Acquisition of New GPS Equipment in Support of the Central Andes GPS Project (CAP)

[0214523]这笔拨款支持购买8台全球定位系统（GPS）接收器，用于南美洲安第斯山脉中部的主动构造研究。其中四个接收机将永久部署在连续模式操作（CGPS），而其他四个将用于战役或调查模式（SGPS）。这些接收器将作为夏威夷大学大地测量组（以下称为太平洋地球科学设施- PGF）使用的老化接收器的补充和/或替代，用于持续收集安第斯山脉中部活跃弧前区域周围的GPS数据。中央安第斯项目（CAP）自1992年以来一直由NSF/EAR资助（EAR-9115576）。该地区GPS测量的时空密度将有助于更好地理解地球物理学中的两个基本问题，包括：1)俯冲带大地震后粘弹性松弛对地壳变形的贡献是什么？2)地幔的粘度是多少？在1960年智利地震震中附近密集化的CGPS测量将有助于解决前一个问题，而CGPS在智利巴塔哥尼亚的垂直定位将进一步限制冰后反弹的速率，从而可以用于计算下地壳和地幔粘度。了解大俯冲带地震后的长期地震周期对减轻安第斯科迪勒拉人口中心的地震灾害具有重要意义。这些接收器还将支持PGF与智利和阿根廷地球科学家之间的合作。国内科学家将以对PGF小组来说在后勤上不现实的频率收集竞选GPS数据，以国家科学基金会的边际成本提高CAPS项目的产出***

0214523BevisThis grant supports the acquisition of eight global positioning system (GPS) receivers for active tectonic research in the central Andes of South America. Four of the proposed receivers will be permanently deployed in continuous mode operation (CGPS) while the other four will be used in campaign or survey mode (SGPS). The receivers will augment and/or act as replacements for aging receivers used by the University of Hawaii Geodesy group (hereafter named the Pacific Geoscience Facility - PGF) for the on-going collection of GPS data surrounding the active fore arc region of the central Andes. The Central Andes Project (CAP) has been funded by NSF/EAR since 1992 (EAR-9115576). Temporal and spatial densification of GPS measurements in this region will contribute to a better understanding of two fundamental questions in geophysics including: 1) what is the contribution of viscoelastic relaxation to crustal deformation following a great subduction zone earthquake?, and 2) what is the viscosity of the mantle? A densification of CGPS measurements surrounding the epicenter of the 1960 Chilean earthquake will help to resolve the former question while CGPS vertical positioning in Chilean Patagonia will further constrain the rate of post-glacial rebound which can then be used to calculate lower crustal and mantle viscosity. An understanding of the long term seismic cycle following a great subduction zone earthquake has significant implications for mitigating seismic hazards for population centers along the Andean Cordillera. These receivers will also support collaborations between the PGF and Chilean and Argentinean geoscientists. In-country scientists will collect campaign GPS data at frequencies that are logistically unrealistic for the PGF group, improving the output of the CAPS project for a marginal cost to the NSF.***