The 2007 caldera collapse of Piton de la Fournaise volcano: Source process from very-long-period seismic signals

In April 2007, Piton de la Fournaise volcano on Réunion Island experienced its largest caldera collapse in at least 300 years, characterized by a series of 48 subsidence increments with seismic signals equivalent to magnitudes Mw 4.4 to 5.4. Analysis of these very-long-period (VLP) seismic events revealed a piston-like mechanism driven by the contraction of the magma reservoir and the collapse of the overlying rock column. The study found that the collapse dynamics were primarily controlled by rapid magma withdrawal, likely from a bubbly state, leading to an acceleration in subsidence increments—a pattern similar to the 2018 Kīlauea collapse. This suggests that such events are linked to progressive weakening of the volcanic edifice and increasing rates of magma extraction.

Duputel, Z., & Rivera, L. (2019). The 2007 caldera collapse of Piton de la Fournaise volcano: Source process from very-long-period seismic signals. Earth and Planetary Science Letters, 527, 115786. https://doi.org/10.1016/j.epsl.2019.115786