TY - JOUR
T1 - The 25 October 2010 Mentawai tsunami earthquake (Mw 7.8) and the tsunami hazard presented by shallow megathrust ruptures
AU - Lay, T.
AU - Ammon, C. J.
AU - Kanamori, H.
AU - Yamazaki, Y.
AU - Cheung, K. F.
AU - Hutko, A. R.
PY - 2011/3/1
Y1 - 2011/3/1
N2 - The 25 October 2010 Mentawai, Indonesia earthquake (Mw 7.8) ruptured the shallow portion of the subduction zone seaward of the Mentawai islands, off-shore of Sumatra, generating 3 to 9 m tsunami run-up along southwestern coasts of the Pagai Islands that took at least 431 lives. Analyses of teleseismic P, SH and Rayleigh waves for finite-fault source rupture characteristics indicate ∼90 s rupture duration with a low rupture velocity of ∼1.5 km/s on the 10 dipping megathrust, with total slip of 2-4 m over an ∼100 km long source region. The seismic moment-scaled energy release is 1.4 × 10-6, lower than 2.4 × 10-6 found for the 17 July 2006 Java tsunami earthquake (Mw 7.8). The Mentawai event ruptured up-dip of the slip region of the 12 September 2007 Kepulauan earthquake (Mw 7.9), and together with the 4 January 1907 (Mw 7.6) tsunami earthquake located seaward of Simeulue Island to the northwest along the arc, demonstrates the significant tsunami generation potential for shallow megathrust ruptures in regions up-dip of great underthrusting events in Indonesia and elsewhere.
AB - The 25 October 2010 Mentawai, Indonesia earthquake (Mw 7.8) ruptured the shallow portion of the subduction zone seaward of the Mentawai islands, off-shore of Sumatra, generating 3 to 9 m tsunami run-up along southwestern coasts of the Pagai Islands that took at least 431 lives. Analyses of teleseismic P, SH and Rayleigh waves for finite-fault source rupture characteristics indicate ∼90 s rupture duration with a low rupture velocity of ∼1.5 km/s on the 10 dipping megathrust, with total slip of 2-4 m over an ∼100 km long source region. The seismic moment-scaled energy release is 1.4 × 10-6, lower than 2.4 × 10-6 found for the 17 July 2006 Java tsunami earthquake (Mw 7.8). The Mentawai event ruptured up-dip of the slip region of the 12 September 2007 Kepulauan earthquake (Mw 7.9), and together with the 4 January 1907 (Mw 7.6) tsunami earthquake located seaward of Simeulue Island to the northwest along the arc, demonstrates the significant tsunami generation potential for shallow megathrust ruptures in regions up-dip of great underthrusting events in Indonesia and elsewhere.
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U2 - 10.1029/2010GL046552
DO - 10.1029/2010GL046552
M3 - Article
SN - 0094-8276
VL - 38
JO - Geophysical Research Letters
JF - Geophysical Research Letters
IS - 6
M1 - L06302
ER -