One of the most deadly and dangerous volcano hazards isn’t lava. Mudflows called lahars can come without clear warning.

Whenever Mt. Hood erupts, Portland will be glad to have David George. As a U.S. Geological Survey mathematician, George models landslides and lahars at the Cascades Volcano Observatory in Vancouver, ...

For many, the word “eruption” brings to mind 1980 when Mount Saint Helens demonstrated that the Washington Cascades are one of the most volcanically active parts of the country. Mount Saint Helens, ...

America’s deadliest volcano has just rattled through more than 1,000 tiny earthquakes in a matter of days, a drumbeat of tremors that has revived old fears about catastrophic mudflows racing down its ...

Recent volcanic activity across the Pacific Ring of Fire has raised alarms among scientists and volcanologists, with several volcanoes experiencing heightened eruptions and seismic tremors. The Ring ...

Studying tree rings helped scientists pinpoint when Mount Rainier last sent a lahar down its steep slopes, which could help planners anticipate future mudflows. By Katherine Kornei Katherine Kornei ...

An outpouring of magma isn’t the biggest risk to people downhill from Mount Rainier. The active volcano’s greatest danger comes from lahars — amalgams of mud, rock and water that are as dense as wet ...