HR: 16:00h
AN: H42L-01    [PDF]
TI: Increased sediment delivery from an active mountain belt caused by earthquake and typhoon disturbance
AU: * Dadson, S J
EM: simon00@esc.cam.ac.uk
AF: Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ United Kingdom
AU: Hovius, N
EM: nhovius@esc.cam.ac.uk
AF: Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ United Kingdom
AU: Chen, H
EM: hchen@ntu.tw.edu
AF: Department of Geosciences, No. 1, Sec. 4, Roosevelt Road, Taipei, ROC Taiwan
AU: Dade, W B
EM: william.b.dade@dartmouth.edu
AF: Department of Earth Sciences, Dartmouth College, Hanover, NH 03755 United States
AU: Lin, J
EM: jclin@ccms.ntu.edu.tw
AF: Department of Geosciences, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Tapei, ROC Taiwan
AU: Hsu, M
EM: hsu@ccms.ntu.edu.tw
AF: Department of Geosciences, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Tapei, ROC Taiwan
AU: Horng, M
EM: mjhorng@wrb.gov.tw
AF: Water Resources Agency, Ministry of Economic Affairs, Hsin-Yi Road, Taipei, ROC Taiwan
AB: Earthquakes in active mountain belts commonly trigger widespread landsliding. Coseismic landsliding is an important geomorphic component of continental tectonics, a fundamental control on the rate of sediment delivery to rivers and ocean basins, and a destructive natural hazard. Here we report measurements of sediment discharge for rivers in Taiwan following the 1999 $M_{w}$ 7.6 Chi-Chi earthquake. Average sediment discharge to the ocean from rivers draining the epicentral area increased by 3--5 times following Chi-Chi earthquake, and by up to an order of magnitude in several mountain catchments. Detailed field mapping reveals that debris from widespread coseismic landsliding remains stored on hillslopes and in channels and is mobilized in subsequent storms. Our findings suggest that sediment discharges will remain elevated for several more years. Using measurements of coseismic deformation and post-seismic erosion, we assess the contribution of large earthquakes to the long-term development of topography.
UR: http://www.esc.cam.ac.uk/~simon00/
DE: 1815 Erosion and sedimentation
DE: 1821 Floods
DE: 1824 Geomorphology (1625)
DE: 7223 Seismic hazard assessment and prediction
SC: Hydrology [H]
MN: 2003 Fall Meeting