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Sample records for preliminary seismic hazard

  1. Preliminary deformation model for National Seismic Hazard map of Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Meilano, Irwan; Gunawan, Endra; Sarsito, Dina; Prijatna, Kosasih; Abidin, Hasanuddin Z. [Geodesy Research Division, Faculty of Earth Science and Technology, Institute of Technology Bandung (Indonesia); Susilo,; Efendi, Joni [Agency for Geospatial Information (BIG) (Indonesia)

    2015-04-24

    Preliminary deformation model for the Indonesia’s National Seismic Hazard (NSH) map is constructed as the block rotation and strain accumulation function at the elastic half-space. Deformation due to rigid body motion is estimated by rotating six tectonic blocks in Indonesia. The interseismic deformation due to subduction is estimated by assuming coupling on subduction interface while deformation at active fault is calculated by assuming each of the fault‘s segment slips beneath a locking depth or in combination with creeping in a shallower part. This research shows that rigid body motion dominates the deformation pattern with magnitude more than 15 mm/year, except in the narrow area near subduction zones and active faults where significant deformation reach to 25 mm/year.

  2. The assessment of seismic hazard for Gori, (Georgia) and preliminary studies of seismic microzonation

    Science.gov (United States)

    Gogoladze, Z.; Moscatelli, M.; Giallini, S.; Avalle, A.; Gventsadze, A.; Kvavadze, N.; Tsereteli, N.

    2016-12-01

    Seismic risk is a crucial issue for South Caucasus, which is the main gateway between Asia and Europe. The goal of this work is to propose new methods and criteria for defining an overall approach aimed at assessing and mitigating seismic risk in Georgia. In this reguard seismic microzonation represents a highly useful tool for seismic risk assessmentin land management, for design of buildings or structures and for emergency planning.Seismic microzonation assessment of local seismic hazard,which is a component of seismicity resulting from specific local characteristics which cause local amplification and soil instability, through identification of zones with seismically homogeneous behavior. This paper presents the results of preliminary study of seismic microzonation of Gori, Georgia. Gori is and is located in the Shida Kartli region and on both sides of Liachvi and Mtkvari rivers, with area of about 135 km2around the Gori fortress. Gori is located in Achara-Trialeti fold-thrust belt, that is tectonically unstable. Half of all earthquakes in Gori area with magnitude M≥3.5 have happened along this fault zone and on basis of damage caused by previous earthquakes, this territory show the highest level of risk (the maximum value of direct losses) in central part of the town. The seismic microzonation map of level 1 for Gori was carried out using: 1) Already available data (i.e., topographic map and boreholes data), 2) Results of new geological surveys and 3) Geophysical measurements (i.e., MASW and noise measurements processed with HVSR technique). Our preliminary results highlight the presence of both stable zones susceptible to local amplifications and unstable zones susceptible to geological instability. Our results are directed to establish set of actions aimed at risk mitigation before initial onset of emergency, and to management of the emergency once the seismic event has occurred. The products obtained, will contain the basic elements of an integrated system

  3. Seismic hazard assessment of Iran

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    M. Ghafory-Ashtiany

    1999-06-01

    Full Text Available The development of the new seismic hazard map of Iran is based on probabilistic seismic hazard computation using the historical earthquakes data, geology, tectonics, fault activity and seismic source models in Iran. These maps have been prepared to indicate the earthquake hazard of Iran in the form of iso-acceleration contour lines, and seismic hazard zoning, by using current probabilistic procedures. They display the probabilistic estimates of Peak Ground Acceleration (PGA for the return periods of 75 and 475 years. The maps have been divided into intervals of 0.25 degrees in both latitudinal and longitudinal directions to calculate the peak ground acceleration values at each grid point and draw the seismic hazard curves. The results presented in this study will provide the basis for the preparation of seismic risk maps, the estimation of earthquake insurance premiums, and the preliminary site evaluation of critical facilities.

  4. Some preliminary results of a worldwide seismicity estimation: a case study of seismic hazard evaluation in South America

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    C. V. Christova

    2000-06-01

    Full Text Available Global data have been widely used for seismicity and seismic hazard assessment by seismologists. In the present study we evaluate worldwide seismicity in terms of maps of maximum observed magnitude (Mmax, seismic moment (M 0 and seismic moment rate (M 0S. The data set used consists of a complete and homogeneous global catalogue of shallow (h £ 60 km earthquakes of magnitude MS ³ 5.5 for the time period 1894-1992. In order to construct maps of seismicity and seismic hazard the parameters a and b derived from the magnitude-frequency relationship were estimated by both: a the least squares, and b the maximum likelihood, methods. The values of a and b were determined considering circles centered at each grid point 1° (of a mesh 1° ´1° and of varying radius, which starts from 30 km and moves with a step of 10 km. Only a and b values which fulfill some predefined conditions were considered in the further procedure for evaluating the seismic hazard maps. The obtained worldwide M max distribution in general delineates the contours of the plate boundaries. The highest values of M max observed are along the circum-Pacific belt and in the Himalayan area. The subduction plate boundaries are characterized by the largest amount of M 0 , while areas of continental collision are next. The highest values of seismic moment rate (per 1 year and per equal area of 10 000 km 2 are found in the Southern Himalayas. The western coasts of U.S.A., Northwestern Canada and Alaska, the Indian Ocean and the eastern rift of Africa are characterized by high values of M 0 , while most of the Pacific subduction zones have lower values of seismic moment rate. Finally we analyzed the seismic hazard in South America comparing the predicted by the NUVEL1 model convergence slip rate between Nazca and South America plates with the average slip rate due to earthquakes. This consideration allows for distinguishing between zones of high and low coupling along the studied convergence

  5. Preliminary re-evaluation of probabilistic seismic hazard assessment in Chile: from Arica to Taitao Peninsula

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    F. Leyton

    2009-12-01

    Full Text Available Chile is one of the most seismically active countries in the world; indeed, having witnessed very large earthquakes associated with high horizontal peak ground accelerations, the use of probabilistic hazard assessment is an important tool in any decision-making. In the present study, we review all the available information to improve the estimation of the probabilistic seismic hazard caused by two main sources: shallow interplate, thrust earthquakes and intermediate depth, intraplate earthquakes. Using previously defined seismic zones, we compute Gutenberg-Richter laws and, along with appropriate attenuation laws, revaluate the probabilistic seismic hazard assessments in Chile. We obtain expected horizontal peak ground acceleration with a 10% of probability of being exceeded in 50 years, reaching from 0.6 g up 1.0 g in the coast and between 0.4 g and 0.6 g towards the Andes Mountains, with larger values in Northern part of the country. The present study improves our knowledge of geological hazards in Chile, enabling the mitigation of important human and material losses due to large earthquakes in the future.

  6. Preliminary seismic hazard assessment, shallow seismic refraction and resistivity sounding studies for future urban planning at the Gebel Umm Baraqa area, Egypt

    Science.gov (United States)

    Khalil, Mohamed H.; Hanafy, Sherif M.; Gamal, Mohamed A.

    2008-12-01

    Gebel Umm Baraqa Fan, west Gulf of Aqaba, Sinai, is one of the most important tourism areas in Egypt. However, it is located on the active Dead Sea-Gulf of Aqaba Levant transform fault system. Geophysical studies, including fresh water aquifer delineation, shallow seismic refraction, soil characterization and preliminary seismic hazard assessment, were conducted to help in future city planning. A total of 11 vertical electrical soundings (1000-3000 m maximum AB/2) and three bore-holes were drilled in the site for the analysis of ground water, total dissolved solids (TDS) and fresh water aquifer properties. The interpretation of the one-dimensional (1D) inversion of the resistivity data delineated the fresh water aquifer and determined its hydro-geologic parameters. Eleven shallow seismic refraction profiles (125 m in length) have been collected and interpreted using the generalized reciprocal method, and the resulting depth-velocity models were verified using an advanced finite difference (FD) technique. Shallow seismic refraction effectively delineates two subsurface layers (VP ~ 450 m s-1 and VP ~ 1000 m s-1). A preliminary seismic hazard assessment in Umm Baraqa has produced an estimate of the probabilistic peak ground acceleration hazard in the study area. A recent and historical earthquake catalog for the time period 2200 BC to 2006 has been compiled for the area. New accurate seismic source zoning is considered because such details affect the degree of hazard in the city. The estimated amount of PGA reveals values ranging from 250 to 260 cm s-2 in the bedrock of the Umm Baraqa area during a 100 year interval (a suitable time window for buildings). Recommendations as to suitable types of buildings, considering the amount of shaking and the aquifer properties given in this study, are expected to be helpful for the Umm Baraqa area.

  7. Geophysics and Seismic Hazard Reduction

    Institute of Scientific and Technical Information of China (English)

    YuGuihua; ZhouYuanze; YuSheng

    2003-01-01

    The earthquake is a natural phenomenon, which often brings serious hazard to the human life and material possession. It is a physical process of releasing interior energy of the earth, which is caused by interior and outer forces in special tectonic environment in the earth, especially within the lithosphere. The earthquake only causes casualty and loss in the place where people inhabit. Seismic hazard reduction is composed of four parts as seismic prediction, hazard prevention and seismic engineering, seismic response and seismic rescuing, and rebuilding.

  8. Updated Colombian Seismic Hazard Map

    Science.gov (United States)

    Eraso, J.; Arcila, M.; Romero, J.; Dimate, C.; Bermúdez, M. L.; Alvarado, C.

    2013-05-01

    The Colombian seismic hazard map used by the National Building Code (NSR-98) in effect until 2009 was developed in 1996. Since then, the National Seismological Network of Colombia has improved in both coverage and technology providing fifteen years of additional seismic records. These improvements have allowed a better understanding of the regional geology and tectonics which in addition to the seismic activity in Colombia with destructive effects has motivated the interest and the need to develop a new seismic hazard assessment in this country. Taking advantage of new instrumental information sources such as new broad band stations of the National Seismological Network, new historical seismicity data, standardized global databases availability, and in general, of advances in models and techniques, a new Colombian seismic hazard map was developed. A PSHA model was applied. The use of the PSHA model is because it incorporates the effects of all seismic sources that may affect a particular site solving the uncertainties caused by the parameters and assumptions defined in this kind of studies. First, the seismic sources geometry and a complete and homogeneous seismic catalog were defined; the parameters of seismic rate of each one of the seismic sources occurrence were calculated establishing a national seismotectonic model. Several of attenuation-distance relationships were selected depending on the type of seismicity considered. The seismic hazard was estimated using the CRISIS2007 software created by the Engineering Institute of the Universidad Nacional Autónoma de México -UNAM (National Autonomous University of Mexico). A uniformly spaced grid each 0.1° was used to calculate the peak ground acceleration (PGA) and response spectral values at 0.1, 0.2, 0.3, 0.5, 0.75, 1, 1.5, 2, 2.5 and 3.0 seconds with return periods of 75, 225, 475, 975 and 2475 years. For each site, a uniform hazard spectrum and exceedance rate curves were calculated. With the results, it is

  9. Seismic hazard assessment: Issues and alternatives

    Science.gov (United States)

    Wang, Z.

    2011-01-01

    Seismic hazard and risk are two very important concepts in engineering design and other policy considerations. Although seismic hazard and risk have often been used inter-changeably, they are fundamentally different. Furthermore, seismic risk is more important in engineering design and other policy considerations. Seismic hazard assessment is an effort by earth scientists to quantify seismic hazard and its associated uncertainty in time and space and to provide seismic hazard estimates for seismic risk assessment and other applications. Although seismic hazard assessment is more a scientific issue, it deserves special attention because of its significant implication to society. Two approaches, probabilistic seismic hazard analysis (PSHA) and deterministic seismic hazard analysis (DSHA), are commonly used for seismic hazard assessment. Although PSHA has been pro-claimed as the best approach for seismic hazard assessment, it is scientifically flawed (i.e., the physics and mathematics that PSHA is based on are not valid). Use of PSHA could lead to either unsafe or overly conservative engineering design or public policy, each of which has dire consequences to society. On the other hand, DSHA is a viable approach for seismic hazard assessment even though it has been labeled as unreliable. The biggest drawback of DSHA is that the temporal characteristics (i.e., earthquake frequency of occurrence and the associated uncertainty) are often neglected. An alternative, seismic hazard analysis (SHA), utilizes earthquake science and statistics directly and provides a seismic hazard estimate that can be readily used for seismic risk assessment and other applications. ?? 2010 Springer Basel AG.

  10. USGS National Seismic Hazard Maps

    Science.gov (United States)

    Frankel, A.D.; Mueller, C.S.; Barnhard, T.P.; Leyendecker, E.V.; Wesson, R.L.; Harmsen, S.C.; Klein, F.W.; Perkins, D.M.; Dickman, N.C.; Hanson, S.L.; Hopper, M.G.

    2000-01-01

    The U.S. Geological Survey (USGS) recently completed new probabilistic seismic hazard maps for the United States, including Alaska and Hawaii. These hazard maps form the basis of the probabilistic component of the design maps used in the 1997 edition of the NEHRP Recommended Provisions for Seismic Regulations for New Buildings and Other Structures, prepared by the Building Seismic Safety Council arid published by FEMA. The hazard maps depict peak horizontal ground acceleration and spectral response at 0.2, 0.3, and 1.0 sec periods, with 10%, 5%, and 2% probabilities of exceedance in 50 years, corresponding to return times of about 500, 1000, and 2500 years, respectively. In this paper we outline the methodology used to construct the hazard maps. There are three basic components to the maps. First, we use spatially smoothed historic seismicity as one portion of the hazard calculation. In this model, we apply the general observation that moderate and large earthquakes tend to occur near areas of previous small or moderate events, with some notable exceptions. Second, we consider large background source zones based on broad geologic criteria to quantify hazard in areas with little or no historic seismicity, but with the potential for generating large events. Third, we include the hazard from specific fault sources. We use about 450 faults in the western United States (WUS) and derive recurrence times from either geologic slip rates or the dating of pre-historic earthquakes from trenching of faults or other paleoseismic methods. Recurrence estimates for large earthquakes in New Madrid and Charleston, South Carolina, were taken from recent paleoliquefaction studies. We used logic trees to incorporate different seismicity models, fault recurrence models, Cascadia great earthquake scenarios, and ground-motion attenuation relations. We present disaggregation plots showing the contribution to hazard at four cities from potential earthquakes with various magnitudes and

  11. Seismic hazard maps for Haiti

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    Frankel, Arthur; Harmsen, Stephen; Mueller, Charles; Calais, Eric; Haase, Jennifer

    2011-01-01

    We have produced probabilistic seismic hazard maps of Haiti for peak ground acceleration and response spectral accelerations that include the hazard from the major crustal faults, subduction zones, and background earthquakes. The hazard from the Enriquillo-Plantain Garden, Septentrional, and Matheux-Neiba fault zones was estimated using fault slip rates determined from GPS measurements. The hazard from the subduction zones along the northern and southeastern coasts of Hispaniola was calculated from slip rates derived from GPS data and the overall plate motion. Hazard maps were made for a firm-rock site condition and for a grid of shallow shear-wave velocities estimated from topographic slope. The maps show substantial hazard throughout Haiti, with the highest hazard in Haiti along the Enriquillo-Plantain Garden and Septentrional fault zones. The Matheux-Neiba Fault exhibits high hazard in the maps for 2% probability of exceedance in 50 years, although its slip rate is poorly constrained.

  12. Seismic hazard studies in Egypt

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    Mohamed, Abuo El-Ela A.; El-Hadidy, M.; Deif, A.; Abou Elenean, K.

    2012-12-01

    The study of earthquake activity and seismic hazard assessment of Egypt is very important due to the great and rapid spreading of large investments in national projects, especially the nuclear power plant that will be held in the northern part of Egypt. Although Egypt is characterized by low seismicity, it has experienced occurring of damaging earthquake effect through its history. The seismotectonic sitting of Egypt suggests that large earthquakes are possible particularly along the Gulf of Aqaba-Dead Sea transform, the Subduction zone along the Hellenic and Cyprean Arcs, and the Northern Red Sea triple junction point. In addition some inland significant sources at Aswan, Dahshour, and Cairo-Suez District should be considered. The seismic hazard for Egypt is calculated utilizing a probabilistic approach (for a grid of 0.5° × 0.5°) within a logic-tree framework. Alternative seismogenic models and ground motion scaling relationships are selected to account for the epistemic uncertainty. Seismic hazard values on rock were calculated to create contour maps for four ground motion spectral periods and for different return periods. In addition, the uniform hazard spectra for rock sites for different 25 periods, and the probabilistic hazard curves for Cairo, and Alexandria cities are graphed. The peak ground acceleration (PGA) values were found close to the Gulf of Aqaba and it was about 220 gal for 475 year return period. While the lowest (PGA) values were detected in the western part of the western desert and it is less than 25 gal.

  13. Seismic hazard studies in Egypt

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    Abuo El-Ela A. Mohamed

    2012-12-01

    Full Text Available The study of earthquake activity and seismic hazard assessment of Egypt is very important due to the great and rapid spreading of large investments in national projects, especially the nuclear power plant that will be held in the northern part of Egypt. Although Egypt is characterized by low seismicity, it has experienced occurring of damaging earthquake effect through its history. The seismotectonic sitting of Egypt suggests that large earthquakes are possible particularly along the Gulf of Aqaba–Dead Sea transform, the Subduction zone along the Hellenic and Cyprean Arcs, and the Northern Red Sea triple junction point. In addition some inland significant sources at Aswan, Dahshour, and Cairo-Suez District should be considered. The seismic hazard for Egypt is calculated utilizing a probabilistic approach (for a grid of 0.5° × 0.5° within a logic-tree framework. Alternative seismogenic models and ground motion scaling relationships are selected to account for the epistemic uncertainty. Seismic hazard values on rock were calculated to create contour maps for four ground motion spectral periods and for different return periods. In addition, the uniform hazard spectra for rock sites for different 25 periods, and the probabilistic hazard curves for Cairo, and Alexandria cities are graphed. The peak ground acceleration (PGA values were found close to the Gulf of Aqaba and it was about 220 gal for 475 year return period. While the lowest (PGA values were detected in the western part of the western desert and it is less than 25 gal.

  14. Preliminary Earthquake Hazard Map of Afghanistan

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    Boyd, Oliver S.; Mueller, Charles S.; Rukstales, Kenneth S.

    2007-01-01

    . Deformation here is expressed as a belt of major, north-northeast-trending, left-lateral strike-slip faults and abundant seismicity. The seismicity intensifies farther to the northeast and includes a prominent zone of deep earthquakes associated with northward subduction of the Indian plate beneath Eurasia that extends beneath the Hindu Kush and Pamirs Mountains. Production of the seismic hazard maps is challenging because the geological and seismological data required to produce a seismic hazard model are limited. The data that are available for this project include historical seismicity and poorly constrained slip rates on only a few of the many active faults in the country. Much of the hazard is derived from a new catalog of historical earthquakes: from 1964 to the present, with magnitude equal to or greater than about 4.5, and with depth between 0 and 250 kilometers. We also include four specific faults in the model: the Chaman fault with an assigned slip rate of 10 mm/yr, the Central Badakhshan fault with an assigned slip rate of 12 mm/yr, the Darvaz fault with an assigned slip rate of 7 mm/yr, and the Hari Rud fault with an assigned slip rate of 2 mm/yr. For these faults and for shallow seismicity less than 50 km deep, we incorporate published ground-motion estimates from tectonically active regions of western North America, Europe, and the Middle East. Ground-motion estimates for deeper seismicity are derived from data in subduction environments. We apply estimates derived for tectonic regions where subduction is the main tectonic process for intermediate-depth seismicity between 50- and 250-km depth. Within the framework of these limitations, we have developed a preliminary probabilistic seismic-hazard assessment of Afghanistan, the type of analysis that underpins the seismic components of modern building codes in the United States. The assessment includes maps of estimated peak ground-acceleration (PGA), 0.2-second spectral acceleration (SA), and 1.0-secon

  15. Time-dependent neo-deterministic seismic hazard scenarios: Preliminary report on the M6.2 Central Italy earthquake, 24th August 2016

    CERN Document Server

    Peresan, Antonella; Romashkova, Leontina; Magrin, Andrea; Soloviev, Alexander; Panza, Giuliano F

    2016-01-01

    A scenario-based Neo-Deterministic approach to Seismic Hazard Assessment (NDSHA) is available nowadays, which permits considering a wide range of possible seismic sources as the starting point for deriving scenarios by means of full waveforms modeling. The method does not make use of attenuation relations and naturally supplies realistic time series of ground shaking, including reliable estimates of ground displacement, readily applicable to complete engineering analysis. Based on the neo-deterministic approach, an operational integrated procedure for seismic hazard assessment has been developed that allows for the definition of time dependent scenarios of ground shaking, through the routine updating of earthquake predictions, performed by means of the algorithms CN and M8S. The integrated NDSHA procedure for seismic input definition, which is currently applied to the Italian territory, combines different pattern recognition techniques, designed for the space-time identification of strong earthquakes, with al...

  16. Global Seismic Hazard Assessment Program - GSHAP legacy

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    Laurentiu Danciu

    2015-04-01

    Full Text Available Global Seismic Hazard Assessment Program - or simply GSHAP, when launched, almost two decades ago, aimed at establishing a common framework to evaluate the seismic hazard over geographical large-scales, i.e. countries, regions, continents and finally the globe. Its main product, the global seismic hazard map was a milestone, unique at that time and for a decade have served as the main reference worldwide. Today, for most of the Earth’s seismically active regions such Europe, Northern and Southern America, Central and South-East Asia, Japan, Australia, New Zealand, the GSHAP seismic hazard map is outdated. The rapid increase of the new data, advance on the earthquake process knowledge, technological progress, both hardware and software, contributed all in updates of the seismic hazard models. We present herein, a short retrospective overview of the achievements as well as the pitfalls of the GSHAP. Further, we describe the next generation of seismic hazard models, as elaborated within the Global Earthquake Model, regional programs: the 2013 European Seismic Hazard Model, the 2014 Earthquake Model for Middle East, and the 2015 Earthquake Model of Central Asia. Later, the main characteristics of these regional models are summarized and the new datasets fully harmonized across national borders are illustrated for the first time after the GSHAP completion.

  17. Probabilistic Seismic Hazard Analysis for Yemen

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    Rakesh Mohindra

    2012-01-01

    Full Text Available A stochastic-event probabilistic seismic hazard model, which can be used further for estimates of seismic loss and seismic risk analysis, has been developed for the territory of Yemen. An updated composite earthquake catalogue has been compiled using the databases from two basic sources and several research publications. The spatial distribution of earthquakes from the catalogue was used to define and characterize the regional earthquake source zones for Yemen. To capture all possible scenarios in the seismic hazard model, a stochastic event set has been created consisting of 15,986 events generated from 1,583 fault segments in the delineated seismic source zones. Distribution of horizontal peak ground acceleration (PGA was calculated for all stochastic events considering epistemic uncertainty in ground-motion modeling using three suitable ground motion-prediction relationships, which were applied with equal weight. The probabilistic seismic hazard maps were created showing PGA and MSK seismic intensity at 10% and 50% probability of exceedance in 50 years, considering local soil site conditions. The resulting PGA for 10% probability of exceedance in 50 years (return period 475 years ranges from 0.2 g to 0.3 g in western Yemen and generally is less than 0.05 g across central and eastern Yemen. The largest contributors to Yemen’s seismic hazard are the events from the West Arabian Shield seismic zone.

  18. Seismic hazard estimation of northern Iran using smoothed seismicity

    Science.gov (United States)

    Khoshnevis, Naeem; Taborda, Ricardo; Azizzadeh-Roodpish, Shima; Cramer, Chris H.

    2017-07-01

    This article presents a seismic hazard assessment for northern Iran, where a smoothed seismicity approach has been used in combination with an updated seismic catalog and a ground motion prediction equation recently found to yield good fit with data. We evaluate the hazard over a geographical area including the seismic zones of Azerbaijan, the Alborz Mountain Range, and Kopeh-Dagh, as well as parts of other neighboring seismic zones that fall within our region of interest. In the chosen approach, seismic events are not assigned to specific faults but assumed to be potential seismogenic sources distributed within regular grid cells. After performing the corresponding magnitude conversions, we decluster both historical and instrumental seismicity catalogs to obtain earthquake rates based on the number of events within each cell, and smooth the results to account for the uncertainty in the spatial distribution of future earthquakes. Seismicity parameters are computed for each seismic zone separately, and for the entire region of interest as a single uniform seismotectonic region. In the analysis, we consider uncertainties in the ground motion prediction equation, the seismicity parameters, and combine the resulting models using a logic tree. The results are presented in terms of expected peak ground acceleration (PGA) maps and hazard curves at selected locations, considering exceedance probabilities of 2 and 10% in 50 years for rock site conditions. According to our results, the highest levels of hazard are observed west of the North Tabriz and east of the North Alborz faults, where expected PGA values are between about 0.5 and 1 g for 10 and 2% probability of exceedance in 50 years, respectively. We analyze our results in light of similar estimates available in the literature and offer our perspective on the differences observed. We find our results to be helpful in understanding seismic hazard for northern Iran, but recognize that additional efforts are necessary to

  19. Seismic hazard estimation of northern Iran using smoothed seismicity

    Science.gov (United States)

    Khoshnevis, Naeem; Taborda, Ricardo; Azizzadeh-Roodpish, Shima; Cramer, Chris H.

    2017-03-01

    This article presents a seismic hazard assessment for northern Iran, where a smoothed seismicity approach has been used in combination with an updated seismic catalog and a ground motion prediction equation recently found to yield good fit with data. We evaluate the hazard over a geographical area including the seismic zones of Azerbaijan, the Alborz Mountain Range, and Kopeh-Dagh, as well as parts of other neighboring seismic zones that fall within our region of interest. In the chosen approach, seismic events are not assigned to specific faults but assumed to be potential seismogenic sources distributed within regular grid cells. After performing the corresponding magnitude conversions, we decluster both historical and instrumental seismicity catalogs to obtain earthquake rates based on the number of events within each cell, and smooth the results to account for the uncertainty in the spatial distribution of future earthquakes. Seismicity parameters are computed for each seismic zone separately, and for the entire region of interest as a single uniform seismotectonic region. In the analysis, we consider uncertainties in the ground motion prediction equation, the seismicity parameters, and combine the resulting models using a logic tree. The results are presented in terms of expected peak ground acceleration (PGA) maps and hazard curves at selected locations, considering exceedance probabilities of 2 and 10% in 50 years for rock site conditions. According to our results, the highest levels of hazard are observed west of the North Tabriz and east of the North Alborz faults, where expected PGA values are between about 0.5 and 1 g for 10 and 2% probability of exceedance in 50 years, respectively. We analyze our results in light of similar estimates available in the literature and offer our perspective on the differences observed. We find our results to be helpful in understanding seismic hazard for northern Iran, but recognize that additional efforts are necessary to

  20. Seismic hazard map of the western hemisphere

    Science.gov (United States)

    Shedlock, K.M.; Tanner, J.G.

    1999-01-01

    Vulnerability to natural disasters increases with urbanization and development of associated support systems (reservoirs, power plants, etc.). Catastrophic earthquakes account for 60% of worldwide casualties associated with natural disasters. Economic damage from earthquakes is increasing, even in technologically advanced countries with some level of seismic zonation, as shown by the 1989 Loma Prieta, CA ($6 billion), 1994 Northridge, CA ($ 25 billion), and 1995 Kobe, Japan (> $ 100 billion) earthquakes. The growth of megacities in seismically active regions around the world often includes the construction of seismically unsafe buildings and infrastructures, due to an insufficient knowledge of existing seismic hazard. Minimization of the loss of life, property damage, and social and economic disruption due to earthquakes depends on reliable estimates of seismic hazard. National, state, and local governments, decision makers, engineers, planners, emergency response organizations, builders, universities, and the general public require seismic hazard estimates for land use planning, improved building design and construction (including adoption of building construction codes), emergency response preparedness plans, economic forecasts, housing and employment decisions, and many more types of risk mitigation. The seismic hazard map of the Americas is the concatenation of various national and regional maps, involving a suite of approaches. The combined maps and documentation provide a useful global seismic hazard framework and serve as a resource for any national or regional agency for further detailed studies applicable to their needs. This seismic hazard map depicts Peak Ground Acceleration (PGA) with a 10% chance of exceedance in 50 years for the western hemisphere. PGA, a short-period ground motion parameter that is proportional to force, is the most commonly mapped ground motion parameter because current building codes that include seismic provisions specify the

  1. Seismic hazard map of the western hemisphere

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    J. G. Tanner

    1999-06-01

    Full Text Available Vulnerability to natural disasters increases with urbanization and development of associated support systems (reservoirs, power plants, etc.. Catastrophic earthquakes account for 60% of worldwide casualties associated with natural disasters. Economic damage from earthquakes is increasing, even in technologically advanced countries with some level of seismic zonation, as shown by the 1989 Loma Prieta, CA ($ 6 billion, 1994 Northridge, CA ($ 25 billion, and 1995 Kobe, Japan (> $ 100 billion earthquakes. The growth of megacities in seismically active regions around the world often includes the construction of seismically unsafe buildings and infrastructures, due to an insufficient knowledge of existing seismic hazard. Minimization of the loss of life, property damage, and social and economic disruption due to earthquakes depends on reliable estimates of seismic hazard. National, state, and local governments, decision makers, engineers, planners, emergency response organizations, builders, universities, and the general public require seismic hazard estimates for land use planning, improved building design and construction (including adoption of building construction codes, emergency response preparedness plans, economic forecasts, housing and employment decisions, and many more types of risk mitigation. The seismic hazard map of the Americas is the concatenation of various national and regional maps, involving a suite of approaches. The combined maps and documentation provide a useful global seismic hazard framework and serve as a resource for any national or regional agency for further detailed studies applicable to their needs. This seismic hazard map depicts Peak Ground Acceleration (PGA with a 10% chance of exceedance in 50 years for the western hemisphere. PGA, a short-period ground motion parameter that is proportional to force, is the most commonly mapped ground motion parameter because current building codes that include seismic provisions

  2. Probabilistic seismic hazard assessment for Central Asia

    Directory of Open Access Journals (Sweden)

    Shahid Ullah

    2015-04-01

    Full Text Available Central Asia is one of the seismically most active regions in the world. Its complex seismicity due to the collision of the Eurasian and Indian plates has resulted in some of the world’s largest intra-plate events over history. The region is dominated by reverse faulting over strike slip and normal faulting events. The GSHAP project (1999, aiming at a hazard assessment on a global scale, indicated that the region of Central Asia is characterized by peak ground accelerations for 10% probability of exceedance in 50 years as high as 9 m/s2. In this study, carried out within the framework of the EMCA project (Earthquake Model Central Asia, the area source model and different kernel approaches are used for a probabilistic seismic hazard assessment (PSHA for Central Asia. The seismic hazard is assessed considering shallow (depth < 50 km seismicity only and employs an updated (with respect to previous projects earthquake catalog for the region. The seismic hazard is calculated in terms of macroseismic intensity (MSK-64, intended to be used for the seismic risk maps of the region. The hazard maps, shown in terms of 10% probability of exceedance in 50 years, are derived by using the OpenQuake software [Pagani et al. 2014], which is an open source software tool developed by the GEM (Global Earthquake Model foundation. The maximum hazard observed in the region reaches an intensity of around 8 in southern Tien Shan for 475 years mean return period. The maximum hazard estimated for some of the cities in the region, Bishkek, Dushanbe, Tashkent and Almaty, is between 7 and 8 (7-8, 8.0, 7.0 and 8.0 macroseismic Intensity, respectively, for 475 years mean return period, using different approaches. The results of different methods for assessing the level of seismic hazard are compared and their underlying methodologies are discussed.

  3. Seismotectonics and seismic Hazard map of Tunisia

    Science.gov (United States)

    Soumaya, Abdelkader; Ben Ayed, Noureddine; Khayati Ammar, Hayet; Kadri, Ali; Zargouni, Fouad; Ghanmi, Mohamed

    2016-04-01

    One natural hazard in Tunisia is caused by earthquakes and one way to measure the shaking risk is the probabilistic seismic-hazard map. The study of seismic hazard and risk assessment in Tunisia started in 1990 within the framework of the National Program for Assessment of Earthquake Risk. Because earthquakes are random events characterized by specific uncertainties, we used a probabilistic method to build the seismic hazard map of Tunisia. Probabilities were derived from the available seismic data and from results of neotectonic, geophysical and geological studies on the main active domains of Tunisia. This map displays earthquake ground motions for various probability levels across Tunisia and it is used in seismic provisions of building codes, insurance rate structures, risk assessment and other public management activities. The product is a seismotectonic map of Tunisia summarizing the available datasets (e.g., active fault, focal mechanism, instrumental and historical seismicity, peak ground acceleration). In addition, we elaborate some thematic seismic hazard maps that represent an important tool for the social and economic development.

  4. Seismic hazard communication in Istanbul

    Science.gov (United States)

    Ickert, Johanna

    2015-04-01

    Conflicting societal conceptions of earthquake safety provide challenges but also opportunities for the communication of seismic hazards. This paradox is exemplified in the controversial social reactions to the ongoing 'urban renewal projects' in Istanbul. Seismologists estimate that there is a high probability that a major earthquake will strike Istanbul in the next decade or so. Detailed earthquake risk analysis, and direct experience of the losses suffered during the major earthquakes that struck Turkey in 1999 and 2011, have engendered a broad societal recognition of the need for extensive earthquake preparedness and response planning. However, there has been dissent concerning the democratic legitimation of some of Istanbul's mitigation measures, most notably the implementation of the 'Law for the Regeneration of Areas Under Disaster Risk' (Law 6306, known as the 'disaster law') in May 2012. The strong interconnections between geological 'matters of fact' and societal 'matters of concern' raise fundamental questions for geocommunication on how to deal with this societal complexity, particularly in terms of maintaining trust in the geoscientist. There is a growing recognition among geoscientists that achieving disaster resilience in Istanbul is not solely the domain of 'earthquake experts' but rather requires a shared societal responsibility. However, the question arises as to how geocommunication can be designed to respond to this increased demand for interdisciplinarity and civil participation. This research will confront this question, exploring ways to combine qualitative and quantitative analyses, values and preferred norms with facts and observations, and be organised around an interactive web-based documentary platform that integrates multiple knowledge bases and seeks to help connect different communication cultures.

  5. Probabilistic Seismic Hazard Assessment for Taiwan

    Directory of Open Access Journals (Sweden)

    Yu-Ju Wang

    2016-06-01

    Full Text Available The Taiwan Earthquake Model (TEM was established to assess the seismic hazard and risk for Taiwan by considering the social and economic impacts of various components from geology, seismology, and engineering. This paper gives the first version of TEM probabilistic seismic hazard analysis for Taiwan in these aspects. We named it TEM PSHA2015. The model adopts the source parameters of 38 seismogenic structures identified by TEM geologists. In addition to specific fault source-based categorization, seismic activities are categorized as shallow, subduction intraplate, and subduction interplate events. To evaluate the potential ground-shaking resulting from each seismic source, the corresponding ground-motion prediction equations for crustal and subduction earthquakes are adopted. The highest hazard probability is evaluated to be in Southwestern Taiwan and the Longitudinal Valley of Eastern Taiwan. Among the special municipalities in the highly populated Western Taiwan region, Taichung, Tainan, and New Taipei City are evaluated to have the highest hazard. Tainan has the highest seismic hazard for peak ground acceleration in the model based on TEM fault parameters. In terms of pseudo-spectral acceleration, Tainan has higher hazard over short spectral periods, whereas Taichung has higher hazard over long spectral periods. The analysis indicates the importance of earthquake-resistant designs for low-rise buildings in Tainan and high-rise buildings in Taichung.

  6. Using strain rates to forecast seismic hazards

    Science.gov (United States)

    Evans, Eileen

    2017-01-01

    One essential component in forecasting seismic hazards is observing the gradual accumulation of tectonic strain accumulation along faults before this strain is suddenly released as earthquakes. Typically, seismic hazard models are based on geologic estimates of slip rates along faults and historical records of seismic activity, neither of which records actively accumulating strain. But this strain can be estimated by geodesy: the precise measurement of tiny position changes of Earth’s surface, obtained from GPS, interferometric synthetic aperture radar (InSAR), or a variety of other instruments.

  7. Numerical earthquake simulations for seismic hazard assessment

    Science.gov (United States)

    Ismail-Zadeh, Alik; Sokolov, Vladimir; Soloviev, Alexander

    2017-04-01

    A comprehensive seismic hazard assessment can contribute to earthquake preparedness and preventive measures aimed to reduce impacts of earthquakes, especially in the view of growing population and increasing vulnerability and exposure. Realistic earthquake simulations coupled with a seismic hazard analysis can provide better assessments of potential ground shaking due to large earthquakes. We present a model of block-and-fault dynamics, which simulates earthquakes in response to lithosphere movements and allows for studying the influence of fault network properties on seismic patterns. Using case studies (e.g., the Tibet-Himalayan region and the Caucasian region), we analyse the model's performance in terms of reproduction of basic features of the observed seismicity, such as the frequency-magnitude relationship, clustering of earthquakes, occurrences of large events, fault slip rates, and earthquake mechanisms. We examine a new approach to probabilistic seismic hazard assessment, which is based on instrumentally recorded, historical and simulated earthquakes. Based on predicted and observed peak ground acceleration values, we show that the hazard level associated with large events significantly increases if the long record of simulated seismicity is considered in the hazard assessment.

  8. Preliminary hazards analysis -- vitrification process

    Energy Technology Data Exchange (ETDEWEB)

    Coordes, D.; Ruggieri, M.; Russell, J.; TenBrook, W.; Yimbo, P. [Science Applications International Corp., Pleasanton, CA (United States)

    1994-06-01

    This paper presents a Preliminary Hazards Analysis (PHA) for mixed waste vitrification by joule heating. The purpose of performing a PHA is to establish an initial hazard categorization for a DOE nuclear facility and to identify those processes and structures which may have an impact on or be important to safety. The PHA is typically performed during and provides input to project conceptual design. The PHA is then followed by a Preliminary Safety Analysis Report (PSAR) performed during Title 1 and 2 design. The PSAR then leads to performance of the Final Safety Analysis Report performed during the facility`s construction and testing. It should be completed before routine operation of the facility commences. This PHA addresses the first four chapters of the safety analysis process, in accordance with the requirements of DOE Safety Guidelines in SG 830.110. The hazards associated with vitrification processes are evaluated using standard safety analysis methods which include: identification of credible potential hazardous energy sources; identification of preventative features of the facility or system; identification of mitigative features; and analyses of credible hazards. Maximal facility inventories of radioactive and hazardous materials are postulated to evaluate worst case accident consequences. These inventories were based on DOE-STD-1027-92 guidance and the surrogate waste streams defined by Mayberry, et al. Radiological assessments indicate that a facility, depending on the radioactive material inventory, may be an exempt, Category 3, or Category 2 facility. The calculated impacts would result in no significant impact to offsite personnel or the environment. Hazardous materials assessment indicates that a Mixed Waste Vitrification facility will be a Low Hazard facility having minimal impacts to offsite personnel and the environment.

  9. Probability seismic hazard maps of Southern Thailand

    Directory of Open Access Journals (Sweden)

    Chinda Sutiwanich

    2012-09-01

    Full Text Available Seismic hazard maps of southern Thailand were obtained from the integration of crustal fault, areal and subductionsource models using probability seismic hazard analysis and the application of a logic tree approach. The hazard maps showthe mean peak ground and spectral accelerations at 0.2, 0.3 and 1.0 second periods with a 10%, 5%, 2% and 0.5% probabilityof exceedance in 50-year hazard levels. The highest hazard areas were revealed to be in the Muang, Phanom, and Viphavadidistricts of Surat Thani province, the Thap Put district of Phang Nga province, and the Plai Phraya district of Krabi province.The lowest hazard areas are in the southernmost part of Thailand e.g. Yala, Pattani and Narathiwat provinces. The maximumvalues of the mean peak ground acceleration for the 475–9,975 yr return period are 0.28-0.52 g and the maximum spectralaccelerations at 0.2 seconds for the same return period are 0.52-0.80 g. Similar hazard is also obtained for different returnperiods. Presented seismic hazard maps are useful as a guideline for the future design of buildings, bridges or dams, for rocksites to resist earthquake forces.

  10. A study on seismicity and seismic hazard for Karnataka State

    Indian Academy of Sciences (India)

    T G Sitharam; Naveen James; K S Vipin; K Ganesha Raj

    2012-04-01

    This paper presents a detailed study on the seismic pattern of the state of Karnataka and also quantifies the seismic hazard for the entire state. In the present work, historical and instrumental seismicity data for Karnataka (within 300 km from Karnataka political boundary) were compiled and hazard analysis was done based on this data. Geographically, Karnataka forms a part of peninsular India which is tectonically identified as an intraplate region of Indian plate. Due to the convergent movement of the Indian plate with the Eurasian plate, movements are occurring along major intraplate faults resulting in seismic activity of the region and hence the hazard assessment of this region is very important. Apart from referring to seismotectonic atlas for identifying faults and fractures, major lineaments in the study area were also mapped using satellite data. The earthquake events reported by various national and international agencies were collected until 2009. Declustering of earthquake events was done to remove foreshocks and aftershocks. Seismic hazard analysis was done for the state of Karnataka using both deterministic and probabilistic approaches incorporating logic tree methodology. The peak ground acceleration (PGA) at rock level was evaluated for the entire state considering a grid size of 0.05° × 0.05°. The attenuation relations proposed for stable continental shield region were used in evaluating the seismic hazard with appropriate weightage factors. Response spectra at rock level for important Tier II cities and Bangalore were evaluated. The contour maps showing the spatial variation of PGA values at bedrock are presented in this work.

  11. Reevaluation of the Seismicity and seismic hazards of Northeastern Libya

    Science.gov (United States)

    Ben Suleman, abdunnur; Aousetta, Fawzi

    2014-05-01

    Libya, located at the northern margin of the African continent, underwent many episodes of orogenic activities. These episodes of orogenic activities affected and shaped the geological setting of the country. This study represents a detailed investigation that aims to focus on the seismicity and its implications on earthquake hazards of Northeastern Libya. At the end of year 2005 the Libyan National Seismological Network starts functioning with 15 stations. The Seismicity of the area under investigation was reevaluated using data recorded by the recently established network. The Al-Maraj earthquake occurred in May 22nd 2005was analyzed. This earthquake was located in a known seismically active area. This area was the sight of the well known 1963 earthquake that kills over 200 people. Earthquakes were plotted and resulting maps were interpreted and discussed. The level of seismic activity is higher in some areas, such as the city of Al-Maraj. The offshore areas north of Al-Maraj seem to have higher seismic activity. It is highly recommended that the recent earthquake activity is considered in the seismic hazard assessments for the northeastern part of Libya.

  12. Probabilistic Seismic Hazard Assessment of Babol, Iran

    Directory of Open Access Journals (Sweden)

    Gholamreza Abdollahzadeh

    2011-01-01

    Full Text Available This paper presents a probabilistic seismic hazard assessment of Babol, one of big cities in north of Iran. Many destructive earthquakes happened in Iran in the last centuries. It comes from historical references that at least many times; Babol has been destroyed by catastrophic earthquakes. In this paper, the peak horizontal ground acceleration over the bedrock (PGA is calculated by a probabilistic seismic hazard assessment (PSHA. For this reason, at first, a collected catalogue, containing both historical and instrumental events that occurred in a radius of 200 km of Babol city and covering the period from 874 to 2004 have been gathered. Then, seismic sources are modeled and recur¬rence relationship is established. After elimination of the aftershocks and foreshocks, the main earthquakes were taken into consideration to calculate the seismic parameters (SP by Kijko method. The calculations were performed using the logic tree method and four weighted attenuation relationships Ghodrati, 0.35, Khademi, 0.25, Ambraseys and Simpson, 0.2, and Sarma and Srbulov, 0.2. Seismic hazard assessment is then carried out for 8 horizontal by 7 vertical lines grid points using SEISRISK III. Finally, two seismic hazard maps of the studied area based on Peak Horizontal Ground Acceleration (PGA over bedrock for 2 and 10% probability of ex¬ceedance in one life cycles of 50 year are presented. These calculations have been performed by the Poisson distribution of two hazard levels. The results showed that the PGA ranges from 0.32 to 0.33 g for a return period of 475 years and from 0.507 to 0.527 g for a return period of 2475 years. Since population is very dense in Babol and vulnerability of buildings is high, the risk of future earthquakes will be very significant.

  13. Seismic hazard assessment in Aswan, Egypt

    Science.gov (United States)

    Deif, A.; Hamed, H.; Ibrahim, H. A.; Abou Elenean, K.; El-Amin, E.

    2011-12-01

    The study of earthquake activity and seismic hazard assessment around Aswan is very important due to the proximity of the Aswan High Dam. The Aswan High Dam is based on hard Precambrian bedrock and is considered to be the most important project in Egypt from the social, agricultural and electrical energy production points of view. The seismotectonic settings around Aswan strongly suggest that medium to large earthquakes are possible, particularly along the Kalabsha, Seiyal and Khor El-Ramla faults. The seismic hazard for Aswan is calculated utilizing the probabilistic approach within a logic-tree framework. Alternative seismogenic models and ground motion scaling relationships are selected to account for the epistemic uncertainty. Seismic hazard values on rock were calculated to create contour maps for eight ground motion spectral periods and for a return period of 475 years, which is deemed appropriate for structural design standards in the Egyptian building codes. The results were also displayed in terms of uniform hazard spectra for rock sites at the Aswan High Dam for return periods of 475 and 2475 years. In addition, the ground-motion levels are also deaggregated at the dam site, in order to provide insight into which events are the most important for hazard estimation. The peak ground acceleration ranges between 36 and 152 cm s-2 for return periods of 475 years (equivalent to 90% probability of non-exceedance in 50 years). Spectral hazard values clearly indicate that compared with countries of high seismic risk, the seismicity in the Aswan region can be described as low at most sites to moderate in the area between the Kalabsha and Seyial faults.

  14. Probabilistic seismic hazard estimation of Manipur, India

    Science.gov (United States)

    Pallav, Kumar; Raghukanth, S. T. G.; Darunkumar Singh, Konjengbam

    2012-10-01

    This paper deals with the estimation of spectral acceleration for Manipur based on probabilistic seismic hazard analysis (PSHA). The 500 km region surrounding Manipur is divided into seven tectonic zones and major faults located in these zones are used to estimate seismic hazard. The earthquake recurrence relations for the seven zones have been estimated from past seismicity data. Ground motion prediction equations proposed by Boore and Atkinson (2008 Earthq. Spectra 24 99-138) for shallow active regions and Atkinson and Boore (2003 Bull. Seismol. Soc. Am. 93 1703-29) for the Indo-Burma subduction zone are used for estimating ground motion. The uniform hazard response spectra for all the nine constituent districts of Manipur (Senapati, Tamenglong, Churachandpur, Chandel, Imphal east, Imphal west, Ukhrul, Thoubal and Bishnupur) at 100-, 500- and 2500-year return periods have been computed from PSHA. A contour map of peak ground acceleration over Manipur is also presented for 100-, 500-, and 2500-year return periods with variations of 0.075-0.225, 0.18-0.63 and 0.3-0.1.15 g, respectively, throughout the state. These results may be of use to planners and engineers for site selection, designing earthquake resistant structures and, further, may help the state administration in seismic hazard mitigation.

  15. Deterministic seismic hazard macrozonation of India

    Science.gov (United States)

    Kolathayar, Sreevalsa; Sitharam, T. G.; Vipin, K. S.

    2012-10-01

    Earthquakes are known to have occurred in Indian subcontinent from ancient times. This paper presents the results of seismic hazard analysis of India (6°-38°N and 68°-98°E) based on the deterministic approach using latest seismicity data (up to 2010). The hazard analysis was done using two different source models (linear sources and point sources) and 12 well recognized attenuation relations considering varied tectonic provinces in the region. The earthquake data obtained from different sources were homogenized and declustered and a total of 27,146 earthquakes of moment magnitude 4 and above were listed in the study area. The sesismotectonic map of the study area was prepared by considering the faults, lineaments and the shear zones which are associated with earthquakes of magnitude 4 and above. A new program was developed in MATLAB for smoothing of the point sources. For assessing the seismic hazard, the study area was divided into small grids of size 0.1° × 0.1° (approximately 10 × 10 km), and the hazard parameters were calculated at the center of each of these grid cells by considering all the seismic sources within a radius of 300 to 400 km. Rock level peak horizontal acceleration (PHA) and spectral accelerations for periods 0.1 and 1 s have been calculated for all the grid points with a deterministic approach using a code written in MATLAB. Epistemic uncertainty in hazard definition has been tackled within a logic-tree framework considering two types of sources and three attenuation models for each grid point. The hazard evaluation without logic tree approach also has been done for comparison of the results. The contour maps showing the spatial variation of hazard values are presented in the paper.

  16. Deterministic seismic hazard macrozonation of India

    Indian Academy of Sciences (India)

    Sreevalsa Kolathayar; T G Sitharam; K S Vipin

    2012-10-01

    Earthquakes are known to have occurred in Indian subcontinent from ancient times. This paper presents the results of seismic hazard analysis of India (6°–38°N and 68°–98°E) based on the deterministic approach using latest seismicity data (up to 2010). The hazard analysis was done using two different source models (linear sources and point sources) and 12 well recognized attenuation relations considering varied tectonic provinces in the region. The earthquake data obtained from different sources were homogenized and declustered and a total of 27,146 earthquakes of moment magnitude 4 and above were listed in the study area. The sesismotectonic map of the study area was prepared by considering the faults, lineaments and the shear zones which are associated with earthquakes of magnitude 4 and above. A new program was developed in MATLAB for smoothing of the point sources. For assessing the seismic hazard, the study area was divided into small grids of size 0.1° × 0.1° (approximately 10 × 10 km), and the hazard parameters were calculated at the center of each of these grid cells by considering all the seismic sources within a radius of 300 to 400 km. Rock level peak horizontal acceleration (PHA) and spectral accelerations for periods 0.1 and 1 s have been calculated for all the grid points with a deterministic approach using a code written in MATLAB. Epistemic uncertainty in hazard definition has been tackled within a logic-tree framework considering two types of sources and three attenuation models for each grid point. The hazard evaluation without logic tree approach also has been done for comparison of the results. The contour maps showing the spatial variation of hazard values are presented in the paper.

  17. Harmonized Probabilistic Seismic Hazard Assessment in Europe: Earthquake Geology Applied

    Science.gov (United States)

    Woessner, J.; Danciu, L.; Giardini, D.; Share Consortium

    2012-04-01

    Probabilistic seismic hazard assessment (PSHA) aims to characterize the best available knowledge on seismic hazard of a study area, ideally taking into account all sources of uncertainty. Results from PSHAs form the baseline for informed decision-making and provide essential input to each risk assessment application. SHARE is an EC-FP7 funded project to create a testable time-independent community-based hazard model for the Euro-Mediterranean region. SHARE scientists are creating a model framework and infrastructure for a harmonized PSHA. The results will serve as reference for the Eurocode 8 application and are envisioned to provide homogeneous input for state-of-the art seismic safety assessment for critical industry. Harmonizing hazard is pursued on the input data level and the model building procedure across borders and tectonic features of the European-Mediterranean region. An updated earthquake catalog, a harmonized database of seismogenic sources together with adjusted ground motion prediction equations (GMPEs) form the bases for a borderless assessment. We require transparent and reproducible strategies to estimate parameter values and their uncertainties within the source model assessment and the contributions of the GMPEs. The SHARE model accounts for uncertainties via a logic tree. Epistemic uncertainties within the seismic source-model are represented by four source model options including area sources, fault sources and kernel-smoothing approaches, aleatory uncertainties for activity rates and maximum magnitudes. Epistemic uncertainties for predicted ground motions are considered by multiple GMPEs as a function of tectonic settings and treated as being correlated. For practical implementation, epistemic uncertainties in the source model (i.e. dip and strike angles) are treated as aleatory, and a mean seismicity model is considered. The final results contain the full distribution of ground motion variability. This contribution will feature preliminary

  18. Seismic hazard assessment; Valutazione della pericolosita` sismica

    Energy Technology Data Exchange (ETDEWEB)

    Paciello, A. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dip. Ambiente

    1998-12-31

    This paper presents a brief summary of the most commonly used methodologies for seismic hazard assessment. The interest is focused on the probabilistic approach, which can take into account the uncertainties of input data and provides results better comparable with those obtained from hazard analyses of other natural phenomena. Calculation methods, input data and treatment of variability are examined. Some examples of probabilistic seismic hazard maps are moreover presented. [Italiano] Questo lavoro presenta un breve sommario delle piu` comuni metodologie utilizzate per la valutazione della pericolosita` sismica di un sito. Una particolare attenzione e` rivolta all`approccio probabilistico, che permette di tener conto delle incertezze legate ai dati iniziali e fornisce risultati piu` facilmente confrontabili con quelli ottenuti da analisi di pericolosita` di altri fenomeni naturali. Vengono presi in esame i metodi di calcolo, i dati di base e il trattamento delle incertezze. Vengono inoltre presentati alcuni esempi di carte di pericolosita` sismica di tipo probabilistico.

  19. Challenges to Seismic Hazard Analysis of Critical Infrastructures

    Science.gov (United States)

    Klügel, J.

    2005-12-01

    Based on the background of the review of a large scale probabilistic seismic hazard analysis (PSHA) performed in Switzerland for the sites of Swiss nuclear power plants- the PEGASOS project (2000-2004) - challenges to seismic hazard analysis of critical infrastructures from the perspective of a professional safety analyst are discussed. The PEGASOS study was performed to provide a meaningful input for the update of the plant specific PRAs (Probabilistic Risk Assessment) of Swiss nuclear power plants. Earlier experience had shown that the results of these studies to a large extend are driven by the results of the seismic hazard analysis. The PEGASOS-study was performed in full compliance with the procedures developed by the Senior Seismic Hazard Analysis Committee (SSHAC) of U.S.A (SSHAC, 1997) developed for the treatment of uncertainties by the use of a structured expert elicitation process. The preliminary results derived from the project did show an unexpected amount of uncertainty and were regarded as not suitable for direct application. A detailed review of the SSHAC-methodology revealed a number of critical issues with respect to the treatment of uncertainties and the mathematical models applied, which will be presented in the paper. The most important issued to be discussed are: * The ambiguous solution of PSHA-logic trees * The inadequate mathematical treatment of the results of expert elicitations based on the assumption of bias free expert estimates * The problems associated with the "think model" of the separation of epistemic and aleatory uncertainties * The consequences of the ergodic assumption used to justify the transfer of attenuation equations of other regions to the region of interest. Based on these observations methodological questions with respect to the development of a risk-consistent design basis for new nuclear power plants as required by the U.S. NRC RG 1.165 will be evaluated. As an principal alternative for the development of a

  20. Final Report: Seismic Hazard Assessment at the PGDP

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhinmeng [KY Geological Survey, Univ of KY

    2007-06-01

    Selecting a level of seismic hazard at the Paducah Gaseous Diffusion Plant for policy considerations and engineering design is not an easy task because it not only depends on seismic hazard, but also on seismic risk and other related environmental, social, and economic issues. Seismic hazard is the main focus. There is no question that there are seismic hazards at the Paducah Gaseous Diffusion Plant because of its proximity to several known seismic zones, particularly the New Madrid Seismic Zone. The issues in estimating seismic hazard are (1) the methods being used and (2) difficulty in characterizing the uncertainties of seismic sources, earthquake occurrence frequencies, and ground-motion attenuation relationships. This report summarizes how input data were derived, which methodologies were used, and what the hazard estimates at the Paducah Gaseous Diffusion Plant are.

  1. Probabilistic Seismic Hazard Assessment for Iraq

    Energy Technology Data Exchange (ETDEWEB)

    Onur, Tuna [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gok, Rengin [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Abdulnaby, Wathiq [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Shakir, Ammar M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mahdi, Hanan [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Numan, Nazar M.S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Al-Shukri, Haydar [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Chlaib, Hussein K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ameen, Taher H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Abd, Najah A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-05-06

    Probabilistic Seismic Hazard Assessments (PSHA) form the basis for most contemporary seismic provisions in building codes around the world. The current building code of Iraq was published in 1997. An update to this edition is in the process of being released. However, there are no national PSHA studies in Iraq for the new building code to refer to for seismic loading in terms of spectral accelerations. As an interim solution, the new draft building code was considering to refer to PSHA results produced in the late 1990s as part of the Global Seismic Hazard Assessment Program (GSHAP; Giardini et al., 1999). However these results are: a) more than 15 years outdated, b) PGA-based only, necessitating rough conversion factors to calculate spectral accelerations at 0.3s and 1.0s for seismic design, and c) at a probability level of 10% chance of exceedance in 50 years, not the 2% that the building code requires. Hence there is a pressing need for a new, updated PSHA for Iraq.

  2. Hydrothermal Liquefaction Treatment Preliminary Hazard Analysis Report

    Energy Technology Data Exchange (ETDEWEB)

    Lowry, Peter P.; Wagner, Katie A.

    2015-08-31

    A preliminary hazard assessment was completed during February 2015 to evaluate the conceptual design of the modular hydrothermal liquefaction treatment system. The hazard assessment was performed in 2 stages. An initial assessment utilizing Hazard Identification and Preliminary Hazards Analysis (PHA) techniques identified areas with significant or unique hazards (process safety-related hazards) that fall outside of the normal operating envelope of PNNL and warranted additional analysis. The subsequent assessment was based on a qualitative What-If analysis. This analysis was augmented, as necessary, by additional quantitative analysis for scenarios involving a release of hazardous material or energy with the potential for affecting the public.

  3. Seismic hazard in the design of oil and gas pipelines

    OpenAIRE

    Zdravković Slavko; Mladenović Biljana; Zlatkov Dragan

    2011-01-01

    Criteria that are adopted in earthquake resistant design of pipelines and gas lines have to take into account seismic movements and seismic generated forces that are of significantly high probability level of appearance along the length of pipeline. A choice of criteria has to include an acceptable level of seismic hazard, while design criteria should be calculated. Seismic hazard is defined as a part of natural hazard and means probability of appearance of earthquake of corresponding c...

  4. Probabilistic Seismic Hazards Update for LLNL

    Energy Technology Data Exchange (ETDEWEB)

    Menchawi, O. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Fernandez, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-03-30

    Fugro Consultants, Inc. (FCL) completed the Probabilistic Seismic Hazard Analysis (PSHA) performed for Building 332 at the Lawrence Livermore National Laboratory (LLNL), near Livermore, CA. The study performed for the LLNL site includes a comprehensive review of recent information relevant to the LLNL regional tectonic setting and regional seismic sources in the vicinity of the site and development of seismic wave transmission characteristics. The Seismic Source Characterization (SSC), documented in Project Report No. 2259-PR-02 (FCL, 2015b), and Ground Motion Characterization (GMC), documented in Project Report No. 2259-PR-06 (FCL, 2015a) were developed in accordance with ANS/ANSI 2.29- 2008 Level 2 PSHA guidelines. The ANS/ANSI 2.29-2008 Level 2 PSHA framework is documented in Project Report No. 2259-PR-05 (FCL, 2016a). The Hazard Input Document (HID) for input into the PSHA developed from the SSC and GMC is presented in Project Report No. 2259-PR-04 (FCL, 2016b). The site characterization used as input for development of the idealized site profiles including epistemic uncertainty and aleatory variability is presented in Project Report No. 2259-PR-03 (FCL, 2015c). The PSHA results are documented in Project Report No. 2259-PR-07 (FCL, 2016c).

  5. Mine aftershocks and implications for seismic hazard assessment

    CSIR Research Space (South Africa)

    Kgarume, T

    2010-11-01

    Full Text Available A methodology of assessing the seismic hazard associated with aftershocks is developed by performing statistical and deterministic analysis of seismic data from two South African deep-level gold mines. A method employing stacking of aftershocks...

  6. Seismic hazard assessments at Islamic Cairo, Egypt

    Science.gov (United States)

    Khalil, A. E.; Deif, A.; Abdel Hafiez, H. E.

    2015-12-01

    Islamic Cairo is one of the important Islamic monumental complexes in Egypt, near the center of present-day metropolitan Cairo. The age of these buildings is up to one thousand years. Unfortunately, many of the buildings are suffering from huge mishandling that may lead to mass damage. Many buildings and masjids were partially and totally collapsed because of 12th October 1992 Cairo earthquake that took place at some 25 km from the study area with a magnitude Mw = 5.8. Henceforth, potential damage assessments there are compulsory. The deterministic and probabilistic techniques were used to predict the expected future large earthquakes' strong-motion characteristics in the study area. The current study started with compiling the available studies concerned with the distribution of the seismogenic sources and earthquake catalogs. The deterministic method is used to provide a description of the largest earthquake effect on the area of interest, while the probabilistic method, on the other hand, is used to define the uniform hazard curves at three time periods 475, 950, 2475 years. Both deterministic and probabilistic results were obtained for bedrock conditions and the resulted hazard levels were deaggregated to identify the contribution of each seismic source to the total hazard. Moreover, the results obtained show that the expected seismic activities combined with the present situation of the buildings pose high alert to rescue both the cultural heritage and expected human losses.

  7. Interval Estimation of Seismic Hazard Parameters

    Science.gov (United States)

    Orlecka-Sikora, Beata; Lasocki, Stanislaw

    2016-11-01

    The paper considers Poisson temporal occurrence of earthquakes and presents a way to integrate uncertainties of the estimates of mean activity rate and magnitude cumulative distribution function in the interval estimation of the most widely used seismic hazard functions, such as the exceedance probability and the mean return period. The proposed algorithm can be used either when the Gutenberg-Richter model of magnitude distribution is accepted or when the nonparametric estimation is in use. When the Gutenberg-Richter model of magnitude distribution is used the interval estimation of its parameters is based on the asymptotic normality of the maximum likelihood estimator. When the nonparametric kernel estimation of magnitude distribution is used, we propose the iterated bias corrected and accelerated method for interval estimation based on the smoothed bootstrap and second-order bootstrap samples. The changes resulted from the integrated approach in the interval estimation of the seismic hazard functions with respect to the approach, which neglects the uncertainty of the mean activity rate estimates have been studied using Monte Carlo simulations and two real dataset examples. The results indicate that the uncertainty of mean activity rate affects significantly the interval estimates of hazard functions only when the product of activity rate and the time period, for which the hazard is estimated, is no more than 5.0. When this product becomes greater than 5.0, the impact of the uncertainty of cumulative distribution function of magnitude dominates the impact of the uncertainty of mean activity rate in the aggregated uncertainty of the hazard functions. Following, the interval estimates with and without inclusion of the uncertainty of mean activity rate converge. The presented algorithm is generic and can be applied also to capture the propagation of uncertainty of estimates, which are parameters of a multiparameter function, onto this function.

  8. The Optimizer Topology Characteristics in Seismic Hazards

    Science.gov (United States)

    Sengor, T.

    2015-12-01

    The characteristic data of the natural phenomena are questioned in a topological space approach to illuminate whether there is an algorithm behind them bringing the situation of physics of phenomena to optimized states even if they are hazards. The optimized code designing the hazard on a topological structure mashes the metric of the phenomena. The deviations in the metric of different phenomena push and/or pull the fold of the other suitable phenomena. For example if the metric of a specific phenomenon A fits to the metric of another specific phenomenon B after variation processes generated with the deviation of the metric of previous phenomenon A. Defining manifold processes covering the metric characteristics of each of every phenomenon is possible for all the physical events; i.e., natural hazards. There are suitable folds in those manifold groups so that each subfold fits to the metric characteristics of one of the natural hazard category at least. Some variation algorithms on those metric structures prepare a gauge effect bringing the long time stability of Earth for largely scaled periods. The realization of that stability depends on some specific conditions. These specific conditions are called optimized codes. The analytical basics of processes in topological structures are developed in [1]. The codes are generated according to the structures in [2]. Some optimized codes are derived related to the seismicity of NAF beginning from the quakes of the year 1999. References1. Taner SENGOR, "Topological theory and analytical configuration for a universal community model," Procedia- Social and Behavioral Sciences, Vol. 81, pp. 188-194, 28 June 2013, 2. Taner SENGOR, "Seismic-Climatic-Hazardous Events Estimation Processes via the Coupling Structures in Conserving Energy Topologies of the Earth," The 2014 AGU Fall Meeting, Abstract no.: 31374, ABD.

  9. Standardization of Seismic Microzonification and Probabilistic Seismic Hazard Study Considering Site Effect for Metropolitan Areas in the State of Veracruz

    Science.gov (United States)

    Torres Morales, G. F.; Leonardo Suárez, M.; Dávalos Sotelo, R.; Castillo Aguilar, S.; Mora González, I.

    2014-12-01

    Preliminary results obtained from the project "Seismic Hazard in the State of Veracruz and Xalapa Conurbation" and "Microzonation of geological and hydrometeorological hazards for conurbations of Orizaba, Veracruz, and major sites located in the lower sub-basins: The Antigua and Jamapa" are presented. These projects were sponsored respectively by the PROMEP program and the Joint Funds CONACyT-Veracruz state government. The study consists of evaluating the probabilistic seismic hazard considering the site effect (SE) in the urban zones of cities of Xalapa and Orizaba; the site effects in this preliminary stage were incorporated through a standard format proposed in studies of microzonation and application in computer systems, which allows to optimize and condense microzonation studies of a city. This study stems from the need to know the seismic hazard (SH) in the State of Veracruz and its major cities, defining SH as the probabilistic description of exceedance of a given level of ground motion intensity (generally designated by the acceleration soil or maximum ordinate in the response spectrum of pseudo-acceleration, PGA and Sa, respectively) as a result of the action of an earthquake in the area of influence for a specified period of time. The evaluation results are presented through maps of seismic hazard exceedance rate curves and uniform hazard spectra (UHS) for different spectral ordinates and return periods, respectively.

  10. Experimental Concepts for Testing Seismic Hazard Models

    Science.gov (United States)

    Marzocchi, W.; Jordan, T. H.

    2015-12-01

    Seismic hazard analysis is the primary interface through which useful information about earthquake rupture and wave propagation is delivered to society. To account for the randomness (aleatory variability) and limited knowledge (epistemic uncertainty) of these natural processes, seismologists must formulate and test hazard models using the concepts of probability. In this presentation, we will address the scientific objections that have been raised over the years against probabilistic seismic hazard analysis (PSHA). Owing to the paucity of observations, we must rely on expert opinion to quantify the epistemic uncertainties of PSHA models (e.g., in the weighting of individual models from logic-tree ensembles of plausible models). The main theoretical issue is a frequentist critique: subjectivity is immeasurable; ergo, PSHA models cannot be objectively tested against data; ergo, they are fundamentally unscientific. We have argued (PNAS, 111, 11973-11978) that the Bayesian subjectivity required for casting epistemic uncertainties can be bridged with the frequentist objectivity needed for pure significance testing through "experimental concepts." An experimental concept specifies collections of data, observed and not yet observed, that are judged to be exchangeable (i.e., with a joint distribution independent of the data ordering) when conditioned on a set of explanatory variables. We illustrate, through concrete examples, experimental concepts useful in the testing of PSHA models for ontological errors in the presence of aleatory variability and epistemic uncertainty. In particular, we describe experimental concepts that lead to exchangeable binary sequences that are statistically independent but not identically distributed, showing how the Bayesian concept of exchangeability generalizes the frequentist concept of experimental repeatability. We also address the issue of testing PSHA models using spatially correlated data.

  11. Seismic hazard from induced seismicity: effect of time-dependent hazard variables

    Science.gov (United States)

    Convertito, V.; Sharma, N.; Maercklin, N.; Emolo, A.; Zollo, A.

    2012-12-01

    Geothermal systems are drawing large attention worldwide as an alternative source of energy. Although geothermal energy is beneficial, field operations can produce induced seismicity whose effects can range from light and unfelt to severe damaging. In a recent paper by Convertito et al. (2012), we have investigated the effect of time-dependent seismicity parameters on seismic hazard from induced seismicity. The analysis considered the time-variation of the b-value of the Gutenberg-Richter relationship and the seismicity rate, and assumed a non-homogeneous Poisson model to solve the hazard integral. The procedure was tested in The Geysers geothermal area in Northern California where commercial exploitation has started in the 1960s. The analyzed dataset consists of earthquakes recorded during the period 2007 trough 2010 by the LBNL Geysers/Calpine network. To test the reliability of the analysis, we applied a simple forecasting procedure which compares the estimated hazard values in terms of ground-motion values having fixed probability of exceedance and the observed ground-motion values. The procedure is feasible for monitoring purposes and for calibrating the production/extraction rate to avoid adverse consequences. However, one of the main assumptions we made concern the fact that both median predictions and standard deviation of the ground-motion prediction equation (GMPE) are stationary. Particularly for geothermal areas where the number of recorded earthquakes can rapidly change with time, we want to investigate how a variation of the coefficients of the used GMPE and of the standard deviation influences the hazard estimates. Basically, we hypothesize that the physical-mechanical properties of a highly fractured medium which is continuously perturbed by field operations can produce variations of both source and medium properties that cannot be captured by a stationary GMPE. We assume a standard GMPE which accounts for the main effects which modify the scaling

  12. Seismic hazards and land-use planning

    Science.gov (United States)

    Nichols, Donald R.; Buchanan-Banks, Jane M.

    1974-01-01

    Basic earth-science data are necessary for a realistic assessment of seismic hazards and as a basis for limiting corrective land-use controls only to those areas of greatest hazard. For example, the location, character, and amount of likely displacement and activity of surface faulting can be predicted if detailed geologic maps and seismic data are available and are augmented by field studies at critical localities. Because few structures can withstand displacement of their foundations, they should be located off active fault traces, the distance varying with the character of faulting, the certainty with which fault traces are known, and the importance of the structure. Recreational activities and other nonoccupancy land uses should be considered for fault zone areas where land is under pressure for development; elsewhere, such areas should remain as open space. Two methods of predicting ground shaking effects have applications to land-use decisions: (1) Relative earthquake effects can be related to firmness of the ground and can be used in a gross way to allocate population density in the absence of more sophisticated analyses; and (2) intensity maps, based on, (a) damage from former earthquakes, or (b) a qualitative analyses of geologic units added to a design earthquake, can be helpful both for general and specific plans. Theoretical models are used with caution to predict ground motion for critical structures to be located at specific sites with unique foundation conditions. Fully adequate methods of assessing possible shaking remain to be developed. Where land-use decisions do not reflect likely ground shaking effects, stringent building codes are needed, particularly for important structures. Ground failure (landsliding, ground cracking and lurching, differential settlement, sand boils, and subsidence) commonly results from liquefaction, loss of soil strength, or compaction. Areas suspected of being most likely to fail should not be developed unless detailed

  13. Increasing seismicity in the U. S. midcontinent: Implications for earthquake hazard

    OpenAIRE

    Ellsworth, William L.; Llenos, Andrea L.; McGarr, Arthur F.; Michael, Andrew J.; Rubinstein, Justin L.; Mueller, Charles S.; Petersen, Mark D.; Calais, Éric

    2015-01-01

    Earthquake activity in parts of the central United States has increased dramatically in recent years. The space-time distribution of the increased seismicity, as well as numerous published case studies, indicates that the increase is of anthropogenic origin, principally driven by injection of wastewater coproduced with oil and gas from tight formations. Enhanced oil recovery and long-term production also contribute to seismicity at a few locations. Preliminary hazard models indicate that area...

