50 USGS earthquake moment tensor catalog

Abstract

The US Geological Survey's National Earthquake Information Center (NEIC) has been computing moment tensor solutions for all moderate-to-large sized earthquakes. Station coverage is mainly responsible for the ability to move the magnitude thresholds lower with time. The inversion procedure is based on multichannel signal enhancement theory. This inversion technique is applied to digitally recorded broadband P -waveform data from US National Network (USNSN) and Global Seismograph Network (GSN) stations that have good signal-to-noise ratios and that are located at epicentral distances between 30° and 95°. The moment tensor solutions, along with the hypocentral parameters determined by the NEIC, are listed in the files such as (1) MT.LIS, which contains the elements of the moment tensors along with detailed event information; (2) FMECH.LIS, which contains the decompositions into the principal axes and best double-couples; and (3) FMECH.DOC, which describes the various fields.