The research achievements of NTU's Department of Geosciences Professor Sheng-Rong Song and a research team of JAMSTEC (Japan Agency for Marine-Earth Science and Technology ) led by Professor Ishikawa were published in the October issue of the internationally renowned journal "Nature—geosciences."

This international cooperative research project mainly used geochemical methods to analyze the concentrations of the major elements, trace elements, and isotopic ratios of core samples obtained from deep drilling of the Chelungpu fault of Taiwan.

The research team found that the rocks in the core part of the fault obviously displayed abnormal phenomenon of distribution. Using a model calculation method, the research team discovered that the main reason for this abnormal phenomenon was caused by the presence of hydrothermal fluid which was generated by fault friction during the Chi-chi Earthquake and heated up to over 350 degrees Celsius, and which interacted with the surrounding rocks of the fault to create fusion.

This finding seems to indicate that the large fault displacement of the Chi-chi Earthquake was caused by thermal pressurization. In other words, high temperature fluids played an important role in faulting and rupture propagation. As the human knowledge about earthquake formation is far from being sufficient, Professor Song's studies provide further analysis and prediction of the distribution of seismic energy. Therefore, his research will provide more detailed data for future studies of seismology.

References:

Journal:　Nature Geoscience V.1, 679-683.
Title:　Coseismic fluid–rock interactions at high temperatures in the Chelungpu fault Authors: TSUYOSHI ISHIKAWA, MASAHARU TANIMIZU, KAZUYA NAGAISHI, JUN MATSUOKA2, OSAMU TADAI, MASUMI SAKAGUCHI, TETSURO HIRONO, TOSHIAKI MISHIMA, WATARU TANIKAWA, WEIREN LIN, HIROYUKI KIKUTA, WONN SOH AND SHENG-RONG SONG