EGU23-4411, updated on 10 Jan 2024
EGU General Assembly 2023
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Anomalous CO2 concentrations of volcanic origing in the ambient air of banana plantations at La Palma, Canary Islands

Gladys V. Melián1,2, Pedro A. Hernández1,2, Fátima Rodríguez1, Antonio J. Alvárez Díaz3,4, Germán D. Padilla1,2, María Asensio-Ramos1, José Barrancos1,2, David Calvo1, Eleazar Padrón1,2, Alexis M González Pérez3,5, and Nemesio M. Pérez1,2
Gladys V. Melián et al.
  • 1Instituto Volcanológico de Canarias (INVOLCAN), 38320 San Cristóbal de La Laguna, Tenerife, Canary Islands (
  • 2Instituto Tecnológico y de Energías Renovables (ITER), 38600 Granadilla de Abona, Tenerife, Canary Islands
  • 3Instituto Volcanológico de Canarias (INVOLCAN), 38740 Fuencaliente, La Palma, Canary Islands
  • 4Agrolaguna, 38760 Los Llanos de Aridane, La Palma, Canary Islands
  • 5Hidrolap Medioambiental S.L., 38750 El Paso, La Palma, Canary Islands

The recent eruption of Tajogaite volcano occurred between September and December 2021 at La Palma Island is considered the most devastating of Europe since that of Vesuvio in 1944. The post-eruptive period is being characterized by the appearance of high outdoor and indoor CO2 concentrations at inhabited areas such as La Bombilla and Puerto Naos (Hernández et al., 2022), forcing the eviction of numerous homes. However, anomalous concentrations of CO2 have not only appeared in inhabited areas, but also in cultivated lands. In fact, the highest CO2 concentration values measured in the outdoor environment during the entire post-eruption period have been in a banana plantation of approximately 4,200 m2 that INVOLCAN has been monitoring since June 2022, named Las Hoyas.

Since June 2022, 26 scientific observation surveys have been carried out at Las Hoyas consisting of the measurement at 39 homogeneously distributed sites of the CO2 and O2 concentration at two heights, 40 and 170 cm from the ground, as well as sampling of atmospheric air in 19 sites at 40 cm for carbon isotope ratio of air CO2. Air CO2 and O2 concentrations are measured with a hand portable Dräger X-am® 8000 meter and the carbon isotope ratio of air CO2 (expressed as δ13C-CO2 ‰ vs. VPDB) is analyzed at ITER/INVOLCAN lab by a Thermo Finnigan MAT 253 mass spectrometer. Spatial distribution maps have been constructed following the sequential Gaussian simulation (sGs) to evaluate the spatial distribution of the air CO2 concentration. Observed air CO2 concentration values ranged from air value (412ppm) up to 69%, the highest ever measured during the post-eruptive period, with an average value of 7.1%. Air O2 concentration values ranged between 7.9% to air value (20.9%), with an average value of 19.2%. δ13C-CO2 values ranged between –8.90 to -2.66‰, with an average value of -4.87‰, indicating a clear volcanic-hydrothermal origin for the anomalous CO2 emitted from Las Hoyas banana plantation and ruling out a single biogenic origin.

In order to investigate the temporal evolution of the observed high CO2 concentrations in Las Hoyas, a Sinclair statistical graphic analysis was applied to the data from each survey. Time series of background and peak populations does not show a clear trend, with the occurrence of peaks and valleys throughout the entire series, and maintaining values much higher than those of the air. Likewise, the temporal evolution of the δ13C-CO2 values shows a trend towards heavier values, indicating that the volcanic-hydrothermal contribution increases with time. The spatial distribution of the air CO2 concentration measured at 40 cm shows that in most of the surveys, the anomalous values (>10%) are located mainly along the walls of Las Hoyas and in the NW sector, where in more than a year after the eruption, the banana plants are still withered and dead terrestrial and aerial fauna constantly appear due to poisoning and suffocation from CO2 inhalation.


Hernández et al. EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7705,, 2022.

How to cite: Melián, G. V., Hernández, P. A., Rodríguez, F., Alvárez Díaz, A. J., Padilla, G. D., Asensio-Ramos, M., Barrancos, J., Calvo, D., Padrón, E., González Pérez, A. M., and Pérez, N. M.: Anomalous CO2 concentrations of volcanic origing in the ambient air of banana plantations at La Palma, Canary Islands, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4411,, 2023.