  14. Active Fault Exploration and Seismic Hazard Assessment in Fuzhou City

    Institute of Scientific and Technical Information of China (English)

    Zhu Jinfang; Han Zhujun; Huang Zonglin; Xu Xiwei; Zheng Rongzhang; Fang Shengmin; Bai Denghai; Wang Guangcai; Min Wei; Wen Xueze

    2005-01-01

    It has been proven by a number of earthquake case studies that an active fault-induced earthquake beneath a city can be devastating. It is an urgent issue for seismic hazard reduction to explore the distribution of active faults beneath the urban area and identify the seismic source and the risks underneath. As a pilot project of active fault exploration in China, the project, entitled "Active fault exploration and seismic hazard assessment in Fuzhou City",started in early 2001 and passed the check before acceptance of China Earthquake Administration in August 2004. The project was aimed to solve a series of scientific issues such as fault location, dating, movement nature, deep settings, seismic risk and hazard,preparedness of earthquake prevention and disaster reduction, and etc. by means of exploration and assessment of active faults by stages, i.e., the preliminary survey and identification of active faults in target area, the exploration of deep seismotectonic settings, the risk evaluation of active seismogenic faults, the construction of geographic information system of active faults, and so on. A lot of exploration methods were employed in the project such as the detection of absorbed mercury, free mercury and radon in soil, the geological radar,multi-channel DC electrical method, tsansient electromagnetic method, shallow seismic refraction and reflection, effect contrast of explored sources, and various sounding experiments, to establish the buried Quaternary standard section of the Fuzhou basin. By summing up, the above explorations and experiments have achieved the following results and conclusions:(1) The results of the synthetic pilot project of active fault exploration in Fuzhou City demonstrate that, on the basis of sufficient collection, sorting out and analysis of geological,geophysical and borehole data, the best method for active fault exploration (location) and seismic risk assessnent (dating and characterizing) in urban area is the combination

  15. Assessing the Seismic Potential Hazard of the Makran Subduction Zone

    Science.gov (United States)

    Frohling, E.; Szeliga, W. M.; Melbourne, T. I.; Abolghasem, A.; Lodi, S. H.

    2013-12-01

    Long quiescent subduction zones like the Makran, Sunda, and Cascadia, which have long recurrence intervals for large (> Mw 8) earthquakes, often have poorly known seismic histories and are particularly vulnerable and often ill-prepared. The Makran subduction zone has not been studied extensively, but the 1945 Mw 8.1 earthquake and subsequent tsunami, as well as more recent mid magnitude, intermediate depth (50-100 km) seismicity, demonstrates the active seismic nature of the region. Recent increases in regional GPS and seismic monitoring now permit the modeling of strain accumulations and seismic potential of the Makran subduction zone. Subduction zone seismicity indicates that the eastern half of the Makran is presently more active than the western half. It has been hypothesized that the relative quiescence of the western half is due to aseismic behavior. However, based on GPS evidence, the entire subduction zone generally appears to be coupled and has been accumulating stress that could be released in another > 8.0 Mw earthquake. To assess the degree of coupling, we utilize existing GPS data to create a fault coupling model for the Makran using a preliminary 2-D fault geometry derived from ISC hypocenters. Our 2-D modeling is done using the backslip approach and defines the parameters in our coupling model; we forego the generation of a 3-D model due to the low spatial density of available GPS data. We compare the use of both NUVEL-1A plate motions and modern Arabian plate motions derived from GPS station velocities in Oman to drive subduction for our fault coupling model. To avoid non-physical inversion results, we impose second order smoothing to eliminate steep strain gradients. The fit of the modeled inter-seismic deformation vectors are assessed against the observed strain from the GPS data. Initial observations indicate that the entire subduction zone is currently locked and accumulating strain, with no identifiable gaps in the interseismic locking

  16. Evaluation of seismic hazard at the northwestern part of Egypt

    Science.gov (United States)

    Ezzelarab, M.; Shokry, M. M. F.; Mohamed, A. M. E.; Helal, A. M. A.; Mohamed, Abuoelela A.; El-Hadidy, M. S.

    2016-01-01

    The objective of this study is to evaluate the seismic hazard at the northwestern Egypt using the probabilistic seismic hazard assessment approach. The Probabilistic approach was carried out based on a recent data set to take into account the historic seismicity and updated instrumental seismicity. A homogenous earthquake catalogue was compiled and a proposed seismic sources model was presented. The doubly-truncated exponential model was adopted for calculations of the recurrence parameters. Ground-motion prediction equations that recently recommended by experts and developed based upon earthquake data obtained from tectonic environments similar to those in and around the studied area were weighted and used for assessment of seismic hazard in the frame of logic tree approach. Considering a grid of 0.2° × 0.2° covering the study area, seismic hazard curves for every node were calculated. Hazard maps at bedrock conditions were produced for peak ground acceleration, in addition to six spectral periods (0.1, 0.2, 0.3, 1.0, 2.0 and 3.0 s) for return periods of 72, 475 and 2475 years. The unified hazard spectra of two selected rock sites at Alexandria and Mersa Matruh Cities were provided. Finally, the hazard curves were de-aggregated to determine the sources that contribute most of hazard level of 10% probability of exceedance in 50 years for the mentioned selected sites.

  17. Seismic hazard in Greece. I. Magnitude recurrence

    Science.gov (United States)

    Makropoulos, Kostas C.; Burton, Paul W.

    1985-08-01

    Two different methods are applied to the earthquake catalogue for Greece (Makropoulos and Burton, 1981), MB catalogue, to evaluate Greek seismic hazard in terms of magnitude: earthquake strain energy release and Gumbel's third asymptotic distribution of extreme values. It is found that there is a close relationship between results from the two methods. In places where the cumulative strain energy release graphs include at least one well defined cycle of periodicity of strain release, then the parameters of the third type asymptote are well defined with small uncertainties. In almost all cases the magnitude distribution shows a remarkably good third type asymptotic behaviour. The results are presented in the form of graphs and contour maps of annual and 80-year modes, and magnitudes with 70% probability of not being exceeded in the next 50 and 100 years. For six of the most heavily industrial and highly populated centres of Greece magnitude hazard parameters are also derived and examined in more detail, thereby illustrating the direct applicability of the methods in terms of zoning. The close agreement between observed and predicted extreme magnitudes shows that the sample period considered (1900-1978), is long enough to obtain statistically stable estimates. For Athens the upper bound magnitude is found to be 6.7 ± 0.3 (within 100 km) and 6.8 ± 0.4 (100 km) from the two methods respectively, whereas for Corinth an earthquake of magnitude 6.5 has a mean return period of 43 years. Greece as a whole has an upper bound magnitude 8.7 ± 0.6 and earthquakes of a size similar to the 1903 Kithira event ( M ≈ 8.0) have a mean return period of about 200 years. The significantly different maps contouring magnitudes of the annual and 80-year modes result from the fact that each place has its own distribution curvature for magnitude occurrence, and thus they are not a linear extrapolation of each other. However, as longer return periods are considered, these differences

  18. Astor Pass Seismic Surveys Preliminary Report

    Energy Technology Data Exchange (ETDEWEB)

    Louie, John [UNR; Pullammanappallil, Satish [Optim; Faulds, James; Eisses, Amy; Kell, Annie; Frary, Roxanna; Kent, Graham

    2011-08-05

    In collaboration with the Pyramid Lake Paiute Tribe (PLPT), the University of Nevada, Reno (UNR) and Optim re-processed, or collected and processed, over 24 miles of 2d seismic-reflection data near the northwest corner of Pyramid Lake, Nevada. The network of 2d land surveys achieved a near-3d density at the Astor Pass geothermal prospect that the PLPT drilled during Nov. 2010 to Feb. 2011. The Bureau of Indian Affairs funded additional seismic work around the Lake, and an extensive, detailed single-channel marine survey producing more than 300 miles of section, imaging more than 120 ft below the Lake bottom. Optim’s land data collection utilized multiple heavy vibrators and recorded over 200 channels live, providing a state-of-the-art reflection-refraction data set. After advanced seismic analysis including first-arrival velocity optimization and prestack depth migration, the 2d sections show clear fault-plane reflections, in some areas as deep as 4000 ft, tying to distinct terminations of the mostly volcanic stratigraphy. Some lines achieved velocity control to 3000 ft depth; all lines show reflections and terminations to 5000 ft depth. Three separate sets of normal faults appear in an initial interpretation of fault reflections and stratigraphic terminations, after loading the data into the OpendTect 3d seismic visualization system. Each preliminary fault set includes a continuous trace more than 3000 ft long, and a swarm of short fault strands. The three preliminary normal-fault sets strike northerly with westward dip, northwesterly with northeast dip, and easterly with north dip. An intersection of all three fault systems documented in the seismic sections at the end of Phase I helped to locate the APS-2 and APS-3 slimholes. The seismic sections do not show the faults connected to the Astor Pass tufa spire, suggesting that we have imaged mostly Tertiary-aged faults. We hypothesize that the Recent, active faults that produced the tufa through hotspring

  19. Assessment of rock burst hazards by means of seismic methods

    Energy Technology Data Exchange (ETDEWEB)

    Proskuryakov, V.M.

    1984-10-01

    Use of seismic methods for assessment of stress distribution in coal seams and in rock strata adjacent to coal seams is discussed. Analysis of information on stress distribution permits rock burst hazards to be forecast. Schemes of seismic logging used in coal mining are compared. Recommendations developed by the VNIMI Institute for optimization of seismic logging are analyzed: selecting a seismic method considering tectonics, stratification and rock properties, arrangement of seismic sources and seismic detectors, selecting the optimum parameters of seismic waves (wave frequency recommended for rocks ranges from 400 to 1000 Hz; recommended wave frequency for coal ranges from 200 to 600 Hz), measuring instruments (e.g. the ShchTsS-2 system), and calculation methods used for evaluations of seismic logging. A standardized procedure for seismic logging is recommended.

  20. Probabilistic seismic hazard assessment for Point Lepreau Generating Station

    Energy Technology Data Exchange (ETDEWEB)

    Mullin, D. [New Brunswick Power Corp., Point Lepreau Generating Station, Lepreau, New Brunswick (Canada); Lavine, A. [AMEC Foster Wheeler Environment and Infrastructure Americas, Oakland, California (United States); Egan, J. [SAGE Engineers, Oakland, California (United States)

    2015-09-15

    A Probabilistic Seismic Hazard Assessment (PSHA) has been performed for the Point Lepreau Generating Station (PLGS). The objective is to provide characterization of the earthquake ground shaking that will be used to evaluate seismic safety. The assessment is based on the current state of knowledge of the informed scientific and engineering community regarding earthquake hazards in the site region, and includes two primary components-a seismic source model and a ground motion model. This paper provides the methodology and results of the PLGS PSHA. The implications of the updated hazard information for site safety are discussed in a separate paper. (author)

  1. Increasing seismicity in the U. S. midcontinent: Implications for earthquake hazard

    Science.gov (United States)

    Ellsworth, William L.; Llenos, Andrea L.; McGarr, Arthur F.; Michael, Andrew J.; Rubinstein, Justin L.; Mueller, Charles S.; Petersen, Mark D.; Calais, Eric

    2015-01-01

    Earthquake activity in parts of the central United States has increased dramatically in recent years. The space-time distribution of the increased seismicity, as well as numerous published case studies, indicates that the increase is of anthropogenic origin, principally driven by injection of wastewater coproduced with oil and gas from tight formations. Enhanced oil recovery and long-term production also contribute to seismicity at a few locations. Preliminary hazard models indicate that areas experiencing the highest rate of earthquakes in 2014 have a short-term (one-year) hazard comparable to or higher than the hazard in the source region of tectonic earthquakes in the New Madrid and Charleston seismic zones.

  2. Observation of seismicity based on DOMERAPI and BMKG seismic networks: A preliminary result from DOMERAPI project

    Science.gov (United States)

    Ramdhan, Mohamad; Nugraha, Andri Dian; Widiyantoro, Sri; Kristyawan, Said; Sembiring, Andry Syaly; Mtaxian, Jean-Philippe

    2016-05-01

    DOMERAPI project has involved earth scientists from Indonesia and France to conduct comprehensively a study of the internal structure of Mt. Merapi and its vicinity based on seismic tomographic imaging. The DOMERAPI seismic network was running from October 2013 to April 2015 consisting of 53 broad-band seismometers, covering Mt. Merapi and Mt. Merbabu, and some geological features such as Opak and Dengkeng faults. Earthquake hypocenter determination conducted in this study is an important step before seismic tomographic imaging. The earthquake events were identified and picked manually and carefully. The majority of earthquakes occured outside the DOMERAPI network. The ray paths of seismic waves from these earthquakes passed through the deep part of the study area around Merapi. The joint data of BMKG and DOMERAPI networks can minimize the azimuthal gap, which is often used to obtain an indication of the reliability of the epicentral solution. Our preliminary results show 279 events from October 2013 to mid August 2014. For future work, we will incorporate the BPPTKG (Center for Research and Technology Development of Geological Disaster) data catalogue in order to enrich seismic ray paths. The combined data catalogues will provide information as input for further advanced studies and volcano hazards mitigation.

  3. Seismic Ground Motion Hazards with 10 Percent Probability

    Data.gov (United States)

    Department of Homeland Security — This map layer shows seismic hazard in the United States. The data represent a model showing the probability that ground motion will reach a certain level. This map...

  4. Seismic Ground Motion Hazards with 2 Percent Probability

    Data.gov (United States)

    Department of Homeland Security — This map layer shows seismic hazard in the United States. The data represent a model showing the probability that ground motion will reach a certain level. This map...

  5. Seismic Hazard Map for the United States - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer shows seismic hazard in the United States. The data represent a model showing the probability that ground motion will reach a certain level. This map...

  6. Open Source Seismic Hazard Analysis Software Framework (OpenSHA)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — OpenSHA is an effort to develop object-oriented, web- & GUI-enabled, open-source, and freely available code for conducting Seismic Hazard Analyses (SHA). Our...

  7. Challenges in assessing seismic hazard in intraplate Europe

    Science.gov (United States)

    Brooks, Edward; Stein, Seth; Liu, Mian; Camelbeeck, Thierry; Merino, Miguel; Landgraf, Angela; Hintersberger, Esther; Kübler, Simon

    2016-04-01

    Intraplate seismicity is often characterized by episodic, clustered and migrating earth- quakes and extended after-shock sequences. Can these observations - primarily from North America, China and Australia - usefully be applied to seismic hazard assessment for intraplate Europe? Existing assessments are based on instrumental and historical seismicity of the past c. 1000 years, as well as some data for active faults. This time span probably fails to capture typical large-event recurrence intervals of the order of tens of thousands of years. Palaeoseismology helps to lengthen the observation window, but preferentially produces data in regions suspected to be seismically active. Thus the expected maximum magnitudes of future earthquakes are fairly uncertain, possibly underestimated, and earthquakes are likely to occur in unexpected locations. These issues particularly arise in considering the hazards posed by low-probability events to both heavily populated areas and critical facilities. For example, are the variations in seismicity (and thus assumed seismic hazard) along the Rhine Graben a result of short sampling or are they real? In addition to a better assessment of hazards with new data and models, it is important to recognize and communicate uncertainties in hazard estimates. The more users know about how much confidence to place in hazard maps, the more effectively the maps can be used.

  8. Comprehensive seismic hazard assessment of Tripura and Mizoram states

    Indian Academy of Sciences (India)

    T G Sitharam; Arjun Sil

    2014-06-01

    Northeast India is one of the most highly seismically active regions in the world with more than seven earthquakes on an average per year of magnitude 5.0 and above. Reliable seismic hazard assessment could provide the necessary design inputs for earthquake resistant design of structures in this region. In this study, deterministic as well as probabilistic methods have been attempted for seismic hazard assessment of Tripura and Mizoram states at bedrock level condition. An updated earthquake catalogue was collected from various national and international seismological agencies for the period from 1731 to 2011. The homogenization, declustering and data completeness analysis of events have been carried out before hazard evaluation. Seismicity parameters have been estimated using G–R relationship for each source zone. Based on the seismicity, tectonic features and fault rupture mechanism, this region was divided into six major subzones. Region specific correlations were used for magnitude conversion for homogenization of earthquake size. Ground motion equations (Atkinson and Boore 2003; Gupta 2010) were validated with the observed PGA (peak ground acceleration) values before use in the hazard evaluation. In this study, the hazard is estimated using linear sources, identified in and around the study area. Results are presented in the form of PGA using both DSHA (deterministic seismic hazard analysis) and PSHA (probabilistic seismic hazard analysis) with 2 and 10% probability of exceedance in 50 years, and spectral acceleration (T = 0.2 s, 1.0 s) for both the states (2% probability of exceedance in 50 years). The results are important to provide inputs for planning risk reduction strategies, for developing risk acceptance criteria and financial analysis for possible damages in the study area with a comprehensive analysis and higher resolution hazard mapping.

  9. Probabilistic seismic hazard maps for the North Balkan region

    Directory of Open Access Journals (Sweden)

    R. M. W. Musson

    1999-06-01

    Full Text Available A set of seismic hazard maps, expressed as horizontal peak ground acceleration, have been computed for a large area of Central and Eastern Europe covering the North Balkan area (Former Yugoslavia, Hungary, Romania. These are based on: a a compound earthquake catalogue for the region; b a seismic source model of 50 zones compiled on the basis of tectonic divisions and seismicity, and c a probabilistic methodology using stochastic (Monte Carlo modelling. It is found that the highest hazard in the region comes from intermediate focus earthquakes occurring in the Vrancea seismic zone; here the hazard exceeds 0.4 g at return periods of 475 years. Special account has been taken of the directional nature of attenuation from this source.

  10. Physics-based Probabilistic Seismic Hazard Analysis for Seismicity Induced by Fluid Injection

    Science.gov (United States)

    Foxall, W.; Hutchings, L. J.; Johnson, S.; Savy, J. B.

    2011-12-01

    Risk associated with induced seismicity (IS) is a significant factor in the design, permitting and operation of enhanced geothermal, geological CO2 sequestration and other fluid injection projects. Whereas conventional probabilistic seismic hazard and risk analysis (PSHA, PSRA) methods provide an overall framework, they require adaptation to address specific characteristics of induced earthquake occurrence and ground motion estimation, and the nature of the resulting risk. The first problem is to predict the earthquake frequency-magnitude distribution of induced events for PSHA required at the design and permitting stage before the start of injection, when an appropriate earthquake catalog clearly does not exist. Furthermore, observations and theory show that the occurrence of earthquakes induced by an evolving pore-pressure field is time-dependent, and hence does not conform to the assumption of Poissonian behavior in conventional PSHA. We present an approach to this problem based on generation of an induced seismicity catalog using numerical simulation of pressure-induced shear failure in a model of the geologic structure and stress regime in and surrounding the reservoir. The model is based on available measurements of site-specific in-situ properties as well as generic earthquake source parameters. We also discuss semi-empirical analysis to sequentially update hazard and risk estimates for input to management and mitigation strategies using earthquake data recorded during and after injection. The second important difference from conventional PSRA is that in addition to potentially damaging ground motions a significant risk associated with induce seismicity in general is the perceived nuisance caused in nearby communities by small, local felt earthquakes, which in general occur relatively frequently. Including these small, usually shallow earthquakes in the hazard analysis requires extending the ground motion frequency band considered to include the high

  11. Delineation of seismic source zones based on seismicity parameters and probabilistic evaluation of seismic hazard using logic tree approach

    Indian Academy of Sciences (India)

    K S Vipin; T G Sitharam

    2013-06-01

    The delineation of seismic source zones plays an important role in the evaluation of seismic hazard. In most of the studies the seismic source delineation is done based on geological features. In the present study, an attempt has been made to delineate seismic source zones in the study area (south India) based on the seismicity parameters. Seismicity parameters and the maximum probable earthquake for these source zones were evaluated and were used in the hazard evaluation. The probabilistic evaluation of seismic hazard for south India was carried out using a logic tree approach. Two different types of seismic sources, linear and areal, were considered in the present study to model the seismic sources in the region more precisely. In order to properly account for the attenuation characteristics of the region, three different attenuation relations were used with different weightage factors. Seismic hazard evaluation was done for the probability of exceedance (PE) of 10% and 2% in 50 years. The spatial variation of rock level peak horizontal acceleration (PHA) and spectral acceleration (Sa) values corresponding to return periods of 475 and 2500 years for the entire study area are presented in this work. The peak ground acceleration (PGA) values at ground surface level were estimated based on different NEHRP site classes by considering local site effects.

  12. Toward Building a New Seismic Hazard Model for Mainland China

    Science.gov (United States)

    Rong, Y.; Xu, X.; Chen, G.; Cheng, J.; Magistrale, H.; Shen, Z.

    2015-12-01

    At present, the only publicly available seismic hazard model for mainland China was generated by Global Seismic Hazard Assessment Program in 1999. We are building a new seismic hazard model by integrating historical earthquake catalogs, geological faults, geodetic GPS data, and geology maps. To build the model, we construct an Mw-based homogeneous historical earthquake catalog spanning from 780 B.C. to present, create fault models from active fault data using the methodology recommended by Global Earthquake Model (GEM), and derive a strain rate map based on the most complete GPS measurements and a new strain derivation algorithm. We divide China and the surrounding regions into about 20 large seismic source zones based on seismotectonics. For each zone, we use the tapered Gutenberg-Richter (TGR) relationship to model the seismicity rates. We estimate the TGR a- and b-values from the historical earthquake data, and constrain corner magnitude using the seismic moment rate derived from the strain rate. From the TGR distributions, 10,000 to 100,000 years of synthetic earthquakes are simulated. Then, we distribute small and medium earthquakes according to locations and magnitudes of historical earthquakes. Some large earthquakes are distributed on active faults based on characteristics of the faults, including slip rate, fault length and width, and paleoseismic data, and the rest to the background based on the distributions of historical earthquakes and strain rate. We evaluate available ground motion prediction equations (GMPE) by comparison to observed ground motions. To apply appropriate GMPEs, we divide the region into active and stable tectonics. The seismic hazard will be calculated using the OpenQuake software developed by GEM. To account for site amplifications, we construct a site condition map based on geology maps. The resulting new seismic hazard map can be used for seismic risk analysis and management, and business and land-use planning.

  13. Seismic hazard estimation based on the distributed seismicity in northern China

    Institute of Scientific and Technical Information of China (English)

    YANG Yong; SHI Bao-ping; SUN Liang

    2008-01-01

    In this paper, we have proposed an alternative seismic hazard modeling by using distributed seismicites. The distributed seismicity model does not need delineation of seismic source zones, and simplify the methodology of probabilistic seismic hazard analysis. Based on the devastating earthquake catalogue, we established three seismi- city model, derived the distribution of a-value in northern China by using Gaussian smoothing function, and cal- culated peak ground acceleration distributions for this area with 2%, 5% and 10% probability of exceedance in a 50-year period by using three attenuation models, respectively. In general, the peak ground motion distribution patterns are consistent with current seismic hazard map of China, but in some specific seismic zones which in- clude Shanxi Province and Shijiazhuang areas, our results indicated a little bit higher peak ground motions and zonation characters which are in agreement with seismicity distribution patterns in these areas. The hazard curves have been developed for Beijing, Tianjin, Taiyuan, Tangshan, and Ji'nan, the metropolitan cities in the northern China. The results showed that Tangshan, Taiyuan, Beijing has a higher seismic hazard than that of other cities mentioned above.

  14. Estimation of seismic hazard in the Kaliningrad region

    Science.gov (United States)

    Ulomov, V. I.; Akatova, K. N.; Medvedeva, N. S.

    2008-09-01

    The paper discusses problems of seismic zoning of the Kaliningrad region, where a series of perceptible earthquakes occurred in 2004; the strongest event had a magnitude of M s = 4.3 and produced shakings of an intensity of 6 in the coastal zone of the Sambiiskii Peninsula, classified as a 5-intensity zone. The enhanced seismic effect is shown to be caused by bad ground conditions, long-term action of seismic effects, resonance phenomena, and other factors. To gain additional constraints on the seismic hazard degree in the Kaliningrad region, the paper discusses an improved version of the model of earthquake sources underlying the compilation of normative maps of seismic zoning (OSR-97). Modified fragments of OSR-97 probability maps of the Kaliningrad region are constructed at different levels of probability that the seismic effect indicated in the maps will be exceeded over 50 yr. It is shown that additional seismological investigations should be conducted in this region.

  15. Seismic Hazard analysis of Adjaria Region in Georgia

    Science.gov (United States)

    Jorjiashvili, Nato; Elashvili, Mikheil

    2014-05-01

    The most commonly used approach to determining seismic-design loads for engineering projects is probabilistic seismic-hazard analysis (PSHA). The primary output from a PSHA is a hazard curve showing the variation of a selected ground-motion parameter, such as peak ground acceleration (PGA) or spectral acceleration (SA), against the annual frequency of exceedance (or its reciprocal, return period). The design value is the ground-motion level that corresponds to a preselected design return period. For many engineering projects, such as standard buildings and typical bridges, the seismic loading is taken from the appropriate seismic-design code, the basis of which is usually a PSHA. For more important engineering projects— where the consequences of failure are more serious, such as dams and chemical plants—it is more usual to obtain the seismic-design loads from a site-specific PSHA, in general, using much longer return periods than those governing code based design. Calculation of Probabilistic Seismic Hazard was performed using Software CRISIS2007 by Ordaz, M., Aguilar, A., and Arboleda, J., Instituto de Ingeniería, UNAM, Mexico. CRISIS implements a classical probabilistic seismic hazard methodology where seismic sources can be modelled as points, lines and areas. In the case of area sources, the software offers an integration procedure that takes advantage of a triangulation algorithm used for seismic source discretization. This solution improves calculation efficiency while maintaining a reliable description of source geometry and seismicity. Additionally, supplementary filters (e.g. fix a sitesource distance that excludes from calculation sources at great distance) allow the program to balance precision and efficiency during hazard calculation. Earthquake temporal occurrence is assumed to follow a Poisson process, and the code facilitates two types of MFDs: a truncated exponential Gutenberg-Richter [1944] magnitude distribution and a characteristic magnitude

  16. Repository Subsurface Preliminary Fire Hazard Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Richard C. Logan

    2001-07-30

    This fire hazard analysis identifies preliminary design and operations features, fire, and explosion hazards, and provides a reasonable basis to establish the design requirements of fire protection systems during development and emplacement phases of the subsurface repository. This document follows the Technical Work Plan (TWP) (CRWMS M&O 2001c) which was prepared in accordance with AP-2.21Q, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities''; Attachment 4 of AP-ESH-008, ''Hazards Analysis System''; and AP-3.11Q, ''Technical Reports''. The objective of this report is to establish the requirements that provide for facility nuclear safety and a proper level of personnel safety and property protection from the effects of fire and the adverse effects of fire-extinguishing agents.

  17. Preliminary Hazards Analysis Plasma Hearth Process

    Energy Technology Data Exchange (ETDEWEB)

    Aycock, M.; Coordes, D.; Russell, J.; TenBrook, W.; Yimbo, P. [Science Applications International Corp., Pleasanton, CA (United States)

    1993-11-01

    This Preliminary Hazards Analysis (PHA) for the Plasma Hearth Process (PHP) follows the requirements of United States Department of Energy (DOE) Order 5480.23 (DOE, 1992a), DOE Order 5480.21 (DOE, 1991d), DOE Order 5480.22 (DOE, 1992c), DOE Order 5481.1B (DOE, 1986), and the guidance provided in DOE Standards DOE-STD-1027-92 (DOE, 1992b). Consideration is given to ft proposed regulations published as 10 CFR 830 (DOE, 1993) and DOE Safety Guide SG 830.110 (DOE, 1992b). The purpose of performing a PRA is to establish an initial hazard categorization for a DOE nuclear facility and to identify those processes and structures which may have an impact on or be important to safety. The PHA is typically performed during and provides input to project conceptual design. The PRA then is followed by a Preliminary Safety Analysis Report (PSAR) performed during Title I and II design. This PSAR then leads to performance of the Final Safety Analysis Report performed during construction, testing, and acceptance and completed before routine operation. Radiological assessments indicate that a PHP facility, depending on the radioactive material inventory, may be an exempt, Category 3, or Category 2 facility. The calculated impacts would result in no significant impact to offsite personnel or the environment. Hazardous material assessments indicate that a PHP facility will be a Low Hazard facility having no significant impacts either onsite or offsite to personnel and the environment.

  18. Spatial-Temporal variability of seismic hazard in Peninsular India

    Indian Academy of Sciences (India)

    Kishor Jaiswal; Ravi Sinha

    2008-11-01

    This paper examines the variability of seismic activity observed in the case of different geological zones of peninsular India (10°N–26°N; 68°E–90°E) based on earthquake catalog between the period 1842 and 2002 and estimates earthquake hazard for the region. With compilation of earthquake catalog in terms of moment magnitude and establishing broad completeness criteria, we derive the seismicity parameters for each geologic zone of peninsular India using maximum likelihood procedure. The estimated parameters provide the basis for understanding the historical seismicity associated with different geological zones of peninsular India and also provide important inputs for future seismic hazard estimation studies in the region. Based on present investigation, it is clear that earthquake recurrence activity in various geologic zones of peninsular India is distinct and varies considerably between its cratonic and rifting zones. The study identifies the likely hazards due to the possibility of moderate to large earthquakes in peninsular India and also presents the influence of spatial rate variation in the seismic activity of this region. This paper presents the influence of source zone characterization and recurrence rate variation pattern on the maximum earthquake magnitude estimation. The results presented in the paper provide a useful basis for probabilistic seismic hazard studies and microzonation studies in peninsular India.

  19. On the Seismic Hazard of Areas with Archaeological Sites.

    Science.gov (United States)

    Teramo, A.; Termini, D.; de Domenico, D.; Sacca, C.

    2007-12-01

    A methodological approach which allows the actual level of seismic hazard of areas with archaeological sites to be evaluated is proposed. The procedure consists of a seismic, geological and geomorphological characterization of the area in study and a subsequent analysis of the observed damage in the archaeological site, arranged on the basis of specific protocols of seismic diagnostics, for the evaluation of the seismic evidence index. This index gives a numerical modelling of the seismic character of the observed damage within a correlation between collapsed structures in the archaeological site and specific endogenous and exogenous elements of the same area. An evaluation of the coherence of the actual level of seismic hazard of the areas which archaeological sites fall within, was done through a comparison between the strong ground motion which determined the observed damage and that one taken from the seismic hazard maps of the same area. A test of the procedure has been performed in different archaeological sites in Eastern Sicily (Italy).

  20. Seismic source characterization for the 2014 update of the U.S. National Seismic Hazard Model

    Science.gov (United States)

    Moschetti, Morgan P.; Powers, Peter; Petersen, Mark D.; Boyd, Oliver; Chen, Rui; Field, Edward H.; Frankel, Arthur; Haller, Kathleen; Harmsen, Stephen; Mueller, Charles S.; Wheeler, Russell; Zeng, Yuehua

    2015-01-01

    We present the updated seismic source characterization (SSC) for the 2014 update of the National Seismic Hazard Model (NSHM) for the conterminous United States. Construction of the seismic source models employs the methodology that was developed for the 1996 NSHM but includes new and updated data, data types, source models, and source parameters that reflect the current state of knowledge of earthquake occurrence and state of practice for seismic hazard analyses. We review the SSC parameterization and describe the methods used to estimate earthquake rates, magnitudes, locations, and geometries for all seismic source models, with an emphasis on new source model components. We highlight the effects that two new model components—incorporation of slip rates from combined geodetic-geologic inversions and the incorporation of adaptively smoothed seismicity models—have on probabilistic ground motions, because these sources span multiple regions of the conterminous United States and provide important additional epistemic uncertainty for the 2014 NSHM.

  1. Kernel Smoothing Methods for Non-Poissonian Seismic Hazard Analysis

    Science.gov (United States)

    Woo, Gordon

    2017-04-01

    For almost fifty years, the mainstay of probabilistic seismic hazard analysis has been the methodology developed by Cornell, which assumes that earthquake occurrence is a Poisson process, and that the spatial distribution of epicentres can be represented by a set of polygonal source zones, within which seismicity is uniform. Based on Vere-Jones' use of kernel smoothing methods for earthquake forecasting, these methods were adapted in 1994 by the author for application to probabilistic seismic hazard analysis. There is no need for ambiguous boundaries of polygonal source zones, nor for the hypothesis of time independence of earthquake sequences. In Europe, there are many regions where seismotectonic zones are not well delineated, and where there is a dynamic stress interaction between events, so that they cannot be described as independent. From the Amatrice earthquake of 24 August, 2016, the subsequent damaging earthquakes in Central Italy over months were not independent events. Removing foreshocks and aftershocks is not only an ill-defined task, it has a material effect on seismic hazard computation. Because of the spatial dispersion of epicentres, and the clustering of magnitudes for the largest events in a sequence, which might all be around magnitude 6, the specific event causing the highest ground motion can vary from one site location to another. Where significant active faults have been clearly identified geologically, they should be modelled as individual seismic sources. The remaining background seismicity should be modelled as non-Poissonian using statistical kernel smoothing methods. This approach was first applied for seismic hazard analysis at a UK nuclear power plant two decades ago, and should be included within logic-trees for future probabilistic seismic hazard at critical installations within Europe. In this paper, various salient European applications are given.

  2. Evaluating the Use of Declustering for Induced Seismicity Hazard Assessment

    Science.gov (United States)

    Llenos, A. L.; Michael, A. J.

    2016-12-01

    The recent dramatic seismicity rate increase in the central and eastern US (CEUS) has motivated the development of seismic hazard assessments for induced seismicity (e.g., Petersen et al., 2016). Standard probabilistic seismic hazard assessment (PSHA) relies fundamentally on the assumption that seismicity is Poissonian (Cornell, BSSA, 1968); therefore, the earthquake catalogs used in PSHA are typically declustered (e.g., Petersen et al., 2014) even though this may remove earthquakes that may cause damage or concern (Petersen et al., 2015; 2016). In some induced earthquake sequences in the CEUS, the standard declustering can remove up to 90% of the sequence, reducing the estimated seismicity rate by a factor of 10 compared to estimates from the complete catalog. In tectonic regions the reduction is often only about a factor of 2. We investigate how three declustering methods treat induced seismicity: the window-based Gardner-Knopoff (GK) algorithm, often used for PSHA (Gardner and Knopoff, BSSA, 1974); the link-based Reasenberg algorithm (Reasenberg, JGR,1985); and a stochastic declustering method based on a space-time Epidemic-Type Aftershock Sequence model (Ogata, JASA, 1988; Zhuang et al., JASA, 2002). We apply these methods to three catalogs that likely contain some induced seismicity. For the Guy-Greenbrier, AR earthquake swarm from 2010-2013, declustering reduces the seismicity rate by factors of 6-14, depending on the algorithm. In northern Oklahoma and southern Kansas from 2010-2015, the reduction varies from factors of 1.5-20. In the Salton Trough of southern California from 1975-2013, the rate is reduced by factors of 3-20. Stochastic declustering tends to remove the most events, followed by the GK method, while the Reasenberg method removes the fewest. Given that declustering and choice of algorithm have such a large impact on the resulting seismicity rate estimates, we suggest that more accurate hazard assessments may be found using the complete catalog.

  3. Seismic hazard assessment of Syria using seismicity, DEM, slope, active tectonic and GIS

    Science.gov (United States)

    Ahmad, Raed; Adris, Ahmad; Singh, Ramesh

    2016-07-01

    In the present work, we discuss the use of an integrated remote sensing and Geographical Information System (GIS) techniques for evaluation of seismic hazard areas in Syria. The present study is the first time effort to create seismic hazard map with the help of GIS. In the proposed approach, we have used Aster satellite data, digital elevation data (30 m resolution), earthquake data, and active tectonic maps. Many important factors for evaluation of seismic hazard were identified and corresponding thematic data layers (past earthquake epicenters, active faults, digital elevation model, and slope) were generated. A numerical rating scheme has been developed for spatial data analysis using GIS to identify ranking of parameters to be included in the evaluation of seismic hazard. The resulting earthquake potential map delineates the area into different relative susceptibility classes: high, moderate, low and very low. The potential earthquake map was validated by correlating the obtained different classes with the local probability that produced using conventional analysis of observed earthquakes. Using earthquake data of Syria and the peak ground acceleration (PGA) data is introduced to the model to develop final seismic hazard map based on Gutenberg-Richter (a and b values) parameters and using the concepts of local probability and recurrence time. The application of the proposed technique in Syrian region indicates that this method provides good estimate of seismic hazard map compared to those developed from traditional techniques (Deterministic (DSHA) and probabilistic seismic hazard (PSHA). For the first time we have used numerous parameters using remote sensing and GIS in preparation of seismic hazard map which is found to be very realistic.

  4. Probabilistic seismic hazard assessment of the Pyrenean region

    Science.gov (United States)

    Secanell, R.; Bertil, D.; Martin, C.; Goula, X.; Susagna, T.; Tapia, M.; Dominique, P.; Carbon, D.; Fleta, J.

    2008-07-01

    A unified probabilistic seismic hazard assessment (PSHA) for the Pyrenean region has been performed by an international team composed of experts from Spain and France during the Interreg IIIA ISARD project. It is motivated by incoherencies between the seismic hazard zonations of the design codes of France and Spain and by the need for input data to be used to define earthquake scenarios. A great effort was invested in the homogenisation of the input data. All existing seismic data are collected in a database and lead to a unified catalogue using a local magnitude scale. PSHA has been performed using logic trees combined with Monte Carlo simulations to account for both epistemic and aleatory uncertainties. As an alternative to hazard calculation based on seismic sources zone models, a zoneless method is also used to produce a hazard map less dependant on zone boundaries. Two seismogenic source models were defined to take into account the different interpretations existing among specialists. A new regional ground-motion prediction equation based on regional data has been proposed. It was used in combination with published ground-motion prediction equations derived using European and Mediterranean data. The application of this methodology leads to the definition of seismic hazard maps for 475- and 1,975-year return periods for spectral accelerations at periods of 0 (corresponding to peak ground acceleration), 0.1, 0.3, 0.6, 1 and 2 s. Median and percentiles 15% and 85% acceleration contour lines are represented. Finally, the seismic catalogue is used to produce a map of the maximum acceleration expected for comparison with the probabilistic hazard maps. The hazard maps are produced using a grid of 0.1°. The results obtained may be useful for civil protection and risk prevention purposes in France, Spain and Andorra.

  5. Using Probabilistic Seismic Hazard Analysis in Assessing Seismic Risk for Taipei City and New Taipei City

    Science.gov (United States)

    Hsu, Ming-Kai; Wang, Yu-Ju; Cheng, Chin-Tung; Ma, Kuo-Fong; Ke, Siao-Syun

    2016-04-01

    In this study, we evaluate the seismic hazard and risk for Taipei city and new Taipei city, which are important municipalities and the most populous cities in Taiwan. The evaluation of seismic risk involves the combination of three main components: probabilistic seismic hazard model, exposure model defining the spatial distribution of elements exposed to the hazard and vulnerability functions capable of describing the distribution of percentage of loss for a set of intensity measure levels. Seismic hazard at Taipei city and New Taipei city assumed as the hazard maps are presented in terms of ground motion values expected to be exceed at a 10% probability level in 50 years (return period 475 years) and a 2% probability level in 50 years (return period 2475 years) according to the Taiwan Earthquake Model (TEM), which assesses two seismic hazard models for Taiwan. The first model adopted the source parameters of 38 seismogenic structures identified by the TEM geologists. The other model considered 33 active faults and was published by the Central Geological Survey (CGS), Taiwan, in 2010. The 500m by 500m Grid-based building data were selected for the evaluation which capable of providing detail information about the location, value and vulnerability classification of the exposed elements. The results from this study were evaluated by the Openquake engine, the open-source software for seismic risk and hazard assessment developed within the global earthquake model (GEM) initiative. Our intention is to give the first attempt on the modeling the seismic risk from hazard in an open platform for Taiwan. An analysis through disaggregation of hazard components will be also made to prioritize the risk for further policy making.

  6. A Bayesian Seismic Hazard Analysis for the city of Naples

    Science.gov (United States)

    Faenza, Licia; Pierdominici, Simona; Hainzl, Sebastian; Cinti, Francesca R.; Sandri, Laura; Selva, Jacopo; Tonini, Roberto; Perfetti, Paolo

    2016-04-01

    In the last years many studies have been focused on determination and definition of the seismic, volcanic and tsunamogenic hazard in the city of Naples. The reason is that the town of Naples with its neighboring area is one of the most densely populated places in Italy. In addition, the risk is increased also by the type and condition of buildings and monuments in the city. It is crucial therefore to assess which active faults in Naples and surrounding area could trigger an earthquake able to shake and damage the urban area. We collect data from the most reliable and complete databases of macroseismic intensity records (from 79 AD to present). For each seismic event an active tectonic structure has been associated. Furthermore a set of active faults, well-known from geological investigations, located around the study area that they could shake the city, not associated with any earthquake, has been taken into account for our studies. This geological framework is the starting point for our Bayesian seismic hazard analysis for the city of Naples. We show the feasibility of formulating the hazard assessment procedure to include the information of past earthquakes into the probabilistic seismic hazard analysis. This strategy allows on one hand to enlarge the information used in the evaluation of the hazard, from alternative models for the earthquake generation process to past shaking and on the other hand to explicitly account for all kinds of information and their uncertainties. The Bayesian scheme we propose is applied to evaluate the seismic hazard of Naples. We implement five different spatio-temporal models to parameterize the occurrence of earthquakes potentially dangerous for Naples. Subsequently we combine these hazard curves with ShakeMap of past earthquakes that have been felt in Naples. The results are posterior hazard assessment for three exposure times, e.g., 50, 10 and 5 years, in a dense grid that cover the municipality of Naples, considering bedrock soil

  7. Are seismic hazard assessment errors and earthquake surprises unavoidable?

    Science.gov (United States)

    Kossobokov, Vladimir

    2013-04-01

    Why earthquake occurrences bring us so many surprises? The answer seems evident if we review the relationships that are commonly used to assess seismic hazard. The time-span of physically reliable Seismic History is yet a small portion of a rupture recurrence cycle at an earthquake-prone site, which makes premature any kind of reliable probabilistic statements about narrowly localized seismic hazard. Moreover, seismic evidences accumulated to-date demonstrate clearly that most of the empirical relations commonly accepted in the early history of instrumental seismology can be proved erroneous when testing statistical significance is applied. Seismic events, including mega-earthquakes, cluster displaying behaviors that are far from independent or periodic. Their distribution in space is possibly fractal, definitely, far from uniform even in a single segment of a fault zone. Such a situation contradicts generally accepted assumptions used for analytically tractable or computer simulations and complicates design of reliable methodologies for realistic earthquake hazard assessment, as well as search and definition of precursory behaviors to be used for forecast/prediction purposes. As a result, the conclusions drawn from such simulations and analyses can MISLEAD TO SCIENTIFICALLY GROUNDLESS APPLICATION, which is unwise and extremely dangerous in assessing expected societal risks and losses. For example, a systematic comparison of the GSHAP peak ground acceleration estimates with those related to actual strong earthquakes, unfortunately, discloses gross inadequacy of this "probabilistic" product, which appears UNACCEPTABLE FOR ANY KIND OF RESPONSIBLE SEISMIC RISK EVALUATION AND KNOWLEDGEABLE DISASTER PREVENTION. The self-evident shortcomings and failures of GSHAP appeals to all earthquake scientists and engineers for an urgent revision of the global seismic hazard maps from the first principles including background methodologies involved, such that there becomes: (a) a

  8. A probabilistic seismic hazard map of India and adjoining regions

    Directory of Open Access Journals (Sweden)

    H. K. Gupta

    1999-06-01

    Full Text Available This paper presents the results of an exercise carried out under GSHAP, over India and adjoining regions bound by 0°N-40°N and 65°E-100°E. A working catalogue of main shocks was prepared by merging the local catalogues with the NOAA catalogue, and removing duplicates, aftershocks and earthquakes without any magnitude. Eighty six potential seismic source zones were delineated based on the major tectonic features and seismicity trends. Using the probabilistic hazard assessment approach of McGuire, adopted by GSHAP, the Peak Ground Accelerations (PGA were computed for 10% probability of exceedance in 50 years, at locations defined by a grid of 0.5° x 0.5°. Since no reliable estimates of attenuation values are available for the Indian region, the attenuation relation of Joyner and Boore (1981 was used. The PGA values over the grid points were contoured to obtain a seismic hazard map. The hazard map depicts that a majority of the Northern Indian plate boundary region and the Tibetan plateau region have hazard level of the order of 0.25 g with prominent highs of the order of 0.35-0.4 g in the seismically more active zones like the Burmese arc, Northeastern India and Hindukush region. In the Indian shield, the regional seismic hazard, covering a major area, is of the order of 0.05-0.1 g whereas some areas like Koyna depict hazard to the level of 0.2 g. The present map can be converted into a conventional seismic zoning map having four zones with zone factors of 0.1 g, 0.2 g, 0.3 g and 0.4 g respectively.

  9. Seismic hazards in Thailand: a compilation and updated probabilistic analysis

    Science.gov (United States)

    Pailoplee, Santi; Charusiri, Punya

    2016-06-01

    A probabilistic seismic hazard analysis (PSHA) for Thailand was performed and compared to those of previous works. This PSHA was based upon (1) the most up-to-date paleoseismological data (slip rates), (2) the seismic source zones, (3) the seismicity parameters ( a and b values), and (4) the strong ground-motion attenuation models suggested as being suitable models for Thailand. For the PSHA mapping, both the ground shaking and probability of exceedance (POE) were analyzed and mapped using various methods of presentation. In addition, site-specific PSHAs were demonstrated for ten major provinces within Thailand. For instance, a 2 and 10 % POE in the next 50 years of a 0.1-0.4 g and 0.1-0.2 g ground shaking, respectively, was found for western Thailand, defining this area as the most earthquake-prone region evaluated in Thailand. In a comparison between the ten selected specific provinces within Thailand, the Kanchanaburi and Tak provinces had comparatively high seismic hazards, and therefore, effective mitigation plans for these areas should be made. Although Bangkok was defined as being within a low seismic hazard in this PSHA, a further study of seismic wave amplification due to the soft soil beneath Bangkok is required.

  10. Probabilistic, Seismically-Induced Landslide Hazard Mapping of Western Oregon

    Science.gov (United States)

    Olsen, M. J.; Sharifi Mood, M.; Gillins, D. T.; Mahalingam, R.

    2015-12-01

    Earthquake-induced landslides can generate significant damage within urban communities by damaging structures, obstructing lifeline connection routes and utilities, generating various environmental impacts, and possibly resulting in loss of life. Reliable hazard and risk maps are important to assist agencies in efficiently allocating and managing limited resources to prepare for such events. This research presents a new methodology in order to communicate site-specific landslide hazard assessments in a large-scale, regional map. Implementation of the proposed methodology results in seismic-induced landslide hazard maps that depict the probabilities of exceeding landslide displacement thresholds (e.g. 0.1, 0.3, 1.0 and 10 meters). These maps integrate a variety of data sources including: recent landslide inventories, LIDAR and photogrammetric topographic data, geology map, mapped NEHRP site classifications based on available shear wave velocity data in each geologic unit, and USGS probabilistic seismic hazard curves. Soil strength estimates were obtained by evaluating slopes present along landslide scarps and deposits for major geologic units. Code was then developed to integrate these layers to perform a rigid, sliding block analysis to determine the amount and associated probabilities of displacement based on each bin of peak ground acceleration in the seismic hazard curve at each pixel. The methodology was applied to western Oregon, which contains weak, weathered, and often wet soils at steep slopes. Such conditions have a high landslide hazard even without seismic events. A series of landslide hazard maps highlighting the probabilities of exceeding the aforementioned thresholds were generated for the study area. These output maps were then utilized in a performance based design framework enabling them to be analyzed in conjunction with other hazards for fully probabilistic-based hazard evaluation and risk assessment. a) School of Civil and Construction

  11. Documentation for the Southeast Asia seismic hazard maps

    Science.gov (United States)

    Petersen, Mark; Harmsen, Stephen; Mueller, Charles; Haller, Kathleen; Dewey, James; Luco, Nicolas; Crone, Anthony; Lidke, David; Rukstales, Kenneth

    2007-01-01

    The U.S. Geological Survey (USGS) Southeast Asia Seismic Hazard Project originated in response to the 26 December 2004 Sumatra earthquake (M9.2) and the resulting tsunami that caused significant casualties and economic losses in Indonesia, Thailand, Malaysia, India, Sri Lanka, and the Maldives. During the course of this project, several great earthquakes ruptured subduction zones along the southern coast of Indonesia (fig. 1) causing additional structural damage and casualties in nearby communities. Future structural damage and societal losses from large earthquakes can be mitigated by providing an advance warning of tsunamis and introducing seismic hazard provisions in building codes that allow buildings and structures to withstand strong ground shaking associated with anticipated earthquakes. The Southeast Asia Seismic Hazard Project was funded through a United States Agency for International Development (USAID)—Indian Ocean Tsunami Warning System to develop seismic hazard maps that would assist engineers in designing buildings that will resist earthquake strong ground shaking. An important objective of this project was to discuss regional hazard issues with building code officials, scientists, and engineers in Thailand, Malaysia, and Indonesia. The code communities have been receptive to these discussions and are considering updating the Thailand and Indonesia building codes to incorporate new information (for example, see notes from Professor Panitan Lukkunaprasit, Chulalongkorn University in Appendix A).

  12. Seismic-hazard maps for the conterminous United States, 2014

    Science.gov (United States)

    Petersen, Mark D.; Moschetti, Morgan P.; Powers, Peter M.; Mueller, Charles S.; Haller, Kathleen M.; Frankel, Arthur D.; Zeng, Yuehua; Rezaeian, Sanaz; Harmsen, Stephen C.; Boyd, Oliver S.; Field, Edward H.; Chen, Rui; Luco, Nicolas; Wheeler, Russell L.; Williams, Robert A.; Olsen, Anna H.; Rukstales, Kenneth S.

    2015-01-01

    The maps presented here provide an update to the 2008 data contained in U.S Geological Survey Scientific Investigations Map 3195 (http://pubs.usgs.gov/sim/3195/).Probabilistic seismic-hazard maps were prepared for the conterminous United States for 2014 portraying peak horizontal acceleration and horizontal spectral response acceleration for 0.2- and 1.0-second periods with probabilities of exceedance of 10 percent in 50 years and 2 percent in 50 years. All of the maps were prepared by combining the hazard derived from spatially smoothed historical seismicity with the hazard from fault-specific sources. The acceleration values contoured are the random horizontal component. The reference site condition is firm rock, defined as having an average shear-wave velocity of 760 m/s in the top 30 meters corresponding to the boundary between NEHRP (National Earthquake Hazards Reduction program) site classes B and C.

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

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Fred W.

    1994-04-22

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

  14. Seismic hazard mitigation for nuclear power plant

    Institute of Scientific and Technical Information of China (English)

    Frieder Seible

    2013-01-01

    The seismic safety of nuclear power plant(NPP) has always been a major consideration in the site selection,design,operation,and more recently recertification of existing installations.In addition to the actual NPP and all their operational and safety related support systems,the storage of spent fuel in temporary or permanent storage facilities also poses a seismic risk.This seismic risk is typically assessed with state-of-the-art modeling and analytical tools that capture everything from the ground rupture or source of the earthquake to the site specific ground shaking,taking geotechnical parameters and soil-foundation-structure-interaction (SFSI) into account to the non-linear structural response of the reactor core,the containment structure,the core cooling system and the emergency cooling system(s),to support systems,piping systems and non-structural components,and finally the performance of spent fuel storage in the probabilistically determined operational basis earthquake (OBE) or the safe shutdown earthquake (SSE) scenario.The best and most meaningful validation and verification of these advanced analytical tools is in the form of full or very large scale experimental testing,designed and conducted in direct support of model and analysis tool calibration.This paper outlines the principles under which such calibration testing should be conducted and illustrates with examples the kind of testing and parameter evaluation required.

  15. Probabilistic Seismic Hazard Assessment of the Chiapas State (SE Mexico)

    Science.gov (United States)

    Rodríguez-Lomelí, Anabel Georgina; García-Mayordomo, Julián

    2015-04-01

    The Chiapas State, in southeastern Mexico, is a very active seismic region due to the interaction of three tectonic plates: Northamerica, Cocos and Caribe. We present a probabilistic seismic hazard assessment (PSHA) specifically performed to evaluate seismic hazard in the Chiapas state. The PSHA was based on a composited seismic catalogue homogenized to Mw and was used a logic tree procedure for the consideration of different seismogenic source models and ground motion prediction equations (GMPEs). The results were obtained in terms of peak ground acceleration as well as spectral accelerations. The earthquake catalogue was compiled from the International Seismological Center and the Servicio Sismológico Nacional de México sources. Two different seismogenic source zones (SSZ) models were devised based on a revision of the tectonics of the region and the available geomorphological and geological maps. The SSZ were finally defined by the analysis of geophysical data, resulting two main different SSZ models. The Gutenberg-Richter parameters for each SSZ were calculated from the declustered and homogenized catalogue, while the maximum expected earthquake was assessed from both the catalogue and geological criteria. Several worldwide and regional GMPEs for subduction and crustal zones were revised. For each SSZ model we considered four possible combinations of GMPEs. Finally, hazard was calculated in terms of PGA and SA for 500-, 1000-, and 2500-years return periods for each branch of the logic tree using the CRISIS2007 software. The final hazard maps represent the mean values obtained from the two seismogenic and four attenuation models considered in the logic tree. For the three return periods analyzed, the maps locate the most hazardous areas in the Chiapas Central Pacific Zone, the Pacific Coastal Plain and in the Motagua and Polochic Fault Zone; intermediate hazard values in the Chiapas Batholith Zone and in the Strike-Slip Faults Province. The hazard decreases

  16. Annotated bibliography, seismicity of and near the island of Hawaii and seismic hazard analysis of the East Rift of Kilauea

    Energy Technology Data Exchange (ETDEWEB)

    Klein, F.W.

    1994-03-28

    This bibliography is divided into the following four sections: Seismicity of Hawaii and Kilauea Volcano; Occurrence, locations and accelerations from large historical Hawaiian earthquakes; Seismic hazards of Hawaii; and Methods of seismic hazard analysis. It contains 62 references, most of which are accompanied by short abstracts.

  17. The Global Seismic Hazard Assessment Program (GSHAP - 1992/1999

    Directory of Open Access Journals (Sweden)

    D. Giardini

    1999-06-01

    Full Text Available The United Nations, recognizing natural disasters as a major threat to human life and development, designed the 1990-1999 period as the International Decade for Natural Disaster Reduction (UN/IDNDR; UN Res. 42/169/ 1987. Among the IDNDR Demonstration Projects is the Global Seismic Hazard Assessment Program (GSHAP, launched in 1992 by the International Lithosphere Program (ILP and implemented in the 1992-1999 period. In order to mitigate the risk associated to the recurrence of earthquakes, the GSHAP promoted a regionally coordinated, homogeneous approach to seismic hazard evaluation. To achieve a global dimension, the GSHAP established initially a mosaic of regions and multinational test areas, then expanded to cover whole continents and finally the globe. The GSHAP Global Map of Seismic Hazard integrates the results obtained in the regional areas and depicts Peak-Ground-Acceleration (PGA with 10% chance of exceedance in 50 years, corresponding to a return period of 475 years. All regional results and the Global Map of Seismic Hazard are published in 1999 and available on the GSHAP homepage on http://seismo.ethz.ch/GSHAP/.

  18. Probabilistic seismic hazard estimates for two cities in Ecuador

    Science.gov (United States)

    Beauval, C.; Yepes, H.; Monelli, D.; Alvarado, A.; Audin, L.

    2013-05-01

    The whole territory of Ecuador is exposed to seismic hazard. Great earthquakes can occur in the subduction zone (e.g. Esmeraldas, 1906, Mw 8.8), whereas lower magnitude but shallower and potentially more destructive earthquakes can occur in the highlands. This study focuses on the estimation of probabilistic seismic hazard for two cities: the capital Quito (˜2.5 millions inhabitants) in the Interandean Valley, and the city of Esmeraldas on the coast close to the subduction trench (location of the oil refineries and export facilities which are key for Ecuador economy). The analysis relies on a seismotectonic model developed for the Ecuadorian territory and borders (Alvarado, 2012; Yepes et al. in prep). Seismic parameters are determined using a recently published unified earthquake catalog extending over five centuries in the Cordillera region, and over 110 years in the subduction zone (Beauval, Yepes, et al. 2010, 2013). Uncertainties are explored through a simple logic tree. All uncertainties identified in the process are taken into account: source zone limits, recurrence time of large earthquakes, equivalent moment magnitude of historical events, maximum magnitudes, declustering algorithm, decisions for homogenizing magnitudes, seismic parameters, ground-motion prediction equations. The aim is to quantify the resulting uncertainty on the hazard curves and to identify the controlling parameters. Mean hazard estimates for the PGA at 475 years reach around 0.4-0.45g in Quito and 0.9-1.0g in Esmeraldas.

  19. Seismic hazard in central Italy and the 2016 Amatrice earthquake

    Directory of Open Access Journals (Sweden)

    Carlo Meletti

    2016-12-01

    Full Text Available The Amatrice earthquake of August 24th, 2016 (Mw 6.0 struck an area that in the national reference seismic hazard model (MPS04 is characterized by expected horizontal peak ground acceleration (PGA with 10% probability of exceedance in 50 years higher than 0.25 g. After the occurrence of moderate-to-large magnitude earthquakes with a strong impact on the population, such as the L’Aquila 2009 and Emilia 2012 ones (Mw 6.1 and 5.9, respectively, possible underestimations of the seismic hazard by MPS04 were investigated, in order to analyze and evaluate the possible need for its update. One of the most common misunderstanding is to compare recorded PGA only with PGA with 10% probability of exceedance in 50 years. Moreover, by definition, probabilistic models cannot be validated (or rejected on the basis of a single event. However, comparisons of forecasted shakings with observed data are useful for understating the consistency of the model. It is then worth highlighting the importance of these comparisons. In fact, MPS04 is the basis for the current Italian building code to provide the effective design procedures and, thus, any modification to the seismic hazard would also affect the building code. In this paper, comparisons between recorded ground motion during the Amatrice earthquake and seismic hazard estimates are performed, showing that the observed accelerations are consistent with the values expected by the MPS04 model.

  20. Seismic Hazard Characterization at the DOE Savannah River Site (SRS): Status report

    Energy Technology Data Exchange (ETDEWEB)

    Savy, J.B.

    1994-06-24

    The purpose of the Seismic Hazard Characterization project for the Savannah River Site (SRS-SHC) is to develop estimates of the seismic hazard for several locations within the SRS. Given the differences in the geology and geotechnical characteristics at each location, the estimates of the seismic hazard are to allow for the specific local conditions at each site. Characterization of seismic hazard is a critical factor for the design of new facilities as well as for the review and potential retrofit of existing facilities at SRS. The scope of the SRS seismic hazard characterization reported in this document is limited to the Probabilistic Seismic Hazard Analysis (PSHA). The goal of the project is to provide seismic hazard estimates based on a state-of-the-art method which is consistent with developments and findings of several ongoing studies which are deemed to bring improvements in the state of the seismic hazard analyses.

  1. Incorporating induced seismicity in the 2014 United States National Seismic Hazard Model: results of the 2014 workshop and sensitivity studies

    Science.gov (United States)

    Petersen, Mark D.; Mueller, Charles S.; Moschetti, Morgan P.; Hoover, Susan M.; Rubinstein, Justin L.; Llenos, Andrea L.; Michael, Andrew J.; Ellsworth, William L.; McGarr, Arthur F.; Holland, Austin A.; Anderson, John G.

    2015-01-01

    The U.S. Geological Survey National Seismic Hazard Model for the conterminous United States was updated in 2014 to account for new methods, input models, and data necessary for assessing the seismic ground shaking hazard from natural (tectonic) earthquakes. The U.S. Geological Survey National Seismic Hazard Model project uses probabilistic seismic hazard analysis to quantify the rate of exceedance for earthquake ground shaking (ground motion). For the 2014 National Seismic Hazard Model assessment, the seismic hazard from potentially induced earthquakes was intentionally not considered because we had not determined how to properly treat these earthquakes for the seismic hazard analysis. The phrases “potentially induced” and “induced” are used interchangeably in this report, however it is acknowledged that this classification is based on circumstantial evidence and scientific judgment. For the 2014 National Seismic Hazard Model update, the potentially induced earthquakes were removed from the NSHM’s earthquake catalog, and the documentation states that we would consider alternative models for including induced seismicity in a future version of the National Seismic Hazard Model. As part of the process of incorporating induced seismicity into the seismic hazard model, we evaluate the sensitivity of the seismic hazard from induced seismicity to five parts of the hazard model: (1) the earthquake catalog, (2) earthquake rates, (3) earthquake locations, (4) earthquake Mmax (maximum magnitude), and (5) earthquake ground motions. We describe alternative input models for each of the five parts that represent differences in scientific opinions on induced seismicity characteristics. In this report, however, we do not weight these input models to come up with a preferred final model. Instead, we present a sensitivity study showing uniform seismic hazard maps obtained by applying the alternative input models for induced seismicity. The final model will be released after

  2. Seismic Hazard Prediction Using Seismic Bumps: A Data Mining Approach

    Directory of Open Access Journals (Sweden)

    Musa Peker

    2016-04-01

    Full Text Available Due to the large number of influencing factors, it is difficult to predict the earthquake which is a natural disaster. Researchers are working intensively on earthquake prediction. Loss of life and property can be minimized with earthquake prediction. In this study, a system is proposed for earthquake prediction with data mining techniques. In the study in which Cross Industry Standard Process for Data Mining (CRISP-DM approach has been used as data mining methodology, seismic bumps data obtained from mines has been analyzed. Extreme learning machine (ELM which is an effective and rapid classification algorithm has been used in the modeling phase. In the evaluation stage, different performance evaluation criteria such as classification accuracy, sensitivity, specificity and kappa value have been used. The results are promising for earthquake prediction.

  3. Intensity Based Seismic Hazard Map of Republic of Macedonia

    Science.gov (United States)

    Dojcinovski, Dragi; Dimiskovska, Biserka; Stojmanovska, Marta

    2016-04-01

    The territory of the Republic of Macedonia and the border terrains are among the most seismically active parts of the Balkan Peninsula belonging to the Mediterranean-Trans-Asian seismic belt. The seismological data on the R. Macedonia from the past 16 centuries point to occurrence of very strong catastrophic earthquakes. The hypocenters of the occurred earthquakes are located above the Mohorovicic discontinuity, most frequently, at a depth of 10-20 km. Accurate short -term prognosis of earthquake occurrence, i.e., simultaneous prognosis of time, place and intensity of their occurrence is still not possible. The present methods of seismic zoning have advanced to such an extent that it is with a great probability that they enable efficient protection against earthquake effects. The seismic hazard maps of the Republic of Macedonia are the result of analysis and synthesis of data from seismological, seismotectonic and other corresponding investigations necessary for definition of the expected level of seismic hazard for certain time periods. These should be amended, from time to time, with new data and scientific knowledge. The elaboration of this map does not completely solve all issues related to earthquakes, but it provides basic empirical data necessary for updating the existing regulations for construction of engineering structures in seismically active areas regulated by legal regulations and technical norms whose constituent part is the seismic hazard map. The map has been elaborated based on complex seismological and geophysical investigations of the considered area and synthesis of the results from these investigations. There were two phases of elaboration of the map. In the first phase, the map of focal zones characterized by maximum magnitudes of possible earthquakes has been elaborated. In the second phase, the intensities of expected earthquakes have been computed according to the MCS scale. The map is prognostic, i.e., it provides assessment of the

  4. Maps showing seismic landslide hazards in Anchorage, Alaska

    Science.gov (United States)

    Jibson, Randall W.

    2014-01-01

    The devastating landslides that accompanied the great 1964 Alaska earthquake showed that seismically triggered landslides are one of the greatest geologic hazards in Anchorage. Maps quantifying seismic landslide hazards are therefore important for planning, zoning, and emergency-response preparation. The accompanying maps portray seismic landslide hazards for the following conditions: (1) deep, translational landslides, which occur only during great subduction-zone earthquakes that have return periods of =300-900 yr; (2) shallow landslides for a peak ground acceleration (PGA) of 0.69 g, which has a return period of 2,475 yr, or a 2 percent probability of exceedance in 50 yr; and (3) shallow landslides for a PGA of 0.43 g, which has a return period of 475 yr, or a 10 percent probability of exceedance in 50 yr. Deep, translational landslide hazards were delineated based on previous studies of such landslides, with some modifications based on field observations of locations of deep landslides. Shallow-landslide hazards were delineated using a Newmark-type displacement analysis for the two probabilistic ground motions modeled.

  5. Department of Energy seismic siting and design decisions: Consistent use of probabilistic seismic hazard analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kimball, J.K.; Chander, H.

    1997-02-01

    The Department of Energy (DOE) requires that all nuclear or non-nuclear facilities shall be designed, constructed and operated so that the public, the workers, and the environment are protected from the adverse impacts of Natural Phenomena Hazards including earthquakes. The design and evaluation of DOE facilities to accommodate earthquakes shall be based on an assessment of the likelihood of future earthquakes occurrences commensurate with a graded approach which depends on the potential risk posed by the DOE facility. DOE has developed Standards for site characterization and hazards assessments to ensure that a consistent use of probabilistic seismic hazard is implemented at each DOE site. The criteria included in the DOE Standards are described, and compared to those criteria being promoted by the staff of the Nuclear Regulatory Commission (NRC) for commercial nuclear reactors. In addition to a general description of the DOE requirements and criteria, the most recent probabilistic seismic hazard results for a number of DOE sites are presented. Based on the work completed to develop the probabilistic seismic hazard results, a summary of important application issues are described with recommendations for future improvements in the development and use of probabilistic seismic hazard criteria for design of DOE facilities.

  6. Influence of seismicity parameter uncertainty on seismic hazard estimation of cities and towns

    Institute of Scientific and Technical Information of China (English)

    黄玮琼; 吴宣

    2003-01-01

    The influence on seismic hazard estimation for 310 cities and towns in the whole nation are studied in particular,owing to uncertainty of seismicity parameters caused by non-uniqueness in selecting statistical time ranges. Andthe regional sketch maps of the average varying values of intensity and the average relative varying values of peakacceleration with different probability of exceedance in 50 years are drawn in the Chinese mainland.

  7. Study of Seismic Hazards in the Center of the State of Veracruz, MÉXICO.

    Science.gov (United States)

    Torres Morales, G. F.; Leonardo Suárez, M.; Dávalos Sotelo, R.; Mora González, I.; Castillo Aguilar, S.

    2015-12-01

    Preliminary results obtained from the project "Microzonation of geological and hydrometeorological hazards for conurbations of Orizaba, Veracruz, and major sites located in the lower sub-basins: The Antigua and Jamapa" are presented. These project was supported by the Joint Funds CONACyT-Veracruz state government. It was developed a probabilistic seismic hazard assessment (henceforth PSHA) in the central area of Veracruz State, mainly in a region bounded by the watersheds of the rivers Jamapa and Antigua, whit the aim to evaluate the geological and hydrometeorological hazards in this region. The project pays most attention to extreme weather phenomena, floods and earthquakes, in order to calculate the risk induced by previous for landslides and rock falls. In addition, as part of the study, the PSHA was developed considered the site effect in the urban zones of the cities Xalapa and Orizaba; the site effects were incorporated by a standard format proposed in studies of microzonation and its application in computer systems, which allows to optimize and condense microzonation studies in a city. The results obtained from the PSHA are presented through to seismic hazard maps (hazard footprints), exceedance rate curves and uniform hazard spectrum for different spectral ordinates, between 0.01 and 5.0 seconds, associated to selected return periods: 72, 225, 475 and 2475 years.

  8. Investigation of techniques for the development of seismic design basis using the probabilistic seismic hazard analysis

    Energy Technology Data Exchange (ETDEWEB)

    Bernreuter, D.L.; Boissonnade, A.C.; Short, C.M.

    1998-04-01

    The Nuclear Regulatory Commission asked Lawrence Livermore National Laboratory to form a group of experts to assist them in revising the seismic and geologic siting criteria for nuclear power plants, Appendix A to 10 CFR Part 100. This document describes a deterministic approach for determining a Safe Shutdown Earthquake (SSE) Ground Motion for a nuclear power plant site. One disadvantage of this approach is the difficulty of integrating differences of opinions and differing interpretations into seismic hazard characterization. In answer to this, probabilistic seismic hazard assessment methodologies incorporate differences of opinion and interpretations among earth science experts. For this reason, probabilistic hazard methods were selected for determining SSEs for the revised regulation, 10 CFR Part 100.23. However, because these methodologies provide a composite analysis of all possible earthquakes that may occur, they do not provide the familiar link between seismic design loading requirements and engineering design practice. Therefore, approaches used to characterize seismic events (magnitude and distance) which best represent the ground motion level determined with the probabilistic hazard analysis were investigated. This report summarizes investigations conducted at 69 nuclear reactor sites in the central and eastern U.S. for determining SSEs using probabilistic analyses. Alternative techniques are presented along with justification for key choices. 16 refs., 32 figs., 60 tabs.

  9. Statistical Seismology Studies in Central America : b-value, seismic hazard and seismic quiescence

    OpenAIRE

    2003-01-01

    The present thesis collects results of research applying theory and methods of statistical seismology to the seismicity of Central America, a region with a complex tectonic setting controlled by the interaction of four major plates, namely the Caribbean, Cocos, Nazca and North American plates. Three different earthquake catalogues were used for studies focused on stress in a tectonic volume, seismic hazard maps and seismicity patterns (precursors), covering the region 94ºW to 81ºW and 5ºN to ...

  10. Seismic survey probes urban earthquake hazards in Pacific Northwest

    Science.gov (United States)

    Fisher, M. A.; Brocher, T. M.; Hyndman, R. D.; Trehu, A. M.; Weaver, C. S.; Creager, K. C.; Crosson, R. S.; Parsons, T.; Cooper, A. K.; Mosher, D.; Spence, G.; Zelt, B. C.; Hammer, P. T.; ten Brink, U.; Pratt, T. L.; Miller, K. C.; Childs, J. R.; Cochrane, G. R.; Chopra, S.; Walia, R.

    A multidisciplinary seismic survey earlier this year in the Pacific Northwest is expected to reveal much new information about the earthquake threat to U.S. and Canadian urban areas there. A disastrous earthquake is a very real possibility in the region.The survey, known as the Seismic Hazards Investigation in Puget Sound (SHIPS), engendered close cooperation among geologists, biologists, environmental groups, and government agencies. It also succeeded in striking a fine balance between the need to prepare for a great earthquake and the requirement to protect a coveted marine environment while operating a large airgun array.

  11. Probabilistic seismic hazard assessment of Italy using kernel estimation methods

    Science.gov (United States)

    Zuccolo, Elisa; Corigliano, Mirko; Lai, Carlo G.

    2013-07-01

    A representation of seismic hazard is proposed for Italy based on the zone-free approach developed by Woo (BSSA 86(2):353-362, 1996a), which is based on a kernel estimation method governed by concepts of fractal geometry and self-organized seismicity, not requiring the definition of seismogenic zoning. The purpose is to assess the influence of seismogenic zoning on the results obtained for the probabilistic seismic hazard analysis (PSHA) of Italy using the standard Cornell's method. The hazard has been estimated for outcropping rock site conditions in terms of maps and uniform hazard spectra for a selected site, with 10 % probability of exceedance in 50 years. Both spectral acceleration and spectral displacement have been considered as ground motion parameters. Differences in the results of PSHA between the two methods are compared and discussed. The analysis shows that, in areas such as Italy, characterized by a reliable earthquake catalog and in which faults are generally not easily identifiable, a zone-free approach can be considered a valuable tool to address epistemic uncertainty within a logic tree framework.

