FY 2001

Empirical relationship of T-wave energy and fault parameters of northeast Pacific Ocean earthquakes

Dziak, R.P.

Geophys. Res. Lett., 28(13), doi: 10.1029/2001GL012939, 2537–2540 (2001)

A total of 179 northeast Pacific Ocean earthquakes that occurred between 1992-1998 are used to investigate the relationship of T-wave acoustic energy and earthquake fault parameters. The moderate-sized (3.7 M 6.9) earthquakes were recorded by ocean hydrophones and had their source parameters estimated by land-based seismic networks. The acoustic energy release at the seafloor-water interface of each earthquake was estimated by removing the signal attenuation along the propagation path and instrument gain from the hydrophone signal. There appears to be a relationship where, for a given magnitude earthquake, T-wave energy is lower for normal and reverse fault earthquakes than strike-slip events. A more detailed comparison indicates acoustic energy of the earthquake will often decrease as the component of dip-slip motion increases. These observations suggest fault parameter information is contained within the T-wave signal packet.