Inside the Cascades Volcano Observatory in Vancouver, Wash., SALI the robot weighs small crucibles holding sediment.SALI ...

Before 1980, volcanologists didn't have a lot of experience with volcanoes that collapse. But since Mount St. Helens, because of all the lessons that they learned from that eruption, they've ...

Mount St. Helens continued to have smaller eruptions through 1986 and then had more between 2004 and 2008. "They are active volcanoes," Westby said of the Cascades, the volcanic arc that runs ...

The 45th anniversary of the catastrophic eruption of Mount St. Helens is on May 18. Here's what to know and when the volcano might erupt again.

Sunday marks 45 years since Mount St. Helens erupted in Washington state. The deadly eruption happened shortly after 8:30 a.m. on May 18, 1980, following months of small explosions and earthquakes.

Aerial view of the May 18, 1980, eruption of Mount St. Helens as seen from the southwest. Columns of ash and volcanic gas reached heights of more than 80,000 feet.

MT. ST. HELENS, Wash — For many people who lived through the 1980 eruption of Mount Saint Helens, it is the biggest news story of their lifetimes. 45 years ago, the mountain that had been ...

Jessica Ball with the California Volcano Observatory joined the show to discuss the Mt. St. Helens eruption 45 years ago and if there's been any recent activity at California's volcanoes.

Sunday marks 45 years since Mount St. Helens erupted in Washington state. The deadly eruption happened shortly after 8:30 a.m. on May 18, 1980, following months of small explosions and earthquakes.

Sunday marks 45 years since Mount St. Helens erupted in Washington state. The deadly eruption happened shortly after 8:30 a.m. on May 18, 1980, following months of small explosions and earthquakes.

Sunday marks 45 years since Mount St. Helens erupted in Washington state. The deadly eruption happened shortly after 8:30 a.m. on May 18, 1980, following months of small explosions and earthquakes.

Mount St. Helens erupted 45 years ago, causing the deadliest volcanic disaster in U.S. history. May 18 marks 45 years since Mount St. Helens erupted, devastating 230 square miles and killing 57.