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1
Rajaure, Sudhir, and Lalu Prasad Paudel. "A comprehensive earthquake catalogue for Nepal and its adjoining region." Journal of Nepal Geological Society 56, no. 1 (June 28, 2018): 65–72. http://dx.doi.org/10.3126/jngs.v56i1.22747.
Повний текст джерелаАнотація:
We have prepared a comprehensive earthquake catalogue for Nepal and its adjoining region. The catalogue contains magnitude - homogenized independent earthquakes of magnitude (Mw) between 4.0 and 8.5, which occurred between 1100 AD and 2018 AD. The catalogue contains date, time, latitude, longitude, depth, and magnitude of earthquakes, which are required in the study of seismic activity, tectonics and seismic hazard. Primary earthquake catalogues were collected from the International Seismological Centre (ISC, 2015), United States Geological Survey (USGS), which contain instrumentally recorded earthquake data and date back to 1900 AD. These primary catalogues of instrumentally recorded earthquakes were supplemented by historical earthquakes reported in published literatures, which occurred before 1900 AD. The collected primary catalogues were compiled and processed to develop a comprehensive catalogue. The developed comprehensive catalogue is expected to serve as a basic database for the study of seismic activity and seismic hazard in Nepal and its adjacent area.
2
Silva, Pablo G., Miguel A. Rodríguez-Pascua, Jorge L. Giner Robles, Javier Élez, Raúl Pérez-López, and M. Begoña Bautista Davila. "Catalogue of the Geological Effects of Earthquakes in Spain Based on the ESI-07 Macroseismic Scale: A New Database for Seismic Hazard Analysis." Geosciences 9, no. 8 (July 29, 2019): 334. http://dx.doi.org/10.3390/geosciences9080334.
Повний текст джерелаАнотація:
This paper summarizes the content and scope of the “Catalogue of Earthquake Geological Effects in Spain”. The catalogue has been published by the Geological Survey of Spain (IGME) and constitutes the first official publication (in Spain) on seismic hazard containing geological information. The catalogue gathers the 51 stronger earthquakes that have occurred in Spain since the Neolithic period to the present and classifies earthquakes with geological or archaeological seismic records in paleoseismic, ancient, historical and instrumental earthquakes. The catalogue offers a variety of parametric information, quality indexes (Qe, Qi, Qg), and Environmental Seismic Intensity Scale (ESI-07) based description of environmental damage structured in individual “event files”. Sixteen of the 51 catalogued events present full information files (full event files), with individualized analyses of the geological and geoarchaeological data as well as graphic information with hybrid ESI-EMS intensity maps, ShakeMaps (seismic scenarios) and complementary kmz files (Google Earth) for each of the sixteen selected earthquakes; among which is the well-known AD 1755 Lisbon earthquake-tsunami. These selected earthquakes present individual environmental earthquake effects (EEE) or earthquake archaeoseismological effects (EAE) files for each catalogued effect containing specific site geo-information and graphic data (photos, graphs, maps, etc.). The second edition of the catalogue record 1027 EEEs and 187 EAEs, of which 322 effects have individual files.
3
Ghayournajarkar, Nematollah, and Yo Fukushima. "Using InSAR for evaluating the accuracy of locations and focal mechanism solutions of local earthquake catalogues." Geophysical Journal International 230, no. 1 (February 24, 2022): 607–22. http://dx.doi.org/10.1093/gji/ggac072.
Повний текст джерелаАнотація:
SUMMARY Earthquake source parameters play a fundamental role in evaluating seismic hazard. In many countries, the relatively low accuracy of the earthquake source parameters owing to sparse seismic monitoring networks prevents accurate seismic hazard evaluation. Interferometric Synthetic Aperture Radar (InSAR) is a useful tool for accurate fault parameter determination of shallow inland earthquakes. We compared the fault parameters (location and rupture geometry) derived from InSAR with those derived from local and global seismic data to assess the credibility of the earthquake catalogues. We set our targets to Iran and Japan, where seismic networks are relatively sparse and dense, respectively, and analysed a total of 10 shallow inland earthquakes. To compare the fault parameters for each studied earthquake, we first created interferograms using InSAR data from multiple satellites and conducted fault model inversions assuming uniform slip on a rectangular finite fault. For the studied Iranian earthquakes, the epicentres of the United States Geological Survey (USGS) catalogue were more consistent with the InSAR-derived fault model compared to those of the local catalogue of the Iranian Seismological Center (IRSC). For the studied Japanese earthquakes, the epicentres of the Japan Meteorological Agency (JMA) catalogue were more consistent with the InSAR-derived fault model compared to those of the USGS. Assuming that the accuracy of the USGS locations is comparable for the two countries, the JMA catalogue has a higher accuracy than the IRSC catalogue. The difference in the accuracy for the two local catalogues can be explained by the larger azimuthal gaps of the IRSC seismic network. We also showed that the IRSC- and JMA-derived centroids were more consistent with the InSAR-derived fault model compared to those of the Global Centroid Moment Tensor (GCMT) catalogue. The focal mechanism solutions derived from InSAR and seismic CMT solutions were significantly different, highlighting the difficulties in determining the focal mechanism parameters from seismic data, even when the seismic station coverage is dense. As InSAR data can be easily accessed, this study presents a cost-effective method to assess and improve the accuracy of the local earthquake catalogues anywhere in the world.
4
Tan, Fengzhou, Honn Kao, Edwin Nissen, and Ryan Visser. "Tracking earthquake sequences in real time: application of Seismicity-Scanning based on Navigated Automatic Phase-picking (S-SNAP) to the 2019 Ridgecrest, California sequence." Geophysical Journal International 223, no. 3 (August 17, 2020): 1511–24. http://dx.doi.org/10.1093/gji/ggaa387.
Повний текст джерелаАнотація:
SUMMARY Recent improvements in seismic data processing techniques have enhanced our ability to detail the evolution of major earthquake sequences in space and time. One such advance is new scanning algorithms that allow large volumes of waveform data to be analysed automatically, removing human biases and inefficiencies that inhibit standardized monitoring. The Seismicity-Scanning based on Navigated Automatic Phase-picking (S-SNAP) workflow has previously been shown to be capable of producing high-quality earthquake catalogues for injection-induced seismicity monitoring. In this study, we modify the original S-SNAP workflow to enable it to delineate the spatiotemporal distribution of major earthquake sequences in real time. We apply it to the 2019 Ridgecrest, southern California earthquake sequence, which culminated in an Mw 6.4 foreshock on July 4 and an Mw 7.1 main shock on July 6 and generated tens of thousands of smaller earthquakes. Our catalogue—which spans the period 2019 June 1 to July 16—details the spatiotemporal evolution of the sequence, including early foreshocks on July 1 and accelerating foreshocks on July 4, a seismicity gap before the main shock around its epicentre, seismicity on discrete structures within a broad fault zone and triggered earthquakes outside the main fault zone. We estimate the accuracy and false detection rate of the S-SNAP catalogue based on the reviewed catalogue reported by Southern California Seismic Network (SCSN) and our own visual inspection. We demonstrate the advantages of S-SNAP over a generalized automatic earthquake monitoring software, Seiscomp3, and a customized real-time earthquake information system for southern California, TriNet. In comparison, the S-SNAP catalogue contains five times more events than the Seiscomp3 catalogue and 1.4–2.2 times as many events per hour as the TriNet catalogue at most times. In addition, S-SNAP is more likely to solve phase association ambiguities correctly and provide a catalogue with consistent quality through time. S-SNAP would be beneficial to both routine network operations and the earthquake review process.
5
Rhoades, David A., Sepideh J. Rastin, and Annemarie Christophersen. "A 20-Year Journey of Forecasting with the “Every Earthquake a Precursor According to Scale” Model." Geosciences 12, no. 9 (September 19, 2022): 349. http://dx.doi.org/10.3390/geosciences12090349.
Повний текст джерелаАнотація:
Nearly 20 years ago, the observation that major earthquakes are generally preceded by an increase in the seismicity rate on a timescale from months to decades was embedded in the “Every Earthquake a Precursor According to Scale” (EEPAS) model. EEPAS has since been successfully applied to regional real-world and synthetic earthquake catalogues to forecast future earthquake occurrence rates with time horizons up to a few decades. When combined with aftershock models, its forecasting performance is improved for short time horizons. As a result, EEPAS has been included as the medium-term component in public earthquake forecasts in New Zealand. EEPAS has been modified to advance its forecasting performance despite data limitations. One modification is to compensate for missing precursory earthquakes. Precursory earthquakes can be missing because of the time-lag between the end of a catalogue and the time at which a forecast applies or the limited lead time from the start of the catalogue to a target earthquake. An observed space-time trade-off in precursory seismicity, which affects the EEPAS scaling parameters for area and time, also can be used to improve forecasting performance. Systematic analysis of EEPAS performance on synthetic catalogues suggests that regional variations in EEPAS parameters can be explained by regional variations in the long-term earthquake rate. Integration of all these developments is needed to meet the challenge of producing a global EEPAS model.
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Kagan, Y. Y. "Distribution of incremental static stress caused by earthquakes." Nonlinear Processes in Geophysics 1, no. 2/3 (September 30, 1994): 172–81. http://dx.doi.org/10.5194/npg-1-172-1994.
