Concept information
Preferred term
WARS
Definition
- Short Title: WARS in Remote Ellsworth Land Proposal URL: http://classic.ipy.org/development/eoi/proposal-details.php?id=109 The aim of the proposed project is to test the model that the West Antarctic Rift System (WARS) is a horse tail structure due to movement of the Marie Byrd Land microplate / Thurston Island block away from Victoria Land to the NE (by 400 km in 100 Ma) (Behrendt and Cooper 1991, Luyendyk et al. 1996). While it is developed as extensional pull apart basin in the Ross Sea embayment it is proposed here that it is expressed as dextral strike slip fault system at its northeastern end in remote Ellsworth land. Ross Sea embayment as well as Marie Byrd Land and its volcanics were studied in great detail over decades (Behrendt et al. 1991, Behrendt 1999, LeMasurier 1972, 1990, 2002, Rocchi et al. 2002). Only during the 1990s investigations of the subglacial geology were performed in restricted areas within the central WARS of the Subglacial Byrd Basin by the West Antarctic Ice Sheet Airborne Gravimetry Initiative, e. g. in the CASERTZ quadrangle as well as in the area of Ice Stream D draining into the Ross Ice Shelf (Behrendt et al. 1994, 1998, Bell et al. 1998, Blankenship et al. 1993). Additional information was gathered by more recent initiatives like the ANUBIS broadband seismic experiment (Winberry and Anandakrishnan 2004). The results of multi-disciplinary aerogeophysical surveys - that must be addressed as restricted with respect to the continental dimensions of the rift system - indicate that the southern boundary fault of WARS extends north of Whitmore Mts. towards Ellsworth Mts. (EWM) while a northern boundary fault cannot be identified clearly. The sedimentary basin with extensional horst and graben structures extends well into the Subglacial Byrd Basin and the basin is associated with active seismicity and volcanism, subglacial caldera structures indicate voluminous magmatic systems within upper crustal levels. In order to test the model investigations are needed in Ellsworth Land, one of the least accessible and most poorly known areas in Antarctica. It stretches between Amundsen Sea, Ronne Ice Shelf and Bellingshausen Sea and encloses a triangle (see map) between Hudson Mts. at the Walgreen Coast, Sentinel Range in the Ellsworth Mountains and Eltanin Bay with the Rydberg Peninsula at the Bryan Coast. The focus of the research activities is a multi-disciplinary aerogeophysical survey within this triangle, including imaging of subglacial topography as well as the magnetic and gravity field. Ground based geoscience fieldwork studies include: structural geology studies to check for indications of the regional stress field at the northern end of the Ellsworth Mts. (EWM); seismic study with temporary broadband seismic stations; GPS measurements in the Hudson Mountains (e.g. on Webber Nunatak), at Eltanin Bay (altern. Mt. Tuve) as well as at the northern end of the Sentinel Range (e.g. Mt. Weems); sampling for fission track dating to describe the exhumation history of individual geodynamic blocks as well as sampling for paleomagnetic studies in order to reconstruct paleopositions mapping and dating of hydroclastic eruptive features within the Bellingshausen Volcanic Provinc from Hudson Mts. in the West over Jones Mts. to Rydberg Peninsula at Bryan Coast in the East in order to deceiver ice sheet dynamics by reconstructing thicknesses of paleo-ice sheets; geo- and mineralchemistry of volcanics and enclosed mantle and crustal xenoliths in order to describe variations in magma genesis including mantle source compositions, mantle melting regimes and differentiation during ascent through the lithosphere; additional fastdrilling might provide sampling of the subglacial geology The project of the IDs 107, 895, 276 and the ANTEC activities of Reinhard Dietrich will be initiated within the framework of the German mission to Pine Island Bay in the season 2005/06 (02-04/2006) by setting up a GPS reference point within the Hudson Mountains at Pine Island Bay as well as by initial volcanological and petrological field studies including sampling and dating the volcanic structures and their exposure ages as well as identifying the point of an eruption recorded by satellites in the Hudson Mountain Volcanic Field in 1985, which is the closest to the fastest flowing glacier in Antarctica, the Pine Island Glacier. (en)
Broader concept
- V - Z (en)
URI
https://gcmd.earthdata.nasa.gov/kms/concept/2bee0fb6-7c3f-4d34-90d4-32673b046d6b
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