Yellowstone Rising: Magma floods into chamber beneath park

From mid-2004 through 2006, parts of the terrain in Yellowstone National Park rose as much as 7 centimeters per year, a rate about three times that previously measured. Analyses suggest that the rapid uplift results from the flow of molten rock into a Los Angeles–size zone of strata beneath the park.

ON THE RISE. Yellowstone’s Grand Prismatic Spring is one of the geothermal features heated by a reservoir of molten rock beneath the park’s central basin (inset map, red).