Study on the transverse structures across Taiwan Strait

Abstract

The mountain ranges are almost NE- or NNE-trending in mainland and Taiwan island across the strait. But a number of correspondent transverse structures across Taiwan Strait have been identified on the basis of morphology, surface structure, deep seismic survey and gravity field etc. Moreover, it is inferred from the square or/and rectangular shape of the isoseist maps of 8 M≥ 6 earthquakes occurring in the western foothill plain of Taiwan that there is an apparent segmentation of the Taiwan Island along the N-S orientation. This has been verified from the GPS’s results of the ground motions measured during the Chi-Chi earthquake in 1999. As a matter of fact, the transverse structures within the Taiwan Island could be correlated with more salient NW- and EW-trending structures in the mainland of Fujian than in Taiwan. The investigation of the transverse structures across Taiwan Strait is conducive to realizing the geology within the strait. Hence, the tectonic sketch map of the strait as well as mainland and island drawn in this context shows NW- and EW-trending structures for the study area.