Cette image peut avoir des imperfections car il s’agit d’une image historique ou de reportage.
First of 2 images for glacial retreat comparison. The 1913 image of Sperry Glacier shows the thickness of the glacial ice that once covered the Sperry basin. Now, at approximately 1/3 of it's maximum area, Sperry Glacier continues to recede at a rapid rate. It is one of the glaciers that USGS scientists are monitoring as a benchmark glacier. Climate change research in Glacier National Park, Montana entails many methods of documenting the landscape change, including the decline of the parks namesake glaciers. While less quantitative than other high-tech methods of recording glacial mass, depth, and rate of retreat, repeat photography has become a valuable tool for communicating effects of global warming. With evidence of worldwide glacial recession and modeled predictions that all of the parks glaciers will melt by the year 2030, USGS scientists have begun the task of documenting glacial decline through photography. The striking images created by pairing historic images with contemporary photos has given global warming a face and made climate change a relevant issue to viewers. The images are an effective visual means to help viewers understand that climate change contributes to the dynamic landscape changes so evident in Glacier National Park.
