Kesan Gempa 7.6 MW Padang Indonesia, 30 September 2009

The earthquake of 30 September 2009, 7.6 MW that strucked the city of Padang, Padang Pariaman and nearby areas in West Sumatra, Indonesia, killed more than 1200 people. Thousands of damaged houses, buildings and infrastructure have been reported with low to severe damage level. This research reports the effect of the Padang earthquake in terms of building damages and landslides that occured in the city of Padang, Padang Pariaman, Pariaman and Agam. Analysis on earthquake effects was carried out based on the geology, geotechnical, building damages and geohazards data collected from various sources and field works in affected areas. Results from field work showed that damages on the building structures in Padang and Padang Pariaman was due to the quality of construction which did not meet the building code and standard requirements, and the effect of geological conditions, i.e., ground amplification on deep layer of alluvial deposit. Some observed damage in the buildings were related to the building location constructed on the fault lines and soil or rock layers discontinuity. From the site visit, it was found that landslide cases which occurred in Pariaman and Agam after the earthquake were caused by the topography, geomorphology of area and steep slopes. Further studies should be carried out for hazard risks identification and assessment in order to prepare for future earthquakes.