Повний текст джерелаАнотація:
Abstract. Theoretical calculations, simulations and measurements of rotation of earthquake focal mechanisms suggest that the stress in earthquake focal zones follows the Cauchy distribution which is one of the stable probability distributions (with the value of the exponent α equal to 1). We review the properties of the stable distributions and show that the Cauchy distribution is expected to approximate the stress caused by earthquakes occurring over geologically long intervals of a fault zone development. However, the stress caused by recent earthquakes recorded in instrumental catalogues, should follow symmetric stable distributions with the value of α significantly less than one. This is explained by a fractal distribution of earthquake hypocentres: the dimension of a hypocentre set, δ, is close to zero for short-term earthquake catalogues and asymptotically approaches 2¼ for long-time intervals. We use the Harvard catalogue of seismic moment tensor solutions to investigate the distribution of incremental static stress caused by earthquakes. The stress measured in the focal zone of each event is approximated by stable distributions. In agreement with theoretical considerations, the exponent value of the distribution approaches zero as the time span of an earthquake catalogue (ΔT) decreases. For large stress values α increases. We surmise that it is caused by the δ increase for small inter-earthquake distances due to location errors.
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Jónasson, Kristján, Bjarni Bessason, Ásdís Helgadóttir, Páll Einarsson, Gunnar B. Guðmundsson, Bryndís Brandsdóttir, Kristín S. Vogfjörd, and Kristín Jónsdóttir. "A harmonised instrumental earthquake catalogue for Iceland and the northern Mid-Atlantic Ridge." Natural Hazards and Earth System Sciences 21, no. 7 (July 21, 2021): 2197–214. http://dx.doi.org/10.5194/nhess-21-2197-2021.
Повний текст джерелаАнотація:
Abstract. A comprehensive catalogue of historical earthquakes, with accurate epicentres and harmonised magnitudes is a crucial resource for seismic hazard mapping. Here we update and combine catalogues from several sources to compile a catalogue of earthquakes in and near Iceland, in the years 1900–2019. In particular the epicentres are based on local information, whereas the magnitudes are based on teleseismic observations, primarily from international online catalogues. The most reliable epicentre information comes from the catalogue of the Icelandic Meteorological Office, but this is complemented with information from several technical reports, scientific publications, and newspaper articles. The catalogue contains 1281 moment magnitude (Mw) ≥4 events, and the estimated completeness magnitude is Mw 5.5 in the first years, going down to Mw 4.5 for recent years. The largest magnitude is Mw 7.0. Such merging of local data and teleseismic catalogues has not been done before for Icelandic earthquakes, and the result is an earthquake map with much more accurate locations than earlier maps. The catalogue also lists 5640 additional earthquakes on the Mid-Atlantic Ridge, north of 43∘, with both epicentres and magnitudes determined teleseismically. When moment magnitudes are not available, proxy Mw values are computed using χ2 regression, normally on the surface-wave magnitude but exceptionally on the body-wave magnitude. Magnitudes of Mw≥4.5 have associated uncertainty estimates. The actual combined seismic moment released in the Icelandic earthquakes is found to be consistent with the moment estimated using a simple plate motion model, indicating that the seismic activity of the catalogue period might be typical of any 120-year time span. The catalogue is named ICEL-NMAR, and it is available online at http://data.mendeley.com (last access: 19 July 2021).
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Rovida, Andrea, Andrea Antonucci, and Mario Locati. "The European Preinstrumental Earthquake Catalogue EPICA, the 1000–1899 catalogue for the European Seismic Hazard Model 2020." Earth System Science Data 14, no. 12 (November 30, 2022): 5213–31. http://dx.doi.org/10.5194/essd-14-5213-2022.
Повний текст джерелаАнотація:
Abstract. The European PreInstrumental Earthquake CAtalogue (EPICA) (Rovida and Antonucci, 2021; https://doi.org/10.13127/epica.1.1) is the 1000–1899 seismic catalogue compiled for the European Seismic Hazard Model 2020 (ESHM20), an outcome of the project Seismology and Earthquake Engineering Research Infrastructure Alliance for Europe (SERA), in the framework of the European Union's Horizon 2020 research and innovation programme. EPICA is the update of the SHARE European Earthquake Catalogue (SHEEC) 1000–1899, with which it shares the main principles – mostly transparency, repeatability and continent-wide harmonisation of data – as well as the compilation strategies and methods. Version 1.1 of EPICA contains 5703 earthquakes with either maximum intensity ≥5 or Mw≥4.0, with a spatial coverage from the Atlantic Ocean to the west to 32∘ E in longitude, and from the Mediterranean Sea to Northern Europe. EPICA relies upon the updated knowledge of the European preinstrumental seismicity provided by the data gathered in the European Archive of Historical Earthquake Data (AHEAD). Such data are both macroseismic intensity data supplied by descriptive historical seismological studies and online macroseismic databases, and parameters contained in regional catalogues. As done for the compilation of SHEEC 1000–1899, these datasets were thoroughly analysed in order to select the most representative of the knowledge of each earthquake, independently from national constraints. Selected intensity distributions are processed with three methods to determine location and magnitude based on the attenuation of macroseismic intensity and are combined with parameters harmonised from modern regional catalogues. This paper describes the compilation procedure of EPICA version 1.1, its input data, the assessment of the earthquake parameters and the resulting catalogue, which is finally compared with its previous version. Technical solutions for accessing the catalogue, both as downloadable files and through web services, are also illustrated.
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Pailoplee, Santi. "Earthquake Catalogue of the Thailand Meteorological Department — A Commentary." Journal of Earthquake and Tsunami 08, no. 05 (December 2014): 1471001. http://dx.doi.org/10.1142/s1793431114710018.
Повний текст джерелаАнотація:
In this study, I investigated qualitatively the earthquake catalogue of the Thai Meteorological Department (TMD), Thailand, with respect to the seismicity patterns of Thailand. The readymade relationships between the different magnitude scales were derived to allow their convenient interconversion. Earthquake declustering was performed in order to screen the main shocks from the foreshocks and aftershocks, reducing the 1998–2009 records from ~48,900 to 2,620 main events. Man-made changes in the seismicity rate were carefully checked for, but only some minor changes were found and these were not related to any network improvements. In order to assess the limit of the earthquake detection in the catalogue the criterion of the magnitude of completeness (Mc) was employed, revealing a high efficiency of earthquake detection at a low Mc (3.0–3.5 Mw), especially for the inland active fault zone that dominates in Southeast Asia. Thus, the TMD's catalogue is one of the alternative catalogues for seismicity investigation of inland earthquakes. Meanwhile for the area surrounding the Sumatra Island and Northern Myanmar, the TMD's network is sufficient only for earthquakes with a Mw > 5.4–6.0 Mw. Thus, some additional seismic recording stations are needed in the Southern and Northern parts of Thailand.
10
Bayliss, T. J., and P. W. Burton. "A new earthquake catalogue for Bulgaria and the conterminous Balkan high hazard region." Natural Hazards and Earth System Sciences 7, no. 3 (May 10, 2007): 345–59. http://dx.doi.org/10.5194/nhess-7-345-2007.
Повний текст джерелаАнотація:
Abstract. A new homogenous earthquake catalogue covering Bulgaria and the surrounding Balkan area has been created with intention of performing a consistent seismic hazard assessment across the region. In keeping with modern requirements of cataloguing seismicity, this catalogue has been made homogenous as far as possible with regards to magnitude, which has been provided on any of four different reported scales for each event; mb, Ms, Mw and ML. A key historical catalogue for the region has been used to represent the early instrumental period of earthquake recording (1900 to 1963), whilst data have been obtained from the International Seismological Centre (ISC), National Earthquake Information Center (NEIC) and National Observatory of Athens (NOA) to cover the instrumental period of earthquake recording (1964 to 2004). ISC data have also been used to develop a new mb→Ms magnitude conversion equation for the catalogued region. Application of this new magnitude conversion relation, in combination with other selected magnitude scale correlations, ensures reported magnitudes can be systematically rendered onto homogenized Ms and Mw scales for all earthquakes. This catalogue contains 3681 events with homogenized magnitudes ≥4.0 Mw, for the time interval 1900 to 2004 (inclusive), located in the region bounded by 39°–45° N, 19°–29° E, at focal depths of 0.0 km to 401.0 km and in a magnitude range 4.0≤Mw≤7.2. Selected large magnitude (M≥6.0 Ms) earthquakes have had their reported magnitudes reassessed – and adjusted if necessary – in light of work by other authors. Applied statistical approaches aimed at determining the lower threshold to magnitude completeness suggest this catalogue is complete down to a homogenized surface-wave magnitude of 4.6 Ms.
11
Tan, Onur. "A homogeneous earthquake catalogue for Turkey." Natural Hazards and Earth System Sciences 21, no. 7 (July 8, 2021): 2059–73. http://dx.doi.org/10.5194/nhess-21-2059-2021.
Повний текст джерелаАнотація:
Abstract. A new homogenized earthquake catalogue for Turkey is compiled for the period 1900–2018. The earthquake parameters are obtained from the Bulletin of International Seismological Centre that was fully updated in 2020. New conversion equations between moment magnitude and the other scales (md, ML, mb, Ms, and M) are determined using the general orthogonal regression method to build up a homogeneous catalogue, which is the essential database for seismic hazard studies. The 95 % confidence intervals are estimated using the bootstrap method with 1000 samples. The equivalent moment magnitudes (Mw*) for the entire catalogue are calculated using the magnitude relations to homogenize the catalogue. The magnitude of completeness is 2.7 Mw*. The final catalogue is not declustered or truncated using a threshold magnitude in order to be a widely usable catalogue. It contains not only Mw* but also the average and median of the observed magnitudes for each event. Contrary to the limited earthquake parameters in the previous catalogues for Turkey, the 45 parameters of ∼378 000 events are presented in this study.
