Collaborative Research: Multi-scale Geodetic Monitoring at Axial Seamount

该项目继续对东北太平洋最活跃的海底火山轴海山进行长期研究和监测。 它位于距离俄勒冈州海岸约300英里的地方，是研究火山如何工作的绝佳场所，因为它经常喷发，有许多监测仪器，并且具有重复性行为。这项研究将提高对岩浆（熔融岩石）如何储存在火山的浅地壳中，如何传递到地表，如何触发喷发以及如何成功预测喷发的理解。 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喷发之间逐渐膨胀的岩浆中，就像气球一样，然后在喷发期间迅速缩小。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，它准备再次爆发。科学家们观察到，轴海山在每次喷发前都会膨胀到类似的水平，这使得前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。轴海山在1998年，2011年爆发，最近一次是在2015年4月，并在2022年重新膨胀超过90%，因此正在朝着另一次爆发的方向发展。 它是长期研究大洋中脊海底火山活动过程的理想天然实验室。 Axial的长期研究和监测已经建立了一个显着的底部压力观测时间序列，揭示了一个重复的通货膨胀和通货紧缩周期，用于预测火山爆发的准确性越来越高。 2015年的火山爆发是海洋观测站倡议（OOI）区域有线阵列（RCA）首次以真实的时间捕获的，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，随着每次喷发，人们的理解得到了改善，新的技术正在揭示以前未知的新的和令人惊讶的现象。 这方面的一个例子来自使用自动水下航行器（AUV）重复使用高分辨率测深图，显示变形场延伸到整个山顶破火山口及以外。 新的自主式水下航行器数据与压力测量数据是互补的，因为自主式水下航行器勘测在空间上是连续的，横向上是广泛的，而压力测量数据在时间上是连续的，但在空间上是有限的。在该项目期间，科学家们将继续进行压力测量，并在2024年、2026年和2028年的实地工作期间使用地形相对导航（TRN）进一步开发AUV重复测深技术。 这两个数据集将成为推进Axial Seamount地下岩浆系统变形建模的强大组合。该奖项反映了NSF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。

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.