On the relationship between seismic activity and structural features of the crust and upper mantle and the Earth's rotation rate (using the example Garm prognostic polygon)

2013;
: pp. 87 - 89
https://doi.org/10.23939/jgd2013.02.087
Received: June 26, 2013
Authors:
1
Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences

Purpose. The purpose of researches – to search the relation of the seismicity, structure of the crust and upper mantle in the Garm region, and - to search of  relation of earthquake scale and the speed of rotation of the Earth. Methodology. A joint analysis of variations of seismic activity and the Earth's rotation for the 1895-2010 years was carried out. Spatial variations in the attenuation field, as a basis of the blocks structure in Garm region, was obtained by the method of short-period coda-waves. Results. The findings suggest that in the Garm region not only strong earthquakes with M ≥ 6.0, but the earthquake of moderate intensity (M = 5.0-5.5), usually associated with specific zones. Within these zones, there are blocks that can, under certain conditions to consolidate into a single conglomerate. This conglomerate blocks accumulate the energy required for the realization of the quake. The possibility of mutual displacement of lithospheric blocks are provided by the existence of weakened zones composed from material with low  viscosity, which are located directly below the relatively  thin and crushed crust. Originality The joint analysis of variations in seismic activity and the rate of rotation of the Earth reveals the existence of definite relation between the size the earthquake and the average speed of rotation of the Earth. In the same area a stronger earthquake occurs at higher speeds of rotation of the Earth than weaker. The energy of the earthquake is also determined by the stage of consolidation units in the source area. Practical significance. The results can be used in solving the problems of earthquake prediction.

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