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Cajamarca-Zuniga, David, Oleg Vasil'evich Kabantsev, and Christopher Marin. "Macroseismic intensity-based catalogue of earthquakes in Ecuador." Structural Mechanics of Engineering Constructions and Buildings 18, no. 2 (July 20, 2022): 161–71. http://dx.doi.org/10.22363/1815-5235-2022-18-2-161-171.
Повний текст джерелаАнотація:
Earthquake magnitude catalogues and peak ground acceleration (PGA) maps for Ecuador may be found in several studies, however, there are rare works on the characterisation of the epicentral macroseismic intensities associated with earthquakes. In view of the concept that macroseismic intensity enables us to categorise the extent and severity of damage to buildings and structures caused by an earthquake, this study aims to compile a macro-seismic intensity-based catalogue of earthquakes in Ecuador, characterise the epicentral macroseismic intensities associated to seismogenic sources and perform a comparison with the National Seismic Hazard Map. This paper is the first that presents a catalogue of earthquakes with macroseismic intensities ≥VII and a series of maps of earthquake epicentres according to intensity, focal depth, data and magnitude of seismic events in Ecuador, based on the study of historical and instrumental records from 1900 to 2021. The obtained data shows that 95% of the territory of Ecuador has a PGA 0.1 g, which corresponds to seismic intensities greater than VII, while regions with seismicityVIII (ag = 0.2 g) constitute 86%, and 3.8% of the territory of Ecuador has very high seismicity (IX), where the PGA exceeds 0.5 g. This information suggests that the normative National Seismic Hazard Map of Ecuador underestimate the hazard mainly in the south-east and in the Central Andes of Ecuador, and require an actualization.
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Braclawska, Agnieszka, and Adam Filip Idziak. "Unification of data from various seismic catalogues to study seismic activity in the Carpathians Mountain arc." Open Geosciences 11, no. 1 (November 30, 2019): 837–42. http://dx.doi.org/10.1515/geo-2019-0065.
Повний текст джерелаАнотація:
Abstract The Carpathian Mountainsarc is the most seismically active area in Central Europe. Analysis of the seismicity of entire Carpathian arc requires data from each of the particular catalogues which have to be properly and uniformly entered, standardized and merged. For our study we first had to prepare a database of seismic events (ML ≥ 1.6) compiled from the data of earthquakes taken from individual national seismic networks as well as data from international seismic centers. However, a careful review of these catalogues has uncovered significant inconsistencies, particularly discrepancies in the description of the location, magnitude and completeness of seismic events. To address these inconsistencies, a newly created compound earthquake catalogue was compiled from the aforementioned seismic catalogues and included events that occurred in the Carpathian Mountains arc area between 1976 and 2017. This work is intended to point out some of the problems associated with collecting data from various seismic catalogues as well as the need for their very careful verification, in order to create a uniform set of seismic data across a large area spanning numerous countries. The results suggest that compiling a uniform and dependable earthquake catalogue is crucial for reliable seismic studies.
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Allen, Trevor I. "A pragmatic approach to adjusting early instrumental local magnitudes for seismic hazard assessments in Australia." Journal of Seismology 25, no. 3 (May 1, 2021): 899–920. http://dx.doi.org/10.1007/s10950-021-10004-5.
Повний текст джерелаАнотація:
AbstractPrior to the development of Australian-specific magnitude formulae, the 1935 magnitude correction factors by Charles Richter—originally developed for southern California—were almost exclusively used to calculate earthquake magnitudes throughout Australia prior to the 1990s. Due to the difference in ground-motion attenuation between southern California and much of the Australian continent, many earthquake magnitudes from the early instrumental era are likely to have been overestimated in the Australian earthquake catalogue. A method is developed that adjusts local magnitudes (ML) using the difference between the original (inappropriate) magnitude formulae (or look-up tables) and the Australian-specific formulae at a distance determined by the nearest recording station likely to have recorded the earthquake. Nationally, these adjustments have reduced the number of earthquakes of ML ≥ 4.5 in the early instrumental catalogue by approximately 25% since 1900, while the number of ML ≥ 5.0 earthquakes has reduced by approximately 32% over the same time period. The reduction in the number of moderate-to-large-magnitude earthquakes over the instrumental period yields long-term earthquake rates that are more consistent with present-day rates, since the development of Australian-specific magnitude formulae (approximately 1990). The adjustment of early instrumental magnitudes to obtain consistently derived earthquake catalogue is important for seismic hazard assessments.
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Chin, Su Na, Tongkul Felix, Zaturrawiah A. Omar, and Roslee Rodeano. "Nowcasting Earthquake Occurrence in Sabah." IOP Conference Series: Earth and Environmental Science 1103, no. 1 (November 1, 2022): 012041. http://dx.doi.org/10.1088/1755-1315/1103/1/012041.
Повний текст джерелаАнотація:
In line with the increasing availability of seismic data, nowcasting method provides a systematic way to depict the current state of earthquake hazard within a specific geographic area. This paper implements nowcasting method to statistically assess the earthquake progression in Sabah region over the large earthquakes cycle. The analysis includes earthquake data in the state of Sabah and the surrounding regions, which is acquired from Malaysia Meteorological Department catalogue and United States Geological Survey (USGS) catalogue from year 2009 to 2018. This study discovered that EPS corresponding to M ≥ 4 events in Ranau and Lahad Datu reach about 92% and 97%, respectively. These findings indicate that both areas are in the last quarter way through their cycle to magnitude 4.0 or larger earthquakes.
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Bayliss, Kirsty, Mark Naylor, Farnaz Kamranzad, and Ian Main. "Pseudo-prospective testing of 5-year earthquake forecasts for California using inlabru." Natural Hazards and Earth System Sciences 22, no. 10 (October 7, 2022): 3231–46. http://dx.doi.org/10.5194/nhess-22-3231-2022.
Повний текст джерелаАнотація:
Abstract. Probabilistic earthquake forecasts estimate the likelihood of future earthquakes within a specified time-space-magnitude window and are important because they inform planning of hazard mitigation activities on different time scales. The spatial component of such forecasts, expressed as seismicity models, generally relies upon some combination of past event locations and underlying factors which might affect spatial intensity, such as strain rate, fault location and slip rate or past seismicity. For the first time, we extend previously reported spatial seismicity models, generated using the open source inlabru package, to time-independent earthquake forecasts using California as a case study. The inlabru approach allows the rapid evaluation of point process models which integrate different spatial datasets. We explore how well various candidate forecasts perform compared to observed activity over three contiguous 5-year time periods using the same training window for the input seismicity data. In each case we compare models constructed from both full and declustered earthquake catalogues. In doing this, we compare the use of synthetic catalogue forecasts to the more widely used grid-based approach of previous forecast testing experiments. The simulated catalogue approach uses the full model posteriors to create Bayesian earthquake forecasts, not just the mean. We show that simulated catalogue based forecasts perform better than the grid-based equivalents due to (a) their ability to capture more uncertainty in the model components and (b) the associated relaxation of the Poisson assumption in testing. We demonstrate that the inlabru models perform well overall over various time periods: The full catalogue models perform favourably in the first testing period (2006–2011) while the declustered catalogue models perform better in the 2011–2016 testing period, with both sets of models performing less well in the most recent (2016–2021) testing period. Together, these findings demonstrate a significant improvement in earthquake forecasting is possible although this has yet to be tested and proven in true prospective mode.
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Pődor, Andrea, and Marta Kiszely. "EXPERIMENTAL INVESTIGATION OF VISUALI ZATION METHODS OF EARTH QUAKE CATALOGUE MAPS." Geodesy and cartography 40, no. 4 (December 16, 2014): 156–62. http://dx.doi.org/10.3846/20296991.2014.987451.
Повний текст джерелаАнотація:
The aim of the study is to find possible solutions to represent earthquake catalogue data and design maps which can help non-professionals to identify those places where earthquakes occurred frequently. The goal is to visualize all available catalogue data sets in a complex way on a single map, displaying the long-term recurrence times of earthquakes. Therefore, raw data and aggregated data were combined with different cartographic visualization techniques to test the applicability of earthquake maps. Preliminary research demonstrates that aggregation can improve the process of retrieving information from earthquake maps and 3D visualization is useful to find the places of earthquakes of highest magnitude. A second result is that 3D visualization is not effective in the comparison of quantities of released energy and the number of earthquakes.
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Taroni, Matteo, and Aybige Akinci. "Good practices in PSHA: declustering, b-value estimation, foreshocks and aftershocks inclusion; a case study in Italy." Geophysical Journal International 224, no. 2 (September 25, 2020): 1174–87. http://dx.doi.org/10.1093/gji/ggaa462.
