Digital Geological Map for Marie Byrd Land, West Antarctica: A resource for investigation of geotectonic frameworks and future glaciological change
Abstract
Bedrock exposures are relatively sparse in Marie Byrd Land (MBL), where rock is concealed by the West Antarctic ice sheet, but they provide direct insight into the geological evolution and glacial history of West Antarctica. MBL is tectonically active, as evidenced by Late Pleistocene to Holocene volcanism and 2012 seismicity (3 events, M4.4 to M5.5) at sites beside Ross Sea. There are geological influences upon the ice sheet, namely, subglacial volcanism and associated geothermal flux, fault zone alteration/mineralization, and bedrock roughess. The former may influence the position and velocity of outlet glaciers and the latter may anchor or accelerate sectors of the ice sheet. To make MBL's geological framework accessible to investigators with diverse research priorities, we are preparing the first digital geological map of MBL by compiling ground-based geological data, incorporating firsthand observations, published geological maps and literature. The map covers an on-continent coastal area of 900 000 km2 between 090°E to 160°E, from 72°S to 80°S, at 1:250 000 scale or better. Exposed rock is delimited by 1976 polygons, occupying 410 km2. Supraglacial features and glacial till, seasonal water and blue ice, are also mapped, as a baseline for past and future glaciological change. Rendered in the ArcMap GIS software by Esri©, the database employs international GeoSciML data protocols for feature classification and description of rock and moraine polygons from the Antarctic Digital Database (www.add.scar.org), with shape and location adjusted to align with features in Landsat Image Mosaic of Antarctica imagery (lima.usgs.gov), where necessary. The GIS database is attribute-rich and queriable; including links to bibliographic source files for primary literature and published maps. It will soon be available as GoogleEarth kmz files and an ArcGIS online map service. An initial application is to the interpretation of sub-ice geology for a subglacial geotectonic map of this active region. This is undertaken as part of ROSETTA-Ice, an integrated systems science investigation of the Ross Ice Shelf that commenced in 2015. The next phases of MBL database development will assess icesheet-ocean interactions near grounding line, environmental domain analysis and ecological research.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.C53C0731S
- Keywords:
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- 0726 Ice sheets;
- CRYOSPHEREDE: 0730 Ice streams;
- CRYOSPHEREDE: 0774 Dynamics;
- CRYOSPHEREDE: 1621 Cryospheric change;
- GLOBAL CHANGE