The role of splay faults in seafloor deformation and tsunami generation during the Mw 9.1-9.3 Sumatra-Andaman Earthquake

Madden, Elizabeth H.; Ulrich, Thomas; Gabriel, Alice-Agnes; Zelst, Iris van; Dinther, Ylona van (2017): The role of splay faults in seafloor deformation and tsunami generation during the Mw 9.1-9.3 Sumatra-Andaman Earthquake. 14th International Conference on Fracture, June 18-23, 2017, Rhodes, Greece.

Abstract

Failure along 1300 km of the Sumatra-Andaman subduction zone on 26 December 2004 caused 8-10 minutes of violent shaking. The resulting M 9.1-9.3 megathrust earthquake generated a 30-50 m tsunami wave along the northern coast of Sumatra. The height of this wave suggests slip on landward and possibly also seaward dipping faults dipping at a high angle to the megathrust. This is supported by evidence for activation of splay faults off the west coast of northern Sumatra from seismic reflection surveys bathymetric data and relocated seismicity. We present physically realistic simulations of this earthquake using SeisSol a software package solving the spontaneous dynamic earthquake rupture problem with high-order accuracy in space and time. We compare seafloor displacements from models without splay faults with a forethrust with a backthrust and with both splay faults. These are used by colleagues at the University of Hamburg as input for tsunami models.

• Item Type: Conference or Workshop Item (Paper)
• Published in: Gdoutos, Emmanuel E. (ed.) . (2017): Proceedings of the 14th International Conference on Fracture.
• Faculties: Geosciences > Department of Earth and Environmental Sciences > Geophysics
• Subjects: 500 Science > 550 Earth sciences and geology
• Language: English