Повний текст джерелаАнотація:
SUMMARY The classical procedure of the probabilistic seismic hazard analysis (PSHA) requires a Poissonian distribution of earthquakes. Seismic catalogues follow a Poisson distribution just after the application of a declustering algorithm that leaves only one earthquake for each seismic sequence (usually the stronger, i.e. the main shock). Removing earthquakes from the seismic catalogues leads to underestimation of the annual rates of the events and consequently associate with low seismic hazard as indicated by several studies. In this study, we aim investigating the performance of two declustering methods on the Italian instrumental catalogue and the impact of declustering on estimation of the b-value and on the seismic hazard analysis. To this end, first the spatial variation in the seismicity rate was estimated from the declustered catalogues using the adaptive smoothed seismicity approach, considering small earthquakes (Mw ≥ 3.0). We then corrected the seismicity rates using new approach that allows for counting all events in the complete seismic catalogue by simply changing the magnitude frequency distribution. The impact of declustering on seismic hazard analysis is illustrated using PSHA maps in terms of peak ground acceleration and spectral acceleration in 2 s, with 10 per cent and 2 per cent probability of exceedance in 50 yr, for Italy. We observed that the hazard calculated from the declustered catalogues was always lower than the hazard computed using the complete catalogue. These results are in agreement with previous results obtained in different parts of the world.
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Chebrov, D., A. Chebrova, I. Abubakirov, E. Matveenko, S. Mityushkina, V. Pavlov, V. Saltikov, P. Voropaev, and S. Droznina. "KAMCHATKA AND COMMANDER ISLANDS." Earthquakes in Northern Eurasia, no. 23 (December 15, 2020): 172–82. http://dx.doi.org/10.35540/1818-6254.2020.23.16.
Повний текст джерелаАнотація:
The seismicity review of Kamchatka and surrounding territories for 2014 is given. In Kamchatka earthquake catalogue minimum local magnitude of completeness is MLmin=3.5, and for earthquakes under the Okhotsk sea with h≥350 kmMLmin=3.6. The Kamchatka earthquake catalogue for 2014 with ML3.5, published in the Appendix to this annual, includes 1114 events. 86 earthquakes of the catalogue with ML=3.35–6.2 were felt in Kamchatka and surrounding areas with seismic intensity I ranged from 2 to 5 according the MSK-64 scale. For all events with ML5.0 occurred in the area of responsibility of the KB GS RAS in 2014, an attempt to calculate the seismic moment tensor (SMT) was made. There are 40 such events in the regional catalogue. For 36 earthquakes, the SMT and depth h of the equivalent point source were calculated successfully. The calcu-lations were performed for the SMT double-couple model using a nonlinear algorithm. In 2014, a typical location of the earthquake epicenters was observed in the Kamchatka zone. In 2014, the seismicity level in all selected zones and in the region as a whole corresponded to the background one according to the “SESL’09” scale. The number of recorded events with ML3.6 and strong earthquakes with ML5.1 is close to the average annual value. Anomalous and outstanding events were not recorded.
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Chebrov, D., V. Saltikov, E. Matveenko, S. Droznina, E. Romasheva, S. Mityushkina, I. Abubakirov, and V. Pavlov. "SEISMICITY of KAMCHATKA and COMMANDER ISLANDS in 2015." Earthquakes in Northern Eurasia, no. 24 (December 14, 2021): 153–63. http://dx.doi.org/10.35540/1818-6254.2021.24.14.
Повний текст джерелаАнотація:
The seismicity review of Kamchatka and surrounding territories for 2015 is given. In the Kamchatka earthquake catalogue, the minimum local magnitude of completeness is MLmin=3.5, and for earthquakes with h≥350 km under the Okhotsk sea MLmin=3.6. The Kamchatka earthquake catalogue for 2015 with ML3.5, published in the Appendix to this issue, includes 1213 events. 92 earthquakes of the catalogue with ML=3.0–6.5 were felt in Kamchatka and surrounding areas with seismic intensity I=2–6 according to the MSK-64 scale. For all events with ML5.0 that occurred in 2015 in the KB GS RAS area of responsibility, an attempt to calculate the seismic moment tensor (SMT) was made. There are 32 such events in the regional catalogue. For 28 earthquakes the SMT and depth h of the equivalent point source were calculated successfully. The calculations were performed for the SMT double-couple model using a nonlinear algorithm. In 2015, a typical location of the earthquake epicenters was observed in the Kamchatka zone. In 2015, the seismicity level in all selected zones and in the region as a whole correspond to the background one according to the “SESL’09” scale. The number of recorded events with ML3.5 and strong earthquakes with ML5.0 is close to the average annual value. Anomalous and significant events were not recorded.
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Rhoades, David A., Sepideh J. J. Rastin, and Annemarie Christophersen. "The Effect of Catalogue Lead Time on Medium-Term Earthquake Forecasting with Application to New Zealand Data." Entropy 22, no. 11 (November 6, 2020): 1264. http://dx.doi.org/10.3390/e22111264.
Повний текст джерелаАнотація:
‘Every Earthquake a Precursor According to Scale’ (EEPAS) is a catalogue-based model to forecast earthquakes within the coming months, years and decades, depending on magnitude. EEPAS has been shown to perform well in seismically active regions like New Zealand (NZ). It is based on the observation that seismicity increases prior to major earthquakes. This increase follows predictive scaling relations. For larger target earthquakes, the precursor time is longer and precursory seismicity may have occurred prior to the start of the catalogue. Here, we derive a formula for the completeness of precursory earthquake contributions to a target earthquake as a function of its magnitude and lead time, where the lead time is the length of time from the start of the catalogue to its time of occurrence. We develop two new versions of EEPAS and apply them to NZ data. The Fixed Lead time EEPAS (FLEEPAS) model is used to examine the effect of the lead time on forecasting, and the Fixed Lead time Compensated EEPAS (FLCEEPAS) model compensates for incompleteness of precursory earthquake contributions. FLEEPAS reveals a space-time trade-off of precursory seismicity that requires further investigation. Both models improve forecasting performance at short lead times, although the improvement is achieved in different ways.
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Console, Rodolfo, Maura Murru, Paola Vannoli, Roberto Carluccio, Matteo Taroni, and Giuseppe Falcone. "Physics-based simulation of sequences with multiple main shocks in Central Italy." Geophysical Journal International 223, no. 1 (June 17, 2020): 526–42. http://dx.doi.org/10.1093/gji/ggaa300.
Повний текст джерелаАнотація:
SUMMARY The application of a physics-based earthquake simulator to Central Italy allowed the compilation of a synthetic seismic catalogue spanning 100 000 yr, containing more than 300 000 M ≥ 4.0 simulated earthquakes, without the limitations that real catalogues suffer in terms of completeness, homogeneity and time duration. The seismogenic model upon which we applied the simulator code was derived from version 3.2.1 of the Database of Individual Seismogenic Sources (DISS; http://diss.rm.ingv.it/diss/), selecting, and modifying where appropriate, all the fault systems that are recognized in the portion of Central Italy considered in this study, with a total of 54 faults. Besides tectonic stress loading and static stress transfer as in the previous versions, the physical model on which the latest version of our simulation algorithm is based also includes the Rate and State constitutive law that helps to reproduce Omori's law. One further improvement in our code was also the introduction of trapezoidal-shaped faults that perform better than known faults. The resulting synthetic seismic catalogue exhibits typical magnitude, space and time features which are comparable to those in real observations. These features include the total seismic moment rate, the earthquake magnitude distribution, and the short- and medium-term earthquake clustering. A typical aspect of the observed seismicity in Central Italy, as well as across the whole Italian landmass and elsewhere, is the occurrence of earthquake sequences characterized by multiple main shocks of similar magnitude. These sequences are different from the usual earthquake clusters and aftershock sequences, since they have at least two main shocks of similar magnitude. Therefore, special attention was devoted to verifying whether the simulated catalogue includes this notable aspect. For this purpose, we developed a computer code especially for this work to count the number of multiple events contained in a seismic catalogue under a quantitative definition. We found that the last version of the simulator code produces a slightly larger number of multiple events than the previous versions, but not as large as in the real catalogue. A possible reason for this drawback is the lack of components such as pore-pressure changes due to fluid-diffusion in the adopted physical model.
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McGinty, Peter. "Preparation of the New Zealand earthquake catalogue for a probabilistic seismic hazard analysis." Bulletin of the New Zealand Society for Earthquake Engineering 34, no. 1 (March 31, 2001): 60–67. http://dx.doi.org/10.5459/bnzsee.34.1.60-67.
Повний текст джерелаАнотація:
The seismic hazard from ground motions during a New Zealand earthquake is variable, and is dependent on the different tectonic processes that occur throughout the country. A modem probabilistic seismic hazard analysis (PSHA) combines various data sets to take account of these different environmental effects and rates of occurrence. Earthquake catalogue data can be used to give the rate of background or distributed seismicity in historical times, while paleoseismic data can be used to constrain the return time of large earthquakes. The background seismicity is assumed to occur as a time-independent Poisson process. To apply this assumption to a new PSHA of New Zealand, completeness levels for the New Zealand earthquake catalogue were established, and aftershocks or clusters of events that occurred close together in both space and time were removed from the catalogue. The level of hazard in a region can be depth-dependent, that is the risk of a large earthquake may come from a shallow crustal event or a deep subduction zone event, both having the same epicentral location but resulting in different levels of damage. The New Zealand earthquake catalogue has too many events that have been assigned restricted depths to be ignored. These events have been statistically redistributed into shallow crustal zones or deep subducted slab zones based on the last eleven years of catalogue data, when improvements in technology have reduced the number of restricted events.
