Continental extension in the Deep Galicia Basin from 3-D wide-angle seismic refraction methods

利用 3-D 广角地震折射方法研究加利西亚盆地深部的大陆伸展

• 批准号: 1421300
• 金额: $ 19.4万
• 依托单位: Karplus Marianne
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1421300&HistoricalAwards=false
• 关键词: Continental; extension; Deep; Galicia; Basin

In this two-year Postdoctoral Research Fellowship project, the fellow will investigate the history and mechanisms of continental break up in the Deep Galicia Basin offshore Spain in the Atlantic Ocean using the large 3-D wide-angle seismic dataset featuring 70 ocean bottom seismometers (OBS) collected during summer 2013. Research results will improve understanding of how continents stretch and break apart, creating new ocean basins and leaving rifted margins at the trailing edge of continents. The fellow is hosted by the University of Southampton with sponsoring scientist Tim Minshull. Dale Sawyer, Rice University, also serves as a sponsoring scientist. The project involves collaboration with a large international group of scientists with extensive, multidisciplinary expertise in the USA, UK, Germany, Spain, and Portugal. Additional broader impacts include educational training for undergraduates, mentoring plans for a graduate student, and community outreach education events to further educate the public about rifting and continental breakup. This award was supported with funding from the Office of International and Integrative Activities.The objectives of the project are to determine the full 3-D structure and composition of the rifted Galician margin including the faulted continental blocks, thinned crust, and exhumed mantle and to understand the tectonic processes and evolution that created those structures. These structures are covered by the OBS grid within the seismic reflection 3-D box, which is 64 km (E-W) by 20 km (N-S). This project builds on traditional 2-D and 3-D travel-time tomography work already underway by using 3-D wide-angle full waveform inversion, a relatively new technique that yields higher resolution P-wave velocity models. Next upper mantle seismic anisotropy will be examined using P- and S-wave refractions. Understanding this complex marine tectonic environment requires the combined application of wide-angle and reflection data, as well as other geological and geophysical methods. A final component of this project involves tracking fin whale behavior in the North Atlantic using passive OBS recordings.

在这个为期两年的博士后研究奖学金项目中，该研究员将利用2013年夏季收集的70个海底地震仪（OBS）的大型三维广角地震数据集，研究大西洋西班牙近海深加利西亚盆地大陆分裂的历史和机制。研究结果将提高对大陆如何伸展和分裂的理解，创造新的海洋盆地，并在大陆的后缘留下裂谷边缘。该研究员由南安普顿大学主办，赞助科学家蒂姆·明舒尔尔。莱斯大学的戴尔·索耶（Dale Sawyer）也担任赞助科学家。该项目涉及与美国、英国、德国、西班牙和葡萄牙拥有广泛多学科专业知识的大型国际科学家小组合作。其他更广泛的影响包括对本科生的教育培训，对研究生的指导计划，以及社区外展教育活动，以进一步教育公众关于裂谷和大陆分裂的知识。该奖项得到了国际和综合活动办公室的资助。该项目的目标是确定加利西亚裂谷边缘的完整三维结构和组成，包括断裂的大陆块体、变薄的地壳和挖掘出来的地幔，并了解形成这些结构的构造过程和演化。这些结构被地震反射三维方框内的OBS网格覆盖，面积为64公里（东西向）乘20公里（南北向）。该项目建立在传统的二维和三维旅行时间断层扫描工作的基础上，利用三维广角全波形反演，这是一种相对较新的技术，可以产生更高分辨率的纵波速度模型。接下来将使用P波和s波折射来检查上地幔地震各向异性。了解这一复杂的海洋构造环境需要综合应用广角和反射数据，以及其他地质和地球物理方法。该项目的最后一个组成部分是使用被动OBS记录在北大西洋追踪长须鲸的行为。