Landsat imagery can capture changes in lake surface water extents. This sequence of images illustrates changes occurring in the Yukon River Basin in Alaska.
Twelve Mile Lake, located southwest of Fort Yukon in interior Alaska, decreased in surface size more than 60% between 1979 and 2009. Drying has also been noted in other northern latitude water bodies around the globe. Landsat can be used to quantify the magnitude of the phenomena. These hydrologic changes have local and global influences on carbon dioxide, methane, heat, and water fluxes.
Causes of the changes in lake hydrology vary by lake and region and include permafrost degradation or negative water balances due to higher temperatures occurring over a longer growing season.
Scientists will use Landsat image sequences as one of many tools for studying changes in responses to climate variations and, potentially, significant climate change. (Support for this study was provided by the USGS Climate Effects Network and USGS Global Change Research & Development Program.)