Vertical Movement in the Southern Alps Constrained by GPS

该合同为购买4套GPS接收机系统以及相关材料和供应品提供部分资金。GPS系统将用于一个合作项目，利用GPS大地测量学和绝对重力测量新西兰南阿尔卑斯山的垂直运动分量。调查人员将沿着南阿尔卑斯山的剖面安装7台连续或半连续的GPS仪器，那里的范围特别大，垂直移动的速度也应该很高。他们将在10个地点使用FG5重力仪器测量g，以校准和补充GPS测量。5年的数据收集工作应能对海平面基准的上升进行量化，并测试这种上升是否由地壳增厚或对侵蚀卸载的反应所补偿。形变的垂直分量有助于理解大陆构造的两个基本过程；1)地表变形是如何与深处的变形联系起来的；2)气候是如何通过侵蚀作用影响构造的。绝对重力和GPS大地测量的结合使用应该允许pi区分抬升在多大程度上是由均衡响应引起的：1)地表载荷的移除和整个地壳的抬升，或2)地壳增厚，其中增厚的速率应该是测量到的抬升速率的6到7倍。这项工作涉及与新西兰和其他地方的国际同事的广泛合作和费用分摊。牵头机构（麻省理工学院）承诺为该GPS系统的收购提供配套资金（总成本的32%）。***

9912071 MolnarThis award provides partial funding for the purchase of four GPS receiver systems and associated materials and supplies. The GPS systems will be used in a collaborative project to measure vertical components of motion across the Southern Alps of New Zealand using both GPS geodesy and absolute gravity. The investigators will install seven continuous or semi-continuous GPS instruments along a profile across the Southern Alps where the range is especially high, and rates of vertical movement should also be high. They will measure g, using the FG5 gravity instrument at 10 sites, both to calibrate and supplement GPS measurements. Five years of data collection should allow a quantification of uplift of benchmarks with respect to sea-level, and a test of whether such uplift is compensated by crustal thickening or a response to erosional unloading. Vertical components of deformation should contribute to understanding two basic processes in continental tectonics; 1) how surface deformation is connected to that at depth, and 2) how climate, through erosion, affects tectonics. The combined use of absolute g and GPS geodesy should allow the PIs to distinguish the extent to which uplift results from the isostatic response to 1) the removal of a surface load and the uplift of the entire crust, or 2) to crustal thickening, for which the rate of thickening should be six to seven times the measured rate of uplift. The work involves extensive collaboration and cost sharing with international colleagues in New Zealand and elsewhere. The lead institution (Massachusetts Institute of Technology) is committed to providing matching funds (32% of total cost) for the acquisition of this GPS system.***