Evidence for an earthquake barrier model from Mw ∼ 7.8 Kokoxili (Tibet) earthquake slip-distribution

The slip distribution of the Mw similar to 7.8 Kokoxili (Tibet, 2001) earthquake has been measured at high resolution using optical correlation of satellite images and provides both the parallel and perpendicular components of the horizontal co-seismic slip. This reveals a variation of the horizontal slip at a scale of similar to 20 km along-strike. Anti-correlation of slip parallel and perpendicular to the fault indicates transfer of slip from the horizontal to the vertical component at the ends of segments. These features suggest a rupture model with segments separated by strong persistent geometric barriers. The unexpected ending of the rupture south of the main fault can be explain by such a structure but bears important implications for the initiation and rupture directivity of the next earthquake. (c) 2006 Elsevier B.V. All rights reserved.