Use of hydroacoustic and seismic arrays to observe rupture propagation and source extent of the Mw = 9.0 Sumatra earthquake

[1] The rupture of the Sumatra earthquake (Mw = 9.0) is complex and quite difficult to estimate using classical source inversion methods due to the exceptional rupture duration. To fix the problem of geographical extent and rupture duration, we use array processing of hydroacoustic and regional seismic data. The CMAR-seismic array and the Diego Garcia hydroacoustic station (H08S) installed by the International Monitoring System are respectively 15.2 and 25.7 far from the hypocenter. The estimation of azimuth and velocity variations of homogeneous wave fronts across the arrays gives us the opportunity to understand how the rupture propagates. The smooth and regular variations of azimuth fit a rupture extension of 1235 km and a duration of 515 s. This study proves that the combination of array analysis using the different technologies installed for the CTBT is an interesting way of research for a rapid estimation of tsunamigenic earthquakes. Citation: Guilbert, J., J. Vergoz, E. Schisselé, A. Roueff, and Y. Cansi (2005), Use of hydroacoustic and seismic arrays to observe rupture propagation and source extent of the Mw = 9.0 Sumatra earthquake,Geophys. Res. Lett., 32, L15310, doi:10.1029/2005GL022966.