A novel magnetometer network to capture the ongoing inflationary episode at Askja volcano, Iceland

We propose to study the ongoing inflation at Askja volcano, Iceland, using magnetometry. This inflation—which started in August 2021 and is well on its way to reversing over 40 years of cumulative subsidence—suggests recharge of the shallow magmatic storage system beneath Askja caldera as the system primes for the next eruption. We will deploy a network of continuous, 3-component magnetometers to measure the time evolution of the subsurface magmatic system in August 2023. Changes to the distribution of magma should produce observable changes to the local magnetic field, which these instruments will measure. This novel technique is based on recent modeling by Biasi et al. (2022) and a successful deployment at Axial Seamount (Fluegel et al. 2022). The proposed network will complement the existing continuous seismic and geodetic networks, as well as benchmarks used for campaign gravimetry surveys. We will combine a 6 3-component fluxgate magnetometers, similar to those which we have successfully deployed in Alaska in 2022, with a large number (14–15) of experimental, low-cost devices to densify coverage.

我们提出采用磁测法（magnetometry）研究冰岛阿斯卡火山当前的岩浆隆升活动。此次隆升始于2021年8月，目前正逐步抵消超过40年的累积沉降，这表明阿斯卡破火山口下方的浅部岩浆储集系统正在获得补给，预示该系统正为下一次喷发做好准备。我们将于2023年8月布设一套连续式三分量磁强计（3-component magnetometers）阵列，以监测地下岩浆系统的时间演化过程。岩浆分布的变化将引发局部磁场的可观测扰动，而该套仪器将对此进行测量。这项创新技术基于Biasi等人2022年的最新模拟研究，以及此前在轴深海山（Axial Seamount）开展的成功布设工作（Fluegel等人，2022）。本次拟布设的阵列将对现有的连续地震与大地测量台网（seismic and geodetic networks），以及流动重力测量（campaign gravimetry surveys）所用的基准点形成有效补充。我们将采用6台三分量磁通门磁强计（fluxgate magnetometers）——此类设备我们已于2022年在阿拉斯加成功部署——搭配14至15台实验型低成本设备，以提升观测覆盖密度。