong ground motion prediction, which uses information on near-surface seismic site effects and fault models; earthquake resistant and proof structures; and cross-discipline infrastructure for effective risk mitigation just after catastrophic events. Risk mitigation strategy for the next greater earthquake caused by the Philippine Sea plate (PSP) subducting beneath the Tokyo metropolitan area is of major concern because it caused past mega-thrust earthquakes, such as the 1703 Genroku earthquake (magnitude M8.0) and the 1923 Kanto earthquake (M7.9) which had 105,000 fatalities. A M7 or greater (M7+) earthquake in this area at present has high potential to produce devastating loss of life and property with even greater global economic repercussions. The Central Disaster Management Council of Japan estimates that the M7+ earthquake will cause 11,000 fatalities and 112 trillion yen (about 1 trillion US$) economic loss. This earthquake is evaluated to occur with a probability of 70% in 30 years by the Earthquake Research Committee of Japan. In order to mitigate disaster for greater Tokyo, the Special Project for Earthquake Disaster Mitigation in the Tokyo Metropolitan Area (2007-2011) was launched in collaboration with scientists, engineers, and social-scientists in nationwide institutions. The results that are obtained in the respective fields will be integrated until project termination to improve information on the strategy assessment for seismic risk mitigation in the Tokyo metropolitan area. In this talk, we give an outline of our project as an example of collaborative research on earthquake risk mitigation. Discussion is extended to our effort in progress and

  9. Candidates of M7-Class Earthquake Beneath Greater Tokyo Area

    NASA Astrophysics Data System (ADS)

    Okada, Y.

    2003-12-01

    In greater Tokyo area, the occurrence of M7-class earthquake is thought to be imminent by the following reasons. (1) In these 20 years, maximum size of shallow microearthquakes beneath Tokyo is steadily increasing. (2) In recent 80 years after Kanto earthquake, maximum size of the earthquakes in Kanto region is gradually increasing. (3) In these 400 years, it was observed twice that two M7-class earthquakes precede the M8 interplate earthquakes in the latter half of the interseismic period. Taking into consideration these background, the Central Disaster Management Council, Japan issued _gGuideline for Countermeasures to the Earthquakes Beneath Southern Kanto Region _h on August 1994, and proposed 19 fault models along the upper boundary of Philippine Sea plate as the candidates of the forthcoming M7-class earthquake. At present, we have no data of abnormal seismic activity or crustal movement to select preferable one among these 19 fault models. Here, we will try to constrain the candidates which may have relatively higher possibility of the occurrence by a elimination method. It seems to be possible to exclude some of the fault models by the following ways. (1) Adopting characteristic earthquake concept, we can exclude 5 models which overlap to the focal region of 1923 Kanto earthquake. (2) A belt like zone of serpentine are found from tomography results at 30-40km depth along the Philippine Sea plate beneath the Kanto Plain and no microearthquake activities are generated along this zone (Kamiya and Kobayashi, GRL, 2000). We can eliminate 4 models which lie in this zone. (3) Beneath the eastern Boso Peninsula, it was found that slow slips of M6.5-class are repeated every 5-6 years. We can exclude 2 models in the area (4) Since plate collision is undertaken beneath eastern Yamanashi Prefecture, we can exclude 1 model in this area. Finally, it remains 7 fault models as the possible candidates of M7-class earthquake beneath Tokyo area. They are 3 models just beneath

  10. 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

  11. 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…

  12. Earthquake supersite project in the Messina Straits area (EQUAMES)

    NASA Astrophysics Data System (ADS)

    Mattia, Mario; Chiarabba, Claudio; Dell'Acqua, Fabio; Faccenna, Claudio; Lanari, Riccardo; Matteuzzi, Francesco; Neri, Giancarlo; Patanè, Domenico; Polonia, Alina; Prati, Claudio; Tinti, Stefano; Zerbini, Susanna

    2015-04-01

    A new permanent supersite is going to be proposed to the GEO GSNL (Geohazard Supersites and National Laboratories) for the Messina Straits area (Italy). The justification for this new supersite can be found in its geological and geophysical features and in the exposure to strong earthquakes, also in the recent past (1908). The Messina Supersite infrastructure (EQUAMES: EarthQUAkes in the MEssina Straits) will host, and contribute to the collection of, large amounts of data, basic for the analysis of seismic hazard/risk in this high seismic risk area, including risk from earthquake-related processes such as submarine mass failures and tsunamis. In EQUAMES, data of different types will coexist with models and methods useful for their analysis/interpretation and with first-level products of analysis that can be of interest for different kinds of users. EQUAMES will help all the interested scientific and non-scientific subjects to find and use data and to increase inter-institutional cooperation by addressing the following main topics in the Messina Straits area: • investigation of the geological and physical processes leading to the earthquake preparation and generation; • analysis of seismic shaking at ground (expected and observed); • combination of seismic hazard with vulnerability and exposure data for risk estimates; • analysis of tsunami generation, propagation and coastal inundation deriving from earthquake occurrence also through landslides due to instability conditions of subaerial and submarine slopes; • overall risk associated to earthquake activity in the Supersite area including the different types of cascade effects Many Italian and international Institutions have shown an effective interest in this project where a large variety of geophysical and geological in-situ data will be collected and where the INGV has the leading role with its large infrastructure of seismic, GPS and geochemical permanent stations. The groups supporting EQUAMES

  13. Earthquake!

    ERIC Educational Resources Information Center

    Markle, Sandra

    1987-01-01

    A learning unit about earthquakes includes activities for primary grade students, including making inferences and defining operationally. Task cards are included for independent study on earthquake maps and earthquake measuring. (CB)

  14. 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 ...

  15. 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)

  16. Earthquakes, active faults, and geothermal areas in the Imperial Valley, California

    USGS Publications Warehouse

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

    1975-01-01

    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.

  17. 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. PMID:17772600

  18. Improved Earthquake Location in the area of N. Euboean Gulf

    NASA Astrophysics Data System (ADS)

    Mouzakiotis, A. S.; Karastathis, V. K.

    2012-12-01

    Considerably improved hypocentral locations of the seismic events recorded during the period from 2009 to 2010 by the Hellenic Unified Seismographic Network (HUSN), have been obtained for the area of North Euboean Gulf, after implementation of a 3D non-linear location algorithm and a local 3D velocity model for both P and S-waves. The velocity model has been produced in previous studies using local earthquake tomography techniques (1D minimum velocity model and simultaneous 3D inversion techniques). In total, 280 events have been recorded in the area covered by the 3D velocity model, by at least 5 local stations. The 223 out of these were well located by the local stations having the azimuthal gap lower than 180o. Within the area covered by the 3D velocity model, there are 7 HUSN stations and two more from other networks. To optimize the hypocentral parameters estimation of the selected events, we used probabilistic non-linear earthquake location method, utilizing the 3D velocity model of the area. The program used produces a misfit function, "optimal" hypocenters and an estimate of the posterior probability density function (PDF) for the spatial hypocenter location. The calculated travel-times are obtained using a 3D version of the Eikonal finite difference scheme and the complete location PDF is calculated by the EDT (equal differential time) function. The results were compared with the ones obtained by the implementation of other 1D velocity models such as a) the 1D velocity model used for the daily earthquake data analysis by NOA and b) the 1D minimum velocity model. In spite of the fact that the local 3D velocity model was based on a completely different dataset than the present, it produced considerably improved event locations with significantly smaller location errors than both the 1D models. This shows the validity of the 3D velocity model. Although the 1D minimum model produced better locations than the NOA model, it was not as effective as the 3D model

  19. In-situ stress measurement in an earthquake focal area

    NASA Astrophysics Data System (ADS)

    Tsukahara, H.; Ikeda, R.; Omura, K.

    1996-09-01

    A 2-km-deep borehole was drilled into granitic rock where many shallow earthquakes, with focal depths from 2 to 15 km, have occurred. The drill site, Ashio, is 100 km north of Tokyo. Downhole testing and measurements were conducted five times: four times after each 500 m drilling and the fifth time after completing the 2000 m borehole. Measurements of in-situ stress orientation and magnitude were conducted by the hydraulic fracturing method, stress-induced well bore breakout analysis, and drilling-mud pressure induced hydraulic fracturing analysis. Breakouts and mud pressure induced hydraulic fractures were observed below 650 m and 1250 m, respectively. The circular well bore is maintained only in limited spots below 650 m because of breakouts indicating a large differential stress condition between the maximum and the minimum principal stresses. The differential stress is calculated at 90 ± 20 MPa at the depth of 2000 m based on the condition under which the breakout with some degree of width appears. It is interpreted that this large differential stress is representative of the regional crustal stress condition in the earthquake swarm area. Each spot of the circular well bore is always adjacent to a fracture zone. This suggests that the fracture zone has small differential stress. The stress values were measured where the well bore is circular by the hydraulic fracturing method. For example, the maximum and the minimum horizontal compressive stresses are about 35 MPa and about 25 MPa, respectively, at the depth of 1650 m; giving the differential stress of 10 MPa. The water pressure in pre-existing fractures was also measured, and found that they were nearly equal to the hydrostatic water pressure at the corresponding depths. The stress direction estimated from the azimuth of the breakouts and the hydraulic fracture is consistent with that estimated from the earthquake focal mechanisms. These results support the following conclusions. The differential stress is

  20. 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)

  1. Three-dimensional sedimentary architecture of Quaternary deposits; a case study of environmental sedimentology (Bam, Iran)

    NASA Astrophysics Data System (ADS)

    Rezaei, K.; Guest, B.; Friedrich, A.; Fayazi, F.; Nakhaei, M.; Bakhtiari, H.; Nouri, L.

    2009-04-01

    relationships suggest that deformation had occured upward into the basin during time. According to our observations, a great number of recently constructed buildings were also damaged in city areas far from the faulted zones. These are areas where silty and clayey soils dominate, exhibiting very low electric resistivity and low wave velocity, together with high thickness, plasticity and compressibility. Rock samples are from volcanism stages in Eocene magmatism. The clay minerals have resulted from weathering of continental environments in upstream. Key Words: Bam, Sediment, facies, 3D sedimentary model, Earthquake.

  2. 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

  3. In vivo roles of BamA, BamB and BamD in the biogenesis of BamA, a core protein of the β-barrel assembly machine of Escherichia coli.

    PubMed

    Misra, Rajeev; Stikeleather, Ryan; Gabriele, Rebecca

    2015-03-13

    Assembly of the β-barrel outer membrane proteins (OMPs) is an essential cellular process in Gram-negative bacteria and in the mitochondria and chloroplasts of eukaryotes--two organelles of bacterial origin. Central to this process is the conserved β-barrel OMP that belongs to the Omp85 superfamily. In Escherichia coli, BamA is the core β-barrel OMP and, together with four outer membrane lipoproteins, BamBCDE, constitutes the β-barrel assembly machine (BAM). In this paper, we investigated the roles of BamD, an essential lipoprotein, and BamB in BamA biogenesis. Depletion of BamD caused impairment in BamA biogenesis and cessation of cell growth. These defects of BamD depletion were partly reversed by single-amino-acid substitutions mapping within the β-barrel domain of BamA. However, in the absence of BamB, the positive effects of the β-barrel substitutions on BamA biogenesis under BamD depletion conditions were nullified. By employing a BamA protein bearing one such substitution, F474L, it was demonstrated that the mutant BamA protein could not only assemble without BamD but also facilitate the assembly of wild-type BamA expressed in trans. Based on these data, we propose a model in which the Bam lipoproteins, which are localized to the outer membrane by the BAM-independent Lol pathway, aid in the creation of new BAM complexes by serving as outer membrane receptors and folding factors for nascent BamA molecules. The newly assembled BAM holocomplex then catalyzes the assembly of substrate OMPs and BamA. These in vivo findings are corroborated by recently published in vitro data. PMID:24792419

  4. Archaeoseismological Study of Prehistoric Earthquakes in Anhui Province, China and Adjacent Areas

    NASA Astrophysics Data System (ADS)

    Yao, D.; Shen, X.; Gong, X.; Wu, W.; Hu, Z.; Zheng, H.; Chen, A.; Zhao, P.; Yang, Y.

    2014-12-01

    Damaging earthquakes on faults typically recur at intervals of centuries to millennia but the seismographs that record them have only been around for about hundred years. Complete records of earthquakes of Ms5 or above for Anhui Province of China and its adjacent areas began in 1336 and most previous records were lost. To reduce the hazard from earthquakes we need a longer record of them than can be provided from such instruments. Archaeoseismological evidence has the potential to determine earthquake activity over millennial time spans, especially when integrated with historical documents and geological evidence. In recent years, taking advantage of large-scale civil excavations, our research team including earthquake and archaeological scientists have cataloged, identified, and analyzed deformation relics of the late-Quaternary period, especially the Neolithic Age. Prehistoric earthquake traces were found in the cultural layers of the Western Zhou Dynasty and the Spring and Autumn Period in Southwest Anhui, the late Dawenkou cultural period in North Anhui, and the Eastern Zhou in South Henan. Along the segment of the Tanlu Fault Zone on the border of Jiangsu-Anhui Provinces, several rapid deformation events mainly in the form of oblique translational thrust had occurred since Late Pleistocene, which was confirmed by microscopic studies. The research findings have partly filled the gap of earthquake records in the area and enriched research methodologies in archaeology, prehistoric earthquakes and earthquake prediction. The project was sponsored by China Earthquake Science Special Research Funding Program (#201308012)

  5. 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.

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

    NASA Astrophysics Data System (ADS)

    Diansari, Angga Vertika; Purwana, Ibnu; Subakti, Hendri

    2015-04-01

    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.

  7. 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.

  8. Prevalence of HCV and HIV infections in 2005-Earthquake-affected areas of Pakistan

    PubMed Central

    Khan, Saeed; Rai, Mohammad A; Khan, Adnan; Farooqui, Amber; Kazmi, Shahana U; Ali, Syed H

    2008-01-01

    Background On October 8, 2005, an earthquake of magnitude 7.6 hit the Northern parts of Pakistan. In the post-earthquake scenario, overcrowding, improper sewage disposal, contamination of food and drinking water, hasty surgical procedures, and unscreened blood transfusions to earthquake victims most likely promotes the spread of infections already prevalent in the area. Objective The objective of the study reported here was to determine the prevalence of Human Immunodeficiency and Hepatitis C viruses (respectively, HIV and HCV) in the earthquake-affected communities of Pakistan. The samples were analyzed 2 months and then again 11 months after the earthquake to estimate the burden of HIV and HCV in these areas, and to determine any rise in the prevalence of these viral infections as a result of the earthquake. Methods Blood samples were initially collected during December, 2005 to March 2006, from 245 inhabitants of the earthquake-affected areas. These samples were screened for HCV and HIV, using immunochromatography and Enzyme-Linked Immuno-Sorbent Assay (ELISA). Results Out of 245 samples tested, 8 (3.26%) were found positive for HCV, and 0 (0.0%) for HIV, indicating the existence of HCV infection in the earthquake-stricken areas. The same methods were used to analyze the samples collected in the second round of screening in the same area, in September, 2006 – 11 months after the earthquake. This time 290 blood samples were collected, out of which 16 (5.51%) samples were positive for HCV, and 0 for HIV. Conclusion A slightly higher prevalence of HCV was recorded 11 months after the earthquake; this increase, however, was not statistically significant. None of the study participants was found HIV-infected. PMID:18954443

  9. Megathrust Friction in the Maule Earthquake Area in Relation to Forearc Morphology and Mechanical Stability, and to Earthquake Rupture Dynamics

    NASA Astrophysics Data System (ADS)

    Cubas, N.; Avouac, J.; Lapusta, N.

    2011-12-01

    Determining the spatio-temporal variations of frictional properties is a key issue in order to advance our understanding of earthquake dynamics. This study aims to characterize these variations for the 2010 Maule Mw 8.8 earthquake area based on the analysis of the forearc morphology and dynamic earthquake simulation. Two different mechanical approaches are applied to determine static and dynamic frictions. The first one relies on the critical taper theory and allows to constrain basal and internal frictions as well as the internal pore fluid pressure. The forearc above aseismic slipping areas of the Megathrust appear to be at critical mechanical state as evidenced from its morphology and indices of active deformation. Aseismic areas updip of the Maule Earthquake rupture area, where the forearc consists of a recently accreted sedimentary prism, show a moderate basal friction (0.17 - 0.21) and an internal pore fluid pressure close to hydrostatic conditions. Aseismic areas downdip of the Maule Earthquake rupture and beneath the Arauco peninsula, known to be a recurrent barrier to earthquake propagation, have higher basal friction (0.4). By contrast the forerarc above the seismogenic zone is observed to be mechanically stable, all the deformation being accommodated by slip along the Megathrust. We use the limit analysis approach to constrain the dynamic friction of the seismogenic zone as the critical taper theory provides only limited insight in this case. We determine spatial variations of the basal friction from the position of active faults. We focus on the Santa Maria island cross-section where an active backthrust splays from the megathrust near the transition from seismic sliding to aseismic sliding. A low basal friction in the seismogenic zone (< 0.1) is required for this splay fault to be active. These frictional properties are then integrated in a three-dimensional earthquake sequence model to investigate whether the low friction in the seismogenic zone is

  10. 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)

  11. 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. 

  12. 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).

  13. Earthquake catalogue for Germany and adjacent areas for the years 800 to 2008

    NASA Astrophysics Data System (ADS)

    Leydecker, Günter

    2010-05-01

    The presented earthquake catalogue for Germany and adjacent areas (47°N - 56°N and 5°E - 16°E) for the years 800 to 2008 contains ca 12000 events with ML ≥ 2.0. The earthquake catalogue in a digital format was published for the first time by the author in the year 1986. It contained ca 2000 earthquakes covering the time period from 1000 to 1981. Since then the spatial area and the time period of the catalogue were extended, the catalogue was annually updated and according to the actual historical earthquake research corrected and supplemented. The immense growth of the number of events since 1986 must be seen parallel to the increase of seismic stations in the local and regional networks. The data for the annual update are taken from the Data Catalogues of the German Regional Seismic Network - compiled and edited by the Federal Institute for Geosciences and Natural Resources (BGR), Hannover - and, with priority, from the later results of the hypocenter computations by the operators of the local networks. Added to the earthquake data are the macroseismic observations as epicentral intensity and isoseismal radii. Each earthquake is linked to its seismo-geographical region. The digital earthquake catalogue actual at any one time was presented for download under www.bgr.de/quakecat. Over the past years an alignment was carried out with the catalogues of the adjacent countries, in particular with the new catalogue of Switzerland. By co-operation with colleagues the data of the Vogtland swarm quakes of the 20th century could be corrected and harmonized with respect to epicenter, magnitude and epicentral intensity. A re-evaluation of the seismic activity of the Upper Rhine Graben was accomplished using the data from the long lasting monitoring with local seismic networks. Furthermore, the moment magnitude was newly added to the list of the earthquake parameters. The appendices to the earthquake catalogue contain detailed references to each earthquake, lists of the

  14. 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.

  15. Earthquake prediction in seismogenic areas of the Iberian Peninsula based on computational intelligence

    NASA Astrophysics Data System (ADS)

    Morales-Esteban, A.; Martínez-Álvarez, F.; Reyes, J.

    2013-05-01

    A method to predict earthquakes in two of the seismogenic areas of the Iberian Peninsula, based on Artificial Neural Networks (ANNs), is presented in this paper. ANNs have been widely used in many fields but only very few and very recent studies have been conducted on earthquake prediction. Two kinds of predictions are provided in this study: a) the probability of an earthquake, of magnitude equal or larger than a preset threshold magnitude, within the next 7 days, to happen; b) the probability of an earthquake of a limited magnitude interval to happen, during the next 7 days. First, the physical fundamentals related to earthquake occurrence are explained. Second, the mathematical model underlying ANNs is explained and the configuration chosen is justified. Then, the ANNs have been trained in both areas: The Alborán Sea and the Western Azores-Gibraltar fault. Later, the ANNs have been tested in both areas for a period of time immediately subsequent to the training period. Statistical tests are provided showing meaningful results. Finally, ANNs were compared to other well known classifiers showing quantitatively and qualitatively better results. The authors expect that the results obtained will encourage researchers to conduct further research on this topic. Development of a system capable of predicting earthquakes for the next seven days Application of ANN is particularly reliable to earthquake prediction. Use of geophysical information modeling the soil behavior as ANN's input data Successful analysis of one region with large seismic activity

  16. 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. PMID:25692790

  17. 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

  18. Study on Features of Secondary Disasters in the Worst-hit Areas of Wenchuan Earthquake

    NASA Astrophysics Data System (ADS)

    Liu, S.; Guo, W.

    2008-12-01

    The Wenchuan earthquake on May 12, 2008 has caused heavy casualties and property losses. The violent earthquake and numerous intense aftershocks also induced secondary natural disasters in large area, which seriously threaten the regional eco-environment and human settlement environment. Based on the field investigation of some disaster area and analysis on RS data collected after the earthquake, the authors present the following opinions on features of secondary disaster caused by the Wenchuan earthquake. The Wenchuan earthquake occurred at the Longmen Mountain fault zone, which starts from east side of the Jiajin Mountain in Tianquan, Ya'an, and extends northeastward connecting with the Daba Mountain fault zone, approximately 500 km long and 70 km wide. This fault zone is composed of the front mountain the fault, central fracture and the rear mountain fault. Primary disaster area is mostly in the central fault zone. Large geomorphological unit of the disaster area is located at the transitional zone between the upmost ladder and middle ladder of landform in China. Primary disaster area is in the high mountain and middle mountain areas at edge of the Sichuan Basin, where valleys are deeply incised by streams and the mountains are very high with very steep slopes, greater than 25 degrees at most sites. The worst-hit area is of subtropical mountainous humid region under monsoon climate. Tendency of the mountain range is in a northeast-southwest orientation, so it is windward to southwestern monsoon, and has plenteous precipitation. Annual precipitation in Dujiangyan is 1178mm, and 1280mm in Beichuan, which are the center of opulent rainfall region in China. It provides conditions for incompact materials to form debris flow after the earthquake. The strong earthquake altered the landscape in disaster area violently. Under the action of seismic force and gravity, a great quantity of materials loosened in the earthquake slide downwards along steep slopes, thus

  19. Earthquake vulnerability and risk modeling for the area of Greater Cairo, Egypt

    NASA Astrophysics Data System (ADS)

    Tyagunov, S.; Abdel-Rahman, K.; El-Hady, S.; El-Ela Mohamed, A.; Stempniewski, L.; Liesch, T.; Zschau, J.

    2009-04-01

    Egypt is a country of low-to-moderate earthquake hazard. However, the earthquake risk potential (in terms of both probable economic and human losses) is rather high. Population of Egypt (according to the Central Agency for Public Mobilisation and Statistics - CAPMAS) is about 80 million. At the same time the distribution of the population in the country is far from uniform. In particular, the area of Greater Cairo attracts migrants from the whole country and the metropolitan area faces the problem of unplanned urbanization. Due to the high density of population and vulnerability of the existing building stock the potential for earthquake damage and loss in the area is a problem of great concern. The area under study covers 43 administrative districts of Greater Cairo (including the City of Cairo, El-Giza and Shubra El-Kheima), where field investigations were conducted aiming at identifying representative building types and assessing their seismic vulnerability. On the base of collected information, combining the findings of the field investigations in different districts with available statistical data about the distribution of buildings in the districts, we constructed vulnerability composition models (in terms of the vulnerability classes of the European Macroseismic Scale, EMS-98) for all the considered districts of Greater Cairo. The vulnerability models are applicable for analysis of potential damage and losses in case of occurring damaging earthquakes in the region, including zonation of the seismic risk in the area, generation of probable earthquake scenarios and rapid damage and loss assessment for the purposes of emergency management.

  20. 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).

  1. Detecting earthquake damage in urban area: application to COSMO-SkyMed imagery of L'Aquila earthquake

    NASA Astrophysics Data System (ADS)

    Anniballe, R.; Chini, M.; Pierdicca, N.; Bignami, C.; Stramondo, S.; Noto, F.; Scalia, T.; Martinelli, A.; Mannella, A.

    2015-10-01

    Due to the improved spatial resolution, Earth observation (EO) data, either from Synthetic Aperture Radar (SAR) or optical sensor, provide the opportunity to assess earthquake damage of individual buildings. However, the operational use of EO data for earthquake damage mapping is basically limited to the visual inspection of Very High Resolution (VHR) optical imagery. In this work we investigate the feasibility of a damage assessment product at single building scale from a pair of VHR SAR images acquired before and after a seismic event. We perform the change analysis using the Kullbach-Leibler divergence and the intensity ratio and then we associate detected changes to a building map provided as GIS layer. Finally the expected SAR signature of a collapsed building is considered to identify severely damaged buildings. In order to test the proposed methodology we use Spotlight COSMO-SkyMed SAR imagery of L'Aquila (Italy) collected before and after the earthquake occurred on April 6, 2009. A macroseismic survey on the whole central area of L'Aquila city based on the European Macroseismic Scale 1998 is used to assess the capability of VHR SAR images to map damage.

  2. Satellite thermal infrared anomalies associated with strong earthquakes in the Vrancea area of Romania

    NASA Astrophysics Data System (ADS)

    Zoran, Maria A.; Savastru, Roxana S.; Savastru, Dan M.

    2015-11-01

    Thermal anomalies which are known to be significant precursors of strong earthquakes can be evidenced by spectral thermal infrared (TIR) bands recorded by sensors on board of NOAA-AVHRR and Terra/Aqua- MODIS satellite. In order to locate relevant thermal anomalous variations prior to some strong even moderate earthquakes recorded in Vrancea tectonic active zone in Romania, satellite derived geophysical parameters have been used: land surface temperature (LST), outgoing long-wave radiation (OLR) and mean air temperature (AT). Spatiotemporal variations of LST, OLR, and AT before and after three strong earthquakes in Vrancea area (Mw = 7.4, 4 March 1977; Mw = 7.1, 30 August 1986; Mw = 6.9, 30 May 1990) and a moderate earthquake (Mw = 5.9, 27 October 2004) have been analyzed. Anomalous spatio-temporal patterns of these parameters developed a few days up to few weeks before the earthquakes disappeared after the main shocks. Significant increases in land surface temperature, outgoing long-wave radiation, and mean air temperature can be assigned to energy exchange mechanism during earthquake preparatory events. Such preseismic anomalies can be considered to be associated with the thermodynamic, degassing and ionization geochemical processes which seem to be activated due to the increased stress in the ground, and microfracturing of the rocks especially along area's active faults.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. ABL and BAM Friction Analysis Comparison

    DOE PAGESBeta

    Warner, Kirstin F.; Sandstrom, Mary M.; Brown, Geoffrey W.; Remmers, Daniel L.; Phillips, Jason J.; Shelley, Timothy J.; Reyes, Jose A.; Hsu, Peter C.; Reynolds, John G.

    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.

  9. Earthquake.

    PubMed

    Cowen, A R; Denney, J P

    1994-04-01

    On January 25, 1 week after the most devastating earthquake in Los Angeles history, the Southern California Hospital Council released the following status report: 928 patients evacuated from damaged hospitals. 805 beds available (136 critical, 669 noncritical). 7,757 patients treated/released from EDs. 1,496 patients treated/admitted to hospitals. 61 dead. 9,309 casualties. Where do we go from here? We are still waiting for the "big one." We'll do our best to be ready when Mother Nature shakes, rattles and rolls. The efforts of Los Angeles City Fire Chief Donald O. Manning cannot be overstated. He maintained department command of this major disaster and is directly responsible for implementing the fire department's Disaster Preparedness Division in 1987. Through the chief's leadership and ability to forecast consequences, the city of Los Angeles was better prepared than ever to cope with this horrendous earthquake. We also pay tribute to the men and women who are out there each day, where "the rubber meets the road." PMID:10133439

  10. 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

  11. 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.

  12. A physically based expression for the total volume and area of earthquake induced landsliding.

    NASA Astrophysics Data System (ADS)

    Hovius, N.; Marc, O.; Meunier, P.; Gorum, T.; Uchida, T.

    2015-12-01

    Earthquake impart a catastrophic forcing on hillslopes, that often lead to widespread landsliding and can contribute significantly to sedimentary and organic matter fluxes. We present a new expression for the total area and volume of populations of earthquake-induced landslides.This model builds on a set of scaling relationships between key parameters, such as landslide density, ground acceleration, fault size, earthquake source depth and seismic moment, derived from geomorphological and seismological observations. To assess the model we have assembled and normalized a catalogue of landslide inventories for 40 earthquakes. We have found that low landscape steepness systematically leads to over-prediction of the total area and volume of landslides.When this effect is accounted for, the model is able to predict within a factor of 2 the landslide areas and associated volumes for about two thirds of the cases in our databases. This is a significant improvement on a previously published empirical expression based only on earthquake moment.The prediction of total area is also sensitive to the landscape steepness, but less than the total volume.It seems also affected by the controls on the landslide frequency distribution that may include ground strength, soil continuity and extent or antecedent moisture. Some outliers in terms of observed landslide intensity are likely to be associated with exceptionally rock strength in the epicentral area, while others may be related to seismic source complexities ignored by the model.However, most cases in our catalogue seem to be relatively unaffected by these two effects despite the variety of lithologies and tectonic settings they cover.This makes our expression suitable for integration into landscape evolution models, and application to the assessment of secondary hazards and risks associated with earthquakes.

  13. 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

  14. 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!

  15. 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

  16. 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.

  17. 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

  18. 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.

  19. 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

  20. 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.

  1. 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).

  2. 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.

  3. 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.

  4. The seismicity in the L'Aquila area (Italy) with particular regard to 1985 earthquake

    NASA Astrophysics Data System (ADS)

    Bernardi, Fabrizio; Grazia Ciaccio, Maria; Palombo, Barbara

    2010-05-01

    We study moderate-magnitude earthquakes (Ml ≥3.5) occurred in the Aquila region recorded by the Istituto Nazionale di Geofisica e Vulcanologia from 1981 to 2009 (CSI, Castello et al., 2006 - http://www.ingv.it/CSI/ ; and ISIDe, http://iside.rm.ingv.it/iside/standard/index.jsp) as well as local temporary seismic networks We identify three major sequences (1985, 1994, 1996) occurring before the 6.th April 2009 Mw=6.3 earthquake. The 1985 earthquake (Ml=4.2) is the larger earthquake occurred in the investigated region till April 2009. The 1994 (Ml=3.9) and 1996 (Ml=4.1) occurred in the Campotosto area (NE to L'Aquila). We computed the source moment tensor using surface waves (Giardini et al., 1993) for the main shocks of the 1985 (Mw=4.7) and 1996 (Mw=4.4) sequences. The solutions show normal fault ruptures. We do not find a reliable solution for the major 1994 sequence earthquake. This suggests, that the magnitude of this event is probably below Mw≈4.2, which is the minimum magnitude threshold for this method.

  5. 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

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

    NASA Astrophysics Data System (ADS)

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

    2015-09-01

    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.

  7. 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

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

    PubMed

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

    2015-01-01

    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. 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

  10. On communicating earthquake risk in low-activity areas

    NASA Astrophysics Data System (ADS)

    Gaspar-Escribano, J. M.; García Rodríguez, M. J.; Rivas-Medina, A.; Benito, B.; Wachowicz, M.; Bernabé, M. A.; Iturrioz, T.

    2009-04-01

    The assessment of natural risks for emergency response and preparedness planning is a transversal discipline that can be studied from many perspectives, including social, political and earth sciences. Accordingly, people with different profiles and backgrounds working on the topic should use of a common language in order to avoid misunderstandings, improve information dissemination, and at the end, facilitate preparedness and response measurements in the right direction. Some ideas aimed at identifying communication barriers between all parties and suppressing them are presented, using the example of regional seismic risk studies of low-hazard areas, where the rare occurrence of destructive events complicates the situation. First, factors related to the actual awareness, the degree of understanding and the interest for getting the information about a given a natural risk, are analyzed taking into account that they differ from user to user (civil protection official, scientist, general public). Subsequently, choices of parameters used to typify seismic risk and ways of representing them graphically are proposed. Finally, whether the incidence of the lack of a common language increases risk vulnerability is discussed.

  11. The Bam machine: A molecular cooper

    PubMed Central

    Ricci, Dante P.; Silhavy, Thomas J.

    2011-01-01

    The bacterial outer membrane (OM) is an exceptional biological structure with a unique composition that contributes significantly to the resiliency of Gram-negative bacteria. Since all OM components are synthesized in the cytosol, the cell must efficiently transport OM-specific lipids and proteins across the cell envelope and stably integrate them into a growing membrane. In this review, we discuss the challenges associated with these processes and detail the elegant solutions that cells have evolved to address the topological problem of OM biogenesis. Special attention will be paid to the Bam machine, a highly conserved multiprotein complex that facilitates OM β-barrel folding. PMID:21893027

  12. 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

  13. 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.

  14. A robust satellite technique for monitoring seismically active areas: The case of Bhuj Gujarat earthquake

    NASA Astrophysics Data System (ADS)

    Genzano, N.; Aliano, C.; Filizzola, C.; Pergola, N.; Tramutoli, V.

    2007-02-01

    A robust satellite data analysis technique (RAT) has been recently proposed as a suitable tool for satellite TIR surveys in seismically active regions and already successfully tested in different cases of earthquakes (both high and medium-low magnitudes). In this paper, the efficiency and the potentialities of the RAT technique have been tested even when it is applied to a wide area with extremely variable topography, land coverage and climatic characteristics (the whole Indian subcontinent). Bhuj-Gujarat's earthquake (occurred on 26th January 2001, MS ˜ 7.9) has been considered as a test case in the validation phase, while a relatively unperturbed period (no earthquakes with MS ≥ 5, in the same region and in the same period) has been analyzed for confutation purposes. To this aim, 6 years of Meteosat-5 TIR observations have been processed for the characterization of the TIR signal behaviour at each specific observation time and location. The anomalous TIR values, detected by RAT, have been evaluated in terms of time-space persistence in order to establish the existence of actually significant anomalous transients. The results indicate that the studied area was affected by significant positive thermal anomalies which were identified, at different intensity levels, not far from the Gujarat coast (since 15th January, but with a clearer evidence on 22nd January) and near the epicentral area (mainly on 21st January). On 25th January (1 day before Gujarat's earthquake) significant TIR anomalies appear on the Northern Indian subcontinent, showing a remarkable coincidence with the principal tectonic lineaments of the region (thrust Himalayan boundary). On the other hand, the results of the confutation analysis indicate that no meaningful TIR anomalies appear in the absence of seismic events with MS ≥ 5.

