Processing 3D Seismic Reflection Dataset From Offshore Costa Rica Through 3D Pre-Stack Depth Migration

智力上的优点：PI要求资金帮助抵消最近从哥斯达黎加边缘获得的3D地震反射数据的处理成本。这些数据是作为美国国家科学基金会资助的一个项目的一部分获得的，该项目旨在对哥斯达黎加太平洋边缘的俯冲带进行成像，特别是针对经常发生俯冲推覆地震的俯冲板块界面。最初的计划在2008年8月提交的NSF-哥斯达黎加3D提案中概述，其中包括西班牙石油公司Repsol进行的3D地震数据处理。与雷普索尔的协议包括一份意向书，要求雷普索尔自费处理这些数据。然而，在与雷普索尔达成协议并提交建议书后的三年里(由于资金延迟一年，以及在获得R/V朗塞斯的时间方面延迟了两年)，雷普索尔与CGGVeritas建立了合作伙伴关系，随后改变了他们处理所有地震数据的安排。因此，如果不对雷普索尔/CGGVeritas伙伴关系进行一些补偿，雷普索尔就无法提供数据处理。Respol/CGGVeritas需要15万美元来进行这项工作，这只是处理成本的一小部分。利用本提案要求的资金，Repsol/CGGVeritas将通过最初的时间处理阶段处理3D数据量，然后是第二阶段的先进3D深度成像。Repsol/CGGVeritas预计将在大约12个月内快速完成这两个阶段。哥斯达黎加三维地震项目旨在对从海沟到地震孕育区的俯冲板块界面进行成像。这是一个经常发生7级以上中等地震的俯冲带。该项目的主要目标是对从地震到地震的过渡过程中的板块界面进行成像，并以非常详细的3D图像显示上覆板块的断层和变形结构。在Marcus Langseth上的数据采集是成功的，调查覆盖了11 x 55公里的区域，37.5米的直列和25米的交叉线间距，几乎完全覆盖。总数据量为4.5TB。在采集巡航期间进行质量控制的初步结果表明，数据质量很高，将产生极好的3D体积。PI已经制定了使用Repsol/CGGVeritas进行处理的计划，他们准备开始这项工作。雷普索尔对这些数据进行处理后将生产出出色的产品感到满意。更广泛的影响：该项目将使PI能够最大限度地提高这些数据的图像质量，并承担这项研究的最大影响。德克萨斯大学的两名硕士研究生和加州大学圣克鲁斯分校的一名博士后将使用这些数据。这些学生和博士后在朗塞斯号上参与了海上数据采集，并将使用处理后的数据进行论文和博士后研究。经过处理的3D数据量将通过综合海洋钻探计划支持一个主要的国际钻探计划-CRISP项目的规划和发展。该项目的总体目标是进一步了解孕震带内的断层条件，这将有助于更好地了解哥斯达黎加的地震危险，并将直接适用于世界各地的俯冲带环境。

Intellectual Merit: The PI requests funds to help offset the costs of processing of recently acquired 3D seismic reflection data from the Costa Rica margin. These data were acquired as part of a project funded by NSF to image the subduction zone on the Pacific margin of Costa Rica, specifically targeting the subducting plate interface where regular subduction thrust earthquake occur. The original plan, outlined in the NSF-Costa Rica 3D proposal that was submitted in August, 2008, included 3D seismic data processing by the Spanish oil company Repsol. The agreement with Repsol included a letter of intent for Repsol to process these data at their expense. However, in the three intervening years since the agreement with Repsol and submission of the proposal (due to a year delay in funding and two-year delay in getting time on the R/V Langseth), Repsol entered into a partnership with CGGVeritas and subsequently changed their arrangements for processing all of their seismic data. Consequently Repsol was unable to offer data processing without some compensation to the Repsol/CGGVeritas partnership. Respol/CGGVeritas requires $150,000 to conduct this work, a fraction of the costs for doing the processing. With the funds requested in this proposal, Repsol/CGGVeritas will process the 3D data volume through an initial time-processing stage followed by a second stage of advanced 3D depth imaging. Repsol/CGGVeritas expects to complete both stages quickly, within ~12 months. The Costa Rica 3D seismic project was designed to image the subducting plate interface from the trench into the seismogenic zone. This is a subduction zone that regularly produces moderate M 7+ earthquakes. The primary goal of the project is to image the plate interface across the aseismic-to-seismic transition and to image the fault and deformational structures of the overriding plate with great detail and in 3D. The data acquisition on the Marcus Langseth was a success with the survey covering an 11 x 55 km area with 37.5 m inline and 25 m crossline spacing with nearly complete coverage. The total data volume is 4.5 Terabytes. Preliminary results from conducting quality control during the acquisition cruise shows the data are of high quality and will produce an excellent 3D volume. The PI has devised a plan for processing with Repsol/CGGVeritas and they are ready to begin the job. Repsol is satisfied these data will produce an excellent product once processed. Broader impacts: The project will enable the PI to maximize the quality of the images from these data and assume the greatest impact from this study. These data will be used by two MS students at the University of Texas and a postdoc at UC Santa Cruz. These students and the postdoc participated at sea with the data acquisition on the Langseth and will use the processed data for their thesis and postdoctoral studies. The processed 3D data volume will support planning and development of a major international program for drilling, the CRISP project, through the Integrated Ocean Drilling Program. The overall goals of the project, further understanding of the fault conditions within the seismogenic zone, will lead to a better understanding of the earthquake hazard in Costa Rica and will be directly applicable to subduction zone settings around the world.