WorldWideScience

Sample records for chuetsu-oki earthquake influences

  1. Field reconnaissance of the 2007 Niigata-Chuetsu Oki earthquake

    Institute of Scientific and Technical Information of China (English)

    Georgios Apostolakis; Bing Qu; Nurhan Ecemis; Seda Dogruel

    2007-01-01

    As part of the 2007 Yri-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 NiigataChuetsu 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.

  2. Seismic Safety of Nuclear Power Plants: Lessons Learned from the 2007 Niigataken Chuetsu-Oki Earthquake

    International Nuclear Information System (INIS)

    Nuclear power plants (NPPs) are designed to withstand earthquakes that can be anticipated to occur during their operating periods and to shut down safely in the event of a major earthquake. In Taiwan, three reactors at the Chinshan and Kuosheng NPPs shut down automatically during the 1999 Chi-Chi earthquake with a magnitude of 7.6. In Japan, one reactor at the Kashiwazaki-Kariwa NPP and three reactors at the Onagawa NPP shut down automatically during the 2004 Niigata-Chuetsu earthquake's aftershock (M=5.2) and the 2005 Miyagi earthquake (M=7.2), respectively. Recently, on July 16, 2007, there was a powerful earthquake with a magnitude of 6.6 occurred in the northwest Niigata region of Japan. Since the strong ground motion significantly exceeded the design basis ground motion level, the operating reactors at the Kashiwazaki-Kariwa NPP were automatically shut down and a number of problems were identified. This paper summarizes the responses and damages of the Kashiwazaki-Kariwa NPP during the 2007 Niigataken Chuetsu-Oki earthquake and then addresses the lessons learned from a seismic or structural point of view

  3. Local government's view on Chuetsu-oki earthquake and nuclear power plant facilities

    International Nuclear Information System (INIS)

    Niigataken Chuetsu-oki earthquake occurred in July 2007 and damaged individual's housing and properties in local residents and Kashiwazaki-Kariwa nuclear power plant facilities. The earthquake caused very strong ground motions far exceeding the assumed values in the design. The impacts were a fire breakout of the Unit 3 transformer and a release of small amount of radioactive materials to the environment at Unit 6 and 7. A joint of the driving shaft of the overhead crane of the Unit 6 reactor building was damaged. The fire of the Unit 3 transformer developed safety concerns among the public because of insufficient effectiveness of the private fire brigade, unavailability of fire control systems, and delayed notification to the external fire station, and as its consequence a lot of time needed to bring the fire under control. Delayed information dissemination gave deep concerns about the possible radioactive contamination in the environment. Based on New Regulatory Guide for Reviewing Seismic Design of Nuclear Power Reactor Facilities revised in September 2006, detail understanding of shakes and additional investigation of geological faults around the plant site were underway. Precise explanations on in-situ investigation and evaluation results to the residents would be necessary to answer their seismic safety concerns. (T. Tanaka)

  4. Dynamic response of unit no.7 reactor building during the Niigataken Chuetsu-oki earthquake in 2007

    International Nuclear Information System (INIS)

    Though the Kashiwazaki-Kariwa Nuclear Power Station was subjected to significantly strong ground motions of the Niigataken Chuetsu-oki Earthquake in 2007, the main facility buildings had almost no damage. Since a large amount of land subsidence was observed near the buildings, the soil around the buildings was expected to be in the strong nonlinear state during the earthquake. In this paper, the authors tried to clarify actual behavior of Unit No.7 reactor building during the earthquake through the simulation analyses using the finite element method. In our analyses, nonlinear effects were considered in contact conditions between the buildings and the surrounding soil by employing joint elements in addition to soil materials. (author)

  5. Investigation of the M6.6 Niigata-Chuetsu Oki, Japan, earthquake of July 16, 2007

    Science.gov (United States)

    Kayen, Robert; Collins, Brian D.; Abrahamson, Norm; Ashford, Scott; Brandenberg, Scott J.; Cluff, Lloyd; Dickenson, Stephen; Johnson, Laurie; Tanaka, Yasuo; Tokimatsu, Kohji; Kabeyasawa, Toshimi; Kawamata, Yohsuke; Koumoto, Hidetaka; Marubashi, Nanako; Pujol, Santiago; Steele, Clint; Sun, Joseph I.; Tsai, Ben; Yanev, Peter; Yashinsky, Mark; Yousok, Kim

    2007-01-01

    The M6.6 mainshock of the Niigata Chuetsu Oki (offshore) earthquake occurred at 10:13 a.m. local time on July 16, 2007, and was followed by a sequence of aftershocks that were felt during the entire time of the reconnaissance effort. The mainshock had an estimated focal depth of 10 km and struck in the Japan Sea offshore Kariwa. Analysis of waveforms from source inversion studies indicates that the event occurred along a thrust fault with a NE trend. The fault plane is either a strike of 34 degrees with a dip of 51 degrees or a strike of 238 degrees with a dip of 41 degrees. Which of these two planes is associated with the mainshock rupture is unresolved, although attenuation relationship analysis indicates that the northwest-dipping fault is favored. The quake affected an approximately 100-km-wide area along the coastal areas of southwestern Niigata prefecture. The event triggered ground failures as far as the Unouma Hills, located in central Niigata approximately 50 km from the shore and the source area of the 2004 Niigata Chuetsu earthquake. The primary event produced tsunami run-ups that reached maximum runup heights of about 20 centimeters along the shoreline of southern Niigata Prrefecture.

  6. ANALYSIS OF LABOUR ACCIDENTS OCCURRING IN DISASTER RESTORATION WORK FOLLOWING THE NIIGATA CHUETSU EARTHQUAKE (2004) AND THE NIIGATA CHUETSU-OKI EARTHQUAKE (2007)

    Science.gov (United States)

    Itoh, Kazuya; Noda, Masashi; Kikkawa, Naotaka; Hori, Tomohito; Tamate, Satoshi; Toyosawa, Yasuo; Suemasa, Naoaki

    Labour accidents in disaster-relief and disaster restoration work following the Niigata Chuetsu Earthquake (2004) and the Niigata Chuetsu-oki Earthquake (2007) were analysed and characterised in order to raise awareness of the risks and hazards in such work. The Niigata Chuetsu-oki Earthquake affected houses and buildings rather than roads and railways, which are generally disrupted due to landslides or slope failures caused by earthquakes. In this scenario, the predominant type of accident is a "fall to lower level," which increases mainly due to the fact that labourers are working to repair houses and buildings. On the other hand, landslides and slope failures were much more prevalent in the Niigata Chuetsu Earthquake, resulting in more accidents occurring in geotechnical works rather than in construction works. Therefore, care should be taken in preventing "fall to lower level" accidents associated with repair work on the roofs of low-rise houses, "cut or abrasion" accidents due to the demolition of damaged houses and "caught in or compressed by equipment" accidents in road works and water and sewage works.

  7. Seismological asperities from the point of view of dynamic rupture modeling: the 2007 Mw6.6 Chuetsu-Oki, Japan, earthquake

    Science.gov (United States)

    Aochi, Hideo; Yoshimi, Masayuki

    2016-03-01

    We study the ground motion simulations based on three finite-source models for the 2007 Mw6.6 Niigata Chuetsu-oki, Japan, earthquake in order to discuss the performance of the input ground motion estimations for the near-field seismic hazard analysis. The three models include a kinematic source inverted from the regional accelerations, a dynamic source on a planar fault with three asperities inferred from the very-near-field ground motion particle motions, and another dynamic source model with conjugate fault segments. The ground motions are calculated for an available 3D geological model using a finite-difference method. For the comparison, we apply a goodness-of-fit score to the ground motion parameters at different stations, including the nearest one that is almost directly above the ruptured fault segments. The dynamic rupture models show good performance. We find that seismologically inferred earthquake asperities on a single fault plane can be expressed with two conjugate segments. The rupture transfer from one segment to another can generate a significant radiation; this could be interpreted as an asperity projected onto a single fault plane. This example illustrates the importance of the fault geometry that has to be taken into account when estimating the very-near-field ground motion.

  8. Rupture process and strong ground motions of the 2007 Niigataken Chuetsu-Oki earthquake -Directivity pulses striking the Kashiwazaki-Kariwa Nuclear Power Plant-

    Science.gov (United States)

    Irikura, K.; Kagawa, T.; Miyakoshi, K.; Kurahashi, S.

    2007-12-01

    The Niigataken Chuetsu-Oki earthquake occurred on July 16, 2007, northwest-off Kashiwazaki in Niigata Prefecture, Japan, causing severe damages of ten people dead, about 1300 injured, about 1000 collapsed houses and major lifelines suspended. In particular, strong ground motions from the earthquake struck the Kashiwazaki-Kariwa nuclear power plant (hereafter KKNPP), triggering a fire at an electric transformer and other problems such as leakage of water containing radioactive materials into air and the sea, although the radioactivity levels of the releases are as low as those of the radiation which normal citizens would receive from the natural environment in a year. The source mechanism of this earthquake is a reverse fault, but whether it is the NE-SW strike and NW dip or the SW-NE strike and SE dip are still controversial from the aftershock distribution and geological surveys near the source. Results of the rupture processes inverted by using the GPS and SAR data, tsunami data and teleseismic data so far did not succeed in determining which fault planes moved. Strong ground motions were recorded at about 390 stations by the K-NET of NIED including the stations very close to the source area. There was the KKNPP which is probably one of buildings and facilities closest to the source area. They have their own strong motion network with 22 three-components' accelerographs locating at ground-surface, underground, buildings and basements of reactors. The PGA attenuation-distance relationships made setting the fault plane estimated from the GPS data generally follow the empirical relations in Japan, for example, Fukushima and Tanaka (1990) and Si and Midorikawa (1999), even if either fault plane, SE dip or NW dip, is assumed. However, the strong ground motions in the site of the KKNPP had very large accelerations and velocities more than those expected from the empirical relations. The surface motions there had the PGA of more than 1200 gals and even underground

  9. Preliminary findings and lessons learned from the 16 July 2007 earthquake at Kashiwazaki-Kariwa NPP- 'The Niigataken Chuetsu-Oki earthquake, Kashiwazaki-Kariwa NPP and Tokyo, Japan, 6-10 August 2007. Mission report. V. 1

    International Nuclear Information System (INIS)

    Upon request from the Government of Japan an IAEA expert mission was conducted at the Kashiwazaki-Kariwa NPP following a strong earthquake that affected the plant on 16 July 2007. The objective, as agreed with the Japanese counterpart, was to conduct a fact finding mission and to identify the preliminary lessons learned that might have implications for the international nuclear safety regime. Although the Niigataken Chuetsu-Oki earthquake on 16 July 2007 significantly exceeded the level of the seismic input taken into account in the design of the plant, the installation behaved in a safe manner, during and after the earthquake. In particular, the automatic shutdown of the reactors of Units 3, 4 and 7, which were operating at full power, and of the reactor of Unit 2, which was in the start up state, were performed successfully. Based on the reports from experts from the Tokyo Electric Power Company (TEPCO) and the limited but representative plant walkdowns and visual observations performed by the IAEA team, safety related structures, systems and components of the plant seem to be in a much better general condition than might be expected for such a strong earthquake, and there is no visible significant damage. This is probably due to the conservatisms introduced at different stages of the design process. The combined effects of these conservatisms were apparently sufficient to compensate for uncertainties in the data and methods available at the time of the design of the plant, which led to the underestimation of the original seismic input. However, important components like the reactor vessels, the core internals and the fuel elements have not yet been examined and in-depth inspections are still to be performed. On the other hand, non-safety related structures, systems and components were affected by significant damage such as soil and anchorage failures and oil leakages. A re-evaluation of the seismic safety the Kashiwazika-Kariwa NPP needs to be done with account

  10. Estimation of strong motions on free rock surface. Identification of soil structures and strong motions on free rock surface in Kashiwazaki-Kariwa nuclear power plant during the 2007 Niigataken Chuetsu-oki earthquake

    International Nuclear Information System (INIS)

    Very strong ground motions (maximum acceleration 993 cm/s2 in the borehole seismometer point of -255m in depth) were observed in the Kashiwazaki Kariwa Nuclear Power Plant during the Niigataken Chuetsu-oki Earthquake on July 16, 2007. In this study, we tried to develop new method, which can simulate waveforms on free rock surface by using the bore hole records. We identified the underground structure model at the Service Hall from aftershock records observed in vertical array, using the simulated annealing method (Ingber(1989)). Based on numerical experiments it is identified that S-wave velocity and Q values of individual layers are inverted very well. Strong motion records of main shock observed by the bore hole seismometers were simulated by using one-dimensional multiple reflection method. In this study, non-linear effect is considered by introducing non-linear coefficient c(f) for under coming wave from surface. The maximum acceleration and phase characteristics in simulated waveforms are similar to the observed one. It means that our method is useful for simulate strong motion in non-linear region. Finally, strong motions on the free rock surface at the Service Hall during the main shock are simulated. The maximum acceleration of EW component on free rock surface is estimated to be 1,207 cm/s2. (author)

  11. Concerns of Disaster Medical Assistance Team (DMAT) members about troubles at the nuclear power plant: experience from the Niigata Chuetsu-Oki earthquake, 16 July 2007, in Japan.

    Science.gov (United States)

    Akashi, Makoto; Kumagaya, Ken; Kondo, Hisayoshi; Hirose, Yasuo

    2010-06-01

    An earthquake measuring 6.8 on the Richter scale struck the Niigata-Chuetsu region of Japan at 10:13 on 16 July 2007. The earthquake was followed by the sustained occurrence of numerous aftershocks, delaying the reconstruction of community lifelines. The earthquake affected the Kashiwazaki-Kariwa nuclear power plants (NPPs), the biggest NPP site in the world. The earthquake caused damage to NPPs, resulting in a small amount of radioactive materials being released into the air and the sea. However, no significant effects were detected in the public and the environment. As medical response to this earthquake, 42 Disaster Medical Assistance Teams (DMATs) were sent to hospitals and first-aid care centers at the NPP site. In order to evaluate the perceptions of the deployed DMAT personnel regarding concerns about the health effects of radiation and information about the damage to NPPs, questionnaires were sent to 40 facilities that dispatched DMATs to the earthquake area. Most of them were concerned with the effects of radiation, and adequate information about the problems at the NPPs was not communicated to them. This preliminary study suggests that communication of information is extremely important for DMAT members in the case of disasters, in particular if there exists a possibility of radiation exposure, since radiation cannot be detected by our senses. DMAT members are critical to any mass casualty incident, whether caused by humans or nature. We have learned from this earthquake that there is urgent need for an all-hazards approach, including a "combined disaster" strategy, which should be emphasized for current disaster planning and response. This is the first report on DMATs deployed to an earthquake site with damage to NPPs. PMID:20445385

  12. Preliminary findings and lessons learned from the 16 July 2007 earthquake at Kashiwazaki-Kariwa NPP - 'The Niigataken Chuetsu-Oki earthquake', Kashiwazaki-Kariwa NPP and Tokyo, Japan, 6-10 August 2007. Mission report. V. 2

    International Nuclear Information System (INIS)

    photographs are presented that give the impression of the way the mission was conducted and showing the atmosphere of the mission, such as the meetings and encounters with the media. The preparatory meeting held at the hotel in Nagaoke, upon arrival on Sunday, is portrayed in the first photograph. The arrival at Kashiwazaki-Kariwa NPP on Monday and the encounter with the media and the technical meetings at the plant are shown in the next three photographs. The interest of the media to this event is also shown in the next two photographs taken at the exit of the meetings in the plant and in Tokyo. In the last photograph the IAEA expert team is shown at the hotel after delivery of the draft mission report to Japanese authorities. Subsequently, Volume II is organized in the following way: 1. Part I: BACKGROUND. First of all, there is a significant amount of information provided by NISA, JNES and TEPCO as general background. This information mainly relates to Japanese regulations and general data about the Kashiwazaki-Kariwa NPP and does not pertain specifically to the 16 July 2007 event. All this information is presented under the title of 'Background' and it is not necessarily referenced to any particular discussion area of the mission. 2. Part II: INFORMATION SPECIFIC TO THE THREE AREAS COVERED BY THE MISSION AS SUPPLIED BY THE JAPANESE COUNTERPART. Secondly, there is information supplied by the Japanese counterpart as information specifically relevant to the purpose of the mission, that is, the 16 July 2007 Niigataken Chuetsu-oki earthquake and in general the plant response to this event. This information includes the presentations made by counterpart specialists at the beginning of the mission and also their response to the queries raised by the IAEA team members during the course of the mission. These presentations and the responses are presented under the three discussion areas A1, A2 and A3. If a presentation or response pertains to more than one area this is also

  13. Follow-up IAEA mission in relation to the findings and lessons learned from the 16 July 2007 earthquake at Kashiwazaki-Kariwa NPP - 'The Niigataken Chuetsu-oki earthquake', Tokyo and Kashiwazaki-Kariwa NPP, Japan, 28 January - 1 February 2008. Mission report. V. 1

    International Nuclear Information System (INIS)

    On 16 July 2007, a strong earthquake, the Niigataken Chuetsu-oki earthquake, with a moment magnitude of 6.6 (MJMA=6.8 according to the Japanese Meteorological Agency), occurred at 10:13 h local time with its hypocentre below the seabed of the Jo-chuetsu area in Niigata prefecture (37 deg. 33' N, 138 deg. 37'E) in Japan, affecting the Kashiwazaki-Kariwa Nuclear Power Plant (NPP) located approximately 16 km south of its epicentre. Kashiwazaki-Kariwa NPP is the biggest nuclear power plant site in the world. It is located in the Niigata prefecture, in the northwest coast of Japan, and it is operated by Tokyo Electric Power Company (TEPCO). The site has seven units with a total of 7965 MW net installed capacity. Five reactors are of BWR type and two reactors are of ABWR type. The five BWR units entered commercial operation between 1985 and 1994 and the two ABWRs in 1996 and 1997, respectively. Following this event, the Government of Japan through the Nuclear and Industrial Safety Agency (NISA) requested the IAEA to carry out a fact finding mission with the main purpose of identifying the preliminary findings and lessons learned from this event in order to share them with the international nuclear community. This first mission took place from 6 - 10 August 2007 and the mission report of the August 2007 mission is available on the IAEA web page http://www.iaea.org. The purpose of the second IAEA mission was to conduct - six months after the event - a follow-up of the preliminary findings of the August 2007 mission on the basis of the results available in January 2008 of the related studies and investigations performed. In accordance with the terms of reference for the follow-up mission and the availability of results from the performed studies and investigations, the scope of the follow-up mission focussed on three subject areas: (1) seismic design basis - design basis ground motions, including the evaluation of the seismic hazard ; (2) plant behaviour - integrity

  14. Analysis of the strong motion records obtained from the 2007 Niigataken Chuetsuoki earthquake and determination of the design basis ground motions at the Kashiwazaki Kariwa Nuclear Power Plant. Part 3. Determination of the design basis ground motions considering findings from the earthquake

    International Nuclear Information System (INIS)

    In the presentation, the new design basis ground motion on the basis of the factors that magnified the earthquake ground motion at the Kashiwazaki Kariwa nuclear power plant in the Niigataken Chuetsu-oki earthquake, which were examined in the part 1 and the part 2 is determined

  15. Performance evaluation on jointed fire pipes buried underground in a nuclear power plant as a lesson learned from the 2007 Niigata-ken Chuetsu-oki earthquake

    International Nuclear Information System (INIS)

    The present study discusses strength and capacity to accommodate ground displacement of jointed fire pipes. For this purpose, a bending test, a finite element analysis and an elastic beam theory analysis were conducted. The bending experiments were conducted for four types of actually used joints, namely a welded joint, a flange joint, a screw joint and a coupling joint. The relationships between the bending moment and the rotation angle at the joint were investigated based on the experimental results. As a result, the welded joint and the flange joint had a significant load capacity if compared with the couple joint. The ratio of the load capacity of the coupled joint to the welded joint was about five times. Furthermore, the bending moment and the rotation angle were identified when the inner pressure of water became the atmospheric pressure based on the bending experiment. In addition, the limit state of the welded joint was determined based on the finite element analysis result. Finally, capacities to accommodate ground displacement for respective joint were estimated based on the elastic beam theory. Consequently, the displacement capacity of the welded joint was more than about five times that of the coupling and screw joints. (author)

  16. OCCUPATIONAL SAFETY AND HEALTH IN DISASTER RESTORATION ACTIVITY AFTER SOME MAJOR EARTHQUAKES

    Science.gov (United States)

    Toyosawa, Yasuo; Itoh, Kazuya; Kikkawa, Naotaka

    Occupational safety and health in disaster restoration activity following the Great Hanshin Earthquake (1995), Niigata Chuetsu Earthquake (2004), Niigata Chuetsu-oki Earthquake (2007) Great East Japan Earthquake (2011) were analyzed and characterized in order to raise awareness on the risks and hazards in such work. In this scenario, the predominant type of accident is a "fall" which increases mainly due to the fact that labourers are working to repair houses and buildings. On the other hand, landslides were prevalent in the Niigata Chuetsu Earthquake, resulting in more accidents occurring during geotechnical works rather than in buildings construction works. In the abnormal conditions that characterize recovery activities, when safety and health measures have a tendency to be neglected, it is important to reinstate adequate measures as soon as possible by carrying out the usial risk assessments.

  17. Atmospheric Signals Associated with Major Earthquakes. A Multi-Sensor Approach. Chapter 9

    Science.gov (United States)

    Ouzounov, Dimitar; Pulinets, Sergey; Hattori, Katsumi; Kafatos, Menas; Taylor, Patrick

    2011-01-01

    We are studying the possibility of a connection between atmospheric observation recorded by several ground and satellites as earthquakes precursors. Our main goal is to search for the existence and cause of physical phenomenon related to prior earthquake activity and to gain a better understanding of the physics of earthquake and earthquake cycles. The recent catastrophic earthquake in Japan in March 2011 has provided a renewed interest in the important question of the existence of precursory signals preceding strong earthquakes. We will demonstrate our approach based on integration and analysis of several atmospheric and environmental parameters that were found associated with earthquakes. These observations include: thermal infrared radiation, radon! ion activities; air temperature and humidity and a concentration of electrons in the ionosphere. We describe a possible physical link between atmospheric observations with earthquake precursors using the latest Lithosphere-Atmosphere-Ionosphere Coupling model, one of several paradigms used to explain our observations. Initial results for the period of2003-2009 are presented from our systematic hind-cast validation studies. We present our findings of multi-sensor atmospheric precursory signals for two major earthquakes in Japan, M6.7 Niigata-ken Chuetsu-oki of July16, 2007 and the latest M9.0 great Tohoku earthquakes of March 11,2011

  18. Rocking motion of structures under earthquakes. Overturning of 2-DOF system

    International Nuclear Information System (INIS)

    In recent years, huge earthquakes happen, for example, The South Hyogo prefecture Earthquake in 1995, The Mid Niigata Prefecture Earthquake in 2004, The Iwate-Miyagi Nairiku Earthquake in 2008. In The Niigataken Chuetsu-oki Earthquake in 2007, hundreds of drums fell down and water spilled out. A lot of studies about rocking behavior of rigid body had been performed from 1960's. However, these studies were only for a specific condition of the structure size or input vibration characteristics. Therefore, generalizes fall condition for earthquake is required. This paper deals with the analytical and the experimental study of the rocking vibration of 1-DOF rocking system, 2-DOF vibration-rocking system and 2-DOF rocking system under earthquakes. In this study, the equation of motion for each rocking systems are developed. The numerical model of 2-DOF rocking system is evaluated by free rocking experiment. In this paper, 'Overturning Map' which can distinguish whether structures falls or not is proposed. The overturning map of each rocking systems excited by the artificial earthquake wave calculated from the design spectrum is shown. As the result, overturning condition of structures is clarified. (author)

  19. Prevent recurrence of nuclear disaster (3). Agenda on nuclear safety from earthquake engineering

    International Nuclear Information System (INIS)

    Based on results of activities of committee on seismic safety of nuclear power plants (NPPs) of Japan Association for Earthquake Engineering, which started activities after Chuetsu-oki earthquake and then experienced Great East Japan Earthquake, (under close collaboration with the committee of Atomic Energy Society of Japan started activities simultaneously), and taking account of further development of concept, agenda on nuclear safety were proposed from earthquake engineering. In order to prevent recurrence of nuclear disaster, individual technical issues of earthquake engineering and comprehensive issues of integration technology, multidisciplinary collaboration and establishment of technology governance based on them were of prime importance. This article described important problems to be solved; (1) technical issues and mission of seismic safety of NPPs, (2) decision making based on risk assessment - basis of technical governance, (3) framework of risk, design and regulation - framework of required technology governance, (4) technical issues of earthquake engineering for nuclear safety, (5) role of earthquake engineering in nuclear power risk communication and (6) importance of multidisciplinary collaboration. Responsibility of engineering would be attributed to establishment of technology governance, cultivation of individual technology and integration technology, and social communications. (T. Tanaka)

  20. Study on post-earthquake plant evaluation and communication (Annual safety research report, JFY 2010)

    International Nuclear Information System (INIS)

    The aims of this study are to establish a post-earthquake plant evaluation method and to develop a communication system for the improving seismic safety regulations as well as encouraging public communication. The Miyagiken-oki earthquake in 2005, Onagawa Nuclear Power Plant shut down automatically. Subsequently, JNES started development of post-earthquake plant evaluation and communication system based on the experience of the cross-check analysis for Onagawa Nuclear Power Plant. The Niigata-ken Chuetsu-oki Earthquake in 2007, the plant situation was not transmitted promptly. The loss of information sharing between local community and related organizations caused the public anxiety. The importance of plant information transmission as well as seismic information gathering were recognized. The proposal for the solution of the information issues were performed by government committee. In this study, the evaluation method for soundness of the main structure and equipment after earthquake event were updated. Moreover, procedure of the post-earthquake plant soundness evaluation and multi-functional seismic information system were developed. In addition, the implementation strategy of the easy-to -understand information dissemination to the public and transparent communication methodology was examined by the Industry-Academia-Government cooperation in the Kashiwazaki-Kariwa region. (author)

  1. Study on post-earthquake plant evaluation and communication (Annual safety research report, JFY 2011)

    International Nuclear Information System (INIS)

    The aims of this study are to establish a post-earthquake plant evaluation method and to develop a communication system for the improving seismic safety regulations as well as encouraging public communication. The Miyagiken-oki earthquake in 2005, Onagawa Nuclear Power Plant shut down automatically. Subsequently, JNES started development of post-earthquake plant evaluation and communication system based on the experience of the cross-check analysis for Onagawa Nuclear Power Plant. The Niigata-ken Chuetsu-oki Earthquake in 2007, the plant situation was not transmitted promptly. The loss of information sharing between local community and related organizations caused the public anxiety. The importance of plant information transmission as well as seismic information gathering were recognized. The proposal for the solution of the information issues were performed by government committee, In this study the evaluation method for soundness of the main structure and equipment after earthquake event were updated. Moreover, information dissemination to the public and transparent communication methodology was examined by the Industry-Academia-Government cooperation in the Kashiwazaki-Kariwa region. (author)

  2. A new interpretation of large amplitude earthquake acceleration from non-linear local soil-structure interaction

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, Kotaro [Department of Architecture and Architectural Engineering, Kyoto University, Kyoto 615-8540 (Japan); Kamagata, Shuichi [Nuclear Power Department, Kajima Corporation, Tokyo 107-8348 (Japan); Takewaki, Izuru, E-mail: takewaki@archi.kyoto-u.ac.jp [Department of Architecture and Architectural Engineering, Kyoto University, Kyoto 615-8540 (Japan)

    2014-07-01

    Highlights: • A new interpretation of large earthquake accelerations is provided. • Non-linear interaction between an embedded building and its surrounding soil is a key. • A bi-linear restoring-force characteristic with a gap-slip process is used for analysis. • Ricker wavelet and a continuous sweep sinusoidal wave are adopted as input. • The amplification is induced by a higher mode due to the change of a support condition. - Abstract: A new interpretation of large amplitude earthquake accelerations recorded at the Kashiwazaki-Kariwa nuclear power station during the Niigata-ken Chuetsu-oki earthquake in 2007 is provided from the viewpoint of non-linear local interaction between an embedded building and its surrounding soil. An occurrence mechanism is investigated by the dynamic response analysis in which a bi-linear restoring-force characteristic with a gap-slip process is used. The Ricker wavelet and the continuous sweep sinusoidal wave are adopted as an input. The amplification is explained to be induced by an additional higher mode due to the change of a support condition, such as a gap between an embedded building and its surrounding soil.

  3. A new interpretation of large amplitude earthquake acceleration from non-linear local soil-structure interaction

    International Nuclear Information System (INIS)

    Highlights: • A new interpretation of large earthquake accelerations is provided. • Non-linear interaction between an embedded building and its surrounding soil is a key. • A bi-linear restoring-force characteristic with a gap-slip process is used for analysis. • Ricker wavelet and a continuous sweep sinusoidal wave are adopted as input. • The amplification is induced by a higher mode due to the change of a support condition. - Abstract: A new interpretation of large amplitude earthquake accelerations recorded at the Kashiwazaki-Kariwa nuclear power station during the Niigata-ken Chuetsu-oki earthquake in 2007 is provided from the viewpoint of non-linear local interaction between an embedded building and its surrounding soil. An occurrence mechanism is investigated by the dynamic response analysis in which a bi-linear restoring-force characteristic with a gap-slip process is used. The Ricker wavelet and the continuous sweep sinusoidal wave are adopted as an input. The amplification is explained to be induced by an additional higher mode due to the change of a support condition, such as a gap between an embedded building and its surrounding soil

  4. Damage evaluation of reinforced concrete underground structures after earthquake. Part 2. Evaluation method based on inspection records and application example

    International Nuclear Information System (INIS)

    The objective of this present series of researches is a development of damage level evaluation method for underground structures which have been subjected to large ground motion. In part 2, items for evaluating and criteria corresponding to them were embodied considering practical use. In the developed method, data of crack width remaining after earthquakes and unusual sound area by hammering test are necessary as inspection records. Check items are constituted of flexural damage focusing on compression of concrete and on tension of rebar, and shear damage focusing on the width of inclined or splitting cracks. The procedure for calculating the maximum deflection angle of member under ground motion and threshold values for shear damage were introduced from Part 1. Moreover, the charts which assist to convert the crack width into rebar strain in a close distance were prepared using the slip formula suggested by Shima. Finally, the use of the developed method was demonstrated through a case study for a real box culvert which experienced the Niigataken Chuetsu-oki Earthquake in 2007. (author)

  5. Necessity of radiation education suggested from press report during earthquake damage of Kashiwazaki-Kariwa Nuclear Power Station

    International Nuclear Information System (INIS)

    Although Kashiwazaki-Kariwa Nuclear Power Station was affected by Chuetsu-Oki earthquake, the important components in the reactor building were hardly damaged, and fundamental nuclear safety was ensured. However, as the mass communication media reported the pictures of the black smoke of fire accident of the transformer, sloshing of the pool, etc. without declaration of 'Safety' by the Central Government or sufficient explanation, the habitants on the site and the Japan's people were put into anxiety and thus, harmful rumor was spread. The people obtain the information from the mass communication media, and they believed all the reports of the mass media. Behind it, there is a fundamental knowledge among them that Radiation = 'dangerous', 'bad for health' and 'awful' = Nuclear Power Generation. This knowledge has been fixed more firmly due to the report of the earthquake damage. In order to escape from this deep-rooted scheme, it is necessary to spread the correct knowledge on the radiation. At this time, the Official Curriculum Guidelines for Junior High School are revised, and the radiation education is started for the first time in 30 years. We analyzed and evaluated the results of the survey performed by Radiation Education Forum, and, simultaneously, we considered the necessity of the radiation education judging from the reports of the mass communication media. (author)

  6. 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

    Science.gov (United States)

    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

  7. Working material. IAEA seismic safety of nuclear power plants. International workshop on lessons learned from strong earthquake

    International Nuclear Information System (INIS)

    The International Workshop on Lessons Learned from Strong Earthquake was held at Kashiwazaki civic plaza, Kashiwazaki, Niigata-prefecture, Japan, for three days in June 2008. Kashiwazaki-Kariwa NPP (KK-NPP) is located in the city of Kashiwazaki and the village of Kariwa, and owned and operated by Tokyo Electric Power Company Ltd. (TEPCO). After it experienced the Niigata-ken Chuetsu-oki earthquake in July 2007, IAEA dispatched experts' missions twice and held technical discussions with TEPCO. Through such activities, the IAEA secretariat and experts obtained up-dated information of plant integrity, geological and seismological evaluation and developments of the consultation in the regulatory framework of Japan. Some of the information has been shared with the member states through the reports on findings and lessons learned from the missions to Japan. The international workshop was held to discuss and share the information of lessons learned from strong earthquakes in member states' nuclear installations. It provided the opportunity for participants from abroad to share the information of the recent earthquake and experience in Japan and to visit KK-NPP. And for experts in Japan, the workshop provided the opportunity to share the international approach on seismic-safety-related measures and experiences. The workshop was organised by the IAEA as a part of an extra budgetary project, in cooperation with OECD/NEA, hosted by Japanese organisations including Nuclear and Industrial Safety Agency (NISA), Nuclear Safety Commission (NSC), and Japan Nuclear Energy Safety Organization (JNES). The number of the workshop participants was 70 experts from outside Japan, 27 countries and 2 international organisations, 154 Japanese experts and 81 audience and media personnel, totalling to 305 participants. The three-day workshop was open to the media including the site visit, and covered by NHK (the nation's public broadcasting corporation) and nation-wide and local television

  8. Influence length and space-time correlation between earthquakes

    CERN Document Server

    Tosi, P; Loreto, V; Pietronero, L; Tosi, Patrizia; Rubeis, Valerio De; Loreto, Vittorio; Pietronero, Luciano

    2004-01-01

    Short and long range interactions between earthquakes are attracting increasing interest. Scale invariant properties of seismicity in time, space and energy argue for the presence of complex triggering mechanisms where, like a cascade process, each event produces aftershocks. A definitive method to assess any connection between two earthquakes separated in time and distance does not exist. Here we propose a novel method of data analysis that, based on the space-time combined generalization of the correlation integral leads to a self-consistent visualization and analysis of both spatial and temporal correlations. When analyzing global seismicity we discovered a universal relation linking the spatial Influence Length of a given earthquake to the time elapsed from the event itself. Following an event, time correlations (i.e. causality effects) exist in a region that shrinks over time, suggesting a long-range dissipating stress transfer. A different process is acting in the short-range where events are randomly s...

  9. Characterising large scenario earthquakes and their influence on NDSHA maps

    Science.gov (United States)

    Magrin, Andrea; Peresan, Antonella; Panza, Giuliano F.

    2016-04-01

    The neo-deterministic approach to seismic zoning, NDSHA, relies on physically sound modelling of ground shaking from a large set of credible scenario earthquakes, which can be defined based on seismic history and seismotectonics, as well as incorporating information from a wide set of geological and geophysical data (e.g. morphostructural features and present day deformation processes identified by Earth observations). NDSHA is based on the calculation of complete synthetic seismograms; hence it does not make use of empirical attenuation models (i.e. ground motion prediction equations). From the set of synthetic seismograms, maps of seismic hazard that describe the maximum of different ground shaking parameters at the bedrock can be produced. As a rule, the NDSHA, defines the hazard as the envelope ground shaking at the site, computed from all of the defined seismic sources; accordingly, the simplest outcome of this method is a map where the maximum of a given seismic parameter is associated to each site. In this way, the standard NDSHA maps permit to account for the largest observed or credible earthquake sources identified in the region in a quite straightforward manner. This study aims to assess the influence of unavoidable uncertainties in the characterisation of large scenario earthquakes on the NDSHA estimates. The treatment of uncertainties is performed by sensitivity analyses for key modelling parameters and accounts for the uncertainty in the prediction of fault radiation and in the use of Green's function for a given medium. Results from sensitivity analyses with respect to the definition of possible seismic sources are discussed. A key parameter is the magnitude of seismic sources used in the simulation, which is based on information from earthquake catalogue, seismogenic zones and seismogenic nodes. The largest part of the existing Italian catalogues is based on macroseismic intensities, a rough estimate of the error in peak values of ground motion can

  10. Earthquake

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

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

  11. Influence of Earthquake Parameters on Tsunami Wave Height and Inundation

    Science.gov (United States)

    Kulangara Madham Subrahmanian, D.; Sri Ganesh, J.; Venkata Ramana Murthy, M.; V, R. M.

    2014-12-01

    After Indian Ocean Tsunami (IOT) on 26th December, 2004, attempts are being made to assess the threat of tsunami originating from different sources for different parts of India. The Andaman - Sumatra trench is segmented by transcurrent faults and differences in the rate of subduction which is low in the north and increases southward. Therefore key board model with initial deformation calculated using different strike directions, slip rates, are used. This results in uncertainties in the earthquake parameters. This study is made to identify the location of origin of most destructive tsunami for Southeast coast of India and to infer the influence of the earthquake parameters in tsunami wave height travel time in deep ocean as well as in the shelf and inundation in the coast. Five tsunamigenic sources were considered in the Andaman - Sumatra trench taking into consideration the tectonic characters of the trench described by various authors and the modeling was carried out using TUNAMI N2 code. The model results were validated using the travel time and runup in the coastal areas and comparing the water elevation along Jason - 1's satellite track. The inundation results are compared from the field data. The assessment of the tsunami threat for the area south of Chennai city the metropolitan city of South India shows that a tsunami originating in Car Nicobar segment of the Andaman - Sumatra subduction zone can generate the most destructive tsunami. Sensitivity analysis in the modelling indicates that fault length influences the results significantly and the tsunami reaches early and with higher amplitude. Strike angle is also modifying the tsunami followed by amount of slip.

  12. Estimating the extent of stress influence by using earthquake triggering groundwater level variations in Taiwan

    Science.gov (United States)

    Wang, Shih-Jung; Hsu, Kuo-Chin; Lai, Wen-Chi; Wang, Chein-Lee

    2015-11-01

    Groundwater level variations associated with earthquake events may reveal useful information. This study estimates the extent of stress influence, defined as the distance over which an earthquake can induce a step change of the groundwater level, using earthquake-triggering groundwater level variations in Taiwan. Groundwater variations were first characterized based on the dynamics of groundwater level changes dominantly triggered by earthquakes. The step-change data in co-seismic groundwater level variations were used to analyze the extent of stress influence for earthquakes. From the data analysis, the maximum extent of stress influence is 250 km around Taiwan. A two-dimensional approach was adopted to develop two models for estimating the maximum extent of stress influence for earthquakes. From the developed models, the extent of stress influence is proportional to the earthquake magnitude and inversely proportional to the groundwater level change. The model equations can be used to calculate the influence radius of stress from an earthquake by using the observed change of groundwater level and the earthquake magnitude. The models were applied to estimate the area of anomalous stress, defined as the possible areas where the strain energy is accumulated, using the cross areas method. The results show that the estimated area of anomalous stress is close to the epicenter. Complex geological structures and material heterogeneity and anisotropy may explain this disagreement. More data collection and model refinements can improve the proposed model. This study shows the potential of using groundwater level variations for capturing seismic information. The proposed concept of extent of stress influence can be used to estimate the earthquake effect in hydraulic engineering, mining engineering, and carbon dioxide sequestration, etc. This study provides a concept for estimating the possible areas of anomalous stress for a forthcoming earthquake.

  13. Earthquakes

    Science.gov (United States)

    ... Emergency Wound Care Wound Management for Healthcare Pros Power Outages When the Power Goes Out Worker Safety Vaccine ... Share Compartir Surviving an earthquake and reducing its health impact requires preparation, planning, and practice. Far in advance, ...

  14. Earthquake

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    CHENGDU,China—A powerful earthquake struck Western China on 12th May2008, toppling thousands of homes,factories and offices,trapping students in schools,the country’s worst natural disaster in three decades.MIANZHU,CHINA—As rescue workers plowed deeper into the wreckage left from Monday’s earthquake,uncovering more victims trapped in the most remote mountain villages near the epicenter in Sichuan Province

  15. Geological and seismological survey for new design-basis earthquake ground motion of Kashiwazaki-Kariwa NPS

    Science.gov (United States)

    Takao, M.; Mizutani, H.

    2009-05-01

    At about 10:13 on July 16, 2007, a strong earthquake named 'Niigata-ken Chuetsu-oki Earthquake' of Mj6.8 on Japan Meteorological Agencyfs scale occurred offshore Niigata prefecture in Japan. However, all of the nuclear reactors at Kashiwazaki-Kariwa Nuclear Power Station (KKNPS) in Niigata prefecture operated by Tokyo Electric Power Company shut down safely. In other words, automatic safety function composed of shutdown, cooling and containment worked as designed immediately after the earthquake. During the earthquake, the peak acceleration of the ground motion exceeded the design-basis ground motion (DBGM), but the force due to the earthquake applied to safety-significant facilities was about the same as or less than the design basis taken into account as static seismic force. In order to assess anew the safety of nuclear power plants, we have evaluated a new DBGM after conducting geomorphological, geological, geophysical, seismological survey and analyses. [Geomorphological, Geological and Geophysical survey] In the land area, aerial photograph interpretation was performed at least within the 30km radius to extract geographies that could possibly be tectonic reliefs as a geomorphological survey. After that, geological reconnaissance was conducted to confirm whether the extracted landforms are tectonic reliefs or not. Especially we carefully investigated Nagaoka Plain Western Boundary Fault Zone (NPWBFZ), which consists of Kakuda-Yahiko fault, Kihinomiya fault and Katakai fault, because NPWBFZ is the one of the active faults which have potential of Mj8 class in Japan. In addition to the geological survey, seismic reflection prospecting of approximate 120km in total length was completed to evaluate the geological structure of the faults and to assess the consecutiveness of the component faults of NPWBFZ. As a result of geomorphological, geological and geophysical surveys, we evaluated that the three component faults of NPWBFZ are independent to each other from the

  16. Evaluation of influence of an earthquake acceleration upon boiling two phase flow behavior

    International Nuclear Information System (INIS)

    The analysis of boiling two-phase flow in a simulated fuel channel under the condition that earthquake acceleration is imposed on was performed in order to evaluate the influence of earthquake acceleration upon the boiling two-phase flow behavior in fuel bundles of nuclear reactors. From a series of numerical simulations, the following summaries were derived: when the earthquake acceleration is given to the horizontal direction, time change of the predicted void fraction aries a time lag depending on an oscillation period of earthquake and the time lag is maintained; and, the fluctuation characteristic of the predicted void fraction receives strongly the influence of lift force and turbulent force to the oscillation period of earthquake. (author)

  17. The influences of Media within the Tsunami & Pakistani earthquake - 2005

    OpenAIRE

    Reymann, Marie Emilie Leth; Pedersen, Mitzi; Mortensen, Thor Storm; Nat-George, Jonathan Arthur; Prole, Rebekah Anne

    2005-01-01

    This project is an analysis of the media coverage of both the Tsunami in South East Asia and the earthquake in Pakistan. This comparison has lead to the conclusion that the Tsunami received most coverage and this project tries to answer why and how media chooses so. In connection to the funding received there has been drawn a parallel between the minutes of coverage (Tv2-news) and the amount given. Furthermore this project contains the background details of the two events, a comparison of ...

  18. Influence of hydrodynamic parameters on tsunami run-up uncertainty induced by earthquake random slip distribtutions

    Science.gov (United States)

    Løvholt, Finn; Kim, Jihwan; Pedersen, Geir; Harbitz, Carl

    2016-04-01

    The standard approach in forward modeling of earthquake tsunamis usually assume a uniform slip pattern. This is assumption is used both in deterministic and probabilistic models. However, the slip distribution for an earthquake is subject to (aleatory) uncertainty, and consequently the induced tsunami run-up will have an uncertainty range even given the same moment magnitude and hypocentre earthquake location. Here, we present studies of run-up variability due to stochastic earthquake slip variation in both two and three dimensions. The approach taken is fully idealized, although we draw upon the experience from two of the most destructive events the last hundred years, namely the Mw8 1976 Moro Gulf earthquake and tsunami as well as the Mw9 2011 Tohoku earthquake tsunami. The former event is used to design the two-dimensional stochastic simulations, and the latter event the three-dimensional simulations. Our primary focus is not reproduce past run-up, but rather to investigate how the hydrodynamics influence uncertainty. These quantities include among others the non-hydrodynamic response during generation, frequency dispersion, friction from the seabed, and wave-breaking. We simulate tsunamis for an ensemble of synthetic random slip over an idealized shelf geometry broken into linear segments. The uncertainty propagation from source to run-up for the two different cases are discussed and compared. As demonstrated, both the dimensionality and the earthquake parameters influence the contributions of the hydrodynamic parameters on the uncertainty. Further work will be needed to explore the transitional behaviour between the two very different cases displayed here. The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement 603839 (Project ASTARTE).

  19. Statistics of Earthquake Influence on Buildings by means of Seismic Acceleration

    Science.gov (United States)

    Pentaris, Fragkiskos P.; Makris, John P.

    2014-05-01

    This work aims to investigate the statistics of earthquake influence on buildings by studying the correlation of earthquake parameters (magnitude, epicentral distance, azimuth, depth) with the observed seismic acceleration of different floors of a building, as well as of buildings of different age. Crete is on the Hellenic arc, a region with very high seismicity. The study exploits the significant and miscellaneous seismicity of the Southern Hellenic Arc (Greece). Structural Health Monitoring Systems (SHMs), composed by high sensitivity accelerometers, are installed in two different age neighboring buildings, each one consisting two floors, of the Technological Educational Institute of Crete (TEI) located in a suburb of the Chania city (Western Crete). Both SHMs are continuously operating more than a year having recorded a great amount of seismic acceleration data from low, medium and high magnitude earthquakes, featuring various epicentral distances and azimuths. A detailed statistical analysis is being performed in order to correlate the seismic responses of the two buildings, characterized by different vulnerability, with key-parameters of associated earthquakes. Furthermore, we examine the earthquake influence on the two buildings before and after a major nearby seismic event to investigate a possible change in the buildings vulnerability. Acknowledgements This research has been co-financed by the European Union (European Social Fund - ESF) and Greek national funds through the Operational Program "Education and Lifelong Learning" of the National Strategic Reference Framework (NSRF) - Research Funding Program: ARCHIMEDES III. Investing in knowledge society through the European Social Fund.

  20. Possibility to explain global climate variations by earthquakes influence

    Science.gov (United States)

    Molchanov, O.

    2009-12-01

    An additional natural source of the global warming could be heat flux from seismicity. Estimated earthquakes energy release in the near-equatorial Pacific area during a year ≈ 1020 J that is equivalent to the energy released in the detonation about one million atomic bombs of Hiroshima class and produce average power flux due to seismicity ≈ 0.3-1 W/m2 . We have analyzed together the slow climate temperature variations in the near-equatorial Pacific Ocean area (SSTOI indices) and crustal seismic activity in the same region during 1973-2008 time period using correlation analysis and found similarity in seismic and ENSO periodicities (the latter with time lag about 1.5 years). Trends of the processes are also similar showing about 2 times increase in average seismic energy release during the whole period of analysis and conventional 0.10C/(10 years) increase in SSTOI index anomalies. Our main conclusion is on real possibility of climate-seismicity coupling. It is rather probable that at least partially climate ENSO oscillations and temperature anomaly trends are induced by similar variation in seismicity. A mechanism of several years periodicity in the seismic activity is unclear at present. Probably it is initiated in the upper mantle of the Earth (depth 600-700 km) and then penetrates in the crust as so-called deformation (or stress) wave with time delay from 3 to 10 years [1] [1] O.A. Molchanov and S. Uyeda, Upward migration of earthquake hypocenters in Japan,Kurile- Kamchatka and Sunda subduction zones, Physics and Chemistry of the Earth, 34, 423-430, 2009; doi:10.1016/j.pce.2008.09.011.

  1. The Influencing Factors of Escaped Radon from the Jiayuguan Fault Zone and Its Earthquake Reflecting Effect

    Institute of Scientific and Technical Information of China (English)

    Wang Bo; Huang Fuqiong; Jian Chunlin

    2011-01-01

    The paper analyzes the radon data of nearly two decades on the Jiayuguan fault zone, discusses the main influencing factors, and puts forward the relationship between radon and air temperature, ground temperature and rainfall. We summarized the earthquake reflecting effect for ML≥5. 0 about 400km within the Jiayuguan station, and reached the conclusion that it has better earthquake-reflecting ability before an earthquake, usually appearing as abnormal changes in sustained low value. By extracting the annual trend of radon in Jiayuguan station over many years, we discovered that the annual trend of radon has a close relationship with the seismic activity in surrounding areas, namely, if the annual variation of radon is larger, the seismic activity in surrounding areas is stronger; Otherwise, if the annual variation of radon is relatively stable, the seismic activity in the vicinity is weak.

  2. Isolating social influences on vulnerability to earthquake shaking: identifying cost-effective mitigation strategies.

    Science.gov (United States)

    Bhloscaidh, Mairead Nic; McCloskey, John; Pelling, Mark; Naylor, Mark

    2013-04-01

    Until expensive engineering solutions become more universally available, the objective targeting of resources at demonstrably effective, low-cost interventions might help reverse the trend of increasing mortality in earthquakes. Death tolls in earthquakes are the result of complex interactions between physical effects, such as the exposure of the population to strong shaking, and the resilience of the exposed population along with supporting critical infrastructures and institutions. The identification of socio-economic factors that contribute to earthquake mortality is crucial to identifying and developing successful risk management strategies. Here we develop a quantitative methodology more objectively to assess the ability of communities to withstand earthquake shaking, focusing on, in particular, those cases where risk management performance appears to exceed or fall below expectations based on economic status. Using only published estimates of the shaking intensity and population exposure for each earthquake, data that is available for earthquakes in countries irrespective of their level of economic development, we develop a model for mortality based on the contribution of population exposure to shaking only. This represents an attempt to remove, as far as possible, the physical causes of mortality from our analysis (where we consider earthquake engineering to reduce building collapse among the socio-economic influences). The systematic part of the variance with respect to this model can therefore be expected to be dominated by socio-economic factors. We find, as expected, that this purely physical analysis partitions countries in terms of basic socio-economic measures, for example GDP, focusing analytical attention on the power of economic measures to explain variance in observed distributions of earthquake risk. The model allows the definition of a vulnerability index which, although broadly it demonstrates the expected income-dependence of vulnerability to

  3. Revisiting the global detection capability of earthquakes during the period immediately after a large earthquake: considering the influence of intermediate-depth and deep earthquakes

    Directory of Open Access Journals (Sweden)

    Takaki Iwata

    2012-03-01

    Full Text Available This study examines the global earthquake detection capability of the Global Centroid Moment Tensor (GCMT catalogue during the periods immediately following large earthquakes, including intermediate-depth (70 ≤ depth < 300 km and deep (300 km ≤ depth events. We have already shown that the detection capability beyond an aftershock zone degrades remarkably and that this condition persists for several hours after the occurrence of large shallow (depth < 70 km earthquakes. Because an intermediate-depth or deep earthquake occasionally generates seismic waves with significant amplitudes, it is necessary to investigate the change in the detection capability caused by such events. To this end, from the GCMT catalogue, we constructed the time sequences of the earthquakes that occurred immediately after the large earthquakes, and stacked these time sequences. To these stacked sequences, we then applied a statistical model representing the magnitude-frequency distribution of all observed earthquakes. This model has a parameter that characterizes the detection capability, and the temporal variation of the parameter is estimated by means of a Bayesian approach with a piecewise linear function. Consequently, we find that the global detection capability is lower after the occurrence of shallow earthquakes with magnitudes ≥ 5.45, intermediate-depth earthquakes with magnitudes ≥ 5.95, and deep earthquakes with magnitudes ≥ 6.95.

  4. Revisiting the global detection capability of earthquakes during the period immediately after a large earthquake: considering the influence of intermediate-depth and deep earthquakes

    OpenAIRE

    Takaki Iwata

    2012-01-01

    This study examines the global earthquake detection capability of the Global Centroid Moment Tensor (GCMT) catalogue during the periods immediately following large earthquakes, including intermediate-depth (70 ≤ depth < 300 km) and deep (300 km ≤ depth) events. We have already shown that the detection capability beyond an aftershock zone degrades remarkably and that this condition persists for several hours after the occurrence of large shallow (depth < 70 km) earthquakes. Because an in...

  5. [A case of "oneiroid Erlebnisform" influenced by the Great East Japan Earthquake].

