The USAC Aeroseophysical Survey of the Basins Surrounding the Antarctic Peninsula

该项目是一项为期三年的航空地球物理调查的最后一年，该调查旨在获取南极半岛周围大陆边缘和盆地的磁场和重力数据。该项目是Lamont-Doherty地质观测站和海军研究实验室的共同努力，海军研究实验室将提供一架P-3飞机来支持该项目。目前的项目是基于1985/86年和1986/87年南方夏季的先前工作，其中通过一系列飞行获得了大约15万公里的地球物理数据，覆盖了以前未调查的威德尔海盆地西部和布兰斯菲尔德海峡的大部分地区。该野外工作的初步结果确定了鲍威尔盆地附近的化石俯冲带，拉西特海岸侏罗纪火山序列延伸的典型海洋-大陆过渡磁异常，以及布兰斯菲尔德海峡的对称异常模式。目前的野外工作将集中于获取斯科舍盆地的磁资料，并对西别林斯豪森边缘进行磁重调查。空中测量的目的是有效和迅速地绘制半岛部分及其东、西边缘的地磁图。该地区大部分地区通常被冰覆盖，船只无法进入，因此该项目将提供其他方式无法获得的数据。NRL P-3是专门为支持地球物理研究而设计的，是该项目的优秀远程平台。这一研究结果将提高我们对构造板块相对运动的认识和南极半岛的地质解释，并为德雷克海峡的开通时间和南大洋环流模式的演变提供约束条件。

This project is the final year of a three-year airborne geophysical survey to obtain magnetic and gravimetric data within the continental margins and basins surrounding the Antarctic Peninsula. The project is a joint effort between the Lamont-Doherty Geological Observatory and the Naval Research Laboratory, which will provide an instrumented P-3 aircraft in support of the project. The present project is based on prior work in the 1985/86 and the 1986/87 austral summer seasons, in which about 150,000 km of geophysical data was obtained in a series of flights covering much of the previously unsurveyed western Weddell Sea Basin and the Bransfield Strait. Preliminary results from that field work have defined a fossil subduction zone bordering the Powell Basin, a magnetic anomaly typical of an ocean-continent transition extending from Jurassic volcanic sequences on the Lassiter Coast, and a symmetric anomaly pattern in the Bransfield Strait. The present field work will concentrate on acquiring magnetic data in the Scotia Basin, and carrying out a magnetic and gravity survey of the western Bellingshausen margin. The airborne surveys have been designed to produce an efficient and rapid geomagnetic picture of the peninsular sector and its eastern and western margins. Much of this area is normally covered by ice and is inaccessible to ships, therefore the project will provide data that could not otherwise be obtained. The NRL P-3 is specifically designed to support geophysical research and is an excellent long-range platform for this project. Results from this work will improve our understanding of the relative motions of tectonic plates and the interpretation of the geology of the Antarctic Peninsula, and provide constraints on the time of opening of the Drake Passage and the evolution of southern ocean circulation patterns.