A Moored Geodetic Seafloor Monitoring System (GEOCE)

系泊海底大地监测系统 (GEOCE)

• 批准号: 0551363
• 负责人: Kevin Brown
• 金额: $ 131.43万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0551363&HistoricalAwards=false
• 关键词: Moored; Geodetic; Seafloor; Monitoring; System

The PI's propose to construct and demonstrate a novel capability to carry out geodetic seafloor motion measurements from oceanographic moorings and observatories. The Moored Geodetic Seafloor Monitoring System (GEOCE) system would integrate several methods and technologies, most of which have been proven separately in different applications already. It consists of continuous raw-waveform differential GPS measurements on the surface buoy of the mooring, to determine the horizontal and vertical motion of the buoy with sub-centimeter accuracy. Horizontal seafloor motion is measured via acoustic transponder interrogations relative to the surface buoy, a variant of an existing ship based approach. Vertical seafloor motion is determined via high-precision bottom pressure measurements, after removing sea surface height motion (using the GPS) and internal ocean density fluctuations (using water column CTD sensors in the mooring). The residual bottom pressure signal is seafloor motion or sensor drift. An in-situ calibration system will be added to determine the drift. Irregular vertical motion or sudden events would be detectable even without this calibration system. The current proposal consists of the engineering development to bring these together in a new (moored) configuration, and to exploit the synergy between the disciplines. Broader ImpactsThis activity will advance discovery by enabling the first true multi-scale temporal studies of plate motions beneath the oceans. Specifically, it should help to understand the processes of stress and strain at convergent margins, which are a major risk area for great earthquakes and tsunamis. Eventually, they could be used to identify locked margins at risk of catastrophic events. The proposed instrumentation will fill the need for a seafloor geodetic system that provides GPS referenced, sub-centimeter resolution of vertical and horizontal deformation over multi-time scales. The GEOCE system has the potential to significantly impact both the geophysical and oceanographic communities by providing information for tectonic/sea floor motion, water column and bottom pressure data, hazard, and climatic studies. This proposal will also involve the participation of 4 graduate students, training the next generation of marine geodesists.

PI 提议构建并展示一种从海洋系泊处和观测站进行大地测量海底运动测量的新颖能力。系泊海底大地监测系统（GEOCE）系统将集成多种方法和技术，其中大多数已经在不同的应用中单独得到验证。它由对系泊表面浮标的连续原始波形差分 GPS 测量组成，以确定浮标的水平和垂直运动，精度达到亚厘米级。水平海底运动是通过声学应答器相对于表面浮标的询问来测量的，这是现有船基方法的一种变体。在消除海面高度运动（使用 GPS）和内部海洋密度波动（使用系泊处的水柱 CTD 传感器）后，通过高精度底部压力测量确定海底垂直运动。残余底部压力信号是海底运动或传感器漂移。将添加现场校准系统来确定漂移。即使没有这个校准系统，不规则的垂直运动或突发事件也可以被检测到。目前的提案包括工程开发，将这些技术整合到一个新的（系泊）配置中，并利用学科之间的协同作用。更广泛的影响这项活动将通过对海洋下板块运动进行首次真正的多尺度时间研究来推进发现。具体来说，它应该有助于了解收敛边缘处的应力和应变过程，这是发生大地震和海啸的主要风险区域。最终，它们可以用来识别处于灾难性事件风险中的锁定利润。拟议的仪器将满足海底大地测量系统的需求，该系统提供多时间尺度垂直和水平变形的 GPS 参考、亚厘米分辨率。 GEOCE 系统通过提供构造/海底运动、水柱和底部压力数据、灾害和气候研究信息，有可能对地球物理和海洋学界产生重大影响。该提案还将涉及 4 名研究生的参与，培养下一代海洋大地测量师。