    Science.gov (United States)

    Hori, Takafumi; Ishii, Terumi; Hisanaga, Akihito; Tatsuki, Aeka; Tachikawa, Hirokazu; Asada, Takashi

    2013-01-01

    Following the Great East Japan Earthquake, although there are a growing number of reports on the care of the mental health of victims and supporters, the influence of this disaster on individuals with mental disorders has not yet been sufficiently clarified. Here, we present a case of "oneiroid Erlebnisform" (Mayer-Gross, W.), which was influenced by the disaster and relapsed one year after the earthquake. We discussed the meaning of this experience and the factors leading to recurrence in this case. A male international student in his thirties had repeatedly suffered from acute episodic alteration of consciousness. Although he had experienced anxiety just after the disaster, he showed improvement during his temporary evacuation to Western Japan. Nearly one year after the disaster, however, he relapsed, with symptoms characteristic of an oneiroid state. The patient stated that he was a fuel rod in the Fukushima nuclear power plant, and he then immersed himself in a bathtub full of water in order to avoid meltdown. According to ICD-10, the patient was diagnosed with acute polymorphic psychotic disorder without symptoms of schizophrenia (F23.0). In addition to the alteration of consciousness as the main symptom, since there was no decrease in the level of personolity function, it was also considered that the diagnosis of this case was atypical psychosis, as proposed by Mitsuda and Hatotani. In the oneiroid experience, a variety of visual hallucinations, illusions, and images had appeared one after another. We can find catastrophe and salvation as the main themes in this state, related to the disaster and nuclear accident. Unloading situation after thesis defense, insufficient sleep, poor medication adherence, and the increased frequency of earthquakes were important factors in the recurrence of the present case. To continue research in Japan after the earthquake, the decision was accompanied by anxiety for the patient. One year after the earthquake, the patient was

  6. Development and implementation of plant diagnostic skills training

    International Nuclear Information System (INIS)

    It was learned from the July 2007 Chuetsu-oki Earthquake that a need exists for simulator training methods to be revised to include the assumption of multiple failures such as those which may occur during a large earthquake. At BWR Operator Training Center Corp., multiple failure team training which focuses on plant diagnostic skills (Plant Diagnostic Skills Training) has been developed and implemented since September 2008. The contents of this training along with the results are presented and considered in this paper. (author)

  7. Influence of earthquake ground motion incoherency on multi-support structures

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A linear response history analysis method is used to determine the influence of three factors: geometric incoherency, wave-passage, and local site characteristics on the response of multi-support structures subjected to differential ground motions. A one-span frame and a reduced model of a 24-span bridge, located in Las Vegas, Nevada are studied, in which the influence of each of the three factors and their combinations are analyzed. It is revealed that the incoherency of earthquake ground motion can have a dramatic influence on structural response by modifying the dynamics response to uniform excitation and inducing pseudo-static response, which does not exist in structures subjected to uniform excitation. The total response when all three sources of ground motion incoherency are included is generally larger than that of uniform excitation.

  8. Understanding Space Weather influence on earthquake triggering to shield people living in seismic regions

    Science.gov (United States)

    Khachikyan, Galina; Inchin, Alexander; Kim, Alexander; Khassanov, Eldar

    2016-07-01

    There is an idea at present that space weather can influence not only the technological infrastructure and people's health, but seismic activity as well. Space weather impact on the Earth results from magnetic reconnection between the Sun's and Earth's magnetic fields. The effectiveness of reconnection depends on sign and magnitude of Z-components in solar wind magnetic field and earth's magnetic field as measured in the geocentric solar magnetosphere (GSM) coordinate system. The more negative value of Zgsm in the solar wind magnetic field, and the more positive value of Zgsm in the geomagnetic field, the more solar wind energy penetrates into the earth's environment due to reconnection. It was found recently by Khachikyan et al. [2012, http://www.scirp.org/journal/ijg] that maximal possible earthquake magnitude in a particular seismic region (seismic potential - Mmax) may be determined, in first approximation, on the base of maximal geomagnetic Zgsm value in this region, namely: Mmax = (5.22 +- 0.17) + (0.78 +- 0.06) x [abs (Zgsm)]. In this report we present statistical results on association between variations in space weather and global seismic activity, and demonstrate that a great Sumatra earthquake (M=9.1, on December 26, 2004, at 00:58:53 GMT) indeed occurred in region where the geomagnetic Zgsm components are largest at the globe. In the time of earthquake occurrence, geomagnetic Zgsm value in the epicenter (3.30N, 95.980E) was equal to ~37147 nT. A range of possible maximal magnitude, as estimated from above relation, could be of 8.8 - 9.2. The recorded magnitude M=9.1 is within this range.

  9. Groundwater level evaluation for river flood control levees and its effect on seismic performance

    OpenAIRE

    Kwak, Dong Youp; Brandenberg, Scott J; Stewart, Jonathan P.; Mikami, Atsushi

    2012-01-01

    We are working towards developing risk assessment tools for levees to identify conditions that correlate with ground failure rates. Our initial data set is from the 2007 Mw6.6 Niigata Chuetsu-oki earthquake in Japan. Liquefaction-induced ground failure is a major source of levee damage in this case, so groundwater elevation is expected to be a critical factor affecting damage locations. What we seek is the water level in or beneath the levees themselves along the full length of the study regi...

  10. Press problem related to nuclear energy news reporting

    International Nuclear Information System (INIS)

    Since the event of Niigataken Chuetsu-oki Earthquake in 2007 and the subsequent press reports on damage of nuclear power station after it, a stance of media is being questioned. In order to clear this problem, basic organizational structure of the press related to nuclear energy news was analyzed. Local news department, social news department, science news department and economical news department involve in nuclear energy news the accordance with their own situations and concerns. This structure makes problem of nuclear energy news reporting complicated. Changing this system is required but very difficult. It is concluded that the press problem around nuclear energy news is strange. (author)

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

    Science.gov (United States)

    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.

  12. Geological Influence on the Site Response of Bantul Earthquake at Yogyakarta Special Province, Indonesia

    Science.gov (United States)

    Karnawati, D.; Pramumijoyo, S.; Hussein, S.; Anderson, R.; Ratdomopurbo, A.

    2007-05-01

    On May 27, 2006 a magnitude 6.2 earthquake struck Yogyakarta Special Province in Central Java. The earthquake designated the Bantul earthquake resulted in the deaths of 5,800 and left 200,000 families homeless. Over 280,000 buildings were damaged or destroyed. Housing quality was generally poor with no accounting for earthquake-resistant design. Housing and building materials were also of poor quality. In spite of the poor design and construction materials, local geological conditions were determined be a significant influence on the site response which affected the intensity of building damage. In addition, strong ground shaking was unusually long at 57 seconds. In response to the findings of the initial field reconnaissance a series of micro-tremor surveys supported by aerial and satellite image interpretations, ground penetration radar and magneto telluric surveys, as well as engineering geological site investigations were conducted. The objectives of the surveys and investigations were: to investigate various factors controlling the levels of site response which induced damage to homes and buildings; and, to produce a seismic hazard micro-zonation map. Provision of this micro-zonation map is crucial to support the enhancement of building code and landuse management in the earthquake prone area at Bantul. The Bantul area is located in a valley formed a graben. This valley was due to two major normal faults extending towards North East - South West. The east border of the valley is bounded major normal fault formed the Progo River, whilst at the west border another major normal fault formed the Opak-Oya Rivers. Drilling correlations of the bedrock (of andesitic breccia) in the valley, was found at a depth of about 40 m below the existing ground surface. Bedrock was covered by a layer of clay produced from paleo-swamps with various thicknesses from 1 to 2 m. After the clay deposition, the basin then was filled by loose fluvial sediments consisting of gravelly sand

  13. Influence of anchor behaviour on the earthquake response of liquid storage tanks

    International Nuclear Information System (INIS)

    The dynamic response of thin liquid storage tanks to earthquakes is a very complicated phenomenon, because it can be highly non linear. Among others, one can meet material and geometric non linearities of the tank shell leading eventually to static or dynamic buckling non linear behavior of anchor bolts, contact non-linearities due to the uplift of the tank base and to the unilateral character of the fluid pressure on the shell and high amplitude fluid oscillations. Moreover, linear or non linear soil structure interaction affects considerably the response of the fluid structure system under consideration. In this paper we focus attention on problems related only to the base uplift and anchors plastification. We study a tank similar to the Hualien project tank, but we neglect the soil structure interaction. The studied tank is representative of medium height to radius ratio ratio tanks with relatively thick bottom plate. The contact is simulated via a simple discrete penalty method in order to facilitate the calculation of the impact forces. Modal coordinates calculated for various Fourier harmonics are used for the dynamic analysis and the coupled modal equations of motion are solved with an explicit time integration algorithm. Obviously, this approach is less precise than a direct finite element analysis on the nodal basis but is less expensive. The scope of this paper is to discuss the efficiency of the proposed method to deal with problems like those aforementioned and to give some qualitative results concerning the influence of anchor bolts behaviour on the earthquake response of tanks. (author). 2 refs., 7 figs., 1 tab

  14. Influence of fortnightly tides on earthquake triggering at the East Pacific Rise at 9°50'N

    Science.gov (United States)

    Bhatnagar, Tarini; Tolstoy, Maya; Waldhauser, Felix

    2016-03-01

    The study of tidal forcing provides an opportunity to view the response of the solid Earth to known changes in stress. Earthquakes triggered by diurnal and semidiurnal tidal forces have been well documented for the deep ocean and some terrestrial environments. However, few studies examine the influence of fortnightly tides on earthquake triggering and only in terrestrial environments. We assess triggering of microearthquakes related to true fortnightly tides and fortnightly tidal modulations along the East Pacific Rise at 9°50'N, where strong diurnal and semidiurnal triggering of earthquakes has been observed. An ocean bottom seismograph experiment collected microearthquake data between October 2003 and January 2007, a time period that included a well-documented submarine eruption culminating in January 2006. We examine how triggering changed through the build up to and aftermath of this seafloor-spreading event. Results show that earthquakes occur preferentially during times of increasing peak volumetric stress leading up to the eruption, with strong statistical significance (Schuster Test p values up to 2.22e-31). However, the correlation loses its strength immediately prior to and during the eruptive period (p value as high as 0.2837), when competing tectonic and magmatic stresses may occur. Post-eruption triggering reappears (p value 1.45e-26) but with opposite phase. Statistical significance is also explored using Monte Carlo method, highlighting limitations of swarm-dominated time series for the Schuster Test. Nevertheless, the observations are consistent with a shift in the dominating stress triggering the earthquakes from extensional tectonics to magmatic processes, followed by a post-eruption period of cooling, relaxation, and possibly magma chamber refilling.

  15. Earthquake Facts

    Science.gov (United States)

    ... Us Earthquakes Hazards Data & Products Learn Monitoring Research Earthquake Facts The largest recorded earthquake in the United ... we know, there is no such thing as "earthquake weather" . Statistically, there is an equal distribution of ...

  16. Influence of Inhomogeneity on Critical Behavior of Earthquake Model on Random Graph

    Institute of Scientific and Technical Information of China (English)

    ZHANG Duan-Ming; SUN Fan; YU Bo-Ming; PAN Gui-Jun; YIN Yan-Ping; LI Rui; SU Xiang-Ying

    2006-01-01

    We consider the earthquake model on a random graph. A detailed analysis of the probability distribution of the size of the avalanches will be given. The model with different inhomogeneities is studied in order to compare the critical behavior of different systems. The results indicate that with the increase of the inhomogeneities, the avalanche exponents reduce, i.e., the different numbers of defects cause different critical behaviors of the system. This is virtually ascribed to the dynamical perturbation.

  17. Analysis of prevalence of PTSD and its influencing factors among college students after the Wenchuan earthquake

    Directory of Open Access Journals (Sweden)

    Fu Yan

    2013-01-01

    Full Text Available Abstract Background This study explored the prevalence and severity of post-traumatic stress disorder (PTSD in college students who lived in earthquake center one year after the Wenchuan earthquake on May 12, 2008, the factors affecting the prevalence of PTSD was also investigated. Methods 2987 students studying at the senior normal school in Tibetan autonomous region which was one of the most devastated regions were selected for this study. The PTSD Checklist-Civilian Version (PCL-C was used as a screening instrument. Results A total of 420 cases (14.1% were diagnosed with PTSD, among which mild, moderate, severe and extreme symptoms were reported in 122, 185, 106 and 7 cases, respectively. The PTSD prevalence in college students lived in the severely affected area was significantly higher than that in the less severe area (P  Conclusions At one year after the earthquake, the PTSD rate in college students in the severely affected area was high. The social support, psychological help and rehabilitation project should be strengthened to improve their ability to cope with the trauma.

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

    Directory of Open Access Journals (Sweden)

    Barbara Theilen-Willige

    2011-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    高孟潭; 金学申; 安卫平; 吕晓健

    2004-01-01

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

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

    Directory of Open Access Journals (Sweden)

    B. Theilen-Willige

    2010-06-01

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

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

    Directory of Open Access Journals (Sweden)

    George Pararas-Carayannis

    2011-01-01

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

  2. Influence of super-shear on simulated near-source ground motion from the 1999 Izmit earthquake

    OpenAIRE

    Aochi, Hideo; Durand, Virginie,; Douglas, John

    2011-01-01

    We numerically simulate seismic wave propagation from the 1999 Mw7.4 Izmit, Turkey, earthquake, using a 3D finite difference method based on published finite source models obtained by waveform inversions. This earthquake has been reported, based on observations at the near-fault station SKR, as an example of super-shear rupture propagation towards the east. Although the modeled ground motion does show a characteristic Mach wave from the fault plane, it is difficult to identify any particular ...

  3. Bounded Earthquakes

    OpenAIRE

    Saric, Dragomir

    2006-01-01

    We give a short proof of the fact that bounded earthquakes of the unit disk induce quasisymmetric maps of the unit circle. By a similar method, we show that symmetric maps are induced by bounded earthquakes with asymptotically trivial measures.

  4. Hidden Earthquakes.

    Science.gov (United States)

    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)

  5. Construction of System for Seismic Observation in Deep Borehole (SODB) - Overview and Achievement Status of the Project

    International Nuclear Information System (INIS)

    The seismic responses of each unit at the Kashiwazaki-Kariwa NPP differed greatly during the 2007 Niigata-ken Chuetsu-oki Earthquake; the deep sedimentary structure around the site greatly affected these differences. To clarify underground structure and to evaluate ground motion amplification and attenuation effects more accurately in accordance with deep sedimentary structure, JNES initiated the SODB project. Deployment of a vertical seismometer array in a 3000-meter deep borehole was completed in June 2012 on the premises of NIIT. Horizontal arrays were also placed on the ground surface. Experiences and achievements in the JNES project were introduced, including development of seismic observation technology in deep boreholes, site amplification measurements from logging data, application of borehole observation data to maintenance of nuclear power plant safety, and so on. Afterwards, the relationships of other presentations in this WS, were explained. (authors)

  6. Study on vessels' seismic buckling

    International Nuclear Information System (INIS)

    Inspection on Kashiwazaki-Kariwa Nuclear Power Station after the Niigateken Chuetsu-oki Earthquake in 2007 observed obvious buckling in some fluid storage vessels, the filtrate tanks and de-ionized Water tanks. All vessels with buckling belong to Seismic class C. Contrary the other vessels such as Diesel tanks showed no damage. Those phenomena presumably are brought about by differences in the vessels' condition (Vessels geometries, Fluid weight, etc.) and the seismic load on each vessel. In this study, the elephant's foot buckling occurred on the filtrate tank was simulated by FEM analysis of the large displacement elastic-plastic model with the recorded time history of seismic acceleration. The same analysis on the diesel was conducted tank to see that no damage took place also in the analysis. (author)

  7. Influence of strong electromagnetic discharges on the dynamics of earthquakes time distribution in the Bishkek test area (Central Asia

    Directory of Open Access Journals (Sweden)

    P. Tosi

    2006-06-01

    Full Text Available From 08/01/1983 to 28/03/1990, at the Bishkek ElectroMagnetic (EM test site (Northern Tien Shan and Chu Valley area, Central Asia, strong currents, up to 2.5 kA, were released at a 4.5 km long electrical (grounded dipole. This area is seismically active and a catalogue with about 14100 events from 1975 to 1996 has been analyzed. The seismic catalogue was divided into three parts: 1975-1983 first part with no EM experiments, 1983-1990 second part during EM experiments and 1988-1996 after experiments part. Qualitative and quantitative time series non- linear analysis was applied to waiting times of earthquakes to the above three sub catalogue periods. The qualitative approach includes visual inspection of reconstructed phase space, Iterated Function Systems (IFS and Recurrence Quantification Analysis (RQA. The quantitative approach followed correlation integral calculation of reconstructed phase space of waiting time distribution, with noise reduction and surrogate testing methods. Moreover the Lempel- Ziv algorithmic complexity measure (LZC was calculated. General dynamics of earthquakes’ temporal distribution around the test area, reveals properties of low dimensional non linearity. Strong EM discharges lead to the increase in extent of regularity in earthquakes temporal distribution. After cessation of EM experiments the earthquakes’ temporal distribution becomes much more random than before experiments. To avoid non valid conclusions several tests were applied to our data set: differentiation of the time series was applied to check results not affected by non stationarity; the surrogate data approach was followed to reject the hypothesis that dynamics belongs to the colored noise type. Small earthquakes, below completeness threshold, were added to the analysis to check results robustness.

  8. Do Earthquakes Shake Stock Markets?

    Science.gov (United States)

    Ferreira, Susana; Karali, Berna

    2015-01-01

    This paper examines how major earthquakes affected the returns and volatility of aggregate stock market indices in thirty-five financial markets over the last twenty years. Results show that global financial markets are resilient to shocks caused by earthquakes even if these are domestic. Our analysis reveals that, in a few instances, some macroeconomic variables and earthquake characteristics (gross domestic product per capita, trade openness, bilateral trade flows, earthquake magnitude, a tsunami indicator, distance to the epicenter, and number of fatalities) mediate the impact of earthquakes on stock market returns, resulting in a zero net effect. However, the influence of these variables is market-specific, indicating no systematic pattern across global capital markets. Results also demonstrate that stock market volatility is unaffected by earthquakes, except for Japan. PMID:26197482

  9. Analog earthquakes

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-09-01

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

  10. Distribution characteristics of Cd, Pb and their influencing factors after earthquake-with example of a disater area named xinhuang village

    International Nuclear Information System (INIS)

    Using hydrochloric acid, nitric acid, hydrofluoric acid and perchloric acid digestion, ICP determination method, combined with geostatistics and GIS, this paper studied the distribution characteristics and influencing factors of Cd, Pb of the soil samples in a typical 5.12 earthquake-stricken area named Xinhuang village as an example. The results showed that the average Cd content of the soil samples was 0.36 ± 0.20 mg /kg, 23.08% of which exceeded the national soil environmental quality standard II, but didn't exceed the standard III. The average Pb content of the soil samples was 28.97 ± 6.82 mg /kg and did not exceed the national standard II. The spatial distribution of Cd, Pb content appeared as belt-shaped and group shape respectively. Cd content took the mid-eastern part as a center, whose concentration was low, and gradually increased to north, to mid-west and to south, respectively; Pb content decreased first and increased afterward from north to south and from east to west. However, Cd, Pb contents in the soil under tent settlements after the earthquake, living garbage dumps and the housing collapse were significantly higher than the soil where were not affected by the earthquake. Cd content in the paddy field soil of 40 ∼ 60 cm depth under tent settlements was the highest, which was 0.46 mg /kg, the highest was 0.57 mg /kg; in the natural paddy field soil of 0 ∼ 20 cm, which. Pb content in the paddy field soil of 0 ∼ 20 cm depth under tent settlements and the natural paddy field soil, were 25.22 mg /kg and 26.16 mg /kg respectively. The influencing factors indicated that: Cd content of paddy fields, dry land and wasteland had not significant difference; Pb content of paddy fields were significantly higher than that of wasteland; The correlation coefficient of organic matter content and the Pb content was 0.616, which took a highly significant positive correlation; Cd content and pH or Cd content and organic matter content did not take significant

  11. What Can Sounds Tell Us About Earthquake Interactions?

    Science.gov (United States)

    Aiken, C.; Peng, Z.

    2012-12-01

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

  12. Earthquakes for Kids

    Science.gov (United States)

    ... 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. Is Earthquake Triggering Driven by Small Earthquakes?

    OpenAIRE

    Helmstetter, Agnes

    2002-01-01

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

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

    OpenAIRE

    B. Theilen-Willige

    2010-01-01

    The potential contribution of remote sensing and GIS techniques to earthquake hazard analysis was investigated in SW-Haiti in order to improve the systematic, standardized inventory of those areas that are more susceptible to earthquake ground motions or to earthquake related secondary effects such as landslides, liquefaction, soil amplifications, compaction or even tsunami-waves. Geophysical, topographical, geological data and satellite images were collected, processed, and integrated into a...

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

    OpenAIRE

    Barbara Theilen-Willige; Felipe Barrios Burnett

    2011-01-01

    The potential contribution of remote sensing and GIS techniques to earthquake hazard analysis was investigated in Valparaiso in Chile in order to improve the systematic, standardized inventory of those areas that are more susceptible to earthquake ground motions or to earthquake related secondary effects such as landslides, liquefaction, soil amplifications, compaction or even tsunami-waves. Geophysical, topographical, geological data and satellite images were collected, processed, and integr...

  16. Earthquake swarms

    Czech Academy of Sciences Publication Activity Database

    Horálek, Josef; Fischer, T.; Einarsson, P.; Jakobsdóttir, S. S.

    Berlin: Springer, 2015 - (Beer, M.; Kougioumtzoglou, I.; Patelli, E.; Au, I.), s. 871-885 ISBN 978-3-642-35343-7 R&D Projects: GA ČR GAP210/12/2336 Institutional support: RVO:67985530 Keywords : clustering of events * driving forces * earthquake location Subject RIV: DC - Siesmology, Volcanology, Earth Structure

  17. Earthquake registration

    International Nuclear Information System (INIS)

    Installation of an array of six portable seismographs in the vicinity of Bushehr has allowed to indicate the precise location of earthquakes of small magnitude. Seismographic Network of Atomic Energy Organization of Iran (SNAEOI) will reports the results of their work at three month intervals. In this bulletin results obtained at Bushehr area is represented in three tables and 3 figures

  18. Earthquake vulnerability evaluation Faizabad district of Kermanshah

    OpenAIRE

    Saba Naderi; Yasmin Kolyai; Sirus Rezaei

    2014-01-01

    This paper as examplehas been studied Faizabad district of Kermanshah and to reach its main purpose, which is reducing the damagecaused by the earthquake on the Faizabad district is been providedand in subsidiary purposes part the research is tried identify factors influence in vulnerability earthquakes,pay to provide the factors required; All these factors havean impact on reducing earthquake vulnerability. This data using geological data, soil texture, getting satelliteimages and layering o...

  19. Connecting slow earthquakes to huge earthquakes.

    Science.gov (United States)

    Obara, Kazushige; Kato, Aitaro

    2016-07-15

    Slow earthquakes are characterized by a wide spectrum of fault slip behaviors and seismic radiation patterns that differ from those of traditional earthquakes. However, slow earthquakes and huge megathrust earthquakes can have common slip mechanisms and are located in neighboring regions of the seismogenic zone. The frequent occurrence of slow earthquakes may help to reveal the physics underlying megathrust events as useful analogs. Slow earthquakes may function as stress meters because of their high sensitivity to stress changes in the seismogenic zone. Episodic stress transfer to megathrust source faults leads to an increased probability of triggering huge earthquakes if the adjacent locked region is critically loaded. Careful and precise monitoring of slow earthquakes may provide new information on the likelihood of impending huge earthquakes. PMID:27418504

  20. On the plant operators performance during earthquake

    International Nuclear Information System (INIS)

    There is little data on which to judge the performance of plant operators during and after strong earthquakes. In order to obtain such data to enhance the reliability on the plant operation, a Japanese utility and a power plant manufacturer carried out a vibration test using a shaking table. The purpose of the test was to investigate operator performance, i.e., the quickness and correctness in switch handling and panel meter read-out. The movement of chairs during earthquake as also of interest, because if the chairs moved significantly or turned over during a strong earthquake, some arresting mechanism would be required for the chair. Although there were differences between the simulated earthquake motions used and actual earthquakes mainly due to the specifications of the shaking table, the earthquake motions had almost no influence on the operators of their capability (performance) for operating the simulated console and the personal computers

  1. Defeating Earthquakes

    Science.gov (United States)

    Stein, R. S.

    2012-12-01

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

  2. Earthquake Early Warning Systems

    OpenAIRE

    Pei-Yang Lin

    2011-01-01

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

  3. The west Andaman fault and its influence on the aftershock pattern of the recent megathrust earthquakes in the Andaman-Sumatra region

    Digital Repository Service at National Institute of Oceanography (India)

    KameshRaju, K.A.; Murty, G.P.S.; Amarnath, D.; MohanKumar, M.L.

    lithospheric scale boundary and together with other tectonic elements modulates the occurrence of large earthquakes and their rupture pattern. The active strike-slip motion along the WAF, presence of backarc spreading coupled with increased obliquity...

  4. Earthquake-triggered landslides in southwest China

    Directory of Open Access Journals (Sweden)

    X. L. Chen

    2012-02-01

    Full Text Available Southwest China is located in the southeastern margin of the Tibetan Plateau and it is a region of high seismic activity. Historically, strong earthquakes that occurred here usually generated lots of landslides and brought destructive damages. This paper introduces several earthquake-triggered landslide events in this region and describes their characteristics. Also, the historical data of earthquakes with a magnitude of 7.0 or greater, having occurred in this region, is collected and the relationship between the affected area of landslides and earthquake magnitude is analysed. Based on the study, it can be concluded that strong earthquakes, steep topography as well as fragile geological environment, are the main reasons responsible for serious landslides in southwest China. At the same time, it is found that the relationship between the area affected by landslides and the earthquake magnitude in this region are consistent with what has been obtained worldwide. Moreover, in this paper, it is seen that the size of the areas affected by landslides change enormously even under the same earthquake magnitude in the study region. While at the same tectonic place or fault belt, areas affected by landslides presented similar outline and size. This means that local geological conditions and historical earthquake background have an important influence on landslides distribution, and they should be considered when assessing earthquake-triggered landslide hazards at Grade 1 according to ISSMGE.

  5. HURRICANE SANDY AND EARTHQUAKES

    OpenAIRE

    MAVASHEV BORIS; MAVASHEV IGOR

    2013-01-01

    Submit for consideration the connection between formation of a hurricane Sandy and earthquakes. As a rule, weather anomalies precede and accompany earthquakes. The hurricane Sandy emerged 2 days prior to strong earthquakes that occurred in the area. And the trajectory of the hurricane Sandy matched the epicenter of the earthquakes. Possibility of early prediction of natural disasters will minimize the moral and material damage.

  6. Earthquake Early Warning Systems

    Directory of Open Access Journals (Sweden)

    Pei-Yang Lin

    2011-12-01

    Full Text Available Because of Taiwan’s unique geographical environment, earthquake disasters occur frequently in Taiwan. The Central Weather Bureau collated earthquake data from between 1901 and 2006 (Central Weather Bureau, 2007 and found that 97 earthquakes had occurred, of which, 52 resulted in casualties. The 921 Chichi Earthquake had the most profound impact. Because earthquakes have instant destructive power and current scientific technologies cannot provide precise early warnings in advance, earthquake prevention is crucial. The earthquake early warning system can provide seconds to tens of seconds of warning time before an earthquake strikes. This paper introduces the  earthquake early warning system build by Taiwan National Center for Research on Earthquake Engineering and a practice case happened in Yilan City, Taiwan.

  7. Characteristics of Soil Structure Interaction for Reactor Building of Kashiwazaki-Kariwa Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Gil, Moon Joo; Jung, Rae Young; Hyun, Chang Hun; Kim, Moon Soo [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Lim, Nam Hyoung [Chungnam National University, Daejeon (Korea, Republic of)

    2010-10-15

    On 16 July 2007, the Nigataken-chuetsu-oki earthquake registering a moment magnitude of 6.8 occurred at a depth of about 15 km. As a result of this earthquake, noticeable shaking exceeding the design ground motion was measured at the Tokyo Electric Power Company (TEPCO) Kashiwazaki-Kariwa Nuclear Power Station (KKN), the biggest nuclear power plant in the world, located at about 16 km away from the epicenter. This earthquake triggered a fire at an electrical transformer and insignificant damage on some parts of facilities. This event gave an impulse to study on the damage and safety margin of nuclear power plant due to the strong earthquake exceeding design basis. As a part of those efforts, KARISMA (KAshiwazaki-Kariwa Research Initiative for Seismic Margin Assessment) benchmark study was launched by the IAEA in terms of an international collaborative research. The main objectives of this research are to estimate the structural behavior and to evaluate the seismic margin of reactor building considering the effects of Soil-Structure Interaction (SSI). This paper presents verification of structural model developed here and validation of soil foundation characteristics through soil-column analysis. It has also been demonstrated that the spring constants and damping coefficient obtained from impedance analysis represent well the soil foundation characteristics

  8. Characteristics of Soil Structure Interaction for Reactor Building of Kashiwazaki-Kariwa Nuclear Power Plant

    International Nuclear Information System (INIS)

    On 16 July 2007, the Nigataken-chuetsu-oki earthquake registering a moment magnitude of 6.8 occurred at a depth of about 15 km. As a result of this earthquake, noticeable shaking exceeding the design ground motion was measured at the Tokyo Electric Power Company (TEPCO) Kashiwazaki-Kariwa Nuclear Power Station (KKN), the biggest nuclear power plant in the world, located at about 16 km away from the epicenter. This earthquake triggered a fire at an electrical transformer and insignificant damage on some parts of facilities. This event gave an impulse to study on the damage and safety margin of nuclear power plant due to the strong earthquake exceeding design basis. As a part of those efforts, KARISMA (KAshiwazaki-Kariwa Research Initiative for Seismic Margin Assessment) benchmark study was launched by the IAEA in terms of an international collaborative research. The main objectives of this research are to estimate the structural behavior and to evaluate the seismic margin of reactor building considering the effects of Soil-Structure Interaction (SSI). This paper presents verification of structural model developed here and validation of soil foundation characteristics through soil-column analysis. It has also been demonstrated that the spring constants and damping coefficient obtained from impedance analysis represent well the soil foundation characteristics

  9. Operational earthquake forecasting can enhance earthquake preparedness

    OpenAIRE

    Jordan, T. H.; Univ Southern California; Marzocchi, W.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Michael, A.; USGS; Gerstenberger, M. C.; GNS

    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. Opera- tional earthquake forecasting (OEF) is the dissemination of authoritative information about these time-dependent proba- bilities to help communities prepare for potentially ...

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

    Science.gov (United States)

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

    2016-04-01

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

  11. Earthquake vulnerability evaluation Faizabad district of Kermanshah

    Directory of Open Access Journals (Sweden)

    Saba Naderi

    2014-07-01

    Full Text Available This paper as examplehas been studied Faizabad district of Kermanshah and to reach its main purpose, which is reducing the damagecaused by the earthquake on the Faizabad district is been providedand in subsidiary purposes part the research is tried identify factors influence in vulnerability earthquakes,pay to provide the factors required; All these factors havean impact on reducing earthquake vulnerability. This data using geological data, soil texture, getting satelliteimages and layering over Arc Gis software identified and for long term periods donepredict using relation kernel PSHA also. In determining the level ofenvironmental risk is to use software crisis. Finally, by recognizing the riskzone, solutions for Faizabad district offered.

  12. Earthquake Damage - General

    Data.gov (United States)

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

  13. Earthquakes in Southern California

    Data.gov (United States)

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

  14. Earthquakes: hydrogeochemical precursors

    Science.gov (United States)

    Ingebritsen, Steven E.; Manga, Michael

    2014-01-01

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

  15. Plant state display device after occurrence of earthquake

    International Nuclear Information System (INIS)

    If a nuclear power plant should encounter earthquakes, an earthquake response analysis value previously stored and the earthquakes observed are compared to judge the magnitude of the earthquakes. From the result of the judgement, a possibility that an abnormality is recognized in plant equipment systems after the earthquakes is evaluated, in comparison with a previously stored earthquake fragility data base of each of equipment/systems. The result of the evaluation is displayed in a central control chamber. The plant equipment system is judged such that abnormalities are recognized at a high probability is evaluated by a previously stored earthquake PSA method for the influence of the abnormality on plant safety, and the result is displayed in the central control chamber. (I.S.)

  16. Tidal triggering of earthquakes

    OpenAIRE

    Heaton, Thomas H.

    1982-01-01

    Analysis of the tidal stress tensor at the time of moderate to large earthquakes strongly suggests that shallow (< 30 km) larger magnitude oblique-slip and dip-slip earthquakes are triggered by tidal stresses. No corresponding triggering effect is seen for shallow strike-slip earthquakes or for any type of intermediate or deep focus earthquakes which have been studied. Tidal triggering is also discussed from the viewpoint of the ‘dilatancy-diffusion’ model. Specifically, the model as usually ...

  17. Redefining Earthquakes and the Earthquake Machine

    Science.gov (United States)

    Hubenthal, Michael; Braile, Larry; Taber, John

    2008-01-01

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

  18. Children's Ideas about Earthquakes

    Science.gov (United States)

    Simsek, Canan Lacin

    2007-01-01

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

  19. School Safety and Earthquakes.

    Science.gov (United States)

    Dwelley, Laura; Tucker, Brian; Fernandez, Jeanette

    1997-01-01

    A recent assessment of earthquake risk to Quito, Ecuador, concluded that many of its public schools are vulnerable to collapse during major earthquakes. A subsequent examination of 60 buildings identified 15 high-risk buildings. These schools were retrofitted to meet standards that would prevent injury even during Quito's largest earthquakes. US…

  20. Behavior of the topside ionosphere during earthquakes

    Science.gov (United States)

    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.

  1. Solar eruptions - soil radon - earthquakes

    International Nuclear Information System (INIS)

    For the first time a new natural phenomenon was established: a contrasting increase in the soil radon level under the influence of solar flares. Such an increase is one of geochemical indicators of earthquakes. Most researchers consider this a phenomenon of exclusively terrestrial processes. Investigations regarding the link of earthquakes to solar activity carried out during the last decade in different countries are based on the analysis of statistical data ΣΕ (t) and W (t). As established, the overall seismicity of the Earth and its separate regions depends of an 11-year long cycle of solar activity. Data provided in the paper based on experimental studies serve the first step on the way of experimental data on revealing cause-and-reason solar-terrestrials bonds in a series solar eruption-lithosphere radon-earthquakes. They need further collection of experimental data. For the first time, through radon constituent of terrestrial radiation objectification has been made of elementary lattice of the Hartmann's network contoured out by bio location method. As found out, radon concentration variations in Hartmann's network nodes determine the dynamics of solar-terrestrial relationships. Of the three types of rapidly running processes conditioned by solar-terrestrial bonds earthquakes are attributed to rapidly running destructive processes that occur in the most intense way at the juncture of tectonic massifs, along transformed and deep failures. The basic factors provoking the earthquakes are both magnetic-structural effects and a long-term (over 5 months) bombing of the surface of lithosphere by highly energetic particles of corpuscular solar flows, this being approved by photometry. As a result of solar flares that occurred from 29 October to 4 November 2003, a sharply contrasting increase in soil radon was established which is an earthquake indicator on the territory of Yerevan City. A month and a half later, earthquakes occurred in San-Francisco, Iran, Turkey

  2. Seismic response analysis of full-scale boiling water reactor using three-dimensional finite element method

    International Nuclear Information System (INIS)

    This paper presents the three-dimensional finite element seismic response analysis of full-scale boiling water reactor BWR5 at Kashiwazaki-Kariwa Nuclear Power Station subjected to the Niigata-ken Chuetsu-Oki earthquake that occurred on 16 July 2007. During the earthquake, the automatic shutdown system of the reactors was activated successfully. Although the monitored seismic acceleration significantly exceeded the design level, it was found that there were no significant damages of the reactor cores or other important systems, structures and components through in-depth investigation. In the seismic design commonly used in Japan, a lumped mass model is employed to evaluate the seismic response of structures and components. Although the lumped mass model has worked well so far for a seismic proof design, it is still needed to develop more precise methods for the visual understanding of response behaviors. In the present study, we propose the three-dimensional finite element seismic response analysis of the full-scale and precise BWR model in order to directly visualize its dynamic behaviors. Through the comparison between both analysis results, we discuss the characteristics of both models. The stress values were also found to be generally under the design value. (author)

  3. Seismic response analysis of full-scale boiling water reactor using three-dimensional finite element method

    International Nuclear Information System (INIS)

    In this paper, we present the three-dimensional finite element seismic response analysis of the full-scale boiling water reactor BWR5 at the Kashiwazaki-Kariwa Nuclear Power Plant subjected to the Niigata-ken Chuetsu-Oki (NCO) earthquake that occurred on 16th July 2007. During the earthquake, the automatic shutdown of the reactors was performed successfully. Although the monitored seismic acceleration significantly exceeded the design level, it was found through in-depth investigation that there was no significant damage of the reactor cores or other important systems, structures and components (SSCs). In the seismic design commonly used in Japan, a lumped mass model is employed to evaluate the seismic response of SSCs. Although the lumped mass model has worked well so far for a seismic proof design, more precise methods should be developed to understand response behaviors visually. In the present study, we propose the three-dimensional finite element seismic response analysis of the full-scale and precise BWR model in order to directly visualize the dynamic behaviors of this model. Through the comparison of the analysis results, we discuss the characteristics of both models. The stress values were also found to be generally under the design value. (author)

  4. 汶川地震灾区居民心理健康状况的影响因素分析%Studying factors influencing mental health status of inhabitants in Wenchuan Earthquake areas

    Institute of Scientific and Technical Information of China (English)

    彭丹; 李晓松; 张强; 朱彩蓉; 张菊英; 袁萍; 刘毅

    2012-01-01

    目的 了解汶川地震一年半后灾区居民心理健康状况及其影响因素,为其心理重建制定合理措施提供参考.方法 通过对汶川、北川、绵竹3个极重灾区882位居民的调查,对居民的心理健康状况进行测评,并采用结构方程模型分析其影响因素.结果 灾区居民焦虑症状阳性率为22.6%,抑郁症状阳性率为19.7%;地震灾区居民心理健康状况影响因素依次为:社会特征、生理健康状况、社会支持、地震创伤暴露情况、地震后居住状况;其中生理健康状况、社会支持、地震创伤暴露情况对灾区居民心理健康有直接作用,社会特征与地震后居住状况对心理健康有间接的影响.结论灾区居民的心理健康需持续关注;灾区居民,特别是老年人的社会支持有待加强;灾区居民的心理重建需要卫生保健、家园重建等多方面工作的支持.%OBJECTIVE To investigate the mental health status of inhabitants in Wenchuan Earthquake areas and main factors affecting it, so order to provide reference for making reasonable measures of improving their mental health. METHODS The mental health conditions of 882 residents in Wenchuan, Beichuan and Mianzhu where were heavy hit were evluated, and structural equation model was used to study the influencing factors. RESULTS A positive rate of 22.6% for anxiety symptoms and the positive rate of depression symptoms was 19.6%; The influencing factors of mental health were social characteristics, physical health status, social support, earthquake trauma exposure, living conditions after the earthquake; physical health status, social support and earthquake trauma exposure directly affected mental health, social characteristics and living conditions after the earthquake. CONCLUSION The mental health of residents in affected areas need sustained attention; Disaster area residents, especially the elder's social supports, need to be strengthened; psychological

  5. Encyclopedia of earthquake engineering

    CERN Document Server

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

    2015-01-01

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

  6. Astronomical tides and earthquakes

    Science.gov (United States)

    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.

  7. Retrospective Evaluation of Earthquake Forecasts during the 2010-12 Canterbury, New Zealand, Earthquake Sequence

    Science.gov (United States)

    Werner, M. J.; Marzocchi, W.; Taroni, M.; Zechar, J. D.; Gerstenberger, M.; Liukis, M.; Rhoades, D. A.; Cattania, C.; Christophersen, A.; Hainzl, S.; Helmstetter, A.; Jimenez, A.; Steacy, S.; Jordan, T. H.

    2014-12-01

    The M7.1 Darfield, New Zealand (NZ), earthquake triggered a complex earthquake cascade that provides a wealth of new scientific data to study earthquake triggering and the predictive skill of statistical and physics-based forecasting models. To this end, the Collaboratory for the Study of Earthquake Predictability (CSEP) is conducting a retrospective evaluation of over a dozen short-term forecasting models that were developed by groups in New Zealand, Europe and the US. The statistical model group includes variants of the Epidemic-Type Aftershock Sequence (ETAS) model, non-parametric kernel smoothing models, and the Short-Term Earthquake Probabilities (STEP) model. The physics-based model group includes variants of the Coulomb stress triggering hypothesis, which are embedded either in Dieterich's (1994) rate-state formulation or in statistical Omori-Utsu clustering formulations (hybrid models). The goals of the CSEP evaluation are to improve our understanding of the physical mechanisms governing earthquake triggering, to improve short-term earthquake forecasting models and time-dependent hazard assessment for the Canterbury area, and to understand the influence of poor-quality, real-time data on the skill of operational (real-time) forecasts. To assess the latter, we use the earthquake catalog data that the NZ CSEP Testing Center archived in near real-time during the earthquake sequence and compare the predictive skill of models using the archived data as input with the skill attained using the best available data today. We present results of the retrospective model comparison and discuss implications for operational earthquake forecasting.

  8. The Global Earthquake History

    OpenAIRE

    Albini, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Musson, R. M. W.; BGS, Edinburgh; Rovida, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Locati, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Gomez Capera, A. A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Viganò, D.; Global Earthquake Model-GEM

    2014-01-01

    The study of earthquakes from historical sources, or historical seismology, was considered an early priority for the Global Earthquake Model (GEM) project, which commissioned a study of historical seismicity at a global scale. This was “The Global Earthquake History” (GEH) project, led jointly by INGV (Milano, Italy) and BGS (UK). GEH was structured around three complementary deliverables: archive, catalogue, and the web infrastructure designed to store both archive and catalogue. The Global ...

  9. Reduction of earthquake disasters

    Institute of Scientific and Technical Information of China (English)

    陈顒; 陈祺福; 黄静; 徐文立

    2003-01-01

    The article summarizes the researches on mitigating earthquake disasters of the past four years in China. The studyof earthquake disasters′ quantification shows that the losses increase remarkably when population concentrates inurban area and social wealth increase. The article also summarizes some new trends of studying earthquake disas-ters′ mitigation, which are from seismic hazard to seismic risk, from engineering disaster to social disaster andintroduces the community-centered approach.

  10. OMG Earthquake! Can Twitter improve earthquake response?

    Science.gov (United States)

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

    2009-12-01

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

  11. Bam Earthquake in Iran

    CERN Multimedia

    2004-01-01

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

  12. Earthquakes and Schools

    Science.gov (United States)

    National Clearinghouse for Educational Facilities, 2008

    2008-01-01

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

  13. Historic Eastern Canadian earthquakes

    International Nuclear Information System (INIS)

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

  14. Numerical earthquake prediction

    International Nuclear Information System (INIS)

    Can earthquakes be predicted? How should people overcome the difficulties encountered in the study of earthquake prediction? This issue can take inspiration from the experiences of weather forecast. Although weather forecasting took a period of about half a century to advance from empirical to numerical forecast, it has achieved significant success. A consensus has been reached among the Chinese seismological community that earthquake prediction must also develop from empirical forecasting to physical prediction. However, it is seldom mentioned that physical prediction is characterized by quantitatively numerical predictions based on physical laws. This article discusses five key components for numerical earthquake prediction and their current status. We conclude that numerical earthquake prediction should now be put on the planning agenda and its roadmap designed, seismic stations should be deployed and observations made according to the needs of numerical prediction, and theoretical research should be carried out. (authors)

  15. Turkish Compulsory Earthquake Insurance and "Istanbul Earthquake

    Science.gov (United States)

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

    2009-04-01

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

  16. Sensationalization of reports of the Kashiwazaki-Kariwa nuclear power plant incident. A search for top stories in Japanese newspapers

    International Nuclear Information System (INIS)

    The purpose of this study is to clarify whether reports of nuclear accidents, particularly the damage done by the 2007 Niigata-ken Chuetsu-Oki earthquake to the Kashiwazaki-Kariwa nuclear power plant in Niigata, Japan, tend to be exaggerated by national media. News related to the Kashiwazaki incident was compared with that for nine other high-profile accidents in Japan, including the 1999 JCO critical accident and the 2005 JR-West Fukuchiyama Line derailment. Articles were extracted from four national newspapers in Japan, focusing on the 30 issues immediately following each accident. The numbers of articles and top stories related to the relevant accidents appearing on the front pages of the newspapers were counted. Based on these numbers, the Kashiwazaki incident was reported at a level similar to the JCO accident and Fukuchiyama line derailment in some newspapers, although these two accidents were more serious than the Kashiwazaki incident. This suggests that at least some newspapers in Japan sensationalized reports of the Kashiwazaki incident. (author)

  17. Spatiotermporal correlations of earthquakes

    International Nuclear Information System (INIS)

    Complete text of publication follows. An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. At the present technological level, earthquakes of magnitude larger than three can be recorded all over the world. In spite of the apparent randomness of earthquake occurrence, long term measurements have revealed interesting scaling laws of earthquake characteristics: the rate of aftershocks following major earthquakes has a power law decay (Omori law); the magnitude distribution of earthquakes exhibits a power law behavior (Gutenberg-Richter law), furthermore, it has recently been pointed out that epicenters form fractal networks in fault zones (Kagan law). The theoretical explanation of earthquakes is based on plate tectonics: the earth's crust has been broken into plates which slowly move under the action of the flowing magma. Neighboring plates touch each other along ridges (fault zones) where a large amount of energy is stored in deformation. Earthquakes occur when the stored energy exceeds a material dependent threshold value and gets released in a sudden jump of the plate. The Burridge-Knopoff (BK) model of earthquakes represents earth's crust as a coupled system of driven oscillators where nonlinearity occurs through a stick-slip frictional instability. Laboratory experiments have revealed that under a high pressure the friction of rock interfaces exhibits a weakening with increasing velocity. In the present project we extend recent theoretical studies of the BK model by taking into account a realistic velocity weakening friction force between tectonic plates. Varying the strength of weakening a broad spectrum of interesting phenomena is obtained: the model reproduces the Omori and Gutenberg-Richter laws of earthquakes, furthermore, it provides information on the correlation of earthquake sequences. We showed by computer simulations that the spatial and temporal correlations of consecutive earthquakes are very

  18. Investigation of Nonlinear Site Response and Seismic Compression from Case History Analysis and Laboratory Testing

    Science.gov (United States)

    Yee, Eric

    ). Aside from the expected strong influence of RC, increasing fines content is found to generally decrease volume change for fines fractions consisting of silts and clayey silts with moderate to low plasticity. With truly non-plastic fines (rock flour), cyclic volume change increases with FC. Some materials also exhibit an effect of as-compacted saturation in which moderate saturation levels associated with high matric suction cause volume change to decrease. A preliminary empirical model to capture these effects is presented. The balance of the dissertation is related to a case history of strongly nonlinear site response and seismic compression associated with a free-field downhole array installed near the Service Hall at the Kashiwazaki-Kariwa nuclear power plant, which recorded strong ground motions from the Mw 6.6 2007 Niigata-ken Chuetsu-oki earthquake. Site conditions at the array consist of about 70 m of medium-dense sands overlying clayey bedrock, with ground water located at 45 m. Ground shaking at the bedrock level had geometric mean peak accelerations of 0.55 g which is reduced to 0.4 g at the ground surface, indicating nonlinear site response. Ground settlements of approximately 15+/-5 cm occurred at the site. A site investigation was performed to develop relevant soil properties for ground response and seismic compression analysis, including shear wave velocities, shear strength, relative density, and modulus reduction and damping curves. (Abstract shortened by UMI.)

  19. Indonesian Earthquake Decision Support System

    OpenAIRE

    Warnars, Spits

    2010-01-01

    Earthquake DSS is an information technology environment which can be used by government to sharpen, make faster and better the earthquake mitigation decision. Earthquake DSS can be delivered as E-government which is not only for government itself but in order to guarantee each citizen's rights for education, training and information about earthquake and how to overcome the earthquake. Knowledge can be managed for future use and would become mining by saving and maintain all the data and infor...

  20. Earthquake Disaster Management and Insurance

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    As one of the most powerful tools to reduce the earthquake loss, the Earthquake Disaster Management [EDM] and Insurance [EI] have been highlighted and have had a great progress in many countries in recent years. Earthquake disaster management includes a series of contents, such as earthquake hazard and risk analysis, vulnerability analysis of building and infrastructure, earthquake aware training, and building the emergency response system. EI, which has been included in EDM after this practice has been...

  1. Earthquakes and plate tectonics

    Science.gov (United States)

    Spall, H.

    1977-01-01

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

  2. Earthquake Damage to Schools

    Data.gov (United States)

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

  3. 1988 Spitak Earthquake Database

    Data.gov (United States)

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

  4. Seismicity anomalies of the 2003 Bam, Iran earthquake

    Science.gov (United States)

    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.

  5. Effects of the 2010 Haiti Earthquake on Women's Reproductive Health.

    Science.gov (United States)

    Behrman, Julia Andrea; Weitzman, Abigail

    2016-03-01

    This article explores the effects of the 2010 Haiti earthquake on women's reproductive health, using geocoded data from the 2005 and 2012 Haiti Demographic and Health Surveys. We use geographic variation in the destructiveness of the earthquake to conduct a difference-in-difference analysis. Results indicate that heightened earthquake intensity reduced use of injectables-the most widely used modern contraceptive method in Haiti-and increased current pregnancy and current unwanted pregnancy. Analysis of impact pathways suggests that severe earthquake intensity significantly increased women's unmet need for family planning and reduced their access to condoms. The earthquake also affected other factors that influence reproductive health, including women's ability to negotiate condom use in their partnerships. Our findings highlight how disruptions to health care services following a natural disaster can have negative consequences for women's reproductive health. PMID:27027990

  6. Injection-induced earthquakes.

    Science.gov (United States)

    Ellsworth, William L

    2013-07-12

    Earthquakes in unusual locations have become an important topic of discussion in both North America and Europe, owing to the concern that industrial activity could cause damaging earthquakes. It has long been understood that earthquakes can be induced by impoundment of reservoirs, surface and underground mining, withdrawal of fluids and gas from the subsurface, and injection of fluids into underground formations. Injection-induced earthquakes have, in particular, become a focus of discussion as the application of hydraulic fracturing to tight shale formations is enabling the production of oil and gas from previously unproductive formations. Earthquakes can be induced as part of the process to stimulate the production from tight shale formations, or by disposal of wastewater associated with stimulation and production. Here, I review recent seismic activity that may be associated with industrial activity, with a focus on the disposal of wastewater by injection in deep wells; assess the scientific understanding of induced earthquakes; and discuss the key scientific challenges to be met for assessing this hazard. PMID:23846903

  7. Charles Darwin's earthquake reports

    Science.gov (United States)

    Galiev, Shamil

    2010-05-01

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

  8. Analysis on post-traumatic stress disorder of adolescents and influence fac-tors after earthquake%地震震后青少年创伤后应激障碍与相关影响因素分析

    Institute of Scientific and Technical Information of China (English)

    柯雄

    2015-01-01

    创伤后应急障碍是地震震后暴露者常见的心理障碍之一,而青少年是易罹患该障碍的高危人群。以文献复习方法归纳地震灾害后青少年创伤后应激障碍的患病情况和影响因素,并展望该问题下一步的研究趋势将有助于为青少年的心理危机干预提供更多的信息。%Post-traumatic stress disorder is one of epidemic psychological barriers in people after the earthquake,and adoles-cents have higher risk in the disorder. With the method of literature review,the research summarized the morbidity,symptom and influ-ence factors of post-traumatic stress disorder,and analyzed the trend for future research,those could contribute to the psychological cri-sis intervention for adolescent.

  9. Review article "Remarks on factors influencing shear wave velocities and their role in evaluating susceptibilities to earthquake-triggered slope instability: case study for the Campania area (Italy"

    Directory of Open Access Journals (Sweden)

    V. Paoletti

    2012-07-01

    Full Text Available Shear wave velocities have a fundamental role in connection with the mitigation of seismic hazards, as their low values are the main causes of site amplification phenomena and can significantly influence the susceptibility of a territory to seismic-induced landslides. The shear wave velocity (Vs and modulus (G of each lithological unit are influenced by factors such as the degree of fracturing and faulting, the porosity, the clay amount and the precipitation, with the latter two influencing the unit water content. In this paper we discuss how these factors can affect the Vs values and report the results of different analyses that quantify the reduction in the rock Vs and shear modulus values connected to the presence of clay and water. We also show that significant results in assessing seismic-induced slope failure susceptibility for land planning targets could be achieved through a careful evaluation, based only on literature studies, of the geo-lithological and geo-seismic features of the study area.

  10. 汶川地震对灾区人群血浆同型半胱氨酸水平的影响%Influence of Wenchuan earthquake on serum homocysteine level of victims

    Institute of Scientific and Technical Information of China (English)

    钟萍; 王汝; 丁怀胜; 周晓芳; 卢青; 金静; 王文艳

    2011-01-01

    Objective The aim of the study was to investigate the influence of earthquake on serum homocysteine (HCY) level in victims. Methods A total of 150 victims were assigned to study group and 150 healthy individuals were assigned to control group. The mental status of the two groups was investigated with Self-Rating Anxiety Scale (SAS) and Self-Rating Depression Scale (SDS). The level of serum HCY was detected. Results The questionnaire score of study group was higher than that of control group. The level of serum HCY of study group was significantly higher than that of control group[(24. 4 ± 10. 9) μmol/L vs. ( 17. 2 ± 3. 8) μmol/L, P < 0. 01 ]. There was a positive correlation between Hcy and SAS (r = 0. 968, P < 0. 01) as well as Hcy and SDS (r = 0.979, P < 0. 01). Conclusions Earthquake can cause physical stress for victims, which leads to the increase of serum HCY leveL%目的 探讨地震对灾区人群血浆同型半胱氨酸( homocysteine,HCY)水平的影响.方法 随机抽取150名汶川地震灾民(研究组)、150名健康体检者(对照组)进行心理问卷调查,测定血浆HCY水平.结果 研究组症状自评量表得分显著高于对照组,血浆HCY水平显著高于对照组[(24.4±10.9)μmol/L vs( 17.2±3.8)mol/L,P<0.01];血浆HCY水平与焦虑自评量表(Self-Rating Anxiety Scale,SAS)和抑郁自评量表(Self-Rating Depression Scale,SDS)得分呈正相关(HCY与SAS:r=0.968;HCY与SDS:r=0.979,均P<0.01).结论 地震可引起灾民生理应激状态,导致机体血浆HCY水平升高.

