EGU2020-11386, updated on 12 Jun 2020
https://doi.org/10.5194/egusphere-egu2020-11386
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Geochemical monitoring of Cumbre Vieja volcano (Canary Islands) by summer diffuse CO2 degassing surveys

Daniel Di Nardo1,2, Ellie-May Redfern3, Filippo Zummo4, Alba Martín-Lorenzo1,2, Claudia Rodríguez-Pérez1, Eleazar Padrón1,2,5, Gladys V. Melián1,2,5, Lucía Sáez-Gabarrón1, Mar Alonso1,2, María Asensio-Ramos1, Nemesio M. Pérez1,2,5, Pedro A. Hernández1,2,5, Francisco A. Morales-González1, and Lía Pitti-Pimienta1,2
Daniel Di Nardo et al.
  • 1Instituto Volcanológico de Canarias (INVOLCAN), 38240 La Laguna, Tenerife, Canary Islands, Spain (daniel.dinardo.beca@iter.es)
  • 2Instituto Tecnológico y de Energías Renovables (ITER), 38611 Granadilla de Abona, Tenerife, Canary Islands, Spain
  • 3Department of Geography, Geology and the Environment, Keele University, Staffordshire, ST5 5BJ, U.K.
  • 4Dipartimento Scienze della Terra e del Mare, Università Degli Studi di Palermo, Via Archirafi, 22, 90123 Palermo, Italy.
  • 5Agencia Insular de la Energía de Tenerife (AIET), 38611 Granadilla de Abona, Tenerife, Canary Islands, Spain.

La Palma Island is the north-westernmost and one of the youngest of the Canarian Archipelago. In the last 123ka, volcanic activity has taken place exclusively at Cumbre Vieja volcano which is located at the southern part of the island. Cumbre Vieja is characterized by a main north–south rift zone 20km long and 1950m in elevation covering an area of 220km2 with volcanic vents located northwest and northeast. Cumbre Vieja is the most active basaltic volcano in the Canaries with 7 historical eruptions, being Teneguía (1971) the most recent one. The most relevant volcanic activity episodes occurred since Teneguía eruption, are two intense seismic swarms occurred beneath Cumbre Vieja on 7-9 and 13-14 of October 2017. Since visible volcanic gas emissions do not occur at the surface of Cumbre Vieja, the geochemical surveillance program has been focused mainly on diffuse degassing studies. In the last 18 years diffuse CO2 emission surveys have been yearly performed in summer periods to minimize the influence of meteorological variations. Measurements have been performed following the accumulation chamber method in about 600 sites and spatial distribution maps have been constructed following the sequential Gaussian simulation (sGs) procedure to quantify the diffuse CO2 emission. Herein we summarize the diffuse CO2 emission time series during this period and describe the results obtained in the last 2019 survey. The soil CO2 efflux values measured in 2019 survey ranged from non-detectable to 72.7gm−2d−1. Diffuse CO2 output was estimated in 1,064 ± 35td-1, a value within the background +1s range (1,254 td-1) (Padrón et al., 2015, Bull. Volcanol. 77:28). In the period 2001-2017, the diffuse CO2 output released to the atmosphere from Cumbre Vieja volcano ranged between 320 to 1,544td-1. Enhanced endogenous contributions of deep seated CO2 might have been responsible for the higher CO2 emission values measured in 2011 and 2013. After the October 2017 seismic swarms, diffuse CO2 output showed an increasing trend from 788 to 3,251td-1 in March 2018, to decrease gradually until 852td-1 in September of that same year, and begin to gradually increase again to 2,371td-1 in November 2018. These changes were possibly caused by an upward magma migration. Our results demonstrate that periodic surveys of diffuse CO2 emission are extremely important for the detection of early warning signals of future volcanic unrest episodes at Cumbre Vieja.

How to cite: Di Nardo, D., Redfern, E.-M., Zummo, F., Martín-Lorenzo, A., Rodríguez-Pérez, C., Padrón, E., Melián, G. V., Sáez-Gabarrón, L., Alonso, M., Asensio-Ramos, M., Pérez, N. M., Hernández, P. A., Morales-González, F. A., and Pitti-Pimienta, L.: Geochemical monitoring of Cumbre Vieja volcano (Canary Islands) by summer diffuse CO2 degassing surveys, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-11386, https://doi.org/10.5194/egusphere-egu2020-11386, 2020