Ea. Okal, Historical seismicity and seismotectonic context of the great 1979 Yapen and 1996 Biak, Irian Jaya earthquakes, PUR A GEOPH, 154(3-4), 1999, pp. 633-675
We present relocations of over 220 historical and recent earthquakes in the
northwestern part of Irian Jaya, in the context of the large earthquakes o
f 1979 and 1996. Our results document continuous activity on a 420-km segme
nt of the Sorong Fault, with a possible extension over an additional 330 km
to the west. We also show that some level of activity did take place on th
e New Guinea Trench prior to the 1996 Biak earthquake, and relocate a large
(M-PAS = 7.4) event on 02 April 1947 to the trench, at 138 degrees E. We s
peculate that the large earthquake of 26 May 1914 may also have taken place
on the New Guinea Trench. We study the pattern of activity following the 1
979 Yapen earthquake, which triggered stress release in the Pandaidori Isla
nds, also the location of stress transfer following the 1996 Biak earthquak
e.