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Suharna, A., Sujiono Eko Hadi, and Pariabti Palloan. "Seismicity and influence of coulomb stress on the risk of earthquakes in South Sulawesi." Journal of Physics: Conference Series 2193, no. 1 (February 1, 2022): 012095. http://dx.doi.org/10.1088/1742-6596/2193/1/012095.
Повний текст джерелаАнотація:
Abstract This study aims to analyze the distribution of earthquake events, analyze seismicity based on the parameters of b value, analyze changes in Coulomb stress and analyze the risk of earthquake events in South Sulawesi based on seismicity levels and changes in Coulomb stress in the range of 1991-2021. The data used in this study is data on earthquake events in 1991-2021 obtained from the IRIS and ISC catalogues. Data from the IRIS catalogue is mapped using ArcGIS software to see the distribution of the next earthquake spread processed by using MATLAB-based ZMapp 7 software to obtain the value of seismicity parameter (b value). Data from the ISC catalogue is mapped using Google Earth software to see the spread of earthquakes and then processed using MATLAB-based Coulomb 3.1 software to obtain analysis of stress Coulomb changes. Based on the results of the analysis obtained a value of b between 0.9-1.5 shows the value of b obtained is relatively low which correlates with a high level of stress. Based on the results of the analysis of changes in Coulomb stress obtained the movement of increased stress towards the red lobe with a value of 0.1 to 1 bar and decreased stress towards the blue lobe with a value of -0.1 to -1 bar. In general, earthquake-prone areas are located in the northern to central parts of South Sulawesi.
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Baskoutas, I., and G. Papadopoulos. "Qualitative precursory pattern before several strong earthquakes in Greece." Bulletin of the Geological Society of Greece 47, no. 3 (December 21, 2016): 1061. http://dx.doi.org/10.12681/bgsg.10949.
Повний текст джерелаАнотація:
The temporal variation of the seismicity, based on the analysis of three seismic parameters i.e., number of earthquakes, b-value and energy released, were investigated before several strong earthquakes occurrence in Greece the time period 2000-2008. The seismic parameters estimates were obtained by the means of new tool, suited to analyze earthquake catalogue, and visualize their spatio-temporalvariation behaviour. The seismic data used were taken from the earthquake catalogue of the Geodynamic Institute of National Observatory of Athens, Greece. The obtained temporal variation series shows significant changes around their relative mean values, which specific phases can be related to the strong earthquakes preparation stages. This relation shows remarkable temporal regularity so that itcan be establish considered as a precursor seismicity pattern. These results suggest that identification of this behaviour, by the continuous monitoring of the temporal variation of the seismic parameters, can contribute to the assessment of the current seismic hazard and to the impending strong earthquake parameters evaluation, in a given area.
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Trippetta, Fabio, Patrizio Petricca, Andrea Billi, Cristiano Collettini, Marco Cuffaro, Anna Maria Lombardi, Davide Scrocca, Giancarlo Ventura, Andrea Morgante, and Carlo Doglioni. "From mapped faults to fault-length earthquake magnitude (FLEM): a test on Italy with methodological implications." Solid Earth 10, no. 5 (September 17, 2019): 1555–79. http://dx.doi.org/10.5194/se-10-1555-2019.
Повний текст джерелаАнотація:
Abstract. Empirical scaling relationships between fault or slip dimensions and earthquake magnitudes are often used to assess the maximum possible earthquake magnitude of a territory. Upon the assumption of the reactivability of any fault, the earthquake magnitudes derived from the surface fault length (FLEM) are compared at the national scale in Italy against catalogued magnitudes. FLEMs are obtained by considering a comprehensive fault dataset regardless of fault age, stress field orientation, strain rate, etc. In particular, (1) a comprehensive catalogue of all known faults is compiled by merging the most complete databases available; (2) FLEM is then derived from fault length; and (3) the resulting FLEMs are compared (i.e. the mathematical difference) with catalogued earthquake magnitudes. Results show that the largest FLEMs as well as the largest differences between FLEMs and catalogued magnitudes are observed for poorly constrained faults, mainly inferred from subsurface data. It is suggested that these areas have to be further characterized to better estimate fault dimension and segmentation and hence properly assess the FLEM. Where, in contrast, the knowledge of faults is geologically well constrained, the calculated FLEM is often consistent with the catalogued seismicity, with the 2σ value of the distribution of differences being 1.47 and reducing to 0.53 when considering only the Mw≥6.5 earthquakes. Our work highlights areas, in Italy, where further detailed studies on faults are required.
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Chebrov, Danila, A. Chebrova, E. Matveenko, S. Droznina, Svetlana Mityushkina, A. Gusev, Vadim Saltikov, and P. Voropaev. "KAMCHATKA AND COMMANDER ISLANDS." Zemletriaseniia Severnoi Evrazii [Earthquakes in Northern Eurasia], no. 22 (November 12, 2019): 198–213. http://dx.doi.org/10.35540/1818-6254.2019.22.17.
Повний текст джерелаАнотація:
The seismicity of Kamchatka and surrounding territories for 2013 is viewed. The minimum local magnitude of completeness is MLmin=3.25 in the Kamchatka earthquake catalogue totally, and MLmin=4 for earthquakes under the Okhotsk sea (with h≥350 km). The Kamchatka earthquake catalogue of 2013 with ML≥3.6, which includes 1750 events, is published. 146 earthquakes of published catalog with ML=3.6–7.8 were felt with seismic intensity ranged from 2 to 7 of the MSK-64 scale in Kamchatka and surrounding areas. Focal mechanisms were determined in two ways: 1) from first motion P-wave arrivals for 107 earthquakes; 2) using waveforms for 25 earthquakes. The background seismicity level (SESL’09) within the Kamchatka responsibility zone was extremely high in 2013. It exceeded the rate of seismicity in all previous years of observations. There were 6672 earthquakes, including 129 events with КS≥11.5 (ML≥5) in the region during the year. The mechanisms of 107 earthquakes were defined. 148 earthquakes were felt with intensity from 2 up to 7 on the territory of Kamchatskii Krai, North Kuril Islands, and Komandor Islands. There were several unusual events in 2013. The strong earthquake with magnitude Mw=5.8 on March 13 in the area of the Kamchatka Isthmus (Il'pyr earthquake), which is a rare phenomenon for the Northern Kamchatka. There was the strongest deep earthquake in the world (Mw=8.3) on May 24 under the Sea of Okhotsk (Okhotsk earthquake) at the depth of 630 km. The event caused an abnormal macro-seismic effect. The intensive earthquake swarm was observed in the Avacha Bay (Mwmax=6.1) in May 2013. It is the strongest earthquake swarm registered by the Kamchatka network during the period of detailed seismological observations since 1962
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Mahmood, Khalid, Naveed Ahmad, Usman Khan, and Qaiser Iqbal. "Seismic hazard maps of Peshawar District for various return periods." Natural Hazards and Earth System Sciences 20, no. 6 (June 5, 2020): 1639–61. http://dx.doi.org/10.5194/nhess-20-1639-2020.
Повний текст джерелаАнотація:
Abstract. Probabilistic seismic hazard analysis of Peshawar District has been performed for a grid size of 0.01∘. The seismic sources for the target location are defined as the area polygon with uniform seismicity. The earthquake catalogue was developed based on the earthquake data obtained from different worldwide seismological networks and historical records. The earthquake events obtained at different magnitude scales were converted into moment magnitude using indigenous catalogue-specific regression relationships. The homogenized catalogue was subdivided into shallow crustal and deep-subduction-zone earthquake events. The seismic source parameters were obtained using the bounded Gutenberg–Richter recurrence law. Seismic hazard maps were prepared for peak horizontal acceleration at bedrock level using different ground motion attenuation relationships. The study revealed the selection of an appropriate ground motion prediction equation is crucial for defining the seismic hazard of Peshawar District. The inclusion of deep subduction earthquakes does not add significantly to the seismic hazard for design base ground motions. The seismic hazard map developed for shallow crustal earthquakes, including also the epistemic uncertainty, was in close agreement with the map given in the Building Code of Pakistan Seismic Provisions (2007) for a return period of 475 years on bedrock. The seismic hazard maps for other return periods i.e., 50, 100, 250, 475 and 2500 years, are also presented.
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SRIVASTAVA, HN, and K. RAMACHANDRAN. "New catalogue of earthquakes for Peninsular India during 1839-1900." MAUSAM 36, no. 3 (April 6, 2022): 351–58. http://dx.doi.org/10.54302/mausam.v36i3.1982.
Повний текст джерелаАнотація:
Based upon the recommendations of the UNESCO experts after the Koyna earthquake of December 1967 a new catalogue of earthquakes for Peninsular India has been prepared for the period 1839-1900. The data has been extracted from the microfilms of Times of India, Statesman and Hindu for the period commencing with theft publication (1839) to installatio!1of seismological instruments in the country (1900).
It is interesting to note that the region where significant earthquakes have occurred, tremors of felt intensity have been reported several years preceding the main events. Also through this catalogue the first case of unusual animal behaviour in the Indian region about one hour prior to an earthquake of intensity V In Manbhoom district on 19 February 1892 is brought to light.