  12. Seismic hazard analysis for Jayapura city, Papua

    Energy Technology Data Exchange (ETDEWEB)

    Robiana, R., E-mail: robiana-geo104@yahoo.com; Cipta, A. [Geological Agency, Diponegoro Road No.57, Bandung, 40122 (Indonesia)

    2015-04-24

    Jayapura city had destructive earthquake which occurred on June 25, 1976 with the maximum intensity VII MMI scale. Probabilistic methods are used to determine the earthquake hazard by considering all possible earthquakes that can occur in this region. Earthquake source models using three types of source models are subduction model; comes from the New Guinea Trench subduction zone (North Papuan Thrust), fault models; derived from fault Yapen, TareraAiduna, Wamena, Memberamo, Waipago, Jayapura, and Jayawijaya, and 7 background models to accommodate unknown earthquakes. Amplification factor using geomorphological approaches are corrected by the measurement data. This data is related to rock type and depth of soft soil. Site class in Jayapura city can be grouped into classes B, C, D and E, with the amplification between 0.5 – 6. Hazard maps are presented with a 10% probability of earthquake occurrence within a period of 500 years for the dominant periods of 0.0, 0.2, and 1.0 seconds.

  13. Constraints on Long-Term Seismic Hazard From Vulnerable Stalagmites

    Science.gov (United States)

    Gribovszki, Katalin; Bokelmann, Götz; Mónus, Péter; Kovács, Károly; Konecny, Pavel; Lednicka, Marketa; Bednárik, Martin; Brimich, Ladislav

    2015-04-01

    Earthquakes hit urban centers in Europe infrequently, but occasionally with disastrous effects. This raises the important issue for society, how to react to the natural hazard: potential damages are huge, but infrastructure costs for addressing these hazards are huge as well. Furthermore, seismic hazard is only one of the many hazards facing society. Societal means need to be distributed in a reasonable manner - to assure that all of these hazards (natural as well as societal) are addressed appropriately. Obtaining an unbiased view of seismic hazard (and risk) is very important therefore. In principle, the best way to test PSHA models is to compare with observations that are entirely independent of the procedure used to produce the PSHA models. Arguably, the most valuable information in this context should be information on long-term hazard, namely maximum intensities (or magnitudes) occuring over time intervals that are at least as long as a seismic cycle - if that exists. Such information would be very valuable, even if it concerned only a single site, namely that of a particularly sensitive infrastructure. Such a request may seem hopeless - but it is not. Long-term information can in principle be gained from intact stalagmites in natural caves. These have survived all earthquakes that have occurred, over thousands of years - depending on the age of the stalagmite. Their "survival" requires that the horizontal ground acceleration has never exceeded a certain critical value within that period. We are focusing here on case studies in Austria, which has moderate seismicity, but a well-documented history of major earthquake-induced damage, e.g., Villach in 1348 and 1690, Vienna in 1590, Leoben in 1794, and Innsbruck in 1551, 1572, and 1589. Seismic intensities have reached levels up to 10. It is clearly important to know which "worst-case" damages to expect. We have identified sets of particularly sensitive stalagmites in the general vicinity of two major cities in

  14. The seismic project of the National Tsunami Hazard Mitigation Program

    Science.gov (United States)

    Oppenheimer, D.H.; Bittenbinder, A.N.; Bogaert, B.M.; Buland, R.P.; Dietz, L.D.; Hansen, R.A.; Malone, S.D.; McCreery, C.S.; Sokolowski, T.J.; Whitmore, P.M.; Weaver, C.S.

    2005-01-01

    In 1997, the Federal Emergency Management Agency (FEMA), National Oceanic and Atmospheric Administration (NOAA), U.S. Geological Survey (USGS), and the five western States of Alaska, California, Hawaii, Oregon, and Washington joined in a partnership called the National Tsunami Hazard Mitigation Program (NTHMP) to enhance the quality and quantity of seismic data provided to the NOAA tsunami warning centers in Alaska and Hawaii. The NTHMP funded a seismic project that now provides the warning centers with real-time seismic data over dedicated communication links and the Internet from regional seismic networks monitoring earthquakes in the five western states, the U.S. National Seismic Network in Colorado, and from domestic and global seismic stations operated by other agencies. The goal of the project is to reduce the time needed to issue a tsunami warning by providing the warning centers with high-dynamic range, broadband waveforms in near real time. An additional goal is to reduce the likelihood of issuing false tsunami warnings by rapidly providing to the warning centers parametric information on earthquakes that could indicate their tsunamigenic potential, such as hypocenters, magnitudes, moment tensors, and shake distribution maps. New or upgraded field instrumentation was installed over a 5-year period at 53 seismic stations in the five western states. Data from these instruments has been integrated into the seismic network utilizing Earthworm software. This network has significantly reduced the time needed to respond to teleseismic and regional earthquakes. Notably, the West Coast/Alaska Tsunami Warning Center responded to the 28 February 2001 Mw 6.8 Nisqually earthquake beneath Olympia, Washington within 2 minutes compared to an average response time of over 10 minutes for the previous 18 years. ?? Springer 2005.

  15. Documentation for Initial Seismic Hazard Maps for Haiti

    Science.gov (United States)

    Frankel, Arthur; Harmsen, Stephen; Mueller, Charles; Calais, Eric; Haase, Jennifer

    2010-01-01

    In response to the urgent need for earthquake-hazard information after the tragic disaster caused by the moment magnitude (M) 7.0 January 12, 2010, earthquake, we have constructed initial probabilistic seismic hazard maps for Haiti. These maps are based on the current information we have on fault slip rates and historical and instrumental seismicity. These initial maps will be revised and improved as more data become available. In the short term, more extensive logic trees will be developed to better capture the uncertainty in key parameters. In the longer term, we will incorporate new information on fault parameters and previous large earthquakes obtained from geologic fieldwork. These seismic hazard maps are important for the management of the current crisis and the development of building codes and standards for the rebuilding effort. The boundary between the Caribbean and North American Plates in the Hispaniola region is a complex zone of deformation. The highly oblique ~20 mm/yr convergence between the two plates (DeMets and others, 2000) is partitioned between subduction zones off of the northern and southeastern coasts of Hispaniola and strike-slip faults that transect the northern and southern portions of the island. There are also thrust faults within the island that reflect the compressional component of motion caused by the geometry of the plate boundary. We follow the general methodology developed for the 1996 U.S. national seismic hazard maps and also as implemented in the 2002 and 2008 updates. This procedure consists of adding the seismic hazard calculated from crustal faults, subduction zones, and spatially smoothed seismicity for shallow earthquakes and Wadati-Benioff-zone earthquakes. Each one of these source classes will be described below. The lack of information on faults in Haiti requires many assumptions to be made. These assumptions will need to be revisited and reevaluated as more fieldwork and research are accomplished. We made two sets of

  16. Mitigation of earthquake hazards using seismic base isolation systems

    Energy Technology Data Exchange (ETDEWEB)

    Wang, C.Y.

    1994-06-01

    This paper deals with mitigation of earthquake hazards using seismic base-isolation systems. A numerical algorithm is described for system response analysis of isolated structures with laminated elastomer bearings. The focus of this paper is on the adaptation of a nonlinear constitutive equation for the isolation bearing, and the treatment of foundation embedment for the soil-structure-interaction analysis. Sample problems are presented to illustrate the mitigating effect of using base-isolation systems.

  17. Seismic Hazard Assessment in the Aspospirgos Area, Athens - Greece

    Science.gov (United States)

    Voulgaris, N.; Drakatos, G.; Lekkas, E.; Karastathis, V.; Valadaki, A.; Plessas, S.

    2005-12-01

    The extensive damages and human life loss related to the September 7, 1999 earthquake in the Athens area (Greece) initiated an effort to re-evaluate seismic hazard in various regions around the capital. One of the target areas selected within the framework of the specially designed research project ESTIA was the industrial area of Aspropirgos, where the epicenter of the main shock was located. The multidisciplinary approach towards seismic hazard assessment included a microseismicity survey and detailed geological and tectonic studies in the area in order to delineate and define the recently activated seismic sources in the area. Initially a portable network, consisting of seventeen (17) digital seismographs was installed and operated for 2 months during the autumn of 2004. A total of five hundred forty five (545) earthquakes (Mengineer is able to calculate specific design spectra for every site while combination with available vulnerability estimates could lead to more realistic seismic risk calculations. Acknowledgments We would like to thank the General Secretariat for Research and Technology of Greece for the partial support of this research, in the framework of ESTIA project.

  18. Errors in Seismic Hazard Assessment are Creating Huge Human Losses

    Science.gov (United States)

    Bela, J.

    2015-12-01

    The current practice of representing earthquake hazards to the public based upon their perceived likelihood or probability of occurrence is proven now by the global record of actual earthquakes to be not only erroneous and unreliable, but also too deadly! Earthquake occurrence is sporadic and therefore assumptions of earthquake frequency and return-period are both not only misleading, but also categorically false. More than 700,000 people have now lost their lives (2000-2011), wherein 11 of the World's Deadliest Earthquakes have occurred in locations where probability-based seismic hazard assessments had predicted only low seismic low hazard. Unless seismic hazard assessment and the setting of minimum earthquake design safety standards for buildings and bridges are based on a more realistic deterministic recognition of "what can happen" rather than on what mathematical models suggest is "most likely to happen" such future huge human losses can only be expected to continue! The actual earthquake events that did occur were at or near the maximum potential-size event that either already had occurred in the past; or were geologically known to be possible. Haiti's M7 earthquake, 2010 (with > 222,000 fatalities) meant the dead could not even be buried with dignity. Japan's catastrophic Tohoku earthquake, 2011; a M9 Megathrust earthquake, unleashed a tsunami that not only obliterated coastal communities along the northern Japanese coast, but also claimed > 20,000 lives. This tsunami flooded nuclear reactors at Fukushima, causing 4 explosions and 3 reactors to melt down. But while this history of huge human losses due to erroneous and misleading seismic hazard estimates, despite its wrenching pain, cannot be unlived; if faced with courage and a more realistic deterministic estimate of "what is possible", it need not be lived again. An objective testing of the results of global probability based seismic hazard maps against real occurrences has never been done by the

  19. Probabilistic seismic hazard assessment for northern Southeast Asia

    Science.gov (United States)

    Chan, C. H.; Wang, Y.; Kosuwan, S.; Nguyen, M. L.; Shi, X.; Sieh, K.

    2016-12-01

    We assess seismic hazard for northern Southeast Asia through constructing an earthquake and fault database, conducting a series of ground-shaking scenarios and proposing regional seismic hazard maps. Our earthquake database contains earthquake parameters from global and local seismic catalogues, including the ISC, ISC-GEM, the global ANSS Comprehensive Catalogues, Seismological Bureau, Thai Meteorological Department, Thailand, and Institute of Geophysics Vietnam Academy of Science and Technology, Vietnam. To harmonize the earthquake parameters from various catalogue sources, we remove duplicate events and unify magnitudes into the same scale. Our active fault database include active fault data from previous studies, e.g. the active fault parameters determined by Wang et al. (2014), Department of Mineral Resources, Thailand, and Institute of Geophysics, Vietnam Academy of Science and Technology, Vietnam. Based on the parameters from analysis of the databases (i.e., the Gutenberg-Richter relationship, slip rate, maximum magnitude and time elapsed of last events), we determined the earthquake recurrence models of seismogenic sources. To evaluate the ground shaking behaviours in different tectonic regimes, we conducted a series of tests by matching the felt intensities of historical earthquakes to the modelled ground motions using ground motion prediction equations (GMPEs). By incorporating the best-fitting GMPEs and site conditions, we utilized site effect and assessed probabilistic seismic hazard. The highest seismic hazard is in the region close to the Sagaing Fault, which cuts through some major cities in central Myanmar. The northern segment of Sunda megathrust, which could potentially cause M8-class earthquake, brings significant hazard along the Western Coast of Myanmar and eastern Bangladesh. Besides, we conclude a notable hazard level in northern Vietnam and the boundary between Myanmar, Thailand and Laos, due to a series of strike-slip faults, which could

  20. Revised seismic hazard map for the Kyrgyz Republic

    Science.gov (United States)

    Fleming, Kevin; Ullah, Shahid; Parolai, Stefano; Walker, Richard; Pittore, Massimiliano; Free, Matthew; Fourniadis, Yannis; Villiani, Manuela; Sousa, Luis; Ormukov, Cholponbek; Moldobekov, Bolot; Takeuchi, Ko

    2017-04-01

    As part of a seismic risk study sponsored by the World Bank, a revised seismic hazard map for the Kyrgyz Republic has been produced, using the OpenQuake-engine developed by the Global Earthquake Model Foundation (GEM). In this project, an earthquake catalogue spanning a period from 250 BCE to 2014 was compiled and processed through spatial and temporal declustering tools. The territory of the Kyrgyz Republic was divided into 31 area sources defined based on local seismicity, including a total area covering 200 km from the border. The results are presented in terms of Peak Ground Acceleration (PGA). In addition, macroseismic intensity estimates, making use of recent intensity prediction equations, were also provided, given that this measure is still widely used in Central Asia. In order to accommodate the associated epistemic uncertainty, three ground motion prediction equations were used in a logic tree structure. A set of representative earthquake scenarios were further identified based on historical data and the nature of the considered faults. The resulting hazard map, as expected, follows the country's seismicity, with the highest levels of hazard in the northeast, south and southwest of the country, with an elevated part around the centre. When considering PGA, the hazard is slightly greater for major urban centres than in previous works (e.g., Abdrakhmatov et al., 2003), although the macroseismic intensity estimates are less than previous studies, e.g., Ulomov (1999). For the scenario assessments, the examples that most affect the urban centres assessed are the Issyk Ata fault (in particular for Bishkek), the Chilik and Kemin faults (in particular Balykchy and Karakol), the Ferghana Valley fault system (in particular Osh, Jalah-Abad and Uzgen), the Oinik Djar fault (Naryn) and the central and western Talas-Ferghanafaukt (Talas). Finally, while site effects (in particular, those dependent on the upper-most geological structure) have an obvious effect on the

  1. The contribution of pattern recognition of seismic and morphostructural data to seismic hazard assessment

    CERN Document Server

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

    2014-01-01

    The reliable statistical characterization of the spatial and temporal properties of large earthquakes occurrence is one of the most debated issues in seismic hazard assessment, due to the unavoidably limited observations from past events. We show that pattern recognition techniques, which are designed in a formal and testable way, may provide significant space-time constraints about impending strong earthquakes. This information, when combined with physically sound methods for ground shaking computation, like the neo-deterministic approach (NDSHA), may produce effectively preventive seismic hazard maps. Pattern recognition analysis of morphostructural data provide quantitative and systematic criteria for identifying the areas prone to the largest events, taking into account a wide set of possible geophysical and geological data, whilst the formal identification of precursory seismicity patterns (by means of CN and M8S algorithms), duly validated by prospective testing, provides useful constraints about impend...

  2. Integrating population dynamics into mapping human exposure to seismic hazard

    Directory of Open Access Journals (Sweden)

    S. Freire

    2012-11-01

    Full Text Available Disaster risk is not fully characterized without taking into account vulnerability and population exposure. Assessment of earthquake risk in urban areas would benefit from considering the variation of population distribution at more detailed spatial and temporal scales, and from a more explicit integration of this improved demographic data with existing seismic hazard maps. In the present work, "intelligent" dasymetric mapping is used to model population dynamics at high spatial resolution in order to benefit the analysis of spatio-temporal exposure to earthquake hazard in a metropolitan area. These night- and daytime-specific population densities are then classified and combined with seismic intensity levels to derive new spatially-explicit four-class-composite maps of human exposure. The presented approach enables a more thorough assessment of population exposure to earthquake hazard. Results show that there are significantly more people potentially at risk in the daytime period, demonstrating the shifting nature of population exposure in the daily cycle and the need to move beyond conventional residence-based demographic data sources to improve risk analyses. The proposed fine-scale maps of human exposure to seismic intensity are mainly aimed at benefiting visualization and communication of earthquake risk, but can be valuable in all phases of the disaster management process where knowledge of population densities is relevant for decision-making.

  3. A Gis Model Application Supporting The Analysis of The Seismic Hazard For The Urban Area of Catania (italy)

    Science.gov (United States)

    Grasso, S.; Maugeri, M.

    rigorous complex methods of analysis or qualitative procedures. A semi quantitative procedure based on the definition of the geotechnical hazard index has been applied for the zonation of the seismic geotechnical hazard of the city of Catania. In particular this procedure has been applied to define the influence of geotechnical properties of soil in a central area of the city of Catania, where some historical buildings of great importance are sited. It was also performed an investigation based on the inspection of more than one hundred historical ecclesiastical buildings of great importance, located in the city. Then, in order to identify the amplification effects due to the site conditions, a geotechnical survey form was prepared, to allow a semi quantitative evaluation of the seismic geotechnical hazard for all these historical buildings. In addition, to evaluate the foundation soil time -history response, a 1-D dynamic soil model was employed for all these buildings, considering the non linearity of soil behaviour. Using a GIS, a map of the seismic geotechnical hazard, of the liquefaction hazard and a preliminary map of the seismic hazard for the city of Catania have been obtained. From the analysis of obtained results it may be noticed that high hazard zones are mainly clayey sites

  4. A new seismic probe for coal seam hazard detection

    Energy Technology Data Exchange (ETDEWEB)

    Peters, W.R.; Owen, T.E.; Thill, R.E.

    1985-01-01

    An experimental hole-to-hole seismic probe system has been developed for use in coal measure geology as a means of determining the structural conditions of coal seams. The source probe produces a 500-joule electric arc discharge whose seismic wavelet has a spectrum in the 200 to 2,000 Hz frequency range. Low compliance hydrophones contained in the source probe as well as in a separate seismic detector probe are matched to the frequency range of the source. Both probes are constructed with 5.72 cm diameter housings. The transducers in the probes are equipped with fluid-inflatable boots to permit operation in either wet or dry boreholes. Preliminary tests in vertical boreholes drilled 213 m apart in sedimentary rock formations show reliable operation and useful seismic propagation measurements along horizontal and oblique paths up to 232 m in length. Because the seismic wavelet has an accurately repeatable waveshape, multiple shots and signal averaging techniques can be used to enhance the signal-to-noise ratio and extend the transmission distances.

  5. Why is Probabilistic Seismic Hazard Analysis (PSHA) still used?

    Science.gov (United States)

    Mulargia, Francesco; Stark, Philip B.; Geller, Robert J.

    2017-03-01

    Even though it has never been validated by objective testing, Probabilistic Seismic Hazard Analysis (PSHA) has been widely used for almost 50 years by governments and industry in applications with lives and property hanging in the balance, such as deciding safety criteria for nuclear power plants, making official national hazard maps, developing building code requirements, and determining earthquake insurance rates. PSHA rests on assumptions now known to conflict with earthquake physics; many damaging earthquakes, including the 1988 Spitak, Armenia, event and the 2011 Tohoku, Japan, event, have occurred in regions relatively rated low-risk by PSHA hazard maps. No extant method, including PSHA, produces reliable estimates of seismic hazard. Earthquake hazard mitigation should be recognized to be inherently political, involving a tradeoff between uncertain costs and uncertain risks. Earthquake scientists, engineers, and risk managers can make important contributions to the hard problem of allocating limited resources wisely, but government officials and stakeholders must take responsibility for the risks of accidents due to natural events that exceed the adopted safety criteria. ********* ;Without an analysis of the physical causes of recorded floods, and of the whole geophysical, biophysical and anthropogenic context which circumscribes the potential for flood formation, results of flood frequency analysis as [now practiced], rather than providing information useful for coping with the flood hazard, themselves represent an additional hazard that can contribute to damages caused by floods. This danger is very real since decisions made on the basis of wrong numbers presented as good estimates of flood probabilities will generally be worse than decisions made with an awareness of an impossibility to make a good estimate and with the aid of merely qualitative information on the general flooding potential.;

  6. Uncertainties in evaluation of hazard and seismic risk

    Science.gov (United States)

    Marmureanu, Gheorghe; Marmureanu, Alexandru; Ortanza Cioflan, Carmen; Manea, Elena-Florinela

    2015-04-01

    Two methods are commonly used for seismic hazard assessment: probabilistic (PSHA) and deterministic(DSHA) seismic hazard analysis.Selection of a ground motion for engineering design requires a clear understanding of seismic hazard and risk among stakeholders, seismologists and engineers. What is wrong with traditional PSHA or DSHA ? PSHA common used in engineering is using four assumptions developed by Cornell in 1968:(1)-Constant-in-time average occurrence rate of earthquakes; (2)-Single point source; (3).Variability of ground motion at a site is independent;(4)-Poisson(or "memory - less") behavior of earthquake occurrences. It is a probabilistic method and "when the causality dies, its place is taken by probability, prestigious term meant to define the inability of us to predict the course of nature"(Nils Bohr). DSHA method was used for the original design of Fukushima Daichii, but Japanese authorities moved to probabilistic assessment methods and the probability of exceeding of the design basis acceleration was expected to be 10-4-10-6 . It was exceeded and it was a violation of the principles of deterministic hazard analysis (ignoring historical events)(Klügel,J,U, EGU,2014, ISSO). PSHA was developed from mathematical statistics and is not based on earthquake science(invalid physical models- point source and Poisson distribution; invalid mathematics; misinterpretation of annual probability of exceeding or return period etc.) and become a pure numerical "creation" (Wang, PAGEOPH.168(2011),11-25). An uncertainty which is a key component for seismic hazard assessment including both PSHA and DSHA is the ground motion attenuation relationship or the so-called ground motion prediction equation (GMPE) which describes a relationship between a ground motion parameter (i.e., PGA,MMI etc.), earthquake magnitude M, source to site distance R, and an uncertainty. So far, no one is taking into consideration strong nonlinear behavior of soils during of strong earthquakes. But

  7. Earthquake Hazard and the Environmental Seismic Intensity (ESI) Scale

    Science.gov (United States)

    Serva, Leonello; Vittori, Eutizio; Comerci, Valerio; Esposito, Eliana; Guerrieri, Luca; Michetti, Alessandro Maria; Mohammadioun, Bagher; Mohammadioun, Georgianna C.; Porfido, Sabina; Tatevossian, Ruben E.

    2016-05-01

    The main objective of this paper was to introduce the Environmental Seismic Intensity scale (ESI), a new scale developed and tested by an interdisciplinary group of scientists (geologists, geophysicists and seismologists) in the frame of the International Union for Quaternary Research (INQUA) activities, to the widest community of earth scientists and engineers dealing with seismic hazard assessment. This scale defines earthquake intensity by taking into consideration the occurrence, size and areal distribution of earthquake environmental effects (EEE), including surface faulting, tectonic uplift and subsidence, landslides, rock falls, liquefaction, ground collapse and tsunami waves. Indeed, EEEs can significantly improve the evaluation of seismic intensity, which still remains a critical parameter for a realistic seismic hazard assessment, allowing to compare historical and modern earthquakes. Moreover, as shown by recent moderate to large earthquakes, geological effects often cause severe damage"; therefore, their consideration in the earthquake risk scenario is crucial for all stakeholders, especially urban planners, geotechnical and structural engineers, hazard analysts, civil protection agencies and insurance companies. The paper describes background and construction principles of the scale and presents some case studies in different continents and tectonic settings to illustrate its relevant benefits. ESI is normally used together with traditional intensity scales, which, unfortunately, tend to saturate in the highest degrees. In this case and in unpopulated areas, ESI offers a unique way for assessing a reliable earthquake intensity. Finally, yet importantly, the ESI scale also provides a very convenient guideline for the survey of EEEs in earthquake-stricken areas, ensuring they are catalogued in a complete and homogeneous manner.

  8. An extended stochastic method for seismic hazard estimation

    Directory of Open Access Journals (Sweden)

    A. K. Abd el-aal

    2015-12-01

    Full Text Available In this contribution, we developed an extended stochastic technique for seismic hazard assessment purposes. This technique depends on the hypothesis of stochastic technique of Boore (2003 "Simulation of ground motion using the stochastic method. Appl. Geophy. 160:635–676". The essential characteristics of extended stochastic technique are to obtain and simulate ground motion in order to minimize future earthquake consequences. The first step of this technique is defining the seismic sources which mostly affect the study area. Then, the maximum expected magnitude is defined for each of these seismic sources. It is followed by estimating the ground motion using an empirical attenuation relationship. Finally, the site amplification is implemented in calculating the peak ground acceleration (PGA at each site of interest. We tested and applied this developed technique at Cairo, Suez, Port Said, Ismailia, Zagazig and Damietta cities to predict the ground motion. Also, it is applied at Cairo, Zagazig and Damietta cities to estimate the maximum peak ground acceleration at actual soil conditions. In addition, 0.5, 1, 5, 10 and 20 % damping median response spectra are estimated using the extended stochastic simulation technique. The calculated highest acceleration values at bedrock conditions are found at Suez city with a value of 44 cm s−2. However, these acceleration values decrease towards the north of the study area to reach 14.1 cm s−2 at Damietta city. This comes in agreement with the results of previous studies of seismic hazards in northern Egypt and is found to be comparable. This work can be used for seismic risk mitigation and earthquake engineering purposes.

  9. Probabilistic seismic hazard assessment in Greece – Part 3: Deaggregation

    Directory of Open Access Journals (Sweden)

    G-A. Tselentis

    2010-01-01

    Full Text Available The present third part of the study, concerning the evaluation of earthquake hazard in Greece in terms of various ground motion parameters, deals with the deaggregation of the obtained results The seismic hazard maps presented for peak ground acceleration and spectral acceleration at 0.2 s and 1.0 s, with 10% probability of exceedance in 50 years, were deaggregated in order to quantify the dominant scenario. There are three basic components of each dominant scenario: earthquake magnitude (M, source-to-site distance (R and epsilon (ε. We present deaggregation maps of mean and mode values of M-R-ε triplet showing the contribution to hazard over a dense grid.

  10. A new probabilistic shift away from seismic hazard reality in Italy?

    CERN Document Server

    Nekrasova, Anastasia; Kossobokov, Volodya; Panza, Giuliano F

    2014-01-01

    Objective testing is a key issue in the process of revision and improvement of seismic hazard assessments. Therefore we continue the rigorous comparative analysis of past and newly available hazard maps for the territory of Italy against the seismic activity observed in reality. The final Global Seismic Hazard Assessment Program (GSHAP) results and the most recent version of Seismic Hazard Harmonization in Europe (SHARE) project maps, along with the reference hazard maps for the Italian seismic code, all obtained by probabilistic seismic hazard assessment (PSHA), are cross-compared to the three ground shaking maps based on the duly physically and mathematically rooted neo-deterministic approach (NDSHA). These eight hazard maps for Italy are tested against the available data on ground shaking. The results of comparison between predicted macroseismic intensities and those reported for past earthquakes (in the time interval from 1000 to 2014 year) show that models provide rather conservative estimates, which ten...

  11. Reassessment of probabilistic seismic hazard in the Marmara region

    Science.gov (United States)

    Kalkan, E.; Gulkan, Polat; Yilmaz, N.; Celebi, M.

    2009-01-01

    In 1999, the eastern coastline of the Marmara region (Turkey) witnessed increased seismic activity on the North Anatolian fault (NAF) system with two damaging earthquakes (M 7.4 Kocaeli and M 7.2 D??zce) that occurred almost three months apart. These events have reduced stress on the western segment of the NAF where it continues under the Marmara Sea. The undersea fault segments have been recently explored using bathymetric and reflection surveys. These recent findings helped scientists to understand the seismotectonic environment of the Marmara basin, which has remained a perplexing tectonic domain. On the basis of collected new data, seismic hazard of the Marmara region is reassessed using a probabilistic approach. Two different earthquake source models: (1) the smoothed-gridded seismicity model and (2) fault model and alternate magnitude-frequency relations, Gutenberg-Richter and characteristic, were used with local and imported ground-motion-prediction equations. Regional exposure is computed and quantified on a set of hazard maps that provide peak horizontal ground acceleration (PGA) and spectral acceleration at 0.2 and 1.0 sec on uniform firm-rock site condition (760 m=sec average shear wave velocity in the upper 30 m). These acceleration levels were computed for ground motions having 2% and 10% probabilities of exceedance in 50 yr, corresponding to return periods of about 2475 and 475 yr, respectively. The maximum PGA computed (at rock site) is 1.5g along the fault segments of the NAF zone extending into the Marmara Sea. The new maps generally show 10% to 15% increase for PGA, 0.2 and 1.0 sec spectral acceleration values across much of Marmara compared to previous regional hazard maps. Hazard curves and smooth design spectra for three site conditions: rock, soil, and soft-soil are provided for the Istanbul metropolitan area as possible tools in future risk estimates.

  12. Seismic hazard assessment over time: Modelling earthquakes in Taiwan

    Science.gov (United States)

    Chan, Chung-Han; Wang, Yu; Wang, Yu-Ju; Lee, Ya-Ting

    2017-04-01

    To assess the seismic hazard with temporal change in Taiwan, we develop a new approach, combining both the Brownian Passage Time (BPT) model and the Coulomb stress change, and implement the seismogenic source parameters by the Taiwan Earthquake Model (TEM). The BPT model was adopted to describe the rupture recurrence intervals of the specific fault sources, together with the time elapsed since the last fault-rupture to derive their long-term rupture probability. We also evaluate the short-term seismicity rate change based on the static Coulomb stress interaction between seismogenic sources. By considering above time-dependent factors, our new combined model suggests an increased long-term seismic hazard in the vicinity of active faults along the western Coastal Plain and the Longitudinal Valley, where active faults have short recurrence intervals and long elapsed time since their last ruptures, and/or short-term elevated hazard levels right after the occurrence of large earthquakes due to the stress triggering effect. The stress enhanced by the February 6th, 2016, Meinong ML 6.6 earthquake also significantly increased rupture probabilities of several neighbouring seismogenic sources in Southwestern Taiwan and raised hazard level in the near future. Our approach draws on the advantage of incorporating long- and short-term models, to provide time-dependent earthquake probability constraints. Our time-dependent model considers more detailed information than any other published models. It thus offers decision-makers and public officials an adequate basis for rapid evaluations of and response to future emergency scenarios such as victim relocation and sheltering.

  13. Probabilistic Seismic Hazard assessment for Sultanate of Oman

    Science.gov (United States)

    El Hussain, I. W.; Deif, A.; El-Hady, S.; Toksoz, M. N.; Al-Jabri, K.; Al-Hashmi, S.; Al-Toubi, K. I.; Al-Shijbi, Y.; Al-Saifi, M.

    2010-12-01

    Seismic hazard assessment for Oman is conducted utilizing probabilistic approach. Probabilistic Seismic Hazard Assessment (PSHA) has been performed within a logic tree framework. An earthquake catalogue for Oman was compiled and declustered to include only independent earthquakes. The declustered catalogue was used to define seismotectonic source model with 26 source zones that characterize earthquakes in the tectonic environments in and around Oman. The recurrence parameters for all the seismogenic zones are determined using the doubly bounded exponential distribution except the seismogenic zones of Makran subduction zone which were modeled using the characteristic distribution. The maximum earthquakes on known faults were determined geologically and the remaining zones were determined statistically from the compiled catalogue. Horizontal ground accelerations in terms of geometric mean were calculated using ground-motion prediction relationships that were developed from seismic data obtained from the shallow active environment, stable craton environment, and from subduction earthquakes. In this analysis, we have used alternative seismotectonic source models, maximum magnitude, and attenuation models and weighted them to account for the epistemic uncertainty. The application of this methodology leads to the definition of 5% damped seismic hazard maps at rock sites for 72, 475, and 2475 year return periods for spectral accelerations at periods of 0.0 (corresponding to peak ground acceleration), 0.1, 0.2, 0.3, 1.0 and 2.0 sec. Mean and 84th percentile acceleration contour maps were represented. The results also were displayed as uniform hazard spectra for rock sites in the cities of Khasab, Diba, Sohar, Muscat, Nizwa, Sur, and Salalah in Oman and the cities of Abu Dhabi and Dubai in UAE. The PGA across Oman ranges from 20 cm/sec2 in the Mid-West and 115 cm/sec2 at the northern part for 475 years return period and between 40 cm/sec2 and 180 cm/sec2 for 2475 years

  14. Seismic hazard assessment of Chennai city considering local site effects

    Indian Academy of Sciences (India)

    A Boominathan; G R Dodagoudar; A Suganthi; R Uma Maheswari

    2008-11-01

    Chennai city suffered moderate tremors during the 2001 Bhuj and Pondicherry earthquakes and the 2004 Sumatra earthquake. After the Bhuj earthquake, Indian Standard IS: 1893 was revised and Chennai city was upgraded from zone II to zone III which leads to a substantial increase of the design ground motion parameters. Therefore, a comprehensive study is carried out to assess the seismic hazard of Chennai city based on a deterministic approach. The seismicity and seismotectonic details within a 100 km radius of the study area have been considered. The one-dimensional ground response analysis was carried out for 38 representative sites by the equivalent linear method using the SHAKE91 program to estimate the ground motion parameters considering the local site effects. The shear wave velocity profile was inferred from the corrected blow counts and it was verified with the Multichannel Analysis of Surface Wave (MASW) test performed for a representative site. The seismic hazard is represented in terms of characteristic site period and Spectral Acceleration Ratio (SAR) contours for the entire city. It is found that structures with low natural period undergo significant amplification mostly in the central and southern parts of Chennai city due to the presence of deep soil sites with clayey or sandy deposits and the remaining parts undergo marginal amplification.

  15. Seismic hazard assessment of Chennai city considering local site effects

    Science.gov (United States)

    Boominathan, A.; Dodagoudar, G. R.; Suganthi, A.; Uma Maheswari, R.

    2008-11-01

    Chennai city suffered moderate tremors during the 2001 Bhuj and Pondicherry earthquakes and the 2004 Sumatra earthquake. After the Bhuj earthquake, Indian Standard IS: 1893 was revised and Chennai city was upgraded from zone II to zone III which leads to a substantial increase of the design ground motion parameters. Therefore, a comprehensive study is carried out to assess the seismic hazard of Chennai city based on a deterministic approach. The seismicity and seismotectonic details within a 100 km radius of the study area have been considered. The one-dimensional ground response analysis was carried out for 38 representative sites by the equivalent linear method using the SHAKE91 program to estimate the ground motion parameters considering the local site effects. The shear wave velocity profile was inferred from the corrected blow counts and it was verified with the Multichannel Analysis of Surface Wave (MASW) test performed for a representative site. The seismic hazard is represented in terms of characteristic site period and Spectral Acceleration Ratio (SAR) contours for the entire city. It is found that structures with low natural period undergo significant amplification mostly in the central and southern parts of Chennai city due to the presence of deep soil sites with clayey or sandy deposits and the remaining parts undergo marginal amplification.

  16. Treatment of kappa in Recent Western US Seismic Nuclear Plant Probabilistic Seismic Hazard Studies

    Science.gov (United States)

    Toro, G. R.; Di Alessandro, C.; Al Atik, L.

    2015-12-01

    The three operating nuclear plants (Diablo Canyon, Palo Verde, and Columbia Generating Station) in the western United States recently performed SSHAC Level 3 seismic hazard studies in response to a Request for Information by the Nuclear Regulatory Commission, following the accident at the Fukushima Dai-ichi nuclear facility. The treatment of zero-distance kappa, referred to as kappa_0 and commonly attributed to material damping and scattering in the shallow crust, was given extensive consideration in these studies. Available ground motion prediction equations (GMPEs) do not typically include kappa_0 as a prediction parameter and are developed for an average kappa_0 of the host region. Kappa scaling is routinely applied to adjust for the differences in average kappa between the GMPEs host regions and the target regions. The impact of kappa scaling on the results of probabilistic seismic hazard analyses is significant for nuclear and other facilities that are sensitive to high frequency ground motions (frequencies greater than about 10 Hz). There are several available approaches for deriving kappa scaling factors to GMPEs, which all require estimating kappa_0 at the target site. It is difficult to constrain the target kappa_0 empirically due to the scarcity of ground-motion data from hard-rock sites in ground-motion databases.The hazard studies for the three nuclear power plants had different data, faced different challenges in the estimation of kappa_0, and used different methods for the estimation of the effect of kappa_0 on the site-specific ground motions. This presentation summarizes the approaches used for the evaluation of kappa_0 and for their incorporation in the probabilistic seismic hazard analysis. Emphasis is given to the quantification of the kappa_0 uncertainty, and on the evaluation of its impact to the resulting seismic hazard at the different sites.

  17. Probabilistic Seismic Hazard Assessment for a NPP in the Upper Rhine Graben, France

    Science.gov (United States)

    Clément, Christophe; Chartier, Thomas; Jomard, Hervé; Baize, Stéphane; Scotti, Oona; Cushing, Edward

    2015-04-01

    The southern part of the Upper Rhine Graben (URG) straddling the border between eastern France and western Germany, presents a relatively important seismic activity for an intraplate area. A magnitude 5 or greater shakes the URG every 25 years and in 1356 a magnitude greater than 6.5 struck the city of Basel. Several potentially active faults have been identified in the area and documented in the French Active Fault Database (web site in construction). These faults are located along the Graben boundaries and also inside the Graben itself, beneath heavily populated areas and critical facilities (including the Fessenheim Nuclear Power Plant). These faults are prone to produce earthquakes with magnitude 6 and above. Published regional models and preliminary geomorphological investigations provided provisional assessment of slip rates for the individual faults (0.1-0.001 mm/a) resulting in recurrence time of 10 000 years or greater for magnitude 6+ earthquakes. Using a fault model, ground motion response spectra are calculated for annual frequencies of exceedance (AFE) ranging from 10-4 to 10-8 per year, typical for design basis and probabilistic safety analyses of NPPs. A logic tree is implemented to evaluate uncertainties in seismic hazard assessment. The choice of ground motion prediction equations (GMPEs) and range of slip rate uncertainty are the main sources of seismic hazard variability at the NPP site. In fact, the hazard for AFE lower than 10-4 is mostly controlled by the potentially active nearby Rhine River fault. Compared with areal source zone models, a fault model localizes the hazard around the active faults and changes the shape of the Uniform Hazard Spectrum at the site. Seismic hazard deaggregations are performed to identify the earthquake scenarios (including magnitude, distance and the number of standard deviations from the median ground motion as predicted by GMPEs) that contribute to the exceedance of spectral acceleration for the different AFE

  18. Digging Our Own Holes: Institutional Perspectives on Seismic Hazards

    Science.gov (United States)

    Stein, S.; Tomasello, J.

    2005-12-01

    It has been observed that there are no true students of the earth; instead, we each dig our own holes and sit in them. A similar situation arises in attempts to assess the hazards of earthquakes and other natural disasters and to develop strategies to mitigate them. Ideally, we would like to look at the interests of society as a whole and develop strategies that best balance hazard mitigation with alternative uses of resources. Doing so, however, is difficult for several reasons. First, estimating seismic hazards requires assumptions about the size, recurrence, and shaking from future earthquakes, none of which are well known. Second, we have to chose a definition of seismic hazard, which is even more arbitrary and at least as significant about future earthquakes. Third, mitigating the risks involves economic and policy issues as well as the scientific one of estimating the hazard itself and the engineering one of designing safe structures. As a result, different public and private organizations with different institutional perspectives naturally adopt different approaches. Most organizations have a single focus. For example, those focusing on economic development tend to discount hazards, whereas emergency management groups tend to accentuate them. Organizations with quasi-regulatory duties (BSSC, FEMA, USGS) focus on reducing losses in future earthquakes without considering the cost of mitigation measures or how this use of resources should be balanced with alternative uses of resources that could mitigate other losses. Some organizations, however, must confront these tradeoffs directly because they allocate resources internally. Hence hospitals implicitly trade off more earthquake resistant construction with treating uninsured patients, highway departments balance stronger bridges with other safety improvements, and schools balance safer buildings with after school programs. These choices are complicated by the fact that such infrastructure typically has longer

  19. CPT site characterization for seismic hazards in the New Madrid seismic zone

    Science.gov (United States)

    Liao, T.; Mayne, P.W.; Tuttle, M.P.; Schweig, E.S.; Van Arsdale, R.B.

    2002-01-01

    A series of cone penetration tests (CPTs) were conducted in the vicinity of the New Madrid seismic zone in central USA for quantifying seismic hazards, obtaining geotechnical soil properties, and conducting studies at liquefaction sites related to the 1811-1812 and prehistoric New Madrid earthquakes. The seismic piezocone provides four independent measurements for delineating the stratigraphy, liquefaction potential, and site amplification parameters. At the same location, two independent assessments of soil liquefaction susceptibility can be made using both the normalized tip resistance (qc1N) and shear wave velocity (Vs1). In lieu of traditional deterministic approaches, the CPT data can be processed using probability curves to assess the level and likelihood of future liquefaction occurrence. ?? 2002 Elsevier Science Ltd. All rights reserved.

  20. Probabilistic properties of injection induced seismicity - implications for the seismic hazard analysis

    Science.gov (United States)

    Lasocki, Stanislaw; Urban, Pawel; Kwiatek, Grzegorz; Martinez-Garzón, Particia

    2017-04-01

    Injection induced seismicity (IIS) is an undesired dynamic rockmass response to massive fluid injections. This includes reactions, among others, to hydro-fracturing for shale gas exploitation. Complexity and changeability of technological factors that induce IIS, may result in significant deviations of the observed distributions of seismic process parameters from the models, which perform well in natural, tectonic seismic processes. Classic formulations of probabilistic seismic hazard analysis in natural seismicity assume the seismic marked point process to be a stationary Poisson process, whose marks - magnitudes are governed by a Gutenberg-Richter born exponential distribution. It is well known that the use of an inappropriate earthquake occurrence model and/or an inappropriate of magnitude distribution model leads to significant systematic errors of hazard estimates. It is therefore of paramount importance to check whether the mentioned, commonly used in natural seismicity assumptions on the seismic process, can be safely used in IIS hazard problems or not. Seismicity accompanying shale gas operations is widely studied in the framework of the project "Shale Gas Exploration and Exploitation Induced Risks" (SHEER). Here we present results of SHEER project investigations of such seismicity from Oklahoma and of a proxy of such seismicity - IIS data from The Geysers geothermal field. We attempt to answer to the following questions: • Do IIS earthquakes follow the Gutenberg-Richter distribution law, so that the magnitude distribution can be modelled by an exponential distribution? • Is the occurrence process of IIS earthquakes Poissonian? Is it segmentally Poissonian? If yes, how are these segments linked to cycles of technological operations? Statistical tests indicate that the Gutenberg-Richter relation born exponential distribution model for magnitude is, in general, inappropriate. The magnitude distribution can be complex, multimodal, with no ready

  1. Seismic Hazard Legislation in California: Challenges and Changes

    Science.gov (United States)

    Testa, S. M.

    2015-12-01

    Seismic hazards in California are legislatively controlled by three specific Acts: the Field Act of 1933; the Alquist-Priolo Earthquake Fault Zoning Act (AP) of 1975; and the Seismic Hazards Mapping Act (SHMA) of 1980. The Field Act recognized the need for earthquake resistant construction for California schools and banned unreinforced masonry buildings, and imposed structural design under seismic conditions. The AP requires the California Geological Survey (CGS) to delineate "active fault zones" for general planning and mitigation by various state and local agencies. Under the AP, surface and near-surface faults are presumed active (about 11,000 years before present) unless proven otherwise; and can only be mitigated by avoidance (setback zones). The SHMA requires that earthquake-induced landslides, liquefaction zones, high ground accelerations, tsunamis and seiches similarly be demarcated on CGS-issued maps. Experience over the past ~45 years and related technological advances now show that more than ~95 percent of seismically induced damage and loss of life stems from high ground accelerations, from related ground deformation and from catastrophic structural failure, often far beyond State-mapped AP zones. The SHMA therefore enables the engineering community to mitigate natural hazards from a holistic standpoint that considers protection of public health, safety and welfare. In conformance with the SHMA, structural design and related planning and building codes focus on acceptable risk for natural hazards with a typical recurrence of ~100 yrs to a few thousand years. This contrasts with the current AP "total avoidance" for surface-fault rupture that may have occurred within the last 11,000 years. Accordingly, avoidance may be reasonable for well expressed surface faults in high-density urban areas or where relative fault activity is uncertain. However, in the interest of overall public, health and safety, and for consistency with the SHMA and current

  2. Reducing Seismic Hazard and Building Capacity Through International Cooperation

    Science.gov (United States)

    Vergino, E. S.; Arakelyan, A.; Babayan, H.; Durgaryan, R.; Elashvili, M.; Godoladze, T.; Javakhishvili, Z.; Kalogeras, I.; Karakhanyan, A.; Martin, R. J.; Yetirmishli, G.

    2012-12-01

    During the last 50 years, the Caucasus, Central Asia and the Caspian Sea regions have experienced several devastating earthquakes. While each country in the region has worked with its neighbors on small, ad-hoc projects to improve preparedness, deeply ingrained political and ethnic rivalries, and severely stressed economies have severely hindered sustained regional cooperation. Future damaging earthquakes are inevitable and without proper planning the negative impact on public safety, security, economics and stability in these regions will be devastating. We have, through twelve years of international scientific cooperation, focused on the development of an expanded skill base and infrastructure, through the installation of new, modern, digital seismic monitoring networks, building of historic databases, sharing seismic, geologic and geophysical data, conducting joint scientific investigations utilizing the new digital data and applying modern techniques, as well as the development of regional hazard models that the scientists of the region share with their governments and use to advise them on the best ways to mitigate the impact of a damaging earthquake. We have established specialized regional scientific task-force teams who can carry out seismological, geological and engineering studies in the epicentral zone, including the collection of new scientific data, for better understanding of seismic and geodynamic processes as well to provide emergency support in crisis and post-crisis situations in the Southern Caucasus countries. "Secrecy" in crisis and post-crisis situations in the former Soviet Union countries, as well as political instabilities, led to an absence of seismic risk reduction and prevention measures as well as little to no training of scientific-technical personnel who could take action in emergency situations. There were few opportunities for the development of a next generation of scientific experts, thus we have placed emphasis on the inclusion

  3. Seismic fragility analysis of a nuclear building based on probabilistic seismic hazard assessment and soil-structure interaction analysis

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, R.; Ni, S.; Chen, R.; Han, X.M. [CANDU Energy Inc, Mississauga, Ontario (Canada); Mullin, D. [New Brunswick Power, Point Lepreau, New Brunswick (Canada)

    2016-09-15

    Seismic fragility analyses are conducted as part of seismic probabilistic safety assessment (SPSA) for nuclear facilities. Probabilistic seismic hazard assessment (PSHA) has been undertaken for a nuclear power plant in eastern Canada. Uniform Hazard Spectra (UHS), obtained from the PSHA, is characterized by high frequency content which differs from the original plant design basis earthquake spectral shape. Seismic fragility calculations for the service building of a CANDU 6 nuclear power plant suggests that the high frequency effects of the UHS can be mitigated through site response analysis with site specific geological conditions and state-of-the-art soil-structure interaction analysis. In this paper, it is shown that by performing a detailed seismic analysis using the latest technology, the conservatism embedded in the original seismic design can be quantified and the seismic capacity of the building in terms of High Confidence of Low Probability of Failure (HCLPF) can be improved. (author)

  4. On the adaptive daily forecasting of seismic aftershock hazard

    Science.gov (United States)

    Ebrahimian, Hossein; Jalayer, Fatemeh; Asprone, Domenico; Lombardi, Anna Maria; Marzocchi, Warner; Prota, Andrea; Manfredi, Gaetano

    2013-04-01

    Post-earthquake ground motion hazard assessment is a fundamental initial step towards time-dependent seismic risk assessment for buildings in a post main-shock environment. Therefore, operative forecasting of seismic aftershock hazard forms a viable support basis for decision-making regarding search and rescue, inspection, repair, and re-occupation in a post main-shock environment. Arguably, an adaptive procedure for integrating the aftershock occurrence rate together with suitable ground motion prediction relations is key to Probabilistic Seismic Aftershock Hazard Assessment (PSAHA). In the short-term, the seismic hazard may vary significantly (Jordan et al., 2011), particularly after the occurrence of a high magnitude earthquake. Hence, PSAHA requires a reliable model that is able to track the time evolution of the earthquake occurrence rates together with suitable ground motion prediction relations. This work focuses on providing adaptive daily forecasts of the mean daily rate of exceeding various spectral acceleration values (the aftershock hazard). Two well-established earthquake occurrence models suitable for daily seismicity forecasts associated with the evolution of an aftershock sequence, namely, the modified Omori's aftershock model and the Epidemic Type Aftershock Sequence (ETAS) are adopted. The parameters of the modified Omori model are updated on a daily basis using Bayesian updating and based on the data provided by the ongoing aftershock sequence based on the methodology originally proposed by Jalayer et al. (2011). The Bayesian updating is used also to provide sequence-based parameter estimates for a given ground motion prediction model, i.e. the aftershock events in an ongoing sequence are exploited in order to update in an adaptive manner the parameters of an existing ground motion prediction model. As a numerical example, the mean daily rates of exceeding specific spectral acceleration values are estimated adaptively for the L'Aquila 2009

  5. Probabilistic seismic hazard estimates incorporating site effects - An example from Indiana, U.S.A

    Science.gov (United States)

    Hasse, J.S.; Park, C.H.; Nowack, R.L.; Hill, J.R.

    2010-01-01

    The U.S. Geological Survey (USGS) has published probabilistic earthquake hazard maps for the United States based on current knowledge of past earthquake activity and geological constraints on earthquake potential. These maps for the central and eastern United States assume standard site conditions with Swave velocities of 760 m/s in the top 30 m. For urban and infrastructure planning and long-term budgeting, the public is interested in similar probabilistic seismic hazard maps that take into account near-surface geological materials. We have implemented a probabilistic method for incorporating site effects into the USGS seismic hazard analysis that takes into account the first-order effects of the surface geologic conditions. The thicknesses of sediments, which play a large role in amplification, were derived from a P-wave refraction database with over 13, 000 profiles, and a preliminary geology-based velocity model was constructed from available information on S-wave velocities. An interesting feature of the preliminary hazard maps incorporating site effects is the approximate factor of two increases in the 1-Hz spectral acceleration with 2 percent probability of exceedance in 50 years for parts of the greater Indianapolis metropolitan region and surrounding parts of central Indiana. This effect is primarily due to the relatively thick sequence of sediments infilling ancient bedrock topography that has been deposited since the Pleistocene Epoch. As expected, the Late Pleistocene and Holocene depositional systems of the Wabash and Ohio Rivers produce additional amplification in the southwestern part of Indiana. Ground motions decrease, as would be expected, toward the bedrock units in south-central Indiana, where motions are significantly lower than the values on the USGS maps.

  6. Seismic and tsunami hazard in Puerto Rico and the Virgin Islands

    Science.gov (United States)

    Dillon, William P.; Frankel, Arthur D.; Mueller, Charles S.; Rodriguez, Rafael W.; Ten Brink, Uri

    1999-01-01

    first day of the workshop, participants from universities, federal institutions, and consulting firms in Puerto Rico, the Virgin Islands, the continental U.S., Dominican Republic, and Europe reviewed the present state of knowledge including a review and discussion of present plate models, recent GPS and seismic reflection data, seismicity, paleoseismology, and tsunamis. The state of earthquake/tsunami studies in Puerto Rico was presented by several faculty members from the University of Puerto Rico at Mayaguez. A preliminary seismic hazard map was presented by the USGS and previous hazard maps and economic loss assessments were considered. During the second day, the participants divided into working groups and prepared specific recommendations for future activities in the region along the six following topics below. Highlights of these recommended activities are:Marine geology and geophysics – Acquire deep-penetration seismic reflection and refraction data, deploy temporary ocean bottom seismometer arrays to record earthquakes, collect high-resolution multibeam bathymetry and side scan sonar data of the region, and in particular, the near shore region, and conduct focussed high-resolution seismic studies around faults. Determine slip rates of specific offshore faults. Assemble a GIS database for available marine geological and geophysical data.Paleoseismology and active faults - Field reconnaissance aimed at identifying Quaternary faults and determining their paleoseismic chronology and slip rates, as well as identifying and dating paleoliquefaction features from large earthquakes. Quaternary mapping of marine terraces, fluvial terraces and basins, beach ridges, etc., to establish framework for understanding neotectonic deformation of the island. Interpretation of aerial photography to identify possible Quaternary faults.Earthquake seismology – Determine an empirical seismic attenuation function using observations from local seismic networks and recently

  7. A New Probabilistic Seismic Hazard for mainland Spain. Main differences with the Building Code Hazard Map

    Science.gov (United States)

    Mezcua, J.; Rueda, J.; Garcia Blanco, R.

    2009-05-01

    A probabilistic seismic hazard analysis (PSHA) for mainland Spain that takes into account recent new results in seismicity, seismic zoning and strong ground attenuation no considered in the previous PSHAs studies published is presented. Those new input data has been obtained by us as a three steep project carried out in order to get a new hazard map for mainland Spain. We have used a new earthquake catalogue obtained for the area in which the earthquakes are given in moment magnitude through specific deduced relationships for our territory based on intensity data, Mezcua et al. (2004). Beside that, we also include a new seismogenetic zoning based in the recent partial zoning studies performed by different authors. Finally we have developed a new strong ground motion relationship for the area, Mezcua et al. (2008). With this new data a logic tree process has been defined to quantify the epistemic uncertainty related with those parts of the process. Finally, after a weighting scheme a mean hazard map for PGA on rock type condition for 10 % exceendence probability in 50 years is presented. In order to investigate main differences with the official hazard map from the Building Code we performed from one side the map of differences and also a map of impact expressed in % of the values obtained in relation with the presented in the official map. Main differences are in both directions: an overestimation (0.04g) of the official hazard map in those areas corresponding with the greatest PGA values corresponding to the south and southeastern part of the country due to the use of local attenuation relations and an underestimation for the rest of the country with a maximum of the order of 0.06g close to the maximum of the map in southern Spain.

  8. A method for producing digital probabilistic seismic landslide hazard maps

    Science.gov (United States)

    Jibson, R.W.; Harp, E.L.; Michael, J.A.

    2000-01-01

    The 1994 Northridge, California, earthquake is the first earthquake for which we have all of the data sets needed to conduct a rigorous regional analysis of seismic slope instability. These data sets include: (1) a comprehensive inventory of triggered landslides, (2) about 200 strong-motion records of the mainshock, (3) 1:24 000-scale geologic mapping of the region, (4) extensive data on engineering properties of geologic units, and (5) high-resolution digital elevation models of the topography. All of these data sets have been digitized and rasterized at 10 m grid spacing using ARC/INFO GIS software on a UNIX computer. Combining these data sets in a dynamic model based on Newmark's permanent-deformation (sliding-block) analysis yields estimates of coseismic landslide displacement in each grid cell from the Northridge earthquake. The modeled displacements are then compared with the digital inventory of landslides triggered by the Northridge earthquake to construct a probability curve relating predicted displacement to probability of failure. This probability function can be applied to predict and map the spatial variability in failure probability in any ground-shaking conditions of interest. We anticipate that this mapping procedure will be used to construct seismic landslide hazard maps that will assist in emergency preparedness planning and in making rational decisions regarding development and construction in areas susceptible to seismic slope failure. ?? 2000 Elsevier Science B.V. All rights reserved.

  9. Probabilistic seismic hazard assessment based on seismic potential of active faults: Example from northern Algeria

    Science.gov (United States)

    Bouhadad, Youcef

    2017-04-01

    Northern Algeria is an interplate area where the African and the Eurasian tectonic plates are converging in the NW-SE direction. Therefore, earthquakes are not distributed randomly but directly related to the activity of active faults. The seismotectonic conditions of occurrence of strong damaging earthquakes in the area are well understood following the numerous detailed studies that followed the El-Asnam October 10th , 1980 earthquake (Ms=7.3) and the Zemmouri May 1st , 2003 (Mw=6.8) earthquake. The potentially active structures consist of active folds or asymmetrical folds underlined by thrust faults. Some of the faults are blind as revealed by the Chenoua 29th , 1989 (Ms=6.0) and the Ain Temouchent 1999 (Ms=5.6) earthquakes. We applied the probabilistic approach to assess seismic hazard in the area of Mostaganem, western Algeria. The following steps are performed (i) Seismic sources are identified on the basis of field geological/geophysical investigations,(ii) Source parameters such as b-values, slip rate and maximum magnitude are assessed for each seismic source, and then given a weight in the framework of a logic tree model, (iii) Attenuation relations which fit Algerian strong motion records are used, (iv) Results are presented as annual frequencies of exceedance versus peak ground acceleration (PGA) as well as maps of hazard for different return periods. Finally, we quantified and discussed the scientific uncertainties related to the state of knowledge and the used alternative models and values. Keywords: seismic hazard- active faults- probabilistic approach- uncertainties-Algeria

  10. Comparison between seismic and domestic risk in moderate seismic hazard prone region: the Grenoble City (France test site

    Directory of Open Access Journals (Sweden)

    F. Dunand

    2012-02-01

    Full Text Available France has a moderate level of seismic activity, characterized by diffuse seismicity, sometimes experiencing earthquakes of a magnitude of more than 5 in the most active zones. In this seismicity context, Grenoble is a city of major economic and social importance. However, earthquakes being rare, public authorities and the decision makers are only vaguely committed to reducing seismic risk: return periods are long and local policy makers do not have much information available. Over the past 25 yr, a large number of studies have been conducted to improve our knowledge of seismic hazard in this region. One of the decision-making concerns of Grenoble's public authorities, as managers of a large number of public buildings, is to know not only the seismic-prone regions, the variability of seismic hazard due to site effects and the city's overall vulnerability, but also the level of seismic risk and exposure for the entire city, also compared to other natural or/and domestic hazards. Our seismic risk analysis uses a probabilistic approach for regional and local hazards and the vulnerability assessment of buildings. Its applicability to Grenoble offers the advantage of being based on knowledge acquired by previous projects conducted over the years. This paper aims to compare the level of seismic risk with that of other risks and to introduce the notion of risk acceptability in order to offer guidance in the management of seismic risk. This notion of acceptability, which is now part of seismic risk consideration for existing buildings in Switzerland, is relevant in moderately seismic-prone countries like France.

  11. Probabilistic Seismic Hazard Analysis of Injection-Induced Seismicity Utilizing Physics-Based Simulation

    Science.gov (United States)

    Johnson, S.; Foxall, W.; Savy, J. B.; Hutchings, L. J.

    2012-12-01

    Risk associated with induced seismicity is a significant factor in the design, permitting and operation of enhanced geothermal, geological CO2 sequestration, wastewater disposal, and other fluid injection projects. The conventional probabilistic seismic hazard analysis (PSHA) approach provides a framework for estimation of induced seismicity hazard but requires adaptation to address the particular occurrence characteristics of induced earthquakes and to estimation of the ground motions they generate. The assumption often made in conventional PSHA of Poissonian earthquake occurrence in both space and time is clearly violated by seismicity induced by an evolving pore pressure field. Our project focuses on analyzing hazard at the pre-injection design and permitting stage, before an induced earthquake catalog can be recorded. In order to accommodate the commensurate lack of pre-existing data, we have adopted a numerical physics-based approach to synthesizing and estimating earthquake frequency-magnitude distributions. Induced earthquake sequences are generated using the program RSQSIM (Dieterich and Richards-Dinger, PAGEOPH, 2010) augmented to simulate pressure-induced shear failure on faults and fractures embedded in a 3D geological structure under steady-state tectonic shear loading. The model uses available site-specific data on rock properties and in-situ stress, and generic values of frictional properties appropriate to the shallow reservoir depths at which induced events usually occur. The space- and time-evolving pore pressure field is coupled into the simulation from a multi-phase flow model. In addition to potentially damaging ground motions, induced seismicity poses a risk of perceived nuisance in nearby communities caused by relatively frequent, low magnitude earthquakes. Including these shallow local earthquakes in the hazard analysis requires extending the magnitude range considered to as low as M2 and the frequency band to include the short

  12. CRISIS2012: An Updated Tool to Compute Seismic Hazard

    Science.gov (United States)

    Ordaz, M.; Martinelli, F.; Meletti, C.; D'Amico, V.

    2013-05-01

    CRISIS is a computer tool for probabilistic seismic hazard analysis (PSHA), whose development started in the late 1980's at the Instituto de Ingeniería, UNAM, Mexico. It started circulating outside the Mexican borders at the beginning of the 1990's, when it was first distributed as part of SEISAN tools. Throughout the years, CRISIS has been used for seismic hazard studies in several countries in Latin America (Mexico, Guatemala, Belize, El Salvador, Honduras, Nicaragua, Costa Rica, Panama, Colombia, Venezuela, Ecuador, Peru, Argentina and Chile), and in many other countries of the World. CRISIS has always circulated free of charge for non-commercial applications. It is worth noting that CRISIS has been mainly written by people that are, at the same time, PSHA practitioners. Therefore, the development loop has been relatively short, and most of the modifications and improvements have been made to satisfy the needs of the developers themselves. CRISIS has evolved from a rather simple FORTRAN code to a relatively complex program with a friendly graphical interface, able to handle a variety of modeling possibilities for source geometries, seismicity descriptions and ground motion prediction models (GMPM). We will describe some of the improvements made for the newest version of the code: CRISIS 2012.These improvements, some of which were made in the frame of the Italian research project INGV-DPC S2 (http://nuovoprogettoesse2.stru.polimi.it/), funded by the Dipartimento della Protezione Civile (DPC; National Civil Protection Department), include: A wider variety of source geometries A wider variety of seismicity models, including the ability to handle non-Poissonian occurrence models and Poissonian smoothed-seismicity descriptions. Enhanced capabilities for using different kinds of GMPM: attenuation tables, built-in models and generalized attenuation models. In the case of built-in models, there is, by default, a set ready to use in CRISIS, but additional custom GMPMs

  13. Updating the Seismic Hazard Determination in southeastern Brazil

    Science.gov (United States)

    Franca, G. S.; Algarte, K. T.

    2012-12-01

    This job presents an update of research by Berrocal in 1996 in the determination of seismic hazard for the Southeast of Brazil, based on the earthquake catalog compiled at the Instituto de Astronomia e Geofisica, Universidade de Sao Paulo and bulletin of Seismological Observatory, Universidade de Brasilia, during the period between 1767 until May 2012. The southeastern Brazil has a level of seismic activity is considered low, typical of intraplate regions. Our database has a total of 3726 events, however 1242 events do not have the magnitude estimated, 1638 events are between magnitudes 0.1 to 1.9 and from 2.0 to 3.9 are 819 events. The largest earthquake in the region occurred on February 28, 1955 with magnitude 6.1 mb (Assumpção, 2000), with its epicenter about 400 km from the coast, this was felt in small cities, especially in Espirito Santo State. The intensity VIII-IX MM was estimated by Berrocal et al. (1984). The database also has four events with magnitude above 5.0 mb in the region that occurred during the past 215 years and a little more than a twenty earthquakes with magnitude between 4.0 and 5.0 mb. Instrumental data are available since the 1970s when the station network was installed in Brasilia. Several other short-period vertical stations have been installed in the region. We used data from the same area defined in the previous survey, located between parallels 15S-32S degree and longitudes 35W-52W degree. It contains the most developed area of Brazil, and the major cities and industrial centers of the country (São Paulo, Rio de Janeiro and Belo Horizonte). Major engineering works, hydroelectric and nuclear power plant (Angra dos Reis) are also in this area. Therefore, the results can be applied to the planning and construction of large engineering within that region. With GIS and seismology tools was calculated relative frequency/magnitude for earthquakes mb > 3.0, the value of b with the maximum likelihood method, and so curves of recurrence was

  14. Considering potential seismic sources in earthquake hazard assessment for Northern Iran

    Science.gov (United States)

    Abdollahzadeh, Gholamreza; Sazjini, Mohammad; Shahaky, Mohsen; Tajrishi, Fatemeh Zahedi; Khanmohammadi, Leila

    2014-07-01

    Located on the Alpine-Himalayan earthquake belt, Iran is one of the seismically active regions of the world. Northern Iran, south of Caspian Basin, a hazardous subduction zone, is a densely populated and developing area of the country. Historical and instrumental documented seismicity indicates the occurrence of severe earthquakes leading to many deaths and large losses in the region. With growth of seismological and tectonic data, updated seismic hazard assessment is a worthwhile issue in emergency management programs and long-term developing plans in urban and rural areas of this region. In the present study, being armed with up-to-date information required for seismic hazard assessment including geological data and active tectonic setting for thorough investigation of the active and potential seismogenic sources, and historical and instrumental events for compiling the earthquake catalogue, probabilistic seismic hazard assessment is carried out for the region using three recent ground motion prediction equations. The logic tree method is utilized to capture epistemic uncertainty of the seismic hazard assessment in delineation of the seismic sources and selection of attenuation relations. The results are compared to a recent practice in code-prescribed seismic hazard of the region and are discussed in detail to explore their variation in each branch of logic tree approach. Also, seismic hazard maps of peak ground acceleration in rock site for 475- and 2,475-year return periods are provided for the region.

  15. Evaluation of seismic design spectrum based on UHS implementing fourth-generation seismic hazard maps of Canada

    Science.gov (United States)

    Ahmed, Ali; Hasan, Rafiq; Pekau, Oscar A.

    2016-12-01

    Two recent developments have come into the forefront with reference to updating the seismic design provisions for codes: (1) publication of new seismic hazard maps for Canada by the Geological Survey of Canada, and (2) emergence of the concept of new spectral format outdating the conventional standardized spectral format. The fourth -generation seismic hazard maps are based on enriched seismic data, enhanced knowledge of regional seismicity and improved seismic hazard modeling techniques. Therefore, the new maps are more accurate and need to incorporate into the Canadian Highway Bridge Design Code (CHBDC) for its next edition similar to its building counterpart National Building Code of Canada (NBCC). In fact, the code writers expressed similar intentions with comments in the commentary of CHBCD 2006. During the process of updating codes, NBCC, and AASHTO Guide Specifications for LRFD Seismic Bridge Design, American Association of State Highway and Transportation Officials, Washington (2009) lowered the probability level from 10 to 2% and 10 to 5%, respectively. This study has brought five sets of hazard maps corresponding to 2%, 5% and 10% probability of exceedance in 50 years developed by the GSC under investigation. To have a sound statistical inference, 389 Canadian cities are selected. This study shows the implications of the changes of new hazard maps on the design process (i.e., extent of magnification or reduction of the design forces).

  16. Preliminary seismic microzonation of Sivas city (Turkey) using microtremor and refraction microtremor (ReMi) measurements

    Science.gov (United States)

    Büyüksaraç, Aydın; Bektaş, Özcan; Yılmaz, Hüseyin; Arısoy, M. Özgü

    2013-04-01

    Sivas city, located in the inner east part of Anatolia (Turkey), is far from seismic sources. However, the city is under risk owing to strong earthquakes occurring around the area, and different soil conditions that can produce variation in the ground motion amplification. Microzonation of cities provides a basis for site-specific hazard analysis in urban settlements. In particular, seismic microzonation can be achieved by means of detailed seismic assessment of the area, including earthquake recordings and geological studies. In this paper, we propose a preliminary microzonation map for the city of Sivas, based on the variation in the dominant periods of the sediments covering the area. The periods are retrieved from microtremor measurements conducted at 114 sites, using the horizontal-to-vertical spectral ratio technique. The results of microtremor analysis were compared with those obtained from refraction microtremor measurements at two profiles crossing the studied area. According to the classification of dominant periods, Sivas area can be divided into four zones, probably prone to different levels of seismic hazard. However, specific studies including analysis of weak earthquakes are required in the future to validate our microzonation map.

  17. Seismic hazard of the Kivu rift (western branch, East African Rift system): new neotectonic map and seismotectonic zonation model

    Science.gov (United States)

    Delvaux, Damien; Mulumba, Jean-Luc; Sebagenzi Mwene Ntabwoba, Stanislas; Fiama Bondo, Silvanos; Kervyn, François; Havenith, Hans-Balder

    2017-04-01

    The first detailed probabilistic seismic hazard assessment has been performed for the Kivu and northern Tanganyika rift region in Central Africa. This region, which forms the central part of the Western Rift Branch, is one of the most seismically active part of the East African rift system. It was already integrated in large scale seismic hazard assessments, but here we defined a finer zonation model with 7 different zones representing the lateral variation of the geological and geophysical setting across the region. In order to build the new zonation model, we compiled homogeneous cross-border geological, neotectonic and sismotectonic maps over the central part of East D.R. Congo, SW Uganda, Rwanda, Burundi and NW Tanzania and defined a new neotectonic sheme. The seismic risk assessment is based on a new earthquake catalogue, compiled on the basis of various local and global earthquake catalogues. The use of macroseismic epicenters determined from felt earthquakes allowed to extend the time-range back to the beginning of the 20th century, spanning 126 years, with 1068 events. The magnitudes have been homogenized to Mw and aftershocks removed. From this initial catalogue, a catalogue of 359 events from 1956 to 2015 and with M > 4.4 has been extracted for the seismic hazard assessment. The seismotectonic zonation includes 7 seismic source areas that have been defined on the basis of the regional geological structure, neotectonic fault systems, basin architecture and distribution of thermal springs and earthquake epicenters. The Gutenberg-Richter seismic hazard parameters were determined using both the least square linear fit and the maximum likelihood method (Kijko & Smit aue program). Seismic hazard maps have been computed with the Crisis 2012 software using 3 different attenuation laws. We obtained higher PGA values (475 years return period) for the Kivu rift region than the previous estimates (Delvaux et al., 2016). They vary laterally in function of the tectonic

  18. Seismic hazard impact of the Lower Tagus Valley Fault Zone (SW Iberia)

    Science.gov (United States)

    Vilanova, Susana P.; Fonseca, Joao F. B. D.

    The seismic hazard of SW Iberia is composed of two contributions: offshore, large to very large events on the plate boundary between Africa and Eurasia such as the Lisbon earthquake of 1755 or the Gorringe Bank earthquake of 1969; and onshore, moderate to strong intraplate earthquakes on inherited crustal fractures. One of these zones of crustal weakness is the Lower Tagus Valley (LTV) fault zone, which displays the highest level of seismic hazard in Western Iberia. In this paper we review the active tectonics and seismicity of the LTV, integrating previous geophysical data with recent results of paleoseismological investigations, and discuss its impact on the seismic hazard of SW Iberia. We conclude that the seismic zonation for hazard assessment currently in force in the building code is biased towards the scenario of distant offshore rupture, and does not take adequately into account the LTV seismic source.

  19. Exploring uncertainties in probabilistic seismic hazard estimates for Quito

    Science.gov (United States)

    Beauval, Celine; Yepes, Hugo; Audin, Laurence; Alvarado, Alexandra; Nocquet, Jean-Mathieu

    2016-04-01

    In the present study, probabilistic seismic hazard estimates at 475 years return period for Quito, capital city of Ecuador, show that the crustal host zone is the only source zone that determines the city's hazard levels for such return period. Therefore, the emphasis is put on identifying the uncertainties characterizing the host zone, i.e. uncertainties in the recurrence of earthquakes expected in the zone and uncertainties on the ground motions that these earthquakes may produce. As the number of local strong-ground motions is still scant, ground-motion prediction equations are imported from other regions. Exploring recurrence models for the host zone based on different observations and assumptions, and including three GMPE candidates (Akkar and Bommer 2010, Zhao et al. 2006, Boore and Atkinson 2008), we obtain a significant variability on the estimated acceleration at 475 years (site coordinates: -78.51 in longitude and -0.2 in latitude, VS30 760 m/s): 1) Considering historical earthquake catalogs, and relying on frequency-magnitude distributions where rates for magnitudes 6-7 are extrapolated from statistics of magnitudes 4.5-6.0 mostly in the 20th century, the acceleration at the PGA varies between 0.28g and 0.55g with a mean value around 0.4g. The results show that both the uncertainties in the GMPE choice and in the seismicity model are responsible for this variability. 2) Considering slip rates inferred form geodetic measurements across the Quito fault system, and assuming that most of the deformation occurs seismically (conservative hypothesis), leads to a much greater range of accelerations, 0.43 to 0.73g for the PGA (with a mean of 0.55g). 3) Considering slip rates inferred from geodetic measurements, and assuming that 50% only of the deformation is released in earthquakes (partially locked fault, model based on 15 years of GPS data), leads to a range of accelerations 0.32g to 0.58g for the PGA, with a mean of 0.42g. These accelerations are in agreement

  20. Real-time Microseismic Processing for Induced Seismicity Hazard Detection

    Energy Technology Data Exchange (ETDEWEB)

    Matzel, Eric M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-10-31

    Induced seismicity is inherently associated with underground fluid injections. If fluids are injected in proximity to a pre-existing fault or fracture system, the resulting elevated pressures can trigger dynamic earthquake slip, which could both damage surface structures and create new migration pathways. The goal of this research is to develop a fundamentally better approach to geological site characterization and early hazard detection. We combine innovative techniques for analyzing microseismic data with a physics-based inversion model to forecast microseismic cloud evolution. The key challenge is that faults at risk of slipping are often too small to detect during the site characterization phase. Our objective is to devise fast-running methodologies that will allow field operators to respond quickly to changing subsurface conditions.

