| 摘要: |
| 以1993-1995年对琉球沟弧盆系各个航次的热流数值进行了搜集整理，发现这一地区热流的分布特征和构造特征有着明显的对应关系，大致上呈现出东西分带南北分块的分布特征。冲绳海槽有着极高的热流值，而琉球海沟则有着极低的热流值，这和板块的撞碰、俯冲、弧后扩张模式相吻合。用二维热传导平流方程采用有限单元法对冲绳海槽进行的地球动力学热模拟显示，冲绳海槽的高热流值和海槽内的岩浆活动有着密切关系，如果不考虑海槽中岩浆因素的影响则无法模拟出海槽中所测到的高热流值，海槽的莫霍面埋深为18km，扩张速率为0.4cm／a，盆地下沉的速率为0.05cm／a，热演化历史为10Ma. |
| 关键词: 琉球沟弧盆系 热流分布 热演化 数值模拟 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目，49376266号 |
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| STUDY OF HEATFLOW DISTRIBUTION OF RYUKYU TA-B-A SYSTEM AND THERMO DYNAMIC MODELING OF OKINAWA TROUGH |
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Luan Xiwu
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Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071
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| Abstract: |
| Review of 320 data sets of heatflow data measured in I993 – 1995 during 15 cruises in the Ryukyu TA-B-A system showed that the heatflow in the deep trench region was sub-normal; that trench-arc gaps were generally characterized by lower heatflow agreeing with the prediction from plate-cooling models the Okinawa Trough, an actively spreading back arc basin had highly variable heatflow indicating modern volcanism and hydro-thermal circulation in the new crust. The distribution of heatflow agreed with the tectonic pattern of the Ryukyu TA-B-A system. 2-D nonsteady-state heat advective-conduction equations were used to simulate tectonically thermal evolution in this study showing that the effects of magmatic activity in the Okinawa Trough region are important to, and can explain, the observed high surface heatflow. A flow function used to describe the mantle flow under the Okinawa Trough shows that the crustal thickness in the region is about 18km; that the trough extension rate is 0.4 cm/a; that the surface subsidence rate is 0.05 cm/a; and that the thermal process of the trough is about 10 million years. |
| Key words: Ryukyu TA-B-A system, Heatflow distribution, Thermo evolution, Modeling |
