Combining thermal, tri-stereo optical and bi-static InSAR satellite imagery for lava volume estimates: the 2021 Cumbre Vieja eruption, La Palma

Abstract

Determining outline, volume and effusion rate during an effusive volcanic eruption is crucial as it is a major controlling factor of the lava flow lengths, the prospective duration and hence the associated hazards. We present for the first time a multi-sensor thermal-and-topographic satellite data analysis for estimating lava effusion rates and volume. At the 2021 lava field of Cumbre Vieja, La Palma, we combine VIIRS + MODIS thermal data-based effusion rate estimates with DSMs analysis derived from optical tri-stereo Pléiades and TanDEM-X bi-static SAR-data. This multi-sensor-approach allows to overcome limitations of single-methodology-studies and to achieve both, high-frequent observation of the relative short-term effusion rate trends and precise total volume estimates. We find a final subaerial-lava volume of $$212\times {10}^{6}\pm 13\times {10}^{6}\; \text{m}^{3}$$ 212 × 10 6 ± 13 × 10 6 m 3 with a MOR of 28.8 ± 1.4 m3/s. We identify an initially sharp eruption-rate-peak, followed by a gradually decreasing trend, interrupted by two short-lived-peaks in mid/end November. High eruption rate accompanied by weak seismicity was observed during the early stages of the eruption, while during later stage the lava effusion trend coincides with seismicity. This article demonstrates the geophysical monitoring of eruption rate fluctuations, that allows to speculate about changes of an underlying pathway during the 2021 Cumbre Vieja eruption.

Discrete magma injections drive the 2021 La Palma eruption

“…2). According to thermal satellite data, our geochemical kink on 25 November (eruption day 67) heralds a decline in lava emission rate [from 26 November following (17); from 2 December following (23)], thus we interpret that the kink from recharge to fractionation indicates waning magma supply.…”

“…Increasing maficity of erupted liquids recorded progressive invasion with fresh melt pulses and peaked around day 67 (25 November), when new eccentric fissures may have effectively tapped unradiogenic melt. The geochemical kink from recharge to fractionation, although subtle, was followed by a decrease in lava emission rates (17,23), seismicity, and SO 2 emissions consistent with waning magma supply, heralding eruption cessation 18 days later.…”

Magma pressure drop as a forecasting tool for the end of the 2021 La Palma eruption (Canary Islands)

“…The proposed offset on length changes temporally correlates with the opening of an unexpected fissures and vents system during the eruption's last phase (González, 2022), the peak of shallow seismicity registered at ~10-14 km depth, an increase of the number of earthquakes registered at ~33-39 km depth (Figure 3b) and it is anticorrelated with peaks of high daily effusion rates observed using satellite observations (Plank et al, 2023). Future work should include detailed investigations on such correlations in order to increment the success and accuracy of the proposed forecasting tool.…”

Tephra sedimentation and grainsize associated with pulsatory activity: the 2021 Tajogaite eruption of Cumbre Vieja (La Palma, Canary Islands, Spain)

“…Regardless of the rapid gas segregation that resulted in the simultaneous emission of fluid lava and ash-rich plumes, the Tajogaite eruption was associated with an efficient, decoupled magma-gas system, with the explosive phase MER consistently lower than the lava emission rate and an overall lava volume >70% of the total erupted material (lava + cone + tephra blanket; Bonadonna et al, 2022;Plank et al, 2023). The higher fraction of lava than that of tephra is also likely related to the lava emission through a fissure as opposed to a central cone (Pioli et al, 2008;.…”

“…Following a few years of low-magnitude seismic unrest at depths of 25-35 km and 7 days of intense seismic unrest associated with ground deformation, a new eruption started on 19 September 2021 in the Cabeza de Vaca area, on the western side of the Cumbre Vieja ridge, that lasted nearly 3 months (Torres-Gonzáles et al, 2020;Fernández et al, 2021;Longprè, 2021;Carracedo et al, 2022;De Luca et al, 2022;Martí et al, 2022;Dayton et al, 2023;Plank et al, 2023) (Figure 1). The eruption involved effusive and explosive activity from multiple vents distributed along a 500-m-long NE-SW fissure (Carracedo et al, 2022;Gonzáles, 2022;Pankhurst et al, 2022) and represents an example of a coneforming, long-lasting, hybrid eruption associated with a decoupled magma-gas system (Bonadonna et al, 2022;Romero et al, 2022).…”