  11. Triggering of repeated earthquakes

    Science.gov (United States)

    Sobolev, G. A.; Zakrzhevskaya, N. A.; Sobolev, D. G.

    2016-03-01

    Based on the analysis of the world's earthquakes with magnitudes M ≥ 6.5 for 1960-2013, it is shown that they cause global-scale coherent seismic oscillations which most distinctly manifest themselves in the period interval of 4-6 min during 1-3 days after the event. After these earthquakes, a repeated shock has an increased probability to occur in different seismically active regions located as far away as a few thousand km from the previous event, i.e., a remote interaction of seismic events takes place. The number of the repeated shocks N( t) decreases with time, which characterizes the memory of the lithosphere about the impact that has occurred. The time decay N( t) can be approximated by the linear, exponential, and powerlaw dependences. No distinct correlation between the spatial locations of the initial and repeated earthquakes is revealed. The probable triggering mechanisms of the remote interaction between the earthquakes are discussed. Surface seismic waves traveling several times around the Earth's, coherent oscillations, and global source are the most preferable candidates. This may lead to the accumulation and coalescence of ruptures in the highly stressed or weakened domains of a seismically active region, which increases the probability of a repeated earthquake.

  12. Earthquake and Geothermal Energy

    CERN Document Server

    Kapoor, Surya Prakash

    2013-01-01

    The origin of earthquake has long been recognized as resulting from strike-slip instability of plate tectonics along the fault lines. Several events of earthquake around the globe have happened which cannot be explained by this theory. In this work we investigated the earthquake data along with other observed facts like heat flow profiles etc... of the Indian subcontinent. In our studies we found a high-quality correlation between the earthquake events, seismic prone zones, heat flow regions and the geothermal hot springs. As a consequence, we proposed a hypothesis which can adequately explain all the earthquake events around the globe as well as the overall geo-dynamics. It is basically the geothermal power, which makes the plates to stand still, strike and slip over. The plates are merely a working solid while the driving force is the geothermal energy. The violent flow and enormous pressure of this power shake the earth along the plate boundaries and also triggers the intra-plate seismicity. In the light o...

  13. EARTHQUAKE LIGHTS IN LEGENDS OF THE GREEK ORTHODOXY

    OpenAIRE

    Florinsky, I.V.

    2015-01-01

    Local legends may contain information about real geological events of the past. Earthquake lights (EQL) can occur in the atmosphere over earthquake epicenter areas and adjacent faults before and during quakes. They may look like diffuse airglow, flashes, fiery pillars, and luminous balls. EQL may cause a mystical experience probably due to the influence of their electromagnetic fields on the brain. Subjective perception and interpretation of EQL depend on religious and cultural traditions. We...

  14. Earth science: lasting earthquake legacy

    Science.gov (United States)

    Parsons, Thomas E.

    2009-01-01

    Earthquakes occur within continental tectonic plates as well as at plate boundaries. Do clusters of such mid-plate events constitute zones of continuing hazard, or are they aftershocks of long-past earthquakes?

  15. Earthquake Damage to Transportation Systems

    Data.gov (United States)

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

  16. Dynamic simulation of interactions between major earthquakes on the Xianshuihe fault zone

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The authors firstly evaluate the strain accumulation rate of the Xianshuihe fault zone based on earth- quake activity. We calculated the stress and seismic moment accumulation rate for each subsection of the Xianshuihe fault zone based on the distribution of geological slip rate and GPS survey results. According to the results, we get the recurrence intervals of characterized earthquakes on each sub- section respectively. A three-dimensional finite element model for western Sichuan is constructed to discuss the earthquakes triggering among major earthquakes (M>6.7) that occurred along the Xianshuihe fault zone since 1893. The calculated Coulomb failure stress changes (ΔCFS) show that 5 of the 6 earthquakes with Ms>6.7 were triggered by positive ΔCFS. The interactions between major earthquakes not only influence recurrence intervals of characterized earthquakes on each subsection, but also change recurrence behavior of major earthquakes along the whole fault zone.

  17. Study on the correlativity of earthquake's impact on cities

    Institute of Scientific and Technical Information of China (English)

    潘华; 赵凤新; 高孟潭

    2004-01-01

    @@ Introduction With rapid development and advancement of economy and society, lots of city groups or city belts with ex-tra-large cities as their centers have been formed in China. The regions these city groups lie in usually havewell-developed economy, dense population, and are regional politics and culture centers. Some groups lie in theregions with high level of earthquake activity, such as the Surrounding Capital City Group with the centers of Bei-jing and Tianjin. Once a large earthquake occurs, its influence will spread to very extensive region and its disasterwill be tremendous too. So earthquake resistance and disaster mitigation of city group will be very significant issue.The cities in a group have close distance with each other; they can carry out unified preparation for disaster as onewhole and reduce the heavy load of single city before an earthquake, and have an advantage of prompt mutual-aidafter an earthquake because of close distance. It is especially significant to mitigate the lose of lives. One importantprecondition is that all the cities in one group cannot be exposed to the same level of destroy during one earth-quake. So the division of city group in the region with dense cities distribution shall be very significant to theemergent mutual-aid in early time after a large earthquake. For this goal, the characteristics and correlativity ofearthquake′s impact on cities in one group need to clearly be considered. The cities with similar features and strongcorrelativity of historical earthquake influence have large chance to suffer same level destroy during the futurestrong earthquake and are disadvantage to provide mutual-aid and shall not be divided into one group.

  18. Testing earthquake predictions

    Science.gov (United States)

    Luen, Brad; Stark, Philip B.

    2008-01-01

    Statistical tests of earthquake predictions require a null hypothesis to model occasional chance successes. To define and quantify 'chance success' is knotty. Some null hypotheses ascribe chance to the Earth: Seismicity is modeled as random. The null distribution of the number of successful predictions - or any other test statistic - is taken to be its distribution when the fixed set of predictions is applied to random seismicity. Such tests tacitly assume that the predictions do not depend on the observed seismicity. Conditioning on the predictions in this way sets a low hurdle for statistical significance. Consider this scheme: When an earthquake of magnitude 5.5 or greater occurs anywhere in the world, predict that an earthquake at least as large will occur within 21 days and within an epicentral distance of 50 km. We apply this rule to the Harvard centroid-moment-tensor (CMT) catalog for 2000-2004 to generate a set of predictions. The null hypothesis is that earthquake times are exchangeable conditional on their magnitudes and locations and on the predictions - a common "nonparametric" assumption in the literature. We generate random seismicity by permuting the times of events in the CMT catalog. We consider an event successfully predicted only if (i) it is predicted and (ii) there is no larger event within 50 km in the previous 21 days. The P-value for the observed success rate is <0.001: The method successfully predicts about 5% of earthquakes, far better than 'chance' because the predictor exploits the clustering of earthquakes - occasional foreshocks - which the null hypothesis lacks. Rather than condition on the predictions and use a stochastic model for seismicity, it is preferable to treat the observed seismicity as fixed, and to compare the success rate of the predictions to the success rate of simple-minded predictions like those just described. If the proffered predictions do no better than a simple scheme, they have little value.

  19. Turkish Children's Ideas about Earthquakes

    Science.gov (United States)

    Simsek, Canan Lacin

    2007-01-01

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

  20. Quantification of social contributions to earthquake mortality

    Science.gov (United States)

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

    2013-12-01

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

  1. Bayesian probabilities of earthquake occurrences in Longmenshan fault system (China)

    Science.gov (United States)

    Wang, Ying; Zhang, Keyin; Gan, Qigang; Zhou, Wen; Xiong, Liang; Zhang, Shihua; Liu, Chao

    2015-01-01

    China has a long history of earthquake records, and the Longmenshan fault system (LFS) is a famous earthquake zone. We believed that the LFS could be divided into three seismogenic zones (north, central, and south zones) based on the geological structures and the earthquake catalog. We applied the Bayesian probability method using extreme-value distribution of earthquake occurrences to estimate the seismic hazard in the LFS. The seismic moment, slip rate, earthquake recurrence rate, and magnitude were considered as the basic parameters for computing the Bayesian prior estimates of the seismicity. These estimates were then updated in terms of Bayes' theorem and historical estimates of seismicity in the LFS. Generally speaking, the north zone seemingly is quite peaceful compared with the central and south zones. The central zone is the most dangerous; however, the periodicity of earthquake occurrences for M s = 8.0 is quite long (1,250 to 5,000 years). The selection of upper bound probable magnitude influences the result, and the upper bound magnitude of the south zone maybe 7.5. We obtained the empirical relationship of magnitude conversion for M s and ML, the values of the magnitude of completeness Mc (3.5), and the Gutenberg-Richter b value before applying the Bayesian extreme-value distribution of earthquake occurrences method.

  2. Earthquake in Haiti

    DEFF Research Database (Denmark)

    Holm, Isak Winkel

    2012-01-01

    In the vocabulary of modern disaster research, Heinrich von Kleist's seminal short story "The Earthquake in Chile" from 1806 is a tale of disaster vulnerability. The story is not just about a natural disaster destroying the innocent city of Santiago but also about the ensuing social disaster...

  3. The EM Earthquake Precursor

    Science.gov (United States)

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

    2013-12-01

    Many attempts have been made to determine a sound forecasting method regarding earthquakes and warn the public in turn. Presently, the animal kingdom leads the precursor list alluding to a transmission related source. By applying the animal-based model to an electromagnetic (EM) wave model, various hypotheses were formed, but the most interesting one required the use of a magnetometer with a differing design and geometry. To date, numerous, high-end magnetometers have been in use in close proximity to fault zones for potential earthquake forecasting; however, something is still amiss. The problem still resides with what exactly is forecastable and the investigating direction of EM. After the 1989 Loma Prieta Earthquake, American earthquake investigators predetermined magnetometer use and a minimum earthquake magnitude necessary for EM detection. This action was set in motion, due to the extensive damage incurred and public outrage concerning earthquake forecasting; however, the magnetometers employed, grounded or buried, are completely subject to static and electric fields and have yet to correlate to an identifiable precursor. Secondly, there is neither a networked array for finding any epicentral locations, nor have there been any attempts to find even one. This methodology needs dismissal, because it is overly complicated, subject to continuous change, and provides no response time. As for the minimum magnitude threshold, which was set at M5, this is simply higher than what modern technological advances have gained. Detection can now be achieved at approximately M1, which greatly improves forecasting chances. A propagating precursor has now been detected in both the field and laboratory. Field antenna testing conducted outside the NE Texas town of Timpson in February, 2013, detected three strong EM sources along with numerous weaker signals. The antenna had mobility, and observations were noted for recurrence, duration, and frequency response. Next, two

  4. Indonesian Earthquake Decision Support System

    CERN Document Server

    Warnars, Spits

    2010-01-01

    Earthquake DSS is an information technology environment which can be used by government to sharpen, make faster and better the earthquake mitigation decision. Earthquake DSS can be delivered as E-government which is not only for government itself but in order to guarantee each citizen's rights for education, training and information about earthquake and how to overcome the earthquake. Knowledge can be managed for future use and would become mining by saving and maintain all the data and information about earthquake and earthquake mitigation in Indonesia. Using Web technology will enhance global access and easy to use. Datawarehouse as unNormalized database for multidimensional analysis will speed the query process and increase reports variation. Link with other Disaster DSS in one national disaster DSS, link with other government information system and international will enhance the knowledge and sharpen the reports.

  5. Detailed source process of the 2007 Tocopilla earthquake.

    Science.gov (United States)

    Peyrat, S.; Madariaga, R.; Campos, J.; Asch, G.; Favreau, P.; Bernard, P.; Vilotte, J.

    2008-05-01

    We investigated the detail rupture process of the Tocopilla earthquake (Mw 7.7) of the 14 November 2007 and of the main aftershocks that occurred in the southern part of the North Chile seismic gap using strong motion data. The earthquake happen in the middle of the permanent broad band and strong motion network IPOC newly installed by GFZ and IPGP, and of a digital strong-motion network operated by the University of Chile. The Tocopilla earthquake is the last large thrust subduction earthquake that occurred since the major Iquique 1877 earthquake which produced a destructive tsunami. The Arequipa (2001) and Antofagasta (1995) earthquakes already ruptured the northern and southern parts of the gap, and the intraplate intermediate depth Tarapaca earthquake (2005) may have changed the tectonic loading of this part of the Peru-Chile subduction zone. For large earthquakes, the depth of the seismic rupture is bounded by the depth of the seismogenic zone. What controls the horizontal extent of the rupture for large earthquakes is less clear. Factors that influence the extent of the rupture include fault geometry, variations of material properties and stress heterogeneities inherited from the previous ruptures history. For subduction zones where structures are not well known, what may have stopped the rupture is not obvious. One crucial problem raised by the Tocopilla earthquake is to understand why this earthquake didn't extent further north, and at south, what is the role of the Mejillones peninsula that seems to act as a barrier. The focal mechanism was determined using teleseismic waveforms inversion and with a geodetic analysis (cf. Campos et al.; Bejarpi et al., in the same session). We studied the detailed source process using the strong motion data available. This earthquake ruptured the interplate seismic zone over more than 150 km and generated several large aftershocks, mainly located south of the rupture area. The strong-motion data show clearly two S

  6. Structural Preconditions of West Bohemia Earthquake Swarms

    Science.gov (United States)

    Novotný, M.; Špičák, A.; Weinlich, F. H.

    2013-07-01

    The West Bohemia and adjacent Vogtland are well known for quasi-periodical earthquake swarms persisting for centuries. The seismogenic area near Nový Kostel involved about 90 % of overall earthquake activity clustered here in space and time. The latest major earthquake swarm took place in August-September 2011. In 1994 and 1997, two minor earthquake swarms appeared in another location, near Lazy. Recently, the depth-recursive tomography yielded a velocity image with an improved resolution along the CEL09 refraction profile passing between these swarm areas. The resolution, achieved in the velocity image and its agreement with the inverse gravity modeling along the collateral 9HR reflection profile, enabled us to reveal the key structural background of these West Bohemia earthquake swarms. The CEL09 velocity image detected two deeply rooted high-velocity bodies adjacent to the Nový Kostel and Lazy focal zones. They correspond to two Variscan mafic intrusions influenced by the SE inclined slab of Saxothuringian crust that subducted beneath the Teplá-Barrandian terrane in the Devonian era. In their uppermost SE inclined parts, they roof both focal zones. The high P-wave velocities of 6,100-6,200 m/s, detected in both roofing caps, indicate their relative compactness and impermeability. The focal domains themselves are located in the almost gradient-free zones with the swarm foci spread near the axial planes of profound velocity depressions. The lower velocities of 5,950-6,050 m/s, observed in the upper parts of focal zones, are indicative of less compact rock complexes corrugated and tectonically disturbed by the SE bordering magma ascents. The high-velocity/high-density caps obviously seal the swarm focal domains because almost no magmatic fluids of mantle origin occur in the Nový Kostel and Lazy seismogenic areas of the West Bohemia/Vogtland territory, otherwise rich in the mantle-derived fluids. This supports the hypothesis of the fluid triggering of earthquake

  7. Tidal stress triggering of earthquakes in Southern California

    Science.gov (United States)

    Bucholc, Magda; Steacy, Sandy

    2016-05-01

    We analyse the influence of the solid Earth tides and ocean loading on the occurrence time of Southern California earthquakes. For each earthquake, we calculate tidal Coulomb failure stress and stress rate on a fault plane that is assumed to be controlled by the orientation of the adjacent fault. To reduce bias when selecting data for testing the tide-earthquake relationship, we create four earthquake catalogues containing events within 1, 1.5, 2.5 and 5 km of nearest faults. We investigate the difference in seismicity rates at times of positive and negative tidal stresses/stress rates given three different cases. We consider seismicity rates during times of positive versus negative stress and stress rate, as well as 2 and 3 hr surrounding the local tidal stress extremes. We find that tidal influence on earthquake occurrence is found to be statistically non-random only in close proximity to tidal extremes meaning that magnitude of tidal stress plays an important role in tidal triggering. A non-random tidal signal is observed for the reverse events. Along with a significant increase in earthquake rates around tidal Coulomb stress maxima, the strength of tidal correlation is found to be closely related to the amplitude of the peak tidal Coulomb stress (τp). The most effective tidal triggering is found for τp ≥ 1 kPa, which is much smaller than thresholds suggested for static and dynamic triggering of aftershocks.

  8. 汶川地震伤残人员2年后生存质量及影响因素调查%Survey of qual ity of l ife of the disabled in Wenchuan earthquake after 2 years and its influencing factors

    Institute of Scientific and Technical Information of China (English)

    王定玺; 李小麟; 吴学华; 朱仕超

    2014-01-01

    Obj ective:To know about the quality of life of the disabled in-Wenchuan earthquake stricken area after 2 years,and to analyze its influen-cing factors,so as to provide evidences for the rehabilitation of disabled per-sons and enhance their quality of life.Methods:After 2 years of Wenchuan earthquake,a total of 172 earthquake disabled persons in heavy disaster area were investigated on their quality of life by cross sectional survey,and the survey tool was concise health survey questionnaire (SF 3 6 ).Results:Af-ter 2 years,all mental health related qualty of life scores of quality of life in 172 cases earthquake disabled persons were lower than that of ordinary residents in Sichuan province;physical function score and general health score were higher than that in 1 year after the earthquake,and after 2 years in addition to the social functions,all dimensions scores were lower than that in 1 year after the earthquake (P<0.05).Single factor analysis was carried out for the 9 factors which may impact the quality of life of the earthquake disabled persons,and the results showed that gender,employ-ment status and disability complications had influence on the quality of life. The quality of life of disabled persons who were male and had disability complications and continued to work was higher than that of disabled per-sons who were female,leisure at home and had disability complications. Multivariate analysis of the quality of life of disabled persons in earthquake showed that the influencing factors of physical health related quality of life of disabled persons in earthquakes were:disability complications,disability complications,per capita monthly income,family structure changes;the in-fluencing factors of the earthquake damage residual mental health related quality of life of disabled persons in earthquakes:disability complications and sex.Conclusion:In 2 years after earthquake the quality of life of the earthquake disabled persons was lower than that of the general

  9. Numerical visualization of boiling two-phase flow behavior in fuel bundles at simulated earthquake condition

    International Nuclear Information System (INIS)

    In order to evaluate an influence of earthquake acceleration to the boiling two-phase flow behavior in nuclear reactors, numerical simulations were performed under the simulated earthquake condition. The two-phase flow analysis code, ACE-3D, was modified as the influence of the earth quake acceleration can calculate. To check out if the modification is adequate, a series of calculations were carried out and the following summaries were derived; 1) the void fraction in the fuel bundle receives the influence of the earthquake, 2) the liquid-phase in the two-phase flow moves in the same direction as the direction of oscillation due to the inputted earthquake acceleration, and 3) due to the density difference in comparison with the liquid phase, the gas phase of that moves in the direction opposite to the oscillating direction. This study enabled visualized evaluation of the boiling two-phase flow behavior in the nuclear reactors at the earthquake condition. (author)

  10. Earthquake hazard evaluation for Switzerland

    International Nuclear Information System (INIS)

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

  11. Turkish Compulsory Earthquake Insurance (TCIP)

    Science.gov (United States)

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

    2009-04-01

    Through a World Bank project a government-sponsored Turkish Catastrophic Insurance Pool (TCIP) is created in 2000 with the essential aim of transferring the government's financial burden of replacing earthquake-damaged housing to international reinsurance and capital markets. Providing coverage to about 2.9 Million homeowners TCIP is the largest insurance program in the country with about 0.5 Billion USD in its own reserves and about 2.3 Billion USD in total claims paying capacity. The total payment for earthquake damage since 2000 (mostly small, 226 earthquakes) amounts to about 13 Million USD. The country-wide penetration rate is about 22%, highest in the Marmara region (30%) and lowest in the south-east Turkey (9%). TCIP is the sole-source provider of earthquake loss coverage up to 90,000 USD per house. The annual premium, categorized on the basis of earthquake zones type of structure, is about US90 for a 100 square meter reinforced concrete building in the most hazardous zone with 2% deductible. The earthquake engineering related shortcomings of the TCIP is exemplified by fact that the average rate of 0.13% (for reinforced concrete buildings) with only 2% deductible is rather low compared to countries with similar earthquake exposure. From an earthquake engineering point of view the risk underwriting (Typification of housing units to be insured, earthquake intensity zonation and the sum insured) of the TCIP needs to be overhauled. Especially for large cities, models can be developed where its expected earthquake performance (and consequently the insurance premium) can be can be assessed on the basis of the location of the unit (microzoned earthquake hazard) and basic structural attributes (earthquake vulnerability relationships). With such an approach, in the future the TCIP can contribute to the control of construction through differentiation of premia on the basis of earthquake vulnerability.

  12. Engineering geological aspect of Gorkha Earthquake 2015, Nepal

    Science.gov (United States)

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

    2016-04-01

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

  13. A review of the 2005 Kashmir earthquake-induced landslides; from a remote sensing prospective

    Science.gov (United States)

    Shafique, Muhammad; van der Meijde, Mark; Khan, M. Asif

    2016-03-01

    The 8th October 2005 Kashmir earthquake, in northern Pakistan has triggered thousands of landslides, which was the second major factor in the destruction of the build-up environment, after earthquake-induced ground shaking. Subsequent to the earthquake, several researchers from home and abroad applied a variety of remote sensing techniques, supported with field observations, to develop inventories of the earthquake-triggered landslides, analyzed their spatial distribution and subsequently developed landslide-susceptibility maps. Earthquake causative fault rupture, geology, anthropogenic activities and remote sensing derived topographic attributes were observed to have major influence on the spatial distribution of landslides. These were subsequently used to develop a landslide susceptibility map, thereby demarcating the areas prone to landsliding. Temporal studies monitoring the earthquake-induced landslides shows that the earthquake-induced landslides are stabilized, contrary to earlier belief, directly after the earthquake. The biggest landslide induced dam, as a result of the massive Hattian Bala landslide, is still posing a threat to the surrounding communities. It is observed that remote sensing data is effectively and efficiently used to assess the landslides triggered by the Kashmir earthquake, however, there is still a need of more research to understand the mechanism of intensity and distribution of landslides; and their continuous monitoring using remote sensing data at a regional scale. This paper, provides an overview of remote sensing and GIS applications, for the Kashmir-earthquake triggered landslides, derived outputs and discusses the lessons learnt, advantages, limitations and recommendations for future research.

  14. Earthquake forecasting and its verification

    Directory of Open Access Journals (Sweden)

    J. R. Holliday

    2005-01-01

    Full Text Available No proven method is currently available for the reliable short time prediction of earthquakes (minutes to months. However, it is possible to make probabilistic hazard assessments for earthquake risk. In this paper we discuss a new approach to earthquake forecasting based on a pattern informatics (PI method which quantifies temporal variations in seismicity. The output, which is based on an association of small earthquakes with future large earthquakes, is a map of areas in a seismogenic region ('hotspots'' where earthquakes are forecast to occur in a future 10-year time span. This approach has been successfully applied to California, to Japan, and on a worldwide basis. Because a sharp decision threshold is used, these forecasts are binary--an earthquake is forecast either to occur or to not occur. The standard approach to the evaluation of a binary forecast is the use of the relative (or receiver operating characteristic (ROC diagram, which is a more restrictive test and less subject to bias than maximum likelihood tests. To test our PI method, we made two types of retrospective forecasts for California. The first is the PI method and the second is a relative intensity (RI forecast based on the hypothesis that future large earthquakes will occur where most smaller earthquakes have occurred in the recent past. While both retrospective forecasts are for the ten year period 1 January 2000 to 31 December 2009, we performed an interim analysis 5 years into the forecast. The PI method out performs the RI method under most circumstances.

  15. The Japanese earthquake of 1978

    International Nuclear Information System (INIS)

    In January 1978, an earthquake of magnitude 7.0 took place off the Pacific coast of Honshu, Japan about 110 km south-west-south of Tokyo, which caused some casualties and property damage. This earthquake was preceded by a large number of foreshocks and followed by many aftershocks. The earthquake itself was not very large as a natural event. However, it did provide a number of lessons on the importance of issuing timely information to the public in order to mitigate the impact of earthquake disasters. (author). 1 fig

  16. Real time earthquake forecasting in Italy

    OpenAIRE

    Murru, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Console, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Falcone, G.; Earth Science Department, Messina University

    2008-01-01

    We have applied an earthquake clustering epidemic model to real time data at the Italian Earthquake Data Center operated by the Istituto Nazionale di Geofisica e Vulcanologia (INGV) for short-term forecasting of moderate and large earthquakes in Italy. In this epidemic-type model every earthquake is regarded, at the same time, as being triggered by previous events and triggering following earthquakes. The model uses earthquake data only, with no explicit use of tectonic, geologic, or geodetic...

  17. On elastic limit margins for earthquake design

    International Nuclear Information System (INIS)

    In the Federal Republic of Germany KTA rule 2201 being the basis for the design of nuclear power plants against seismic events is now under discussion for revisions. One of the main demands to modify KTA rule 2201 consists in cancelling the existing design philosophy, i.e. design against an operating basis earthquake (AEB) as well as against a safe shutdown earthquake (SEB). When using the present rule the 'lower' earthquake (AEB) can become design-predominant, since for AEB and SEB different types of load cases are to be superimposed with different safety factors. The scope of this study is to quantify by parametric analyses so-called 'elastic bearing capacity limit margins' for seismic events; hereby different seismic input criteria - conventional as well as recently proposed are taken into account to investigate the influence of eventual modifications in seismic design philosophy. This way a relation between AEB and SEB has to be defined so that SEB is just still predominant for the design while AEB still will yield to elastic behaviour. The study covers all German site conditions

  18. Forecast of Large Earthquakes Through Semi-periodicity Analysis of Labeled Point Processes - Semi-Periodicity Analysis of Large Earthquakes

    Science.gov (United States)

    Quinteros Cartaya, C. B.; Nava Pichardo, F. A.; Glowacka, E.; Gómez Treviño, E.; Dmowska, R.

    2016-07-01

    Large earthquakes have semi-periodic behavior as a result of critically self-organized processes of stress accumulation and release in seismogenic regions. Hence, large earthquakes in a given region constitute semi-periodic sequences with recurrence times varying slightly from periodicity. In previous papers, it has been shown that it is possible to identify these sequences through Fourier analysis of the occurrence time series of large earthquakes from a given region, by realizing that not all earthquakes in the region need belong to the same sequence, since there can be more than one process of stress accumulation and release in the region. Sequence identification can be used to forecast earthquake occurrence with well determined confidence bounds. This paper presents improvements on the above mentioned sequence identification and forecasting method: the influence of earthquake size on the spectral analysis, and its importance in semi-periodic events identification are considered, which means that earthquake occurrence times are treated as a labeled point process; a revised estimation of non-randomness probability is used; a better estimation of appropriate upper limit uncertainties to use in forecasts is introduced; and the use of Bayesian analysis to evaluate the posterior forecast performance is applied. This improved method was successfully tested on synthetic data and subsequently applied to real data from some specific regions. As an example of application, we show the analysis of data from the northeastern Japan Arc region, in which one semi-periodic sequence of four earthquakes with M ≥ 8.0, having high non-randomness probability was identified. We compare the results of this analysis with those of the unlabeled point process analysis.

  19. Anthropogenic Triggering of Large Earthquakes

    Science.gov (United States)

    Mulargia, Francesco; Bizzarri, Andrea

    2014-08-01

    The physical mechanism of the anthropogenic triggering of large earthquakes on active faults is studied on the basis of experimental phenomenology, i.e., that earthquakes occur on active tectonic faults, that crustal stress values are those measured in situ and, on active faults, comply to the values of the stress drop measured for real earthquakes, that the static friction coefficients are those inferred on faults, and that the effective triggering stresses are those inferred for real earthquakes. Deriving the conditions for earthquake nucleation as a time-dependent solution of the Tresca-Von Mises criterion applied in the framework of poroelasticity yields that active faults can be triggered by fluid overpressures < 0.1 MPa. Comparing this with the deviatoric stresses at the depth of crustal hypocenters, which are of the order of 1-10 MPa, we find that injecting in the subsoil fluids at the pressures typical of oil and gas production and storage may trigger destructive earthquakes on active faults at a few tens of kilometers. Fluid pressure propagates as slow stress waves along geometric paths operating in a drained condition and can advance the natural occurrence of earthquakes by a substantial amount of time. Furthermore, it is illusory to control earthquake triggering by close monitoring of minor ``foreshocks'', since the induction may occur with a delay up to several years.

  20. Can Satellites Aid Earthquake Predictions?

    Institute of Scientific and Technical Information of China (English)

    John Roach; 李晓辉

    2004-01-01

    @@ Earthquake prediction is an imprecise science, and to illustrate the point,many experts point to the story of Tangshen①, China. On July 28, 1976, a magnitude② 7. 6 earthquake struck the city of Tangshen, China, without warning. None of the signs of the successful prediction from a year and half earlier were present. An estimated 250,000 people died.

  1. Make an Earthquake: Ground Shaking!

    Science.gov (United States)

    Savasci, Funda

    2011-01-01

    The main purposes of this activity are to help students explore possible factors affecting the extent of the damage of earthquakes and learn the ways to reduce earthquake damages. In these inquiry-based activities, students have opportunities to develop science process skills and to build an understanding of the relationship among science,…

  2. Earthquakes Threaten Many American Schools

    Science.gov (United States)

    Bailey, Nancy E.

    2010-01-01

    Millions of U.S. children attend schools that are not safe from earthquakes, even though they are in earthquake-prone zones. Several cities and states have worked to identify and repair unsafe buildings, but many others have done little or nothing to fix the problem. The reasons for ignoring the problem include political and financial ones, but…

  3. Early Earthquakes of the Americas

    Science.gov (United States)

    Ni, James

    2004-11-01

    Robert Kovach's second book looks at the interplay of earthquake and volcanic events, archeology, and history in the Americas. Throughout history, major earthquakes have caused the deaths of millions of people and have damaged countless cities. Earthquakes undoubtedly damaged prehistoric cities in the Americas, and evidence of these events could be preserved in archeological records. Kovach asks, Did indigenous native cultures-Indians of the Pacific Northwest, Aztecs, Mayas, and Incas-document their natural history? Some events have been explicitly documented, for example, in Mayan codices, but many may have been recorded as myth and legend. Kovach's discussions of how early cultures dealt with fearful events such as earthquakes and volcanic eruptions are colorful, informative, and entertaining, and include, for example, a depiction of how the Maya would talk to maize plants in their fields during earthquakes to reassure them.

  4. Testing earthquake source inversion methodologies

    KAUST Repository

    Page, Morgan T.

    2011-01-01

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

  5. The CATDAT damaging earthquakes database

    Science.gov (United States)

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

    2011-08-01

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

  6. Subdiffusion of volcanic earthquakes

    CERN Document Server

    Abe, Sumiyoshi

    2016-01-01

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

  7. New perspective of Earthquake generation in the east margins of Tibet, China

    Science.gov (United States)

    Wang, Zhi; Wang, Xuben

    2016-04-01

    Global seismic waveform inversion can reveal where rupture initiated and how it expanded for the 2013 Ms 7.0 Lushan earthquake, Sichuan province of China. To investigate the generation mechanism of the Lushan earthquake and its relation to the 2008 Wenchuan earthquake (Ms 8.0), we installed 50 temporal seismic stations at the source area following the Lushan earthquake. We also collected crustal stress data along the Longmen-Shan fault zone (LMFZ) to reveal its influence on the Lushan earthquake generation. Our seismic imaging and crustal stress analysis indicates that the Lushan earthquake occurred in a distinct area with high-velocity (Vp, Vs), low-Poisson's ratio (σp and high crustal stress. The high velocity zone at the Lushan source may reflect the metamafic seismogenic layer that enables the accumulation of high crustal stress for large earthquake generation. However, a sharp contrast gap zone with low velocity and high-gσ anomalies is clearly imaged in the upper crust under the conjunction area between the Lushan and Wenchuan earthquakes. Our seismic images indicate that the slow velocity gap zone is associated with fluid-bearing ductile flow from the lower crustal materials of Tibet being pushed into the weakened segment of the LMFZ. Our study suggests that the 2013 Lushan earthquake may have been triggered by the high crustal stress accumulation together with the high coseismic stress increased by the Wenchuan Earthquake in the metamafic seismogenic layer. The contrasting rheological variation in the crust and crustal stress change along the LMFZ controls the rupture processes of the Lushan and Wenchuan earthquakes, as well as the generation of new earthquakes in the future.

  8. Remarkable changes in behavior and physiology of laboratory mice after the massive 2011 Tohoku earthquake in Japan.

    Directory of Open Access Journals (Sweden)

    Shuichi Yanai

    Full Text Available A devastating earthquake and tsunami hit Japan on March 11, 2011, followed by several long and intense aftershocks. Laboratory mice housed in the Tokyo, located approximately 330 km south of this earthquake's epicenter, displayed remarkable changes in a variety of behaviors and physiological measures. Although unusual pre-earthquake behaviors have been previously reported in laboratory animals, little is known about behavioral and physiological changes that occur after a great earthquake. In the present study, the effects of Tohoku earthquake on mice behavior were investigated. "Earthquake-experienced" mice displayed a marked increase in food consumption without gaining body weight in response to the earthquake. They also displayed enhanced anxiety, and in a formal fear memory task, showed significantly greater tone- and context-dependent conditioned freezing. Water maze performance of earthquake-experienced mice showed the quicker acquisition of the task, faster swim speed and longer swim distance than the naive mice. Serum corticosterone levels were elevated compared to the naive mice, indicating that the earthquake and aftershocks were stressful for the mice. These results demonstrate that great earthquakes strongly affect mouse behaviors and physiology. Although the effects of a variety of experimental manipulations on mouse behaviors in disease models or in models of higher cognitive functions have been extensively examined, researchers need to be aware how natural phenomena, such as earthquakes and perhaps other natural environmental factors, influence laboratory animal behaviors and physiology.

  9. Time-history simulation of civil architecture earthquake disaster relief- based on the three-dimensional dynamic finite element method

    OpenAIRE

    Liu Bing; Qi Yaoguang; Du Jiyun

    2014-01-01

    Earthquake action is the main external factor which influences long-term safe operation of civil construction, especially of the high-rise building. Applying time-history method to simulate earthquake response process of civil construction foundation surrounding rock is an effective method for the anti-knock study of civil buildings. Therefore, this paper develops a civil building earthquake disaster three-dimensional dynamic finite element numerical simulation system. The system ...

  10. Determination of Design Basis Earthquake ground motion

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Muneaki [Japan Atomic Power Co., Tokyo (Japan)

    1997-03-01

    This paper describes principle of determining of Design Basis Earthquake following the Examination Guide, some examples on actual sites including earthquake sources to be considered, earthquake response spectrum and simulated seismic waves. In sppendix of this paper, furthermore, seismic safety review for N.P.P designed before publication of the Examination Guide was summarized with Check Basis Earthquake. (J.P.N.)

  11. PRECURSORS OF EARTHQUAKES: VLF SIGNALSIONOSPHERE IONOSPHERE RELATION

    OpenAIRE

    Mustafa ULAS; ATA, Fikret; Hasan Hüseyin BALIK

    2013-01-01

    lot of people have died because of earthquakes every year. Therefore It is crucial to predict the time of the earthquakes reasonable time before it had happed. This paper presents recent information published in the literature about precursors of earthquakes. The relationships between earthquakes and ionosphere are targeted to guide new researches in order to study further to find novel prediction methods.

  12. Earthquake prediction by Kina Method

    International Nuclear Information System (INIS)

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

  13. The physics of an earthquake

    International Nuclear Information System (INIS)

    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

  14. Ionospheric phenomena before strong earthquakes

    Directory of Open Access Journals (Sweden)

    A. S. Silina

    2001-01-01

    Full Text Available A statistical analysis of several ionospheric parameters before earthquakes with magnitude M > 5.5 located less than 500 km from an ionospheric vertical sounding station is performed. Ionospheric effects preceding "deep" (depth h > 33 km and "crust" (h 33 km earthquakes were analysed separately. Data of nighttime measurements of the critical frequencies foF2 and foEs, the frequency fbEs and Es-spread at the middle latitude station Dushanbe were used. The frequencies foF2 and fbEs are proportional to the square root of the ionization density at heights of 300 km and 100 km, respectively. It is shown that two days before the earthquakes the values of foF2 averaged over the morning hours (00:00 LT–06:00 LT and of fbEs averaged over the nighttime hours (18:00 LT–06:00 LT decrease; the effect is stronger for the "deep" earthquakes. Analysing the coefficient of semitransparency which characterizes the degree of small-scale turbulence, it was shown that this value increases 1–4 days before "crust" earthquakes, and it does not change before "deep" earthquakes. Studying Es-spread which manifests itself as diffuse Es track on ionograms and characterizes the degree of large-scale turbulence, it was found that the number of Es-spread observations increases 1–3 days before the earthquakes; for "deep" earthquakes the effect is more intensive. Thus it may be concluded that different mechanisms of energy transfer from the region of earthquake preparation to the ionosphere occur for "deep" and "crust" events.

  15. Fracking, wastewater disposal, and earthquakes

    Science.gov (United States)

    McGarr, Arthur

    2016-03-01

    In the modern oil and gas industry, fracking of low-permeability reservoirs has resulted in a considerable increase in the production of oil and natural gas, but these fluid-injection activities also can induce earthquakes. Earthquakes induced by fracking are an inevitable consequence of the injection of fluid at high pressure, where the intent is to enhance permeability by creating a system of cracks and fissures that allow hydrocarbons to flow to the borehole. The micro-earthquakes induced during these highly-controlled procedures are generally much too small to be felt at the surface; indeed, the creation or reactivation of a large fault would be contrary to the goal of enhancing permeability evenly throughout the formation. Accordingly, the few case histories for which fracking has resulted in felt earthquakes have been due to unintended fault reactivation. Of greater consequence for inducing earthquakes, modern techniques for producing hydrocarbons, including fracking, have resulted in considerable quantities of coproduced wastewater, primarily formation brines. This wastewater is commonly disposed by injection into deep aquifers having high permeability and porosity. As reported in many case histories, pore pressure increases due to wastewater injection were channeled from the target aquifers into fault zones that were, in effect, lubricated, resulting in earthquake slip. These fault zones are often located in the brittle crystalline rocks in the basement. Magnitudes of earthquakes induced by wastewater disposal often exceed 4, the threshold for structural damage. Even though only a small fraction of disposal wells induce earthquakes large enough to be of concern to the public, there are so many of these wells that this source of seismicity contributes significantly to the seismic hazard in the United States, especially east of the Rocky Mountains where standards of building construction are generally not designed to resist shaking from large earthquakes.

  16. Fractal Models of Earthquake Dynamics

    CERN Document Server

    Bhattacharya, Pathikrit; Kamal,; Samanta, Debashis

    2009-01-01

    Our understanding of earthquakes is based on the theory of plate tectonics. Earthquake dynamics is the study of the interactions of plates (solid disjoint parts of the lithosphere) which produce seismic activity. Over the last about fifty years many models have come up which try to simulate seismic activity by mimicking plate plate interactions. The validity of a given model is subject to the compliance of the synthetic seismic activity it produces to the well known empirical laws which describe the statistical features of observed seismic activity. Here we present a review of two such models of earthquake dynamics with main focus on a relatively new model namely The Two Fractal Overlap Model.

  17. The SME (site margin earthquake)

    International Nuclear Information System (INIS)

    A methodology is proposed for assessing the seismic safety margin of existing CANDU nuclear generating stations. The available seismic margin assessment approaches and the unique features of the CANDU system, were appraised. The proposed methodology includes: the characterization of the site margin earthquake, the definition of the performance criteria for the elements of a success path and determination of its seismic withstand capacity. It is proposed that the margin earthquake be established on the basis of a combined approach of using historical records and regional seismotectonic and site specific evaluations. The ability of the components and systems to withstand the margin earthquake is determined by database comparisons, inspection and analysis. (author)

  18. Sumatra earthquake and Earth rotation

    OpenAIRE

    Pisani, A. R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Piersanti, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Piatanesi, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Melini, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Soldati, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia

    2006-01-01

    The giant earthquake of December 26 2004 off the west coast of northern Sumatra is likely to have affected Earth rotational parameters. A preliminary analysis of data obtained by Satellite Laser Ranging technique evidenced a step discontinuity of (1.5±0.4) mas in the instantaneous pole path in correspondence with the earthquake occurrence. Since a step-like temporal dependence is not compatible with the action of an earthquake on the inertia tensor, we test the hypothesis that the effect isní...

  19. Earthquake damage to transportation systems

    Science.gov (United States)

    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.

  20. Earthquake Zoning Maps of Turkey

    International Nuclear Information System (INIS)

    Earthquake Zoning Maps (1945, 1947, 1963, 1972 and 1996) and Specifications for Construction in Disaster Areas (1947, 1953, 1962, 1968, 1975, 1996, 1997 and 2006) have been changed many times following the developments in engineering seismology, tectonic and seismo-tectonic invention and improved earthquake data collection. The aim of this study is to give information about this maps, which come into force at different dates since the introduction of the firs official Earthquake Zoning Map published in 1945 and is to assist for better understanding of the development phases of these maps

  1. Predicting the Impact of Earthquakes

    International Nuclear Information System (INIS)

    Consistently monitor seismicity over the world to alert civilian security forces, assess hazards, model and test building and industrial facilities behavior in the event of an earthquake. Thanks to instruments unique in Europe, CEA researchers acquired extensive know-how and international renown in the field. The recent commissioning of the CENALT Tsunami Warning Center and the setup of the SEISM Institute for research on earthquake hazards is just another proof of their expertise. For want of being able to predict earthquakes, these organizations aim at limiting losses in human lives and material damage. (authors)

  2. Dynamics of Earthquake Faults

    CERN Document Server

    Carlson, J M; Shaw, B E

    1993-01-01

    We present an overview of our ongoing studies of the rich dynamical behavior of the uniform, deterministic Burridge--Knopoff model of an earthquake fault. We discuss the behavior of the model in the context of current questions in seismology. Some of the topics considered include: (1) basic properties of the model, such as the magnitude vs. frequency distribution and the distinction between small and large events; (2) dynamics of individual events, including dynamical selection of rupture propagation speeds; (3) generalizations of the model to more realistic, higher dimensional models; (4) studies of predictability, in which artificial catalogs generated by the model are used to test and determine the limitations of pattern recognition algorithms used in seismology.

  3. Earthquakes in cities revisited

    CERN Document Server

    Wirgin, Armand

    2016-01-01

    During the last twenty years, a number of publications of theoretical-numerical nature have appeared which come to the apparently-reassuring conclusion that seismic motion on the ground in cities is smaller than what this motion would be in the absence of the buildings (but for the same underground and seismic load). Other than the fact that this finding tells nothing about the motion within the buildings, it must be confronted with the overwhelming empirical evidence (e.g, earthquakes in Sendai (2011), Kathmandu (2015), Tainan City (2016), etc.) that shaking within buildings of a city is often large enough to damage or even destroy these structures. I show, on several examples, that theory can be reconciled with empirical evidence, and suggest that the crucial subject of seismic response in cities is in need of more thorough research.

  4. 抗震救灾官兵生活质量和心理健康状况及影响因素研究%Study on the quality of life and mental health as well as their influence factors in armed officers and soldiers from earthquake relief work

    Institute of Scientific and Technical Information of China (English)

    夜晓亮; 张步振

    2011-01-01

    目的 了解抗震救灾官兵生活质量和心理健康状况及影响因素.方法 采用随机整群抽样法,应用WHOQOL-BREF和SCL-90量表,对驻昆明某部280名抗震救灾官兵和330名非抗震救灾官兵进行问卷调查.结果 (1)抗震救灾官兵生活质量的生理、心理、社会及环境各领域百分制得分分别为(58.65±15.02)分、(56.88±14.66)分、(63.01±17.92)分、(50.73±15.16)分.除社会领域外,其余三个领域与非抗震救灾官兵之间的差异有统计学意义(P<0.01或P< 0.05).(2)在SCL-90评分中,除躯体化因子分外,抗震救灾官兵在其余各因子分均高于非抗震救灾官兵,且在强迫、抑郁、焦虑、恐怖、偏执和总均分两组之间的差异有统计学意义(P<0.01).(3)民族、籍贯、学历、职别、婚姻状况和是否为独生子女对抗震救灾官兵生活质量和SCL-90评分有不同程度的影响和相关性(P<0.01或P< 0.05).结论 抗震救灾官兵生活质量和心理健康水平均比非抗震救灾官兵差,其影响因素主要有民族、籍贯、学历、职别、婚姻状况和是否为独生子女等.%Objective To understand the quality of life and mental health status and influence factors on armed officers and soldiers from earthquake relief work. Methods sing cluster sampling and WHOQOL-BREF as well as the SCL-90 scale, a questionnaire survey was conducted in 280 officers and soldiers from earthquake relief work and 330 officers and soldiers not from earthquake relief work in Kunming. Results The scores of physiological, psychological, social and environmental domains of QOL among officers and soldiers from earthquake relief work were (58.65±15.02), (56.88±14.66), (63.01±l7.92), and (50.73±15.16), respectively. Statistically significant difference was found in the physiological, psychological, and environmental domains between officers and soldiers from earthquake relief work and those not from earthquake relief work (P<0.01 or P<0

  5. Sichuan Earthquake in China

    Science.gov (United States)

    2008-01-01

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

  6. Historical earthquake investigation and research in China

    OpenAIRE

    J. Wang

    2004-01-01

    China is one of the countries with the longest tradition of culture and has suffered many earthquake disasters, so many earthquake documents have therefore been conserved. In this paper we try to outline some basic information of historical earthquake investigation and research in China, such as collection of historical earthquake data from archives, historical earthquake catalogues, seismic intensity scales. We introduce briefly the huge accomplishments of historical research and discuss ...

  7. Earthquakes trigger the loss of groundwater biodiversity

    OpenAIRE

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

    2014-01-01

    Earthquakes are among the most destructive natural events. The 6 April 2009, 6.3-Mw earthquake in L'Aquila (Italy) markedly altered the karstic Gran Sasso Aquifer (GSA) hydrogeology and geochemistry. The GSA groundwater invertebrate community is mainly comprised of small-bodied, colourless, blind microcrustaceans. We compared abiotic and biotic data from two pre-earthquake and one post-earthquake complete but non-contiguous hydrological years to investigate the effects of the 2009 earthquake ...

  8. Deterministic earthquake scenarios for the city of Sofia

    CERN Document Server

    Slavov, S I; Panza, G F; Paskaleva, I; Vaccari, P

    2002-01-01

    The city of Sofia is exposed to a high seismic risk. Macroseismic intensities in the range of VIII-X (MSK) can be expected in the city. The earthquakes, that can influence the hazard at Sofia, originate either beneath the city or are caused by seismic sources located within a radius of 40km. The city of Sofia is also prone to the remote Vrancea seismic zone in Romania, and particularly vulnerable are the long - period elements of the built environment. The high seismic risk and the lack of instrumental recordings of the regional seismicity makes the use of appropriate credible earthquake scenarios and ground motion modelling approaches for defining the seismic input for the city of Sofia necessary. Complete synthetic seismic signals, due to several earthquake scenarios, were computed along chosen geological profiles crossing the city, applying a hybrid technique, based on the modal summation technique and finite differences. The modelling takes into account simultaneously the geotechnical properties of the si...

  9. The 1992 'cairo earthquake': cause, effect and response.

    Science.gov (United States)

    Degg, M

    1993-09-01

    This paper examines the geological and socio-political setting of the 1992 earthquake in northern Egypt. The main conclusions concern the importance of surface geology in controlling the nature of the earthquake impact, and the role of poor construction and maintenance standards (and lapses in building regulation enforcement) in influencing the vulnerability of buildings to failure. The heaviest human losses were associated with two main types of construction: firstly the old, dilapidated adobe houses of the poor in rural areas and in Cairo's inner city slums, and secondly certain modern, engineered (in some cases illegally) high-rise concrete constructions inhabited by the wealthy. The paper concludes by analysing the immediate response of the government and some non-governmental organisations in Egypt to the earthquake. Politicisation of the event is linked to broader issues of economic and social reform in the country and to the rise of Islamic Fundamentalist activity in all its forms. PMID:20958770

  10. Earthquake, GIS and multimedia. The 1883 Casamicciola earthquake

    OpenAIRE

    M. Rebuffat; Martini, M. G.; Cubellis, E.; 0; S. Castenetto; F. Bramerini; P SODDU

    1995-01-01

    A series of multimedia monographs concerning the main seismic events that have affected the Italian territory are in the process of being produced for the Documental Integrated Multimedia Project (DIMP) started by the Italian National Seismic Survey (NSS). The purpose of the project is to reconstruct the historical record of earthquakes and promote an earthquake public education. Producing the monographs. developed in ARC INFO and working in UNIX. involved designing a special filing and manag...

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

    Science.gov (United States)

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

    2011-01-01

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

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

    OpenAIRE

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

    2011-01-01

    The U.S. Geological Survey (USGS) is investigating how the social networking site Twitter, a popular service for sending and receiving short, public text messages, can augment USGS earthquake response products and the delivery of hazard information. Rapid detection and qualitative assessment of shaking events are possible because people begin sending public Twitter messages (tweets) with in tens of seconds after feeling shaking. Here we present and evaluate an earthquake detection procedure t...

  13. Connectivity of earthquake-triggered landslides with the fluvial network: Implications for landslide sediment transport after the 2008 Wenchuan earthquake

    Science.gov (United States)

    Li, Gen; West, A. Joshua; Densmore, Alexander L.; Hammond, Douglas E.; Jin, Zhangdong; Zhang, Fei; Wang, Jin; Hilton, Robert G.

    2016-04-01

    Evaluating the influence of earthquakes on erosion, landscape evolution, and sediment-related hazards requires understanding fluvial transport of material liberated in earthquake-triggered landslides. The location of landslides relative to river channels is expected to play an important role in postearthquake sediment dynamics. In this study, we assess the position of landslides triggered by the Mw 7.9 Wenchuan earthquake, aiming to understand the relationship between landslides and the fluvial network of the steep Longmen Shan mountain range. Combining a landslide inventory map and geomorphic analysis, we quantify landslide-channel connectivity in terms of the number of landslides, landslide area, and landslide volume estimated from scaling relationships. We observe a strong spatial variability in landslide-channel connectivity, with volumetric connectivity (ξ) ranging from ~20% to ~90% for different catchments. This variability is linked to topographic effects that set local channel densities, seismic effects (including seismogenic faulting) that regulate landslide size, and substrate effects that may influence both channelization and landslide size. Altogether, we estimate that the volume of landslides connected to channels comprises 43 + 9/-7% of the total coseismic landslide volume. Following the Wenchuan earthquake, fine-grained (influence of connectivity on suspended sediment yield may be related to mobilization of fine-grained landslide material that resides in hillslope domains, i.e., not directly connected to river channels. In contrast, transport of the coarser fraction (which makes up >90% of the total landslide volume) may be more significantly affected by landslide locations.

  14. Precursory specialties of apparent stresses in Yunnan earthquake series

    Institute of Scientific and Technical Information of China (English)

    LIU Hong-gui; LIU Jie; DING Ye-ling; SUN Ye-jun; YU Xin

    2006-01-01

    On the basis of the assumption that ω2 model accords with source displacement spectra, we have obtained the mathematical expressions for calculating apparent stresses of moderate-small shocks from low-frequency flat level and comer frequency. By using digital seismic records, apparent stress values are calculated for 823 moderate-small shocks of 4 earthquake series in Yunnan area following corrections for instrument response, propagation influence and site effect. The results show that for the 4 earthquake series in Yunnan area, apparent stress hints precursory information, which means that if a moderate-small shock occurs with apparent stress larger than 1 MPa in an earthquake series, a moderate-strong earthquake will occur afterwards; and if there is not moderate-small shock with apparent stress larger than 1 MPa after a moderate-strong event in an earthquake series, strong aftershock will not occur. The research also indicates that the average apparent stress value is 0.8 MPa in Yunnan area, therefore, apparent stress is not obviously related to seismic magnitude.

  15. Earthquakes and relative sealevel changes

    Science.gov (United States)

    Melini, D.; Piersanti, A.; Spada, G.; Soldati, G.; Casarotti, E.; Boschi, E.

    2004-05-01

    Using a spherical model of postseismic deformation, for the first time we have computed the global contribution of large earthquakes to the relative sealevel variations in the twentieth century. We have found that great earthquakes have the overall tendency to produce a sealevel rise, and that they affect the measurements taken at those tide-gauge sites that are commonly employed to obtain global estimates of sealevel rise. Though on a global scale most of the signal is associated with thrust events, on a regional scale the effects of great transcurrent earthquakes cannot be neglected. Depending on the viscosity of the asthenosphere, the contribution of earthquakes to the long-term sealevel changes amounts to at least 0.1 mm/yr. Thus, the climate-driven long-term sealevel changes deduced by tide-gauge observations may be slightly, but not negligibly, overestimated.

  16. Behavior of Columns During Earthquakes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The behavior of columns during earthquakes is very important since column failures may lead to additional structural failures and result in total building...

  17. Seismology: Remote-controlled earthquakes

    Science.gov (United States)

    Hayes, Gavin

    2016-04-01

    Large earthquakes cause other quakes near and far. Analyses of quakes in Pakistan and Chile suggest that such triggering can occur almost instantaneously, making triggered events hard to detect, and potentially enhancing the associated hazards.

  18. Electrostatics in sandstorms and earthquakes

    Science.gov (United States)

    Shinbrot, Troy; Thyagu, Nirmal; Paehtz, Thomas; Herrmann, Hans

    2010-11-01

    We present new data demonstrating (1) that electrostatic charging in sandstorms is a necessary outcome in a class of rapid collisional flows, and (2) that electrostatic precursors to slip events - long reported in earthquakes - can be reproduced in the laboratory.

