BSRs levels in the west Antarctic Peninsula margin: an inventory of seismic indicators of marine gas hydrates

• Main Authors: León Buendía, Ricardo F., Urgeles, Roger, Pérez, Lara F.
• Format: Conference Object
• Language: English
• Published: 2022
• Subjects: Antarctic; The Antarctic; Antarctic Peninsula; South Shetland Islands; Bransfield Strait; Anvers; Anvers Island; George Islands; King George Islands; Bransfield Island; Antarc*; Ice Sheet
• Online Access: http://hdl.handle.net/10261/333182

European Conference on Gas Hydrate (ECGH 2022), 13-16 June 2022, Lyon In the frame of ICEFLAME project (PID2020-114856RB-I00, Spanish Ministry of Science and Innovation), an inventory of BSRs levels in the west Antarctic Peninsula margin has been carried out. The aim of this inventory is to assess the theoretical transient state of these geological structures due to the global ice-sheet retreat in the Polar Regions.In the west Antarctic Peninsula margin, three areas with characteristics BSR levels have been found: (i) north South Shetland Islands (reported in previous studies, (ii) North Bransfield Island (Bransfield Strait, AP margin), and (iii) Anvers Island (AP margin). North of the South Shetland Islands, BSR levels had been reported in between the Elephant–King George islands accretionary wedge sector (Lodolo et al., 1993). Two extensive and discontinuous BSR levels (named BSR-1 and BSR-2) have been mapped in the inventory. The BSR-1 appears as local, disconnected and discontinuous patches, about 10 km diameter in geographical extension, of high amplitude reflections of inverse polarity. Its burial depth ranges from ca. 150-200 ms TWT (at the base of the accretionary wedge) to ca. 300 ms TWT (in the middle slope). BSR-2 shows more extensive spatial continuity than BSR-1. BSR-2 levels are well-defined high amplitude reflections of inverse polarity. They simulate the seafloor increasing the burial-depth with water depth from ca. 250 ms TWT in the upper slope to ca. 1s TWT at the base of the accretionary wedge. North off Bransfield Island, BSR levels had been reported in the distal continental shelf of the Antarctic Peninsula margin (Oliveira, 2017). The BSR in this area constitutes a continuous high amplitude reflection of inverse polarity. It shows a shallow and homogeneous burial depth ranging from 145 to 170 ms TWT. South of Anvers Island, a BSR level had been reported to the west of the island in the middle continental shelf of the Antarctic Peninsula margin (Solovyov et al., 2017). Here, the BSR forms ...