Global Positioning System Measurements of Crustal Motion in Antarctica

全球定位系统对南极洲地壳运动的测量

• 批准号: 9527606
• 负责人: Barclay Kamb
• 金额: $ 33.58万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-09-01 至 2001-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9527606&HistoricalAwards=false
• 关键词: Global; Positioning; System; Measurements; Crustal

Kamb Raymond 9527606 Abstract This award supports a project to establish a Global Positioning System geodetic network in the Transantarctic Mountains of Antarctica to measure vertical and horizontal crustal velocities. The vertical crustal velocities measured by GPS reflect the viscoelastic response of the solid Earth to Antarctic deglaciation. Data from this GPS network will be used to test models of late Pleistocene-early Holocene versus late Holocene deglaciation of Antarctica. These data will also constrain the length of time over which the Antarctic ice sheet disintegrated, and the distribution of the peak glacial load. A mid-Holocene deglaciation model produces a predicted uplift pattern in the vicinity of the Transantarctic Mountains that can be measured by high-precision GPS geodetic measurements within a time span of four years. Horizontal deformation induced by rebound will also be measured. These data will also help constrain present-day changes in Antarctic ice mass by monitoring the elastic deformation of the lithosphere resulting from ongoing glacial loading and unloading. The lithospheric response to ongoing ice mass changes is predicted to be an order of magnitude less than the viscoelastic response to late-Pleistocene-Holocene deglaciation. Tectonic uplift rates are also predicted to be very small compared to the predicted rebound signal for this region. Baselines across faults in the Transantarctics may capture co-seismic motion if an earthquake were to occur, or aseismic slip. The first year of the project will be spent in technology development for, and a proof-of-concept demonstration of, a prototype autonomous GPS station (AGS) under joint funding with JPL. This prototype station will be powered by solar panels and will collect data continuously during the deployment period. Data transmission via long-range Radio Frequency (RF) transceivers acting as modems will also be tested. The prototype station will be modified as neede d to implement a reliable, operational network of four autonomous GPS stations in the following year of the project, contingetn upon joint funding by NASA. The AGS network will send daily data reports McMurdo. The network will be a permanent installation that will continue to monitor motion in the region beyond the term of this project. Advanced processing techniques will be employed to increase the accuracy of the crustal velocity measurements, especially for the vertical component. These include orbit modeling, troposphere correction, ionosphere correction, and extraction of annual and seasonal solid Earth and ocean tidal signals.

Kamb Raymond 9527606 摘要 该奖项支持在南极洲横贯南极山脉建立全球定位系统大地测量网的项目，以测量地壳的垂直和水平速度。 GPS测量的地壳垂直速度反映了固体地球对南极冰消作用的粘弹性响应。 来自这一全球定位系统网络的数据将用于检验晚更新世-早全新世与晚全新世南极洲冰川消退的模型。 这些数据还将限制南极冰盖解体的时间长度，以及冰川负荷峰值的分布。 一个中全新世冰川消退模型产生了一个预测的隆升模式，在附近的跨南极山脉，可以测量的高精度GPS大地测量在四年的时间跨度。 还将测量回弹引起的水平变形。这些数据还将有助于通过监测冰川不断加载和卸载造成的岩石圈弹性变形来限制南极冰量的当今变化。 岩石圈对持续冰量变化的响应预计将比晚更新世-全新世冰消作用的粘弹性响应小一个量级。 与该区域的预测反弹信号相比，构造抬升速率也预测为非常小。 如果发生地震或无震滑动，跨南极洲断层的基线可能会捕获同震运动。 该项目的第一年将用于与喷气推进实验室联合资助的原型自主GPS站（AGS）的技术开发和概念验证。 该原型站将由太阳能电池板供电，并将在部署期间持续收集数据。 还将测试通过充当调制解调器的远程射频收发器进行的数据传输。 原型站将根据尼德进行修改，以便在项目的下一年建立一个由四个自主全球定位系统站组成的可靠的运行网络，这一网络由美国航天局联合资助。 AGS网络将发送每日数据报告麦克默多。 该网络将是一个永久性装置，将继续监测该地区的运动超出本项目的期限。 将采用先进的处理技术来提高地壳速度测量的准确性，特别是垂直部分。 这些包括轨道建模、对流层校正、电离层校正以及提取年度和季节固体地球和海洋潮汐信号。