Map of the Iceland’s Reykjanes Peninsula.
Map of the Iceland’s Reykjanes Peninsula showing fiber-optic channels and lava flow outlines. On November 10, 2023, a dike intrusion (red) formed, triggering eruptions with overlapping lava flows (darker areas). Before the 2023-2024 eruptions, a fiber-optic cable (yellow) was converted into a seismic sensor array, with channels as measuring points that detect seismic velocity changes. Channel numbers are marked at 1,000-channel intervals. Credit: Bird et al. [2025], Figure 1
Editors’ Highlights are summaries of recent papers by AGU’s journal editors.
Source: AGU Advances

Over the past five years, fiber-optic telecommunication networks have increasingly been used as dense sensor arrays, transforming cables into high-resolution strain detectors at meter-scale intervals. This innovative approach has opened new possibilities for monitoring subsurface processes, including volcanic activity.

During a volcanic eruption, magma movement stretches and compresses the surrounding rock, causing both deformation and changes in seismic wave speed—critical data for estimating magma intrusion. Before the 2023-2024 eruption sequence on Iceland’s Reykjanes Peninsula, a 100-kilometer fiber-optic cable was converted into a dense seismic sensor array, allowing the tracking of seismic velocity variations of about 2% linked to dike intrusions. Notably, the inferred geometry of the first dike matched independent geodetic measurements and surface fissures.

Bird et al. [2025] validates fiber-optic sensing as a new tool for monitoring dike intrusions and highlights its potential for detecting seismic velocity changes and their underlying processes in regions where geodetic and seismic methods are difficult to combine, such as offshore environments. While some uncertainties remain, fiber-optic sensing is rapidly advancing as a key tool for early warning systems.

Citation: Bird, E., Atterholt, J., Li, J., Biondi, E., Zhai, Q., Li, L., et al. (2025). Constraining dike opening models with seismic velocity changes associated with the 2023–2024 eruption sequence on the Reykjanes Peninsula. AGU Advances, 6, e2024AV001516. https://doi.org/10.1029/2024AV001516

—Marcos Moreno, Editor, AGU Advances

Text © 2024. The authors. CC BY-NC-ND 3.0
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