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的建议，建设和展示一个新的能力，进行大地测量海底运动测量从海洋系泊和观测站。系泊大地测量海底监测系统将综合若干方法和技术，其中大多数已在不同的应用中分别得到验证。它包括对系泊的水面浮标进行连续的原始波形差分GPS测量，以确定浮标的水平和垂直运动，精度为亚厘米。水平海底运动是通过相对于水面浮标的声学应答器询问来测量的，这是现有船基方法的一种变体。垂直海底运动是通过高精度的海底压力测量确定的，在去除海面高度运动（使用全球定位系统）和内部海洋密度波动（使用系泊中的水柱CTD传感器）之后。剩余海底压力信号是海底运动或传感器漂移。将增加一个现场校准系统，以确定漂移。即使没有这个校准系统，也可以检测到不规则的垂直运动或突发事件。目前的建议包括工程开发，将这些结合在一个新的（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首次对海洋下的板块运动进行真正的多尺度时间研究来推进发现。具体而言，它应该有助于了解收敛边缘的应力和应变过程，这是大地震和海啸的主要风险区域。最终，它们可以用来识别有灾难性事件风险的锁定利润。拟议的仪器将满足对海底大地测量系统的需要，该系统提供以全球定位系统为基准的亚厘米分辨率的多时间尺度垂直和水平变形。地球同步观测系统通过提供构造/海底运动、水柱和海底压力数据、灾害和气候研究方面的信息，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，培训下一代海洋测地学家。