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Di Giacomo, Domenico, E. Robert Engdahl, and Dmitry A. Storchak. "The ISC-GEM Earthquake Catalogue (1904–2014): status after the Extension Project." Earth System Science Data 10, no. 4 (October 16, 2018): 1877–99. http://dx.doi.org/10.5194/essd-10-1877-2018.
Повний текст джерелаАнотація:
Abstract. We outline the work done to extend and improve the ISC-GEM Global Instrumental Earthquake Catalogue, a dataset which was first released in 2013 (Storchak et al., 2013, 2015). In its first version (V1) the catalogue included global earthquakes selected according to time-dependent cut-off magnitudes: 7.5 and above between 1900 and 1918 (plus significant continental earthquakes 6.5 and above); 6.25 between 1918 and 1959; 5.5 between 1960 and 2009. Such selection criteria were dictated by time and resource limitations. With the Extension Project we added both pre-1960 events below the original cut-off magnitudes (if enough station data were available to perform relocation and magnitude recomputation) and added events with magnitude 5.5 and above from 2010 to 2014. The project ran over a 4-year period during which a new version of the ISC-GEM Catalogue was released each year via the ISC website (http://http://www.isc.ac.uk/iscgem/, last access: 10 October 2018). For each year, not only have we added new events to the catalogue for a given time range but also revised events already in V1 if additional data became available or location and/or magnitude reassessments were required. Here we recall the general background behind the production of the ISC-GEM Catalogue and describe the features of the different periods in which the catalogue has been extended. Compared to the 2013 release, we eliminated earthquakes during the first 4 years (1900–1903) of the catalogue (due to lack of reliable station data), added approximately 12 000 and 2500 earthquakes before 1960 and between 2010 and 2014, respectively, and improved the solution for approximately 2000 earthquakes already listed in previous versions. We expect the ISC-GEM Catalogue to continue to be one of the most useful datasets for studies of the Earth's global seismicity and an important benchmark for seismic hazard analyses, and, ultimately, an asset for the seismological community as well as other geoscience fields, education and outreach activities. The ISC-GEM Catalogue is freely available at https://doi.org/10.31905/D808B825.
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Mikhailova, N., I. Sokolova, and B. Bekturganova. "KAZAKHSTAN." Earthquakes in Northern Eurasia, no. 23 (December 15, 2020): 113–21. http://dx.doi.org/10.35540/1818-6254.2020.23.10.
Повний текст джерелаАнотація:
The article presents the detailed information on seismic observation networks and catalogue of seismic events in Kazakhstan for 2014 made by data of two organizations - Seismological Experience-Methodical expedition of the Ministry of Education and Science of the Republic of Kazakhstan (SEME), and the Institute of Geophysical Research of the Ministry of Energy of the Republic of Kazakhstan (IGR). The catalogue includes 559 earthquakes with energy class КР=6.6–13.6. The largest earthquake of the year occurred on November 14, 2014 at the southern side of the Issyk-Kul Lake, near Kadzhysay settlement. The earthquake magnitude was MPVA=6.2, energy class КР=13.6. The most interesting was the earthquake occurred at aseismic region of Central Kazakhstan near Karaganda on June 21, 2014. The earthquake was recorded by the seismic stations of Kazakhstan and the world (MPVA=5.2, КР=11.7), it was felt in many settlements. The authors suppose that this earthquake is a natural-induced event.
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PAPANASTASSIOU, D., J. LATOUSSAKIS, and G. STAVRAKAKIS. "A revised catalogue of earthquaqes in the broader area of Greece for the period 1950-2000." Bulletin of the Geological Society of Greece 34, no. 4 (January 1, 2001): 1563. http://dx.doi.org/10.12681/bgsg.17263.
Повний текст джерелаАнотація:
An earthquake catalogue for Greece and the surrounding areas for the time period 1950 - 2000, is presented. This catalogue contains more than 59,000 earthquakes recorded and located by the seismological network of the Institute of Geodynamics, National Observatory of Athens. The accuracy of the determinations of the source parameters as well as the completeness of the catalogue have been improved significantly, but they vary according to the period of observation as both depend on the number and quality of the seismological stations consisting the network. This revised catalogue is listed on the Worldwide Web Page http//www.gein.noa.gr, of the Institute of Geodynamics
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Albini, Paola, Roger M. W. Musson, Andrea Rovida, Mario Locati, Antonio A. Gomez Capera, and Daniele Viganò. "The Global Earthquake History." Earthquake Spectra 30, no. 2 (May 2014): 607–24. http://dx.doi.org/10.1193/122013eqs297.
Повний текст джерелаАнотація:
The study of earthquakes from historical sources, or historical seismology, was considered an early priority for the Global Earthquake Model (GEM) project, which commissioned a study of historical seismicity on a global scale. This was the Global Earthquake History (GEH) project, led jointly by the Istituto Nazionale di Geofisica e Vulcanologia (INGV; Milan, Italy) and the British Geological Survey (BGS; UK). GEH was structured around three complementary deliverables: archive, catalog, and the Web infrastructure designed to store both the archive and catalog. The Global Historical Earthquake Archive (GHEA) provides a complete account of the global situation in historical seismology for large earthquakes. From GHEA, the Global Historical Earthquake Catalogue (GHEC v1.0) was derived—a world catalog of earthquakes for the period 1000–1903, with magnitudes of Mw7 and over. Though much remains to be done, the data here presented show that the compilation of both archive and catalog contribute to an improved understanding of the Global Earthquake History.
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Chebrov, D. V., V. A. Saltikov, S. Ya Droznina,, E. I. Romasheva, S. V. Mityushkina, I. R. Abubakirov, V. M. Pavlov, A. A. Raevskaya, and E. A. Matveenko. "SEISMICITY of KAMCHATKA and COMMANDER ISLANDS in 2016–2017." Earthquakes in Northern Eurasia, no. 25 (December 20, 2022): 164–75. http://dx.doi.org/10.35540/1818-6254.2022.25.14.
Повний текст джерелаАнотація:
The seismicity review of Kamchatka and surrounding territories for 2016–2017 is given. In the Kamchatka earthquake catalogue, the minimum local magnitude of completeness is MLmin=4.0, and for earth-quakes with h≥350 km under the Okhotsk sea MLmin=4.3. The Kamchatka catalogue of earthquakes with ML=3.6–7.3 for 2016–2017, published in the Appendix to this article, includes 2898 events. 191 earthquakes of the catalogue were felt in Kamchatka and surrounding areas with seismic intensity I=2–6 according to the MSK-64 scale. For all events with ML≥5.0 that occurred in 2016–2017 within the area of responsibility of Kamchatka branch of Geophysical Survey RAS, an attempt to calculate the seismic moment tensor (SMT) was made. There are 109 such events in the regional catalogue. For 102 earthquakes the SMT and depth of the equivalent point source were calculated. The calculations were performed for the SMT double-couple model using a nonlinear algorithm. The level of seismicity according to the “SOUS'09” scale in 2016 corresponds to the “background increased”, for 2017 it is also the “background increased”, but within the assessment accuracy – “high”. In 2016–2017 within the Kamchatka branch area of responsibility, an atypical pattern of the location of earthquake epicenters was observed due to the occurrence of two strong events – the Near Aleutian (Mw=7.8, July 17, 2017) and South Ozernovsky (Mw=6.6, March 29, 2017) earthquakes and their aftershock processes.
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Makropoulos, K., G. Kaviris, and V. Kouskouna. "An updated and extended earthquake catalogue for Greece and adjacent areas since 1900." Natural Hazards and Earth System Sciences 12, no. 5 (May 11, 2012): 1425–30. http://dx.doi.org/10.5194/nhess-12-1425-2012.
Повний текст джерелаАнотація:
Abstract. A homogeneous earthquake catalogue for Greece and adjacent areas covering the period 1900–2009 is presented, to be used for reliable seismic hazard studies. The catalogues of Makropoulos and Burton (1981) and Makropoulos et al. (1989), covering the time span 1900–1985, were updated for the period 1986–2009 using instrumentally determined focal coordinates, except for the magnitude from the bulletin of the ISC. For Ms, which is the magnitude scale included in the previous versions, the same procedure applied since 1964 was adopted, using the ISC body wave magnitude (mb) and a regression equation. In the present update, Mw is also calculated for the entire period 1900–2009 using a formula derived from all available moment magnitudes and directly determined by the moment tensor inversion method. Thus, a magnitude homogeneous catalogue concerning both Ms and Mw scales is presented. The extended catalogue contains 7352 events, 70% more than the 4310 events of the previous published (1989) version. The completeness test revealed that the catalogue is complete for magnitudes above 4 for the last 34 yr and that no earthquake with magnitude 6 or greater has been omitted in the whole instrumental era (1900–2009).
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Rovida, Andrea, Mario Locati, Romano Camassi, Barbara Lolli, and Paolo Gasperini. "The Italian earthquake catalogue CPTI15." Bulletin of Earthquake Engineering 18, no. 7 (March 16, 2020): 2953–84. http://dx.doi.org/10.1007/s10518-020-00818-y.
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Chen, Jinbiao, Peiyan Chen, Quanlin Li, Kexiag Wang, Chunzhen Wu, and Bomin Li. "Earthquake catalogue database of China." Acta Seismologica Sinica 1, no. 3 (June 1988): 107–16. http://dx.doi.org/10.1007/bf02652500.