  19. History of earthquake prediction researches

    International Nuclear Information System (INIS)

    The main procedures of diffusion of knowledge on earthquake prediction researches in space and time have been reconstructed. Scientific and economic constraint factors that caused difficulties or accelerations in seismic precursors researches have been investigated and commented

  20. Ionospheric total electron content variations observed before earthquakes: Possible physical mechanism and modeling

    CERN Document Server

    Namgaladze, A A; Zakharenkova, I E; Shagimuratov, I I; Martynenko, O V

    2009-01-01

    The GPS derived anomalous TEC disturbances before earthquakes were discovered in the last years using global and regional TEC maps, measurements over individual stations as well as measurements along individual GPS satellite passes. For strong mid-latitudinal earthquakes the seismo-ionospheric anomalies look like local TEC enhancements or decreases located in the vicinity of the forthcoming earthquake epicenter In case of strong low-latitudinal earthquakes there are effects related with the modification of the equatorial F2-region anomaly: deepening or filling of the ionospheric electron density trough over the magnetic equator. We consider that the most probable reason of the NmF2 and TEC disturbances observed before the earthquakes is the vertical drift of the F2-region ionospheric plasma under the influence of the zonal electric field of seismic origin. To check this hypothesis, the model calculations have been carried out with the use of the Upper Atmosphere Model. The electric potential distribution at t...

  1. Analysis of worldwide earthquake mortality using multivariate demographic and seismic data.

    Science.gov (United States)

    Gutiérrez, E; Taucer, F; De Groeve, T; Al-Khudhairy, D H A; Zaldivar, J M

    2005-06-15

    In this paper, mortality in the immediate aftermath of an earthquake is studied on a worldwide scale using multivariate analysis. A statistical method is presented that analyzes reported earthquake fatalities as a function of a heterogeneous set of parameters selected on the basis of their presumed influence on earthquake mortality. The ensemble was compiled from demographic, seismic, and reported fatality data culled from available records of past earthquakes organized in a geographic information system. The authors consider the statistical relation between earthquake mortality and the available data ensemble, analyze the validity of the results in view of the parametric uncertainties, and propose a multivariate mortality analysis prediction method. The analysis reveals that, although the highest mortality rates are expected in poorly developed rural areas, high fatality counts can result from a wide range of mortality ratios that depend on the effective population size. PMID:15937024

  2. Preliminary investigation of some large landslides triggered by the 2008 Wenchuan earthquake, Sichuan Province, China

    Science.gov (United States)

    Wang, F.; Cheng, Q.; Highland, L.; Miyajima, M.; Wang, Hongfang; Yan, C.

    2009-01-01

    The M s 8.0 Wenchuan earthquake or "Great Sichuan Earthquake" occurred at 14:28 p.m. local time on 12 May 2008 in Sichuan Province, China. Damage by earthquake-induced landslides was an important part of the total earthquake damage. This report presents preliminary observations on the Hongyan Resort slide located southwest of the main epicenter, shallow mountain surface failures in Xuankou village of Yingxiu Town, the Jiufengchun slide near Longmenshan Town, the Hongsong Hydro-power Station slide near Hongbai Town, the Xiaojiaqiao slide in Chaping Town, two landslides in Beichuan County-town which destroyed a large part of the town, and the Donghekou and Shibangou slides in Qingchuan County which formed the second biggest landslide lake formed in this earthquake. The influences of seismic, topographic, geologic, and hydro-geologic conditions are discussed. ?? 2009 Springer-Verlag.

  3. Pseudotachylytes and Earthquake Source Mechanics

    OpenAIRE

    Di Toro, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Pennacchioni, G.; Nielsen, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia

    2008-01-01

    Destructive earthquakes nucleate at depth (10-15 km), therefore monitoring active faults at the Earth’s surface, or interpreting seismic waves, yields only limited information on earthquake mechanics. Tectonic pseudotachylytes (solidified friction-induced melts) decorate some exhumed ancient faults and remain, up to now, the only fault rocks recognized as the unambiguous signature of seismic slip. It follows that pseudotachylyte-bearing fault networks might retain a wealth of info...

  4. Earthquake Forecast via Neutrino Tomography

    OpenAIRE

    Wang, Bin(Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China); Chen, Ya-Zheng; Li, Xue-Qian

    2010-01-01

    We discuss the possibility of forecasting earthquakes by means of (anti)neutrino tomography. Antineutrinos emitted from reactors are used as a probe. As the antineutrinos traverse through a region prone to earthquakes, observable variations in the matter effect on the antineutrino oscillation would provide a tomography of the vicinity of the region. In this preliminary work, we adopt a simplified model for the geometrical profile and matter density in a fault zone. We calculate the survival p...

  5. Empirical Analysis on the Influencing Factors of Rural Land Usage Right Circulation in Wenchuan Earthquake Disaster Area%汶川地震灾区农户土地使用权流转行为影响因素的实证分析

    Institute of Scientific and Technical Information of China (English)

    袁惊柱; 姜太碧

    2011-01-01

    Based on the sampling survey data of farmers in Wenchuan earthquake disaster area, Logistic regression analysis are carried out for whether farmers participate in the behavior of land usage right circulation and whether they will transfer the right of land use in or out, moreover,the hypothesized affecting factors of land usage right circulation are analyzed with principal component analysis. The results show that the influencing factors of rural land usage right circulation in earthquake disaster areas are basically consistent with the rational hypothesis, but the land circulation market has a series of problems, which deserves further study.%根据汶川地震灾区农户抽样调查数据,对农户是否参与土地使用权流转行为以及是否参与土地使用权的转入或转出行为进行了Logistic回归分析,并针对假设的土地使用权流特行为影响因素进行了主成分分析.结果表明,地震灾区农户土地流转行为的影响因素基本上符合理性假设.但农户土地流转市场还存在一系列问题,值得进一步研究.

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

    Directory of Open Access Journals (Sweden)

    Xu Liu

    2015-12-01

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

  7. Seismological study on earthquake engineering

    Energy Technology Data Exchange (ETDEWEB)

    Chi, Heon Cheol; Lee, Hee Il; Jeon, Jeong Soo; Shin, In Chul; Kim, Dong Kyun; Park, Jung Ho; Kim, Geun Young [Korea Institute of Geology Mining and Materials, Taejon (Korea)

    1998-12-01

    Building Code was recently amended in order to secure the safety and/or tolerance against disastrous earthquake. For the adequate but economical earthquake-resistant design, the possible maximum earthquake and the relevant waveform are crucial as input data with site characteristics. In this paper, the future plan of seismic observation network is proposed with both velocity and acceleration recordings : KIGAM, KEPRI and universities are presently involved in this plan. Nuclear power plant is fortified against earthquake since its failure results in unpredictable catastrophe. Nuclear power plant is strong enough to keep its function from big earthquake if the epicentral distance is greater than 15 Km. Here, the geological features around Youngkwang, Kori, Weolsung and Uljin nuclear power sites within 15 Km are described with geological map. Internet communications is rapidly popular at Korea. For efficient data exchange and convenient maintenance. the standard configuration of seismic station with TCP/IP communication is suggested. The procedure of constructing station is also explained with the emphasis of earth grounding. KIGAM purchased the automatic data retrieving and processing software, so-called Korea Earthquake Monitoring System (KEMS), with source code. KEMS uses CSS 3.0 schema for relational database with Oracle SQL engine. KIGAM is in charge of distributing down-sizing KEMS to seismic research universities. KIGAM is willing to supply the modified KEMS to any institute which wants to make network with KIGAM. Here, the networking through Internet is explained by sharing KEMS. (author). 85 refs., 15 tabs., 71 figs.

  8. Building with Earthquakes in Mind

    Science.gov (United States)

    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.

  9. Intracontinental basins and strong earthquakes

    Institute of Scientific and Technical Information of China (English)

    邓起东; 高孟潭; 赵新平; 吴建春

    2004-01-01

    The September 17, 1303 Hongtong M=8 earthquake occurred in Linfen basin of Shanxi down-faulted basin zone. It is the first recorded M=8 earthquake since the Chinese historical seismic records had started and is a great earthquake occurring in the active intracontinental basin. We had held a Meeting of the 700th Anniversary of the 1303 Hongtong M=8 Earthquake in Shanxi and a Symposium on Intracontinental Basins and Strong Earthquakes in Taiyuan City of Shanxi Province on September 17~18, 2003. The articles presented on the symposium discussed the relationships between active intracontinental basins of different properties, developed in different regions, including tensional graben and semi-graben basins in tensile tectonic regions, compression-depression basins and foreland basins in compressive tectonic regions and pull-apart basins in strike-slip tectonic zones, and strong earthquakes in China. In this article we make a brief summary of some problems. The articles published in this special issue are a part of the articles presented on the symposium.

  10. Earthquakes - Volcanoes (Causes and Forecast)

    Science.gov (United States)

    Tsiapas, E.

    2009-04-01

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

  11. Earthquake damage to underground facilities

    International Nuclear Information System (INIS)

    The potential seismic risk for an underground nuclear waste repository will be one of the considerations in evaluating its ultimate location. However, the risk to subsurface facilities cannot be judged by applying intensity ratings derived from the surface effects of an earthquake. A literature review and analysis were performed to document the damage and non-damage due to earthquakes to underground facilities. Damage from earthquakes to tunnels, s, and wells and damage (rock bursts) from mining operations were investigated. Damage from documented nuclear events was also included in the study where applicable. There are very few data on damage in the subsurface due to earthquakes. This fact itself attests to the lessened effect of earthquakes in the subsurface because mines exist in areas where strong earthquakes have done extensive surface damage. More damage is reported in shallow tunnels near the surface than in deep mines. In mines and tunnels, large displacements occur primarily along pre-existing faults and fractures or at the surface entrance to these facilities.Data indicate vertical structures such as wells and shafts are less susceptible to damage than surface facilities. More analysis is required before seismic criteria can be formulated for the siting of a nuclear waste repository

  12. Earthquake data base for Romania

    International Nuclear Information System (INIS)

    A new earthquake database for Romania is being constructed, comprising complete earthquake information and being up-to-date, user-friendly and rapidly accessible. One main component of the database consists from the catalog of earthquakes occurred in Romania since 984 up to present. The catalog contains information related to locations and other source parameters, when available, and links to waveforms of important earthquakes. The other very important component is the 'strong motion database', developed for strong intermediate-depth Vrancea earthquakes where instrumental data were recorded. Different parameters to characterize strong motion properties as: effective peak acceleration, effective peak velocity, corner periods Tc and Td, global response spectrum based intensities were computed and recorded into this database. Also, information on the recording seismic stations as: maps giving their positioning, photographs of the instruments and site conditions ('free-field or on buildings) are included. By the huge volume and quality of gathered data, also by its friendly user interface, the Romania earthquake data base provides a very useful tool for geosciences and civil engineering in their effort towards reducing seismic risk in Romania. (authors)

  13. Evaluating the role of large earthquakes on aquifer dynamics using data fusion and knowledge discovery techniques

    Science.gov (United States)

    Friedel, Michael; Cox, Simon; Williams, Charles; Holden, Caroline

    2016-04-01

    Artificial adaptive systems are evaluated for their usefulness in modeling earthquake hydrology of the Canterbury region, NZ. For example, an unsupervised machine-learning technique, self-organizing map, is used to fuse about 200 disparate and sparse data variables (such as, well pressure response, ground acceleration, intensity, shaking, stress and strain; aquifer and well characteristics) associated with the M7.1 Darfield earthquake in 2010 and the M6.3 Christchurch earthquake in 2011. The strength of correlations, determined using cross-component plots, varied between earthquakes with pressure changes more strongly related to dynamic- than static stress-related variables during the M7.1 earthquake, and vice versa during the M6.3. The method highlights the importance of data distribution and that driving mechanisms of earthquake-induced pressure change in the aquifers are not straight forward to interpret. In many cases, data mining revealed that confusion and reduction in correlations are associated with multiple trends in the same plot: one for confined and one for unconfined earthquake response. The autocontractive map and minimum spanning tree techniques are used for grouping variables of similar influence on earthquake hydrology. K-means clustering of neural information identified 5 primary regions influenced by the two earthquakes. The application of genetic doping to a genetic algorithm is used for identifying optimal subsets of variables in formulating predictions of well pressures. Predictions of well pressure changes are compared and contrasted using machine-learning network and symbolic regression models with prediction uncertainty quantified using a leave-one-out cross-validation strategy. These preliminary results provide impetus for subsequent analysis with information from another 100 earthquakes that occurred across the South Island.

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

    Directory of Open Access Journals (Sweden)

    Daniel C. Bowden

    2011-06-01

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

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

    Science.gov (United States)

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

    2010-05-01

    outermost layer was treated this way, the core of the shrines was made of simple rectangular blocks. The system resisted both in-plane and out-of-plane shaking quite well, as proven by survival of many shrines for more than a millennium, and by fracturing of blocks instead of displacement during the 2006 Yogyakarta earthquake. Systematic use or disuse of known earthquake-resistant techniques in any one society depends on the perception of earthquake risk and on available financial resources. Earthquake-resistant construction practice is significantly more expensive than regular construction. Perception is influenced mostly by short individual and longer social memory. If earthquake recurrence time is longer than the preservation of social memory, if damaging quakes fade into the past, societies commit the same construction mistakes again and again. Length of the memory is possibly about a generation's lifetime. Events occurring less frequently than 25-30 years can be readily forgotten, and the risk of recurrence considered as negligible, not worth the costs of safe construction practices. (Example of recurring flash floods in Hungary.) Frequent earthquakes maintain safe construction practices, like the Java masonry technique throughout at least two centuries, and like the Fachwerk tradition on Modern Aegean Samos throughout 500 years of political and technological development. (OTKA K67583)

  16. Safety study of fire protection for nuclear fuel cycle facility

    International Nuclear Information System (INIS)

    Insufficiencies in the fire protection system of the nuclear reactor facilities were pointed out when the fire occurred due to the Niigata prefecture-Chuetsu-oki Earthquake in July, 2007. This prompted the revision of the fire protection safety examination guideline for nuclear reactors as well as commercial guidelines. The commercial guidelines have been endorsed by the regulatory body. Now commercial fire protection standards for nuclear facilities such as the design guideline and the management guideline for protecting fire in the Light Water Reactors (LWRs) are available, however, those to apply to the nuclear fuel cycle facilities such as mixed oxide fuel fabrication facility (MFFF) have not been established. For the improvement of fire protection system of the nuclear fuel cycle facilities, the development of a standard for the fire protection, corresponding to the commercial standard for LWRs were required. Thus, Japan Nuclear Energy Safety Organization (JNES) formulated a fire protection guidelines for nuclear fuel cycle facilities as a standard relevant to the fire protection of the nuclear fuel cycle facilities considering functions specific to the nuclear fuel cycle facilities. In formulating the guidelines, investigation has been conduced on the commercial guidelines for nuclear reactors in Japan and the standards relevant to the fire protection of nuclear facilities in USA and other countries as well as non-nuclear industrial fire protection standards. The guideline consists of two parts; Equipments and Management, as the commercial guidances of the nuclear reactor. In addition, the acquisition of fire evaluation data for a components (an electric cabinet, cable, oil etc.) targeted for spread of fire and the evaluation model of fire source were continued for the fire hazard analysis (FHA). (author)

  17. The Electronic Encyclopedia of Earthquakes

    Science.gov (United States)

    Benthien, M.; Marquis, J.; Jordan, T.

    2003-12-01

    The Electronic Encyclopedia of Earthquakes is a collaborative project of the Southern California Earthquake Center (SCEC), the Consortia of Universities for Research in Earthquake Engineering (CUREE) and the Incorporated Research Institutions for Seismology (IRIS). This digital library organizes earthquake information online as a partner with the NSF-funded National Science, Technology, Engineering and Mathematics (STEM) Digital Library (NSDL) and the Digital Library for Earth System Education (DLESE). When complete, information and resources for over 500 Earth science and engineering topics will be included, with connections to curricular materials useful for teaching Earth Science, engineering, physics and mathematics. Although conceived primarily as an educational resource, the Encyclopedia is also a valuable portal to anyone seeking up-to-date earthquake information and authoritative technical sources. "E3" is a unique collaboration among earthquake scientists and engineers to articulate and document a common knowledge base with a shared terminology and conceptual framework. It is a platform for cross-training scientists and engineers in these complementary fields and will provide a basis for sustained communication and resource-building between major education and outreach activities. For example, the E3 collaborating organizations have leadership roles in the two largest earthquake engineering and earth science projects ever sponsored by NSF: the George E. Brown Network for Earthquake Engineering Simulation (CUREE) and the EarthScope Project (IRIS and SCEC). The E3 vocabulary and definitions are also being connected to a formal ontology under development by the SCEC/ITR project for knowledge management within the SCEC Collaboratory. The E3 development system is now fully operational, 165 entries are in the pipeline, and the development teams are capable of producing 20 new, fully reviewed encyclopedia entries each month. Over the next two years teams will

  18. Comparison of two large earthquakes: the 2008 Sichuan Earthquake and the 2011 East Japan Earthquake.

    Science.gov (United States)

    Otani, Yuki; Ando, Takayuki; Atobe, Kaori; Haiden, Akina; Kao, Sheng-Yuan; Saito, Kohei; Shimanuki, Marie; Yoshimoto, Norifumi; Fukunaga, Koichi

    2012-01-01

    Between August 15th and 19th, 2011, eight 5th-year medical students from the Keio University School of Medicine had the opportunity to visit the Peking University School of Medicine and hold a discussion session titled "What is the most effective way to educate people for survival in an acute disaster situation (before the mental health care stage)?" During the session, we discussed the following six points: basic information regarding the Sichuan Earthquake and the East Japan Earthquake, differences in preparedness for earthquakes, government actions, acceptance of medical rescue teams, earthquake-induced secondary effects, and media restrictions. Although comparison of the two earthquakes was not simple, we concluded that three major points should be emphasized to facilitate the most effective course of disaster planning and action. First, all relevant agencies should formulate emergency plans and should supply information regarding the emergency to the general public and health professionals on a normal basis. Second, each citizen should be educated and trained in how to minimize the risks from earthquake-induced secondary effects. Finally, the central government should establish a single headquarters responsible for command, control, and coordination during a natural disaster emergency and should centralize all powers in this single authority. We hope this discussion may be of some use in future natural disasters in China, Japan, and worldwide. PMID:22410538

  19. A Prospect of Earthquake Prediction Research

    CERN Document Server

    Ogata, Yosihiko

    2013-01-01

    Earthquakes occur because of abrupt slips on faults due to accumulated stress in the Earth's crust. Because most of these faults and their mechanisms are not readily apparent, deterministic earthquake prediction is difficult. For effective prediction, complex conditions and uncertain elements must be considered, which necessitates stochastic prediction. In particular, a large amount of uncertainty lies in identifying whether abnormal phenomena are precursors to large earthquakes, as well as in assigning urgency to the earthquake. Any discovery of potentially useful information for earthquake prediction is incomplete unless quantitative modeling of risk is considered. Therefore, this manuscript describes the prospect of earthquake predictability research to realize practical operational forecasting in the near future.

  20. Do earthquakes exhibit self-organized criticality?

    International Nuclear Information System (INIS)

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

  1. Earthquake, GIS and multimedia. The 1883 Casamicciola earthquake

    Directory of Open Access Journals (Sweden)

    M. Rebuffat

    1995-06-01

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

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

    Science.gov (United States)

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

    2015-02-01

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

  3. Failure time analysis with unobserved heterogeneity: Earthquake duration time of Turkey

    Science.gov (United States)

    Ata, Nihal; Kadilar, Gamze Özel

    2016-04-01

    Failure time models assume that all units are subject to same risks embodied in the hazard functions. In this paper, unobserved sources of heterogeneity that are not captured by covariates are included into the failure time models. Destructive earthquakes in Turkey since 1900 are used to illustrate the models and inter-event time between two consecutive earthquakes are defined as the failure time. The paper demonstrates how seismicity and tectonics/physics parameters that can potentially influence the spatio-temporal variability of earthquakes and presents several advantages compared to more traditional approaches.

  4. The music of earthquakes and Earthquake Quartet #1

    Science.gov (United States)

    Michael, Andrew J.

    2013-01-01

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

  5. Study of local interactions between earthquakes in Pannonian basin

    International Nuclear Information System (INIS)

    Different hypotheses on the nature of seismotectonic processes in Vrancea seismogenic region inside Pannonian basin are investigated via a statistical study of properties of earthquake sequences. Vrancea seismogenic region produces large destructive earthquakes with intermediate depth of focus which may seriously affect vulnerable constructions such as nuclear power plants, chemical plants, large dams, pipelines, etc. on a wide territory of Central Europe up to Moscow City. The nature of intermediate depth earthquakes has attracted increased attention recently of the part of seismologists in an attempt to find out the adequate source mechanism which would produce wave forms in the far field similar to the normal earthquakes despite of radical difference in their confining pressure, temperature, physical and chemical composition of minerals in rupture zone. The properties under study are the following: positive and negative influence of large initial earthquakes on the intensity flow of successive seismic events, their relation to seismic cycle concept and velocity and Q-factor structure of the region. The method of investigation is the so called local statistics technique. For a better understanding of possible mechanisms of positive and negative interaction between earthquakes in Vrancea region similar local statistics are calculated for the flow of events in mathematical model of this region. The lithosphere structure is considered in the model as absolutely rigid 3-D blocks, separated by infinitely thin layers of visco-elastic material. The external forces (tectonic and gravitational) deform the system with a finite velocity of accumulation of stress in inter-blocks media. Accumulated stress is released completely when it reaches critical value at some cell of the discrete grid covering all boundaries between blocks. Immediately afterwards the neighbour boundary areas are a subject of stress redistribution according to laws of static. 11 refs, 11 tabs

  6. Earthquake and Tsunami booklet based on two Indonesia earthquakes

    Science.gov (United States)

    Hayashi, Y.; Aci, M.

    2014-12-01

    Many destructive earthquakes occurred during the last decade in Indonesia. These experiences are very important precepts for the world people who live in earthquake and tsunami countries. We are collecting the testimonies of tsunami survivors to clarify successful evacuation process and to make clear the characteristic physical behaviors of tsunami near coast. We research 2 tsunami events, 2004 Indian Ocean tsunami and 2010 Mentawai slow earthquake tsunami. Many video and photographs were taken by people at some places in 2004 Indian ocean tsunami disaster; nevertheless these were few restricted points. We didn't know the tsunami behavior in another place. In this study, we tried to collect extensive information about tsunami behavior not only in many places but also wide time range after the strong shake. In Mentawai case, the earthquake occurred in night, so there are no impressive photos. To collect detail information about evacuation process from tsunamis, we contrived the interview method. This method contains making pictures of tsunami experience from the scene of victims' stories. In 2004 Aceh case, all survivors didn't know tsunami phenomena. Because there were no big earthquakes with tsunami for one hundred years in Sumatra region, public people had no knowledge about tsunami. This situation was highly improved in 2010 Mentawai case. TV programs and NGO or governmental public education programs about tsunami evacuation are widespread in Indonesia. Many people know about fundamental knowledge of earthquake and tsunami disasters. We made drill book based on victim's stories and painted impressive scene of 2 events. We used the drill book in disaster education event in school committee of west Java. About 80 % students and teachers evaluated that the contents of the drill book are useful for correct understanding.

  7. Discriminating between explosions and earthquakes

    Science.gov (United States)

    Cho, Kwang-Hyun

    2014-12-01

    Earthquake, explosion, and a nuclear test data are compared with forward modeling and band-pass filtered surface wave amplitude data for exploring methodologies to improve earthquake-explosion discrimination. The proposed discrimination method is based on the solutions of a double integral transformation in the wavenumber and frequency domains. Recorded explosion data on June 26, 2001 (39.212°N, 125.383°E) and October 30, 2001 (38.748°N, 125.267°E), a nuclear test on October 9, 2006 (41.275°N, 129.095°E), and two earthquakes on April 14, 2002 (39.207°N, 125.686°E) and June 7, 2002 (38.703°N, 125.638°E), all in North Korea, are used to discriminate between explosions and earthquakes by seismic wave analysis and numerical modeling. The explosion signal is characterized by first P waves with higher energy than that of S waves. Rg waves are clearly dominant at 0.05-0.5 Hz in the explosion data but not in the earthquake data. This feature is attributed to the dominant P waves in the explosion and their coupling with the SH components.

  8. Book review: Earthquakes and water

    Science.gov (United States)

    Bekins, Barbara A.

    2012-01-01

    It is really nice to see assembled in one place a discussion of the documented and hypothesized hydrologic effects of earthquakes. The book is divided into chapters focusing on particular hydrologic phenomena including liquefaction, mud volcanism, stream discharge increases, groundwater level, temperature and chemical changes, and geyser period changes. These hydrologic effects are inherently fascinating, and the large number of relevant publications in the past decade makes this summary a useful milepost. The book also covers hydrologic precursors and earthquake triggering by pore pressure. A natural need to limit the topics covered resulted in the omission of tsunamis and the vast literature on the role of fluids and pore pressure in frictional strength of faults. Regardless of whether research on earthquake-triggered hydrologic effects ultimately provides insight into the physics of earthquakes, the text provides welcome common ground for interdisciplinary collaborations between hydrologists and seismologists. Such collaborations continue to be crucial for investigating hypotheses about the role of fluids in earthquakes and slow slip. 

  9. Earthquake forecast via neutrino tomography

    Institute of Scientific and Technical Information of China (English)

    WANG Bin; CHEN Ya-Zheng; LI Xue-Qian

    2011-01-01

    We discuss the possibility of forecasting earthquakes by means of (anti)neutrino tomography. An- tineutrinos emitted from reactors are used as a probe. As the antineutrinos traverse through a region prone to earthquakes, observable variations in the matter effect on the antineutrino oscillation would provide a tomog- raphy of the vicinity of the region. In this preliminary work, we adopt a simplified model for the geometrical profile and matter density in a fault zone. We calculate the survival probability of electron antineutrinos for cases without and with an anomalous accumulation of electrons which can be considered as a clear signal of the coming earthquake, at the geological region with a fault zone, and find that the variation may reach as much as 3% for ν emitted from a reactor. The case for a ν beam from a neutrino factory is also investigated, and it is noted that, because of the typically high energy associated with such neutrinos, the oscillation length is too large and the resultant variation is not practically observable. Our conclusion is that with the present reactor facilities and detection techniques, it is still a difficult task to make an earthquake forecast using such a scheme, though it seems to be possible from a theoretical point of view while ignoring some uncertainties. However, with the development of the geology, especially the knowledge about the fault zone, and with the improvement of the detection techniques, etc., there is hope that a medium-term earthquake forecast would be feasible.

  10. Earthquake forecast via neutrino tomography

    International Nuclear Information System (INIS)

    We discuss the possibility of forecasting earthquakes by means of (anti) neutrino tomography. Antineutrinos emitted from reactors are used as a probe. As the antineutrinos traverse through a region prone to earthquakes, observable variations in the matter effect on the antineutrino oscillation would provide a tomography of the vicinity of the region. In this preliminary work, we adopt a simplified model for the geometrical profile and matter density in a fault zone. We calculate the survival probability of electron antineutrinos for cases without and with an anomalous accumulation of electrons which can be considered as a clear signal of the coming earthquake, at the geological region with a fault zone, and find that the variation may reach as much as 3% for (anti nu)e emitted from a reactor. The case for a νe beam from a neutrino factory is also investigated, and it is noted that, because of the typically high energy associated with such neutrinos, the oscillation length is too large and the resultant variation is not practically observable. Our conclusion is that with the present reactor facilities and detection techniques, it is still a difficult task to make an earthquake forecast using such a scheme, though it seems to be possible from a theoretical point of view while ignoring some uncertainties. However, with the development of the geology, especially the knowledge about the fault zone, and with the improvement of the detection techniques, etc., there is hope that a medium-term earthquake forecast would be feasible. (authors)

  11. Tectonic earthquakes of anthropogenic origin

    Science.gov (United States)

    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.

  12. Social media use and goals after the Great East Japan Earthquake

    OpenAIRE

    Jung, Joo-Young

    2012-01-01

    This paper examines the use of social media after the 2011 Great East Japan Earthquake. Based on media system dependency theory, the study focuses on the ways in which people used different types of social media to cope with a highly ambiguous situation created by the earthquake. A survey of Japanese university students revealed that the respondents used different forms of social media with different goals. Moreover, use of a particular social media type influenced the relative importance of ...

  13. Triggering of Aftershocks of the Japan 2011 Earthquake by Earth Tides

    CERN Document Server

    Datta, Arjun

    2011-01-01

    The aftershock sequence of the devastating Japan earthquake of March 2011 is analyzed for the presence of periodicities at the Earth tide periods. We use spectral analysis as well as a time-domain method KORRECT developed earlier to detect presence of diurnal and semi-diurnal periodicities in the sequence of aftershocks (M \\geq 4). This suggests that large aftershocks in the fault zone of the Japan 2011 earthquake were strongly influenced by Earth tides.

  14. Retrospection on the Conclusions of Earthquake Tendency Forecast before the Wenchuan Ms8.0 Earthquake

    Institute of Scientific and Technical Information of China (English)

    Liu Jie; Guo Tieshuan; Yang Liming; Su Youjin; Li Gang

    2009-01-01

    The reason for the failure to forecast the Wenchuan Ms8.0 earthquake is under study, based on the systematically collection of the seismicity anomalies and their analysis results from annual earthquake tendency forecasts between the 2001 Western Kuulun Mountains Pass Ms8.1 earthquake and the 2008 Wenchuan Ms8.0 earthquake. The results show that the earthquake tendency estimation of Chinese Mainland is for strong earthquakes to occur in the active stage, and that there is still potential for the occurrence of a Ms8.0 large earthquake in Chinese Mainland after the 2001 Western Kunlun Mountains Pass earthquake. However the phenomena that many large earthquakes occurred around Chinese Mainland, and the 6-year long quietude of Ms7.0 earthquake and an obvious quietude of Ms5.0 and Ms6.0 earthquakes during 2002 ~2007 led to the distinctly lower forecast estimation of earthquake tendency in Chinese Mainland after 2006. The middle part in the north-south seismic belt has been designated a seismic risk area of strong earthquake in recent years, but, the estimation of the risk degree in Southwestern China is insufficient after the Ning'er Ms6.4 earthquake in Yunnan in 2007. There are no records of earthquakes with Ms≥7.0 in the Longmenshan fault, which is one of reasons that this fault was not considered a seismic risk area of strong earthquakes in recent years.

  15. Earthquakes in Central California, 1980-1984

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — There have been many earthquake occurrences in central California. This set of slides shows earthquake damage from the following events: Livermore, 1980, Coalinga,...

  16. The influence of vegetation restoration on soil archaeal communities in Fuyun earthquake fault zone of Xinjiang%新疆富蕴地震断裂带植被恢复对土壤古菌群落的影响

    Institute of Scientific and Technical Information of China (English)

    林青; 曾军; 张涛; 马晶; 王重; 娄恺

    2013-01-01

    Strong earthquake could cause a variety of secondary geological disasters, and severely damage ecological environment. After earthquake, the vulnerable and sensitive ecosystems are going through a series of vegetation restoration and soil succession. Of this, vegetation recovery was regarded as the core of reconstruction of ecological restoration. However, the current research mainly focused on the investigation, recovery and reconstruction of the ecosystem damage from a macro perspective. Research in regard to the relationship between vegetation and soil microbial was rarely reported. Fuyun earthquake fault zone is located in Fuyun county of Altay in Xinjiang, which was caused by a serious earthquake of 8 scales on August 11, 1931 and formed a 176 km long rift. It was one of the rare earthquake fault zones in the world. The aim of this study therefore was to investigate the effect of secondary plants on soil archaeal communities in the secondary barren of Fuyun seismic fault zone in Xinjiang. In a 300×30m range (collapse region was long and narrow) , 8 different plants were selected as dominant plant species after investigation. They were Salix vistita, Salix rectijulis, Eremopyrum orientate, Seriphidium nitrosum, Geranium sibiricum, Spiraea media, Galium verum and Rosa spinosissima. The rhizosphere soils collected from the 8 different plants were studied by testing soil chemical properties ( mainly include soil organic matter, pH, total nitrogen, available nitrogen, available phosphorus and available potassium) and soil archaeal community structures were surveyed by employing Terminal restriction fragment length polymorphism (T-RFLP ). Unplanted soil in the same depth served as control. The results showed that the soil in study site was alkaline (pH = 8. 28-8. 51). The soil nutrient contents in Eremopyrum orientate's rhizosphere were generally higher compared with other plant. There were great differences in soil nutrient content among samples, but the overall

  17. Historical earthquake investigations in Greece

    Directory of Open Access Journals (Sweden)

    K. Makropoulos

    2004-06-01

    Full Text Available The active tectonics of the area of Greece and its seismic activity have always been present in the country?s history. Many researchers, tempted to work on Greek historical earthquakes, have realized that this is a task not easily fulfilled. The existing catalogues of strong historical earthquakes are useful tools to perform general SHA studies. However, a variety of supporting datasets, non-uniformly distributed in space and time, need to be further investigated. In the present paper, a review of historical earthquake studies in Greece is attempted. The seismic history of the country is divided into four main periods. In each one of them, characteristic examples, studies and approaches are presented.

  18. Fault geometry and earthquake mechanics

    Directory of Open Access Journals (Sweden)

    D. J. Andrews

    1994-06-01

    Full Text Available Earthquake mechanics may be determined by the geometry of a fault system. Slip on a fractal branching fault surface can explain: 1 regeneration of stress irregularities in an earthquake; 2 the concentration of stress drop in an earthquake into asperities; 3 starting and stopping of earthquake slip at fault junctions, and 4 self-similar scaling of earthquakes. Slip at fault junctions provides a natural realization of barrier and asperity models without appealing to variations of fault strength. Fault systems are observed to have a branching fractal structure, and slip may occur at many fault junctions in an earthquake. Consider the mechanics of slip at one fault junction. In order to avoid a stress singularity of order 1/r, an intersection of faults must be a triple junction and the Burgers vectors on the three fault segments at the junction must sum to zero. In other words, to lowest order the deformation consists of rigid block displacement, which ensures that the local stress due to the dislocations is zero. The elastic dislocation solution, however, ignores the fact that the configuration of the blocks changes at the scale of the displacement. A volume change occurs at the junction; either a void opens or intense local deformation is required to avoid material overlap. The volume change is proportional to the product of the slip increment and the total slip since the formation of the junction. Energy absorbed at the junction, equal to confining pressure times the volume change, is not large enongh to prevent slip at a new junction. The ratio of energy absorbed at a new junction to elastic energy released in an earthquake is no larger than P/µ where P is confining pressure and µ is the shear modulus. At a depth of 10 km this dimensionless ratio has th value P/µ= 0.01. As slip accumulates at a fault junction in a number of earthquakes, the fault segments are displaced such that they no longer meet at a single point. For this reason the

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

    Science.gov (United States)

    Tsiapas, Elias

    2014-05-01

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

  20. Continental dynamics and continental earthquakes

    Institute of Scientific and Technical Information of China (English)

    张东宁; 张国民; 张培震

    2003-01-01

    Two key research projects in geoscience field in China since the IUGG meeting in Birmingham in 1999, the project of "East Asian Continental Geodynamics" and the project of "Mechanism and Prediction of Strong Continental Earthquakes" are introduced in this paper. Some details of two projects, such as their sub-projects, some initial research results published are also given here. Because of the large magnitude of the November 14, 2001 Kunlun Mountain Pass MS=8.1 earthquake, in the third part of this paper, some initial research results are reviewed for the after-shock monitoring and the multi-discipline field survey, the impact and disaster of this earthquake on the construction site of Qinghai-Xizang (Tibet) railway and some other infrastructure.

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

    Science.gov (United States)

    Tsiapas, Elias

    2015-04-01

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

  2. Evaluating the Economic Response to Japan's Earthquake

    OpenAIRE

    Molly K. SCHNELL; David E. Weinstein

    2012-01-01

    This paper compares the 1995 Kobe earthquake with the more recent one in Tohoku. The impact of the recent earthquake on industrial production was much larger and long-lasting than that of the 1995 earthquake. We find that very little of this can be explained by differences in government expenditures or private consumption. However, we find very substantial differences in energy production in the wake of the two earthquakes. The substantial and persistent drop in energy output is likely to hav...

  3. PRECURSORS OF EARTHQUAKES: VLF SIGNALSIONOSPHERE IONOSPHERE RELATION

    Directory of Open Access Journals (Sweden)

    Mustafa ULAS

    2013-01-01

    Full Text Available lot of people have died because of earthquakes every year. Therefore It is crucial to predict the time of the earthquakes reasonable time before it had happed. This paper presents recent information published in the literature about precursors of earthquakes. The relationships between earthquakes and ionosphere are targeted to guide new researches in order to study further to find novel prediction methods.

  4. Earthquake geology: science, society and critical facilities

    Directory of Open Access Journals (Sweden)

    Christoph Grützner

    2014-02-01

    Full Text Available Earthquake geology studies the effects, the mechanics and the impacts of earthquakes in the geological environment. Its role is also to decode the fault history, therefore its approach is fault specific and its outcomes are of decisive value for seismic hazard assessment and planning. The term Earthquake geology includes aspects of modern instrumental studies, tectonics and structural geology, historical surface deformation and tectonic geomorphology, whereas paleoseismology is considered part of earthquake geology [...].

  5. 13 CFR 120.174 - Earthquake hazards.

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Earthquake hazards. 120.174... Applying to All Business Loans Requirements Imposed Under Other Laws and Orders § 120.174 Earthquake..., the construction must conform with the “National Earthquake Hazards Reduction Program...

  6. Easily magnetic anomalies earthquake prediction

    Directory of Open Access Journals (Sweden)

    Jiang Min

    2016-01-01

    Full Text Available Low power consumption long time offset magnetic field detector (earthquake prediction .The design of the hardware circuit of the magnetic field detector seismic geomagnetic acquisition and pre processing module mainly includes. Electronic compass, compass. monitoring device while the magnetic azimuth for monitoring and analyzing the object, GSM, but it can also be applied to other seismic precursor information analysis, such as earthquake precursory infrasound abnormality, only need infrasound abnormality intelligent sensor replace geomagnetic anomaly intelligent sensor, and modify the relevant parameters can be.

  7. Earthquake Education in Prime Time

    Science.gov (United States)

    de Groot, R.; Abbott, P.; Benthien, M.

    2004-12-01

    Since 2001, the Southern California Earthquake Center (SCEC) has collaborated on several video production projects that feature important topics related to earthquake science, engineering, and preparedness. These projects have also fostered many fruitful and sustained partnerships with a variety of organizations that have a stake in hazard education and preparedness. The Seismic Sleuths educational video first appeared in the spring season 2001 on Discovery Channel's Assignment Discovery. Seismic Sleuths is based on a highly successful curriculum package developed jointly by the American Geophysical Union and The Department of Homeland Security Federal Emergency Management Agency. The California Earthquake Authority (CEA) and the Institute for Business and Home Safety supported the video project. Summer Productions, a company with a reputation for quality science programming, produced the Seismic Sleuths program in close partnership with scientists, engineers, and preparedness experts. The program has aired on the National Geographic Channel as recently as Fall 2004. Currently, SCEC is collaborating with Pat Abbott, a geology professor at San Diego State University (SDSU) on the video project Written In Stone: Earthquake Country - Los Angeles. Partners on this project include the California Seismic Safety Commission, SDSU, SCEC, CEA, and the Insurance Information Network of California. This video incorporates live-action demonstrations, vivid animations, and a compelling host (Abbott) to tell the story about earthquakes in the Los Angeles region. The Written in Stone team has also developed a comprehensive educator package that includes the video, maps, lesson plans, and other supporting materials. We will present the process that facilitates the creation of visually effective, factually accurate, and entertaining video programs. We acknowledge the need to have a broad understanding of the literature related to communication, media studies, science education, and

  8. Deep Continental Crustal Earthquakes and Lithospheric Structure: A Global Synthesis

    Science.gov (United States)

    Devlin, S.; Isacks, B. L.

    2007-12-01

    The distribution of earthquake depths within the continental crust defines the seismogenic thickness (TS), over which at least some part of crustal deformation is accommodated by rapid release of stored elastic strains. Intraplate continental seismicity is often thought to be restricted to the upper crust where TS is within the range of 15 to 20 km. This appears consistent with a lithospheric strength profile involving a weak, ductile lower crust located beneath a stronger, brittle upper crust. With the assumption of a strong uppermost mantle lid, this is often referred to the Jelly Sandwich model of lithosphere rheology. Studies in many places, however, document lower crustal earthquakes beneath continents in apparent disagreement with the model. We explore this and related issues through a survey of where and in what tectonic settings deep intraplate earthquakes are well documented in the continental crust. TS reaches Moho depth in many intraplate regions \\--- Sierra Nevada, Colorado Plateau, East African and Baikal Rift Systems, North Island New Zealand, Tien Shan, and the Andean and Alpine forelands. A review of possible deformation mechanisms which could control continental earthquake depth and facilitate seismicity beneath the brittle-ductile transition suggests that the influence of fluids is the only mechanism capable of encouraging earthquake occurrence throughout the continental crust at any tectonic setting. Surface derived fluids can induce pore fluid pressure changes to depths of 25 km and melt-reactions can induce earthquakes at depths throughout continental crust. On a global scale, fluid-enhanced embrittlement is not limited by depth or tectonic environment. We find that deep crustal earthquakes occur where the lithosphere is in a transitional state between primarily stable (e.g., shields) and highly deformed (e.g., U.S. Basin and Range or Southern California). Observations of relative intensity of tectonic deformation and regional percent strain

  9. Earthquake Risk and Earthquake Catastrophe Insurance for the People's Republic of China

    OpenAIRE

    Wang, Zifa; Lin, Tun; Walker, George

    2009-01-01

    The year 2008 witnessed the renewed interests in earthquake risk management and insurance in the People's Republic of China (PRC), after the Wenchuan earthquake hit the country in May. Located along the southeastern edge of the Euro-Asian Plate, the PRC has a relatively high seismicity, which is manifested by the frequent occurrence of large and disastrous earthquakes. Buildings and infrastructure in the earthquake-prone regions of the PRC have relatively low earthquake resistance levels. Hen...

  10. Earthquake insurance and post-disaster housing in the case of canterbury earthquakes in new zealand

    OpenAIRE

    Otani, Junko

    2016-01-01

    The Canterbury earthquake, which struck New Zealand on February 22nd, 2011 took 186 lives. Of this number, 28 were Japanese overseas students. Looking simply at the number of casualties, this may appear to have been a minor earthquake which seems incomparable with respect to other major earthquakes. However, this was one of the most violent and costly earthquakes recorded in recent years. This was also major one in a regional context. The situation was grave: this earthquake caused the collap...

  11. 4 Earthquake: Major offshore earthquakes recall the Aztec myth

    Science.gov (United States)

    United States Department of Commerce

    1970-01-01

    Long before the sun clears the eastern mountains of April 29, 1970, the savanna highlands of Chiapas tremble from a magnitude 6.7 earthquake centered off the Pacific coast near Mexico’s southern border. Then, for a few hours, he Isthmus of Tehuantepec is quiet.

  12. Dancing Earthquake Science Assists Recovery from the Christchurch Earthquakes

    Science.gov (United States)

    Egan, Candice J.; Quigley, Mark C.

    2015-01-01

    The 2010-2012 Christchurch (Canterbury) earthquakes in New Zealand caused loss of life and psychological distress in residents throughout the region. In 2011, student dancers of the Hagley Dance Company and dance professionals choreographed the performance "Move: A Seismic Journey" for the Christchurch Body Festival that explored…

  13. Building damage due to structural pounding during earthquakes

    Science.gov (United States)

    Sołtysik, B.; Jankowski, R.

    2015-07-01

    Earthquake-induced pounding between adjacent buildings has been identified as one of the reasons for substantial damage or even total collapse of colliding structures. A major reason leading to interactions in buildings results from the differences in their dynamic parameters and also from insufficient distance between the structures. Although the research on structural pounding has been much advanced, the studies have mainly been conducted for concrete structures. The aim of this paper is to show the results of the non-linear numerical analysis focuses on damage due to pounding between two steel buildings under earthquake excitation. The numerical analysis has been performed using models of steel asymmetric structures with different number of storeys which makes them vibrate out-of-phase. Pounding between buildings has been controlled using three-dimensional gap-friction elements which become active when contact is detected. In order to identify the dynamic characteristics of analyzed structures, the modal analysis has been first conducted. Then, the detailed non-linear dynamic analysis of colliding structures has been performed. The acceleration time histories of the El Centro earthquake have been used in the numerical analysis. The results of the study clearly indicate that pounding may substantially influence the response of steel buildings intensifying their damage during earthquakes.

  14. Disaster mental health service at Fukushima after 2011 Tohoku earthquake

    International Nuclear Information System (INIS)

    The 2011 Tohoku earthquake was the most powerful earthquake ever to have hit Japan, which triggered the devastating tsunami sweeping through the cities, and caused the nuclear crisis in Fukushima. Due to the disaster, numerous people in Fukushima had to be in emergency evacuation, which also must have influenced people's mental states. After the earthquake, department of psychiatry, Yokohama City University School of Medicine, organized the disaster mental health service teams, and participated in psychological aid at Fukushima prefecture during March, May and June 2011. Our teams visited the shelters, schools and healthcare center, to evaluate psychological condition of the evacuees, and provide counseling to the people who had psychological problems. Many people at the disaster site who have prolonged psychological symptoms, also had some problems related to the social situations. Therefore, managing social support of evacuees is equally an important role of the disaster mental health service team as caring acute symptoms of stress and helping damaged psychiatric service network. In addition, the earthquake made the people aware of importance of sharing information in the time of disaster, especially via internet. We should take this opportunity to think more about information exchange for medical support, such as collaboration of medical teams and provision of expert knowledge to sufferers. (author)

  15. Diurnal changes of earthquake activity and geomagnetic Sq-variations

    Science.gov (United States)

    Duma, G.; Ruzhin, Y.

    Statistic analyses demonstrate that the probability of earthquake occurrence in many earthquake regions strongly depends on the time of day, that is on Local Time (e.g. Conrad, 1909, 1932; Shimshoni, 1971; Duma, 1997; Duma and Vilardo, 1998). This also applies to strong earthquake activity. Moreover, recent observations reveal an involvement of the regular diurnal variations of the Earth's magnetic field, commonly known as Sq-variations, in this geodynamic process of changing earthquake activity with the time of day (Duma, 1996, 1999). In the article it is attempted to quantify the forces which result from the interaction between the induced Sq-variation currents in the Earth's lithosphere and the regional Earth's magnetic field, in order to assess the influence on the tectonic stress field and on seismic activity. A reliable model is obtained, which indicates a high energy involved in this process. The effect of Sq-induction is compared with the results of the large scale electromagnetic experiment "Khibiny" (Velikhov, 1989), where a giant artificial current loop was activated in the Barents Sea.

  16. Diurnal changes of earthquake activity and geomagnetic Sq-variations

    Directory of Open Access Journals (Sweden)

    G. Duma

    2003-01-01

    Full Text Available Statistic analyses demonstrate that the probability of earthquake occurrence in many earthquake regions strongly depends on the time of day, that is on Local Time (e.g. Conrad, 1909, 1932; Shimshoni, 1971; Duma, 1997; Duma and Vilardo, 1998. This also applies to strong earthquake activity. Moreover, recent observations reveal an involvement of the regular diurnal variations of the Earth’s magnetic field, commonly known as Sq-variations, in this geodynamic process of changing earthquake activity with the time of day (Duma, 1996, 1999. In the article it is attempted to quantify the forces which result from the interaction between the induced Sq-variation currents in the Earth’s lithosphere and the regional Earth’s magnetic field, in order to assess the influence on the tectonic stress field and on seismic activity. A reliable model is obtained, which indicates a high energy involved in this process. The effect of Sq-induction is compared with the results of the large scale electromagnetic experiment "Khibiny" (Velikhov, 1989, where a giant artificial current loop was activated in the Barents Sea.

  17. Influence of near-fault long-period pulse-type earthquake ground motions on vertical response spectra%近断层长周期脉冲型地震动对竖向反应谱的影响研究

    Institute of Scientific and Technical Information of China (English)

    江辉; 李新乐; 窦慧娟

    2012-01-01

    The long-period large-amplitude pulse is a remarkable characteristic of near-fault earthquake ground motions, which is also an important factor leading the structure to damage or collapse. The database and regression relation for near-fault long-period pulse-type earthquake records were established based on the available data. The influence of pulse period and structural natural vibration period on the acceleration response spectra ratio of vertical to horizontal components was discussed in-depth. The response spectra ratios obtained from near-fault long-period pulse-type records are greater than those given by existing seismic design codes. The simplified relationship of response spectra ratio obtained by using piecewise linearization method varies as a function of pulse period and structural natural vibration period. The statistical results and attenuation relationship of characteristic ratio for vertical response spectra curves were given, which controls the inflection point periods of vertical response spectra and is related to earthquake magnitude and fault distance.%长周期大幅值脉冲运动是近断层地震动的重要特征,也是引起结构震害的重要因素.在既有的地震动数据库基础上,筛选建立了长周期脉冲型记录的统计样本库,并构建了地震动特征参数的回归关系式.针对竖向反应谱,深入分析了竖向分量与水平向分量的加速度反应谱比值随脉冲周期和结构自振周期的变化规律,结果表明反应谱比值显著大于现行规范取值,进而采用分段线性化方法,建立了竖向反应谱比值随脉冲周期、自振周期变化的简化关系式,并对影响竖向反应谱曲线各拐点周期的特征比值进行统计分析,拟合得到了其随震级和断层距的衰减模型.

  18. Historical earthquake investigation and research in China

    Directory of Open Access Journals (Sweden)

    J. Wang

    2004-06-01

    Full Text Available China is one of the countries with the longest tradition of culture and has suffered many earthquake disasters, so many earthquake documents have therefore been conserved. In this paper we try to outline some basic information of historical earthquake investigation and research in China, such as collection of historical earthquake data from archives, historical earthquake catalogues, seismic intensity scales. We introduce briefly the huge accomplishments of historical research and discuss some problems encountered. Through examples, we illustrate the solutions to some typical problems. There are some suggestions on further work.

  19. Intraslab earthquakes: dehydration of the Cascadia slab.

    Science.gov (United States)

    Preston, Leiph A; Creager, Kenneth C; Crosson, Robert S; Brocher, Thomas M; Trehu, Anne M

    2003-11-14

    We simultaneously invert travel times of refracted and wide-angle reflected waves for three-dimensional compressional-wave velocity structure, earthquake locations, and reflector geometry in northwest Washington state. The reflector, interpreted to be the crust-mantle boundary (Moho) of the subducting Juan de Fuca plate, separates intraslab earthquakes into two groups, permitting a new understanding of the origins of intraslab earthquakes in Cascadia. Earthquakes up-dip of the Moho's 45-kilometer depth contour occur below the reflector, in the subducted oceanic mantle, consistent with serpentinite dehydration; earthquakes located down-dip occur primarily within the subducted crust, consistent with the basalt-to-eclogite transformation. PMID:14615535

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

    Directory of Open Access Journals (Sweden)

    G. Babayev

    2010-12-01

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

  1. Anomalous frequency characteristics of groundwater levels before major earthquakes in Taiwan

    Directory of Open Access Journals (Sweden)

    C.-H. Chen

    2012-06-01

    Full Text Available Unusual decreases in water levels were consistently observed in 78% (=42/54 of the wells in the Choshuichi Alluvial Fan of central Taiwan roughly 150 days before the Chi-Chi earthquake (M = 7.6 on 20 September 1999 when the influences of barometric pressure, earth tides, precipitation and artificial pumping were removed. Variations in groundwater levels measured in the anomalous wells between 1 August 1997 and 19 September 1999, the time period covering the unusual decreases, were transferred into the frequency domain to examine anomalous frequency bands associated with the Chi-Chi earthquake. Analytical results show that amplitudes at the frequency band between 0.02 day−1 and 0.04 day−1 were generally maintained at the low stage and were enhanced in the few weeks before the Chi-Chi earthquake. Variations in amplitude within this particular frequency band were further examined in association with earthquakes (M > 6 between 1 August 1997 and 31 December 2009. Enhanced amplitude phenomena are consistently observed prior to the other two earthquakes (the Rei-Li and Ming-Jian earthquakes during the 12.5 yr, which sheds a promising light on research into precursors of strong earthquakes when combined with other geophysical observations such as geomagnetic anomalies and crustal displacements.

  2. Earthquake triggering and delaying caused by fault interaction on Xianshuihe fault belt, southwestern China

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The coseismic Coulomb stress change caused by fault interaction and its influences on the triggering and delaying of earthquake are briefly discussed. The Xianshuihe fault belt consists of Luhuo, Daofu, Kangding, Qianning and Ganzi fault. Luohuo (MS=7.6, 1973)-Kangding (MS=6.2, 1975)-Daofu (MS=6.9, 1981)-Ganzi (MS=6.0,1982) earthquake is a seismic sequence continuous on the time axis with magnitude greater than 6.0. They occurred on the Luhuo, Kangding, Daofu and Ganzi fault, respectively. The coseismic Coulomb stress changes caused by each earthquake on its surrounding major faults and microcracks are calculated, and their effectson the triggering and delaying of the next earthquake and aftershocks are analyzed. It is shown that each earthquake of the sequence occurred on the fault segment with coseismic Coulomb stress increases caused by its predecessors, and mostaftershocks are distributed along the microcracks with relatively larger coseismic Coulomb stress increases resulted from the main shock. With the fault interaction considered, the seismic potential of each segment along Xianshuihe fault belt is reassessed, and contrasted with those predicted results ignoring coseismic Coulomb stress change, the significance of fault interaction and its effect ontriggering and delaying of earthquake are emphasized. It is concluded that fault interaction plays a very important role on seismic potential of Xianshuihe fault belt, and the maximal change of future earthquake probability on fault segment is up to 30.5%.