  15. The evolution of new lipoprotein subunits of the bacterial outer membrane BAM complex

    PubMed Central

    Anwari, Khatira; Webb, Chaille T; Poggio, Sebastian; Perry, Andrew J; Belousoff, Matthew; Celik, Nermin; Ramm, Georg; Lovering, Andrew; Sockett, R Elizabeth; Smit, John; Jacobs-Wagner, Christine; Lithgow, Trevor

    2012-01-01

    The β-barrel assembly machine (BAM) complex is an essential feature of all bacteria with an outer membrane. The core subunit of the BAM complex is BamA and, in Escherichia coli, four lipoprotein subunits: BamB, BamC, BamD and BamE, also function in the BAM complex. Hidden Markov model analysis was used to comprehensively assess the distribution of subunits of the BAM lipoproteins across all subclasses of proteobacteria. A patchwork distribution was detected which is readily reconciled with the evolution of the α-, β-, γ-, δ- and ε-proteobacteria. Our findings lead to a proposal that the ancestral BAM complex was composed of two subunits: BamA and BamD, and that BamB, BamC and BamE evolved later in a distinct sequence of events. Furthermore, in some lineages novel lipoproteins have evolved instead of the lipoproteins found in E. coli. As an example of this concept, we show that no known species of α-proteobacteria has a homologue of BamC. However, purification of the BAM complex from the model α-proteobacterium Caulobacter crescentus identified a novel subunit we refer to as BamF, which has a conserved sequence motif related to sequences found in BamC. BamF and BamD can be eluted from the BAM complex under similar conditions, mirroring the BamC:D module seen in the BAM complex of γ-proteobacteria such as E. coli. PMID:22524202

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. Did stress field change after the 2011 Tohoku-Oki earthquake in the inland areas of Tohoku?

    NASA Astrophysics Data System (ADS)

    Yoshida, K.; Hasegawa, A.; Okada, T.; Nakajima, J.; Iinuma, T.; Ito, Y.; Asano, Y.

    2012-12-01

    We investigated the stress field in the inland area of Tohoku to clarify whether the 2011 Tohoku-oki earthquake changed the stress field or not based on the new arrival time and initial-motion polarity data that were observed at seismic stations in Akita Prefecture and near Iwaki City, where the change in the orientation of the principal stress axis has already been reported by Yoshida et al. [2012, GRL]. We first relocated hypocenters by the double-difference location method. Focal mechanisms are estimated using initial-motion polarity data with the relocated hypocenters. Then, we estimated stress fields before and after the Tohoku-oki earthquake by applying the stress tensor inversion method to the well-estimated focal mechanism solutions. The total numbers of focal mechanisms analyzed for the pre-Tohoku-oki earthquake period are 140 and 67 in Akita Prefecture and near Iwaki City, respectively. The total numbers for the post-Tohoku-oki earthquake period are 260 and 580, respectively. These focal mechanisms were determined not only in this study but also in other studies. Orientations of the principal stress axes estimated after the Tohoku-oki earthquake differ significantly from those before the earthquake in Akita Prefecture. The σ1 axis was horizontally oriented in E-W direction and the σ3 axis was vertical before the Tohoku-oki Earthquake, while the σ1 and σ3 axes are oriented in NE-SW and NW-SE directions, respectively, after the earthquake. The σ1 axis estimated before the earthquake was parallel to the plate convergence direction, whereas the σ1 and σ3 axes after the earthquake are oriented in the directions of the static stress change due to the Tohoku-oki earthquake. Since hypocenter distributions before and after the Tohoku-oki earthquake do not show substantial differences, the change in the orientations of the principal stress axes should be caused by the M9 mainshock. On the other hand, a depth dependency of the principal stress directions is

  1. 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.

  2. 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.

  3. Symptoms of posttraumatic stress disorder among health care workers in earthquake-affected areas in southwest China.

    PubMed

    Wang, Li; Zhang, Jianxin; Zhou, Mingjie; Shi, Zhanbiao; Liu, Ping

    2010-04-01

    The symptoms of posttraumatic stress disorder and associated risk factors were investigated among health care workers in earthquake-affected areas in southwest China. 343 health care workers completed the Chinese version of the Impact of Event Scale-Revised 3 mo. after the Wenchuan Earthquake. The prevalence of probable PTSD was 19%. The significant risk factors identified for PTSD severity included being female, being bereaved, being injured, and higher intensity of initial fear. These findings suggest that PTSD is a common mental health problem among health care workers in earthquake-affected areas. The present information can be useful in directing, strengthening, and evaluating disaster-related mental health needs and interventions after an earthquake. PMID:20524558

  4. Gigantic lateral spreading of mountains in the epicentral area of the expected Tokai earthquake, central Japan

    NASA Astrophysics Data System (ADS)

    Chigira, Masahiro; Nakamura, Takeshi

    2010-05-01

    Lateral spreading of mountains is not only a degradation process itself but also it could become the background of a catastrophic landslide that occurs at its spreading rims. We found gigantic lateral spreading behind the Yui landsllide area, which is located along the Pacific Sea coast in the epicentral area of the expected Tokai earthquake, central Japan. The Yui landslide area is located on a socially very important place, where are major lifelines connecting east and west Japan: Tokaido railway, Tokaido Shinkansen, and Tomei highway. The Yui landslide area comprises many landslide units and has been causing many catastrophs. The lateral spreading is characterized by NS-trending multiple ridges and linear depressions as long as 1 to 2 km and up to 60 m deep. These features are observable on the aerial photographs and are clearly identified by using airborne laser scanner. Mountains subjected to the lateral spreading is 3 km wide in EW and 6 km long in NS and are 250 to 500 m high above sea level. These morphological features suggest that the NS trending ridges spread laterally to EW and their central parts settled down like the way by which horsts and grabens are made. The ridges are underlain by Miocene beds consisting of the alternating beds of mudstone and sandstone in the lower part and of sandstone and conglomerate in the upper part. The spreading ridge occupies the axial part of a NS-trending syncline, which has a half wave length longer than 2 km and comprises minor folds with a wavelength on the order of hundred meters. This structure, synclinorium, suggests that there could be decollements along the enveloping surface of the minor folds and that the lateral spreading could have a low-angle slip surface along the enveloping surface of the minor folds. There are many landslides along the side slopes of the laterally spread ridges and they have been moving many times by rainstorms and also by earthquakes. The movements are recorded since 1781, but the

  5. 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.

  6. 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

  7. Comparative analysis for detecting areas with building damage from several destructive earthquakes using satellite synthetic aperture radar images

    NASA Astrophysics Data System (ADS)

    Matsuoka, Masashi; Yamazaki, Fumio

    2010-11-01

    Earthquakes that have caused large-scale damage in developed areas, such as the 1994 Northridge and 1995 Kobe events, remind us of the importance of making quick damage assessments in order to facilitate the resumption of normal activities and restoration planning. Synthetic aperture radar (SAR) can be used to record physical aspects of the Earth's surface under any weather conditions, making it a powerful tool in the development of an applicable method for assessing damage following natural disasters. Detailed building damage data recorded on the ground following the 1995 Kobe earthquake may provide an invaluable opportunity to investigate the relationship between the backscattering properties and the degree of damage. This paper aims to investigate the differences between the backscattering coefficients and the correlations derived from pre- and post-earthquake SAR intensity images to smoothly detect areas with building damage. This method was then applied to SAR images recorded over the areas affected by the 1999 Kocaeli earthquake in Turkey, the 2001 Gujarat earthquake in India, and the 2003 Boumerdes earthquake in Algeria. The accuracy of the proposed method was examined and confirmed by comparing the results of the SAR analyses with the field survey data.

  8. The study of recent seismicity in the aftershock area of Neftegorsk earthquake using waveform cross correlation

    NASA Astrophysics Data System (ADS)

    Kitov, Ivan; Turuntaev, Sergey; Konovalov, Alexei; Stepnov, Andrey

    2016-04-01

    Unusually long duration of seismic activity (more than 20 years) was observed in the aftershock area of the 1995 Neftegorsk, Sakhalin, Russia catastrophic earthquake (Ms=7.6). To study the phenomena, we have processed seismic data from 130 events occurred within that area as measured between 2006 and 2015. In order to improve the accuracy of relative location and magnitude estimation of these events we have applied new techniques based on waveform cross correlation. We use 7 three-component (3-C) seismic stations which detected most of these events. Three-component waveform templates were prepared for these stations from those events which had signals with SNR>5 at vertical channels. The events with 3 and more templates are used as master-events for waveform cross correlation. Overall, the re-estimated location and magnitudes demonstrate higher precisions and are used for the statistical analysis and numerical modelling of seismo-tectonic regime within the studied zone.

  9. Deep seismic transect across the Tonankai earthquake area obtained from the onshore- offshore wide-angle seismic study

    NASA Astrophysics Data System (ADS)

    Nakanishi, A.; Obana, K.; Kodaira, S.; Miura, S.; Fujie, G.; Ito, A.; Sato, T.; Park, J.; Kaneda, Y.; Ito, K.; Iwasaki, T.

    2008-12-01

    In the Nankai Trough subduction seismogenic zone, M8-class great earthquake area can be divided into three segments; they are source regions of the Nankai, Tonankai and presumed Tokai earthquakes. The Nankai and Tonankai earthquakes had often occurred simultaneously, and caused a great event. Hypocenters of these great earthquakes were usually located off the cape Shiono, Kii Peninsula, and the rupture propagated westwards and eastwards, respectively. To obtain the deep structure of the down-dip limit of around the Nankai Trough seismogenic zone, the segment boundary and first break area off the Kii Peninsula, the onshore-offshore wide-angle seismic studies was conducted in the western and eastern part of the Kii Peninsula and their offshore area in 2004 and 2006, respectively. The result of the seismic study in 2004 is mainly shown here. Structural images along the onshore and offshore profiles have already been separately obtained. In this study, an onshore-offshore integrated image of the western part of the Kii Peninsula, ~400km in a total length, is obtained from first arrival tomography and traveltime mapping of reflection phases by combining dataset of 13 land explosions, 2269 land stations, 36 OBSs and 1806 offshore airgun shots. The subduction angle of the Philippine Sea plate (PSP) gradually increases landward up to ~20-25 degree. Beneath the onshore part, the subducting PSP is estimated at ~5km shallower than that previously derived from seismicity. Low frequency earthquakes (identified and picked by Japan Meteorological Agency) are relocated around the plate interface of the subducting PSP by using the deep seismic transect obtained in this study. The offshore research is part of 'Structure research on plate dynamics of the presumed rupture zone of the Tonankai-Nankai Earthquakes' funded by Ministry of Education, Culture, Sports, Science and Technology (MEXT). The onshore research carried by the Kyoto University is part of 'Special Project for

  10. 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.

  11. Real-Time GPS Monitoring for Earthquake Rapid Assessment in the San Francisco Bay Area

    NASA Astrophysics Data System (ADS)

    Guillemot, C.; Langbein, J. O.; Murray, J. R.

    2012-12-01

    The U.S. Geological Survey Earthquake Science Center has deployed a network of eight real-time Global Positioning System (GPS) stations in the San Francisco Bay area and is implementing software applications to continuously evaluate the status of the deformation within the network. Real-time monitoring of the station positions is expected to provide valuable information for rapidly estimating source parameters should a large earthquake occur in the San Francisco Bay area. Because earthquake response applications require robust data access, as a first step we have developed a suite of web-based applications which are now routinely used to monitor the network's operational status and data streaming performance. The web tools provide continuously updated displays of important telemetry parameters such as data latency and receive rates, as well as source voltage and temperature information within each instrument enclosure. Automated software on the backend uses the streaming performance data to mitigate the impact of outages, radio interference and bandwidth congestion on deformation monitoring operations. A separate set of software applications manages the recovery of lost data due to faulty communication links. Displacement estimates are computed in real-time for various combinations of USGS, Plate Boundary Observatory (PBO) and Bay Area Regional Deformation (BARD) network stations. We are currently comparing results from two software packages (one commercial and one open-source) used to process 1-Hz data on the fly and produce estimates of differential positions. The continuous monitoring of telemetry makes it possible to tune the network to minimize the impact of transient interruptions of the data flow, from one or more stations, on the estimated positions. Ongoing work is focused on using data streaming performance history to optimize the quality of the position, reduce drift and outliers by switching to the best set of stations within the network, and

  12. Strong near-trench locking and its temporal change in the rupture area of the 2011 Tohoku-oki earthquake estimated from cumulative slip and slip vectors of interplate earthquakes

    NASA Astrophysics Data System (ADS)

    Uchida, N.; Hasegawa, A.; Matsuzawa, T.

    2012-12-01

    The 2011 Mw 9.0 Tohoku-oki earthquake is characterized by large near-trench slip that excited disastrous Tsunami. It is of great importance to estimate the coupling state near the trench to understand temporal evolution of interplate coupling near the earthquake source as well as for the assessment of tsunami risk along the trench. However, the coupling states at the near trench areas far from the land are usually not well constrained. The cumulative offset of small repeating earthquakes reflects the in situ slip history on a fault and the slip vectors of interplate earthquakes reflect heterogeneous distribution of coupling on the plate boundary. In this study, we use the repeating earthquake and slip vector data to estimate spatio-temporal change in slip and coupling in and around the source area of the Tohoku-oki earthquake near the Japan trench. The repeating earthquake data for 27 years before the Tohoku-oki earthquake show absence of repeating earthquake groups in the large-coseismic-slip area and low and variable slip rates in the moderate-coseismic-slip region surrounding the large-slip. The absence of repeaters itself could have been explained by both models with very weak coupling and very strong coupling. However, the rotation of slip vectors of interplate earthquakes at the deeper extension of the large-coseismic-slip suggest the plate boundary was locked in the near-trench area before the earthquake, which is consistent with the estimation by Hasegawa et al. (2012) based on stress tensor analysis of the upper plate events near the trench axis. The repeating earthquake data, on the other hand, show small but distinct increases in the slip rate in the 3-5 years before the earthquake near the area of large coseismic slip suggesting preseismic unfastening of the locked area in the last stage of the earthquake cycle. After the Tohoku-oki earthquake, repeating earthquakes activity in the main rupture area disappeared almost completely and slip vectors of

  13. 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.

  14. 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.

  15. Analysis of landslide hazard area in Ludian earthquake based on Random Forests

    NASA Astrophysics Data System (ADS)

    Xie, J.-C.; Liu, R.; Li, H.-W.; Lai, Z.-L.

    2015-04-01

    With the development of machine learning theory, more and more algorithms are evaluated for seismic landslides. After the Ludian earthquake, the research team combine with the special geological structure in Ludian area and the seismic filed exploration results, selecting SLOPE(PODU); River distance(HL); Fault distance(DC); Seismic Intensity(LD) and Digital Elevation Model(DEM), the normalized difference vegetation index(NDVI) which based on remote sensing images as evaluation factors. But the relationships among these factors are fuzzy, there also exists heavy noise and high-dimensional, we introduce the random forest algorithm to tolerate these difficulties and get the evaluation result of Ludian landslide areas, in order to verify the accuracy of the result, using the ROC graphs for the result evaluation standard, AUC covers an area of 0.918, meanwhile, the random forest's generalization error rate decreases with the increase of the classification tree to the ideal 0.08 by using Out Of Bag(OOB) Estimation. Studying the final landslides inversion results, paper comes to a statistical conclusion that near 80% of the whole landslides and dilapidations are in areas with high susceptibility and moderate susceptibility, showing the forecast results are reasonable and adopted.

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

    PubMed

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

    2015-01-01

    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

  17. 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

  18. 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

  19. 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

  20. Substance Misuse Patterns and Blood Types of Self-Introduced Addicts to Substance Rehabilitation Centers of Bam City

    PubMed Central

    Aflatoonian, Mohammadreza; Ziaaddini, Hassan; Kheradmand, Ali; Shamsi Meimandi, Manzumeh; Divsalar, Kouros; Mahmoodi, Majid

    2010-01-01

    Background With regard to the perceptible population, cultural, social andenvironmental changes in the aftermath of the earthquake in Bam City,this study was conducted to pinpoint substance misuse patterns and tofigure out the probable relationship between substance misuse andblood types of the addicts referred to Substance rehabilitation Clinicsfrom 2006 to 2007 in Bam City. Methods In this case-control study, the sample size includes volunteering andself-introduced addicts and also a random selection of 360 healthyclients referred to the Blood Transfusion Organization as the controlgroup. Both groups' data were analyzed using descriptive statistics andChi square and the odds ratio was estimated too. Findings Three-hundred ninety nine individuals from nearly 3000 clients referred tothe rehabilitation clinic from 2005 to 2008 participated with completeconsent in the study. The highest frequency belonged to opium addicts(85.6%) and the most prevalent addiction type pertains to opiumconsumption via smoke inhalation (58.2%). The probability rate of ABnegative blood type compared to other blood types among the addicts was6.07 fold the control group. Conclusion There has been an increasing rate of addiction in bam after earthquakeand The substance consumption pattern has moved towards moredangerous methods. The high prevalence of AB blood type bringsabout a lot of presuppositions for geneticists, epidemiologists,hematologists and all majors in basic sciences. PMID:24494107

  1. The Influence of Increasing Rain and Earthquake Activities on Landslide Slope Stability in Forest Areas

    NASA Astrophysics Data System (ADS)

    Kubota, T.; Aditian, A.

    2014-12-01

    Deriving the analysis of rainfall data in various mountainous locations, increase in rainfall that is deemed to be induced by the global climate change is obvious in Kyushu district, western Japan. On this point of view, its long term impact on the forest slope stability is analyzed with field investigation and numerical simulation such as finite element method (FEM). On the other hand, the influence of earthquake such as cracks on the slope due to seismic vibration was also analyzed with FEM. In this case, the slope stability analysis to obtain the factor of safety "Fs" is conducted. Here, in case of the Fs > 1.0, the slope is stable. In addition, the slope stabilizing effect of the forest mainly due to the roots strength is evaluated on some unstable slopes. Simultaneously, a holistic estimation over landslide groups is conducted by comparing "Fs" on forest slopes with non- forest slopes. Therefore, the following conclusions are obtained: 1) Comparing the Fs without increased rainfall from the previous decade and the one with actual rainfall, the former case is 1.04 ~1.06 times more stable than the latter. 2) On the other hand, the forest slopes are estimated to be up to approximately 1.5 to 2.5 times more stable than the slope without forest. Therefore, the slope stabilizing effect by the forest is much higher than the increasing rainfall influence i.e. the climate change effect. These results imply that an appropriate forest existence is important under the climate change condition to prevent forest slope degradation. 3) Comparing with the destabilization of the slope by seismic activities (vibration) due to the reduction of soil strength and "cracks = slope deformation" (8~9 % to 30% reduction in Fs even after an earthquake of 490gal), the influence of the long term rainfall increase on slopes (such as 1% decrease in Fs) is relatively small in the study area.

  2. Onsite infectious agents and toxins monitoring in 12 May Sichuan earthquake affected areas.

    PubMed

    Yao, Maosheng; Zhu, Tong; Li, Kejun; Dong, Shuofei; Wu, Yan; Qiu, Xinghua; Jiang, Bo; Chen, Liansheng; Zhen, Shiqi

    2009-11-01

    At 14:28 on 12 May 2008, Sichuan Province of China suffered a devastating earthquake measuring 8.0 on the Richter scale with more than 80 000 human lives lost and millions displaced. With inadequate shelter, poor access to health services, and disrupted ecology, the survivors were at enormous risk of infectious disease outbreaks. This work, believed to be unprecedented, was carried out to contain a possible outbreak through onsite monitoring of airborne biological agents in the high-risk areas. In such a mission, a mobile laboratory was developed using a customized vehicle along with state-of-art bioaerosol and molecular equipment and tools, and deployed to Sichuan 11 days after the earthquake. Using a high volume bioaerosol sampler (RCS High Flow) and Button Inhalable Aerosol Sampler equipped with gelatin filters, a total of 55 air samples, among which are 28 filter samples, were collected from rubble, medical centers, and camps of refugees, troops and rescue workers between 23 May and 9 June, 2008. After pre-treatment of the air samples, quantitative polymerase chain reaction (qPCR), gel electrophoresis, limulus amebocyte lysate (LAL) assay and enzyme-linked immunosorbent assay (ELISA) were applied to detect infectious agents and to quantify environmental toxins and allergens. The results revealed that, while high levels of endotoxin (180 approximately 975 ng/m3) and (1,3)-beta-d-glucans (11 approximately 100 ng/m3) were observed, infectious agents such as Bacillus anthracis, Bordetella pertussis, Neisseria meningitidis, Mycobacterium tuberculosis, influenza A virus, bird flu virus (H5N1), enteric viruses, and Meningococcal meningitis were found below their detection limits. The total bacterial concentrations were found to range from 250 to 2.5 x 10(5) DNA copies/L. Aspergillus fumigatus (Asp f 1) and dust mite allergens (Der p 1 and Der f 1) were also found below their detection limits. PMID:19890556

  3. Engineering and socioeconomic impacts of earthquakes: An analysis of electricity lifeline disruptions in the New Madrid area

    SciTech Connect

    Shinozuka, M.; Rose, A.; Eguchi, R.T.

    1998-12-31

    This monograph examines the potential effects of a repeat of the New Madrid earthquake to the metropolitan Memphis area. The authors developed a case study of the impact of such an event to the electric power system, and analyzed how this disruption would affect society. In nine chapters and 189 pages, the book traces the impacts of catastrophic earthquakes through a curtailment of utility lifeline services to its host regional economy and beyond. the monographs` chapters include: Modeling the Memphis economy; seismic performance of electric power systems; spatial analysis techniques for linking physical damage to economic functions; earthquake vulnerability and emergency preparedness among businesses; direct economic impacts; regional economic impacts; socioeconomic and interregional impacts; lifeline risk reduction; and public policy formulation and implementation.

  4. Fault activity in the epicentral area of the 1580 Dover Strait (Pas-de-Calais) earthquake (northwestern Europe)

    NASA Astrophysics Data System (ADS)

    García-Moreno, D.; Verbeeck, K.; Camelbeeck, T.; De Batist, M.; Oggioni, F.; Zurita Hurtado, O.; Versteeg, W.; Jomard, H.; Collier, J. S.; Gupta, S.; Trentesaux, A.; Vanneste, K.

    2015-05-01

    On 1580 April 6 one of the most destructive earthquakes of northwestern Europe took place in the Dover Strait (Pas de Calais). The epicentre of this seismic event, the magnitude of which is estimated to have been about 6.0, has been located in the offshore continuation of the North Artois shear zone, a major Variscan tectonic structure that traverses the Dover Strait. The location of this and two other moderate magnitude historical earthquakes in the Dover Strait suggests that the North Artois shear zone or some of its fault segments may be presently active. In order to investigate the possible fault activity in the epicentral area of the AD 1580 earthquake, we have gathered a large set of bathymetric and seismic-reflection data covering the almost-entire width of the Dover Strait. These data have revealed a broad structural zone comprising several subparallel WNW-ESE trending faults and folds, some of them significantly offsetting the Cretaceous bedrock. The geophysical investigation has also shown some indication of possible Quaternary fault activity. However, this activity only appears to have affected the lowermost layers of the sediment infilling Middle Pleistocene palaeobasins. This indicates that, if these faults have been active since Middle Pleistocene, their slip rates must have been very low. Hence, the AD 1580 earthquake appears to be a very infrequent event in the Dover Strait, representing a good example of the moderate magnitude earthquakes that sometimes occur in plate interiors on faults with unknown historical seismicity.

  5. Episodic sediment disturbance on the mega-splay fault at Tonankai earthquake area, Nankai trough, Japan

    NASA Astrophysics Data System (ADS)

    Sakaguchi, A.; Kimura, G.; Strasser, M.; Murayama, M.; Curewitz, D.; Fergusson, C.; Milliken, K.; Nicholson, U.; Screaton, L.; Iodp, E.

    2008-12-01

    The cores at hanging wall (C0004) and footwall (C0008) of mega splay fault are obtained in the Stage 1A of the Nankai Trough Seismogenic Zone Experiment during IODP Expeditions 316 (Kimura et al., 2008). The mega splay fault develops in the area where the coseismic slip (Ichinose et al., 2003) and tsunami source (Baba and Cumming, 2005) are reconstructed for the 1944 Tonankai earthquake. The X-ray computed tomography (X-CT) makes 3D image depending on X-ray attenuation coefficient that is a function of chemical composition and density of the target material. Whereas optical observation my not resolve small differences, emphasizing by the CT-scanner enables to find small difference in sediment composition and structures. The CT image has been taken for all cores during preliminary core processing. Episodic event deposits are found at uppermost core of hanging wall (C0004). The core sample is composed of un-consolidated silt clay and looks homogeneous in optical observation. The X-CT can show complex structure indicating some horizontal layers, scattered mud clasts and mud-filling burrows. The X-CT 3D observation can distinguish a mud clasts and mud-filling burrow. Because tubular burrow is formed by mud- eating worm or mollusks, the cross section area is constant along long axis. On the other hand, the cross section area changes along long axis in distorted shape mud clast. The mud clasts are intercalated between horizontal layers, indicating episodic event. At least five events are observed. The boundary of some mud- clasts are dim, may have suffered diffusion, and this implies very short transportation or in-situ formation. Thus, repeated mud clast deposit was not found at footwall of the fault (C0008). Strong seismic ground motion can shake surface soft sediment, and sediment suspensions were often observed after large earthquakes (Thunell et al., 1999; Itou et al., 2000; Seeber et al., 2007). The difference of occurrence of sediment disturbance between C0004 and

  6. Experimental Methods for Studying the BAM Complex in Neisseria meningitidis.

    PubMed

    Bos, Martine P; Boxtel, Ria Tommassen-van; Tommassen, Jan

    2015-01-01

    Neisseria meningitidis is a human pathogen. It is intensively studied for host-pathogen interactions and vaccine development. However, its favorable growth properties, genetic accessibility, and small genome size also make it an excellent model organism for studying fundamental biological processes, such as outer membrane biogenesis. Indeed, the first component of the assembly machinery for outer-membrane proteins, the BAM complex, was identified in N. meningitidis. Here, we describe protocols to inactivate chromosomal genes and to express genes from a well-controlled promoter on a plasmid in N. meningitidis. Together, these protocols can be used, for example, to deplete cells from essential components of the BAM complex. We also describe a simple, gel-based assay to assess the proper functioning of the BAM complex in vivo. PMID:26427674

  7. [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. PMID:26031097

  8. Ambient noise as the new source for urban engineering seismology and earthquake engineering: a case study from Beijing metropolitan area

    NASA Astrophysics Data System (ADS)

    Liu, Lanbo; Chen, Qi-fu; Wang, Weijun; Rohrbach, Eric

    2014-02-01

    In highly populated urban centers, traditional seismic survey sources can no longer be properly applied due to restrictions in modern civilian life styles. The ambient vibration noise, including both microseisms and microtremor, though are generally weak but available anywhere and anytime, can be an ideal supplementary source for conducting seismic surveys for engineering seismology and earthquake engineering. This is fundamentally supported by advanced digital signal processing techniques for effectively extracting the useful information out from the noise. Thus, it can be essentially regarded as a passive seismic method. In this paper we first make a brief survey of the ambient vibration noise, followed by a quick summary of digital signal processing for passive seismic surveys. Then the applications of ambient noise in engineering seismology and earthquake engineering for urban settings are illustrated with examples from Beijing metropolitan area. For engineering seismology the example is the assessment of site effect in a large area via microtremor observations. For earthquake engineering the example is for structural characterization of a typical reinforced concrete high-rise building using background vibration noise. By showing these examples we argue that the ambient noise can be treated as a new source that is economical, practical, and particularly valuable to engineering seismology and earthquake engineering projects for seismic hazard mitigation in urban areas.

  9. 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.

  10. Tomography of the Source Area of the 1995 Kobe Earthquake: Evidence for Fluids at the Hypocenter?

    PubMed

    Zhao; Kanamori; Negishi; Wiens

    1996-12-13

    Seismic tomography revealed a low seismic velocity (-5%) and high Poisson's ratio (+6%) anomaly covering about 300 square kilometers at the hypocenter of the 17 January 1995, magnitude 7.2, Kobe earthquake in Japan. This anomaly may be due to an overpressurized, fluid-filled, fractured rock matrix that contributed to the initiation of the Kobe earthquake. PMID:8943198

  11. Self-potential Anomalies Around the Earthquake Swarm Area in the Southeastern Flank of Ontake Volcano, Central Japan

    NASA Astrophysics Data System (ADS)

    Yoshimura, R.; Yamazaki, K.; Okada, Y.; Oshiman, N.

    2006-12-01

    Ontake Volcano is located in the southern end of the Norikura Volcanic Chain, central Japan, close to the junction of the Izu Bonin and Mariana and Southwestern Japan volcanic arcs. It is almost conical and made of andesite. Earthquake swarm activity has been continuously observed around the southeastern flank of Mt. Ontake since 1976. A phreatic explosion occurred in 1979 at a fissure on the southwestern slope of the Kengamine, the main peak of Mt. Ontake. And a large earthquake with the depth about 2 km and a magnitude of 6.8 occurred in 1984 in the southeastern flank of the volcano. Recently, Kimata et al. (2004) revealed uplift ground deformation above the earthquake swarm area by using repeated leveling. Furthermore, Magnetotelluric soundings estimated a low resistivity region with the depth about 2km beneath the uplift area [Kasaya et al., 2002]. In order to investigate a relationship between tectonic movements and subsurface low resistivity zone, we carried out self-potential(SP) measurements from 2003 and 2006 around the focal region of the 1984 Earthquake and the summit area of Mt. Ontake. The equipment for measuring surface self-potentials consists of a pair of non-polarizing copper-copper sulfate/silver-silver chloride electrodes, an insulated connecting conductor cable, and a high input impedance digital multimeter. In this survey, profiles totaling to about 90km length (982 sites) were made, with an average measurement interval of 100m. Two distinctive SP features are found around the active earthquake cluster and inside of the aseismic area of southeastern flank of Mt. Ontake. In this presentation, we will report a detail of SP measurements and results.

  12. The Entry Mechanism of Membrane-Containing Phage Bam35 Infecting Bacillus thuringiensis

    PubMed Central

    Gaidelytė, Aušra; Cvirkaitė-Krupovic, Virginija; Daugelavicius, Rimantas; Bamford, Jaana K. H.; Bamford, Dennis H.

    2006-01-01

    The temperate double-stranded DNA bacteriophage Bam35 infects gram-positive Bacillus thuringiensis cells. Bam35 has an icosahedral protein coat surrounding the viral membrane that encloses the linear 15-kbp DNA genome. The protein coat of Bam35 uses the same assembly principle as that of PRD1, a lytic bacteriophage infecting gram-negative hosts. In this study, we dissected the process of Bam35 entry into discrete steps: receptor binding, peptidoglycan penetration, and interaction with the plasma membrane (PM). Bam35 very rapidly adsorbs to the cell surface, and N-acetyl-muramic acid is essential for Bam35 binding. Zymogram analysis demonstrated that peptidoglycan-hydrolyzing activity is associated with the Bam35 virion. We showed that the penetration of Bam35 through the PM is a divalent-cation-dependent process, whereas adsorption and peptidoglycan digestion are not. PMID:16885461

  13. A Modular BAM Complex in the Outer Membrane of the α-Proteobacterium Caulobacter crescentus

    PubMed Central

    Anwari, Khatira; Poggio, Sebastian; Perry, Andrew; Gatsos, Xenia; Ramarathinam, Sri Harsha; Williamson, Nicholas A.; Noinaj, Nicholas; Buchanan, Susan; Gabriel, Kipros; Purcell, Anthony W.; Jacobs-Wagner, Christine; Lithgow, Trevor

    2010-01-01

    Mitochondria are organelles derived from an intracellular α-proteobacterium. The biogenesis of mitochondria relies on the assembly of β-barrel proteins into the mitochondrial outer membrane, a process inherited from the bacterial ancestor. Caulobacter crescentus is an α-proteobacterium, and the BAM (β-barrel assembly machinery) complex was purified and characterized from this model organism. Like the mitochondrial sorting and assembly machinery complex, we find the BAM complex to be modular in nature. A ∼150 kDa core BAM complex containing BamA, BamB, BamD, and BamE associates with additional modules in the outer membrane. One of these modules, Pal, is a lipoprotein that provides a means for anchorage to the peptidoglycan layer of the cell wall. We suggest the modular design of the BAM complex facilitates access to substrates from the protein translocase in the inner membrane. PMID:20062535

  14. 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., Jr.

    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

  15. Development of urban planning guidelines for improving emergency response capacities in seismic areas of Iran.

    PubMed

    Hosseini, Kambod Amini; Jafari, Mohammad Kazem; Hosseini, Maziar; Mansouri, Babak; Hosseinioon, Solmaz

    2009-10-01

    This paper presents the results of research carried out to improve emergency response activities in earthquake-prone areas of Iran. The research concentrated on emergency response operations, emergency medical care, emergency transportation, and evacuation-the most important issues after an earthquake with regard to saving the lives of victims. For each topic, some guidelines and criteria are presented for enhancing emergency response activities, based on evaluations of experience of strong earthquakes that have occurred over the past two decades in Iran, notably Manjil (1990), Bam (2003), Firouz Abad-Kojour (2004), Zarand (2005) and Broujerd (2006). These guidelines and criteria are applicable to other national contexts, especially countries with similar seismic and social conditions as Iran. The results of this study should be incorporated into comprehensive plans to ensure sustainable development or reconstruction of cities as well as to augment the efficiency of emergency response after an earthquake. PMID:19500324

  16. 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.

  17. 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.

  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. Coda Attenuation Analysis in the West Bohemia/Vogtland Earthquake Swarm Area

    NASA Astrophysics Data System (ADS)

    Bachura, Martin; Fischer, Tomáš

    2016-02-01

    Seismic coda represents a valuable source of information about the attenuation of the high-frequency waves in the studied region. The quality factor Q derived from coda is an integral parameter of the volume surrounding the hypocenter and seismic station and, according to the applied method, represents the total attenuation or the intrinsic and scattering parts. We analyzed records of 13 selected earthquakes in the magnitude range 1.7-2.9 of the 2011 swarm from West Bohemian/Vogtland area (central Europe), which were recorded at epicentral distances from 7 to 50 km. Two methods were applied: coda method for estimation of the Q c and the Multiple Lapse Time Windows Analysis for separation of the scattering and intrinsic loss by estimation of Q i and Q sc. Careful selection of the analyzed events was necessary due to the frequent contamination of coda decays by the running seismic swarm activity. The resulting coda Q c is relatively high with respect to the geodynamic activity and varies between 100 and 2500 within the analyzed frequency range of 1-18 Hz. The intrinsic loss dominates over scattering attenuation with Q i increasing from 100 and 1850 and Q sc from 300 to 3400 in the same frequency range, which is consistent with the geodynamic activity of the region. We find that the intrinsic attenuation in West-Bohemia/Vogtland is higher that in neighboring Germany, which could be attributed to the heterogeneity of the crust in central Europe.

  20. 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.

  1. 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.

  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. Mega-thrust and Intra-slab Earthquakes beneath Tokyo Metropolitan Area around subduction and collision zones in JAPAN

    NASA Astrophysics Data System (ADS)

    Hirata, N.; Kasahara, K.; Hagiwara, H.; Satow, H.; Shimazaki, K.; Koketsu, K.; Wu, F.; Okaya, D.

