文章基本信息

标题：The Crustal Thickness of the Philippine Sea Plate Derived from Gravity Data
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作者：Horng-Yuan Yen ; Yu-Tsung Lo ; Yu-Lien Yeh 等
期刊名称：Terrestrial Atmospheric and Oceanic Sciences
印刷版ISSN：1017-0839
出版年度：2015
卷号：26
期号：3
页码：253-258
DOI：10.3319/TAO.2014.11.17.01(T)
出版社：Chinese Geoscience Union
摘要：We constructed a new free-air gravity anomaly map of the Philippine Sea Plate (PSP) using ship-tracked gravity data from the National Geophysical Data Center (NGDC). Our results show that the isogals trend correlates well with the tectonic structures in the PSP. After removing the gravity induced by sea water from the free-air gravity data, we obtained the regional Bouguer gravity anomaly, which is later used to compute the Moho geometry in the PSP by applying the Parker-Oldenburg iterative method. Our results indicate that in the southern part of the West Philippine Basin (WPB) the crustal thickness is nearly homogeneous with a value of about 5 km, which implies that the WPB is quite stable. The low-amplitude and near-zero free-air gravity anomalies clearly indicate that the whole WPB, except at trenches and island arcs, is nearly in a state of isostatic equilibrium. The average crustal thickness of the Palau Kyushu Ridge (PKR) is more than 10 km. In the eastern PSP the crustal thickness gradually increases eastward. Our results also imply that a relatively thin and low density mantle exists beneath the Parece Vela Basin (PVB) as a consequence of back-arc spreading and serpentinized upwells of the thin crustal thickness.
关键词：Free air gravity anomaly; Bouguer gravity anomaly; Crustal thickness; Philippine Sea Plate; Mantle upwelling;