Uncovering the hidden signature of a magmatic recharge at Piton de la Fournaise volcano using small earthquakes

A ring-shaped zone of weakness beneath Piton de la Fournaise volcano, revealed through advanced seismic analysis, suggests preexisting structural vulnerabilities that influence eruptive behavior. Using a template matching method, researchers detected thousands of small earthquakes in 2014 and 2015, uncovering persistent seismicity patterns linked to magma recharge. Notably, deep earthquake migration in 2015 preceded a shallow seismic swarm, indicating the formation of a hydraulic connection between deep magma sources and a near-sea-level reservoir—likely missed in past observations due to detection limitations. This study highlights how subtle seismic signals can decode volcanic processes, offering insights into the hidden dynamics shaping eruptions at UNESCO-listed Réunion Island's volcanic landscapes.

Lengliné, O., Duputel, Z., & Ferrazzini, V. (2016). Uncovering the hidden signature of a magmatic recharge at Piton de la Fournaise volcano using small earthquakes. Geophysical Research Letters, 43(9), 4255–4262. Portico. https://doi.org/10.1002/2016gl068383