The Dependence of the Earthquake Parameter Determination Uncertainties on the Set of Surface Wave Records

Abstract—For determining the focal mechanism and source depth of an earthquake, a frequent practice is to use surface wave records which can be highly noisy. In this case, these records should be preliminarily selected and filtered in a certain spectral band using a frequency-time analysis program. In this paper, we study how the determination uncertainties of earthquake parameters (source depth and focal mechanism) depend on the set of the records used in the analysis. For doing this, we use the jackknife statistical procedure. The results are presented for four events: the strongest aftershock in Tohoku, Japan, that occurred on March 11, 2011, the earthquake of April 25, 2015 in Nepal, and two earthquakes in Alaska on January 23 and November 30, 2018. The analysis conducted for these events shows that the effect of the selected set of records on the determination error of earthquake parameters depends on the focal mechanism and the source depth of the earthquake, the number of the considered records, and the degree of detail of the parametric grid used for constructing the earthquake source model.