BRAVOSEIS: Geophysical investigation of rifting and volcanism in the Bransfield strait, Antarctica

被引：26

作者：

Almendros, J. ^{[1
]}

Wilcock, W. ^{[2
]}

Soule, D. ^{[3
]}

Teixido, T. ^{[1
]}

Vizcaino, L. ^{[1
]}

Ardanaz, O. ^{[1
]}

Granja-Bruna, J. L. ^{[4
]}

Martin-Jimenez, D. ^{[1
]}

Yuan, X. ^{[5
]}

Heit, B. ^{[5
]}

Schmidt-Aursch, M. C. ^{[6
]}

Geissler, W. ^{[6
]}

Dziak, R. ^{[7
]}

Carrion, F. ^{[1
]}

Ontiveros, A. ^{[8
]}

Abella, R. ^{[9
]}

Carmona, E. ^{[1
]}

Agui-Fernandez, J. F. ^{[1
]}

Sanchez, N. ^{[10
]}

Serrano, I. ^{[1
]}

Davoli, R. ^{[1
]}

Krauss, Z. ^{[2
]}

Kidiwela, M. ^{[2
]}

Schmahl, L. ^{[3
]}

机构：

[1] Univ Granada, Granada, Spain

[2] Univ Washington, Seattle, WA 98195 USA

[3] CUNY Queens Coll, Flushing, NY 11367 USA

[4] Univ Complutense Madrid, Madrid, Spain

[5] GFZ Potsdam, Potsdam, Germany

[6] Helmholtz Ctr Polar & Marine Res, Alfred Wegener Inst, Bremerhaven, Germany

[7] NOAA, Washington, DC USA

[8] Univ Jaen, Jaen, Spain

[9] Natl Geog Inst, Madrid, Spain

[10] Spanish Geol Survey, Madrid, Spain

来源：

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES | 2020年 / 104卷

基金：

美国国家科学基金会;

关键词：

Bransfield strait; Antarctica; Orca volcano; Humpback volcano; Amphibious seismic network; Marine geophysics; Back-arc basin; Submarine volcano; SOUTH SHETLAND ISLANDS; WAVE VELOCITY STRUCTURE; DECEPTION ISLAND; SEISMIC STRUCTURE; WEST ANTARCTICA; BASIN; EVOLUTION; PENINSULA; GRAVITY; PLATE;

D O I：

10.1016/j.jsames.2020.102834

中图分类号：

P [天文学、地球科学];

学科分类号：

07 ;

摘要：

The Bransfield Basin is a back-arc basin located in Western Antarctica between the South Shetland Islands and Antarctic Peninsula. Although the subduction of the Phoenix plate under the South Shetland block has ceased, extension continues through a combination of slab rollback and transtensional motions between the Scotia and Antarctic plates. This process has created a continental rift in the basin, interleaved with volcanic islands and seamounts, which may be near the transition from rifting to seafloor spreading. In the framework of the BRAVOSEIS project (2017-2020), we deployed a dense amphibious seismic network in the Bransfield Strait comprising 15 land stations and 24 ocean-bottom seismometers, as well as a network of 6 moored hydrophones; and acquired marine geophysics data including multibeam bathymetry, sub-bottom profiler, gravity & magnetics, multi-channel seismics, and seismic refraction data. The experiment has collected a unique, high quality, and multifaceted geophysical data set in the Central Bransfield Basin, with a special focus on Orca and Humpback seamounts. Preliminary results confirm that the Bransfield region has slab-related intermediate depth seismicity, with earthquake characteristics suggesting distributed extension across the rift. Gravity and magnetic highs delineate a segmented rift with along-axis variations that are consistent with increased accumulated strain to the northeast. Orca volcano shows evidences of an active caldera and magma accumulation at shallow depths, while Humpback volcano has evolved past the caldera stage and is currently dominated by rifting structures. These differences suggest that volcanic evolution is influenced by the position along the rift. Although a lot of analysis remains, these results provide useful constraints on the structure and dynamics of the Bransfield rift and associated volcanoes.

引用

页数：19

共 88 条

[1]

Alfred-Wegener-Institut Helmholtz-Zentrum f <spacing diaeresis>ur Polarund Meeresforschung, 2017, J LARGESCALE RES FAC, V3, pA122, DOI [10.17815/jlsrf-3-165, DOI 10.17815/JLSRF-3-165]

[2] Array tracking of the volcanic tremor source at Deception Island, Antarctica [J].