Tsunami Earthquakes - Tsunami Warning and Preparedness - page 238

activation of splay faults rupturing in sedimentary prisms (Sanriku, Japan; Kurils), 5 or rupture
propagating in a jagged mode along poorly coupled interfaces in sediment-starved environ-
ments (Nicaragua, Peru). 6 In turn, this raises the questions whether any subduction zone can be
the site of a tsunami earthquake, and conversely whether the documented occurrence of such
events (most often comparatively small in the magnitude 7.5 range) precludes the occurrence
of mega-earthquakes as would be suggested by the available historical record in Nicaragua or
Java. Despite active research efforts in this domain, we presently have no irm answers in this
respect.
REFERENCES
1. Abe, K., K. Abe, Y. Tsuji, F. Imamura, H. Katao, I. Yohihisa, K. Satake, J. Bourgeois, E. Noguera, and F. Estrada. 1993. Field
survey of the Nicaragua earthquake and tsunami of September 2, 1992. Bulletin of the Earthquake Research Institute
University of Tokyo 68(1):23-70.
2. Polet, J. and H. Kanamori. 2000. Shallow subduction zone earthquakes and their tsunamigenic potential. Geophysical
Journal International 142(3):684-702.
3. Newman, A.V. and E.A. Okal. 1998. Teleseismic estimates of radiated seismic energy: The E/M 0 discriminant for tsunami
earthquakes. Journal of Geophysical Research 103(B11):26885-26898.
4. Weinstein, S.A. and E.A. Okal. 2005. The mantle wave magnitude M m and the slowness parameter THETA: Five years of
real-time use in the context of tsunami warning. Bulletin of the Seismological Society of America 95(3):779-799.
5. Tanioka, Y., L.J. Ruff, and K. Satake. 1997. What controls the lateral variation of large earthquake occurrence along the
Japan trench? Island Arc 6(3):261-266.
6. Fukao, Y. 1979. Tsunami earthquakes and subduction processes near deep-sea trenches. Journal of Geophysical Research
84(B5):2303-2314.