Suchergebnisse

Deception Island (South Shetland Islands) is one of the most active volcanoes in Antarctica, with more than 20 explosive eruptive events registered over the past centuries. Recent eruptions (1967, 1969, and 1970) and volcanic unrest episodes (1992, 1999, and 2014–2015) demonstrate that volcanic activity is likely occurring in the future. This is of special concern for scientists, logistic personnel, and tourists, since the South Shetland Islands are an important tourist destination and host numerous year-round and seasonal scientific stations and base camps. Significant efforts have been made to understand the complex magmatic and volcanic evolution of Deception Island with special interest on its subaerial part. However, studies on submerged volcanic cones within Port Foster, the sea-flooded part of Deception Island's caldera depression, are comparatively scarce. Here, we provide a full characterization of Stanley Patch volcano, the largest of these volcanic edifices. Estimated morphometric parameters based on new multibeam bathymetric data, supported by petrographic and chemical observations from rock samples collected on the crater rim, reveal that Stanley Patch volcano grew in a subaerial environment. This result, combined with previous findings and new sedimentological evidence from our ultra-high resolution seismic profiles, allow to further detail the island's geologic evolution since the caldera collapse. We conclude that the complete flooding of Port Foster could have only occurred after the formation of Stanley Patch volcano, i.e. during the last ~2000 years, and in a time period of a few days or less. ; This research was supported by the Spanish Government RECALDEC (CTM2009-05919-E/ANT), PEVOLDEC (CTM2011-13578-E/ANT), POSVOLDEC (CTM2016-79617-P)(AEI/FEDER, UE), VOLGASDEC (PGC2018-095693-B-I00), USAL-2019 project (Programa Propio - mod. 1B) and the GALIEO-IHM Program. A.G. is grateful for her Ramón y Cajal contract (RYC-2012-11024), and A.M.A-V for the grant under the "JSPS invitation fellowship" program (S18113). D.P. is grateful for his Beatriu de Pinós (2016 BP 00086) and Juan de la Cierva (IJCI-2016-30482) contracts. We thank all the military staff of the Spanish Antarctic Base "Gabriel de Castilla", BIO Hespérides oceanographic cruise and the Marine Hydrographic Institute, for their constant help and logistic support. This research is part of POLARCSIC and PTI VOLCAN activities. English editing by Grant George Buffett (www.terranova.barcelona). We thank the Editor, J.L. Macías, and both reviewers A. Di Roberto and P. Nomikou for their constructive comments that have allowed improving a previous version of this manuscript. ; This work acknowledges the 'Severo Ochoa Centre of Excellence' accreditation (CEX2019-000928-S) to ICM-CSIC ; Peer reviewed