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Supplementary material accompanying publication of paper in Science magazine,
"Deformation and Slip Along the Sunda Megathrust in the Great 2005 Nias-Simeulue Earthquake"

Caltech media release (online)

Caltech media release (pdf PDF icon)

2005 Earthquake location
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Caltech geologists surveying coral heads uplifted 0.74 m (2.4 feet) by the 2005 Sunda megathrust rupture, on Bangkaru island, west of Sumatra, Indonesia
photo: Danny Natawidjaja
Caltech and LIPI (Indonesian Institute of Sciences) geologists surveyed coral reefs that were uplifted nearly 3 m (nearly 10 feet) during the March 2005 megathrust rupture.
photo: Rich Briggs
Caltech geologist John Galetzka surveying a newly formed beach ridge on the outer edge of a coral reef uplifted 1.74 m (5.7 feet) in the Hinako islands, west of Nias island, Indonesia
photo: Rich Briggs

Children atop coral uplifted 1.74 m (5.7 feet)in the Hinako islands, west of Nias island, Indonesia
photo: Rich Briggs

Coral heads uplifted 1.81 m (5.9 feet) on Hilimakora island, north of Nias island, Indonesia
photo: Danny Natawidjaja
A mere three months after the giant Sumatra-Andaman earthquake and tsunami of December 2004, tragedy struck again when another great earthquake (shown in red) shook the area directly to the south, killing over two thousand Indonesians. The Mw 8.7 Nias-Simeulue earthquake just over a year ago was one of the most powerful earthquakes ever recorded: only six others have had greater magnitudes.

A team from the California Institute of Technology, the Indonesian Institute of Sciences (LIPI), and Scripps Institution of Oceanography reconstruct the fault rupture that caused the 28 March 2005 event from detailed measurements of ground displacements. Their analysis illuminates the pattern and magnitude of fault slip, the relationship between the 2004 and 2005 ruptures, and the surface deformation that is likely to accompany future megathrust rupture south of the equator.

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Spectacular uplift of coral reefs due to megathrust rupture in March, 2005 along the Hinako islands, west of Nias, Indonesia
photo: Aron Meltzner
Some places subsided during megathrust rupture: The village of Haloban in the Banyak islands sank 0.62 m (2.0 feet)
photo: Danny Natawidjaja
Before the March 2005 earthquake, the southwestern coast of Nias island was slowly subsiding, as evidenced here by a stand of dead coconut palms seaward of the beach (upper photo). During the earthquake, the coast rose about 2.5 m, elevating the dead grove and neighboring coral reef out of the surf zone and re-uniting the small islands in the background with the mainland of Nias island.
photos: Kerry Sieh
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