FY 1995

Inversion of deep-ocean tsunami records for 1987–88 Gulf of Alaska earthquake parameters

Ritsema, J., S.N. Ward, and F.I. González

Bull. Seismol. Soc. Am., 85, 747–754 (1995)

High-quality deep-ocean records of tsunamis generated by the 30 November 1987 (M = 7.8) and 6 March 1988 (M = 7.7) earthquakes in the Gulf of Alaska were inverted for fault-plane parameters and seismic moment using a model that consists of a uniform ocean layer overlaying an elastic half-space. Results were poor for the 30 November 1987 event, the more complex of the two earthquakes. Results were excellent for the 6 March 1988 event, being consistent with values derived from seismic data. Furthermore, the tsunami waveform inversion provided an additional constraint on the rupture length (less than 50 km) of the latter event, demonstrating the supplementary value of tsunami data to analyses of earthquake finite-faulting characteristics.