  1. Probabilistic seismic hazard in the San Francisco Bay area based on seismicity simulation

    Science.gov (United States)

    Pollitz, F. F.

    2008-12-01

    Understanding how fault systems evolve in time under a relevant set of governing physical laws is a needed critical step towards reliable earthquake forecasting. We can address issues relevant to probabilistic seismic hazard analysis (e.g. recurrence time, coefficient of variation, probability of multi-segment rupture) with numerical simulations of seismicity. A seismicity simulator essentially provides a means of tracking the increasing tectonic stress as it loads the faults and determines how stress is redistributed among the network faults as the result of an earthquake. I implement a seismicity simulator that includes the effects of: (1) tectonic loading of a plate boundary zone; (2) static stress transfer; (3) viscoelasticity of the ductile lower crust and mantle; (4) length- and depth-dependent fault slip. I apply it to a network of multiple interacting faults in the San Francisco Bay area. Earthquake initiation, propagation, and termination are governed by a cascade model using a Coulomb failure function. 30000 years of simulated seismicity yield probability density functions of inter-event times on all major faults at practically a continuum of magnitude thresholds. At a threshold of M6.5, reasonable combinations of controlling parameters yield mean inter-event times of ~ 140 years for the southern Hayward and Rodgers Creek faults and ~ 250 years for the northern Hayward and northern Calaveras faults. To help interpret simulation results I explore systematic covariations among mean characteristic magnitude, coefficient of variation (typical values are 0.4 to 0.6), degree of dynamic overshoot, and mantle viscosity.

  2. The 1909 Taipei earthquake: implication for seismic hazard in Taipei

    Science.gov (United States)

    Kanamori, Hiroo; Lee, William H.K.; Ma, Kuo-Fong

    2012-01-01

    The 1909 April 14 Taiwan earthquake caused significant damage in Taipei. Most of the information on this earthquake available until now is from the written reports on its macro-seismic effects and from seismic station bulletins. In view of the importance of this event for assessing the shaking hazard in the present-day Taipei, we collected historical seismograms and station bulletins of this event and investigated them in conjunction with other seismological data. We compared the observed seismograms with those from recent earthquakes in similar tectonic environments to characterize the 1909 earthquake. Despite the inevitably large uncertainties associated with old data, we conclude that the 1909 Taipei earthquake is a relatively deep (50–100 km) intraplate earthquake that occurred within the subducting Philippine Sea Plate beneath Taipei with an estimated M_W of 7 ± 0.3. Some intraplate events elsewhere in the world are enriched in high-frequency energy and the resulting ground motions can be very strong. Thus, despite its relatively large depth and a moderately large magnitude, it would be prudent to review the safety of the existing structures in Taipei against large intraplate earthquakes like the 1909 Taipei earthquake.

  3. Intensity measures for seismic liquefaction hazard evaluation of sloping site

    Institute of Scientific and Technical Information of China (English)

    陈志雄; 程印; 肖杨; 卢谅; 阳洋

    2015-01-01

    This work investigates the correlation between a large number of widely used ground motion intensity measures (IMs) and the corresponding liquefaction potential of a soil deposit during earthquake loading. In order to accomplish this purpose the seismic responses of 32 sloping liquefiable site models consisting of layered cohesionless soil were subjected to 139 earthquake ground motions. Two sets of ground motions, consisting of 80 ordinary records and 59 pulse-like near-fault records are used in the dynamic analyses. The liquefaction potential of the site is expressed in terms of the the mean pore pressure ratio, the maximum ground settlement, the maximum ground horizontal displacement and the maximum ground horizontal acceleration. For each individual accelerogram, the values of the aforementioned liquefaction potential measures are determined. Then, the correlation between the liquefaction potential measures and the IMs is evaluated. The results reveal that the velocity spectrum intensity (VSI) shows the strongest correlation with the liquefaction potential of sloping site. VSI is also proven to be a sufficient intensity measure with respect to earthquake magnitude and source-to-site distance, and has a good predictability, thus making it a prime candidate for the seismic liquefaction hazard evaluation.

  4. A preliminary census of engineering activities located in Sicily (Southern Italy) which may "potentially" induce seismicity

    Science.gov (United States)

    Aloisi, Marco; Briffa, Emanuela; Cannata, Andrea; Cannavò, Flavio; Gambino, Salvatore; Maiolino, Vincenza; Maugeri, Roberto; Palano, Mimmo; Privitera, Eugenio; Scaltrito, Antonio; Spampinato, Salvatore; Ursino, Andrea; Velardita, Rosanna

    2015-04-01

    The seismic events caused by human engineering activities are commonly termed as "triggered" and "induced". This class of earthquakes, though characterized by low-to-moderate magnitude, have significant social and economical implications since they occur close to the engineering activity responsible for triggering/inducing them and can be felt by the inhabitants living nearby, and may even produce damage. One of the first well-documented examples of induced seismicity was observed in 1932 in Algeria, when a shallow magnitude 3.0 earthquake occurred close to the Oued Fodda Dam. By the continuous global improvement of seismic monitoring networks, numerous other examples of human-induced earthquakes have been identified. Induced earthquakes occur at shallow depths and are related to a number of human activities, such as fluid injection under high pressure (e.g. waste-water disposal in deep wells, hydrofracturing activities in enhanced geothermal systems and oil recovery, shale-gas fracking, natural and CO2 gas storage), hydrocarbon exploitation, groundwater extraction, deep underground mining, large water impoundments and underground nuclear tests. In Italy, induced/triggered seismicity is suspected to have contributed to the disaster of the Vajont dam in 1963. Despite this suspected case and the presence in the Italian territory of a large amount of engineering activities "capable" of inducing seismicity, no extensive researches on this topic have been conducted to date. Hence, in order to improve knowledge and correctly assess the potential hazard at a specific location in the future, here we started a preliminary study on the entire range of engineering activities currently located in Sicily (Southern Italy) which may "potentially" induce seismicity. To this end, we performed: • a preliminary census of all engineering activities located in the study area by collecting all the useful information coming from available on-line catalogues; • a detailed compilation

  5. How well can we test probabilistic seismic hazard maps?

    Science.gov (United States)

    Vanneste, Kris; Stein, Seth; Camelbeeck, Thierry; Vleminckx, Bart

    2017-04-01

    Recent large earthquakes that gave rise to shaking much stronger than shown in probabilistic seismic hazard (PSH) maps have stimulated discussion about how well these maps forecast future shaking. These discussions have brought home the fact that although the maps are designed to achieve certain goals, we know little about how well they actually perform. As for any other forecast, this question involves verification and validation. Verification involves assessing how well the algorithm used to produce hazard maps implements the conceptual PSH model ("have we built the model right?"). Validation asks how well the model forecasts the shaking that actually occurs ("have we built the right model?"). We explore the verification issue by simulating shaking histories for an area with assumed uniform distribution of earthquakes, Gutenberg-Richter magnitude-frequency relation, Poisson temporal occurrence model, and ground-motion prediction equation (GMPE). We compare the maximum simulated shaking at many sites over time with that predicted by a hazard map generated for the same set of parameters. The Poisson model predicts that the fraction of sites at which shaking will exceed that of the hazard map is p = 1 - exp(-t/T), where t is the duration of observations and T is the map's return period. Exceedance is typically associated with infrequent large earthquakes, as observed in real cases. The ensemble of simulated earthquake histories yields distributions of fractional exceedance with mean equal to the predicted value. Hence, the PSH algorithm appears to be internally consistent and can be regarded as verified for this set of simulations. However, simulated fractional exceedances show a large scatter about the mean value that decreases with increasing t/T, increasing observation time and increasing Gutenberg-Richter a-value (combining intrinsic activity rate and surface area), but is independent of GMPE uncertainty. This scatter is due to the variability of earthquake

  6. Seismic Hazard Assessment for a Characteristic Earthquake Scenario: Probabilistic-Deterministic Method

    Science.gov (United States)

    mouloud, Hamidatou

    2016-04-01

    The objective of this paper is to analyze the seismic activity and the statistical treatment of seismicity catalog the Constantine region between 1357 and 2014 with 7007 seismic event. Our research is a contribution to improving the seismic risk management by evaluating the seismic hazard in the North-East Algeria. In the present study, Earthquake hazard maps for the Constantine region are calculated. Probabilistic seismic hazard analysis (PSHA) is classically performed through the Cornell approach by using a uniform earthquake distribution over the source area and a given magnitude range. This study aims at extending the PSHA approach to the case of a characteristic earthquake scenario associated with an active fault. The approach integrates PSHA with a high-frequency deterministic technique for the prediction of peak and spectral ground motion parameters in a characteristic earthquake. The method is based on the site-dependent evaluation of the probability of exceedance for the chosen strong-motion parameter. We proposed five sismotectonique zones. Four steps are necessary: (i) identification of potential sources of future earthquakes, (ii) assessment of their geological, geophysical and geometric, (iii) identification of the attenuation pattern of seismic motion, (iv) calculation of the hazard at a site and finally (v) hazard mapping for a region. In this study, the procedure of the earthquake hazard evaluation recently developed by Kijko and Sellevoll (1992) is used to estimate seismic hazard parameters in the northern part of Algeria.

  7. Probabilistic seismic hazard maps from seismicity patterns analysis: the Iberian Peninsula case

    Directory of Open Access Journals (Sweden)

    A. Jiménez

    2004-01-01

    Full Text Available Earthquake prediction is a main topic in Seismology. Here, the goal is to know the correlation between the seismicity at a certain place at a given time with the seismicity at the same place, but at a following interval of time. There are no ways for exact predictions, but one can wonder about the causality relations between the seismic characteristics at a given time interval and another in a region. In this paper, a new approach to this kind of studies is presented. Tools which include cellular automata theory and Shannon's entropy are used. First, the catalogue is divided into time intervals, and the region into cells. The activity or inactivity of each cell at a certain time is described using an energy criterion; thus a pattern which evolves over time is given. The aim is to find the rules of the stochastic cellular automaton which best fits the evolution of the pattern. The neighborhood utilized is the cross template (CT. A grid search is made to choose the best model, being the mutual information between the different times the function to be maximized. This function depends on the size of the cells β on and the interval of time τ which is considered for studying the activity of a cell. With these β and τ, a set of probabilities which characterizes the evolution rules is calculated, giving a probabilistic approach to the spatiotemporal evolution of the region. The sample catalogue for the Iberian Peninsula covers since 1970 till 2001. The results point out that the seismic activity must be deduced not only from the past activity at the same region but also from its surrounding activity. The time and spatial highest interaction for the catalogue used are of around 3.3 years and 290x165 km2, respectively; if a cell is inactive, it will continue inactive with a high probability; an active cell has around the 60% probability of continuing active in the future. The Probabilistic Seismic Hazard Map obtained marks the main seismic active

  8. PSHAe (Probabilistic Seismic Hazard enhanced): the case of Istanbul.

    Science.gov (United States)

    Stupazzini, Marco; Allmann, Alexander; Infantino, Maria; Kaeser, Martin; Mazzieri, Ilario; Paolucci, Roberto; Smerzini, Chiara

    2016-04-01

    The Probabilistic Seismic Hazard Analysis (PSHA) only relying on GMPEs tends to be insufficiently constrained at short distances and data only partially account for the rupture process, seismic wave propagation and three-dimensional (3D) complex configurations. Given a large and representative set of numerical results from 3D scenarios, analysing the resulting database from a statistical point of view and implementing the results as a generalized attenuation function (GAF) into the classical PSHA might be an appealing way to deal with this problem (Villani et al., 2014). Nonetheless, the limited amount of computational resources or time available tend to pose substantial constrains in a broad application of the previous method and, furthermore, the method is only partially suitable for taking into account the spatial correlation of ground motion as modelled by each forward physics-based simulation (PBS). Given that, we envision a streamlined and alternative implementation of the previous approach, aiming at selecting a limited number of scenarios wisely chosen and associating them a probability of occurrence. The experience gathered in the past year regarding 3D modelling of seismic wave propagation in complex alluvial basin (Pilz et al., 2011, Guidotti et al., 2011, Smerzini and Villani, 2012) allowed us to enhance the choice of simulated scenarios in order to explore the variability of ground motion, preserving the full spatial correlation necessary for risk modelling, on one hand and on the other the simulated losses for a given location and a given building stock. 3D numerical modelling of scenarios occurring the North Anatolian Fault in the proximity of Istanbul are carried out through the spectral element code SPEED (http://speed.mox.polimi.it). The results are introduced in a PSHA, exploiting the capabilities of the proposed methodology against a traditional approach based on GMPE. References Guidotti R, M Stupazzini, C Smerzini, R Paolucci, P Ramieri

  9. Assessment of seismic hazards along the northern Gulf of Aqaba

    Science.gov (United States)

    Abueladas, Abdel-Rahman Aqel

    Aqaba and Elat are very important port and recreation cities for the Hashemite Kingdom of Jordan and Israel, respectively. The two cities are the most susceptible to damage from a destructive future earthquake because they are located over the tectonically active Dead Sea transform fault (DST) that is the source of most of the major historical earthquakes in the region. The largest twentieth century earthquake on the DST, the magnitude Mw 7.2 Nuweiba earthquake of November 22, 1995, caused damage to structures in both cities. The integration of geological, geophysical, and earthquake engineering studies will help to assess the seismic hazards by determining the location and slip potential of active faults and by mapping areas of high liquefaction susceptibility. Ground Penetrating Radar (GPR) as a high resolution shallow geophysical tool was used to map the shallow active faults in Aqaba, Taba Sabkha area, and Elat. The GPR data revealed the onshore continuation of the Evrona, West Aqaba, Aqaba fault zones, and several transverse faults. The integration of offshore and onshore data confirm the extension of these faults along both sides of the Gulf of Aqaba. A 3D model of GPR data at one site in Aqaba indicates that the NW-trending transverse faults right laterally offset older than NE-trending faults. The most hazardous fault is the Evrona fault which extends north to the Tabs Sabkha. A geographic information system (GIS) database of the seismic hazard was created in order to facilitate the analyzing, manipulation, and updating of the input parameters. Liquefaction potential maps were created for the region based on analysis of borehole data. The liquefaction map shows high and moderate liquefaction susceptibility zones along the northern coast of the Gulf of Aqaba. In Aqaba several hotels are located within a high and moderate liquefaction zones. The Yacht Club, Aqaba, Ayla archaeological site, and a part of commercial area are also situated in a risk area. A part

  10. Sensitivity of seismic hazard evaluations to uncertainties determined from seismic source characterization

    Science.gov (United States)

    Tavakoli, Behrooz

    The sensitivity and overall uncertainty in peak ground acceleration (PGA)estimates have been calculated for the city of Tabriz, northwestern Iran byusing a specific randomized blocks design. Eight seismic hazard models andparameters with randomly selected uncertainties at two levels have beenconsidered and then a linear model between predicted PGA at a givenprobability level and the uncertainties has been performed. The inputmodels and parameters are those related to the attenuation, magnituderupture-length and recurrence relationships with their uncertainties.Application of this procedure to the studied area indicates that effects ofthe simultaneous variation of all eight input models and parameters on thesensitivity of the seismic hazard can be investigated with a decreasingnumber of computations for all possible combinations at a fixed annualprobability. The results show that the choice of a mathematical model ofthe source mechanism, attenuation relationships and the definition ofseismic parameters are most critical in estimating the sensitivity of seismichazard evaluation, in particular at low levels of probability of exceedance.The overall uncertainty in the expected PGA for an annual probability of0.0021 (10% exceedence in 50 yr) is expressed by a coefficient ofvariation (CV) of about 34% at 68% confidence level for a distance ofabout 5km from the field of the major faults. The CV will decrease withincreasing site-source distance and remains constant, CV = 15%, fordistances larger than 15 km. Finally, treating alternative models on theoverall uncertainty are investigated by additional outliers in input decision.

  11. Preliminary consideration on the seismic actions recorded during the 2016 Central Italy seismic sequence

    Science.gov (United States)

    Carlo Ponzo, Felice; Ditommaso, Rocco; Nigro, Antonella; Nigro, Domenico S.; Iacovino, Chiara

    2017-04-01

    After the Mw 6.0 mainshock of August 24, 2016 at 03.36 a.m. (local time), with the epicenter located between the towns of Accumoli (province of Rieti), Amatrice (province of Rieti) and Arquata del Tronto (province of Ascoli Piceno), several activities were started in order to perform some preliminary evaluations on the characteristics of the recent seismic sequence in the areas affected by the earthquake. Ambient vibration acquisitions have been performed using two three-directional velocimetric synchronized stations, with a natural frequency equal to 0.5Hz and a digitizer resolution of equal to 24bit. The activities are continuing after the events of the seismic sequence of October 26 and October 30, 2016. In this paper, in order to compare recorded and code provision values in terms of peak (PGA, PGV and PGD), spectral and integral (Housner Intensity) seismic parameters, several preliminary analyses have been performed on accelerometric time-histories acquired by three near fault station of the RAN (Italian Accelerometric Network): Amatrice station (station code AMT), Norcia station (station code NRC) and Castelsantangelo sul Nera station (station code CNE). Several comparisons between the elastic response spectra derived from accelerometric recordings and the elastic demand spectra provided by the Italian seismic code (NTC 2008) have been performed. Preliminary results retrieved from these analyses highlight several apparent difference between experimental data and conventional code provision. Then, the ongoing seismic sequence appears compatible with the historical seismicity in terms of integral parameters, but not in terms of peak and spectral values. It seems appropriate to reconsider the necessity to revise the simplified design approach based on the conventional spectral values. Acknowledgements This study was partially funded by the Italian Department of Civil Protection within the project DPC-RELUIS 2016 - RS4 ''Seismic observatory of structures and

  12. Seismic Hazard Assessment for the Tianshui Urban Area, Gansu Province, China

    Directory of Open Access Journals (Sweden)

    Zhenming Wang

    2012-01-01

    Full Text Available A scenario seismic hazard analysis was performed for the city of Tianshui. The scenario hazard analysis utilized the best available geologic and seismological information as well as composite source model (i.e., ground motion simulation to derive ground motion hazards in terms of acceleration time histories, peak values (e.g., peak ground acceleration and peak ground velocity, and response spectra. This study confirms that Tianshui is facing significant seismic hazard, and certain mitigation measures, such as better seismic design for buildings and other structures, should be developed and implemented. This study shows that PGA of 0.3 g (equivalent to Chinese intensity VIII should be considered for seismic design of general building and PGA of 0.4 g (equivalent to Chinese intensity IX for seismic design of critical facility in Tianshui.

  13. Time-dependent probabilistic seismic hazard assessment and its application to Hualien City, Taiwan

    Directory of Open Access Journals (Sweden)

    C.-H. Chan

    2013-05-01

    Full Text Available Here, we propose a time-dependent probabilistic seismic hazard assessment and apply it to Hualien City, Taiwan. A declustering catalog from 1940 to 2005 was used to build up a long-term seismicity rate model using a smoothing Kernel function. We also evaluated short-term seismicity rate perturbations according to the rate-and-state friction model, and the Coulomb stress changes imparted by earthquakes from 2006 to 2010. We assessed both long-term and short-term probabilistic seismic hazards by considering ground motion prediction equations for crustal and subduction earthquakes. The long-term seismic hazard in Hualien City gave a PGA (peak ground acceleration of 0.46 g for the 2.1‰ annual exceedance probability. The result is similar to the levels determined in previous studies. Seismic hazards were significantly elevated following the 2007 ML =5.8 earthquake that occurred approximately 10 km from Hualien City. This work presents an assessment of a suitable mechanism for time-dependent probabilistic seismic hazard determinations using an updated earthquake catalog. Using minor model assumptions, our approach provides a suitable basis for rapid re-evaluations and will benefit decision-makers and public officials regarding seismic hazard mitigation.

  14. An Earthquake Source Ontology for Seismic Hazard Analysis and Ground Motion Simulation

    Science.gov (United States)

    Zechar, J. D.; Jordan, T. H.; Gil, Y.; Ratnakar, V.

    2005-12-01

    Representation of the earthquake source is an important element in seismic hazard analysis and earthquake simulations. Source models span a range of conceptual complexity - from simple time-independent point sources to extended fault slip distributions. Further computational complexity arises because the seismological community has established so many source description formats and variations thereof; what this means is that conceptually equivalent source models are often expressed in different ways. Despite the resultant practical difficulties, there exists a rich semantic vocabulary for working with earthquake sources. For these reasons, we feel it is appropriate to create a semantic model of earthquake sources using an ontology, a computer science tool from the field of knowledge representation. Unlike the domain of most ontology work to date, earthquake sources can be described by a very precise mathematical framework. Another uniqueness associated with developing such an ontology is that earthquake sources are often used as computational objects. A seismologist generally wants more than to simply construct a source and have it be well-formed and properly described; additionally, the source will be used for performing calculations. Representation and manipulation of complex mathematical objects presents a challenge to the ontology development community. In order to enable simulations involving many different types of source models, we have completed preliminary development of a seismic point source ontology. The use of an ontology to represent knowledge provides machine interpretability and the ability to validate logical consistency and completeness. Our ontology, encoded using the OWL Web Ontology Language - a standard from the World Wide Web Consortium, contains the conceptual definitions and relationships necessary for source translation services. For example, specification of strike, dip, rake, and seismic moment will automatically translate into a double

  15. Probabilistic hazard for seismically induced tsunamis: accuracy and feasibility of inundation maps

    Science.gov (United States)

    Lorito, S.; Selva, J.; Basili, R.; Romano, F.; Tiberti, M. M.; Piatanesi, A.

    2015-01-01

    Probabilistic tsunami hazard analysis (PTHA) relies on computationally demanding numerical simulations of tsunami generation, propagation, and non-linear inundation on high-resolution topo-bathymetric models. Here we focus on tsunamis generated by co-seismic sea floor displacement, that is, on Seismic PTHA (SPTHA). A very large number of tsunami simulations are typically needed to incorporate in SPTHA the full expected variability of seismic sources (the aleatory uncertainty). We propose an approach for reducing their number. To this end, we (i) introduce a simplified event tree to achieve an effective and consistent exploration of the seismic source parameter space; (ii) use the computationally inexpensive linear approximation for tsunami propagation to construct a preliminary SPTHA that calculates the probability of maximum offshore tsunami wave height (HMax) at a given target site; (iii) apply a two-stage filtering procedure to these `linear' SPTHA results, for selecting a reduced set of sources and (iv) calculate `non-linear' probabilistic inundation maps at the target site, using only the selected sources. We find that the selection of the important sources needed for approximating probabilistic inundation maps can be obtained based on the offshore HMax values only. The filtering procedure is semi-automatic and can be easily repeated for any target sites. We describe and test the performances of our approach with a case study in the Mediterranean that considers potential subduction earthquakes on a section of the Hellenic Arc, three target sites on the coast of eastern Sicily and one site on the coast of southern Crete. The comparison between the filtered SPTHA results and those obtained for the full set of sources indicates that our approach allows for a 75-80 per cent reduction of the number of the numerical simulations needed, while preserving the accuracy of probabilistic inundation maps to a reasonable degree.

  16. A new probabilistic seismic hazard assessment for greater Tokyo

    Science.gov (United States)

    Stein, R.S.; Toda, S.; Parsons, T.; Grunewald, E.; Blong, R.; Sparks, S.; Shah, H.; Kennedy, J.

    2006-01-01

    Tokyo and its outlying cities are home to one-quarter of Japan's 127 million people. Highly destructive earthquakes struck the capital in 1703, 1855 and 1923, the last of which took 105 000 lives. Fuelled by greater Tokyo's rich seismological record, but challenged by its magnificent complexity, our joint Japanese-US group carried out a new study of the capital's earthquake hazards. We used the prehistoric record of great earthquakes preserved by uplifted marine terraces and tsunami deposits (17 M???8 shocks in the past 7000 years), a newly digitized dataset of historical shaking (10 000 observations in the past 400 years), the dense modern seismic network (300 000 earthquakes in the past 30 years), and Japan's GeoNet array (150 GPS vectors in the past 10 years) to reinterpret the tectonic structure, identify active faults and their slip rates and estimate their earthquake frequency. We propose that a dislodged fragment of the Pacific plate is jammed between the Pacific, Philippine Sea and Eurasian plates beneath the Kanto plain on which Tokyo sits. We suggest that the Kanto fragment controls much of Tokyo's seismic behaviour for large earthquakes, including the damaging 1855 M???7.3 Ansei-Edo shock. On the basis of the frequency of earthquakes beneath greater Tokyo, events with magnitude and location similar to the M??? 7.3 Ansei-Edo event have a ca 20% likelihood in an average 30 year period. In contrast, our renewal (time-dependent) probability for the great M??? 7.9 plate boundary shocks such as struck in 1923 and 1703 is 0.5% for the next 30 years, with a time-averaged 30 year probability of ca 10%. The resulting net likelihood for severe shaking (ca 0.9g peak ground acceleration (PGA)) in Tokyo, Kawasaki and Yokohama for the next 30 years is ca 30%. The long historical record in Kanto also affords a rare opportunity to calculate the probability of shaking in an alternative manner exclusively from intensity observations. This approach permits robust estimates

  17. New seismic sources parameterization in El Salvador. Implications to seismic hazard.

    Science.gov (United States)

    Alonso-Henar, Jorge; Staller, Alejandra; Jesús Martínez-Díaz, José; Benito, Belén; Álvarez-Gómez, José Antonio; Canora, Carolina

    2014-05-01

    El Salvador is located at the pacific active margin of Central America, here, the subduction of the Cocos Plate under the Caribbean Plate at a rate of ~80 mm/yr is the main seismic source. Although the seismic sources located in the Central American Volcanic Arc have been responsible for some of the most damaging earthquakes in El Salvador. The El Salvador Fault Zone is the main geological structure in El Salvador and accommodates 14 mm/yr of horizontal displacement between the Caribbean Plate and the forearc sliver. The ESFZ is a right lateral strike-slip fault zone c. 150 km long and 20 km wide .This shear band distributes the deformation among strike-slip faults trending N90º-100ºE and secondary normal faults trending N120º- N170º. The ESFZ is relieved westward by the Jalpatagua Fault and becomes less clear eastward disappearing at Golfo de Fonseca. Five sections have been proposed for the whole fault zone. These fault sections are (from west to east): ESFZ Western Section, San Vicente Section, Lempa Section, Berlin Section and San Miguel Section. Paleoseismic studies carried out in the Berlin and San Vicente Segments reveal an important amount of quaternary deformation and paleoearthquakes up to Mw 7.6. In this study we present 45 capable seismic sources in El Salvador and their preliminary slip-rate from geological and GPS data. The GPS data detailled results are presented by Staller et al., 2014 in a complimentary communication. The calculated preliminary slip-rates range from 0.5 to 8 mm/yr for individualized faults within the ESFZ. We calculated maximum magnitudes from the mapped lengths and paleoseismic observations.We propose different earthquakes scenario including the potential combined rupture of different fault sections of the ESFZ, resulting in maximum earthquake magnitudes of Mw 7.6. We used deterministic models to calculate acceleration distribution related with maximum earthquakes of the different proposed scenario. The spatial distribution of

  18. Seismic hazard assessment based on the Unified Scaling Law for Earthquakes: the Greater Caucasus

    Science.gov (United States)

    Nekrasova, A.; Kossobokov, V. G.

    2015-12-01

    Losses from natural disasters continue to increase mainly due to poor understanding by majority of scientific community, decision makers and public, the three components of Risk, i.e., Hazard, Exposure, and Vulnerability. Contemporary Science is responsible for not coping with challenging changes of Exposures and their Vulnerability inflicted by growing population, its concentration, etc., which result in a steady increase of Losses from Natural Hazards. Scientists owe to Society for lack of knowledge, education, and communication. In fact, Contemporary Science can do a better job in disclosing Natural Hazards, assessing Risks, and delivering such knowledge in advance catastrophic events. We continue applying the general concept of seismic risk analysis in a number of seismic regions worldwide by constructing regional seismic hazard maps based on the Unified Scaling Law for Earthquakes (USLE), i.e. log N(M,L) = A - B•(M-6) + C•log L, where N(M,L) is the expected annual number of earthquakes of a certain magnitude M within an seismically prone area of linear dimension L. The parameters A, B, and C of USLE are used to estimate, first, the expected maximum magnitude in a time interval at a seismically prone cell of a uniform grid that cover the region of interest, and then the corresponding expected ground shaking parameters including macro-seismic intensity. After a rigorous testing against the available seismic evidences in the past (e.g., the historically reported macro-seismic intensity), such a seismic hazard map is used to generate maps of specific earthquake risks (e.g., those based on the density of exposed population). The methodology of seismic hazard and risks assessment based on USLE is illustrated by application to the seismic region of Greater Caucasus.

  19. Earthquake Hazards Program: U.S. Seismic Design Maps

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The USGS collaborates with organizations (such as the Building Seismic Safety Council) that develop model building and bridge design codes to make seismic design...

  20. Seismic hazard in the Po Plain and the 2012 Emilia earthquakes

    Directory of Open Access Journals (Sweden)

    Carlo Meletti

    2012-10-01

    Full Text Available The Emilia earthquakes of May 20, 2012 (Ml 5.9, INGV; Mw 6.11, http://www.bo.ingv.it/RCMT/ and May 29, 2012 (Ml 5.8, INGV; Mw 5.96, http://www.bo.ingv.it/RCMT/ struck an area that in the national reference seismic hazard model [MPS04; http://zonesismiche.mi.ingv.it, and Stucchi et al. 2011] is characterized by expected horizontal peak ground acceleration (PGA with a 10% probability of exceedance in 50 years that ranges between 0.10 g and 0.15 g (Figure 1, which is a medium level of seismic hazard in Italy. The strong impact of the earthquakes on a region that is not included among the most hazardous areas of Italy, and the ground motion data recorded by accelerometric networks, have given the impression to the population and the media that the current seismic hazard map is not correct, and thus needs to be updated. Since the MPS04 seismic hazard model was adopted by the current Italian building code [Norme Tecniche per le Costruzioni 2008, hereafter termed NTC08; http://www.cslp.it/cslp/] as the basis to define seismic action (the design spectra, any modification to the seismic hazard model would also affect the building code. The aim of this paper is to briefly present the data that support the seismic hazard model in the area, and to perform some comparisons between recorded ground motion with seismic hazard estimates and design spectra. All of the comparisons presented in this study are for the horizontal components only, as the Italian hazard model did not perform any estimates for the vertical component. […

  1. The view of seismic hazard in the Halmahera region

    Science.gov (United States)

    Zulkifli, M.; Rudyanto, Ariska; Sakti, Artadi Pria

    2017-07-01

    Seismic hazard analysis for Halmahera region was conducted using PSHA and DSHA methods. The USGS Harmsen 2007 software was used to run probability calculation for return periods of 500 years 10% probability of exceedance within 50 years age of the building on the condition T = 0, T = 0.2 and T = 1. The results show a maximum PGA value in bedrock (0.15 g - 0.26 g), SA T = 0.2 (0.30 g - 0.53 g) and T = 1 (0.12 g - 0.192 g). The Shakemap software modificated by BMKG 2015 was used to run deterministic calculations with earthquake source scenario form a fault plane with magnitude Mw = 8.1, in depth of 20 km. The results obtained a maximum PGA (0.21 g - 0.44 g) with PGA distribution shaped fault plane trace, nearby areas by fault plane have a maximum PGA and away from the fault plane have a minimum PGA.

  2. Probabilistic seismic hazard map for Bulgaria as a basis for a new building code

    Directory of Open Access Journals (Sweden)

    S. D. Simeonova

    2006-01-01

    Full Text Available A seismic hazard map proposed as part of a new building code for Bulgaria is presented here on basis of the recommendations in EUROCODE 8. Seismic source zones within an area of about 200 km around Bulgaria were constructed considering seismicity, neotectonic and geological development. The most time consuming work was to establish a homogeneous earthquake catalogue out of different catalogues. The probabilistic seismic hazard assessment in terms of intensities is performed following Cornell (1968 with the program EQRISK (see McGuire, 1976, modified by us for use of intensities. To cope with the irregular isoseismals of the Vrancea intermediate depth earthquakes a special attenuation factor is introduced (Ardeleanu et al., 2005, using detailed macroseismic maps of three major earthquakes. The final seismic hazard is the combination of both contributions, of zones with crustal earthquakes and of the Vrancea intermediate depth earthquakes zone. Calculations are done for recurrence periods of 95, 475 and 10 000 years.

  3. Location of high seismic activity zones and seismic hazard assessment in Zabrze Bielszowice coal mine using passive tomography

    Institute of Scientific and Technical Information of China (English)

    LURKA A

    2008-01-01

    In the paper results of passive tomography calculations have been presented to assess rockburst hazard and locate high seismic activity zones in the vicinity of longwall 306 in Zabrze Bielszowice coal mine. The area of study was 1000 m in X direction by 900 m in Y direction. The zones of high values of P-wave propagation velocity have been found to correlate with the distribution of large seismic tremors.

  4. Recent research in earth structure, earthquake and mine seismology, and seismic hazard evaluation in South Africa

    CSIR Research Space (South Africa)

    Wright, C

    2003-07-01

    Full Text Available Research in earth structure, earthquake and mine seismology, and seismic hazard evaluation in South Africa is summarized for the last four years. Improvements to the South African National Seismograph Network (SANSN) include the gradual replacement...

  5. Probabilistic seismic hazard assessment in Greece – Part 1: Engineering ground motion parameters

    Directory of Open Access Journals (Sweden)

    G-A. Tselentis

    2010-01-01

    Full Text Available Seismic hazard assessment represents a basic tool for rational planning and designing in seismic prone areas. In the present study, a probabilistic seismic hazard assessment in terms of peak ground acceleration, peak ground velocity, Arias intensity and cumulative absolute velocity computed with a 0.05 g acceleration threshold, has been carried out for Greece. The output of the hazard computation produced probabilistic hazard maps for all the above parameters estimated for a fixed return period of 475 years. From these maps the estimated values are reported for 52 Greek municipalities. Additionally, we have obtained a set of probabilistic maps of engineering significance: a probabilistic macroseismic intensity map, depicting the Modified Mercalli Intensity scale obtained from the estimated peak ground velocity and a probabilistic seismic-landslide map based on a simplified conversion of the estimated Arias intensity and peak ground acceleration into Newmark's displacement.

  6. Preliminary macroseismic survey of the 2016 Amatrice seismic sequence

    Directory of Open Access Journals (Sweden)

    Mariano Angelo Zanini

    2016-11-01

    Full Text Available After the recent destructive L’Aquila 2009 and Emilia-Romagna 2012 earthquakes, a sudden Mw 6.0 seismic event hit Central Italy on August 24, 2016. A low population density characterizes the area but, due to its nighttime occurrence, about 300 victims were registered. This work presents the first preliminary results of a macroseismic survey conducted by two teams of the University of Padova in the territories that suffered major damages. Macroseismic intensities were assessed according to the European Macroseismic Scale (EMS98 for 180 sites.

  7. Seismic hazard in the DRC and Western Rift Valley of Africa

    CSIR Research Space (South Africa)

    Mavonga, T

    2009-09-01

    Full Text Available .R. Congo 3Council for Scientific and Industrial Research, South Africa ABSTRACT A probabilistic approach was used to assess the seismic hazard in Democratic Republic of Congo and surrounding areas. Seismic hazard maps were prepared using a 90-year... September 1992. The main shock claimed 11 lives, 109 people were seriously injured, and more than 2000 families were left homeless. However, the relationship between the surface structures and deeper features needs to be determined in order to establish...

  8. Challenges in seismic hazard assessment: Analyses of ground motion modelling and seismotectonic sources

    OpenAIRE

    Sørensen, Mathilde Bøttger

    2006-01-01

    Seismic hazard assessment has an important societal impact in describing levels of ground motions to be expected in a given region in the future. Challenges in seismic hazard assessment are closely associated with the fact that different regions, due to their differences in seismotectonics setting (and hence in earthquake occurrence) as well as socioeconomic conditions, require different and innovative approaches. One of the most important aspects in this regard is the seismici...

  9. Seismic hazard evaluation for Department of Energy Oak Ridge Reservations, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    McGuire, R.K.; Toro, G.F. [Risk Engineering, Inc., Golden, CO (United States); Hunt, R.J. [Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States). Center for Natural Phenomena Engineering

    1992-09-30

    This study presents the results of an investigation of seismic hazard at the Department of Energy Oak Ridge Reservations (K-25 Site, Oak Ridge National Laboratories, and Oak Ridge Y-12 Plant), located in Oak Ridge, Tennessee. Oak Ridge is located in eastern Tennessee, in an area of moderate to high historical seismicity. Results from two separate seismic hazard analyses are presented. The EPRI/SOG analysis uses the input data and methodology developed by the Electric Power Research Institute, under the sponsorship of several electric utilities, for the evaluation of seismic hazard in the central and eastern United States. The LLNL analysis uses the input data and methodology developed by the Lawrence Livermore National Laboratory for the Nuclear Regulatory Commission. Both the EPRI/SOG and LLNL studies characterize earth-science uncertainty on the causes and characteristics of earthquakes in the central and eastern United States. This is accomplished by considering multiple hypotheses on the locations and parameters of seismic source zones and by considering multiple attenuation functions for the prediction of ground shaking given earthquake size and location. These hypotheses were generated by multiple expert teams and experts. Furthermore, each team and expert was asked to generate multiple hypotheses in order to characterize his own internal uncertainty. The seismic-hazard calculations are performed for all hypotheses. Combining the results from each hypothesis with the weight associated to that hypothesis, one obtains an overall representation of the seismic hazard at the Oak Ridge site and its uncertainty.

  10. Seismicity and Seismic Hazard along the Western part of the Eurasia-Nubia plate boundary

    Science.gov (United States)

    Bezzeghoud, Mourad; Fontiela, João; Ferrão, Celia; Borges, José Fernando; Caldeira, Bento; Dib, Assia; Ousadou, Farida

    2016-04-01

    The seismic phenomenon is the most damaging natural hazard known in the Mediterranean area. The western part of the Eurasia-Nubia plate boundary extends from the Azores to the Mediterranean region. The oceanic part of the plate boundary is well delimited from the Azores Islands, along the Azores-Gibraltar fault to approximately 12°W (west of the Strait of Gibraltar). From 12°W to 3.5°E, including the Iberia-Nubia region and extending to the western part of Algeria, the boundary is more diffuse and forms a wider area of deformation. The boundary between the Iberia and Nubia plates is the most complex part of the margin. This region corresponds to the transition from an oceanic boundary to a continental boundary, where Iberia and Nubia collide. Although most earthquakes along this plate boundary are shallow and generally have magnitudes less than 5.5, there have been several high-magnitude events. Many devastating earthquakes, some of them tsunami-triggering, inflicted heavy loss and considerable economic damage to the region. From 1920 to present, three earthquakes with magnitudes of about 8.0 (Mw 8.2, 25 November 1941; Ms 8.0, 25 February 1969; and Mw 7.9, 26 May 1975) occurred in the oceanic region, and four earthquakes with magnitudes of about 7.0 (Mw 7.1, 8 May 1939, Santa Maria Island and Mw 7.1, January 1980, Terceira and Graciosa Islands, both in the Azores; Ms 7.1, 20 May 1931, Azores-Gibraltar fracture zone; and Mw 7.3, 10 October 1980, El Asnam, Algeria) occurred along the western part of the Eurasia-Nubia plate boundary. In general, large earthquakes (M ≥7) occur within the oceanic region, with the exception of the El Asnam (Algeria) earthquakes. Some of these events caused extensive damage. The 1755 Lisbon earthquake (˜Mw 9) on the Portugal Atlantic margin, about 200 km W-SW of Cape St. Vincent, was followed by a tsunami and fires that caused the near-total destruction of Lisbon and adjacent areas. Estimates of the death toll in Lisbon alone (~70

  11. Preliminary seismicity and focal mechanisms for the southern Great Basin of Nevada and California: January 1992 through September 1992

    Energy Technology Data Exchange (ETDEWEB)

    Harmsen, S.C.

    1994-06-01

    The telemetered southern Great Basin seismic network (SGBSN) is operated for the Department of Energy`s Yucca Mountain Project (YMP). The US Geological Survey, Branch of Earthquake and Landslide Hazards, maintained this network until September 30, 1992, at which time all operational and analysis responsibilities were transferred to the University of Nevada at Reno Seismological Laboratory (UNRSL). This report contains preliminary earthquake and chemical explosion hypocenter listings and preliminary earthquake focal mechanism solutions for USGS/SGBSN data for the period January 1, 1992 through September 30, 1992, 15:00 UTC.

  12. Proposed seismic hazard maps of Sumatra and Java Islands and microzonation study of Jakarta City, Indonesia

    Indian Academy of Sciences (India)

    Masyhur Irsyam; Donny T Dangkua; Hendriyawan; Drajat Hoedajanto; Bigman M Hutapea; Engkon K Kertapati; Teddy Boen; Mark D Petersen

    2008-11-01

    This paper presents the development of spectral hazard maps for Sumatra and Java islands, Indonesia and microzonation study for Jakarta city. The purpose of this study is to propose a revision of the seismic hazard map in Indonesian Seismic Code SNI 03-1726-2002. Some improvements in seismic hazard analysis were implemented in the analysis by considering the recent seismic activities around Java and Sumatra. The seismic hazard analysis was carried out using 3-dimension (3-D) seismic source models (fault source model) using the latest research works regarding the tectonic setting of Sumatra and Java. Two hazard levels were analysed for representing 10% and 2% probability of exceedance (PE) in 50 years ground motions for Sumatra and Java. Peak ground acceleration contour maps for those two hazard levels and two additional macrozonation maps for 10% PE in 50 years were produced during this research. These two additional maps represent short period (0.2 s) and long-period (1.0 s) spectra values at the bedrock. Microzonation study is performed in order to obtain ground motion parameters such as acceleration, amplification factor and response spectra at the surface of Jakarta. The analyses were carried out using nonlinear approach. The results were used to develop contour of acceleration at the surface of Jakarta. Finally, the design response spectra for structural design purposes are proposed in this study.

  13. Documentation for the 2008 Update of the United States National Seismic Hazard Maps

    Science.gov (United States)

    Petersen, Mark D.; Frankel, Arthur D.; Harmsen, Stephen C.; Mueller, Charles S.; Haller, Kathleen M.; Wheeler, Russell L.; Wesson, Robert L.; Zeng, Yuehua; Boyd, Oliver S.; Perkins, David M.; Luco, Nicolas; Field, Edward H.; Wills, Chris J.; Rukstales, Kenneth S.

    2008-01-01

    The 2008 U.S. Geological Survey (USGS) National Seismic Hazard Maps display earthquake ground motions for various probability levels across the United States and are applied in seismic provisions of building codes, insurance rate structures, risk assessments, and other public policy. This update of the maps incorporates new findings on earthquake ground shaking, faults, seismicity, and geodesy. The resulting maps are derived from seismic hazard curves calculated on a grid of sites across the United States that describe the frequency of exceeding a set of ground motions. The USGS National Seismic Hazard Mapping Project developed these maps by incorporating information on potential earthquakes and associated ground shaking obtained from interaction in science and engineering workshops involving hundreds of participants, review by several science organizations and State surveys, and advice from two expert panels. The National Seismic Hazard Maps represent our assessment of the 'best available science' in earthquake hazards estimation for the United States (maps of Alaska and Hawaii as well as further information on hazard across the United States are available on our Web site at http://earthquake.usgs.gov/research/hazmaps/).

  14. Scenario for a Short-Term Probabilistic Seismic Hazard Assessment (PSHA in Chiayi, Taiwan

    Directory of Open Access Journals (Sweden)

    Chung-Han Chan

    2013-01-01

    Full Text Available Using seismic activity and the Meishan earthquake sequence that occurred from 1904 to 1906, a scenario for short-term probabilistic seismic hazards in the Chiayi region of Taiwan is assessed. The long-term earthquake occurrence rate in Taiwan was evaluated using a smoothing kernel. The highest seismicity rate was calculated around the Chiayi region. To consider earthquake interactions, the rate-and-state friction model was introduced to estimate the seismicity rate evolution due to the Coulomb stress change. As imparted by the 1904 Touliu earthquake, stress changes near the 1906 Meishan and Yangshuigang epicenters was higher than the magnitude of tidal triggering. With regard to the impact of the Meishan earthquake, the region close to the Yangshuigang earthquake epicenter had a +0.75 bar stress increase. The results indicated significant interaction between the three damage events. Considering the path and site effect using ground motion prediction equations, a probabilistic seismic hazard in the form of a hazard evolution and a hazard map was assessed. A significant elevation in hazards following the three earthquakes in the sequence was determined. The results illustrate a possible scenario for seismic hazards in the Chiayi region which may take place repeatly in the future. Such scenario provides essential information on earthquake preparation, devastation estimations, emergency sheltering, utility restoration, and structure reconstruction.

  15. Non-invasive shallow seismic source comparison for hazardous waste site investigations

    Energy Technology Data Exchange (ETDEWEB)

    Doll, W.E. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.; Miller, R.D.; Xia, J. [Kansas Geological survey, Lawrence, KS (United States)

    1994-12-31

    Many commonly used shallow seismic sources are unacceptable for hazardous waste site investigations because they risk exhumation of contaminants in the soil, they add contaminants (e.g. lead) which are not allowed by regulations, or they add new migration paths for contaminants. Furthermore, recently developed high frequency vibrators for shallow investigations could be more effective at some sites than non-invasive impulsive sources because of their ability to tailor the source spectrum and reduce interference. The authors show preliminary results of a comparison test of eight non-invasive impulsive and swept sources in preparation for seismic reflection profiling on the Oak Ridge Reservation, Tennessee. Well log data are used to determine geologic contacts and to generate synthetic seismograms for the site. Common midpoint (CMP) seismic data for each source were collected at 95 geophone groups from 125 shot points along a 400m test line. Hydrophone data were obtained at 1.5m spacing between 61m and 133m depth in a hole near the center of the CMP line. As of March, 1994, brute stacks have been completed for three of the eight sources. Depth penetration is demonstrated in brute stacks and shot gathers, which show a 200ms reflector for all of the sources tested along portions of the line. Source effectiveness will also be evaluated by comparing images of several shallower reflectors (40--150ms) which are apparent in many of the records. Imaging of these reflectors appears to depend upon the ability of the source to generate sufficient high frequency energy (>100 Hz).

  16. Probabilistic seismic hazard assessment of the historical peninsula of Istanbul

    Directory of Open Access Journals (Sweden)

    G. Ç. Ince

    2012-11-01

    Full Text Available In order to design buildings that are resistant to earthquakes, first it is necessary to determine the parameters of ground motion. In this study, the earthquake seismic hazard analysis of the Old City Districts of Istanbul (Fatih and Eminonu was probabilistically defined. For the analysis, the study zone was divided into 307 cells of 250 × 250 m using geographical information systems, and these cells were used in the mapping of all the data obtained. Then, for a building lifetime of 50 yr, the acceleration parameters of earthquake ground motions, peak ground acceleration, peak ground velocity, and spectral acceleration values of 0.2 s and 1 s were obtained at the bedrock level according to 10% and 40% exceedances. Additionally, in order to produce the artificial acceleration-time records of the ground movement in accordance with the NEHRP acceleration spectrum, the TARSCHTS computer simulation program was utilized. The results of the analysis showed that for the 10% probability of exceedance, the peak bedrock acceleration values ranged from 0.30 g to 0.40 g, and for the 40% exceedance probability the acceleration values ranged from 0.22 g to 0.17 g. The Ss 10% exceedance probability, calculated according to the spectral acceleration parameter, ranged from 0.67 g to 0.85 g and the spectral acceleration parameter S1 varied between 0.22 g–0.28 g. The Ss 40% exceedance probability, calculated according to the spectral acceleration parameter, ranged from 0.46 g to 0.38 g and the spectral acceleration parameter S1 varied from 0.12 g to 0.14 g.

  17. Seismic hazard map of North and Central America and the Caribbean

    Directory of Open Access Journals (Sweden)

    K. M. Shedlock

    1999-06-01

    Full Text Available Minimization of the loss of life, property damage, and social and economic disruption due to earthquakes depends on reliable estimates of seismic hazard. National, state, and local governments, decision makers, engineers, planners, emergency response organizations, builders, universities, and the general public require seismic hazard estimates for land use planning, improved building design and construction (including adoption of building construction codes, emergency response preparedness plans, economic forecasts, housing and employment decisions, and many more types of risk mitigation. The seismic hazard map of North and Central America and the Caribbean is the concatenation of various national and regional maps, involving a suite of approaches. The combined maps and documentation provide a useful regional seismic hazard framework and serve as a resource for any national or regional agency for further detailed studies applicable to their needs. This seismic hazard map depicts Peak Ground Acceleration (PGA with a 10% chance of exceedance in 50 years. PGA, a short-period ground motion parameter that is proportional to force, is the most commonly mapped ground motion parameter because current building codes that include seismic provisions specify the horizontal force a building should be able to withstand during an earthquake. This seismic hazard map of North and Central America and the Caribbean depicts the likely level of short-period ground motion from earthquakes in a fifty-year window. Short-period ground motions effect short-period structures (e.g., one-to-two story buildings. The highest seismic hazard values in the region generally occur in areas that have been, or are likely to be, the sites of the largest plate boundary earthquakes.

  18. Considering the ranges of uncertainties in the New Probabilistic Seismic Hazard Assessment of Germany - Version 2016

    Science.gov (United States)

    Grunthal, Gottfried; Stromeyer, Dietrich; Bosse, Christian; Cotton, Fabrice; Bindi, Dino

    2017-04-01

    The seismic load parameters for the upcoming National Annex to the Eurocode 8 result from the reassessment of the seismic hazard supported by the German Institution for Civil Engineering . This 2016 version of hazard assessment for Germany as target area was based on a comprehensive involvement of all accessible uncertainties in models and parameters into the approach and the provision of a rational framework for facilitating the uncertainties in a transparent way. The developed seismic hazard model represents significant improvements; i.e. it is based on updated and extended databases, comprehensive ranges of models, robust methods and a selection of a set of ground motion prediction equations of their latest generation. The output specifications were designed according to the user oriented needs as suggested by two review teams supervising the entire project. In particular, seismic load parameters were calculated for rock conditions with a vS30 of 800 ms-1 for three hazard levels (10%, 5% and 2% probability of occurrence or exceedance within 50 years) in form of, e.g., uniform hazard spectra (UHS) based on 19 sprectral periods in the range of 0.01 - 3s, seismic hazard maps for spectral response accelerations for different spectral periods or for macroseismic intensities. The developed hazard model consists of a logic tree with 4040 end branches and essential innovations employed to capture epistemic uncertainties and aleatory variabilities. The computation scheme enables the sound calculation of the mean and any quantile of required seismic load parameters. Mean, median and 84th percentiles of load parameters were provided together with the full calculation model to clearly illustrate the uncertainties of such a probabilistic assessment for a region of a low-to-moderate level of seismicity. The regional variations of these uncertainties (e.g. ratios between the mean and median hazard estimations) were analyzed and discussed.

  19. Declustered Seismicity catalog used in the 2017 one-year seismic hazard forecast for the Central and Eastern United States from induced and natural earthquakes

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The U. S. Geological Survey (USGS) makes long-term seismic hazard forecasts that are used in building codes. The hazard models usually consider only natural...

  20. Induced and Natural Seismicity: Earthquake Hazards and Risks in Ohio:

    Science.gov (United States)

    Besana-Ostman, G. M.; Worstall, R.; Tomastik, T.; Simmers, R.

    2013-12-01

    To adapt with increasing need to regulate all operations related to both the Utica and Marcellus shale play within the state, ODNR had recently strengthen its regulatory capability through implementation of stricter permit requirements, additional human resources and improved infrastructure. These ODNR's efforts on seismic risk reduction related to induced seismicity led to stricter regulations and many infrastructure changes related particularly to Class II wells. Permit requirement changes and more seismic monitoring stations were implemented together with additional injection data reporting from selected Class II well operators. Considering the possible risks related to seismic events in a region with relatively low seismicity, correlation between limited seismic data and injection volume information were undertaken. Interestingly, initial results showed some indications of both plugging and fracturing episodes. The real-time data transmission from seismic stations and availability of injection volume data enabled ODNR to interact with operators and manage wells dynamically. Furthermore, initial geomorphic and structural analyses indicated possible active faults in the northern and western portion of the state oriented NE-SW. The newly-mapped structures imply possible relatively bigger earthquakes in the region and consequently higher seismic risks. With the above-mentioned recent changes, ODNR have made critical improvement of its principal regulatory role in the state for oil and gas operations but also an important contribution to the state's seismic risk reduction endeavors. Close collaboration with other government agencies and the public, and working together with the well operators enhanced ODNR's capability to build a safety culture and achieve further public and industry participation towards a safer environment. Keywords: Induced seismicity, injection wells, seismic risks

  1. A Preliminary Feasibility Study On Seismic Monitoring Of Polymer Flooding

    Science.gov (United States)

    Nguyen, P. K.; Park, C.; Lim, B.; Nam, M.

    2012-12-01

    Polymer flooding using water with soluble polymers is an enhanced oil recovery technique, which intends to maximize oil-recovery sweep efficiency by minimizing fingering effects and as a result creating a smooth flood front; polymer flooding decreases the flow rates within high permeability zone while enhances those of lower permeabilities. Understanding of fluid fronts and saturations is critical to not only optimizing polymer flooding but also monitoring the efficiency. Polymer flooding monitoring can be made in single well scale with high-resolution wireline logging, in inter-well scale with tomography, and in reservoir scale with surface survey. For reservoir scale monitoring, this study makes a preliminary feasibility study based on constructing rock physics models (RPMs), which can bridge variations in reservoir parameters to the changes in seismic responses. For constructing RPMs, we change reservoir parameters with consideration of polymer flooding to a reservoir. Time-lapse seismic data for corresponding RPMs are simulated using a time-domain staggered-finite-difference modeling with implementation of a boundary condition of conventional perfect match layer. Analysis on time-lapse seismic data with respect to the changes in fluid front and saturation can give an insight on feasibility of surface seismic survey to polymer flooding. Acknowledgements: This work was supported by the Energy Efficiency & Resources of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Knowledge Economy (No. 2012T100201588). Myung Jin Nam was partially supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MEST) (No. 2011-0014684).

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

    Science.gov (United States)

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

    2007-12-01

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

  3. Seismic hazard related to rate of face advance in Lubin copper ore mine

    Directory of Open Access Journals (Sweden)

    Anna Gogolewska

    2013-09-01

    Full Text Available Seismic hazard was depicted by means of seismic activity. The rate of face advance was defined as the output-energy ratio (J/kg and as the distance in meters, which the face overcomes in a given time (for example six months. Seismic activity was analyzed in relation to such the rates of face advance. The analyses were performed for two mining districts (G-7 and G-8 of Lubin copper ore mine. The period of 2008-2009 years was taken into account. In both mining districts the outputenergy ratio did not show any strict connection between the rate of face advance and seismic activity. Whilst seismic hazard increased with increasing rate of face advance defined as the distance between two sequential positions of face in most panels of the two mining districts.

  4. An analysis of seismic hazard in the Upper Rhine Graben enlightened by the example of the New Madrid seismic zone.

    Science.gov (United States)

    Doubre, Cécile; Masson, Frédéric; Mazzotti, Stéphane; Meghraoui, Mustapha

    2014-05-01

    Seismic hazard in the "stable" continental regions and low-level deformation zones is one of the most difficult issues to address in Earth sciences. In these zones, instrumental and historical seismicity are not well known (sparse seismic networks, seismic cycle too long to be covered by the human history, episodic seismic activity) and many active structures remain poorly characterized or unknown. This is the case of the Upper Rhine Graben, the central segment of the European Cenozoic rift system (ECRIS) of Oligocene age, which extends from the North Sea through Germany and France to the Mediterranean coast over a distance of some 1100 km. Even if this region has already experienced some destructive earthquakes, its present-day seismicity is moderate and the deformation observed by geodesy is very small (below the current measurement accuracy). The strain rate does not exceed 10-10 and paleoseismic studies indicate an average return period of 2.5 to 3 103 ka for large earthquakes. The largest earthquake known for this zone is the 1356 Basel earthquake, with a magnitude generally estimated about 6.5 (Meghraoui et al., 2001) but recently re-evaluated between 6.7 and 7.1 (Fäh et al et al., 2009). A comparison of the Upper Rhine Graben with equivalent regions around the world could help improve our evaluation of seismic hazard of this region. This is the case of the New Madrid seismic zone, one of the best studied intraplate system in central USA, which experienced an M 7.0 - 7.5 earthquake in 1811-1812 and shares several characteristics with the Upper Rhine Graben, i.e. the general framework of inherited geological structures (reactivation of a failed rift / graben), seismicity patterns (spatial variability of small and large earthquakes), the null or low rate of deformation, and the location in a "stable" continental interior. Looking at the Upper Rhine Graben as an analogue of the New Madrid seismic zone, we can re-evaluate its seismic hazard and consider the

  5. Dynamic evaluation of seismic hazard and risks based on the Unified Scaling Law for Earthquakes

    Science.gov (United States)

    Kossobokov, V. G.; Nekrasova, A.

    2016-12-01

    We continue applying the general concept of seismic risk analysis in a number of seismic regions worldwide by constructing seismic hazard maps based on the Unified Scaling Law for Earthquakes (USLE), i.e. log N(M,L) = A + B•(6 - M) + C•log L, where N(M,L) is the expected annual number of earthquakes of a certain magnitude M within an seismically prone area of linear dimension L, A characterizes the average annual rate of strong (M = 6) earthquakes, B determines the balance between magnitude ranges, and C estimates the fractal dimension of seismic locus in projection to the Earth surface. The parameters A, B, and C of USLE are used to assess, first, the expected maximum magnitude in a time interval at a seismically prone cell of a uniform grid that cover the region of interest, and then the corresponding expected ground shaking parameters. After a rigorous testing against the available seismic evidences in the past (e.g., the historically reported macro-seismic intensity or paleo data), such a seismic hazard map is used to generate maps of specific earthquake risks for population, cities, and infrastructures. The hazard maps for a given territory change dramatically, when the methodology is applied to a certain size moving time window, e.g. about a decade long for an intermediate-term regional assessment or exponentially increasing intervals for a daily local strong aftershock forecasting. The of dynamical seismic hazard and risks assessment is illustrated by applications to the territory of Greater Caucasus and Crimea and the two-year series of aftershocks of the 11 October 2008 Kurchaloy, Chechnya earthquake which case-history appears to be encouraging for further systematic testing as potential short-term forecasting tool.

  6. Compilation of the GSHAP regional seismic hazard for Europe, Africa and the Middle East

    Directory of Open Access Journals (Sweden)

    D. Mayer-Rosa

    1999-06-01

    Full Text Available The seismic hazard map of the larger Europe-Africa-Middle East region has been generated as part of the global GSHAP hazard map. The hazard, expressing Peak Ground Acceleration (PGA expected at 10% probability of exceedance in 50 years, is obtained by combining the results of 16 independent regional and national projects; among these is the hazard assessment for Libya and for the wide sub-Saharan Western African region, specifically produced for this regional compilation and here discussed to some length. Features of enhanced seismic hazard are observed along the African rift zone and in the Alpine-Himalayan belt, where there is a general eastward increase in hazard with peak levels in Greece, Turkey, Caucasus and Iran.

  7. On the development of a seismic source zonation model for seismic hazard assessment in western Saudi Arabia

    Science.gov (United States)

    Zahran, Hani M.; Sokolov, Vladimir; Roobol, M. John; Stewart, Ian C. F.; El-Hadidy Youssef, Salah; El-Hadidy, Mahmoud

    2016-07-01

    A new seismic source model has been developed for the western part of the Arabian Peninsula, which has experienced considerable earthquake activity in the historical past and in recent times. The data used for the model include an up-to-date seismic catalog, results of recent studies of Cenozoic faulting in the area, aeromagnetic anomaly and gravity maps, geological maps, and miscellaneous information on volcanic activity. The model includes 18 zones ranging along the Red Sea and the Arabian Peninsula from the Gulf of Aqaba and the Dead Sea in the north to the Gulf of Aden in the south. The seismic source model developed in this study may be considered as one of the basic branches in a logic tree approach for seismic hazard assessment in Saudi Arabia and adjacent territories.

  8. Checking of seismic and tsunami hazard for coastal NPP of Chinese continent after Fukushima nuclear accident

    Institute of Scientific and Technical Information of China (English)

    Chang Xiangdong; Zhou Bengang; Zhao Lianda

    2013-01-01

    A checking on seismic and tsunami hazard for coastal nuclear power plant (NPP) of Chinese continent has been made after Japanese Fukushima nuclear accident caused by earthquake tsunami.The results of the checking are introduced briefly in this paper,including the evaluations of seismic and tsunami hazard in NPP siting period,checking results on seismic and tsunami hazard.Because Chinese coastal area belongs to the continental shelf and far from the boundary of plate collision,the tsunami hazard is not significant for coastal area of Chinese continent.However,the effect from tsunami still can' t be excluded absolutely since calculated result of Manila trench tsunami source although the tsunami wave is lower than water level from storm surge.The research about earthquake tsunami will continue in future.The tsunami warning system and emergency program of NPP will be established based on principle of defense in depth in China.

  9. Earthquake Rate Models for Evolving Induced Seismicity Hazard in the Central and Eastern US

    Science.gov (United States)

    Llenos, A. L.; Ellsworth, W. L.; Michael, A. J.

    2015-12-01

    Injection-induced earthquake rates can vary rapidly in space and time, which presents significant challenges to traditional probabilistic seismic hazard assessment methodologies that are based on a time-independent model of mainshock occurrence. To help society cope with rapidly evolving seismicity, the USGS is developing one-year hazard models for areas of induced seismicity in the central and eastern US to forecast the shaking due to all earthquakes, including aftershocks which are generally omitted from hazards assessments (Petersen et al., 2015). However, the spatial and temporal variability of the earthquake rates make them difficult to forecast even on time-scales as short as one year. An initial approach is to use the previous year's seismicity rate to forecast the next year's seismicity rate. However, in places such as northern Oklahoma the rates vary so rapidly over time that a simple linear extrapolation does not accurately forecast the future, even when the variability in the rates is modeled with simulations based on an Epidemic-Type Aftershock Sequence (ETAS) model (Ogata, JASA, 1988) to account for earthquake clustering. Instead of relying on a fixed time period for rate estimation, we explore another way to determine when the earthquake rate should be updated. This approach could also objectively identify new areas where the induced seismicity hazard model should be applied. We will estimate the background seismicity rate by optimizing a single set of ETAS aftershock triggering parameters across the most active induced seismicity zones -- Oklahoma, Guy-Greenbrier, the Raton Basin, and the Azle-Dallas-Fort Worth area -- with individual background rate parameters in each zone. The full seismicity rate, with uncertainties, can then be estimated using ETAS simulations and changes in rate can be detected by applying change point analysis in ETAS transformed time with methods already developed for Poisson processes.

  10. Seismic hazard analysis application of methodology, results, and sensitivity studies. Volume 4

    Energy Technology Data Exchange (ETDEWEB)

    Bernreuter, D. L

    1981-08-08

    As part of the Site Specific Spectra Project, this report seeks to identify the sources of and minimize uncertainty in estimates of seismic hazards in the Eastern United States. Findings are being used by the Nuclear Regulatory Commission to develop a synthesis among various methods that can be used in evaluating seismic hazard at the various plants in the Eastern United States. In this volume, one of a five-volume series, we discuss the application of the probabilistic approach using expert opinion. The seismic hazard is developed at nine sites in the Central and Northeastern United States, and both individual experts' and synthesis results are obtained. We also discuss and evaluate the ground motion models used to develop the seismic hazard at the various sites, analyzing extensive sensitivity studies to determine the important parameters and the significance of uncertainty in them. Comparisons are made between probabilistic and real spectral for a number of Eastern earthquakes. The uncertainty in the real spectra is examined as a function of the key earthquake source parameters. In our opinion, the single most important conclusion of this study is that the use of expert opinion to supplement the sparse data available on Eastern United States earthquakes is a viable approach for determining estimted seismic hazard in this region of the country. 29 refs., 15 tabs.

  11. Estimating the detectability of faults in 3D-seismic data - A valuable input to Induced Seismic Hazard Assessment (ISHA)

    Science.gov (United States)

    Goertz, A.; Kraft, T.; Wiemer, S.; Spada, M.

    2012-12-01

    In the past several years, some geotechnical operations that inject fluid into the deep subsurface, such as oil and gas development, waste disposal, and geothermal energy development, have been found or suspected to cause small to moderate sized earthquakes. In several cases the largest events occurred on previously unmapped faults, within or in close vicinity to the operated reservoirs. The obvious conclusion drawn from this finding, also expressed in most recently published best practice guidelines and recommendations, is to avoid injecting into faults. Yet, how certain can we be that all faults relevant to induced seismic hazard have been identified, even around well studied sites? Here we present a probabilistic approach to assess the capability of detecting faults by means of 3D seismic imaging. First, we populate a model reservoir with seed faults of random orientation and slip direction. Drawing random samples from a Gutenberg-Richter distribution, each seed fault is assigned a magnitude and corresponding size using standard scaling relations based on a circular rupture model. We then compute the minimum resolution of a 3D seismic survey for given acquisition parameters and frequency bandwidth. Assuming a random distribution of medium properties and distribution of image frequencies, we obtain a probability that a fault of a given size is detected, or respectively overlooked, by the 3D seismic. Weighting the initial Gutenberg-Richter fault size distribution with the probability of imaging a fault, we obtain a modified fault size distribution in the imaged volume from which we can constrain the maximum magnitude to be considered in the seismic hazard assessment of the operation. We can further quantify the value of information associated with the seismic image by comparing the expected insured value loss between the image-weighted and the unweighted hazard estimates.

  12. Seismogenic zonation and seismic hazard estimates in a Southern Italy area (Northern Apulia) characterised by moderate seismicity rates

    Science.gov (United States)

    Del Gaudio, V.; Pierri, P.; Calcagnile, G.

    2009-02-01

    The northernmost part of Apulia, in Southern Italy, is an emerged portion of the Adriatic plate, which in past centuries was hit by at least three disastrous earthquakes and at present is occasionally affected by seismic events of moderate energy. In the latest seismic hazard assessment carried out in Italy at national scale, the adopted seismogenic zonation (named ZS9) has defined for this area a single zone including parts of different structural units (chain, foredeep, foreland). However significant seismic behaviour differences were revealed among them by our recent studies and, therefore, we re-evaluated local seismic hazard by adopting a zonation, named ZNA, modifying the ZS9 to separate areas of Northern Apulia belonging to different structural domains. To overcome the problem of the limited datasets of historical events available for small zones having a relatively low rate of earthquake recurrence, an approach was adopted that integrates historical and instrumental event data. The latter were declustered with a procedure specifically devised to process datasets of low to moderate magnitude shocks. Seismicity rates were then calculated following alternative procedural choices, according to a "logic tree" approach, to explore the influence of epistemic uncertainties on the final results and to evaluate, among these, the importance of the uncertainty in seismogenic zonation. The comparison between the results obtained using zonations ZNA and ZS9 confirms the well known "spreading effect" that the use of larger seismogenic zones has on hazard estimates. This effect can locally determine underestimates or overestimates by amounts that make necessary a careful reconsideration of seismic classification and building code application.

  13. Seismogenic zonation and seismic hazard estimates in a Southern Italy area (Northern Apulia characterised by moderate seismicity rates

    Directory of Open Access Journals (Sweden)

    V. Del Gaudio

    2009-02-01

    Full Text Available The northernmost part of Apulia, in Southern Italy, is an emerged portion of the Adriatic plate, which in past centuries was hit by at least three disastrous earthquakes and at present is occasionally affected by seismic events of moderate energy. In the latest seismic hazard assessment carried out in Italy at national scale, the adopted seismogenic zonation (named ZS9 has defined for this area a single zone including parts of different structural units (chain, foredeep, foreland. However significant seismic behaviour differences were revealed among them by our recent studies and, therefore, we re-evaluated local seismic hazard by adopting a zonation, named ZNA, modifying the ZS9 to separate areas of Northern Apulia belonging to different structural domains. To overcome the problem of the limited datasets of historical events available for small zones having a relatively low rate of earthquake recurrence, an approach was adopted that integrates historical and instrumental event data. The latter were declustered with a procedure specifically devised to process datasets of low to moderate magnitude shocks. Seismicity rates were then calculated following alternative procedural choices, according to a "logic tree" approach, to explore the influence of epistemic uncertainties on the final results and to evaluate, among these, the importance of the uncertainty in seismogenic zonation. The comparison between the results obtained using zonations ZNA and ZS9 confirms the well known "spreading effect" that the use of larger seismogenic zones has on hazard estimates. This effect can locally determine underestimates or overestimates by amounts that make necessary a careful reconsideration of seismic classification and building code application.

  14. Preliminary hazards analysis of thermal scrap stabilization system. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, W.S.

    1994-08-23

    This preliminary analysis examined the HA-21I glovebox and its supporting systems for potential process hazards. Upon further analysis, the thermal stabilization system has been installed in gloveboxes HC-21A and HC-21C. The use of HC-21C and HC-21A simplified the initial safety analysis. In addition, these gloveboxes were cleaner and required less modification for operation than glovebox HA-21I. While this document refers to glovebox HA-21I for the hazards analysis performed, glovebox HC-21C is sufficiently similar that the following analysis is also valid for HC-21C. This hazards analysis document is being re-released as revision 1 to include the updated flowsheet document (Appendix C) and the updated design basis (Appendix D). The revised Process Flow Schematic has also been included (Appendix E). This Current revision incorporates the recommendations provided from the original hazards analysis as well. The System Design Description (SDD) has also been appended (Appendix H) to document the bases for Safety Classification of thermal stabilization equipment.

  15. Probabilistic Seismic Hazard Assesment for Bulgaria as a Basis for a new National Building Code

    Science.gov (United States)

    Solakov, D.; Simeonova, S.; Christoskov, L.; Trifonova, P.; Aleksandrova, I.

    2012-04-01

    The territory of Bulgaria represents a typical example of high seismic risk area in the eastern part of the Balkan Peninsula. Bulgaria contains important industrial areas that face considerable earthquake risk. Moreover, the seismicity of the neighboring countries, like Greece, Turkey, former Yugoslavia and Romania (especially Vrancea-Romania intermediate earthquakes involving the non-crustal lithosphere), influences the seismic hazard in Bulgaria. Seismic hazard maps proposed as part of a new building code for Bulgaria based on the recommendations in EUROCODE 8 are presented in the study. The probabilistic seismic hazard analysis (PSHA) carries out integration over the total expected seismicity during a given exposure period to provide the estimate of a strong-motion parameter of interest with a specified confidence level. The basic approach used for the creation of ground motion maps combines via GIS, source-geometry, earthquake occurrence model, the strength of the earthquake sources, and the appropriate attenuation relations. In the study seismic hazard maps for Bulgaria are presented in terms of Peak Ground Acceleration (PGA) in agreement with EC8. As recommended in EC8, the maps are calculated for a 475 years return period (probability of exceedance of 10% in 50 years) for the design earthquake and for a 95 years return period (probability of exceedance of 10% in 10 years) for weaker earthquakes with higher frequency of occurrence. The PSHA was performed, using the Bulgarian version of computer code EQRISK. For the sensitivity analysis on the characterization of the seismicity in the seismic sources a PSHA for 500 randomly chosen models was run. The results suggested that uncertainties in seismic characteristics have relatively small effect on the final seismic hazard. A procedure called disaggregation has been applied to examine the spatial and magnitude dependence of PSHA results. The aim is to determine the magnitudes and distances that contribute to the

  16. Submarine landslide and tsunami hazards offshore southern Alaska: Seismic strengthening versus rapid sedimentation

    Science.gov (United States)

    Sawyer, Derek E.; Reece, Robert S.; Gulick, Sean P. S.; Lenz, Brandi L.

