scholarly journals Seismotectonics of Armenia: main problems

2021 ◽  
Vol 66 (3) ◽  
Author(s):  
Rudolf S. Sargsyan ◽  
◽  
Karlen S. Ghazaryan ◽  
Valeriy Yu. Burmin ◽  
◽  
...  
Keyword(s):  
Seismic Hazard ◽  
Historical Earthquakes ◽  
Probabilistic Assessment ◽  
Strong Earthquakes ◽  
Seismological Data ◽  
Observation Systems ◽  
Fault Tectonics ◽  
Discrete Nature ◽  
Lattice Network ◽  
Instrumental Period

The article describes the main problems in the existing researches on the seismotectonics of the territory of Armenia. A review was conducted on certain issues related to the accuracy of the initial seismological data, the problem of identifying possible focal zones of strong earthquakes, and the probabilistic assessment of the seismic hazard of the territory of Armenia. As the results of numerous studies show, the initial seismological data from catalogs and bulletins are characterized by their heterogeneity. Different observation systems and different methods of seismological data processing have led to the fact that when visualizing the spatial distribution of earthquake epicenters on the territory of Armenia, during the instrumental period of observations, an artificially lattice network of epicenters is obtained, which does not agree in any way with the fault tectonics of the territory. During the stud of distribution of earthquake hypocenters by depth, the discrete nature of their distribution was revealed. There is also a number of disadvantages in the area of allocation of focal zones of strong earthquakes. The main part of the conducted research was mainly based on data on previously recorded strong seismic events, as well as on data on historical earthquakes, as a result, for the most part of the studied territory, in fact, no research was conducted. In addition, there are relevant questions about the tectonic basis used in these studies. The last group of problems concerns the probabilistic assessment of the seismic hazard of the territory of Armenia. It is shown that in the existing works, there are quite a lot of unsubstantiated assumptions.Based on the analysis, it is concluded that in the field of seismotectonic studies of the territory of Armenia, there are a number of urgent tasks that require priority solutions.

The Gutenberg-Richter or characteristic earthquake distribution, which is it?

1994 ◽  
Vol 84 (6) ◽  
pp. 1940-1959 ◽  
Author(s):  
Steven G. Wesnousky
Keyword(s):  
Seismic Hazard ◽  
Hazard Analysis ◽  
Slip Rate ◽  
Historical Earthquakes ◽  
Practical Implementation ◽  
Characteristic Earthquake ◽  
Earthquake Model ◽  
Earthquake Distribution ◽  
Fault Trace ◽  
Major Strike

Abstract Paleoearthquake and fault slip-rate data are combined with the CIT-USGS catalog for the period 1944 to 1992 to examine the shape of the magnitude-frequency distribution along the major strike-slip faults of southern California. The resulting distributions for the Newport-Inglewood, Elsinore, Garlock, and San Andreas faults are in accord with the characteristic earthquake model of fault behavior. The distribution observed along the San Jacinto fault satisfies the Gutenberg-Richter relationship. If attention is limited to segments of the San Jacinto that are marked by the rupture zones of large historical earthquakes or distinct steps in fault trace, the observed distribution along each segment is consistent with the characteristic earthquake model. The Gutenberg-Richter distribution observed for the entirety of the San Jacinto may reflect the sum of seismicity along a number of distinct fault segments, each of which displays a characteristic earthquake distribution. The limited period of instrumental recording is insufficient to disprove the hypothesis that all faults will display a Gutenberg-Richter distribution when averaged over the course of a complete earthquake cycle. But, given that (1) the last 5 decades of seismicity are the best indicators of the expected level of small to moderate-size earthquakes in the next 50 years, and (2) it is generally about this period of time that is of interest in seismic hazard and engineering analysis, the answer to the question posed in the title of the article, at least when concerned with practical implementation of seismic hazard analysis at sites along these major faults, appears to be the “characteristic earthquake distribution.”

scholarly journals Seismic hazard assessment of Iran

1999 ◽  
Vol 42 (6) ◽  
Author(s):  
B. Tavakoli ◽  
M. Ghafory-Ashtiany
Keyword(s):  
Seismic Hazard ◽  
Peak Ground Acceleration ◽  
Grid Point ◽  
Seismic Hazard Assessment ◽  
Earthquake Hazard ◽  
Seismic Source ◽  
Historical Earthquakes ◽  
Earthquake Insurance ◽  
Ground Acceleration ◽  
Seismic Source Models

