Deformation and slip along the Sunda megathrust in the Great 2005 Nias-Simeulue earthquake

• Main Authors: Sieh, Kerry, Galetzka, John, Simons, Mark, Hananto, Nugroho, Suprihanto, Imam, Prayudi, Dudi, Avouac, Jean-Philippe, Prawirodirdjo, Linette, Bock, Yehuda, Hsu, Ya-Ju, Briggs, Richard W., Meltzner, Aron J., Natawidjaja, Danny H., Suwargadi, Bambang W.
• Format: Article
• Language: English
• Published: 2012
• Subjects: DRNTU::Science::Geology::Volcanoes and earthquakes
• Online Access: https://hdl.handle.net/10356/79825; http://hdl.handle.net/10220/8730
• Institution: Nanyang Technological University

Seismic rupture produced spectacular tectonic deformation above a 400-kilometer strip of the Sunda megathrust, offshore northern Sumatra, in March 2005. Measurements from coral microatolls and Global Positioning System stations reveal trench-parallel belts of uplift up to 3 meters high on the outer-arc islands above the rupture and a 1-meter-deep subsidence trough farther from the trench. Surface deformation reflects more than 11 meters of fault slip under the islands and a pronounced lessening of slip trenchward. A saddle in megathrust slip separates the northwestern edge of the 2005 rupture from the great 2004 Sumatra-Andaman rupture. The southeastern edge abuts a predominantly aseismic section of the megathrust near the equator.