Collaborative Research: Multi-scale Geodetic Monitoring at Axial Seamount

合作研究：轴向海山多尺度大地测量监测

• 批准号: 2226445
• 负责人: Scott Nooner
• 金额: $ 25.06万
• 依托单位: University of North Carolina at Wilmington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-10-01 至 2028-09-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2226445&HistoricalAwards=false
• 关键词: Collaborative; Research; Multi; scale; Geodetic

This project continues long-term research and monitoring of the most active submarine volcano in the NE Pacific named Axial Seamount. It is located about 300 miles off the coast of Oregon and represents an excellent site to study how volcanoes work because it erupts frequently, has numerous monitoring instruments, and has repetitive behavior. This research will improve understanding of how magma (molten rock) is stored in the shallow crust at volcanoes, how it is delivered to the surface, how eruptions are triggered, and how eruptions can be successfully forecast. Scientists will use pressure sensors and underwater vehicles to measure movements of the seafloor at Axial Seamount. These movements take place as the volcano gradually inflates with magma between eruptions, like a balloon, and then rapidly deflates during eruptions. The seafloor moves up and down as much as 8-12 feet during these cycles. When the volcano is fully inflated it is ready to erupt again. Scientists have observed that Axial Seamount inflates to a similar level before each eruption, which has enabled two previous eruptions to be successfully forecast months in advance. Therefore, this research has broad implications for reducing hazards at volcanoes around the world. This work will improve eruption forecasting at all volcanoes, including those on land. Axial Seamount erupted in 1998, 2011, and most recently in April 2015 and is more than 90% re-inflated in 2022, so is building toward another eruption. It is an ideal natural laboratory for the long-term study of active processes at a submarine volcano in a mid-ocean ridge setting. Long-term research and monitoring at Axial have built a remarkable time-series of bottom pressure observations that have revealed a repeated cycle of inflation and deflation that has been used to forecast eruptions with increasing accuracy. The 2015 eruption was the first captured in real time by the Ocean Observatories Initiative (OOI) Regional Cabled Array (RCA) and the network of sensors revealed the inner workings of the volcano in unprecedented detail. Nevertheless, understanding is improved with every eruption and novel techniques are revealing new and surprising phenomena that were previously unknown. An example of this derives from the use of repeated high-resolution bathymetric mapping using Autonomous Underwater Vehicles (AUVs) that show that the deformation field extends over the entire summit caldera and beyond. The new AUV data are complementary to the pressure measurements in that the AUV surveys are spatially continuous and laterally extensive, whereas the pressure measurements are temporally continuous but are spatially limited. During this project, scientists will continue the pressure measurements and further develop the AUV repeat bathymetry technique using Terrain Relative Navigation (TRN) during fieldwork in 2024, 2026, and 2028. The two datasets will be a powerful combination for advancing deformation modeling of the subsurface magmatic system at Axial Seamount.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.

该项目继续对东北太平洋最活跃的海底火山轴向海山进行长期研究和监测。它位于俄勒冈州海岸外约300英里处，是研究火山活动的绝佳地点，因为它经常喷发，有许多监测仪器，并且有重复的活动。这项研究将提高人们对岩浆（熔融岩石）如何储存在火山浅层地壳中的理解，它是如何被输送到地表的，火山爆发是如何引发的，以及如何成功地预测火山爆发。科学家们将使用压力传感器和水下航行器来测量轴向海山海底的运动。这些运动发生在火山在喷发之间随着岩浆逐渐膨胀，就像一个气球，然后在喷发期间迅速收缩。在这些周期中，海底上下移动多达8-12英尺。当火山完全膨胀时，它准备再次喷发。科学家们观察到，轴向海底山在每次喷发前都会膨胀到相似的水平，这使得之前的两次喷发能够提前几个月成功预测。因此，这项研究对减少世界各地火山的危害具有广泛的意义。这项工作将改善所有火山的喷发预测，包括陆地上的火山。轴状海山于1998年、2011年喷发，最近一次是在2015年4月，到2022年再次膨胀了90%以上，因此正在酝酿另一次喷发。它是一个理想的自然实验室，可以长期研究海洋中脊海底火山的活动过程。阿克塞克斯的长期研究和监测已经建立了一个了不起的底部压力观测时间序列，揭示了一个反复的通货膨胀和通货紧缩循环，用于预测火山爆发的准确性越来越高。海洋观测倡议组织（OOI）区域电缆阵列（RCA）首次实时捕捉到2015年的火山喷发，传感器网络以前所未有的细节揭示了火山的内部运作。然而，随着每次火山爆发，人们的理解都在提高，新的技术正在揭示以前未知的新的和令人惊讶的现象。其中一个例子是使用自主水下航行器（auv）进行重复的高分辨率测深测绘，结果显示变形场延伸到整个山顶火山口及更远的地方。新的AUV数据是对压力测量的补充，因为AUV测量在空间上是连续的，横向上是广泛的，而压力测量在时间上是连续的，但在空间上是有限的。在该项目期间，科学家们将在2024年、2026年和2028年的现场工作中继续进行压力测量，并进一步开发使用地形相对导航（TRN）的AUV重复测深技术。这两个数据集将为轴向海山地下岩浆系统的超前变形建模提供有力的支持。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。