Collaborative Research: Vertical Movement in the Southern Alps Constrained by GPS and Absolute Gravity

9902981Bilham这是一个合作项目，使用GPS大地测量和绝对重力测量新西兰南阿尔卑斯山的垂直运动分量。调查人员将在南阿尔卑斯山的一个剖面上安装七个连续或半连续的GPS仪器，那里的距离特别大，垂直运动速度也应该很高。他们将在10个地点使用FG5重力仪测量g，以校准和补充GPS测量。五年的数据收集应该能够量化基准相对于海平面的抬升，并测试这种抬升是由地壳增厚补偿的，还是对侵蚀卸荷的反应。变形的垂直分量应有助于理解大陆构造中的两个基本过程：1)地表变形如何与深层变形联系在一起；2)气候如何通过侵蚀影响构造。结合使用绝对g和全球定位系统大地测量应能使PI区分均衡响应引起的隆起程度：1)地表载荷的去除和整个地壳的隆起，或2)地壳加厚，其增厚速率应是测量的隆起速率的6至7倍。这项工作涉及与新西兰和其他地方的国际同事进行广泛的合作和分担费用。

9902981Bilham This is 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.