    2004-12-01

    In central Japan the Philippine Sea plate (PSP) subducts beneath the Tokyo Metropolitan area, the Kanto region, where it causes mega-thrust earthquakes, such as the 1703 Genroku earthquake (M8.0) and the 1923 Kanto earthquake (M7.9). The vertical proximity of this down going lithospheric plate is of concern because the greater Tokyo urban region has a population of 42 million and is the center of approximately 40 % of the nation's economic activities. A M7+ earthquake in this region at present has high potential to produce devastating loss of life and property with even greater global economic repercussions.The M7+ earthquake is evaluated to occur with a probability of 70 % in 30 years by the Earthquake Research Committee of Japan.We started the Special Project for Earthquake Disaster Mitigation in Tokyo metropolitan areas, a project to improve information needed for seismic hazards analyses of the largest urban centers. Under the project we will deploy a 400-sation dense seismic array in metropolitan Tokyo and Kanto, referred to as the Metropolitan Seismic Observation network (MeSO-net) in next 4 years. The target area of the present project is unique in tectonic setting because two oceanic plates, Philippine Sea plate (PSP) and Pacific plate (PAC), are subducting beneath the Kanto and also a volcanic arc, Izu-Bonin arc, is colliding with Honshu arc. The situation makes the tectonics complicated: there are both zones of smooth subduction and collision of the oceanic plate with the landward plate, either the Eurasian plate or the North American plate. Furthermore, the PSP encounters the PAC at shallow depth in the eastern Kanto region. The newly developing MeSO-net will contribute to understand the generation mechanism associated with the plate subduction and collision. Assessment in Kanto of the seismic hazard requires identification of all significant faults and possible earthquake scenarios and rupture behavior, regional characterizations of the PSP geometry and

  5. Mega-thrust and Intra-slab Earthquakes beneath Tokyo Metropolitan Area around subduction and collision zones in JAPAN

    NASA Astrophysics Data System (ADS)

    Hirata, N.; Kasahara, K.; Hagiwara, H.; Satow, H.; Shimazaki, K.; Koketsu, K.; Wu, F.; Okaya, D.

    2007-12-01

    In central Japan the Philippine Sea plate (PSP) subducts beneath the Tokyo Metropolitan area, the Kanto region, where it causes mega-thrust earthquakes, such as the 1703 Genroku earthquake (M8.0) and the 1923 Kanto earthquake (M7.9). The vertical proximity of this down going lithospheric plate is of concern because the greater Tokyo urban region has a population of 42 million and is the center of approximately 40 % of the nation's economic activities. A M7+ earthquake in this region at present has high potential to produce devastating loss of life and property with even greater global economic repercussions.The M7+ earthquake is evaluated to occur with a probability of 70 % in 30 years by the Earthquake Research Committee of Japan.We started the Special Project for Earthquake Disaster Mitigation in Tokyo metropolitan areas, a project to improve information needed for seismic hazards analyses of the largest urban centers. Under the project we will deploy a 400-sation dense seismic array in metropolitan Tokyo and Kanto, referred to as the Metropolitan Seismic Observation network (MeSO-net) in next 4 years. The target area of the present project is unique in tectonic setting because two oceanic plates, Philippine Sea plate (PSP) and Pacific plate (PAC), are subducting beneath the Kanto and also a volcanic arc, Izu-Bonin arc, is colliding with Honshu arc. The situation makes the tectonics complicated: there are both zones of smooth subduction and collision of the oceanic plate with the landward plate, either the Eurasian plate or the North American plate. Furthermore, the PSP encounters the PAC at shallow depth in the eastern Kanto region. The newly developing MeSO-net will contribute to understand the generation mechanism associated with the plate subduction and collision. Assessment in Kanto of the seismic hazard requires identification of all significant faults and possible earthquake scenarios and rupture behavior, regional characterizations of the PSP geometry and

  6. 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.

  7. 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.

  8. 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

  9. Earthquake occurrence and effects.

    PubMed

    Adams, R D

    1990-01-01

    Although earthquakes are mainly concentrated in zones close to boundaries of tectonic plates of the Earth's lithosphere, infrequent events away from the main seismic regions can cause major disasters. The major cause of damage and injury following earthquakes is elastic vibration, rather than fault displacement. This vibration at a particular site will depend not only on the size and distance of the earthquake but also on the local soil conditions. Earthquake prediction is not yet generally fruitful in avoiding earthquake disasters, but much useful planning to reduce earthquake effects can be done by studying the general earthquake hazard in an area, and taking some simple precautions. PMID:2347628

  10. 3-D velocity heterogeneity in earthquake swarm area of NW Bohemia/Vogtland (German-Czech border region)

    NASA Astrophysics Data System (ADS)

    Mousavi, Sima; Bauer, Klaus; Korn, Michael

    2014-05-01

    3-D Vp and Vp/Vs structure of the geodynamically active NW Bohemia/Vogtland area, located at the border region between Germany and Czech republic, has been determined from local earthquake tomography using 543 earthquakes which have been recorded during 2000 to 2010. This region is known for the occurrence of earthquake swarms that are supposed to be triggered by fluid upwelling in the crust, although fluid behaviour and migration paths in the subsurface of NW Bohemia is still poorly known. The events used in this study were selected based on a minimum 12 P and S phase observations and an azimuthal gap less than 160º. This data set is employed to derive a minimum 1-D velocity model and to relocate the hypocenters. The minimum 1-D velocity model is then used as an initial model in non-linear inversion to derive 3-D P-velocity and Vp/Vs ratio. Using synthetic tests, it can be shown that a high resolution is obtained in the central part of the studied region with the given source and receiver configuration. Two branches of high Vp/Vs ratio anomalies have been detected above the swarm quakes' focal zone. These anomalies support the existence of two main fluid passages toward Bad Brambach and Bublak moffette. Another interesting result is a high Vp/Vs line-like anomaly along Mariánské Lázně fault where most of the swarm quakes occur, which could be due to a fluid saturated area around the cracked zone of the fault plain. Hypocenters in the swarm region are located in a low Vp and Vp/Vs anomaly. The correlation between the detected Vp and Vp/Vs anomalies and the location of earthquake swarm suggests a model in which CO2 as part of magmatic fluids exist in a vast area beneath NW Bohemia and frequently migrate up to the surface.

  11. 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

  12. 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

  13. Sediment source areas of earthquake-triggered megaturbidites in marine or lacustrine confined basins: implications for regional paleoseismicity

    NASA Astrophysics Data System (ADS)

    emmanuel, Chapron; Hervé, Guyard; Flavio, Anselmetti; Giuseppe, Siani

    2016-04-01

    Earthquake triggered megaturbidites documented in different confined Mediterranean confined basins are bearing several similarities with so-called seiche deposits induced by earthquakes in several large and deep Alpine lakes. Both of these mega beds are resulting from coeval subaquatic slope failures and the propagation of violent waves developing erosive currents along shore lines and shallow water depths but also locally within deep waters. They have a similar acoustic signature (i.e. a decimetric to plurimetric transparent acoustic facies ponded in the deepest part of confined basins with a high-amplitude basal reflection) and are characterized by maximal thicknesses ranging between 0.2 and 1.6 % of the basin's water depth. While lacustrine megaturbidites are essentially resulting from the remobilization of fine-grained clastic sediments (either deltaic depot-centers or slopes loaded by sediment plumes during deglaciation) and shallow water coarser particles by waves and bottom currents; little is known about the soft-sediment source areas of megaturbidites in the Mediterranean. Based on our understanding of sedimentary process associated with seiche deposits in lakes and taking into consideration the oceanographic characteristics of the Mediterranean Sea, multiples soft-sediment source areas can be identified and a new conceptual depositional model can be proposed for the development of tsunamigenic earthquake-triggered megaturbidites.

  14. Upper Plate Geology Controls the Rupture Area Segmentation of Subduction Zone Earthquake - A Case Study of the Nankai Trough

    NASA Astrophysics Data System (ADS)

    Kimura, G.; Hashimoto, Y.; Kitamura, Y.; Yamaguchi, A.; Hamahashi, M.; Koge, H.; Morita, S.

    2014-12-01

    What controls the earthquake rupture area of megathrust is one of the most fundamental questions in subduction zones. In the Nankai Trough, Japan, three major controlling factors have been proposed; surface topographic highs of the subducting plate such as seamounts, locally strong rigidity of upper plate, and friction property of the plate boundary megathrust with abnormal pore fluid pressure. For example, the topographic highs may control the location of asperity due to stronger coupling. The topographic highs also work as a barrier for rock deformation. From the geological point of view, plate boundary megathrust in the seismogenic zone must be composed of fault rock in the brittle regime because of its temperature range from ~150℃ to ~350℃. The friction behaviors of these fault rocks and the effects of abnormal pore fluid pressure are recently one of the major concerns. The third factor is the mechanical property of the upper plate. The property changes through geological time scale due to the growth of the accretionary prism or tectonic erosion. In the case of the Nankai Trough, a pultonic body is situated beneath the place of epicenter and is suggested to have been functioned as an asperity of 1944 and 1946 earthquakes. We examined the on-land geology of the Shikoku island and the Kii Peninsula, SW Japan, and their basement structure and composition beneath the forearc Kumano Basin. We conclude that middle to late Miocene episodic magmatic intrusion and extrusion now controls the rupture area segmentation of the great earthquakes in the Nankai Trough.

  15. Effect of the Loma Prieta earthquake on surface slip along the Calaveras fault in the Hollister area

    SciTech Connect

    Galehouse, J.S. )

    1990-07-01

    Over the past ten years the author has made over 800 measurements of slip rates at 20 sites on various faults in the San Francisco Bay region. This data set enables them to compare rates and amounts of slip on these various faults before and after the Loma Prieta earthquake (LPEQ) on the San Andreas fault. No surface slip rate changes associated with the earthquake occurred at any of the sites on the San Andreas, Hayward, northern Calaveras, Concord-Green Valley, Seal Cove-San Gregorio, Antioch, Rodgers Creek, or West Napa faults. The LPEQ apparently triggered up to 12-14 mm of right slip on the southern Calaveras fault at two sites in the Hollister area less than 50 km from the epicenter. Most of this slip was probably coseismic or nearly so. About the same amount of slip was triggered at these sites in 1984 by the Morgan Hill earthquake. This slip, in contrast, occurred as afterslip within about a 2.5-month interval. The Calaveras fault in the Hollister area moves episodically, with shorter times of more rapid slip alternating with longer times of slower slip. The alternation occurs whether or not the times of faster slip are triggered by any nearby seismic event(s).

  16. Examining and Comparing Earthquake Readiness in East San Francisco Bay Area Communities (Invited)

    NASA Astrophysics Data System (ADS)

    Ramirez, N.; Bul, V.; Chavez, A.; Chin, W.; Cuff, K. E.; Girton, C.; Haynes, D.; Kelly, G.; Leon, G.; Ramirez, J.; Ramirez, R.; Rodriquez, F.; Ruiz, D.; Torres, J.

    2009-12-01

    Based on past experiences, the potential for casualties and mass destruction that can result from a high magnitude earthquake are well known. Nevertheless, given the East San Francisco Bay Area’s proximity to the Hayward and San Andreas faults, learning about earthquakes and disaster preparedness is of particular importance. While basic educational programs and materials are available both through emergency relief agencies and schools, little research has been done on their effectiveness. Because of the wide socioeconomic spread between communities in the East Bay, we decided to investigate understandings of issues related to disaster and earthquake preparedness among local populations based upon average household income. To accomplish this, we created a survey that was later uploaded to and implemented using Palm Treo Smart Phones. Survey locations were selected in such a way that they reflected the understandings of residents in a diverse set of socio-economic settings. Thus, these locations included a grocery store and nearby plaza in the Fruitvale district of Oakland, CA (zip=94601; median household income= 33,152), as well as the nearby town of Alameda, CA (zip=94502, median household income= 87,855). Preliminary results suggest that in terms of the objective questions on the survey, people from Alameda who participated in our study performed significantly better (difference in percentage correct greater than 10%) than the people from Fruitvale on two of the advanced earthquake knowledge questions. Interestingly enough, people in Fruitvale significantly outperformed people in Alameda on two of the basic earthquake knowledge questions. The final important finding was that while houses in Alameda tended to be newer and more often retrofitted than houses in Fruitvale, the people of the latter location tended to have a higher percentage of respondents claim confidence in the ability of their house to withstand a major earthquake. Based on preliminary results we

  17. 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.

  18. 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

  19. 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

  20. Estimation of Damaged Areas due to the 2010 Chile Earthquake and Tsunami Using SAR Imagery of Alos/palsar

    NASA Astrophysics Data System (ADS)

    Made, Pertiwi Jaya Ni; Miura, Fusanori; Besse Rimba, A.

    2016-06-01

    A large-scale earthquake and tsunami affect thousands of people and cause serious damages worldwide every year. Quick observation of the disaster damage is extremely important for planning effective rescue operations. In the past, acquiring damage information was limited to only field surveys or using aerial photographs. In the last decade, space-borne images were used in many disaster researches, such as tsunami damage detection. In this study, SAR data of ALOS/PALSAR satellite images were used to estimate tsunami damage in the form of inundation areas in Talcahuano, the area near the epicentre of the 2010 Chile earthquake. The image processing consisted of three stages, i.e. pre-processing, analysis processing, and post-processing. It was conducted using multi-temporal images before and after the disaster. In the analysis processing, inundation areas were extracted through the masking processing. It consisted of water masking using a high-resolution optical image of ALOS/AVNIR-2 and elevation masking which built upon the inundation height using DEM image of ASTER-GDEM. The area result was 8.77 Km2. It showed a good result and corresponded to the inundation map of Talcahuano. Future study in another area is needed in order to strengthen the estimation processing method.

  1. Degradation of the herbicide dichlobenil and its metabolite BAM in soils and subsurface sediments

    NASA Astrophysics Data System (ADS)

    Clausen, Liselotte; Arildskov, Niels P.; Larsen, Flemming; Aamand, Jens; Albrechtsen, Hans-Jørgen

    2007-01-01

    The worldwide used herbicide dichlobenil (2,6-dichlorobenzonitrile) has resulted in widespread presence of its metabolite 2,6-dichlorobenzamide (BAM) in surface water and groundwater. To evaluate the potential for natural attenuation of this BAM pollution in groundwater, we studied the degradation of BAM and dichlobenil in 16 samples of clayey till, unconsolidated sand and limestone, including sediments from both oxidized and reduced conditions. The degradation of dichlobenil occurred primarily in the upper few meters below surface, although dichlobenil was strongly sorbed to these sediments. However, the degradation of dichlobenil to BAM could not be correlated to either sorption, water chemistry, composition of soils or sediments. Degradation of dichlobenil to BAM was limited (< 2% degraded) in the deeper unsaturated zones, and no degradation was observed in aquifer sediments. This illustrates, that dichlobenil transported to aquifers does not contribute to the BAM-contamination in aquifers. A small, but significant degradation of BAM was observed in the upper part of the unsaturated zones in sandy sediments, but no degradation was observed in the clayey till sediment or in the deeper unsaturated zones. The insignificant degradation of BAM in aquifer systems shows that BAM pollution detected in aquifers will appear for a long time; and consequently the potential for natural attenuation of BAM in aquifer systems is limited.

  2. 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

  3. 3D Seismic Velocity Structure in the Rupture Area of the 2010 Maule Mw=8.8 Earthquake

    NASA Astrophysics Data System (ADS)

    Hicks, S. P.; Rietbrock, A.; Ryder, I. M.; Nippress, S.; Haberland, C. A.

    2011-12-01

    The 2010 Mw=8.8 Maule, Chile earthquake is one of the largest subduction zone earthquakes ever recorded. Up to now numerous co-seismic and some post-seismic slip models have been published based entirely on seismological, geodetic, or tsunami run-up heights, or combinations of these data. Most of these models use a simplified megathrust geometry derived mainly from global earthquake catalogues, and also simplified models of seismic parameters (e.g. shear modulus). By using arrival times for a vast number of aftershocks that have been recorded on a temporary seismic array, we present a new model for the slab geometry based on earthquake locations together with a new 3D seismic velocity model of the region, for both vp and vp/vs. We analyzed 3552 aftershocks that occurred between 18 March and 24 May 2011, recorded by the International Maule Aftershock Dataset (IMAD) seismic network. Event selection from a catalogue of automatically-determined events was based on 20 or more arrival times, from which at least 10 are S-wave observations. In total over 170,000 arrival times (~125,000 and 45,000 P and S wave arrival times respectively) are used for the tomographic reconstructions. Initially, events were relocated in a 2D velocity model based on a previously published model for the southern end of the rupture area (Haberland et al., 2009). Afterwards a staggered inversion scheme is implemented, starting with a 2D inversion followed by a coarse 3D and a subsequent fine 3D inversion. Based on our preliminary inversions we conclude that aftershock seismicity is mainly concentrated between 20 and 35 km depth along the subduction interface. A second band of seismicity between 40 and 50 km depth is also observed. Low seismic velocities and an increased vp/vs ratio characterize the marine forearc. The obtained velocity model will be discussed.

  4. 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. PMID:25485193

  5. 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.

  6. Fault interactions and large complex earthquakes in the Los Angeles area.

    PubMed

    Anderson, Greg; Aagaard, Brad; Hudnut, Ken

    2003-12-12

    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. PMID:14671298

  7. 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.

  8. Assessing the ability of Pleiades stereo imagery to determine height changes in earthquakes: A case study for the El Mayor-Cucapah epicentral area

    NASA Astrophysics Data System (ADS)

    Zhou, Yu; Parsons, Barry; Elliott, John R.; Barisin, Ivana; Walker, Richard T.

    2015-12-01

    High-resolution surface topography is valuable for studying coseismic fault zone deformation and fault geometry. It enables us to measure three-dimensional surface displacements in earthquakes, as shown in recent studies that used light detection and ranging (lidar) to determine coseismic motion. However, the applicability of lidar is limited by its relatively high cost and low availability. In this study, we use the 2010 El Mayor-Cucapah earthquake to demonstrate the capability of Pleiades stereo imagery to measure coseismic vertical ground displacement. We acquired post-earthquake Pleiades tristereo imagery from backward, near-nadir, and forward orientations for a 45 km × 7 km portion of the epicentral area. One meter resolution digital elevation models (DEMs) were produced with the four different combinations of incidence angles and compared to the post-earthquake lidar DEM. Elevations from tristereo have slightly (˜15%) smaller uncertainties than bistereo as the tristereo DEM incorporates more observations. Elevation differences between the Pleiades and post-earthquake lidar DEMs show that the vertical accuracy of the Pleiades DEMs is ˜0.3 m. By differencing the Pleiades DEM and the pre-earthquake, 5 m resolution lidar DEM, we mapped meter and submeter offsets along the faults obtaining results comparable to a previous study that differenced the two lidar DEMs. This is the first case study of assessing very high resolution (VHR) satellite stereo imagery to determine submeter vertical ground displacement in an earthquake. By extension, we expect it to be possible to measure submeter vertical offsets occurring in earthquakes using pre-earthquake and post-earthquake VHR stereo imagery.

  9. 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. PMID:22285064

  10. Characteristic tetanus infection in disaster-affected areas: case study of the Yogyakarta earthquakes in Indonesia

    PubMed Central

    Sutiono, Agung Budi; Qiantori, Andri; Suwa, Hirohiko; Ohta, Toshizumi

    2009-01-01

    Background Tetanus is an infectious disease caused by the contamination of wounds from bacteria that live in soil. The tetanus mortality rate remains high in developing countries affected by natural disasters. Whether the socio-demography and geographical conditions may influence the tetanus treatment outcome on the earthquake situation in Yogyakarta, Indonesia has not been investigated. Findings We present 26 tetanus patients who were admitted to eight hospitals following the earthquakes that occurred on May, 27, 2006, in Yogyakarta, Indonesia. The independent variables were age, gender, distance, admission, hospitalization, and type of hospital with the dependent variable surviving or perishing. Data were analyzed by logistic regression methods on SPSS 17.0. The distance from the patient's place of residence to the hospital were obtained and analyzed by using geospatial tools MapInfo 7.8 SCP and Global Mapper 7. Eight of the 26 patients were dead (30.8%) and statistical results showed that the distance (OR = 1.740, 95% CI = 1.068–2.835) and type of hospital (OR = 0.067, 95% CI = 0.001–3.520) were significant predictors of death. Conclusion Our findings show that in order to reduce the mortality rates, performing triage systems based on the distance and type of hospital priority for internally displaced persons could be proposed as well as making provisions for the generally old population in order to prevent an outbreak of tetanus following earthquakes in Yogyakarta, Indonesia. PMID:19284531

  11. 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. PMID:22302568

  12. Feasibility and Interest in Earthquake Early Warning Systems for Areas of Moderate Seismicity: Case Study for the Pyrenees

    NASA Astrophysics Data System (ADS)

    Auclair, Samuel; Goula, Xavier; Jara, Jose-Antonio; Colom, Yolanda

    2015-09-01

    Seismic risk in areas of moderate seismicity (AMS) is a reality and destructive earthquakes may occur there. This is why stakeholders and risk managers in these areas show an increasing interest in Earthquake Early Warning Systems (EEWS) and are wondering about the possibility of equipping their territories with such systems. This question of feasibility has to be broached globally: distinguishing technical feasibility from notions of opportunity and utility, an, thus, it has to involve both scientific experts and stakeholders. Moreover, it is necessary to consider each situation specifically without any preconceptions, specifically concerning potential uses that can be made of early warnings, in particular, it is clear that when applied to AMS, the EEWS principles translate into shorter lead times than the ones expected for more seismic areas and would, consequently, require considering new ways of using early warnings. Through the experience conducted for the Pyrenees (France-Spain border) as part of the SISPyr project, this study aims at identifying responses to the potential value of EEWS as real-time seismic risk mitigation tools for AMS as well as to offer a methodological framework to guide stakeholders in their assessment of opportunities to set up EEWS.

  13. Seismic reflection imaging in the ruptured area of The Tohoku-Oki Earthquake - Results from rapid response seismic reflection surveys -

    NASA Astrophysics Data System (ADS)

    Nakamura, Y.; No, T.; Fujie, G.; Kaiho, Y.; Sato, T.; Barnes, J.; Boston, B.; Yamashita, M.; Park, J.; Miura, S.; Takahashi, N.; Kodaira, S.; Kaneda, Y.; Moore, G. F.

    2011-12-01

    The 2011 off the Pacific coast of Tohoku Earthquake is one of the largest earthquakes ever observed and generated devastating Tsunamis. Seismological analysis revealed that the large slip occurred beneath the lower trench slope area, close to the Japan trench axis, (e.g. Ide et al. 2011), which seems to be related with the Tsunami generation. We conducted rapid response reflection seismic surveys using R/V Kairei after the main shock to delineate the structure of the ruptured area off Miyagi. Ten E-W lines with at least 120 km of length were surveyed using a 6 km-long, 444 channel streamer cable and a 7800 inch^3 tuned air gun array. The line spacing was 10-20 km. Preliminary processed data and their interpretation demonstrate that the structure considerably varies from south to north in the survey area. Normal faults dominate in the deep sea terrace. Those faults cut sedimentary sequence in this area, and sometimes offset the reflector at the top of cretaceous sequence. Beneath the trench slope, there are few reflectors especially in the shallower depth below the seafloor. Low angle landward dipping reflectors are observed in most of the survey area, some of them coincides with the backstop interface pointed out by Tsuru et al. (2000), but apparent shape and location of these reflectors are not consistent through the survey area. These reflectors may represent faults, but it is difficult to determine the sense of faulting. In the northern part of the survey area, prominent seaward dipping normal faults are observed in the upper to middle slope. Similar normal faults in small scale can be also recognized in some other lines, and should be one of key features offshore Tohoku region.

  14. 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.

  15. 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.

  16. 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

  17. Pattern recognition method applied to the forecast of strong earthquakes in South American seismic prone areas

    SciTech Connect

    Benavidez, A.

    1986-01-01

    The pattern recognition method is applied to the Andean seismic region that extends from southern latitudes 2 to 27 in the South American continent, to set a criterion for the prediction of the potential sites of strong earthquakes epicenters in the zone. It is assumed that two hypothesis hold. First, the strong earthquake epicenters typically cluster around the intersection of morphostructural lineaments. Second, the rules of recognition obtained for neighboring zones which exhibit distinctive neotectonic evolution, state of stress, spatial earthquake distribution and geological development, may be different in spite of the fact that the morphostructural zoning does not reflect a separation between them. Hence, the region is divided into two broad-scale tectonic segments located above slabs of similar scale in the Nazca plate in which subduction takes place almost subhorizontally (dipping at an angle of about 10) between latitudes 2S and 15S, and at a steeper angle (of approximately 30) within latitudes 15S to 27S. The morphostructural zoning is carried out for both zones with the determination of the lineaments and the corresponding disjunctive knots which are defined as the objects of recognition when applying the pattern recognition method. The Cora-3 algorithm is used as the computational procedure for the search of the rule of recognition of dangerous and non-dangerous sites for each zone. The set criteria contain in each case several characteristic features that represent the topography, geology and tectonics of each region. Also, it is shown that they have a physical meaning that mostly reflects the style of tectonic deformation in the related regions.

  18. Reducing atmospheric noise in RST analysis of TIR satellite radiances for earthquakes prone areas satellite monitoring

    NASA Astrophysics Data System (ADS)

    Lisi, Mariano; Filizzola, Carolina; Genzano, Nicola; Paciello, Rossana; Pergola, Nicola; Tramutoli, Valerio

    Space-time fluctuations of the Earth's emitted Thermal Infrared (TIR) radiation observed from satellite from months to weeks before an earthquake are reported in several studies. Among the others, a Robust Satellite data analysis Technique (RST) was proposed (and applied to different satellite sensors in various geo-tectonic contexts) to discriminate anomalous signal transients possibly associated with earthquake occurrence from normal TIR signal fluctuations due to other possible causes (e.g. solar diurnal-annual cycle, meteorological conditions, changes in observational conditions, etc.). Variations in satellite view angle depending on satellite's passages (for polar satellites) and atmospheric water vapour fluctuations were recognized in the past as the main factors affecting the residual signal variability reducing the overall Signal-to-Noise (S/N) ratio and the potential of the RST-based approach in identifying seismically related thermal anomalies. In this paper we focus on both factors for the first time, applying the RST approach to geostationary satellites (which guarantees stable view angles) and using Land Surface Temperature (LST) data products (which are less affected by atmospheric water vapour variability) instead of just TIR radiances at the sensor. The first results, obtained in the case of the Abruzzo earthquake (6 April 2009, MW ∼ 6.3) by analyzing 6 years of SEVIRI (Spinning Enhanced Visible and Infrared Imager on board the geostationary Meteosat Second Generation satellite) LST products provided by EUMETSAT, seem to confirm the major sensitivity of the proposed approach in detecting perturbations of the Earth's thermal emission a few days before the main shock. The results achieved in terms of increased S/N ratio (in validation) and reduced "false alarms" rate (in confutation) are discussed comparing results obtained by applying RST to LST products with those achieved by applying an identical RST analysis (using the same MSG-SEVIRI 2005

  19. One-year overview of deep vein thrombosis prevalence in the ishinomaki area since the great East Japan earthquake.

    PubMed

    Ueda, Shinsaku; Hanzawa, Kazuhiko; Shibata, Muneichi

    2014-01-01

    After the Great East-Japan Earthquake, the prevalence of deep vein thrombosis (DVT) in disaster shelters in Ishinomaki (Pacific coast, Miyagi, Japan) was found much higher than that ever reported in Japan. In Ishinomaki, twelve patients were found to have pulmonary thromboembolism for one month since the earthquake and DVT was found in 10 of those patients. The calf DVT was examined using ultrasonography in the shelters (from March to July 2011) and in temporary emergency housings (from August to December 2011). Calf DVT was found in 190 of 701 evacuees. DVT prevalence was higher in the tsunami-flooded shelters (34.2%) than in that in the non-flooded shelters (19.1%). This indicated that deteriorated and crowded condition in the tsunami-flooded shelters might induce thrombogenesis in calf veins. Therefore, evacuees were recommended to leave tsunami-flooded areas. DVT prevalence in the shelters was gradually reduced, however, that was still higher in the temporary emergency housings (8.9%) than in the non-disaster area in Japan (2.2% in Yokohama city). The risk of calf DVT in the temporary emergency housings was increased because of reduced blood flow in the calf veins caused by immobility. The residents of the housings were required to be physically active to avoid calf DVT. (English translation of Jpn J Phlebol 2013; 24: 380-384). PMID:25593620

  20. Recent developments in understanding the tectonic evolution of the Southern California offshore area: Implications for earthquake-hazard analysis

    USGS Publications Warehouse

    Fisher, M.A.; Langenheim, V.E.; Nicholson, C.; Ryan, H.F.; Sliter, R.W.

    2009-01-01

    During late Mesozoic and Cenozoic time, three main tectonic episodes affected the Southern California offshore area. Each episode imposed its unique structural imprint such that early-formed structures controlled or at least influenced the location and development of later ones. This cascaded structural inheritance greatly complicates analysis of the extent, orientation, and activity of modern faults. These fault attributes play key roles in estimates of earthquake magnitude and recurrence interval. Hence, understanding the earthquake hazard posed by offshore and coastal faults requires an understanding of the history of structural inheritance and modifi-cation. In this report we review recent (mainly since 1987) findings about the tectonic development of the Southern California offshore area and use analog models of fault deformation as guides to comprehend the bewildering variety of offshore structures that developed over time. This report also provides a background in regional tectonics for other chapters in this section that deal with the threat from offshore geologic hazards in Southern California. ?? 2009 The Geological Society of America.

  1. Photon multiplication in wide-gap BAM and SAM aluminates

    NASA Astrophysics Data System (ADS)

    Lushchik, Aleksandr; Lushchik, Cheslav; Feldbach, Eduard; Kudryavtseva, Irina; Liblik, Peeter; Maaroos, Aarne; Nagirnyi, Vitali; Savikhin, Fjodor; Vasil'chenko, Eugeni

    2005-08-01

    Processes of various intrinsic and impurity luminescence excitation by 4-32 eV photons or 18 and 300 keV electrons have been studied in pure and doped BaMgAl10O17 (BAM) and SrMgAl10O17 (SAM) phosphors at 6-300 K. In BAM:Eu (l0%), the quantum yield of Eu2+ center emission is QY = 1 in the region of exciting photon energies of hνec = 7-12 eV, the value of QY reaches 2 at 14-21 eV and sharply increases at hνec = 22-32 eV, where secondary electron-hole pairs are created by hot conduction electrons. The processes connected with the rise of QY for various types of emission in the region of 14-21 eV have been thoroughly studied for BAM and SAM phosphors. It has been suggested that such exciting photons cause the ionization of oxygen ions and form hot valence holes, the energy of which is partially used for the excitation of Eu2+ ions (4f7→4f65d1 transitions) due to nonradiative Auger transitions. The intensity of the Eu2+ emission increases after a single nanosecond electron pulse with a rise time of 50-150 ns. This rise is connected with the energy transfer from spinel blocks to Eu2+ ions located at cation planes of the β-alumina-type materials.

  2. 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

    2015-12-01

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

  3. Seismic high attenuation area beneath the 2008 Iwate-Miyagi Nairiku earthquake (M7.2) and Mt. Chokai in NE Japan

    NASA Astrophysics Data System (ADS)

    Shikasho, K.; Okada, T.; Nakajima, J.; Hayami, E.; Uchida, N.; Matsuzawa, T.; Umino, N.; Hasegawa, A.

    2011-12-01

    The Iwate-Miyagi Nairiku earthquake with a magnitude of 7.2 occurred in the southwestern part of Iwate Prefecture and the northwest part of Miyagi Prefecture on June 14, 2008. The earthquake occurred in the zone of concentrated deformation along of the Ou Mountain Range. After the quake, the dense temporary seismic network was deployed by the group for the aftershock observations of the 2008 Iwate-Miyagi Nairiku earthquake. From the aftershock distribution, it seemed westward dipping aftershock alignment, and the earthquake was shallow intraplate earthquake with the high-angle reverse-type focal mechanism (Okada et al., 2010). In this study, we investigate the detailed seismic attenuation structure in and around the focal area of the Iwate-Miyagi Nairiku earthquake to understand the generation process of inland (intraplate) earthquake. We used the data obtained by the temporary seismic network, the routine network (JMA and Hi-net) and the other temporary network (JNES, Hizumi network and Naruko network ). We estimated the seismic attenuation structure by using t* (Eberhart-Phillips and Chadwick, 2002). It is difficult to estimate the proper t* by the original spectral inversion method due to the tradeoff between t* and the corner frequency (Scherbaum, 1990). As in the previous study (Shikasho et al., JPGU, 2011), we used the corner frequency which was obtained by the spectral ratio method using the coda wave, and estimated the seismic attenuation structure (Qs). The spectral ratio method enables to estimate the corner frequency without the effect of the site and path. For this reason, estimating t* by using the corner frequency which is decided by the spectral ratio method enables to estimate the proper t*.. For the earthquake we cannot estimate the corner frequency by the spectral ratio method We estimated the corner frequency by assuming the range of stress drop of the earthquakes. As a result, we found the high attenuation area below the volcanoes along the

  4. BamA POTRA Domain Interacts with a Native Lipid Membrane Surface.

    PubMed

    Fleming, Patrick J; Patel, Dhilon S; Wu, Emilia L; Qi, Yifei; Yeom, Min Sun; Sousa, Marcelo Carlos; Fleming, Karen G; Im, Wonpil

    2016-06-21

    The outer membrane of Gram-negative bacteria is an asymmetric membrane with lipopolysaccharides on the external leaflet and phospholipids on the periplasmic leaflet. This outer membrane contains mainly β-barrel transmembrane proteins and lipidated periplasmic proteins (lipoproteins). The multisubunit protein β-barrel assembly machine (BAM) catalyzes the insertion and folding of the β-barrel proteins into this membrane. In Escherichia coli, the BAM complex consists of five subunits, a core transmembrane β-barrel with a long periplasmic domain (BamA) and four lipoproteins (BamB/C/D/E). The BamA periplasmic domain is composed of five globular subdomains in tandem called POTRA motifs that are key to BAM complex formation and interaction with the substrate β-barrel proteins. The BAM complex is believed to undergo conformational cycling while facilitating insertion of client proteins into the outer membrane. Reports describing variable conformations and dynamics of the periplasmic POTRA domain have been published. Therefore, elucidation of the conformational dynamics of the POTRA domain in full-length BamA is important to understand the function of this molecular complex. Using molecular dynamics simulations, we present evidence that the conformational flexibility of the POTRA domain is modulated by binding to the periplasmic surface of a native lipid membrane. Furthermore, membrane binding of the POTRA domain is compatible with both BamB and BamD binding, suggesting that conformational selection of different POTRA domain conformations may be involved in the mechanism of BAM-facilitated insertion of outer membrane β-barrel proteins. PMID:27332128

  5. Development of Tools for the Rapid Assessment of Landslide Potential in Areas Exposed to Intense Storms, Earthquakes, and Other Triggering Mechanisms

    NASA Astrophysics Data System (ADS)

    Highland, Lynn

    2014-05-01

    Landslides frequently occur in connection with other types of hazardous phenomena such as earthquake or volcanic activity and intense rainstorms. Strong shaking, for example, often triggers extensive landslides in mountainous areas, which can then complicate response and compound socio-economic impacts over shaking losses alone. The U.S. Geological Survey (USGS) is exploring different ways to add secondary hazards to its Prompt Assessment of Global Earthquakes for Response (PAGER) system, which has been developed to deliver rapid earthquake impact and loss assessments following significant global earthquakes. The PAGER team found that about 22 percent of earthquakes with fatalities have deaths due to secondary causes, and the percentage of economic losses they incur has not been widely studied, but is probably significant. The current approach for rapid assessment and reporting of the potential and distribution of secondary earthquake-induced landslides involves empirical models that consider ground acceleration, slope, and rock-strength. A complementary situational awareness tool being developed is a region-specific landslide database for the U.S. The latter will be able to define, in a narrative form, the landslide types (debris flows, rock avalanches, shallow versus deep) that generally occur in each area, along with the type of soils, geology and meteorological effects that could have a bearing on soil saturation, and thus susceptibility. When a seismic event occurs in the U.S. and the PAGER system generates web-based earthquake information, these landslide narratives will simultaneously be made available, which will help in the assessment of the nature of landslides in that particular region. This landslide profile database could also be applied to landslide events that are not triggered by earthquake shaking, in conjunction with National Weather Service Alerts and other landslide/debris-flow alerting systems. Currently, prototypes are being developed for both

  6. Lateral inhomogeneity deduced from 3-D magnetotelluric modeling around the hypocentral area of the 1984 Western Nagano Prefecture earthquake, central Japan

    NASA Astrophysics Data System (ADS)

    Kasaya, T.; Oshiman, N.

