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

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 ...

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, ...

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 ...

For a moment, it seemed like a blast from the past: a plume over Mount St. Helens on Tuesday looked like the volcano might be erupting again. But fortunately, this was not an eruption — just a ...

Learn how stress inside a volcano can make gas bubbles form early, helping explain why some eruptions stay quiet instead of ...

Some Pacific Northwesterners woke Tuesday to an unusual sight: A smoky haze shrouded Mount St. Helens, the large, active stratovolcano in Washington state that erupted catastrophically in 1980. But a ...

When Mount St. Helens erupted in 1980, lava incinerated anything living for miles around. As an experiment, scientists dropped gophers onto parts of the scorched mountain for only 24 hours. The ...

Residents of the Pacific Northwest often cast a wary eye toward Mount St. Helens, but airborne ash this week isn’t a sign of a new eruption. That’s according to the U.S. Geological Survey, which ...

The explosiveness of a volcanic eruption depends on how many gas bubbles form in the magma—and when. Until now, it was ...