ALBERT

Description: In recent years the use of Distributed Acoustic Sensing (DAS) in seismology is gaining extensive usage in different applications. A High-Fidelity DAS system (HDAS) was deployed during the 2021 Tajogaite eruption on Cumbre Volcano (La Palma, Canary Islands), allowing the recording of most of the syn-eruptive and post-eruptive seismicity. The eruption lasted from Sep. 19th until Dec. 13th of 2021. The HDAS was installed on 19th Oct. 2021 and is still operating. The HDAS was installed around 10 km from the eruptive vent and was connected to a submarine fibre optic cable directed toward Tenerife Island. Since then, the HDAS has been recording seismic with a temporal sampling rate of 100 Hz and a spatial sampling rate of 10m for a total length of 30 (first phase) and 50 km using Raman Amplification (last period). The HDAS recorded thousands of local earthquakes as well as regional and teleseismic events. It was revealed to be an excellent tool for volcanic monitoring, allowing a better location of deeper events which location was made difficult by the small aperture of the seismic network of La Palma. The HDAS was also able to record the low-frequency (〈1 Hz) component of the volcanic tremor up to a distance of tens of kilometres from the volcano. We show how, using array-like techniques, it is possible to identify and separate the volcanic tremor signals from the oceanic ambient noise. In this work, we demonstrate the effectiveness of using DAS as a real-time volcano monitoring tool.