TY - JOUR

T1 - Inflating Shallow Plumbing System of Bezymianny Volcano, Kamchatka, Studied by InSAR and Seismicity Data Prior to the 20 December 2017 Eruption

AU - Mania, René

AU - Cesca, Simone

AU - Walter, Thomas R.

AU - Koulakov, Ivan

AU - Senyukov, Sergey L.

N1 - Funding Information: This is a contribution to VOLCAPSE, a research project funded by the European Research Council under the European Union’s H2020 Program/ERC consolidator grant ERC-CoG Q7 646858. Funding Information: This is a contribution to VOLCAPSE, a research project funded by the European Research Council under the European Union?s H2020 Program/ERC consolidator grant ERC-CoG Q7 646858. We thank the DLR for support; the acquisition of the spot-mode TerraSAR-X data was realized through proposal GEO1505. This study was also supported by the Russian Science Foundation Grant #20-17-00075 and Russian Foundation for Basic Research Grant #19-05-00101. Publisher Copyright: Copyright © 2021 Mania, Cesca, Walter, Koulakov and Senyukov.

PY - 2021/12/16

Y1 - 2021/12/16

N2 - Explosive eruptions at steep-sided volcanoes may develop with complex precursor activity occurring in a poorly-understood magma plumbing system so that timelines and possible interactions with the geologic surrounding are often unresolved. Here we investigate the episode prior to the energetic December 20, 2017 eruption at Bezymianny volcano, Kamchatka. We compare degassing activity inferred from time-lapse camera images, seismicity and real-time seismic amplitude (RSAM) data derived from a temporary station network, as well as high-resolution InSAR displacement maps. Results show that the first changes can be identified in low-frequency seismicity and degassing at least 90 days before the eruption, while the first volcano-tectonic (VT) seismicity occurred 50 days before the eruption. Coinciding with significant changes of the RSAM, surface displacements affect the volcanic flanks at least 9 days prior to the eruption. Inversion modeling of the pre-eruptive surface deformation as well as deflation-type, co-eruptive surface changes indicate the presence of a shallow and transient reservoir. We develop a conceptual model for Bezymianny volcano initiating with deep seismicity, followed by shallow events, rockfalls, steaming and an inflating reservoir. The eruption is then associated with subsidence, caused by deflation of the same reservoir. This sequence and conceivable causality of these observations are providing a valuable contribution to our understanding of the shallow magma plumbing system beneath Bezymianny and may have relevance for volcano monitoring and early warning strategies at similar volcanoes elsewhere.

AB - Explosive eruptions at steep-sided volcanoes may develop with complex precursor activity occurring in a poorly-understood magma plumbing system so that timelines and possible interactions with the geologic surrounding are often unresolved. Here we investigate the episode prior to the energetic December 20, 2017 eruption at Bezymianny volcano, Kamchatka. We compare degassing activity inferred from time-lapse camera images, seismicity and real-time seismic amplitude (RSAM) data derived from a temporary station network, as well as high-resolution InSAR displacement maps. Results show that the first changes can be identified in low-frequency seismicity and degassing at least 90 days before the eruption, while the first volcano-tectonic (VT) seismicity occurred 50 days before the eruption. Coinciding with significant changes of the RSAM, surface displacements affect the volcanic flanks at least 9 days prior to the eruption. Inversion modeling of the pre-eruptive surface deformation as well as deflation-type, co-eruptive surface changes indicate the presence of a shallow and transient reservoir. We develop a conceptual model for Bezymianny volcano initiating with deep seismicity, followed by shallow events, rockfalls, steaming and an inflating reservoir. The eruption is then associated with subsidence, caused by deflation of the same reservoir. This sequence and conceivable causality of these observations are providing a valuable contribution to our understanding of the shallow magma plumbing system beneath Bezymianny and may have relevance for volcano monitoring and early warning strategies at similar volcanoes elsewhere.

KW - atmosphere

KW - Bezymianny

KW - InSAR

KW - magma plumbing system

KW - seismic precursors

KW - volcano deformation

UR - http://www.scopus.com/inward/record.url?scp=85121980658&partnerID=8YFLogxK

UR - https://www.elibrary.ru/item.asp?id=47549297

U2 - 10.3389/feart.2021.765668

DO - 10.3389/feart.2021.765668

M3 - Article

AN - SCOPUS:85121980658

VL - 9

JO - Frontiers in Earth Science

JF - Frontiers in Earth Science

SN - 2296-6463

M1 - 765668

ER -