    2004-05-01

    Earthquake swarms have been observed since 1976 in the southeastern region of Mt. Ontake, where the 1984 Western Nagano Prefecture earthquake (M6.8) occurred. Most earthquake swarm activities show a dense distribu-tion in a narrow area and at shallow depths. We have carried out forward 3-D magnetotelluric modeling for the data set observed around the focal region of the earthquake swarms. An initial 3-D image was constructed based on previous 2-D magnetotelluric analysis results. The resistivity structure shows remarkable lateral inhomogeneity: a low resistivity zone is located at shallow depth around the center of the study area and the low resistivity zone is surrounded by a high resistive structure and its shape is about a 4-km cube. This feature agrees well with the distribution of the degree of water saturation deduced from seismic information. Hypocenters of recent seismicity are distributed around an area between the resistivity boundary and the relatively high-resistance region. This fact strongly suggests that earthquakes in the study area are triggered by fluid (water) in the crust.

  7. 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. PMID:23551260

  8. 2D and 3D Visualizations of the Fault Areas, Initial Heights and Tsunami Simulations of Five Largest Historical Earthquakes in Mediterrenean Region.

    NASA Astrophysics Data System (ADS)

    Gürleme, Beran; Tarık Meriç, Hakan; Ulutaş, Ergin; Anunziato, Alessandro

    2016-04-01

    The aim of this study is the simulation and visualization of the initial and maximum tsunami wave heights in 2D and 3D along the Mediterranean coasts inferred from the five largest earthquakes in history in this region. The earthquakes considered in the study are 21 July 365 Crete, 8 August 1303 Crete, 3 May 1481 Rhodes, 28 December Messina and 21 May 2003 Algeria. All these earthquakes spawned tsunamis and inflicted damage in coastal regions. The study was conducted to explain which could be the potential Tsunami consequences caused by similar earthquakes occurring in the region in the future. The methodology used for the calculation of tsunami wave heights from the earthquakes includes the determination of earthquake parameters, modeling of the initial wave height, simulation of the wave propagation and calculation of the maximum wave heights near coastal areas. The parameters of the earthquakes are based on previously published fault mechanism solutions and known tectonic features of the regions. Static dislocation algorithm for the initial wave height is used from the parameters of focal mechanism solutions. The study was conducted also to understand the reliability of the previously published focal mechanism solutions for the earthquakes by using the principal stress axis in the regions. The 2D and 3D visualized models of tsunamis from the earthquakes include isometric grid representing the sea surface for the purpose of a better understanding of the initial tsunami mechanism compared to 1D visualizations. In many studies, the earthquake locations, tectonic features of the regions, initial heights and tsunami simulations are shown on maps as bird's eye in 1D visualization. However these kinds of features are related in depths and bathymetric features. For that reason, our approaches will contribute to have better understanding where the uplift- subsidence of initial heights and crests-troughs of simulated wave heights and thus provide a better insight of the

  9. Brown dwarf Atmosphere Monitoring (BAM): Characterizing the Coolest Atmosphere

    NASA Astrophysics Data System (ADS)

    Patience, Jennifer

    2014-10-01

    Using the G141 WFC3/IR grism, we propose a HST spectrophotometric monitoring study of the coolest variable brown dwarf (~650K) identified as part of our Brown dwarf Atmosphere Monitoring (BAM) program. The proposed observations will enable exploration of the dynamic atmospheric evolution of a benchmark T8.5 binary brown dwarf system, which we have discovered to exhibit the second-largest amplitude variation amongst all currently known brown dwarf variables. The close binarity of this system requires the exquisite stability of the HST point spread function to enable resolved monitoring of both components and to discriminate the source of the variability - the second component is a planetary mass object based on evolutionary models. This BAM follow-up study is designed to characterize both the longitudinal and vertical structure of the atmospheric properties of this system via multi-wavelength observations covering the entire spectral range of the WFC3/IR detector. Additionally, by monitoring the target over two separate epochs we will measure the evolution of atmospheric features giving rise to the flux variations. The proposed program will provide a comprehensive dataset serving as a benchmark comparison to directly imaged planets, intensely irradiated Hot Jupiters, and synthetic atmospheric models incorporating different physical processes.

  10. 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. 

  11. 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.

  12. A rapid method to identify the potential of debris flow development induced by rainfall in catchments of the Wenchuan earthquake area

    NASA Astrophysics Data System (ADS)

    Zhou, Wei; Tang, Chuan; Van Asch, ThWJ; Chang, Ming

    2014-05-01

    In many mountainous areas, the limited space in the valley floors has created a need to construct the temporary settlements in zones potentially exposed to debris flow hazards after a strong earthquake. In these zones, a rapid identification of catchments with a high hazard level for debris flows is then necessary, to provide information for future risk management. This paper presents an empirical model to identify debris flow prone catchments at a regional scale. Sixty-nine debris flow catchments in the Wenchuan earthquake area were selected and investigated using high-resolution aerial photography to estimate the area of loose materials in the debris-flow catchments The statistical results show that debris flow prone catchments, have areas lower than 5 km2, and channel gradients which vary between 364 and 1192o and an internal relief lower than 2 km. But the level of debris flow hazard in these catchments is more closely related to the area of loose materials than basin relief and channel gradient. So basin area and area of loose materials were selected as the key factor to establish an applicable identification model. A mathematical model was constructed to estimate the thresholds of areas of loose materials for debris-flow prone catchments. The validation showed that the established model was suitable and met the requirements for identification of potential debris flows in the Wenchuan earthquake area. The results of the study will help the local government to select safe sites for rehabilitation and relocation in the future and can also be used as an important basis for debris-flow risk management. The approach may be applied to other earthquake areas, when adapting the threshold parameters according to new local conditions. Key words: Wenchuan earthquake; statistical model; debris flow thresholds

  13. Heterogeneous stress field in the source area of the 2003 M6.4 Northern Miyagi Prefecture, NE Japan, earthquake

    NASA Astrophysics Data System (ADS)

    Yoshida, Keisuke; Hasegawa, Akira; Okada, Tomomi

    2016-07-01

    We investigated a detailed spatial distribution of principal stress axis orientations in the source area of the 2003 M6.4 Northern Miyagi Prefecture earthquake that occurred in the forearc of northeastern Japan. Aftershock hypocentres were precisely relocated by applying the double difference method to arrival time data obtained at temporary stations as well as at surrounding routine stations. We picked many P-wave polarity data from seismograms at these stations, which enabled us to obtain 312 well-determined focal mechanism solutions. Stress tensor inversions were performed by using these focal mechanism data. The results show that quite a lot of focal mechanisms are difficult to explain by the uniform stress field, especially near the large slip area of the main-shock rupture. Stress tensor inversions at the location of individual earthquakes show that σ1 axes are orientated mainly to WSW-ENE in the northern part of the source area, while they are oriented to NW-SE in the southern part. This spatial pattern is roughly similar to those of the static stress change by the main shock, which suggests that the observed spatially heterogeneous stress field was formed by the static stress change. If this is the case, the deviatoric stress magnitude before the main shock was very small. Another possibility is the heterogeneous stress field observed after the main shock had existed even before the main shock, although we do not know why it was formed. Unfavourable orientation of the main shock fault with respect to this stress field suggests that the fault is not strong in this case too.

  14. Investigating P- and S-wave velocity structure beneath the Marmara region (Turkey) and the surrounding area from local earthquake tomography

    NASA Astrophysics Data System (ADS)

    Polat, Gulten; Özel, Nurcan Meral; Koulakov, Ivan

    2016-07-01

    We investigated the crustal structure beneath the Marmara region and the surrounding area in the western part of the North Anatolian fault zone. These areas have high seismicity and are of critical significance to earthquake hazards. The study was based on travel-time tomography using local moderate and micro-earthquakes occurring in the study area recorded by the Multi-Disciplinary Earthquake Research in High Risk Regions of Turkey project and Kandilli Observatory and Earthquake Research Institute. We selected 2131 earthquakes and a total of 92,858 arrival times, consisting of 50,044 P-wave and 42,814 S-wave arrival times. We present detailed crustal structure down to 50 km depth beneath the Marmara region for P- and S-wave velocities using the LOTOS code based on iterative inversion. We used the distributions of the resulting seismic parameters ( Vp, Vs) to pick out significant geodynamical features. The high-velocity anomalies correlate well with fracturing segments of the North Anatolian fault. High seismicity is mostly concentrated in these segments. In particular, low velocities were observed beneath the central Marmara Sea at 5 km depth.

  15. 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).

  16. Preceding seismic activity and slow slip events in the source area of the 2011 Mw 9.0 Tohoku-Oki earthquake: a review

    NASA Astrophysics Data System (ADS)

    Hasegawa, Akira; Yoshida, Keisuke

    2015-12-01

    The 2011 Tohoku-Oki earthquake ruptured a large area of the megathrust east of NE Japan. The earthquake's magnitude was 9.0, substantially larger than predicted. It is important to know what occurred in the source area prior to this great megathrust earthquake to improve understanding of the nucleation processes of large earthquakes and risk assessments in subduction zones. Seafloor observation data revealed the existence of two extremely large slip patches: one just updip of the mainshock hypocenter and the other 80-100 km to the north near the trench axis. For 70-90 years before 2003, M > 6 events and slips of M > c. 7 events on the megathrust occurred in the areas surrounding these two large slip patches. Seismic activity had increased since at least 2003 in the downdip portion of the source area of the Tohoku-Oki earthquake. In addition, long-term accelerated slow slip occurred in this downdip portion of the source area in the decades before the Tohoku-Oki earthquake. About 1 month before the earthquake, a slow slip event (SSE) took place at relatively shallow depths between the two large slip patches, accompanied by foreshock activity. Both the slow slip and foreshocks propagated from north to south toward the southern large slip patch. Two days before the earthquake, an M 7.3 foreshock and an associated postseismic slip began at relatively deep depths in the megathrust between the two large slip patches. In addition, a slow slip type event seems to have occurred approximately half a day after the M 7.3 foreshock near the mainshock hypocenter. This slow slip event and the foreshock activity again propagated from north to south toward the mainshock hypocenter. These long- and short-term preceding seismic and aseismic slip gradually reduced the interplate coupling, increased shear stresses at the two large slip patches (i.e., two strong asperity patches), and finally led to the rupture of the great Tohoku-Oki earthquake.

  17. The Expression, Purification, and Structure Determination of BamA from E. coli.

    PubMed

    Ni, Dongchun; Huang, Yihua

    2015-01-01

    In gram-negative bacteria, assembly of outer membrane proteins requires the multicomponent β-barrel assembly machinery (BAM) complex, of which BamA is an essential and evolutionarily conserved integral outer membrane protein. To understand how BamA facilitates outer membrane protein biogenesis, it is important to obtain sufficient amounts of purified recombinant BamA protein for in vitro functional analysis and structure determination. In this chapter, we describe the protocol that we used in our laboratory for the cloning, expression, and purification of E. coli BamA and its N-terminal deletion variants for in vitro functional studies and for structure determination of the β-barrel domain alone (residues 426-810). PMID:26427684

  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. PMID:26792489

  19. Potential for larger earthquakes in the East San Francisco Bay Area due to the direct connection between the Hayward and Calaveras Faults

    NASA Astrophysics Data System (ADS)

    Chaussard, E.; Bürgmann, R.; Fattahi, H.; Nadeau, R. M.; Taira, T.; Johnson, C. W.; Johanson, I.

    2015-04-01

    The Hayward and Calaveras Faults, two strike-slip faults of the San Andreas System located in the East San Francisco Bay Area, are commonly considered independent structures for seismic hazard assessment. We use Interferometric Synthetic Aperture RADAR to show that surface creep on the Hayward Fault continues 15 km farther south than previously known, revealing new potential for rupture and damage south of Fremont. The extended trace of the Hayward Fault, also illuminated by shallow repeating micro-earthquakes, documents a surface connection with the Calaveras Fault. At depths greater than 3-5 km, repeating micro-earthquakes located 10 km north of the surface connection highlight the 3-D wedge geometry of the junction. Our new model of the Hayward and Calaveras Faults argues that they should be treated as a single system with potential for earthquake ruptures generating events with magnitudes greater than 7, posing a higher seismic hazard to the East San Francisco Bay Area than previously considered.

  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. 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.

  2. Structure of the Coalinga area and thrust origin of the earthquake

    SciTech Connect

    Zoback, M.D. ); Wentworth, C.M.

    1990-01-01

    The 1983 Coalinga main shock occurred at the eastern margin of the Coast Ranges beneath Coalinga anticline, which forms the northwest segment in a 100-km-long zone of young anticlines about 35 km northeast of the San Andreas fault. Northeast-directed thrusts (here named the Coalinga thrust zone) terminated beneath the anticline at a depth of about 10 km in a series of upward-splaying reverse faults, above which the anticline has grown in the past 2 Ma. A distinct flattening near the center of the northeastern limb of the fold separates it into upper and lower tiers, which are related to separate reverse-fault splays below. The main shock appears to have occurred at the base of a reverse-fault splay beneath the upper tier of the fold and produced a focal mechanism with a gently southwest-dipping focal plane that strikes parallel to the fold axis. Rupture propagated bilaterally back down the thrust and up the reverse fault. Thrusting of the type responsible for the growth of Coalinga anticline probably extends the length of the Coalinga-Kettleman Hills-Lost Hills anticlinal trend, with tear faults at the echelon steps in the trend. The earthquake occurred east of the north-trending Pleasant Valley cross-structure. The structural setting for this recent thrusting east of the San Andreas fault was established in the Mesozoic under a different tectonic regime. The basement shallows northeastward from its 15-km depth beneath the Diablo Range, first at 15{degree}-20{degree} beneath the west side of the San Joaquin Valley and then more gently. This shallowing of basement probably limited northeastward penetration of the Franciscan wedge and seems to be limiting the more recent thrusting as well.

  3. The ratio of injured to fatalities in earthquakes, estimated from intensity and building properties

    NASA Astrophysics Data System (ADS)

    Wyss, M.; Trendafiloski, G.

    2009-04-01

    a city with poorly constructed buildings. The over all ratio for Bam was R=0.33 and for three districts it was R=0.2. In the only other city in the epicentral area, Baravat, located within about four kilometers of the epicenter R=0.55. Our contention that R is a function of I is further supported by analyzing R(I) for earthquakes where R is known for several settlements. The uncertainties in input parameters like earthquake source properties and Fat are moderate, those in Inj are large. Nevertheless our results are robust because the difference between R in the developed and developing world is enormous and the dependence on I is obvious. We conclude that R in most earthquakes results from a mixture of low values near the epicenter and high values farther away where intensities decrease to VI. The range between settlements in one single earthquake can be approximately 0.2 < R < 100, due to varying distance and hence varying I. Further, R(developed) = 25 R(developing), approximately. We also simulated several past earthquakes in Algeria, Peru and Iran to compare the values of estimated R(I) resulting from the use of ATC-13 and HAZUS casualty matrices with observations. We evaluated these matrices because they are supposed to apply worldwide and they consider all damage states as possible cause of casualties. Our initial conclusion is that the later matrices fit the observations better, in particular for intensity range VII-IX. However, to improve the estimates for all intensity values, we propose that casualty matrices for estimating human losses due to earthquakes should account for differences in I and in the building quality in different parts of the world.

  4. Structural basis of outer membrane protein insertion by the BAM complex.

    PubMed

    Gu, Yinghong; Li, Huanyu; Dong, Haohao; Zeng, Yi; Zhang, Zhengyu; Paterson, Neil G; Stansfeld, Phillip J; Wang, Zhongshan; Zhang, Yizheng; Wang, Wenjian; Dong, Changjiang

    2016-03-01

    All Gram-negative bacteria, mitochondria and chloroplasts have outer membrane proteins (OMPs) that perform many fundamental biological processes. The OMPs in Gram-negative bacteria are inserted and folded into the outer membrane by the β-barrel assembly machinery (BAM). The mechanism involved is poorly understood, owing to the absence of a structure of the entire BAM complex. Here we report two crystal structures of the Escherichia coli BAM complex in two distinct states: an inward-open state and a lateral-open state. Our structures reveal that the five polypeptide transport-associated domains of BamA form a ring architecture with four associated lipoproteins, BamB-BamE, in the periplasm. Our structural, functional studies and molecular dynamics simulations indicate that these subunits rotate with respect to the integral membrane β-barrel of BamA to induce movement of the β-strands of the barrel and promote insertion of the nascent OMP. PMID:26901871

  5. 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

  6. Impact of the 2001 Tohoku-oki earthquake to Tokyo Metropolitan area observed by the Metropolitan Seismic Observation network (MeSO-net)

    NASA Astrophysics Data System (ADS)

    Hirata, N.; Hayashi, H.; Nakagawa, S.; Sakai, S.; Honda, R.; Kasahara, K.; Obara, K.; Aketagawa, T.; Kimura, H.; Sato, H.; Okaya, D. A.

    2011-12-01

    The March 11, 2011 Tohoku-oki earthquake brought a great impact to the Tokyo metropolitan area in both seismological aspect and seismic risk management although Tokyo is located 340 km from the epicenter. The event generated very strong ground motion even in the metropolitan area and resulted severe requifaction in many places of Kanto district. National and local governments have started to discuss counter measurement for possible seismic risks in the area taking account for what they learned from the Tohoku-oki event which is much larger than ever experienced in Japan Risk mitigation strategy for the next greater earthquake caused by the Philippine Sea plate (PSP) subducting beneath the Tokyo metropolitan area is of major concern because it caused past mega-thrust earthquakes, such as the 1703 Genroku earthquake (M8.0) and the 1923 Kanto earthquake (M7.9). An M7 or greater (M7+) earthquake in this area at present has high potential to produce devastating loss of life and property with even greater global economic repercussions. The Central Disaster Management Council of Japan estimates that an M7+ earthquake will cause 11,000 fatalities and 112 trillion yen (about 1 trillion US$) economic loss. In order to mitigate disaster for greater Tokyo, the Special Project for Earthquake Disaster Mitigation in the Tokyo Metropolitan Area was launched in collaboration with scientists, engineers, and social-scientists in nationwide institutions. We will discuss the main results that are obtained in the respective fields which have been integrated to improve information on the strategy assessment for seismic risk mitigation in the Tokyo metropolitan area; the project has been much improved after the Tohoku event. In order to image seismic structure beneath the Metropolitan Tokyo area we have developed Metropolitan Seismic Observation network (MeSO-net; Hirata et al., 2009). We have installed 296 seismic stations every few km (Kasahara et al., 2011). We conducted seismic

  7. 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.

  8. Seismic characterization of the j-reflector near the meizoseismal area of the 1886 Charleston earthquake for lithologic constraint

    NASA Astrophysics Data System (ADS)

    Cunningham, Craig

    Investigations into the relationship between geologic structure and seismicity in and around the meizoseismal area of the 1886 Charleston earthquake have been ongoing since the 1970s. Seismic reflection profiles collected in this area display a prominent, laterally continuous, high amplitude, low frequency, two cycle reflection at ~0.7-1.2 s TWT, termed the "J" reflector, which has been correlated with Lower to Middle Jurassic tholeiitic basalt flows encountered in the Clubhouse Crossroads wells. The "J" reflector was also extended offshore onto the continental shelf. Recent reevaluation of sub Coastal Plain wells within the South Georgia Rift (SGR) Basin, including wells around the meizoseismal area of the 1886 Charleston earthquake, has shown most do not encounter basalt rising suspicions as to the true lithology of the "J"-reflector. Moreover, this same reflector has been interpreted to be the unconformity at the base of the Cretaceous-age Coastal Plain sediments. In order to define the regional extent of the Clubhouse Crossroads basalt, seismic inversion and attribute analysis were performed on two recently acquired reflection profiles, SC02_1 and SC02_5. Beginning in December 2010 through February 2011, seven 2D reflection profiles: SC02_1 - SC02_7 (total length 240 km) were acquired to the immediate west and northwest of the Charleston meizoseismal zone and legacy seismic data as part of DOE Award DE-FE0001965: Geologic Characterization of the South Georgia Rift Basin for Source Proximal C02 Storage project. The first profile, SC02_1, passes Norris Lightsey #1 and Rizer #1, two wells that never encountered basalt at the base of coastal plain. SC02_5, passes Dorchester 211, a well that bottomed into basalt at the base of the coastal plain. Variations in seismic attributes provides evidence for a western termination of the clubhouse crossroads basalt flow on SC02_1 and key support for visible amplitude variations at the contact between coastal plain

  9. 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

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

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

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

  11. 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

  12. 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.

  13. Crustal and uppermost mantle structure beneath the continental rifting area of the Gulf of Suez from earthquake tomography

    NASA Astrophysics Data System (ADS)

    El Khrepy, Sami; Koulakov, Ivan; Al-Arifi, Nassir

    2016-02-01

    Suez rift is one of the active seismic zones in the northward continuation of the Red Sea, as indicated by recent earthquake records from the Egyptian National Seismological Network (ENSN). We present a new model of P and S wave velocities in the crust and uppermost mantle beneath the Gulf of Suez and surrounding areas, including the northern portion of the Red Sea. Using the records from 94 seismic stations, we analyzed ~ 66,000 P and ~ 17,000 S wave arrival times from 9700 events. The travel time tomography inversion was performed using the iterative LOTOS code. The spatial resolutions of the derived models were assessed using several synthetic tests. The most prominent anomaly is a sharp high-velocity anomaly beneath the Red Sea, which is observed in both the P and S models at all depth intervals. We interpret this anomaly to be oceanic crust that was formed through extension associated with a dispersed system of spreading centers. Beneath the Gulf of Suez, the upper and middle crusts appear to be strongly heterogeneous and are dominated by low-velocity anomalies, indicative of the continental nature of the crusts. In contrast, at a depth of 30 km, we observe a prominent high-velocity anomaly along Gulf of Suez, which is interpreted to be the result of crustal thinning associated with extension between the Sinai block and the African Plate. The thickness of the crust beneath the rift is estimated to be approximately 25 km, whereas that in the surrounding areas appears to be 30-35 km. In the northwestern part of the area, we observe a low-velocity zone in the middle and lower crusts that coincide with intense seismicity and a well-developed system of recent faults on the surface. This region may mark a possible area of northward propagation of the Suez Rift zone.

  14. Earthquake swarms in Greenland

    NASA Astrophysics Data System (ADS)

    Larsen, Tine B.; Voss, Peter H.; Dahl-Jensen, Trine

    2014-05-01

    Earthquake swarms occur primarily near active volcanoes and in areas with frequent tectonic activity. However, intraplate earthquake swarms are not an unknown phenomenon. They are located near zones of weakness, e.g. in regions with geological contrasts, where dynamic processes are active. An earthquake swarm is defined as a period of increased seismicity, in the form of a cluster of earthquakes of similar magnitude, occurring in the same general area, during a limited time period. There is no obvious main shock among the earthquakes in a swarm. Earthquake swarms occur in Greenland, which is a tectonically stable, intraplate environment. The first earthquake swarms in Greenland were detected more than 30 years ago in Northern and North-Eastern Greenland. However, detection of these low-magnitude events is challenging due to the enormous distances and the relatively sparse network of seismographs. The seismograph coverage of Greenland has vastly improved since the international GLISN-project was initiated in 2008. Greenland is currently coved by an open network of 19 BB seismographs, most of them transmitting data in real-time. Additionally, earthquake activity in Greenland is monitored by seismographs in Canada, Iceland, on Jan Mayen, and on Svalbard. The time-series of data from the GLISN network is still short, with the latest station been added in NW Greenland in 2013. However, the network has already proven useful in detecting several earthquake swarms. In this study we will focus on two swarms: one occurring near/on the East Greenland coast in 2008, and another swarm occurring in the Disko-area near the west coast of Greenland in 2010. Both swarms consist of earthquakes with local magnitudes between 1.9 and 3.2. The areas, where the swarms are located, are regularly active with small earthquakes. The earthquake swarms are analyzed in the context of the general seismicity and the possible relationship to the local geological conditions.

  15. Everyday Earthquakes.

    ERIC Educational Resources Information Center

    Svec, Michael

    1996-01-01

    Describes methods to access current earthquake information from the National Earthquake Information Center. Enables students to build genuine learning experiences using real data from earthquakes that have recently occurred. (JRH)

  16. 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.

  17. Application of a bi-directional associative memory (BAM) network in computer assisted learning in chemistry.

    PubMed

    Chau, F T; Cheung, B; Tam, K Y; Li, L K

    1994-12-01

    A computer assisted learning software based on a bi-directional associative memory (BAM) network was developed. The software was implemented to assist students in associating the names of the elements in the periodic table with their chemical symbols. The use of the BAM facilitates the analysis and interpretation of students' responses. The software package can be modified easily as an educational tool for other disciplines. PMID:7812638

  18. 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.

  19. 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. PMID:24914988

  20. Detection of shallow crustal discontinuities from high frequency waveforms of swarm earthquakes in West Bohemia/Vogtland seismoactive area

    NASA Astrophysics Data System (ADS)

    Hrubcová, Pavla; Vavryčuk, Václav; Boušková, Alena

    2015-04-01

    The western part of the Bohemian Massif, the West Bohemia/Vogtland region, is the area of the increased geodynamic activity manifested by repeated occurrence of intraplate earthquake swarms and fluid degassing. To understand geodynamic processes, knowledge of a detailed crustal structure is essential for all advanced studies of seismicity and focal parameters of the micro-earthquake swarms that occur in this region. The crustal structure is usually inferred from active seismic investigations, i.e., reflection and refraction seismic imaging. Passive seismic investigation focused on swarm microearthquakes has an advantage over the active exploration. The microseismic investigation typically handles large amount of data ideal for stacking, foci are usually far from the shallowest structure so waveforms are rather simple, and data acquisition is not expensive. The standard microseismic monitoring of swarms is prevalently used for retrieving information on seismic source parameters, such as magnitude, location, seismic moment, and moment tensors. However, high-frequency seismic waves generated by local sources are sensitive to sharp changes in velocities or density and the structure can be determined from reflected and converted phases secondarily originating at deep and shallow subsurface layers. In our study we concentrate on the velocity distribution in the upper crust. The upper crustal structure is studied from waveforms of local microearthquakes that occurred during the 2008 swarm in West Bohemia/Vogtland seismoactive region. They were recorded by the WEBNET network consisting of 22 three-component seismic stations. We focus on high-frequency PS and SP converted waves generated at shallow interfaces at depths between 2 and 5 km. Apart from velocity contrast at the interfaces, the amplitudes of converted waves are significantly affected by source-receiver geometry and focal mechanisms of the earthquakes. This observation complicates the analysis, being absent in

  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. PMID:19664588

  2. 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

  3. 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

    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.

  4. 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.

  5. Seven years of postseismic deformation in the Mw=6.8, 2003 Zemmouri (Algeria) earthquake area from PS-InSAR

    NASA Astrophysics Data System (ADS)

    Cetin, E.; Meghraoui, M.; Cakir, Z.; Mimouni, O.; Belabbes, S.; Akoglu, A.; Bouraoui, S.; Chebbah, M.

    2012-04-01

    We study the postseismic deformation of the Mw 6.9, 2003 Zemmouri earthquake using both Persistent Scatterer (PS) and Small Baseline (SB) InSAR techniques. InSAR time series calculated from 31 Envisat ASAR images reveal subtle (sub cm) ground movements along the shoreline between Cap Matifou and Dellys between 2003 and 2010 where remarkable coseismic uplift was observed after the earthquake. Measurements show line of sight (LOS) ground subsidence at rates up to 4 mm/yr in the region of coseismic surface deformation. There are two lobes of subsidence in the deformation field at a maximum rate of ~2.0 mm/yr in Cap Djenet and ~3.5 mm/yr in Zemmouri-Boumerdes. These lobes correlate well with the regions of maximum coseismic uplift determined by InSAR and coastal uplift measurements, supporting the previous inferences that the earthquake was associated with two segments. Modeling with elastic dislocations on rectangular faults suggests that subsidence in the area of high coseismic uplift and GPS measurements can be adequately explained by afterslip on the shallow sections of the coseismic fault rupture. The impact of coseismic rupture and geologic background made of soft sedimentation allow us to characterize the ground deformation of non-tectonic origin away from the earthquake area. Indeed, ground movements also recorded in PS-InSAR time series in the Quaternary Mitidja Basin seem to result largely from seasonal water level fluctuation and water pumping for farming. Comparison of PS time series with water level changes in the eastern Mitidja Basin displays a remarkable correlation; it also indicates that the postseismic ground deformation in the western end of the 2003 earthquake rupture can be considered as negligible.

  6. 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.

  7. 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

  8. Assessing the Ability of Pleiades Stereo Imagery to Determine Height Changes in Earthquakes: A Case Study for the El Mayor-Cucapah Epicentral Area

    NASA Astrophysics Data System (ADS)

    Parsons, B.; Zhou, Y.; Elliott, J. R.; Barisin, I.; Walker, R. T.

    2014-12-01

    Very high-resolution (VHR) imagery can in principle measure surface topography with decimetric precision. The question is how well 3D mapping based on VHR stereo imagery is capable of capturing sub-metric height changes occurring in an earthquake, particularly those in remote areas? The aim of this study is to assess the capability of the Pleiades satellites to determine such height changes. We acquired Pleiades stereo imagery with backward (B), near-nadir (N) and forward (F) orientations over a 40 km × 5 km area in Baja California, Mexico, part of the epicentral area of the 2010 Mw 7.2 El Mayor-Cucapah earthquake. Coverage was chosen to coincide with the post-seismic LiDAR digital elevation model (DEM) for the area. DEMs have been produced with four different combinations of incidence angles (B-N, N-F, B-F and B-N-F). The raw point cloud has the lowest average density of ~0.7 points/m2 for B-F, ~1.0 points/m2 for B-N and N-F, and the greatest average density of ~3 points/m2 for tri-stereo (B-N-F). Compared to the post-earthquake LiDAR DEM, the Pleiades DEMs have a mean error of 1 m to 4 m, with a standard deviation of 0.5 m to 0.7 m. A series of topographic profiles from the Pleiades DEMs across the earthquake rupture were used to measure vertical offsets. These profiles show that the Pleiades DEM is capable of capturing vertical offsets of ~0.5 m. The measurements of vertical offsets from tri-stereo have smaller uncertainties than bi-stereo; this suggests that the tri-stereo DEM incorporating redundant observations is more robust and reliable. By differencing the 1-m tri-stereo Pleiades DEM and the pre-earthquake, lower-resolution (5-m) LiDAR DEM, we mapped metre and sub-metre offsets along the faults obtaining results comparable to a previous study that differenced the two LiDAR DEMs (Fig. 1). By extension, we expect it to be possible in similar settings to measure sub-metre vertical offsets occurring in earthquakes using pre- and post-event Pleiades stereo

  9. Waveform through the subducted plate under the Tokyo region in Japan observed by a ultra-dense seismic network (MeSO-net) and seismic activity around mega-thrust earthquakes area

    NASA Astrophysics Data System (ADS)

    Sakai, S.; Kasahara, K.; Nanjo, K.; Nakagawa, S.; Tsuruoka, H.; Morita, Y.; Kato, A.; Iidaka, T.; Hirata, N.; Tanada, T.; Obara, K.; Sekine, S.; Kurashimo, E.

    2009-12-01

    In central Japan, the Philippine Sea plate (PSP) subducts beneath the Tokyo Metropolitan area, the Kanto region, where it causes mega-thrust earthquakes, such as the 1703 Genroku earthquake (M8.0) and the 1923 Kanto earthquake (M7.9) which had 105,000 fatalities. A M7 or greater earthquake in this region at present has high potential to produce devastating loss of life and property with even greater global economic repercussions. The Central Disaster Management Council of Japan estimates the next great earthquake will cause 11,000 fatalities and 112 trillion yen (1 trillion US$) economic loss. This great earthquake is evaluated to occur with a probability of 70 % in 30 years by the Earthquake Research Committee of Japan. We had started the Special Project for Earthquake Disaster Mitigation in Tokyo Metropolitan area (2007-2012). Under this project, the construction of the Metropolitan Seismic Observation network (MeSO-net) that consists of about 400 observation sites was started [Kasahara et al., 2008; Nakagawa et al., 2008]. Now, we had 178 observation sites. The correlation of the wave is high because the observation point is deployed at about 2 km intervals, and the identification of the later phase is recognized easily thought artificial noise is very large. We also discuss the relation between a deformation of PSP and intra-plate M7+ earthquakes: the PSP is subducting beneath the Honshu arc and also colliding with the Pacific plate. The subduction and collision both contribute active seismicity in the Kanto region. We are going to present a high resolution tomographic image to show low velocity zone which suggests a possible internal failure of the plate; a source region of the M7+ intra-plate earthquake. Our study will contribute a new assessment of the seismic hazard at the Metropolitan area in Japan. Acknowledgement: This study was supported by the Earthquake Research Institute cooperative research program.

