Site survey data evaluation IODP Proposal 633

现场调查数据评估 IODP 提案 633

• 批准号: 86504975
• 负责人: Dr. Warner Brückmann
• 金额: --
• 依托单位: GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2011-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/86504975?language=en
• 关键词: Site; survey; data; evaluation; IODP

IODP drilling proposal (Costa Rica Mud Mounds) aims to enhance the general understanding of complex forearc dewatering processes of the erosive subduction system off Costa Rica and Nicaragua. Scientific evaluation recently resulted in a high ranking of the drilling proposal. Major sites of dewatering planned for drilling are mounds, related to mud diapirism/volcanism and precipitation of authigenic carbonates, and large-scale slides related to the subduction of seamounts. New pre-site survey seismic data was collected during a cruise of R/V Marcus Langseth in 2008 at the proposed sites of Mound Culebra and Mounds 11&12. These new data – together with the reprocessed pre-existing geophysical data – were submitted to the IODP safety panel for a final decision and scheduling of the R/V Joides Resolution leg. The new data are of exceptionally high quality and allow a detailed analysis of the processes that control fluid migration in the Costa Rican margin. Therefore we propose to (1) investigate the role of the acoustic basement for the fluid ascent, (2) understand the effect of mud volcanism on the gas hydrate system and the interactions between gas hydrate formation and dissociation with the fluid ascent from the deep sources, and (3) to invert the seismic data for gas and gas hydrate concentrations. The extension of the project will provide a wealth of geological information and further promote the drilling proposal.

IODP钻探建议（哥斯达黎加泥土丘）旨在提高对哥斯达黎加和尼加拉瓜近海侵蚀俯冲系统复杂的弧前脱水过程的总体认识。科学评估最近对钻探提案进行了高评级。计划钻探的主要脱水地点是与泥底辟作用/火山作用和自生碳酸盐沉淀有关的土丘，以及与海山俯冲有关的大规模滑坡。2008年，Marcus Langseth号研究船在拟定的库莱布拉和土丘11和12号场地巡航期间收集了新的现场前勘测地震数据。这些新的数据--连同重新处理的先前存在的地球物理数据--被提交给IODP安全小组，以供R/V Joides Resolution腿的最终决定和时间安排。新的数据质量极高，可以详细分析控制哥斯达黎加边缘流体迁移的过程。因此，我们建议（1）调查流体上升的声学基底的作用，（2）了解泥火山作用对天然气水合物系统的影响，以及天然气水合物的形成和分解与来自深源的流体上升之间的相互作用，和（3）反演天然气和天然气水合物浓度的地震数据。该项目的延期将提供丰富的地质资料，并进一步推动钻探建议。