    2017-08-01

    The southern Alaskan offshore margin is prone to submarine landslides and tsunami hazards due to seismically active plate boundaries and extreme sedimentation rates from glacially enhanced mountain erosion. We examine the submarine landslide potential with new shear strength measurements acquired by Integrated Ocean Drilling Program Expedition 341 on the continental slope and Surveyor Fan. These data reveal lower than expected sediment strength. Contrary to other active margins where seismic strengthening enhances slope stability, the high-sedimentation margin offshore southern Alaska behaves like a passive margin from a shear strength perspective. We interpret that seismic strengthening occurs but is offset by high sedimentation rates and overpressure. This conclusion is supported by shear strength outside of the fan that follow an active margin trend. More broadly, seismically active margins with wet-based glaciers are susceptible to submarine landslide hazards because of the combination of high sedimentation rates and earthquake shaking.

  17. Earthquake damage potential and critical scour depth of bridges exposed to flood and seismic hazards under lateral seismic loads

    Science.gov (United States)

    Song, Shin-Tai; Wang, Chun-Yao; Huang, Wen-Hsiu

    2015-12-01

    Many bridges located in seismic hazard regions suffer from serious foundation exposure caused by riverbed scour. Loss of surrounding soil significantly reduces the lateral strength of pile foundations. When the scour depth exceeds a critical level, the strength of the foundation is insufficient to withstand the imposed seismic demand, which induces the potential for unacceptable damage to the piles during an earthquake. This paper presents an analytical approach to assess the earthquake damage potential of bridges with foundation exposure and identify the critical scour depth that causes the seismic performance of a bridge to differ from the original design. The approach employs the well-accepted response spectrum analysis method to determine the maximum seismic response of a bridge. The damage potential of a bridge is assessed by comparing the imposed seismic demand with the strengths of the column and the foundation. The versatility of the analytical approach is illustrated with a numerical example and verified by the nonlinear finite element analysis. The analytical approach is also demonstrated to successfully determine the critical scour depth. Results highlight that relatively shallow scour depths can cause foundation damage during an earthquake, even for bridges designed to provide satisfactory seismic performance.

  18. Setting the Stage for Harmonized Risk Assessment by Seismic Hazard Harmonization in Europe (SHARE)

    Science.gov (United States)

    Woessner, Jochen; Giardini, Domenico; SHARE Consortium

    2010-05-01

    Probabilistic seismic hazard assessment (PSHA) is arguably one of the most useful products that seismology can offer to society. PSHA characterizes the best available knowledge on the seismic hazard of a study area, ideally taking into account all sources of uncertainty. Results form the baseline for informed decision making, such as building codes or insurance rates and provide essential input to each risk assessment application. Several large scale national and international projects have recently been launched aimed at improving and harmonizing PSHA standards around the globe. SHARE (www.share-eu.org) is the European Commission funded project in the Framework Programme 7 (FP-7) that will create an updated, living seismic hazard model for the Euro-Mediterranean region. SHARE is a regional component of the Global Earthquake Model (GEM, www.globalquakemodel.org), a public/private partnership initiated and approved by the Global Science Forum of the OECD-GSF. GEM aims to be the uniform, independent and open access standard to calculate and communicate earthquake hazard and risk worldwide. SHARE itself will deliver measurable progress in all steps leading to a harmonized assessment of seismic hazard - in the definition of engineering requirements, in the collection of input data, in procedures for hazard assessment, and in engineering applications. SHARE scientists will create a unified framework and computational infrastructure for seismic hazard assessment and produce an integrated European probabilistic seismic hazard assessment (PSHA) model and specific scenario based modeling tools. The results will deliver long-lasting structural impact in areas of societal and economic relevance, they will serve as reference for the Eurocode 8 (EC8) application, and will provide homogeneous input for the correct seismic safety assessment for critical industry, such as the energy infrastructures and the re-insurance sector. SHARE will cover the whole European territory, the

  19. Integrating fault and seismological data into a probabilistic seismic hazard model for Italy.

    Science.gov (United States)

    Valentini, Alessandro; Visini, Francesco; Pace, Bruno

    2017-04-01

    We present the results of new probabilistic seismic hazard analysis (PSHA) for Italy based on active fault and seismological data. Combining seismic hazard from active fault with distributed seismic sources (where there are no data on active faults) is the backbone of this work. Far away from identifying a best procedure, currently adopted approaches combine active faults and background sources applying a threshold magnitude, generally between 5.5 and 7, over which seismicity is modelled by faults, and under which is modelled by distributed sources or area sources. In our PSHA we (i) apply a new method for the treatment of geologic data of major active faults and (ii) propose a new approach to combine these data with historical seismicity to evaluate PSHA for Italy. Assuming that deformation is concentrated in correspondence of fault, we combine the earthquakes occurrences derived from the geometry and slip rates of the active faults with the earthquakes from the spatially smoothed earthquake sources. In the vicinity of an active fault, the smoothed seismic activity is gradually reduced by a fault-size driven factor. Even if the range and gross spatial distribution of expected accelerations obtained in our work are comparable to the ones obtained through methods applying seismic catalogues and classical zonation models, the main difference is in the detailed spatial pattern of our PSHA model: our model is characterized by spots of more hazardous area, in correspondence of mapped active faults, while the previous models give expected accelerations almost uniformly distributed in large regions. Finally, we investigate the impact due to the earthquake rates derived from two magnitude-frequency distribution (MFD) model for faults on the hazard result and in respect to the contribution of faults versus distributed seismic activity.

  20. Uncertainty treatment and sensitivity analysis of the European Probabilistic Seismic Hazard Assessment

    Science.gov (United States)

    Woessner, J.; Danciu, L.; Giardini, D.

    2013-12-01

    Probabilistic seismic hazard assessment (PSHA) aims to characterize the best available knowledge on seismic hazard of a study area, ideally taking into account all sources of uncertainty. The EC-FP7 funded project Seismic Hazard Harmonization for Europe (SHARE) generated a time-independent community-based hazard model for the European region for ground motion parameters spanning from spectral ordinates of PGA to 10s and annual exceedance probabilities from one-in-ten to one-in-ten thousand years. The results will serve as reference to define engineering applications within the EuroCode 8 and provide homogeneous input for state-of-the art seismic safety assessment of critical infrastructure. The SHARE model accounts for uncertainties, whether aleatory or epistemic, via a logic tree. Epistemic uncertainties within the seismic source-model are represented by three source models including a traditional area source model, a model that characterizes fault sources, and an approach that uses kernel-smoothing for seismicity and fault source moment release. Activity rates and maximum magnitudes in the source models are treated as aleatory uncertainties. For practical implementation and computational purposes, some of the epistemic uncertainties in the source model (i.e. dip and strike angles) are treated as aleatory, and a mean seismicity model is considered. Epistemic uncertainties for ground motions are considered by multiple Ground Motion Prediction Equations as a function of tectonic settings and treated as being correlated. The final results contain the full distribution of ground motion variability. We show how we used the logic-tree approach to consider the alternative models and how, based on the degree-of-belief in the models, we defined the weights of the single branches. This contribution features results and sensitivity analysis of the entire European hazard model and selected sites.

  1. Reduction of uncertainties in probabilistic seismic hazard analysis

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Jeong Moon; Choun, Young Sun; Choi, In Kil [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-02-01

    An integrated research for the reduction of conservatism and uncertainties in PSHA in Korea was performed. The research consisted of five technical task areas as follows; Task 1: Earthquake Catalog Development for PSHA. Task 2: Evaluation of Seismicity and Tectonics of the Korea Region. Task 3: Development of a Ground Motion Relationships. Task 4: Improvement of PSHA Modelling Methodology. Task 5: Development of Seismic Source Interpretations for the region of Korea for Inputs to PSHA. A series of tests on an ancient wooden house and an analysis on medium size earthquake in Korea were performed intensively. Signification improvement, especially in the estimation of historical earthquake, ground motion attenuation, and seismic source interpretations, were made through this study. 314 refs., 180 figs., 54 tabs. (Author)

  2. A probabilistic seismic hazard assessment for Greece and the surrounding region including site-specific considerations

    Directory of Open Access Journals (Sweden)

    P. Mäntyniemi

    2004-06-01

    Full Text Available A probabilistic approach was applied to map the seismic hazard in Greece and the surrounding region. The procedure does not require any specification of seismic sources or/and seismic zones and allows for the use of the whole seismological record, comprising both historical and instrumental data, available for the region of interest. The new seismic hazard map prepared for Greece and its vicinity specifies a 10% probability of exceedance of the given Peak Ground Acceleration (PGA values for shallow seismicity and intermediate soil conditions for an exposure time of 50 years. When preparing the map, the new PGA attenuation relation given by Margaris et al. (2001 was employed. The new map shows a spatial distribution of the seismic hazard that corresponds well with the features of shallow seismicity within the examined region. It depicts the level of seismic hazard in which the exceedance of the PGA value of 0.25 g may be expected to occur within limited areas. The highest estimated levels of seismic hazard inside the territory of Greece are found in the Northern Sporades Islands, where PGA values in excess of 0.50 g are reached at individual sites, and in the Zante Island in Western Greece, where PGA values in the range of 0.35 g to 0.40 g are obtained at more numerous localities. High values are also observed in the sea between the Karpathos and Rhodes islands, near the Island of Amorgos (Cyclades Archipelago and in the Southwestern Peloponnesus. The levels of seismic hazard at the sites of seven Greek cities (Athens, Jannena, Kalamata, Kozani, Larisa, Rhodes and Thessaloniki were also estimated in terms of probabilities that a given PGA value will be exceeded at least once during a time interval of 1, 50 and 100 years at those sites. These probabilities were based on the maximum horizontal PGA values obtained by applying the design earthquake procedure, and the respective median values obtained were 0.24 g for Athens, 0.28 g

  3. A first-order seismotectonic regionalization of Mexico for seismic hazard and risk estimation

    Science.gov (United States)

    Zúñiga, F. Ramón; Suárez, Gerardo; Figueroa-Soto, Ángel; Mendoza, Avith

    2017-06-01

    The purpose of this work is to define a seismic regionalization of Mexico for seismic hazard and risk analyses. This seismic regionalization is based on seismic, geologic, and tectonic characteristics. To this end, a seismic catalog was compiled using the more reliable sources available. The catalog was made homogeneous in magnitude in order to avoid the differences in the way this parameter is reported by various agencies. Instead of using a linear regression to converts from m b and M d to M s or M w , using only events for which estimates of both magnitudes are available (i.e., paired data), we used the frequency-magnitude relations relying on the a and b values of the Gutenberg-Richter relation. The seismic regions are divided into three main categories: seismicity associated with the subduction process along the Pacific coast of Mexico, in-slab events within the down-going COC and RIV plates, and crustal seismicity associated to various geologic and tectonic regions. In total, 18 seismic regions were identified and delimited. For each, the a and b values of the Gutenberg-Richter relation were determined using a maximum likelihood estimation. The a and b parameters were repeatedly estimated as a function of time for each region, in order to confirm their reliability and stability. The recurrence times predicted by the resulting Gutenberg-Richter relations obtained are compared with the observed recurrence times of the larger events in each region of both historical and instrumental earthquakes.

  4. Current issues and related activities in seismic hazard analysis in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Jeong-Moon [Korea Atomic Energy Research Inst., Taejon (Korea, Republic of); Lee, Jong-Rim; Chang, Chun-Joong

    1997-03-01

    This paper discusses some technical issues identified from the seismic hazard analyses for probabilistic safety assessment on the operating Korean nuclear power plants and the related activities to resolve the issues. Since there are no strong instrumental earthquake records in Korea, the seismic hazard analysis is mainly dependent on the historical earthquake records. Results of the past seismic hazard analyses show that there are many uncertainties in attenuation function and intensity level and that there is a need to improve statistical method. The identification of the activity of the Yangsan Fault, which is close to nuclear power plant sites, has been an important issue. But the issue has not been resolved yet in spite of much research works done. Recently, some capable faults were found in the offshore area of Gulupdo Island in the Yellow Sea. It is anticipated that the results of research on both the Yangsan Fault and reduction of uncertainty in seismic hazard analysis will have an significant influence on seismic design and safety assessment of nuclear power plants in the future. (author)

  5. Seismic hazard methodology for the Central and Eastern United States. Volume 1: methodology. Final report

    Energy Technology Data Exchange (ETDEWEB)

    McGuire, R.K.; Veneziano, D.; Toro, G.; O' Hara, T.; Drake, L.; Patwardhan, A.; Kulkarni, R.; Kenney, R.; Winkler, R.; Coppersmith, K.

    1986-07-01

    A methodology to estimate the hazard of earthquake ground motion at a site has been developed. The methodology consists of systematic procedures to characterize earthquake sources, the seismicity parameters of those sources, and functions for the attenuation of seismic energy, incorporating multiple input interpretations by earth scientists. Uncertainties reflecting permissible alternative inperpretations are quantified by use of probability logic trees and are propagated through the hazard results. The methodology is flexible and permits, for example, interpretations of seismic sources that are consistent with earth-science practice in the need to depict complexity and to accommodate alternative hypotheses. This flexibility is achieved by means of a tectonic framework interpretation from which alternative seismic sources are derived. To estimate rates of earthquake recurrence, maximum use is made of the historical earthquake database in establishing a uniform measure of earthquake size, in identifying independent events, and in detemining the completeness of the earthquake record in time, space, and magnitude. Procedures developed as part of the methodology permit relaxation of the usual assumption of homogeneous seismicity within a source and provide unbiased estimates of recurrence parameters. The methodology incorporates the Poisson-exponential earthquake recurrence model and an extensive assessment of its applicability is provided. Finally, the methodology includes procedures to aggregate hazard results from a number of separate input interpretations to obtain a best-estimate value of hazard, together with its uncertainty, at a site.

  6. OCEAN-BOTTOM BROADBAND SEISMIC STATIONS AS TOOLS TO IDENTIFY AND MONITOR SEISMIC HAZARD IN COASTAL ZONES (Invited)

    Science.gov (United States)

    Dolenc, D.; Romanowicz, B. A.

    2009-12-01

    Ocean-bottom broadband seismic stations (OBSs) are installed at the interface of the solid earth and the ocean. As such, they are sensitive to the processes that originate in the solid earth (e.g., earthquakes), ocean (e.g., tsunamis), and even atmosphere (e.g., cyclones). Observations of ground motions at the OBSs can therefore be used to study and monitor processes that contribute to hazards in the coastal zones. These processes include earthquakes, underwater landslides, underwater volcanoes, and tsunamis. Numerous offshore faults are located too far from the shore for their background seismicity to be studied by land seismic stations alone, yet they are capable of generating large earthquakes that can threaten coastal communities. OBSs can record offshore seismicity that would be missed by relying only on the land stations. OBS data can also significantly improve locations and source mechanism determination for stronger offshore events that are observed on the land stations as they can significantly improve azimuthal coverage. As such, OBSs are essential for identifying seismic hazard from offshore faults. In addition, nearshore OBSs can improve studies of earthquakes on the land faults, in particular when the faults are located close to the ocean, resulting in limited azimuthal coverage provided by land stations alone. OBSs can also provide information about the offshore subsurface velocity structure, which can significantly affect the amount of shaking in the coastal regions. Velocity structure can be determined by compliance analysis that takes advantage of the seafloor deformation due to infragravity waves (long-period ocean surface waves). Reliable offshore velocity models are needed for modeling seismic wave propagation and for subsequent modeling of the amount of shaking expected in the coastal regions due to strong local and regional offshore earthquakes. We will present examples from the permanent ocean-bottom broadband seismic station MOBB located at

  7. The social psychology of seismic hazard adjustment: re-evaluating the international literature

    Science.gov (United States)

    Solberg, C.; Rossetto, T.; Joffe, H.

    2010-08-01

    The majority of people at risk from earthquakes do little or nothing to reduce their vulnerability. Over the past 40 years social scientists have tried to predict and explain levels of seismic hazard adjustment using models from behavioural sciences such as psychology. The present paper is the first to synthesise the major findings from the international literature on psychological correlates and causes of seismic adjustment at the level of the individual and the household. It starts by reviewing research on seismic risk perception. Next, it looks at norms and normative beliefs, focusing particularly on issues of earthquake protection responsibility and trust between risk stakeholders. It then considers research on attitudes towards seismic adjustment attributes, specifically beliefs about efficacy, control and fate. It concludes that an updated model of seismic adjustment must give the issues of norms, trust, power and identity a more prominent role. These have been only sparsely represented in the social psychological literature to date.

  8. Geophysical Studies of Seismic Hazard in the Tahoe City Sub-basin, Lake Tahoe, California

    Science.gov (United States)

    Muehlberg, J. M.; Schweickert, R. A.; McHugh, J.; Rasmussen, T.; Louie, J. N.

    2003-12-01

    The Lake Tahoe basin has the potential for serious earthquakes and earthquake-related tsunamis. The history of lake level fluctuations should be recorded in sediments beneath the Lake's outlet at Tahoe City. Borehole data show the sediments consist primarily of a thick sequence of lacustrine silts and clays with interbedded sands. Beneath this unit is an older Q-T (?) sand and gravel sequence of unknown origin. The lacustrine deposits locally rest upon 2.0 Ma latites, which in turn rest upon the older sand and gravel sequence. Near the outlet, several fault scarps displace units less than 2.0 m.y. old. These scarps may influence the stability of the dam across the outlet and the sequence and extent of lake level high stands. Our project is integrating geophysical and stratigraphic data to further define and describe the Tahoe City sub-basin. We collected new gravity data to provide an estimate of basin depths across the outlet and help define subsurface faults. Preliminary data suggest the maximum basin depth is 180 m, near the outlet. Refraction microtremor surveys yielded information about stratigraphy and shear velocities of the Quaternary deposits. The average shear wave velocity to 30-m depth obtained for this area is 334 m/s. These values correspond to a NEHRP soil hazard class of D, similar to that found in other lacustrine basins of the region. Soils in this NEHRP class tend to show a significant amplification of shaking, posing increased hazard to structures. We are combining stratigraphic with gravity and seismic data to produce geologic cross sections having information on basin depths and Quaternary faults.

  9. Global seismic hazard assessment program (GSHAP) in continental Asia

    Energy Technology Data Exchange (ETDEWEB)

    Peizen Zhang [China Seismological Bureau, Beijing (Switzerland). Inst. of Geology; Zhixian Yang [China Seismological Bureau, Beijing (Switzerland). Inst. of Crustal Dynamics; Gupta, H.K.; Bathia, S.C. [National Geophysical Research Institute, Hyderabad (India); Shedlock, K.M. [United States Geological Survey, Golden, CO (United States)

    1999-12-01

    The regional hazard mapping for the whole Eastern Asia was coordinated by the SSB Regional Centre in Beijing originating from the expansion of the test area initially established in the border region of China-India-Nepal-Myanmar-Bangladesh, in coordination with the other Regional Centres (JIPE, Moscow and AGSO, Canberra) and with the direct assistance of the USGS. All Eastern Asian countries have participated directly in the this regional effort, with the additional of Japan, for which an existing national hazard map was incorporated. The regional hazard depicts the expected peak ground acceleration with 10% exceedance probability in 50 years.

  10. Global Seismic Hazard Assessment Program (GSHAP in continental Asia

    Directory of Open Access Journals (Sweden)

    S. C. Bhatia

    1999-06-01

    Full Text Available The regional hazard mapping for the whole Eastern Asia was coordinated by the SSB Regional Centre in Beijing, originating from the expansion of the test area initially established in the border region of China-India-Nepal-Myanmar- Bangla Dash, in coordination with the other Regional Centres (JIPE, Moscow, and AGSO, Canberra and with the direct assistance of the USGS. All Eastern Asian countries have participated directly in this regional effort, with the addition of Japan, for which an existing national hazard map was incorporated. The regional hazard depicts the expected peak ground acceleration with 10% exceedance probability in 50 years.

  11. SRS BEDROCK PROBABILISTIC SEISMIC HAZARD ANALYSIS (PSHA) DESIGN BASIS JUSTIFICATION (U)

    Energy Technology Data Exchange (ETDEWEB)

    (NOEMAIL), R

    2005-12-14

    This represents an assessment of the available Savannah River Site (SRS) hard-rock probabilistic seismic hazard assessments (PSHAs), including PSHAs recently completed, for incorporation in the SRS seismic hazard update. The prior assessment of the SRS seismic design basis (WSRC, 1997) incorporated the results from two PSHAs that were published in 1988 and 1993. Because of the vintage of these studies, an assessment is necessary to establish the value of these PSHAs considering more recently collected data affecting seismic hazards and the availability of more recent PSHAs. This task is consistent with the Department of Energy (DOE) order, DOE O 420.1B and DOE guidance document DOE G 420.1-2. Following DOE guidance, the National Map Hazard was reviewed and incorporated in this assessment. In addition to the National Map hazard, alternative ground motion attenuation models (GMAMs) are used with the National Map source model to produce alternate hazard assessments for the SRS. These hazard assessments are the basis for the updated hard-rock hazard recommendation made in this report. The development and comparison of hazard based on the National Map models and PSHAs completed using alternate GMAMs provides increased confidence in this hazard recommendation. The alternate GMAMs are the EPRI (2004), USGS (2002) and a regional specific model (Silva et al., 2004). Weights of 0.6, 0.3 and 0.1 are recommended for EPRI (2004), USGS (2002) and Silva et al. (2004) respectively. This weighting gives cluster weights of .39, .29, .15, .17 for the 1-corner, 2-corner, hybrid, and Greens-function models, respectively. This assessment is judged to be conservative as compared to WSRC (1997) and incorporates the range of prevailing expert opinion pertinent to the development of seismic hazard at the SRS. The corresponding SRS hard-rock uniform hazard spectra are greater than the design spectra developed in WSRC (1997) that were based on the LLNL (1993) and EPRI (1988) PSHAs. The

  12. Seismic Hazard Assessment in Stable Continental Regions of Northen Eurasia

    Science.gov (United States)

    Levshenko, V.; Yunga, S.

    2009-04-01

    Assessment of the seismic potential and related risk level of stable continental regions (SCR) is a highly complex problem, as the applicability of techniques developed for seismically active areas to the areas that have no or limited seismic records is still under discussion. The seismotectonic data of the SCR are very poor because of low seismic activity and an insufficient seismological monitoring system. On the other hand, the geological knowledge is rather good owing to extensive geological and geophysical surveys held during the past decades. Digital data base is compiled from all collected data. Procedure of its interpretation use current internationally recognized methods and criteria and include several stages. 1) Microearthquake detection on the base of seismograms which used polarization analysis, artificial intellect method, wavelet analysis. 2) Paleoearthquakes, prehistorical, historical and instrumentally recorded earthquakes are investigated. 3) The faults capability are analyzed and appropriate seismotectonic model is created. 4) Amplitudes of neotectonic vertical movements, basement and Moho boundaries are interpreted numerically in terms of deformation of earth crust in the investigated region through curvatures calculations. 5) Seismotectonic deformation rate (seismic strain release) are estimated analytically and thus it dependence from maximum earthquake magnitude (Mmax) and the seismic activity parameters are derived. 6) Maximum earthquake potential Mmax of capable faults is evaluated on the base of comparison of geological and seismic deformation. Magnitude of design basis earthquake is estimated using recurrence plot. 7) Engineering Seismology Studies included estimation of peak ground acceleration (PGA) and duration of strong shaking. The PGA is derived from the regional attenuation lows for ground motion versus distance. We apply the above approach to the several critical facilities which have been investigated during last years. The

  13. Neo-deterministic seismic hazard scenarios for India—a preventive tool for disaster mitigation

    Science.gov (United States)

    Parvez, Imtiyaz A.; Magrin, Andrea; Vaccari, Franco; Ashish; Mir, Ramees R.; Peresan, Antonella; Panza, Giuliano Francesco

    2017-08-01

    Current computational resources and physical knowledge of the seismic wave generation and propagation processes allow for reliable numerical and analytical models of waveform generation and propagation. From the simulation of ground motion, it is easy to extract the desired earthquake hazard parameters. Accordingly, a scenario-based approach to seismic hazard assessment has been developed, namely the neo-deterministic seismic hazard assessment (NDSHA), which allows for a wide range of possible seismic sources to be used in the definition of reliable scenarios by means of realistic waveforms modelling. Such reliable and comprehensive characterization of expected earthquake ground motion is essential to improve building codes, particularly for the protection of critical infrastructures and for land use planning. Parvez et al. (Geophys J Int 155:489-508, 2003) published the first ever neo-deterministic seismic hazard map of India by computing synthetic seismograms with input data set consisting of structural models, seismogenic zones, focal mechanisms and earthquake catalogues. As described in Panza et al. (Adv Geophys 53:93-165, 2012), the NDSHA methodology evolved with respect to the original formulation used by Parvez et al. (Geophys J Int 155:489-508, 2003): the computer codes were improved to better fit the need of producing realistic ground shaking maps and ground shaking scenarios, at different scale levels, exploiting the most significant pertinent progresses in data acquisition and modelling. Accordingly, the present study supplies a revised NDSHA map for India. The seismic hazard, expressed in terms of maximum displacement (Dmax), maximum velocity (Vmax) and design ground acceleration (DGA), has been extracted from the synthetic signals and mapped on a regular grid over the studied territory.

  14. Probabilistic seismic hazard assessment of Bishkek, Kyrgyzstan, considering empirically estimated site effects

    Directory of Open Access Journals (Sweden)

    Shahid Ullah

    2015-04-01

    Full Text Available It is well known that variability in the surface geology potentially leads to the modification of earthquake-induced ground motion over short distances. Although this effect is of major importance when seismic hazard is assessed at the urban level, it is very often not appropriately accounted for. In this paper, we present a first attempt at taking into account the influence of the shallow geological structure on the seismic hazard assessment for Bishkek, Kyrgyzstan, using a proxy (Vs30 that has been estimated from in situ seismic noise array analyses, and considering response spectral ratios calculated by analyzing a series of earthquake recordings of a temporary seismic network. To highlight the spatial variability of the observed ground motion, the obtained results are compared with those estimated assuming a homogeneous Vs30 value over the whole urban area. The seismic hazard is evaluated in terms of peak ground acceleration (PGA and spectral acceleration (SA at different periods (frequencies. The presented results consider the values obtained for a 10% probability of exceedance in 50 years. The largest SA estimated considering a rock site classification of the area (0.43 g is observed for a period of 0.1 s (10 Hz, while the maximum PGA reaches 0.21 g. When site effects are included through the Vs30 proxy in the seismic hazard calculation, the largest SA, 0.67 g, is obtained for a period of 0.3 s (about 3.3 Hz. In terms of PGA, in this case the largest estimated value reaches 0.31 g in the northern part of the town. When the variability of ground motion is accounted for through response spectrum ratios, the largest SA reaches a value as high as 1.39 g at a period of 0.5 s. In general, considering site effects in the seismic hazard assessment of Bishkek leads to an increase of seismic hazard in the north of the city, which is thus identified as the most hazardous part within the study area and which is more far away from the faults.

  15. Assessing sensitivity of Probabilistic Seismic Hazard Analysis (PSHA) to fault parameters: Sumatra case study

    Science.gov (United States)

    Omang, A.; Cummins, P. R.; Horspool, N.; Hidayati, S.

    2012-12-01

    Slip rate data and fault geometry are two important inputs in determining seismic hazard, because they are used to estimate earthquake recurrence intervals which strongly influence the hazard level in an area. However, the uncertainty of slip-rates and geometry of the fault are rarely considered in any probabilistic seismic hazard analysis (PSHA), which is surprising given the estimates of slip-rates can vary significantly from different data sources (e.g. geological vs. Geodetic). We use the PSHA method to assess the sensitivity of seismic hazard to fault slip-rates along the Great Sumatran Fault in Sumatra, Indonesia. We will consider the epistemic uncertainty of fault slip rate by employing logic trees to include alternative slip rate models. The weighting of the logic tree is determined by the probability density function of the slip rate estimates using the approach of Zechar and Frankel (2009). We consider how the PSHA result accounting for slip rate uncertainty differs from that for a specific slip rate by examining hazard values as a function of return period and distance from the fault. We also consider the geometry of the fault, especially the top and the bottom of the rupture area within a fault, to study the effect from different depths. Based on the results of this study, in some cases the uncertainty in fault slip-rates, fault geometry and maximum magnitude have a significant effect on hazard level and area impacted by earthquakes and should be considered in PSHA studies.

  16. A Sensitivity Study for an Evaluation of Input Parameters Effect on a Preliminary Probabilistic Tsunami Hazard Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Rhee, Hyun-Me; Kim, Min Kyu; Choi, In-Kil [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Sheen, Dong-Hoon [Chonnam National University, Gwangju (Korea, Republic of)

    2014-10-15

    The tsunami hazard analysis has been based on the seismic hazard analysis. The seismic hazard analysis has been performed by using the deterministic method and the probabilistic method. To consider the uncertainties in hazard analysis, the probabilistic method has been regarded as attractive approach. The various parameters and their weight are considered by using the logic tree approach in the probabilistic method. The uncertainties of parameters should be suggested by analyzing the sensitivity because the various parameters are used in the hazard analysis. To apply the probabilistic tsunami hazard analysis, the preliminary study for the Ulchin NPP site had been performed. The information on the fault sources which was published by the Atomic Energy Society of Japan (AESJ) had been used in the preliminary study. The tsunami propagation was simulated by using the TSUNAMI{sub 1}.0 which was developed by Japan Nuclear Energy Safety Organization (JNES). The wave parameters have been estimated from the result of tsunami simulation. In this study, the sensitivity analysis for the fault sources which were selected in the previous studies has been performed. To analyze the effect of the parameters, the sensitivity analysis for the E3 fault source which was published by AESJ was performed. The effect of the recurrence interval, the potential maximum magnitude, and the beta were suggested by the sensitivity analysis results. Level of annual exceedance probability has been affected by the recurrence interval.. Wave heights have been influenced by the potential maximum magnitude and the beta. In the future, the sensitivity analysis for the all fault sources in the western part of Japan which were published AESJ would be performed.

  17. Robust satellite techniques for volcanicand seismic hazards monitoring

    Directory of Open Access Journals (Sweden)

    I. Scaffidi

    2004-06-01

    Full Text Available Several satellite techniques have been proposed to monitor events related to seismic and volcanic activity. A selfadaptive approach (RAT, Robust AVHRR Techniques has recently been proposed which seems able to recognise space-time anomalies, differently related to such events, also in the presence of highly variable contributions from atmospheric (transmittance, surface (emissivity and morphology and observational (time/season, but also solar and satellite zenithal angles conditions. On the basis of NOAA-AVHRR data, the RAT aprroach has already been applied to Mount Etna volcanic ash cloud monitoring in daytime, and to seismic area monitoring in Southern Italy. This paper presents the theoretical basis for the extension of RAT approach also to nighttime volcanic ash cloud detection, together with its possible implementation to lava flow monitoring. One example of successful forecasting (few days before of a new lava vent opening during the Mount Etna eruption of July 2001 will be discussed in some detail. Progress on the use of the same approach on seismically active area monitoring will be discussed by comparison with previous results achieved on the Irpinia-Basilicata earthquake (MS = 6.9, which occurred on November 23rd 1980 in Southern Italy.

  18. Re-evaluation and updating of the seismic hazard of Lebanon

    Science.gov (United States)

    Huijer, Carla; Harajli, Mohamed; Sadek, Salah

    2016-01-01

    This paper presents the results of a study undertaken to evaluate the implications of the newly mapped offshore Mount Lebanon Thrust (MLT) fault system on the seismic hazard of Lebanon and the current seismic zoning and design parameters used by the local engineering community. This re-evaluation is critical, given that the MLT is located at close proximity to the major cities and economic centers of the country. The updated seismic hazard was assessed using probabilistic methods of analysis. The potential sources of seismic activities that affect Lebanon were integrated along with any/all newly established characteristics within an updated database which includes the newly mapped fault system. The earthquake recurrence relationships of these sources were developed from instrumental seismology data, historical records, and earlier studies undertaken to evaluate the seismic hazard of neighboring countries. Maps of peak ground acceleration contours, based on 10 % probability of exceedance in 50 years (as per Uniform Building Code (UBC) 1997), as well as 0.2 and 1 s peak spectral acceleration contours, based on 2 % probability of exceedance in 50 years (as per International Building Code (IBC) 2012), were also developed. Finally, spectral charts for the main coastal cities of Beirut, Tripoli, Jounieh, Byblos, Saida, and Tyre are provided for use by designers.

  19. Probabilistic seismic hazard assessment of NW and central Himalayas and the adjoining region

    Indian Academy of Sciences (India)

    Madan Mohan Rout; Josodhir Das; Kamal; Ranjit Das

    2015-04-01

    The Himalayan region has undergone significant development and to ensure safe and secure progress in such a seismically vulnerable region there is a need for hazard assessment. For seismic hazard assessment, it is important to assess the quality, consistency, and homogeneity of the seismicity data collected from different sources. In the present study, an improved magnitude conversion technique has been used to convert different magnitude scales to moment magnitude scale. The study area and its adjoining region have been divided into 22 seismogenic zones based upon the geology, tectonics, and seismicity including source mechanism relevant to the region. Region specific attenuation equations have been used for seismic hazard assessment. Standard procedure for PSHA has been adopted for this study and peak ground motion is estimated for 10% and 2% probability of exceedance in 50 years at the bed rock level. For the 10% and 2% probability of exceedance in 50 years, the PGA values vary from 0.06 to 0.36 g and 0.11 to 0.65 g, respectively considering varying -value. Higher PGA values are observed in the southeast part region situated around Kaurik Fault System (KFS) and western parts of Nepal.

  20. Seismic hazard assessment in the Catania and Siracusa urban areas (Italy) through different approaches

    Science.gov (United States)

    Panzera, Francesco; Lombardo, Giuseppe; Rigano, Rosaria

    2010-05-01

    The seismic hazard assessment (SHA) can be performed using either Deterministic or Probabilistic approaches. In present study a probabilistic analysis was carried out for the Catania and Siracusa towns using two different procedures: the 'site' (Albarello and Mucciarelli, 2002) and the 'seismotectonic' (Cornell 1968; Esteva, 1967) methodologies. The SASHA code (D'Amico and Albarello, 2007) was used to calculate seismic hazard through the 'site' approach, whereas the CRISIS2007 code (Ordaz et al., 2007) was adopted in the Esteva-Cornell procedure. According to current international conventions for PSHA (SSHAC, 1997), a logic tree approach was followed to consider and reduce the epistemic uncertainties, for both seismotectonic and site methods. The code SASHA handles the intensity data taking into account the macroseismic information of past earthquakes. CRISIS2007 code needs, as input elements, a seismic catalogue tested for completeness, a seismogenetic zonation and ground motion predicting equations. Data concerning the characterization of regional seismic sources and ground motion attenuation properties were taken from the literature. Special care was devoted to define source zone models, taking into account the most recent studies on regional seismotectonic features and, in particular, the possibility of considering the Malta escarpment as a potential source. The combined use of the above mentioned approaches allowed us to obtain useful elements to define the site seismic hazard in Catania and Siracusa. The results point out that the choice of the probabilistic model plays a fundamental role. It is indeed observed that when the site intensity data are used, the town of Catania shows hazard values higher than the ones found for Siracusa, for each considered return period. On the contrary, when the Esteva-Cornell method is used, Siracusa urban area shows higher hazard than Catania, for return periods greater than one hundred years. The higher hazard observed

  1. Seismic Hazard and Risk Assessments for Beijing-Tianjin-Tangshan, China, Area

    Science.gov (United States)

    Xie, F.; Wang, Z.; Liu, J.

    2011-01-01

    Seismic hazard and risk in the Beijing-Tianjin-Tangshan, China, area were estimated from 500-year intensity observations. First, we digitized the intensity observations (maps) using ArcGIS with a cell size of 0.1 ?? 0.1??. Second, we performed a statistical analysis on the digitized intensity data, determined an average b value (0.39), and derived the intensity-frequency relationship (hazard curve) for each cell. Finally, based on a Poisson model for earthquake occurrence, we calculated seismic risk in terms of a probability of I ??? 7, 8, or 9 in 50 years. We also calculated the corresponding 10 percent probability of exceedance of these intensities in 50 years. The advantages of assessing seismic hazard and risk from intensity records are that (1) fewer assumptions (i. e., earthquake source and ground motion attenuation) are made, and (2) site-effect is included. Our study shows that the area has high seismic hazard and risk. Our study also suggests that current design peak ground acceleration or intensity for the area may not be adequate. ?? 2010 Birkh??user / Springer Basel AG.

  2. Seismic hazard analysis of nuclear installations in France. Current practice and research

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadioun, B. [CEA Centre d`Etudes de Fontenay-aux-Roses, 92 (France). Inst. de Protection et de Surete Nucleaire

    1997-03-01

    The methodology put into practice in France for the evaluation of seismic hazard on the sites of nuclear facilities is founded on data assembled country-wide over the past 15 years, in geology, geophysics and seismology. It is appropriate to the regional seismotectonic context (interplate), characterized notably by diffuse seismicity. Extensive use is made of information drawn from historical seismicity. The regulatory practice described in the RFS I.2.c is reexamined periodically and is subject to up-dating so as to take advantage of new earthquake data and of the results gained from research work. Acquisition of the basic data, such as the identification of active faults and the quantification of site effect, which will be needed to achieve improved preparedness versus severe earthquake hazard in the 21st century, will necessarily be the fruit of close international cooperation and collaboration, which should accordingly be actively promoted. (J.P.N.)

  3. Paleoseismic targets, seismic hazard, and urban areas in the Central and Eastern United States

    Science.gov (United States)

    Wheeler, R.L.

    2008-01-01

    Published geologic information from the central and eastern United States identifies 83 faults, groups of sand blows, named seismic zones, and other geological features as known or suspected products of Quaternary tectonic faulting. About one fifth of the features are known to contain faulted Quaternary materials or seismically induced liquefaction phenomena, but the origin and associated seismic hazard of most of the other features remain uncertain. Most of the features are in or near large urban areas. The largest cluster of features is in the Boston-Washington urban corridor (2005 estimated population: 50 million). The proximity of most features to populous areas identifies paleoseismic targets with potential to impact urban-hazard estimates.

  4. Considering both aleatory variability and epistemic variability in probabilistic seismic hazard analysis

    Science.gov (United States)

    Sung, Chih-Hsuan; Gao, Jia-Cian; Lee, Chyi-Tyi

    2015-04-01

    In the modern probabilistic seismic hazard analysis (PSHA), a standard deviation (sigma) of total variability was considered in the integration for seismic exceeding rate, and this lead to increased seismic hazard estimates. Epistemic uncertainty results from incomplete knowledge of the earthquake process and has nothing to do with neither the temporal variation nor the spatial variation of ground motions. It is not could be considered in the integration, epistemic variability may be included in the logic trees. This study uses Taiwan data as example to test a case in Taipei. Results reveal that if only the aleatory variability is considered in the integration, the hazard level could be reduced about 33% at the 475-year return period, and it reduced about 36% and 50% at 10000-year and 100000-year, respectively. However, if epistemic variability is considered in the logic trees besides the aleatory variability is considered in the integration, then the hazard level is similar to that from using total variability; it shows only a little bit smaller at long return period. Much effort in reducing the hazard level to a reasonable value still remains to be studied.

  5. Scale of seismic and rock burst hazard in the Silesian companies in Poland

    Institute of Scientific and Technical Information of China (English)

    PATY(N)SKA Renata; KABIESZ Józef

    2009-01-01

    Presently the seismic and rock burst hazard appears still to be important in most of hard coal mines in Poland. Recently, there was a significant increase of seismic activity of the Silesian rock massive, when compared with the previous years. In the period 1999-2008 the hard coal mines experienced 34 rock bursts. The causes of rockburst occurrence are presented based on the analysis of the rockbursts occurring in the Polish hard coal mines. The scale of the rockburst hazard has been characterized with respect to the mining and geological conditions of the existing exploitation. Of the factors influencing the state of rockburst hazard, the most essential one is considered the depth interval ranging from 600 m to 900 m. The basic factors that promote the rockburst occurrence are as follows: seismogenic strata, edges and remnants, goaf, faults, pillars and excessive paneling.

  6. Scale of seismic and rock burst hazard in the Silesian companies in Poland

    Energy Technology Data Exchange (ETDEWEB)

    Renata Patynska; Jozef Kabiesz [Central Mining Institute, Katowice (Poland)

    2009-09-15

    Presently the seismic and rock burst hazard appears still to be important in most of hard coal mines in Poland. Recently, there was a significant increase of seismic activity of the Silesian rock massive, when compared with the previous years. In the period 1999-2008 the hard coal mines experienced 34 rock bursts. The causes of rockburst occurrence are presented based on the analysis of the rockbursts occurring in the Polish hard coal mines. The scale of the rockburst hazard has been characterized with respect to the mining and geological conditions of the existing exploitation. Of the factors influencing the state of rockburst hazard, the most essential one is considered the depth interval ranging from 600 m to 900 m. The basic factors that promote the rockburst occurrence are as follows: seismogenic strata, edges and remnants, goaf, faults, pillars and excessive paneling. 5 refs., 3 figs., 2 tabs.

  7. A preliminary probabilistic analysis of tsunami sources of seismic and non-seismic origin applied to the city of Naples, Italy

    Science.gov (United States)

    Tonini, R.; Anita, G.

    2011-12-01

    In both worldwide and regional historical catalogues, most of the tsunamis are caused by earthquakes and a minor percentage is represented by all the other non-seismic sources. On the other hand, tsunami hazard and risk studies are often applied to very specific areas, where this global trend can be different or even inverted, depending on the kind of potential tsunamigenic sources which characterize the case study. So far, few probabilistic approaches consider the contribution of landslides and/or phenomena derived by volcanic activity, i.e. pyroclastic flows and flank collapses, as predominant in the PTHA, also because of the difficulties to estimate the correspondent recurrence time. These considerations are valid, for example, for the city of Naples, Italy, which is surrounded by a complex active volcanic system (Vesuvio, Campi Flegrei, Ischia) that presents a significant number of potential tsunami sources of non-seismic origin compared to the seismic ones. In this work we present the preliminary results of a probabilistic multi-source tsunami hazard assessment applied to Naples. The method to estimate the uncertainties will be based on Bayesian inference. This is the first step towards a more comprehensive task which will provide a tsunami risk quantification for this town in the frame of the Italian national project ByMuR (http://bymur.bo.ingv.it). This three years long ongoing project has the final objective of developing a Bayesian multi-risk methodology to quantify the risk related to different natural hazards (volcanoes, earthquakes and tsunamis) applied to the city of Naples.

  8. Seismic hazard and risk assessment for large Romanian dams situated in the Moldavian Platform

    Science.gov (United States)

    Moldovan, Iren-Adelina; Popescu, Emilia; Otilia Placinta, Anica; Petruta Constantin, Angela; Toma Danila, Dragos; Borleanu, Felix; Emilian Toader, Victorin; Moldoveanu, Traian

    2016-04-01

    Besides periodical technical inspections, the monitoring and the surveillance of dams' related structures and infrastructures, there are some more seismic specific requirements towards dams' safety. The most important one is the seismic risk assessment that can be accomplished by rating the dams into seismic risk classes using the theory of Bureau and Ballentine (2002), and Bureau (2003), taking into account the maximum expected peak ground motions at the dams site - values obtained using probabilistic hazard assessment approaches (Moldovan et al., 2008), the structures vulnerability and the downstream risk characteristics (human, economical, historic and cultural heritage, etc) in the areas that might be flooded in the case of a dam failure. Probabilistic seismic hazard (PSH), vulnerability and risk studies for dams situated in the Moldavian Platform, starting from Izvorul Muntelui Dam, down on Bistrita and following on Siret River and theirs affluent will be realized. The most vulnerable dams will be studied in detail and flooding maps will be drawn to find the most exposed downstream localities both for risk assessment studies and warnings. GIS maps that clearly indicate areas that are potentially flooded are enough for these studies, thus giving information on the number of inhabitants and goods that may be destroyed. Geospatial servers included topography is sufficient to achieve them, all other further studies are not necessary for downstream risk assessment. The results will consist of local and regional seismic information, dams specific characteristics and locations, seismic hazard maps and risk classes, for all dams sites (for more than 30 dams), inundation maps (for the most vulnerable dams from the region) and possible affected localities. The studies realized in this paper have as final goal to provide the local emergency services with warnings of a potential dam failure and ensuing flood as a result of an large earthquake occurrence, allowing further

  9. Comments on Potential Geologic and Seismic Hazards Affecting Proposed Liquefied Natural Gas Site in Santa Monica Bay, California

    Science.gov (United States)

    Ross, Stephanie L.; Lee, Homa J.; Parsons, Tom E.; Beyer, Larry A.; Boore, David M.; Conrad, James E.; Edwards, Brian D.; Fisher, Michael A.; Frankel, Arthur D.; Geist, Eric L.; Hudnut, Kenneth W.; Hough, Susan E.; Kayen, Robert E.; Lorenson, T.D.; Luco, Nicolas; McCrory, Patricia A.; McGann, Mary; Nathenson, Manuel; Nolan, Michael; Petersen, Mark D.; Ponti, Daniel J.; Powell, Charles L.; Ryan, Holly F.; Tinsley, John C.; Wills, Chris J.; Wong, Florence L.; Xu, Jingping

    2008-01-01

    West, Inc., had already prepared a document discussing geologic hazards in the area, titled 'Exhibit B Topic Report 6 - Geological Resources' (Fugro West, Inc., 2007); hereafter, this will be called the 'Geological Resources document'. The USGS agreed to evaluate the information in the Geological Resources document regarding (1) proximity of active faults to the proposed project, (2) potential magnitude of seismic events from nearby faults, (3) thoroughness of the assessment of earthquake hazards in general, (4) potential hazards from ground rupture and strong shaking, (5) potential hazards from tsunamis, and (6) other geologic hazards including landslides and debris flows. Because two new earthquake probability reports were scheduled to be released in mid-April, 2008, by the USGS and the California Geological Survey (CGS), the USGS suggested a 6-month review period to enable a thorough incorporation of this new information. Twenty-seven scientists from the USGS and the CGS reviewed various sections of the Geological Resources document. This report outlines our major conclusions. The appendix is a longer list of comments by these reviewers, grouped by section of the Geological Resources document. Before discussing our reviews, we first provide a brief overview of geologic hazards in the proposed site area. This report is a snapshot in time and any future work in the area will need to take into account ongoing research efforts. For example, USGS scientists collected seismic reflection data in the spring of 2008 to study the structure and seismic potential of several faults in the area. Their interpretations (Conrad and others, 2008a and 2008b) are too preliminary to be included in this report, but their final results, along with other researchers' studies in the project area, should be considered in any future work on the Deepwater Port project.

  10. A new probabilistic seismic hazard assessment for greater Tokyo

    Science.gov (United States)

    Stein, R.; Toda, S.; Parsons, T.; Grunewald, E.

    2006-12-01

    Tokyo and its outlying cities are home to one-quarter of Japan's 127 million people. Highly destructive earthquakes struck the capital in 1703, 1855 and 1923, the last of which took 105,000 lives. Unlike California's seismic environment of shallow and largely strike-slip faults, Tokyo lies 200 km from a triple junction with two subduction zones, and 80 km from a front of active volcanoes. Further, some of the region's megathust faults are seismically coupled, some undergo episodic slip events, and others appear to be permanently aseismic. To reinterpret the tectonic structure, identify active faults and their slip rates, and estimate their earthquake frequency, we analyzed the 7,000-yr record of seventeen M~8 shocks preserved by uplifted marine terraces and tsunami deposits, and 150 GPS vectors in the past 10 years from Japan's GeoNet array. We also digitized 10,000 observations of historical shaking recorded over the past 400 years, and examined 300,000 earthquakes registered by the dense NIED/JMA network in a 3D geographic information system. In a principal departure from previous work, we propose that a 100-km-wide, 25-km-thick dislodged fragment of the Pacific plate is jammed between the Pacific, Philippine Sea and Eurasian plates beneath Tokyo, and argue that the this fragment controls much of Tokyo's seismic behavior, including the damaging 1855 M~7.1 Ansei-Edo shock. On the basis of the frequency of earthquakes beneath greater Tokyo, we estimate that events with magnitude and location similar to the Ansei-Edo event have a 20% likelihood in an average 30-yr period. In contrast, our renewal (time-dependent) probability for great M~7.9 megathrust shocks such as struck in 1923 and 1703 is just 0.5% for the next 30 years, with a time-averaged 30-yr probability of ~10%. The resulting net likelihood for severe shaking (~0.9 g peak ground acceleration) in Tokyo, Kawasaki, and Yokohama for the next 30 years is ~30%, and the annual probability is 1.3%.

  11. How well should probabilistic seismic hazard maps work?

    Science.gov (United States)

    Vanneste, K.; Stein, S.; Camelbeeck, T.; Vleminckx, B.

    2016-12-01

    Recent large earthquakes that gave rise to shaking much stronger than shown in earthquake hazard maps have stimulated discussion about how well these maps forecast future shaking. These discussions have brought home the fact that although the maps are designed to achieve certain goals, we know little about how well they actually perform. As for any other forecast, this question involves verification and validation. Verification involves assessing how well the algorithm used to produce hazard maps implements the conceptual PSHA model ("have we built the model right?"). Validation asks how well the model forecasts the shaking that actually occurs ("have we built the right model?"). We explore the verification issue by simulating the shaking history of an area with assumed distribution of earthquakes, frequency-magnitude relation, temporal occurrence model, and ground-motion prediction equation. We compare the "observed" shaking at many sites over time to that predicted by a hazard map generated for the same set of parameters. PSHA predicts that the fraction of sites at which shaking will exceed that mapped is p = 1 - exp(t/T), where t is the duration of observations and T is the map's return period. This implies that shaking in large earthquakes is typically greater than shown on hazard maps, as has occurred in a number of cases. A large number of simulated earthquake histories yield distributions of shaking consistent with this forecast, with a scatter about this value that decreases as t/T increases. The median results are somewhat lower than predicted for small values of t/T and approach the predicted value for larger values of t/T. Hence, the algorithm appears to be internally consistent and can be regarded as verified for this set of simulations. Validation is more complicated because a real observed earthquake history can yield a fractional exceedance significantly higher or lower than that predicted while still being consistent with the hazard map in question

  12. Seismic Hazard and risk assessment for Romania -Bulgaria cross-border region

    Science.gov (United States)

    Simeonova, Stela; Solakov, Dimcho; Alexandrova, Irena; Vaseva, Elena; Trifonova, Petya; Raykova, Plamena

    2016-04-01

    Among the many kinds of natural and man-made disasters, earthquakes dominate with regard to their social and economical impact on the urban environment. Global seismic hazard and vulnerability to earthquakes are steadily increasing as urbanization and development occupy more areas that are prone to effects of strong earthquakes. The assessment of the seismic hazard and risk is particularly important, because it provides valuable information for seismic safety and disaster mitigation, and it supports decision making for the benefit of society. Romania and Bulgaria, situated in the Balkan Region as a part of the Alpine-Himalayan seismic belt, are characterized by high seismicity, and are exposed to a high seismic risk. Over the centuries, both countries have experienced strong earthquakes. The cross-border region encompassing the northern Bulgaria and southern Romania is a territory prone to effects of strong earthquakes. The area is significantly affected by earthquakes occurred in both countries, on the one hand the events generated by the Vrancea intermediate-depth seismic source in Romania, and on the other hand by the crustal seismicity originated in the seismic sources: Shabla (SHB), Dulovo, Gorna Orjahovitza (GO) in Bulgaria. The Vrancea seismogenic zone of Romania is a very peculiar seismic source, often described as unique in the world, and it represents a major concern for most of the northern part of Bulgaria as well. In the present study the seismic hazard for Romania-Bulgaria cross-border region on the basis of integrated basic geo-datasets is assessed. The hazard results are obtained by applying two alternative approaches - probabilistic and deterministic. The MSK64 intensity (MSK64 scale is practically equal to the new EMS98) is used as output parameter for the hazard maps. We prefer to use here the macroseismic intensity instead of PGA, because it is directly related to the degree of damages and, moreover, the epicentral intensity is the original

  13. Research on the spatial analysis method of seismic hazard for island

    Science.gov (United States)

    Jia, Jing; Jiang, Jitong; Zheng, Qiuhong; Gao, Huiying

    2017-05-01

    Seismic hazard analysis(SHA) is a key component of earthquake disaster prevention field for island engineering, whose result could provide parameters for seismic design microscopically and also is the requisite work for the island conservation planning’s earthquake and comprehensive disaster prevention planning macroscopically, in the exploitation and construction process of both inhabited and uninhabited islands. The existing seismic hazard analysis methods are compared in their application, and their application and limitation for island is analysed. Then a specialized spatial analysis method of seismic hazard for island (SAMSHI) is given to support the further related work of earthquake disaster prevention planning, based on spatial analysis tools in GIS and fuzzy comprehensive evaluation model. The basic spatial database of SAMSHI includes faults data, historical earthquake record data, geological data and Bouguer gravity anomalies data, which are the data sources for the 11 indices of the fuzzy comprehensive evaluation model, and these indices are calculated by the spatial analysis model constructed in ArcGIS’s Model Builder platform.

  14. SSHAC Level 1 Probabilistic Seismic Hazard Analysis for the Idaho National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Payne, Suzette Jackson [Idaho National Lab. (INL), Idaho Falls, ID (United States); Coppersmith, Ryan [Idaho National Lab. (INL), Idaho Falls, ID (United States); Coppersmith, Kevin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Rodriguez-Marek, Adrian [Idaho National Lab. (INL), Idaho Falls, ID (United States); Falero, Valentina Montaldo [Idaho National Lab. (INL), Idaho Falls, ID (United States); Youngs, Robert [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-09-01

    A Probabilistic Seismic Hazard Analysis (PSHA) was completed for the Materials and Fuels Complex (MFC), Advanced Test Reactor (ATR), and Naval Reactors Facility (NRF) at the Idaho National Laboratory (INL). The PSHA followed the approaches and procedures for Senior Seismic Hazard Analysis Committee (SSHAC) Level 1 study and included a Participatory Peer Review Panel (PPRP) to provide the confident technical basis and mean-centered estimates of the ground motions. A new risk-informed methodology for evaluating the need for an update of an existing PSHA was developed as part of the Seismic Risk Assessment (SRA) project. To develop and implement the new methodology, the SRA project elected to perform two SSHAC Level 1 PSHAs. The first was for the Fuel Manufacturing Facility (FMF), which is classified as a Seismic Design Category (SDC) 3 nuclear facility. The second was for the ATR Complex, which has facilities classified as SDC-4. The new methodology requires defensible estimates of ground motion levels (mean and full distribution of uncertainty) for its criteria and evaluation process. The INL SSHAC Level 1 PSHA demonstrates the use of the PPRP, evaluation and integration through utilization of a small team with multiple roles and responsibilities (four team members and one specialty contractor), and the feasibility of a short duration schedule (10 months). Additionally, a SSHAC Level 1 PSHA was conducted for NRF to provide guidance on the potential use of a design margin above rock hazard levels for the Spent Fuel Handling Recapitalization Project (SFHP) process facility.

  15. Seismic hazard analysis of Sinop province, Turkey using probabilistic and statistical methods

    Indian Academy of Sciences (India)

    Recai Feyiz Kartal; Günay Beyhan; Ayhan Keskinsezer

    2014-04-01

    Using 4.0 and greater magnitude earthquakes which occurred between 1 January 1900 and 31 December 2008 in the Sinop province of Turkey this study presents a seismic hazard analysis based on the probabilistic and statistical methods. According to the earthquake zonation map, Sinop is divided into first, second, third and fourth-degree earthquake regions. Our study area covered the coordinates between 40.66°–42.82°N and 32.20°–36.55°E. The different magnitudes of the earthquakes during the last 108 years recorded on varied scales were converted to a common scale (Mw). The earthquake catalog was then recompiled to evaluate the potential seismic sources in the aforesaid province. Using the attenuation relationships given by Boore et al. (1997) and Kalkan and Gülkan (2004), the largest ground accelerations corresponding to a recurrence period of 475 years are found to be 0.14 g for bedrock at the central district. Comparing the seismic hazard curves, we show the spatial variations of seismic hazard potential in this province, enumerating the recurrence period in the order of 475 years.

  16. Seismic Hazard Analysis Using the Adaptive Kernel Density Estimation Technique for Chennai City

    Science.gov (United States)

    Ramanna, C. K.; Dodagoudar, G. R.

    2012-01-01

    Conventional method of probabilistic seismic hazard analysis (PSHA) using the Cornell-McGuire approach requires identification of homogeneous source zones as the first step. This criterion brings along many issues and, hence, several alternative methods to hazard estimation have come up in the last few years. Methods such as zoneless or zone-free methods, modelling of earth's crust using numerical methods with finite element analysis, have been proposed. Delineating a homogeneous source zone in regions of distributed seismicity and/or diffused seismicity is rather a difficult task. In this study, the zone-free method using the adaptive kernel technique to hazard estimation is explored for regions having distributed and diffused seismicity. Chennai city is in such a region with low to moderate seismicity so it has been used as a case study. The adaptive kernel technique is statistically superior to the fixed kernel technique primarily because the bandwidth of the kernel is varied spatially depending on the clustering or sparseness of the epicentres. Although the fixed kernel technique has proven to work well in general density estimation cases, it fails to perform in the case of multimodal and long tail distributions. In such situations, the adaptive kernel technique serves the purpose and is more relevant in earthquake engineering as the activity rate probability density surface is multimodal in nature. The peak ground acceleration (PGA) obtained from all the three approaches (i.e., the Cornell-McGuire approach, fixed kernel and adaptive kernel techniques) for 10% probability of exceedance in 50 years is around 0.087 g. The uniform hazard spectra (UHS) are also provided for different structural periods.

  17. Earthquake Scenario for the City of Gyumri Including Seismic Hazard and Risk Assessment

    Science.gov (United States)

    Babayan, H.; Karakhanyan, A.; Arakelyan, A.; Avanesyan, M.; Durgaryan, R.; Babayan, S.; Gevorgyan, M.; Hovhannisyan, G.

    2012-12-01

    The city of Gyumri situated in the north of Armenia falls in the zone of active Akhouryan Fault and during the 20th century it suffered from catastrophic earthquakes twice. The Mw=6.2 earthquake in 1926 and the Spitak earthquake with a magnitude of 6.9 in 1988 killed more than 20,000 people in total. Therefore, current seismic hazard and risk assessment for the city are of great importance. It is also very important to answer how properly the lessons of the Spitak earthquake have been learned for this largest city in the Spitak earthquake disaster zone, what the real level of seismic risk is now, and what losses the city could expect if a similar or stronger earthquake occurred nowadays. For this purposes, the most probable earthquakes scenarios have been developed by means of comprehensive assessment of seismic hazard and risk, The conducted study helped to produce the actual pattern of effects caused by the Spitak earthquake in terms of losses and damage caused to diverse types of buildings and thus enabled correct selection of required parameter values to estimate vulnerability of the structures and test the ELER software package (designated for estimation of losses and damages developed in the framework of GEM-EMME Project). The work was realized by the following sequence of steps: probabilistic and deterministic assessment of seismic hazard for the Gyumri city region - choice of earthquake scenario (based on the disaggregation and seismotectonic model) - risk estimation for each selected earthquake scenario. In the framework of this study, different parameters of seismic hazard such as peak ground acceleration and spectral acceleration were investigated and mapped, and soil model for city was developed. Subsequently, these maps were used as the basic inputs to assess the expected life, building, and lifeline losses. The presented work was realized with the financial support of UNDP. The results of the Project will serve the basis for national and local

  18. Seismic Indexing System for Army Installations. Volume II. Seismic Hazard Priority-Ranking Procedure for Army Buildings: Basic Concept.

    Science.gov (United States)

    1981-05-01

    1904 o Stockton _2 Francisco o Modesto + lose "e-, ! FresnoI d "’,T 2 01 4Los Vegas SEISM IC ZO NE M AP l eer" ’k ’ ’ Californi~wland Nevada d- *44...ranging between 0 and 100. Within a given population of buildings, the building with the greatest potential hazard (i.e., the largest numerical value for...seismic vulnera- bility index value for other buildings in the population is proportioned accordingly. The exposure index represents the level of

  19. New Evaluation of Seismic Hazard in Cental America and la Hispaniola

    Science.gov (United States)

    Benito, B.; Camacho, E. I.; Rojas, W.; Climent, A.; Alvarado-Induni, G.; Marroquin, G.; Molina, E.; Talavera, E.; Belizaire, D.; Pierristal, G.; Torres, Y.; Huerfano, V.; Polanco, E.; García, R.; Zevallos, F.

    2013-05-01

    The results from seismic hazard studies carried out in two seismic scenarios, Central America Region (CA) and La Hispaniola Island, are presented here. Both cases follow the Probabilistic Seismic Hazard Assessment (PSHA) methodology and they are developed in terms of PGA, and SA (T), for T of 0.1, 0.2, 0.5, 1 and 2s. In both anaysis, hybrid zonation models are considered, integrated by seismogenic zones and faults where data of slip rate and recurrence time are available. First, we present a new evaluation of seismic hazard in CA, starting with the results of a previous study by Benito et al (2011). Some improvements are now included, such as: updated catalogue till 2011, corrections in the zonning model in particular for subduction regime taken into account the variation of the dip in Costa Rica and Panama, and modelization of some faults as independent units for the hazard estimation. The results allow us to carry out a sensitivity analysis comparing the ones obtained with and without faults. In a second part we present the results of the PSHA in La Hispaniola, carried out as part of the cooperative project SISMO-HAITI supported by UPM and developed in cooperation with ONEV. It started a few months after the 2010 event, as an answer to a required help from the Haitian government to UPM. The study was aimed at obtaining results suitable for seismic design purposes and started with the elaboration of a seismic catalogue for the Hispaniola, requiring an exhaustive revision of data reported by around 30 seismic agencies, apart from these from Puerto Rico and Dominican Republic Seismic Networks. Seismotectonic models for the region were reviewed and a new regional zonation was proposed, taking into account different geophysical data. Attenuation models for subduction and crustal zones were also reviewed and the more suitable were calibrated with data recorded inside the Caribbean plate. As a result of the PSHA, different maps were generated for the quoted parameters

  20. The Contribution of Paleoseismology to Seismic Hazard Assessment in Site Evaluation for Nuclear Installations

    Science.gov (United States)

    Decker, Kurt; Guerrieri, Luca; Fukushima, Yoshimitsu

    2015-04-01

    In the framework of site evaluation/re-evaluation procedures for nuclear power plants (NPP), paleoseismology plays an essential role not only for Fault Displacement Hazard Assessment (FDHA) but also for Seismic Hazard Assessment (SHA). The relevance of paleoseismology is recommended in the reference IAEA Safety Guide (IAEA SSG-9) and has been dramatically confirmed in recent time especially after the accident at the Fukushima Daiichi NPP caused by the disastrous great Tohoku earthquake and tsunami occurred on 11 March 2011. After this event, the IAEA International Seismic Safety Center promoted a technical document aimed at encouraging and supporting Member States, especially from newcomer countries, to include paleoseismic investigations into the geologic database, highlighting the value of earthquake geology studies and paleoseismology for nuclear safety and providing standard methodologies to perform such investigations. In detail, paleoseismic investigations in the context of site evaluation of nuclear installations have the following main objectives: i) identification of seismogenic structures based on the recognition of effects of past earthquakes in the regional area; ii) improvement of the completeness of earthquake catalogs, through the identification and dating of ancient moderate to large earthquakes, whose trace has been preserved in the geologic records; iii) estimation of the maximum seismic potential associated with an identified seismogenic structure/source, typically on the basis of the amount of displacement per event (evaluable in paleoseismic trenches), as well as of the geomorphic and stratigraphic features interpretable as the cumulative effect of repeated large seismic events (concept of "seismic landscape"); iv) rough calibration of probabilistic seismic hazard assessment (PSHA), by using the recurrence interval of large earthquakes detectable by paleoseismic investigations, and providing a "reality check" based on direct observations of

  1. Seismic hazard assessment of Sub-Saharan Africa using geodetic strain rate models

    Science.gov (United States)

    Poggi, Valerio; Pagani, Marco; Weatherill, Graeme; Garcia, Julio; Durrheim, Raymond J.; Mavonga Tuluka, Georges

    2016-04-01

    The East African Rift System (EARS) is the major active tectonic feature of the Sub-Saharan Africa (SSA) region. Although the seismicity level of such a divergent plate boundary can be described as moderate, several earthquakes have been reported in historical times causing a non-negligible level of damage, albeit mostly due to the high vulnerability of the local buildings and structures. Formulation and enforcement of national seismic codes is therefore an essential future risk mitigation strategy. Nonetheless, a reliable risk assessment cannot be done without the calibration of an updated seismic hazard model for the region. Unfortunately, the major issue in assessing seismic hazard in Sub-Saharan Africa is the lack of basic information needed to construct source and ground motion models. The historical earthquake record is largely incomplete, while instrumental catalogue is complete down to sufficient magnitude only for a relatively short time span. In addition, mapping of seimogenically active faults is still an on-going program. Recent studies have identified major seismogenic lineaments, but there is substantial lack of kinematic information for intermediate-to-small scale tectonic features, information that is essential for the proper calibration of earthquake recurrence models. To compensate this lack of information, we experiment the use of a strain rate model recently developed by Stamps et al. (2015) in the framework of a earthquake hazard and risk project along the EARS supported by USAID and jointly carried out by GEM and AfricaArray. We use the inferred geodetic strain rates to derive estimates of total scalar moment release, subsequently used to constrain earthquake recurrence relationships for both area (as distributed seismicity) and fault source models. The rates obtained indirectly from strain rates and more classically derived from the available seismic catalogues are then compared and combined into a unique mixed earthquake recurrence model

  2. Regional seismic hazard for Revithoussa, Greece: an earthquake early warning Shield and selection of alert signals

    Directory of Open Access Journals (Sweden)

    Y. Xu

    2003-01-01

    Full Text Available The feasibility of an earthquake early warning Shield in Greece is being explored as a European demonstration project. This will be the first early warning system in Europe. The island of Revithoussa is a liquid natural gas storage facility near Athens from which a pipeline runs to a gas distribution centre in Athens. The Shield is being centred on these facilities. The purpose here is to analyze seismicity and seismic hazard in relation to the Shield centre and the remote sensor sites in the Shield network, eventually to help characterize the hazard levels, seismic signals and ground vibration levels that might be observed or create an alert situation at a station. Thus this paper mainly gives estimation of local seismic hazard in the regional working area of Revithoussa by studying extreme peak ground acceleration (PGA and magnitudes. Within the Shield region, the most important zone to be detected is WNW from the Shield centre and is at a relatively short distance (50 km or less, the Gulf of Corinth (active normal faults region. This is the critical zone for early warning of strong ground shaking. A second key region of seismicity is at an intermediate distance (100 km or more from the centre, the Hellenic seismic zone south or southeast from Peloponnisos. A third region to be detected would be the northeastern region from the centre and is at a relatively long distance (about 150 km, Lemnos Island and neighboring region. Several parameters are estimated to characterize the seismicity and hazard. These include: the 50-year PGA with 90% probability of not being exceeded (pnbe using Theodulidis & Papazachos strong motion attenuation for Greece, PGANTP; the 50-year magnitude and also at the 90% pnbe, M50 and MP50, respectively. There are also estimates of the earthquake that is most likely to be felt at a damaging intensity level, these are the most perceptible earthquakes at intensities VI, VII and VIII with magnitudes MVI, MVII and MVIII

  3. Problems of seismic hazard estimation in regions with few large earthquakes: Examples from eastern Canada

    Science.gov (United States)

    Basham, P. W.; Adams, John

    1989-10-01

    Seismic hazard estimates and seismic zoning maps are based on an assessment of historical and recent seismieity and any correlations with geologic and tectonic features that might define the earthquake potential. Evidence is accumulating that the large earthquakes in eastern Canada ( M ~ 7) may be associated with the rift systems hat surround or break the integrity of the North American craton. The problem for seismic hazard estimation is that the larger historical earthquakes are not uniformly distributed along the Paleozoic St. Lawrence-Ottawa rift system and are too rare on the Mesozoic eastern margin rift to assess the overall seismogenic potential. Multiple source zone models for hazard estimation could include hypotheses of future M = 7 earthquakes at any location along these rift systems, but at a moderate probability (such as that used in the Canadian zoning maps) the resultant hazard will be so diluted that it will not result in adequate design against the near-source effects of such earthquakes. The near-source effects of large, rare earthquakes can, however, be accommodated in conservative codes and standards for critical facilities, if society is willing to pay the price.

  4. Probabilistic seismic hazard assessment for the two layer fault system of Antalya (SW Turkey) area

    Science.gov (United States)

    Dipova, Nihat; Cangir, Bülent

    2017-09-01

    Southwest Turkey, along Mediterranean coast, is prone to large earthquakes resulting from subduction of the African plate under the Eurasian plate and shallow crustal faults. Maximum observed magnitude of subduction earthquakes is Mw = 6.5 whereas that of crustal earthquakes is Mw = 6.6. Crustal earthquakes are sourced from faults which are related with Isparta Angle and Cyprus Arc tectonic structures. The primary goal of this study is to assess seismic hazard for Antalya area (SW Turkey) using a probabilistic approach. A new earthquake catalog for Antalya area, with unified moment magnitude scale, was prepared in the scope of the study. Seismicity of the area has been evaluated by the Gutenberg-Richter recurrence relationship. For hazard computation, CRISIS2007 software was used following the standard Cornell-McGuire methodology. Attenuation model developed by Youngs et al. Seismol Res Lett 68(1):58-73, (1997) was used for deep subduction earthquakes and Chiou and Youngs Earthq Spectra 24(1):173-215, (2008) model was used for shallow crustal earthquakes. A seismic hazard map was developed for peak ground acceleration and for rock ground with a hazard level of a 10% probability of exceedance in 50 years. Results of the study show that peak ground acceleration values on bedrock change between 0.215 and 0.23 g in the center of Antalya.

  5. Probabilistic seismic hazard characterization and design parameters for the Pantex Plant

    Energy Technology Data Exchange (ETDEWEB)

    Bernreuter, D. L.; Foxall, W.; Savy, J. B.

    1998-10-19

    The Hazards Mitigation Center at Lawrence Livermore National Laboratory (LLNL) updated the seismic hazard and design parameters at the Pantex Plant. The probabilistic seismic hazard (PSH) estimates were first updated using the latest available data and knowledge from LLNL (1993, 1998), Frankel et al. (1996), and other relevant recent studies from several consulting companies. Special attention was given to account for the local seismicity and for the system of potentially active faults associated with the Amarillo-Wichita uplift. Aleatory (random) uncertainty was estimated from the available data and the epistemic (knowledge) uncertainty was taken from results of similar studies. Special attention was given to soil amplification factors for the site. Horizontal Peak Ground Acceleration (PGA) and 5% damped uniform hazard spectra were calculated for six return periods (100 yr., 500 yr., 1000 yr., 2000 yr., 10,000 yr., and 100,000 yr.). The design parameters were calculated following DOE standards (DOE-STD-1022 to 1024). Response spectra for design or evaluation of Performance Category 1 through 4 structures, systems, and components are presented.

