A special mechanism for some Antarctic earthquakes

Abstract

Frequent small earthquakes recorded at Scott Base constitute the main seismic activity so far discovered within Antarctica. Prominent in many Scott Base seismograms is a sinusoidal wave of period 1½-2 sec with an onset velocity of about 650 m/sec; this has been interpreted as an air-coupled wave associated with flexural waves in the Ross Ice Shelf. Other unusual features of the earthquakes also suggest that they are caused by fractures in the ice near the shelf edge, leading to the calving of icebergs.