EGU25-14458, updated on 15 Mar 2025
https://doi.org/10.5194/egusphere-egu25-14458
EGU General Assembly 2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
Minute-scale Dynamics of Repeated Dike Intrusion in Iceland with Fiber-Optic Geodesy
Jiaxuan Li1,2, Ettore Biondi2, ‪Elías Heimisson‬3, Simone Puel2,4, Qiushi Zhai2, Shane Zhang2, Vala Hjörleifsdóttir5, Xiaozhuo Wei2, Elijah Bird2, Andy Klesh6, Valey Kamalov7, Theodór Gunnarsson8, Halldór Geirsson3, and Zhongwen Zhan2
Jiaxuan Li et al.
  • 1Department of Earth and Atmospheric Sciences, University of Houston, USA
  • 2Seismological Laboratory, California Institute of Technology, USA
  • 3Institute of Earth Sciences, University of Iceland, Iceland
  • 4Moody’s, Newark, USA
  • 5Reykjavik University, Iceland
  • 6NASA Jet Propulsion Laboratory, USA
  • 7Valey Kamalov LLC, USA
  • 8Google, USA

Continuous geodetic measurements near volcanic systems have advanced our understanding of magma transport dynamics. However, capturing high spatio-temporal resolution dike intrusion dynamics remains challenging. In this study, we introduce fiber-optic geodesy, an approach that enabled us to track dike intrusions near Grindavík, Iceland, on a minute time scale. This approach utilizes low-frequency distributed acoustic sensing (LFDAS) along a telecommunication fiber cable to measure quasi-static signals during dike intrusions. We captured nine intrusive events over a one-year recording period, six resulting in fissure eruptions. Distinct LFDAS signals, characterized by consistent initial spatial strain response, emerged tens of minutes to several hours before eruptions. We used these signals to assist the Icelandic Meteorological Office (IMO) in issuing early warnings for volcanic eruptions. Moreover, LFDAS signals enable us to image dike intrusions on the minute time scale, revealing their evolution into eruptive lava fissures or their arrest at depth. Our results highlight the feasibility of using DAS for a dense array of strainmeters, 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 volcanic hazard assessment.

How to cite: Li, J., Biondi, E., Heimisson‬, ‪., Puel, S., Zhai, Q., Zhang, S., Hjörleifsdóttir, V., Wei, X., Bird, E., Klesh, A., Kamalov, V., Gunnarsson, T., Geirsson, H., and Zhan, Z.: Minute-scale Dynamics of Repeated Dike Intrusion in Iceland with Fiber-Optic Geodesy, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14458, https://doi.org/10.5194/egusphere-egu25-14458, 2025.