Cliff cracks grow as temperatures rise
As the weather warms, watch for falling rocks. While monitoring a cracked cliff in Yosemite National Park, researchers watched the fissure widen as temperatures rose. The risk of rockfalls could increase as climate change cranks the thermostat, one scientist predicts.
For three and a half years, geologists Brian Collins of the U.S. Geological Survey in Menlo Park, Calif., and Greg Stock of the National Park Service in Yosemite monitored a 19-meter-long crack in one of the park’s cliffs. The crack had a maximum width of about 12 centimeters. A measuring device anchored to both sides of the crack recorded changes in its size. The gap grew and shrank by as much as a centimeter daily as temperature changes caused the rock to expand and contract, the researchers report online March 28 in Nature Geoscience. Some effects lingered, however: The gap widened over the course of several summers and the