Collaborative Research: Meshed GNSS-Acoustic Array Design for Lower-Cost Dense Observation Fields

合作研究：用于低成本密集观测场的网状 GNSS 声学阵列设计

• 批准号: 2321299
• 负责人: Mark Zumberge
• 金额: $ 196.13万
• 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: 2024
• 资助国家: 美国
• 起止时间: 2024-01-01 至 2026-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2321299&HistoricalAwards=false
• 关键词: Collaborative; Research; Meshed; GNSS; Acoustic

Precise observations of seafloor deformation is important for assessing ongoing geologic processes and the hazards they pose, including the largest earthquakes, tsunamis, submarine volcanism, hydrocarbon changes, and submarine landslides. Making observations of the centimeter-scale deformation that occurs over a year or longer using a combination of sea surface and seafloor instrumentation is currently expensive, particularly when using a large research vessel as a part of the measurement design. In this project, the team will use a rather new but previously tested autonomous, green-powered vessel that replaces the ship-based measurement design, reducing measurement costs by more than an order of magnitude over prior methods. To further reduce instrumentation costs and enable more broad use, the project will test new design geometries that have the potential to significantly increase capabilities where dense observations are needed. During this project, a postdoctoral scholar will be trained as a next-generation scientist and educator. The data collected will be contributed to a community data archive, and methods will be incorporated into community software for research. Following the project, the instrumentation will become a part of an existing NSF-funded instrument pool, doubling the capabilities for deep-water observations from 3000 to 6000 meters. The surface vessel for these operations, a commercially available Wave Glider, will be outfitted with antennas for positioning itself using Global Navigational Satellite Systems (GNSS). The vessel will interrogate a mesh-network of seafloor transponders during the summers of 2024 and 2025 using a lower frequency acoustic signal than currently available with the US instrument pool to allow for the extended ranging needed for deeper water operation. The 10-transponder array will be deployed between 4 and 6 km depth along a segment of the Aleutian trench in 2024, combining ship-activities with an existing community geodetic experiment, that can only extend to 3 km depth. The dense mesh-network design with the shared use of transponders could potentially allow for a ten-fold increase in instrumental efficiency, depending on geometry, over existing methods existing methods that require three transponders per observation point. Lastly, the experiment will additionally evaluate the potentially increased errors associated with necessarily high-gradient seafloor environments that are common in subduction zones. Such steep measurements could be similarly applied to passive continental slopes that have the potential for destructive submarine landslides. While the design experiment tests methodology, the location was chosen because little is known about the behavior of faults in the region, where a large earthquake in 1946 created an outsized tsunami. Detailed information about ongoing fault behavior in the region can illuminate the currently unknown mechanical coupling in the region that builds for future earthquakes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

海底变形的精确观察对于评估正在进行的地质过程及其构成的危害至关重要，包括最大的地震，海啸，海底火山剂，碳氢化合物变化和海底滑坡。 目前使用海面和海底仪器组合使用一年或更长时间发生的厘米尺度变形的观察目前很昂贵，尤其是在使用大型研究容器作为测量设计的一部分时。 在这个项目中，团队将使用一个相当新的但先前测试过的自主绿色船只，该容器取代了基于船舶的测量设计，从而将测量成本降低了超过先前方法的数量级。 为了进一步降低仪器成本并实现更广泛的利用，该项目将测试新的设计几何形状，这些几何形状有可能在需要密集的观察结果的情况下显着提高功能。在此项目中，博士后学者将接受下一代科学家和教育者的培训。 收集的数据将介绍社区数据存档，方法将纳入社区软件进行研究。 在项目之后，该仪器将成为现有的NSF资助仪器池的一部分，使深水观测的能力从3000米到6000米增加了一倍。这些操作的表面容器（一种可商购的波滑翔机）将配备使用全球导航卫星系统（GNSS）定位的天线。 该容器将使用比美国仪器池当前可用的频率较低的声学信号在2024年和2025年的夏季询问海底发音器的网状网络，以允许更深入的水运行所需的扩展范围。 10条带阵列将在2024年沿着阿留申沟的一部分沿着4到6公里的深度部署，将船舶活性与现有社区的大地测量实验相结合，只能扩展到3公里的深度。与现有方法相比，现有的方法相比，通过几何形状，通过共同使用发音器的密集网络网络设计可能会使仪器效率提高十倍，而现有方法每个观察点需要三个分发次数。 最后，该实验还将评估与俯冲带中常见的高梯度海底环境相关的潜在增加误差。 这种陡峭的测量可以类似地应用于具有破坏性海底滑坡的被动大陆斜坡。在设计实验测试方法学的同时，选择了该位置，因为对该地区的故障行为知之甚少，该地区在1946年发生的大地震造成了一场大型的海啸。有关该地区正在进行的断层行为的详细信息可以阐明该地区为未来地震构建的目前未知的机械耦合。该奖项反映了NSF的法定任务，并被认为是通过基金会的智力优点和更广泛影响的评估标准来通过评估来获得支持的。