It was a quiet Sunday morning, at 8:32 a.m., 38 years ago when Mount St. Helens blew its top, sending tons of ash into the sky. The volcano had been quiet since the 1850s, but in 1980, geologists were ...

May 18 marks the 45th anniversary of the catastrophic eruption of Mount St. Helens in southwestern Washington. The blast in 1980 killed dozens of people and reshaped the volcanic peak in the Cascade ...

A new study explains why even gas-rich, supposedly explosive volcanoes sometimes erupt quietly instead of blowing apart.

Sunday, May 18 marks 45 years since the disastrous eruption of Mount St. Helens. Fifty-seven people were killed and it remains the deadliest volcanic eruption in U.S. history. At 8:32 a.m. on May 18, ...

Wind gusts that stirred up ash around Mount St. Helens in Washington have people asking: Is the sleeping giant awake? The National Weather Service in Portland responded to reports of volcanic ash ...

The explosiveness of a volcanic eruption depends on how many gas bubbles form in the magma—and when. Until now, it was thought that gas bubbles were formed primarily when the ambient pressure dropped ...

Mount St. Helens in Washington State was once the "Mount Fuji of America"—admired for its symmetrical cone shape similar to Japan's highest peak. It was a popular Pacific Northwest destination, ...