Structural positions and settings of the paleoearthquakes in area of the mount Vottovaara (Middle Karelia, eastern part of the Fennoscandian sheet)
1 Institute of Geography, Russian Academy of Sciences, Moscow, Russia
2 Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russia
3 Institute of Earthquake Prediction Theory and Mathematical Geophysics, Russian Academy of Sciences, Moscow, Russia
4 Institute of Marine Geology and Geophysics, Far Eastern Branch of the Russian Academy of Sciences, Yuzhno-Sakhalinsk, Russia
2 Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russia
3 Institute of Earthquake Prediction Theory and Mathematical Geophysics, Russian Academy of Sciences, Moscow, Russia
4 Institute of Marine Geology and Geophysics, Far Eastern Branch of the Russian Academy of Sciences, Yuzhno-Sakhalinsk, Russia
Journal: Problems of Engineering Seismology
Tome: 44
Number: 2
Year: 2017
Pages: 35-60
UDK: 551.248+550.34+551.432
DOI: 10.21455/VIS2017.2-3
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Shvarev S., Rodkin M. Structural positions and settings of the paleoearthquakes in area of the mount Vottovaara (Middle Karelia, eastern part of the Fennoscandian sheet) // . 2017. Т. 44. № 2. С. 35-60. DOI: 10.21455/VIS2017.2-3
@article{ShvarevStructural2017,
author = "Shvarev, S. and Rodkin, M.",
title = "Structural positions and settings of the paleoearthquakes in area of the mount Vottovaara (Middle Karelia, eastern part of the Fennoscandian sheet)",
journal = "Problems of Engineering Seismology",
year = 2017,
volume = "44",
number = "2",
pages = "35-60",
doi = "10.21455/VIS2017.2-3",
language = "English"
}
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Keywords: paleoearthquakes, morphostructure, parametrization, paleoseismodeformations
Аnnotation: Evidences of strong paleoearthquakes in the Fennoscandia have been noted by many researchers for several decades. In Sweden, Norway, and Finland numerous postglacial discontinuities in the crystalline basement accompanied by a complex of deformations in loose sediments were discovered, and the spatial correlation of the postglacial fault deformations with the modern seismicity was established. In the Russian sector of Fennoscandia the structures of similar magnitude have not been detected yet, but the signs of strong paleoearthquakes in rock deformations and in postglacial deposits were found by different groups of researchers. The totality of data makes it possible to reveal the linear zones of paleoearthquake concentrations (seismolineaments) that can be seen also both in modern relief and in recent weak seismicity. However, the post-glacial seismicity remains controversial both in the issue of localization of foci, and in their genesis and regime. Besides, the question of discrimination between seismogenic, cryogenic, and glacial dislocations is crucial. Having aforementioned in mind the problem of parametrization of paleoearthquakes, concerning their nature, localization, age, and magnitude are actual. One of the key areas of strong seismic deformations occurs in the Votovaara Mountain area in the middle Karelia, it belongs to the Vottovaara-Girvas seismolineament where numerical seismic deformations were revealed. For the detailed study of this area the remote sensing data, field geological and geomorphological observations, and computational methods for estimating the peak values of mass velocities (PGVs) occurring during paleoearthquakes were used. Zones of development of different types of seismic deformations were revealed. A supposed seismogenerating fault related to the Vottovaara-Girvas seismolineament of the northwestern strike was found, and its probable shear kinematics was determined from the direction of impulses of rock blocks located on different wings of the fault. The sequence of a few strong events which occurred here in pre-glacial (inter-glacial) and post-glacial period was found. The effects of interaction between the seismic activity and the glacial deformation have been revealed also. The estimations of paleointensity were carried out from the macroseismic scale INQUA, the new scale of F.F. Aptikayev, and from the nomogram of M.V. Rodkin. According to the agreed estimations, the last strong seismic event of the Early Holocene, which occurred here according to A.D. Lukashov 8.9 thousand of years ago, was of intensity 9-10 and magnitude 7.5-8. The presented work was carried out using a number of new approaches developed by the authors and allowed studying the paleoseismicity in more details.