  10. A Collaborative Program for Earthquake Fault Hazard Characterization and Community Outreach for the Reno, Nevada Area

    NASA Astrophysics Data System (ADS)

    Frary, R.; Louie, J. N.; Stephenson, W. J.; Odum, J. K.; Liberty, L. M.; Pullammanappallil, S.; Kell, A. M.; Michaels, J.; Prina, N.; Dhar, M. S.; Cashman, P. H.; Trexler, J. H.; Kent, R.; Hoffpauir, C.

    2010-12-01

    Quantifying seismic hazards has been ongoing in the Reno, Nevada area for many years. The urban basin sits between the Sierra Nevada frontal normal faults and the borders of two structural domains of the Walker Lane. These domains are characterized by northwest-striking dextral faults and northeast-striking sinistral faults, respectively. Within the basin, thick volcanic fill is overlain by sandstone and diatomite as young as 2.6 Ma, which is then overlain by Plio-Pleistocene fluvial, lacustrine, and outwash deposits. Subsequent tilting, normal faulting and strike-slip faulting record deformation since 2.6 Ma. Seismicity occurs along both reactivated Tertiary faults and young faults for which surface traces have not been found. To begin unifying this complex history into products that will be useful to the community, the Western Basin and Range Community Velocity Model and the Reno-Carson City Urban Hazard Maps were proposed, and will be the main products of this quantification. Many groups have collaborated on these projects, with contributions in collecting, processing, analyzing, or interpreting various geological and geophysical data. Several high-resolution seismic imaging profiles have been collected in downtown Reno, east to Sparks, and in southwest Reno in the last two years. By employing detailed time and depth migration techniques and incorporating stratigraphic information, we were able to image many previously-mapped faults as well as additional newly-recognized faults, aiding in understanding the basin structure. A key to our research is engaging local municipalities and the community at large. The cities of Reno and Sparks have been very supportive of our seismic hazards characterization research and outstanding in their contributions to this project thus far, but lack funding to initiate and carry out planning and hazard mitigation activities. While generally well-received by local citizens during our field studies, we will continue to reach out to

  11. 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.

  12. 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

  13. BAM8-22 peptide produces itch and nociceptive sensations in humans independent of histamine release.

    PubMed

    Sikand, Parul; Dong, Xinzhong; LaMotte, Robert H

    2011-05-18

    Chronic itch accompanying many dermatological, neurological, and systemic diseases is unresponsive to antihistamines. Our knowledge of endogenous chemicals that evoke histamine-independent itch and their molecular targets is very limited. Recently it was demonstrated in behavioral and cellular experiments that bovine adrenal medulla 8-22 peptide (BAM8-22), a proteolytically cleaved product of proenkephalin A, is a potent activator of Mas-related G-protein-coupled receptors (Mrgprs), MrgprC11 and hMrgprX1, and induces scratching in mice in an Mrgpr-dependent manner. To study the sensory qualities that BAM8-22 evokes in humans, we tested the volar forearm of 15 healthy volunteers with heat-inactivated cowhage spicules previously soaked in the peptide. BAM8-22 produced itch in each subject, usually accompanied by sensations of pricking/stinging and burning. The sensations were occasionally accompanied by one or more mechanically evoked dysesthesias, namely alloknesis, hyperknesis, and/or hyperalgesia, but no wheal or neurogenic flare in the skin surrounding the application site. The inactive truncated peptide BAM8-18 produced weak or no sensations. Pretreatment of the tested skin with an antihistamine cream (doxepin) inhibited histamine-induced sensations, dysesthesias, and skin reactions but not the sensations and dysesthesias evoked by BAM8-22. We show that BAM8-22 produces itch and nociceptive sensations in humans in a histamine-independent manner. Thus, BAM8-22 may be an endogenous itch mediator that activates, in humans, MrgprX1, a novel target for potential anti-itch treatments. PMID:21593341

  14. BAM8–22 peptide produces itch and nociceptive sensations in humans independent of histamine release

    PubMed Central

    Sikand, Parul; Dong, Xinzhong; LaMotte, Robert H.

    2011-01-01

    Chronic itch accompanying many dermatological, neurological and systemic diseases is unresponsive to antihistamines. Our knowledge of endogenous chemicals that evoke histamine-independent itch and their molecular targets is very limited. Recently it was demonstrated in behavioral and cellular experiments that bovine adrenal medulla 8–22 peptide (BAM8–22), a proteolytically cleaved product of proenkephalin A, is a potent activator of Mas-related G protein-coupled receptors (Mrgprs), MrgprC11 and hMrgprX1, and induces scratching in mice in a Mrgpr-dependent manner. To study the sensory qualities that BAM8–22 evokes in humans we tested the volar forearm of 15 healthy volunteers with heat-inactivated cowhage spicules previously soaked in the peptide. BAM8–22 produced itch in each subject, usually accompanied by sensations of pricking/stinging and burning. The sensations were occasionally accompanied by one or more mechanically evoked dysesthesias, namely alloknesis, hyperknesis, and hyperalgesia, but no wheal or neurogenic flare in the skin surrounding the application site. The inactive truncated peptide BAM8–18 produced weak or no sensations. Pretreatment of the tested skin with an antihistamine cream (doxepin) inhibited the histamine-induced sensations, dysesthesias and skin reactions but not the sensations and dysesthesias evoked by BAM8–22. We show that BAM8–22 produces itch and nociceptive sensations in humans in a histamine-independent manner. Thus, BAM8–22 may be an endogenous itch mediator that activates, in humans, MrgprX1, a novel target for potential anti-itch treatments. PMID:21593341

  15. BB0324 and BB0028 are constituents of the Borrelia burgdorferi β-barrel assembly machine (BAM) complex

    PubMed Central

    2012-01-01

    Background Similar to Gram-negative bacteria, the outer membrane (OM) of the pathogenic spirochete, Borrelia burgdorferi, contains integral OM-spanning proteins (OMPs), as well as membrane-anchored lipoproteins. Although the mechanism of OMP biogenesis is still not well-understood, recent studies have indicated that a heterooligomeric OM protein complex, known as BAM (β-barrel assembly machine) is required for proper assembly of OMPs into the bacterial OM. We previously identified and characterized the essential β-barrel OMP component of this complex in B. burgdorferi, which we determined to be a functional BamA ortholog. Results In the current study, we report on the identification of two additional protein components of the B. burgdorferi BAM complex, which were identified as putative lipoproteins encoded by ORFs BB0324 and BB0028. Biochemical assays with a BamA-depleted B. burgdorferi strain indicate that BB0324 and BB0028 do not readily interact with the BAM complex without the presence of BamA, suggesting that the individual B. burgdorferi BAM components may associate only when forming a functional BAM complex. Cellular localization assays indicate that BB0324 and BB0028 are OM-associated subsurface lipoproteins, and in silico analyses indicate that BB0324 is a putative BamD ortholog. Conclusions The combined data suggest that the BAM complex of B. burgdorferi contains unique protein constituents which differ from those found in other proteobacterial BAM complexes. The novel findings now allow for the B. burgdorferi BAM complex to be further studied as a model system to better our understanding of spirochetal OM biogenesis in general. PMID:22519960

  16. Physical activity and sedentary behavior among children and adolescents living in an area affected by the 2011 Great East Japan earthquake and tsunami for 3 years.

    PubMed

    Okazaki, Kanzo; Suzuki, Koya; Sakamoto, Yuzuru; Sasaki, Keiji

    2015-01-01

    The purpose of this study is to examine the change in physical activity levels among children and adolescents living in the area affected by the 2011 earthquake and tsunami for 3 years immediately following the disaster. Children and adolescents graded four to nine and attending school in the Pacific coastal area of northern Japan were included in a total of four serial prevalence investigations: the first at 6 months after the earthquake/tsunami (I, n = 434) and additional surveys at 1 year (II, n = 437), 2 years (III, n = 401), and 3 years (IV, n = 365) after the earthquake. Students were also required to undergo assessment of their accelerometer-determined daily steps and sedentary time using a self-administrated questionnaire. Accelerometer-determined median daily steps of children and adolescents were significantly different (p < 0.05) on both weekdays and weekends over 3 years. The median daily steps of children of both genders on weekdays and those of girls on weekends at period IV were significantly lower than those at period I. In addition, the median daily steps of adolescents on weekdays among girls and weekends among boys at period IV were significantly lower than those at period I. It appears that children and adolescents who survive the earthquake and tsunami experience a decrease in physical activity levels. Future research should elucidate longitudinal demographic and sociocultural factors that contribute to changes in physical activity levels among children and adolescents living in the areas affected by these disasters. PMID:26844143

  17. 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

  18. 3D P-wave velocity structure of the crust and relocation of earthquakes in the Lushan, China, source area

    NASA Astrophysics Data System (ADS)

    Yu, Xiangwei; Wang, Xiaona; Zhang, Wenbo

    2016-04-01

    Many researchers have investigated the Lushan source area with geological and geophysical approaches since the 2013 Lushan, China, earthquake happened. Compared with the previous tomographic studies, we have used a much large data set and an updated tomographic method to determine a small scale three-dimensional P wave velocity structure with spatial resolution less than 5km, which plays the important role for understanding the deep structure and the genetic mechanism beneath the Lushan area. The double difference seismic tomography method is applied to 50,711 absolute first arrival P wave arrival times and 7,294,691 high quality relative P arrival times of 5,285 events of Lushan seismic sequence to simultaneously determine the detailed crustal 3D P wave velocity structure and the hypocenter parameters in the Lushan seismic area. This method takes account of the path anomaly biases explicitly by making full use of valuable information of seismic wave propagation jointly with absolute and relative arrival time data. Our results show that the Lushan mainshock locates at 30.28N, 103.98E, with the depth of 16.38km. The front edge of aftershock in the northeast of mainshock present a spade with a steep dip angle, the aftershocks' extended length is about 12km. In the southwest of Lushan mainshock, the front edge of aftershock in low velocity zone slope gently, the aftershocks' extended length is about 23km. Our high-resolution tomographic model not only displays the general features contained in the previous models, but also reveals some new features. The Tianquan, Shuangshi and Daguan line lies in the transition zone between high velocity anomalies to the southeast and low velocity anomalies to the northwest at the ground surface. An obvious high-velocity anomaly is visible in Daxing area. With the depth increasing, Baoxing high velocity anomaly extends to Lingguan, while the southeast of the Tianquan, Shuangshi and Daguan line still shows low velocity. The high

  19. 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

  20. Post-earthquake road damage assessment using region-based algorithms from high-resolution satellite images

    NASA Astrophysics Data System (ADS)

    Haghighattalab, A.; Mohammadzadeh, A.; Valadan Zoej, M. J.; Taleai, M.

    2010-10-01

    Receiving accurate and comprehensive knowledge about the conditions of roads after earthquake strike are crucial in finding optimal paths and coordinating rescue missions. Continuous coverage of the disaster region and rapid access of high-resolution satellite images make this technology as a useful and powerful resource for post-earthquake damage assessment and the evaluation process. Along with this improved technology, object-oriented classification has become a promising alternative for classifying high-resolution remote sensing imagery, such as QuickBird, Ikonos. Thus, in this study, a novel approach is proposed for the automatic detection and assessment of damaged roads in urban areas based on object based classification techniques using post-event satellite image and vector map. The most challenging phase of the proposed region-based algorithm is the segmentation procedure. The extracted regions are then classified using nearest neighbor classifier making use of textural parameters. Then, an appropriate fuzzy inference system (FIS) is proposed for road damage assessment. Finally, the roads are correctly labeled as 'Blocked road' or 'Unblocked road' in the road damage assessment step. The proposed method was tested on QuickBird pan-sharpened image of Bam, Iran, concerning the devastating earthquake that occurred in December 2003. The visual investigation of the obtained results demonstrates the efficiency of the proposed approach.

  1. 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

  2. Slow earthquakes triggered by typhoons.

    PubMed

    Liu, ChiChing; Linde, Alan T; Sacks, I Selwyn

    2009-06-11

    The first reports on a slow earthquake were for an event in the Izu peninsula, Japan, on an intraplate, seismically active fault. Since then, many slow earthquakes have been detected. It has been suggested that the slow events may trigger ordinary earthquakes (in a context supported by numerical modelling), but their broader significance in terms of earthquake occurrence remains unclear. Triggering of earthquakes has received much attention: strain diffusion from large regional earthquakes has been shown to influence large earthquake activity, and earthquakes may be triggered during the passage of teleseismic waves, a phenomenon now recognized as being common. Here we show that, in eastern Taiwan, slow earthquakes can be triggered by typhoons. We model the largest of these earthquakes as repeated episodes of slow slip on a reverse fault just under land and dipping to the west; the characteristics of all events are sufficiently similar that they can be modelled with minor variations of the model parameters. Lower pressure results in a very small unclamping of the fault that must be close to the failure condition for the typhoon to act as a trigger. This area experiences very high compressional deformation but has a paucity of large earthquakes; repeating slow events may be segmenting the stressed area and thus inhibiting large earthquakes, which require a long, continuous seismic rupture. PMID:19516339

  3. Genetic, Biochemical, and Molecular Characterization of the Polypeptide Transport-Associated Domain of Escherichia coli BamA

    PubMed Central

    Workman, Patricia; Heide, Kristina; Giuliano, Nicolas; Lee, Nanhee; Mar, James; Vuong, Phu; Bennion, Drew

    2012-01-01

    The BamA protein of Escherichia coli plays a central role in the assembly of β-barrel outer membrane proteins (OMPs). The C-terminal domain of BamA folds into an integral outer membrane β-barrel, and the N terminus forms a periplasmic polypeptide transport-associated (POTRA) domain for OMP reception and assembly. We show here that BamA misfolding, caused by the deletion of the R44 residue from the α2 helix of the POTRA 1 domain (ΔR44), can be overcome by the insertion of alanine 2 residues upstream or downstream from the ΔR44 site. This highlights the importance of the side chain orientation of the α2 helix residues for normal POTRA 1 activity. The ΔR44-mediated POTRA folding defect and its correction by the insertion of alanine were further demonstrated by using a construct expressing just the soluble POTRA domain. Besides misfolding, the expression of BamAΔR44 from a low-copy-number plasmid confers a severe drug hypersensitivity phenotype. A spontaneous drug-resistant revertant of BamAΔR44 was found to carry an A18S substitution in the α1 helix of POTRA 1. In the BamAΔR44, A18S background, OMP biogenesis improved dramatically, and this correlated with improved BamA folding, BamA-SurA interactions, and LptD (lipopolysaccharide transporter) biogenesis. The presence of the A18S substitution in the wild-type BamA protein did not affect the activity of BamA. The discovery of the A18S substitution in the α1 helix of the POTRA 1 domain as a suppressor of the folding defect caused by ΔR44 underscores the importance of the helix 1 and 2 regions in BamA folding. PMID:22544271

  4. 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.

  5. Earthquake prediction

    SciTech Connect

    Ma, Z.; Fu, Z.; Zhang, Y.; Wang, C.; Zhang, G.; Liu, D.

    1989-01-01

    Mainland China is situated at the eastern edge of the Eurasian seismic system and is the largest intra-continental region of shallow strong earthquakes in the world. Based on nine earthquakes with magnitudes ranging between 7.0 and 7.9, the book provides observational data and discusses successes and failures of earthquake prediction. Derived from individual earthquakes, observations of various phenomena and seismic activities occurring before and after earthquakes, led to the establishment of some general characteristics valid for earthquake prediction.

  6. Identification of the Amidase BbdA That Initiates Biodegradation of the Groundwater Micropollutant 2,6-dichlorobenzamide (BAM) in Aminobacter sp. MSH1.

    PubMed

    T'Syen, Jeroen; Tassoni, Raffaella; Hansen, Lars; Sorensen, Søren J; Leroy, Baptiste; Sekhar, Aswini; Wattiez, Ruddy; De Mot, René; Springael, Dirk

    2015-10-01

    2,6-dichlorobenzamide (BAM) is a recalcitrant groundwater micropollutant that poses a major problem for drinking water production in European countries. Aminobacter sp. MSH1 and related strains have the unique ability to mineralize BAM at micropollutant concentrations but no information exists on the genetics of BAM biodegradation. An amidase-BbdA-converting BAM to 2,6-dichlorobenzoic acid (DCBA) was purified from Aminobacter sp. MSH1. Heterologous expression of the corresponding bbdA gene and its absence in MSH1 mutants defective in BAM degradation, confirmed its BAM degrading function. BbdA shows low amino acid sequence identity with reported amidases and is encoded by an IncP1-β plasmid (pBAM1, 40.6 kb) that lacks several genes for conjugation. BbdA has a remarkably low KM for BAM (0.71 μM) and also shows activity against benzamide and ortho-chlorobenzamide (OBAM). Differential proteomics and transcriptional reporter analysis suggest the constitutive expression of bbdA in MSH1. Also in other BAM mineralizing Aminobacter sp. strains, bbdA and pBAM1 appear to be involved in BAM degradation. BbdA's high affinity for BAM and its constitutive expression are of interest for using strain MSH1 in treatment of groundwater containing micropollutant concentrations of BAM for drinking water production. PMID:26308673

  7. BAMS2 workspace: a comprehensive and versatile neuroinformatic platform for collating and processing neuroanatomical connections.

    PubMed

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

    2014-10-01

    We describe a novel neuroinformatic platform, the BAMS2 Workspace (http://brancusi1.usc.edu), designed for storing and processing information on gray matter region axonal connections. This de novo constructed module allows registered users to collate their data directly 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

  8. 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

  9. 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.

  10. Effects of lithospheric viscoelastic relaxation on the contemporary deformation following the 1959 Mw 7.3 Hebgen Lake, Montana, earthquake and other areas of the intermountain seismic belt

    NASA Astrophysics Data System (ADS)

    Chang, Wu-Lung; Smith, Robert B.; Puskas, Christine M.

    2013-01-01

    The 1959 Mw 7.3 Hebgen Lake, MT, normal-faulting earthquake occurred in an extensional stress regime near the Yellowstone volcanic field. Time-dependent crustal deformation data following this major earthquake were acquired by precise trilateration and GPS surveys from 1973 to 2000 around the Hebgen Lake fault zone. Modeling the changes of baseline lengths across and near the fault reveals a lateral variation of transient rheology, in which the lithosphere is stronger near the Hebgen Lake fault zone than in the vicinity of the Yellowstone volcano system. The models also imply that the lower crust is stronger than the upper mantle, in agreement with results from studies of postseismic and post-lake-filling relaxations (<~100 years). In addition, evaluations of the postseismic motion produced by the Hebgen Lake and the 1983 Mw 6.9 Borah Peak, ID, earthquakes indicate that horizontal transient motion of up to ~1 mm/yr contribute significantly to the contemporary regional crustal deformation near the epicentral areas. For the eastern Basin and Range, ~500 km south of the Hebgen Lake fault, similar rheologic models were derived from the observed uplift associated with the Lake Bonneville rebound and were used to evaluate the postseismic deformation associated with six most recent paleoearthquakes of the Wasatch fault zone and three M ≥ 5.6 historic earthquakes of northern Utah. The results show ≤0.1 mm/yr of horizontal postseismic motion at present time that are within the horizontal uncertainties of continuous GPS velocity from the Basin and Range and significantly smaller than the contemporary extension of 1-3 mm/yr in the Wasatch Front.

  11. 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. PMID:27468321

  12. 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. PMID:23670436

  13. 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

  14. Preservation of submarine event deposits: Where is the most preferable area to reconstruct the past earthquake/tsunami events from marine sediment records?

    NASA Astrophysics Data System (ADS)

    Ikehara, K.; Kanamatsu, T.; Ashi, J.; Strasser, M.; Usami, K.; Nakamura, Y.; Kodaira, S.

    2014-12-01

    Large earthquakes and their related tsunami impact submarine geological processes that can form specific submarine event deposits. Most of widely distributed event beds are typically fine-grained turbidites. Examples from the Nankai Trough and the Beppu Bay suggest that a terminal isolated depression is area with the highest potential for the deposition of fine-grained turbidites. The 2004 off the Kii Peninsula earthquakes caused a fine-grained turbidite deposited in a small basin on the Nankai accretionary prism slope, and formed a thick acoustically transparent layer. Off Sanriku thickness of the 2011 Tohoku-oki earthquake and tsunami event beds was usually a few-several cm, but was highest in the Japan Trench with several tens cm. The Japan Trench floor is the deepest and terminal basin. The terminal basin is a potential area for marine paleoseismology. Preservation potential is a factor for usage of submarine event beds as paleoseimsological tool. Repeated sampling of surface sediments from off Sanriku after the 2011 event suggests that the preservation potential of fine-grained event bed is low in the strong benthos activity zone. Sedimentation rate is another factor on the preservation potential. Quick and high sediment accumulation after the event bed deposition diminishes the pressure for the destruction of the event beds by benthos activity. Thus, a small basin covered by the bottom water with low dissolved oxygen concentration, and occurred under the high primary productivity areas is a good example of basins with high preservation potential of event beds. High resolution seismic profiles in the central Japan Trench indicate that occurrence of the well-stratified strata filling the trench and subducting graben depressions. These strata have high potential for seismo-turbidite deposition. Thus, small basins on the mid-slope terrace and the trench floor of the central Japan Trench are most preferable and potential candidates for submarine paleoseismology.

  15. 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)

  16. PRE SEISMIC ANOMALIES REVEALED IN THE AREA WHERE THE ABRUZZO EARTHQUAKE (M = 6.3) OCCURRED ON APRIL 6, 2009

    NASA Astrophysics Data System (ADS)

    Biagi, P. F.; Castellana, L.; Maggipinto, T.; Ermini, A.

    2009-12-01

    Since 1996, the intensity of CLT (f=189 kHz, Sicily, Italy), MCO (f=216 kHz, France) and CZE (f=270 kHz, Czech Republic) broadcast signals has been collected with a ten minutes sampling rate by a receiver operating in a place located about 13 km far from the epicenter of the Abruzzo earthquake (M=6.3, April 6, 2009). During March 2009, the old receiver was substituted with a new one for measuring, with one minute sampling rate, the intensity of five VLF signals and five LF signals radiated by transmitters located in different zone of Europe. Two of the previous transmitters are included among them. In the period March 31-April 1 the intensity of the MCO radio signal dropped and this drop was observed only in this signal. The possibility that the drop was connected to problems in the transmitter or in the receiver was investigated and excluded. So, the drop indicates a defocusing of the radiated signal. Since none particular meteorological situation along the path transmitter-receiver happened, the defocusing must be related to other causes. The possibility that it is a precursor of the Abruzzo earthquake is presented. Beside, the flow rate of a natural spring located in the same place of the receiver is being sampled from 1992. During September-October 2008 the flow rate was abnormal with respect to all the previous periods. Also this anomaly takes the shape of a precursor of the Abruzzo earthquake. Probably, it is mainly related to the seismic sequence that started in the zone in the middle of January 2009 and that lasted up to the earthquake.

  17. Seismic structure of southern margin of the 2011 Tohoku-Oki Earthquake aftershocks area: slab-slab contact zone beneath northeastern Kanto, central Japan

    NASA Astrophysics Data System (ADS)

    Kurashimo, E.; Sato, H.; Abe, S.; Mizohata, S.; Hirata, N.

    2011-12-01

    The 2011 Tohoku-Oki Earthquake (Mw9.0) occurred on the Japan Trench off the eastern shore of northern Honshu, Japan. The southward expansion of the afterslip area has reached the Kanto region, central Japan (Ozawa et al., 2011). The Philippine Sea Plate (PHS) subducts beneath the Kanto region. The bottom of the PHS is in contact with the upper surface of the Pacific Plate (PAC) beneath northeastern Kanto. Detailed structure of the PHS-PAC contact zone is important to constrain the southward rupture process of the Tohoku-Oki Earthquake and provide new insight into the process of future earthquake occurrence beneath the Kanto region. Active and passive seismic experiments were conducted to obtain a structural image beneath northeastern Kanto in 2010 (Sato et al., 2010). The geometry of upper surface of the PHS has been revealed by seismic reflection profiling (Sato et al., 2010). Passive seismic data set is useful to obtain a deep structural image. Two passive seismic array observations were conducted to obtain a detailed structure image of the PHS-PAC contact zone beneath northeastern Kanto. One was carried out along a 50-km-long seismic line trending NE-SW (KT-line) and the other was carried out along a 65-km-long seismic line trending NW-SE (TM-line). Sixty-five 3-component portable seismographs were deployed on KT-line with 500 to 700 m interval and waveforms were continuously recorded during a four-month period from June, 2010. Forty-five 3-component portable seismographs were deployed on TM-line with about 1-2 km spacing and waveforms were continuously recorded during the seven-month period from June, 2010. Arrival times of earthquakes were used in a joint inversion for earthquake locations and velocity structure, using the iterative damped least-squares algorithm, simul2000 (Thurber and Eberhart-Phillips, 1999). The relocated hypocenter distribution shows that the seismicity along the upper surface of the PAC is located at depths of 45-75 km beneath

  18. 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

  19. 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.

  20. 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.

  1. 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

  2. Lessons learned from the Great East Japan Earthquake: The need for disaster preparedness in the area of disaster mental health for children.

    PubMed

    Kozu, Shuei; Homma, Hiroaki

    2014-01-01

    The Great East Japan Earthquake on March 11, 2011 brought unprecedented challenges to individuals, families, and communities of the Tohoku region in Japan. Children are especially vulnerable to the postdisaster risk factors that impact their ability to heal. The destruction of the infrastructure by the disasters made it more challenging to reach out to children in an area where the stigma against mental illness is persistent. The authors share their experiences, what they heard from patients, and their reflections on lessons learned. The authors recommend the development of a coordinated mental health response system in preparation for the next disaster. PMID:25530559

  3. 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., (Edited By); Hays, Walter W.; Kitzmiller, Carla, (compiler)

    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.

  4. 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. PMID:27020285

  5. 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

  6. 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

  7. The SOUTHERN PUNA Seismic Experiment: Shape of the Subducting Nazca Plate, Areas of Concentrated Mantle and Crustal Earthquakes, and Crustal Focal Mechanisms

    NASA Astrophysics Data System (ADS)

    Mulcahy, P.; Chen, C.; Kay, S. M.; Brown, L. D.; Alvarado, P. M.; Sandvol, E. A.; Heit, B.; Yuan, X.

    2010-12-01

    The SOUTHERN PUNA Seismic Experiment in the Central Andes between 25° - 28°S and 70° - 65°W recorded data in a 74-instrument array from Dec 07 to Nov 09 with the purpose of evaluating the structure and seismic character of the mantle and crust at the southern end of the Puna-Antiplano Plateau. Hypocenter locations for local and regional mantle earthquakes from 16 months of continuous recording confirm the persistence of the backarc teleseismic Antofalla Gap in intermediate depth mantle seismicity between 25.5° and 27.5°S consistent with the interpretation of a hot mantle wedge under this region. The best located Wadati Benioff Zone events agree with the subducting Nazca Plate contours of Cahill and Isacks (1992) north of 27°S, but show a more abrupt southward shallowing of contours in agreement with the Anderson et al. (2007) contours outlining the projected path of the already subducted Juan Fernandez Ridge. Another prominent feature in the data is the concentration of hypocenters in the Pipanaco nest to the south of the Antofalla Gap between 27° and 29°S. New PUNA results together with available HCMT solutions indicate NW oriented normal and strike-slip faulting in three general clusters within this nest at ~130km, 150km and 180km depth. Hypocenter locations and fault solutions for the Pipanaco Nest suggest flexure associated with steepening of the subducting slab consistent with the revised Wadati Benioff Zone contours. In an area of little to no crustal seismicity in global catalogs over the same time period, hundreds of well-located crustal earthquakes at depths less than 15km were recorded by the PUNA array. Among these earthquakes are three distinct clusters near relatively young volcanic centers. One cluster defines a nest northeast of the < 1 Ma Cerro Blanco caldera. The other two clusters are characterized by large quantities of earthquakes within 24-36 hours (swarms) near the Cerro Galan caldera that last erupted at ~2 Ma and near a ~1 Ma or

  8. 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

  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. 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.

  11. Ground breakage and associated effects in the Cook Inlet area, Alaska, resulting from the March 27, 1964 earthquake: Chapter F in The Alaska earthquake, March 27, 1964: regional effects

    USGS Publications Warehouse

    Foster, Helen L.; Karlstrom, Thor N.V.

    1967-01-01

    The great 1964 Alaska earthquake caused considerable ground breakage in the Cook Inlet area of south-central Alaska. The breakage occurred largely in thick deposits of unconsolidated sediments. The most important types of ground breakage were (1) fracturing or cracking and the extrusion of sand and gravel with ground water along fractures in various types of landforms, and (2) slumping and lateral extension of unconfined faces, particularly along delta fronts. The principal concentration of ground breakage within the area covered by this report was in a northeast-trending zone about 60 miles long and 6 miles wide in the northern part of the Kenai Lowland. The zone cut across diverse topography and stratigraphy. Cracks were as much as 30 feet across and 25 feet deep. Sand, gravel, and pieces of coal and lignite were extruded along many fissures. It is suggested that the disruption in this zone may be due to movement along a fault in the underlying Tertiary rocks. The outwash deltas of Tustumena and Skilak Lakes in the Kenai Lowland, of Eklutna Lake and Lake George in the Chugach Mountains, of Bradley Lake in the Kenai Mountains, and at the outlet of upper Beluga Lake at the base of the Alaska Range showed much slumping, as did the delta of the Susitna River. Parts of the flood plains of the Skilak River, Fox River, and Eagle River were extensively cracked. A few avalanches and slumps occurred along the coast of Cook Inlet in scattered localities. Some tidal flats were cracked. However, in view of the many thick sections of unconsolidated sediments and the abundance of steep slopes, the cracking was perhaps less than might have been expected. Observations along the coasts indicated changes in sea level which, although caused partly by compaction of unconsolidated sediments, may largely be attributed to crus1tal deformation accompanying the earthquake. Most of the Cook Inlet area was downwarped, although the northwest side of Cook Inlet may have been slightly unwarped

  12. 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

  13. [Survey report on magnetic resonance equipment damage in areas in Miyagi Prefecture affected by the Great East Japan Earthquake].

    PubMed

    Maeyatsu, Fumio; Abe, Yoshihiro; Hishinuma, Makoto; Hikiti, Takeo; Tanji, Hajime; Seino, Shinya; Adachi, Kojiro; Musashi, Yasunori; Tuchihashi, Toshio; Machida, Yosihio; Yamaguchi-Sekino, Sachiko; Nakai, Toshiharu

    2014-03-01

    A questionnaire comprising 14 items, inquiring about the state of damage, whether safety could be ensured, and progress of repair and restoration was distributed to 984 facilities in seven prefectures on the Pacific coast as part of a fact-finding survey of damage caused to magnetic resonance (MR) devices by the Great East Japan Earthquake. In all, 458 responses (46.6%) were collected. In Miyagi Prefecture alone, 65 responses from 105 questionnaires were collected (response rate: 61.9%). The overall incidence of damage was 19.2%, with 57 facilities (12.4%) reporting that displacement of the magnets was the most common problem. The damage event rate in Miyagi Prefecture was 51.3%, with displacement of the magnet being highest at 17 cases (26.2%). There was a high rate of 13 cases (26.5%) of chiller and air conditioning failures and a rapid loss of He in ten MR scanners (20.4%). Notably, 87.8% of facilities in Miyagi Prefecture (24.5% of the total) were affected by earthquakes exceeding 6 on the Japanese Seismic Intensity Scale. Flood damage caused by the tsunami was also seen along the Sanriku coast to Sendai City (six MR scanners, 50% of the total), and was typical of the damage seen in Miyagi Prefecture. PMID:24647061

  14. Suppression of Arabidopsis protophloem differentiation and root meristem growth by CLE45 requires the receptor-like kinase BAM3.

    PubMed

    Depuydt, Stephen; Rodriguez-Villalon, Antia; Santuari, Luca; Wyser-Rmili, Céline; Ragni, Laura; Hardtke, Christian S

    2013-04-23

    Peptide signaling presumably occupies a central role in plant development, yet only few concrete examples of receptor-ligand pairs that act in the context of specific differentiation processes have been described. Here we report that second-site null mutations in the Arabidopsis leucine-rich repeat receptor-like kinase gene barely any meristem 3 (BAM3) perfectly suppress the postembryonic root meristem growth defect and the associated perturbed protophloem development of the brevis radix (brx) mutant. The roots of bam3 mutants specifically resist growth inhibition by the CLAVATA3/ENDOSPERM SURROUNDING REGION 45 (CLE45) peptide ligand. WT plants transformed with a construct for ectopic overexpression of CLE45 could not be recovered, with the exception of a single severely dwarfed and sterile plant that eventually died. By contrast, we obtained numerous transgenic bam3 mutants transformed with the same construct. These transgenic plants displayed a WT phenotype, however, supporting the notion that CLE45 is the likely BAM3 ligand. The results correlate with the observation that external CLE45 application represses protophloem differentiation in WT, but not in bam3 mutants. BAM3, BRX, and CLE45 are expressed in a similar spatiotemporal trend along the developing protophloem, up to the end of the transition zone. Induction of BAM3 expression upon CLE45 application, ectopic overexpression of BAM3 in brx root meristems, and laser ablation experiments suggest that intertwined regulatory activity of BRX, BAM3, and CLE45 could be involved in the proper transition of protophloem cells from proliferation to differentiation, thereby impinging on postembryonic growth capacity of the root meristem. PMID:23569225

  15. Sun, Moon and Earthquakes

    NASA Astrophysics Data System (ADS)

    Kolvankar, V. G.

    2013-12-01

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

  16. 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

  17. Cross‐species chimeras reveal BamA POTRA and β‐barrel domains must be fine‐tuned for efficient OMP insertion

    PubMed Central

    Bavro, Vassiliy N.; Mason, Jessica L.; Sevastsyanovich, Yanina R.; Rossiter, Amanda E.; Jeeves, Mark; Wells, Timothy J.; Knowles, Timothy J.; Cunningham, Adam F.; Donald, James W.; Palmer, Tracy; Overduin, Michael

    2015-01-01

    Summary BAM is a conserved molecular machine, the central component of which is BamA. Orthologues of BamA are found in all Gram‐negative bacteria, chloroplasts and mitochondria where it is required for the folding and insertion of β‐barrel containing integral outer membrane proteins (OMPs) into the outer membrane. BamA binds unfolded β‐barrel precursors via the five polypeptide transport‐associated (POTRA) domains at its N‐terminus. The C‐terminus of BamA folds into a β‐barrel domain, which tethers BamA to the outer membrane and is involved in OMP insertion. BamA orthologues are found in all Gram‐negative bacteria and appear to function in a species‐specific manner. Here we investigate the nature of this species‐specificity by examining whether chimeric E scherichia coli  BamA fusion proteins, carrying either the β‐barrel or POTRA domains from various BamA orthologues, can functionally replace E . coli  BamA. We demonstrate that the β‐barrel domains of many BamA orthologues are functionally interchangeable. We show that defects in the orthologous POTRA domains can be rescued by compensatory mutations within the β‐barrel. These data reveal that the POTRA and barrel domains must be precisely aligned to ensure efficient OMP insertion. PMID:25943387

  18. Hidden earthquakes

    SciTech Connect

    Stein, R.S.; Yeats, R.S.

