Problems of Engineering Seismology: article

Macroseismic intensity increment for seismic stations of Kamchatka relative to seismic station «Petropavlovsk»
Y. Shevchenko
V. Yakovenko
Kamchatka Branch of Federal Research Center «United Geophysical Survey of RAS», Petropavlovsk-Kamchatsky, Russia
Journal: Problems of Engineering Seismology
Tome: 44
Number: 4
Year: 2017
Pages: 63-76
UDK: 550.34
DOI: 10.21455/VIS2017.4-4
Keywords: macroseismic, intensity, increment, Kamchatka
Аnnotation: The method and results of calculating the increment of macroseismic intensity at seismic stations in Kamchatka are presented. The basis of the calculation is the measurement of the relative level of maximum accelerations of intense earth vibrations in the phase of S -wave of comparatively strong regional earthquakes and the root-mean-square deviation of acceleration in the phase of P -waves of a strong distant earthquake. In the latter case, records of an earthquake with a magnitude of 9.1, which occurred in Japan on 11.03.2011, were used. The seismic station "Petropavlovsk" was used as a reference station. At the base of the pedestal of this station is a rocky soil, composed of siliceous shales. The estimation of the increment for the majority of digital stations is presented. Anomalously high values of intensity were noted at a number of stations. The data obtained are used to assess the properties of soils in the investigated area. At several stations, the intensity of the horizontal component of soil vibrations above the intensity of the vertical component is much greater than the corresponding design value, which is probably due to the presence of resonant soil layers under these stations. The discrepancy in the intensity incremental estimates from the records of intense oscillations from regional earthquakes and from records of a very strong distant earthquake obtained from sensors located in basements of heavy frame structures from concrete is revealed. To avoid distortion of recording ground vibrations, it is desirable to place seismic instruments away from such structures. The results obtained in the work can be used for seismic microzoning of construction sites located on the investigated territory.