HR: 09:00h
AN: G31A-05    [Abstracts]
TI: Slow slip events, temperature, and interseismic coupling at the Hikurangi subduction zone, New Zealand
AU: * McCaffrey, R
EM: mccafr@rpi.edu
AF: GNS Science, PO Box 30368, Lower Hutt, New Zealand
AU: Wallace, L M
EM: L.Wallace@gns.cri.nz
AF: GNS Science, PO Box 30368, Lower Hutt, New Zealand
AU: Beavan, J
EM: J.Beavan@gns.cri.nz
AF: GNS Science, PO Box 30368, Lower Hutt, New Zealand
AU: Douglas, A
EM: A.Douglas@gns.cri.nz
AF: GNS Science, PO Box 30368, Lower Hutt, New Zealand
AB: The Pacific Plate subducts beneath New Zealand's North Island at the Hikurangi subduction zone. Campaign GPS results show that large portions of the subduction thrust are locked during the interseismic period. However, the down-dip limit of locking beneath the southern North Island is deeper (35 to 50 km) than beneath the northern and central North Island where it terminates at 10 to 15 km depth. Continuous GPS in New Zealand operating since 2002 has revealed several slow slip events (SSE) on the Hikurangi subduction zone. We observe a rich variety of SSEs with widely varying durations, depths, magnitudes and recurrence intervals. Thus far, we observe that deeper slow slip events (25 to 60 km depth) have longer durations (about 1 to 2 years) and longer times between them, while shallower slow slip events (10 to 15 km) occur more rapidly (within weeks) and more frequently. Despite the along-strike variability in the maximum depth of the interseismic locking, the SSEs recorded to date have all occurred at or near the down-dip transition from interseismic locking to creep. This observation allows us to examine the role of temperature in controlling the transition zone. We will present the results of methods to extract SSEs from the GPS time series and estimate fault zone temperatures where the SSEs occur.
DE: 1207 Transient deformation (6924, 7230, 7240)
DE: 1240 Satellite geodesy: results (6929, 7215, 7230, 7240)
SC: Geodesy [G]
MN: 2007 Joint Assembly