scholarly journals CHINGIZ EARTHQUAKE on January 20, 2015, KR=12.2, mb=5.6, I_0^P=5–6 NEAR the SEMIPALATINSK POLYGON (Eastern Kazakhstan)

Author(s):  
A. Mukambayev ◽  
N. Mikhailova ◽  
A. Sokolov

The work presents the results of data analysis of the earthquake on January 20, 2015, mb=5.6 occurred at the low-active region of Eastern Kazakhstan near the border of the former Semipalatinsk Test Site. The work briefly describes the seismicity of the Semipalatinsk Test Site related to aseismic regions according to the acting map of general seismic zoning. The earthquake was recorded by permanent seismic stations of the Institute of Geophysical Research of the Ministry of Energy of the Republic of Kazakhstan and by two strong-motion accelerometers. The earthquake was felt at distances up to 300 km from the epicentre, its maximum intensity was noted at Medeu settlement where the shaking intensity was 56 by the MSK-64 scale. The earthquake focal mechanism is shown, the parameters of seismic effects and response spectra are calculated.

Author(s):  
N. Mikhailova ◽  
I. Sokolova ◽  
B. Bektyurganova

In 2015, the seismic monitoring in Kazakhstan was conducted by two Organizations: Seismological Experience-Methodical Expedition of the Ministry of Education and Science of the Republic of Kazakhstan (SEME), and the Republican State Enterprise Institute of Geophysical Research of the Ministry of Energy of the Republic of Kazakhstan (IGR). The paper presents detailed information on seismic observation networks. The joint catalogue based on the data of two organizations was compiled. It includes 489 earthquakes having energy class KR=6.6–12.2. The largest earthquake occurred on January 20, 2015 near the Semipalatinsk Test Site. The earthquake had magnitude MPVA=5.3, energy class KR=12.2, and was felt in a range of Kazakhstan settlements.


2020 ◽  
Vol 24 (11) ◽  
pp. 30-35
Author(s):  
G.M. Yessilkanov ◽  
M.T. Dyussembayeva ◽  
L.P. Rikhvanov ◽  
N.Zh. Mukhamediyarov ◽  
A.Zh. Tashekova

The results of the study of ecological and geochemical features and assessment of the water quality of water sources located on the territory of the Semipalatinsk test site are presented. The studied waters are diverse in chemical composition: 14 % of the samples had hydrocarbonate, 69 % – sulfate, and 17 % – chloride types of waters. On the basis of the revealed features of the elemental composition of the underground waters of the Semipalatinsk test site, decreasing series of excess of the average concentrations of elements in water in relation to the composition of waters of the zones of hypergenesis and continental salinization were constructed: U14 > Mo8 > Sr8 > V3 (hypergenesis zone), U5 > Mo3 > Sr3 > V2 (zone of continental salinization). For the groundwater of the Semipalatinsk test site, specific elements were identified, such as U, Mo, Sr and V. The water quality was assessed for the studied chemical components based on comparison with the standards of the Republic of Kazakhstan and the World Health Organization (SaNPiN No. 209, WHO 2011).


Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 74
Author(s):  
Luis A. Pinzón ◽  
Luis G. Pujades ◽  
Irving Medranda ◽  
Rodrigo E. Alva

In this work, the directionality effects during the MW 7.8 earthquake, which occurred in Muisne (Ecuador) on 16 April 2016, were analyzed under two perspectives. The first one deals with the influence of these effects on seismic intensity measures (IMs), while the second refers to the assessment of the expected damage of a specific building located in Manta city, Ecuador, as a function of its azimuthal orientation. The records of strong motion in 21 accelerometric stations were used to analyze directionality in seismic actions. At the closest station to the epicenter (RRup = 20 km), the peak ground acceleration was 1380 cm/s2 (EW component of the APED station). A detailed study of the response spectra ratifies the importance of directionality and confirms the need to consider these effects in seismic hazard studies. Differences between IMs values that consider the directionality and those obtained from the as-recorded accelerograms are significant and they agree with studies carried out in other regions. Concerning the variation of the expected damage with respect to the building orientation, a reinforced concrete building, which was seriously affected by the earthquake, was taken as a case study. For this analysis, the accelerograms recorded at a nearby station and detailed structural documentation were used. The ETABS software was used for the structural analysis. Modal and pushover analyses were performed, obtaining capacity curves and capacity spectra in the two main axes of the building. Two advanced methods for damage assessment were used to obtain fragility and mean damage state curves. The performance points were obtained through the linear equivalent approximation. This allows estimation and analysis of the expected mean damage state and the probability of complete damage as functions of the building orientation. Results show that the actual probability of complete damage is close to 60%. This fact is mainly due to the greater severity of the seismic action in one of the two main axes of the building. The results are in accordance with the damage produced by the earthquake in the building and confirm the need to consider the directionality effects in damage and seismic risk assessments.


2002 ◽  
Vol 18 (1) ◽  
pp. 1-17 ◽  
Author(s):  
K. Anastassiadis ◽  
I. E. Avramidis ◽  
P. Panetsos

According to the model of Penzien and Watabe, the three translational ground motion components on a specific point of the ground are statistically noncorrelated along a well-defined orthogonal system of axes p, w, and v, whose orientation remains reasonably stable over time during the strong motion phase of an earthquake. This orthotropic ground motion is described by three generally independent response spectra Sa, Sb, and Sc, respectively. The paper presents an antiseismic design procedure for structures according to the above seismic motion model. This design includes a) determination of the critical orientation of the seismic input, i.e., the orientation that gives the largest response, b) calculation of the maximum and the minimum values of any response quantity, and c) application of either the Extreme Stress Method or the Extreme Force Method for determining the most unfavorable combinations of several stress resultants (or sectional forces) acting concurrently at a specified section of a structural member.


1990 ◽  
Vol 80 (6B) ◽  
pp. 2089-2105 ◽  
Author(s):  
Thomas J. Sereno

Abstract The frequency-dependent attenuation of regional seismic phases recorded by three stations near the nuclear explosion test site in eastern Kazakhstan is estimated by inverting spectra from 21 events with magnitudes between 2.3 and 4.6 at distances between 200 and 1300 km. The Pn spectra are inverted between 1 and 10 Hz, and the Lg spectra are inverted between 0.5 and 2.5 Hz. The motivation for this study is that previous estimates of detection capability in the Soviet Union are based on data recorded in other regions (eastern North America and Scandinavia) and therefore have large uncertainty. The data recently recorded in eastern Kazakhstan provide an excellent opportunity to compare regional wave propagation and noise characteristics at these sites to conditions assumed in previous detection capability simulations. It is found that attenuation in eastern Kazakhstan is not much different from attenuation in Scandinavia, but it is greater than attenuation in eastern North America. This implies that estimates of detection thresholds that assume attenuation like that observed in eastern North America will be lower than estimates of detection thresholds that assume attenuation like that observed in eastern Kazakhstan or Scandinavia. However, it is not known how well data recorded in eastern Kazakhstan represent conditions in other areas of the Soviet Union.


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