Green’s Functions Determined From Moment Tensors

Date: 4/25/2019

Time: 11:30 AM

Room: Cascade I

The determination of moment tensors of earthquakes requires observations from many stations, good station coverage of the focal zone, accurate locations, and good knowledge of the velocity model. All this information is needed for calculating a large set of Green’s functions, which is the key and most difficult point in the moment tensor inversion. Obviously, if the Green’s functions cannot be calculated for some stations because of a complex structure, unknown site effects or unknown amplification of sensors, such data are lost for the inversion. In this paper, we propose a method of retrieving the Green’s functions for such ‘problematic’ stations. If the target focal zone is active and sufficiently small with respect to the epicentral distance, a set of available moment tensors calculated from a network of reliable stations can be used for determining the Green’s functions of the problematic stations. Once the Green’s functions are obtained, moment tensors of the other earthquakes that occurred in the target focal zone can be calculated using a full network of stations. The efficiency of the proposed method is tested on synthetic data. Finally, the method is applied to local observations of micro-earthquakes in West Bohemia, Czech Republic.

Presenting Author: Vaclav Vavrycuk

Authors