The Lyell and Maclure glaciers in Yosemite – like glaciers and ice sheets worldwide – are in rapid state of retreat. The Lyell and Maclure were presumed to be “true” glaciers – that is, thick slabs of ice dragged downhill under their own weight, scouring the land as they move – but scientists are discovering that the Maclure is deteriorating as it moves, and the Lyell is no longer moving at all.
Earlier this year, geologists in Yosemite Park came to the sad conclusion that one of California's iconic glaciers, the Lyell, had ground to a halt, having lost too much mass to sustain its downward movement. Knowing that California's approximately 130 glaciers will not be around forever, Tim Palmer spent a summer on a personal quest to climb and photograph as many of these frozen giants as he could manage.
Snow runoff from the Sierra Nevada provides about a third of the state's water supply. Current estimates of how much water is in the mountains combine patchy measurements with a kind of sophisticated guesswork. But that may be about to change with new technology that's currently being tested.