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Stratigraphic record of Holocene coseismic subsidence, Padang, West Sumatra

Authors: 
Dura, T., Rubin, C. M., Kelsey, H. M., Horton, B. P., Hawkes, A., Vane, C. H., Daryono, M., Pre, C. G., Ladinsky, T., Bradley, S.
Year: 
2 011
Source: 
Journal of Geophysical Research-Solid Earth
Abstract: 
Stratigraphic evidence is found for two coseismic subsidence events that underlie a floodplain 20 km south of Padang, West Sumatra along the Mentawai segment (0.5 S- 0.3 S) of the Sunda subduction zone. Each earthquake is marked by a sharp soil-mud contact that represents a sudden change from mangrove to tidal flat. The earthquakes occurred about 4000 and 3000 cal years B.P. based on radiocarbon ages of detrital plant fragments and seeds. The absence of younger paleoseismic evidence suggests that late Holocene relative sea level fall left the floodplain too high for an earthquake to lower it into the intertidal zone. Our results point to a brief, few thousand year window of preservation of subsidence events in tidal-wetland stratigraphic sequences, a result that is generally applicable to other emergent coastlines of West Sumatra.
EES Authors: 
Tina Dura (2014)
Andrea Hawkes (2008)
Candace Grand Pre (2011)
Research Track Category: 

Department of Earth and Environmental Science / University of Pennsylvania, 251 Hayden Hall, 240 South 33rd Street, Philadelphia, PA 19104-6316