Skip to content

Mobile high-resolution CO2 and stable isotope surveys in ambient air using Delta Ray® measurements in an electric vehicle: assessing volcanic degassing hazards in La Palma, Canary Islands

María Asensio-Ramos1, Eleazar Padrón1,2, Ana Gironés1,2, Antonio J. Álvarez Díaz3,4, Héctor de los Ríos Díaz1,2, David Afonso Falcón1,2, Germán D. Padilla1,2, Pedro A. Hernández1,2, Gladys V. Melián1,2, Juan Cutillas3,5, Nemesio M. Pérez1 ,2

  • Affiliations: 1Instituto Volcanológico de Canarias (INVOLCAN), San Cristóbal de La Laguna, Tenerife, Canary Islands 2Instituto Tecnológico y de Energías Renovables (ITER), Granadilla de Abona, Tenerife, Canary Islands 3Instituto Volcanológico de Canarias (INVOLCAN), Fuencaliente, La Palma, Canary Islands 4Agrolaguna, Los Llanos de Aridane, La Palma, Canary Islands 5Taller Cutillas, Los Llanos de Aridane, La Palma, Canary Islands 

  • Presentation type: Talk

  • Presentation time: Tuesday 09:30 - 09:45, Room R280

  • Programme No: 3.15.8

  • Theme 3 > Session 15

Abstract

In November 2021, unusual CO2 emissions were detected in the neighbourhoods of La Bombilla and Puerto Naos, located on the western flank of La Palma, about 5 km southwest of the 2021 Tajogaite eruption vents. To investigate the dynamics of volcanic CO2 emissions affecting both neighbourhoods, 27 high-resolution CO2 and stable isotope surveys were undertaken in Puerto Naos between 19 October 2022 and 22 February 2024 (~ 2,200 measurements), and 17 surveys in La Bombilla between 2 March 2023 and 22 February 2024 (~ 700 measurements). These surveys utilized a Delta Ray analyzer mounted on an electric vehicle, enabling mobile measurements at 140 cm above ground level. The Delta Ray is a cutting-edge mid-infrared isotope ratio infrared spectrometer (IRIS) that simultaneously measures δ13C and δ18O in CO2 with a precision of 0.05‰.  In Puerto Naos, CO2 concentrations ranged from 420 to 4,500 ppm, while δ13C-CO2 values varied from -9.0 to -2.7 ‰ vs. VPDB. In La Bombilla, concentrations were slightly higher, ranging from 420 to 8,000 ppm, with δ13C-CO2 values between -8.1 and -0.7 ‰. Analysis revealed that higher CO2 concentrations in both areas were spatially associated with δ13C-CO2 values less depleted in 13C, indicative of a volcanic origin. These findings underscore the utility of stable isotope surveys in assessing the impact of volcanic degassing on air quality and identifying hazardous zones in populated areas.