EGU22-12491, updated on 10 Mar 2024
https://doi.org/10.5194/egusphere-egu22-12491
EGU General Assembly 2022
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

The 2021 Cumbre Vieja eruption: an overview of the geochemical monitoring program

Nemesio M. Pérez1,2, Pedro A. Hernández1,2, Gladys V. Melián1,2, Eleazar Padrón1,2, María Asensio-Ramos1, José Barrancos1,2, Germán D. Padilla1,2, Fátima Rodríguez1, Luca D'Auria1,2, Cecilia Amonte1,2, Mar Alonso1, Alba Martín-Lorenzo1,2, David Calvo1, Claudia Rodríguez1,2, William Hernández1, Beverley Coldwell1,2, Matthew J. Pankhurst1,2, and the International Collaborative Research TEAM*
Nemesio M. Pérez et al.
  • 1Instituto Volcanológico de Canarias (INVOLCAN), 38320 San Cristóbal de La laguna, Tenerife, Canary Islands (nperez@iter.es)
  • 2Instituto Tecnológico y de Energías Renovables (ITER), 38611 Granadilla de Abona, Tenerife, Canary Islands, Spain
  • *A full list of authors appears at the end of the abstract

Cumbre Vieja (220 km2) is the most active volcano in the Canary Islands. It has been the location of 8 of the 17 historical eruptions in the archipelago during the last 600 years. The establishment of a geochemical monitoring program by our research group for the volcanic surveillance of Cumbre Vieja started in 1997. This program was mainly focused on diffuse degassing monitoring because of the absence of visible volcanic degassing manifestations (fumaroles, plumes, etc.) as well as other obvious geothermal features at Cumbre Vieja up to the 2021 eruption which started on September 19, ended on December 13 and lasted 85 days.

The INVOLCAN’s soil degassing monitoring at Cumbre Vieja is carried out by means of a geochemical instrumental permanent network (soil CO2 efflux, soil gas 222Rn and soil C isotope ratio) and regular geochemical surveys covering the entire area of Cumbre Vieja (diffuse CO2, He and H2 emissions). Several soil degassing anomalies have been observed and some of them years before the 2021 eruption, which illustrates the importance of diffuse degassing monitoring for volcanic surveillance. The single visible manifestation of volcanic degassing at La Palma is a cold CO2-rich site at Taburiente volcano. Regular helium-3 emission monitoring of this observation site has been carried out since 1991 in collaboration with Tokyo Univ., and provided a clear early warning signal of the 2021 Cumbre Vieja eruption. Because of the registration of seismic swarms, and to strengthen the INVOLCAN geochemical monitoring program of Cumbre Vieja volcano,  regular sampling of groundwater for chemical and isotopic analysis started in October 2017. The results of this hydrogeochemical monitoring also showed significant changes related to the recent volcanic unrest of Cumbre Vieja.

Since the 2021 eruption onset, INVOLCAN performed daily observations of SO2 emissions using a miniDOAS in traverse mode, on terrestrial (car), sea (ship) and air (helicopter) mobile position recording relatively high SO2 emissions (> 50.000 t/d). Static scanners and satellite instruments were used also to monitoring the SO2 emission released by this eruption; a task lead by the volcano research group of Manchester University. Additional plume geochemical monitoring was carried out using OP-FTIR spectrometers and UAV, helicopter and ground-base MultiGas units to characterize the chemical composition of the plume degassing in collaboration with scientists from Manchester Univ., Palermo Univ., UCL, INGV, IPGP and Azores Univ.  Carbon isotope analysis of the CO2 gas plume was also undertaken in collaboration with New Mexico Univ. Analysis of pristine ash leachates has been also performed in collaboration with Durham Univ. and Tokyo Institute of Technology since it is often used to estimate the composition of the gas phase during volcanic eruptions and provides important information on the eruption processes was also performed.

The results of these geochemical observations during the inter-eruptive, pre-eruptive, eruptive and post-erupive phases have been tremendously useful to understand the recent magmatic reactivation of Cumbre Vieja volcano.

 

International Collaborative Research TEAM:

Manchester Univ, Palermo Univ., UCL, INGV, IPGP, Azores Univ., New Mexico Univ., Durham Univ., Tokyo Univ., Tokyo Institute of Technology

How to cite: Pérez, N. M., Hernández, P. A., Melián, G. V., Padrón, E., Asensio-Ramos, M., Barrancos, J., Padilla, G. D., Rodríguez, F., D'Auria, L., Amonte, C., Alonso, M., Martín-Lorenzo, A., Calvo, D., Rodríguez, C., Hernández, W., Coldwell, B., and Pankhurst, M. J. and the International Collaborative Research TEAM: The 2021 Cumbre Vieja eruption: an overview of the geochemical monitoring program, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12491, https://doi.org/10.5194/egusphere-egu22-12491, 2022.

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