  6. An Updated Probabilistic Seismic Hazard Assessment for Romania and Comparison with the Approach and Outcomes of the SHARE Project

    Science.gov (United States)

    Pavel, Florin; Vacareanu, Radu; Douglas, John; Radulian, Mircea; Cioflan, Carmen; Barbat, Alex

    2016-06-01

    The probabilistic seismic hazard analysis for Romania is revisited within the framework of the BIGSEES national research project (http://infp.infp.ro/bigsees/default.htm) financed by the Romanian Ministry of Education and Scientific Research in the period 2012-2016. The scope of this project is to provide a refined description of the seismic action for Romanian sites according to the requirements of Eurocode 8. To this aim, the seismicity of all the sources influencing the Romanian territory is updated based on new data acquired in recent years. The ground-motion models used in the analysis, as well as their corresponding weights, are selected based on the results from several recent papers also published within the framework of the BIGSEES project. The seismic hazard analysis for Romania performed in this study are based on the traditional Cornell-McGuire approach. Finally, the results are discussed and compared with the values obtained in the recently completed SHARE research project. The BIGSEES and SHARE results are not directly comparable since the considered soil conditions are different—actual soil classes for BIGSEES and rock for SHARE. Nevertheless, the analyses of the seismic hazard results for 200 sites in Romania reveal considerable differences between the seismic hazard levels obtained in the present study and the SHARE results and point out the need for further analyses and thorough discussions related to the two seismic hazard models, especially in the light of a possible future harmonized hazard map for Europe.

  7. A Preliminary Study on Seismicity and Stages of Seismic Energy Accumulation in Seismotectonic Regions of Tianshan

    Institute of Scientific and Technical Information of China (English)

    Li Yingzhen; Shen Jun; Wang Haitao

    2006-01-01

    Using seismic parameters, the characteristics of the seismic activity in various seismotectonic regions of Tianshan were studied in this paper. These regions are going through different stages of seismic energy accumulation. Current seismic risk levels of these areas were analyzed synthetically by the tectonic movement rates, as well as the characteristics of the seismic activity and the recurrence intervals of strong earthquakes. We preliminarily studied the characteristics of seismic activity in different seismic energy accumulating stages. The result shows that the characteristics of the seismic activity in various seismotectonic regions of the Tianshan area are influenced, not only by the regional tectonic movement, but also by the energy accumulating stage of various seismic tectonics. In the intense tectonic movement areas, it is important to estimate its stage of energy accumulating in order to predict the upper limit of the potential earthquake magnitude. In the less intense tectonic movement areas, the estimating of the stage of energy accumulation will help us recognize the dangerous level of the potential strong earthquake. The study shows that the seismotectonic regions in southern Tianshan have reached the mid-stage and late-stage of energy accumulation, with a higher seismic activity and thus a higher seismic dangerous level than those in the northern and middle Tianshan. The earthquake risk of southern Tianshan is up to Ms7.0, while that of the middle Tianshan is up to Ms6.0 and that of northern Tianshan is only around Ms5.0 ~ 6.0.

  8. Site specific probabilistic seismic hazard analysis at Dubai Creek on the west coast of UAE

    Science.gov (United States)

    Shama, Ayman A.

    2011-03-01

    A probabilistic seismic hazard analysis (PSHA) was conducted to establish the hazard spectra for a site located at Dubai Creek on the west coast of the United Arab Emirates (UAE). The PSHA considered all the seismogenic sources that affect the site, including plate boundaries such as the Makran subduction zone, the Zagros fold-thrust region and the transition fault system between them; and local crustal faults in UAE. PSHA indicated that local faults dominate the hazard. The peak ground acceleration (PGA) for the 475-year return period spectrum is 0.17 g and 0.33 g for the 2,475-year return period spectrum. The hazard spectra are then employed to establish rock ground motions using the spectral matching technique.

  9. Seismic hazard assessment for Myanmar: Earthquake model database, ground-motion scenarios, and probabilistic assessments

    Science.gov (United States)

    Chan, C. H.; Wang, Y.; Thant, M.; Maung Maung, P.; Sieh, K.

    2015-12-01

    We have constructed an earthquake and fault database, conducted a series of ground-shaking scenarios, and proposed seismic hazard maps for all of Myanmar and hazard curves for selected cities. Our earthquake database integrates the ISC, ISC-GEM and global ANSS Comprehensive Catalogues, and includes harmonized magnitude scales without duplicate events. Our active fault database includes active fault data from previous studies. Using the parameters from these updated databases (i.e., the Gutenberg-Richter relationship, slip rate, maximum magnitude and the elapse time of last events), we have determined the earthquake recurrence models of seismogenic sources. To evaluate the ground shaking behaviours in different tectonic regimes, we conducted a series of tests by matching the modelled ground motions to the felt intensities of earthquakes. Through the case of the 1975 Bagan earthquake, we determined that Atkinson and Moore's (2003) scenario using the ground motion prediction equations (GMPEs) fits the behaviours of the subduction events best. Also, the 2011 Tarlay and 2012 Thabeikkyin events suggested the GMPEs of Akkar and Cagnan (2010) fit crustal earthquakes best. We thus incorporated the best-fitting GMPEs and site conditions based on Vs30 (the average shear-velocity down to 30 m depth) from analysis of topographic slope and microtremor array measurements to assess seismic hazard. The hazard is highest in regions close to the Sagaing Fault and along the Western Coast of Myanmar as seismic sources there have earthquakes occur at short intervals and/or last events occurred a long time ago. The hazard curves for the cities of Bago, Mandalay, Sagaing, Taungoo and Yangon show higher hazards for sites close to an active fault or with a low Vs30, e.g., the downtown of Sagaing and Shwemawdaw Pagoda in Bago.

  10. Proceedings of Conference XIII, evaluation of regional seismic hazards and risk

    Science.gov (United States)

    Charonnat, Barbara B.

    1981-01-01

    The participants in the conference concluded that a great deal of useful research has been performed in the national Earthquake Hazards Reduction Program by USGS and non-USGS scientists and engineers and that the state-of-knowledge concerning the evaluation of seismic hazards and risk has been advanced substantially. Many of the technical issues raised during the conference are less controversial now because of new information and insights gained during the first three years of the expanded research program conducted under the Earthquake Hazards Reduction Act. Utilization of research results by many groups of users has also improved during this period and further improvement in utilization appears likely. Additional research is still required to resolve more completely the many complex technical issues summarized above and described in the papers contained in the proceedings. Improved certainty of research results on the evaluation of regional seismic hazards and risk is required before full utilization can be made by state and local governments who deal. with people frequently having a different perception of the hazard and its risk to them than that perceived by scientists or engineers. Each of the papers contained in the proceedings contain throughtful recommendations for improving the state-of-knowledge. Two papers, in particular, focussed on this particular theme. The first was presented by Lynn Sykes in the Geologic Keynote Address. He identified geographic areas throughout the world which may be considered as counterparts or analogues of seismic zones in the United States. He concluded that much can be learned about prediction, tectonic settings, earthquake hazards, and earthquake risk for sites in the United States by studying their tectonic analogues in other countries. The second paper was presented by John Blume in the Engineering Keynote Address. He suggested 20 specific research topics that, in his opinion, will significantly advance the state

  11. Seismicity and seismotectonics of southern Ghana: lessons for seismic hazard mitigation

    Science.gov (United States)

    Amponsah, Paulina

    2014-05-01

    Ghana is located on the West African craton and is far from the major earthquake zone of the world. It is therefore largely considered a stable region. However, the southern part of the country is seismically active. Records of damaging earthquakes in Ghana date as far back as 1615. A study on the microseismic activity in southern Ghana shows that the seismic activity is linked with active faulting between the east-west trending Coastal boundary fault and a northeast-southwest trending Akwapim fault zone. Epicentres of most of the earthquakes have been located close to the area where the two major faults intersect. This can be related to the level of activity of the faults. Some of the epicentres have been located offshore and can be associated with the level of activity of the coastal boundary fault. A review of the geological and instrumental recordings of earthquakes in Ghana show that earthquakes have occurred in the past and are still liable to occur within the vicinity of the intersection of the Akwapim fault zone and the Coastal boundary fault. Data from both historical and instrumental records indicate that the most seismically active areas in Ghana are the west of Accra, where the Akwapim fault zone and the Coastal boundary fault intersect. There are numerous minor faults in the intersection area between the Akwapim fault zone and the Coastal boundary fault. This mosaic of faults has a major implication for seismic activity in the area. Earthquake disaster mitigation measures are being put in place in recent times to reduce the impact of any major event that may occur in the country. The National Disaster Management Organization has come out with a building guide to assist in the mitigation effort of earthquake disasters and floods in the country. The building guide clearly stipulates the kind of material to be used, the proportion, what should go into the foundation for one or two storey building, the electrical materials to be used and many others.

  12. Near-Field ETAS Constraints and Applications to Seismic Hazard Assessment

    Science.gov (United States)

    Yoder, Mark R.; Rundle, John B.; Glasscoe, Margaret T.

    2015-08-01

    The epidemic type aftershock sequence (ETAS) statistical model of aftershock seismicity combines various earthquake scaling relations to produce synthetic earthquake catalogs, or estimates of aftershock seismicity rates, based on recent earthquake activity. One challenge to ETAS-based hazard assessment is the large number of free parameters involved. In this paper, we introduce an approach to constrain this parameter space from canonical scaling relations, empirical observations, and fundamental physics. We show that ETAS parameters can be estimated as a function of an earthquake's magnitude m based on the finite temporal and spatial extents of the rupture area. This approach facilitates fast ETAS-based estimates of seismicity from large "seed" catalogs, and it is particularly well suited to web-based deployment and otherwise automated implementations. It constitutes a significant improvement over contemporary ETAS by mitigating variability related to instrumentation and subjective catalog selection.

  13. Seismic hazard in Romania associated to Vrancea subcrustal source Deterministic evaluation

    CERN Document Server

    Radulian, M; Moldoveanu, C L; Panza, G F; Vaccari, F

    2002-01-01

    Our study presents an application of the deterministic approach to the particular case of Vrancea intermediate-depth earthquakes to show how efficient the numerical synthesis is in predicting realistic ground motion, and how some striking peculiarities of the observed intensity maps are properly reproduced. The deterministic approach proposed by Costa et al. (1993) is particularly useful to compute seismic hazard in Romania, where the most destructive effects are caused by the intermediate-depth earthquakes generated in the Vrancea region. Vrancea is unique among the seismic sources of the World because of its striking peculiarities: the extreme concentration of seismicity with a remarkable invariance of the foci distribution, the unusually high rate of strong shocks (an average frequency of 3 events with magnitude greater than 7 per century) inside an exceptionally narrow focal volume, the predominance of a reverse faulting mechanism with the T-axis almost vertical and the P-axis almost horizontal and the mo...

  14. Modifications to risk-targeted seismic design maps for subduction and near-fault hazards

    Science.gov (United States)

    Liel, Abbie B.; Luco, Nicolas; Raghunandan, Meera; Champion, C.; Haukaas, Terje

    2015-01-01

    ASCE 7-10 introduced new seismic design maps that define risk-targeted ground motions such that buildings designed according to these maps will have 1% chance of collapse in 50 years. These maps were developed by iterative risk calculation, wherein a generic building collapse fragility curve is convolved with the U.S. Geological Survey hazard curve until target risk criteria are met. Recent research shows that this current approach may be unconservative at locations where the tectonic environment is much different than that used to develop the generic fragility curve. This study illustrates how risk-targeted ground motions at selected sites would change if generic building fragility curve and hazard assessment were modified to account for seismic risk from subduction earthquakes and near-fault pulses. The paper also explores the difficulties in implementing these changes.

  15. Non-parametric seismic hazard analysis in the presence of incomplete data

    Science.gov (United States)

    Yazdani, Azad; Mirzaei, Sajjad; Dadkhah, Koroush

    2017-01-01

    The distribution of earthquake magnitudes plays a crucial role in the estimation of seismic hazard parameters. Due to the complexity of earthquake magnitude distribution, non-parametric approaches are recommended over classical parametric methods. The main deficiency of the non-parametric approach is the lack of complete magnitude data in almost all cases. This study aims to introduce an imputation procedure for completing earthquake catalog data that will allow the catalog to be used for non-parametric density estimation. Using a Monte Carlo simulation, the efficiency of introduced approach is investigated. This study indicates that when a magnitude catalog is incomplete, the imputation procedure can provide an appropriate tool for seismic hazard assessment. As an illustration, the imputation procedure was applied to estimate earthquake magnitude distribution in Tehran, the capital city of Iran.

  16. Present-day shortening in Southern Haiti from GPS measurements and implications for seismic hazard

    Science.gov (United States)

    Symithe, Steeve; Calais, Eric

    2016-06-01

    The ~ 3 M inhabitant capital region of Haiti, severely affected by the devastating January 12, 2010, M7.0 earthquake, continues to expand at a fast rate. Accurate characterization of regional earthquake sources is key to inform urban development and construction practices through improved regional seismic hazard estimates. Here we use a recently updated Global Positioning System (GPS) data set to show that seismogenic strain accumulation in southern Haiti involves an overlooked component of shortening on a south-dipping reverse fault along the southern edge of the Cul-de-Sac basin, in addition to the well-known component of left-lateral strike-slip motion. This tectonic model implies that ground shaking may be twice that expected if the major fault was purely strike-slip, as assumed in the current seismic hazard map for the region.

  17. Challenges in making a seismic hazard map for Alaska and the Aleutians

    Science.gov (United States)

    Wesson, R.L.; Boyd, O.S.; Mueller, C.S.; Frankel, A.D.; Freymueller, J.T.

    2008-01-01

    We present a summary of the data and analyses leading to the revision of the time-independent probabilistic seismic hazard maps of Alaska and the Aleutians. These maps represent a revision of existing maps based on newly obtained data, and reflect best current judgments about methodology and approach. They have been prepared following the procedures and assumptions made in the preparation of the 2002 National Seismic Hazard Maps for the lower 48 States, and will be proposed for adoption in future revisions to the International Building Code. We present example maps for peak ground acceleration, 0.2 s spectral amplitude (SA), and 1.0 s SA at a probability level of 2% in 50 years (annual probability of 0.000404). In this summary, we emphasize issues encountered in preparation of the maps that motivate or require future investigation and research.

  18. Comparing USGS national seismic hazard maps with internet-based macroseismic intensity observations

    Science.gov (United States)

    Mak, Sum; Schorlemmer, Danijel

    2016-04-01

    Verifying a nationwide seismic hazard assessment using data collected after the assessment has been made (i.e., prospective data) is a direct consistency check of the assessment. We directly compared the predicted rate of ground motion exceedance by the four available versions of the USGS national seismic hazard map (NSHMP, 1996, 2002, 2008, 2014) with the actual observed rate during 2000-2013. The data were prospective to the two earlier versions of NSHMP. We used two sets of somewhat independent data, namely 1) the USGS "Did You Feel It?" (DYFI) intensity reports, 2) instrumental ground motion records extracted from ShakeMap stations. Although both are observed data, they come in different degrees of accuracy. Our results indicated that for California, the predicted and observed hazards were very comparable. The two sets of data gave consistent results, implying robustness. The consistency also encourages the use of DYFI data for hazard verification in the Central and Eastern US (CEUS), where instrumental records are lacking. The result showed that the observed ground-motion exceedance was also consistent with the predicted in CEUS. The primary value of this study is to demonstrate the usefulness of DYFI data, originally designed for community communication instead of scientific analysis, for the purpose of hazard verification.

  19. Probabilistic seismic hazard study based on active fault and finite element geodynamic models

    Science.gov (United States)

    Kastelic, Vanja; Carafa, Michele M. C.; Visini, Francesco

    2016-04-01

    We present a probabilistic seismic hazard analysis (PSHA) that is exclusively based on active faults and geodynamic finite element input models whereas seismic catalogues were used only in a posterior comparison. We applied the developed model in the External Dinarides, a slow deforming thrust-and-fold belt at the contact between Adria and Eurasia.. is the Our method consists of establishing s two earthquake rupture forecast models: (i) a geological active fault input (GEO) model and, (ii) a finite element (FEM) model. The GEO model is based on active fault database that provides information on fault location and its geometric and kinematic parameters together with estimations on its slip rate. By default in this model all deformation is set to be released along the active faults. The FEM model is based on a numerical geodynamic model developed for the region of study. In this model the deformation is, besides along the active faults, released also in the volumetric continuum elements. From both models we calculated their corresponding activity rates, its earthquake rates and their final expected peak ground accelerations. We investigated both the source model and the earthquake model uncertainties by varying the main active fault and earthquake rate calculation parameters through constructing corresponding branches of the seismic hazard logic tree. Hazard maps and UHS curves have been produced for horizontal ground motion on bedrock conditions VS 30 ≥ 800 m/s), thereby not considering local site amplification effects. The hazard was computed over a 0.2° spaced grid considering 648 branches of the logic tree and the mean value of 10% probability of exceedance in 50 years hazard level, while the 5th and 95th percentiles were also computed to investigate the model limits. We conducted a sensitivity analysis to control which of the input parameters influence the final hazard results in which measure. The results of such comparison evidence the deformation model and

  20. Seismic hazard and risks based on the Unified Scaling Law for Earthquakes

    Science.gov (United States)

    Kossobokov, Vladimir; Nekrasova, Anastasia

    2014-05-01

    Losses from natural disasters continue to increase mainly due to poor understanding by majority of scientific community, decision makers and public, the three components of Risk, i.e., Hazard, Exposure, and Vulnerability. Contemporary Science is responsible for not coping with challenging changes of Exposures and their Vulnerability inflicted by growing population, its concentration, etc., which result in a steady increase of Losses from Natural Hazards. Scientists owe to Society for lack of knowledge, education, and communication. In fact, Contemporary Science can do a better job in disclosing Natural Hazards, assessing Risks, and delivering such knowledge in advance catastrophic events. Any kind of risk estimates R(g) at location g results from a convolution of the natural hazard H(g) with the exposed object under consideration O(g) along with its vulnerability V(O(g)). Note that g could be a point, or a line, or a cell on or under the Earth surface and that distribution of hazards, as well as objects of concern and their vulnerability, could be time-dependent. There exist many different risk estimates even if the same object of risk and the same hazard are involved. It may result from the different laws of convolution, as well as from different kinds of vulnerability of an object of risk under specific environments and conditions. Both conceptual issues must be resolved in a multidisciplinary problem oriented research performed by specialists in the fields of hazard, objects of risk, and object vulnerability, i.e. specialists in earthquake engineering, social sciences and economics. To illustrate this general concept, we first construct seismic hazard assessment maps based on the Unified Scaling Law for Earthquakes (USLE). The parameters A, B, and C of USLE, i.e. log N(M,L) = A - B•(M-6) + C•log L, where N(M,L) is the expected annual number of earthquakes of a certain magnitude M within an area of linear size L, are used to estimate the expected maximum

  1. A reliable simultaneous representation of seismic hazard and of ground shaking recurrence

    Science.gov (United States)

    Peresan, A.; Panza, G. F.; Magrin, A.; Vaccari, F.

    2015-12-01

    Different earthquake hazard maps may be appropriate for different purposes - such as emergency management, insurance and engineering design. Accounting for the lower occurrence rate of larger sporadic earthquakes may allow to formulate cost-effective policies in some specific applications, provided that statistically sound recurrence estimates are used, which is not typically the case of PSHA (Probabilistic Seismic Hazard Assessment). We illustrate the procedure to associate the expected ground motions from Neo-deterministic Seismic Hazard Assessment (NDSHA) to an estimate of their recurrence. Neo-deterministic refers to a scenario-based approach, which allows for the construction of a broad range of earthquake scenarios via full waveforms modeling. From the synthetic seismograms the estimates of peak ground acceleration, velocity and displacement, or any other parameter relevant to seismic engineering, can be extracted. NDSHA, in its standard form, defines the hazard computed from a wide set of scenario earthquakes (including the largest deterministically or historically defined credible earthquake, MCE) and it does not supply the frequency of occurrence of the expected ground shaking. A recent enhanced variant of NDSHA that reliably accounts for recurrence has been developed and it is applied to the Italian territory. The characterization of the frequency-magnitude relation can be performed by any statistically sound method supported by data (e.g. multi-scale seismicity model), so that a recurrence estimate is associated to each of the pertinent sources. In this way a standard NDSHA map of ground shaking is obtained simultaneously with the map of the corresponding recurrences. The introduction of recurrence estimates in NDSHA naturally allows for the generation of ground shaking maps at specified return periods. This permits a straightforward comparison between NDSHA and PSHA maps.

  2. SSHAC Level 1 Probabilistic Seismic Hazard Analysis for the Idaho National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Payne, Suzette [Idaho National Lab. (INL), Idaho Falls, ID (United States); Coppersmith, Ryan [Idaho National Lab. (INL), Idaho Falls, ID (United States); Coppersmith, Kevin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Rodriguez-Marek, Adrian [Idaho National Lab. (INL), Idaho Falls, ID (United States); Falero, Valentina Montaldo [Idaho National Lab. (INL), Idaho Falls, ID (United States); Youngs, Robert [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-09-01

    A Probabilistic Seismic Hazard Analysis (PSHA) was completed for the Materials and Fuels Complex (MFC), Naval Reactors Facility (NRF), and the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) (Figure 1-1). The PSHA followed the approaches and procedures appropriate for a Study Level 1 provided in the guidance advanced by the Senior Seismic Hazard Analysis Committee (SSHAC) in U.S. Nuclear Regulatory Commission (NRC) NUREG/CR-6372 and NUREG-2117 (NRC, 1997; 2012a). The SSHAC Level 1 PSHAs for MFC and ATR were conducted as part of the Seismic Risk Assessment (SRA) project (INL Project number 31287) to develop and apply a new-risk informed methodology, respectively. The SSHAC Level 1 PSHA was conducted for NRF to provide guidance on the potential use of a design margin above rock hazard levels. The SRA project is developing a new risk-informed methodology that will provide a systematic approach for evaluating the need for an update of an existing PSHA. The new methodology proposes criteria to be employed at specific analysis, decision, or comparison points in its evaluation process. The first four of seven criteria address changes in inputs and results of the PSHA and are given in U.S. Department of Energy (DOE) Standard, DOE-STD-1020-2012 (DOE, 2012a) and American National Standards Institute/American Nuclear Society (ANSI/ANS) 2.29 (ANS, 2008a). The last three criteria address evaluation of quantitative hazard and risk-focused information of an existing nuclear facility. The seven criteria and decision points are applied to Seismic Design Category (SDC) 3, 4, and 5, which are defined in American Society of Civil Engineers/Structural Engineers Institute (ASCE/SEI) 43-05 (ASCE, 2005). The application of the criteria and decision points could lead to an update or could determine that such update is not necessary.

  3. The Impact of the Subduction Modeling Beneath Calabria on Seismic Hazard

    Science.gov (United States)

    Morasca, P.; Johnson, W. J.; Del Giudice, T.; Poggi, P.; Traverso, C.; Parker, E. J.

    2014-12-01

    The aim of this work is to better understand the influence of subduction beneath Calabria on seismic hazard, as very little is known about present-day kinematics and the seismogenic potential of the slab interface in the Calabrian Arc region. This evaluation is significant because, depending on stress conditions, subduction zones can vary from being fully coupled to almost entirely decoupled with important consequences in the seismic hazard assessment. Although the debate is still open about the current kinematics of the plates and microplates lying in the region and the degree of coupling of Ionian lithosphere beneath Calabria, GPS data suggest that this subduction is locked in its interface sector. Also the lack of instrumentally recorded thrust earthquakes suggests this zone is locked. The current seismotectonic model developed for the Italian National territory is simplified in this area and does not reflect the possibility of locked subduction beneath the Calabria that could produce infrequent, but very large earthquakes associated with the subduction interface. Because of this we have conducted an independent seismic source analysis to take into account the influence of subduction as part of a regional seismic hazard analysis. Our final model includes two separate provinces for the subduction beneath the Calabria: inslab and interface. From a geometrical point of view the interface province is modeled with a depth between 20-50 km and a dip of 20°, while the inslab one dips 70° between 50 -100 km. Following recent interpretations we take into account that the interface subduction is possibly locked and, in such a case, large events could occur as characteristic earthquakes. The results of the PSHA analysis show that the subduction beneath the Calabrian region has an influence in the total hazard for this region, especially for long return periods. Regional seismotectonic models for this region should account for subduction.

  4. Time-dependent seismic hazard in Bobrek coal mine, Poland, assuming different magnitude distribution estimations

    Science.gov (United States)

    Leptokaropoulos, Konstantinos; Staszek, Monika; Cielesta, Szymon; Urban, Paweł; Olszewska, Dorota; Lizurek, Grzegorz

    2017-01-01

    The purpose of this study is to evaluate seismic hazard parameters in connection with the evolution of mining operations and seismic activity. The time-dependent hazard parameters to be estimated are activity rate, Gutenberg-Richter b-value, mean return period and exceedance probability of a prescribed magnitude for selected time windows related with the advance of the mining front. Four magnitude distribution estimation methods are applied and the results obtained from each one are compared with each other. Those approaches are maximum likelihood using the unbounded and upper bounded Gutenberg-Richter law and the non-parametric unbounded and non-parametric upper-bounded kernel estimation of magnitude distribution. The method is applied for seismicity occurred in the longwall mining of panel 3 in coal seam 503 in Bobrek colliery in Upper Silesia Coal Basin, Poland, during 2009-2010. Applications are performed in the recently established Web-Platform for Anthropogenic Seismicity Research, available at https://tcs.ah-epos.eu/.

  5. Time-dependent seismic hazard in Bobrek coal mine, Poland, assuming different magnitude distribution estimations

    Science.gov (United States)

    Leptokaropoulos, Konstantinos; Staszek, Monika; Cielesta, Szymon; Urban, Paweł; Olszewska, Dorota; Lizurek, Grzegorz

    2017-06-01

    The purpose of this study is to evaluate seismic hazard parameters in connection with the evolution of mining operations and seismic activity. The time-dependent hazard parameters to be estimated are activity rate, Gutenberg-Richter b-value, mean return period and exceedance probability of a prescribed magnitude for selected time windows related with the advance of the mining front. Four magnitude distribution estimation methods are applied and the results obtained from each one are compared with each other. Those approaches are maximum likelihood using the unbounded and upper bounded Gutenberg-Richter law and the non-parametric unbounded and non-parametric upper-bounded kernel estimation of magnitude distribution. The method is applied for seismicity occurred in the longwall mining of panel 3 in coal seam 503 in Bobrek colliery in Upper Silesia Coal Basin, Poland, during 2009-2010. Applications are performed in the recently established Web-Platform for Anthropogenic Seismicity Research, available at https://tcs.ah-epos.eu/.

  6. High-Resolution Seismic Reflection Profiling Across the Black Hills Fault, Clark County, Nevada: Preliminary Results

    Science.gov (United States)

    Zaragoza, S. A.; Snelson, C. M.; Jernsletten, J. A.; Saldana, S. C.; Hirsch, A.; McEwan, D.

    2005-12-01

    The Black Hills fault (BHF) is located in the central Basin and Range Province of western North America, a region that has undergone significant Cenozoic extension. The BHF is an east-dipping normal fault that forms the northwestern structural boundary of the Eldorado basin and lies ~20 km southeast of Las Vegas, Nevada. A recent trench study indicated that the fault offsets Holocene strata, and is capable of producing Mw 6.4-6.8 earthquakes. These estimates indicate a subsurface rupture length at least 10 km greater than the length of the scarp. This poses a significant hazard to structures such as the nearby Hoover Dam Bypass Bridge, which is being built to withstand a Mw 6.2-7.0 earthquake on local faults. If the BHF does continue in the subsurface, this structure, as well as nearby communities (Las Vegas, Boulder City, and Henderson), may not be as safe as previously expected. Previous attempts to image the fault with shallow seismics (hammer source) were inconclusive. However, gravity studies imply that the fault continues south of the scarp. Therefore, a new experiment utilizing high-resolution seismic reflection was performed to image subsurface geologic structures south of the scarp. At each shot point, a stack of four 30-160 Hz vibroseis sweeps of 15 s duration was recorded on a 60-channel system with 40 Hz geophones. This produced two 300 m reflection profiles, with a maximum depth of 500-600 m. A preliminary look at these data indicates the existence of two faults, potentially confirming that the BHF continues in the subsurface south of the scarp.

  7. The preliminary results: Internal seismic velocity structure imaging beneath Mount Lokon

    Science.gov (United States)

    Firmansyah, Rizky; Nugraha, Andri Dian; Kristianto

    2015-04-01

    Historical records that before the 17th century, Mount Lokon had been dormant for approximately 400 years. In the years between 1350 and 1400, eruption ever recorded in Empung, came from Mount Lokon's central crater. Subsequently, in 1750 to 1800, Mount Lokon continued to erupt again and caused soil damage and fall victim. After 1949, Mount Lokon dramatically increased in its frequency: the eruption interval varies between 1 - 5 years, with an average interval of 3 years and a rest interval ranged from 8 - 64 years. Then, on June 26th, 2011, standby alert set by the Center for Volcanology and Geological Hazard Mitigation. Peak activity happened on July 4th, 2011 that Mount Lokon erupted continuously until August 28th, 2011. In this study, we carefully analyzed micro-earthquakes waveform and determined hypocenter location of those events. We then conducted travel time seismic tomographic inversion using SIMULPS12 method to detemine Vp, Vs and Vp/Vs ratio structures beneath Lokon volcano in order to enhance our subsurface geological structure. During the tomographic inversion, we started from 1-D seismic velocities model obtained from VELEST33 method. Our preliminary results show low Vp, low Vs, and high Vp/Vs are observed beneath Mount Lokon-Empung which are may be associated with weak zone or hot material zones. However, in this study we used few station for recording of micro-earthquake events. So, we suggest in the future tomography study, the adding of some seismometers in order to improve ray coverage in the region is profoundly justified.

  8. The preliminary results: Internal seismic velocity structure imaging beneath Mount Lokon

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-04-24

    Historical records that before the 17{sup th} century, Mount Lokon had been dormant for approximately 400 years. In the years between 1350 and 1400, eruption ever recorded in Empung, came from Mount Lokon’s central crater. Subsequently, in 1750 to 1800, Mount Lokon continued to erupt again and caused soil damage and fall victim. After 1949, Mount Lokon dramatically increased in its frequency: the eruption interval varies between 1 – 5 years, with an average interval of 3 years and a rest interval ranged from 8 – 64 years. Then, on June 26{sup th}, 2011, standby alert set by the Center for Volcanology and Geological Hazard Mitigation. Peak activity happened on July 4{sup th}, 2011 that Mount Lokon erupted continuously until August 28{sup th}, 2011. In this study, we carefully analyzed micro-earthquakes waveform and determined hypocenter location of those events. We then conducted travel time seismic tomographic inversion using SIMULPS12 method to detemine Vp, Vs and Vp/Vs ratio structures beneath Lokon volcano in order to enhance our subsurface geological structure. During the tomographic inversion, we started from 1-D seismic velocities model obtained from VELEST33 method. Our preliminary results show low Vp, low Vs, and high Vp/Vs are observed beneath Mount Lokon-Empung which are may be associated with weak zone or hot material zones. However, in this study we used few station for recording of micro-earthquake events. So, we suggest in the future tomography study, the adding of some seismometers in order to improve ray coverage in the region is profoundly justified.

  9. Near-Field Probabilistic Seismic Hazard Analysis of Metropolitan Tehran Using Region-Specific Directivity Models

    Science.gov (United States)

    Yazdani, Azad; Nicknam, Ahmad; Dadras, Ehsan Yousefi; Eftekhari, Seyed Nasrollah

    2017-01-01

    Ground motions are affected by directivity effects at near-fault regions which result in low-frequency cycle pulses at the beginning of the velocity time history. The directivity features of near-fault ground motions can lead to significant increase in the risk of earthquake-induced damage on engineering structures. The ordinary probabilistic seismic hazard analysis (PSHA) does not take into account such effects; recent studies have thus proposed new frameworks to incorporate directivity effects in PSHA. The objective of this study is to develop the seismic hazard mapping of Tehran City according to near-fault PSHA procedure for different return periods. To this end, the directivity models required in the modified PSHA were developed based on a database of the simulated ground motions. The simulated database was used in this study because there are no recorded near-fault data in the region to derive purely empirically based pulse prediction models. The results show that the directivity effects can significantly affect the estimate of regional seismic hazard.

  10. Develop and implement preconditioning techniques to control face ejection rockbursts for safer mining in seismically hazardous areas

    CSIR Research Space (South Africa)

    Toper, AZ

    1998-01-01

    Full Text Available This research report discusses the development of preconditioning techniques to control face bursts, for safer mining in seismically hazardous areas. Preconditioning involves regularly setting off carefully tailored blasts in the fractured rock...

  11. Earthquake hazard in northeast India – A seismic microzonation approach with typical case studies from Sikkim Himalaya and Guwahati city

    Indian Academy of Sciences (India)

    Sankar Kumar Nath; Kiran Kumar Singh Thingbaijam; Abhishek Raj

    2008-11-01

    A comprehensive analytical as well as numerical treatment of seismological, geological, geomorphological and geotechnical concepts has been implemented through microzonation projects in the northeast Indian provinces of Sikkim Himalaya and Guwahati city, representing cases of contrasting geological backgrounds – a hilly terrain and a predominantly alluvial basin respectively. The estimated maximum earthquakes in the underlying seismic source zones, demarcated in the broad northeast Indian region, implicates scenario earthquakes of 8.3 and 8.7 to the respective study regions for deterministic seismic hazard assessments. The microzonation approach as undertaken in the present analyses involves multi-criteria seismic hazard evaluation through thematic integration of contributing factors. The geomorphological themes for Sikkim Himalaya include surface geology, soil cover, slope, rock outcrop and landslide integrated to achieve geological hazard distribution. Seismological themes, namely surface consistent peak ground acceleration and predominant frequency were, thereafter, overlaid on and added with the geological hazard distribution to obtain the seismic hazard microzonation map of the Sikkim Himalaya. On the other hand, the microzonation study of Guwahati city accounts for eight themes – geological and geomorphological, basement or bedrock, landuse, landslide, factor of safety for soil stability, shear wave velocity, predominant frequency, and surface consistent peak ground acceleration. The five broad qualitative hazard classifications – `low’, `moderate’, `high’, `moderate high’ and `very high’ could be applied in both the cases, albeit with different implications to peak ground acceleration variations. These developed hazard maps offer better representation of the local specific seismic hazard variation in the terrain.

  12. Scenario based seismic hazard assessment and its application to the seismic verification of relevant buildings

    Science.gov (United States)

    Romanelli, Fabio; Vaccari, Franco; Altin, Giorgio; Panza, Giuliano

    2016-04-01

    The procedure we developed, and applied to a few relevant cases, leads to the seismic verification of a building by: a) use of a scenario based neodeterministic approach (NDSHA) for the calculation of the seismic input, and b) control of the numerical modeling of an existing building, using free vibration measurements of the real structure. The key point of this approach is the strict collaboration, from the seismic input definition to the monitoring of the response of the building in the calculation phase, of the seismologist and the civil engineer. The vibrometry study allows the engineer to adjust the computational model in the direction suggested by the experimental result of a physical measurement. Once the model has been calibrated by vibrometric analysis, one can select in the design spectrum the proper range of periods of interest for the structure. Then, the realistic values of spectral acceleration, which include the appropriate amplification obtained through the modeling of a "scenario" input to be applied to the final model, can be selected. Generally, but not necessarily, the "scenario" spectra lead to higher accelerations than those deduced by taking the spectra from the national codes (i.e. NTC 2008, for Italy). The task of the verifier engineer is to act so that the solution of the verification is conservative and realistic. We show some examples of the application of the procedure to some relevant (e.g. schools) buildings of the Trieste Province. The adoption of the scenario input has given in most of the cases an increase of critical elements that have to be taken into account in the design of reinforcements. However, the higher cost associated with the increase of elements to reinforce is reasonable, especially considering the important reduction of the risk level.

  13. Fault Specific Seismic Hazard Maps as Input to Loss Reserves Calculation for Attica Buildings

    Science.gov (United States)

    Deligiannakis, Georgios; Papanikolaou, Ioannis; Zimbidis, Alexandros; Roberts, Gerald

    2014-05-01

    Greece is prone to various natural disasters, such as wildfires, floods, landslides and earthquakes, due to the special environmental and geological conditions dominating in tectonic plate boundaries. Seismic is the predominant risk, in terms of damages and casualties in the Greek territory. The historical record of earthquakes in Greece has been published from various researchers, providing useful data in seismic hazard assessment of Greece. However, the completeness of the historical record in Greece, despite being one of the longest worldwide, reaches only 500 years for M ≥ 7.3 and less than 200 years for M ≥ 6.5. Considering that active faults in the area have recurrence intervals of a few hundred to several thousands of years, it is clear that many active faults have not been activated during the completeness period covered by the historical records. New Seismic Hazard Assessment methodologies tend to follow fault specific approaches where seismic sources are geologically constrained active faults, in order to address problems related to the historical records incompleteness, obtain higher spatial resolution and calculate realistic source locality distances, since seismic sources are very accurately located. Fault specific approaches provide quantitative assessments as they measure fault slip rates from geological data, providing a more reliable estimate of seismic hazard. We used a fault specific seismic hazard assessment approach for the region of Attica. The method of seismic hazard mapping from geological fault throw-rate data combined three major factors: Empirical data which combine fault rupture lengths, earthquake magnitudes and coseismic slip relationships. The radiuses of VI, VII, VIII and IX isoseismals on the Modified Mercalli (MM) intensity scale. Attenuation - amplification functions for seismic shaking on bedrock compared to basin filling sediments. We explicitly modeled 22 active faults that could affect the region of Attica, including

  14. An updated probabilistic seismic hazard assessment for Romania and comparison with the approach and outcomes of the SHARE Project

    OpenAIRE

    Pavel, Florin; Vacareanu, Radu; Douglas, John; Radulian, Micrea; Cioflan, Carmen; Barbat Barbat, Horia Alejandro

    2016-01-01

    The probabilistic seismic hazard analysis for Romania is revisited within the framework of the BIGSEES national research project (http://infp.infp.ro/bigsees/default.htm) financed by the Romanian Ministry of Education and Scientific Research in the period 2012-2016. The scope of this project is to provide a refined description of the seismic action for Romanian sites according to the requirements of Eurocode 8. To this aim, the seismicity of all the sources influencing the Romanian territory ...

  15. Geoethical and socio-political aspects of seismic and tsunami hazard assessment, quantification and mapping

    Science.gov (United States)

    Tinti, Stefano; Armigliato, Alberto

    2016-04-01

    Seismic hazard and, more recently, tsunami hazard assessments have been undertaken in several countries of the world and globally for the whole Earth planet with the aim of providing a scientifically sound basis to the engineers, technicians, urban and industrial planners, politicians, civil protection operators and in general to the authorities for devising rational risk mitigation strategies and corresponding adequate policies. The main point of this presentation is that the chief-value of all seismic and tsunami hazard studies (including theory, concept, quantification and mapping) resides in the social and political values of the provided products, which is a standpoint entailing a number of relevant geoethical implications. The most relevant implication regards geoscientists who are the subjects mainly involved in carrying out hazard evaluations. Viewed from the classical perspective, the main ethical obligations of geoscientists are restricted to performing hazard estimations in the best possible way from a scientific point of view, which means selecting the "best" available data, adopting sound theoretical models, making use of rigorous methods… What is outlined here, is that this is an insufficient minimalistic position, since it overlooks the basic socio-political and therefore practical value of the hazard-analysis final products. In other words, if one views hazard assessment as a production process leading from data and theories (raw data and production means) to hazard maps (products), the criterion to judge whether it is good or bad needs also to include the usability factor. Seismic and tsunami hazard reports and maps are products that should be usable, which means that they should meet user needs and requirements, and therefore they should be evaluated according to how much they are clearly understandable to, and appropriate for, making-decision users. In the traditional view of a science serving the society, one could represent the interaction

  16. An updated Probabilistic Seismic Hazard Analysis of the Trans Mexican Volcanic Belt, Mexico.

    Science.gov (United States)

    Bayona, J. A., Sr.; Suarez, G.; Zuniga, R. R.; Jaimes, M. Á.

    2014-12-01

    The Trans Mexican Volcanic Belt is the volcanic arc located in Central Mexico. This zone is not as seismically active as some other regions in Mexico, such as the subduction zone along the Pacific coast. However, there is evidence of major historical earthquakes (M > 7) occurring on the volcanic belt near densely populated cities such as Mexico City, Guadalajara and Morelia. Furthermore, almost 50% of the population of the country lives in cities and towns located on the Volcanic Belt. Using empirical magnitude-Intensity regressions, data obtained from historical descriptions of earthquakes were calibrated with instrumental data to determine their moment magnitude in order to create a complete seismic catalogue of this geological province. We propose a methodology to solve the problem of merging both historical and instrumental datasets. The method consists of dividing our catalogue into three different segments, according to the temporary nature and magnitude of our records. This segmentation was made considering the cut-off magnitude of our catalogue. In this way, we determined three Gutenberg-Richter distributions and correlated them geometrical and statistically. Based on the local seismic sources and using Bayesian statistics as well as appropriate seismic waves attenuation models, we generate seismic hazard maps that would be useful for more than 40 million people that live in the zone.

  17. 75 FR 16202 - Office of New Reactors; Interim Staff Guidance on Ensuring Hazard-Consistent Seismic Input for...

    Science.gov (United States)

    2010-03-31

    ... Site Response and Soil Structure Interaction Analyses AGENCY: Nuclear Regulatory Commission (NRC...-Consistent Seismic Input for Site Response and Soil Structure Interaction Analyses,'' (ADAMS Accession No...) DC/COL-ISG-017 titled ``Ensuring Hazard-Consistent Seismic Input for Site Response and Soil...

  18. FiSH: put fault data in a seismic hazard basket

    Science.gov (United States)

    Pace, Bruno; Visini, Francesco; Peruzza, Laura

    2016-04-01

    The practice of using fault sources in seismic hazard studies is growing in popularity, including in regions with moderate seismic activity, such as the European countries. In these areas, fault identification may be affected by similarly large uncertainties in the historical and instrumental seismic histories of more active areas that have not been inhabited for long periods of time. Certain studies have effectively applied a time-dependent perspective to combine historical and instrumental seismic data with geological and paleoseismological information, partially compensating for a lack of information. We present a package of Matlab® tools (called FiSH), in publication on Seismological Research Letters, designed to help seismic hazard modellers analyse fault data. These tools enable the derivation of expected earthquake rates given common fault data, and allow you to test the consistency between the magnitude frequency distributions assigned to a fault and some available observations. The basic assumption of FiSH is that the geometric and kinematic features of a fault are the expression of its seismogenic potential. Three tools have been designed to integrate the variable levels of information available: (a) the first tool allows users to convert fault geometry and slip rates into a global budget of the seismic moment released in a given time frame, taking uncertainties into account; (b) the second tool computes the recurrence parameters and associated uncertainties from historical and/or paleoseismological data; 
(c) the third tool outputs time-independent or time-dependent earthquake rates for different magnitude frequency distribution models. We present moreover a test case to illustrate the capabilities of FiSH, on the Paganica normal fault in Central Italy that ruptured during the L'Aquila 2009 earthquake sequence (mainshock Mw 6.3). FiSH is available at http://fish-code.com, and the source codes are open. We encourage users to handle the scripts

  19. 2017 one-year seismic hazard forecast for the central and eastern United States from induced and natural earthquakes

    Science.gov (United States)

    Petersen, Mark D.; Mueller, Charles; Moschetti, Morgan P.; Hoover, Susan M.; Shumway, Allison; McNamara, Daniel E.; Williams, Robert A.; Llenos, Andrea L.; Ellsworth, William L.; Michael, Andrew J.; Rubinstein, Justin L.; McGarr, Arthur F.; Rukstales, Kenneth S.

    2017-01-01

    We produce the 2017 one-year seismic hazard forecast for the central and eastern United States from induced and natural earthquakes that updates the 2016 one-year forecast; this map is intended to provide information to the public and to facilitate the development of induced seismicity forecasting models, methods, and data. The 2017 hazard model applies the same methodology and input logic tree as the 2016 forecast, but with an updated earthquake catalog. We also evaluate the 2016 seismic hazard forecast to improve future assessments. The 2016 forecast indicated high seismic hazard (greater than 1% probability of potentially damaging ground shaking in one-year) in five focus areas: Oklahoma-Kansas, the Raton Basin (Colorado/New Mexico border), north Texas, north Arkansas, and the New Madrid Seismic Zone. During 2016, several damaging induced earthquakes occurred in Oklahoma within the highest hazard region of the 2016 forecast; all of the 21 magnitude (M) ≥ 4 and three M ≥ 5 earthquakes occurred within the highest hazard area in the 2016 forecast. Outside the Oklahoma-Kansas focus area two earthquakes with M ≥ 4 occurred near Trinidad, Colorado (in the Raton Basin focus area), but no earthquakes with M ≥ 2.7 were observed in the north Texas or north Arkansas focus areas. Several observations of damaging ground shaking levels were also recorded in the highest hazard region of Oklahoma. The 2017 forecasted seismic rates are lower in regions of induced activity due to lower rates of earthquakes in 2016 compared to 2015, which may be related to decreased wastewater injection, caused by regulatory actions or by a decrease in unconventional oil and gas production. Nevertheless, the 2017 forecasted hazard is still significantly elevated in Oklahoma compared to the hazard calculated from seismicity before 2009.

  20. Including foreshocks and aftershocks in time-independent probabilistic seismic hazard analyses

    Science.gov (United States)

    Boyd, Oliver S.

    2012-01-01

    Time‐independent probabilistic seismic‐hazard analysis treats each source as being temporally and spatially independent; hence foreshocks and aftershocks, which are both spatially and temporally dependent on the mainshock, are removed from earthquake catalogs. Yet, intuitively, these earthquakes should be considered part of the seismic hazard, capable of producing damaging ground motions. In this study, I consider the mainshock and its dependents as a time‐independent cluster, each cluster being temporally and spatially independent from any other. The cluster has a recurrence time of the mainshock; and, by considering the earthquakes in the cluster as a union of events, dependent events have an opportunity to contribute to seismic ground motions and hazard. Based on the methods of the U.S. Geological Survey for a high‐hazard site, the inclusion of dependent events causes ground motions that are exceeded at probability levels of engineering interest to increase by about 10% but could be as high as 20% if variations in aftershock productivity can be accounted for reliably.

  1. Deterministic Seismic Hazard Assessment at Bed Rock Level: Case Study for the City of Bhubaneswar, India

    Directory of Open Access Journals (Sweden)

    Sukanti Rout

    2015-04-01

    Full Text Available In this study an updated deterministic seismic hazard contour map of Bhubaneswar (20°12'0"N to 20°23'0"N latitude and 85°44'0"E to 85° 54'0"E longitude one of the major city of India with tourist importance, has been prepared in the form of spectral acceleration values. For assessing the seismic hazard, the study area has been divided into small grids of size 30˝×30˝ (approximately 1.0 km×1.0 km, and the hazard parameters in terms of spectral acceleration at bedrock level, PGA are calculated as the center of each of these grid cells by considering the regional Seismo-tectonic activity within 400 km radius around the city center. The maximum credible earthquake in terms of moment magnitude of 7.2 has been used for calculation of hazard parameter, results in PGA value of 0.017g towards the northeast side of the city and the corresponding maximum spectral acceleration as 0.0501g for a predominant period of 0.05s at bedrock level.

  2. Seismic Hazard Analysis of Aizawl, India with a Focus on Water System Fragilities

    Science.gov (United States)

    Belair, G. M.; Tran, A. J.; Dreger, D. S.; Rodgers, J. E.

    2015-12-01

    GeoHazards International (GHI) has partnered with the University of California, Berkeley in a joint Civil Engineering and Earth Science summer internship program to investigate geologic hazards. This year the focus was on Aizawl, the capital of India's Mizoram state, situated on a ridge in the Burma Ranges. Nearby sources have the potential for large (M > 7) earthquakes that would be devastating to the approximately 300,000 people living in the city. Earthquake induced landslides also threaten the population as well as the city's lifelines. Fieldwork conducted in June 2015 identified hazards to vital water system components. The focus of this abstract is a review of the seismic hazards that affect Aizawl, with special attention paid to water system locations. To motivate action to reduce risk, GHI created an earthquake scenario describing effects of a M7 right-lateral strike-slip intraplate earthquake occurring 30 km below the city. We extended this analysis by exploring additional mapped faults as well as hypothetical blind reverse faults in terms of PGA, PGV, and PSA. Ground motions with hanging wall and directivity effects were also examined. Several attenuation relationships were used in order to assess the uncertainty in the ground motion parameters. Results were used to determine the likely seismic performance of water system components, and will be applied in future PSHA studies.

  3. Marine geophysical research helps to assess the seismic hazard at the Hispaniola Island

    Science.gov (United States)

    Carbó-Gorosabel, A.; Granja Bruña, J.; Llanes Estrada, M.; Munoz Martin, A.; Gómez Ballesteros, M.; Druet, M.; Martín-Dávila, J.; Pazos, A.; Catalan, M.; ten Brink, U. S.; Hernaiz-Huerta, P.; Olaiz, A. J.; Torres, R.; Brothers, D. S.

    2011-12-01

    Detailed swath bathymetry mapping of complete geological provinces together with high-resolution seismic profiles provide critical perspective for the detection and study of active faults and their seismic and tsunami hazard. Since 2003 the Universidad Complutense de Madrid has been leading an international research group to study the north-eastern Caribbean, from the Lesser Antilles to Jamaica. This area comprises the 200 km-wide boundary zone between the North American and the Caribbean plates, where the relative plate motion is 18-20 ±3 mm/year towards 070-075. The highly-oblique convergence between the plates in Hispaniola is accommodated by strain partitioning on seismic fault systems sub-parallel to the plate boundary: strike-slip (the Enriquillo-Plantain Garden and the Septentrional fault zones) and the compressive deformed belts (the Muertos thrust belt and the North Hispaniola thrust belt). Results from several research cruises offshore Hispaniola have identified and characterized zones of active deformation that were not observed onshore, such as the Muertos out-of-sequence thrust or the Beata Ridge crest fault zone. The Muertos out-of-sequence thrust could be related to the M≈8 event occurred the 18th of October in 1751 that shook central and south-eastern Hispaniola. In other seismic fault zones, such as the Enriquillo-Plantain Garden and the Septentrional fault zones, knowledge of their offshore continuity is limited. Future research cruises will target the offshore continuity of these strike-slip seismic fault zones in the vicinity of Southern Peninsula of Haiti, in the Jamaica Passage and in the Gonave Bay. As part of the NORCARIBE project, a research cruise will be taking place in the spring of 2012 aboard the Spanish R/V Hespérides. Multichannel, high-resolution and wide-angle seismic profiles will be acquired together with swath bathymetry, magnetic and gravity data. The scientific and social interest in studying this region has greatly

  4. Review of Seismic Hazard Issues Associated with Auburn Dam Project, Sierra Nevada Foothills, California

    Science.gov (United States)

    Schwartz, D.P.; Joyner, W.B.; Stein, R.S.; Brown, R.D.; McGarr, A.F.; Hickman, S.H.; Bakun, W.H.

    1996-01-01

    Summary -- The U.S. Geological Survey was requested by the U.S. Department of the Interior to review the design values and the issue of reservoir-induced seismicity for a concrete gravity dam near the site of the previously-proposed Auburn Dam in the western foothills of the Sierra Nevada, central California. The dam is being planned as a flood-control-only dam with the possibility of conversion to a permanent water-storage facility. As a basis for planning studies the U.S. Army Corps of Engineers is using the same design values approved by the Secretary of the Interior in 1979 for the original Auburn Dam. These values were a maximum displacement of 9 inches on a fault intersecting the dam foundation, a maximum earthquake at the site of magnitude 6.5, a peak horizontal acceleration of 0.64 g, and a peak vertical acceleration of 0.39 g. In light of geological and seismological investigations conducted in the western Sierran foothills since 1979 and advances in the understanding of how earthquakes are caused and how faults behave, we have developed the following conclusions and recommendations: Maximum Displacement. Neither the pre-1979 nor the recent observations of faults in the Sierran foothills precisely define the maximum displacement per event on a fault intersecting the dam foundation. Available field data and our current understanding of surface faulting indicate a range of values for the maximum displacement. This may require the consideration of a design value larger than 9 inches. We recommend reevaluation of the design displacement using current seismic hazard methods that incorporate uncertainty into the estimate of this design value. Maximum Earthquake Magnitude. There are no data to indicate that a significant change is necessary in the use of an M 6.5 maximum earthquake to estimate design ground motions at the dam site. However, there is a basis for estimating a range of maximum magnitudes using recent field information and new statistical fault

  5. 2016 one-year seismic hazard forecast for the Central and Eastern United States from induced and natural earthquakes

    Science.gov (United States)

    Petersen, Mark D.; Mueller, Charles S.; Moschetti, Morgan P.; Hoover, Susan M.; Llenos, Andrea L.; Ellsworth, William L.; Michael, Andrew J.; Rubinstein, Justin L.; McGarr, Arthur F.; Rukstales, Kenneth S.

    2016-03-28

    The U.S. Geological Survey (USGS) has produced a 1-year seismic hazard forecast for 2016 for the Central and Eastern United States (CEUS) that includes contributions from both induced and natural earthquakes. The model assumes that earthquake rates calculated from several different time windows will remain relatively stationary and can be used to forecast earthquake hazard and damage intensity for the year 2016. This assessment is the first step in developing an operational earthquake forecast for the CEUS, and the analysis could be revised with updated seismicity and model parameters. Consensus input models consider alternative earthquake catalog durations, smoothing parameters, maximum magnitudes, and ground motion estimates, and represent uncertainties in earthquake occurrence and diversity of opinion in the science community. Ground shaking seismic hazard for 1-percent probability of exceedance in 1 year reaches 0.6 g (as a fraction of standard gravity [g]) in northern Oklahoma and southern Kansas, and about 0.2 g in the Raton Basin of Colorado and New Mexico, in central Arkansas, and in north-central Texas near Dallas. Near some areas of active induced earthquakes, hazard is higher than in the 2014 USGS National Seismic Hazard Model (NHSM) by more than a factor of 3; the 2014 NHSM did not consider induced earthquakes. In some areas, previously observed induced earthquakes have stopped, so the seismic hazard reverts back to the 2014 NSHM. Increased seismic activity, whether defined as induced or natural, produces high hazard. Conversion of ground shaking to seismic intensity indicates that some places in Oklahoma, Kansas, Colorado, New Mexico, Texas, and Arkansas may experience damage if the induced seismicity continues unabated. The chance of having Modified Mercalli Intensity (MMI) VI or greater (damaging earthquake shaking) is 5–12 percent per year in north-central Oklahoma and southern Kansas, similar to the chance of damage caused by natural earthquakes

  6. Seismic hazard analysis with PSHA method in four cities in Java.

    Science.gov (United States)

    Elistyawati, Y.; Palupi, I. R.; Suharsono

    2016-11-01

    In this study the tectonic earthquakes was observed through the peak ground acceleration through the PSHA method by dividing the area of the earthquake source. This study applied the earthquake data from 1965 - 2015 that has been analyzed the completeness of the data, location research was the entire Java with stressed in four large cities prone to earthquakes. The results were found to be a hazard map with a return period of 500 years, 2500 years return period, and the hazard curve were four major cities (Jakarta, Bandung, Yogyakarta, and the city of Banyuwangi). Results Java PGA hazard map 500 years had a peak ground acceleration within 0 g ≥ 0.5 g, while the return period of 2500 years had a value of 0 to ≥ 0.8 g. While, the PGA hazard curves on the city's most influential source of the earthquake was from sources such as fault Cimandiri backgroud, for the city of Bandung earthquake sources that influence the seismic source fault dent background form. In other side, the city of Yogyakarta earthquake hazard curve of the most influential was the source of the earthquake background of the Opak fault, and the most influential hazard curve of Banyuwangi earthquake was the source of Java and Sumba megatruts earthquake.

  7. Toward a ground-motion logic tree for probabilistic seismic hazard assessment in Europe

    Science.gov (United States)

    Delavaud, Elise; Cotton, Fabrice; Akkar, Sinan; Scherbaum, Frank; Danciu, Laurentiu; Beauval, Céline; Drouet, Stéphane; Douglas, John; Basili, Roberto; Sandikkaya, M. Abdullah; Segou, Margaret; Faccioli, Ezio; Theodoulidis, Nikos

    2012-07-01

    The Seismic Hazard Harmonization in Europe (SHARE) project, which began in June 2009, aims at establishing new standards for probabilistic seismic hazard assessment in the Euro-Mediterranean region. In this context, a logic tree for ground-motion prediction in Europe has been constructed. Ground-motion prediction equations (GMPEs) and weights have been determined so that the logic tree captures epistemic uncertainty in ground-motion prediction for six different tectonic regimes in Europe. Here we present the strategy that we adopted to build such a logic tree. This strategy has the particularity of combining two complementary and independent approaches: expert judgment and data testing. A set of six experts was asked to weight pre-selected GMPEs while the ability of these GMPEs to predict available data was evaluated with the method of Scherbaum et al. (Bull Seismol Soc Am 99:3234-3247, 2009). Results of both approaches were taken into account to commonly select the smallest set of GMPEs to capture the uncertainty in ground-motion prediction in Europe. For stable continental regions, two models, both from eastern North America, have been selected for shields, and three GMPEs from active shallow crustal regions have been added for continental crust. For subduction zones, four models, all non-European, have been chosen. Finally, for active shallow crustal regions, we selected four models, each of them from a different host region but only two of them were kept for long periods. In most cases, a common agreement has been also reached for the weights. In case of divergence, a sensitivity analysis of the weights on the seismic hazard has been conducted, showing that once the GMPEs have been selected, the associated set of weights has a smaller influence on the hazard.

  8. Neo-Deterministic and Probabilistic Seismic Hazard Assessments: a Comparative Analysis

    Science.gov (United States)

    Peresan, Antonella; Magrin, Andrea; Nekrasova, Anastasia; Kossobokov, Vladimir; Panza, Giuliano F.

    2016-04-01

    Objective testing is the key issue towards any reliable seismic hazard assessment (SHA). Different earthquake hazard maps must demonstrate their capability in anticipating ground shaking from future strong earthquakes before an appropriate use for different purposes - such as engineering design, insurance, and emergency management. Quantitative assessment of maps performances is an essential step also in scientific process of their revision and possible improvement. Cross-checking of probabilistic models with available observations and independent physics based models is recognized as major validation procedure. The existing maps from the classical probabilistic seismic hazard analysis (PSHA), as well as those from the neo-deterministic analysis (NDSHA), which have been already developed for several regions worldwide (including Italy, India and North Africa), are considered to exemplify the possibilities of the cross-comparative analysis in spotting out limits and advantages of different methods. Where the data permit, a comparative analysis versus the documented seismic activity observed in reality is carried out, showing how available observations about past earthquakes can contribute to assess performances of the different methods. Neo-deterministic refers to a scenario-based approach, which allows for consideration of a wide range of possible earthquake sources as the starting point for scenarios constructed via full waveforms modeling. The method does not make use of empirical attenuation models (i.e. Ground Motion Prediction Equations, GMPE) and naturally supplies realistic time series of ground shaking (i.e. complete synthetic seismograms), readily applicable to complete engineering analysis and other mitigation actions. The standard NDSHA maps provide reliable envelope estimates of maximum seismic ground motion from a wide set of possible scenario earthquakes, including the largest deterministically or historically defined credible earthquake. In addition

  9. Description and Preliminary Testing of the CDSN Seismic Sensor Systems

    Science.gov (United States)

    Peterson, Jon; Tilgner, Edwin E.

    1985-01-01

    INTRODUCTION The China Digital Seismograph Network (CDSN) is being designed and installed to provide the People's Republic of China with the facilities needed to create a national digital database for earthquake research. The CDSN, which is being developed jointly by the PRC State Seismological Bureau and the U.S. Geological Survey, will consist initially of nine digitally-recording seismograph stations, a data management system to be used for compiling network-day tapes, and a depot maintenance center. Data produced by the network will be shared with research scientists throughout the world. A national seismograph network must be designed to support a variety of research objectives. From this standpoint, the choices and tradeoffs involved in specifying signal bandwidth, resolution, and dynamic range are the most important decisions in system design. As in the case of the CDSN, these decisions are made during the selection and design of the seismic sensor system and encoder components. The purpose of this report is to describe the CDSN sensor systems, their important signal characteristics, and the results of preliminary tests that have been performed on the instruments. Four overlapping data bands will be recorded at each station: short period (SP), broadband (BB), long period (LP), and very long period (VLP). Amplitude response curves are illustrated in Figure I. Vertical and horizontal components will be recorded for each data band. The SP and LP channels will be recorded with sufficient sensitivities to resolve earth background noise at seismically quiet sites. The BB channels will have a lower sensitivity and are intended for broadband recording of moderate-to-large body-wave signals and for increasing the effective amplitude range in the short- and long-period bands. The VLP channel does not provide additional spectral coverage at long periods; its purpose is to make use of on-site filtration and decimation to reduce post processing requirements for VLP

  10. Probabilistic assessment of surface level seismic hazard in India using topographic gradient as a proxy for site condition

    Institute of Scientific and Technical Information of China (English)

    T.G. Sitharam; Sreevalsa Kolathayar; Naveen James

    2015-01-01

    This paper presents spatial variation of seismic hazard at the surface level for India, covering 6e38? N and 68e98? E. The most recent knowledge on seismic activity in the region has been used to evaluate the hazard incorporating uncertainties associated with the seismicity parameters using different modeling methodologies. Three types of seismic source models, viz. linear sources, gridded seismicity model and areal sources, were considered to model the seismic sources and different sets of ground motion pre-diction equations were used for different tectonic provinces to characterize the attenuation properties. The hazard estimation at bedrock level has been carried out using probabilistic approach and the results obtained from various methodologies were combined in a logic tree framework. The seismic site char-acterization of India was done using topographic slope map derived from Digital Elevation Model data. This paper presents estimation of the hazard at surface level, using appropriate site amplification factors corresponding to various site classes based on VS30 values derived from the topographic gradient. Spatial variation of surface level peak horizontal acceleration (PHA) for return periods of 475 years and 2475 years are presented as contour maps.

  11. Probabilistic assessment of surface level seismic hazard in India using topographic gradient as a proxy for site condition

    Directory of Open Access Journals (Sweden)

    T.G. Sitharam

    2015-11-01

    Full Text Available This paper presents spatial variation of seismic hazard at the surface level for India, covering 6–38° N and 68–98° E. The most recent knowledge on seismic activity in the region has been used to evaluate the hazard incorporating uncertainties associated with the seismicity parameters using different modeling methodologies. Three types of seismic source models, viz. linear sources, gridded seismicity model and areal sources, were considered to model the seismic sources and different sets of ground motion prediction equations were used for different tectonic provinces to characterize the attenuation properties. The hazard estimation at bedrock level has been carried out using probabilistic approach and the results obtained from various methodologies were combined in a logic tree framework. The seismic site characterization of India was done using topographic slope map derived from Digital Elevation Model data. This paper presents estimation of the hazard at surface level, using appropriate site amplification factors corresponding to various site classes based on VS30 values derived from the topographic gradient. Spatial variation of surface level peak horizontal acceleration (PHA for return periods of 475 years and 2475 years are presented as contour maps.

  12. Subduction zone locking, strain partitioning, intraplate deformation and their implications to Seismic Hazards in South America

    Science.gov (United States)

    Galgana, G. A.; Mahdyiar, M.; Shen-Tu, B.; Pontbriand, C. W.; Klein, E.; Wang, F.; Shabestari, K.; Yang, W.

    2014-12-01

    We analyze active crustal deformation in South America (SA) using published GPS observations and historic seismicity along the Nazca Trench and the active Ecuador-Colombia-Venezuela Plate boundary Zone. GPS-constrained kinematisc models that incorporate block and continuum techniques are used to assess patterns of regional tectonic deformation and its implications to seismic potential. We determine interplate coupling distributions, fault slip-rates, and intraplate crustal strain rates in combination with historic earthquakes within 40 seismic zones crust to provide moment rate constraints. Along the Nazca subduction zone, we resolve a series of highly coupled patches, interpreted as high-friction producing "asperities" beneath the coasts of Ecuador, Peru and Chile. These include areas responsible for the 2010 Mw 8.8 Maule Earthquake and the 2014 Mw 8.2 Iquique Earthquake. Predicted tectonic block motions and fault slip rates reveal that the northern part of South America deforms rapidly, with crustal fault slip rates as much as ~20 mm/a. Fault slip and locking patterns reveal that the Oca Ancón-Pilar-Boconó fault system plays a key role in absorbing most of the complex eastward and southward convergence patterns in northeastern Colombia and Venezuela, while the near-parallel system of faults in eastern Colombia and Ecuador absorb part of the transpressional motion due to the ~55 mm/a Nazca-SA plate convergence. These kinematic models, in combination with historic seismicity rates, provide moment deficit rates that reveal regions with high seismic potential, such as coastal Ecuador, Bucaramanga, Arica and Antofagasta. We eventually use the combined information from moment rates and fault coupling patterns to further constrain stochastic seismic hazard models of the region by implementing realistic trench rupture scenarios (see Mahdyiar et al., this volume).

  13. Region-specific deterministic and probabilistic seismic hazard analysis of Kanpur city

    Indian Academy of Sciences (India)

    Anbazhagan P; Ketan Bajaj; Nairwita Dutta; Sayed S R Moustafa; Nassir S N Al-Arifi

    2017-02-01

    A seismic hazard map of Kanpur city has been developed considering the region-specific seismotectonic parameters within a 500-km radius by deterministic and probabilistic approaches. The maximum probable earthquake magnitude \\textit(Mmax) for each seismic source has been estimated by considering the regional rupture characteristics method and has been compared with the maximum magnitude observed \\textit(Mobsmax), \\textit(Mobsmax) + 0.5 and Kijko method. The best suitable ground motion prediction equations (GMPE) were selected from 27 applicable GMPEs based on the ‘efficacy test’. Furthermore, different weight factors were assigned to different Mmax values and the selected GMPE to calculate the final hazard value. Peak ground acceleration and spectral acceleration at 0.2 and 1 s were estimated and mapped for worstcase scenario and 2 and 10% probability of exceedance for 50 years. Peak ground acceleration (PGA) showed a variation from 0.04 to 0.36 g for DSHA, from 0.02 to 0.32 g and 0.092 to 0.1525 g for 2 and 10% probability in 50 years, respectively. A normalised site-specific design spectrum has been developed considering three vulnerable sources based on deaggregation at the city center and the results are compared with the recent 2011 Sikkim and 2015 Nepal earthquakes, and the Indian seismic code IS 1893.

  14. Physical Exposure to Seismic Hazards of Health Facilities in Mexico City, Mexico

    Science.gov (United States)

    Rodriguez, S. M.; Novelo Casanova, D.

    2010-12-01

    Although health facilities are essential infrastructure during disasters and emergencies, they are also usually highly vulnerable installations in the case of the occurrence of large and major earthquakes. Hospitals are one of the most complex critical facilities in modern cities and they are used as first response in emergency situations. The operability of a hospital must be maintained after the occurrence of a local strong earthquake in order to satisfy the need for medical care of the affected population. If a health facility is seriously damaged, it cannot fulfill its function when most is needed. In this case, hospitals become a casualty of the disaster. To identify the level of physical exposure of hospitals to seismic hazards in Mexico City, we analyzed their geographic location with respect to the seismic response of the different type of soils of the city from past earthquakes, mainly from the events that occurred on September 1985 (Ms= 8.0) and April 1989 (Ms= 6.9). Seismic wave amplification in this city is the result of the interaction of the incoming seismic waves with the soft and water saturated clay soils, on which a large part of Mexico City is built. The clay soils are remnants of the lake that existed in the Valley of Mexico and which has been drained gradually to accommodate the growing urban sprawl. Hospital facilities were converted from a simple database of names and locations into a map layer of resources. This resource layer was combined with other map layers showing areas of seismic microzonation in Mexico City. This overlay was then used to identify those hospitals that may be threatened by the occurrence of a large or major seismic event. We analyzed the public and private hospitals considered as main health facilities. Our results indicate that more than 50% of the hospitals are highly exposed to seismic hazards. Besides, in most of these health facilities we identified the lack of preventive measures and preparedness to reduce their

  15. Seismic hazard methodology for the Central and Eastern United States: Volume 1: Part 2, Methodology (Revision 1): Final report

    Energy Technology Data Exchange (ETDEWEB)

    McGuire, R.K.; Veneziano, D.; Van Dyck, J.; Toro, G.; O' Hara, T.; Drake, L.; Patwardhan, A.; Kulkarni, R.; Keeney, R.; Winkler, R.

    1988-11-01

    Aided by its consultant, the US Geologic Survey (USGS), the Nuclear Regulatory Commission (NRC) reviewed ''Seismic Hazard Methodology for the Central and Eastern United States.'' This topical report was submitted jointly by the Seismicity Owners Group (SOG) and the Electric Power Research Institute (EPRI) in July 1986 and was revised in February 1987. The NRC staff concludes that SOG/EPRI Seismic Hazard Methodology as documented in the topical report and associated submittals, is an acceptable methodology for use in calculating seismic hazard in the Central and Eastern United States (CEUS). These calculations will be based upon the data and information documented in the material that was submitted as the SOG/EPRI topical report and ancillary submittals. However, as part of the review process the staff conditions its approval by noting areas in which problems may arise unless precautions detailed in the report are observed. 23 refs.

  16. SLUDGE TREATMENT PROJECT ENGINEERED CONTAINER RETRIEVAL AND TRANSFER SYSTEM PRELIMINARY DESIGN HAZARD ANALYSIS SUPPLEMENT 1

    Energy Technology Data Exchange (ETDEWEB)

    FRANZ GR; MEICHLE RH

    2011-07-18

    This 'What/If' Hazards Analysis addresses hazards affecting the Sludge Treatment Project Engineered Container Retrieval and Transfer System (ECRTS) NPH and external events at the preliminary design stage. In addition, the hazards of the operation sequence steps for the mechanical handling operations in preparation of Sludge Transport and Storage Container (STSC), disconnect STSC and prepare STSC and Sludge Transport System (STS) for shipping are addressed.

  17. Preliminary Study of m(b) Bias at Selected Soviet Seismic Stations.

    Science.gov (United States)

    1986-03-21

    8217-R66 395 PRELIMINARY STUDY OF M(B) BIRS AT SELECTED SOVIET 1/1 SEISMIC STRTIONS(U) SCIENCE APPLICATIONS INTERNATIONAL CORP ARLINGTON VR A S RYRLL...earthquakes in each source region was not given in the ,.t 1980 paper, but in the earlier work it ranged from 35 events for Asia and the Mediter - ranean to

  18. Application of a time probabilistic approach to seismic landslide hazard estimates in Iran

    Science.gov (United States)

    Rajabi, A. M.; Del Gaudio, V.; Capolongo, D.; Khamehchiyan, M.; Mahdavifar, M. R.