    1989-06-01

    Seismologists generally look for earthquakes to happen along visible fault lines, e.g., the San Andreas fault. The authors maintain that another source of dangerous quakes has been overlooked: the release of stress along a fault that is hidden under a fold in the earth's crust. The paper describes the differences between an earthquake which occurs on a visible fault and one which occurs under an anticline and warns that Los Angeles greatest earthquake threat may come from a small quake originating under downtown Los Angeles, rather than a larger earthquake which occurs 50 miles away at the San Andreas fault.

  19. Inference of small-scale Vp/Vs ratio along the rupture area of the Tocopilla earthquake, Northern Chile (Mw 7.7, 14/11/2007)

    NASA Astrophysics Data System (ADS)

    Tilmann, F. J.; Palo, M.; Schurr, B.

    2014-12-01

    We have inferred the Vp/Vs ratio along the segment of the Peru-Chile subduction margin corresponding to the rupture area of the Tocopilla earthquake (TE, Mw 7.7, 14/11/2007). This event nucleated in Northern Chile and broke the southern ~100 km of the ~500 km Northern Chile Southern Peru seismic gap, which had not seen an earthquake of this magnitude since the M~9 event of 1877. TE activated two main co-seismic slip patches: one around the epicenter and another north-east of the Mejillones Peninsula. We have applied the Lin and Shearer approach [1] to the aftershock sequence of TE. In this approach, the relative time shift between the S phases of a pair of nearby events at one station are plotted as function of the time shift between the P phases of the same pair. The process is repeated for a set of events. If the events are close enough to assume a uniform local Vp/Vs and the P-reciprocal wavefront can be approximated as planar, the points lay on a line, whose slope is an estimation of the local Vp/Vs. The technique is extended to a set of stations demeaning the time shifts from each pair of events. The time shifts are inferred maximizing the cross-correlation function between the event pairs. The technique has been applied to clusters of events sharing similar waveforms and spatially clustered hypocentres. We have adopted a robust linear L2 regression and have assigned a statistical error to the best fit. Most clusters are identified within a sub-vertical branch of the subduction interface hosting a major aftershock (Michilla earthquake, 16/12/2007, Ml 6.8) and its aftershocks. This branch falls inside the subducted Nazca Plate at depths of 40-50 km, north-east of the Mejillones Peninsula, and shows Vp/Vs mostly in the range 1.8-1.9. Clusters close to the Mejillones Peninsula and to the epicenter displays Vp/Vs around 1.7 and 1.8, respectively. References [1] - Lin, G., & Shearer, P. (2007). Estimating local Vp/Vs ratios within similar earthquake clusters

  20. A Backscatter Moessbauer Spectrometer (BaMS) for use on Mars

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

    The use of Moessbauer spectroscopy for in situ analysis on the surface of Mars was proposed and the design and implementation of a backscatter Moessbauer spectrometer (BaMS) instrument suitable for planetary missions to the surfaces of Mars (MESUR), the Moon (Artemis and lunar outpost), asteroids, or other solid solar system objects is discussed. The BaMS instrument is designed to be capable of analysis of a sample for the mineralogy of its iron-bearing phases without any sample preparation. A requirement of lander missions to Mars is instrumentation for in situ mineralogical analyses. Such analyses provide data needed for primary characterization as to the type of surface materials present and by inference the processes that formed and subsequently modified them. For purposes of providing diagnostic information about naturally occurring materials, the element iron is particularly important because it is abundant and multivalent (primarily 0, +2, and +3 oxidation states). Knowledge of the oxidation state of iron and its distribution among iron-bearing mineralogies tightly constrains the types of materials present. The pivotal role of iron was already recognized in 1978 by COMPLEX, who recommended development of flight instruments that would identify mineralogy and the oxidation state of iron in planetary surface materials. The near-term U.S. strategy for the exploration of Mars is the MESUR (Mars Environmental SURvey) program, which entails emplacement of a network of small, long-lived surface landers. For the Moon, BaMS was recommended as part of a three-instrument landed payload for the Artemis missions, targeted for 1997. BaMS would prospect for ilmenite, an oxygen resource material, and provide data to assess the maturity of lunar soil. Because instrumental characteristics are low mass, low volume, and low power consumption, BaMS is suitable for implementation on even small landers and rovers, as are being envisioned in MESUR and Artemis concepts. In addition

  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. Earthquakes with non--double-couple mechanisms.

    PubMed

    Frohlich, C

    1994-05-01

    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. PMID:17794721

  3. 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)

  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. 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. PMID:26752438

  6. Exponential stability preservation in semi-discretisations of BAM networks with nonlinear impulses

    NASA Astrophysics Data System (ADS)

    Mohamad, Sannay; Gopalsamy, K.

    2009-01-01

    This paper demonstrates the reliability of a discrete-time analogue in preserving the exponential convergence of a bidirectional associative memory (BAM) network that is subject to nonlinear impulses. The analogue derived from a semi-discretisation technique with the value of the time-step fixed is treated as a discrete-time dynamical system while its exponential convergence towards an equilibrium state is studied. Thereby, a family of sufficiency conditions governing the network parameters and the impulse magnitude and frequency is obtained for the convergence. As special cases, one can obtain from our results, those corresponding to the non-impulsive discrete-time BAM networks and also those corresponding to continuous-time (impulsive and non-impulsive) systems. A relation between the Lyapunov exponent of the non-impulsive system and that of the impulsive system involving the size of the impulses and the inter-impulse intervals is obtained.

  7. 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.

  8. State of Stress in the Interseismic in the Salar Grande Area and its Relationship with the Foreshock Sequence of Mw8.1 Pisagua Earthquake

    NASA Astrophysics Data System (ADS)

    Salazar, P.; Gonzalez, G.; Latorre, C.; Pasten, F.; Sarmiento, A.; Kummerow, J.; Wigger, P.; Bloch, W.; Shapiro, S. A.

    2014-12-01

    We have installed short period network in order to monitor the crustal seismicity in the Tarapacá region. The main task is to try to understand the stress transference from the interplate contact to the upper crustal. The network consisted in a total of 21 short period stations, which were installed in the Coastal Cordillera (around Salar Grande) and the Precordillera (around Quebrada Blanca). The processing of the records in this network permitted the analysis of ~5000 events occurred during 2005-2012, each were localized using the NonLinLoc software. A part of this catalog, specifically the data collected during 2010, were processed in order to obtain some parameters associated to the stress as stress tensor, b-value and the maximum horizontal stress (σHMAX). The results of the σHMAX and the stress tensor show that the direction of shortening in the upper crust is NS, which is clearly deviated from the direction of convergence. This pattern, found in the Salar Grande, is practically the same that we observed in the Mw6.7 earthquake occurred on March 16th -event that triggered the sequence of foreshock associated to the Mw8.1 Pisagua earthquake (ca. 170 km to the NW of the Salar Grande area). The NS direction of shortening is also seen in several upper crustal events occurred in the first days, before Mw8.1 Pisagua earthquake. On the other hand, the b-value > 0.9, calculated for the Salar Grande area, coincides with places where the seismic activity is associated to EW reverse faults mapped in the surface by geological studies -these structures are a common feature in the Atacama Fault System at these latitudes. They are also an indication of a NS direction of shortening, being in agreement with our seismological observations. The NS direction of shortening is not restricted to shallow depth, but it is extended to the interplate contact between the deeper part of the couple zone and the transitional zone. The last indicates that the NS shortening is a

  9. Statistical physics of earthquakes: Comparison of distribution exponents for source area and potential energy and the dynamic emergence of log-periodic energy quanta

    NASA Astrophysics Data System (ADS)

    Main, Ian G.; O'Brien, Gareth; Henderson, Jeremy R.

    2000-03-01

    We investigate the relationship between the size distribution of earthquake rupture area and the underlying elastic potential energy distribution in a cellular automaton model for earthquake dynamics. The frequency-rupture area distribution has the form n(S) ˜Sτ exp (-S/So) and the system potential energy distribution from the elastic Hamiltonian has the form n(E) ˜Ev exp (-E/θ), both gamma distributions. Here n(S) reduces to the Gutenberg-Richter frequency-magnitude law, with slope b ˜τ, in the limit that the correlation length ξ, related to the characteristic source size So, tends to infinity. The form of the energy distribution is consistent with a statistical mechanical model with l degrees of freedom, where v = (l-2)/2 and θ is proportional to the mean energy per site ? . We examine the effect of the local energy conservation factor β and the degree of material heterogeneity (quenched disorder) on the distribution parameters, which vary systematically with the controlling variables. The inferred correlation length increases systematically with increasing material homogeneity and with increasing β. The thermal parameter θ varies systematically between the leaf springs and the connecting springs, and is proportional to ? as predicted. For heterogeneous faults, τ ˜1 stays relatively constant, consistent with field observation, and S0 increases with increasing β or decreasing heterogeneity. In contrast, smooth faults produce a systematic decrease in τ with respect to β and So remains relatively constant. For high β approximately log-periodic quanta emerge spontaneously from the dynamics in the form of modulations on the energy distribution. The output energy for both types of fault shows a transition from strongly quasi-periodic temporal fluctuations for strong dissipation, to more chaotic fluctuations for more conservative models. Only strongly heterogeneous faults show the small fluctuations in energy strictly required by models of self

  10. 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. PMID:23353617

  11. Lipids assist the membrane insertion of a BAM-independent outer membrane protein

    PubMed Central

    Huysmans, Gerard H. M.; Guilvout, Ingrid; Chami, Mohamed; Nickerson, Nicholas N.; Pugsley, Anthony P.

    2015-01-01

    Like several other large, multimeric bacterial outer membrane proteins (OMPs), the assembly of the Klebsiella oxytoca OMP PulD does not rely on the universally conserved β-barrel assembly machinery (BAM) that catalyses outer membrane insertion. The only other factor known to interact with PulD prior to or during outer membrane targeting and assembly is the cognate chaperone PulS. Here, in vitro translation-transcription coupled PulD folding demonstrated that PulS does not act during the membrane insertion of PulD, and engineered in vivo site-specific cross-linking between PulD and PulS showed that PulS binding does not prevent membrane insertion. In vitro folding kinetics revealed that PulD is atypical compared to BAM-dependent OMPs by inserting more rapidly into membranes containing E. coli phospholipids than into membranes containing lecithin. PulD folding was fast in diC14:0-phosphatidylethanolamine liposomes but not diC14:0-phosphatidylglycerol liposomes, and in diC18:1-phosphatidylcholine liposomes but not in diC14:1-phosphatidylcholine liposomes. These results suggest that PulD efficiently exploits the membrane composition to complete final steps in insertion and explain how PulD can assemble independently of any protein-assembly machinery. Lipid-assisted assembly in this manner might apply to other large OMPs whose assembly is BAM-independent. PMID:26463896

  12. Arabidopsis MAKR5 is a positive effector of BAM3-dependent CLE45 signaling.

    PubMed

    Kang, Yeon Hee; Hardtke, Christian S

    2016-08-01

    Receptor kinases convey diverse environmental and developmental inputs by sensing extracellular ligands. In plants, one group of receptor-like kinases (RLKs) is characterized by extracellular leucine-rich repeat (LRR) domains, which interact with various ligands that include the plant hormone brassinosteroid and peptides of the CLAVATA3/EMBRYO SURROUNDING REGION (CLE) type. For instance, the CLE45 peptide requires the LRR-RLK BARELY ANY MERISTEM 3 (BAM3) to prevent protophloem formation in Arabidopsis root meristems. Here, we show that other proposed CLE45 receptors, the two redundantly acting LRR-RLKs STERILITY-REGULATING KINASE MEMBER 1 (SKM1) and SKM2 (which perceive CLE45 in the context of pollen tube elongation), cannot substitute for BAM3 in the root. Moreover, we identify MEMBRANE-ASSOCIATED KINASE REGULATOR 5 (MAKR5) as a post-transcriptionally regulated amplifier of the CLE45 signal that acts downstream of BAM3. MAKR5 belongs to a small protein family whose prototypical member, BRI1 KINASE INHIBITOR 1, is an essentially negative regulator of brassinosteroid signaling. By contrast, MAKR5 is a positive effector of CLE45 signaling, revealing an unexpected diversity in the conceptual roles of MAKR genes in different signaling pathways. PMID:27354416

  13. Success! Detailed Pre-event Analysis Identified the Slip Area and Magnitude of the Sept. 2012 MW 7.6 Nicoya Earthquake

    NASA Astrophysics Data System (ADS)

    Newman, A. V.; Protti, M.; Gonzalez, V. M.; Dixon, T. H.; Schwartz, S. Y.; Feng, L.; Peng, Z.; Marshall, J.; Malservisi, R.; Owen, S. E.

    2013-05-01

    On September 5th, 2012 a moment magnitude (MW) 7.6 earthquake struck the seismogenic megathrust of Nicoya Costa Rica. Though, we knew not precisely when, this event was not unexpected, and occurred after the development of substantial pre-event scientific discovery and earthquake infrastructural development. Beginning in the late- 1990's Nicoya Costa Rica was recognized by the U.S. National Science Foundation -MARGINS program as a focus area for seismogenic zone studies in part because of the unique proximity of land to the active subduction megathrust. The region also has very fast convergence (~9 cm/a) and has suffered from regular M7+ earthquakes in 1853, 1900 and 1950. Another similar event was expected by many. Pre-event analysis identified the structure of the subduction interface [Newman et al., GRL, 2002; DeShon et al., GJI, 2006], the location and rate changes of ongoing microseismicity [Newman et al., GRL, 2002, Ghosh et al.,GRL, 2008], the location and degree of locking that developed during the late interseismic [Norabuena et al., JGR, 2006; Feng et al., JGR, 2012], and its relation to ongoing low-frequency earthquakes, subduction tremor, and episodic slip events [Walter et al., GRL, 2011; Outerbridge et al., JGR, 2010, Jiang et al., G3, 2012]. Feng et al., [2012] using campaign and continuous GPS data through 2012, identified complex locked 50x50 km patch along the central coast of Nicoya, the locale that failed in Sept 2012, and concluded that the region had the potential to fail in an MW 7.8 event should the most recent locking be representative of behavior since the last major event in 1950. In operation at the time of the event was a substantial NSF-funded continuous GPS (17 station) and seismic (18 station) network maintained by USF, UCSC, and GIT, in cooperation with OVSICORI. The seismic network captured the initial motions of the mainshock before clipping, as well as pre-shock and aftershock activity [Walter et al., (this meeting), 2013]. The

  14. 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

  15. Investigation of the role of the BAM complex and SurA chaperone in outer-membrane protein biogenesis and type III secretion system expression in Salmonella.

    PubMed

    Fardini, Yann; Trotereau, Jérôme; Bottreau, Elisabeth; Souchard, Charlène; Velge, Philippe; Virlogeux-Payant, Isabelle

    2009-05-01

    In Escherichia coli, the assembly of outer-membrane proteins (OMP) requires the BAM complex and periplasmic chaperones, such as SurA or DegP. Previous work has suggested a potential link between OMP assembly and expression of the genes encoding type-III secretion systems. In order to test this hypothesis, we studied the role of the different lipoproteins of the BAM complex (i.e. BamB, BamC, BamD and BamE), and the periplasmic chaperones SurA and DegP, in these two phenotypes in Salmonella. Analysis of the corresponding deletion mutants showed that, as previously described with the DeltabamB mutant, BamD, SurA and, to a lesser extent, BamE play a role in outer-membrane biogenesis in Salmonella Enteritidis, while the membrane was not notably disturbed in DeltabamC and DeltadegP mutants. Interestingly, we found that BamD is not essential in Salmonella, unlike its homologues in Escherichia coli and Neisseria gonorrhoeae. In contrast, BamD was the only protein required for full expression of T3SS-1 and flagella, as demonstrated by transcriptional analysis of the genes involved in the biosynthesis of these T3SSs. In line with this finding, bamD mutants showed a reduced secretion of effector proteins by these T3SSs, and a reduced ability to invade HT-29 cells. As DeltasurA and DeltabamE mutants had lower levels of OMPs in their outer membrane, but showed no alteration in T3SS-1 and flagella expression, these results demonstrate the absence of a systematic link between an OMP assembly defect and the downregulation of T3SSs in Salmonella; therefore, this link appears to be related to a more specific mechanism that involves at least BamB and BamD. PMID:19372159

  16. Turkish Compulsory Earthquake Insurance and "Istanbul Earthquake

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

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

  17. 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.

  18. 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. PMID:26965277

  19. 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.

  20. 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.

  1. 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

  2. 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

  3. 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)

  4. 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.

  5. Recent earthquakes in northern New York

    SciTech Connect

    Revetta, F.A.; Bockus, C.; O'Brian, B. . Dept. of Geology)

    1993-03-01

    The Massena, New York area located along the St. Lawrence River in northern New York has been the site of significant earthquake activity including the largest earthquake in New York (m = 6.0) on September 5, 1944. Historic earthquake data indicates the Cornwall-Massena area is a region of relatively high seismic activity, and the earthquake activity has been persistent for over a 400 year period. During the past year eleven small earthquakes have been recorded by the Potsdam Seismic Network in northern New York. Four of these earthquakes had epicenters located in the Massena-Cornwall area. One epicenter was located along the Carthage-Colton Mylonite Zone and one epicenter was located n the epicentral region of the October 7, 1984 Goodnow earthquake. Five earthquakes had epicenters located in Ontario and Quebec. These earthquake epicenters lie in a belt of seismicity that extends north-westerly from the northern Adirondacks into the Canadian Shield of western Quebec. Several explanations that have been presented to explain these earthquakes are (1) mafic intrusions (2) unmapped northwest trending faults (3) extension of the New England seamount chain and (4) crustal fractures due to the area passing over a hotspot. Four earthquakes in the Massena area lie very near extensions of the Gloucester and Winchester Spring faults into New York and may be related to the faults. Focal mechanism solutions of two earthquakes indicate thrusting along NW striking fault planes. Another possibility is the earthquakes are related to the Carthage-Colton Mylonite Zone. One earthquake is within four kms of the CCMZ and if the zone is extended northward beneath the lower Paleozoics, it passes through the epicenters on the Cornwall-Massena area.

  6. Headaches prior to earthquakes

    NASA Astrophysics Data System (ADS)

    Morton, L. L.

    1988-06-01

    In two surveys of headaches it was noted that their incidence had increased significantly within 48 h prior to earthquakes from an incidence of 17% to 58% in the first survey using correlated samples and from 20.4% to 44% in the second survey using independent samples. It is suggested that an increase in positive air ions from rock compression may trigger head pain via a decrease in brain levels of the neurotransmitter serotonin. The findings are presented as preliminary, with the hope of generating further research efforts in areas more prone to earthquakes.

  7. Seismic velocity structure in the Hemet Stepover and Trifurcation Areas of the San Jacinto Fault Zone from double-difference earthquake tomography

    NASA Astrophysics Data System (ADS)

    Allam, A. A.; Ben-Zion, Y.; Vernon, F.; Kurzon, I.

    2013-12-01

    We present tomographic images of crustal velocity structures in the Hemet Stepover and Trifurcation areas of the San Jacinto Fault Zone (SJFZ) based on double-difference inversions of earthquake arrival times. We discretize both regions with a horizontal 250m grid spacing and a vertical 500m spacing within 50km by 50km by 20km volumes. We invert for VP, VS, and hypocenter location using data from 16064 earthquakes recorded at 136 stations. In total, we use 266,969 P and 148,249 S arrivals to constrain the seismic velocity structures in the two regions. With large numbers of both arrivals, we are able to obtain images of VP and VS at similar resolutions, enabling us to make spatial maps of and interpret the VP/VS ratios. Though ray coverage is limited at shallow depths, we obtain high-fidelity images of seismic velocities from 2 to 12 km, and validate the results using checkerboard tests. The tomographic images indicate that the velocity of the trifurcation area as a whole is lower than adjacent unfaulted material. We interpret a 4km-wide low velocity zone in the trifurcation itself as fault zone damage related due to high VP/VS ratio. We also observe clear velocity contrasts across the Buck Ridge, Clark, and Coyote Creek segments of the SJFZ. The Anza segment of the SJFZ, to the NW of the trifurcation area, displays a strong (up to 27%) contrast of VS from 2km to 9km. In the Hemet Stepover, a low velocity zone between the Claremont and Casa Loma Strands narrows with depth, with clear velocity contrasts observed across both segments. A roughly 10km-wide zone of low velocity and low VP/VS ratio at the NW tip of the Hot Springs fault is indicative of either unconsolidated sediments associated with the San Jacinto basin, or fluid-filled cracks within a broad deformation zone. Relocated seismicity tends to align with the surface traces of the various fault strands, though it is offset to the northeast of the Casa Loma-Clark strand and to the southwest of the Hot Springs

  8. 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

  9. 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

  10. Forecasting California’s earthquakes

    USGS Publications Warehouse

    Kerr, R. A.

    1988-01-01

    For the first time, researchers have reached to a consensus on the threat of large earthquakes to California, things look no worse for Los Angles than before. It still has about a 60 percent chance of being shaken by a large earthquake sometime during the next 30 years. But other heavily populated areas of California, such as San Bernardino and the East Bay area of San Francisco, are now getting their fair share of attention. The new consensus also points up the considerable uncertainties invloved in earthquake forecasting. 

  11. Outbreak of Culex inatomii in disaster areas of the Great East Japan earthquake and tsunami in 2011, with ecological notes on their larval habitats, biting behavior, and reproduction.

    PubMed

    Tsuda, Yoshio; Kim, Kyeong Soon

    2013-03-01

    Outbreaks of Culex inatomii occurred widely in disaster areas of the tsunami caused by the Great East Japan earthquake in March 2011. Mosquitoes were collected in southern Miyagi Prefecture and northern Fukushima Prefecture in August and September 2011, respectively. In southern Miyagi Prefecture, the average number of adult Cx. inatomii collected by a suction trap baited with 1 kg of dry ice ranged between 69.3 and 132.8 per day in locations within 2.6 km from the coast in tsunami areas, while no Cx. inatomii individuals were collected 8.3 km from the coast, where seawater did not reach, and which therefore escaped the tsunami disaster. There were many ground pools of brackish water of various sizes, and larvae of Cx. inatomii were collected in 48% and 36% of the pools examined in Miyagi Prefecture and Fukushima Prefecture, respectively. Ecological notes on the larval habitats, biting behavior, seasonal prevalence, and reproduction of Cx. inatomii are presented for reference based on ecological studies conducted in Sakata Wetland, Niigata Prefecture, central Japan, in June and August 2011. Ecological factors relating to the current outbreak and the potential medical importance of Cx. inatomii are discussed. PMID:23687851

  12. Earthquakes for Kids

    MedlinePlus

    ... Hazards Data & Products Learn Monitoring Research Earthquakes for Kids Kid's Privacy Policy Earthquake Topics for Education FAQ Earthquake Glossary For Kids Prepare Google Earth/KML Files Earthquake Summary Posters ...

  13. 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.

  14. SAMMate: a GUI tool for processing short read alignments in SAM/BAM format

    PubMed Central

    2011-01-01

    Background Next Generation Sequencing (NGS) technology generates tens of millions of short reads for each DNA/RNA sample. A key step in NGS data analysis is the short read alignment of the generated sequences to a reference genome. Although storing alignment information in the Sequence Alignment/Map (SAM) or Binary SAM (BAM) format is now standard, biomedical researchers still have difficulty accessing this information. Results We have developed a Graphical User Interface (GUI) software tool named SAMMate. SAMMate allows biomedical researchers to quickly process SAM/BAM files and is compatible with both single-end and paired-end sequencing technologies. SAMMate also automates some standard procedures in DNA-seq and RNA-seq data analysis. Using either standard or customized annotation files, SAMMate allows users to accurately calculate the short read coverage of genomic intervals. In particular, for RNA-seq data SAMMate can accurately calculate the gene expression abundance scores for customized genomic intervals using short reads originating from both exons and exon-exon junctions. Furthermore, SAMMate can quickly calculate a whole-genome signal map at base-wise resolution allowing researchers to solve an array of bioinformatics problems. Finally, SAMMate can export both a wiggle file for alignment visualization in the UCSC genome browser and an alignment statistics report. The biological impact of these features is demonstrated via several case studies that predict miRNA targets using short read alignment information files. Conclusions With just a few mouse clicks, SAMMate will provide biomedical researchers easy access to important alignment information stored in SAM/BAM files. Our software is constantly updated and will greatly facilitate the downstream analysis of NGS data. Both the source code and the GUI executable are freely available under the GNU General Public License at http://sammate.sourceforge.net. PMID:21232146

  15. 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

  16. Paleoseismic evidence for seismogenic faulting in the epicentrical area of the 1755/56 Düren earthquake series, Lower Rhine Embayment, NW Germany

    NASA Astrophysics Data System (ADS)

    Kuebler, Simon; Friedrich, Anke M.; Strecker, Manfred R.

    2010-05-01

    The Lower Rhine Embayment (LRE), the NW branch of the western European Cenozoic rift system, is currently one of the most tectonically active regions in central Europe. This intraplate fault-system is generally characterized by long recurrence intervals of M ≥ 6 events. Historical records for the LRE document the occurrence of at least 21 M > 5 events, the largest of which appears to have been the 1755/56 earthquake series in the area of Düren city (ML 5.8 - 6.1). The space-time-distribution of earthquake and fault-rupture patterns in the LRE is still poorly understood but is important to understand the mechanical behaviour of faulting in this tectonically active region. Historic damage related to the 1755/56 events implies that any of four recently active faults in the epicentrical area may have ruptured. Possible seismogenic faults are the Feldbiss-, Rurrand-, Sandgewand-, and Schafberg faults. We carried out trench investigations along the Schafberg fault, a 6 km long E-dipping normal fault approximately 10 km SSW of Düren. Previous studies estimated a total offset in the range of 5-10 m on the fault since early Pleistocene times. At the trench location in the Rur River valley, SW of Untermaubach, the Schafberg fault is covered by late Pleistocene fluvial gravel, Holocene gravel and sand deposits, and late Holocene flood deposits. The suspected surface rupture is expressed in a NNW-trending topographic scarp of 0.5-1m. We excavated the fault along a 5 m deep and 85 m long trench approximately 200 m W of the recent Rur river course. Seasonal variations of the groundwater level in this part of the valley lead to intensive alteration of the unconsolidated sediments. Within the sedimentary layers, earthquake-related deformation is mostly focused in the late Pleistocene gravel units exhibiting many (>200) fractured and rotated clasts along vertical deformation zones. Furthermore, we mapped several types of soft-sediment deformation in the Holocene sandy and

  17. High codimensional bifurcation analysis to a six-neuron BAM neural network.

    PubMed

    Liu, Yanwei; Li, Shanshan; Liu, Zengrong; Wang, Ruiqi

    2016-04-01

    In this article, the high codimension bifurcations of a six-neuron BAM neural network system with multiple delays are addressed. We first deduce the existence conditions under which the origin of the system is a Bogdanov-Takens singularity with multiplicities two or three. By choosing the connection coefficients as bifurcation parameters and using the formula derived from the normal form theory and the center manifold, the normal forms of Bogdanov-Takens and triple zero bifurcations are presented. Some numerical examples are shown to support our main results. PMID:27066152

  18. 3D P-Wave Velocity Structure of the Crust and Relocation of Earthquakes in 21 the Lushan Source Area

    NASA Astrophysics Data System (ADS)

    Yu, X.; Wang, X.; Zhang, W.

    2014-12-01

    The double difference seismic tomography method is applied to the absolute first arrival P wave arrival times and high quality relative P arrival times of the Lushan seismic sequence to determine the detailed crustal 3D P wave velocity structure and the hypocenter parameters in the Lushan seismic area. The results show that the Lushan mainshock locates at 30.28 N, 103.98 E, with the depth of 16.38 km. The leading edge of aftershock in the northeast of mainshock present a spade with a steep dip angle, the aftershocks' extended length is about 12 km. In the southwest of the Lushan mainshock, the leading edge of aftershock in low velocity zone slope gently, the aftershocks' extended length is about 23 km. The P wave velocity structure of the Lushan seismic area shows obviously lateral heterogeneity. The P wave velocity anomalies represent close relationship with topographic relief and geological structure. In Baoxing area the complex rocks correspond obvious high-velocity anomalies extending down to 15 km depth,while the Cenozoic rocks are correlated with low-velocity anomalies. Our high-resolution tomographic model not only displays the general features contained in the previous models, but also reveals some new features. An obvious high-velocity anomaly is visible in Daxing area. The high-velocity anomalies beneath Baoxing and Daxing connect each other in 10 km depth, which makes the contrast between high and low velocity anomalies more sharp. Above 20 km depth the velocity structure in southwest and northeast segment of the mainshock shows a big difference: low-velocity anomalies are dominated the southwest segment, while high-velocity anomalies rule the northeast segment. The Lushan mainshock locates at the leading edge of a low-velocity anomaly surrounded by the Baoxing and Daxing high-velocity anomalies. The Lushan aftershocks in southwest are distributed in low-velocity anomalies or the transition belt: the footwall represents low-velocity anomalies, while

  19. 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).

  20. 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.

  1. 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 Central

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

    2016-01-01

    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. PMID:26661855

  2. 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. PMID:26661855

  3. 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

  4. Heterogeneous stress field in the source area of the 2003 M6.4 Northern Miyagi Prefecture, NE Japan, earthquake

    NASA Astrophysics Data System (ADS)

    Yoshida, Keisuke; Hasegawa, Akira; Okada, Tomomi

    2016-04-01

    > axes are orientated mainly to WSW-ENE in the northern part of the source area, while they are oriented to NW-SE in the southern part. This spatial pattern is roughly similar to those of the static stress change by the mainshock, which suggests that the observed spatially heterogeneous stress field was formed by the static stress change. If this is the case, the deviatoric stress magnitude before the mainshock was very small. Another possibility is the heterogeneous stress field observed after the mainshock had existed even before the mainshock, although we don't know why it was formed. Unfavorable orientation of the mainshock fault with respect to this stress field suggests that the fault is not strong in this case too.

  5. 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.

  6. Changes in the frequency and clinical features of suicide attempts in the midwestern area of Kanagawa after the great East Japan earthquake.

    PubMed

    Kato, Koji; Mikami, Katsunaka; Kimoto, Keitaro; Kimoto, Kousuke; Takahashi, Yuki; Sato, Reiko; Matsumoto, Hideo

    2014-03-01

    The aim of this study was to investigate the relationship between the clinical features of suicide attempts and the Great East Japan earthquake in Kanagawa. We enrolled 592 patients who attempted suicide and were hospitalized for inpatient treatment. Clinical features were compared between before the earthquake (A) and after the earthquake (B) groups. The number of suicide attempts increased from 286 to 306. The rate of increase in suicide attempts in men was the highest in the age group of 40-59 years. The frequency of joblessness, family psychiatric histories, precipitating event, and alcohol intake at suicide attempt was significantly higher in the B group than in the A group. The number of patients in serious condition in the B group was significantly higher than that in the A group. Other clinical features related to suicide in people who were indirectly affected by the earthquake disaster should be investigated to develop targeted prevention strategies. PMID:24502322

  7. Earthquake Hazard Mitigation Strategy in Indonesia

    NASA Astrophysics Data System (ADS)

    Karnawati, D.; Anderson, R.; Pramumijoyo, S.

    2008-05-01

    Because of the active tectonic setting of the region, the risks of geological hazards inevitably increase in Indonesian Archipelagoes and other ASIAN countries. Encouraging community living in the vulnerable area to adapt with the nature of geology will be the most appropriate strategy for earthquake risk reduction. Updating the Earthquake Hazard Maps, enhancement ofthe existing landuse management , establishment of public education strategy and method, strengthening linkages among stake holders of disaster mitigation institutions as well as establishement of continues public consultation are the main strategic programs for community resilience in earthquake vulnerable areas. This paper highlights some important achievements of Earthquake Hazard Mitigation Programs in Indonesia, together with the difficulties in implementing such programs. Case examples of Yogyakarta and Bengkulu Earthquake Mitigation efforts will also be discussed as the lesson learned. The new approach for developing earthquake hazard map which is innitiating by mapping the psychological aspect of the people living in vulnerable area will be addressed as well.

  8. 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. PMID:26310949

  9. Structural and magnetic properties of Ni-Zn doped BaM nanocomposite via citrate precursor

    NASA Astrophysics Data System (ADS)

    Rana, Kush; Thakur, Preeti; Tomar, Monika; Gupta, Vinay; Thakur, Atul

    2016-05-01

    Ni-Zn substituted M-type barium ferrite nanocomposite has been prepared via citrate precursor method. Nanocomposite having composition BaNi0.5Zn0.5Fe11O19 was sintered at 900°C for 3hrs and characterized by using different characterization techniques. X-ray diffraction (XRD) confirmed the formation of double phase with most prominent peak at (114). Average crystallite size for pure BaM and BNZFO were found to be 36 nm & 45 nm. Field emission scanning electron microscopy (FESEM) confirmed the formation of hexagonal platelets with a layered structure. Magnetic properties of these samples were investigated by using vibrating sample magnetometer (VSM). Magnetic parameters like saturation magnetization (Ms), coericivity (Hc) and squareness ratio (SQR) of nanocomposite were found to be 60 emu/g, 3663 Oe and 0.6163 respectively. These values were noticed to be higher as compared to pure BaM. Enhanced magnetic properties of nanocomposite were strongly dependent on exchange coupling. Therefore these properties make this nanocomposite a suitable candidate for magnetic recording and high frequency applications.

  10. 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.

  11. Characterization of the San Jacinto Fault Zone Northwest of the Trifurcation Area from Earthquake Data Recorded by a Dense Linear Array

    NASA Astrophysics Data System (ADS)

    Share, P. E.; Ben-Zion, Y.; Ross, Z.; Qiu, H.; Vernon, F.

    2015-12-01

    Data generated by earthquakes and recorded by a linear seismic array at Blackburn saddle NW of the trifurcation area, crossing the Clark branch of the San Jacinto Fault Zone, are used to study the internal fault zone structure in the area. The linear array (BB) is 180 m long and comprises 7 broadband three-component 1-Hz seismometers. Automatic algorithms are used to detect P and S body waves and fault zone head and trapped waves. Statistical analyses of P body wave travel times of 765 events, occurring during 2012-2014 within a 110 by 20 km window centered along the length of the Clark fault, show a 0.6-0.8 % gradual increase in slowness from the SW most (BB01) to the NE most (BB07) station. The results suggest the NE most stations overlie a zone of greater damage. Sharp velocity contrasts across the fault are imaged using fault zone head waves. In total, 72 events (within the same 110 by 20 km window) are found to produce phases with clear head wave characteristics. Further analysis of the candidate events leads to the characterization of two separate groups. The first, consisting of 51 events within approximately 11 km epicentral distance from the array, shows a clear increase of head to P body wave differential times with increasing along fault distance. Based on this moveout, an average velocity contrast across of the fault of 4 % (SW block is slower) is calculated for the portion of the Clark Fault beneath the array. Differential times for the second group show no moveout with along fault distance, suggesting a local secondary bimaterial interface with limited along-strike and/or depth extent. Events located in a broad region that also includes the San Andreas and Elsinore Faults produce candidate trapped waves that are most clear at stations BB05, BB06 and BB07 (the three NE most stations). Waveform modeling results will be presented in the meeting.

