A Great Earthquake Rupture Across a Rapidly Evolving Three-Plate Boundary
Kevin P. Furlong,1*
Thorne Lay,2
Charles J. Ammon1
On 1 April 2007 a great, tsunamigenic earthquake (moment magnitude
8.1) ruptured the Solomon Islands subduction zone at the triple
junction where the Australia and Solomon Sea–Woodlark
Basin plates simultaneously underthrust the Pacific plate with
different slip directions. The associated abrupt change in slip
direction during the great earthquake drove convergent anelastic
deformation of the upper Pacific plate, which generated localized
uplift in the forearc above the subducting Simbo fault, potentially
amplifying local tsunami amplitude. Elastic deformation during
the seismic cycle appears to be primarily accommodated by the
overriding Pacific forearc. This earthquake demonstrates the
seismogenic potential of extremely young subducting oceanic
lithosphere, the ability of ruptures to traverse substantial
geologic boundaries, and the consequences of complex coseismic
slip for uplift and tsunamigenesis.
2 Department of Earth and Planetary Sciences, University of California, Santa Cruz, CA 95064, USA.
* To whom correspondence should be addressed. E-mail: kevin{at}geodyn.psu.edu
