排序方式： 共有29条查询结果，搜索用时 31 毫秒
1.
A. A. Gusev E. I. Gordeev E. M. Guseva A. G. Petukhin V. N. Chebrov 《Pure and Applied Geophysics》1997,149(2):299-312
—To estimate for the first time the typical relation between peak acceleration A max?, moment magnitude M W and hypocentral distance R for Kamchatka, 101 analog strong motion records for 1969–1993 were employed as the initial data set. Records of acceleration and velocity meters were obtained at 15 rock to medium-ground Kamchatkan sites from 33 earthquakes with M W = 4.5–7.8, at R = 30–250?km. A max values were determined from "true" acceleration time histories calculated by spectral deconvolution of digitized records. The maximum value over the two horizontal components was used as the A max value in the further analysis. With the scarce data available, there were no chances to determine reliably the whole A max?(M W ?,?R) average surface; thus the shape of this trend surface was determined on a theoretical basis and only the level was fitted to the data. The theoretical model employed included: (1) source spectrum: according to the Brune's spectral model; (2) point-source attenuation: as 1/R plus loss specified by Q(f) = 250?f 0.8; (3) finite-source correction for a disc-shaped incoherent source, its size depending on M W ?; (4) accelerogram duration: including source-dependent and distance-dependent terms; (5) A max value: based on random process representation. Distance trends calculated with this model agree with the empirical ones of FUKUSHIMA and TANAKA (1990). To calculate the absolute level for these trends, observed A max?(M W ?,?R) values were reduced to M W = 8, R = 100?km using the theoretical trends as reference. The median of the reduced values, A max?(8,?100), equal to 188?gal. was taken as the absolute reference level for the relation we sought. Note that in the process of data analysis we were forced to entirely reject relatively abundant data of two particular stations because of their prominent local amplification (×5.5) or deamplification (×0.45). 相似文献
2.
Variations of seismic mode in the region of the Avachinsky Gulf (Kamchatka, Russia) are considered. Observed anomalies (seismic quiescence, the ring seismicity, reduction of the slope of the earthquake recurrence diagram) provide a basis to consider this region as a place of strong earthquake preparation. The Kamchatka regional catalogues of earthquakes between 1962–1995 were used in the analysis. A reduced seismicity rate is observed during 10 years in an area of 150 km × 60 km in size. During the last five years, in the vicinity of the area considered, earthquakes with M > 5 occurred three times more often than the average over thirty years. It is interpreted as ring seismicity. The block of 220 km × 220~km in size, including the quiescence zone, is characterized by a continuous decrease of the recurrence diagram slope, which has reached a minimum value for the last 33 years in this region. 相似文献
3.
The aftershock processes that occurred in 1990–2008 on the Kamchatka Peninsula and in the adjacent water area are numerically modeled with the aim of forecasting the aftershock activity. The aftershocks are identified by the Molchan-Dmitrieva algorithm followed by the analysis of spatiotemporal distribution of the earthquakes, which gives the final aftershock sequences. The simulations are based on the relaxation and triggering models of the aftershock processes. The studied models adequately describe and reliably simulate the temporal behavior of the aftershock sequences. An attempt is made to forecast the aftershock processes in Kamchatka using the ETAS model. It is shown that forecasting based on the data observed during the preceding time intervals is quite accurate. This approach can be applied in the centers of seismological monitoring for estimating the aftershock activity within the first days after a strong earthquake.
相似文献4.
We studied broadband digital records of the M
W
= 7.6 Olyutorskii earthquake of April 20, 2006 and its aftershocks at local and regional distances. We have made a detailed
analysis of data on peak ground motion velocities and accelerations due to aftershocks based on records of two digital seismic
stations, Tilichiki (TLC) and Kamenskoe (KAM). The first step in this analysis was to find the station correction for soil
effects at TLC station using coda spectra. The correction was applied to the data to convert them to the reference bedrock
beneath the Kamenskoe station. The second step involved multiple linear regression to derive average relationshis of peak
amplitude to local magnitude ML and distance R for the Koryak Upland conditions. The data scatter about the average relationshis is comparatively low (0.22–0.25 log units).
The acceleration amplitudes for M
L
= 5, R = 25 km are lower by factors of 2–3 compared with those for eastern Kamchatka, the western US, or Japan. A likely cause of
this anomaly could be lower stress drops for the aftershocks. 相似文献
5.