  3. Seismic wave triggering of nonvolcanic tremor, episodic tremor and slip, and earthquakes on Vancouver Island

    Science.gov (United States)

    Rubinstein, Justin L.; Gomberg, Joan; Vidale, John E.; Wech, Aaron G.; Kao, Honn; Creager, Kenneth C.; Rogers, Garry

    2009-02-01

    We explore the physical conditions that enable triggering of nonvolcanic tremor and earthquakes by considering local seismic activity on Vancouver Island, British Columbia during and immediately after the arrival of large-amplitude seismic waves from 30 teleseismic and 17 regional or local earthquakes. We identify tremor triggered by four of the teleseismic earthquakes. The close temporal and spatial proximity of triggered tremor to ambient tremor and aseismic slip indicates that when a fault is close to or undergoing failure, it is particularly susceptible to triggering of further events. The amplitude of the triggering waves also influences the likelihood of triggering both tremor and earthquakes such that large amplitude waves triggered tremor in the absence of detectable aseismic slip or ambient tremor. Tremor and energy radiated from regional/local earthquakes share the same frequency passband so that tremor cannot be identified during these smaller, more frequent events. We confidently identify triggered local earthquakes following only one teleseism, that with the largest amplitude, and four regional or local events that generated vigorous aftershock sequences in their immediate vicinity. Earthquakes tend to be triggered in regions different from tremor and with high ambient seismicity rates. We also note an interesting possible correlation between large teleseismic events and episodic tremor and slip (ETS) episodes, whereby ETS events that are "late" and have built up more stress than normal are susceptible to triggering by the slight nudge of the shaking from a large, distant event, while ETS events that are "early" or "on time" are not.

  4. Summary of earthquake experience database

    International Nuclear Information System (INIS)

    Strong-motion earthquakes frequently occur throughout the Pacific Basin, where power plants or industrial facilities are included in the affected areas. By studying the performance of these earthquake-affected (or database) facilities, a large inventory of various types of equipment installations can be compiled that have experienced substantial seismic motion. The primary purposes of the seismic experience database are summarized as follows: to determine the most common sources of seismic damage, or adverse effects, on equipment installations typical of industrial facilities; to determine the thresholds of seismic motion corresponding to various types of seismic damage; to determine the general performance of equipment during earthquakes, regardless of the levels of seismic motion; to determine minimum standards in equipment construction and installation, based on past experience, to assure the ability to withstand anticipated seismic loads. To summarize, the primary assumption in compiling an experience database is that the actual seismic hazard to industrial installations is best demonstrated by the performance of similar installations in past earthquakes

  5. Pre-earthquake magnetic pulses

    Science.gov (United States)

    Scoville, J.; Heraud, J.; Freund, F.

    2015-08-01

    A semiconductor model of rocks is shown to describe unipolar magnetic pulses, a phenomenon that has been observed prior to earthquakes. These pulses are suspected to be generated deep in the Earth's crust, in and around the hypocentral volume, days or even weeks before earthquakes. Their extremely long wavelength allows them to pass through kilometers of rock. Interestingly, when the sources of these pulses are triangulated, the locations coincide with the epicenters of future earthquakes. We couple a drift-diffusion semiconductor model to a magnetic field in order to describe the electromagnetic effects associated with electrical currents flowing within rocks. The resulting system of equations is solved numerically and it is seen that a volume of rock may act as a diode that produces transient currents when it switches bias. These unidirectional currents are expected to produce transient unipolar magnetic pulses similar in form, amplitude, and duration to those observed before earthquakes, and this suggests that the pulses could be the result of geophysical semiconductor processes.

  6. Using Smartphones to Detect Earthquakes

    Science.gov (United States)

    Kong, Q.; Allen, R. M.

    2012-12-01

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

  7. Earthquake observation at underground cavern

    International Nuclear Information System (INIS)

    The earthquake observation has been examined at a cylindrical type cavern hydroelectric power station of 15 m in diameter, 22 m in depth in rock mass in purpose of evaluating the earthquake resistance of semi-underground nuclear power plants. The behavior of the cylindrical cavern has been analysed by fourty-three observed seismic waves. And following results were obtained. (1) Ratios of cavern buttom maximum accelerations to cavern top maximum accelerations are concentrated in the range from 1/2 to 1. This shows that the accelerations are declined at underground. (2) The decline ratios of on-ground spectrum amplitude to the underground at the earthquakes of less than 100 km epicentral distance with shorter predominant periods are generally larger than these at the earthquakes of more than 100 km epicentral distance with longer predominant periods. (3) The peak periods of normalized response spectrum at underground tend to be longer as the epicentral distances are longer. This phenominons of underground are similar to the on-ground. (author)

  8. Loss estimation of Membramo earthquake

    Science.gov (United States)

    Damanik, R.; Sedayo, H.

    2016-05-01

    Papua Tectonics are dominated by the oblique collision of the Pacific plate along the north side of the island. A very high relative plate motions (i.e. 120 mm/year) between the Pacific and Papua-Australian Plates, gives this region a very high earthquake production rate, about twice as much as that of Sumatra, the western margin of Indonesia. Most of the seismicity occurring beneath the island of New Guinea is clustered near the Huon Peninsula, the Mamberamo region, and the Bird's Neck. At 04:41 local time(GMT+9), July 28th 2015, a large earthquake of Mw = 7.0 occurred at West Mamberamo Fault System. The earthquake focal mechanism are dominated by northwest-trending thrust mechanisms. GMPE and ATC vulnerability curve were used to estimate distribution of damage. Mean of estimated losses was caused by this earthquake is IDR78.6 billion. We estimated insurance loss will be only small portion in total general due to deductible.

  9. Earthquake sources near Uturuncu Volcano

    Science.gov (United States)

    Keyson, L.; West, M. E.

    2013-12-01

    Uturuncu, located in southern Bolivia near the Chile and Argentina border, is a dacitic volcano that was last active 270 ka. It is a part of the Altiplano-Puna Volcanic Complex, which spans 50,000 km2 and is comprised of a series of ignimbrite flare-ups since ~23 ma. Two sets of evidence suggest that the region is underlain by a significant magma body. First, seismic velocities show a low velocity layer consistent with a magmatic sill below depths of 15-20 km. This inference is corroborated by high electrical conductivity between 10km and 30km. This magma body, the so called Altiplano-Puna Magma Body (APMB) is the likely source of volcanic activity in the region. InSAR studies show that during the 1990s, the volcano experienced an average uplift of about 1 to 2 cm per year. The deformation is consistent with an expanding source at depth. Though the Uturuncu region exhibits high rates of crustal seismicity, any connection between the inflation and the seismicity is unclear. We investigate the root causes of these earthquakes using a temporary network of 33 seismic stations - part of the PLUTONS project. Our primary approach is based on hypocenter locations and magnitudes paired with correlation-based relative relocation techniques. We find a strong tendency toward earthquake swarms that cluster in space and time. These swarms often last a few days and consist of numerous earthquakes with similar source mechanisms. Most seismicity occurs in the top 10 kilometers of the crust and is characterized by well-defined phase arrivals and significant high frequency content. The frequency-magnitude relationship of this seismicity demonstrates b-values consistent with tectonic sources. There is a strong clustering of earthquakes around the Uturuncu edifice. Earthquakes elsewhere in the region align in bands striking northwest-southeast consistent with regional stresses.

  10. On the agreement between small-world-like OFC model and real earthquakes

    CERN Document Server

    Ferreira, Douglas S R; Menezes, Ronaldo

    2014-01-01

    In this article we implemented simulations of the OFC model for earthquakes for two different topologies: regular and small-world, where in the latter the links are randomly rewired with probability $p$ . In both topologies, we have studied the distribution of time intervals between consecutive earthquakes and the border effects present in each one. In addition, we also have characterized the influence that the probability $p$ produces in certain characteristics of the lattice and in the intensity of border effects. From the two topologies, networks of consecutive epicenters were constructed, that allowed us to analyze the distribution of connectivities of each one. In our results distributions arise belonging to a family of non-traditional distributions functions, which agrees with previous studies using data from actual earthquakes. Our results reinforce the idea that the Earth is in a critical self-organized state and furthermore point towards temporal and spatial correlations between earthquakes in differ...

  11. Post-earthquake comprehensive inspection and assessment of performances of nuclear facility

    International Nuclear Information System (INIS)

    In order to assess the influences of 5.12 Wenchuan earthquake on the nuclear facilities affiliated with Nuclear Power Institute of China, comprehensive inspection and assessment of those nuclear facilities were performed by different approaches such as inspection (RT, UT, PT and underwater video inspection), testing, analysis and confirmative review. It is the first time that this aspect of work was developed in China. The main inspection results and conclusions show that no damages to the research reactors and critical installations are found in the inspection range, and the three safety functions including safe shutdown, cooling and constrain of radiation release are ensured. It is recommended to continue site earthquake research work, determine site earthquake design base, revise emergency plan and develop special earthquake emergency plan, and so on. (authors)

  12. Discriminating Mining Induced Seismicity from Natural Tectonic Earthquakes in the Wasatch Plateau Region of Central Utah

    Science.gov (United States)

    Stein, J. R.; Pankow, K. L.; Koper, K. D.; McCarter, M. K.

    2014-12-01

    On average, several hundred earthquakes are located each year within the Wasatch Plateau region of central Utah. This region includes the boundary between the relatively stable Colorado Plateau and the actively extending Basin and Range physiographic provinces. Earthquakes in this region tend to fall in the intermountain seismic belt (ISB), a continuous band of seismicity that extends from Montana to Arizona. While most of the earthquakes in the ISB are of tectonic origin, events in the Wasatch Plateau also include mining induced seismicity (MIS) from local underground coal mining operations. Using a catalog of 16,182 seismic events (-0.25 finely group seismic events occurring in the Wasatch Plateau. The results of this study provide both an increased understanding of the influence mining induced seismicity has on the number of earthquakes detected within this region, as well as better constraints on the deeper tectonic structure.

  13. Effect of heterogeneities on evaluating earthquake triggering of volcanic eruptions

    Directory of Open Access Journals (Sweden)

    J. Takekawa

    2013-02-01

    Full Text Available Recent researches have indicated coupling between volcanic eruptions and earthquakes. Some of them calculated static stress transfer in subsurface induced by the occurrences of earthquakes. Most of their analyses ignored the spatial heterogeneity in subsurface, or only took into account the rigidity layering in the crust. On the other hand, a smaller scale heterogeneity of around hundreds of meters has been suggested by geophysical investigations. It is difficult to reflect that kind of heterogeneity in analysis models because accurate distributions of fluctuation are not well understood in many cases. Thus, the effect of the ignorance of the smaller scale heterogeneity on evaluating the earthquake triggering of volcanic eruptions is also not well understood. In the present study, we investigate the influence of the assumption of homogeneity on evaluating earthquake triggering of volcanic eruptions using finite element simulations. The crust is treated as a stochastic media with different heterogeneous parameters (correlation length and magnitude of velocity perturbation in our simulations. We adopt exponential and von Karman functions as spatial auto-correlation functions (ACF. In all our simulation results, the ignorance of the smaller scale heterogeneity leads to underestimation of the failure pressure around a chamber wall, which relates to dyke initiation. The magnitude of the velocity perturbation has a larger effect on the tensile failure at the chamber wall than the difference of the ACF and the correlation length. The maximum effect on the failure pressure in all our simulations is about twice larger than that in the homogeneous case. This indicates that the estimation of the earthquake triggering due to static stress transfer should take account of the heterogeneity of around hundreds of meters.

  14. Earthquake safety assessment of concrete arch and gravity dams

    Institute of Scientific and Technical Information of China (English)

    Lin Gao; Hu Zhiqiang

    2005-01-01

    Based on research studies currently being carried out at Dalian University of Technology, some important aspects for the earthquake safety assessment of concrete dams are reviewed and discussed. First, the rate-dependent behavior of concrete subjected to earthquake loading is examined, emphasizing the properties of concrete under cyclic and biaxial loading conditions. Second, a modified four-parameter Hsieh-Ting-Chen viscoplastic consistency model is developed to simulate the rate-dependent behavior of concrete. The earthquake response of a 278m high arch dam is analyzed, and the results show that the strain-rate effects become noticeable in the inelastic range. Third, a more accurate non-smooth Newton algorithm for the solution of three-dimensional frictional contact problems is developed to study the joint opening effects of arch dams during strong earthquakes. Such effects on two nearly 300m high arch dams have been studied. It was found that the canyon shape has great influence on the magnitude and distribution of the joint opening along the dam axis. Fourth, the scaled boundary finite element method presented by Song and Wolf is employed to study the dam-reservoir-foundation interaction effects of concrete dams. Particular emphases were placed on the variation of foundation stiffness and the anisotropic behavior of the foundation material on the dynamic response of concrete dams. Finally, nonlinear modeling of concrete to study the damage evolution of concrete dams during strong earthquakes is discussed. An elastic-damage mechanics approach for damage prediction of concrete gravity dams is described as an example. These findings are helpful in understanding the dynamic behavior of concrete dams and promoting the improvement of seismic safety assessment methods.

  15. The USGS Earthquake Scenario Project

    Science.gov (United States)

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

    2009-12-01

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

  16. The Influence of the Great Kanto Earthquake on Public Finance of the City of Tokyo%关东大地震对东京市财政的影响

    Institute of Scientific and Technical Information of China (English)

    郭小鹏

    2015-01-01

    The Great Kanto Earthquake in 1923 was a holocaust for Japan where economy of Tokyo especially the finance of Tokyo suffered a critical hit. The disaster hit numerous social resource and the revenue greatly reduced. The disaster relief and reconstruction relied much on the financial funds and the fiscal expenditure increased. The financial capacity of Tokyo was therefore limited. Taking debt to recover from the disaster was the only way to cope with the Capital Reconstruction Project, and debt was one of the factors to hinder the economic development of Tokyo for the future.%1923年发生的关东大地震给日本带来惨重损失。作为主要受灾地,东京市1⃝的经济遭到沉重打击,在财政方面体现得尤为明显。地震造成东京市社会财富严重受损,财政收入缩减。而灾后的应急救援和城市重建却需要依靠大量财政资金,财政支出增多。对此,东京市财政力所不逮,只能依靠政府债务完成东京城市复兴事业,但累积债务也成为此后阻碍东京市经济发展的关键因素。

  17. Hydrological anomalies connected to earthquakes in southern Apennines (Italy

    Directory of Open Access Journals (Sweden)

    E. Esposito

    2001-01-01

    Full Text Available The study of hydrological variations in the watersheds of seismic areas can be useful in order to acquire a new knowledge of the mechanisms by which earthquakes can produce hydrological anomalies. Italy has the availability of many long historical series both of hydrological parameters and of seismological data, and is an ideal laboratory to verify the validity of theoretical models proposed by various authors. In this work we analyse the hydrological anomalies associated with some of the big earthquakes that occurred in the last century in the southern Apennines: 1930, 1980 and 1984. For these earthquakes we analysed hydrometric and pluviometric data looking for significant anomalies in springs, water wells and mountain streams. The influence of rainfalls on the normal flows of rivers, springs and wells has been ascertained. Also, the earthquake of 1805, for which a lot of hydrological perturbations have been reported, is considered in order to point out effects imputable to this earthquake that can be similar to the effects of the other big earthquakes. The considered seismic events exhibit different modes of energy release, different focal mechanisms and different propagation of effects on the invested areas. Furthermore, even if their epicentres were not localised in contiguous seismogenetic areas, it seems that the hydrological effects imputable to them took place in the same areas. Such phenomena have been compared with macroseismic fields and transformed in parameters, in order to derive empirical relationships between the dimensions of the event and the characteristics of the hydrological variations. The results of this work point to a close dependence among hydrological anomalies, regional structures and fault mechanisms, and indicate that many clear anomalies have been forerunners of earthquakes. In 1993, the Naples Bureau of the Hydrographic National Service started the continuous monitoring of hydrologic parameters by a network of

  18. Strong motions and engineering structure performances in recent major earthquakes

    Institute of Scientific and Technical Information of China (English)

    Xiaojun Li

    2010-01-01

    @@ In recent years, a series of major earthquakes occurred, which resulted in considerable engineering damage and collapse, triggered heavy geological hazards, and caused extremely high casualties and huge property and economic loss. The earthquakes include the 1994 Northridge earthquake (M6.8), the 1995 Kobe earthquake (M6.8), the 1999 Izmit earthquake (M7.6), the 1999 Jiji (Chi-Chi) earthquake (M7.6), the 2005 northern Pakistan earthquake (M7.6), the 2008 Wenchuan earthquake (M8.0) and the 2010 Haiti earthquake (M7.0). Some villages, towns and even cities were devastated in the earthquakes, especially in the 2005 northern Pakistan earthquake, the 2008 Wenchuan earthquake and the 2010 Haiti earthquake.

  19. Extending the quantitative assessment of industrial risks to earthquake effects.

    Science.gov (United States)

    Campedel, Michela; Cozzani, Valerio; Garcia-Agreda, Anita; Salzano, Ernesto

    2008-10-01

    In the general framework of quantitative methods for natural-technological (NaTech) risk analysis, a specific methodology was developed for assessing risks caused by hazardous substances released due to earthquakes. The contribution of accidental scenarios initiated by seismic events to the overall industrial risk was assessed in three case studies derived from the actual plant layout of existing oil refineries. Several specific vulnerability models for different equipment classes were compared and assessed. The effect of differing structural resistances for process equipment on the final risk results was also investigated. The main factors influencing the final risk values resulted from the models for equipment vulnerability and the assumptions for the reference damage states of the process equipment. The analysis of case studies showed that in seismic zones the additional risk deriving from damage caused by earthquakes may be up to more than one order of magnitude higher than that associated to internal failure causes. Critical equipment was determined to be mainly pressurized tanks, even though atmospheric tanks were more vulnerable to containment loss. Failure of minor process equipment having a limited hold-up of hazardous substances (such as pumps) was shown to have limited influence on the final values of the risk increase caused by earthquakes. PMID:18657068

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

    Institute of Scientific and Technical Information of China (English)

    Ming Yuehong; Su Wei; Fang Lihua

    2006-01-01

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

  1. Small size very low frequency earthquakes in the Nankai accretionary prism, following the 2011 Tohoku-Oki earthquake

    Science.gov (United States)

    To, Akiko; Obana, Koichiro; Sugioka, Hiroko; Araki, Eiichiro; Takahashi, Narumi; Fukao, Yoshio

    2015-08-01

    A large number of shallow low frequency events were recorded after the 2011 Mw 9.0 Tohoku-oki earthquake by the cabled network of broadband ocean bottom seismometers (DONET) deployed in the eastern part of the Nankai trough. This low frequency event activity was intense for the first few days after the great earthquake and gradually decreased. Signals of the events are most clearly visible at the frequency range around 2-8 Hz. Some of the events are accompanied by a very long frequency (VLF) signal, which is clearly observed at around 0.02-0.05 Hz. The magnitude and source duration estimated by waveform analysis for one of the largest very low frequency earthquakes (VLFEs) was 3.0-3.5 and 17 s. This source duration is extremely long compared to ordinary earthquakes of comparable magnitude. These newly detected VLFEs are likely to be normal fault earthquakes located at shallow depths within the accretionary prism, in contrast to the previously reported VLFEs that were explained by a low angle thrusting along the decollement zone. On the other hand, the low frequency events with no clear VLF signal were previously regarded as being low frequency tremors (LFTs). We show that events with and without the VLF signal likely represent the same phenomenon, and the VLF signal is only observed when a large magnitude event occurs near the station. The waveforms of VLFEs are characterized by the coexistence of long source duration and high-frequency radiation of signals, and such features were previously explained by the co-occurrence of shear failure and hydrofractures under the influence of fluid brought into the decollement zone. Our result indicates that the stress state and the mechanical environment, which promote the occurrence of VLFEs, exist not only along the decollement zone but also in the shallower part of the accretionary prism.

  2. A Brownian model for recurrent earthquakes

    Science.gov (United States)

    Matthews, M.V.; Ellsworth, W.L.; Reasenberg, P.A.

    2002-01-01

    We construct a probability model for rupture times on a recurrent earthquake source. Adding Brownian perturbations to steady tectonic loading produces a stochastic load-state process. Rupture is assumed to occur when this process reaches a critical-failure threshold. An earthquake relaxes the load state to a characteristic ground level and begins a new failure cycle. The load-state process is a Brownian relaxation oscillator. Intervals between events have a Brownian passage-time distribution that may serve as a temporal model for time-dependent, long-term seismic forecasting. This distribution has the following noteworthy properties: (1) the probability of immediate rerupture is zero; (2) the hazard rate increases steadily from zero at t = 0 to a finite maximum near the mean recurrence time and then decreases asymptotically to a quasi-stationary level, in which the conditional probability of an event becomes time independent; and (3) the quasi-stationary failure rate is greater than, equal to, or less than the mean failure rate because the coefficient of variation is less than, equal to, or greater than 1/???2 ??? 0.707. In addition, the model provides expressions for the hazard rate and probability of rupture on faults for which only a bound can be placed on the time of the last rupture. The Brownian relaxation oscillator provides a connection between observable event times and a formal state variable that reflects the macromechanics of stress and strain accumulation. Analysis of this process reveals that the quasi-stationary distance to failure has a gamma distribution, and residual life has a related exponential distribution. It also enables calculation of "interaction" effects due to external perturbations to the state, such as stress-transfer effects from earthquakes outside the target source. The influence of interaction effects on recurrence times is transient and strongly dependent on when in the loading cycle step pertubations occur. Transient effects may

  3. Relation between the characteristics of strong earthquake activities in Chinese mainland and the Wenchuan earthquake

    Institute of Scientific and Technical Information of China (English)

    Xiaodong Zhang; Guohua Yang; Xian Lu; Mingxiao Li; Zhigao Yang

    2009-01-01

    This paper studies the relations between the great Wenchuan earthquake and the active-quiet periodic characteristics of strong earthquakes, the rhythmic feature of great earthquakes, and the grouped spatial distribution of MS8.0 earthquakes in Chinese mainland. We also studied the relation between the Wenchuan earthquake and the stepwise migration characteristics of MS≥7.0 earthquakes on the North-South seismic belt, the features of the energy releasing acceleration in the active crustal blocks related to the Wenchuan earthquake and the relation between the Wenchuan earthquake and the so called second-arc fault zone. The results can be summarized as follows: ① the occurrence of the Wenchuan earthquake was consistent with the active-quiet periodic characteristics of strong earthquakes; ② its occurrence is consistent with the features of grouped occurrence of MS8.0 earthquakes and follows the 25 years rhythm (each circulation experiences the same time) of great earthquakes; ③ the Wenchuan MS8.0 earthquake follows the well known stepwise migration feature of strong earthquakes on the North-South seismic belt; ④ the location where the Wenchuan MS8.0 earthquake took place has an obvious consistency with the temporal and spatial characteristic of grouped activity of MS≥7.0 strong earthquakes on the second-arc fault zone; ⑤ the second-arc fault zone is not only the lower boundary for earthquakes with more than 30 km focal depth, but also looks like a lower boundary for deep substance movement; and ⑥ there are obvious seismic accelerations nearby the Qaidam and Qiangtang active crustal blocks (the northern and southern neighbors of the Bayan Har active block, respectively), which agrees with the GPS observation data.

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

    International Nuclear Information System (INIS)

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

  5. The Characteristics of Earthquake Swarms in and around Jiangsu Province

    Institute of Scientific and Technical Information of China (English)

    Huang Yun; Tian Jianming; Miao Ali

    2011-01-01

    This paper systematically analyzed 36 earthquake swarms in and around Jiangsu Province, summarized their characteristics and discussed the relationship between earthquske swarms and subsequent strong earthquakes. It also analyzed the judgment criteria for precursory earthquake swarms. Earthquake swarms in Jiangsu Province are concentrated in several areas. Most of them were of magnitude ML2. 0 ~ 3. 9. For most earthquake swarms, the number of earthquakes was less than 30. Time duration for about 55% of earthquake swarms was less than 15 days. The biggest magnitude of one earthquake swarm was not proportional to the number of earthquakes and time duration. There are 78% of earthquake swarms corresponded to the forthcoming earthquakes of M 〉 4. 6 in which there're 57% occured in one year, This shows a medium- and short-term criterion. Distance between earthquake swarm and future earthquake was distributed dispersedly. There were no earthquakes occurring in the same location as earthquake swarms. There was no good correlation between the magnitude and the corresponding rate of future earthquakes and the intensity of earthquake swarms. There was also no good correlation between the number of earthquakes in an earthquake swarm and the corresponding rate. The study also shows that it's better to use U-p or whole-combination to determine the type of earthquake swarm.

  6. A resonance mechanism of earthquakes

    CERN Document Server

    Flambaum, V V

    2015-01-01

    It had been observed in [1] that there are periodic 4-6 hours pulses of ? 200 ?Hz seismogravita- tional oscillations ( SGO ) before 95 % of powerful earthquakes. We explain this by beating between an oscillation eigenmode of a whole tectonic plate and a local eigenmode of an active zone which tranfers the oscillation energy from the tectonic plate to the active zone causing the eathrquake. Oscillation frequencies of the plate and ones of the active zone are tuned to a resonance by an additional pressure applied to the active zone due to collision of neighboring plates or convection in the upper mantia (plume). Corresponding theory may be used for short-term prediction of the earthquakes and tsunami.

  7. Pre-earthquake Magnetic Pulses

    CERN Document Server

    Scoville, John; Freund, Friedemann

    2014-01-01

    A semiconductor model of rocks is shown to describe unipolar magnetic pulses, a phenomenon that has been observed prior to earthquakes. These pulses are observable because their extremely long wavelength allows them to pass through the Earth's crust. Interestingly, the source of these pulses may be triangulated to pinpoint locations where stress is building deep within the crust. We couple a semiconductor drift-diffusion model to a magnetic field in order to describe the electromagnetic effects associated with electrical currents flowing within rocks. The resulting system of equations is solved numerically and it is seen that a volume of rock may act as a diode that produces transient currents when it switches bias. These unidirectional currents are expected to produce transient unipolar magnetic pulses similar in form, amplitude, and duration to those observed before earthquakes, and this suggests that the pulses could be the result of geophysical semiconductor processes.

  8. Mechanics of Multifault Earthquake Ruptures

    Science.gov (United States)

    Fletcher, J. M.; Oskin, M. E.; Teran, O.

    2015-12-01

    The 2010 El Mayor-Cucapah earthquake of magnitude Mw 7.2 produced the most complex rupture ever documented on the Pacific-North American plate margin, and the network of high- and low-angle faults activated in the event record systematic changes in kinematics with fault orientation. Individual faults have a broad and continuous spectrum of slip sense ranging from endmember dextral strike slip to normal slip, and even faults with thrust sense of dip slip were commonly observed in the aftershock sequence. Patterns of coseismic slip are consistent with three-dimensional constrictional strain and show that integrated transtensional shearing can be accommodated in a single earthquake. Stress inversions of coseismic surface rupture and aftershock focal mechanisms define two coaxial, but permuted stress states. The maximum (σ1) and intermediate (σ2) principal stresses are close in magnitude, but flip orientations due to topography- and density-controlled gradients in lithostatic load along the length of the rupture. Although most large earthquakes throughout the world activate slip on multiple faults, the mechanical conditions of their genesis remain poorly understood. Our work attempts to answer several key questions. 1) Why do complex fault systems exist? They must do something that simple, optimally-oriented fault systems cannot because the two types of faults are commonly located in close proximity. 2) How are faults with diverse orientations and slip senses prepared throughout the interseismic period to fail spontaneously together in a single earthquake? 3) Can a single stress state produce multi-fault failure? 4) Are variations in pore pressure, friction and cohesion required to produce simultaneous rupture? 5) How is the fabric of surface rupture affected by variations in orientation, kinematics, total geologic slip and fault zone architecture?

  9. Bayesian kinematic earthquake source models

    Science.gov (United States)

    Minson, S. E.; Simons, M.; Beck, J. L.; Genrich, J. F.; Galetzka, J. E.; Chowdhury, F.; Owen, S. E.; Webb, F.; Comte, D.; Glass, B.; Leiva, C.; Ortega, F. H.

    2009-12-01

    Most coseismic, postseismic, and interseismic slip models are based on highly regularized optimizations which yield one solution which satisfies the data given a particular set of regularizing constraints. This regularization hampers our ability to answer basic questions such as whether seismic and aseismic slip overlap or instead rupture separate portions of the fault zone. We present a Bayesian methodology for generating kinematic earthquake source models with a focus on large subduction zone earthquakes. Unlike classical optimization approaches, Bayesian techniques sample the ensemble of all acceptable models presented as an a posteriori probability density function (PDF), and thus we can explore the entire solution space to determine, for example, which model parameters are well determined and which are not, or what is the likelihood that two slip distributions overlap in space. Bayesian sampling also has the advantage that all a priori knowledge of the source process can be used to mold the a posteriori ensemble of models. Although very powerful, Bayesian methods have up to now been of limited use in geophysical modeling because they are only computationally feasible for problems with a small number of free parameters due to what is called the "curse of dimensionality." However, our methodology can successfully sample solution spaces of many hundreds of parameters, which is sufficient to produce finite fault kinematic earthquake models. Our algorithm is a modification of the tempered Markov chain Monte Carlo (tempered MCMC or TMCMC) method. In our algorithm, we sample a "tempered" a posteriori PDF using many MCMC simulations running in parallel and evolutionary computation in which models which fit the data poorly are preferentially eliminated in favor of models which better predict the data. We present results for both synthetic test problems as well as for the 2007 Mw 7.8 Tocopilla, Chile earthquake, the latter of which is constrained by InSAR, local high

  10. Priorities in earthquake damage reduction

    International Nuclear Information System (INIS)

    The potential gain from a reasonably precise risk optimization depends decisively on the elements constituting a building, their relative importance and their vulnerability which in turn often depends on many parameters. It also depends on 'external' factors like foundation material and the subsoil in the general region and, of course, on the characteristics of the earthquake and of shaking of the site. 34 refs, 8 figs

  11. Seismicity dynamics and earthquake predictability

    OpenAIRE

    G. A. Sobolev

    2011-01-01

    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...

  12. The Value, Protocols, and Scientific Ethics of Earthquake Forecasting

    Science.gov (United States)

    Jordan, Thomas H.

    2013-04-01

    Earthquakes are different from other common natural hazards because precursory signals diagnostic of the magnitude, location, and time of impending seismic events have not yet been found. Consequently, the short-term, localized prediction of large earthquakes at high probabilities with low error rates (false alarms and failures-to-predict) is not yet feasible. An alternative is short-term probabilistic forecasting based on empirical statistical models of seismic clustering. During periods of high seismic activity, short-term earthquake forecasts can attain prospective probability gains up to 1000 relative to long-term forecasts. The value of such information is by no means clear, however, because even with hundredfold increases, the probabilities of large earthquakes typically remain small, rarely exceeding a few percent over forecasting intervals of days or weeks. Civil protection agencies have been understandably cautious in implementing operational forecasting protocols in this sort of "low-probability environment." This paper will explore the complex interrelations among the valuation of low-probability earthquake forecasting, which must account for social intangibles; the protocols of operational forecasting, which must factor in large uncertainties; and the ethics that guide scientists as participants in the forecasting process, who must honor scientific principles without doing harm. Earthquake forecasts possess no intrinsic societal value; rather, they acquire value through their ability to influence decisions made by users seeking to mitigate seismic risk and improve community resilience to earthquake disasters. According to the recommendations of the International Commission on Earthquake Forecasting (www.annalsofgeophysics.eu/index.php/annals/article/view/5350), operational forecasting systems should appropriately separate the hazard-estimation role of scientists from the decision-making role of civil protection authorities and individuals. They should

  13. Historical earthquakes studies in Eastern Siberia: State-of-the-art and plans for future

    Science.gov (United States)

    Radziminovich, Ya. B.; Shchetnikov, A. A.

    2013-01-01

    Many problems in investigating historical seismicity of East Siberia remain unsolved. A list of these problems may refer particularly to the quality and reliability of data sources, completeness of parametric earthquake catalogues, and precision and transparency of estimates for the main parameters of historical earthquakes. The main purpose of this paper is to highlight the current status of the studies of historical seismicity in Eastern Siberia, as well as analysis of existing macroseismic and parametric earthquake catalogues. We also made an attempt to identify the main shortcomings of existing catalogues and to clarify the reasons for their appearance in the light of the history of seismic observations in Eastern Siberia. Contentious issues in the catalogues of earthquakes are considered by the example of three strong historical earthquakes, important for assessing seismic hazard in the region. In particular, it was found that due to technical error the parameters of large M = 7.7 earthquakes of 1742 were transferred from the regional catalogue to the worldwide database with incorrect epicenter coordinates. The way some stereotypes concerning active tectonics influences on the localization of the epicenter is shown by the example of a strong М = 6.4 earthquake of 1814. Effect of insufficient use of the primary data source on completeness of earthquake catalogues is illustrated by the example of a strong M = 7.0 event of 1859. Analysis of the state-of-the-art of historical earthquakes studies in Eastern Siberia allows us to propose the following activities in the near future: (1) database compilation including initial descriptions of macroseismic effects with reference to their place and time of occurrence; (2) parameterization of the maximum possible (magnitude-unlimited) number of historical earthquakes on the basis of all the data available; (3) compilation of an improved version of the parametric historical earthquake catalogue for East Siberia with

  14. Intermediate-term earthquake prediction.

    Science.gov (United States)

    Keilis-Borok, V I

    1996-04-30

    An earthquake of magnitude M and linear source dimension L(M) is preceded within a few years by certain patterns of seismicity in the magnitude range down to about (M - 3) in an area of linear dimension about 5L-10L. Prediction algorithms based on such patterns may allow one to predict approximately 80% of strong earthquakes with alarms occupying altogether 20-30% of the time-space considered. An area of alarm can be narrowed down to 2L-3L when observations include lower magnitudes, down to about (M - 4). In spite of their limited accuracy, such predictions open a possibility to prevent considerable damage. The following findings may provide for further development of prediction methods: (i) long-range correlations in fault system dynamics and accordingly large size of the areas over which different observed fields could be averaged and analyzed jointly, (ii) specific symptoms of an approaching strong earthquake, (iii) the partial similarity of these symptoms worldwide, (iv) the fact that some of them are not Earth specific: we probably encountered in seismicity the symptoms of instability common for a wide class of nonlinear systems. PMID:11607660

  15. Pre-earthquake magnetic pulses

    Directory of Open Access Journals (Sweden)

    J. Scoville

    2014-12-01

    Full Text Available A semiconductor model of rocks is shown to describe unipolar magnetic pulses, a phenomenon that has been observed prior to earthquakes. These pulses are generated deep in the Earth's crust, in and around the Hypocentral volume, days or even weeks before Earthquakes. They are observable at the surface because their extremely long wavelength allows them to pass through kilometers of rock. Interestingly, the source of these pulses may be triangulated to pinpoint locations where stresses are building deep within the crust. We couple a semiconductor drift-diffusion model to a magnetic field in order to describe the electromagnetic effects associated with electrical currents flowing within rocks. The resulting system of equations is solved numerically and it is seen that a volume of rock may act as a diode that produces transient currents when it switches bias. These unidirectional currents are expected to produce transient unipolar magnetic pulses similar in form, amplitude, and duration to those observed before earthquakes, and this suggests that the pulses could be the result of geophysical semiconductor processes.

  16. Earthquake evaluation of a substation network

    International Nuclear Information System (INIS)

    The impact of the occurrence of a large, damaging earthquake on a regional electric power system is a function of the geographical distribution of strong shaking, the vulnerability of various types of electric equipment located within the affected region, and operational resources available to maintain or restore electric system functionality. Experience from numerous worldwide earthquake occurrences has shown that seismic damage to high-voltage substation equipment is typically the reason for post-earthquake loss of electric service. In this paper, the authors develop and apply a methodology to analyze earthquake impacts on Pacific Gas and Electric Company's (PG and E's) high-voltage electric substation network in central and northern California. The authors' objectives are to identify and prioritize ways to reduce the potential impact of future earthquakes on our electric system, refine PG and E's earthquake preparedness and response plans to be more realistic, and optimize seismic criteria for future equipment purchases for the electric system

  17. Insignificant solar-terrestrial triggering of earthquakes

    Science.gov (United States)

    Love, Jeffrey J.; Thomas, Jeremy N.

    2013-01-01

    We examine the claim that solar-terrestrial interaction, as measured by sunspots, solar wind velocity, and geomagnetic activity, might play a role in triggering earthquakes. We count the number of earthquakes having magnitudes that exceed chosen thresholds in calendar years, months, and days, and we order these counts by the corresponding rank of annual, monthly, and daily averages of the solar-terrestrial variables. We measure the statistical significance of the difference between the earthquake-number distributions below and above the median of the solar-terrestrial averages by χ2 and Student's t tests. Across a range of earthquake magnitude thresholds, we find no consistent and statistically significant distributional differences. We also introduce time lags between the solar-terrestrial variables and the number of earthquakes, but again no statistically significant distributional difference is found. We cannot reject the null hypothesis of no solar-terrestrial triggering of earthquakes.

  18. The physics of rock failure and earthquakes

    CERN Document Server

    Ohnaka, Mitiyasu

    2013-01-01

    Despite significant advances in the understanding of earthquake generation processes and derivation of underlying physical laws, controversy remains regarding the constitutive law for earthquake ruptures and how it should be formulated. Laboratory experiments are necessary to obtain high-resolution measurements that allow the physical nature of shear rupture processes to be deduced, and to resolve the controversy. This important book provides a deeper understanding of earthquake processes from nucleation to their dynamic propagation. Its key focus is a deductive approach based on laboratory-derived physical laws and formulae, such as a unifying constitutive law, a constitutive scaling law, and a physical model of shear rupture nucleation. Topics covered include: the fundamentals of rock failure physics, earthquake generation processes, physical scale dependence, and large-earthquake generation cycles. Designed for researchers and professionals in earthquake seismology, rock failure physics, geology and earthq...

  19. Earthquakes in Virginia and vicinity 1774 - 2004

    Science.gov (United States)

    Tarr, Arthur C.; Wheeler, Russell L.

    2006-01-01

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

  20. Data base pertinent to earthquake design basis

    International Nuclear Information System (INIS)

    Mitigation of earthquake risk from impending strong earthquakes is possible provided the hazard can be assessed, and translated into appropriate design inputs. This requires defining the seismic risk problem, isolating the risk factors and quantifying risk in terms of physical parameters, which are suitable for application in design. Like all other geological phenomena, past earthquakes hold the key to the understanding of future ones. Quantificatio n of seismic risk at a site calls for investigating the earthquake aspects of the site region and building a data base. The scope of such investigations is il lustrated in Figure 1 and 2. A more detailed definition of the earthquake problem in engineering design is given elsewhere (Sharma, 1987). The present document discusses the earthquake data base, which is required to support a seismic risk evaluation programme in the context of the existing state of the art. (author). 8 tables, 10 figs., 54 refs

  1. 虹吸井对尾矿坝地震液化的影响分析%Influence Analysis of Siphon Well on Liquefaction of Tailing Dam during Earthquake

    Institute of Scientific and Technical Information of China (English)

    宋宜祥; 李俊杰; 康飞

    2012-01-01

    In order to understand the impact of the siphon wells on the tailings dam earthquake liquefaction, taking Gongchangling tailings dam in the northeast China for an example, dynamic calculation is implemented by the method of imposing siphon well on the dam. The effects of liquefaction area distribution of the dam and reservoir area after the failure of draining measures and application of the siphon well are compared. And the slope safety factor of the dam is calculated by using finite element method and quasi-static method. The results show that the primarily liquefied area is in the reservoir and the area below overflow point if the measures of draining leakage is failure; the dam safety factor does not meet the specification requirements and the tailings dam is not safe; after application of the siphon well, the liquefied area reduces significantly, which is only in the reservoir area; the region near water line is the maximum and the dam safety factor reaches the current specification requirements; the tailings dam is safety and stability.%为了解虹吸井对尾矿坝地震液化的影响,以东北地区弓长岭尾矿坝为例,通过在坝体施加虹吸井的方法进行动力计算,比较了排渗措施失效后与施加虹吸井后对坝体及库区液化区分布的影响,并通过有限元方法和拟静力法计算了坝坡的安全系数.结果表明,排渗措施失效后液化区主要分布于坝体溢出点以下区域及尾矿库库区内,坝体安全系数不符合规范要求,且尾矿坝不安全;施加虹吸井后液化区显著减小,仅分布于尾矿库库区内,库区水边线附近分布区域最大,且坝体安全系数能满足现行规范要求,尾矿坝安全稳定.

  2. Common dependence on earthquake magnitudes for the trapped particles bursts approaching the earthquake

    OpenAIRE

    Ping WANG; Wang, Huanyu; Lu, Hong; Meng, Xiangcheng; Zhang, Jilong; Wang, Hui; Shi, Feng; Xu, Yanbing; Li, Xinqiao; Yu, Xiaoxia; Zhao, Xiaoyun; Wu, Feng; An, Zhenghua; Jiang, Wenqi; Liu, Hanyi

    2012-01-01

    Trapped particles bursts have long been observed to be frequently occurred several hours before earthquakes, especially for strong earthquakes, from several space experiments during past decades. However, the validity of earthquake origin of particles bursts events is still unsolved. In this paper, we firstly reported the frequency distribution and time evolution of particles bursts within different time windows centered around earthquakes for various magnitudes. The results showed nearly the...

  3. Seismicity and earthquake risk in Portugal

    OpenAIRE

    Bezzeghoud, M.; Borges, J. F.; Caldeira, B.; Grandin, R.

    2006-01-01

    The workshop “Earthquake monitoring and Earthquake Risk in WEstern Mediterranean” (EERWEM) will summarize the current knowledge, on-going projects and research plans with regard to seismic activity and risk in the region. This work is organized in two topics: i) presentation of our current research on seismic activity and earthquake risk in the Western Mediterranean region, particularly in Portugal and ii) a short training course about seismic data processing and waveform analysis. Some appli...

  4. History of earthquake studies in Russia

    OpenAIRE

    Tatevossian, R.

    2004-01-01

    To evaluate the completeness of modern knowledge on historical seismicity it is necessary to know the general geopolitical and socio-cultural background in the country. It determines the possibility to record the evidence of an earthquake and conserve the record in original form for a long time-period. The potential duration of historical earthquake study in Russia is assessed based on these considerations. Certain stages of earthquake study in Russia have been detected. Specific problems ...

  5. Power of earthquake cluster detection tests

    OpenAIRE

    de Oliveira, Felipe Dimer

    2012-01-01

    Testing the global earthquake catalogue for indications of non-Poissonian attributes has been an area of intense research, especially since the 2011 Tohoku earthquake. The usual approach is to test statistically for the hypothesis that the global earthquake catalogue is well explained by a Poissonian process. In this paper we analyse one aspect of this problem which has been disregarded by the literature: the power of such tests to detect non-Poissonian features if they existed; that is, the ...

  6. Modeling Spatial and Temporal Dependencies between Earthquakes

    OpenAIRE

    2000-01-01

    Two new different stochastic models for earthquake occurrence are discussed. Both models are focusing on the spatio-temporal interactions between earthquakes. The parameters of the models are estimated from a Bayesian updating of priors, using empirical data to derive posterior distributions. The first model is a marked point process model in which each earthquake is represented by its magnitude and coordinates in space and time. This model incorporates the occurrence of aftershocks as well a...

  7. Electromagnetic Anomalies around The Wenchuan Earthquake and Their Relationship with Earthquake Preparation

    OpenAIRE

    Xuemin Zhang; Xuhui Shen

    2011-01-01

    Electromagnetic precursors before the Wenchuan earthquake on May 12, 2008 were collected and summarized on the basis of related published papers. The relationship between electromagnetic anomalies and different earthquake preparation stages was analyzed, and an entire seismic preparation process was constructed according to corresponding anomalies in different electromagnetic parameters. It is illustrated that stereo electromagnetic observation is useful in the understanding of earthquake pr...

  8. Earthquake prediction decision and risk matrix

    Science.gov (United States)

    Zou, Qi-Jia

    1993-08-01

    The issuance of an earthquake prediction must cause widespread social responses. It is suggested and discussed in this paper that the comprehensive decision issue for earthquake prediction considering the factors of the social and economic cost. The method of matrix decision for earthquake prediction (MDEP) is proposed in this paper and it is based on the risk matrix. The goal of decision is that search the best manner issuing earthquake prediction so that minimize the total losses of economy. The establishment and calculation of the risk matrix is discussed, and the decision results taking account of economic factors and not considering the economic factors are compared by examples in this paper.

  9. A minimalist model of characteristic earthquakes

    Directory of Open Access Journals (Sweden)

    M. Vázquez-Prada

    2002-01-01

    Full Text Available In a spirit akin to the sandpile model of self-organized criticality, we present a simple statistical model of the cellular-automaton type which simulates the role of an asperity in the dynamics of a one-dimensional fault. This model produces an earthquake spectrum similar to the characteristic-earthquake behaviour of some seismic faults. This model, that has no parameter, is amenable to an algebraic description as a Markov Chain. This possibility illuminates some important results, obtained by Monte Carlo simulations, such as the earthquake size-frequency relation and the recurrence time of the characteristic earthquake.

  10. A minimalist model of characteristic earthquakes

    DEFF Research Database (Denmark)

    Vázquez-Prada, M.; González, Á.; Gómez, J.B.;

    2002-01-01

    In a spirit akin to the sandpile model of self- organized criticality, we present a simple statistical model of the cellular-automaton type which simulates the role of an asperity in the dynamics of a one-dimensional fault. This model produces an earthquake spectrum similar to the characteristic-earthquake...... behaviour of some seismic faults. This model, that has no parameter, is amenable to an algebraic description as a Markov Chain. This possibility illuminates some important results, obtained by Monte Carlo simulations, such as the earthquake size-frequency relation and the recurrence time of the...... characteristic earthquake....

  11. Earthquake risk assessment for Istanbul metropolitan area

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

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

  12. Evaluation and cataloging of Korean historical earthquakes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kew Hwa; Han, Young Woo; Lee, Jun Hui; Park, Ji Eok; Na, Kwang Wooing; Shin, Byung Ju [The Reaearch Institute of Basic Sciences, Seoul Nationl Univ., Seoul (Korea, Republic of)

    1998-03-15

    In order to systematically collect and analyze the historical earthquake data of the Korean peninsula which are very important in analyzing the seismicity and seismic risk of the peninsula by seismologist and historian, extensive governmental and private historical documents are investigated and relative reliabilities of these documents are examined. This research unearthed about 70 new earthquake records and revealed the change in the cultural, political and social effects of earthquakes with time in Korea. Also, the results of the vibration test of the Korean traditional wooden house are obtained in order to better estimate intensities of the historical earthquakes.

  13. A Simple Model for Earthquake Instability

    Institute of Scientific and Technical Information of China (English)

    Li Ping'en; Yin Youquan

    2010-01-01

    Based on the heterogeneity of fault plane strength,the macro rupture process of a fault plane can be treated as the rupture accumulation process of local micro-elements in the fault surface.Assuming that the strength of the local micro-elements follows the Weibull probability distribution,the macro-fault constitutive relationship of the complete load-deformation process is derived from a statistical mechanics viewpoint.Applying a one-dimensional earthquake mechanics model and using far-field displacement a as the control variable,the problem of earthquake instability is investigated by employing the stability theory.The results show that the system stiffness ratio(stiffness ratio of fault to surroun-ding rock)β is the important parameter that affects the occurrence of earthquakes.Earthquake instability occurs only when β < 1,and the sudden stress jump appears at the displacement turning point of the equilibrium path curve.The expression of three important parameters for earthquakes(fault half-dislocation distance after earthquake,earthquake stress drop and elastic energy release)is also given.When β≥ 1,the earthquake does not occur and the fault only slips slowly without an earthquake.

  14. Thermoluminescence dating of Australian palaeo-earthquakes

    Science.gov (United States)

    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.

  15. Global Significant Earthquake Database, 2150 BC to present

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Significant Earthquake Database is a global listing of over 5,700 earthquakes from 2150 BC to the present. A significant earthquake is classified as one that...

  16. Salient beliefs about earthquake hazards and household preparedness.

    Science.gov (United States)

    Becker, Julia S; Paton, Douglas; Johnston, David M; Ronan, Kevin R

    2013-09-01

    Prior research has found little or no direct link between beliefs about earthquake risk and household preparedness. Furthermore, only limited work has been conducted on how people's beliefs influence the nature and number of preparedness measures adopted. To address this gap, 48 qualitative interviews were undertaken with residents in three urban locations in New Zealand subject to seismic risk. The study aimed to identify the diverse hazard and preparedness-related beliefs people hold and to articulate how these are influenced by public education to encourage preparedness. The study also explored how beliefs and competencies at personal, social, and environmental levels interact to influence people's risk management choices. Three main categories of beliefs were found: hazard beliefs; preparedness beliefs; and personal beliefs. Several salient beliefs found previously to influence the preparedness process were confirmed by this study, including beliefs related to earthquakes being an inevitable and imminent threat, self-efficacy, outcome expectancy, personal responsibility, responsibility for others, and beliefs related to denial, fatalism, normalization bias, and optimistic bias. New salient beliefs were also identified (e.g., preparedness being a "way of life"), as well as insight into how some of these beliefs interact within the wider informational and societal context. PMID:23339741

  17. On the agreement between small-world-like OFC model and real earthquakes

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Douglas S.R., E-mail: douglas.ferreira@ifrj.edu.br [Instituto Federal de Educação, Ciência e Tecnologia do Rio de Janeiro, Paracambi, RJ (Brazil); Geophysics Department, Observatório Nacional, Rio de Janeiro, RJ (Brazil); Papa, Andrés R.R., E-mail: papa@on.br [Geophysics Department, Observatório Nacional, Rio de Janeiro, RJ (Brazil); Instituto de Física, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Menezes, Ronaldo, E-mail: rmenezes@cs.fit.edu [BioComplex Laboratory, Computer Sciences, Florida Institute of Technology, Melbourne (United States)

    2015-03-20

    In this article we implemented simulations of the OFC model for earthquakes for two different topologies: regular and small-world, where in the latter the links are randomly rewired with probability p. In both topologies, we have studied the distribution of time intervals between consecutive earthquakes and the border effects present in each one. In addition, we also have characterized the influence that the probability p produces in certain characteristics of the lattice and in the intensity of border effects. From the two topologies, networks of consecutive epicenters were constructed, that allowed us to analyze the distribution of connectivities of each one. In our results distributions arise belonging to a family of non-traditional distributions functions, which agrees with previous studies using data from actual earthquakes. Our results reinforce the idea that the Earth is in a critical self-organized state and furthermore point towards temporal and spatial correlations between earthquakes in different places. - Highlights: • OFC model simulations for regular and small-world topologies. • For small-world topology distributions agree remarkably well with actual earthquakes. • Reinforce the idea of a critical self-organized state for the Earth's crust. • Point towards temporal and spatial correlations between far earthquakes in far places.

  18. On the agreement between small-world-like OFC model and real earthquakes

    International Nuclear Information System (INIS)

    In this article we implemented simulations of the OFC model for earthquakes for two different topologies: regular and small-world, where in the latter the links are randomly rewired with probability p. In both topologies, we have studied the distribution of time intervals between consecutive earthquakes and the border effects present in each one. In addition, we also have characterized the influence that the probability p produces in certain characteristics of the lattice and in the intensity of border effects. From the two topologies, networks of consecutive epicenters were constructed, that allowed us to analyze the distribution of connectivities of each one. In our results distributions arise belonging to a family of non-traditional distributions functions, which agrees with previous studies using data from actual earthquakes. Our results reinforce the idea that the Earth is in a critical self-organized state and furthermore point towards temporal and spatial correlations between earthquakes in different places. - Highlights: • OFC model simulations for regular and small-world topologies. • For small-world topology distributions agree remarkably well with actual earthquakes. • Reinforce the idea of a critical self-organized state for the Earth's crust. • Point towards temporal and spatial correlations between far earthquakes in far places

  19. Contrasting décollement and prism properties over the Sumatra 2004-2005 earthquake rupture boundary.

    Science.gov (United States)

    Dean, Simon M; McNeill, Lisa C; Henstock, Timothy J; Bull, Jonathan M; Gulick, Sean P S; Austin, James A; Bangs, Nathan L B; Djajadihardja, Yusuf S; Permana, Haryadi

    2010-07-01

    Styles of subduction zone deformation and earthquake rupture dynamics are strongly linked, jointly influencing hazard potential. Seismic reflection profiles across the trench west of Sumatra, Indonesia, show differences across the boundary between the major 2004 and 2005 plate interface earthquakes, which exhibited contrasting earthquake rupture and tsunami generation. In the southern part of the 2004 rupture, we interpret a negative-polarity sedimentary reflector approximately 500 meters above the subducting oceanic basement as the seaward extension of the plate interface. This predécollement reflector corresponds to unusual prism structure, morphology, and seismogenic behavior that are absent along the 2005 rupture zone. Although margins like the 2004 rupture zone are globally rare, our results suggest that sediment properties influence earthquake rupture, tsunami hazard, and prism development at subducting plate boundaries. PMID:20616276

  20. Insurance Stock Prices Following the 1994 Los Angeles Earthquake

    OpenAIRE

    Thomas A. Aiuppa; Thomas M. Krueger

    1995-01-01

    This study examines the changes in insurance firm value following the 1994 Los Angeles earthquake. While prior studies found that the 1989 San Francisco earthquake was associated with an increase in earthquake insurers’ firm value, the findings of this study indicate that earthquake firms sustained their value following the 1994 earthquake. These results and their implications provide insight for investors, regulators, and other policymakers as regards future earthquakes.

