Lava dome cycles reveal rise and fall of magma column at Popocatépetl volcano

Abstract

Lava domes exhibit highly unpredictable and hazardous behavior, which is why imaging their morphological evolution to decipher the underlying governing mechanisms remains a major challenge. Using high-resolution satellite radar imagery enhanced with deep-learning, we image the repetitive dome construction-subsidence cycles at Popocatépetl volcano (Mexico) with very high temporal and spatial resolution. We show that these cycles resemble gas-driven rise and fall of the upper magma column, where buoyant bubble-rich magma is extruded from the conduit (in ~hours-days), and successively drained back (in ~days-months) as magma degasses and crystallizes. These cycles are superimposed on a progressive decadal crater deepening, accompanied by heat and gas flux decrease, which could be partially explained by gas depletion within the magma plumbing system. Results reinforce the idea that gas retention and escape from the magma column play a key role in the short- and long-term morphological evolution of low-viscosity lava domes and their associated hazards.

Excess degassing drives long-term volcanic unrest at Nevado del Ruiz

“…Between 2018 and 2021, this "steady-state" behavior has resulted from a complex but overall "balanced" interplay between inputs of volatile-rich magma, shallow magma crystallization and degassing, and dome extrusion, which has only produced relatively mild explosive activity. Similar slow-unrest systems 20 , of equally evolved magma compositions, such as Popocatépetl 17,18 , in Mexico, and Sabancaya 16 , in Peru show similar longevity in their unrest periods and surface activity. Therefore, a crucial question for these systems, and in particular of Nevado del Ruiz, is how, and over what timescales, volcanic activity can escalate into more voluminous/energetic eruptive events of potential threat to vulnerable communities.…”

“…In other dome-forming volcanoes (e.g. Sabancaya 16 and Popocatepetl 18 ), V Thermal > V Extruded unbalances have been ascribed to an "excess radiation" process whereby the majority of the thermal anomalies (reported as VRP) were sourced by additional processes other than surface dome extrusion 16,18 . We caution that, at Nevado del Ruiz, the latter may be somewhat underestimated, considering the cycles of dome building and partial destruction (potentially sudden) can be relatively short, and hence difficult to capture with the relatively low temporal resolution measurements reported by Ordoñez et al Short-lived dome (emplacement/destruction) cycles may, in fact, explain (i) the relatively mild explosive activity of the arenas crater and the lack of a major explosive event since the beginning of the long-lasting unrest; and (ii) the relatively efficient (partial) clearing of the top of the magma column allowing for the conduit to sustain a high level of gas permeability.…”

“…We, therefore, argue against the possibility that large volumes of magma are being stored at shallow levels within the edifice. Models of convecting magma columns 40 have been evoked to explain excess degassing and thermal radiation associated with dome-forming activity at andesitic volcanoes 16,18,42 . At Nevado del Ruiz, due to significant degassing-induced crystallization in the shallow part of the conduit (Fig.…”

“…Explosive eruptions at lava domes are thought to be caused by spatial and temporal changes in their permeability and of their ability to exsolve and release volatiles 14,15 . Volcanic gas observations, especially if combined with thermal satellite observations 16 , are thus especially relevant to understanding lava dome activity and behaviour 17,18 . For Nevado del Ruiz, no information on the fluxes of other major volatile species, such as H 2 O and CO 2 , was available until 2017, when the first discontinuous measurements started 19 .…”

The utility of TerraSAR-X, TanDEM-X, and PAZ for studying global volcanic activity: Successes, challenges, and future prospects

“…2018], and amplitude changes of repeated lava dome formation and destruction within the inner crater at Popocatépetl, Mexico [Valade et al 2023].…”