Earthquake Rupture Stalled by a Subducting Fracture Zone
D. P. Robinson,*
S. Das,
A. B. Watts
We showed that the rupture produced by the great Peru earthquake
(moment magnitude 8.4) on 23 June 2001 propagated for

70 kilometers
before encountering a 6000-square-kilometer area of fault that
acted as a barrier. The rupture continued around this barrier,
which remained unbroken for

30 seconds and then began to break
when the main rupture front was

200 kilometers from the epicenter.
The barrier had relatively low rupture speed, slip, and aftershock
density as compared to its surroundings, and the time of the
main energy release in the earthquake coincided with the barrier's
rupture. We associate this barrier with a fracture zone feature
on the subducting oceanic plate.
Department of Earth Sciences, University of Oxford, Parks Road, Oxford, OX1 3PR, UK.
* To whom correspondence should be addressed. E-mail: David.Robinson{at}earth.ox.ac.uk