  1. Retrospective cohort analysis of chest injury characteristics and concurrent injuries in patients admitted to hospital in the Wenchuan and Lushan earthquakes in Sichuan, China.

    Directory of Open Access Journals (Sweden)

    Xi Zheng

    Full Text Available BACKGROUND: The aim of this study was to compare retrospectively the characteristics of chest injuries and frequencies of other, concurrent injuries in patients after earthquakes of different seismic intensity. METHODS: We compared the cause, type, and body location of chest injuries as well as the frequencies of other, concurrent injuries in patients admitted to our hospital after the Wenchuan and Lushan earthquakes in Sichuan, China. We explored possible relationships between seismic intensity and the causes and types of injuries, and we assessed the ability of the Injury Severity Score, New Injury Severity Score, and Chest Injury Index to predict respiratory failure in chest injury patients. RESULTS: The incidence of chest injuries was 9.9% in the stronger Wenchuan earthquake and 22.2% in the less intensive Lushan earthquake. The most frequent cause of chest injuries in both earthquakes was being accidentally struck. Injuries due to falls were less prevalent in the stronger Wenchuan earthquake, while injuries due to burial were more prevalent. The distribution of types of chest injury did not vary significantly between the two earthquakes, with rib fractures and pulmonary contusions the most frequent types. Spinal and head injuries concurrent with chest injuries were more prevalent in the less violent Lushan earthquake. All three trauma scoring systems showed poor ability to predict respiratory failure in patients with earthquake-related chest injuries. CONCLUSIONS: Previous studies may have underestimated the incidence of chest injury in violent earthquakes. The distributions of types of chest injury did not differ between these two earthquakes of different seismic intensity. Earthquake severity and interval between rescue and treatment may influence the prevalence and types of injuries that co-occur with the chest injury. Trauma evaluation scores on their own are inadequate predictors of respiratory failure in patients with earthquake

  2. Advances in Earthquake Prediction Research and the June 2000 Earthquakes in Iceland

    Science.gov (United States)

    Stefansson, R.

    2006-12-01

    In June 2000, two earthquakes with magnitude 6.6 (Ms) occurred in the central part of the South Iceland seismic zone (SISZ). Earthquakes in this region have, according to historical information, in some cases caused collapse of the majority of houses in areas encompassing 1,000 square kilometers in this relatively densely populated farming region. Because large earthquakes were expected to occur soon, much attention was given to preparedness in the region and for the last two decades it has been the subject of multi- national, mainly European, co-operation in earthquake prediction research and in the development of a high- level micro-earthquake system: the SIL system. Despite intensive surface fissuring caused by the earthquakes and measured accelerations reaching 0.8 g, the earthquakes in 2000 caused no serious injuries and no structural collapse. The relatively minor destruction led to more optimism regarding the safety of living in the area. But it also lead to some optimism about the significance of earthquake prediction research. Both earthquakes had a long-term prediction and the second of the two earthquakes had a short- term warning about place, size and immediacy. In this presentation, I will describe the warnings that were given ahead of the earthquakes. Also, I will reconsider these warnings in light of new results from multi-national earthquake prediction research in Iceland. This modeling work explains several observable patterns caused by crustal process ahead of large earthquakes. Micro-seismic observations and modeling show that, in conditions prevailing in the Icelandic crust, fluids can be carried upward from the brittle-ductile boundary in response to strain, bringing high, near- lithostatic pore pressures into the brittle crust, preparing a region for the release of a large earthquake; monitoring this process will enable long- and short- term earthquakes warnings.

  3. Identification of High Frequency Pulses from Earthquake Asperities Along Chilean Subduction Zone Using Strong Motion

    Science.gov (United States)

    Ruiz, S.; Kausel, E.; Campos, J.; Saragoni, G. R.; Madariaga, R.

    2011-01-01

    The Chilean subduction zone is one of the most active of the world with M = 8 or larger interplate thrust earthquakes occurring every 10 years or so on the average. The identification and characterization of pulses propagated from dominant asperities that control the rupture of these earthquakes is an important problem for seismology and especially for seismic hazard assessment since it can reduce the earthquake destructiveness potential. A number of studies of large Chilean earthquakes have revealed that the source time functions of these events are composed of a number of distinct energy arrivals. In this paper, we identify and characterize the high frequency pulses of dominant asperities using near source strong motion records. Two very well recorded interplate earthquakes, the 1985 Central Chile (Ms = 7.8) and the 2007 Tocopilla (Mw = 7.7), are considered. In particular, the 2007 Tocopilla earthquake was recorded by a network with absolute time and continuos recording. From the study of these strong motion data it is possible to identify the arrival of large pulses coming from different dominant asperities. The recognition of the key role of dominant asperities in seismic hazard assessment can reduce overestimations due to scattering of attenuation formulas that consider epicentral distance or shortest distance to the fault rather than the asperity distance. The location and number of dominant asperities, their shape, the amplitude and arrival time of pulses can be one of the principal factors influencing Chilean seismic hazard assessment and seismic design. The high frequency pulses identified in this paper have permitted us to extend the range of frequency in which the 1985 Central Chile and 2007 Tocopilla earthquakes were studied. This should allow in the future the introduction of this seismological result in the seismic design of earthquake engineering.

  4. Historical Earthquakes in the Yellow Sea and Its Adjacent Area

    Institute of Scientific and Technical Information of China (English)

    Wu Ge; Wang Andong; Wu Di

    2005-01-01

    As a result of sorting out, estimating and cataloging of historical earthquakes, from the year of 2 A.D. to Aug., 1949, we found that there were 2187 earthquakes with M≥3.0 in the area of the Yellow Sea and its adjacent area. Among the earthquakes, the number of earthquakes with M ≥ 5.0 is 209, and at least 43 of the earthquakes caused serious losses, 20 of the earthquakes caused human causalities. It is demonstrated that there were 3 areas of historical earthquake concentration and the earthquake activity was higher in the 16th century and the first half if the 20th century.

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

    Science.gov (United States)

    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.

  6. GEM - The Global Earthquake Model

    Science.gov (United States)

    Smolka, A.

    2009-04-01

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

  7. Downscaling of slip distribution for strong earthquakes

    Science.gov (United States)

    Yoshida, T.; Oya, S.; Kuzuha, Y.

    2013-12-01

    We intend to develop a downscaling model to enhance the earthquake slip distribution resolution. Slip distributions have been obtained by other researchers using various inversion methods. As a downscaling model, we are discussing fractal models that include mono-fractal models (fractional Brownian motion, fBm; fractional Lévy motion, fLm) and multi-fractal models as candidates. Log - log-linearity of k (wave number) versus E (k) (power spectrum) is the necessary condition for fractality: the slip distribution is expected to satisfy log - log-linearity described above if we can apply fractal model to a slip distribution as a downscaling model. Therefore, we conducted spectrum analyses using slip distributions of 11 earthquakes as explained below. 1) Spectrum analyses using one-dimensional slip distributions (strike direction) were conducted. 2) Averaging of some results of power spectrum (dip direction) was conducted. Results show that, from the viewpoint of log - log-linearity, applying a fractal model to slip distributions can be inferred as valid. We adopt the filtering method after Lavallée (2008) to generate fBm/ fLm. In that method, generated white noises (random numbers) are filtered using a power law type filter (log - log-linearity of the spectrum). Lavallée (2008) described that Lévy white noise that generates fLm is more appropriate than the Gaussian white noise which generates fBm. In addition, if the 'alpha' parameter of the Lévy law, which governs the degree of attenuation of tails of the probability distribution, is 2.0, then the Lévy distribution is equivalent to the Gauss distribution. We analyzed slip distributions of 11 earthquakes: the Tohoku earthquake (Wei et al., 2011), Haiti earthquake (Sladen, 2010), Simeulue earthquake (Sladen, 2008), eastern Sichuan earthquake (Sladen, 2008), Peru earthquake (Konca, 2007), Tocopilla earthquake (Sladen, 2007), Kuril earthquake (Sladen, 2007), Benkulu earthquake (Konca, 2007), and southern Java

  8. Peak ground motion distribution in Romania due to Vrancea earthquakes

    International Nuclear Information System (INIS)

    Vrancea is a particular seismic region situated at the SE-Carpathians bend (Romania). It is characterized by persistent seismicity in a concentrated focal volume, at depths of 60-200 km, with 2 to 3 major earthquakes per century (MW>7). The purpose of our study is to investigate in detail the ground motion patterns for small and moderate Vrancea events (MW = 3.5 to 5.3) occurred during 1999, taking advantage of the unique data set offered by the Calixto'99 Project and the permanent Vrancea-K2 network (150 stations). The observed patterns are compared with available macroseismic maps of large Vrancea earthquakes, showing similar general patterns elongated in the NE-SW direction which mimic the S-waves source radiation, but patches with pronounced maxima are also evidenced rather far from the epicenter, at the NE and SW edges of the Focsani sedimentary basin, as shown firstly by Atanasiu (1961). This feature is also visible on instrumental data of strong events (Mandrescu and Radulian, 1999) as well as for moderate events recently recorded by digital K2 network (Bonjer et al., 2001) and correlates with the distribution of predominant response frequencies of shallow sedimentary layers. The influence of the local structure and/or focussing effects, caused by deeper lithospheric structure, on the observed site effects and the implications on the seismic hazard assessment for Vrancea earthquakes are discussed. (authors)

  9. Radon and earthquake prediction in India: present status

    International Nuclear Information System (INIS)

    Radon is present in trace amounts almost everywhere on the earth, being distributed in the soil, groundwater and in the lower atmosphere. Continuous and long term measurements of radon in sub-surface soil and groundwater are carried out using electronic alpha-counter, alphalogger, emanometer and plastic detector, LR-115 type II. Radon concentration level is being monitored daily at Amritsar, Pubjab and other stations in Kangra valley, Himachal Pradesh India. Radon anomalies and correlatable to some of the earthquakes which occurred in the region. Radon diffusion from soil and groundwater and influence of meteorological variables on radon emanation have been studied to differentiate true from false anomalies. A network of ten radon recording stations is being set up in the highly seismic zone near the Main Boundary Trust (MBT) in the Himalayas to forecast future earthquakes using radon as a precursor. Radon is posing a deep concern to human life from health-hazard point of view; it can prove as a saviour of human life if exploited for earthquake prediction. (Author)

  10. Estimation of earthquake risk curves of physical building damage

    Science.gov (United States)

    Raschke, Mathias; Janouschkowetz, Silke; Fischer, Thomas; Simon, Christian

    2014-05-01

    In this study, a new approach to quantify seismic risks is presented. Here, the earthquake risk curves for the number of buildings with a defined physical damage state are estimated for South Africa. Therein, we define the physical damage states according to the current European macro-seismic intensity scale (EMS-98). The advantage of such kind of risk curve is that its plausibility can be checked more easily than for other types. The earthquake risk curve for physical building damage can be compared with historical damage and their corresponding empirical return periods. The number of damaged buildings from historical events is generally explored and documented in more detail than the corresponding monetary losses. The latter are also influenced by different economic conditions, such as inflation and price hikes. Further on, the monetary risk curve can be derived from the developed risk curve of physical building damage. The earthquake risk curve can also be used for the validation of underlying sub-models such as the hazard and vulnerability modules.

  11. Modeling earthquake indexes derived from the earthquake warning system upon the planet earth

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    By studying the correlation between historical earthquake data and the distributional characteristics of parameters of solid earth tides in the earthquake epicenter, we are able to design a forecasting function of earthquake probability. We put forward a design method for the Earthquake Warning System. The model could theoretically simulate and be used to predict the probability of strong earthquakes that could occur anywhere at any time. In addition, the system could also conveniently obtain global or partial Modeling Earthquake Indexes to finally combine the precise pointing prediction and forecast of partial indexes. The literature quotes global data values, provided by NEIC, of 1544 M ≥ 6.5 earthquakes. It also gives examples of instantaneous earthquake indexes of the whole world and Taiwan Area on 1st January 2010, UT=0:00 and the average earthquake index near the Taiwan Area. According to the 10-year pointing prediction of strong earthquakes in San Francisco, the literature provides the average earthquake index on 24th June 2015 (± 15 days), in its neighborhood.

  12. Common dependence on earthquake magnitudes for the trapped particles bursts approaching the earthquake

    CERN Document Server

    Wang, Ping; Lu, Hong; Meng, Xiangcheng; Zhang, Jilong; Wang, Hui; Shi, Feng; Xu, Yanbing; Li, Xinqiao; Yu, Xiaoxia; Zhao, Xiaoyun; Wu, Feng; An, Zhenghua; Jiang, Wenqi; Liu, Hanyi

    2012-01-01

    Trapped particles bursts have long been observed to be frequently occurred several hours before earthquakes, especially for strong earthquakes, from several space experiments during past decades. However, the validity of earthquake origin of particles bursts events is still unsolved. In this paper, we firstly reported the frequency distribution and time evolution of particles bursts within different time windows centered around earthquakes for various magnitudes. The results showed nearly the same systematic dependence of particle bursts frequency on earthquake magnitude and characteristic time decay behavior of average number of particles bursts for various magnitudes. These findings should strengthen the validity of earthquake origin of particles bursts and further understanding of particles bursts as possible precursor of earthquake.

  13. Stress adjustment revealed by seismicity and earthquake focal mechanisms in northeast China before and after the 2011 Tohoku-Oki earthquake

    Science.gov (United States)

    Yu, Hongyu; Zhao, Li; Liu, Yajing; Ning, Jieyuan; Chen, Qi-Fu; Lin, Jian

    2016-01-01

    In order to understand the influence of the March 11, 2011, MW 9.0 Tohoku-Oki earthquake on regional-scale seismicity, we study the seismicity rate and focal mechanism solutions (FMSs) of earthquakes in northeast China (NEC) before and after the megathrust event. Broadband seismic waveforms from 270 permanent and temporary stations are used to invert for the moment tensors of 69 earthquakes between 2009 and 2013 in the NEC. Our results show that there are distinct changes in seismicity rate on major NEC faults before and after the 2011 Tohoku-Oki event although the seismic moment rate of the whole region remains roughly constant. In comparison to a wide distribution of earthquakes before the Tohoku-Oki event, FMSs of crustal earthquakes in the NEC after the megathrust event can be categorized into two groups: strike-slip events with E-W compression and normal-faulting events with N-S extension. Stress field inversions before and after the Tohoku-Oki event suggest that the variations in seismicity and FMSs are due to a minor adjustment of regional stress state imposed by the megathrust event, which is further confirmed by static Coulomb stress change calculations. Mantle-depth seismicity is also influenced by the megathrust event, possibly via a down-dip transfer of compressional stress along the subducting plate, as manifested by the absence of moderate-sized mantle-depth earthquakes (~ MW 4-5) between May 2011 and April 2013 and the occurrence of deep-focus events with P axes along the dip direction of the subducting Pacific Plate in E-W vertical cross-sectional view and in WNW-ESE direction in map view.

  14. Relationship between Earth's Rotation and Several Strong Earthquakes and Moderate-small Earthquakes Occurring around the Epicenter Regions Prior to Strong Earthquakes

    Institute of Scientific and Technical Information of China (English)

    Wang Hengxin; Zhao Xiaoyan; Li Yan'e; Chen Xuezhong

    2011-01-01

    The relationships between Earth's rotation and the 1975 Haicheng, Liaoning Ms7.3 earthquake, 2008 Wenchuan, Sichuan Ms8.0 earthquake and the 2004 Sumatra Msg. 0 earthquake, as well as moderate-small earthquakes occurring around the epicenter regions prior to them are investigated in this study. The obtained results could benefit the further understanding of the relationship between the Earth's rotation and earthquakes.

  15. Systematic Characterization of Radiated Energy and Static Stress Drop of Global Subduction Earthquakes from Source Time Functions Analysis

    Science.gov (United States)

    Vallee, M.; Chounet, A.

    2014-12-01

    Source Time Functions (STFs) describe how the seismic moment (Mo) is released with time. In addition to moment magnitude Mw, they carry information on more detailed rupture properties, such as static stress drop Δσ and radiated energy Er. Here we systematically analyze a set of 1500 STFs extracted from the SCARDEC method (Vallée et al 2011), containing the Mw>5.8, shallow (zglobal scale, we confirm the scale-invariance of Δσ with magnitude, while the apparent stress µEr/Mo slightly increases with seismic moment. In a second step, the source parameters distribution is investigated in light of the tectonic context of the earthquakes: we find that subduction interplate earthquakes have lower stress drop and apparent stress relative to all other earthquakes (e.g. crustal earthquakes), in agreement with other approaches (Houston, 2001; Allmann and Shearer, 2009). This observation may reflect the fact that subduction plate boundaries host a very large number of earthquakes, making the fault zone "mature"; or, it may be the consequence of the hydrated subducted materials leading to specific frictional properties. This finding may explain why damages observed after crustal earthquakes tend to be larger than the ones due to subduction earthquakes of the same magnitude. We finally focus on subduction interplate earthquakes (approximately 700 earthquakes) by considering 18 regional segments of subduction zones. We find that these segments do not have the same signature in terms of dynamic rupture properties, which means that large scale plate convergence properties influence rupture behavior. In a given segment, local heterogeneities of stress drop or radiated energy can be associated with local features of the subduction zone: in particular, we find that low coupled zones generate earthquakes with low stress drop and apparent stress.

  16. Understanding earthquake design criteria used in Japan

    International Nuclear Information System (INIS)

    This paper summarizes the current earthquake design criteria used in Japan for nuclear power plants. Information is presented on the codes and standards and seismic requirements for reactor buildings and containment structures. The most interesting features of the earthquake design criteria used in Japan, in the light of those used in the United States, are summarized

  17. Stress,strain and earthquake activity

    Institute of Scientific and Technical Information of China (English)

    Yaolin Shi

    2009-01-01

    @@ There are 13 papers in this special issue on stress field,crustal deformation and seismicity.The great Wenchuan earthquake is a grievous disaster,but Chinese scientists are trying to learn more from the event in order to understand better the physics of earthquakes for future hazard mitigation planning.

  18. Wood-framed houses for earthquake zones

    DEFF Research Database (Denmark)

    Hansen, Klavs Feilberg

    Wood-framed houses with a sheathing are suitable for use in earthquake zones. The Direction describes a method of determining the earthquake forces in a house and shows how these forces can be resisted by diaphragm action in the walls, floors, and roof, of the house. An appendix explains how to...

  19. Forecasting characteristic earthquakes in a minimalist model

    DEFF Research Database (Denmark)

    Vázquez-Prada, M.; Pacheco, A.; González, Á.;

    2003-01-01

    Using error diagrams, we quantify the forecasting of characteristic-earthquake occurence in a recently introduced minimalist model. Initially we connect the earthquake alarm at a fixed time after the occurence of a characteristic event. The evaluation of this strategy leads to a one...

  20. Earthquake effect on the geological environment

    International Nuclear Information System (INIS)

    Acceleration caused by the earthquake, changes in the water pressure, and the rock-mass strain were monitored for a series of 344 earthquakes from 1990 to 1998 at Kamaishi In Situ Test Site. The largest acceleration was registered to be 57.14 gal with the earthquake named 'North coast of Iwate Earthquake' (M4.4) occurred in June, 1996. Changes of the water pressure were recorded with 27 earthquakes; the largest change was -0.35 Kgt/cm2. The water-pressure change by earthquake was, however, usually smaller than that caused by rainfall in this area. No change in the electric conductivity or pH of ground water was detected before and after the earthquake throughout the entire period of monitoring. The rock-mass strain was measured with a extensometer whose detection limit was of the order of 10-8 to 10-9 degrees and the remaining strain of about 2.5x10-9 degrees was detected following the 'Offshore Miyagi Earthquake' (M5.1) in October, 1997. (H. Baba)

  1. Structural Earthquake Resistance Design Using Energy Method

    Institute of Scientific and Technical Information of China (English)

    Hu Rongrong

    2003-01-01

    A summary of status of researches in the field of structural earthquake resistance design on energy concept is presented in three parts: earthquake input, demands on the structure and supplied capacity of the structure. A new approach is proposed for analysis of the seismic response and damage criteria based on the momentary input energy.

  2. Research on Earthquakes in Cities of China

    Institute of Scientific and Technical Information of China (English)

    Shi Zhenliang; Cao Xuefeng; Yan Xiujie

    2003-01-01

    In this paper, we briefly describe the general destruction caused by historic earthquakes inmajor cities of China, preliminarily analyze the heaviness and widespread occurrence ofearthquakes in cities of China, and suggest that research on scenario earthquakes in citiesshotdd be developed as a part urban disaster reduction research.

  3. Acoustic wave-equation-based earthquake location

    Science.gov (United States)

    Tong, Ping; Yang, Dinghui; Liu, Qinya; Yang, Xu; Harris, Jerry

    2016-04-01

    We present a novel earthquake location method using acoustic wave-equation-based traveltime inversion. The linear relationship between the location perturbation (δt0, δxs) and the resulting traveltime residual δt of a particular seismic phase, represented by the traveltime sensitivity kernel K(t0, xs) with respect to the earthquake location (t0, xs), is theoretically derived based on the adjoint method. Traveltime sensitivity kernel K(t0, xs) is formulated as a convolution between the forward and adjoint wavefields, which are calculated by numerically solving two acoustic wave equations. The advantage of this newly derived traveltime kernel is that it not only takes into account the earthquake-receiver geometry but also accurately honours the complexity of the velocity model. The earthquake location is obtained by solving a regularized least-squares problem. In 3-D realistic applications, it is computationally expensive to conduct full wave simulations. Therefore, we propose a 2.5-D approach which assumes the forward and adjoint wave simulations within a 2-D vertical plane passing through the earthquake and receiver. Various synthetic examples show the accuracy of this acoustic wave-equation-based earthquake location method. The accuracy and efficiency of the 2.5-D approach for 3-D earthquake location are further verified by its application to the 2004 Big Bear earthquake in Southern California.

  4. Earthquake engineering research program in Chile

    Science.gov (United States)

    Saragoni, G. R.

    1982-01-01

    Earthquake engineering research in Chile has been carried out for more than 30 years. Systematic research is done at the university of Chile in Santiago. Other universities such as the Catholic University, university of Concepcion, and the Federico Santa Maria Technical University have begun to teach and conduct research in earthquake engineering in recent years. 

  5. Earthquake swarms reveal submarine magma unrest induced by distant mega-earthquakes: Andaman Sea region

    Science.gov (United States)

    Špičák, Aleš; Vaněk, Jiří

    2016-02-01

    Little is known about earthquake-triggered magma intrusions or eruptions of submarine volcanoes. The analysis of teleseismic earthquake occurrence performed in this study offers a tool to address such enigmatic and inaccessible processes. In the past ten years, the Andaman Sea region repeatedly became a site of shallow earthquake swarms that followed distant mega-earthquakes by days to weeks. The MW 9.1 December 26, 2004 Sumatra-Andaman earthquake was followed by two earthquake swarms about 600 km northward in the Andaman Sea region, delayed by 30 and 35 days, respectively. Earthquakes of one of these seismic episodes, the extensive January 2005 earthquake swarm, migrated laterally at a rate of about 0.25 km per hour during the swarm evolution. The strong Indian Ocean MW 8.6 and 8.2 April 11, 2012 earthquake doublet west of Northern Sumatra was followed by an earthquake swarm approximately 800 km northward in the Andaman Sea region, delayed by 13 days. All the three swarms that followed the 2004 and 2012 mega-earthquakes occurred beneath distinct seamounts and seafloor ridges. Based on the observations of migration of earthquakes during the swarm and swarm occurrence beneath distinct highs at the seafloor, we conclude that these earthquake swarms probably resulted as a consequence of magma unrest induced by static and/or dynamic stress changes following the distant mega-earthquakes. Repeated occurrence of such a phenomenon suggests that the arc magma reservoirs beneath the Andaman Sea have recently reached some form of criticality and are vulnerable to even small stress changes. The Andaman seafloor could thus become a site of submarine volcanic eruptions in near future and deserves close attention of Earth scientists.

  6. Deterministic Earthquake Scenarios for the City of Sofia

    Science.gov (United States)

    Slavov, S.; Paskaleva, I.; Kouteva, M.; Vaccari, F.; Panza, G. F.

    The city of Sofia is exposed to a high seismic risk. Macroseismic intensities in the range of VIII - X (MSK) can be expected in the city. The earthquakes that can influence the hazard in Sofia originate either beneath the city or are caused by seismic sources located within a radius of 40 km. The city of Sofia is also prone to the remote Vrancea seismic zone in Romania, and particularly vulnerable are the long-period elements of the built environment. The high seismic risk and the lack of instrumental recordings of the regional seismicity make the use of appropriate credible earthquake scenarios and ground-motion modelling approaches for defining the seismic input for the city of Sofia necessary. Complete synthetic seismic signals, due to several earthquake scenarios, were computed along chosen geological profiles crossing the city, applying a hybrid technique, which combines the modal summation technique and finite differences. The modelling takes into account simultaneously the geotechnical properties of the site, the position and geometry of the seismic source and the mechanical properties of the propagation medium. Acceleration, velocity and displacement time histories and related quantities of earthquake engineering interest (e.g., response spectra, ground-motion amplification along the profiles) have been supplied. The approach applied in this study allows us to obtain the definition of the seismic input at low cost, exploiting large quantities of existing data (e.g. geotechnical, geological, seismological). It may be efficiently used to estimate the ground motion for the purposes of microzonation, urban planning, retrofitting or insurance of the built environment, etc.

  7. Scale models for studying the soil-structure interaction during earthquakes

    International Nuclear Information System (INIS)

    This paper deals with scale modelling for earthquake problems, taking into account the three different time scales according to inertia, liquefaction and viscosity. The methods of centrifugation, hydraulic gradient and two-dimensional sand are compared to each other. Improvements to the method of two-dimensional sand are presented in order to consider the influence of viscosity

  8. History of earthquake studies in Russia

    Directory of Open Access Journals (Sweden)

    R. Tatevossian

    2004-06-01

    Full Text Available To evaluate the completeness of modern knowledge on historical seismicity it is necessary to know the general geopolitical and socio-cultural background in the country. It determines the possibility to record the evidence of an earthquake and conserve the record in original form for a long time-period. The potential duration of historical earthquake study in Russia is assessed based on these considerations. Certain stages of earthquake study in Russia have been detected. Specific problems of seismicity studies of low active areas are discussed as an example of Russian platform. The value of each (even moderate magnitude event becomes crucial for seismic hazard assessment in such territories. A correct identification of event nature (tectonic earthquake or exogenous phenomena - landslides, karsts, etc. is practically impossible without using primary sources with detailed descriptions. Occurrence of modern earthquakes can be used to assess the accuracy of historical seismicity knowledge.

  9. Low cost earthquake resistant ferrocement small house

    International Nuclear Information System (INIS)

    The greatest humanitarian challenge faced even today after one year of Kashmir Hazara earthquake is that of providing shelter. Currently on the globe one in seven people live in a slum or refugee camp. The earthquake of October 2005 resulted in a great loss of life and property. This research work is mainly focused on developing a design of small size, low cost and earthquake resistant house. Ferrocement panels are recommended as the main structural elements with lightweight truss roofing system. Earthquake resistance is ensured by analyzing the structure on ETABS for a seismic activity of zone 4. The behavior of structure is found satisfactory under the earthquake loading. An estimate of cost is also presented which shows that it is an economical solution. (author)

  10. Parallelization of the Coupled Earthquake Model

    Science.gov (United States)

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

    2007-01-01

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

  11. Antioptimization of earthquake exitation and response

    Directory of Open Access Journals (Sweden)

    G. Zuccaro

    1998-01-01

    Full Text Available The paper presents a novel approach to predict the response of earthquake-excited structures. The earthquake excitation is expanded in terms of series of deterministic functions. The coefficients of the series are represented as a point in N-dimensional space. Each available ccelerogram at a certain site is then represented as a point in the above space, modeling the available fragmentary historical data. The minimum volume ellipsoid, containing all points, is constructed. The ellipsoidal models of uncertainty, pertinent to earthquake excitation, are developed. The maximum response of a structure, subjected to the earthquake excitation, within ellipsoidal modeling of the latter, is determined. This procedure of determining least favorable response was termed in the literature (Elishakoff, 1991 as an antioptimization. It appears that under inherent uncertainty of earthquake excitation, antioptimization analysis is a viable alternative to stochastic approach.

  12. Daytime variations of foE connected to earthquakes

    Science.gov (United States)

    Liperovskaya, E. V.; Bogdanov, V. V.; Biagi, P.-F.; Meister, C.-V.; Liperovsky, V. A.

    2011-06-01

    In the present work it is shown that, in accordance with the observations of the vertical sounding station "Tashkent", the critical foE-frequency of the daytime E-layer increases about one day before winter-earthquakes with magnitudes M > 5 and depths of the epicentre of h E-layer influence the ionisation density in the F-region. Therefore, no synchronous growth of the foE- and foF2-frequencies 1-2 days before seismic shocks could be observed.

  13. Earthquake response considerations of broad liquid storage tanks

    Science.gov (United States)

    Cambra, F. J.

    1982-11-01

    The influences of tank geometry and foundation stiffness variation on the simulated seismic structural response of a model broad tank are discussed. An empirical method for describing tank bottom plate uplift geometry is proposed which recognizes radial catenary force and foundation stiffness. Axial symmetric lift, static tilt and dynamic shaking table tests were performed in the University of California, Berkeley, earthquake simulator laboratory. A structural geometric survey of a 63 ft - 10 inches tall by 289 ft - 6 inches diameter crude oil storage tank was conducted to establish a comparative base by which to evaluate the model tank eccentricities.

  14. Use of earthquake experience data

    International Nuclear Information System (INIS)

    At many of the older existing US Department of Energy (DOE) facilities, the need has arisen for evaluation guidelines for natural phenomena hazard assessment. The effect of a design basis earthquake at most of these facilities is one of the main concerns. Earthquake experience data can provide a basis for the needed seismic evaluation guidelines, resulting in an efficient screening evaluation methodology for several of the items that are in the scope of the DOE facility reviews. The experience-based screening evaluation methodology, when properly established and implemented by trained engineers, has proven to result in sufficient safety margins and focuses on real concerns via facility walkdowns, usually at costs much less than the alternative options of analysis and testing. This paper summarizes a program that is being put into place to establish uniform seismic evaluation guidelines and criteria for evaluation of existing DOE facilities. The intent of the program is to maximize use of past experience, in conjunction with a walkdown screening evaluation process

  15. Ground motion modeling of the 1906 San Francisco earthquake II: Ground motion estimates for the 1906 earthquake and scenario events

    Energy Technology Data Exchange (ETDEWEB)

    Aagaard, B; Brocher, T; Dreger, D; Frankel, A; Graves, R; Harmsen, S; Hartzell, S; Larsen, S; McCandless, K; Nilsson, S; Petersson, N A; Rodgers, A; Sjogreen, B; Tkalcic, H; Zoback, M L

    2007-02-09

    We estimate the ground motions produced by the 1906 San Francisco earthquake making use of the recently developed Song et al. (2008) source model that combines the available geodetic and seismic observations and recently constructed 3D geologic and seismic velocity models. Our estimates of the ground motions for the 1906 earthquake are consistent across five ground-motion modeling groups employing different wave propagation codes and simulation domains. The simulations successfully reproduce the main features of the Boatwright and Bundock (2005) ShakeMap, but tend to over predict the intensity of shaking by 0.1-0.5 modified Mercalli intensity (MMI) units. Velocity waveforms at sites throughout the San Francisco Bay Area exhibit characteristics consistent with rupture directivity, local geologic conditions (e.g., sedimentary basins), and the large size of the event (e.g., durations of strong shaking lasting tens of seconds). We also compute ground motions for seven hypothetical scenarios rupturing the same extent of the northern San Andreas fault, considering three additional hypocenters and an additional, random distribution of slip. Rupture directivity exerts the strongest influence on the variations in shaking, although sedimentary basins do consistently contribute to the response in some locations, such as Santa Rosa, Livermore, and San Jose. These scenarios suggest that future large earthquakes on the northern San Andreas fault may subject the current San Francisco Bay urban area to stronger shaking than a repeat of the 1906 earthquake. Ruptures propagating southward towards San Francisco appear to expose more of the urban area to a given intensity level than do ruptures propagating northward.

  16. Earthquake-Ionosphere Coupling Processes

    Science.gov (United States)

    Kamogawa, Masashi

    After a giant earthquake (EQ), acoustic and gravity waves are excited by the displacement of land and sea surface, propagate through atmosphere, and then reach thermosphere, which causes ionospheric disturbances. This phenomenon was detected first by ionosonde and by HF Doppler sounderin the 1964 M9.2 Great Alaskan EQ. Developing Global Positioning System (GPS), seismogenic ionospheric disturbance detected by total electron content (TEC) measurement has been reported. A value of TEC is estimated by the phase difference between two different carrier frequencies through the propagation in the dispersive ionospheric plasma. The variation of TEC is mostly similar to that of F-region plasma. Acoustic-gravity waves triggered by an earthquake [Heki and Ping, EPSL, 2005; Liu et al., JGR, 2010] and a tsunami [Artu et al., GJI, 2005; Liu et al., JGR, 2006; Rolland, GRL, 2010] disturb the ionosphere and travel in the ionosphere. Besides the traveling ionospheric disturbances, ionospheric disturbances excited by Rayleigh waves [Ducic et al, GRL, 2003; Liu et al., GRL, 2006] as well as post-seismic 4-minute monoperiodic atmospheric resonances [Choosakul et al., JGR, 2009] have been observed after the large earthquakes. Since GPS Earth Observation Network System (GEONET) with more than 1200 GPS receiving points in Japan is a dense GPS network, seismogenic ionospheric disturbance is spatially observed. In particular, the seismogenic ionospheric disturbance caused by the M9.0 off the Pacific coast of Tohoku EQ (henceforth the Tohoku EQ) on 11 March 2011 was clearly observed. Approximately 9 minutes after the mainshock, acoustic waves which propagated radially emitted from the tsunami source area were observed through the TEC measurement (e. g., Liu et al. [JGR, 2011]). Moreover, there was a depression of TEC lasting for several tens of minutes after a huge earthquake, which was a large-scale phenomenon extending to a radius of a few hundred kilometers. This TEC depression may be

  17. Spatial distributions of earthquake-induced landslides and hillslope preconditioning in the northwest South Island, New Zealand

    Science.gov (United States)

    Parker, R. N.; Hancox, G. T.; Petley, D. N.; Massey, C. I.; Densmore, A. L.; Rosser, N. J.

    2015-10-01

    Current models to explain regional-scale landslide events are not able to account for the possible effects of the legacy of previous earthquakes, which have triggered landslides in the past and are known to drive damage accumulation in brittle hillslope materials. This paper tests the hypothesis that spatial distributions of earthquake-induced landslides are determined by both the conditions at the time of the triggering earthquake (time-independent factors) and the legacy of past events (time-dependent factors). To explore this, we undertake an analysis of failures triggered by the 1929 Buller and 1968 Inangahua earthquakes, in the northwest South Island of New Zealand. The spatial extents of landslides triggered by these events were in part coincident. Spatial distributions of earthquake-triggered landslides are determined by a combination of earthquake and local characteristics, which influence the dynamic response of hillslopes. To identify the influence of a legacy from past events, we first use logistic regression to control for the effects of time-independent variables. Through this analysis we find that seismic ground motion, hillslope gradient, lithology, and the effects of topographic amplification caused by ridge- and slope-scale topography exhibit a consistent influence on the spatial distribution of landslides in both earthquakes. We then assess whether variability unexplained by these variables may be attributed to the legacy of past events. Our results suggest that hillslopes in regions that experienced strong ground motions in 1929 were more likely to fail in 1968 than would be expected on the basis of time-independent factors alone. This effect is consistent with our hypothesis that unfailed hillslopes in the 1929 earthquake were weakened by damage accumulated during this earthquake and its associated aftershock sequence, which influenced the behaviour of the landscape in the 1968 earthquake. While our results are tentative, they suggest that the

  18. Earthquakes

    Science.gov (United States)

    ... High-Pressure Water Injection Injury Trench Foot or Immersion Foot Emergency Wound Care Wound Management for Healthcare ... Pets Resources for Emergency Health Professionals Training and Education Social Media What CDC is Doing Blog: Public ...

  19. 33 CFR 222.4 - Reporting earthquake effects.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Reporting earthquake effects. 222..., DEPARTMENT OF DEFENSE ENGINEERING AND DESIGN § 222.4 Reporting earthquake effects. (a) Purpose. This... significant earthquakes. It primarily concerns damage surveys following the occurrences of earthquakes....

  20. Scaling of Seismic Memory with Earthquake Size

    CERN Document Server

    Zheng, Zeyu; Tenenbaum, Joel; Podobnik, Boris; Stanley, H Eugene

    2011-01-01

    It has been observed that the earthquake events possess short-term memory, i.e. that events occurring in a particular location are dependent on the short history of that location. We conduct an analysis to see whether real-time earthquake data also possess long-term memory and, if so, whether such autocorrelations depend on the size of earthquakes within close spatiotemporal proximity. We analyze the seismic waveform database recorded by 64 stations in Japan, including the 2011 "Great East Japan Earthquake", one of the five most powerful earthquakes ever recorded which resulted in a tsunami and devastating nuclear accidents. We explore the question of seismic memory through use of mean conditional intervals and detrended fluctuation analysis (DFA). We find that the waveform sign series show long-range power-law anticorrelations while the interval series show long-range power-law correlations. We find size-dependence in earthquake auto-correlations---as earthquake size increases, both of these correlation beha...

  1. A critical history of British earthquakes

    Directory of Open Access Journals (Sweden)

    R. M. W. Musson

    2004-06-01

    Full Text Available This paper reviews the history of the study of historical British earthquakes. The publication of compendia of British earthquakes goes back as early as the late 16th Century. A boost to the study of earthquakes in Britain was given in the mid 18th Century as a result of two events occurring in London in 1750 (analogous to the general increase in earthquakes in Europe five years later after the 1755 Lisbon earthquake. The 19th Century saw a number of significant studies, culminating in the work of Davison, whose book-length catalogue was published finally in 1924. After that appears a gap, until interest in the subject was renewed in the mid 1970s. The expansion of the U.K. nuclear programme in the 1980s led to a series of large-scale investigations of historical British earthquakes, all based almost completely on primary historical data and conducted to high standards. The catalogue published by BGS in 1994 is a synthesis of these studies, and presents a parametric catalogue in which historical earthquakes are assessed from intensity data points based on primary source material. Since 1994, revisions to parameters have been minor and new events discovered have been restricted to a few small events.

  2. Strong motion duration and earthquake magnitude relationships

    International Nuclear Information System (INIS)

    Earthquake duration is the total time of ground shaking from the arrival of seismic waves until the return to ambient conditions. Much of this time is at relatively low shaking levels which have little effect on seismic structural response and on earthquake damage potential. As a result, a parameter termed ''strong motion duration'' has been defined by a number of investigators to be used for the purpose of evaluating seismic response and assessing the potential for structural damage due to earthquakes. This report presents methods for determining strong motion duration and a time history envelope function appropriate for various evaluation purposes, for earthquake magnitude and distance, and for site soil properties. There are numerous definitions of strong motion duration. For most of these definitions, empirical studies have been completed which relate duration to earthquake magnitude and distance and to site soil properties. Each of these definitions recognizes that only the portion of an earthquake record which has sufficiently high acceleration amplitude, energy content, or some other parameters significantly affects seismic response. Studies have been performed which indicate that the portion of an earthquake record in which the power (average rate of energy input) is maximum correlates most closely with potential damage to stiff nuclear power plant structures. Hence, this report will concentrate on energy based strong motion duration definitions

  3. Seismicity prior to the 2016 Kumamoto earthquakes

    CERN Document Server

    Nanjo, K Z; Orihara, Y; Furuse, N; Togo, S; Nitta, H; Okada, T; Tanaka, R; Kamogawa, M; Nagao, T

    2016-01-01

    The 2016 Kumamoto earthquakes occurred under circumstance that seismicity remains high in all parts of Japan since the 2011 Tohoku-Oki earthquake. Identifying what happened before this incident is one starting point for promote earthquake forecast research to prepare for subsequent large earthquakes in the near future in Japan. Here we report precursory seismic patterns prior to the Kumamoto earthquakes, measured by four different methods based on seismicity changes that can be used for earthquake forecasting: b-value method, two kinds of seismic quiescence evaluation methods, and a method of detailed foreshock evaluation. The spatial extent of precursory patterns differs from one method to the other and ranges from local scales (typically asperity size), to regional scales (e.g., 2{\\deg} x 3{\\deg} around the source zone). The earthquakes are preceded by periods of pronounced anomalies, which lasted decade scales (e.g., 20 years or longer) to yearly scales (e.g., 1~2 years). We demonstrate that combination of...

  4. Ionospheric precursors for crustal earthquakes in Italy

    Science.gov (United States)

    Perrone, L.; Korsunova, L. P.; Mikhailov, A. V.

    2010-04-01

    Crustal earthquakes with magnitude 6.0>M≥5.5 observed in Italy for the period 1979-2009 including the last one at L'Aquila on 6 April 2009 were considered to check if the earlier obtained relationships for ionospheric precursors for strong Japanese earthquakes are valid for the Italian moderate earthquakes. The ionospheric precursors are based on the observed variations of the sporadic E-layer parameters (h'Es, fbEs) and foF2 at the ionospheric station Rome. Empirical dependencies for the seismo-ionospheric disturbances relating the earthquake magnitude and the epicenter distance are obtained and they have been shown to be similar to those obtained earlier for Japanese earthquakes. The dependences indicate the process of spreading the disturbance from the epicenter towards periphery during the earthquake preparation process. Large lead times for the precursor occurrence (up to 34 days for M=5.8-5.9) tells about a prolong preparation period. A possibility of using the obtained relationships for the earthquakes prediction is discussed.

  5. New geological perspectives on earthquake recurrence models

    International Nuclear Information System (INIS)

    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

  6. New geological perspectives on earthquake recurrence models

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, D.P. [Geological Survey, Menlo Park, CA (United States)

    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.

  7. Ionospheric precursors for crustal earthquakes in Italy

    Directory of Open Access Journals (Sweden)

    L. Perrone

    2010-04-01

    Full Text Available Crustal earthquakes with magnitude 6.0>M≥5.5 observed in Italy for the period 1979–2009 including the last one at L'Aquila on 6 April 2009 were considered to check if the earlier obtained relationships for ionospheric precursors for strong Japanese earthquakes are valid for the Italian moderate earthquakes. The ionospheric precursors are based on the observed variations of the sporadic E-layer parameters (h'Es, fbEs and foF2 at the ionospheric station Rome. Empirical dependencies for the seismo-ionospheric disturbances relating the earthquake magnitude and the epicenter distance are obtained and they have been shown to be similar to those obtained earlier for Japanese earthquakes. The dependences indicate the process of spreading the disturbance from the epicenter towards periphery during the earthquake preparation process. Large lead times for the precursor occurrence (up to 34 days for M=5.8–5.9 tells about a prolong preparation period. A possibility of using the obtained relationships for the earthquakes prediction is discussed.

  8. Smartphone MEMS accelerometers and earthquake early warning

    Science.gov (United States)

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

    2015-12-01

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

  9. Mapping of earthquakes vulnerability area in Papua

    Science.gov (United States)

    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.

  10. Earthquake rate and magnitude distributions of great earthquakes for use in global forecasts

    Science.gov (United States)

    Kagan, Yan Y.; Jackson, David D.

    2016-04-01

    We have obtained new results in the statistical analysis of global earthquake catalogs with special attention to the largest earthquakes, and we examined the statistical behavior of earthquake rate variations. These results can serve as an input for updating our recent earthquake forecast, known as the "Global Earthquake Activity Rate 1" model (GEAR1), which is based on past earthquakes and geodetic strain rates. The GEAR1 forecast is expressed as the rate density of all earthquakes above magnitude 5.8 within 70 km of sea level everywhere on earth at 0.1 by 0.1 degree resolution, and it is currently being tested by the Collaboratory for Study of Earthquake Predictability. The seismic component of the present model is based on a smoothed version of the Global Centroid Moment Tensor (GCMT) catalog from 1977 through 2013. The tectonic component is based on the Global Strain Rate Map, a "General Earthquake Model" (GEM) product. The forecast was optimized to fit the GCMT data from 2005 through 2012, but it also fit well the earthquake locations from 1918 to 1976 reported in the International Seismological Centre-Global Earthquake Model (ISC-GEM) global catalog of instrumental and pre-instrumental magnitude determinations. We have improved the recent forecast by optimizing the treatment of larger magnitudes and including a longer duration (1918-2011) ISC-GEM catalog of large earthquakes to estimate smoothed seismicity. We revised our estimates of upper magnitude limits, described as corner magnitudes, based on the massive earthquakes since 2004 and the seismic moment conservation principle. The new corner magnitude estimates are somewhat larger than but consistent with our previous estimates. For major subduction zones we find the best estimates of corner magnitude to be in the range 8.9 to 9.6 and consistent with a uniform average of 9.35. Statistical estimates tend to grow with time as larger earthquakes occur. However, by using the moment conservation principle that

  11. Earthquake rate and magnitude distributions of great earthquakes for use in global forecasts

    Science.gov (United States)

    Kagan, Yan Y.; Jackson, David D.

    2016-07-01

    We have obtained new results in the statistical analysis of global earthquake catalogues with special attention to the largest earthquakes, and we examined the statistical behaviour of earthquake rate variations. These results can serve as an input for updating our recent earthquake forecast, known as the `Global Earthquake Activity Rate 1' model (GEAR1), which is based on past earthquakes and geodetic strain rates. The GEAR1 forecast is expressed as the rate density of all earthquakes above magnitude 5.8 within 70 km of sea level everywhere on earth at 0.1 × 0.1 degree resolution, and it is currently being tested by the Collaboratory for Study of Earthquake Predictability. The seismic component of the present model is based on a smoothed version of the Global Centroid Moment Tensor (GCMT) catalogue from 1977 through 2013. The tectonic component is based on the Global Strain Rate Map, a `General Earthquake Model' (GEM) product. The forecast was optimized to fit the GCMT data from 2005 through 2012, but it also fit well the earthquake locations from 1918 to 1976 reported in the International Seismological Centre-Global Earthquake Model (ISC-GEM) global catalogue of instrumental and pre-instrumental magnitude determinations. We have improved the recent forecast by optimizing the treatment of larger magnitudes and including a longer duration (1918-2011) ISC-GEM catalogue of large earthquakes to estimate smoothed seismicity. We revised our estimates of upper magnitude limits, described as corner magnitudes, based on the massive earthquakes since 2004 and the seismic moment conservation principle. The new corner magnitude estimates are somewhat larger than but consistent with our previous estimates. For major subduction zones we find the best estimates of corner magnitude to be in the range 8.9 to 9.6 and consistent with a uniform average of 9.35. Statistical estimates tend to grow with time as larger earthquakes occur. However, by using the moment conservation

  12. Procedures and actions proposed in Belgium to improve the preparedness of the nuclear power plants in case of earthquakes

    International Nuclear Information System (INIS)

    In Belgium, an evaluation has been made on the actions and decisions to be taken after the occurrence of an earthquake which is felt in a nuclear power plant. Initially, the procedures recommended to stop the plant if the earthquake was above a certain level (OBE or S2 earthquake) or if some damage due to the earthquake was observed. No more details were given on the level of damage and its influence on the safety of the plant, as well as on the damaging potential of the earthquake. No indications were given to the operator on the type and the most likely location of the damage that he could observe after an earthquake. No priorities were given to the operator on the specific immediate actions to be taken in case of earthquake, in addition to the measures dictated by the safety rules. Moreover, if the decision was taken to stop the plant, no instructions were given about a verification of the readiness of the plant for a shut-down. No criteria were given to the operator to allow him to restart the plant when it had been stopped, in case of damage not affecting the safety of the plant. To answer these questions, it was decided to adapt the EPRI recommendations to the Belgian nuclear practice. This paper describes the procedures that were recommended by the authors to the Belgian utility for the immediate and restart actions after an earthquake, as well as the long term evaluations to be made to give the assurance that the plant is ready again to sustain a SSE or S1 earthquake. The authors have supplemented these procedures by a walk-down and a screening of the files of seismic evaluation of the equipment in order to set up a list of the most earthquake sensitive representative equipment and the associated locations. To enable the implementation of these procedures, it was necessary to replace the obsolete seismic instrumentation as well as to propose more realistic criteria to decide whether the observed earthquake was more severe than the reference earthquake (OBE

  13. Ionospheric Signatures of the Earthquake in South Korea on 31 March 2014

    Science.gov (United States)

    Choi, P. H.; Yoon, M.; Yang, Y. M.; Lee, J.; Komjathy, A.

    2015-12-01

    Previous studies on interactions between the atmospheric waves and ionospheric perturbations concluded that the acoustic-gravity waves triggered by solid earth events such as earthquakes, tsunamis and underground nuclear tests may be used in detecting the ionospheric perturbations. Ionospheric perturbations have been observed using sounding radars and GPS remote sensing techniques since 1970s. As primary examples, ionospheric disturbances associated with the Tohoku earthquake and tsunami on March 11, 2011 were observed and analyzed using GPS measurements. In this work, we processed GPS stations in South Korea and analyzed traveling ionospheric disturbances that were coincident with the 2014 South Korean earthquake. The 31 March 2014 earthquake occurred at 19:48 UTC and the magnitude of this event was registered to be 5.0 Mw. This earthquake is the fourth strongest in South Korea since records began. After analyzing GPS measurements from nearby stations, strong ionospheric perturbations were observed about 20 minutes after the reported event, and the disturbances were shown to have primarily a wave train with periods of 60-120 minutes. The maximum VTEC perturbations turned out to be between 0.6 to 1.3 TECU. In this research, we will analyze the characteristics of the detected ionospheric perturbations associated with the earthquake and compare these results with those from man-made earthquakes such as underground nuclear tests. These findings are expected to verify our modeling results. We also hope to get a better understanding of the influence of both natural hazards and man-made hazards on the temporal and spatial variability of the global ionosphere

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

    Science.gov (United States)

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

    2011-01-01

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

  15. Earthquake prediction with electromagnetic phenomena

    International Nuclear Information System (INIS)

    Short-term earthquake (EQ) prediction is defined as prospective prediction with the time scale of about one week, which is considered to be one of the most important and urgent topics for the human beings. If this short-term prediction is realized, casualty will be drastically reduced. Unlike the conventional seismic measurement, we proposed the use of electromagnetic phenomena as precursors to EQs in the prediction, and an extensive amount of progress has been achieved in the field of seismo-electromagnetics during the last two decades. This paper deals with the review on this short-term EQ prediction, including the impossibility myth of EQs prediction by seismometers, the reason why we are interested in electromagnetics, the history of seismo-electromagnetics, the ionospheric perturbation as the most promising candidate of EQ prediction, then the future of EQ predictology from two standpoints of a practical science and a pure science, and finally a brief summary

  16. Earthquake prediction with electromagnetic phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, Masashi, E-mail: hayakawa@hi-seismo-em.jp [Hayakawa Institute of Seismo Electomagnetics, Co. Ltd., University of Electro-Communications (UEC) Incubation Center, 1-5-1 Chofugaoka, Chofu Tokyo, 182-8585 (Japan); Advanced Wireless & Communications Research Center, UEC, Chofu Tokyo (Japan); Earthquake Analysis Laboratory, Information Systems Inc., 4-8-15, Minami-aoyama, Minato-ku, Tokyo, 107-0062 (Japan); Fuji Security Systems. Co. Ltd., Iwato-cho 1, Shinjyuku-ku, Tokyo (Japan)

    2016-02-01

    Short-term earthquake (EQ) prediction is defined as prospective prediction with the time scale of about one week, which is considered to be one of the most important and urgent topics for the human beings. If this short-term prediction is realized, casualty will be drastically reduced. Unlike the conventional seismic measurement, we proposed the use of electromagnetic phenomena as precursors to EQs in the prediction, and an extensive amount of progress has been achieved in the field of seismo-electromagnetics during the last two decades. This paper deals with the review on this short-term EQ prediction, including the impossibility myth of EQs prediction by seismometers, the reason why we are interested in electromagnetics, the history of seismo-electromagnetics, the ionospheric perturbation as the most promising candidate of EQ prediction, then the future of EQ predictology from two standpoints of a practical science and a pure science, and finally a brief summary.

  17. Optimal digitization of earthquake records

    International Nuclear Information System (INIS)

    The optimal time interval for sampling an earthquake timehistory in order to recover the orginal record in a unique manner is derived. If the sampling time interval is too large, the high frequency components of the timehistory can 'impersonate' low frequencies. This results in 'aliasing', which is a major source of distortion in the reconstruction of the original timehistory from its discretized values. In the present study, the optimal sampling time interval known as the Nyquist interval in signal processing is derived. The results indicate that if the optimal time interval is exceeded, loss of information occurs. The use of a smaller time interval results in additional computer cost without any increase in the information necessary to reconstruct the original timehistory. (Auth.)

