Operational Determination of Double-Couple Moment Tensors of Kamchatka and Commander Islands Earthquakes in 2023

The Kamchatka Branch, Federal Research Center Geophysical Survey, Russian Academy of Sciences (KB FRC GS RAS) has carried out studies to determine the focal mechanisms of the Kamchatka and Commander Islands earthquakes. Since the early 1970s, these mechanisms have been calculated based on the signs of the first arrival of body waves. Since 2010, with the deployment of a broadband digital seismic network in Kamchatka, seismic moment tensors have been determined using the regional seismic moment tensor (RSMT) technique developed at the KB FRC GS RAS. Since January 1, 2023, focal mechanisms and parameters have been determined using RSMT on an online basis; maintenance of the catalog based on the signs of first arrivals has been completed. This article presents the operational catalog of focal mechanisms and parameters of Kamchatka earthquakes for 2023 obtained at KB FRC GS RAS using RSMT for double-couple tensors without a moment. The determined focal mechanisms of focal points, moment magnitude MW, and equivalent point source depths given in the catalog agree well with the solutions obtained by the Global Centroid Moment Tensor (GCMT) Agency.