MCMURDO DRY VALLEYS

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This image and others were released for public use on 15 September 1999 under a cooperative project of the National Science Foundation, the National Imagery and Mapping Agency, and the DCI Environmental Center. The main image (scale: 1:300,000) shows the McMurdo Dry Valleys, in the Transantarctic Mountains. The inset (scale: 1:50,000) shows the eastern end of Lake Bonney and vicinity in the Taylor Valley.

The McMurdo Dry Valleys Long-Term Ecological Research (LTER) site, one of 21 sites comprising the NSF-supported LTER network (see http://lternet.edu), is a cold desert terrestrial and aquatic ecosystem. The Dry Valleys form the largest relatively ice-free area in Antarctica (approximately 4,800 square kilometers within a 75 x 60 kilometer region).

Recognizing the unique contribution that U.S. photoreconnaissance systems could make to the environmental understanding gained through this research, the Director of the National Imagery and Mapping Agency, Lieutenant General James C. King, has approved the release of this image product created from still-classified imagery. The image product is an important data source to further scientific research and to enhance understanding of life in this extreme environment. The data, collected by the classified system in 1975 and 1980, provide the earliest available high-resolution regional coverage of the McMurdo Dry Valleys.

LAKE BONNEY, MCMURDO DRY VALLEYS

For a larger version of this image, click here. To download a higher-resolution TIFF version of a particular image, click here. Please note that the TIFF file is 7.3 MB.

These imagery products have a nominal spatial resolution of 8 meters, 10 times better than Landsat imagery available in the 1970s, and thus provide important research opportunities. First, as the earliest available images of the region, NSF-supported scientists will be able to analyze hydrologic changes, which influence the presence and stability of life forms. Photographic data collected in the 1980s (Landsat and Radarsat data) and more recent photography form the basis for comparison. Second, the newly released products are in stereo.

Currently, the best available maps of the regions, derived from 1980s imagery, are at a scale of 1:50,000 with 50-meter topographic contour intervals. Using recently developed digital methods, the satellite images will improve the topographic record by 2 to 4 times and will provide the first high-resolution, digital terrain-elevation model of the region, yielding accurate elevation data every 20 meters. A more precise digital model will improve study and modeling of hydrography and will enable more effective planning for placement of communications relay towers and flight route planning. Both the imagery products and the image-derived elevation data will serve future research needs by providing for geospatial control of photographic products or commercial imagery. Currently, commercial imagery can be acquired for this region at spatial resolutions of 6, 10, 15, 30 meters and greater. Soon commercial imagery will be available at 1-meter spatial resolution.

Five images of this region obtained on 5 December 1975 and two images obtained on 22 September 1980, will be available, as will elevation data derived from the stereo pairs of the 1975 images.