The study, led by postgraduate student Iván Cabrera-Pérez, who is conducting his Doctoral Thesis at the Volcanological Institute of the Canary Islands (INVOLCAN) under the supervision of Dr. Luca D’Auria, has recently been published in the prestigious international scientific journal Scientific Reports.
The research involved collaboration with investigators from various institutions and countries, including experts from ISTerre (France), the Icelandic Meteorological Office, the Trofimuk Institute of Petroleum Geology and Geophysics (Russia), Novosibirsk State University (Russia), the Department of Theoretical and Cosmos Physics at the University of Granada, the Andalusian Institute of Geophysics, and the Nagoya University Disaster Mitigation Research Center (Japan).
The volcanic eruption on the island of La Palma, which began on September 19, 2021, was preceded by seismic activity that started only 9.5 days before the eruptive event. The researchers applied the advanced technique of seismic noise interferometry to the data recorded by six broadband seismic stations, which allowed them to estimate the variations in subsurface velocity in La Palma during the week prior to the eruption.
The findings reveal that before the eruption, a reduction in seismic velocities was observed near the eruptive centers that subsequently opened. This area coincides with the epicenters of a group of volcanic-tectonic earthquakes located at shallow depths (< 4 km) and disconnected from the main set of deeper seismicity. The researchers interpret this decrease in seismic wave velocities as the effect of hydrothermal fluids released from the magma, which reached the surface faster than the magma itself.
Once again, this result emphasizes the critical importance of having automatic analysis systems for early volcanic alert, an area in which INVOLCAN has invested significantly in efforts and human and material resources.
This research by INVOLCAN was made possible thanks to the VOLRISKMAC II project (MAC2/3.5b/328), co-financed by the European Commission’s INTERREG V-A Spain-Portugal MAC 2014–2020 program, and the Cumbre Vieja Emergencia project, funded by the Ministry of Science and Innovation of the Government of Spain.
Reference of the article:
Cabrera-Pérez I., D’Auria L., Soubestre J., Przeor M., Barrancos L., García-Hernández R., Ibáñez J.M., Koulakov I., Martínez van Dorth D., Ortega V., Padilla G.D., Sagiya T. & Pérez N.M. Spatio-temporal velocity variations observed during the pre-eruptive episode of La Palma 2021 eruption inferred from ambient noise interferometry. Sci Rep 13, 12039 (2023). https://doi.org/10.1038/s41598-023-39237-9