Earthquake-triggered increase in sediment delivery from an active mountain belt
Resource
Geology 32 (8): 733-736
Journal
Geology
Journal Volume
32
Journal Issue
8
Pages
733-736
Date Issued
2004
Author(s)
Dadson, Simon J.
Hovius, Niels
Brian Dade, W.
Hsu, Mei-Ling
Lin, Ching-Weei
Horng, Ming-Jame
Chen, Tien-Chien
Milliman, John
Abstract
In tectonically active mountain belts, earthquake-triggered landslides deliver large amounts of sediment to rivers. We quantify the geomorphic impact of the 1999 Mw 7.6 Chi-Chi earthquake in Taiwan, which triggered >20,000 landslides. Coseismic weakening of substrate material caused increased landsliding during subsequent typhoons. Most coseismic landslides remained confined to hillslopes. Downslope transport of sediment into the channel network occurred during later storms. The sequential processes have led to a factor-of-four increase in unit sediment concentration in rivers draining the epicentral area and increased the magnitude and frequency of hyperpycnal sediment delivery to the ocean. Four years after the earthquake, rates of hillslope mass wasting remain elevated in the epicentral area.
SDGs
Type
journal article