Scaling of two corner frequencies of source spectra for earthquakes of the Bering fault

Abstract

The Komandorsky Islands region, tectonically, is unique, being at the junction of the Pacific plate and Bering plate, surrounded by edges of two subduction zones. The tectonic deformation is distributed in the region between a few sub parallel shear faults, of which the Aleutian transform is the most evident. Another one, the Bering fault, was activated again in 2017, when on its section the 7.8 earthquake caused a tsunami of limited scale. In this paper for the first time for earthquakes of this region with of 3.0-7.0, using more than 500 records of 6 stations equipped by accelerometers, within 300 km from the epicenters, source spectra of S-waves were recovered. The seismic moment and two corner frequencies were determined. Also, the presence of two separate corner frequencies were checked with the spectral ratio method. The estimates of the first, 1 , and second, 2 , corner frequencies were used to study their scaling properties. We found that 1 scales as −0.34±0.02 0 what agrees with assumption of source similarity, and 2 scales as −0.18±0.01 0 what disagrees. In few cases, the third corner frequency of source acceleration spectra were observed.