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.

scholarly journals Seismogenic ancient structures of the central and northern part of the East European platform

2019 ◽  
Vol 489 (4) ◽  
pp. 405-408
Author(s):  
V. V. Adushkin ◽  
I. A. Sanina ◽  
G. N. Ivanchenko ◽  
E. M. Gorbunova ◽  
I. P. Gabsatarova ◽  
...  
Keyword(s):  
Seismic Hazard ◽  
Seismic Activity ◽  
East European Platform ◽  
Historical Earthquakes ◽  
Seismic Array ◽  
Small Aperture ◽  
Seismic Stations ◽  
East European

The analysis of the location of the epicenters of earthquakes that occurred in the central and northern part of the East European platform in 2009-2016, recorded by the seismic stations of the GS RAS and the small aperture seismic array of IGD RAS Mikhnevo was performed. The results obtained indirectly indicate the seismic activity of the Riphean structures of the region, disturbing the surface of the basement, and their possible activation at the present time. Available data on historical earthquakes also confirm their relevance to paleorifts. It seems important to take into account the position of the ancient aulacogens in assessing the seismic hazard of the East European platform.

Seismic hazard sensitivity analysis: A multi-parameter approach

1991 ◽  
Vol 81 (3) ◽  
pp. 796-817
Author(s):  
Nitzan Rabinowitz ◽  
David M. Steinberg
Keyword(s):  
Sensitivity Analysis ◽  
Seismic Hazard ◽  
Subjective Probability ◽  
Probability Distributions ◽  
Input Parameter ◽  
The Other ◽  
Probabilistic Assessment ◽  
Input Parameters ◽  
Parameter Approach

Abstract We propose a novel multi-parameter approach for conducting seismic hazard sensitivity analysis. This approach allows one to assess the importance of each input parameter at a variety of settings of the other input parameters and thus provides a much richer picture than standard analyses, which assess each input parameter only at the default settings of the other parameters. We illustrate our method with a sensitivity analysis of seismic hazard for Jerusalem. In this example, we find several input parameters whose importance depends critically on the settings of other input parameters. This phenomenon, which cannot be detected by a standard sensitivity analysis, is easily diagnosed by our method. The multi-parameter approach can also be used in the context of a probabilistic assessment of seismic hazard that incorporates subjective probability distributions for the input parameters.

scholarly journals New Perspectives in the Definition/Evaluation of Seismic Hazard through Analysis of the Environmental Effects Induced by Earthquakes

Geosciences ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 58 ◽  
Author(s):  
Sabina Porfido ◽  
Giuliana Alessio ◽  
Germana Gaudiosi ◽  
Rosa Nappi
Keyword(s):  
Seismic Hazard ◽  
Environmental Effects ◽  
State Of The Art ◽  
Seismic Intensity ◽  
Seismic Hazards ◽  
Special Issue ◽  
Strong Earthquakes ◽  
Innovative Methods ◽  
Esi Scale ◽  
Earthquake Environmental Effects

The application of the Environmental Seismic Intensity (ESI) scale 2007 to moderate and strong earthquakes, in different geological context all over the word, highlights the importance of Earthquake Environmental Effects (EEEs) for the assessment of seismic hazards. This Special Issue “New Perspectives in the Definition/Evaluation of Seismic Hazard through Analysis of the Environmental Effects Induced by Earthquakes” presents a collection of scientific contributions that provide a sample of the state-of-the-art in this field. Moreover the collected papers also analyze new data produced with multi-disciplinary and innovative methods essential for development of new seismic hazard models.

