Sherburn, S.; Scott, B.J.; Nishi, Yuji; Sugihara, Mituhiko 1993 White Island seismic experiment 1992 : preliminary report on microearthquake locations. Lower Hutt: Institute of Geological & Nuclear Sciences Institute of Geological & Nuclear Sciences science report 93/33 14 p.
Abstract: During the period January to March 1992, a joint DSIR Geology and Geophysics and Geological Survey of Japan microearthquake survey was conducted at White Island Volcano. Almost three thousand volcano-tectonic or volcanic earthquakes and/or short short sequences of volcanic tremor were recorded during the survey. Preliminary analysis of these data has been undertaken, and locations for about fifty volcano-tectonic earthquakes have been determined. Earthquakes were concentrated beneath Main Crater at depths of up to 2.5 km, with some also occurring on the northern flanks of the island. However, there were very few earthquakes at depths between 1.5 km and 2 km beneath Main Crater, and this may be related to the location of magma beneath the island. The first focal mechanism so far obtained from a White Island volcano-tectonic earthquake shows normal faulting down to the east on a fault plane oriented north-south. (auth)