Coseismic release of water from mountains:: Evidence from the 1999 (MW=7.5) Chi-Chi, Taiwan, earthquake

Earthquake-induced increases in streamflow, producing similar to0.7 km(3) of total excess water, were documented after the 1999 (M-w = 7.5) Chi-Chi earthquake in central Taiwan. Analysis of stream gauge data and well records suggests that the excess water originated in the mountains. We propose that the extensive high-angle fractures formed during the earthquake allow rapid release of water from mountains and that mountains in tectonically active areas may be repeatedly flushed by meteoric water at time intervals comparable to the recurrence time of large earthquakes.