BSR热流的三维地貌校正和流体汇聚探测(英文)

doi:10.1007/s11770-014-0429-1

CORC > 北京大学 > 地球与空间科学学院

	BSR热流的三维地貌校正和流体汇聚探测(英文); 3D topographic correction of the BSR heat flow and detection of focused fluid flow
	何涛 ; 李洪林 ; 邹长春
刊名	applied geophysics
	2014
关键词	天然气水合物三维有限元热流流体 BSR gas hydrate BSR 3D finite element heat flow fluid flow
DOI	10.1007/s11770-014-0429-1
英文摘要	从天然气水合物稳定区底界的地震似海底反射BSR(Bottom Simulating Reflector)深度计算得到的BSR热流包含了海底地貌(热流在凹地型会聚,在凸地形发散)和增生楔内部流体活动的影响。从BSR热流中移除地貌效应的贡献就能揭示出流体是否发生了汇聚。在难以使用解析方法计算地貌效应的复杂海底区域,三维有限元方法可以高精度的模拟地貌对背景热流的影响,从而可以对BSR热流进行地貌效应校正,得到平坦地形条件下的BSR热流,并进一步通过与背景热流值的对比,识别目前仪器所不能探测的流体汇聚区。在北卡斯卡底(Cascadia)俯冲边缘陆坡中部的研究区应用该方法,显示黄瓜岭(Cucumber ...; The bottom-simulating reflector (BSR) is a seismic indicator of the bottom of a gas hydrate stability zone. Its depth can be used to calculate the seafloor surface heat flow. The calculated BSR heat flow variations include disturbances from two important factors: (1) seafloor topography, which focuses the heat flow over regions of concave topography and defocuses it over regions of convex topography, and (2) the focused warm fluid flow within the accretionary prism coming from depths deeper than BSR. The focused fluid flow can be detected if the contribution of the topography to the BSR heat flow is removed. However, the analytical equation cannot solve the topographic effect at complex seafloor regions. We prove that 3D finite element method can model the topographic effect on the regional background heat flow with high accuracy, which can then be used to correct the topographic effect and obtain the BSR heat flow under the condition of perfectly flat topography. By comparing the corrected BSR heat flow with the regional background heat flow, focused fluid flow regions can be detected that are originally too small and cannot be detected using present-day equipment. This method was successfully applied to the mid-slope region of northern Cascadia subducting margin. The results suggest that the Cucumber Ridge and its neighboring area are positive heat flow anomalies, about 10%-20% higher than the background heat flow after 3D topographic correction. Moreover, the seismic imaging associated the positive heat flow anomaly areas with seabed fracture cavity systems. This suggests flow of warm gas-carrying fluids along these high-permeability pathways, which could result in higher gas hydrate concentrations.; SCI(E); 中国科学引文数据库(CSCD); 0; taohe@pku.edu.cn; 02; 197-206+254; 11
语种	中文
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/310965]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	何涛,李洪林,邹长春. BSR热流的三维地貌校正和流体汇聚探测(英文), 3D topographic correction of the BSR heat flow and detection of focused fluid flow[J]. applied geophysics,2014.
APA	何涛,李洪林,&邹长春.(2014).BSR热流的三维地貌校正和流体汇聚探测(英文).applied geophysics.
MLA	何涛,et al."BSR热流的三维地貌校正和流体汇聚探测(英文)".applied geophysics (2014).