Magma Chamber Detected Beneath an Arc Volcano With Full‐Waveform Inversion of Active‐Source Seismic Data

Abstract

Arc volcanoes are the surface expression of magmatic processes that originate from the partial melting of the mantle above subducting plates (England & Katz, 2010). The thermodynamic conditions encountered by the melt as it moves toward the surface govern the volcanic eruption style (Cashman et al., 2017). Highly explosive eruptions of evolved, volatile-rich, viscous magmas at volcanic arcs (Bachmann & Bergantz, 2009) account for ∼95% of human fatalities associated with eruptive phenomena (Brown et al., 2017). The explosivity is enhanced at (semi-)submerged volcanoes due to magma-water interactions (Peckover et al., 1973;Wohletz & Heiken, 1992). Such events can lead to high and voluminous ash clouds, tsunami, and extensive pumice rafts, as occurred in the 1600

Transfer of sulfur and chalcophile metals via sulfide-volatile compound drops in the Christiana-Santorini-Kolumbo volcanic field

“… Volcanic architecture based on the Kolumbo volcano 67 , 68 . 1) Compound drops formation and coalescence upon andesitic melt injection in the magmatic chamber.…”

The magmatic system under Hunga volcano before and after the 15 January 2022 eruption

“…Magmatic systems under other submarine volcanoes have been imaged using passive and active seismic methods. For example, seismic reflection data imaged the fine-scale melt distribution under Axial seamount ( 43 , 44 ), 3D velocity models from tomographic inversions revealed the architecture of the magmatic systems under the offshore Mayotte ( 45 ) and Santorini ( 46 ) volcanoes, and full waveform inversion detected a small magma chamber under Kolumbo submarine volcano offshore Santorini, Greece ( 47 ). While we assume that the gravity changes happening over the 2021–2022 interval are dominated by coeruptive changes, posteruptive gravity changes of smaller amplitude could arise from small residual fluid movement (melt or hydrothermal fluids re-equilibrating after eruption) or changes to the seafloor morphology (e.g., landslide and pyroclastic density current deposits) as a result of the eruption column and caldera collapse and magmatic system readjustments.…”

Magmatic evolution of the Kolumbo submarine volcano and its implication to seafloor massive sulfide formation

“…Injection of the less evolved, hydrous, mafic magma at the base of the upper chamber likely acted as an eruption trigger (Cantner et al 2014;Klaver et al 2016;Konstantinou 2020). Seismic tomography and the analysis of seismic activity during the last 20 years indicates a shallow magma chamber (Chrapkiewicz et al 2022;Dimitriadis et al 2010;Schmid et al 2022). Seismic tomography using data from earthquakes between 2002 and 2005 highlights a low velocity zone interpreted as a magma chamber at 6-7 km below the seafloor (Dimitriadis et al 2010).…”

“…Seismic tomography using data from earthquakes between 2002 and 2005 highlights a low velocity zone interpreted as a magma chamber at 6-7 km below the seafloor (Dimitriadis et al 2010). Alternatively, Schmid et al (2022) suggest that the strong seismic activity at these depths reflects a rheologically strong layer obstructing melt ascending toward a 2-4-km-deep magma chamber that was located by Chrapkiewicz et al (2022) using seismic data from the PROTEUS experiment (Hooft et al 2017). However, McVey et al (2020, working on the same set of data, do not recognize any melts between 3 and 5 km depth.…”