    2009-04-01

    Iran is a country located in a tectonic active belt and is prone to earthquake and related phenomena. In the recent years, several earthquakes caused many fatalities and damages to facilities, e.g. the Manjil (1990), Avaj (2002), Bam (2003) and Firuzabad-e-Kojur (2004) earthquakes. These earthquakes generated many landslides. For instance, catastrophic landslides triggered by the Manjil Earthquake (Ms = 7.7) in 1990 buried the village of Fatalak, killed more than 130 peoples and cut many important road and other lifelines, resulting in major economic disruption. In general, earthquakes in Iran have been concentrated in two major zones with different seismicity characteristics: one is the region of Alborz and Central Iran and the other is the Zagros Orogenic Belt. Understanding where seismically induced landslides are most likely to occur is crucial in reducing property damage and loss of life in future earthquakes. For this purpose a time probabilistic approach for earthquake-induced landslide hazard at regional scale, proposed by Del Gaudio et al. (2003), has been applied to the whole Iranian territory to provide the basis of hazard estimates. This method consists in evaluating the recurrence of seismically induced slope failure conditions inferred from the Newmark's model. First, by adopting Arias Intensity to quantify seismic shaking and using different Arias attenuation relations for Alborz - Central Iran and Zagros regions, well-established methods of seismic hazard assessment, based on the Cornell (1968) method, were employed to obtain the occurrence probabilities for different levels of seismic shaking in a time interval of interest (50 year). Then, following Jibson (1998), empirical formulae specifically developed for Alborz - Central Iran and Zagros, were used to represent, according to the Newmark's model, the relation linking Newmark's displacement Dn to Arias intensity Ia and to slope critical acceleration ac. These formulae were employed to evaluate

  19. Seismic hazards of the Iberian Peninsula – evaluation with kernel functions

    Directory of Open Access Journals (Sweden)

    M. J. Crespo

    2013-08-01

    Full Text Available The seismic hazard of the Iberian Peninsula is analysed using a nonparametric methodology based on statistical kernel functions; the activity rate is derived from the catalogue data, both its spatial dependence (without a seismogenetic zonation and its magnitude dependence (without using Gutenberg–Richter's law. The catalogue is that of the Instituto Geográfico Nacional, supplemented with other catalogues around the periphery; the quantification of events has been homogenised and spatially or temporally interrelated events have been suppressed to assume a Poisson process. The activity rate is determined by the kernel function, the bandwidth and the effective periods. The resulting rate is compared with that produced using Gutenberg–Richter statistics and a zoned approach. Three attenuation laws have been employed, one for deep sources and two for shallower events, depending on whether their magnitude was above or below 5. The results are presented as seismic hazard maps for different spectral frequencies and for return periods of 475 and 2475 yr, which allows constructing uniform hazard spectra.

  20. New Seismic Hazard study in Spain Aimed at the revision of the Spanish Building Code

    Science.gov (United States)

    Rivas-Medina, A.; Benito, B.; Cabañas, L.; Martínez-Solares, J. M.; Ruíz, S.; Gaspar-Escribano, J. M.; Carreño, E.; Crespo, M.; García-Mayordomo, J.

    2013-05-01

    In this paper we present a global overview of the recent study carried out in Spain for the new hazard map, which final goal is the revision of the Building Code in our country (NCSE-02). The study was carried our for a working group joining experts from The Instituto Geografico Nacional (IGN) and the Technical University of Madrid (UPM) , being the different phases of the work supervised by an expert Committee integrated by national experts from public institutions involved in subject of seismic hazard. The PSHA method (Probabilistic Seismic Hazard Assessment) has been followed, quantifying the epistemic uncertainties through a logic tree and the aleatory ones linked to variability of parameters by means of probability density functions and Monte Carlo simulations. In a first phase, the inputs have been prepared, which essentially are: 1) a project catalogue update and homogenization at Mw 2) proposal of zoning models and source characterization 3) calibration of Ground Motion Prediction Equations (GMPE's) with actual data and development of a local model with data collected in Spain for Mw logic tree and their weights. Finally, the hazard estimation was done with the logic tree shown in figure 1, including nodes for quantifying uncertainties corresponding to: 1) method for estimation of hazard (zoning and zoneless); 2) zoning models, 3) GMPE combinations used and 4) regression method for estimation of source parameters. In addition, the aleatory uncertainties corresponding to the magnitude of the events, recurrence parameters and maximum magnitude for each zone have been also considered including probability density functions and Monte Carlo simulations The main conclusions of the study are presented here, together with the obtained results in terms of PGA and other spectral accelerations SA (T) for return periods of 475, 975 and 2475 years. The map of the coefficient of variation (COV) are also represented to give an idea of the zones where the dispersion among

  1. Wind turbines and seismic hazard: a state-of-the-art review

    DEFF Research Database (Denmark)

    Katsanos, Evangelos; Thöns, Sebastian; Georgakis, Christos T.

    2016-01-01

    and assessment of wind turbines. Based on numerical simulation, either deterministic or probabilistic approaches are reviewed, because they have been adopted to investigate the sensitivity of wind turbines’ structural capacity and reliability in earthquake-induced loading. The relevance of seismic hazard...... for wind turbines is further enlightened by available experimental studies, being also comprehensively reported through this paper. The main contribution of the study presented herein is to identify the key factors for wind turbines’ seismic performance, while important milestones for ongoing and future......Wind energy is a rapidly growing field of renewable energy, and as such, intensive scientific and societal interest has been already attracted. Research on wind turbine structures has been mostly focused on the structural analysis, design and/or assessment of wind turbines mainly against normal...

  2. Modeling of the Sedimentary Interbedded Basalt Stratigraphy for the Idaho National Laboratory Probabilistic Seismic Hazard Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Suzette Payne

    2006-04-01

    This report summarizes how the effects of the sedimentary interbedded basalt stratigraphy were modeled in the probabilistic seismic hazard analysis (PSHA) of the Idaho National Laboratory (INL). Drill holes indicate the bedrock beneath INL facilities is composed of about 1.1 km of alternating layers of basalt rock and loosely consolidated sediments. Alternating layers of hard rock and “soft” loose sediments tend to attenuate seismic energy greater than uniform rock due to scattering and damping. The INL PSHA incorporated the effects of the sedimentary interbedded basalt stratigraphy by developing site-specific shear (S) wave velocity profiles. The profiles were used in the PSHA to model the near-surface site response by developing site-specific stochastic attenuation relationships.

  3. Modeling of the Sedimentary Interbedded Basalt Stratigraphy for the Idaho National Laboratory Probabilistic Seismic Hazard Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Suzette Payne

    2007-08-01

    This report summarizes how the effects of the sedimentary interbedded basalt stratigraphy were modeled in the probabilistic seismic hazard analysis (PSHA) of the Idaho National Laboratory (INL). Drill holes indicate the bedrock beneath INL facilities is composed of about 1.1 km of alternating layers of basalt rock and loosely consolidated sediments. Alternating layers of hard rock and “soft” loose sediments tend to attenuate seismic energy greater than uniform rock due to scattering and damping. The INL PSHA incorporated the effects of the sedimentary interbedded basalt stratigraphy by developing site-specific shear (S) wave velocity profiles. The profiles were used in the PSHA to model the near-surface site response by developing site-specific stochastic attenuation relationships.

  4. The MITMOTION Project - A seismic hazard overview of the Mitidja Basin (Northern Algeria)

    Science.gov (United States)

    Borges, José; Ouyed, Merzouk; Bezzeghoud, Mourad; Idres, Mouloud; Caldeira, Bento; Boughacha, Mohamed; Carvalho, João; Samai, Saddek; Fontiela, João; Aissa, Saoussen; Benfadda, Amar; Chimouni, Redouane; Yalaoui, Rafik; Dias, Rui

    2017-04-01

    The Mitidja Basin (MB) is located in northern Algeria and is filled by quaternary sediments with a length of about 100 km on the EW direction and approximately 20 km width. This basin is limited to the south by the Boumerdes - Larbaa - Blida active fault system and to the north by the Thenia - Sahel fault system. Both fault systems are of the reverse type with opposed dips and accommodate a general slip rate of 4 mm/year. This basin is associated with important seismic events that affected northern Algeria since the historical period until the present. The available earthquake catalogues reported numerous destructive earthquakes that struke different regions, such as Algiers (1365, Io= X; 1716, Io = X). Recently, on May 2003 the Bourmedes earthquake (Mw = 6.9) affected the area of Zemmouri and caused 2.271 deaths. The event was caused by the reactivation of the MB boundary faults. The epicenter was located offshore and generated a maximum uplift of 0.8 m along the coast with a horizontal maximum slip of 0.24 m. Recent studies show that the Boumerdes earthquake overloaded the system of adjacent faults with a stress increase between 0.4 and 1.5 bar. This induced an increase of the seismic hazard potential of the region and recommends a more detailed study of this fault system. The high seismogenic potential of the fault system bordering the MB, the exposure to danger of the most densely populated region of Algiers and the amplification effect caused by the basin are the motivation for this project proposal that will focus on the evaluation of the seismic hazard of the region. The general purpose of the project is to improve the seismic hazard assessment on the MB producing realistic predictions of strong ground motion caused by moderate and large earthquakes. To achieve this objective, it is important to make an effort in 3 directions: 1) the development of a detailed 3D velocity/structure model of the MB that includes geological constraints, seismic reflection data

  5. Some Factors Controlling the Seismic Hazard due to Earthquakes Induced by Fluid Injection at Depth

    Science.gov (United States)

    McGarr, A.

    2012-12-01

    The maximum seismic moment (or moment magnitude) is an important measure of the seismic hazard associated with earthquakes induced by deep fluid injection. Although it would be advantageous to be able to predict the induced earthquake outcome, including the maximum seismic moment, of a specified fluid injection project in advance, this capability has, to date, proved to be elusive because the geomechanical and hydrological factors that control the seismic response to injection are too poorly understood. Fortunately, the vast majority of activities involving the injection of fluids into deep aquifers do not cause earthquakes that are large enough to be of any consequence. There have been, however, significant exceptions during the past 50 years, starting with the earthquakes induced by injection of wastewater at the Rocky Mountain Arsenal Well, during the 1960s, that caused extensive damage in the Denver, CO, area. Results from numerous case histories of earthquakes induced by injection activities, including wastewater disposal at depth and the development of enhanced geothermal systems, suggest that it may be feasible to estimate bounds on maximum magnitudes based on the volume of injected liquid. For these cases, volumes of injected liquid ranged from approximately 11.5 thousand to 5 million cubic meters and resulted in main shock moment magnitudes from 3.4 to 5.3. Because the maximum seismic moment appears to be linearly proportional to the total volume of injected fluid, this upper bound is expected to increase with time as long as a given injection well remains active. For example, in the Raton Basin, southern Colorado and northern New Mexico, natural gas is produced from an extensive coal bed methane field. The deep injection of wastewater associated with this gas production has induced a sequence of earthquakes starting in August 2001, shortly after the beginning of major injection activities. Most of this seismicity defines a northeast striking plane dipping

  6. The 2014 Update of the United States National Seismic Hazard Maps

    Science.gov (United States)

    Petersen, M. D.; Mueller, C. S.; Moschetti, M. P.; Haller, K. M.; Zeng, Y.; Harmsen, S.; Frankel, A. D.; Rezaeian, S.; Powers, P.; Field, E. H.; Boyd, O. S.; Chen, R.; Rukstales, K. S.; Wheeler, R. L.; Luco, N.; Williams, R. A.; Olson, A.

    2013-12-01

    The USGS is in the process of updating the U.S. National Seismic Hazard Maps for the lower 48 States that will be considered for inclusion in future building codes, risk assessments, and other public policy applications. These seismic hazard maps are based on our assessment of the best available science at the time of the update, and incorporate a broad range of scientific models and parameters. The maps were discussed in regional workshops held across the U.S., reviewed by our Steering Committee, and available on-line during a 45-day period for public comment. The USGS hazard maps depict earthquake ground-shaking exceedance levels for various probabilities over a 50-year time period and are based on calculations at several hundred thousand sites across the U.S. Inputs to the hazard maps are based on scientific estimates of the locations, magnitudes, and rates of earthquakes as well as ground motion models describing each earthquake's ground shaking. We model rates of earthquakes either on known faults or as seismicity-based background earthquakes that account for unknown faults and an incomplete fault inventory. Probabilities of ground shaking are calculated from ground motion models that estimate the likely shaking caused by an earthquake. Several new datasets and models have been developed since the 2008 update of the maps. For the Central and Eastern U.S. we implemented a new moment magnitude catalog and completeness estimates, updated the maximum magnitude distribution, updated and tested the smoothing algorithms for adaptive and fixed-radius methods, extended the fault model -including the sizes and rates of New Madrid Seismic Zone earthquakes, considered induced earthquakes, and included updated and new ground motion models along with a new weighting scheme. In the Intermountain West we implemented new smoothing algorithms, fault geometry for normal faults, Wasatch fault model, and fault slip rates based on models obtained by inverting geodetic and geologic

  7. CyberShake: A Physics-Based Seismic Hazard Model for Southern California

    Science.gov (United States)

    Graves, R.; Jordan, T.H.; Callaghan, S.; Deelman, E.; Field, E.; Juve, G.; Kesselman, C.; Maechling, P.; Mehta, G.; Milner, K.; Okaya, D.; Small, P.; Vahi, K.

    2011-01-01

    CyberShake, as part of the Southern California Earthquake Center's (SCEC) Community Modeling Environment, is developing a methodology that explicitly incorporates deterministic source and wave propagation effects within seismic hazard calculations through the use of physics-based 3D ground motion simulations. To calculate a waveform-based seismic hazard estimate for a site of interest, we begin with Uniform California Earthquake Rupture Forecast, Version 2.0 (UCERF2.0) and identify all ruptures within 200 km of the site of interest. We convert the UCERF2.0 rupture definition into multiple rupture variations with differing hypocenter locations and slip distributions, resulting in about 415,000 rupture variations per site. Strain Green Tensors are calculated for the site of interest using the SCEC Community Velocity Model, Version 4 (CVM4), and then, using reciprocity, we calculate synthetic seismograms for each rupture variation. Peak intensity measures are then extracted from these synthetics and combined with the original rupture probabilities to produce probabilistic seismic hazard curves for the site. Being explicitly site-based, CyberShake directly samples the ground motion variability at that site over many earthquake cycles (i. e., rupture scenarios) and alleviates the need for the ergodic assumption that is implicitly included in traditional empirically based calculations. Thus far, we have simulated ruptures at over 200 sites in the Los Angeles region for ground shaking periods of 2 s and longer, providing the basis for the first generation CyberShake hazard maps. Our results indicate that the combination of rupture directivity and basin response effects can lead to an increase in the hazard level for some sites, relative to that given by a conventional Ground Motion Prediction Equation (GMPE). Additionally, and perhaps more importantly, we find that the physics-based hazard results are much more sensitive to the assumed magnitude-area relations and

  8. Quantification of source uncertainties in Seismic Probabilistic Tsunami Hazard Analysis (SPTHA)

    Science.gov (United States)

    Selva, J.; Tonini, R.; Molinari, I.; Tiberti, M. M.; Romano, F.; Grezio, A.; Melini, D.; Piatanesi, A.; Basili, R.; Lorito, S.

    2016-06-01

    We propose a procedure for uncertainty quantification in Probabilistic Tsunami Hazard Analysis (PTHA), with a special emphasis on the uncertainty related to statistical modelling of the earthquake source in Seismic PTHA (SPTHA), and on the separate treatment of subduction and crustal earthquakes (treated as background seismicity). An event tree approach and ensemble modelling are used in spite of more classical approaches, such as the hazard integral and the logic tree. This procedure consists of four steps: (1) exploration of aleatory uncertainty through an event tree, with alternative implementations for exploring epistemic uncertainty; (2) numerical computation of tsunami generation and propagation up to a given offshore isobath; (3) (optional) site-specific quantification of inundation; (4) simultaneous quantification of aleatory and epistemic uncertainty through ensemble modelling. The proposed procedure is general and independent of the kind of tsunami source considered; however, we implement step 1, the event tree, specifically for SPTHA, focusing on seismic source uncertainty. To exemplify the procedure, we develop a case study considering seismic sources in the Ionian Sea (central-eastern Mediterranean Sea), using the coasts of Southern Italy as a target zone. The results show that an efficient and complete quantification of all the uncertainties is feasible even when treating a large number of potential sources and a large set of alternative model formulations. We also find that (i) treating separately subduction and background (crustal) earthquakes allows for optimal use of available information and for avoiding significant biases; (ii) both subduction interface and crustal faults contribute to the SPTHA, with different proportions that depend on source-target position and tsunami intensity; (iii) the proposed framework allows sensitivity and deaggregation analyses, demonstrating the applicability of the method for operational assessments.

  9. Strong Ground-Motion Prediction in Seismic Hazard Analysis: PEGASOS and Beyond

    Science.gov (United States)

    Scherbaum, F.; Bommer, J. J.; Cotton, F.; Bungum, H.; Sabetta, F.

    2005-12-01

    The SSHAC Level 4 approach to probabilistic seismic hazard analysis (PSHA), which could be considered to define the state-of-the-art in PSHA using multiple expert opinions, has been fully applied only twice, firstly in the multi-year Yucca Mountain study and subsequently (2002-2004) in the PEGASOS project. The authors of this paper participated as ground-motion experts in this latter project, the objective of which was comprehensive seismic hazard analysis for four nuclear power plant sites in Switzerland, considering annual exceedance frequencies down to 1/10000000. Following SSHAC procedure, particular emphasis was put on capturing both the aleatory and epistemic uncertainties. As a consequence, ground motion prediction was performed by combining several empirical ground motion models within a logic tree framework with the weights on each logic tree branch expressing the personal degree-of-belief of each ground-motion expert. In the present paper, we critically review the current state of ground motion prediction methodology in PSHA in particular for regions of low seismicity. One of the toughest lessons from PEGASOS was that in systematically and rigorously applying the laws of uncertainty propagation to all of the required conversions and adjustments of ground motion models, a huge price has to be paid in an ever-growing aleatory variability. Once this path has been followed, these large sigma values will drive the hazard, particularly for low annual frequencies of exceedance. Therefore, from a post-PEGASOS perspective, the key issues in the context of ground-motion prediction for PSHA for the near future are to better understand the aleatory variability of ground motion and to develop suites of ground-motion prediction equations that employ the same parameter definitions. The latter is a global rather than a regional challenge which might be a desirable long-term goal for projects similar to the PEER NGA (Pacific Earthquake Engineering Research Center, Next

  10. Seismic and tsunami hazard investigation in Valparaiso in the framework of the project "MAR VASTO"

    Science.gov (United States)

    Romanelli, F.; Razafindrakoto, H.

    2009-04-01

    In the framework of the MAR VASTO Project ("Risk Management in Valparaíso/Manejo de Riesgos en Valparaíso"), completed in 2008 and funded by BID/IDB (Banco InterAmericano de Desarrollo/ InterAmerican Development Bank), managed by ENEA (Italian Agency for New Technologies, Energy and Environment), with the participation of Italian and Chilean partners and the support of local stakeholders, the most important hazards have been investigated carried out. Valparaíso represents a distinctive case of growth, inside a remarkable landscape, of an important Pacific Ocean seaport (over the 19th and 20th centuries), up to reaching a strategic importance in shipping trade, declined after the Panama Canal opening (1914). Thus, Valparaíso tells the never-ending story of a tight interaction between society and environment, stratifying different urban and architectonic layers, sometimes struck by disasters and always in danger. Certainly, the city has been subjected to various natural hazards (seismic events, but also tsunamis, landslides, etc.) and anthropic calamities (mainly wild and human-induced fires). These features make Valparaíso a paradigmatic study case about hazard mitigation, and risk factors must be very well evaluated during the restoration phases to be planned in the future. Seismic Hazrad. The major goal is to provide a dataset of synthetic time series representative of the potential ground motion at the bedrock of Valparaiso, especially at selected sites (e.g. the three important churches located in the Valparaiso urban area: La Matriz, San Francisco, Las Hermanitas de la Providencia), for different scenarios; the characteristics of the calculated signals (e.g. amplitude, frequency content and duration of shaking) are determined by the earthquake source process and the wave propagation effects of the path between the source and the site. The synthetic signals, to be used as seismic input in a subsequent engineering analysis, have been produced at a very low

  11. Seismic hazard assessment of Kashmir and Kangra valley region, Western Himalaya, India

    OpenAIRE

    Basab Mukhopadhyay; Sujit Dasgupta

    2015-01-01

    A complete earthquake catalogue of the Western Himalaya (latitudes 30°N–36°N and longitudes 72°E–78°E) for the period of 1501–2010 has been compiled with earthquake magnitude computed in moment magnitude (Mw) scale. Pre- and early twentieth century records of earthquake damage have been documented from rare and out of print publications. Seismotectonics and seismic hazard for Kohistan arc, Kashmir–Hazara Syntaxis, Nanga-Parbat (Western Syntaxis), Karakoram and Himachal Himalaya are discussed ...

  12. Seismic hazard review for the systematic evaluation program: a use of probability in decision making

    Energy Technology Data Exchange (ETDEWEB)

    Reiter, L.; Jackson, R.E.

    1983-03-01

    This document presents the US Nuclear Regulatory Commission (NRC) Geosciences Branch review and recommendations with respect to earthquake ground motion considerations in the Systematic Evaluation Program (SEP) Phases I and II. It evaluates the probabilistic estimates presented in the 5-volume report entitled Seismic Hazard Analysis (NUREG/CR-1582) and compares and modifies them to take into account deterministic estimates. It presents the NRC's Geosciences Branch first approach to utilizing complex state-of-the-art probabilistic studies in an area where probabilistic criteria have not yet been set and where decisions for specific plants have been previously made in a non-probabilistic way.

  13. Seismic hazard assessment of Western Coastal Province of Saudi Arabia: deterministic approach

    Science.gov (United States)

    Rehman, Faisal; El-Hady, Sherif M.; Atef, Ali H.; Harbi, Hussein M.

    2016-10-01

    Seismic hazard assessment is carried out by utilizing deterministic approach to evaluate the maximum expected earthquake ground motions along the Western Coastal Province of Saudi Arabia. The analysis is accomplished by incorporating seismotectonic source model, determination of earthquake magnitude ( M max), set of appropriate ground motion predictive equations (GMPE), and logic tree sequence. The logic tree sequence is built up to assign weight to ground motion scaling relationships. Contour maps of ground acceleration are generated at different spectral periods. These maps show that the largest ground motion values are emerged in northern and southern regions of the western coastal province in Saudi Arabia in comparison with the central region.

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

    Directory of Open Access Journals (Sweden)

    Maura Murru

    2016-11-01

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

  15. Seismic Hazard Maps for Seattle, Washington, Incorporating 3D Sedimentary Basin Effects, Nonlinear Site Response, and Rupture Directivity

    Science.gov (United States)

    Frankel, Arthur D.; Stephenson, William J.; Carver, David L.; Williams, Robert A.; Odum, Jack K.; Rhea, Susan

    2007-01-01

    This report presents probabilistic seismic hazard maps for Seattle, Washington, based on over 500 3D simulations of ground motions from scenario earthquakes. These maps include 3D sedimentary basin effects and rupture directivity. Nonlinear site response for soft-soil sites of fill and alluvium was also applied in the maps. The report describes the methodology for incorporating source and site dependent amplification factors into a probabilistic seismic hazard calculation. 3D simulations were conducted for the various earthquake sources that can affect Seattle: Seattle fault zone, Cascadia subduction zone, South Whidbey Island fault, and background shallow and deep earthquakes. The maps presented in this document used essentially the same set of faults and distributed-earthquake sources as in the 2002 national seismic hazard maps. The 3D velocity model utilized in the simulations was validated by modeling the amplitudes and waveforms of observed seismograms from five earthquakes in the region, including the 2001 M6.8 Nisqually earthquake. The probabilistic seismic hazard maps presented here depict 1 Hz response spectral accelerations with 10%, 5%, and 2% probabilities of exceedance in 50 years. The maps are based on determinations of seismic hazard for 7236 sites with a spacing of 280 m. The maps show that the most hazardous locations for this frequency band (around 1 Hz) are soft-soil sites (fill and alluvium) within the Seattle basin and along the inferred trace of the frontal fault of the Seattle fault zone. The next highest hazard is typically found for soft-soil sites in the Duwamish Valley south of the Seattle basin. In general, stiff-soil sites in the Seattle basin exhibit higher hazard than stiff-soil sites outside the basin. Sites with shallow bedrock outside the Seattle basin have the lowest estimated hazard for this frequency band.

  16. Site-specific seismic probabilistic tsunami hazard analysis: performances and potential applications

    Science.gov (United States)

    Tonini, Roberto; Volpe, Manuela; Lorito, Stefano; Selva, Jacopo; Orefice, Simone; Graziani, Laura; Brizuela, Beatriz; Smedile, Alessandra; Romano, Fabrizio; De Martini, Paolo Marco; Maramai, Alessandra; Piatanesi, Alessio; Pantosti, Daniela

    2017-04-01

    Seismic Probabilistic Tsunami Hazard Analysis (SPTHA) provides probabilities to exceed different thresholds of tsunami hazard intensity, at a specific site or region and in a given time span, for tsunamis caused by seismic sources. Results obtained by SPTHA (i.e., probabilistic hazard curves and inundation maps) represent a very important input to risk analyses and land use planning. However, the large variability of source parameters implies the definition of a huge number of potential tsunami scenarios, whose omission could lead to a biased analysis. Moreover, tsunami propagation from source to target requires the use of very expensive numerical simulations. At regional scale, the computational cost can be reduced using assumptions on the tsunami modeling (i.e., neglecting non-linear effects, using coarse topo-bathymetric meshes, empirically extrapolating maximum wave heights on the coast). On the other hand, moving to local scale, a much higher resolution is required and such assumptions drop out, since detailed inundation maps require significantly greater computational resources. In this work we apply a multi-step method to perform a site-specific SPTHA which can be summarized in the following steps: i) to perform a regional hazard assessment to account for both the aleatory and epistemic uncertainties of the seismic source, by combining the use of an event tree and an ensemble modeling technique; ii) to apply a filtering procedure which use a cluster analysis to define a significantly reduced number of representative scenarios contributing to the hazard of a specific target site; iii) to perform high resolution numerical simulations only for these representative scenarios and for a subset of near field sources placed in very shallow waters and/or whose coseismic displacements induce ground uplift or subsidence at the target. The method is applied to three target areas in the Mediterranean located around the cities of Milazzo (Italy), Thessaloniki (Greece) and

  17. Chemical Safety Alert: Identifying Chemical Reactivity Hazards Preliminary Screening Method

    Science.gov (United States)

    Introduces small-to-medium-sized facilities to a method developed by Center for Chemical Process Safety (CCPS), based on a series of twelve yes-or-no questions to help determine hazards in warehousing, repackaging, blending, mixing, and processing.

  18. Probabilistic seismic hazard assessment of the Eastern and Central groups of the Azores - Portugal

    Science.gov (United States)

    Fontiela, João; Bezzeghoud, Mourad; Rosset, Philippe; Borges, José; Rodrigues, Francisco; Caldeira, Bento

    2017-04-01

    Azores islands of the Eastern and Central groups are located at the triple junction of the American, Eurasian and Nubian plates inducing a large number of low magnitude earthquakes. Since its settlement in the 15th century, 33 earthquakes with intensity ≥ VII have caused severe damage and high death toll. The most severe ones occurred in 1522 at São Miguel Island with a maximum MM intensity of X; in 1614 at Terceira Island (X) in 1757 at São Jorge Island (XI); 1852 at São Miguel Island (VIII); 1926 at Faial Island (Mb 5.3-5.9); in 1980 at Terceira Island (Mw7.1) and in 1998 at Faial Island (Mw6.2). The analysis of the Probabilistic Seismic Hazard Assessment (PSHA) were carried out using the classical Cornell-McGuire approach using seismogenic zones recently defined by Fontiela et al. (2014). We create a new earthquake catalogue merging local and global datasets with a large time span (1522 - 2016) to calculate recurrence times and maximum magnitudes. In order to reduce the epistemic uncertainties, we test several ground motion prediction equations in agreement with the geological heterogeneities typical of young volcanic islands. Probabilistic seismic hazard maps are proposed for 475 and 975 years returns periods as well as hazard curves and uniform hazard spectra for the main cities. REFERENCES: Fontiela, J. et al., 2014. Azores seismogenic zones. Comunicações Geológicas, 101(1), pp.351-354. ACKNOWLEDGMENTS: João Fontiela is supported by grant M3.1.2/F/060/2011 of Regional Science Fund of the Regional Government Azores and this study is co-funded by the European Union through the European fund of Regional Development, framed in COMPETE 2020 (Operational Competitiveness Programme and Internationalization) through the ICT project (UID/GEO/04683/2013) with the reference POCI-01-0145-FEDER-007690.

  19. Probabilistic tsunami hazard assessment at Seaside, Oregon, for near- and far-field seismic sources

    Science.gov (United States)

    GonzáLez, F. I.; Geist, E. L.; Jaffe, B.; KâNoǧLu, U.; Mofjeld, H.; Synolakis, C. E.; Titov, V. V.; Arcas, D.; Bellomo, D.; Carlton, D.; Horning, T.; Johnson, J.; Newman, J.; Parsons, T.; Peters, R.; Peterson, C.; Priest, G.; Venturato, A.; Weber, J.; Wong, F.; Yalciner, A.

    2009-11-01

    The first probabilistic tsunami flooding maps have been developed. The methodology, called probabilistic tsunami hazard assessment (PTHA), integrates tsunami inundation modeling with methods of probabilistic seismic hazard assessment (PSHA). Application of the methodology to Seaside, Oregon, has yielded estimates of the spatial distribution of 100- and 500-year maximum tsunami amplitudes, i.e., amplitudes with 1% and 0.2% annual probability of exceedance. The 100-year tsunami is generated most frequently by far-field sources in the Alaska-Aleutian Subduction Zone and is characterized by maximum amplitudes that do not exceed 4 m, with an inland extent of less than 500 m. In contrast, the 500-year tsunami is dominated by local sources in the Cascadia Subduction Zone and is characterized by maximum amplitudes in excess of 10 m and an inland extent of more than 1 km. The primary sources of uncertainty in these results include those associated with interevent time estimates, modeling of background sea level, and accounting for temporal changes in bathymetry and topography. Nonetheless, PTHA represents an important contribution to tsunami hazard assessment techniques; viewed in the broader context of risk analysis, PTHA provides a method for quantifying estimates of the likelihood and severity of the tsunami hazard, which can then be combined with vulnerability and exposure to yield estimates of tsunami risk.

  20. Probabilistic tsunami hazard assessment at Seaside, Oregon, for near-and far-field seismic sources

    Science.gov (United States)

    Gonzalez, F.I.; Geist, E.L.; Jaffe, B.; Kanoglu, U.; Mofjeld, H.; Synolakis, C.E.; Titov, V.V.; Areas, D.; Bellomo, D.; Carlton, D.; Horning, T.; Johnson, J.; Newman, J.; Parsons, T.; Peters, R.; Peterson, C.; Priest, G.; Venturato, A.; Weber, J.; Wong, F.; Yalciner, A.

    2009-01-01

    The first probabilistic tsunami flooding maps have been developed. The methodology, called probabilistic tsunami hazard assessment (PTHA), integrates tsunami inundation modeling with methods of probabilistic seismic hazard assessment (PSHA). Application of the methodology to Seaside, Oregon, has yielded estimates of the spatial distribution of 100- and 500-year maximum tsunami amplitudes, i.e., amplitudes with 1% and 0.2% annual probability of exceedance. The 100-year tsunami is generated most frequently by far-field sources in the Alaska-Aleutian Subduction Zone and is characterized by maximum amplitudes that do not exceed 4 m, with an inland extent of less than 500 m. In contrast, the 500-year tsunami is dominated by local sources in the Cascadia Subduction Zone and is characterized by maximum amplitudes in excess of 10 m and an inland extent of more than 1 km. The primary sources of uncertainty in these results include those associated with interevent time estimates, modeling of background sea level, and accounting for temporal changes in bathymetry and topography. Nonetheless, PTHA represents an important contribution to tsunami hazard assessment techniques; viewed in the broader context of risk analysis, PTHA provides a method for quantifying estimates of the likelihood and severity of the tsunami hazard, which can then be combined with vulnerability and exposure to yield estimates of tsunami risk. Copyright 2009 by the American Geophysical Union.

  1. Earthquake catalogs for the 2017 Central and Eastern U.S. short-term seismic hazard model

    Science.gov (United States)

    Mueller, Charles S.

    2017-01-01

    The U. S. Geological Survey (USGS) makes long-term seismic hazard forecasts that are used in building codes. The hazard models usually consider only natural seismicity; non-tectonic (man-made) earthquakes are excluded because they are transitory or too small. In the past decade, however, thousands of earthquakes related to underground fluid injection have occurred in the central and eastern U.S. (CEUS), and some have caused damage.  In response, the USGS is now also making short-term forecasts that account for the hazard from these induced earthquakes. Seismicity statistics are analyzed to develop recurrence models, accounting for catalog completeness. In the USGS hazard modeling methodology, earthquakes are counted on a map grid, recurrence models are applied to estimate the rates of future earthquakes in each grid cell, and these rates are combined with maximum-magnitude models and ground-motion models to compute the hazard The USGS published a forecast for the years 2016 and 2017.Here, we document the development of the seismicity catalogs for the 2017 CEUS short-term hazard model.  A uniform earthquake catalog is assembled by combining and winnowing pre-existing source catalogs. The initial, final, and supporting earthquake catalogs are made available here.

  2. Enriquillo–Plantain Garden fault zone in Jamaica: paleoseismology and seismic hazard

    Science.gov (United States)

    Koehler, R.D.; Mann, P.; Prentice, Carol S.; Brown, L.; Benford, B.; Grandison-Wiggins, M.

    2013-01-01

    The countries of Jamaica, Haiti, and the Dominican Republic all straddle the Enriquillo–Plantain Garden fault zone ( EPGFZ), a major left-lateral, strike-slip fault system bounding the Caribbean and North American plates. Past large earthquakes that destroyed the capital cities of Kingston, Jamaica (1692, 1907), and Port-au-Prince, Haiti (1751, 1770), as well as the 2010 Haiti earthquake that killed more than 50,000 people, have heightened awareness of seismic hazards in the northern Caribbean. We present here new geomorphic and paleoseismic information bearing on the location and relative activity of the EPGFZ, which marks the plate boundary in Jamaica. Documentation of a river bank exposure and several trenches indicate that this fault is active and has the potential to cause major destructive earthquakes in Jamaica. The results suggest that the fault has not ruptured the surface in at least 500 yr and possibly as long as 28 ka. The long period of quiescence and subdued geomorphic expression of the EPGFZ indicates that it may only accommodate part of the ∼7–9 mm=yr plate deformation rate measured geodetically and that slip may be partitioned on other undocumented faults. Large uncertainties related to the neotectonic framework of Jamaica remain and more detailed fault characterization studies are necessary to accurately assess seismic hazards.

  3. A new concept in seismic landslide hazard analysis for practical application

    Science.gov (United States)

    Lee, Chyi-Tyi

    2017-04-01

    A seismic landslide hazard model could be constructed using deterministic approach (Jibson et al., 2000) or statistical approach (Lee, 2014). Both approaches got landslide spatial probability under a certain return-period earthquake. In the statistical approach, our recent study found that there are common patterns among different landslide susceptibility models of the same region. The common susceptibility could reflect relative stability of slopes at a region; higher susceptibility indicates lower stability. Using the common susceptibility together with an earthquake event landslide inventory and a map of topographically corrected Arias intensity, we can build the relationship among probability of failure, Arias intensity and the susceptibility. This relationship can immediately be used to construct a seismic landslide hazard map for the region that the empirical relationship built. If the common susceptibility model is further normalized and the empirical relationship built with normalized susceptibility, then the empirical relationship may be practically applied to different region with similar tectonic environments and climate conditions. This could be feasible, when a region has no existing earthquake-induce landslide data to train the susceptibility model and to build the relationship. It is worth mentioning that a rain-induced landslide susceptibility model has common pattern similar to earthquake-induced landslide susceptibility in the same region, and is usable to build the relationship with an earthquake event landslide inventory and a map of Arias intensity. These will be introduced with examples in the meeting.

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

    Science.gov (United States)

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

    2014-05-01

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

  5. Using a physics-based earthquake simulator to evaluate seismic hazard in NW Iran

    Science.gov (United States)

    Khodaverdian, A.; Zafarani, H.; Rahimian, M.

    2016-07-01

    NW Iran is a region of active deformation in the Eurasia-Arabia collision zone. This high strain field has caused intensive faulting accompanied by several major (M > 6.5) earthquakes as it is evident from historical records. Whereas seismic data (i.e. instrumental and historical catalogues) are either short, or inaccurate and inhomogeneous, physics-based long-term simulations are beneficial to better assess seismic hazard. In this study, a deterministic seismicity model, which consists of major active faults, is first constructed, and used to generate a synthetic catalogue of large-magnitude (M > 5.5) earthquakes. The frequency-magnitude distribution of the synthetic earthquake catalogue, which is based on the physical characteristic and slip rate of the mapped faults, is consistent with the empirical distribution evaluated using record of instrumental and historical events. The obtained results are also in accordance with palaeoseismic studies and other independent kinematic deformation models of the Iranian Plateau. Using the synthetic catalogue, characteristic magnitude for all 16 active faults in the study area is determined. Magnitude and epicentre of these earthquakes are comparable with the historical records. Large earthquake recurrence times and their variations are evaluated, either for an individual fault or for the region as a whole. Goodness-of-fitness tests revealed that recurrence times can be well described by the Weibull distribution. Time-dependent conditional probabilities for large earthquakes in the study area are also estimated for different time intervals. The resulting synthetic catalogue can be utilized as a useful data set for hazard and risk assessment instead of short, incomplete and inhomogeneous available catalogues.

  6. Seismic hazard evaluation for the high-flux isotope reactor (HFIR) Oak Ridge National Laboratory, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    McGuire, R.K.; Toro, G.R. (Risk Engineering, Inc., Golden, CO (United States))

    1991-09-01

    This study investigates the probabilistic hazard of earthquake-induced ground shaking at the HFIR facility, Oak Ridge, Tennessee. These results will be used to calculate plant response and potential effects in a Probabilistic Risk Assessment (PRA). For this purpose, several guidelines apply to this work. First, both the frequency of exceedance and the uncertainty in frequency of exceedance of various ground motion levels must be represented. These are required by the PRA so that the frequency and uncertainty of various possible plant states can be expressed. Second, there is a deliberate attempt to provide an unbiased distribution of frequencies of exceedance, i.e. to present results that are neither conservative nor unconservative. This is consistent with the goals of a PRA, to provide unbiased estimates of plant effects from which appropriate decisions (for instance about evaluating existing levels of seismic design) can be reached. Recent intensive studies of seismic hazard in the central and eastern United States (CEUS) have been completed by the Electric Power Research Institute (EPRI). These studies represent major efforts to characterize the seismic hazard for nuclear power plants in the CEUS, and use the most recent, up-to-date understandings of seismicity and ground motion relations for the region. With these studies as a resource, the current effort relies exclusively on the seismicity and ground motion assumptions therein to formulate seismic hazard curves for the HFIR facility. The interpretation of these studies to derive seismic hazard curves in a format suitable for input to a PRA is described in this report. 29 refs., 40 figs., 22 tabs.

  7. Implementation of MASW and waveform inversion techniques for new seismic hazard estimation technique

    Science.gov (United States)

    el-aziz abd el-aal, abd; Kamal, heba

    2016-04-01

    In this contribution, an integrated multi-channel analysis of Surface Waves (MASW) technique is applied to explore the geotechnical parameters of subsurface layers at the Zafarana Wind Farm site. The study area includes many active fault systems along the Gulf of Suez that cause many moderate and large earthquakes. Overall, the seismic activity of the area has recently become better understood following the use of waveform inversion method and software to develop accurate focal mechanism solutions for recent recorded earthquakes around the studied area. These earthquakes resulted in major stress-drops in the Eastern Desert and the Gulf of Suez area. These findings have helped to reshape the understanding of the seismotectonic environment of the Gulf of Suez area, which is a perplexing tectonic domain. Based on the collected new information and data, this study uses new an extended stochastic technique to re-examine the seismic hazard for the Gulf of Suez region, particularly the wind turbine towers sites at Zafarana Wind Farm and its vicinity. The essential characteristics of the extended stochastic technique are to obtain and simulate ground motion in order to minimize future earthquake consequences. The first step of this technique is defining the seismic sources which mostly affect the study area. Then, the maximum expected magnitude is defined for each of these seismic sources. It is followed by estimating the ground motion using an empirical attenuation relationship. Finally, the site amplification is implemented in calculating the peak ground acceleration (PGA) at each site of interest. Key words: MASW, waveform inversion, extended stochastic technique, Zafarana Wind Farm

  8. Hybrid zoneless probabilistic seismic hazard analysis: Test and first application to SW Germany

    Science.gov (United States)

    Chan, C.; Gruenthal, G.

    2007-12-01

    Zoneless approaches are one option to assess probabilistic seismic hazard (PSHA). They rely simply on smoothing the epicenter locations of past events according to the fractal distribution of earthquakes in space without defining seismic source zones. However, some shortcomings are connected with these zoneless approaches. Sometimes, one cannot apply one single magnitude completeness, especially when the study area covers different catalogue areas, where different completeness patterns are valid. Furthermore, the characteristic depths of the strongest earthquakes generally differ over larger areas. With respect to these two reasons, a hybrid approach for zoneless PSHA is introduced in this study; i.e. a combination of a zoneless approach with a seismic source model based solely on the large scale geological architecture. This large scale model meets the requirements of introducing different magnitude completeness. But the probability of the earthquake occurrence is based on a pure zoneless approach. Then, instead of a time set of magnitude completeness for the entire studying area, as it is the standard procedure for zoneless approaches, various time sets for different large zones are considered. Another innovation of our approach is to take into account the actual depth of each earthquake rather than assuming a certain weighting set of depths. We apply the hybrid zoneless approach to the SW part of Germany, which represents one of the highest seismicity areas in the country. The use of area specific magnitude completeness and actual depths of all events clearly results in a more realistic PSHA. Furthermore, we compare the results of the hybrid zoneless approach with the results of a recent study using a zone-based methodology. The zone-based approach shows more significant contrasts in the study area; i.e the hybrid zoneless approach provides a rather smoothed pattern. This corresponds to comparisons between zoneless and zone-based approaches by previous studies.

  9. Seismic Hazard and Risk Posed by the Mentawai Segment of the Sumatran Megathrust

    Science.gov (United States)

    Megawati, K.; Han, X.

    2010-12-01

    Several lines of evidence have indicated that the Mentawai segment of the Sumatran megathrust is very likely to rupture within the next few decades. The present study is to investigate seismic hazard and risk levels at major cities in Sumatra, Java, Singapore and the Malay Peninsula caused by the potential giant earthquakes. Two scenarios are considered. The first one is an Mw 8.6 earthquake rupturing the 280-km segment that has been locked since 1797; in the second scenario, rupture occurs along a 400-km segment covering the combined rupture areas of the 1797 and 1833 historical events, of which the southern portion has partially slipped on 12 and 13 September 2007, producing an Mw 8.8 earthquake. Simulation results indicate that ground motions produced by the hypothetical scenarios are strong enough to cause yielding to medium and high-rise buildings in many major cities in Sumatra. It is vital to ensure that the overall strength, stiffness and integrity of the structures are maintained throughout the entire duration of shaking. However, the ductile detailing in current practice is formulated based on an assumption that ground motions would last 20 to 40 seconds. This has not been tested for longer durations of three to five minutes, expected from giant earthquakes. In Singapore and Kuala Lumpur, only medium and high-rise buildings, especially those located on soft-soil sites, are at risk. Given that seismic design has not been required in both cities, and thus the resulting structures are relatively brittle, it is crucial to investigate their performance under moderate-amplitude, long-duration, ground motions. The present study also points out that the shift of response spectrum toward longer period range becomes prominent for sites located far from potential seismic sources, which should be carefully considered in formulation of future seismic codes for Singapore, Malaysia and Indonesia.

  10. Site-specific probabilistic seismic hazard analyses for the Idaho National Engineering Laboratory. Volume 1: Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-05-01

    This report describes and summarizes a probabilistic evaluation of ground motions for the Idaho National Engineering Laboratory (INEL). The purpose of this evaluation is to provide a basis for updating the seismic design criteria for the INEL. In this study, site-specific seismic hazard curves were developed for seven facility sites as prescribed by DOE Standards 1022-93 and 1023-96. These sites include the: Advanced Test Reactor (ATR); Argonne National Laboratory West (ANL); Idaho Chemical Processing Plant (ICPP or CPP); Power Burst Facility (PBF); Radioactive Waste Management Complex (RWMC); Naval Reactor Facility (NRF); and Test Area North (TAN). The results, probabilistic peak ground accelerations and uniform hazard spectra, contained in this report are not to be used for purposes of seismic design at INEL. A subsequent study will be performed to translate the results of this probabilistic seismic hazard analysis to site-specific seismic design values for the INEL as per the requirements of DOE Standard 1020-94. These site-specific seismic design values will be incorporated into the INEL Architectural and Engineering Standards.

  11. A Study on Seismic Hazard Evaluation at the Nagaoka CO2 Storage Site, Japan

    Science.gov (United States)

    Horikawa, S.

    2015-12-01

    RITE carried out the first Japanese pilot-scale CO2 sequestration project from July, 2003 to January, 2005 in Nagaoka City.Supercritical CO2 was injected into an onshore saline aquifer at a depth of 1,100m. CO2 was injected at a rate of 10,400 tonnes. 'Mid Niigata Prefecture Earthquake in 2004' (Mw6.6) and 'The Niigataken Chuetsu-oki Earthquake in 2007' (Mw6.6) occurred during the CO2 injection-test and after the completion of injection-test. Japan is one of the world's major countries with frequent earthquakes.This paper presents a result of seismic response analysis, and reports of seismic hazard evaluation of a reservoir and a caprock. In advance of dynamic response analysis, the earthquake motion recorded on the earth surface assumed the horizontally layer model, and set up the input wave from a basement layer by SHAKE ( = One-Dimensional Seismic Response Analysis). This wave was inputted into the analysis model and the equation of motion was solved using the direct integral calculus by Newmark Beta Method. In Seismic Response Analysis, authors have used Multiple Yield Model (MYM, Iwata, et al., 2013), which can respond also to complicated geological structure. The intensity deformation property of the foundation added the offloading characteristic to the composition rule of Duncan-Chang model in consideration of confining stress dependency, and used for and carried out the nonlinear repetition model. And the deformation characteristic which made it depend on confining stress with the cyclic loadings and un-loadings, and combined Mohr-Coulomb's law as a strength characteristic.The maximum dynamic shearing strain of caprock was generated about 1.1E-04 after the end of an earthquake. Although the dynamic safety factor was 1.925 on the beginning, after the end of an earthquake fell 0.05 point. The dynamic safety factor of reservoir fell to 1.20 from 1.29. As a result of CO2 migration monitoring by the seismic cross-hole tomography, CO2 has stopped in the reservoir

  12. Microseismicity in the Seoul Metropolitan Area, Korea, and its implications for the seismic hazards

    Science.gov (United States)

    Kim, K.; Kim, W.; Kang, S.; Ryoo, Y.; Kim, M.; Park, Y.; Kyung, J.

    2012-12-01

    On 9 February 2010, a minor earthquake occurred in the northwest of South Korea. The earthquake was widely felt in the Seoul National Capital Area (SNCA). The earthquake attracted much attention from media, politicians, policy makers and the public, who raised concerns about seismic hazards and risks in the Korea Peninsula, in particular, to the SNCA. SNCA includes the Seoul and Incheon metropolitans and most of the Gyeonggi province. It has a population of 24.5 million (as of 2007) and is ranked as the second largest metropolitan area in the world. The SNCA has been the center of the economics, politics, and culture during the past half millennium since the city has been designated as the capital city in 1394. We applied waveform correlation detector to 2007-2010 continuously recorded seismic data to identify repeating earthquakes. We identify 9 micro-earthquakes during 2007-2010 periods which are not reported in the KNSN bulletin because their magnitudes are too small. Estimated magnitudes using amplitude ratios measured at the station SEO indicate the smallest event detected by the waveform cross correlation technique in the study is as low as 0.19. The number of events for our interpretation becomes 11 including two previously reported events and nine newly identified micro-earthquakes. All of them occur in a very small area. While there are historic documents reporting earthquakes in the SNCA, repeating earthquakes or clustered seismicity from the instrumental earthquake record have not reported before. We have determined the focal mechanism solution for the representative events (9 February 2010, ML 3.0) using the first-motion polarities. The preferred focal mechanism solution for the representative event is the WNW-ESE striking fault, which are consistent with the precisely determined earthquake hypocenter distribution. It is also consistent with the results in the previous studies of stress orientation in and around the Korean peninsula. The new list of

  13. Testing probabilistic seismic hazard estimates against accelerometric data in two countries: France and Turkey

    Science.gov (United States)

    Tasan, Hilal; Beauval, Céline; Helmstetter, Agnès; Sandikkaya, Abdullah; Guéguen, Philippe

    2014-09-01

    Probabilistic seismic hazard models (PSHM) are used for quantifying the seismic hazard at a site or a grid of sites. In this study, a methodology is proposed to compare the distribution of the expected number of sites with exceedance with the observed number considering an acceleration threshold at a set of recording sites. The method is applied to France and Turkey. The French accelerometric database is checked to produce a reliable accelerometric data set. In addition, we also used a synthetic data set inferred from an instrumental catalogue combined with a ground-motion prediction equation. The results show that the MEDD2002 and AFPS2006 PSH models overestimate the number of sites with exceedance for low acceleration levels (below 40 cm s-2) or short return periods (smaller than 50 yr for AFPS2006 and 475 yr for MEDD2002). For larger acceleration levels, there are few observations and none of the models is rejected. In Turkey, the SHARE hazard estimates can be tested against ground-motion levels of interest in earthquake engineering. As the completeness issue is crucial, the recorded data at each station is analysed to detect potential gaps in the recording. As most accelerometric stations are located on soil, accelerations at rock are estimated using a site-amplification model. Different minimum intersite distances and station configurations are considered. The observed numbers of sites with exceedance are well within the bounds of the predicted distribution for accelerations between 103 and 397 cm s-2. For higher levels, both the observed number and the predicted percentile 2.5 are zero, and no conclusion can be drawn.

  14. Development of methodology and computer programs for the ground response spectrum and the probabilistic seismic hazard analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Joon Kyoung [Semyung Univ., Research Institute of Industrial Science and Technol , Jecheon (Korea, Republic of)

    1996-12-15

    Objective of this study is to investigate and develop the methodologies and corresponding computer codes, compatible to the domestic seismological and geological environments, for estimating ground response spectrum and probabilistic seismic hazard. Using the PSHA computer program, the Cumulative Probability Functions(CPDF) and Probability Functions (PDF) of the annual exceedence have been investigated for the analysis of the uncertainty space of the annual probability at ten interested seismic hazard levels (0.1 g to 0.99 g). The cumulative provability functions and provability functions of the annual exceedence have been also compared to those results from the different input parameter spaces.

  15. Improved seismic risk estimation for Bucharest, based on multiple hazard scenarios, analytical methods and new techniques

    Science.gov (United States)

    Toma-Danila, Dragos; Florinela Manea, Elena; Ortanza Cioflan, Carmen

    2014-05-01

    Bucharest, capital of Romania (with 1678000 inhabitants in 2011), is one of the most exposed big cities in Europe to seismic damage. The major earthquakes affecting the city have their origin in the Vrancea region. The Vrancea intermediate-depth source generates, statistically, 2-3 shocks with moment magnitude >7.0 per century. Although the focal distance is greater than 170 km, the historical records (from the 1838, 1894, 1908, 1940 and 1977 events) reveal severe effects in the Bucharest area, e.g. intensities IX (MSK) for the case of 1940 event. During the 1977 earthquake, 1420 people were killed and 33 large buildings collapsed. The nowadays building stock is vulnerable both due to construction (material, age) and soil conditions (high amplification, generated within the weak consolidated Quaternary deposits, their thickness is varying 250-500m throughout the city). A number of 373 old buildings, out of 2563, evaluated by experts are more likely to experience severe damage/collapse in the next major earthquake. The total number of residential buildings, in 2011, was 113900. In order to guide the mitigation measures, different studies tried to estimate the seismic risk of Bucharest, in terms of buildings, population or economic damage probability. Unfortunately, most of them were based on incomplete sets of data, whether regarding the hazard or the building stock in detail. However, during the DACEA Project, the National Institute for Earth Physics, together with the Technical University of Civil Engineering Bucharest and NORSAR Institute managed to compile a database for buildings in southern Romania (according to the 1999 census), with 48 associated capacity and fragility curves. Until now, the developed real-time estimation system was not implemented for Bucharest. This paper presents more than an adaptation of this system to Bucharest; first, we analyze the previous seismic risk studies, from a SWOT perspective. This reveals that most of the studies don't use

  16. Building a risk-targeted regional seismic hazard model for South-East Asia

    Science.gov (United States)

    Woessner, J.; Nyst, M.; Seyhan, E.

    2015-12-01

    The last decade has tragically shown the social and economic vulnerability of countries in South-East Asia to earthquake hazard and risk. While many disaster mitigation programs and initiatives to improve societal earthquake resilience are under way with the focus on saving lives and livelihoods, the risk management sector is challenged to develop appropriate models to cope with the economic consequences and impact on the insurance business. We present the source model and ground motions model components suitable for a South-East Asia earthquake risk model covering Indonesia, Malaysia, the Philippines and Indochine countries. The source model builds upon refined modelling approaches to characterize 1) seismic activity from geologic and geodetic data on crustal faults and 2) along the interface of subduction zones and within the slabs and 3) earthquakes not occurring on mapped fault structures. We elaborate on building a self-consistent rate model for the hazardous crustal fault systems (e.g. Sumatra fault zone, Philippine fault zone) as well as the subduction zones, showcase some characteristics and sensitivities due to existing uncertainties in the rate and hazard space using a well selected suite of ground motion prediction equations. Finally, we analyze the source model by quantifying the contribution by source type (e.g., subduction zone, crustal fault) to typical risk metrics (e.g.,return period losses, average annual loss) and reviewing their relative impact on various lines of businesses.

  17. Seismic hazard analyses for Taipei city including deaggregation, design spectra, and time history with excel applications

    Science.gov (United States)

    Wang, Jui-Pin; Huang, Duruo; Cheng, Chin-Tung; Shao, Kuo-Shin; Wu, Yuan-Chieh; Chang, Chih-Wei

    2013-03-01

    Given the difficulty of earthquake forecast, Probabilistic Seismic Hazard Analysis (PSHA) has been a method to best estimate site-specific ground motion or response spectra in earthquake engineering and engineering seismology. In this paper, the first in-depth PSHA study for Taipei, the economic center of Taiwan with a six-million population, was carried out. Unlike the very recent PSHA study for Taiwan, this study includes the follow-up hazard deaggregation, response spectra, and the earthquake motion recommendations. Hazard deaggregation results show that moderate-size and near-source earthquakes are the most probable scenario for this city. Moreover, similar to the findings in a few recent studies, the earthquake risk for Taipei should be relatively high and considering this city's importance, the high risk should not be overlooked and a potential revision of the local technical reference would be needed. In addition to the case study, some innovative Excel applications to PSHA are introduced in this paper. Such spreadsheet applications are applicable to geosciences research as those developed for data reduction or quantitative analysis with Excel's user-friendly nature and wide accessibility.

  18. Mapping sediment thickness of Islamabad city using empirical relationships: Implications for seismic hazard assessment

    Indian Academy of Sciences (India)

    Sarfraz Khan; M Asif Khan

    2016-04-01

    Soft sediments make an important component of the subsurface lithology, especially in areas underlain by river/stream basins. Occupying a position directly above the bedrock up to the land surface, these soft sediments can range in thickness from few centimeters to hundreds of meters. They carry a specialnuisance in seismic hazards, as they serve as a source of seismic amplification that may enhance the seismic shaking of many folds. Determination of the thickness of the soft sediments is therefore crucial in seismic hazard analysis. A number of studies in recent years have demonstrated that frequency andamplitude spectrum obtained from the noise measurements during the recording of natural seismicitycan be used to obtain thickness of soft sediments covering the bedrock. Nakamura (1989) presented atechnique to determine such spectrum using ratio of horizontal to vertical components of the Rayleighwaves. The present study is based on an extensive set of microtremor measurements carried out in theIslamabad city, Pakistan. Fundamental frequencies were obtained from weak motion sensors and TrominoEngy Plus instruments to show that the correlation is clearly valid for a wide range of sediment thickness.A simple formula was derived for the investigated area to determine directly the thickness of sedimentsfrom the main peaks in the H/V spectrum for seismometer and Tromino data separately. A comparisonis made between sediment thicknesses derived from empirical relations developed in this study withthose given in literature to demonstrate a positive correlation. The correlation of instrumental resonantfrequencies with calculated resonant frequencies (theoretical) suggests that the relation derived from thenoise measurements mostly depends on the velocity depth function of the shear wave. The fundamentalfrequency of the main peak of spectral ratio of H/V using the both instruments correlates well withthe thickness of sediments at the site obtained from the borehole data. It

  19. Probabilistic Hazard for Seismically-Induced Tsunamis in Complex Tectonic Contexts: Event Tree Approach to Seismic Source Variability and Practical Feasibility of Inundation Maps

    Science.gov (United States)

    Lorito, Stefano; Selva, Jacopo; Basili, Roberto; Romano, Fabrizio; Tiberti, Mara Monica; Piatanesi, Alessio

    2014-05-01

    Probabilistic Tsunami Hazard Analysis (PTHA) rests on computationally demanding numerical simulations of the tsunami generation and propagation up to the inundated coastline. We here focus on tsunamis generated by the co-seismic sea floor displacement, which constitute the vast majority of the observed tsunami events, i.e. on Seismic PTHA (SPTHA). For incorporating the full expected seismic source variability, aiming at a complete SPTHA, a very large number of numerical tsunami scenarios is typically needed, especially for complex tectonic contexts, where SPTHA is not dominated by large subduction earthquakes only. Here, we propose a viable approach for reducing the number of simulations for a given set of input earthquakes representing the modelled aleatory uncertainties of the seismic rupture parameters. Our approach is based on a preliminary analysis of the SPTHA of maximum offshore wave height (HMax) at a given target location, and assuming computationally cheap linear propagation. We start with defining an operational SPTHA framework in which we then introduce a simplified Event Tree approach, combined with a Green's functions approach, for obtaining a first controlled sampling and reduction of the effective source parameter space size. We then apply a two-stage filtering procedure to the 'linear' SPTHA results. The first filter identifies and discards all the sources producing a negligible contribution at the target location, for example the smallest earthquakes or those directing most of tsunami energy elsewhere. The second filter performs a cluster analysis aimed at selecting groups of source parameters producing comparable HMax profiles for each earthquake magnitude at the given test site. We thus select a limited set of sources that is subsequently used for calculating 'nonlinear' probabilistic inundation maps at the target location. We find that the optimal subset of simulations needed for inundation calculations can be obtained basing on just the

  20. Assessing the seismic coupling of shallow continental faults and its impact on seismic hazard estimates: a case-study from Italy

    Science.gov (United States)

    Carafa, Michele M. C.; Valensise, Gianluca; Bird, Peter

    2017-01-01

    SUMMARYWe propose an objective and reproducible algorithmic path to forecast seismicity in Italy from long-term deformation models. These models are appropriate for Italy and its neighboring countries and seas thanks to the availability of rich, reliable and regularly updated historical earthquake and seismogenic fault databases, and to the density of permanent GPS stations. However, so far little has been done to assess the seismic coupling of Italian active faults, i.e. to quantify their ability to release earthquakes. This must be determined in order to use geodetic and active faulting observations in alternative seismicity models, to overcome possible limitations of the earthquake record for the assessment of seismic hazard. We use a probabilistic method to assign upper crustal earthquakes from the historical catalogue to their presumed causative faults, then collect all the events into three subcatalogues corresponding to the compressional, extensional and strike-slip faulting classes. We then determine the parameters of their Gutenberg-Richter frequency/magnitude relations using maximum-likelihood methods and integrate these distributions to estimate the long-term seismic moment rate for each class. Finally, we compare these seismicity rates to the long-term tectonic deformation based on GPS data, thus determining the coupled thickness (and estimating seismic coupling) for each fault class. We find that in our study region the seismic coupling and the related coupled thickness is on average two times larger for extensional than for compressional faults. As for the spatial distribution of earthquake rates, a larger number of events is predicted for the extensional settings of the Apennines chain, in agreement with the inferred seismic coupling but also with the long-term strain rates. We also find that the frequency/magnitude distributions indicate that the largest earthquakes occur in extensional settings, whereas compressional faults are expected to host

  1. Use of remote sensing and seismotectonic parameters for seismic hazard analysis of Bangalore

    Directory of Open Access Journals (Sweden)

    T. G. Sitharam

    2006-01-01

    Full Text Available Deterministic Seismic Hazard Analysis (DSHA for the Bangalore, India has been carried out by considering the past earthquakes, assumed subsurface fault rupture lengths and point source synthetic ground motion model. The sources have been identified using satellite remote sensing images and seismotectonic atlas map of India and relevant field studies. Maximum Credible Earthquake (MCE has been determined by considering the regional seismotectonic activity in about 350 km radius around Bangalore. The seismotectonic map has been prepared by considering the faults, lineaments, shear zones in the area and past moderate earthquakes of more than 470 events having the moment magnitude of 3.5 and above. In addition, 1300 number of earthquake tremors having moment magnitude of less than 3.5 has been considered for the study. Shortest distance from the Bangalore to the different sources is measured and then Peak Horizontal Acceleration (PHA is calculated for the different sources and moment magnitude of events using regional attenuation relation for peninsular India. Based on Wells and Coppersmith (1994 relationship, subsurface fault rupture length of about 3.8% of total length of the fault shown to be matching with past earthquake events in the area. To simulate synthetic ground motions, Boore (1983, 2003 SMSIM programs have been used and the PHA for the different locations is evaluated. From the above approaches, the PHA of 0.15 g was established. This value was obtained for a maximum credible earthquake having a moment magnitude of 5.1 for a source Mandya-Channapatna-Bangalore lineament. This particular source has been identified as a vulnerable source for Bangalore. From this study, it is very clear that Bangalore area can be described as seismically moderately active region. It is also recommended that southern part of Karnataka in particular Bangalore, Mandya and Kolar, need to be upgraded from current Indian Seismic Zone II to Seismic Zone III

  2. Multi-Hazard Advanced Seismic Probabilistic Risk Assessment Tools and Applications

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, Justin L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bolisetti, Chandu [Idaho National Lab. (INL), Idaho Falls, ID (United States); Veeraraghavan, Swetha [Idaho National Lab. (INL), Idaho Falls, ID (United States); Parisi, Carlo [Idaho National Lab. (INL), Idaho Falls, ID (United States); Prescott, Steven R. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Gupta, Abhinav [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-09-01

    Design of nuclear power plant (NPP) facilities to resist natural hazards has been a part of the regulatory process from the beginning of the NPP industry in the United States (US), but has evolved substantially over time. The original set of approaches and methods was entirely deterministic in nature and focused on a traditional engineering margins-based approach. However, over time probabilistic and risk-informed approaches were also developed and implemented in US Nuclear Regulatory Commission (NRC) guidance and regulation. A defense-in-depth framework has also been incorporated into US regulatory guidance over time. As a result, today, the US regulatory framework incorporates deterministic and probabilistic approaches for a range of different applications and for a range of natural hazard considerations. This framework will continue to evolve as a result of improved knowledge and newly identified regulatory needs and objectives, most notably in response to the NRC activities developed in response to the 2011 Fukushima accident in Japan. Although the US regulatory framework has continued to evolve over time, the tools, methods and data available to the US nuclear industry to meet the changing requirements have not kept pace. Notably, there is significant room for improvement in the tools and methods available for external event probabilistic risk assessment (PRA), which is the principal assessment approach used in risk-informed regulations and risk-informed decision-making applied to natural hazard assessment and design. This is particularly true if PRA is applied to natural hazards other than seismic loading. Development of a new set of tools and methods that incorporate current knowledge, modern best practice, and state-of-the-art computational resources would lead to more reliable assessment of facility risk and risk insights (e.g., the SSCs and accident sequences that are most risk-significant), with less uncertainty and reduced conservatisms.

  3. 230Th/U ages Supporting Hanford Site‐Wide Probabilistic Seismic Hazard Analysis

    Science.gov (United States)

    Paces, James B.

    2014-01-01

    This product represents a USGS Administrative Report that discusses samples and methods used to conduct uranium-series isotope analyses and resulting ages and initial 234U/238U activity ratios of pedogenic cements developed in several different surfaces in the Hanford area middle to late Pleistocene. Samples were collected and dated to provide calibration of soil development in surface deposits that are being used in the Hanford Site-Wide probabilistic seismic hazard analysis conducted by AMEC. The report includes description of sample locations and physical characteristics, sample preparation, chemical processing and mass spectrometry, analytical results, and calculated ages for individual sites. Ages of innermost rinds on a number of samples from five sites in eastern Washington are consistent with a range of minimum depositional ages from 17 ka for cataclysmic flood deposits to greater than 500 ka for alluvium at several sites.

  4. 230Th/U ages Supporting Hanford Site-Wide Probabilistic Seismic Hazard Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Paces, James B. [U.S. Geological Survey

    2014-08-31

    This product represents a USGS Administrative Report that discusses samples and methods used to conduct uranium-series isotope analyses and resulting ages and initial 234U/238U activity ratios of pedogenic cements developed in several different surfaces in the Hanford area middle to late Pleistocene. Samples were collected and dated to provide calibration of soil development in surface deposits that are being used in the Hanford Site-Wide probabilistic seismic hazard analysis conducted by AMEC. The report includes description of sample locations and physical characteristics, sample preparation, chemical processing and mass spectrometry, analytical results, and calculated ages for individual sites. Ages of innermost rinds on a number of samples from five sites in eastern Washington are consistent with a range of minimum depositional ages from 17 ka for cataclysmic flood deposits to greater than 500 ka for alluvium at several sites.

  5. Seismic hazard assessment of Western Coastal Province of Saudi Arabia: deterministic approach

    Directory of Open Access Journals (Sweden)

    Faisal Rehman

    2016-10-01

    Full Text Available Abstract Seismic hazard assessment is carried out by utilizing deterministic approach to evaluate the maximum expected earthquake ground motions along the Western Coastal Province of Saudi Arabia. The analysis is accomplished by incorporating seismotectonic source model, determination of earthquake magnitude (M max, set of appropriate ground motion predictive equations (GMPE, and logic tree sequence. The logic tree sequence is built up to assign weight to ground motion scaling relationships. Contour maps of ground acceleration are generated at different spectral periods. These maps show that the largest ground motion values are emerged in northern and southern regions of the western coastal province in Saudi Arabia in comparison with the central region.

  6. Site-specific probabilistic seismic hazard analyses for the Idaho National Engineering Laboratory. Volume 2: Appendices

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-05-01

    The identification of seismic sources is often based on a combination of geologic and tectonic considerations and patterns of observed seismicity; hence, a historical earthquake catalogue is important. A historical catalogue of earthquakes of approximate magnitude (M) 2.5 and greater for the time period 1850 through 1992 was compiled for the INEL region. The primary data source used was the Decade of North American Geology (DNAG) catalogue for the time period from about 1800 through 1985 (Engdahl and Rinehart, 1988). A large number of felt earthquakes, especially prior to the 1970`s, which were below the threshold of completeness established in the DNAG catalogue (Engdahl and Rinehart, 1991), were taken from the state catalogues compiled by Stover and colleagues at the National Earthquake Information Center (NEIC) and combined with the DNAG catalogue for the INEL region. The state catalogues were those of Idaho, Montana, Nevada, Utah, and Wyoming. NEIC`s Preliminary Determination of Epicenters (PDE) and the state catalogues compiled by the Oregon Department of Geology and Mineral Industries (DOGAMI), and the University of Nevada at Reno (UNR) were also used to supplement the pre-1986 time period. A few events reanalyzed by Jim Zollweg (Boise State University, written communication, 1994) were also modified in the catalogue. In the case of duplicate events, the DNAG entry was preferred over the Stover et al. entry for the period 1850 through 1985. A few events from Berg and Baker (1963) were also added to the catalogue. This information was and will be used in determining the seismic risk of buildings and facilities located at the Idaho National Engineering Laboratory.

  7. Recommendations for probabilistic seismic hazard analysis: Guidance on uncertainty and use of experts

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-01

    Probabilistic Seismic Hazard Analysis (PSHA) is a methodology that estimates the likelihood that various levels of earthquake-caused ground motion will be exceeded at a given location in a given future time period. Due to large uncertainties in all the geosciences data and in their modeling, multiple model interpretations are often possible. This leads to disagreement among experts, which in the past has led to disagreement on the selection of ground motion for design at a given site. In order to review the present state-of-the-art and improve on the overall stability of the PSHA process, the U.S. Nuclear Regulatory Commission (NRC), the U.S. Department of Energy (DOE), and the Electric Power Research Institute (EPRI) co-sponsored a project to provide methodological guidance on how to perform a PSHA. The project has been carried out by a seven-member Senior Seismic Hazard Analysis Committee (SSHAC) supported by a large number other experts. The SSHAC reviewed past studies, including the Lawrence Livermore National Laboratory and the EPRI landmark PSHA studies of the 1980`s and examined ways to improve on the present state-of-the-art. The Committee`s most important conclusion is that differences in PSHA results are due to procedural rather than technical differences. Thus, in addition to providing a detailed documentation on state-of-the-art elements of a PSHA, this report provides a series of procedural recommendations. The role of experts is analyzed in detail. Two entities are formally defined-the Technical Integrator (TI) and the Technical Facilitator Integrator (TFI)--to account for the various levels of complexity in the technical issues and different levels of efforts needed in a given study.

  8. Probabilistic and Deterministic Seismic Hazard Assessment: A Case Study in Babol

    Directory of Open Access Journals (Sweden)

    H.R. Tavakoli

    2013-01-01

    Full Text Available The risk of earthquake ground motion parameters in seismic design of structures and Vulnerabilityand risk assessment of these structures against earthquake damage are important. The damages caused by theearthquake engineering and seismology of the social and economic consequences are assessed. This paperdetermined seismic hazard analysis in Babol via deterministic and probabilistic methods. Deterministic andprobabilistic methods seem to be practical tools for mutual control of results and to overcome the weaknessof approach alone. In the deterministic approach, the strong-motion parameters are estimated for the maximumcredible earthquake, assumed to occur at the closest possible distance from the site of interest, withoutconsidering the likelihood of its occurrence during a specified exposure period. On the other hand, theprobabilistic approach integrates the effects of all earthquakes expected to occur at different locations duringa specified life period, with the associated uncertainties and randomness taken into account. The calculatedbedrock horizontal and vertical peak ground acceleration (PGA for different years return period of the studyarea are presented.

  9. Site specific seismic hazard analysis and determination of response spectra of Kolkata for maximum considered earthquake

    Science.gov (United States)

    Shiuly, Amit; Sahu, R. B.; Mandal, Saroj

    2017-06-01

    This paper presents site specific seismic hazard analysis of Kolkata city, former capital of India and present capital of state West Bengal, situated on the world’s largest delta island, Bengal basin. For this purpose, peak ground acceleration (PGA) for a maximum considered earthquake (MCE) at bedrock level has been estimated using an artificial neural network (ANN) based attenuation relationship developed on the basis of synthetic ground motion data for the region. Using the PGA corresponding to the MCE, a spectrum compatible acceleration time history at bedrock level has been generated by using a wavelet based computer program, WAVEGEN. This spectrum compatible time history at bedrock level has been converted to the same at surface level using SHAKE2000 for 144 borehole locations in the study region. Using the predicted values of PGA and PGV at the surface, corresponding contours for the region have been drawn. For the MCE, the PGA at bedrock level of Kolkata city has been obtained as 0.184 g, while that at the surface level varies from 0.22 g to 0.37 g. Finally, Kolkata has been subdivided into eight seismic subzones, and for each subzone a response spectrum equation has been derived using polynomial regression analysis. This will be very helpful for structural and geotechnical engineers to design safe and economical earthquake resistant structures.

  10. Documentation for the 2014 update of the United States national seismic hazard maps

    Science.gov (United States)

    Petersen, Mark D.; Moschetti, Morgan P.; Powers, Peter M.; Mueller, Charles S.; Haller, Kathleen M.; Frankel, Arthur D.; Zeng, Yuehua; Rezaeian, Sanaz; Harmsen, Stephen C.; Boyd, Oliver S.; Field, Ned; Chen, Rui; Rukstales, Kenneth S.; Luco, Nico; Wheeler, Russell L.; Williams, Robert A.; Olsen, Anna H.

