Three Compliance Instruments for Axial Volcano to Observe Long Term Evolution of the Magma Chamber and in Support of OOI Observations

用于轴状火山观测岩浆室长期演化并支持 OOI 观测的三种顺应性仪器

• 批准号: 1924024
• 负责人: Spahr Webb
• 金额: $ 62.78万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-10-01 至 2023-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1924024&HistoricalAwards=false
• 关键词: Three; Compliance; Instruments; Axial; Volcano

Despite decades of observations, how magma migrates and is stored within volcanoes remains poorly understood because there are few means to continuously monitor changes within magma chambers beneath volcanoes. Such measurements are needed to understand when and how the gradual emplacement of magma finally triggers an eruption. The instrumentation developed will provide the potential to monitor changes in the magma content continuously beneath undersea volcanoes and thereby provide a better understanding of volcano processes that can also be applied to volcanos on land that pose a major hazard to millions of people.Axial Volcano, a large, very active undersea volcano offshore the US West Coast is currently monitored using sensors that transmit data through the NSF supported Ocean Observatories Initiative cable to shore. Sensors on these cables measured changes in the compliance of seafloor preceding and following an eruption in 2015 associated with changes in the magma chamber, but the noise level of these sensors limited the sensitivity of the observations and the observation period to the winter months when the compliance signal was larger. New compliance sensors with better sensitivity and a lower noise level will be constructed using more optimal sensors and placed on the seafloor beneath large shields that protect the sensors from noise from ocean currents. Compliance, a measure the deformation of the seafloor under the loading of long period ocean waves, depends on the elastic properties of the underlying Earth and thereby to the fraction of magma within the magma chamber. The current shielding developed will also have applicability for reducing the noise levels for the horizontal components of broadband seismometers installed on the seafloor. Ocean bottom seismometers are critical to understanding many Earth processes, but the high noise levels due to ocean floor currents limits the types and quality of observations that can be made.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.

尽管进行了数十年的观察，但人们对岩浆如何迁移和储存在火山内的了解仍然知之甚少，因为几乎没有方法可以连续监测火山下方岩浆室内的变化。需要进行此类测量来了解岩浆的逐渐就位何时以及如何最终引发喷发。 所开发的仪器将提供连续监测海底火山下方岩浆含量变化的潜力，从而更好地了解火山过程，这也可以应用于对数百万人构成重大危险的陆地火山。目前，美国西海岸附近一座非常活跃的大型海底火山正在使用传感器进行监测，这些传感器通过美国国家科学基金会支持的海洋观测计划电缆将数据传输到岸上。 这些电缆上的传感器测量了 2015 年火山喷发前后海底顺应性的变化，这些变化与岩浆室的变化相关，但这些传感器的噪声水平限制了观测的灵敏度和观测周期，限制在冬季月份。信号较大。将使用更优化的传感器构建具有更高灵敏度和更低噪声水平的新合规性传感器，并将其放置在大型屏蔽层下方的海底，以保护传感器免受洋流噪声的影响。柔度是长期海浪载荷下海底变形的量度，取决于地下地球的弹性特性，从而取决于岩浆室内岩浆的比例。目前开发的屏蔽还可用于降低安装在海底的宽带地震计水平部件的噪声水平。海底地震仪对于了解许多地球过程至关重要，但海底洋流造成的高噪声水平限制了观测的类型和质量。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准。