  18. Magnitude and energy of earthquakes

    Directory of Open Access Journals (Sweden)

    Charles Francis Richter

    2010-02-01

    Full Text Available Discrepancies arise among magnitudes as derived from local earthquake data (ML, body waves (MB and surface waves (MS. The relation of ML to the others is as yet not definitive; but MS – mB = a (MS – b. The latest revision gives a = 0.37, b = 6.76. Pending further research it is recommended that ML continue to be used as heretofore, but MS (and ultimately ML should be referred to mB as a general standard, called the unified magnitude and denoted by m. Tentatively log E = 5.8 + 2.4 m (E in ergs. Revised tables and charts for determining m are given.

  19. Earthquake Risk - EARTHQUAKE_LIQUEFACTION_IN: Earthquake Paleoliquefaction Sites in Indiana (Indiana Geological Survey, 1:24,000, Point Shapefile)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — EARTHQUAKE_LIQUEFACTION_IN is a point shapefile that shows sites where paleoliquefaction features have been identified in the field by Pat Munson of the Indiana...

  20. Time-history simulation of civil architecture earthquake disaster relief- based on the three-dimensional dynamic finite element method

    Directory of Open Access Journals (Sweden)

    Liu Bing

    2014-10-01

    Full Text Available Earthquake action is the main external factor which influences long-term safe operation of civil construction, especially of the high-rise building. Applying time-history method to simulate earthquake response process of civil construction foundation surrounding rock is an effective method for the anti-knock study of civil buildings. Therefore, this paper develops a civil building earthquake disaster three-dimensional dynamic finite element numerical simulation system. The system adopts the explicit central difference method. Strengthening characteristics of materials under high strain rate and damage characteristics of surrounding rock under the action of cyclic loading are considered. Then, dynamic constitutive model of rock mass suitable for civil building aseismic analysis is put forward. At the same time, through the earthquake disaster of time-history simulation of Shenzhen Children’s Palace, reliability and practicability of system program is verified in the analysis of practical engineering problems.

  1. Strong Ground Motion in the 2011 Tohoku Earthquake: a 1Directional - 3Component Modeling

    CERN Document Server

    D'Avila, Maria Paola Santisi; Lenti, Luca

    2013-01-01

    Local wave amplification due to strong seismic motions in surficial multilayered soil is influenced by several parameters such as the wavefield polarization and the dynamic properties and impedance contrast between soil layers. The present research aims at investigating seismic motion amplification in the 2011 Tohoku earthquake through a one-directional three-component (1D-3C) wave propagation model. A 3D nonlinear constitutive relation for dry soils under cyclic loading is implemented in a quadratic line finite element model. The soil rheology is modeled by mean of a multi-surface cyclic plasticity model of the Masing-Prandtl-Ishlinskii-Iwan (MPII) type. Its major advantage is that the rheology is characterized by few commonly measured parameters. Ground motions are computed at the surface of soil profiles in the Tohoku area (Japan) by propagating 3C signals recorded at rock outcrops, during the 2011 Tohoku earthquake. Computed surface ground motions are compared to the Tohoku earthquake records at alluvial ...

  2. Sensitivity of earthquake risk models to uncertainties in hazards, exposure and vulnerability parameters

    International Nuclear Information System (INIS)

    Sensitivity of earthquake risk models to uncertainties in hazard, exposure and vulnerability components has been investigated. The study is conducted for two test beds with distinctive socio-economic characteristics; Zeytinburnu and Los Angeles. Results are evaluated in terms of overall damage estimates as well as damage estimates of individual building typologies relative to one another. The distribution of damage estimates shows that the respective earthquake risk models are significantly affected by the vulnerability model. Further, the vulnerability model used in the earthquake risk model also influences the ranking of the building typologies according to their damage estimates. In comparison to that, the quality and the level of details of the building exposure database and the selected ground motion prediction equation seem to have less effect on the damage estimates. (author)

  3. Earthquake Energy Distribution along the Earth Surface and Radius

    International Nuclear Information System (INIS)

    The global earthquake catalog of seismic events with MW ≥ 7.0, for the time interval from 1950 to 2007, shows that the depth distribution of earthquake energy release is not uniform. The 90% of the total earthquake energy budget is dissipated in the first ∼30km, whereas most of the residual budget is radiated at the lower boundary of the transition zone (410 km - 660 km), above the upper-lower mantle boundary. The upper border of the transition zone at around 410 km of depth is not marked by significant seismic energy release. This points for a non-dominant role of the slabs in the energy budged of plate tectonics. Earthquake number and energy release, although not well correlated, when analysed with respect to the latitude, show a decrease toward the polar areas. Moreover, the radiated energy has the highest peak close to (±5o) the so-called tectonic equator defined by Crespi et al. (2007), which is inclined about 30o with respect to the geographic equator. At the same time the presence of a clear axial co- ordination of the radiated seismic energy is demonstrated with maxima at latitudes close to critical (±45o). This speaks about the presence of external forces that influence seismicity and it is consistent with the fact that Gutenberg-Richter law is linear, for events with M>5, only when the whole Earth's seismicity is considered. These data are consistent with an astronomical control on plate tectonics, i.e., the despinning (slowing of the Earth's angular rotation) of the Earth's rotation caused primarily by the tidal friction due to the Moon. The mutual position of the shallow and ∼660 km deep earthquake energy sources along subduction zones allows us to conclude that they are connected with the same slab along the W-directed subduction zones, but they may rather be disconnected along the opposed E-NE-directed slabs, being the deep seismicity controlled by other mechanisms. (author)

  4. Characteristics of 2009 L'Aquila earthquake with an emphasis on earthquake prediction and geotechnical damage

    OpenAIRE

    アイダン, オメル||Aydan, Ömer; KUMSAR, Halil; Toprak, Selçuk; Barla, Giovanni

    2010-01-01

    The 2009 L'Aquila earthquake with moment magnitude Mw 6.3 occurred in the Abruzzi Region in Central Italy. The earthquake caused the loss of 294 lives and the casualties were particularly heavy in the old city of L'Aquila. The authors have readily investigated the damages due to this earthquake, which was caused by a normal fault with the heavily damaged part being on the hanging-wall side of the causative fault. Approximately 2 weeks before the earthquake, a technician involved with radon mo...

  5. GPS Technologies as a Tool to Detect the Pre-Earthquake Signals Associated with Strong Earthquakes

    Science.gov (United States)

    Pulinets, S. A.; Krankowski, A.; Hernandez-Pajares, M.; Liu, J. Y. G.; Hattori, K.; Davidenko, D.; Ouzounov, D.

    2015-12-01

    The existence of ionospheric anomalies before earthquakes is now widely accepted. These phenomena started to be considered by GPS community to mitigate the GPS signal degradation over the territories of the earthquake preparation. The question is still open if they could be useful for seismology and for short-term earthquake forecast. More than decade of intensive studies proved that ionospheric anomalies registered before earthquakes are initiated by processes in the boundary layer of atmosphere over earthquake preparation zone and are induced in the ionosphere by electromagnetic coupling through the Global Electric Circuit. Multiparameter approach based on the Lithosphere-Atmosphere-Ionosphere Coupling model demonstrated that earthquake forecast is possible only if we consider the final stage of earthquake preparation in the multidimensional space where every dimension is one from many precursors in ensemble, and they are synergistically connected. We demonstrate approaches developed in different countries (Russia, Taiwan, Japan, Spain, and Poland) within the framework of the ISSI and ESA projects) to identify the ionospheric precursors. They are also useful to determine the all three parameters necessary for the earthquake forecast: impending earthquake epicenter position, expectation time and magnitude. These parameters are calculated using different technologies of GPS signal processing: time series, correlation, spectral analysis, ionospheric tomography, wave propagation, etc. Obtained results from different teams demonstrate the high level of statistical significance and physical justification what gives us reason to suggest these methodologies for practical validation.

  6. Contribution of Turkish Scholars to Earthquake Literature: The Impact of the Marmara Earthquake

    OpenAIRE

    Taşkın, Zehra

    2010-01-01

    This paper addresses the question of whether the Marmara Earthquake of August 17, 1999, has had an impact on the contribution of Turkish scholars to the earthquake literature. We identified a total of 1,098 papers published between 1990 and 2009 by Turkish earthquake scientists. These papers were cited 7,691 times. Both the number of papers and the citations they generated increased considerably after the Marmara Earthquake. This may be explained, in part, by the increase in the number of pro...

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

    Science.gov (United States)

    Oommen, Thomas; Rebbapragada, Umaa; Cerminaro, Daniel

    2012-01-01

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

  8. Magnetic storm free ULF analysis in relation with earthquakes in Taiwan

    Directory of Open Access Journals (Sweden)

    S. Wen

    2012-05-01

    Full Text Available Despite early optimism, pre-earthquake anomalous phenomena can be determined by using enhanced amplitude at the ultra-low-frequency range from geomagnetic data via the Fourier transform. In reality, accuracy of the enhanced amplitude in relation to earthquakes (deduced from time-varied geomagnetic data would be damaged by magnetic storms and/or other unwanted influences resulting from solar activity and/or variations in the ionosphere, respectively. We substitute values of the cross correlation between amplitudes, summarized from the earthquake-related (0.1–0.01 Hz and the comparable (0.01–0.001 Hz frequency bands, for isolated amplitude enhancements as indexes of determination associated with seismo-magnetic anomalies to mitigate disturbance caused by magnetic storms. A station located about 300 km away from the others is also taken into account to further examine whether changes of the cross correlation values are caused by seismo-magnetic anomalies limited within local regions or not. Analytical results show that the values suddenly decrease near epicenters a few days before and after 67% (= 6/9 of earthquakes (M > = 5 in Taiwan between September 2010 and March 2011. Seismo-magnetic signals determined by using the values of cross correlation methods partially improve results yielded from the Fourier transform alone and provide advantageous information of earthquake locations.

  9. Electro-diagnostic and Clinical Changes of Peripheral Neuropathies in Bam Earthquake Victims

    Directory of Open Access Journals (Sweden)

    Naser Zangiabadi

    2005-01-01

    Full Text Available To examine and diagnose patients who injured in Bam earthquake at 5:26:52 Am (local time on Friday, December 26, 2003 with traumatic peripheral neuropathies then treat and follow up. A longitudinal study was deigned. 159 patients with traumatic neuropathies were selected at the first stage of study. After six months follow up only 39 patients satisfied to enter the study. Clinical examination, Nerve conduction velocity, F wave and H wave were done and registered. The male and female frequency was equal (19M/20F and average of age was 31.1+/-11.6. During 6 months period following earthquake 19 cases (48.7% were improved in healing of neuropathies and were better in both neurological examination and electro-diagnostic tests. The repeated measurement analysis of variances did not reveal any difference in healing of nerves in sex and age groups. So patients'gender and age did not influence on recovery of neuropathies. The neuropathy injuries in Bam earthquake was the same as other earthquakes in Japan, China and Turkey, approximately. The notification to neuropathy in crush injuries and extremity damage for early diagnosis and treatment of neuropathies is considerable. At the earthquake disaster management, It is important that trained person rescue the victims to prevent extra injuries.

  10. Effects of acoustic waves on stick-slip in granular media and implications for earthquakes

    Science.gov (United States)

    Johnson, P.A.; Savage, H.; Knuth, M.; Gomberg, J.; Marone, C.

    2008-01-01

    It remains unknown how the small strains induced by seismic waves can trigger earthquakes at large distances, in some cases thousands of kilometres from the triggering earthquake, with failure often occurring long after the waves have passed. Earthquake nucleation is usually observed to take place at depths of 10-20 km, and so static overburden should be large enough to inhibit triggering by seismic-wave stress perturbations. To understand the physics of dynamic triggering better, as well as the influence of dynamic stressing on earthquake recurrence, we have conducted laboratory studies of stick-slip in granular media with and without applied acoustic vibration. Glass beads were used to simulate granular fault zone material, sheared under constant normal stress, and subject to transient or continuous perturbation by acoustic waves. Here we show that small-magnitude failure events, corresponding to triggered aftershocks, occur when applied sound-wave amplitudes exceed several microstrain. These events are frequently delayed or occur as part of a cascade of small events. Vibrations also cause large slip events to be disrupted in time relative to those without wave perturbation. The effects are observed for many large-event cycles after vibrations cease, indicating a strain memory in the granular material. Dynamic stressing of tectonic faults may play a similar role in determining the complexity of earthquake recurrence. ??2007 Nature Publishing Group.

  11. Key parameters for single-input earthquake analysis of arch dams

    Energy Technology Data Exchange (ETDEWEB)

    Proulx, J.; Ayala-Paredes, C. [Sherbrooke Univ., PQ (Canada). Dept. of Civil Engineering

    2010-07-01

    An adequate representation of a dam, its water reservoir and its foundation substructure is needed in modeling the earthquake response of concrete dams. Advanced three-dimensional finite element programs include sophisticated models to account for dam-reservoir-foundation interaction. The calibration of such programs and of their key parameters is best achieved by comparing the computed responses to recorded data obtained from on-site investigation or during actual earthquakes. This paper discussed the influence of the modeling parameters for the earthquake analysis of arch dams using single-input motions obtained from recorded earthquake data. The computed accelerations were compared to recordings of moderate earthquakes using three-dimensional numerical models with properties extracted from on-site dynamic test results for a large arch dam in Switzerland. The paper discussed model parameters for the dam, including mesh size; stiffness; damping; and foundation (damping). Several other important parameters related to the reservoir that were presented in a previous study were also briefly summarized. These parameters included geometry; water level; and damping by wave propagation and absorption. It was concluded that although the computation of a foundation impedance matrix could be time consuming, especially for larger models, the use of a finer, more complex mesh is necessary to predict the response in terms of amplitude and frequency content. 10 refs., 1 tab., 7 figs.

  12. Analysis of Taipei Basin Response for Earthquakes of Various Depths and Locations Using Empirical Data

    Directory of Open Access Journals (Sweden)

    Vladimir Sokolov

    2009-01-01

    Full Text Available The response of Taipei basin upon earthquake excitation was studied using records of recent earthquakes. The strong-motion database includes records obtained at 32 stations of the Taipei TSMIP net work from 83 deep and 142 shallow earthquakes (M > 4.0 that occurred in 1992 - 2004. The characteristics of frequency-de pendent site response were obtained as spectral ratios between the actual earthquake records (horizontal components and those modelled for a hypothetical Very Hard Rock (VHR condition. The models for VHR spectra of Taiwan earthquakes had been recently proposed by Sokolov et al. (2005b, 2006. Analysis of site response characteristics and comparison with simple 1D models of the soil column resulted in the following conclusions: (1 The spectral ratios through out the basin obtained from deep earth quakes (depth > 35 km exhibit good agreement with the theoretical ratios calculated using the 1D models constructed using avail able geological and geotechnical data. (2 The spectral ratios obtained from shallow earth quakes show influence of: (a surface waves generated when travelling from distant sources to the basin and (b relatively low-frequency (< 1 - 2 Hz waves generated within the basin. (3 Some shallow earth quakes pro duce extremely high amplification at frequencies 0.3 - 1 Hz within the basin that may be dangerous for high-rise buildings and high way bridges. (4 The obtained results may be used in probabilistic seismic microzonation of the basin when many possible earth quakes located at various distances are considered. 2D and 3D simulation is necessary to model the seismic influence from particularly large earthquakes.

  13. HAZGRIDX: earthquake forecasting model for ML ≥ 5.0 earthquakes in Italy based on spatially smoothed seismicity

    OpenAIRE

    Akinci, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia

    2010-01-01

    We present a five-year, time-independent, earthquake-forecast model for earthquake magnitudes of 5.0 and greater in Italy using spatially smoothed seismicity data. The model is called HAZGRIDX, and it was developed based on the assumption that future earthquakes will occur near locations of historical earthquakes; it does not take into account any information from tectonic, geological, or geodetic data. Thus HAZGRIDX is based on observed earthquake occurrence from seismicity data, without con...

  14. Adaptively Smoothed Seismicity Earthquake Forecasts for Italy

    CERN Document Server

    Werner, M J; Jackson, D D; Kagan, Y Y; Wiemer, S

    2010-01-01

    We present a model for estimating the probabilities of future earthquakes of magnitudes m > 4.95 in Italy. The model, a slightly modified version of the one proposed for California by Helmstetter et al. (2007) and Werner et al. (2010), approximates seismicity by a spatially heterogeneous, temporally homogeneous Poisson point process. The temporal, spatial and magnitude dimensions are entirely decoupled. Magnitudes are independently and identically distributed according to a tapered Gutenberg-Richter magnitude distribution. We estimated the spatial distribution of future seismicity by smoothing the locations of past earthquakes listed in two Italian catalogs: a short instrumental catalog and a longer instrumental and historical catalog. The bandwidth of the adaptive spatial kernel is estimated by optimizing the predictive power of the kernel estimate of the spatial earthquake density in retrospective forecasts. When available and trustworthy, we used small earthquakes m>2.95 to illuminate active fault structur...

  15. Masonry infill performance during the Northridge earthquake

    Energy Technology Data Exchange (ETDEWEB)

    Flanagan, R.D. [Lockheed Martin Energy Systems, Oak Ridge, TN (United States); Bennett, R.M.; Fischer, W.L. [Univ. of Tennesee, Knoxville, TN (United States); Adham, S.A. [Agbabian Associates, Pasadena, CA (United States)

    1996-03-08

    The response of masonry infills during the 1994 Northridge, California earthquake is described in terms of three categories: (1) lowrise and midrise structures experiencing large near field seismic excitations, (2) lowrise and midrise structures experiencing moderate far field excitation, and (3) highrise structures experiencing moderate far field excitation. In general, the infills provided a positive beneficial effect on the performance of the buildings, even those experiencing large peak accelerations near the epicenter. Varying types of masonry infills, structural frames, design conditions, and construction deficiencies were observed and their performance during the earthquake indicated. A summary of observations of the performance of infills in other recent earthquakes is given. Comparison with the Northridge earthquake is made and expected response of infill structures in lower seismic regions of the central and eastern United States is discussed.

  16. Earthquake Damage, Northern Iran, June 21, 1990

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A magnitude 7.7 earthquake occurred in the Gilan Province between the towns of Rudbar and Manjil in northern Iran on Thursday, June 21, 1990. The event, the largest...

  17. Earthquake networks based on similar activity patterns.

    Science.gov (United States)

    Tenenbaum, Joel N; Havlin, Shlomo; Stanley, H Eugene

    2012-10-01

    Earthquakes are a complex spatiotemporal phenomenon, the underlying mechanism for which is still not fully understood despite decades of research and analysis. We propose and develop a network approach to earthquake events. In this network, a node represents a spatial location while a link between two nodes represents similar activity patterns in the two different locations. The strength of a link is proportional to the strength of the cross correlation in activities of two nodes joined by the link. We apply our network approach to a Japanese earthquake catalog spanning the 14-year period 1985-1998. We find strong links representing large correlations between patterns in locations separated by more than 1000 kilometers, corroborating prior observations that earthquake interactions have no characteristic length scale. We find network characteristics not attributable to chance alone, including a large number of network links, high node assortativity, and strong stability over time. PMID:23214652

  18. El Quindio Colombia Earthquake, January 25, 1999

    Data.gov (United States)

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

  19. Computer systems for automatic earthquake detection

    Science.gov (United States)

    Stewart, S.W.

    1974-01-01

    U.S Geological Survey seismologists in Menlo park, California, are utilizing the speed, reliability, and efficiency of minicomputers to monitor seismograph stations and to automatically detect earthquakes. An earthquake detection computer system, believed to be the only one of its kind in operation, automatically reports about 90 percent of all local earthquakes recorded by a network of over 100 central California seismograph stations. The system also monitors the stations for signs of malfunction or abnormal operation. Before the automatic system was put in operation, all of the earthquakes recorded had to be detected by manually searching the records, a time-consuming process. With the automatic detection system, the stations are efficiently monitored continuously. 

  20. The enigmatic Bala earthquake of 1974

    Science.gov (United States)

    Musson, R. M. W.

    2006-10-01

    The earthquake that shook most of North Wales on the night of 23 January 1974 appears unremarkable from its entry in the UK earthquake catalogue. With a magnitude of 3.5 ML it represents the size of earthquake to be expected in the UK with a return period of about one year. However, the prominent atmospheric lights observed at the time of the shock led to speculation that an aircraft had crashed, and search-and-rescue teams were deployed. Since nothing was discovered, it was concluded that a meteorite was responsible; more imaginative members of the public decided (and still believe) that a UFO had crashed. In this paper the record of events is set out, and the nature of the earthquake is discussed with reference to its geological setting.

  1. Oil extraction linked to Oklahoma earthquakes

    Science.gov (United States)

    Woo, Marcus

    2014-08-01

    Pumping waste water into the ground - a by-product of new oil and gas extraction processes - was the likely cause of a recent surge of earthquakes in the US state of Oklahoma, according to researchers in the US.

  2. Is It Possible to Predict Strong Earthquakes?

    CERN Document Server

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

    2015-01-01

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

  3. Increased earthquake safety through optimised mounting concept

    International Nuclear Information System (INIS)

    Since Fukushima, there has been intensive work on earthquake safety in all nuclear power plants. A large part of these efforts aim at the earthquake safety of safety-relevant pipeline systems. The problem with earthquake safety here is not the pipeline system itself but rather its mountings and connections to components. This is precisely the topic that the KAE dealt with in years of research and development work. It has developed an algorithm that determines the optimal mounting concept with a few iteration steps depending on arbitrary combinations of loading conditions whilst maintaining compliance with relevant regulations for any pipeline systems. With this tool at hand, we are now in a position to plan and realise remedial measures accurately with minimum time and hardware expenditure, and so distinctly improve the earthquake safety of safety-relevant systems. (orig.)

  4. Disturbances in equilibrium function after major earthquake

    Science.gov (United States)

    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.

  5. NGA Nepal Earthquake Support Data Services

    Data.gov (United States)

    National Geospatial Intelligence Agency — In support of the Spring 2015 Nepal earthquake response, NGA is providing to the public and humanitarian disaster response community these Nepal data services. They...

  6. Power of earthquake cluster detection tests

    CERN Document Server

    de Oliveira, Felipe Dimer

    2012-01-01

    Testing the global earthquake catalogue for indications of non-Poissonian attributes has been an area of intense research, especially since the 2011 Tohoku earthquake. The usual approach is to test statistically for the hypothesis that the global earthquake catalogue is well explained by a Poissonian process. In this paper we analyse one aspect of this problem which has been disregarded by the literature: the power of such tests to detect non-Poissonian features if they existed; that is, the probability of type II statistical errors. We argue that the low frequency of large events and the brevity of our earthquake catalogues reduces the power of the statistical tests so that an unequivocal answer for this question is not granted. We do this by providing a counter example of a stochastic process that is clustered by construction and by analysing the resulting distribution of p-values given by the current tests.

  7. Frog Swarms: Earthquake Precursors or False Alarms?

    Science.gov (United States)

    Grant, Rachel A; Conlan, Hilary

    2013-01-01

    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 juvenile animals migrating away from their breeding pond, after a fruitful reproductive season. As amphibian populations undergo large fluctuations in numbers from year to year, this phenomenon will not occur on a yearly basis but will depend on successful reproduction, which is related to numerous climatic and geophysical factors. Hence, most large swarms of amphibians, particularly those involving very small frogs and occurring in late spring or summer, are not unusual and should not be considered earthquake precursors. In addition, it is likely that reports of several mass migration of small toads prior to the Great Sichuan Earthquake in 2008 were not linked to the subsequent M = 7.9 event (some occurred at a great distance from the epicentre), and were probably co

  8. Earthquakes in Italy: past, present and future

    Institute of Scientific and Technical Information of China (English)

    GianlucaValensise; AlessandroAmato; PaolaMontone; DanielaPantosti

    2003-01-01

    Italy has a long-standing tradition of earthquake investi-gations. Seismologists can rely on one of the longest and most detailed records of historical seismic#y, 20 years of homogeneous and reliable instrumental data, systematic and widespread active stress data and a comprehensive database of potential seismogenic sources. Here wed escribe these datasets and discuss how they may help usanticipate the large earthquakes of the future.

  9. Evaluation of near-field earthquake effects

    Energy Technology Data Exchange (ETDEWEB)

    Shrivastava, H.P.

    1994-11-01

    Structures and equipment, which are qualified for the design basis earthquake (DBE) and have anchorage designed for the DBE loading, do not require an evaluation of the near-field earthquake (NFE) effects. However, safety class 1 acceleration sensitive equipment such as electrical relays must be evaluated for both NFE and DBE since they are known to malfunction when excited by high frequency seismic motions.

  10. Postseismic stress diffusion associated with Sumatra earthquake

    OpenAIRE

    Pisani, A. R.; Istituto Nazionale di Geofisica e Vulcanologia - Roma - Italy; Melini, D.; Istituto Nazionale di Geofisica e Vulcanologia - Roma - Italy; Volpe, M.; Istituto Nazionale di Geofisica e Vulcanologia - Roma - Italy; Piersanti, A.; Istituto Nazionale di Geofisica e Vulcanologia - Roma - Italy

    2007-01-01

    The giant megathrust occurred on 26th December 2004 off the west coast of northern Sumatra perturbated the stress field configuration over a wide area surrounding the event source. By means of a viscoelastic spherical model of global postseismic deformation and a new computational finite elements package (FEMSA) we perform an analysis of the stress diffusion following the earthquake near and far from the Sunda trench. We evaluated the stress changes due to the Sumatra earthquake by p...

  11. Children and the San Fernando earthquake

    Science.gov (United States)

    Howard, S. J.

    1980-01-01

    Before dawn, on February 9, 1971, a magnitude 6.4 earthquake occurred in the San Fernando Valley of California. On the following day, theSan Fernando Valley Child Guidance Clinic, through radio and newspapers, offered mental health crises services to children frightened by the earthquake. Response to this invitation was immediate and almost overwhelming. During the first 2 weeks, the Clinic's staff counseled hundreds of children who were experiencing various degrees of anxiety. 

  12. The Development of an Earthquake Mind Mapping

    OpenAIRE

    Sri Adelila Sari; Nurul Husna

    2016-01-01

    The students were difficult to understand about earthquake caused the teaching methods used by teachers were still using the classic method. The teachers only used a textbook to teach the students without any other supporting equipments. Learning process by using the discourse method makes students thinking monotonically, so that only concentrated on the students' understanding of the matter presented by the teacher. Therefore, this study was aimed to develop an earthquake mind mapping to hel...

  13. Mexican Earthquakes and Tsunamis Catalog Reviewed

    Science.gov (United States)

    Ramirez-Herrera, M. T.; Castillo-Aja, R.

    2015-12-01

    Today the availability of information on the internet makes online catalogs very easy to access by both scholars and the public in general. The catalog in the "Significant Earthquake Database", managed by the National Center for Environmental Information (NCEI formerly NCDC), NOAA, allows access by deploying tabular and cartographic data related to earthquakes and tsunamis contained in the database. The NCEI catalog is the product of compiling previously existing catalogs, historical sources, newspapers, and scientific articles. Because NCEI catalog has a global coverage the information is not homogeneous. Existence of historical information depends on the presence of people in places where the disaster occurred, and that the permanence of the description is preserved in documents and oral tradition. In the case of instrumental data, their availability depends on the distribution and quality of seismic stations. Therefore, the availability of information for the first half of 20th century can be improved by careful analysis of the available information and by searching and resolving inconsistencies. This study shows the advances we made in upgrading and refining data for the earthquake and tsunami catalog of Mexico since 1500 CE until today, presented in the format of table and map. Data analysis allowed us to identify the following sources of error in the location of the epicenters in existing catalogs: • Incorrect coordinate entry • Place name erroneous or mistaken • Too general data that makes difficult to locate the epicenter, mainly for older earthquakes • Inconsistency of earthquakes and the tsunami occurrence: earthquake's epicenter located too far inland reported as tsunamigenic. The process of completing the catalogs directly depends on the availability of information; as new archives are opened for inspection, there are more opportunities to complete the history of large earthquakes and tsunamis in Mexico. Here, we also present new earthquake and

  14. Great Sumatra Earthquake Registers on Electrostatic Sensor

    OpenAIRE

    Röder, H.; Physikalisch Vulkanologisches Labor Universität Würzburg, Germany; Braun, T.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Schuhmann, W.; Physikalisch Vulkanologisches Labor Universität Würzburg, Germany; Boschi, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione AC, Roma, Italia; Büttner, R.; Physikalisch Vulkanologisches Labor Universität Würzburg, Germany; Zimanowski, B.; Physikalisch Vulkanologisches Labor Universität Würzburg, Germany

    2005-01-01

    Strong electrical signals that correspond to the Mw = 9.3 earthquake of 26 December 2004, which occurred at 0058:50.7 UTC off the west coast of northern Sumatra, Indonesia, were recorded by an electrostatic sensor (a device that detects short-term variations in Earth’s electrostatic fi eld) at a seismic station in Italy, which had been installed to study the infl uence of local earthquakes on a new landslide monitoring system. Electrical signals arrived at the st...

  15. Natural Gas Extraction, Earthquakes and House Prices

    OpenAIRE

    Hans R. A. Koster; Jos N. van Ommeren

    2015-01-01

    The production of natural gas is strongly increasing around the world. Long-run negative external effects of extraction are understudied and often ignored in social) cost-benefit analyses. One important example is that natural gas extraction leads to soil subsidence and subsequent induced earthquakes that may occur only after a couple of decades. We show that induced earthquakes that are noticeable to residents generate substantial non-monetary economic effects, as measured by their effects o...

  16. Earthquake detection through computationally efficient similarity search.

    Science.gov (United States)

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

    2015-12-01

    Seismology is experiencing rapid growth in the quantity of data, which has outpaced the development of processing algorithms. Earthquake detection-identification of seismic events in continuous data-is a fundamental operation for observational seismology. We developed an efficient method to detect earthquakes using waveform similarity that overcomes the disadvantages of existing detection methods. Our method, called Fingerprint And Similarity Thresholding (FAST), can analyze a week of continuous seismic waveform data in less than 2 hours, or 140 times faster than autocorrelation. FAST adapts a data mining algorithm, originally designed to identify similar audio clips within large databases; it first creates compact "fingerprints" of waveforms by extracting key discriminative features, then groups similar fingerprints together within a database to facilitate fast, scalable search for similar fingerprint pairs, and finally generates a list of earthquake detections. FAST detected most (21 of 24) cataloged earthquakes and 68 uncataloged earthquakes in 1 week of continuous data from a station located near the Calaveras Fault in central California, achieving detection performance comparable to that of autocorrelation, with some additional false detections. FAST is expected to realize its full potential when applied to extremely long duration data sets over a distributed network of seismic stations. The widespread application of FAST has the potential to aid in the discovery of unexpected seismic signals, improve seismic monitoring, and promote a greater understanding of a variety of earthquake processes. PMID:26665176

  17. Earthquakes trigger the loss of groundwater biodiversity

    Science.gov (United States)

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

    2014-09-01

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

  18. Critical behavior in earthquake energy dissipation

    Directory of Open Access Journals (Sweden)

    J. Wanliss

    2015-04-01

    Full Text Available We explore bursty multiscale energy dissipation from earthquakes flanked by latitudes 29 and 35.5° S, and longitudes 69.501 and 73.944° W (in the Chilean central zone. Our work compares the predictions of a theory of nonequilibrium phase transitions with nonstandard statistical signatures of earthquake complex scaling behaviors. For temporal scales less than than 84 h, time development of earthquake radiated energy activity follows an algebraic arrangement consistent with estimates from the theory of nonequilibrium phase transitions. There are no characteristic scales for probability distributions of sizes and lifetimes of the activity bursts in the scaling region. The power-law exponents describing the probability distributions suggest that the main energy dissipation takes place due to largest bursts of activity, such as major earthquakes, as opposed to smaller activations which contribute less significantly though they have greater relative occurrence. The results obtained provide statistical evidence that earthquake energy dissipation mechanisms are essentially "scale-free," displaying statistical and dynamical self-similarity. Our results provide some evidence that earthquake radiated energy and directed percolation belong to a similar universality class.

  19. Critical behavior in earthquake energy dissipation

    Science.gov (United States)

    Wanliss, J.; Muñoz, V.; Pastén, D.; Toledo, B.; Valdivia, J. A.

    2015-04-01

    We explore bursty multiscale energy dissipation from earthquakes flanked by latitudes 29 and 35.5° S, and longitudes 69.501 and 73.944° W (in the Chilean central zone). Our work compares the predictions of a theory of nonequilibrium phase transitions with nonstandard statistical signatures of earthquake complex scaling behaviors. For temporal scales less than than 84 h, time development of earthquake radiated energy activity follows an algebraic arrangement consistent with estimates from the theory of nonequilibrium phase transitions. There are no characteristic scales for probability distributions of sizes and lifetimes of the activity bursts in the scaling region. The power-law exponents describing the probability distributions suggest that the main energy dissipation takes place due to largest bursts of activity, such as major earthquakes, as opposed to smaller activations which contribute less significantly though they have greater relative occurrence. The results obtained provide statistical evidence that earthquake energy dissipation mechanisms are essentially "scale-free," displaying statistical and dynamical self-similarity. Our results provide some evidence that earthquake radiated energy and directed percolation belong to a similar universality class.

  20. Parameterization of historical earthquakes in Switzerland

    Science.gov (United States)

    Álvarez-Rubio, Sonia; Kästli, Philipp; Fäh, Donat; Sellami, Souad; Giardini, Domenico

    2012-01-01

    Macroseismic earthquake parameters of historical events have been reassessed in the framework of the update of the Earthquake Catalogue of Switzerland ECOS-09. The Bakun and Wentworth method (Bakun and Wentworth 1997) has been used to assess location, magnitude, and, when possible, focal depth. We apply a two-step procedure. Intensity attenuation is assessed first by fitting a model with a logarithmic and a linear term, using a set of 111 earthquakes. The magnitude range is 3 and 5.8. Then, intensity to magnitude relation is developed. A subset of the 111 events, all having an instrumental moment magnitude, was used to perform this intensity to magnitude calibration. Five final calibration strategies were developed based on different intensity calibration datasets, regionalized or non-regionalized models, and fixed or variable source depth. The final assessment of the macroseismic earthquake parameters is based on an expert judgment procedure, using the results derived from all five strategies, and taking into consideration the historical knowledge available for the particular earthquake. A bootstrap procedure has been applied to assess the uncertainty of parameters. Indicative lower and upper bounds of uncertainty are derived from distributions of location and magnitude for a number of events, obtained through bootstrap sampling of the intensity field and of the single intensity values. The final uncertainties are given in terms of parameter uncertainty classes already used in previous versions of the earthquake catalogue of Switzerland.

  1. Maximum magnitude earthquakes induced by fluid injection

    Science.gov (United States)

    McGarr, A.

    2014-02-01

    Analysis of numerous case histories of earthquake sequences induced by fluid injection at depth reveals that the maximum magnitude appears to be limited according to the total volume of fluid injected. Similarly, the maximum seismic moment seems to have an upper bound proportional to the total volume of injected fluid. Activities involving fluid injection include (1) hydraulic fracturing of shale formations or coal seams to extract gas and oil, (2) disposal of wastewater from these gas and oil activities by injection into deep aquifers, and (3) the development of enhanced geothermal systems by injecting water into hot, low-permeability rock. Of these three operations, wastewater disposal is observed to be associated with the largest earthquakes, with maximum magnitudes sometimes exceeding 5. To estimate the maximum earthquake that could be induced by a given fluid injection project, the rock mass is assumed to be fully saturated, brittle, to respond to injection with a sequence of earthquakes localized to the region weakened by the pore pressure increase of the injection operation and to have a Gutenberg-Richter magnitude distribution with a b value of 1. If these assumptions correctly describe the circumstances of the largest earthquake, then the maximum seismic moment is limited to the volume of injected liquid times the modulus of rigidity. Observations from the available case histories of earthquakes induced by fluid injection are consistent with this bound on seismic moment. In view of the uncertainties in this analysis, however, this should not be regarded as an absolute physical limit.

  2. A century of induced earthquakes in Oklahoma?

    Science.gov (United States)

    Hough, Susan E.; Page, Morgan T.

    2015-01-01

    Seismicity rates have increased sharply since 2009 in the central and eastern United States, with especially high rates of activity in the state of Oklahoma. Growing evidence indicates that many of these events are induced, primarily by injection of wastewater in deep disposal wells. The upsurge in activity has raised two questions: What is the background rate of tectonic earthquakes in Oklahoma? How much has the rate varied throughout historical and early instrumental times? In this article, we show that (1) seismicity rates since 2009 surpass previously observed rates throughout the twentieth century; (2) several lines of evidence suggest that most of the significant earthquakes in Oklahoma during the twentieth century were likely induced by oil production activities, as they exhibit statistically significant temporal and spatial correspondence with disposal wells, and intensity measurements for the 1952 El Reno earthquake and possibly the 1956 Tulsa County earthquake follow the pattern observed in other induced earthquakes; and (3) there is evidence for a low level of tectonic seismicity in southeastern Oklahoma associated with the Ouachita structural belt. The 22 October 1882 Choctaw Nation earthquake, for which we estimate Mw 4.8, occurred in this zone.

  3. Distribution Characteristics of Geohazards Induced by the Lushan Earthquake and Their Comparisons with the Wenchuan Earthquake

    Institute of Scientific and Technical Information of China (English)

    Zhiqiang Yin; Wuji Zhao; Xiaoguang Qin

    2014-01-01

    The Lushan Earthquake induced a large number of geohazards. They are widely distrib-uted and caused serious damages. The basic characteristics, formation mechanisms and typical cases of geohazards induced by Lushan Earthquake are described, and compares to the relationships of Lushan and Wenchuan earthquakes between geohazards and earthquake magnitude, geomorphology, slope an-gle, elevation and seismic intensity in the most affected areas in the article. (1) The numbers and vol-umes of landslides and rockslides differ significantly between the two earthquakes due to their differing magnitudes. The Lushan Earthquake is associated with fewer and smaller-magnitude geohazards, within the immediate area, which mainly consist of small-and medium-sized shallow landslides and rockslides, and occur on steep slopes and mountain valleys. The largest landslide induced by Lushan Earthquake is the Gangoutou Landslide debris flow with a residual volume of about 2.48×106 m3. The most dangerous debris flow is at Lengmugou gulley in Baoxing County, which has similar geomor-phological features and disaster modes as a previous disaster in Zhouqu County, Gansu Province. (2) Geohazards induced by the Lushan Earthquake show four mechanisms: cracking-rockslides-collision- scraping and then debris flows, cracking-rockslides, vibration-rainfall-rockslides-landslide and then debris flow, vibration-throwing or scrolling. (3) There are significant similarities and differences be-tween the geohazards induced by these two earthquakes. The types of geohazards are the same but the volume, quantity and other factors differ: geohazards are concentrated on slope angles of 10°-40° in the Lushan Earthquake area, especially within 10°-20°, and at absolute elevation of 500-2 000 m above sea level (a.s.l.). Geohazards within the Wenchuan Earthquake area are concentrated on steeper slope an-gles of 30°-40° at higher absolute elevations of 1 500-2 000 m.s.l..

  4. Numerical simulations of deformation and movement of blocks within North China in response to 1976 Tangshan earthquake

    Institute of Scientific and Technical Information of China (English)

    BAI; Wuming; (白武明); LIN; Banghui; (林邦慧); CHEN; Zu'an; (陈祖安)

    2003-01-01

    Using methods of discontinuous deformation analysis and finite element (DDA+FEM), this paper simulates dynamic processes of the Tangshan earthquake of 1976, which occurred in the northern North China where its internal blocks apparently interacted. Studies focus upon both the movement and deformation of the blocks, in particular, the Ordos block, and variations of stress states on the boundary faults. The Tangshan earthquake was composed of three events: slipping motions of NNE-striking major fault, NE-striking fault near the northeastern end of the NNE-striking fault, and NW-striking fault on the southeastern side of the NNE-striking fault. Compared with previous studies, our model yields a result that is more agreeable with the configuration of aftershock distributions. A number of data are presented, such as the principle stress field during the earthquake, contours of the maximum shear stress, the strike-slip deformation between blocks near the earthquake focus, time-dependent variations of slips of earthquake-triggered faulting, the maximum slip distance, and stress drops. These results are in accord with the earthquake source mechanism, basic parameters from earthquake wave study, macro-isoseismic line, observed horizontal displacement vectors, etc. The Tangshan earthquake exerted different influences on the adjacent blocks and boundary faults between them, thus resulting in differential movement and deformation. The Ordos block seems to have experienced the small-scale counterclockwise rotation and deformation, but its northeast part, bounded on the east by the Taihangshan and on the north by the Yanshan and Yinshan belts, underwent relatively stronger deformation. The Tangshan earthquake also changed the stress state of boundary faults of the North China, leading to an increase in shear stress and a decrease in normal stress in the NW-trending Zhangjiakou-Penglai fault through Tangshan City and the northern border faults of the Ordos block, and therefore

  5. Small Stress Change Triggering a Big Earthquake: a Test of the Critical Point Hypothesis for Earthquakes

    Institute of Scientific and Technical Information of China (English)

    万永革; 吴忠良; 周公威

    2003-01-01

    Whether or not a small stress change can trigger a big earthquake is one of the most important problems related to the critical point hypothesis for earthquakes. We investigate global earthquakes with different focal mechanisms which have different levels of ambient shear stress. This ambient stress level is the stress level required by the earthquakes for their occurrence. Earthquake pairs are studied to see whether the occurrence of the preceding event encourages the occurrence of the succeeding one in terms of the Coulomb stress triggering. It is observed that the stress triggering effect produced by the change of Coulomb failure stress in the same order of magnitudes,about 10-2 MPa, is distinctly different for different focal mechanisms, and thus for different ambient stress levels.For non-strike-slip earthquakes with a relatively low ambient stress level, the triggering effect is more evident,while for strike-slip earthquakes with a relatively high ambient stress level, there is no evident triggering effect.This water level test provides an observational support to the critical point hypothesis for earthquakes.

  6. Accurate Location of the Yao'an Earthquake Sequence and the Yongsheng Earthquake Sequence

    Institute of Scientific and Technical Information of China (English)

    Wang Xinling; Liu Jie; Zhang Guomin; Zhao Cuiping

    2006-01-01

    The Yao'an Ms6.5 earthquake occurred on Jan. 15, 2000 and the Yongsheng Ms6.0 earthquake occurred on Oct. 27, 2001 in Yunnan Province, China. They are both located in the middle of the Dian block. Their epicenters are close to each other, the tectonic and strain characters of the earthquakes were similar, and there were many aftershocks after the two main shocks. In order to further study the spatial-temporal distributions and fault rupture characters of the main shocks and aftershocks, the latter are located using the Geiger earthquake location algorithm (Geiger) and the double difference earthquake location algorithm (DD) based on the seismic phase data of the two earthquake sequences. They were recorded by two Near Source Digital Seismic Networks (YNSSN and YSNSSN) deployed by the Yunnan Seismological Bureau (YNSB). Then, two main shock parameters were relocated using DD based on the data of larger magnitude aftershocks and the two main shocks that were recorded by the Kunming Regional Digital Seismic Network (KMSN). Combining the spatialtemporal distributions of the two earthquake sequences, the tectonic and strain characters of earthquakes, the rupture processes of the two aftershock sequences along faults are analyzed and discussed contrastively.

  7. Characterisation of Liquefaction Effects for Beyond-Design Basis Safety Assessment of Nuclear Power Plants

    Science.gov (United States)

    Bán, Zoltán; Győri, Erzsébet; János Katona, Tamás; Tóth, László

    2015-04-01

    Preparedness of nuclear power plants to beyond design base external effects became high importance after 11th of March 2011 Great Tohoku Earthquakes. In case of some nuclear power plants constructed at the soft soil sites, liquefaction should be considered as a beyond design basis hazard. The consequences of liquefaction have to be analysed with the aim of definition of post-event plant condition, identification of plant vulnerabilities and planning the necessary measures for accident management. In the paper, the methodology of the analysis of liquefaction effects for nuclear power plants is outlined. The case of Nuclear Power Plant at Paks, Hungary is used as an example for demonstration of practical importance of the presented results and considerations. Contrary to the design, conservatism of the methodology for the evaluation of beyond design basis liquefaction effects for an operating plant has to be limited to a reasonable level. Consequently, applicability of all existing methods has to be considered for the best estimation. The adequacy and conclusiveness of the results is mainly limited by the epistemic uncertainty of the methods used for liquefaction hazard definition and definition of engineering parameters characterizing the consequences of liquefaction. The methods have to comply with controversial requirements. They have to be consistent and widely accepted and used in the practice. They have to be based on the comprehensive database. They have to provide basis for the evaluation of dominating engineering parameters that control the post-liquefaction response of the plant structures. Experience of Kashiwazaki-Kariwa plant hit by Niigata-ken Chuetsu-oki earthquake of 16 July 2007 and analysis of site conditions and plant layout at Paks plant have shown that the differential settlement is found to be the dominating effect in case considered. They have to be based on the probabilistic seismic hazard assessment and allow the integration into logic

  8. Earthquake response of inelastic structures

    International Nuclear Information System (INIS)

    The most commonly used method in the seismic analysis of structures is the response spectrum method. For seismic re-evaluation of existing facilities elastic response spectrum method cannot be used directly as large deformation above yield may be observed under Safe Shutdown Earthquake (SSE). The plastic deformation, i.e. hysteretic characteristics of various elements of the structure cause dissipation of energy. Hence the values of damping given by the code, which does not account hysteretic energy dissipation cannot be directly used. In this paper, appropriate damping values are evaluated for 5-storey, 10-storey and 15-storey shear beam structures, which deform beyond their yield limit. Linear elastic analysis is performed for the same structures using these damping values and the storey forces are compared with those obtained using inelastic time history analysis. A damping model, which relates ductility of the structure and damping, is developed. Using his damping model, a practical structure is analysed and results are compared with inelastic time history analysis and the comparison is found to be good

  9. Ionospheric manifestations of earthquakes and tsunamis in a dynamic atmosphere

    Science.gov (United States)

    Godin, Oleg A.; Zabotin, Nikolay A.; Zabotina, Liudmila

    2015-04-01

    Observations of the ionosphere provide a new, promising modality for characterizing large-scale physical processes that occur on land and in the ocean. There is a large and rapidly growing body of evidence that a number of natural hazards, including large earthquakes, strong tsunamis, and powerful tornadoes, have pronounced ionospheric manifestations, which are reliably detected by ground-based and satellite-borne instruments. As the focus shifts from detecting the ionospheric features associated with the natural hazards to characterizing the hazards for the purposes of improving early warning systems and contributing to disaster recovery, it becomes imperative to relate quantitatively characteristics of the observed ionospheric disturbances and the underlying natural hazard. The relation between perturbations at the ground level and their ionospheric manifestations is strongly affected by parameters of the intervening atmosphere. In this paper, we employ the ray theory to model propagation of acoustic-gravity waves in three-dimensionally inhomogeneous atmosphere. Huygens' wavefront-tracing and Hamiltonian ray-tracing algorithms are used to simulate propagation of body waves from an earthquake hypocenter through the earth's crust and ocean to the upper atmosphere. We quantify the influence of temperature stratification and winds, including their seasonal variability, and air viscosity and thermal conductivity on the geometry and amplitude of ionospheric disturbances that are generated by seismic surface waves and tsunamis. Modeling results are verified by comparing observations of the velocity fluctuations at altitudes of 150-160 km by a coastal Dynasonde HF radar system with theoretical predictions of ionospheric manifestations of background infragravity waves in the ocean. Dynasonde radar systems are shown to be a promising means for monitoring acoustic-gravity wave activity and observing ionospheric perturbations due to earthquakes and tsunamis. We will discuss

  10. The success of the prediction of Haicheng earthquake and the negligence of the Tangshan earthquake

    Institute of Scientific and Technical Information of China (English)

    Peng Funan

    2008-01-01

    The success of the prediction of Haicheng earthquake and the failure of the prediction of Tangshan earthquake were both well known in the world. What happened, why such a strong earthquake as occurred in Haicheng had been predicted successfully and with a small loss of lives and property? Why a successively strong earthquake about a year lat-er in a region not so further was failure in the imminent stage of prediction and there were so many fatalities and a great degree of property? The author addresses these points based on these true experiences including the first hand experi-ences leading up to, during, and following these two earthquarter. In addition, he also introduced some seimic phenom-ena which he had seen after Chi-chi earthquake in Taiwan.

  11. A modified exponential model for reported death toll during earthquakes

    Institute of Scientific and Technical Information of China (English)

    Xinyan Wu; Jianhua Gu

    2009-01-01

    Reliable earthquake death toll estimate can provide valuable references for disaster relief headquarters and civil administration departments to make arrangement and deployment plan during post-earthquake relief work, thus increasing the efficiency of the relief work to a certain extent. In this study, we acquired the death toll data of Wenchuan earthquake, fitted the data using modified exponential curve and compared the result with that of the exponential function. Experimental verification with Chi-Chi earthquake and Kobe earthquake data shows that the fitted result by modified exponential curve is more satisfactory. The final death toll resulting from future destructive earthquakes can be estimated by the acquired fitting function.

  12. Fractals and Forecasting in Earthquakes and Finance

    Science.gov (United States)

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

    2011-12-01

    It is now recognized that Benoit Mandelbrot's fractals play a critical role in describing a vast range of physical and social phenomena. Here we focus on two systems, earthquakes and finance. Since 1942, earthquakes have been characterized by the Gutenberg-Richter magnitude-frequency relation, which in more recent times is often written as a moment-frequency power law. A similar relation can be shown to hold for financial markets. Moreover, a recent New York Times article, titled "A Richter Scale for the Markets" [1] summarized the emerging viewpoint that stock market crashes can be described with similar ideas as large and great earthquakes. The idea that stock market crashes can be related in any way to earthquake phenomena has its roots in Mandelbrot's 1963 work on speculative prices in commodities markets such as cotton [2]. He pointed out that Gaussian statistics did not account for the excessive number of booms and busts that characterize such markets. Here we show that both earthquakes and financial crashes can both be described by a common Landau-Ginzburg-type free energy model, involving the presence of a classical limit of stability, or spinodal. These metastable systems are characterized by fractal statistics near the spinodal. For earthquakes, the independent ("order") parameter is the slip deficit along a fault, whereas for the financial markets, it is financial leverage in place. For financial markets, asset values play the role of a free energy. In both systems, a common set of techniques can be used to compute the probabilities of future earthquakes or crashes. In the case of financial models, the probabilities are closely related to implied volatility, an important component of Black-Scholes models for stock valuations. [2] B. Mandelbrot, The variation of certain speculative prices, J. Business, 36, 294 (1963)

  13. Unusual low-angle normal fault earthquakes after the 2011 Tohoku-oki megathrust earthquake

    Science.gov (United States)

    Yagi, Yuji; Okuwaki, Ryo; Enescu, Bogdan; Fukahata, Yukitoshi

    2015-06-01

    A few low-angle normal fault earthquakes at approximately the depth of the plate interface, with a strike nearly parallel to the trench axis, were detected immediately after the 2011 Tohoku-oki earthquake. After that, however, no such normal fault events have been observed until the occurrence of the 2014 M W 6.6 Fukushima-oki earthquake. Here we analyze the teleseismic body waveforms of the 2014 Fukushima-oki earthquake. We first compare the observed teleseismic body waves of the 2014 Fukushima-oki earthquake with those of the largest previous low-angle normal fault aftershock ( M W 6.6), which occurred on 12 March 2011, and then estimate the centroid depth and moment tensor solution of the 2014 Fukushima-oki earthquake. The teleseismic body waves and moment tensor solution of the 2014 Fukushima-oki earthquake are similar to those of the 2011 normal fault aftershock, which suggests that the 2014 Fukushima-oki earthquake occurred at a similar depth and had a similar mechanism to that of the 2011 aftershock. We detected five low-angle normal fault aftershocks at approximately the depth of the plate interface, with a strike nearly parallel to the trench axis, and confirmed that all of them except for the 2014 Fukushima-oki earthquake occurred within 17 days after the mainshock. The occurrence of these low-angle normal fault events is likely to reflect the reversal of shear stress due to overshooting of slip during the 2011 Tohoku-oki earthquake. We speculate that a fast but heterogeneous recovery of stress state at the plate interface may explain why these events preferentially occurred immediately after the megathrust event, while one of them occurred with a significant delay. In order to better understand the characteristics of stress state in the crust, we have to carefully observe the ongoing seismic activity around this region.

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

    International Nuclear Information System (INIS)

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

  15. Estimating Casualties for Large Earthquakes Worldwide Using an Empirical Approach

    Science.gov (United States)

    Jaiswal, Kishor; Wald, David J.; Hearne, Mike

    2009-01-01

    We developed an empirical country- and region-specific earthquake vulnerability model to be used as a candidate for post-earthquake fatality estimation by the U.S. Geological Survey's Prompt Assessment of Global Earthquakes for Response (PAGER) system. The earthquake fatality rate is based on past fatal earthquakes (earthquakes causing one or more deaths) in individual countries where at least four fatal earthquakes occurred during the catalog period (since 1973). Because only a few dozen countries have experienced four or more fatal earthquakes since 1973, we propose a new global regionalization scheme based on idealization of countries that are expected to have similar susceptibility to future earthquake losses given the existing building stock, its vulnerability, and other socioeconomic characteristics. The fatality estimates obtained using an empirical country- or region-specific model will be used along with other selected engineering risk-based loss models for generation of automated earthquake alerts. These alerts could potentially benefit the rapid-earthquake-response agencies and governments for better response to reduce earthquake fatalities. Fatality estimates are also useful to stimulate earthquake preparedness planning and disaster mitigation. The proposed model has several advantages as compared with other candidate methods, and the country- or region-specific fatality rates can be readily updated when new data become available.

  16. A Statistical Correlation Between Low L-shell Electrons Measured by NOAA Satellites and Strong Earthquakes

    Science.gov (United States)

    Fidani, C.

