Erosion effects assessed by repeated gravity measurements in southern Taiwan
Journal article, 2013
We analyse temporal variations of gravity measured in southern Taiwan since November 2006 at 10 sites using absolute gravimeters and, since November 2008, at 70 sites using a relative gravimeter. We describe and apply methods to interpret the gravity changes in terms of local hydrological processes and vertical ground motions. The effect of land water is computed from local rainfall data and a model of rain accumulation and discharge in the ground. The effect of the vertical motions of the ground is estimated using time-series of permanent Global Positioning System (GPS) stations and the theoretical gravity to height ratio of -2 μGal cm-1. Unexpectedly, Morakot typhoon (2009 August), the strongest typhoon in Taiwan in 50 yr, was responsible for the highest gravity changes. Morakot triggered numerous large landslides and debris flow deposits. Their thicknesses are estimated from the gravity changes (up to 280 μGal) along with field observations and satellite images.
Time variable gravity
Creep and deformation
Asia
Hydrology
Author
Maxime Mouyen
National Chiao Tung University
University of Strasbourg
Frederic Masson
University of Strasbourg
Cheinway Hwang
National Chiao Tung University
Ching-Chung Chen
National Chiao Tung University
Nicolas Le Moigne
University of Montpellier
C.W. Lee
Industrial Technology Research Institute of Taiwan
Ricky Kao
Industrial Technology Research Institute of Taiwan
National Chiao Tung University
University of Calgary
Wen-Chi Hsieh
National Central University
National Chiao Tung University
Geophysical Journal International
0956-540X (ISSN)
Vol. 192 1 113-136Subject Categories
Geophysics
Geology
Geosciences, Multidisciplinary
DOI
10.1093/gji/ggs019