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Fan, Gang, Jun Wang, Shunchao Qi, Gongda Lu, Xingguo Yang, and Jiawen Zhou. "Spatiotemporal Evolution of Earthquakes in Longmenshan Fault and Adjacent Area, before and after the 2008 Wenchuan Earthquake." Shock and Vibration 2021 (November 24, 2021): 1–13. http://dx.doi.org/10.1155/2021/9400276.
Повний текст джерелаАнотація:
Seismicity sequence following a main earthquake usually contains much meaningful information for unveiling the focal mechanism and predicting the reoccurrence interval of large earthquakes. The spatiotemporal evolution of earthquakes before and after the 2008 Wenchuan earthquake (Ms 8.0) is analysed comprehensively in this study. The frequency-magnitude relation of the 3493 earthquake events retrieved from the database of the International Seismological Centre indicates that the adopted catalogue is complete for magnitudes ≥Ms 3.4. The seismicity during the 10 years before the Wenchuan earthquake remained stable, including the magnitudes and focal depths. However, seismicity attenuated sharply in the year following the Wenchuan earthquake, and the magnitude of earthquakes before the Wenchuan earthquake decreased gradually. The area of the seismogenic zone of the 2008 Wenchuan earthquake was smaller than the earthquake stricken area. The earthquakes that occurred in the Longmenshan fault area and adjacent area in the study period were mainly shallow earthquakes. The focal depths of earthquakes in the study area became stable gradually after the Wenchuan earthquake, mainly within the range from 10 to 16 km. The earthquakes in the study area were mainly distributed with an along-dip distance of 0–20 km, and the seismicity was distributed uniformly along the fault strike.
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Bayona, J. A., W. Savran, A. Strader, S. Hainzl, F. Cotton, and D. Schorlemmer. "Two global ensemble seismicity models obtained from the combination of interseismic strain measurements and earthquake-catalogue information." Geophysical Journal International 224, no. 3 (November 20, 2020): 1945–55. http://dx.doi.org/10.1093/gji/ggaa554.
Повний текст джерелаАнотація:
SUMMARY Global seismicity models provide scientific hypotheses about the rate, location and magnitude of future earthquakes to occur worldwide. Given the aleatory variability of earthquake activity and epistemic uncertainties in seismicity forecasting, the veracity of these hypotheses can only be confirmed or rejected after prospective forecast evaluation. In this study, we present the construction of and test results for two updated global earthquake models, aimed at providing mean estimates of shallow (d ≤ 70 km) seismicity for seismic hazard assessment. These approaches, referred to as the Tectonic Earthquake Activity Model (TEAM) and the World Hybrid Earthquake Estimates based on Likelihood scores (WHEEL) model, use the Subduction Megathrust Earthquake Rate Forecast (SMERF2), an earthquake-rate model for subduction zones constrained by geodetic strain measurements and earthquake-catalogue information. Thus, these global ensemble seismicity models capture two independent components necessary for long-term earthquake forecasting, namely interseismic crustal strain accumulation and sudden lithospheric stress release. The calibration period for TEAM and WHEEL extends from 1977 January 1 to 2013 December 31. Accordingly, we use m ≥ 5.95 earthquakes recorded during the 2014–2019 period to pseudo-prospectively evaluate the forecasting skills of these earthquake models, and statistically compare their performances to that of the Global Earthquake Activity Rate (GEAR1) model. As a result, GEAR1 and WHEEL are the most informative global seismicity models during the pseudo-prospective test period, as both rank with the highest information scores among all participant earthquake-rate forecasts. Nonetheless, further prospective evaluations are required to more accurately assess the abilities of these global ensemble seismicity models to forecast long-term earthquake activity.
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Rastin, Sepideh J., David A. Rhoades, and Annemarie Christophersen. "Space–Time Trade-Off of Precursory Seismicity in New Zealand and California Revealed by a Medium-Term Earthquake Forecasting Model." Applied Sciences 11, no. 21 (October 31, 2021): 10215. http://dx.doi.org/10.3390/app112110215.
Повний текст джерелаАнотація:
The ‘Every Earthquake a Precursor According to Scale’ (EEPAS) medium-term earthquake forecasting model is based on the precursory scale increase (Ψ) phenomenon and associated scaling relations, in which the precursor magnitude MP is predictive of the mainshock magnitude Mm, precursor time TP and precursory area AP. In early studies of Ψ, a relatively low correlation between TP and AP suggested the possibility of a trade-off between time and area as a second-order effect. Here, we investigate the trade-off by means of the EEPAS model. Existing versions of EEPAS in New Zealand and California forecast target earthquakes of magnitudes M > 4.95 from input catalogues with M > 2.95. We systematically vary one parameter each from the EEPAS distributions for time and location, thereby varying the temporal and spatial scales of these distributions by two orders of magnitude. As one of these parameters is varied, the other is refitted to a 20-year period of each catalogue. The resulting curves of the temporal scaling factor against the spatial scaling factor are consistent with an even trade-off between time and area, given the limited temporal and spatial extent of the input catalogue. Hybrid models are formed by mixing several EEPAS models, with parameter sets chosen from points on the trade-off line. These are tested against the original fitted EEPAS models on a subsequent period of the New Zealand catalogue. The resulting information gains suggest that the space–time trade-off can be exploited to improve forecasting.
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Rhoades, David A., and Annemarie Christophersen. "Time-varying probabilities of earthquake occurrence in central New Zealand based on the EEPAS model compensated for time-lag." Geophysical Journal International 219, no. 1 (July 4, 2019): 417–29. http://dx.doi.org/10.1093/gji/ggz301.
Повний текст джерелаАнотація:
SUMMARY The ‘Every Earthquake a Precursor According to Scale’ (EEPAS) model treats every earthquake as a precursor of larger earthquakes to follow it within a time-span ranging from months to decades, depending on magnitude. Each earthquake contributes a transient increment to the expected rate of earthquake occurrence in its vicinity, based on empirical predictive scaling relations associated with the precursory scale increase phenomenon. Incomplete information on precursory earthquakes causes the EEPAS model to underpredict the expected number of earthquakes, in particular when forecasting across a time-lag for periods beginning several years ahead. We demonstrate how the model can be modified to compensate for such time-lags when calculating future forecasts. Given the model parameters, the completeness of precursory information can be expressed as a function of the target earthquake magnitude and the time-lag. We consider two end-members for compensating the model for incompleteness. In one end-member, only the background smoothed-seismicity component of the EEPAS model is compensated, in the other, only the time-varying component of the EEPAS model is compensated. We estimate an optimal mixture of these two end-members for time-lags out to 12 yr, using several different versions of the EEPAS model and subsets of the New Zealand earthquake catalogue to which the models were previously fitted. Performance is checked on an independent test period. The optimal compensated model has increasingly high information gains over the original EEPAS model with increasing time-lags. Using catalogue data complete to 2018, the compensated models forecast increased annual probabilities of earthquake occurrence above magnitude thresholds from 6.0 to 8.0 in central New Zealand in the period 2019–2030 relative to the preceding period 2008–2018.
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Iwata, Takaki. "Revisiting the global detection capability of earthquakes during the period immediately after a large earthquake: considering the influence of intermediate-depth and deep earthquakes." Research in Geophysics 2, no. 1 (March 29, 2012): 4. http://dx.doi.org/10.4081/rg.2012.e4.
Повний текст джерелаАнотація:
This study examines the global earthquake detection capability of the Global Centroid Moment Tensor (GCMT) catalogue during the periods immediately following large earthquakes, including intermediate-depth (70 ≤ depth < 300 km) and deep (300 km ≤ depth) events. We have already shown that the detection capability beyond an aftershock zone degrades remarkably and that this condition persists for several hours after the occurrence of large shallow (depth < 70 km) earthquakes. Because an intermediate-depth or deep earthquake occasionally generates seismic waves with significant amplitudes, it is necessary to investigate the change in the detection capability caused by such events. To this end, from the GCMT catalogue, we constructed the time sequences of the earthquakes that occurred immediately after the large earthquakes, and stacked these time sequences. To these stacked sequences, we then applied a statistical model representing the magnitude-frequency distribution of all observed earthquakes. This model has a parameter that characterizes the detection capability, and the temporal variation of the parameter is estimated by means of a Bayesian approach with a piecewise linear function. Consequently, we find that the global detection capability is lower after the occurrence of shallow earthquakes with magnitudes ≥ 5.45, intermediate-depth earthquakes with magnitudes ≥ 5.95, and deep earthquakes with magnitudes ≥ 6.95.
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Soloviev, A. "Transformation of frequency-magnitude relation prior to large events in the model of block structure dynamics." Nonlinear Processes in Geophysics 15, no. 1 (February 27, 2008): 209–20. http://dx.doi.org/10.5194/npg-15-209-2008.