    2015-12-01

    More than 11 years of the Medium Energy Protons Electrons Detector data from the NOAA polar orbiting satellites were analyzed. Significant electron counting rate fluctuations were evidenced during geomagnetic quiet periods by using a set of adiabatic coordinates. Electron counting rates were compared to earthquakes by defining a seismic event L-shell obtained radially projecting the epicenter geographical positions to a given altitude. Counting rate fluctuations were grouped in every satellite semi-orbit together with strong seismic events and these were chosen with the L-shell coordinates close to each other. Electron data from July 1998 to December 2011 were compared for nearly 1,800 earthquakes with magnitudes larger than or equal to 6, occurring worldwide. When considering 30 - 100 keV energy channels by the vertical NOAA telescopes and earthquake epicenter projections at altitudes greater that 1,300 km, a 4 sigma correlation appeared where time of particle precipitations Tpp occurred 2 - 3 hour prior time of large seismic events Teq. This was in physical agreement with different correlation times obtained from past studies that considered particles with greater energies. The correlation suggested a 4-8 hour advance in preparedness of strong earthquakes influencing the ionosphere. Considering this strong correlation between earthquakes and electron rate fluctuations, and the hypothesis that such fluctuations originated with magnetic disturbances generated underground, a small scale experiment with low cost at ground level is advisable. Plans exists to perform one or more unconventional experiments around an earthquake affected area by private investor in Italy.

  17. Magnitude-frequency of earthquake-induced rockfall events in carbonate rocks

    Science.gov (United States)

    Crosta, Giovanni B.; Agliardi, Federico; Frattini, Paolo; Cucchiaro, Samuel; Colucci, Francesca; Crema, Andrea; Valagussa, Andrea; Fabrizio, Kranitz; Bensi, Sara; Manca, Paolo

    2010-05-01

    Defining sound magnitude-frequency relationships for rockfall events is of great importance both to model the pattern and rate of cliff retreat, and to set up Quantitative Risk Analyses aimed at both landplanning or protective measure design. Nevertheless, magnitude-frequency relationships are based on rockfall inventories that are generally incomplete or biased. Moreover, the role played by geomechanical factors and rockfall triggering processes (e.g. earthquakes) in controlling magnitude-frequency relationships is still poorly understood. In the framework of the Interreg MASSMOVE project, we collected a large dataset of rockfall volumes related to the 1976 catastrophic Friuli earthquake sequence. The dataset includes several thousands of blocks related to both co-seismic and inter-seismic rockfall events affecting steep carbonate rock slopes in areas located at different distance from the earthquake epicentre: Venzone-Carnia (close to the epicentre), Villa Santina (about 15 km from the epicentre), and Timau (about 30 km from the epicentre, substantially unaffected by the earthquake). In order to build the dataset, we integrated historical data, field data collected immediately after the earthquake, and new geomorphological data obtained both in the field and through a multi-temporal analysis of aerial photos. Different magnitude frequency relationships were derived for the entire dataset and for specific subsets of rockfall blocks or events. The obtained results allow to discuss several issues relating to the influence of epicentral distance, the related geological and geomechanical controls, and the effects of fragmentation processes in single events on earthquake-related M-F relationships.

  18. Computing Earthquake Probabilities on Global Scales

    Science.gov (United States)

    Holliday, James R.; Graves, William R.; Rundle, John B.; Turcotte, Donald L.

    2016-03-01

    Large devastating events in systems such as earthquakes, typhoons, market crashes, electricity grid blackouts, floods, droughts, wars and conflicts, and landslides can be unexpected and devastating. Events in many of these systems display frequency-size statistics that are power laws. Previously, we presented a new method for calculating probabilities for large events in systems such as these. This method counts the number of small events since the last large event and then converts this count into a probability by using a Weibull probability law. We applied this method to the calculation of large earthquake probabilities in California-Nevada, USA. In that study, we considered a fixed geographic region and assumed that all earthquakes within that region, large magnitudes as well as small, were perfectly correlated. In the present article, we extend this model to systems in which the events have a finite correlation length. We modify our previous results by employing the correlation function for near mean field systems having long-range interactions, an example of which is earthquakes and elastic interactions. We then construct an application of the method and show examples of computed earthquake probabilities.

  19. Earthquake Hazard and Risk Assessment for Turkey

    Science.gov (United States)

    Betul Demircioglu, Mine; Sesetyan, Karin; Erdik, Mustafa

    2010-05-01

    Using a GIS-environment to present the results, seismic risk analysis is considered as a helpful tool to support the decision making for planning and prioritizing seismic retrofit intervention programs at large scale. The main ingredients of seismic risk analysis consist of seismic hazard, regional inventory of buildings and vulnerability analysis. In this study, the assessment of the national earthquake hazard based on the NGA ground motion prediction models and the comparisons of the results with the previous models have been considered, respectively. An evaluation of seismic risk based on the probabilistic intensity ground motion prediction for Turkey has been investigated. According to the Macroseismic approach of Giovinazzi and Lagomarsino (2005), two alternative vulnerability models have been used to estimate building damage. The vulnerability and ductility indices for Turkey have been taken from the study of Giovinazzi (2005). These two vulnerability models have been compared with the observed earthquake damage database. A good agreement between curves has been clearly observed. In additional to the building damage, casualty estimations based on three different methods for each return period and for each vulnerability model have been presented to evaluate the earthquake loss. Using three different models of building replacement costs, the average annual loss (AAL) and probable maximum loss ratio (PMLR) due to regional earthquake hazard have been provided to form a basis for the improvement of the parametric insurance model and the determination of premium rates for the compulsory earthquake insurance in Turkey.

  20. A Deterministic Approach to Earthquake Prediction

    Directory of Open Access Journals (Sweden)

    Vittorio Sgrigna

    2012-01-01

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

  1. Roaming earthquakes in China highlight midcontinental hazards

    Science.gov (United States)

    Liu, Mian; Wang, Hui

    2012-11-01

    Before dawn on 28 July 1976, a magnitude (M) 7.8 earthquake struck Tangshan, a Chinese industrial city only 150 kilometers from Beijing (Figure 1a). In a brief moment, the earthquake destroyed the entire city and killed more than 242,000 people [Chen et al., 1988]. More than 30 years have passed, and upon the ruins a new Tangshan city has been built. However, the memory of devastation remains fresh. For this reason, a sequence of recent small earthquakes in the Tangshan region, including an M 4.8 event on 28 May and an M 4.0 event on 18 June 2012, has caused widespread concerns and heated debate in China. In the science community, the debate is whether the recent Tangshan earthquakes are the aftershocks of the 1976 earthquake despite the long gap in time since the main shock or harbingers of a new period of active seismicity in Tangshan and the rest of North China, where seismic activity seems to fluctuate between highs and lows over periods of a few decades [Ma, 1989].

  2. Wenchuan earthquake fault and seismic disaster

    Institute of Scientific and Technical Information of China (English)

    Boming Zhao; XiweiXu

    2009-01-01

    Major cases of the MS8.0 Wenchuan earthquake are obtained through field investigations of the epicenter and high-intensity areas, and the relationships among earthquake faults, ground motion and earthquake disasters near fault zones are analyzed. Both strong deformation and ground rupture lead to significant damages of the buildings, indicating that it is necessary to keep safe distance away from active faults and to take other necessary measures. There are two reasons for that the buildings near the surface rupture zones have withstood in the strong earthquake, other than their seismic resistance capacities, with the first being the site condition, and the second the reduced effective stress and low rupture velocity. The forms of structural damages are complex in the fault areas, with shear failure and tensile and compressive damages. Those structures in urban areas that have used qualified materials and followed the building codes performed well in the earthquake. Survey results also indicate that structures of flexible materials may show better seismic performance.

  3. Electrostatically actuated resonant switches for earthquake detection

    KAUST Repository

    Ramini, Abdallah H.

    2013-04-01

    The modeling and design of electrostatically actuated resonant switches (EARS) for earthquake and seismic applications are presented. The basic concepts are based on operating an electrically actuated resonator close to instability bands of frequency, where it is forced to collapse (pull-in) if operated within these bands. By careful tuning, the resonator can be made to enter the instability zone upon the detection of the earthquake signal, thereby pulling-in as a switch. Such a switching action can be functionalized for useful functionalities, such as shutting off gas pipelines in the case of earthquakes, or can be used to activate a network of sensors for seismic activity recording in health monitoring applications. By placing a resonator on a printed circuit board (PCB) of a natural frequency close to that of the earthquake\\'s frequency, we show significant improvement on the detection limit of the EARS lowering it considerably to less than 60% of the EARS by itself without the PCB. © 2013 IEEE.

  4. The investigation of electromagnetic precursors to earthquakes in Armenia

    Directory of Open Access Journals (Sweden)

    M. Babayan

    1997-06-01

    Full Text Available The present work provides a sufficient theoretical substantiation of the anomalous distribution for Very-Low-Frequency (VLF radio waves which is observed for all radio routes controlled by the National Survey for Seismic Protection (NSSP of the Republic of Armenia. This event is connected with the ionosphere excitement over the strong seismic event preparation zone under the influence of intensively oscillated VLF electromagnetic waves falling on the ionosphere from the source called an area of uniformly oriented Zones of Separated Charges (ZSC in the strong seismic preparation zone. ZSC, formed at the interfaces of solid, liquid, and gaseous phases of rocks, acquire identical orientation under the action of increasing elastic strain forces. These strain forces may cause the effect of mutual polarisation of ZSC in the field of their high concentration. As a result, in the strong earthquake preparation zone, the most sensitive to the deformation ZSC, non-linear electromagnetic effects may be observed. One of these effects is the irreversibility of non-stationary electromagnetic processes (INP. It is shown that the INP method developed by Balassanian and Kabilsky (Balassanian, 1990 may prove to be very sensitive to the deformations of geological medium in the earthquake preparation zone.

  5. Phase response curves for models of earthquake fault dynamics.

    Science.gov (United States)

    Franović, Igor; Kostić, Srdjan; Perc, Matjaž; Klinshov, Vladimir; Nekorkin, Vladimir; Kurths, Jürgen

    2016-06-01

    We systematically study effects of external perturbations on models describing earthquake fault dynamics. The latter are based on the framework of the Burridge-Knopoff spring-block system, including the cases of a simple mono-block fault, as well as the paradigmatic complex faults made up of two identical or distinct blocks. The blocks exhibit relaxation oscillations, which are representative for the stick-slip behavior typical for earthquake dynamics. Our analysis is carried out by determining the phase response curves of first and second order. For a mono-block fault, we consider the impact of a single and two successive pulse perturbations, further demonstrating how the profile of phase response curves depends on the fault parameters. For a homogeneous two-block fault, our focus is on the scenario where each of the blocks is influenced by a single pulse, whereas for heterogeneous faults, we analyze how the response of the system depends on whether the stimulus is applied to the block having a shorter or a longer oscillation period. PMID:27368770

  6. Measuring county resilience after the 2008 Wenchuan earthquake

    Directory of Open Access Journals (Sweden)

    X. Li

    2015-01-01

    Full Text Available The catastrophic earthquake in 2008 has caused serious damage to Wenchuan County and the surrounding area in China. In recent years, great attention has been paid to the resilience of the affected area. This study applied a new framework, the Resilience Inference Measurement (RIM model, to quantify and validate the community resilience of 105 counties in the affected area. The RIM model uses cluster analysis to classify counties into four resilience levels according to the exposure, damage, and recovery conditions, and then applies discriminant analysis to quantify the influence of socioeconomic characteristics on the county resilience. The analysis results show that counties located right at the epicenter had the lowest resilience, but counties immediately adjacent to the epicenter had the highest resilience capacities. Counties that were farther away from the epicenter returned to normal resiliency. The socioeconomic variables, including sex ratio, per capita GDP, percent of ethnic minority, and medical facilities, were identified as the most influential socio-economic characteristics on resilience. This study provides useful information to improve county resilience to earthquakes and support decision-making for sustainable development.

  7. Soil/structure interactions of eastern US type earthquakes

    International Nuclear Information System (INIS)

    This paper presents analyses and conclusions pertaining to the earthquake motions felt at Virgil C. Summer, Perry and Krsko nuclear power plants. Consideration is given to promote an improved understanding of these events, describe common characteristics, assess damage potential, and recommend operating procedures for similar future events. An easy-to-follow analytical investigation is performed to describe how the earthquakes recorded at Krsko may be influenced by soil/structure interaction including a few parametric studies to account for uncertainties in the soil properties. These consist of variations in the shear and compressional wave velocities and variations in the seismic wave environment in the form of arbitrarily oriented body waves or Rayleigh waves. The analysis takes into account nonlinearity of the soil material, radiation and hysteretic damping, ground-water table level, structural embedment, and structure/structure interaction. The analysis is based on state-of-the-art computer software, elaborate analysis techniques and simpler engineering approximations. Results of analysis show clear evidence of soil/structure interaction, nonlinear softening of the soil material and encouraging qualitative and quantitative agreement with the recorded measurements. The structural response motions display high rocking mode

  8. Phase response curves for models of earthquake fault dynamics

    CERN Document Server

    Franović, Igor; Perc, Matjaz; Klinshov, Vladimir; Nekorkin, Vladimir; Kurths, Jürgen

    2016-01-01

    We systematically study effects of external perturbations on models describing earthquake fault dynamics. The latter are based on the framework of the Burridge-Knopoff spring-block system, including the cases of a simple mono-block fault, as well as the paradigmatic complex faults made up of two identical or distinct blocks. The blocks exhibit relaxation oscillations, which are representative for the stick-slip behavior typical for earthquake dynamics. Our analysis is carried out by determining the phase response curves of first and second order. For a mono-block fault, we consider the impact of a single and two successive pulse perturbations, further demonstrating how the profile of phase response curves depends on the fault parameters. For a homogeneous two-block fault, our focus is on the scenario where each of the blocks is influenced by a single pulse, whereas for heterogeneous faults, we analyze how the response of the system depends on whether the stimulus is applied to the block having a shorter or a ...

  9. Loma Prieta Earthquake, October 18, 1989, Part 2

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — On October 17, 1989, a 7.1 magnitude earthquake occurred near Loma Prieta in the Santa Cruz Mountains. This earthquake is also known as the "San Francisco World...

  10. San Fernando Valley California Earthquakes of 1971 and 1994

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This slide set compares two earthquakes that were separated by a distance of 10 miles and a time of 23 years. Disproving the notion that once an earthquake has...

  11. Parent Guidelines for Helping Children After an Earthquake

    Science.gov (United States)

    Parent Guidelines for Helping Children after an Earthquake Being in an earthquake is very frightening, and the days, weeks, and months following are very stressful. Your children and family will recover ...

  12. Lessons from the 2004 Sumatra-Andaman earthquake.

    Science.gov (United States)

    Kanamori, Hiroo

    2006-08-15

    The 2004 Sumatra-Andaman earthquake (M(w) = 9.0-9.3) is one of the greatest earthquakes ever recorded. In terms of its physical size, it is comparable to the 1960 Chilean (M(w) = 9.5) and the 1965 Alaskan (M(w) = 9.2) earthquakes. However, the damage caused by this earthquake is far greater than that caused by other great earthquakes. The 2004 Sumatra-Andaman earthquake has been studied in great detail over broad time-scales, from a fraction of seconds to hours and months, using the modern seismic data available from global seismic networks and the Global Positioning System data. We summarize the findings obtained mainly from seismic data, and discuss the unique feature of this earthquake, and possible directions of research to minimize the impact of great earthquakes on our society. PMID:16844642

  13. Characteristic earthquake model, 1884 -- 2011, R.I.P

    CERN Document Server

    Kagan, Yan Y; Geller, Robert J

    2012-01-01

    Unfortunately, working scientists sometimes reflexively continue to use "buzz phrases" grounded in once prevalent paradigms that have been subsequently refuted. This can impede both earthquake research and hazard mitigation. Well-worn seismological buzz phrases include "earthquake cycle," "seismic cycle," "seismic gap," and "characteristic earthquake." They all assume that there are sequences of earthquakes that are nearly identical except for the times of their occurrence. If so, the complex process of earthquake occurrence could be reduced to a description of one "characteristic" earthquake plus the times of the others in the sequence. A common additional assumption is that characteristic earthquakes dominate the displacement on fault or plate boundary "segments." The "seismic gap" (or the effectively equivalent "seismic cycle") model depends entirely on the "characteristic" assumption, with the added assumption that characteristic earthquakes are quasi-periodic. However, since the 1990s numerous statistica...

  14. United States Earthquake Intensity Database, 1638-1985

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The United States Earthquake Intensity Database is a collection of damage and felt reports for over 23,000 U.S. earthquakes from 1638-1985. The majority of...

  15. Protecting Your Family From Earthquakes-The Seven Steps to Earthquake Safety (in Spanish and English)

    Science.gov (United States)

    Developed by American Red Cross, Asian Pacific Fund, California Earthquake Authority, Governor's Office of Emergency Services, New America Media, U.S. Department of Homeland Security Federal Emergency Management Agency, and U.S. Geological Survey

    2007-01-01

    This book is provided here to share an important message on emergency preparedness. Historically, we have suffered earthquakes here in the San Francisco Bay Area that have caused severe hardship for residents and incredible damage to our cities. It is likely we will experience a severe earthquake within the next 30 years. Many of us come from other countries where we have experienced earth- quakes, so we believe that we understand them. However, the way we prepare for earthquakes in our home country may be different from the way it is necessary to prepare for earthquakes here. Very f w people die from collapsing buildings in the Bay Area because most structures are built to stand up to the shaking. But it is quite possible that your family will be without medical care or grocery stores and separated from one another for several days to weeks. It will ultimately be up to you to keep your family safe until help arrives, so we are asking you to join us in learning to take care of your family before, during, and after an earthquake. The first step is to read this book. Everyone in your family, children and adults, can learn how to prepare for an earthquake. Then take advantage of the American Red Cross Earthquake Preparedness training courses offered in your community. These preparedness courses are free, and also offered in Spanish and available to everyone in the community regardless of family history, leg al status, gender, or age. We encourage you to take one of these free training workshops. Look on the back cover for more information. Remember that an earthquake can occur without warning, and the only way that we can reduce the harm caused by earthquakes is to be prepared. Get Prepared!

  16. 1/f and the Earthquake Problem: Scaling constraints to facilitate operational earthquake forecasting

    Science.gov (United States)

    Yoder, M. R.; Rundle, J. B.; Glasscoe, M. T.

    2013-12-01

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

  17. 1/f and the Earthquake Problem: Scaling constraints that facilitate operational earthquake forecasting

    Science.gov (United States)

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

    2012-12-01

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

  18. Transition matrix analysis of earthquake magnitude sequences

    International Nuclear Information System (INIS)

    Estimation of complexity is a fascinating research topic in nonlinear signal and system analysis. Information theoretic functionals can be used to identify and quantify general relationships among variables; these relationships can be considered as the fingerprints of complexity. Up to now, the complexity of seismic sequences has been mostly related to the concept of self-similarity, suggesting that the earthquake dynamics can be interpreted as due to many components interacting over a wide range of time or space scales. This paper deals with a new idea of complexity of seismicity, focusing, in particular, on the transition probability between magnitudes. Using the Transition Matrix Method, a set of complexity parameters can be defined for earthquakes. Furthermore, the relationships among these parameters and those characterizing the earthquake magnitude dynamics have been analyzed in simulated and observational seismic sequences

  19. The Rotational and Gravitational Effect of Earthquakes

    Science.gov (United States)

    Gross, Richard

    2000-01-01

    The static displacement field generated by an earthquake has the effect of rearranging the Earth's mass distribution and will consequently cause the Earth's rotation and gravitational field to change. Although the coseismic effect of earthquakes on the Earth's rotation and gravitational field have been modeled in the past, no unambiguous observations of this effect have yet been made. However, the Gravity Recovery And Climate Experiment (GRACE) satellite, which is scheduled to be launched in 2001, will measure time variations of the Earth's gravitational field to high degree and order with unprecedented accuracy. In this presentation, the modeled coseismic effect of earthquakes upon the Earth's gravitational field to degree and order 100 will be computed and compared to the expected accuracy of the GRACE measurements. In addition, the modeled second degree changes, corresponding to changes in the Earth's rotation, will be compared to length-of-day and polar motion excitation observations.

  20. Origin of coda waves: earthquake source resonance

    CERN Document Server

    Liu, Yinbin

    2015-01-01

    Seismic coda in local earthquake exhibits the characteristics of uniform spatial distribution energy, selective frequency, and slow temporal decay oscillation. It is usually assumed to be the incoherent waves scattered from random heterogeneity in the earth's lithosphere. Here I show by wave field modeling for 1D heterogeneity that seismic coda is related to the natural resonance of earthquake source around the earthquake's focus. This natural resonance is a kind of wave coherent scattering enhancement phenomenon or coupling oscillations happened in steady state regime in strong small-scale heterogeneity. Its resonance frequency is inversely proportional to the heterogeneous scale and contrast and will shift toward lower frequency with increasing random heterogeneous scale and velocity fluctuations. Its energy weakens with decreasing impedance contrast and increasing random heterogeneous scale and velocity fluctuations.

  1. Lessons learned from the 1994 Northridge Earthquake

    Energy Technology Data Exchange (ETDEWEB)

    Eli, M.W.; Sommer, S.C. [Lawrence Livermore National Lab., CA (United States)

    1995-04-01

    Southern California has a history of major earthquakes and also has one of the largest metropolitan areas in the United States. The 1994 Northridge Earthquake challenged the industrial facilities and lifetime infrastructure in the northern Los Angeles (LA) area. Lawrence Livermore National Laboratory (LLNL) sent a team of engineers to conduct an earthquake damage investigation in the Northridge area, on a project funded jointly by the United States Nuclear Regulatory Commission (USNRC) and the United States Department of Energy (USDOE). Many of the structures, systems, and components (SSCs) and lifelines that suffered damage are similar to those found in nuclear power plants and in USDOE facilities. Lessons learned from these experiences can have some applicability at commercial nuclear power plants.

  2. ASSESSMENT OF EARTHQUAKE HAZARDS ON WASTE LANDFILLS

    DEFF Research Database (Denmark)

    Zania, Varvara; Tsompanakis, Yiannis; Psarropoulos, Prodromos

    Earthquake hazards may arise as a result of: (a) transient ground deformation, which is induced due to seismic wave propagation, and (b) permanent ground deformation, which is caused by abrupt fault dislocation. Since the adequate performance of waste landfills after an earthquake is of outmost...... importance, the current study examines the impact of both types of earthquake hazards by performing efficient finite-element analyses. These took also into account the potential slip displacement development along the geosynthetic interfaces of the composite base liner. At first, the development of permanent...... of the fault rupture through the waste mass. In addition the stability of the waste mass, the seismic slip deformations along low-shear-strength interfaces and the tension of the geosynthetics were estimated. Results indicate that the basic factors that designate the types of failure are the ratio of the shear...

  3. Ergodicity in Natural Earthquake Fault Networks

    CERN Document Server

    Tiampo, K F; Klein, W; Holliday, J; Martins, J S S; Ferguson, C D

    2006-01-01

    Numerical simulations suggest that certain driven nonlinear systems can be characterized by mean-field statistical properties often associated with ergodic dynamics [1-3]. These driven mean-field threshold systems feature long-range interactions and can be treated as equilibrium-like systems with dynamics that are statistically stationary over long time intervals. Recently the equilibrium property of ergodicity was identified in one example of a natural, driven threshold system, an earthquake fault network, by means of the Thirumalai-Mountain (TM) fluctuation metric developed in the study of diffusive systems [4]. In this work we analyze the seismicity of three earthquake faults networks from a variety of tectonic settings around the world in an attempt to investigate the range of applicability of effective ergodicity, using the TM metric and other associated statistics for each data set. Results suggest that all of these natural earthquake systems display effective ergodicity, and that ergodicity depends on ...

  4. An eyewitness account of the Bhuj earthquake

    Indian Academy of Sciences (India)

    M K Gupta

    2003-09-01

    The occurrence of a severe earthquake is a rare event with its effect localized in a limited region. There are no prior indications of its occurrence too; hence experiencing such an event is just a matter of chance, which the author had by virtue of his posting at Bhuj. This paper presents a detailed account of observations made in the wake of the Bhuj earthquake of January 26th 2001, describing physical and mental reactions during the earthquake, the post-quake scenario, the nature and cause of damage to buildings, the trend of aftershocks, various deformities, including ruptures and fissures on the surface of the earth, etc. which may be useful for a detailed study of the seismological activity in the region.

  5. Volcanotectonic earthquakes induced by propagating dikes

    Science.gov (United States)

    Gudmundsson, Agust

    2016-04-01

    Volcanotectonic earthquakes are of high frequency and mostly generated by slip on faults. During chamber expansion/contraction earthquakes are distribution in the chamber roof. Following magma-chamber rupture and dike injection, however, earthquakes tend to concentrate around the dike and follow its propagation path, resulting in an earthquake swarm characterised by a number of earthquakes of similar magnitudes. I distinguish between two basic processes by which propagating dikes induce earthquakes. One is due to stress concentration in the process zone at the tip of the dike, the other relates to stresses induced in the walls and surrounding rocks on either side of the dike. As to the first process, some earthquakes generated at the dike tip are related to pure extension fracturing as the tip advances and the dike-path forms. Formation of pure extension fractures normally induces non-double couple earthquakes. There is also shear fracturing in the process zone, however, particularly normal faulting, which produces double-couple earthquakes. The second process relates primarily to slip on existing fractures in the host rock induced by the driving pressure of the propagating dike. Such pressures easily reach 5-20 MPa and induce compressive and shear stresses in the adjacent host rock, which already contains numerous fractures (mainly joints) of different attitudes. In piles of lava flows or sedimentary beds the original joints are primarily vertical and horizontal. Similarly, the contacts between the layers/beds are originally horizontal. As the layers/beds become buried, the joints and contacts become gradually tilted so that the joints and contacts become oblique to the horizontal compressive stress induced by a driving pressure of the (vertical) dike. Also, most of the hexagonal (or pentagonal) columnar joints in the lava flows are, from the beginning, oblique to an intrusive sheet of any attitude. Consequently, the joints and contacts function as potential shear

  6. Earthquake hazard analysis in northern Egypt

    International Nuclear Information System (INIS)

    Earthquake activity and seismic hazard analysis are important components of the seismic aspects for very essential structures such as major dams and nuclear power plants. Setting of nuclear power plants becomes of increasing important in northern Egypt with the commitment towards promoting nuclear electric generation. Therefore, the annual seismic hazard maps with non-exceedence probability of 80%, 85% and 90% are given. These maps show that northern Egypt is severely affects by earthquakes from potential sources around Sinai peninsula. Three sites (Nile Delta, Cairo, and Ismailia region) have been chosen to estimated the earthquake hazard in more detailes to serve as a basic parameter to the safety factor of different projects in these regions. A seismic safety factor of intensity 8.5 should be considered in designing the vital projects in northern Egypt. (author)

  7. Relationship between earthquake and volcanic eruption inferred from historical records

    Institute of Scientific and Technical Information of China (English)

    陈洪洲; 高峰; 吴雪娟; 孟宪森

    2004-01-01

    A large number of seismic records are discovered for the first time in the historical materials about Wudalianchi volcanic group eruption in 1720~1721, which provides us with abundant volcanic earthquake information. Based on the written records, the relationship between earthquake and volcanic eruption is discussed in the paper. Furthermore it is pointed that earthquake swarm is an important indication of volcanic eruption. Therefore, monitoring volcanic earthquakes is of great significance for forecasting volcanic eruption.

  8. Operational Earthquake Forecasting: State of Knowledge and Guidelines for Utilization

    OpenAIRE

    Koshun Yamaoka; Gerassimos Papadopoulos; Gennady Sobolev; Warner Marzocchi; Ian Main; Raul Madariaga; Paolo Gasparini; Yun-Tai Chen; Thomas H. Jordan; Jochen Zschau

    2011-01-01

    Following the 2009 L'Aquila earthquake, the Dipartimento della Protezione Civile Italiana (DPC), appointed an International Commission on Earthquake Forecasting for Civil Protection (ICEF) to report on the current state of knowledge of short-term prediction and forecasting of tectonic earthquakes and indicate guidelines for utilization of possible forerunners of large earthquakes to drive civil protection actions, including the use of probabilistic seismic hazard analysis in the wake of a lar...

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

    Science.gov (United States)

    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.    

  10. Early Warning for Earthquakes with Large Rupture Dimension

    OpenAIRE

    Yamada, Masumi

    2007-01-01

    Earthquake early warning systems have become popular these days, and many seismologists and engineers are making research efforts for their practical application. The existing earthquake early warning systems provide estimates of the location and size of earthquakes, and then ground motions at a site are estimated as a function of the epicentral distance and site soil properties. However, for large earthquakes, the energy is radiated from a large area surrounding the entire fault plane, and t...

  11. Earth's rotation variations and earthquakes 2010–2011

    OpenAIRE

    L. Ostřihanský

    2012-01-01

    In contrast to unsuccessful searching (lasting over 150 years) for correlation of earthquakes with biweekly tides, the author found correlation of earthquakes with sidereal 13.66 days Earth's rotation variations expressed as length of a day (LOD) measured daily by International Earth's Rotation Service. After short mention about earthquakes M 8.8 Denali Fault Alaska 3 November 2002 triggered on LOD maximum and M 9.1 Great Sumatra earthquake 26 December 2004 triggered on LOD minimum an...

  12. Statistical Approaches Regarding the Evolution of the Earthquakes in Romania

    OpenAIRE

    Gabriela OPAIT

    2015-01-01

    This paper reflects the statistical modeling of the values regarding the magnitudes of the earthquakes in Romania, respectively the depth of the earthquakes, through by means of the „Least Squares Method”, which is a method through we can to reflect the trend line of the best fit concerning a model. If we achieve in time and space an analysis concerning the earthquakes, we can to say that any earthquake has an unexpected character and the fortuitous factor playes the principal role.

  13. Adaptively smoothed seismicity earthquake forecasts for Italy

    Directory of Open Access Journals (Sweden)

    Yan Y. Kagan

    2010-11-01

    Full Text Available We present a model for estimation of the probabilities of future earthquakes of magnitudes m ≥ 4.95 in Italy. This model is a modified version of that proposed for California, USA, by Helmstetter et al. [2007] and Werner et al. [2010a], and it approximates seismicity using a spatially heterogeneous, temporally homogeneous Poisson point process. The temporal, spatial and magnitude dimensions are entirely decoupled. Magnitudes are independently and identically distributed according to a tapered Gutenberg-Richter magnitude distribution. We have estimated the spatial distribution of future seismicity by smoothing the locations of past earthquakes listed in two Italian catalogs: a short instrumental catalog, and a longer instrumental and historic catalog. The bandwidth of the adaptive spatial kernel is estimated by optimizing the predictive power of the kernel estimate of the spatial earthquake density in retrospective forecasts. When available and reliable, we used small earthquakes of m ≥ 2.95 to reveal active fault structures and 29 probable future epicenters. By calibrating the model with these two catalogs of different durations to create two forecasts, we intend to quantify the loss (or gain of predictability incurred when only a short, but recent, data record is available. Both forecasts were scaled to five and ten years, and have been submitted to the Italian prospective forecasting experiment of the global Collaboratory for the Study of Earthquake Predictability (CSEP. An earlier forecast from the model was submitted by Helmstetter et al. [2007] to the Regional Earthquake Likelihood Model (RELM experiment in California, and with more than half of the five-year experimental period over, the forecast has performed better than the others.

  14. Earthquake correlations and networks: A comparative study

    International Nuclear Information System (INIS)

    We quantify the correlation between earthquakes and use the same to extract causally connected earthquake pairs. Our correlation metric is a variation on the one introduced by Baiesi and Paczuski [M. Baiesi and M. Paczuski, Phys. Rev. E 69, 066106 (2004)]. A network of earthquakes is then constructed from the time-ordered catalog and with links between the more correlated ones. A list of recurrences to each of the earthquakes is identified employing correlation thresholds to demarcate the most meaningful ones in each cluster. Data pertaining to three different seismic regions (viz., California, Japan, and the Himalayas) are comparatively analyzed using such a network model. The distribution of recurrence lengths and recurrence times are two of the key features analyzed to draw conclusions about the universal aspects of such a network model. We find that the unimodal feature of recurrence length distribution, which helps to associate typical rupture lengths with different magnitude earthquakes, is robust across the different seismic regions. The out-degree of the networks shows a hub structure rooted on the large magnitude earthquakes. In-degree distribution is seen to be dependent on the density of events in the neighborhood. Power laws, with two regimes having different exponents, are obtained with recurrence time distribution. The first regime confirms the Omori law for aftershocks while the second regime, with a faster falloff for the larger recurrence times, establishes that pure spatial recurrences also follow a power-law distribution. The crossover to the second power-law regime can be taken to be signaling the end of the aftershock regime in an objective fashion.

  15. Physically based prediction of earthquake induced landsliding

    Science.gov (United States)

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

    2015-04-01

    Earthquakes are an important trigger of landslides and can contribute significantly to sedimentary or organic matter fluxes. We present a new physically based expression for the prediction of total area and volume of populations of earthquake-induced landslides. This model implements essential seismic processes, linking key parameters such as ground acceleration, fault size, earthquake source depth and seismic moment. To assess the model we have compiled and normalized a database of landslide inventories for 40 earthquakes. We have found that low landscape steepness systematically leads to overprediction 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, even though the prediction of total landslide area is more difficult than that of volume because it is affected by additional parameters such as the depth and continuity of soil cover. Some outliers in terms of observed landslide intensity are likely to be associated with exceptional rock mass properties in the epicentral area. 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 the model suitable for integration into landscape evolution models, and application to the assessment of secondary hazards and risks associated with earthquakes.

  16. Investigation on evaluation method for characteristic seismic transmission. Standard earthquake basement from observation records of earthquakes

    International Nuclear Information System (INIS)

    Evaluation of standard earthquake movement in seismic-resistant design for nuclear power plants is important and carried out at free surface of base stratum according to the guidelines. However, the seismic transmittance differs from site to site depending on the geological features, basement depth, and the state of uppers above the basement. The present method takes into account site characteristic propagation character between the basement surface and top surface and using standard and uniform earthquake motion throughout the country. Thus, the report presents investigation results of characteristic seismic motion at the basement from the records of observed earthquakes. (S. Ohno)

  17. Space-Time Clustering and Correlations of Major Earthquakes

    CERN Document Server

    Holliday, J R; Turcotte, D L; Klein, W; Tiampo, K F; Holliday, James R.; Rundle, John B.; Turcotte, Donald L.; Klein, William; Tiampo, Kristy F.

    2006-01-01

    Earthquake occurrence in nature is thought to result from correlated elastic stresses, leading to clustering in space and time. We show that occurrence of major earthquakes in California correlates with time intervals when fluctuations in small earthquakes are suppressed relative to the long term average. We estimate a probability of less than 1% that this coincidence is due to random clustering.

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

    Data.gov (United States)

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

  19. 75 FR 66388 - Scientific Earthquake Studies Advisory Committee

    Science.gov (United States)

    2010-10-28

    ....S. Geological Survey Scientific Earthquake Studies Advisory Committee AGENCY: U.S. Geological Survey. ACTION: Notice of Meeting. SUMMARY: Pursuant to Public Law 106-503, the Scientific Earthquake Studies... work, and USGS role within the four-agency National Earthquake Hazards Reduction Program....

  20. An scientific evaluation of annual earthquake prediction ability

    Institute of Scientific and Technical Information of China (English)

    张国民; 刘杰; 石耀霖

    2002-01-01

    The scientific idea of earthquake prediction in China is introduced in this paper. The various problems on evaluation of earthquake prediction ability are analyzed. The practical effect of prediction on annual seismic risk areas in 1990~2000 in China is discussed based on R-value evaluation method, and the ability of present earthquake prediction in China is reviewed.

  1. New research and tools lead to improved earthquake alerting protocols

    Science.gov (United States)

    Wald, David J.

    2009-01-01

    What’s the best way to get alerted about the occurrence and potential impact of an earthquake? The answer to that question has changed dramatically of late, in part due to improvements in earthquake science, and in part by the implementation of new research in the delivery of earthquake information

  2. Local earthquake activity around Syowa Station, Antarctica

    OpenAIRE

    Kaminuma,Katsutada/Kanao,Masaki/Kubo,Atsuki

    1998-01-01

    The Japanese Antarctic Station, Syowa (69°S, 39°E), is located at the edge of the east Antarctic shield. Seismic observations at Syowa Station were started in 1959. Phase readings of earthquakes have been published by National Institute of Polar Research once a year since 1968, as one of the Data Report Series. Nine local earthquakes were detected empirically on short-period seismograms at Syowa Station in 1990-1996 on the basis of long term records of many different types of events. The seis...

  3. Iconography of the 1755 Lisbon Earthquake

    Institute of Scientific and Technical Information of China (English)

    Manuel S. Pinto

    2006-01-01

    @@ Here is a fine book with a timely publication date: 2005 marked the 250th anniversary of the great Lisbon earthquake. Among the many books and papers that were published about the catastrophe in 2005, in Portugal and elsewhere, Iconography of the 1755 Lisbon Earthquake stands out because of its excellent illustrations and a most readable text. Intended for readers interested in the history of geological sciences, and also for those interested in natural catastrophes that generated philosophical and theological controversies in Europe, the book commemorates the event in a truly distinctive way.

  4. BMER - Balanced Mitigation of Earthquake Responses - Theory

    International Nuclear Information System (INIS)

    Seismic isolation of structures and equipment has been the focus of intense attention this last decade. The published documents are too numerous to list here. Strictly speaking seismic isolation is not feasible. What isolation, as presently practiced, does is to move the system frequency away from the acceleration amplification range of earthquake motions to the velocity or displacement regimes. Thus, isolation simply changes an acceleration problem to a displacement problem. Under these circumstances what can really be achieved is an explicit trade-off between acceleration and displacement responses. Hence, the title of the paper, Balanced Mitigation of Earthquake Responses - BMER

  5. a Collaborative Cyberinfrastructure for Earthquake Seismology

    Science.gov (United States)

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

    2013-12-01

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

  6. Pump Damage in the Hanshin Earthquake

    Directory of Open Access Journals (Sweden)

    Toshiyuki Osada

    2000-01-01

    Full Text Available There was a severe earthquake in the southern area ofHyogo prefecture in Japan on January 17, 1995. In this paper the damage to pump facilities caused by the earthquake, based on field investigation results in the Hanshin (Osaka–Kobe area is reported. In particular a lot of damage was reported in the pumping facilities for sewage or drainage of storm sewage. This paper also presents recommendations for aseismic design of pump facilities based on the results of the survey.

  7. Earthquakes in Tuhinj Valley (Slovenia) In 1840

    Science.gov (United States)

    Cecić, Ina

    2015-04-01

    A less known damaging earthquake in southern part of Kamnik-Savinja Alps, Slovenia, in 1840 is described. The main shock was on 27 August 1840 with the epicentre in Tuhinj Valley. The maximum intensity was VII EMS-98 in Ljubljana, Slovenia, and in Eisenkappel, Austria. It was felt as far as Venice, Italy, 200 km away. The macroseismic magnitude of the main shock, estimated from the area of intensity VI EMS-98, was 5.0. The effects of the main shock and its aftershocks are described, and an earthquake catalogue for Slovenia in 1840 is provided. Available primary sources (newspaper articles) are presented.

  8. Evaluation and cataloging of Korean historical earthquakes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kew Hwa; Han, Young Woo; Lee, Jun Hui; Park, Ji Eok; Na, Kwang Wooing; Shin, Byung Ju [The Reaearch Institute of Basic Sciences, Seoul Nationl Univ., Seoul (Korea, Republic of)

    1999-03-15

    Historical earthquake data of the Korean Peninsula which are very important is evaluating seismicity and seismic hazard of the peninsula were collected and analyzed by seismologist and historian. A preliminary catalog of Korean historical earthquake data translated in English was made. Felt places of 528 events felt at more than 2 places were indicated on maps and MMI III isoseismal were drawn for 52 events of MMI{>=}VII. Epicenters and intensities of these MMI{>=}VII events were estimated from these isoseismal maps.

  9. Earthquake Safety Tips in the Classroom

    Science.gov (United States)

    Melo, M. O.; Maciel, B. A. P. C.; Neto, R. P.; Hartmann, R. P.; Marques, G.; Gonçalves, M.; Rocha, F. L.; Silveira, G. M.

    2014-12-01

    The catastrophes induced by earthquakes are among the most devastating ones, causing an elevated number of human losses and economic damages. But, we have to keep in mind that earthquakes don't kill people, buildings do. Earthquakes can't be predicted and the only way of dealing with their effects is to teach the society how to be prepared for them, and how to deal with their consequences. In spite of being exposed to moderate and large earthquakes, most of the Portuguese are little aware of seismic risk, mainly due to the long recurrence intervals between strong events. The acquisition of safe and correct attitudes before, during and after an earthquake is relevant for human security. Children play a determinant role in the establishment of a real and long-lasting "culture of prevention", both through action and new attitudes. On the other hand, when children assume correct behaviors, their relatives often change their incorrect behaviors to mimic the correct behaviors of their kids. In the framework of a Parents-in-Science initiative, we started with bi-monthly sessions for children aged 5 - 6 years old and 9 - 10 years old. These sessions, in which parents, teachers and high-school students participate, became part of the school's permanent activities. We start by a short introduction to the Earth and to earthquakes by story telling and by using simple science activities to trigger children curiosity. With safety purposes, we focus on how crucial it is to know basic information about themselves and to define, with their families, an emergency communications plan, in case family members are separated. Using a shaking table we teach them how to protect themselves during an earthquake. We then finish with the preparation on an individual emergency kit. This presentation will highlight the importance of encouraging preventive actions in order to reduce the impact of earthquakes on society. This project is developed by science high-school students and teachers, in

  10. Learning from the Hanshin-Awaji earthquake

    International Nuclear Information System (INIS)

    The earthquake that struck the southern part of Hyogo Prefecture in January, 1995 claimed large numbers of deaths and casualties and caused severe damage to buildings and facilities in the region. Nuclear power plants (NPPs) are located more than 100 km away from the epicenter, and were not affected in any way. In the light of the Earthquake, the validity of aseismic design methodology for NPPs was re-evaluated thoroughly to ensure their aseismic safety. This paper describes the aseismic safety of NPPs in Japan, as well as the re-evaluation results of their design methodology. (author)

  11. Evaluation and cataloging of Korean historical earthquakes

    International Nuclear Information System (INIS)

    Historical earthquake data of the Korean Peninsula which are very important is evaluating seismicity and seismic hazard of the peninsula were collected and analyzed by seismologist and historian. A preliminary catalog of Korean historical earthquake data translated in English was made. Felt places of 528 events felt at more than 2 places were indicated on maps and MMI III isoseismal were drawn for 52 events of MMI≥VII. Epicenters and intensities of these MMI≥VII events were estimated from these isoseismal maps

  12. Hayward fault: Large earthquakes versus surface creep

    Science.gov (United States)

    Lienkaemper, James J.; Borchardt, Glenn

    1992-01-01

    The Hayward fault, thought a likely source of large earthquakes in the next few decades, has generated two large historic earthquakes (about magnitude 7), one in 1836 and another in 1868. We know little about the 1836 event, but the 1868 event had a surface rupture extending 41 km along the southern Hayward fault. Right-lateral surface slip occurred in 1868, but was not well measured. Witness accounts suggest coseismic right slip and afterslip of under a meter. We measured the spatial variation of the historic creep rate along the Hayward fault, deriving rates mainly from surveys of offset cultural features, (curbs, fences, and buildings). Creep occurs along at least 69 km of the fault's 82-km length (13 km is underwater). Creep rate seems nearly constant over many decades with short-term variations. The creep rate mostly ranges from 3.5 to 6.5 mm/yr, varying systemically along strike. The fastest creep is along a 4-km section near the south end. Here creep has been about 9mm/yr since 1921, and possibly since the 1868 event as indicated by offset railroad track rebuilt in 1869. This 9mm/yr slip rate may approach the long-term or deep slip rate related to the strain buildup that produces large earthquakes, a hypothesis supported by geoloic studies (Lienkaemper and Borchardt, 1992). If so, the potential for slip in large earthquakes which originate below the surficial creeping zone, may now be 1/1m along the southern (1868) segment and ≥1.4m along the northern (1836?) segment. Substracting surface creep rates from a long-term slip rate of 9mm/yr gives present potential for surface slip in large earthquakes of up to 0.8m. Our earthquake potential model which accounts for historic creep rate, microseismicity distribution, and geodetic data, suggests that enough strain may now be available for large magnitude earthquakes (magnitude 6.8 in the northern (1836?) segment, 6.7 in the southern (1868) segment, and 7.0 for both). Thus despite surficial creep, the fault may be

  13. Report of Earthquake Drills with Experiences of Ground Motion in Childcare for Young Children, Japan

    Science.gov (United States)

    Yamada, N.

    2013-12-01

    After the Great East Japan Earthquake of 2011, this disaster has become one of the opportunities to raise awareness of earthquake and tsunami disaster prevention, and the improvement of disaster prevention education is to be emphasized. The influences of these bring the extension to the spatial axis in Japan, and also, it is important to make a development of the education with continuous to the expansion of time axes. Although fire or earthquake drills as the disaster prevention education are often found in Japan, the children and teachers only go from school building to outside. Besides, only the shortness of the time to spend for the drill often attracts attention. The complementary practice education by the cooperation with experts such as the firefighting is practiced, but the verification of the effects is not enough, and it is the present conditions that do not advance to the study either. Although it is expected that improvement and development of the disaster prevention educations are accomplished in future, there are a lot of the problems. Our target is construction and utilization of material contributing to the education about "During the strong motion" in case of the earthquake which may experience even if wherever of Japan. One of the our productions is the handicraft shaking table to utilize as teaching tools of the education to protect the body which is not hurt at the time of strong motion. This made much of simplicity than high reproduction of the earthquake ground motions. We aimed to helping the disaster prevention education including not only the education for young children but also for the school staff and their parents. In this report, the focusing on a way of the non-injured during the time of the earthquake ground motion, and adopting activity of the play, we are going to show the example of the framework of earthquake disaster prevention childcare through the virtual experience. This presentation has a discussion as a practice study with

  14. Earthquake Sources, the Stress Field and Seismic Hazard : A Study in Eritrea and its Surrounding

    OpenAIRE

    Hagos, Lijam Zemichael

    2006-01-01

    Presented in this thesis are some basic concepts and applications of seismic hazard analysis and the elements that influence the amplitude and geometric attenuation of earthquake ground motion. This thesis centers on the identification of the styles of failure, focal mechanisms, and the state of regional stress in the study area. Seismic hazard is a complex problem often involving considerable uncertainties. Therefore it is reasonable to consider different seismic hazard analysis approaches i...

  15. Earthquake-induced landslide-susceptibility mapping using an artificial neural network

    OpenAIRE

    Lee, S.; Evangelista, D. G.

    2006-01-01

    The purpose of this study was to apply and verify landslide-susceptibility analysis techniques using an artificial neural network and a Geographic Information System (GIS) applied to Baguio City, Philippines. The 16 July 1990 earthquake-induced landslides were studied. Landslide locations were identified from interpretation of aerial photographs and field survey, and a spatial database was constructed from topographic maps, geology, land cover and terrain mapping units. Factors that influence...

  16. Comment on the report "Operational Earthquake Forecasting" by the International Commission on Earthquake Forecasting for Civil Protection

    OpenAIRE

    Stuart Crampin

    2012-01-01

    The recently published report Operational Earthquake Forecasting: State of Knowledge and Guidelines for Utilization by the International Commission on Earthquake Forecasting for Civil Protection (ICEF) presupposes that there is no method for the short-term prediction of large earthquakes that has been demonstrated to be both reliable and skillful. This is no longer correct. Earthquakes can be deterministically stress-forecast by using shear-wave splitting to monitor stress-accumulati...

  17. Light for Earthquake Prediction:Shocks before the L'Aquila Earthquake of April 6,2009

    Institute of Scientific and Technical Information of China (English)

    Li Li; Chen Yong

    2010-01-01

    The temporal-spatial distribution of mid-small earthquakes in Italy and its surroundings from January 1 to April 5,2009 shows that there were significant foreshocks before the moderate L'Aquila earthquake of April 6,2009.The enhancement of frequency and intensity of small earthquakes and their concentrating tendency to the future main shock have provided a comprehensive case for digging methods of earthquake forecasting with foreshocks.

  18. Trends in global earthquake loss

    Science.gov (United States)

    Arnst, Isabel; Wenzel, Friedemann; Daniell, James

    2016-04-01

    Based on the CATDAT damage and loss database we analyse global trends of earthquake losses (in current values) and fatalities for the period between 1900 and 2015 from a statistical perspective. For this time period the data are complete for magnitudes above 6. First, we study the basic statistics of losses and find that losses below 10 bl. US satisfy approximately a power law with an exponent of 1.7 for the cumulative distribution. Higher loss values are modelled with the General Pareto Distribution (GPD). The 'transition' between power law and GPD is determined with the Mean Excess Function. We split the data set into a period of pre 1955 and post 1955 loss data as in those periods the exposure is significantly different due to population growth. The Annual Average Loss (AAL) for direct damage for events below 10 bl. US differs by a factor of 6, whereas the incorporation of the extreme loss events increases the AAL from 25 bl. US/yr to 30 bl. US/yr. Annual Average Deaths (AAD) show little (30%) difference for events below 6.000 fatalities and AAD values of 19.000 and 26.000 deaths per year if extreme values are incorporated. With data on the global Gross Domestic Product (GDP) that reflects the annual expenditures (consumption, investment, government spending) and on capital stock we relate losses to the economic capacity of societies and find that GDP (in real terms) grows much faster than losses so that the latter one play a decreasing role given the growing prosperity of mankind. This reasoning does not necessarily apply on a regional scale. Main conclusions of the analysis are that (a) a correct projection of historic loss values to nowadays US values is critical; (b) extreme value analysis is mandatory; (c) growing exposure is reflected in the AAL and AAD results for the periods pre and post 1955 events; (d) scaling loss values with global GDP data indicates that the relative size - from a global perspective - of losses decreases rapidly over time.

  19. The great East Japan earthquake

    International Nuclear Information System (INIS)

    'Full text:' More formally called the Tohoku-Chihou-Taiheiyo-Oki Earthquake of March 11, 2011, it was the ensuing tsunami that caused the most death and destruction to the north-east coastal region of Japan. It is also what caused the multiple meltdowns at Fukushima Dai-ichi. Reactor Unit 1, ironically, was scheduled to be permanently shut down for decommissioning just two weeks later. The Fukushima Dai-ichi nuclear power plant has a tsunami protection barrier designed for the worst recorded tsunami in that area since 1896 - to a height of 5.7 m. The plant itself is on an elevated grade of about 10 m. The tsunami, reported to be 14-15 m, caused inundation of the entire site with at least four metres of seawater. The seawater flooded the turbine building and damaged electrical equipment including the emergency diesel generators, leaving the entire six-unit nuclear power plan without any source of AC power, known as the 'station blackout scenario'. There are numerous reports available on-line at various sites. The Japanese Government report is frank and forthcoming on the causes and the lessons learned, and the lAEA Mission report is in-depth and well presented, not only as a factual account of the events but as a unified source of the conclusions and lessons learned. Photos of the catastrophe are available at the TEPCO web site: http://www.tepco.co.jp/en/index-e.html. In this edition of the Bulletin there is a 'layman's' description of CANDU and BWR design in terms of the fundamental safety principles - Control, Cool and Contain as well as a description of how these principles were met, or not met at Fukushima Dai-ichi. Also, an excerpt from the IAEA Expert Mission is included. We 'technocrats' sometimes forget about the human aspects of a nuclear disaster. An essay by Dr. Michael Edwards is included entitled 'Psychology, Philosophy and Nuclear Science'. Other references to the events appear throughout this edition.(author)

  20. Dynamic Response of Intraplate Seismicity to the 2011 Tohoku-Oki Earthquake

    Science.gov (United States)

    Houng, S. E.; Hong, T. K.

    2014-12-01

    Great earthquakes with magnitudes equal to or greater than 9.0 rarely occur over the globe. The influence of great earthquake on intraplate regions in regional distances has been poorly known. The Korean Peninsula belongs to intraplate regime with low seismicity, and is located in the far-eastern Eurasia plate. The instrumental seismicity present diffused seismicity with relatively high population around paleo-tectonic regions. The Korean Peninsula is placed at about 1300 km away from the 2011 M9.0 Tohoku-Oki earthquake. Earthquakes triggered by the Tohoku-Oki megathrust are searched from continuous waveform data using an automated event detection algorithm. The detection algorithm is to find the optimum event location where inner product of theoretical and observed STA/LTA of the waveform is maximized at hypothetical origin time. Events are declared when the inner product is greater than an empirically determined threshold. The detected events are approved after manual examination of signals. Sixty-one earthquakes with magnitudes of 0.5-2.5 are detected in the Korean Peninsula within 18 hours after the megathrust, including 17 clustered earthquakes in northwestern peninsula. The spatial distribution of clustered events suggests ˜sim279∘^circ-directional strike-slip faulting. This fault geometry comprises a situation in which the great-circle direction is approximately subparallel with the fault strike. Most events occurred within 5 hours after the mainshock, yielding the p-value of ˜sim1.0 in Omori's law. The elevated Gutenberg-Richter (GR) a value suggests the increase of seismicity after the megathrust. The spatial distribution of seismicity, GR b values, and focal mechanisms solutions of triggered events are consistent with those of natural earthquakes before the megathrust. The observations suggest that only the occurrence rates were increased for dynamic stress change inducing increase of pore pressure by fluid transfer or fault weakening by fault plane