Acoustic signals from the 2021 Cumbre Vieja eruption
- 1Ludwig-Maximilians-Universität Munich, Department of Geosciences, Munich, Germany (valeria.cigala@min.uni-muenchen.de)
- 2Instituto Volcanológico de Canarias (INVOLCAN)
- 3Instituto Tecnológico y de Energías Renovables (ITER)
- 4Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Roma1, Rome
- 5Geophysical Institute, University of Alaska Fairbanks
After 50 years of volcanic quiescence, on 19 September 2021, an eruption started on the western flank of the Cumbre Vieja ridge of La Palma, Canary Islands, Spain. The eruption was characterised by simultaneous effusive and explosive activity from a several hundred-meter-long fissure, which later built up a cone and showed variable eruptive behaviour at different vents, suggesting a spatially complex plumbing system. Explosive eruptive activity ranged from mild ash emissions, Strombolian explosions to fire fountaining episodes.
We carried out field measurements to study the variable explosive eruptive activity and associated acoustic signals. A single microphone initially deployed at about 2 km SW of the vents from 6 to 11 October was later replaced by an array of 3 microphones from 6 November to 13 December at about 300 m W of the microphone location in October. The microphones (PCB ½” free field acoustic sensors, 3.15-20 kHz frequency range) were each connected to an OptiMeas SmartPro digitiser continuously sampling at 5000 Hz. The digitisers are GPS synchronised for accurate acoustic array processing. The acoustic array was complemented by a thunderstorm detector continuously recording (since 11 October) lightning and electrical activity generated by the volcanic explosions (Vossen et al., 2022). Additionally, at the beginning of November 2021, thermal videos of the eruptive activity were acquired.
Preliminary analysis of the large and unique acoustic dataset shows varying waveforms indicating evolving source conditions: eruption intensity, source mechanism, vent geometry, fragmentation depth and amount of ash ejected. Moreover, we observe a variability of frequency (peak and mean) and amplitude with time. Further analysis includes the characterisation of the acoustic source location within the growing volcanic edifice and the comparison and correlation with lightning and thermal infrared data to detail changes in explosive activity related to the evolving eruption sources.
Caron E.J. Vossen et al. (2022), Electrical activity of the 2021 Cumbre Vieja eruption, EGU22-8052.
How to cite: Cigala, V., Kueppers, U., Vossen, C. E. J., Barrancos, J., Spina, L., Fee, D., Cimarelli, C., Gestrich, J., Schmid, M., Hernández, P., Pankhurst, M., D'Auria, L., Pérez, N., and Dingwell, D. B.: Acoustic signals from the 2021 Cumbre Vieja eruption, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9295, https://doi.org/10.5194/egusphere-egu22-9295, 2022.
