Volcanoes, including Mt. Hood, can go from dormant to active quickly, Feb. 19

A new study suggests that the magma sitting 4-5 kilometers beneath the surface of Oregon’s Mount Hood has been stored in near-solid conditions for thousands of years, but that the time it takes to liquefy and potentially erupt is surprisingly short – perhaps as little as a couple of months. The key, scientists say, is to elevate the temperature of the rock to more than 750 degrees Celsius, which can happen when hot magma from deep within the Earth’s crust rises to the surface. It is the mixing of the two types of magma that triggered Mount Hood’s last two eruptions – about 220 and 1,500 years ago, said Adam Kent, an Oregon State University geologist and co-author of the study. Results of the research, which was funded by the National Science Foundation, were published this week in the journal Nature.