Science When will Mount Rainier erupt again? Magma study offers clues.

Scientists have mapped the electric and magnetic signatures of magma flows beneath Mount Rainier, which scientists expect to erupt again. 

By , Reuters

Rachel La Corte/AP

Experts have mapped a huge magma reservoir below Mount Rainier in Washington state that begins melting deep in the Earth's mantle before pushing upwards to where it will eventually be tapped for eruption.