Taiwan scholar offers fresh take on temblor study

2014-11-27

A recent study by researchers from National Taiwan University and three leading French universities was published November 21 in renowned multidisciplinary journal Nature Communications.

The research was conducted by J. Bruce H. Shyu, associate professor of NTU Department of Geosciences, in collaboration with Martine Simoes from Paris Diderot University, Philippe Steer from University of Rennes 1 and Rodolphe Cattin from the Montpellier University 2.

According to Shyu, deep tectonic processes are traditionally considered the only persistent mechanism driving the stress loading of active faults over a seismic cycle. “Using a mechanical model, our study shows that surface processes such as erosion and sedimentation may also increase stresses on active faults and result in shallow earthquakes,” he said.

The researcher said typhoons and resulting landslides, like those experienced in southern Taiwan during Typhoon Morakot five years ago, can cause rapid changes to the shape of the earth’s surface in a short period and alter the balance of forces at the site of deep active faults.

“Such extreme events have a far more significant impact on seismic activities than the erosions caused by rivers, as illustrated by the major Bingham Canyon mine collapse in 2013.”

Based on data collected in Taiwan, where erosion and deformation rates are among the highest in the world, the study shows that erosion of 0.1 to 20 millimeters a year can cause an increase of 0.1 to 10 bars in stresses on nearby faults.

“This research shows that Taiwan and its distinct patterns of geological activity are playing a key role in helping advance the scientific world’s understanding of the causes of earthquakes,” Shyu said.

Source: Taiwan Today (http://taiwantoday.tw/ct.asp?xItem=224485&CtNode=413)