  12. Cloning of the BamHI repeat from Amaranthus and study of its methylation in genomic DNA during dedifferentiation.

    PubMed

    Pradhan, S; Sharma, A K; Sopory, S K

    1993-07-01

    A 670 bp BamHI repeat was isolated from the genomic DNA of Amaranthus paniculatus and was cloned in pUC19 vector (pABH3). The level of methylation of total genomic DNA and the BamHI repeat therein was studied by employing methylation sensitive enzymes to digest genomic DNA isolated from whole seedlings, hypocotyl, callus, and suspension culture of Amaranthus. The restriction pattern indicated double methylation of the target site CCGG. Methylation pattern of both the total genomic DNA and the cloned repeat was found to be similar during dedifferentiation indicating that there may not be a general relationship between hypomethylation and dedifferentiation. PMID:8401314

  13. Horizontal to vertical spectral ratio measurements in Port-au-Prince (Haiti) area damaged by the 2010 Haiti earthquake

    NASA Astrophysics Data System (ADS)

    Navarro, M.; Enomoto, T.; Benito, B.; Belizaire, D.; Navarro, D.; García-Jerez, A.; Dorfeuille, J.

    2013-05-01

    In order to evaluate ground shaking characteristics due to surface soil layers in the urban area of Port-au-Prince, short-period ambient noise observation has been performed approximately in a 500x500m grid. The HVSR method was applied to this set of 36 ambient noise measurement points to determine a distribution map of soil predominant periods. This map reveals a general increasing trend in the period values, from the Miocene conglomerates in the northern and southern parts of the town to the central and western zones formed of Pleistocene and Holocene alluvial deposits respectively, where the shallow geological materials that cover the basement increase in thickness. Shorter predominant periods (less than 0.3 s) were found in mountainous and neighbouring zones, where the thickness of sediments is smaller whereas longer periods (greater than 0.5 s) appear in Holocene alluvial fans, where the thickness of sediments is larger. The shallow shear-wave velocity structure have been estimated by means of inversion of Rayleigh wave dispersion data obtained from vertical-component array records of ambient noise. The measurements were carried out at one open space located in Holocene alluvial deposits, using 3 regular pentagonal arrays with 5, 10 and 20m respectively. Reliable dispersion curves were retrieved for frequencies between 4.0 and 14 Hz, with phase velocity values ranging from 420m/s down to 270 m/s. Finally, the average shear-wave velocity of the upper 30 m (VS30) was inverted for characterization of this geological unit.

  14. The physics of an earthquake

    NASA Astrophysics Data System (ADS)

    McCloskey, John

    2008-03-01

    The Sumatra-Andaman earthquake of 26 December 2004 (Boxing Day 2004) and its tsunami will endure in our memories as one of the worst natural disasters of our time. For geophysicists, the scale of the devastation and the likelihood of another equally destructive earthquake set out a series of challenges of how we might use science not only to understand the earthquake and its aftermath but also to help in planning for future earthquakes in the region. In this article a brief account of these efforts is presented. Earthquake prediction is probably impossible, but earth scientists are now able to identify particularly dangerous places for future events by developing an understanding of the physics of stress interaction. Having identified such a dangerous area, a series of numerical Monte Carlo simulations is described which allow us to get an idea of what the most likely consequences of a future earthquake are by modelling the tsunami generated by lots of possible, individually unpredictable, future events. As this article was being written, another earthquake occurred in the region, which had many expected characteristics but was enigmatic in other ways. This has spawned a series of further theories which will contribute to our understanding of this extremely complex problem.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  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. 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.

  1. America's faulty earthquake plans

    SciTech Connect

    Rosen, J

    1989-10-01

    In this article, the author discusses the liklihood of major earthquakes in both the western and eastern United States as well as the level of preparedness of each region of the U.S. for a major earthquake. Current technology in both earthquake-resistance design and earthquake detection is described. Governmental programs for earthquake hazard reduction are outlined and critiqued.

  2. Observations on water system and pipeline performance in the Limon area of Costa Rica due to the April 22, 1991 earthquake. Technical report

    SciTech Connect

    O'Rourke, M.J.; Ballantyne, D.

    1992-06-30

    The document focuses on earthquake damage to water and oil pipelines, water supply, and water treatment following the 22 April 1991 Costa Rica Earthquake. The moment magnitude 7.5 earthquake occurred approximately 40 km south-southwest of Limon, and resulted in a coseismic uplift of up to 1.5 meters along Costa Rica's east coast. The report also provides an overview of the engineering aspects of the event and recovery activities. Turbidity in the watershed which provides Limon's primary water supply increased to as high as 2.4 percent solids, making it extremely difficult to treat. In addition, the water treatment plant was damaged by the earthquake. Cast iron, ductile iron and reinforced concrete cylinder pipe water transmission lines were damaged by both wave propagation and permanent ground deformation. Water distribution piping, also including PVC and galvanized iron, was similarly impacted. Documentation and evaluation of that damage is described, and compared with empirical estimates from previous earthquakes. Twin 150 mm (6 in), 100 km long, oil transmission lines suffered only a single failure from wrinkling. A description of the pipelines and the failure is provided.

  3. 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. PMID:21038753

  4. Blue Mountain Lake, New York, earthquake of October 7, 1983.

    USGS Publications Warehouse

    Wendt, G.

    1984-01-01

    The October 7 earthquake near Blue Mountain Lake in the central Adirondack Mountains registered a preliminary Richter magnitude of 5.2. It was widely felt throughout the Northeastern United States and Canada and occurred in an area that has been periodically shaken by earthquakes throughout recorded history. Since 1737, at least 346 felt earthquakes have occurred in New York; an earthquake of similar magnitude last shook the Blue Mountain Lake area on June 9, 1975.    

  5. Transformation by Epstein-Barr virus requires DNA sequences in the region of BamHI fragments Y and H.

    PubMed Central

    Skare, J; Farley, J; Strominger, J L; Fresen, K O; Cho, M S; zur Hausen, H

    1985-01-01

    Eight independent recombinant Epstein-Barr virus genomes, each of which was a transforming strain, were made by superinfecting cell lines containing Epstein-Barr virus DNA (Raji or B95-8 strain) with a nontransforming virus (P3HR1 strain). A knowledge of the constitution of each transforming recombinant allowed the localization of the defect in the genome of the nontransforming parent to a 12-megadalton sequence within the EcoRI A fragment. Within this region, the nontransforming virus has a deletion of the BamHI Y fragment and about half of the sequences in the adjacent BamHI H fragment. The present data suggest that this deletion is responsible for the nontransforming phenotype. Furthermore, mapping a deletion in one of the recombinant genomes allowed the conclusion that a sequence (comprising about 20% of the Epstein-Barr virus genome) from the center of BamHI-D to BamHI-I' is not necessary for the maintenance of transformation by Epstein-Barr virus. Images PMID:2991556

  6. TP0326, a Treponema pallidum β-Barrel Assembly Machinery A (BamA) Ortholog and Rare Outer Membrane Protein

    PubMed Central

    Desrosiers, Daniel C.; Anand, Arvind; Luthra, Amit; Dunham-Ems, Star M; LeDoyt, Morgan; Cummings, Michael A. D.; Eshghi, Azad; Cameron, Caroline E.; Cruz, Adriana R.; Salazar, Juan C.; Caimano, Melissa J.; Radolf, Justin D.

    2011-01-01

    SUMMARY Definitive identification of Treponema pallidum (Tp) rare outer membrane proteins (OMPs) has long eluded researchers. TP0326, the sole protein in Tp with sequence homology to a Gram-negative OMP, belongs to the BamA family of proteins essential for OM biogenesis. Structural modeling predicted that five polypeptide transport-associated (POTRA) domains comprise the N-terminus of TP0326, while the C-terminus forms an 18-stranded amphipathic β-barrel. Circular dichroism, heat-modifiability by SDS-PAGE, Triton X-114 phase partitioning and liposome incorporation supported these topological predictions and confirmed that the β-barrel is responsible for the native protein's amphiphilicity. Expression analyses revealed that native TP0326 is expressed at low abundance, while a protease-surface accessibility assay confirmed surface exposure. Size-exclusion chromatography and blue native polyacrylamide gel electrophoresis revealed a modular Bam complex in Tp considerably larger than that of E. coli. Non-orthologous ancillary factors and self-association of TP0326 via its β-barrel may both contribute to the Bam complex. Tp-infected rabbits mount a vigorous antibody response to both POTRA and β-barrel portions of TP0326, whereas humans with secondary syphilis respond predominantly to POTRA. The syphilis spirochete appears to have devised a stratagem for harnessing the Bam pathway while satisfying its need to limit surface antigenicity. PMID:21488980

  7. Earthquake Apparent Stress Scaling

    NASA Astrophysics Data System (ADS)

    Mayeda, K.; Walter, W. R.

    2003-04-01

    There is currently a disagreement within the geophysical community on the way earthquake energy scales with magnitude. One set of recent papers finds evidence that energy release per seismic moment (apparent stress) is constant (e.g. Choy and Boatwright, 1995; McGarr, 1999; Ide and Beroza, 2001). Another set of recent papers finds the apparent stress increases with magnitude (e.g. Kanamori et al., 1993 Abercrombie, 1995; Mayeda and Walter, 1996; Izutani and Kanamori, 2001). The resolution of this issue is complicated by the difficulty of accurately accounting for and determining the seismic energy radiated by earthquakes over a wide range of event sizes in a consistent manner. We have just started a project to reexamine this issue by applying the same methodology to a series of datasets that spans roughly 10 orders in seismic moment, M0. We will summarize recent results using a coda envelope methodology of Mayeda et al, (2003) which provide the most stable source spectral estimates to date. This methodology eliminates the complicating effects of lateral path heterogeneity, source radiation pattern, directivity, and site response (e.g., amplification, f-max and kappa). We find that in tectonically active continental crustal areas the total radiated energy scales as M00.25 whereas in regions of relatively younger oceanic crust, the stress drop is generally lower and exhibits a 1-to-1 scaling with moment. In addition to answering a fundamental question in earthquake source dynamics, this study addresses how one would scale small earthquakes in a particular region up to a future, more damaging earthquake. This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48.

  8. Difference in Surface Properties between Insoluble Monolayer and Adsorbed Film from Kinetics of Water Evaporation and BAM Image.

    PubMed

    Moroi, Yoshikiyo; Rusdi, Muhammad; Kubo, Izumi

    2004-05-20

    The evaporation rate of water molecules across three kinds of interfaces (air/water interface (1), air/surfactant solution interface (2), and air/water interface covered by insoluble monolayer (3)) was examined using a remodeled thermogravimetric balance. There was no difference in both the evaporation rate and the activation energy for the first two interfaces for three types of surfactant solutions below and above the critical micelle concentration (cmc). This means that the molecular surface area from the Gibbs surface excess has nothing to do with the evaporation rate. In the third case, the insoluble monolayer of 1-heptadecanol decreased the evaporation rate and increased the activation energy, indicating a clear difference between an insoluble monolayer and an adsorbed film of soluble surfactant. This difference was substantiated by BAM images, too. The images of three surfactant solution interfaces were similar to that of just the water surface, while distinct structures of molecular assemblies were observed for the insoluble monolayer. The concentration profile of water molecules in an air/liquid interfacial region was derived by Fix's second law. The profile indicates that a definite layer just beneath the air/liquid interface of the surfactant solution is made mostly of water molecules and that the layer thickness is a few times the root-mean-square displacement %@mt;sys@%%@rl;;@%2%@ital@%Dt%@rsf@%%@rlx@%%@mx@% of the water molecules. The thickness was found to be more than a few nanometers, as estimated from several relaxation times derived from the other kinetics than evaporation of amphiphilic molecules in aqueous systems and a maximum evaporation rate of purified water. PMID:18950121

  9. Connecting slow earthquakes to huge earthquakes

    NASA Astrophysics Data System (ADS)

    Obara, Kazushige; Kato, Aitaro

    2016-07-01

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

  10. 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. PMID:27418504

  11. Geochemical challenge to earthquake prediction.

    PubMed Central

    Wakita, H

    1996-01-01

    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. PMID:11607665

  12. 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

  13. Alview: Portable Software for Viewing Sequence Reads in BAM Formatted Files

    PubMed Central

    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. PMID:26417198

  14. 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. PMID:26417198

  15. 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

    2014-12-01

    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. PMID:25404327

  16. 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

  17. 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

  18. 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.

  19. Real time of earthquakes prone areas by RST analysis of satellite TIR radiances: results of continuous monitoring over Italy and Turkey regions.

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

    Meteorological satellites offering global coverage, continuity of observations and long term time series (starting even 30 years ago) offer a unique possibility not only to learn from the past but also to guarantee continuous monitoring whereas other observation technologies are lacking because too expensive or (like in the case of earthquake precursor studies) or considered useless by decision-makers. Space-time fluctuations of Earth's emitted Thermal Infrared (TIR) radiation have been observed from satellite months to weeks before earthquakes occurrence. The general RST approach has been proposed (since 2001) in order to discriminate normal (i.e. related to the change of natural factor and/or observation conditions) TIR signal fluctuations from anomalous signal transient possibly associated to earthquake occurrence. Since then several earthquakes occurred in Europe, Africa and America have been studied by analyzing decades of satellite observations always using a validation/confutation approach in order to verify the presence/absence of anomalous space-time TIR transients in presence/absence of significant seismic activity. In the framework of PRE-EARTHQUAKES EU-FP7 Project (www.pre-earthquakes.org) , starting from October 2010 (still continuing) RST approach has been applied to MSG/SEVIRI data to generate TIR anomaly maps over Italian peninsula, continuously for all the midnight slots. Since September 2011 the same monitoring activity (still continuing) started for Turkey region. For the first time a similar analysis has been performed in real-time, systematically analyzing TIR anomaly maps in order to identify day by day possible significant (e.g. persistent in the space-time domain) thermal anomalies. During 2011 only in very few cases (1 in Italy in July and 2 in the Turkish region in September and November) the day by day analysis enhanced significant anomalies that in two cases were communicated to the other PRE-EARTHQUAKES partners asking for their

  20. 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.

  1. Precise hypocentral distribution in the source area of the 1964 Niigata earthquake based on an actual crustal model recorded by Ocean Bottom Cabled Seismometers in Japan Sea

    NASA Astrophysics Data System (ADS)

    Machida, Y.; Shimbo, T.; Shinohara, M.; Mochizuki, K.; Yamada, T.; Kanazawa, T.

    2012-12-01

    At the eastern margin of the Japan Sea, large earthquakes have been occurred (e.g., 1964 Niigata earthquake, the 1983 Japan Sea earthquake, the 2004 Chuetsu earthquake and the 2007 Chuetsu-oki earthquake) along the Niigata-Kobe Tectonic Zone (NKTZ). The NKTZ is recognized as a region of large strain rate along the Japan Sea coast and in the northern Chubu and Kinki distinct. Among these events, the 2004 Chuetsu earthquake and the 2007 Chuetsu-oki earthquake is triggered by reactivation of pre-existing faults within ancient rift systems by stress loading through a ductile creeping of the weak lower crust (Kato et al., 2008). Because the tectonic zone is thought to be spread in offshore region, it is difficult to understand a precise activity of the tectonic zone from only land-base observations. In order to understand precise seismic activities in the NKTZ, especially in offshore region, we installed Ocean Bottom Cabled Seismometers (OBCSs) in the source region of the 1964 Niigata earthquake in 2010 (Shinohara et al., 2010). The OBCS system has a length of 25 km and 4 OBCSs were developed with 5 km interval. The OBCSs have three accelerometers as seismic sensor. We estimated hypocenters using a locations program for finding a maximum likelihood solution using a Bayesian approach (Hirata and Matsu'ura, 1987). We used a simple one dimensional Vp structure, and we assumed a Vp/Vs of 1.73. In general, seismic waves recorded by OBCSs arrive later than those estimated from the average structural model due to unconsolidated sediments just below the sea floor. Therefore the delay of arrival times by the sedimentary layer should be taken into account for the location. In 2011, a seismic survey using airgun and OBCSs was carried out to obtain a seismic velocity model. We obtained station corrections of the P- and S-arrivals for each station using differences of traveltimes estimated by the assumed model and the actual model. This procedure helps us to obtain precise seismic

  2. 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.

  3. 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. PMID:26601200

  4. 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.

  5. 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. PMID:25765170

  6. The B Cell Adaptor Molecule Bam32 Is Critically Important for Optimal Antibody Response and Resistance to Trypanosoma congolense Infection in Mice

    PubMed Central

    Onyilagha, Chukwunonso; Jia, Ping; Jayachandran, Nipun; Hou, Sen; Okwor, Ifeoma; Kuriakose, Shiby; Marshall, Aaron; Uzonna, Jude E.

    2015-01-01

    Background Bam32, a 32 kDa adaptor molecule, plays important role in B cell receptor signalling, T cell receptor signalling and antibody affinity maturation in germinal centres. Since antibodies against trypanosome variant surface glycoproteins (VSG) are critically important for control of parasitemia, we hypothesized that Bam32 deficient (Bam32-/-) mice would be susceptible to T. congolense infection. Methodology/Principal Findings We found that T. congolense-infected Bam32-/- mice successfully control the first wave of parasitemia but then fail to control subsequent waves and ultimately succumb to their infection unlike wild type (WT) C57BL6 mice which are relatively resistant. Although infected Bam32-/- mice had significantly higher hepatomegaly and splenomegaly, their serum AST and ALT levels were not different, suggesting that increased liver pathology may not be responsible for the increased susceptibility of Bam32-/- mice to T. congolense. Using direct ex vivo flow cytometry and ELISA, we show that CD4+ T cells from infected Bam32-/- mice produced significantly increased amounts of disease-exacerbating proinflammatory cytokines (including IFN-γ, TNF-α and IL-6). However, the percentages of regulatory T cells and IL-10-producing CD4+ cells were similar in infected WT and Bam32-/- mice. While serum levels of parasite-specific IgM antibodies were normal, the levels of parasite-specific IgG, (particularly IgG1 and IgG2a) were significantly lower in Bam32-/- mice throughout infection. This was associated with impaired germinal centre response in Bam32-/- mice despite increased numbers of T follicular helper (Tfh) cells. Adoptive transfer studies indicate that intrinsic B cell defect was responsible for the enhanced susceptibility of Bam32-/- mice to T. congolense infection. Conclusions/Significance Collectively, our data show that Bam32 is important for optimal anti-trypanosome IgG antibody response and suppression of disease-promoting proinflammatory cytokines

  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. Earthquakes - Volcanoes (Causes and Forecast)

    NASA Astrophysics Data System (ADS)

    Tsiapas, E.

    2009-04-01

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

  9. Earthquake Alert System feasibility study

    SciTech Connect

    Harben, P.E.

    1991-12-01

    An Earthquake Alert System (EAS) could give several seconds to several tens of seconds warning before the strong motion from a large earthquake arrives. Such a system would include a large network of sensors distributed within an earthquake-prone region. The sensors closest to the epicenter of a particular earthquake would transmit data at the speed of light to a central processing center, which would broadcast an area-wide alarm in advance of the spreading elastic wave energy from the earthquake. This is possible because seismic energy travels slowly (3--6 km/s) compared to the speed of light. Utilities, public and private institutions, businesses, and the general public would benefit from an EAS. Although many earthquake protection systems exist that automatically shut down power, gas mains, etc. when ground motion at a facility reaches damaging levels, not EAS -- that is, a system that can provide warning in advance of elastic wave energy arriving at a facility -- has ever been developed in the United States. A recent study by the National Academy of Sciences (NRC, 1991) concludes that an EAS is technically feasible and strongly recommends installing a prototype system that makes use of existing microseismic stations as much as possible. The EAS concept discussed here consists of a distributed network of remote seismic stations that measure weak and strong earth motion and transmit the data in real time to central facility. This facility processes the data and issues warning broadcasts in the form of information packets containing estimates of earthquake location, zero time (the time the earthquake began), magnitude, and reliability of the predictions. User of the warning broadcasts have a dedicated receiver that monitors the warning broadcast frequency. The user also has preprogrammed responses that are automatically executed when the warning information packets contain location and magnitude estimates above a facility`s tolerance.

  10. Earthquake Alert System feasibility study

    SciTech Connect

    Harben, P.E.

    1991-12-01

    An Earthquake Alert System (EAS) could give several seconds to several tens of seconds warning before the strong motion from a large earthquake arrives. Such a system would include a large network of sensors distributed within an earthquake-prone region. The sensors closest to the epicenter of a particular earthquake would transmit data at the speed of light to a central processing center, which would broadcast an area-wide alarm in advance of the spreading elastic wave energy from the earthquake. This is possible because seismic energy travels slowly (3--6 km/s) compared to the speed of light. Utilities, public and private institutions, businesses, and the general public would benefit from an EAS. Although many earthquake protection systems exist that automatically shut down power, gas mains, etc. when ground motion at a facility reaches damaging levels, not EAS -- that is, a system that can provide warning in advance of elastic wave energy arriving at a facility -- has ever been developed in the United States. A recent study by the National Academy of Sciences (NRC, 1991) concludes that an EAS is technically feasible and strongly recommends installing a prototype system that makes use of existing microseismic stations as much as possible. The EAS concept discussed here consists of a distributed network of remote seismic stations that measure weak and strong earth motion and transmit the data in real time to central facility. This facility processes the data and issues warning broadcasts in the form of information packets containing estimates of earthquake location, zero time (the time the earthquake began), magnitude, and reliability of the predictions. User of the warning broadcasts have a dedicated receiver that monitors the warning broadcast frequency. The user also has preprogrammed responses that are automatically executed when the warning information packets contain location and magnitude estimates above a facility's tolerance.

  11. Earthquake history of the United States

    USGS Publications Warehouse

    Coffman, Jerry L., (Edited By); 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

  12. 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

  13. A COMPARATIVE STUDY ON CHARACTERISTICS OF EARTHQUAKES IN 2011 TOHOKU-PACIFIC OCEAN EARTHQUAKE AND 2003 SANRIKU MINAMI EARTHQUAKE

    NASA Astrophysics Data System (ADS)

    Nakaaki, Shusuke; Sakai, Kimitoshi; Murono, Yoshitaka

    In the 2001 Tohoku-Pacific Ocean Earthquake (TPO-EQ), damage of railway structures were limited although the scale of earthquake was too large as compared with past large earthquakes. In this paper, relationships between properties of seismic waves and damage of viaducts were investigated. As a comparative example, 2003 Sanriku minami Earthquake(SM-EQ) was chosen, in which damage of viaducts was almost the same with that in TPO-EQ. Analytical results showed that difference of structural response were not significant although scale of earthquake were very different. In addition, it was found that structures located at damaged area observed in TPO-EQ showed 1.1 ~ 1.5 times larger response as compared in SM-EQ at the area, where severe damage was observed in TPO-EQ.

  14. Major earthquake shakes northern Pakistan

    NASA Astrophysics Data System (ADS)

    Kumar, Mohi

    A magnitude 7.6 earthquake that shook the western Himalayas on 8 October killed at least 23,000 in Pakistan and 1,400 in India, injured more than 50,000 people, and left more 2.5 million people homeless across the Kashmir region. The official death toll could exceed 30,000, placing this among most deadly earthquakes to have ever occurred on the Indian subcontinent.Scientists warn that, given the lack of development and poor construction in the area, future earthquakes in more densely populated areas could be devastating. David Simpson, president of the Incorporated Research Institutes for Seismology, said the 8 October quake ‘was a terrible disaster, but not to the level of what could happen in the future. This is yet again another warning message of things to come.”

  15. Earthquake clusters in Corinth Rift

    NASA Astrophysics Data System (ADS)

    Mesimeri, Maria; Papadimitriou, Eleftheria; Karakostas, Vasilios; Tsaklidis, George

    2013-04-01

    Clusters commonly occur as main shock-aftershock (MS-AS) sequences but also as earthquake swarms, which are empirically defined as an increase in seismicity rate above the background rate without a clear triggering main shock earthquake. Earthquake swarms occur in a variety of different environments and might have a diversity of origins, characterized by a high b-value in their magnitude distribution. The Corinth Rift, which was selected as our target area, appears to be the most recent extensional structure, with a likely rate of fault slip of about 1cm/yr and opening of 7mm/yr. High seismic activity accommodates the active deformation with frequent strong (M≥6.0) events and several seismic excitations without a main shock with clearly discriminative magnitude. Identification of earthquake clusters that occurred in this area in last years and investigation of their spatio-temporal distribution is attempted, with the application of known declustering algorithms, aiming to associate their occurrence with certain patterns in seismicity behavior. The earthquake catalog of the National Hellenic Seismological Network is used, and a certain number of clusters were extracted from the dataset, with the MS-AS sequences being distinguished from earthquake swarms. Spatio-temporal properties of each subset were analyzed in detail, after determining the respective completeness magnitude. This work was supported in part by the THALES Program of the Ministry of Education of Greece and the European Union in the framework of the project entitled "Integrated understanding of Seismicity, using innovative Methodologies of Fracture mechanics along with Earthquake and non-extensive statistical physics - Application to the geodynamic system of the Hellenic Arc, SEISMO FEAR HELLARC".

  16. Facts relating to Well No. 5, Lease OCS-P 0234, Pitas Point Unit area, and the earthquake of August 13, 1978, Santa Barbara Channel, California

    USGS Publications Warehouse

    Wayland, Russell G.; Acuff, A. Dewey; McCulloh, Thane M.; Raleigh, C. Barry; Vedder, John G.; Yenne, Keith A.

    1978-01-01

    A build-up of pressures developed in an exploratory well being drilled in the Santa Barbara Channel during the period August 9 to 15, 1978. Nearly coincidentally, a sharp earthquake occurred 2 miles south of the city of Santa Barbara at 3:55 p.m. PDT on August 13, 1978. A task group was formed by the Director, Geological Survey, on August 14, mainly because of concern over the high down-hole pressures in the well. The charge to the task group was to study the situation fully in order that appropriate and immediate measures could be directed to protect against a fracturing of rock formations in the vicinity of the hole that might permit the escape of gas or oil to the surface. The task group was also asked to look into the possibility of any relationship between the well problems and the earthquake.

  17. Post-traumatic stress disorder, anxiety and depression among the elderly: a survey of the hard-hit areas a year after the Wenchuan earthquake.

    PubMed

    Zhang, Zhen; Shi, Zhanbiao; Wang, Li; Liu, Mingxin

    2012-02-01

    Few studies to date have examined psychological sequelae of natural disasters among the elderly in China. The aim of this study was to investigate the prevalence rates of probable post-traumatic stress disorder (PTSD), anxiety and depression in the elderly survivors a year after the Wenchuan earthquake as well as to analyse related risk factors. The community-based sample of the study consisted of 284 elderly survivors (≥60 years). PTSD was assessed by the PTSD Checklist--Civilian version, and anxiety and depression were assessed by the Hopkins Symptoms Checklist. In total, the estimated prevalence rates of probable PTSD, anxiety and depression were 26.3%, 42.9% and 35.2%, respectively. Nearly a fifth of the elderly participants reported symptoms that meet the criteria for all three of these mental disorders. Results indicated that some factors associated with earthquake-exposure intensity, which included loss of livelihood, bereavement, injury and initial fear during the earthquake, were among the significant risk factors for these mental disorders. Women had a higher risk of suffering from probable anxiety as compared to men. Finally, the significance and limitations of this study were also discussed. PMID:22259159

  18. EARTHQUAKE HAZARDS IN THE OFFSHORE ENVIRONMENT.

    USGS Publications Warehouse

    Page, Robert A.; Basham, Peter W.

    1985-01-01

    This report discusses earthquake effects and potential hazards in the marine environment, describes and illustrates methods for the evaluation of earthquake hazards, and briefly reviews strategies for mitigating hazards. The report is broadly directed toward engineers, scientists, and others engaged in developing offshore resources. The continental shelves have become a major frontier in the search for new petroleum resources. Much of the current exploration is in areas of moderate to high earthquake activity. If the resources in these areas are to be developed economically and safely, potential earthquake hazards must be identified and mitigated both in planning and regulating activities and in designing, constructing, and operating facilities. Geologic earthquake effects that can be hazardous to marine facilities and operations include surface faulting, tectonic uplift and subsidence, seismic shaking, sea-floor failures, turbidity currents, and tsunamis.

  19. 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

  20. New LMI-Based Passivity Criteria for Neutral-Type BAM Neural Networks with Randomly Occurring Uncertainties

    NASA Astrophysics Data System (ADS)

    Sakthivel, R.; Anbuvithya, R.; Mathiyalagan, K.; Arunkumar, A.; Prakash, P.

    2013-12-01

    In this paper, we study the passivity analysis for a class of neutral-type BAM neural networks with time-varying delays and randomly occurring uncertainties as well as generalized activation functions. Linear matrix inequality (LMI) approach together with the construction of proper Lyapunov-Krasovskii functional involving triple integrals and augmented type constraint is implemented to derive a new set of sufficient conditions for obtaining the required result. More precisely, first we derive the passivity condition for BAM neural networks without uncertainties and then the result is extended to the case with randomly occurring uncertainties. In particular, the presented results depend not only upon discrete delay but also distributed time varying delay. The obtained passivity conditions are formulated in terms of linear matrix inequalities that can be easily solved by using the MATLAB-LMI toolbox. Finally, the effectiveness of the proposed passivity criterion is demonstrated through numerical example.

  1. Dissection of β-barrel Outer Membrane Protein Assembly Pathways through Characterizing BamA POTRA 1 Mutants of Escherichia coli

    PubMed Central

    Bennion, Drew; Charlson, Emily S.; Coon, Eric; Misra, Rajeev

    2010-01-01

    Summary BamA of Escherichia coli is an essential component of the hetero-oligomeric machinery that mediates β-barrel outer membrane protein (OMP) assembly. The C- and N-termini of BamA fold into trans-membrane β-barrel and five soluble POTRA domains, respectively. Detailed characterization of BamA POTRA 1 missense and deletion mutants revealed two competing OMP assembly pathways, one of which is followed by the archetypal trimeric β-barrel OMPs, OmpF and LamB, and is dependent on POTRA 1. Interestingly, our data suggest that BamA also requires its POTRA 1 domain for proper assembly. The second pathway is independent of POTRA 1 and is exemplified by TolC. Site-specific cross-linking analysis revealed that the POTRA 1 domain of BamA interacts with SurA, a periplasmic chaperone required for the assembly of OmpF and LamB, but not that of TolC and BamA. The data suggest that SurA and BamA POTRA 1 domain function in concert to assist folding and assembly of most β-barrel OMPs except for TolC, which folds into a unique soluble α-helical barrel and an OM-anchored β-barrel. The two assembly pathways finally merge at some step beyond POTRA 1 but presumably before membrane insertion, which is thought to be catalyzed by the trans-membrane β-barrel domain of Bam A. PMID:20598079

  2. Dissection of β-barrel outer membrane protein assembly pathways through characterizing BamA POTRA 1 mutants of Escherichia coli.

    PubMed

    Bennion, Drew; Charlson, Emily S; Coon, Eric; Misra, Rajeev

    2010-09-01

    BamA of Escherichia coli is an essential component of the hetero-oligomeric machinery that mediates β-barrel outer membrane protein (OMP) assembly. The C- and N-termini of BamA fold into trans-membrane β-barrel and five soluble POTRA domains respectively. Detailed characterization of BamA POTRA 1 missense and deletion mutants revealed two competing OMP assembly pathways, one of which is followed by the archetypal trimeric β-barrel OMPs, OmpF and LamB, and is dependent on POTRA 1. Interestingly, our data suggest that BamA also requires its POTRA 1 domain for proper assembly. The second pathway is independent of POTRA 1 and is exemplified by TolC. Site-specific cross-linking analysis revealed that the POTRA 1 domain of BamA interacts with SurA, a periplasmic chaperone required for the assembly of OmpF and LamB, but not that of TolC and BamA. The data suggest that SurA and BamA POTRA 1 domain function in concert to assist folding and assembly of most β-barrel OMPs except for TolC, which folds into a unique soluble α-helical barrel and an OM-anchored β-barrel. The two assembly pathways finally merge at some step beyond POTRA 1 but presumably before membrane insertion, which is thought to be catalysed by the trans-membrane β-barrel domain of BamA. PMID:20598079

  3. 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. PMID:26125500

  4. EBNA-2 transactivates a lymphoid-specific enhancer in the BamHI C promoter of Epstein-Barr virus.

    PubMed Central

    Sung, N S; Kenney, S; Gutsch, D; Pagano, J S

    1991-01-01

    Among the few Epstein-Barr virus (EBV) genes expressed during latency are the Epstein-Barr nuclear antigens (EBNAs), at least one of which contributes to the ability of the virus to transform B lymphocytes. We have analyzed a promoter located in the BamHI-C fragment of EBV which is responsible for the expression of EBNA-1 in some cell lines. Deletion analysis of a 1.4-kb region 5' of the RNA start site has identified a 700-bp fragment that is required for optimal promoter activity in latently infected B lymphocytes, as shown by promoter constructs linked to the chloramphenicol acetyltransferase reporter gene. This fragment is also able to enhance activity, in an orientation-independent manner, of the simian virus 40 early promoter linked to the chloramphenicol acetyltransferase gene. The enhancer element has some constitutive activity in EBV-negative lymphoid cells, which is increased in the presence of the EBNA-2 gene product. Further deletions have shown that the EBNA-2-responsive region requires a 98-bp region that contains a degenerate octamer-binding motif. In epithelial cells there was no enhancer activity regardless of the presence of EBNA-2. These results demonstrate that BamHI-C promoter activity may be dependent not on an enhancer contained in the ori-P, as was previously assumed, but rather on EBNA-2 transactivation of this more proximal enhancer located in the upstream region of the BamHI C promoter itself. Images PMID:1850003

  5. Deep electromagnetic investigation to study the geological and structural setting of the epicentral area of the April 6, 2009 Abruzzo earthquake

    NASA Astrophysics Data System (ADS)

    Balasco, Marianna; Giocoli, Alessandro; Gueguen, Erwan; Lapenna, Vincenzo; Perrone, Angela; Piscitelli, Sabatino; Rizzo, Enzo; Romano, Gerardo; Siniscalchi, Agata; Votta, Mario

    2010-05-01

    Deep electromagnetic investigation, using magnetotelluric (MT) and Deep Electrical Resistivity Tomography (DERT) methods, has been carried out across the Aterno Valley, in the epicentral area of April 6, 2009 (Mw=6.3) Abruzzo earthquake, with the aim to study the geological and structural setting of the subsurface. The L'Aquila Basin is a 60 Km long intermountain depression of the Central Apennines, with a NW-SE-trending, bounded to SW by Monti Sirente-Monte Ocre and by Gran Sasso to NE. This depression is filled in Quaternary continental sediments of the Aterno River while the bedrock is composed by Mesocenozoic calcareous of platform. In the middle part of the basin, from Bagno (SW) to Paganica village (NE), along a profile about 9 km long were carried out 10 MT soundings with site separations of about of 1 km. The acquisition of MT data were obtained with MT24-LF systems (Schlumberger/EMI). The frequency of data recording was set to 6.25 Hz for at least 24 hours and during night-time we launched high frequency sampling acquisition events (500 Hz) for at least 2 hour. Time series data were analyzed using the processing based on Egbert's robust code (Egbert, 1997) to compute estimates of the MT transfer function in the period range 0.00931-238.313 s. Applying an inversion 2D model we have obtained the distribution resistivity of subsoil, as function of depth. The apparent resistivity and phase for TE and TM mode (in all investigated period range) were inverted by using an algorithm developed by Rodi & Mackie, 2001. Almost coincident with MT profile, a DERT with "dipole-dipole" array configuration has been carried out along a profile of 8Km, using 21 stations with an electrode spacing of 400 m and a maximum distance between current and potential probes 7-8 times the basic spacing. In this way, the electrode array geometry allows us to obtain a an exploration depth of about 900 m. The acquisition system consists of a transmitting stations which injects the current

  6. H3K36 Trimethylation-Mediated Epigenetic Regulation is Activated by Bam and Promotes Germ Cell Differentiation During Early Oogenesis in Drosophila.

