Collaborative Research: Seismic Refraction Wide-Angle Reflection Investigation of the Byrd Subglacial Basin, Antarctica

合作研究：南极洲伯德冰下盆地地震折射广角反射调查

基本信息

批准号：
9222428
负责人：
Scott Smithson
金额：
$ 15.04万
依托单位：
University of Wyoming
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
1993
资助国家：
美国
起止时间：
1993-07-01 至 1997-12-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=9222428&HistoricalAwards=false
关键词：
Collaborative Research Seismic Refraction Wide

项目摘要

This award supports an in situ and short traverse seismic reflection/refraction and magnetotelluric experiment in West Antarctica. This collaborative experiment involves four awards at four institutions. The four-fold purpose is 1) to investigate part of the Byrd Subglacial Basin, 2) to test techniques for this work that could be done in a long traverse, 3) to determine the viability of the magnetotelluric method on a thick (electrically resistive) ice sheet, and 4) to evaluate the relative merits of refraction with wide reflection versus reflection with narrow refraction seismic studies in imaging the lithosphere. The geophysical techniques that will be employed are capable of imaging the ice sheet, the continental lithosphere, and the upper mantle, as well as determining physical properties of parts of the lithosphere and mantle. Investigations of outcrop geology over the last thirty years in West Antarctica and the Transantarctic Mountains have lead to recent interpretations that the crust is made up of many different lithospheric blocks. Seismic reflection work is the only way to image the crust in detail and the refraction work is the only way to determine physical properties of the layers and blocks defined by the reflection work. The magnetotelluric work is scientifically risky because it may not yield useful information when used over the electrically resistive ice sheet; however, if it works it has the potential to image molten rock in the crust and upper mantle. In a continental rift region such as West Antarctica, the presence of melt in the lithosphere is likely and, if documented, has very important ramifications to ice sheet dynamics. Research work supported by this award is expected to provide constraints to models of a range of crustal processes from models of ice sheet dynamics to tectonic and kinematic models of lithospheric thinning and rifting.

该奖项支持南极洲西部的原位和短穿越地震反射/倒数和磁铁性实验。该协作实验涉及四个机构的四个奖项。四倍的目的是1）调查部分伯德冰川盆地的一部分，2）对这项工作的测试技术，可以在较长的遍历中完成，3）确定磁铁纤维化方法在厚（电阻）冰盖上的可行性和4），以评估与范围反射的相对优点，以评估与范围的反映相对的相对优点，以缩回反映范围的反映。将要使用的地球物理技术能够对冰盖，大陆岩石圈和上地幔进行成像，并确定岩石圈和地幔的部分物理性质。在过去的三十年中，在南极洲西部和跨北极山脉对露头地质的调查导致了最近的解释，即外壳由许多不同的岩石圈块组成。地震反射工作是详细映射外壳的唯一方法，而折射工作是确定反射工作定义的层和块的物理特性的唯一方法。磁铁性工作在科学上是有风险的，因为在电阻冰盖上使用时可能不会产生有用的信息。但是，如果起作用，它有可能在地壳和上地幔中成像熔融岩石。在南极西部的大陆裂谷区域中，岩石圈中的熔体存在可能存在，如果有记载，对冰盖动态具有非常重要的后果。该奖项支持的研究工作有望为从冰盖动力学模型到岩石圈稀疏和裂缝的构造和运动学模型的一系列地壳过程的模型提供限制。