| dc.description.abstract | So far, there are scarce studies about the variation in the thickness of the earth’s crust in the Taiwan Strait. Therefore, we used the gravity data in Taiwan Strait and it’s surrounding by method of sinx/x to calculate the depth of the Moho-discontinuity. The gravity data were compiled of three parts: Taiwan island and it’s off-shore islands, Fujian Province﹐and the marine area around Taiwan island.
To remove the shorter wavelength of gravity data, the convolution method (as the filter function sinx/x) is used to deal with the gravity data. In the study, we select six profiles across the Taiwan Strait. Furthermore, we consider about the gravity effects due to the thick layer of sediments in the Taiwan Strait. Eventually, we estimate the undulation of the Moho.
The main results of this study are as follows: (1) the crustal thinkness beneath the Taiwan Strait is about 23-30 km; the thinnest area locates the off-shore nearby Changhua County with 23 km and the thickening toward the Nanjihtao Basin reaches up to 30 km; (2) the thickness decreases from Fujian Province to the central Taiwan Strait, and then increases to the Taiwan island; (3) the undulation of the Moho is related to the observed gravity anomaly and regional structure, such as structural high, sedimentary basin or depression; (4) Numerous earthquakes occurred in the Taiwan Strait belong to the shallower earthquakes, that is, the hypocenters concentrate above the Moho. Consequently, the earthquake occurred in the Taiwan Strait is caused by the crustal activities. | en_US |