Reconnaissance report of the 2004 Great Sumatra-Andaman, Indonesia, Earthquake : Damage to geotechnical works in Banda Aceh and Meulaboh

Abstract

One of the largest earthquakes in our history occurred at 7:58AM (local time) on December 26 2004, off the west coast of Northern Sumatra Island, Indonesia (M_w 9.3). The earthquake triggered a huge tsunami along the coastlines of the Indian Ocean and caused a huge number of casualties. From March 1 to 6, 2005, reconnaissance was conducted in the region of Banda Aceh and Meulaboh, Indonesia, where strong shaking and tsunamis were observed. The primary objective of reconnaissance was to investigate and record damage mainly due to strong motions and to estimate the seismic intensity in the region. This paper reports on the damage to earth structures, waterfront structures, and roads washed away by tsunamis. Eyewitness evidence of liquefaction in Banda Aceh, about 250 km away from the epicenter, was likely caused by the strong shaking of M_w 9.3. In Kuala Bubon village located about 15 km north of Meulaboh, settlements of embankments attached to bridge abutments collapsed just after the earthquake and before the arrival of the tsunami, so villagers could not use motorcycles or bicycles to evacuate. Lessons must be learned from this devastating earthquake, and disaster mitigation improved.