Physical Characterization of Long‐Lasting Hybrid Eruptions: The 2021 Tajogaite Eruption of Cumbre Vieja (La Palma, Canary Islands)

Abstract

Volcanic eruptions are commonly subdivided into effusive and explosive activity depending on conduit dynamics that can either result in the outflow of lava when the degassed magma reaches the surface (effusive eruptions), or in the fragmentation of magma at various depths (dry explosive eruptions, from Hawaiian to Ultra-Plinian, and wet explosive eruptions from Surtseyan to phreato-Plinian in the classification of Walker ( 1980)). Nonetheless, some

Deep magma storage during the 2021 La Palma eruption

“…The eruption opened a series of successive vents (six major craters) as it progressed along a >550-m northwest-southeast alignment, ultimately building up a sizable cinder cone (300 m high) and an extensive lava flow field. Throughout the three-month eruption, the intensity of the explosive activity was highly variable, reflected by the variation in seismic intensities and an eruptive column height that was typically around 3500 m above sea level (asl) but reaching up to 8500 m ( 21 ). Plume height together with emitted pyroclastic volume (~45 million m 3 ) defines the event as a volcanic explosivity index (VEI) 3, with a total volume (pyroclastic deposits and lava) of >200 million m 3 ( Fig.…”

The Explosive Activity of the 2021 Tajogaite Eruption (La Palma, Canary Islands, Spain)

“…Bonadonna et al. (2022) report maximum MER values of 1.0 ± 0.023 and 0.6 ± 0.16 × 10 4 kg/s for the cone and the tephra blanket in our observational time windows, respectively. UAV‐based surveys indicate that in the days from the beginning of the eruption until 25 September the cone complex formed at a rate of ∼2.41 × 10 6 m 3 /day (Civico et al., 2022a; Romero et al., 2022), which, assuming a pyroclasts density of 1,000 kg/m 3 , corresponds to 2.8 × 10 4 kg/s.…”

“…Mass eruption rate values from Romero et al ( 2022) range 3-18 × 10 3 kg/s before 25 September and ∼1.4 × 10 3 kg/s afterward, suggesting that at the beginning of the eruption the magma flux was higher than in the following weeks and months, in agreement with our observations that fountaining and comparatively high mass flux dominated during our September field campaign, while jetting and lower flux dominated in November. Bonadonna et al (2022) report maximum MER values of 1.0 ± 0.023 and 0.6 ± 0.16 × 10 4 kg/s for the cone and the tephra blanket in our observational time windows, respectively. UAV-based surveys indicate that in the days from the beginning of the eruption until 25 September the cone complex formed at a rate of ∼2.41 × 10 6 m 3 /day (Civico et al, 2022a;Romero et al, 2022), which, assuming a pyroclasts density of 1,000 kg/m 3 , corresponds to 2.8 × 10 4 kg/s.…”

“…All the features of the Tajogaite eruption match well the general descriptions of violent Strombolian eruptions, as summarized by Pioli et al. (2008) “strongly pulsatory, with production of moderately high eruption columns (2–6 km) that eject abundant fine ash.” Equally, the products of the Tajogaite eruption (Bonadonna et al., 2022; Romero et al., 2022) mirror those of other violent Strombolian eruptions (Pioli et al., 2008; Valentine et al., 2005). The Tajogaite eruption thus represents, at the time of writing, the most recent case of violent Strombolian eruption as broadly defined.…”

“…Anticipated by seismic, geodetic, and geochemical precursors (Amonte et al., 2022; Di Nardo et al., 2022; Melián et al., 2022; Padrón et al., 2022; Pérez, D'Auria, et al., 2022; Pérez, Hernández, et al., 2022; Rodríguez‐Pérez et al., 2022; Santana de León et al., 2022), the eruption began on 19 September 2021 and terminated on 13 December 2021, after the sustained eruption of more than 2.4 × 10 8 m 3 of alkali basalt to tephritic/basanitic tephra and lava (Carracedo et al., 2022; Civico et al., 2022a; D’Auria et al., 2022; Pankhurst et al., 2022; Torres‐González et al., 2020). Simultaneous explosive and effusive activity persisted through almost all the eruption, mostly at multiple vents, with a volcanic plume being constantly detected with top elevation ranging 1–8 km above the vent (Bonadonna et al., 2022; Romero et al., 2022). Styles of explosive activity alternating during the Tajogaite eruption have been described as follows: lava fountains, “rapid” Strombolian explosions, Hawaiian fountaining, normal Strombolian activity, gas jetting, ash‐laden Strombolian columns, phreatomagmatic episodes, and ash emissions (Bonadonna et al., 2022; Carracedo et al., 2022; Romero et al., 2022).…”