Minute-scale dynamics of recurrent dike intrusions in Iceland with fiber-optic geodesy

作者：Jiaxuan Li, Ettore Biondi, Elías Rafn Heimisson, Simone Puel, Qiushi Zhai, Shane Zhang, Vala Hjörleifsdóttir, Xiaozhuo Wei, Elijah Bird, A. T. Klesh, Valey Kamalov, Theodór Gunnarsson, Halldór Geirsson, Zhongwen Zhan · 发表于：Science · 年份：2025 · DOI：10.1126/science.adu0225 · 被引用次数：20 · 研究领域：Seismic Waves and Analysis、earthquake and tectonic studies、Geological and Geochemical Analysis

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 revealed 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 quasistatic deformations. In active volcanic regions, LFDAS recordings can offer critical insights into magmatic evolution, eruption forecasting, and hazard assessment.