Повний текст джерелаАнотація:
Abstract. The b-value change in the frequency-magnitude (FM) distribution for a synthetic earthquake catalogue obtained by means of the model of block structure dynamics has been studied. The catalogue is divided into time periods preceding strong earthquakes and time periods that do not precede strong earthquakes. The separate analysis of these periods shows that the b-value is smaller before strong earthquakes. The similar phenomenon has been found also for the observed seismicity of the Southern California. The model of block structure dynamics represents a seismic region as a system of perfectly rigid blocks divided by infinitely thin plane faults. The blocks interact between themselves and with the underlying medium. The system of blocks moves as a consequence of prescribed motion of the boundary blocks and of the underlying medium. As the blocks are perfectly rigid, all deformation takes place in the fault zones and at the block base in contact with the underlying medium. Relative block displacements take place along the fault zones. Block motion is defined so that the system is in a quasistatic equilibrium state. The interaction of blocks along the fault zones is viscous-elastic ("normal state") while the ratio of the stress to the pressure remains below a certain strength level. When the critical level is exceeded in some part of a fault zone, a stress-drop ("failure") occurs (in accordance with the dry friction model), possibly causing failure in other parts of the fault zones. These failures produce earthquakes. Immediately after the earthquake and for some time after, the affected parts of the fault zones are in a state of creep. This state differs from the normal state because of a faster growth of inelastic displacements, lasting until the stress falls below some other level. This numerical simulation gives rise a synthetic earthquake catalogue.
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SRIVASTAVA, H. N., R. K. SINGH, DAL SINGH, RAJESH PRAKASH, and A. K. SHUKLA. "Bhuj (2001) aur Muzaffarabad (2005) bhukampon ke purv tatha baad ke bhukampon ka tulnatmak addhyayan." MAUSAM 64, no. 2 (April 1, 2013): 323–44. http://dx.doi.org/10.54302/mausam.v64i2.5868.
Повний текст джерелаАнотація:
Bhuj (2001) and Muzaffarabad (2005) earthquakes of same moment magnitude of Mw : 7.6 occured in different techtonic regions i.e., intraplate and interplate regions of Indo-Eurasian plates respectevely. Keeping this in view, their comparative study has been attempted in this paper. A detailed catalogue of earthquakes has been prepared to study seismicity of Kutchh region by including historical and paleoseismic data. Discussion on seismicity of Muzaffarabad (2005) earthquake is based on IMD catalogoue of earthquakes. Difference has been found between Bhuj (2001) and Muzaffarabad (2005) earthquakes based on their foreshocks, magnitudes of aftershocks and their decay, b-value and their spectra. Though no relation between magnitudes of aftershocks and stress drop could be found but mostly the corner frequency and magnitude are inversely related. Difference in both these large earthquakes (M>=7.6) occurring in different tectonic plate set up is clearly evident from their stress drop. Seismic gap is noticed prior to main event of Muzaffarabad earthquake; which is similar to other Himalayan earthquakes of that region like Uttarkashi (1991) and Chamoli (1999). From the point of view earthquake prediction, the results based on satellite thermal anamolies, ionosphere, electromagnetic and sodar observations reported for these earthquakes are considered to be of limited value due to the large influence of atmospheric parameters. Though approximate displacement measured through GPS is useful for calculating the plate motion but their results to derive large vertical displacement is questionable in any case of Bhuj earthquake due to use of standard radio atmosphere. The errors in such results can be reduced by adopting radio atmosphere for the Indian region. Through a review of methodologies to predict the strong ground motion in the near field, it is evident that further research is called for.
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Guerrieri, Luca. "The EEE Catalogue: a global catalogue of Earthquake Environmental Effects." Quaternary International 279-280 (November 2012): 179–80. http://dx.doi.org/10.1016/j.quaint.2012.08.273.
Повний текст джерела
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Takemura, Shunsuke, Ryo Okuwaki, Tatsuya Kubota, Katsuhiko Shiomi, Takeshi Kimura, and Akemi Noda. "Centroid moment tensor inversions of offshore earthquakes using a three-dimensional velocity structure model: slip distributions on the plate boundary along the Nankai Trough." Geophysical Journal International 222, no. 2 (May 15, 2020): 1109–25. http://dx.doi.org/10.1093/gji/ggaa238.
Повний текст джерелаАнотація:
SUMMARY Due to complex 3-D heterogeneous structures, conventional 1-D analysis techniques using onshore seismograms can yield incorrect estimation of earthquake source parameters, especially dip angles and centroid depths of offshore earthquakes. Combining long-term onshore seismic observations and numerical simulations of seismic wave propagation in a 3-D model, we conducted centroid moment tensor (CMT) inversions of earthquakes along the Nankai Trough between April 2004 and August 2019 to evaluate decade-scale seismicity. Green's functions for CMT inversions of earthquakes with moment magnitudes of 4.3–6.5 were evaluated using finite-difference method simulations of seismic wave propagation in the regional 3-D velocity structure model. Significant differences of focal mechanisms and centroid depths between previous 1-D and our 3-D catalogues were found in the solutions of offshore earthquakes. By introducing the 3-D structures of the low-velocity accretionary prism and the Philippine Sea Plate, dip angles and centroid depths for offshore earthquakes were well-constrained. Teleseismic CMT also provides robust solutions, but our regional 3-D CMT could provide better constraints of dip angles. Our 3-D CMT catalogue and published slow earthquake catalogues depicted spatial distributions of slip behaviours on the plate boundary along the Nankai Trough. The regular and slow interplate earthquakes were separately distributed, with these distributions reflecting the heterogeneous distribution of effective strengths along the Nankai Trough plate boundary. By comparing the spatial distribution of seismic slip on the plate boundary with the slip-deficit rate distribution, regions with strong coupling were clearly identified.
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Telesca, L., and C. C. Chen. "Nonextensive analysis of crustal seismicity in Taiwan." Natural Hazards and Earth System Sciences 10, no. 6 (June 22, 2010): 1293–97. http://dx.doi.org/10.5194/nhess-10-1293-2010.
Повний текст джерелаАнотація:
Abstract. Using the Taiwan Central Weather Bureau earthquake catalogue, the crustal seismicity of Taiwan was analyzed by means of a nonextensive approach. The time span of the analyzed catalogue is from 1 January 1990 to 30 November 2007, and only earthquakes with magnitude M≥2.0 were considered. Our findings reveal that the nonextensive statistics furnishes a very good prediction of the cumulative magnitude distribution of crustal seismicity in Taiwan, even if the aftershocks are removed, indicating that the approach is robust for clustered as well as declustered seismicity.
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Simeonova, S. D., D. E. Solakov, G. Leydecker, H. Busche, T. Schmitt, and D. Kaiser. "Probabilistic seismic hazard map for Bulgaria as a basis for a new building code." Natural Hazards and Earth System Sciences 6, no. 6 (October 10, 2006): 881–87. http://dx.doi.org/10.5194/nhess-6-881-2006.
Повний текст джерелаАнотація:
Abstract. 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.
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Christopoulos, Stavros-Richard G., and Nicholas V. Sarlis. "An Application of the Coherent Noise Model for the Prediction of Aftershock Magnitude Time Series." Complexity 2017 (2017): 1–27. http://dx.doi.org/10.1155/2017/6853892.
Повний текст джерелаАнотація:
Recently, the study of the coherent noise model has led to a simple (binary) prediction algorithm for the forthcoming earthquake magnitude in aftershock sequences. This algorithm is based on the concept of natural time and exploits the complexity exhibited by the coherent noise model. Here, using the relocated catalogue from Southern California Seismic Network for 1981 to June 2011, we evaluate the application of this algorithm for the aftershocks of strong earthquakes of magnitudeM≥6. The study is also extended by using the Global Centroid Moment Tensor Project catalogue to the case of the six strongest earthquakes in the Earth during the last almost forty years. The predictor time series exhibits the ubiquitous1/fnoise behavior.
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Zhu, Gaohua, Hongfeng Yang, Jian Lin, Zhiyuan Zhou, Min Xu, Jinlong Sun, and Kuiyuan Wan. "Along-strike variation in slab geometry at the southern Mariana subduction zone revealed by seismicity through ocean bottom seismic experiments." Geophysical Journal International 218, no. 3 (June 10, 2019): 2122–35. http://dx.doi.org/10.1093/gji/ggz272.
Повний текст джерелаАнотація:
SUMMARYWe have conducted the first passive Ocean Bottom Seismograph (OBS) experiment near the Challenger Deep at the southernmost Mariana subduction zone by deploying and recovering an array of 6 broad-band OBSs during December 2016–June 2017. The obtained passive-source seismic records provide the first-ever near-field seismic observations in the southernmost Mariana subduction zone. We first correct clock errors of the OBS recordings based on both teleseismic waveforms and ambient noise cross-correlation. We then perform matched filter earthquake detection using 53 template events in the catalogue of the US Geological Survey and find >7000 local earthquakes during the 6-month OBS deployment period. Results of the two independent approaches show that the maximum clock drifting was ∼2 s on one instrument (OBS PA01), while the rest of OBS waveforms had negligible time drifting. After timing correction, we locate the detected earthquakes using a newly refined local velocity model that was derived from a companion active source experiment in the same region. In total, 2004 earthquakes are located with relatively high resolution. Furthermore, we calibrate the magnitudes of the detected earthquakes by measuring the relative amplitudes to their nearest relocated templates on all OBSs and acquire a high-resolution local earthquake catalogue. The magnitudes of earthquakes in our new catalogue range from 1.1 to 5.6. The earthquakes span over the Southwest Mariana rift, the megathrust interface, forearc and outer-rise regions. While most earthquakes are shallow, depths of the slab earthquakes increase from ∼100 to ∼240 km from west to east towards Guam. We also delineate the subducting interface from seismicity distribution and find an increasing trend in dip angles from west to east. The observed along-strike variation in slab dip angles and its downdip extents provide new constraints on geodynamic processes of the southernmost Mariana subduction zone.