Abstract
The Pukaki microearthquake network has revealed significant earthquake activity deeper than 15 km in the central South Island, New Zealand, extending to a depth of 73 km beneath the crest of the Southern Alps. Events deeper than 25 km define a planar seismic zone that has a strike of 41° and dips northwest at 19°. Gravity models suggest that earthquakes in this zone are occurring in a seismogenic uppermost mantle underlying an aseismic lower crustal root to the Southern Alps. The 17° difference in strike of the dipping seismic zone and the Alpine fault provides an explanation for the pattern of uplift and crustal thickening seen in the central South Island.
This content is PDF only. Please click on the PDF icon to access.
You do not have access to this content, please speak to your institutional administrator if you feel you should have access.