Strombolian fingerprint unveiled from multiresolution analysis of geophysical observations during the 2021 eruption at Cumbre Vieja, La Palma, Canary Islands
| Autor: | Arnoso, Jose, Riccardi, Umberto, Blanco-Montenegro, Isabel, Montesinos, Fuensanta G., Benavent, Maite, Vélez, Emilio J., Sánchez, Nieves, Sainz-Maza, Sergio, Del Barrio, Carolina |
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| Jazyk: | angličtina |
| Rok vydání: | 2023 |
| Zdroj: | XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
| Popis: | Geodetic and geophysical observations are widely used to understand magmatic processes during volcanic eruptions, e.g. to asses magma ascent, accumulated magma volumes, dike distributions or small-scale pressure cycles preceding lava outflow. The last volcanic eruption in La Palma (Canary Islands, Spain) occurred at the western flank of Cumbre Vieja ridge and lasted 85 days, from September to December 2021. The eruption was a basaltic fissure type, dominated by strombolian activity with episodes of phreatomagmatic pulses. The volcanic eruption alternated lava fountains and periods of increasing frequency of strombolian explosions, forming a new edifice of about 200 m from its base around the main vent of the eruptive fissure. We deployed three magnetic and three dual-axis tiltmeter stations in La Palma during the 2021 eruptive process, at different distances from the emission centre. All equipment was operating in continuous mode and allowed us to gather 1-minute logging data. Also, we used the residual gravity signal from one spring-gravimeter situated in the vicinity of the eruptive centre. We present the results of the application of the Lomb–Scargle periodogram, cross wavelet transform and wavelet coherence to the geophysical time series. We develop a multiresolution wavelet analysis by splitting signals into suitable sets of different frequency ranges, in order to decompose the variability of the data into physically meaningful and interpretable parts. Our data revealed periodic geomagnetic, tilt and gravity signals with different amplitudes associated to explosive cycles that maybe related to magma bubbling during the strombolian phases of the eruption. The 28th IUGG General Assembly (IUGG2023) (Berlin 2023) |
| Databáze: | OpenAIRE |
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