Minute-scale dynamics of recurrent dike intrusions in Iceland with fiber-optic geodesy
利用光纤大地测量学研究冰岛反复发生的岩脉滑坡微小尺度动力学
Abstract
Continuous geodetic measurements near volcanic systems can image magma transport dynamics, yet resolving dike intrusions with high spatiotemporal resolution remains challenging. We introduce fiber-optic geodesy, leveraging low-frequency distributed acoustic sensing (LFDAS) recordings along a telecommunication fiber-optic cable, to track dike intrusions near Grindavík, Iceland, on a minute timescale. LFDAS reveals distinct strain responses from nine intrusive events, six resulting in fissure eruptions. Geodetic inversion of LFDAS strain reveals detailed magmatic intrusions, with inferred dike volume rate peaking systematically 15 to 22 min before the onset of each eruption. Our results demonstrate DAS’s potential for a dense strainmeter array, enabling high-resolution, nearly real-time imaging of subsurface quasi-static deformations. In active volcanic regions, LFDAS recordings can offer critical insights into magmatic evolution, eruption forecasting, and hazard assessment.
文章采用光纤大地测量技术，利用电信光纤电缆进行的低频分布式声学传感（LFDAS），以分钟为单位跟踪冰岛格林达维克附近的岩脉滑坡情况。LFDAS 显示了九次滑坡事件的不同应变反应，其中六次导致裂缝喷发。LFDAS 应变的大地反演显示了滑坡的细节，推断出的岩脉体积率在每次喷发开始前15到22分钟达到系统峰值。研究结果证明了DAS在密集应变计阵列方面的潜力，可对地下准静态变形进行高分辨率、近乎实时的成像。在活火山地区，LFDAS记录可为岩浆演变、喷发预报和危害评估提供重要依据。
J. Li, E. Biondi, E. R. Heimisson, S. Puel, Q. Zhai, S. Zhang, V. Hjörleifsdóttir, E. Bird, A. Klesh, V. Kamalov, T. Gunnarsson, H. Geirsson, and Z. Zhan, “Minute-scale dynamics of recurrent dike intrusions in Iceland with fiber-optic geodesy,” Science 0225, 1–10 (2025).
https://doi.org/10.1126/science.adu0225
朴牛科技HiFi-DAS的低频响应可达0.001Hz。
