An Inventory of Environmental Features in the McMurdo Dry Valleys, Antarctica, and Their Recent Changes Using a Geographic Information System

点击翻译按钮获取中文摘要

Abstract This project is a collaborative effort among the University of New Hampshire, U.S. Geological Survey, International Center for Antarctic Information and Research (ICAIR), and the Institute for Geological and Nuclear Sciences Ltd. (New Zealand). The purpose of this project is to build a Geographic Information System (GIS) describing the of the Dry Valleys in Antarctica as it existed in 1993-95. To ascertain recent natural changes in this environment, the Principal Investigators will add to the GIS environmental information on a decadal over the preceding forty years. The study region, consisting of the Wright Valley, Victoria Valley, and Taylor Valley, will be mapped at a scale of 1:50,000. Inside the study area, two "supersites" will be studied at a scale of 1:10,000. To support the environmental inventory for 1993-95, the framework will be significantly enhanced. SPOT panchromatic and Landsat Thematic Mapper will be rectified and merged for the entire study region. Topographic data at the 1:50,000, currently referenced to an outdated astronomic datum, will be updated to the current WGS84 satellite datum. Digital orthophotographic maps at 1:50,000 for the entire region and 1:10,000 for the supersites, will be produced. Numerous aerial photographs of the regions will be computerized. Digital basemaps of glacier and hydrologic features will be derived from satellite imagery for the 1:50,000 analysis and from digital orthophotographic maps for the 1:10,000 analysis. The geological inventory will use a genetic systems approach to compile surface and subsurface data on unconsolidated sediments, bedrock, and geomorphic features. In the glacial//hydrological meltwater summary, various lake stream and glacier attributes will be compiled to quantify glacial meltwater production and transportation. To describe changes in the Dry Valleys, environmental data will be compiled into the GIS for 1983-85, 1972-74 and 1957-59. Satellite imagery for 1973-74 and 1983-85 will be rectified and used to provide basemaps of glacier and hydrologic features. Pertinent aerial photography acquired during the latter intervals and during 1957-59 will be inventoried and used to supplement the characterization of glacier and hydrologic features. Pertinent aerial photography acquired during the latter intervals and during 1957-59 will be inventoried and used to supplement the characterization of glacier and hyrdologic features. A comparison of four time periods will reveal physical rates of change in the study area over the past forty years. This research will provide a foundation for long-term environmental management of the Dry Valleys and short-term environmental impact assessments. This research will result in the digital availability of enhanced framework data including topography, satellite imagery, and aerial photography. It will establish an Antarctic scientific data repository that will increase the availability of Antarctic scientific data for scientists and for improved management of science. Finally, the quantification of recent change in the Dry Valleys constitutes a contribution the study of Antarctic climate change.