Effective discrimination of icequakes on seismic records from Mawson station

The telemetered seismic station at Mawson, Antarctica, was one of the prima ry Australian stations participating in the Group of Scientific Experts Tec hnical Test (GSETT) experiment to test an international seismic monitoring system. Mawson signals are continuously transmitted to the National Data Ce nter (NDC) in Canberra and also forwarded to the International Data Centre (IDC) in Washington, where further event analysis is performed. Numerous se ismic signals are recorded on seismograms from the Mawson station, with a l ikely mechanism of sudden fracturing of ice. The aim of this study was to f ind a procedure which will effectively discriminate seismic signals from th ese icequakes and thus speed up the analysis of the other detected events. An automatic algorithm was designed to identify icequakes according to thei r characteristics: frequency content, duration, azimuth, inclination and ma gnitude. The program was tested on a few datasets of randomly selected peri ods and one comprised of records of nuclear explosions detonated in the per iod of 1995/96. The preliminary results showed that this method was capable of distinguishing icequakes and could substantially improve the production of an automated event list. (C) 1999 Elsevier Science B.V. All rights rese rved.