I. Popova A. Rozhnoi M. Solovieva B. Levin V. Chebrov 《Izvestiya Physics of the Solid Earth》2016,52(2):305-317
In this paper, we suggest a technique for forecasting seismic events based on the very low and low frequency (VLF and LF) signals in the 10 to 50 Hz band using the neural network approach, specifically, the error back-propagation method (EBPM). In this method, the solution of the problem has two main stages: training and recognition (forecasting). The training set is constructed from the combined data, including the amplitudes and phases of the VLF/LF signals measured in the monitoring of the Kuril-Kamchatka region and the corresponding parameters of regional seismicity. Training the neural network establishes the internal relationship between the characteristic changes in the VLF/LF signals a few days before a seismic event and the corresponding level of seismicity. The trained neural network is then applied in a prognostic mode for automated detection of the anomalous changes in the signal which are associated with seismic activity exceeding the assumed threshold level. By the example of several time intervals in 2004, 2005, 2006, and 2007, we demonstrate the efficiency of the neural network approach in the short-term forecasting of earthquakes with magnitudes starting from M ≥ 5.5 from the nighttime variations in the amplitudes and phases of the LF signals on one radio path. We also discuss the results of the simultaneous analysis of the VLF/LF data measured on two partially overlapping paths aimed at revealing the correlations between the nighttime variations in the amplitude of the signal and seismic activity. 相似文献
6.
V. N. Chebrov D. V. Droznin S. Ya. Droznina N. Z. Zakharchenko Yu. A. Kugaenko D. V. Melnikov V. N. Mishatkin Ya. D. Murav’ev I. N. Nuzhdina A. V. Rybin S. L. Senyukov V. A. Sergeev S. S. Serovetnikov N. N. Titkov P. P. Firstov V. V. Yaschuk 《Seismic Instruments》2013,49(3):254-264
This work presents the project of the first stage of implementation of the integrated instrumental system of volcanic activity monitoring in Kamchatka and the Kuril Islands. The system of monitoring was designed for the purpose of ensuring public safety, aviation safety, and reducing economic losses caused by volcanic eruptions. The most active and dangerous volcanoes in Kamchatka (North and Avacha groups of volcanoes) and the Kuril Islands (volcanoes on the islands of Kunashir and Paramushir) are of first priority for monitoring. For this purpose, special observation points are planned to be installed on the volcanoes. The system of monitoring will include a complex of observations (broadband seismic station with a large dynamic range, tiltmeter, devices for gas, acoustic, and electromagnetic observations, and video camera). All the data will be passed to information processing centers in real time. New methods and algorithms of automatic and automated identification of the volcanic activity level and the probabilistic volcano hazard assessment have been developed. 相似文献
7.
A number of terrain features and objects of the settlements of Tilichiki and Korf and the village of Khailino in the epicentral zone of the strongest earthquake in the north of the Kamchatka region were examined in the first days after the earthquake. Primary and secondary coseismic ruptures were identified on the surface. An outcrop of the seismic source was discovered in the form of an extended seismic fault about 140 km in traceable length. The settlements were inspected for the purpose of elucidating the macroseismic effect, structural maps were compiled, and the main types of ruptures were identified. The network of seismic stations on Kamchatka and in eastern Russia recorded a few thousand aftershocks. The gathered data provide insight into the structure of the source and its tectonic position at the Asian active continental margin. 相似文献
8.
V. N. Chebrov D. V. Droznin N. Z. Zakharchenko V. N. Mishatkin V. A. Sergeyev V. A. Sinitsyn Yu. V. Shevchenko 《Seismic Instruments》2011,47(1):1-7
Hardware and software are developed for the first base seismic station in the modernized seismic subsystem for tsunami warning
on Kamchatka. The station is formed as a seismic array. The structure of the equipment and its communication systems are described.
The station is introduced into experimental operation. The first results of recording of a local strong earthquake at points
of the Petropavlovsk station are discussed. 相似文献
9.
O.Molchanov E.Fedorov A.Schekotov E.Gordeev V.Chebrov V.Surkov A.Rozhnoi S.Andreevsky D.Iudin S.Yunga A.Lutikov M.Hayakawa P.F.Biagi 滕荣荣 《世界地震译丛》2009,(2):40-52
介绍了大气层和电离层震前现象机制的基本观念。简短回顾了观测结果后,我们得出结论：1．流体下层物质（气泡）向上迁移能导致近地表的热水／气体被逐出,并在强度弱化的地区引发地震;2．因此,气泡出现的时间和地点是随机的,但是地震、地球化学异常和前震（地震、SA和超低频电磁异常）是随机关联的;3．大气温度和密度扰动跟随着震前热水／气体释放,导致产生周期为6～60min的大气重力波（AGW）;4．地震引发的大气重力波能导致电离层扰动变化并导致大气层中地平线上无线电波传播、下部电离层低频波扰动和地面超低频辐射衰减的变化。 相似文献
10.
V. N. Chebrov A. A. Gusev V. K. Gusyakov V. N. Mishatkin A. A. Poplavskii 《Seismic Instruments》2010,46(3):275-285
The initial information and requirements for developing a seismologic observation system and data-processing and transfer
tools for a tsunami warning system and its functions and tasks are considered. The structure of the seismologic observation
system for the tsunami warning service (TWS) in the Russian Far East is proposed. A study of general technical and methodological
problems is carried out to increase the efficiency for urgent tsunami prediction from continuous seismic monitoring data of
territories of the Russian Far East and the world. Special attention is paid to the problem of tsunami prediction from seismologic
data on strong earthquakes in near zone of a protected territory (up to 200 km). 相似文献