Pre‐ and Co‐Eruptive Analysis of the September 2021 Eruption at Cumbre Vieja Volcano (La Palma, Canary Islands) Through DInSAR Measurements and Analytical Modeling

Abstract

We investigate the 19 September 2021 eruption of the Cumbre Vieja volcano (La Palma, Canary Islands, Spain). In particular, we analyze the Differential Interferometric Synthetic Aperture Radar (DInSAR) measurements obtained by processing Sentinel‐1 images acquired from both ascending and descending orbits. First, we show the importance, for oceanic islands like La Palma, of investigating DInSAR products retrieved from time series, instead of single interferograms, to effectively remove possible atmospheric artifacts within the displacement measurements. Subsequently, we invert the retrieved data through analytical modeling. Our results highlight that a sill–like source was active in the pre–eruptive phase (8–16 September), whereas the action of two dikes prevailed during the co‐eruptive phase (17–22 September). This evolution suggests a process of magma rising through a network of interconnected sills and dikes. The seismicity, that preceded and accompanied the onset of the eruption, is consistent with our findings.

Shallow magmatic intrusion evolution below La Palma before and during the 2021 eruption

“…7 ). Our results for the pre-eruptive period (1) are consistent with those obtained by De Luca et al 19 , although our results are more detailed and complete because we apply time series inversion and a new modeling tool which adjusts the free 3D geometry of the sources 3 , 15 . Eruption onset, 09/13/2021–09/20/2021: In this period, contemporaneously with the development of the seismic swarm (Supplementary Table 1 ) preceding and accompanying the eruption onset, a large magma intrusion occurs (Fig.…”

“…The deformation that occurred before and during the onset of the 2021 eruption was studied by de Luca et al 19 , but our study extends the analysis period and the modeling approach allow for both a spatial reconstruction and more detailed temporal sequence of the observed deformation sources.…”

“…Supplementary Fig. 3 shows LOS displacement time series for selected pixels, compared with the LOS projected GNSS displacements for the stations available on La Palma island 12 , 19 . Good agreement is observed between both techniques, validating the InSAR results.…”

Early Precursory Changes in the 3He/4He Ratio Prior to the 2021 Tajogaite Eruption at Cumbre Vieja Volcano, La Palma, Canary Islands

“…Together with the seismic swarms of October 2017 and February 2018, a relevant deformation detected by De Luca et al. (2022), with good spatial correspondence with a low‐resistivity anomaly measured through a magnetotelluric survey by Di Paolo et al. (2020) after seismic swarms of 2017 and February 2018, represent clear evidences of the magma pockets' rise that took place in 2017–2018 beneath Cumbre Vieja volcano.…”

Cross-domain fusion in smart seafloor sensor networks

“…Unlike earthquakes, volcanic eruptions and landslides are generally preceded by a wide range of precursory signs ranging from deformation, heat and gas emissions or seismicity, which in the case of onshore volcanoes can be monitored on-site or by remote sensing. Satellite-based remote sensing has become one of the most important tools in monitoring (especially remote) volcanoes [4] and not only allows monitoring the course of an eruption, but also precursory processes like gas and ash emissions or deformation using Interferometric Synthetic Aperture Radar (InSar) data seen for the 2018 Anak Kraktau eruption [5,6] or the 2021 Cubre Vieja (La Palma, Canary Islands) eruptions [7]. However, some crucial volcanological measurements like seismicity or the analysis of gas compositions can only be done with ground-based sensors, while the submerged part of marine volcanoes cannot be monitored by satellite at all.…”