Leveraged acquisition of a Seattle fault GPS network: Four dimensional constraint on seismic and aseismic strain accumlation and release in the urbanized Puget Lowlands

利用西雅图断层 GPS 网络的采集：城市化普吉特低地地震和抗震应变积累和释放的四维约束

• 批准号: 0216626
• 负责人: M. Meghan Miller
• 金额: $ 22.5万
• 依托单位: Central Washington University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2006-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0216626&HistoricalAwards=false
• 关键词: Leveraged; acquisition; Seattle; fault; GPS

0216626MillerContinuous observations using Global Positioning System (GPS) geodesy yield high-precision determination of horizontal and vertical deformation rates and their variation in time and space. This project builds on the stunning advances that data from the regional Pacific Northwest Geodetic Array (PANGA) has yielded over the last year. In partnership with the surveying community in Puget Sound, PANGA scientists will install a continuous GPS network that is optimally designed to determine the kinematics and locking of the Seattle fault zone, a major fault within the North America plate. In addition, this network provides important new constraints on the periodic recurrence of slow or silent earthquakes, which have been recently discovered along the transition zone of the Cascadia plate interface. Both studies have fundamental importance to characterizing the geodynamics of plate interaction, they also have broader impacts on quantifying seismic strain energy accumulation on a crustal fault that lies in the heart of the urbanized Puget Lowlands. This network will add new constraints to the relative balance between seismic and aseismic strain release mechanisms on the plate boundary fault that is known to generate great earthquakes (approximately magnitude 9) at frequencies of about 500 years. Finally, this project will foster the nascent collaboration between regional professional and academic communities.The Puget Sound surveying community has formed a consortium to support coordination of new GPS technology to the urbanized Puget Lowlands. This collaboration of cities, counties, state agencies, and engineering firms is committed to installing a "virtual reference system" GPS network known as the Puget Reference System Utility (PRSU) that can provide cm-level positioning in real time. Fortuitously, this network is optimal for the earthquake and geodynamics studies outlined above, with the caveat that the solid earth deformation community has the highest standards for monumentation in order that GPS antennas track real earth motion rather than the effects of soil, gourndwater or man-made structures. The Puget Lowlands present the greatest first-order challenges to stable monument design: thick soil horizons, deep sedimentary basins in the foot wall of the Seattle fault and a mantle of debris left behind in the last glacial retreat require use of the deeply anchored drilled braced monument. Such monumentation is thus critical to making geophysically meaningful observations of great precision required by the problems posed here. This project funds geodetic quality monuments in order to leverage the PRSU GPS network for solid earth deformation studies in a highly leveraged fashion. ***

0216626米勒使用全球定位系统（GPS）大地测量学进行的连续观测可以高精度地确定水平和垂直形变率及其在时间和空间上的变化。 该项目建立在区域太平洋西北大地测量阵列（PANGA）数据在过去一年中取得的惊人进展的基础上。 PANGA科学家将与普吉特海湾的测量界合作，安装一个连续的GPS网络，该网络经过优化设计，用于确定西雅图断层带的运动学和锁定，这是北美板块内的一个主要断层。 此外，这个网络提供了重要的新的限制周期性复发的缓慢或无声的地震，这是最近发现的沿着过渡带的卡斯卡迪亚板块界面。 这两项研究对表征板块相互作用的地球动力学具有根本的重要性，它们对量化位于城市化普吉特低地中心的地壳断层上的地震应变能积累也具有更广泛的影响。 该网络将对板块边界断层上地震和抗震应变释放机制之间的相对平衡增加新的限制，已知该断层以约500年的频率产生大地震（约9级）。 最后，该项目将促进区域专业界和学术界之间的初步合作，普吉特海湾测量界已组成一个联合会，以支持协调全球定位系统新技术在城市化的普吉特低地的应用。 市、县、国家机构和工程公司的合作致力于安装一个“虚拟参考系统”GPS网络，称为普吉参考系统实用程序（PRSU），可以提供真实的厘米级定位。 幸运的是，这个网络是上述地震和地球动力学研究的最佳选择，但需要说明的是，固体地球变形界对观测具有最高标准，以便GPS天线跟踪真实的地球运动，而不是土壤、地下水或人造结构的影响。 普吉特低地对稳定的纪念碑设计提出了最大的一级挑战：厚土层、西雅图断层下盘的深沉积盆地和末次冰川退缩留下的碎片地幔需要使用深锚钻孔支撑纪念碑。 因此，这样的纪念对于进行具有重要意义的观察至关重要，这些观察具有这里提出的问题所要求的高度精确性。该项目为大地测量质量的纪念碑提供资金，以便利用PRSU全球定位系统网络，以高度杠杆化的方式进行固体地球变形研究。***