    2014-01-01

    The national seismic hazard maps for the conterminous United States have been updated to account for new methods, models, and data that have been obtained since the 2008 maps were released (Petersen and others, 2008). The input models are improved from those implemented in 2008 by using new ground motion models that have incorporated about twice as many earthquake strong ground shaking data and by incorporating many additional scientific studies that indicate broader ranges of earthquake source and ground motion models. These time-independent maps are shown for 2-percent and 10-percent probability of exceedance in 50 years for peak horizontal ground acceleration as well as 5-hertz and 1-hertz spectral accelerations with 5-percent damping on a uniform firm rock site condition (760 meters per second shear wave velocity in the upper 30 m, VS30). In this report, the 2014 updated maps are compared with the 2008 version of the maps and indicate changes of plus or minus 20 percent over wide areas, with larger changes locally, caused by the modifications to the seismic source and ground motion inputs.

  11. Evaluation of potential surface rupture and review of current seismic hazards program at the Los Alamos National Laboratory. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1991-12-09

    This report summarizes the authors review and evaluation of the existing seismic hazards program at Los Alamos National Laboratory (LANL). The report recommends that the original program be augmented with a probabilistic analysis of seismic hazards involving assignment of weighted probabilities of occurrence to all potential sources. This approach yields a more realistic evaluation of the likelihood of large earthquake occurrence particularly in regions where seismic sources may have recurrent intervals of several thousand years or more. The report reviews the locations and geomorphic expressions of identified fault lines along with the known displacements of these faults and last know occurrence of seismic activity. Faults are mapped and categorized into by their potential for actual movement. Based on geologic site characterization, recommendations are made for increased seismic monitoring; age-dating studies of faults and geomorphic features; increased use of remote sensing and aerial photography for surface mapping of faults; the development of a landslide susceptibility map; and to develop seismic design standards for all existing and proposed facilities at LANL.

  12. Marine and land active-source seismic investigation of geothermal potential, tectonic structure, and earthquake hazards in Pyramid Lake, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Eisses, A.; Kell, A.; Kent, G. [UNR; Driscoll, N. [UCSD; Karlin, R.; Baskin, R. [USGS; Louie, J.; Pullammanappallil, S. [Optim

    2016-08-01

    Amy Eisses, Annie M. Kell, Graham Kent, Neal W. Driscoll, Robert E. Karlin, Robert L. Baskin, John N. Louie, Kenneth D. Smith, Sathish Pullammanappallil, 2011, Marine and land active-source seismic investigation of geothermal potential, tectonic structure, and earthquake hazards in Pyramid Lake, Nevada: presented at American Geophysical Union Fall Meeting, San Francisco, Dec. 5-9, abstract NS14A-08.

  13. Marine and land active-source seismic investigation of geothermal potential, tectonic structure, and earthquake hazards in Pyramid Lake, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Eisses, A.; Kell, A.; Kent, G. [UNR; Driscoll, N. [UCSD; Karlin, R.; Baskin, R. [USGS; Louie, J. [UNR; Pullammanappallil, S. [Optim

    2016-08-01

    Amy Eisses, Annie M. Kell, Graham Kent, Neal W. Driscoll, Robert E. Karlin, Robert L. Baskin, John N. Louie, Kenneth D. Smith, Sathish Pullammanappallil, 2011, Marine and land active-source seismic investigation of geothermal potential, tectonic structure, and earthquake hazards in Pyramid Lake, Nevada: presented at American Geophysical Union Fall Meeting, San Francisco, Dec. 5-9, abstract NS14A-08.

  14. Preliminary Interpretations of Multi-Channel Seismic Reflection and Magnetic Data on North Anatolian Fault (NAF) in the Eastern Marmara Region, Turkey

    Science.gov (United States)

    Gözde Okut Toksoy, Nigar; Kurt, Hülya; İşseven, Turgay

    2017-04-01

    of Istanbul Technical University is used for processing. Proton magnetometer is used for measuring the magnetic field variations on the one of the profiles. Total magnetic field values are corrected using base readings from Bogazici University Kandilli Observatory, Iznik Earthquake Hazard Mitigation Center. Processed seismic and magnetic data are interpreted and compared to see effect of the NAF. Preliminary interpretations show vertical seismic discontinuities related to the fault figured out on the time-migrated seismic sections from surface to the about 1 s two-way travel time depth. Magnetic anomalies are also realized on the profile related to the NAF supporting the seismic data.

  15. A preliminary regional assessment of earthquake-induced landslide susceptibility for Vrancea Seismic Region

    Science.gov (United States)

    Micu, Mihai; Balteanu, Dan; Ionescu, Constantin; Havenith, Hans; Radulian, Mircea; van Westen, Cees; Damen, Michiel; Jurchescu, Marta

    2015-04-01

    In seismically-active regions, earthquakes may trigger landslides enhancing the short-to-long term slope denudation and sediment delivery and conditioning the general landscape evolution. Co-seismic slope failures present in general a low frequency - high magnitude pattern which should be addressed accordingly by landslide hazard assessment, with respect to the generally more frequent precipitation-triggered landslides. The Vrancea Seismic Region, corresponding to the curvature sector of the Eastern Romanian Carpathians, represents the most active sub-crustal (focal depth > 50 km) earthquake province of Europe. It represents the main seismic energy source throughout Romania with significant transboundary effects recorded as far as Ukraine and Bulgaria. During the last 300 years, the region featured 14 earthquakes with M>7, among which seven events with magnitude above 7.5 and three between 7.7 and 7.9. Apart from the direct damages, the Vrancea earthquakes are also responsible for causing numerous other geohazards, such as ground fracturing, groundwater level disturbances and possible deep-seated landslide occurrences (rock slumps, rock-block slides, rock falls, rock avalanches). The older deep-seated landslides (assumed to have been) triggered by earthquakes usually affect the entire slope profile. They often formed landslide dams strongly influencing the river morphology and representing potential threats (through flash-floods) in case of lake outburst. Despite the large potential of this research issue, the correlation between the region's seismotectonic context and landslide predisposing factors has not yet been entirely understood. Presently, there is a lack of information provided by the geohazards databases of Vrancea that does not allow us to outline the seismic influence on the triggering of slope failures in this region. We only know that the morphology of numerous large, deep-seated and dormant landslides (which can possibly be reactivated in future

  16. Climate services for adapting landslide hazard prevention measures in the Vrancea Seismic Region

    Science.gov (United States)

    Micu, Dana; Balteanu, Dan; Jurchescu, Marta; Sima, Mihaela; Micu, Mihai

    2014-05-01

    The Vrancea Seismic Region is covering an area of about 8 000 km2 in the Romanian Curvature Carpathians and Subcarpathians and it is considered one of Europe's most intensely multi-hazard-affected areas. Due to its geomorphic traits (heterogeneous morphostructural units of flysch mountains and molasse hills and depressions), the area is strongly impacted by extreme hydro-meteorological events which are potentially enhancing the numerous damages inflicted to a dense network of human settlements. An a priori knowledge of future climate change is a useful climate service for local authorities to develop regional adapting strategies and adequate prevention/preparedness frameworks. This paper aims at integrating the results of the high-resolution climate projections over the 21st century (within the FP7 ECLISE project) into the regional landslide hazard assessment. The requirements of users (Civil Protection, Land management, local authorities) for this area refer to reliable and high-resolution spatial data on landslide and flood hazard for short and medium-term risk management strategies. An insight into the future behavior of climate variability in the Vrancea Seismic Region, based on future climate projections of three regional models, under three RCPs (2.6, 4.5, 8.6), suggests a clear warming, both annually and seasonally and a rather limited annual precipitation decrease, but with a strong change of seasonality. A landslide inventory of 2485 cases (shallow and medium seated earth, debris and rock slides and earth and debris flows) was obtained based on large scale geomorphological mapping and aerial photos support (GeoEye, DigitalGlobe; provided by GoogleEarth and BingMaps). The landslides are uniformly distributed across the area, being considered representative for the entire morphostructural environment. Landslide susceptibility map was obtained using multivariate statistical analysis (logistic regression), while a relative landslide hazard index was computed

  17. Modelling Active Faults in Probabilistic Seismic Hazard Analysis (PSHA) with OpenQuake: Definition, Design and Experience

    Science.gov (United States)

    Weatherill, Graeme; Garcia, Julio; Poggi, Valerio; Chen, Yen-Shin; Pagani, Marco

    2016-04-01

    The Global Earthquake Model (GEM) has, since its inception in 2009, made many contributions to the practice of seismic hazard modeling in different regions of the globe. The OpenQuake-engine (hereafter referred to simply as OpenQuake), GEM's open-source software for calculation of earthquake hazard and risk, has found application in many countries, spanning a diversity of tectonic environments. GEM itself has produced a database of national and regional seismic hazard models, harmonizing into OpenQuake's own definition the varied seismogenic sources found therein. The characterization of active faults in probabilistic seismic hazard analysis (PSHA) is at the centre of this process, motivating many of the developments in OpenQuake and presenting hazard modellers with the challenge of reconciling seismological, geological and geodetic information for the different regions of the world. Faced with these challenges, and from the experience gained in the process of harmonizing existing models of seismic hazard, four critical issues are addressed. The challenge GEM has faced in the development of software is how to define a representation of an active fault (both in terms of geometry and earthquake behaviour) that is sufficiently flexible to adapt to different tectonic conditions and levels of data completeness. By exploring the different fault typologies supported by OpenQuake we illustrate how seismic hazard calculations can, and do, take into account complexities such as geometrical irregularity of faults in the prediction of ground motion, highlighting some of the potential pitfalls and inconsistencies that can arise. This exploration leads to the second main challenge in active fault modeling, what elements of the fault source model impact most upon the hazard at a site, and when does this matter? Through a series of sensitivity studies we show how different configurations of fault geometry, and the corresponding characterisation of near-fault phenomena (including

  18. Constraints on Long-Term Seismic Hazard From Vulnerable Stalagmites for the surroundings of Katerloch cave, Austria

    Science.gov (United States)

    Gribovszki, Katalin; Bokelmann, Götz; Mónus, Péter; Kovács, Károly; Kalmár, János

    2016-04-01

    Earthquakes hit urban centers in Europe infrequently, but occasionally with disastrous effects. This raises the important issue for society, how to react to the natural hazard: potential damages are huge, and infrastructure costs for addressing these hazards are huge as well. Obtaining an unbiased view of seismic hazard (and risk) is very important therefore. In principle, the best way to test Probabilistic Seismic Hazard Assessments (PSHA) is to compare with observations that are entirely independent of the procedure used to produce the PSHA models. Arguably, the most valuable information in this context should be information on long-term hazard, namely maximum intensities (or magnitudes) occurring over time intervals that are at least as long as a seismic cycle. Such information would be very valuable, even if it concerned only a single site. Long-term information can in principle be gained from intact stalagmites in natural karstic caves. These have survived all earthquakes that have occurred, over thousands of years - depending on the age of the stalagmite. Their "survival" requires that the horizontal ground acceleration has never exceeded a certain critical value within that period. We are focusing here on a case study from the Katerloch cave close to the city of Graz, Austria. A specially-shaped (candle stick style: high, slim, and more or less cylindrical form) intact and vulnerable stalagmites (IVSTM) in the Katerloch cave has been examined in 2013 and 2014. This IVSTM is suitable for estimating the upper limit for horizontal peak ground acceleration generated by pre-historic earthquakes. For this cave, we have extensive information about ages (e.g., Boch et al., 2006, 2010). The approach, used in our study, yields significant new constraints on seismic hazard, as the intactness of the stalagmites suggests that tectonic structures close to Katerloch cave, i.p. the Mur-Mürz fault did not generate very strong paleoearthquakes in the last few thousand years

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

    Science.gov (United States)

    Waythomas, Christopher F.; Miller, Thomas P.

    1999-01-01

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

  20. Risk-Informed External Hazards Analysis for Seismic and Flooding Phenomena for a Generic PWR

    Energy Technology Data Exchange (ETDEWEB)

    Parisi, Carlo [Idaho National Lab. (INL), Idaho Falls, ID (United States); Prescott, Steve [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ma, Zhegang [Idaho National Lab. (INL), Idaho Falls, ID (United States); Spears, Bob [Idaho National Lab. (INL), Idaho Falls, ID (United States); Szilard, Ronaldo [Idaho National Lab. (INL), Idaho Falls, ID (United States); Coleman, Justin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kosbab, Ben [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2017-07-26

    This report describes the activities performed during the FY2017 for the US-DOE Light Water Reactor Sustainability Risk-Informed Safety Margin Characterization (LWRS-RISMC), Industry Application #2. The scope of Industry Application #2 is to deliver a risk-informed external hazards safety analysis for a representative nuclear power plant. Following the advancements occurred during the previous FYs (toolkits identification, models development), FY2017 focused on: increasing the level of realism of the analysis; improving the tools and the coupling methodologies. In particular the following objectives were achieved: calculation of buildings pounding and their effects on components seismic fragility; development of a SAPHIRE code PRA models for 3-loops Westinghouse PWR; set-up of a methodology for performing static-dynamic PRA coupling between SAPHIRE and EMRALD codes; coupling RELAP5-3D/RAVEN for performing Best-Estimate Plus Uncertainty analysis and automatic limit surface search; and execute sample calculations for demonstrating the capabilities of the toolkit in performing a risk-informed external hazards safety analyses.

  1. Parameter estimation in Probabilistic Seismic Hazard Analysis: current problems and some solutions

    Science.gov (United States)

    Vermeulen, Petrus

    2017-04-01

    A typical Probabilistic Seismic Hazard Analysis (PSHA) comprises identification of seismic source zones, determination of hazard parameters for these zones, selection of an appropriate ground motion prediction equation (GMPE), and integration over probabilities according the Cornell-McGuire procedure. Determination of hazard parameters often does not receive the attention it deserves, and, therefore, problems therein are often overlooked. Here, many of these problems are identified, and some of them addressed. The parameters that need to be identified are those associated with the frequency-magnitude law, those associated with earthquake recurrence law in time, and the parameters controlling the GMPE. This study is concerned with the frequency-magnitude law and temporal distribution of earthquakes, and not with GMPEs. TheGutenberg-Richter frequency-magnitude law is usually adopted for the frequency-magnitude law, and a Poisson process for earthquake recurrence in time. Accordingly, the parameters that need to be determined are the slope parameter of the Gutenberg-Richter frequency-magnitude law, i.e. the b-value, the maximum value at which the Gutenberg-Richter law applies mmax, and the mean recurrence frequency,λ, of earthquakes. If, instead of the Cornell-McGuire, the "Parametric-Historic procedure" is used, these parameters do not have to be known before the PSHA computations, they are estimated directly during the PSHA computation. The resulting relation for the frequency of ground motion vibration parameters has an analogous functional form to the frequency-magnitude law, which is described by parameters γ (analogous to the b¬-value of the Gutenberg-Richter law) and the maximum possible ground motion amax (analogous to mmax). Originally, the approach was possible to apply only to the simple GMPE, however, recently a method was extended to incorporate more complex forms of GMPE's. With regards to the parameter mmax, there are numerous methods of estimation

  2. Quantification of source uncertainties in Seismic Probabilistic Tsunami Hazard Analysis (SPTHA): towards PTHA assessment for the coasts of Italy

    Science.gov (United States)

    Selva, Jacopo; Tonini, Roberto; Molinari, Irene; Tiberti, Mara M.; Romano, Fabrizio; Grezio, Anita; Melini, Daniele; Piatanesi, Alessio; Basili, Roberto; Lorito, Stefano

    2016-04-01

    We propose a procedure for uncertainty quantification in Probabilistic Tsunami Hazard Analysis (PTHA), with a special emphasis on the uncertainty related to statistical modelling of the earthquake source in Seismic PTHA (SPTHA), and on the separate treatment of subduction and crustal earthquakes. Differently from classical approaches that commonly adopt the hazard integral and logic tree, we use an event tree approach and ensemble modelling. The procedure was developed in the framework of the EC projects ASTARTE and STREST, of the Italian National Flagship project RITMARE, and of the agreement between Italian Civil Protection and INGV. A total of about 2 × 107 different potential seismic sources covering the entire Mediterranean Sea, and more than 1 × 105 alternative model implementations have been considered to quantify both the aleatory variability and the epistemic uncertainty. A set of hazard curves is obtained along the coasts of the entire Italian territory. They are the prototype of the first homogeneous Italian national SPTHA map.

  3. Preliminary Analysis of Remote Triggered Seismicity in Northern Baja California Generated by the 2011, Tohoku-Oki, Japan Earthquake

    Science.gov (United States)

    Wong-Ortega, V.; Castro, R. R.; Gonzalez-Huizar, H.; Velasco, A. A.

    2013-05-01

    We analyze possible variations of seismicity in the northern Baja California due to the passage of seismic waves from the 2011, M9.0, Tohoku-Oki, Japan earthquake. The northwestern area of Baja California is characterized by a mountain range composed of crystalline rocks. These Peninsular Ranges of Baja California exhibits high microseismic activity and moderate size earthquakes. In the eastern region of Baja California shearing between the Pacific and the North American plates takes place and the Imperial and Cerro-Prieto faults generate most of the seismicity. The seismicity in these regions is monitored by the seismic network RESNOM operated by the Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE). This network consists of 13 three-component seismic stations. We use the seismic catalog of RESNOM to search for changes in local seismic rates occurred after the passing of surface waves generated by the Tohoku-Oki, Japan earthquake. When we compare one month of seismicity before and after the M9.0 earthquake, the preliminary analysis shows absence of triggered seismicity in the northern Peninsular Ranges and an increase of seismicity south of the Mexicali valley where the Imperial fault jumps southwest and the Cerro Prieto fault continues.

  4. Preliminary correlations of lithology and seismic reflectors in prograding Neogene carbonate of Great Bahama Bank

    Energy Technology Data Exchange (ETDEWEB)

    Eberli, G.P. (Geological Inst., Zurich (Switzerland)); Ginsburg, R.N.; Swart, P.K.; McNeill, D.F.; Kenter, J.A.M. (Univ. of Miami, FL (United States))

    1991-03-01

    Excellent overall recovery of 80% in two continuous core borings provides the data on lithology necessary to calibrate prograding late Cenozoic sequences and their seismic signatures. Hole UNDA, 10 km inside the modern platform edge of Great Bahama Bank (GBB), penetrated onlapping and topset reflectors and a buried platform rim. The 500 m core revealed two platform sequences alternating with fine grainstone units with internal hardground surfaces. At hole CLINO, 5.5 km farther basinward, 657 m of core document the progradation of GBB with 150 m of shallow platform deposits and reefal sequences over mostly fine-grained, foraminifera-rich periplatform slope sediments with intercalations of coarser beds, some of which contain platform lithoclasts. Within these slope deposits, there is significant variation in the degree of cementation; friable, porous limestones alternate with well cemented beds. Preliminary correlations between lithofacies and seismic signatures suggest a strong influence of both the sedimentologic and diagenetic facies on the seismic signal. Major lithologic changes, such as from mudstone to coral-bearing packstone or from skeletal sand to reefal limestone, produce strong reflectors. These latter transitions also coincide with seismic sequence boundaries. Within the more homogeneous slope sections, where seismic reflection horizons are not characterized by a facies change, differential cementation seems to be responsible for the seismic signal. Nevertheless, three reflectors identified as sequence boundaries are overlain by units containing coarse-grained beds with platform lithoclasts and blackened grains, indicating that these deposits were shed during low sea level and represent parts of the lowstand systems tract.

  5. Miscellaneous High-Resolution Seismic Imaging Investigations in Salt Lake and Utah Valleys for Earthquake Hazards

    Science.gov (United States)

    Stephenson, W.J.; Williams, R.A.; Odum, J.K.; Worley, D.M.

    2007-01-01

    Introduction In support of earthquake hazards and ground motion studies by researchers at the Utah Geological Survey, University of Utah, Utah State University, Brigham Young University, and San Diego State University, the U.S. Geological Survey Geologic Hazards Team Intermountain West Project conducted three high-resolution seismic imaging investigations along the Wasatch Front between September 2003 and September 2005. These three investigations include: (1) a proof-of-concept P-wave minivib reflection imaging profile in south-central Salt Lake Valley, (2) a series of seven deep (as deep as 400 m) S-wave reflection/refraction soundings using an S-wave minivib in both Salt Lake and Utah Valleys, and (3) an S-wave (and P-wave) investigation to 30 m at four sites in Utah Valley and at two previously investigated S-wave (Vs) minivib sites. In addition, we present results from a previously unpublished downhole S-wave investigation conducted at four sites in Utah Valley. The locations for each of these investigations are shown in figure 1. Coordinates for the investigation sites are listed in Table 1. With the exception of the P-wave common mid-point (CMP) reflection profile, whose end points are listed, these coordinates are for the midpoint of each velocity sounding. Vs30 and Vs100, also shown in Table 1, are defined as the average shear-wave velocities to depths of 30 and 100 m, respectively, and details of their calculation can be found in Stephenson and others (2005). The information from these studies will be incorporated into components of the urban hazards maps along the Wasatch Front being developed by the U.S. Geological Survey, Utah Geological Survey, and numerous collaborating research institutions.

  6. Preliminary volcano-hazard assessment for Augustine Volcano, Alaska

    Science.gov (United States)

    Waythomas, Christopher F.; Waitt, Richard B.

    1998-01-01

    Augustine Volcano is a 1250-meter high stratovolcano in southwestern Cook Inlet about 280 kilometers southwest of Anchorage and within about 300 kilometers of more than half of the population of Alaska. Explosive eruptions have occurred six times since the early 1800s (1812, 1883, 1935, 1964-65, 1976, and 1986). The 1976 and 1986 eruptions began with an initial series of vent-clearing explosions and high vertical plumes of volcanic ash followed by pyroclastic flows, surges, and lahars on the volcano flanks. Unlike some prehistoric eruptions, a summit edifice collapse and debris avalanche did not occur in 1812, 1935, 1964-65, 1976, or 1986. However, early in the 1883 eruption, a portion of the volcano summit broke loose forming a debris avalanche that flowed to the sea. The avalanche initiated a small tsunami reported on the Kenai Peninsula at English Bay, 90 kilometers east of the volcano. Plumes of volcanic ash are a major hazard to jet aircraft using Anchorage International and other local airports. Ashfall from future eruptions could disrupt oil and gas operations and shipping activities in Cook Inlet. Eruptions similar to the historical and prehistoric eruptions are likely in Augustine's future.

  7. Potentially hazardous plants of Puerto Rico: preliminary guide

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, F.F.; Medina, F.R.

    1975-08-01

    General information is presented about the kinds of native and imported plants in Puerto Rico (weeds, grasses, vines, cactuses, shrubs, trees and parts thereof) that should be avoided, or not ingested. Small amounts of eaten wild plant materials are usually not likely to be hazardous although large amounts may be dangerous; the striking exception is mushrooms. While a number of Puerto Rican plants are lethal to cattle, only a few are known to cause death to man as, for example, the fruit of the Deadly Manchineel, Hippomane mancinella and the seed of the Rosary Pea, Abrus precatorius. Tourists especially should avoid tasting any green or yellowish apples growing on a medium-sized tree. The Hippomane fruit resembles the Crabapple of temperate zones. It is now unlawful to use the Rosary Pea in the local handicraft industry. An item of special interest is the delicious fruit of Mamey often offered for sale at roadside, the outer coating of which is poisonous. All of the light brown outer covering, including especially all of the inner whitish tunic, must be carefully removed from the golden yellow fruit before eating, or else illness may result. Relatively few of the plants presented here will produce major physical problems if only contacted or chewed, but ingestion of some plant parts produces severe toxic symptoms.

  8. Fault2SHA- A European Working group to link faults and Probabilistic Seismic Hazard Assessment communities in Europe

    Science.gov (United States)

    Scotti, Oona; Peruzza, Laura

    2016-04-01

    The key questions we ask are: What is the best strategy to fill in the gap in knowledge and know-how in Europe when considering faults in seismic hazard assessments? Are field geologists providing the relevant information for seismic hazard assessment? Are seismic hazard analysts interpreting field data appropriately? Is the full range of uncertainties associated with the characterization of faults correctly understood and propagated in the computations? How can fault-modellers contribute to a better representation of the long-term behaviour of fault-networks in seismic hazard studies? Providing answers to these questions is fundamental, in order to reduce the consequences of future earthquakes and improve the reliability of seismic hazard assessments. An informal working group was thus created at a meeting in Paris in November 2014, partly financed by the Institute of Radioprotection and Nuclear Safety, with the aim to motivate exchanges between field geologists, fault modellers and seismic hazard practitioners. A variety of approaches were presented at the meeting and a clear gap emerged between some field geologists, that are not necessarily familiar with probabilistic seismic hazard assessment methods and needs and practitioners that do not necessarily propagate the "full" uncertainty associated with the characterization of faults. The group thus decided to meet again a year later in Chieti (Italy), to share concepts and ideas through a specific exercise on a test case study. Some solutions emerged but many problems of seismic source characterizations with people working in the field as well as with people tackling models of interacting faults remained. Now, in Wien, we want to open the group and launch a call for the European community at large to contribute to the discussion. The 2016 EGU session Fault2SHA is motivated by such an urgency to increase the number of round tables on this topic and debate on the peculiarities of using faults in seismic hazard

  9. Preliminary tsunami hazard assessment in British Columbia, Canada

    Science.gov (United States)

    Insua, T. L.; Grilli, A. R.; Grilli, S. T.; Shelby, M. R.; Wang, K.; Gao, D.; Cherniawsky, J. Y.; Harris, J. C.; Heesemann, M.; McLean, S.; Moran, K.

    2015-12-01

    Ocean Networks Canada (ONC), a not-for-profit initiative by the University of Victoria that operates several cabled ocean observatories, is developing a new generation of ocean observing systems (referred to as Smart Ocean Systems™), involving advanced undersea observation technologies, data networks and analytics. The ONC Tsunami project is a Smart Ocean Systems™ project that addresses the need for a near-field tsunami detection system for the coastal areas of British Columbia. Recent studies indicate that there is a 40-80% probability over the next 50 for a significant tsunami impacting the British Columbia (BC) coast with runups higher than 1.5 m. The NEPTUNE cabled ocean observatory, operated by ONC off of the west coast of British Columbia, could be used to detect near-field tsunami events with existing instrumentation, including seismometers and bottom pressure recorders. As part of this project, new tsunami simulations are underway for the BC coast. Tsunami propagation is being simulated with the FUNWAVE-TVD model, for a suite of new source models representing Cascadia megathrust rupture scenarios. Simulations are performed by one-way coupling in a series of nested model grids (from the source to the BC coast), whose bathymetry was developed based on digital elevation maps (DEMs) of the area, to estimate both tsunami arrival time and coastal runup/inundation for different locations. Besides inundation, maps of additional parameters such as maximum current are being developed, that will aid in tsunami hazard assessment and risk mitigation, as well as developing evacuation plans. We will present initial results of this work for the Port Alberni inlet, in particular Ucluelet, based on new source models developed using the best available data. We will also present a model validation using measurements of the 2011 transpacific Tohoku-oki tsunami recorded in coastal BC by several instruments from various US and Canadian agencies.

  10. Assessing soil-structure interaction during the 2016 central Italy seismic sequence (Italy: preliminary results

    Directory of Open Access Journals (Sweden)

    Arrigo Caserta

    2016-12-01

    Full Text Available We used the moderate-magnitude aftershocks succeeding to the 2016 August 24th, Mw = 6.0, Amatrice (Italy mainshok to asses, specially during an ongoing seismic sequence, the soil-structure interaction where cultural Heritage is involved. We have chosen as case study the San Giovanni Battista church (A.D. 1039  in Acquasanta Terme town, about 20 Km northeast of Amatrice. First of all we studied the soil shaking features in order to characterize the input to the monument. Then, using the recordings in the church, we tried to figure out  how the input seismic energy is distributed over the different monument parts. Some preliminary results are shown and discussed.

  11. Earthquake scenario in West Bengal with emphasis on seismic hazard microzonation of the city of Kolkata, India

    Science.gov (United States)

    Nath, S. K.; Adhikari, M. D.; Maiti, S. K.; Devaraj, N.; Srivastava, N.; Mohapatra, L. D.

    2014-09-01

    Seismic microzonation is a process of estimating site-specific effects due to an earthquake on urban centers for its disaster mitigation and management. The state of West Bengal, located in the western foreland of the Assam-Arakan Orogenic Belt, the Himalayan foothills and Surma Valley, has been struck by several devastating earthquakes in the past, indicating the need for a seismotectonic review of the province, especially in light of probable seismic threat to its capital city of Kolkata, which is a major industrial and commercial hub in the eastern and northeastern region of India. A synoptic probabilistic seismic hazard model of Kolkata is initially generated at engineering bedrock (Vs30 ~ 760 m s-1) considering 33 polygonal seismogenic sources at two hypocentral depth ranges, 0-25 and 25-70 km; 158 tectonic sources; appropriate seismicity modeling; 14 ground motion prediction equations for three seismotectonic provinces, viz. the east-central Himalaya, the Bengal Basin and Northeast India selected through suitability testing; and appropriate weighting in a logic tree framework. Site classification of Kolkata performed following in-depth geophysical and geotechnical investigations places the city in D1, D2, D3 and E classes. Probabilistic seismic hazard assessment at a surface-consistent level - i.e., the local seismic hazard related to site amplification performed by propagating the bedrock ground motion with 10% probability of exceedance in 50 years through a 1-D sediment column using an equivalent linear analysis - predicts a peak ground acceleration (PGA) range from 0.176 to 0.253 g in the city. A deterministic liquefaction scenario in terms of spatial distribution of liquefaction potential index corresponding to surface PGA distribution places 50% of the city in the possible liquefiable zone. A multicriteria seismic hazard microzonation framework is proposed for judicious integration of multiple themes, namely PGA at the surface, liquefaction potential

  12. Space-time clustering of seismic events and hazard assessment in the Zabrze-Bielszowice coal mine, Poland

    Energy Technology Data Exchange (ETDEWEB)

    Lesniak, A.; Isakow, Z. [AGH University of Science & Technology, Krakow (Poland)

    2009-07-15

    The results of the statistical analysis of seismic activity recorded in the 'Zabrze-Bielszowice' coal mine in Poland are presented in this article. The monitoring was conducted by a small network consisting of four triaxial geophones deployed in vertical holes in the roof. For over 1000 seismic events recorded during the two month's experiment, the location of sources was realized. The seismic sources were mostly located ahead of the active face of the long wall. Since the first day of the monitoring, cluster analysis was sequentially performed for increasing number of sources. At the end of the experiment, 31 clusters were identified. They consisted of different numbers of events and were separated in space. About 40% of the events were not included in the clusters. For each large cluster, hazard analysis was separately performed. The hazard function evaluated for the largest cluster was compared with hypocenters of high energy tremors (E > 1000 J) recorded by the geophones in that area. For some cases, recorded tremors occurred after an abrupt decrease of hazard function, but only one of them was located in the vicinity of the appropriate cluster. We concluded that for the analyzed cluster, a correlation between evaluated hazard function and time occurrences of the high energy tremors existed. Except for one case, there is no space correlation between analyzed clusters and high energy tremors.

  13. Issues in testing the new national seismic hazard model for Italy

    Science.gov (United States)

    Stein, S.; Peresan, A.; Kossobokov, V. G.; Brooks, E. M.; Spencer, B. D.

    2016-12-01

    It is important to bear in mind that we know little about how earthquake hazard maps actually describe the shaking that will actually occur in the future, and have no agreed way of assessing how well a map performed in the past, and, thus, whether one map performs better than another. Moreover, we should not forget that different maps can be useful for different end users, who may have different cost-and-benefit strategies. Thus, regardless of the specific tests we chose to use, the adopted testing approach should have several key features: We should assess map performance using all the available instrumental, paleo seismology, and historical intensity data. Instrumental data alone span a period much too short to capture the largest earthquakes - and thus strongest shaking - expected from most faults. We should investigate what causes systematic misfit, if any, between the longest record we have - historical intensity data available for the Italian territory from 217 B.C. to 2002 A.D. - and a given hazard map. We should compare how seismic hazard maps developed over time. How do the most recent maps for Italy compare to earlier ones? It is important to understand local divergences that show how the models are developing to the most recent one. The temporal succession of maps is important: we have to learn from previous errors. We should use the many different tests that have been proposed. All are worth trying, because different metrics of performance show different aspects of how a hazard map performs and can be used. We should compare other maps to the ones we are testing. Maps can be made using a wide variety of assumptions, which will lead to different predicted shaking. It is possible that maps derived by other approaches may perform better. Although Italian current codes are based on probabilistic maps, it is important from both a scientific and societal perspective to look at all options including deterministic scenario based ones. Comparing what works

  14. Seismic hazard assessment of Kashmir and Kangra valley region, Western Himalaya, India

    Directory of Open Access Journals (Sweden)

    Basab Mukhopadhyay

    2015-02-01

    Full Text Available A complete earthquake catalogue of the Western Himalaya (latitudes 30°N–36°N and longitudes 72°E–78°E for the period of 1501–2010 has been compiled with earthquake magnitude computed in moment magnitude (Mw scale. Pre- and early twentieth century records of earthquake damage have been documented from rare and out of print publications. Seismotectonics and seismic hazard for Kohistan arc, Kashmir–Hazara Syntaxis, Nanga-Parbat (Western Syntaxis, Karakoram and Himachal Himalaya are discussed with special reference to 1905 Kangra and 2005 Muzaffarabad earthquakes. Analyses of spatio-temporal variation in b-value from the region indicate significant precursor prior to the 2005 Muzaffarabad earthquake; progressive rise of background b-value observed and the main shock locates close to relative high b-value domains. Regions surrounding the location of the 1905 Kangra earthquake also display such high b-value for the period of 2005–2010 that calls for closer scrutiny. Temporal analysis of b-value from the epicentral block of Muzaffarabad earthquake clearly showed a high–low b-value couplet of 1.45–0.72, which may be treated as a typical precursor before an imminent large earthquake. Gumbel extreme value statistics indicate probability of occurrence of an event of Mw > 7.0 within 50 years in the region.

  15. Seismic Hazard Analysis in EL Paso/juarez Area from Study of Young Fault Scarps

    Science.gov (United States)

    ashenfelter, K. R.

    2012-12-01

    The El Paso-Juarez metropolitan area contains a known record of active faulting, but also has one of the most poorly known paleoseismic records. The scarcity of data means that nearly 2 million people are exposed to a seismic hazard with little known on the actual risk. Active faults are known along the eastern side of the Franklin Mountains as well as young ruptures within the Hueco Bolson in East El Paso, yet the only fault with paleoseismic studies is the East Franklin's fault. Recent population increases in the El Paso region have led to a construction boom in east El Paso, and many of these construction sites cross known Quaternary fault ruptures. This research project contains two potential components: 1) An exploratory component: students can use existing fault maps and high resolution aerial photography to seek out sites where active construction sites might be unearthing exposures of young fault ruptures. The study is exploratory, and involves carefully mapping using field GIS systems to document areas for potential study, map possible faults, etc. 2) An active fault study in an urbanized environment: The east Franklins fault is a known active fault. The scarp is exposed near trans-mountain road, and along some side streets in NE El Paso. Potential studies include careful mapping of fault scarp topographic profiles, and mapping surface traces.

  16. Proposed Risk-Informed Seismic Hazard Periodic Reevaluation Methodology for Complying with DOE Order 420.1C

    Energy Technology Data Exchange (ETDEWEB)

    Kammerer, Annie [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-03-01

    Department of Energy (DOE) nuclear facilities must comply with DOE Order 420.1C Facility Safety, which requires that all such facilities review their natural phenomena hazards (NPH) assessments no less frequently than every ten years. The Order points the reader to Standard DOE-STD-1020-2012. In addition to providing a discussion of the applicable evaluation criteria, the Standard references other documents, including ANSI/ANS-2.29-2008 and NUREG-2117. These documents provide supporting criteria and approaches for evaluating the need to update an existing probabilistic seismic hazard analysis (PSHA). All of the documents are consistent at a high level regarding the general conceptual criteria that should be considered. However, none of the documents provides step-by-step detailed guidance on the required or recommended approach for evaluating the significance of new information and determining whether or not an existing PSHA should be updated. Further, all of the conceptual approaches and criteria given in these documents deal with changes that may have occurred in the knowledge base that might impact the inputs to the PSHA, the calculated hazard itself, or the technical basis for the hazard inputs. Given that the DOE Order is aimed at achieving and assuring the safety of nuclear facilities—which is a function not only of the level of the seismic hazard but also the capacity of the facility to withstand vibratory ground motions—the inclusion of risk information in the evaluation process would appear to be both prudent and in line with the objectives of the Order. The purpose of this white paper is to describe a risk-informed methodology for evaluating the need for an update of an existing PSHA consistent with the DOE Order. While the development of the proposed methodology was undertaken as a result of assessments for specific SDC-3 facilities at Idaho National Laboratory (INL), and it is expected that the application at INL will provide a demonstration of the

  17. Proposed Risk-Informed Seismic Hazard Periodic Reevaluation Methodology for Complying with DOE Order 420.1C

    Energy Technology Data Exchange (ETDEWEB)

    Kammerer, Annie [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-10-01

    Department of Energy (DOE) nuclear facilities must comply with DOE Order 420.1C Facility Safety, which requires that all such facilities review their natural phenomena hazards (NPH) assessments no less frequently than every ten years. The Order points the reader to Standard DOE-STD-1020-2012. In addition to providing a discussion of the applicable evaluation criteria, the Standard references other documents, including ANSI/ANS-2.29-2008 and NUREG-2117. These documents provide supporting criteria and approaches for evaluating the need to update an existing probabilistic seismic hazard analysis (PSHA). All of the documents are consistent at a high level regarding the general conceptual criteria that should be considered. However, none of the documents provides step-by-step detailed guidance on the required or recommended approach for evaluating the significance of new information and determining whether or not an existing PSHA should be updated. Further, all of the conceptual approaches and criteria given in these documents deal with changes that may have occurred in the knowledge base that might impact the inputs to the PSHA, the calculated hazard itself, or the technical basis for the hazard inputs. Given that the DOE Order is aimed at achieving and assuring the safety of nuclear facilities—which is a function not only of the level of the seismic hazard but also the capacity of the facility to withstand vibratory ground motions—the inclusion of risk information in the evaluation process would appear to be both prudent and in line with the objectives of the Order. The purpose of this white paper is to describe a risk-informed methodology for evaluating the need for an update of an existing PSHA consistent with the DOE Order. While the development of the proposed methodology was undertaken as a result of assessments for specific SDC-3 facilities at Idaho National Laboratory (INL), and it is expected that the application at INL will provide a demonstration of the

  18. Fractal properties and simulation of micro-seismicity for seismic hazard analysis: a comparison of North Anatolian and San Andreas Fault Zones

    Directory of Open Access Journals (Sweden)

    Naside Ozer

    2012-02-01

    Full Text Available We analyzed statistical properties of earthquakes in western Anatolia as well as the North Anatolian Fault Zone (NAFZ in terms of spatio-temporal variations of fractal dimensions, p- and b-values. During statistically homogeneous periods characterized by closer fractal dimension values, we propose that occurrence of relatively larger shocks (M >= 5.0 is unlikely. Decreases in seismic activity in such intervals result in spatial b-value distributions that are primarily stable. Fractal dimensions decrease with time in proportion to increasing seismicity. Conversely, no spatiotemporal patterns were observed for p-value changes. In order to evaluate failure probabilities and simulate earthquake occurrence in the western NAFZ, we applied a modified version of the renormalization group method. Assuming an increase in small earthquakes is indicative of larger shocks, we apply the mentioned model to micro-seismic (M<= 3.0 activity, and test our results using San Andreas Fault Zone (SAFZ data. We propose that fractal dimension is a direct indicator of material heterogeneity and strength. Results from a model suggest simulated and observed earthquake occurrences are coherent, and may be used for seismic hazard estimation on creeping strike-slip fault zones.

  19. Seismic rupture modelling, strong motion prediction and seismic hazard assessment: fundamental and applied approaches; Modelisation de la rupture sismique, prediction du mouvement fort, et evaluation de l'alea sismique: approches fondamentale et appliquee

    Energy Technology Data Exchange (ETDEWEB)

    Berge-Thierry, C

    2007-05-15

    The defence to obtain the 'Habilitation a Diriger des Recherches' is a synthesis of the research work performed since the end of my Ph D. thesis in 1997. This synthesis covers the two years as post doctoral researcher at the Bureau d'Evaluation des Risques Sismiques at the Institut de Protection (BERSSIN), and the seven consecutive years as seismologist and head of the BERSSIN team. This work and the research project are presented in the framework of the seismic risk topic, and particularly with respect to the seismic hazard assessment. Seismic risk combines seismic hazard and vulnerability. Vulnerability combines the strength of building structures and the human and economical consequences in case of structural failure. Seismic hazard is usually defined in terms of plausible seismic motion (soil acceleration or velocity) in a site for a given time period. Either for the regulatory context or the structural specificity (conventional structure or high risk construction), seismic hazard assessment needs: to identify and locate the seismic sources (zones or faults), to characterize their activity, to evaluate the seismic motion to which the structure has to resist (including the site effects). I specialized in the field of numerical strong-motion prediction using high frequency seismic sources modelling and forming part of the IRSN allowed me to rapidly working on the different tasks of seismic hazard assessment. Thanks to the expertise practice and the participation to the regulation evolution (nuclear power plants, conventional and chemical structures), I have been able to work on empirical strong-motion prediction, including site effects. Specific questions related to the interface between seismologists and structural engineers are also presented, especially the quantification of uncertainties. This is part of the research work initiated to improve the selection of the input ground motion in designing or verifying the stability of structures. (author)

  20. Coulomb stress transfer and accumulation on the Sagaing Fault, Myanmar, over the past 110 years and its implications for seismic hazard

    Science.gov (United States)

    Xiong, X.; Shan, B.; Zhou, Y. M.; Wei, S. J.; Li, Y. D.; Wang, R. J.; Zheng, Y.

    2017-05-01

    Myanmar is drawing rapidly increasing attention from the world for its seismic hazard. The Sagaing Fault (SF), an active right-lateral strike-slip fault passing through Myanmar, has been being the source of serious seismic damage of the country. Thus, awareness of seismic hazard assessment of this region is of pivotal significance by taking into account the interaction and migration of earthquakes with respect to time and space. We investigated a seismic series comprising10 earthquakes with M > 6.5 that occurred along the SF since 1906. The Coulomb failure stress modeling exhibits significant interactions among the earthquakes. After the 1906 earthquake, eight out of nine earthquakes occurred in the positively stress-enhanced zone of the preceding earthquakes, verifying that the hypothesis of earthquake triggering is applicable on the SF. Moreover, we identified three visible positively stressed earthquake gaps on the central and southern SF, on which seismic hazard is increased.

  1. Seismic Investigations of the Murci Geothermal Field (Southern Tuscany, Italy): Preliminary Results

    Science.gov (United States)

    Riedel, M.; Alexandrakis, C.; Buske, S.

    2013-12-01

    The Monte Amiata region in the Southern Tuscany, Central Italy, describes a volcanic complex with great significance in terms of the regional fresh water supply, mining and geothermal power generation. Mainly for the latter purpose, the volcanic area of Mt Amiata has been the subject of extensive geological and geophysical research (e.g. Dini et al., 2010 and references therein). The insights from these studies have led to successful geothermal production in the Mt Amiata region since the early 1960s (e.g. Batini et al., 2003). Today's most important reservoirs in this area are the Bagnore and the Piancastagnaio fields which are both operated by the company Enel Green Power. The work presented here deals with the Murci area, another potential reservoir located about 10 km southwest of the Mt Amiata volcanic complex. Therefore, in order to get a more detailed understanding of this area, five reflection seismic profiles were carried out. We have performed on three of them a preliminary depth-migrated images, through Kirchhoff prestack depth migration (KPSDM). The vital point of depth migration algorithms is the accuracy of the velocity model that is used for the backpropagation of the seismic data. Therefore, we derived a suitable 1D starting model from nearby well logs and VSP measurements. In order to remove the large topography effects along the profiles, we then utilized first-arrival tomography for each seismic line. For the following processing we incorporated these 2D tomographic results into our starting model which compensates for static effects and improves the resolution in the near-surface area. The velocity models were then used in the application of KPSDM to the seismic data for each profile, respectively. The resulting preliminary images show a zone of high seismic reflectivity, known as the 'K-horizon' (e.g. Brogi, 2008), and could improve its geological interpretation. These promising results encourage us to proceed with deeper migration velocity

  2. Implication of fault interaction to seismic hazard assessment in Sichuan-Yunnan provinces of Southeastern China

    Science.gov (United States)

    Gkarlaouni, C.; Papadimitriou, E. E.; Karakostas, V. G.; Wen, Xue–Ze; Jin, Xue–Shen; Kilias, A.; Pan, Hua

    2009-04-01

    ) the postseismic slip when exists, will reinforce both regional stress and stress change caused by coseismic slip. None the less, the results of our study, revealing a correspondence between positive changes and earthquake occurrence, evidence that Coulomb stress changes certainly influence the location and timing of the following earthquakes and can serve as a fundamental tool in seismic hazard assessment.

  3. The SeIsmic monitoring and vulneraBilitY framework for civiL protection (SIBYL) Project: An overview and preliminary results

    Science.gov (United States)

    Fleming, Kevin; Parolai, Stefano; Iervolino, Iunio; Pitilakis, Kyriazis; Petryna, Yuriy

    2016-04-01

    The SIBYL project is setting out to contribute to enhancing the capacity of Civil Protection (CP) authorities to rapidly and cost-effectively assess the seismic vulnerability of the built environment. The reason for this arises from the occurrence of seismic swarms or foreshocks, which leads to the requirement that CP authorities must rapidly assess the threatened area's vulnerability. This is especially important for those regions where there is a dearth of up-to-date and reliable information. The result will be a multi-faceted framework, made up of methodologies and software tools, that provides information to advise decision makers as to the most appropriate preventative actions to be taken. It will cover cases where there is a need for short-notice vulnerability assessment in a pre-event situation, and the monitoring of the built environment's dynamic vulnerability during a seismic sequence. Coupled with this will be the ability to stimulate long-term management plans, independent of the hazard or disaster of concern. The monitoring itself will involve low-cost sensing units which may be easily installed in critical infrastructures. The framework will be flexible enough to be employed over multiple spatial scales, and it will be developed with a modular structure which will ease its applicability to other natural hazard types. Likewise, it will be able to be adapted to the needs of CP authorities in different countries within their own hazard context. This presentation therefore provides an overview of the aims and expected outcomes of SIBYL, while explaining the tools currently being developed and refined, as well as preliminary results of several field campaigns.

  4. Growth and seismic hazard of the Montserrat anticline in the North Canterbury fold and thrust belt, South Island, New Zealand

    Science.gov (United States)

    VanderLeest, R. A.; Fisher, D. M.; Oakley, D. O. S.; Gardner, T. W.

    2017-08-01

    Fault-related fold growth is a seismic hazard in North Canterbury, New Zealand. The North Canterbury fold and thrust belt (NCFTB) is located at the southern end of the Hikurangi subduction zone, South Island, New Zealand where the Pacific plate transitions from subduction to transpression along the Alpine fault. Transpression causes shortening beneath the South Island, resulting in basement thrusts generating folds such as the Montserrat anticline. We focus on fault geometry and seismic hazard associated with this structure, exposed along the coast where Pleistocene marine terraces on the backlimb record tectonic uplift. To constrain parameters associated with evolution of this fault-related fold, we model the fold using several trishear kinematic models. A listric fault is most compatible with field and regional geophysical studies. Ages of marine terraces and inner edge elevations constrain uplift rate due to slip on the Glendhu fault to 1.1 ± 0.1 m(ka)-1. An ∼800 year recurrence interval is calculated for the Glendhu fault. Listric fault geometry lengthens the recurrence interval relative to other fault geometry models. An accurate understanding of subsurface fault geometry and kinematics is important for estimating seismic hazard in regions of fault-related folding such as the NCFTB because it affects recurrence interval estimations.

  5. Probabilistic Seismic Hazard Characterization and Design Parameters for the Sites of the Nuclear Power Plants of Ukraine

    Energy Technology Data Exchange (ETDEWEB)

    Savy, J.B.; Foxall, W.

    2000-01-26

    The U.S. Department of Energy (US DOE), under the auspices of the International Nuclear Safety Program (INSP) is supporting in-depth safety assessments (ISA) of nuclear power plants in Eastern Europe and the former Soviet Union for the purpose of evaluating the safety and upgrades necessary to the stock of nuclear power plants in Ukraine. For this purpose the Hazards Mitigation Center at Lawrence Livermore National Laboratory (LLNL) has been asked to assess the seismic hazard and design parameters at the sites of the nuclear power plants in Ukraine. The probabilistic seismic hazard (PSH) estimates were updated using the latest available data and knowledge from LLNL, the U.S. Geological Survey, and other relevant recent studies from several consulting companies. Special attention was given to account for the local seismicity, the deep focused earthquakes of the Vrancea zone, in Romania, the region around Crimea and for the system of potentially active faults associated with the Pripyat Dniepro Donnetts rift. Aleatory (random) uncertainty was estimated from the available data and the epistemic (knowledge) uncertainty was estimated by considering the existing models in the literature and the interpretations of a small group of experts elicited during a workshop conducted in Kiev, Ukraine, on February 2-4, 1999.

  6. Preparing a seismic hazard model for Switzerland: the view from PEGASOS Expert Group 3 (EG1c)

    Energy Technology Data Exchange (ETDEWEB)

    Musson, R. M. W. [British Geological Survey, West Mains Road, Edinburgh, EH9 3LA (United Kingdom); Sellami, S. [Swiss Seismological Service, ETH-Hoenggerberg, Zuerich (Switzerland); Bruestle, W. [Regierungspraesidium Freiburg, Abt. 9: Landesamt fuer Geologie, Rohstoffe und Bergbau, Ref. 98: Landeserdbebendienst, Freiburg im Breisgau (Germany)

    2009-05-15

    The seismic hazard model used in the PEGASOS project for assessing earth-quake hazard at four NPP sites was a composite of four sub-models, each produced by a team of three experts. In this paper, one of these models is described in detail by the authors. A criticism sometimes levelled at probabilistic seismic hazard studies is that the process by which seismic source zones are arrived at is obscure, subjective and inconsistent. Here, we attempt to recount the stages by which the model evolved, and the decisions made along the way. In particular, a macro-to-micro approach was used, in which three main stages can be described. The first was the characterisation of the overall kinematic model, the 'big picture' of regional seismo-genesis. Secondly, this was refined to a more detailed seismotectonic model. Lastly, this was used as the basis of individual sources, for which parameters can be assessed. Some basic questions had also to be answered about aspects of the approach to modelling to be used: for instance, is spatial smoothing an appropriate tool to apply? Should individual fault sources be modelled in an intra-plate environment? Also, the extent to which alternative modelling decisions should be expressed in a logic tree structure has to be considered. (author)

  7. A new view for the geodynamics of Ecuador: Implication in seismogenic source definition and seismic hazard assessment

    Science.gov (United States)

    Yepes, Hugo; Audin, Laurence; Alvarado, Alexandra; Beauval, Céline; Aguilar, Jorge; Font, Yvonne; Cotton, Fabrice

    2016-05-01

    A new view of Ecuador's complex geodynamics has been developed in the course of modeling seismic source zones for probabilistic seismic hazard analysis. This study focuses on two aspects of the plates' interaction at a continental scale: (a) age-related differences in rheology between Farallon and Nazca plates—marked by the Grijalva rifted margin and its inland projection—as they subduct underneath central Ecuador, and (b) the rapidly changing convergence obliquity resulting from the convex shape of the South American northwestern continental margin. Both conditions satisfactorily explain several characteristics of the observed seismicity and of the interseismic coupling. Intermediate-depth seismicity reveals a severe flexure in the Farallon slab as it dips and contorts at depth, originating the El Puyo seismic cluster. The two slabs position and geometry below continental Ecuador also correlate with surface expressions observable in the local and regional geology and tectonics. The interseismic coupling is weak and shallow south of the Grijalva rifted margin and increases northward, with a heterogeneous pattern locally associated to the Carnegie ridge subduction. High convergence obliquity is responsible for the North Andean Block northeastward movement along localized fault systems. The Cosanga and Pallatanga fault segments of the North Andean Block-South American boundary concentrate most of the seismic moment release in continental Ecuador. Other inner block faults located along the western border of the inter-Andean Depression also show a high rate of moderate-size earthquake production. Finally, a total of 19 seismic source zones were modeled in accordance with the proposed geodynamic and neotectonic scheme.

  8. A Fault-based Crustal Deformation Model for UCERF3 and Its Implication to Seismic Hazard Analysis

    Science.gov (United States)

    Zeng, Y.; Shen, Z.

    2012-12-01

    shear zone and northern Walker Lane. This implies a significant increase in seismic hazard in the eastern California and northern Walker Lane region, but decreased seismic hazard in the southern San Andreas area, relative to the current model used in the USGS 2008 seismic hazard map evaluation. Overall the geodetic model suggests an increase in total regional moment rate of 24% compared with the UCERF2 model and the 150-yr California earthquake catalog. However not all the increases are seismic so the seismic/aseismic slip rate ratios are critical for future seismic hazard assessment.

  9. Using CyberShake Workflows to Manage Big Seismic Hazard Data on Large-Scale Open-Science HPC Resources

    Science.gov (United States)

    Callaghan, S.; Maechling, P. J.; Juve, G.; Vahi, K.; Deelman, E.; Jordan, T. H.

    2015-12-01

    The CyberShake computational platform, developed by the Southern California Earthquake Center (SCEC), is an integrated collection of scientific software and middleware that performs 3D physics-based probabilistic seismic hazard analysis (PSHA) for Southern California. CyberShake integrates large-scale and high-throughput research codes to produce probabilistic seismic hazard curves for individual locations of interest and hazard maps for an entire region. A recent CyberShake calculation produced about 500,000 two-component seismograms for each of 336 locations, resulting in over 300 million synthetic seismograms in a Los Angeles-area probabilistic seismic hazard model. CyberShake calculations require a series of scientific software programs. Early computational stages produce data used as inputs by later stages, so we describe CyberShake calculations using a workflow definition language. Scientific workflow tools automate and manage the input and output data and enable remote job execution on large-scale HPC systems. To satisfy the requests of broad impact users of CyberShake data, such as seismologists, utility companies, and building code engineers, we successfully completed CyberShake Study 15.4 in April and May 2015, calculating a 1 Hz urban seismic hazard map for Los Angeles. We distributed the calculation between the NSF Track 1 system NCSA Blue Waters, the DOE Leadership-class system OLCF Titan, and USC's Center for High Performance Computing. This study ran for over 5 weeks, burning about 1.1 million node-hours and producing over half a petabyte of data. The CyberShake Study 15.4 results doubled the maximum simulated seismic frequency from 0.5 Hz to 1.0 Hz as compared to previous studies, representing a factor of 16 increase in computational complexity. We will describe how our workflow tools supported splitting the calculation across multiple systems. We will explain how we modified CyberShake software components, including GPU implementations and

  10. Integrating Caribbean Seismic and Tsunami Hazard into Public Policy and Action

    Science.gov (United States)

    von Hillebrandt-Andrade, C.

    2012-12-01

    processes. For example, earthquake and tsunami exercises are conducted separately, without taking into consideration the compounding effects. Recognizing this deficiency, the UNESCO IOC Intergovernmental Coordination Group for the Tsunami and other Coastal Hazards Warning System for the Caribbean and Adjacent Regions (CARIBE EWS) which was established in 2005, decided to include the tsunami and earthquake impacts for the upcoming March 20, 2013 regional CARIBE WAVE/LANTEX tsunami exercise. In addition to the tsunami wave heights predicted by the National Weather Service Tsunami Warning Centers in Alaska and Hawaii, the USGS PAGER and SHAKE MAP results for the M8.5 scenario earthquake in the southern Caribbean were also integrated into the manual. Additionally, in recent catastrophic planning for Puerto Rico, FEMA did request the local researchers to determine both the earthquake and tsunami impacts for the same source. In the US, despite that the lead for earthquakes and tsunamis lies within two different agencies, USGS and NOAA/NWS, it has been very beneficial that the National Tsunami Hazard Mitigation Program partnership includes both agencies. By working together, the seismic and tsunami communities can achieve an even better understanding of the hazards, but also foster more actions on behalf of government officials and the populations at risk.

  11. SCEC Community Modeling Environment (SCEC/CME) - Seismic Hazard Analysis Applications and Infrastructure

    Science.gov (United States)

    Maechling, P. J.; Jordan, T. H.; Kesselman, C.; Moore, R.; Minster, B.; SCEC ITR Collaboration

    2003-12-01

    The Southern California Earthquake Center (SCEC) has formed a Geoscience/IT partnership to develop an advanced information infrastructure for system-level earthquake science in Southern California. This SCEC/ITR partnership comprises SCEC, USC's Information Sciences Institute (ISI), the San Diego Supercomputer Center (SDSC), the Incorporated Institutions for Research in Seismology (IRIS), and the U.S. Geological Survey. This collaboration recently completed the second year in a five-year National Science Foundation (NSF) funded ITR project called the SCEC Community Modeling Environment (SCEC/CME). The goal of the SCEC/CME is to develop seismological applications and information technology (IT) infrastructure to support the development of Seismic Hazard Analysis (SHA) programs and other geophysical simulations. The SHA application programs developed by project collaborators include a Probabilistic Seismic Hazard Analysis system called OpenSHA [Field et al., this meeting]. OpenSHA computational elements that are currently available include a collection of attenuation relationships, and several Earthquake Rupture Forecasts (ERF's). Geophysicists in the collaboration have also developed Anelastic Wave Models (AWMs) using both finite-difference and finite-element approaches. Earthquake simulations using these codes have been run for a variety of earthquake sources. A Rupture Dynamic Model (RDM) has also been developed that couples a rupture dynamics simulation into an anelastic wave model. The collaboration has also developed IT software and hardware infrastructure to support the development, execution, and analysis of SHA programs. To support computationally expensive simulations, we have constructed a grid-based system utilizing Globus software [Kesselman et al., this meeting]. Using the SCEC grid, project collaborators can submit computations from the SCEC/CME servers to High Performance Computers at USC, NPACI and Teragrid High Performance Computing Centers. We have

  12. Optimizing CyberShake Seismic Hazard Workflows for Large HPC Resources

    Science.gov (United States)

    Callaghan, S.; Maechling, P. J.; Juve, G.; Vahi, K.; Deelman, E.; Jordan, T. H.

    2014-12-01

    The CyberShake computational platform is a well-integrated collection of scientific software and middleware that calculates 3D simulation-based probabilistic seismic hazard curves and hazard maps for the Los Angeles region. Currently each CyberShake model comprises about 235 million synthetic seismograms from about 415,000 rupture variations computed at 286 sites. CyberShake integrates large-scale parallel and high-throughput serial seismological research codes into a processing framework in which early stages produce files used as inputs by later stages. Scientific workflow tools are used to manage the jobs, data, and metadata. The Southern California Earthquake Center (SCEC) developed the CyberShake platform using USC High Performance Computing and Communications systems and open-science NSF resources.CyberShake calculations were migrated to the NSF Track 1 system NCSA Blue Waters when it became operational in 2013, via an interdisciplinary team approach including domain scientists, computer scientists, and middleware developers. Due to the excellent performance of Blue Waters and CyberShake software optimizations, we reduced the makespan (a measure of wallclock time-to-solution) of a CyberShake study from 1467 to 342 hours. We will describe the technical enhancements behind this improvement, including judicious introduction of new GPU software, improved scientific software components, increased workflow-based automation, and Blue Waters-specific workflow optimizations.Our CyberShake performance improvements highlight the benefits of scientific workflow tools. The CyberShake workflow software stack includes the Pegasus Workflow Management System (Pegasus-WMS, which includes Condor DAGMan), HTCondor, and Globus GRAM, with Pegasus-mpi-cluster managing the high-throughput tasks on the HPC resources. The workflow tools handle data management, automatically transferring about 13 TB back to SCEC storage.We will present performance metrics from the most recent Cyber

  13. Tsunami hazard assessment in El Salvador, Central America, from seismic sources through flooding numerical models.

    Science.gov (United States)

    Álvarez-Gómez, J. A.; Aniel-Quiroga, Í.; Gutiérrez-Gutiérrez, O. Q.; Larreynaga, J.; González, M.; Castro, M.; Gavidia, F.; Aguirre-Ayerbe, I.; González-Riancho, P.; Carreño, E.

    2013-11-01

    obtained with the high-resolution numerical modelling, being a good and fast approximation to obtain preliminary tsunami hazard estimations. In Acajutla and La Libertad, both important tourism centres being actively developed, flooding depths between 2 and 4 m are frequent, accompanied with high and very high person instability hazard. Inside the Gulf of Fonseca the impact of the waves is almost negligible.

  14. Tsunami hazard assessment in El Salvador, Central America, from seismic sources through flooding numerical models

    Directory of Open Access Journals (Sweden)

    J. A. Álvarez-Gómez

    2013-05-01

    with the high resolution numerical modelling, being a good and fast approximation to obtain preliminary tsunami hazard estimations. In Acajutla and La Libertad, both important tourism centres being actively developed, flooding depths between 2 and 4 m are frequent, accompanied with high and very high person instability hazard. Inside the Gulf of Fonseca the impact of the waves is almost negligible.

  15. The 24th January 2016 Hawassa earthquake: Implications for seismic hazard in the Main Ethiopian Rift

    Science.gov (United States)

    Wilks, Matthew; Ayele, Atalay; Kendall, J.-Michael; Wookey, James

    2017-01-01

    Earthquakes of low to intermediate magnitudes are a commonly observed feature of continental rifting and particularly in regions of Quaternary to Recent volcanism such as in the Main Ethiopian Rift (MER). Although the seismic hazard is estimated to be less in the Hawassa region of the MER than further north and south, a significant earthquake occurred on the 24th January 2016 in the Hawassa caldera basin and close to the Corbetti volcanic complex. The event was felt up to 100 km away and caused structural damage and public anxiety in the city of Hawassa itself. In this paper we first refine the earthquake's location using data from global network and Ethiopian network stations. The resulting location is at 7.0404°N, 38.3478°E and at 4.55 km depth, which suggests that the event occurred on structures associated with the caldera collapse of the Hawassa caldera in the early Pleistocene and not through volcano-tectonic processes at Corbetti. We calculate local and moment magnitudes, which are magnitude scales more appropriate at regional hypocentral distances than (mb) at four stations. This is done using a local scale (attenuation term) previously determined for the MER and spectral analysis for ML and MW respectively and gives magnitude estimates of 4.68 and 4.29. The event indicates predominantly normal slip on a N-S striking fault structure, which suggests that slip continues to occur on Wonji faults that have exploited weaknesses inherited from the preceding caldera collapse. These results and two previous earthquakes in the Hawassa caldera of M > 5 highlight that earthquakes continue to pose a risk to structures within the caldera basin. With this in mind, it is suggested that enhanced monitoring and public outreach should be considered.

  16. Flash Mob Science - Increasing Seismic Hazard Awareness and Preparedness in Oregon

    Science.gov (United States)

    Hoffman, J. S.; Lownsbery, D. S.

    2015-12-01

    Living in a region of imminent threat of a magnitude-9.0 (M­­­w ≈ ­9) earthquake is a daily reality for the millions of people predicted to be directly affected by a full rupture of the Cascadia Subduction Zone (CSZ), a fault line extending for hundreds of miles off the western coast of North America. Many coastal residents and visitors will also be affected by the tsunami caused by the rupture. How can the scientific community effectively communicate with those who are unaware of the threat and unprepared to respond? We are studying the effects of a novel approach to science outreach we have called Flash Mob Science. You have probably seen examples of flash mobs staging dynamic musical and dance routines to unsuspecting audiences. Similarly, Flash Mob Science takes the challenging (and often avoided) topic of earthquake and tsunami awareness and preparedness to unsuspecting audiences. However, Flash Mob Science seeks to move beyond having an audience of observers by engaging others as participants who enact important roles in an unfolding drama. We simulate the effects of seismic and tsunami events (e.g., prolonged surface shaking, falling debris, repeated tsunami surges) and model best practices in response (e.g., "Drop, Cover, Hold On" and moving quickly to high ground). True to the general flash mob model, when the Cascadia event inevitably does occur, it will come suddenly, and everyone affected will unavoidably be involved as actors in a real-life drama of immense scale. We seek to embed the learning of basic understandings and practices for an actual Cascadia event in a very small-scale, memorable, and sometimes even humorous, dramatization. We present here the lessons we have learned in the background, planning, and implementation of Flash Mob Science. We highlight the successes, limitations, and preliminary results evaluating the effectiveness of this outreach in developing learners' understandings and preparedness in an Oregon community affected by

  17. Study of seismic hazard mitigation at different time scales: applications and technological development

    OpenAIRE

    Caccavale, Mauro

    2011-01-01

    Earthquakes, weak or strong, represent always a psychological and emotional stress for people, but also a strong socio-economic impact for the affected area. The earthquake generation, the propagation of seismic waves, the seismic waves modification due to the propagation media and the interaction between seismic wave and human structures, are the main topics of different research disciplines. In the last years a wide interdisciplinary research program (physics, seismology, mathematics, geolo...

  18. Tsujal Marine Survey: Crustal Characterization of the Rivera Plate-Jalisco Block Boundary and its Implications for Seismic and Tsunami Hazard Assessment

    Science.gov (United States)

    Bartolome, R.; Danobeitia, J.; Barba, D. C., Sr.; Nunez-Cornu, F. J.; Cameselle, A. L.; Estrada, F.; Prada, M.; Bandy, W. L.

    2014-12-01

    During the spring of 2014, a team of Spanish and Mexican scientists explored the western margin of Mexico in the frame of the TSUJAL project. The two main objectives were to characterize the nature and structure of the lithosphere and to identify potential sources triggering earthquakes and tsunamis at the contact between Rivera plate-Jalisco block with the North American Plate. With these purposes a set of marine geophysical data were acquired aboard the RRS James Cook. This work is focus in the southern part of the TSUJAL survey, where we obtain seismic images from the oceanic domain up to the continental shelf. Thus, more than 800 km of MCS data, divided in 7 profiles, have been acquired with a 6km long streamer and using an air-gun sources ranging from 5800 c.i. to 3540 c.i. Furthermore, a wide-angle seismic profile of 190 km length was recorded in 16 OBS deployed perpendicular to the coast of Manzanillo. Gravity and magnetic, multibeam bathymetry and sub-bottom profiler data were recorded simultaneously with seismic data in the offshore area. Preliminary stacked MCS seismic sections reveal the crustal structure in the different domains of the Mexican margin. The contact between the Rivera and NA Plates is observed as a strong reflection at 6 s two way travel time (TWTT), in a parallel offshore profile (TS01), south of Manzanillo. This contact is also identified in a perpendicular profile, TS02, along a section of more than 100 km in length crossing the Rivera transform zone, and the plate boundary between Cocos and Rivera Plates. Northwards, offshore Pto. Vallarta, the MCS data reveals high amplitude reflections at around 7-8.5 s TWTT, roughly 2.5-3.5 s TWTT below the seafloor, that conspicuously define the subduction plane (TS06b). These strong reflections which we interpret as the Moho discontinuity define the starting bending of subduction of Rivera Plate. Another clear pattern observed within the first second of the MCS data shows evidences of a bottom

  19. GIS-based landslide hazard evaluation at the regional scale: some critical points in the permanent displacement approach for seismically-induced landslide maps

    Science.gov (United States)

    Vessia, Giovanna; Parise, Mario

    2013-04-01

    local practitioners. Seismically-induced landslide hazard maps have been drawn using the aforementioned three expressions. The preliminary results show Quaternary deposits (including alluvium deposits, slope wash, and terrace deposits) as the lithologies most affected by permanent displacement. Moreover, Towsley and Modelo formations, that are stiffer than the previous rock units, and consist mostly of shales, siltstones and subordinate sandstones, show high hazard value where the slopes increase. The relevant role of local slope in permanent displacement extent is evident where lithologies are characterized by both cohesive and frictional resistance components. Finally, a comparison among the maps produced by using the three expressions for permanent displacements is discussed. References Ambraseys N.N. and Menu J.M. (1988) Earthquake-induced ground displacements. Earthquake Engineering and Structural Dynamics, 16: 985-1006. Harp E.L. and Jibson R.W. (1995) Inventory of landslides triggered by the 1994 Northridge, California earthquake. US Geol. Surv. Open-File Rep. 95-213 17 pp. Jibson R. (2007) Regression models for estimating coseismic landslide displacement. Engineering Geology, 91: 209-218. Luzi L. and Pergalani F. (2000) A correlation between slope failures and accelerometric parameters: the 26 September 1997 earthquake (Umbria-Marche, Italy). Soil Dynamics and Earthquake Engineering, 20: 301-313. Newmark N.M. (1965) Effects of earthquakes on dams and embankments. Geotechnique 965, 15(2): 139-160. Parise M. and Jibson R.W. (2000) A seismic landslide susceptibility rating of geologic units based on analysis of characteristics of landslides triggered by the 17 January, 1994 Northridge, California earthquake. Engineering Geology, 58: 251-270. Romeo R. (2000) Seismically induced landslide displacements: a predictive model. Engineering Geology, 58: 337-351.

  20. A Case Study of Geologic Hazards Affecting School Buildings: Evaluating Seismic Structural Vulnerability and Landslide Hazards at Schools in Aizawl, India

    Science.gov (United States)

    Perley, M. M.; Guo, J.

    2016-12-01

    India's National School Safety Program (NSSP) aims to assess all government schools in earthquake prone regions of the country. To supplement the Mizoram State Government's recent survey of 141 government schools, we screened an additional 16 private and 4 government schools for structural vulnerabilities due to earthquakes, as well as landslide hazards, in Mizoram's capital of Aizawl. We developed a geomorphologically derived landslide susceptibility matrix, which was cross-checked with Aizawl Municipal Corporation's landslide hazard map (provided by Lettis Consultants International), to determine the geologic hazards at each school. Our research indicates that only 7% of the 22 assessed school buildings are located within low landslide hazard zones; 64% of the school buildings, with approximately 9,500 students, are located within very high or high landslide hazard zones. Rapid Visual Screening (RVS) was used to determine the structural earthquake vulnerability of each school building. RVS is an initial vulnerability assessment procedure used to inventory and rank buildings that may be hazardous during an earthquake. Our study indicates that all of the 22 assessed school buildings have a damageability rating of Grade 3 or higher on the 5-grade EMS scale, suggesting a significant vulnerability and potential for damage in buildings, ranging from widespread cracking of columns and beam column joints to collapse. Additionally, 86% of the schools we visited had reinforced concrete buildings constructed before Aizawl's building regulations were passed in 2007, which can be assumed to lack appropriate seismic reinforcement. Using our findings, we will give recommendations to the Government of Mizoram to prevent unnecessary loss of life by minimizing each school's landslide risk and ensuring schools are earthquake-resistant.

  1. Implementation of NGA-West2 ground motion models in the 2014 U.S. National Seismic Hazard Maps

    Science.gov (United States)

    Rezaeian, Sanaz; Petersen, Mark D.; Moschetti, Morgan P.; Powers, Peter; Harmsen, Stephen C.; Frankel, Arthur D.

    2014-01-01

    The U.S. National Seismic Hazard Maps (NSHMs) have been an important component of seismic design regulations in the United States for the past several decades. These maps present earthquake ground shaking intensities at specified probabilities of being exceeded over a 50-year time period. The previous version of the NSHMs was developed in 2008; during 2012 and 2013, scientists at the U.S. Geological Survey have been updating the maps based on their assessment of the “best available science,” resulting in the 2014 NSHMs. The update includes modifications to the seismic source models and the ground motion models (GMMs) for sites across the conterminous United States. This paper focuses on updates in the Western United States (WUS) due to the use of