Collaborative Research: A GPS Network to Determine Crustal Motions in the Bedrock of the West Antarctic Ice Sheet: Phase I - Installation

合作研究：确定西南极冰盖基岩地壳运动的 GPS 网络：第一阶段 - 安装

• 批准号: 0003619
• 负责人: Ian Dalziel
• 金额: $ 35.32万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-15 至 2006-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0003619&HistoricalAwards=false
• 关键词: Collaborative; Research; GPS; Network; Determine

0003619DalzielThis award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a collaborative research program to initiate a Global Positioning System (GPS) network to measure crustal motions in the bedrock surrounding and underlying the West Antarctic Ice Sheet (WAIS). Evaluation of the role of both tectonic and ice-induced crustal motions of the WAIS bedrock is a critical goal for understanding past, present, and future dynamics of WAIS and its potential role in future global change scenarios, as well as improving our understanding of the role of Antarctica in global plate motions. The extent of active tectonism in West Antarctica is largely speculative, as few data exist that constrain its geographic distribution, directions, or rates of deformation. Active tectonism and the influence of bedrock on the WAIS have been highlighted recently by geophysical data indicating active subglacial volcanism and control of ice streaming by the presence of sedimentary basins. The influence of bedrock crustal motion on the WAIS and its future dynamics is a fundamental issue. Existing GPS projects are located only on the fringe of the ice sheet and do not address the regional picture. It is important that baseline GPS measurements on the bedrock around and within the WAIS be started so that a basis is established for detecting change.To measure crustal motions, this project will build a West Antarctica GPS Network (WAGN) of at least 15 GPS sites across the interior of West Antarctica (approximately the size of the contiguous United States from the Rocky Mountains to the Pacific coast) over a two-year period beginning in the Antarctic field season 2001-2002. The planned network is designed using the Multi-modal Occupation Strategy (MOST), in which a small number of independent GPS "roving" receivers make differential measurements against a network of continuous GPS stations for comparatively short periods at each site. This experimental strategy, successfully implemented by a number of projects in California, S America, the SW Pacific and Central Asia, minimizes logistical requirements, an essential element of application of GPS geodesy in the scattered and remote outcrops of the WAIS bedrock.The WAGN program will be integrated with the GPS network that has been established linking the Antarctic Peninsula with South America through the Scotia arc (Scotia Arc GPS Project (SCARP)). It will also interface with stations currently measuring motion across the Ross Embayment, and with the continent-wide GIANT program of the Working Group on Geodesy and Geographic Information Systems of the Scientific Committee on Antarctic Research (SCAR). The GPS network will be based on permanent monuments set in solid rock outcrops that will have near-zero set-up error for roving GPS occupations, and that can be directly converted to a continuous GPS site when future technology makes autonomous operation and satellite data linkage throughout West Antarctica both reliable and economical. The planned network both depends on and complements the existing and planned continuous networks. It is presently not practical, for reasons of cost and logistics, to accomplish the measurements proposed herein with either a network of continuous stations or traditional campaigns.The proposed WAGN will complement existing GPS projects by filling a major gap in coverage among several discrete crustal blocks that make up West Antarctica, a critical area of potential bedrock movements. If crustal motions are relatively slow, meaningful results will only begin to emerge within the five-year maximum period of time for an individual funded project. Hence this proposal is only to initiate the network and test precision and velocities at the most critical sites. Once built, however, the network will yield increasingly meaningful results with the passage of time. Indeed, the slower the rates turn out to be, the more important an early start to measuring. It is anticipated that the results of this project will initiate an iterative process that will gradually resolve into an understanding of the contributions from plate rotations and viscoelastic and elastic motions resulting from deglaciation and ice mass changes. Velocities obtained from initial reoccupation of the most critical sites will dictate the timing of a follow-up proposal for reoccupation of the entire network when detectable motions have occurred.

0003619DALZIELTHIS奖由《极地计划办公室的南极地质与地球物理学计划》提供，支持了一项协作研究计划，以启动全球定位系统（GPS）网络，以衡量周围基地的地壳动作周围的地壳动作，并在西方反盘中（WIAS）下降。评估WAIS基岩的构造和冰诱导的地壳运动的作用是理解WAIS的过去，现在和未来动态及其在未来全球变化情景中的潜在作用的关键目标，并提高了我们对南极洲在全球板块运动中的作用的理解。南极西部的主动构造的程度在很大程度上是投机性的，因为很少有数据限制其地理分布，方向或变形率。最近，通过地球物理数据强调了主动构造和基岩对WAIS的影响，表明有效的冰山下火山和通过沉积盆地的控制对冰流进行控制。基岩地壳运动对WAIS及其未来动态的影响是一个基本问题。现有的GPS项目仅位于冰盖的边缘，并且没有解决区域图片。重要的是要开始在周围及其内部的基础上的基线GPS测量，以便建立一个基础来检测变化。要测量地壳运动，该项目将建立一个西部的南极GPS网络（WAGN）至少15个GPS地点，该网络至少要在西方的内部范围内（大约是一年一度的ocky ocky Mornes of cocky Mornes of coctific Mornitains of the of cocky Mornitains of the Ondicific Mornational）的地点（ 2001-2002季。计划的网络是使用多模式职业策略（大多数）设计的，其中少数独立的GPS“ Roving”接收器对每个站点的连续GPS站网络进行了差异测量。 这种实验策略是由加利福尼亚州，美国，西部太平洋和中亚的许多项目成功实施的，最小化后勤要求，这是GPS Geodesy在WAIS BEDROCK的分散和远程露头中应用的重要组成部分（SCARP））。它还将与目前在Ross嵌入整个Ross嵌入的动作以及与科学研究委员会（SCAR）的地理学和地理信息系统工作组的整个大陆巨型计划进行交互。 GPS网络将基于固体岩石露头中设置的永久性古迹，这些岩石厂商将在Roving GPS职业中遇到接近零的设置错误，并且当将来的技术使自主操作和卫星数据链接整个整个西南极洲可靠和经济上时，可以直接转换为连续的GPS站点。计划的网络都取决于并补充现有和计划的连续网络。目前，出于成本和后勤的原因，目前不实用，以通过连续电台或传统活动网络来完成本文提出的测量。拟议的WAGN将通过在几个离散的地壳块中填补覆盖范围的重大差距，以补充现有的GPS项目，以构成西方南方的构成西部的几个离散的地壳块，这是潜在的基地运动的关键领域。如果地壳运动相对较慢，则有意义的结果只会在个人资助项目的最长五年内开始出现。因此，该建议仅是为了在最关键的地点启动网络和测试精度和速度。但是，一旦构建，网络将随着时间的流逝而产生越来越有意义的结果。实际上，速率的速度越慢，早期开始衡量的速度就越重要。可以预料，该项目的结果将启动一个迭代过程，该过程将逐渐解决，以理解板旋转以及脱气和冰质量变化所产生的板弹性和弹性运动的贡献。最关键位点的初始重新关注获得的速度将决定在发生可检测动作时重新关注整个网络的后续提案的时机。