The 1922 Peninsula Malaysia Earthquakes: Rare Intraplate Seismicity within the Sundaland Block in Southeast Asia

2020 ◽  
Vol 91 (5) ◽  
pp. 2531-2545 ◽  
Author(s):  
Stacey Servito Martin ◽  
Yu Wang ◽  
Muzli Muzli ◽  
Shengji Wei
Keyword(s):  
Seismic Hazard ◽  
Southeast Asia ◽  
Historical Earthquakes ◽  
Historical Seismicity ◽  
Point Of View ◽  
Malay Peninsula ◽  
Building Stock ◽  
Period Effects ◽  
Need To Evaluate ◽  
The Impact

Abstract Seismic hazard in the southern Malay Peninsula located within the Sundaland block in Southeast Asia is poorly understood. The paucity of historical earthquakes and low-magnitude instrumented seismicity has led to the assumption that this region is largely aseismic. We question this point of view by reassessing historical seismicity in this region and, in particular, a pair of moderate earthquakes in the 1920s. The first of these struck on 31 January 1922 at ≈9:10  a.m. local time (LT) for which we estimate an intensity magnitude (MI) ≈5.4, and for the second earthquake on 7 February 1922 at ≈12:15  p.m. LT, we estimate MI≈5.0. We also identify at least 34 felt earthquakes between 1803 and 1950 that were potentially local within the Sundaland block. These include a very widely felt shock (or set of shocks) on 26 June 1874 that was felt in parts of Borneo, Java, and Sumatra. The discovery of these earthquakes challenges the tectonic stability of the Malay Peninsula and the stable interior of the Sundaland block. The record of historical seismicity in this region relies heavily on European sources, and we recommend locating and consulting indigenous sources to improve the current understanding of regional seismic hazard. We also underscore the need to evaluate the impact of ground motions from rare local earthquakes on the extant building stock and on transportation infrastructure that are otherwise relatively immune to the long-period effects of distant earthquakes commonly felt in the Malay Peninsula.

scholarly journals Uncertain historical earthquakes and seismic hazard: theoretical and practical considerations

2013 ◽  
Vol 5 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Päivi Mäntyniemi ◽  
Ruben E. Tatevossian ◽  
Tatiana N. Tatevossian
Keyword(s):  
Seismic Hazard ◽  
Historical Earthquakes

The analysis of historical seismograms: an important tool for seismic hazard assessment. Case histories from French and Italian earthquakes

2011 ◽  
Vol 182 (4) ◽  
pp. 367-379 ◽  
Author(s):  
Nicola Alessandro Pino
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Southern Italy ◽  
Source Parameters ◽  
Seismic Hazard Assessment ◽  
Historical Earthquakes ◽  
Waveform Analysis ◽  
Source Characteristics ◽  
Seismic Waveform ◽  
Earthquake Source Parameters

AbstractSeismic hazard assessment relies on the knowledge of the source characteristics of past earthquakes. Unfortunately, seismic waveform analysis, representing the most powerful tool for the investigation of earthquake source parameters, is only possible for events occurred in the last 100–120 years, i.e., since seismographs with known response function were developed. Nevertheless, during this time significant earthquakes have been recorded by such instruments and today, also thanks to technological progress, these data can be recovered and analysed by means of modern techniques.In this paper, aiming at giving a general sketch of possible analyses and attainable results in historical seismogram studies, I briefly describe the major difficulties in processing the original waveforms and present a review of the results that I obtained from previous seismogram analysis of selected significant historical earthquakes occurred during the first decades of the XXth century, including (A) the December 28, 1908, Messina straits (southern Italy), (B) the June 11, 1909, Lambesc (southern France) – both of which are the strongest ever recorded instrumentally in their respective countries –and (C) the July 13, 1930, Irpinia (southern Italy) events. For these earthquakes, the major achievements are represented by the assessment of the seismic moment (A, B, C), the geometry and kinematics of faulting (B, C), the fault length and an approximate slip distribution (A, C). The source characteristics of the studied events have also been interpreted in the frame of the tectonic environment active in the respective region of interest. In spite of the difficulties inherent to the investigation of old seismic data, these results demonstrate the invaluable and irreplaceable role of historical seismogram analysis in defining the local seismogenic potential and, ultimately, for assessing the seismic hazard. The retrieved information is crucial in areas where important civil engineering works are planned, as in the case of the single-span bridge to be built across the Messina straits and the ITER nuclear fusion power plant to be built in Cadarache, close to the location of the Lambesc event, and in regions characterized by high seismic risk, such as southern Apennines.

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