    PubMed

    Mukai, Masanori; Hira, Seiji; Nakamura, Katsuhiro; Nakamura, Shoichi; Kimura, Hiroshi; Sato, Masanao; Kobayashi, Satoru

    2015-01-01

    Epigenetic silencing is critical for maintaining germline stem cells in Drosophila ovaries. However, it remains unclear how the differentiation factor, Bag-of-marbles (Bam), counteracts transcriptional silencing. We found that the trimethylation of lysine 36 on histone H3 (H3K36me3), a modification that is associated with gene activation, is enhanced in Bam-expressing cells. H3K36me3 levels were reduced in flies deficient in Bam. Inactivation of the Set2 methyltransferase, which confers the H3K36me3 modification, in germline cells markedly reduced H3K36me3 and impaired differentiation. Genetic analyses revealed that Set2 acts downstream of Bam. Furthermore, orb expression, which is required for germ cell differentiation, was activated by Set2, probably through direct H3K36me3 modification of the orb locus. Our data indicate that H3K36me3-mediated epigenetic regulation is activated by bam, and that this modification facilitates germ cell differentiation, probably through transcriptional activation. This work provides a novel link between Bam and epigenetic transcriptional control. PMID:25572421

  7. 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

  8. Precision in 2D temperature measurements using the thermographic phosphor BAM

    NASA Astrophysics Data System (ADS)

    Lindén, J.; Knappe, C.; Richter, M.; Aldén, M.

    2012-08-01

    Investigation of optimized spatial precision for surface temperature measurements is performed. The temperature is measured by means of two-color ratio imaging with ICCD cameras, using the thermographic phosphor BAM. The precision in temperature is put in relation to the spatial resolution, two quantities which involve a trade-off in this case: the more spatial smoothing the better precision, but also the worse spatial resolution. Two different setups are used in order to investigate the influence of laser shot-to-shot variations, the flat-field correction and image registration process on the precision. In order to achieve high precision it is crucial to operate the ICCD cameras with a gain setting that does not introduce nonlinearity effects at the present level of irradiance. The results provide guidance on the precision to be expected from surface temperature measurements using the two-color ratio technique in combination with thermographic phosphors and also confirm the importance of highly stable and linear ICCD detectors. At room temperature and low spatial resolution the precision is evaluated to 0.4%.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. Tectonic earthquakes of anthropogenic origin

    NASA Astrophysics Data System (ADS)

    Adushkin, V. V.

    2016-03-01

    The enhancement of seismicity induced by industrial activity in Russia in the conditions of present-day anthropization is noted. In particular, the growth in the intensity and number of strong tectonic earthquakes with magnitudes M ≥ 3 (seismic energy 109 J) due to human activity is revealed. These man-made tectonic earthquakes have started to occur in the regions of the East European Platform which were previously aseismic. The development of such seismicity is noted in the areas of intense long-term mineral extraction due to the increasing production depth and extended mining and production. The mechanisms and generation conditions of man-made tectonic earthquakes in the anthropogenically disturbed medium with the changed geodynamical and fluid regime is discussed. The source zones of these shallow-focus tectonic earthquakes of anthropogenic origin are formed in the setting of stress state rearrangement under anthropogenic loading both near these zones and at a significant distance from them. This distance is determined by the tectonic structure of the rock mass and the character of its energy saturation, in particular, by the level of the formation pressure or pore pressure. These earthquakes occur at any time of the day, have a triggered character, and are frequently accompanied by catastrophic phenomena in the underground mines and on the surface due to the closeness to the source zones.

  14. 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

  15. Characteristic and uncharacteristic earthquakes as possible artifacts: what does the seismic history actually tell us?

    NASA Astrophysics Data System (ADS)

    Stein, S.; Newman, A.

    2004-05-01

    A challenge for tectonic studies and seismic hazard analysis is that the rates and sizes of the largest observed earthquakes in an area may differ significantly from their true long-term values. This especially likely for intraplate areas or others where recurrence intervals are long, so the earthquake record length is comparable to the mean recurrence time of large earthquakes. In many areas, the largest earthquakes - termed characteristic - appear more common than expected from the log-linear frequency-magnitude relation observed for smaller earthquakes. In others, large earthquakes which we term "uncharacteristic" appear less frequently than expected from the small earthquakes. These effects may be real, or may arise from several possible situations. Apparent characteristic earthquakes can occur if earthquake recurrence intervals are distributed about the mean for that magnitude range, because sampling bias makes those with shorter intervals more likely to be observed than those with longer ones (fractions of earthquakes cannot be observed). A second possibility is suggested by the fact that characteristic earthquakes are often inferred because paleoseismic data are discordant with instrumental or historical data. Hence apparent characteristic earthquakes would occur if paleoseismic data overestimate earthquake magnitudes. This appears to have occurred for the New Madrid zone, because paleoliquification data were calibrated assuming the 1811-12 earthquakes were M 8.3 events, whereas more recent analyses find that these earthquakes were low M 7. Conversely, paleoearthquakes in the Wabash seismic zone appear "uncharacteristic", perhaps because or the paleoseismic record captures only some of the large earthquakes.

  16. A pre seismic radio anomaly revealed in the area where the Abruzzo earthquake (M=6.3) occurred on 6 April 2009

    NASA Astrophysics Data System (ADS)

    Biagi, P. F.; Castellana, L.; Maggipinto, T.; Loiacono, D.; Schiavulli, L.; Ligonzo, T.; Fiore, M.; Suciu, E.; Ermini, A.

    2009-09-01

    On 6 April 2009 a strong (Mw=6.3) earthquake occurred in the Abruzzo region (central Italy). Since 1996, the intensity of CLT (f=189 kHz, Sicily, Italy), MCO (f=216 kHz, France) and CZE (f=270 kHz, Czech Republic) broadcast signals has been collected with a ten minutes sampling rate by a receiver operating in a place located about 13 km far from the epicenter. During March 2009, the old receiver was substituted with a new one able to measure, with one minute sampling rate, the intensity of five VLF signals and five LF signals radiated by transmitters located in different zones of Europe. The MCO and CZE transmitters mentioned above are included among them. From 31 March to 1 April the intensity of the MCO radio signal dropped and this drop was observed only in this signal. The possibility that the drop was connected to problems in the transmitter or in the receiver was investigated and excluded. So, the drop indicates a defocusing of the radiated signal. Since no particular meteorological situation along the path transmitter-receiver happened, the defocusing must be related to other causes, and a possibility is presented that it is a precursor of the Abruzzo earthquake.

  17. 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

  18. Earthquakes - Volcanoes (Causes - Forecast - Counteraction)

    NASA Astrophysics Data System (ADS)

    Tsiapas, Elias

    2013-04-01

    going to be, when we know the record of specific earthquakes and the routes they have followed towards the East. For example, to foresee an earthquake in the Mediterranean region, we take starting point earthquakes to Latin America (0°-40°).The aforementioned elements will reach Italy in an average time period of 49 days and Greece in 53 days. The most reliable preceding phenomenon to determine the epicenter of an earthquake is the rise of the crust's temperature at the area where a large quantity of elements is concentrated, among other phenomena that can be detected either by instruments or by our senses. When there is an active volcano along the route between the area where the "starting-point" earthquake occurred and the area where we expect the same elements to cause a new earthquake, it is possible these elements will escape through the volcano's crater, carrying lava with them. We could contribute to that end, nullifying earthquakes that might be triggered by these elements further to the east, by using manmade resources, like adequate quantities of explosives at the right moment.

  19. Earthquakes - Volcanoes (Causes - Forecast - Counteraction)

    NASA Astrophysics Data System (ADS)

    Tsiapas, Elias

    2015-04-01

    going to be, when we know the record of specific earthquakes and the routes they have followed towards the East. For example, to foresee an earthquake in the Mediterranean region, we take starting point earthquakes to Latin America (0°-40°).The aforementioned elements will reach Italy in an average time period of 49 days and Greece in 53 days. The most reliable preceding phenomenon to determine the epicenter of an earthquake is the rise of the crust's temperature at the area where a large quantity of elements is concentrated, among other phenomena that can be detected either by instruments or by our senses. When there is an active volcano along the route between the area where the "starting-point" earthquake occurred and the area where we expect the same elements to cause a new earthquake, it is possible these elements will escape through the volcano's crater, carrying lava with them. We could contribute to that end, nullifying earthquakes that might be triggered by these elements further to the east, by using manmade resources, like adequate quantities of explosives at the right moment.

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

    NASA Astrophysics Data System (ADS)

    Tsiapas, Elias

    2014-05-01

    going to be, when we know the record of specific earthquakes and the routes they have followed towards the East. For example, to foresee an earthquake in the Mediterranean region, we take starting point earthquakes to Latin America (0°-40°).The aforementioned elements will reach Italy in an average time period of 49 days and Greece in 53 days. The most reliable preceding phenomenon to determine the epicenter of an earthquake is the rise of the crust's temperature at the area where a large quantity of elements is concentrated, among other phenomena that can be detected either by instruments or by our senses. When there is an active volcano along the route between the area where the "starting-point" earthquake occurred and the area where we expect the same elements to cause a new earthquake, it is possible these elements will escape through the volcano's crater, carrying lava with them. We could contribute to that end, nullifying earthquakes that might be triggered by these elements further to the east, by using manmade resources, like adequate quantities of explosives at the right moment.

  1. 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

  2. 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

  3. Earthquake Induced Water Waves in Washington State

    NASA Astrophysics Data System (ADS)

    Barberopoulou, A.; Qamar, A.; Pratt, T. L.

    2003-12-01

    The Mw 7.9 Denali earthquake of 3 November 2002 caused minor damage to at least 20 houseboats by initiating water waves in Lake Union, Seattle, Washington. Damage caused by unusual water activity is not uncommon in Washington State. Newspaper reports show that damage also has been caused by water waves in the Seattle area during local or distant earthquakes in 1899 (Yakutat Bay Alaska earthquake), 1949 (Olympia earthquake) and 1965 (Seattle-Tacoma earthquake). Analysis of Pacific Northwest Seismic Network (PNSN) recordings of the Denali earthquake demonstrates that large water waves are due in part to local amplification of seismic waves by the underlying Seattle sedimentary basin. Simple formulae predict water wave amplitudes only half or smaller than those reported for swimming pools and lakes. Resonance initiated by multiple cycles of surface waves, focusing, and near-shore effects could further amplify the water waves. To understand the type and origins of these water waves, we are examining the response of a water body of rectangular shape and rectangular cross-section subjected to hypothetical forcing functions, and to forcing functions derived from seismograph records of major earthquakes. The results provide estimates of the potential wave heights during future large earthquakes on the nearby subduction zone or on local faults.

  4. 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.

  5. 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).

  6. 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.

  7. 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.

  8. 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.

  9. Testing the USGS 3D San Francisco Bay Area Seismic Velocity Model using Observations of 0.5 to 2 s Surface Waves from Local and Regional Earthquakes (Invited)

    NASA Astrophysics Data System (ADS)

    Brocher, T. M.; Frankel, A. D.; Oppenheimer, D. H.; Fletcher, J. B.; Luetgert, J. H.

    2010-12-01

    We summarize recent observations of long-period (0.5 - 2 s) seismic waves from seven local and regional earthquakes in the magnitude range 3.5 - 6.5, made using accelerograph arrays in the Sacramento/San Joaquin Delta, in the San Leandro basin, and in the Livermore Valley. The observations were made on both isolated accelerometers (both NetQuakes and traditional instruments) and on arrays consisting of clusters of 3 instruments with an aperture of 200-300 meters. These recordings demonstrate that large-amplitude, long-period surface wave arrivals are commonly observed in the urbanized low-lying areas in the East Bay. In the Sacramento/San Joaquin Delta, late arriving Rayleigh waves observed on the vertical component have apparent velocities of about 610 m/s although they range from 300 to 1000 m/s for waves having a period of about 2 s. The azimuth of the arrivals is within 20 degrees of that expected for direct propagation from the epicenters indicating that they are related to the low seismic velocity of the shallow sediments in the Great Valley. Strong basin surface waves produced by the September 6, 2008 M4.1 Alamo earthquake observed throughout San Leandro and Oakland substantially increase the duration of shaking at periods of 1 sec and longer. These basin surface waves exhibit dispersion with group velocities as low as about 300 m/s and are apparent at frequencies from 0.8 - 2 s. These observations indicate that relatively shallow sedimentary basins, such as the San Leandro basin with a sediment thickness of about 1 km, support sizeable basin surface waves that amplify and prolong ground shaking. The M4.1 Alamo earthquake also produced a strong basin surface wave in the Livermore Valley, observed by our array in Pleasanton, that strongly amplifies periods of 0.5 s and longer. Array analysis indicates that late arrivals represent surface waves from an azimuth more westerly than that of the hypocenter. These surface waves are currently not well modeled by the

  10. A Simplified Approach to Earthquake Risk in Mainland China

    NASA Astrophysics Data System (ADS)

    Chen, Qi-Fu; Mi, Hongliang; Huang, Jing

    2005-06-01

    There are limitations in conventional earthquake loss procedures if attempts are made to apply these to assess the social and economic impacts of recent disastrous earthquakes. This paper addresses the need to develop an applicable model for estimating the significant increases of earthquake loss in mainland China. The casualties of earthquakes were studied first. The casualties of earthquakes are strongly related to earthquake strength, occurrence time (day or night) and the distribution of population in the affected area. Using data on earthquake casualties in mainland China from 1980 to 2000, we suggest a relationship between average losses of life and the magnitude of earthquakes. Combined with information on population density and earthquake occurrence times, we use these data to give a further relationship between the loss of life and factors like population density, intensity and occurrence time of the earthquake. Earthquakes that occurred from 2001 to 2003 were tested for the given relationships. This paper also explores the possibility of using a macroeconomic indicator, here GDP (Gross Domestic Product), to roughly estimate earthquake exposure in situations where no detailed insurance or similar inventories exist, thus bypassing some problems of the conventional method.

  11. 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…

  12. 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.

  13. 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…

  14. 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…

  15. 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…

  16. 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.

  17. 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.

  18. 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).

  19. Earthquakes and trauma: review of triage and injury-specific, immediate care.

    PubMed

    Gautschi, Oliver P; Cadosch, Dieter; Rajan, Gunesh; Zellweger, René

    2008-01-01

    Earthquakes present a major threat to mankind. Increasing knowledge about geophysical interactions, progressing architectural technology, and improved disaster management algorithms have rendered modern populations less susceptible to earthquakes. Nevertheless, the mass casualties resulting from earthquakes in Great Kanto (Japan), Ancash (Peru), Tangshan (China), Guatemala, Armenia, and Izmit (Turkey) or the recent earthquakes in Bhuj (India), Bam (Iran), Sumatra (Indonesia) and Kashmir (Pakistan) indicate the devastating effect earthquakes can have on both individual and population health. Appropriate preparation and implementation of crisis management algorithms are of utmost importance to ensure a large-scale medical-aid response is readily available following a devastating event. In particular, efficient triage is vital to optimize the use of limited medical resources and to effectively mobilize these resources so as to maximize patient salvage. However, the main priorities of disaster rescue teams are the rescue and provision of emergency care for physical trauma. Furthermore, the establishment of transport evacuation corridors, a feature often neglected, is essential in order to provide the casualties with a chance for survival. The optimal management of victims under such settings is discussed, addressing injuries of the body and psyche by means of simple diagnostic and therapeutic procedures globally applicable and available. PMID:18557301

  20. Depth segmentation of the seismogenic continental crust: The 2008 and 2009 Qaidam earthquakes

    NASA Astrophysics Data System (ADS)

    Elliott, J. R.; Parsons, B.; Jackson, J. A.; Shan, X.; Sloan, R. A.; Walker, R. T.

    2011-03-01

    The seismic hazard in the immediate vicinity of an earthquake is usually assumed to be reduced after rupture of a continental fault, with along-strike portions being brought closer to failure and aftershocks being significantly smaller. This period of reduced hazard will persist as strain re-accumulates over decades or centuries. However, this is only realised if the entire seismogenic layer ruptured in the event. Here we use satellite radar measurements to show the ruptures of two Mw 6.3 earthquakes, occurring in almost the same epicentral location ten months apart in the Qaidam region, China, were nearly coplanar. The 2008 earthquake ruptured the lower half of the seismogenic layer, the 2009 event the upper half. Fault segmentation with depth allows a significant seismic hazard to remain even after a moderate and potentially devastating earthquake. This depth segmentation possibly exists in the case of the 2003 Bam earthquake where satellite radar and aftershock measurements showed that it ruptured only the upper half of the 15-20 km deep seismogenic region [Jackson et al., 2006], and that the lower, unruptured part may remain as a continuing seismic hazard.

  1. BAM 1 and RECEPTOR-LIKE PROTEIN KINASE 2 constitute a signaling pathway and modulate CLE peptide-triggered growth inhibition in Arabidopsis root.

    PubMed

    Shimizu, Noriko; Ishida, Takashi; Yamada, Masashi; Shigenobu, Shuji; Tabata, Ryo; Kinoshita, Atsuko; Yamaguchi, Katsushi; Hasebe, Mitsuyasu; Mitsumasu, Kanako; Sawa, Shinichiro

    2015-12-01

    Ligand receptor-based signaling is a means of cell-to-cell communication for coordinating developmental and physiological processes in multicellular organisms. In plants, cell-producing meristems utilize this signaling to regulate their activities and ensure for proper development. Shoot and root systems share common requirements for carrying out this process; however, its molecular basis is largely unclear. It has been suggested that synthetic CLV3/EMBRYO SURROUNDING REGION (CLE) peptide shrinks the root meristem through the actions of CLAVATA2 (CLV2) and the RECEPTOR-LIKE PROTEIN KINASE 2 (RPK2) pathway in Arabidopsis thaliana. Our genetic screening for mutations that resist CLE peptide signaling in roots determined that BAM1, which is a member of the leucine-rich repeat receptor-like kinase (LRR-RLK) family, is also involved in this pathway. BAM1 is preferentially expressed in the root tip, including the quiescent center and its surrounding stem cells. Our genetic analysis revealed that BAM1 functions together with RPK2. Using coimmunoprecipitation assay, we showed that BAM1 is capable of forming heteromeric complexes with RPK2. These findings suggest that the BAM1 and RPK2 receptors constitute a signaling pathway that modulates cell proliferation in the root meristem and that related molecules are employed in root and shoot meristems. PMID:26083273

  2. 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

  3. Incubation of Chile's 1960 Earthquake

    NASA Astrophysics Data System (ADS)

    Atwater, B. F.; Cisternas, M.; Salgado, I.; Machuca, G.; Lagos, M.; Eipert, A.; Shishikura, M.

    2003-12-01

    Infrequent occurrence of giant events may help explain how the 1960 Chile earthquake attained M 9.5. Although old documents imply that this earthquake followed great earthquakes of 1575, 1737 and 1837, only three earthquakes of the past 1000 years produced geologic records like those for 1960. These earlier earthquakes include the 1575 event but not 1737 or 1837. Because the 1960 earthquake had nearly twice the seismic slip expected from plate convergence since 1837, much of the strain released in 1960 may have been accumulating since 1575. Geologic evidence for such incubation comes from new paleoseismic findings at the R¡o Maullin estuary, which indents the Pacific coast at 41.5§ S midway along the 1960 rupture. The 1960 earthquake lowered the area by 1.5 m, and the ensuing tsunami spread sand across lowland soils. The subsidence killed forests and changed pastures into sandy tidal flats. Guided by these 1960 analogs, we inferred tsunami and earthquake history from sand sheets, tree rings, and old maps. At Chuyaquen, 10 km upriver from the sea, we studied sand sheets in 31 backhoe pits on a geologic transect 1 km long. Each sheet overlies the buried soil of a former marsh or meadow. The sand sheet from 1960 extends the entire length of the transect. Three earlier sheets can be correlated at least half that far. The oldest one, probably a tsunami deposit, surrounds herbaceous plants that date to AD 990-1160. Next comes a sandy tidal-flat deposit dated by stratigraphic position to about 1000-1500. The penultimate sheet is a tsunami deposit younger than twigs from 1410-1630. It probably represents the 1575 earthquake, whose accounts of shaking, tsunami, and landslides rival those of 1960. In that case, the record excludes the 1737 and 1837 events. The 1737 and 1837 events also appear missing in tree-ring evidence from islands of Misquihue, 30 km upriver from the sea. Here the subsidence in 1960 admitted brackish tidal water that defoliated tens of thousands of

  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. 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. PMID:26601167

  6. 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.

  7. 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

  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. Seismicity dynamics and earthquake predictability

    NASA Astrophysics Data System (ADS)

    Sobolev, G. A.

    2011-02-01

    Many factors complicate earthquake sequences, including the heterogeneity and self-similarity of the geological medium, the hierarchical structure of faults and stresses, and small-scale variations in the stresses from different sources. A seismic process is a type of nonlinear dissipative system demonstrating opposing trends towards order and chaos. Transitions from equilibrium to unstable equilibrium and local dynamic instability appear when there is an inflow of energy; reverse transitions appear when energy is dissipating. Several metastable areas of a different scale exist in the seismically active region before an earthquake. Some earthquakes are preceded by precursory phenomena of a different scale in space and time. These include long-term activation, seismic quiescence, foreshocks in the broad and narrow sense, hidden periodical vibrations, effects of the synchronization of seismic activity, and others. Such phenomena indicate that the dynamic system of lithosphere is moving to a new state - catastrophe. A number of examples of medium-term and short-term precursors is shown in this paper. However, no precursors identified to date are clear and unambiguous: the percentage of missed targets and false alarms is high. The weak fluctuations from outer and internal sources play a great role on the eve of an earthquake and the occurrence time of the future event depends on the collective behavior of triggers. The main task is to improve the methods of metastable zone detection and probabilistic forecasting.

  10. 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".  

  11. 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.

  12. Reconsidering earthquake scaling

    NASA Astrophysics Data System (ADS)

    Gomberg, J.; Wech, A.; Creager, K.; Obara, K.; Agnew, D.

    2016-06-01

    The relationship (scaling) between scalar moment, M0, and duration, T, potentially provides key constraints on the physics governing fault slip. The prevailing interpretation of M0-T observations proposes different scaling for fast (earthquakes) and slow (mostly aseismic) slip populations and thus fundamentally different driving mechanisms. We show that a single model of slip events within bounded slip zones may explain nearly all fast and slow slip M0-T observations, and both slip populations have a change in scaling, where the slip area growth changes from 2-D when too small to sense the boundaries to 1-D when large enough to be bounded. We present new fast and slow slip M0-T observations that sample the change in scaling in each population, which are consistent with our interpretation. We suggest that a continuous but bimodal distribution of slip modes exists and M0-T observations alone may not imply a fundamental difference between fast and slow slip.

  13. 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. PMID:16605393

  14. 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

  15. 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.

  16. 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.

  17. 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.

  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. 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.

  20. Testing hypotheses of earthquake occurrence

    NASA Astrophysics Data System (ADS)

    Kagan, Y. Y.; Jackson, D. D.; Schorlemmer, D.; Gerstenberger, M.

    2003-12-01

    We present a relatively straightforward likelihood method for testing those earthquake hypotheses that can be stated as vectors of earthquake rate density in defined bins of area, magnitude, and time. We illustrate the method as it will be applied to the Regional Earthquake Likelihood Models (RELM) project of the Southern California Earthquake Center (SCEC). Several earthquake forecast models are being developed as part of this project, and additional contributed forecasts are welcome. Various models are based on fault geometry and slip rates, seismicity, geodetic strain, and stress interactions. We would test models in pairs, requiring that both forecasts in a pair be defined over the same set of bins. Thus we offer a standard "menu" of bins and ground rules to encourage standardization. One menu category includes five-year forecasts of magnitude 5.0 and larger. Forecasts would be in the form of a vector of yearly earthquake rates on a 0.05 degree grid at the beginning of the test. Focal mechanism forecasts, when available, would be also be archived and used in the tests. The five-year forecast category may be appropriate for testing hypotheses of stress shadows from large earthquakes. Interim progress will be evaluated yearly, but final conclusions would be made on the basis of cumulative five-year performance. The second category includes forecasts of earthquakes above magnitude 4.0 on a 0.05 degree grid, evaluated and renewed daily. Final evaluation would be based on cumulative performance over five years. Other types of forecasts with different magnitude, space, and time sampling are welcome and will be tested against other models with shared characteristics. All earthquakes would be counted, and no attempt made to separate foreshocks, main shocks, and aftershocks. Earthquakes would be considered as point sources located at the hypocenter. For each pair of forecasts, we plan to compute alpha, the probability that the first would be wrongly rejected in favor of

  1. Bio-samtools: Ruby bindings for SAMtools, a library for accessing BAM files containing high-throughput sequence alignments

    PubMed Central

    2012-01-01

    Background The SAMtools utilities comprise a very useful and widely used suite of software for manipulating files and alignments in the SAM and BAM format, used in a wide range of genetic analyses. The SAMtools utilities are implemented in C and provide an API for programmatic access, to help make this functionality available to programmers wishing to develop in the high level Ruby language we have developed bio-samtools, a Ruby binding to the SAMtools library. Results The utility of SAMtools is encapsulated in 3 main classes, Bio::DB::Sam, representing the alignment files and providing access to the data in them, Bio::DB::Alignment, representing the individual read alignments inside the files and Bio::DB::Pileup, representing the summarised nucleotides of reads over a single point in the nucleotide sequence to which the reads are aligned. Conclusions Bio-samtools is a flexible and easy to use interface that programmers of many levels of experience can use to access information in the popular and common SAM/BAM format. PMID:22640879

  2. BamHI E region of the Epstein-Barr virus genome encodes three transformation-associated nuclear proteins.

    PubMed Central

    Ricksten, A; Kallin, B; Alexander, H; Dillner, J; Fåhraeus, R; Klein, G; Lerner, R; Rymo, L

    1988-01-01

    Recombinant vectors carrying DNA fragments from the BamHI E region of the B95-8 Epstein-Barr virus (EBV) genome were transfected into COS-1 cells, and the transient expression of EBV-encoded nuclear antigens (EBNAs) was analyzed by using polyvalent human antisera and rabbit antibodies to synthetic peptides. Vector DNA containing two rightward open reading frames in the BamHI E fragment, BERF2a and BERF2b, induced the expression of a nuclear antigen identical serologically and with respect to size to the larger of the two polypeptides previously designated as EBNA4 in B95-8 cells. An antigen corresponding to the smaller polypeptide was induced in cells transfected with constructs that contained two neighboring reading frames, BERF3 and BERF4. This antigen also reacted with a rabbit antiserum to the synthetic peptide 203, deduced from BERF4. Thus, the findings show that the two components of the EBNA4 doublet in B95-8 cells are encoded by separate genes. The antigen encoded by BERF2a and/or BERF2b has been designated as EBNA4 and the antigen encoded by BERF3 and/or BERF4 has been designated as EBNA6. Polyvalent human antisera detected EBNA4 and EBNA6 in 9 of 11 lymphoid cell lines carrying independent EBV isolates. In the remaining two lines, either EBNA4 or EBNA6 was not detectable. Images PMID:2829223

  3. 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.

  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. The loma prieta, california, earthquake: an anticipated event.

    PubMed

    1990-01-19

    The first major earthquake on the San Andreas fault since 1906 fulfilled a long-term forecast for its rupture in the southern Santa Cruz Mountains. Severe damage occurred at distances of up to 100 kilometers from the epicenter in areas underlain by ground known to be hazardous in strong earthquakes. Stronger earthquakes will someday strike closer to urban centers in the United States, most of which also contain hazardous ground. The Loma Prieta earthquake demonstrated that meaningful predictions can be made of potential damage patterns and that, at least in well-studied areas, long-term forecasts can be made of future earthquake locations and magnitudes. Such forecasts can serve as a basis for action to reduce the threat major earthquakes pose to the United States. PMID:17735847

  6. 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

  7. 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

  8. Continuing megathrust earthquake potential in Chile after the 2014 Iquique earthquake.

    PubMed

    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

    2014-08-21

    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. PMID:25119028

  9. 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; 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.

  10. Earthquake Prognosis With Applied Microseism.

    NASA Astrophysics Data System (ADS)

    Ahmedov, N.; Nagiyev, A.

    Earthquakes are the most dangerous natural catastrophy in terms of numerous casualties, amount of damages, areal coverage and difficulties associated with a need to provide secure measures. Inability to forecast these events makes the situation worse due to the following circumstances:-their buried focuses are invisible in the subsurface, they occur suddenly as a thunder, and some tens of the seconds later they leave devastated areas and casualties of tens of thousands of people. Currently earthquake forecausting is actually absolutely inefficient. Microseism application is one of the possible ways to forecast earthquakes. These small oscillation of up-going low-ampitude, irregular wawes observed on seismograms are refered to as microseism. Having been different from earhquakes itself, they are continuous, that is, have no origin coordinate on time axis. Their occurence is associated with breakers observed along shorelines, strong wind and hurricane patterns and so on. J.J.Linch has discovered a new tool to monitor hurricane motion trend over the seas with applied microseism recorded at ad hocstations. Similar to these observations it became possible to monitor the formation of the earthquake focuses based on correlation between low-frequency horizontal ahannels'N-S and E-W components. Microseism field and preceding abnormal variations monitoring data derived from "Cherepaha" 3M and 6/12 device enable to draw out some systematic trend in amplitude/frecuency domain. This relationship observed in a certain frequency range made it possible to define the generation of earthquake focuses with regard to the monitoring station. This variation trend was observed while Turkish and Iranian events happened during 1990,1992, and 1997. It is suggested to be useful to verify these effects in other regions to further correlate available data and work out common forecausting criteria.

  11. Behavior of the topside ionosphere during earthquakes

    NASA Astrophysics Data System (ADS)

    Maltseva, Olga; Nikitenko, Tatyana; Zhbankov, Gennadii

    2016-07-01

    Investigation of behavior of the ionosphere during earthquakes has long and steady interest. Basically, it concerns to studying behavior of parameters foF2 and hmF2 of the bottomside ionosphere. There are indirect indications of influence of the processes connected with earthquakes on the higher area. Recently, data of measurements of an electron density Ne on low-orbit satellites were appeared over zones of earthquakes. It allows estimating modifications of density Ne in the topside part of the ionosphere. In the present work, N(h)-profiles are calculated with use of the IRI-Plas model and its adaptation not only to experimental values of foF2 and hmF2, but also to the total electron content TEC during periods of earthquakes. Thus in some cases it was possible to adapt model for the plasma frequencies measured on satellites. The cases analyzed in references, concerning, basically, to events in the European and Southeast zones were selected. On an example of a specific case of earthquake on February, 14th 2008 near to Athens, absolute and relative variations of deviations of plasma frequency from a median at various heights (close to hmF2, 400 km, 600 km, 1000 km, 1500 km) are considered for 0 - 12 days before earthquake for various options of adaptation of the model. If to consider that here there can be the variations connected with earthquake, a sign of deviations in most cases was negative with maximum value of magnitude during 8th day before earthquake and in half smaller deviation a day before earthquake. Relative deviations are minimum close hmF2 and maximum at height of 400 km. Since in most cases investigations are fulfilled with a view of search of the precursors, the given work includes the critical analysis of the published and received results. Authors thank Southern Federal University for support by grant #213.01-11/2014-22.

  12. Astronomical tides and earthquakes

    NASA Astrophysics Data System (ADS)

    Wu, Xiaoping; Mao, Wei; Huang, Yong

    2001-03-01

    A review on the studies of correlation between astronomical tides and earthquakes is given in three categories, including (1) earthquakes and the relative locations of the sun, the moon and the earth, (2) earthquakes and the periods and phases of tides and (3) earthquakes and the tidal stress. The first two categories mainly investigate whether or not there exist any dominant pattern of the relative locations of the sun, the moon and the earth during earthquakes, whether or not the occurrences of earthquakes are clustered in any special phase during a tidal period, whether or not there exists any tidal periodic phenomenon in seismic activities, By empasizing the tidal stress in seismic focus, the third category investigates the relationship between various seismic faults and the triggering effects of tidal stress, which reaches the crux of the issue. Possible reasons to various inconsistent investigation results by using various methods and samples are analyzed and further investigations are proposed.

  13. 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.

  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. Safety and survival in an earthquake

    USGS Publications Warehouse

    U.S. Geological Survey

    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.

  16. Coping with earthquakes induced by fluid injection

    USGS Publications Warehouse

    McGarr, Arthur F.; Bekins, Barbara; Burkardt, Nina; Dewey, James W.; Earle, Paul; 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. Rapid Reoccurrence of Large Earthquakes due to Depth Segmentation of the Seismogenic Crust

    NASA Astrophysics Data System (ADS)

    Elliott, J. R.; Parsons, B. E.; Jackson, J. A.; Shan, X.; Sloan, R.; Walker, R. T.

    2010-12-01

    The Mw 6.3 November 2008 and Mw 6.3 August 2009 thrust-fault earthquakes occurred in almost the same location within the North Qaidam thrust system, south of the Qilian Shan/Nan Shan thrust belt and on the northern margin of the Qaidam basin, NE Tibet. This fold-and-thrust belt is th