A System for Continuous Measurement of Horizontal and Vertical Crustal Deformation of the Seafloor

海底水平和垂直地壳变形连续测量系统

• 批准号: 0084968
• 负责人: C. David Chadwell
• 金额: $ 33.95万
• 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: 2000
• 资助国家: 美国
• 起止时间: 2000-12-01 至 2003-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0084968&HistoricalAwards=false
• 关键词: System; Continuous; Measurement; Horizontal; Vertical

0084968ChadwellThis project addresses techniques to measure present-day deformation of seafloor crust in the vicinity of mid-ocean ridges. By measuring the acoustic range directly between seafloor mounted transducers on the Juan de Fuca Ridge, the rate at which crustal plates move over long time periods can be precisely measured. To continue an ongoing plate monitoring effort, the existing installation will be replaced prior to 2002 at which time the batteries will likely be depleted to a level that will not permit intra-transponder ranging. This project allows construction of a second generation instrument that will address shortcomings in the existing installation while maintaining an unbroken time series of crustal motion measurements from 1994 through 2001 to 2006. The proposed design will be a new type of seafloor instrument that can be configured to extend the temporal and spatial sampling to hourly/daily measurements over 10-km scale distances. The new design will incorporate both horizontal and vertical crustal deformation measurements in an intelligent controller that will respond to changes in background measurements of temperature, pressure, tilt and travel times as sustained deviations from background measurements may indicate the onset of tectonic activity. The multiple sensors and extended spatial coverage of the new system will be applicable to other ridges or across other seafloor faults e.g., on continental shelves at subduction zones. In year one, the instruments will be constructed and tested during a month-long deployment in waters off-shore San Diego. In year two, the instruments will be deployed across axial Cleft of the South Cleft Segment on the Juan de Fuca Ridge.

0084968 Chadwell该项目涉及测量大洋中脊附近海底地壳现今变形的技术。通过直接测量胡安·德富卡海岭海底安装的传感器之间的声波范围，可以精确测量地壳板块长时间移动的速度。 为了继续进行正在进行的车牌监测工作，现有装置将在2002年之前更换，届时电池可能会耗尽，无法进行转发器内测距。该项目允许建造第二代仪器，以解决现有装置的缺陷，同时保持1994年至2001年至2006年期间地壳运动测量的连续时间序列。拟议的设计将是一种新型海底仪器，可将时间和空间采样扩展到10公里尺度距离上的每小时/每日测量。新的设计将把地壳水平和垂直形变测量纳入一个智能控制器，该控制器将对温度、压力、倾斜和旅行时间的背景测量的变化作出反应，因为与背景测量的持续偏差可能表明构造活动的开始。新系统的多个传感器和扩展的空间覆盖范围将适用于其他海脊或其他海底断层，在大陆架的俯冲带。在第一年，这些仪器将在圣地亚哥近海的沃茨进行为期一个月的部署和测试。在第二年，这些仪器将部署在Juan de Fuca海岭南裂段的轴向裂上。