Seismic instruments: article

RELOCATION OF THE EARLY INSTRUMENTAL EARTHQUAKES IN THE ARCTIC
MOROZOV ALEXEY NIKOLAEVICH1
VAGANOVA NATALYA VLADISLAVOVNA2
ASMING VLADIMIR ERNESTOVICH3
KREMENETSKAYA ELENA OLEGOVNA3
1 Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences, 123242, Moscow, ul. Bolshaya Gruzinskaya, 10, building 1 2 N. Laverov Federal Center for Integrated Arctic Research of the Ural Branch of the Russian Academy of Sciences, Russia, 163000, Arkhangelsk, nab. Severnoy Dviny 23 3 Kola Branch of Geophysical Survey of the Russian Academy of Sciences, Russia, 184200, Apatity, Murmansk region, Fersman str. 14
Journal: Seismic instruments
Tome: 57
Number: 4
Year: 2021
Pages: 5-20
UDK: 550.34
DOI: 10.21455/si2021.4-1
Keywords: SEISMICITY OF THE ARCTIC, EARLY INSTRUMENTAL EARTHQUAKES, REFINEMENT OF THE SOURCE PARAMETERS
Аnnotation: The calculation of the parameters of earthquake sources in the Arctic during the entire instrumental period took place under conditions of a small number of stations and their remoteness from each other. At the same time, during the 20th century, the parameters of the sources of Arctic earthquakes, most often, were calculated on the basis of the bulletins data of only a part of the seismic stations that operated at that time, using outdated velocity models and location algorithms. This article describes an approach that is successfully used by the authors to refine the parameters of the sources of early instrumental earthquakes in the Arctic. The approach is based on the use of all currently available archives of bulletins and seismograms of seismic stations operating at the beginning of the 20th century, the modern velocity model ak 135 and an improved location algorithm implemented in the NAS program. We have relocated earthquakes recorded within the Arctic region beginning from the early 20th century with a view to creating a relocated catalog. The transfer procedure was applied to 18 of the 25 earthquakes in the Arctic region. The new coordinates of some earthquakes turned out to be significantly different from the previously determined ones. As a result, this can significantly affect the final assessment of the seismic hazard of the territory of the Severnaya Zemlya and Franz Josef Land archipelagoes, which are characterized by weak seismicity. Most of the displaced earthquake epicenters are confined to the main seismic zones of the Arctic, namely to the mid-ocean ridges, the Spitsbergen archipelago and the Laptev Sea shelf.