Evidence for hydrothermal venting and sediment volcanism discharged after recent short-lived volcanic eruptions at Deception Island, Bransfield Strait, Antarctica
Somoza, L.; Martínez-Frías, J.; Smellie, J.L.; Rey, J.; Maestro, A.. 2004 Evidence for hydrothermal venting and sediment volcanism discharged after recent short-lived volcanic eruptions at Deception Island, Bransfield Strait, Antarctica. Marine Geology, 203 (1-2). 119-140. 10.1016/S0025-3227(03)00285-8Full text not available from this repository.
The results of a combined geophysical and geochemical research programme on Deception Island, an active volcano at 62degrees43'S, 60degrees57'W in Bransfield Strait (Antarctica), are presented. Ultrahigh-resolution acoustic data obtained with a TOPAS (Topographic PArameter Sonar) system and multibeam bathymetry (Simrad EM1000) allow a detailed analysis of submarine vents in Port Foster, the submerged caldera of Deception Island. The data show three different types of seafloor structures: low-relief mounds, high-relief mounds ('wasp nest'-like) and spire-like structures. We interpret these structures as products of sediment volcanisin and seeps caused by heating and boiling of pore fluids in gas-charged sediments, and related to recent short-lived volcanic events, possibly those that occurred in 1967, 1969 and 1970. In addition, subsurface vertical disturbed zones, formed by increased amplitude and phase-inverse reflectors beneath the mounds, suggest the presence of fluidised and brecciated sediments within hydrofracture systems. A key finding of this study is that there appears to be a close relationship between the submarine mounds detected by our ultrahigh-resolution seismic study, geochemical haloes, fault-pathways and present-day thermal anomalies in surface waters. We suggest that seafloor hydrofracture systems and subsurface pipes can be re-used as fluid migration pathways, resulting in hydrothermal seeps and vents on the seafloor, possibly up to decades after coeval volcanic eruptions.
|Programmes:||BAS Programmes > Other|
|Additional Keywords:||hydrothermal vents, submarine volcanoes, geophysical surveys, geochemical investigations, Antarctica|
|NORA Subject Terms:||Earth Sciences|
|Date made live:||23 Feb 2012 15:01|
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