Notes

The epicenter of the earthquake was about 250 kilometers off the west coast of Aceh Province. Strong to violent shaking in Aceh Province reportedly lasted five to six minutes. Banda Aceh was the only major city that experienced earthquake-shaking damage. One- to two-story, traditional, concrete-frame and wood-frame buildings survived well and were largely undamaged by the strong ground shaking. However, because the earthquake occurred a significant distance offshore, the resulting long-period ground motions caused serious damage to, or the collapse of, buildings more than three stories high.

Fault Deformation
A compounding problem was tectonic subsidence resulting in 20 to 100 centimeters of down-warping of the Earth’s crust beneath the Aceh region. The subsidence extends for at least 280 kilometers along the entire northwestern Aceh coast (Figure 1—see PDF version for figures). This submergence thwarted rescue efforts and has hindered the restoration of roads, bridges, and utility distribution systems.

Tsunami Damage
The fault rupture uplifted the ocean floor, releasing the most destructive series of tsunami waves in recorded history. The waves spread throughout the Indian Ocean, causing damage in the coastal communities of 12 countries. By far, the most damaging effects were sustained by Aceh Province, where three devastating waves struck the western shore within about 30 minutes. The tsunami waves ranged from 4 to 39 meters high and destroyed more than 250 coastal communities.