At 8:32 a.m. May 18, 1980, Mount St. Helens’ top collapsed in the largest landslide in recorded history. It uncorked a blast that flattened 230 square miles. Fifty-seven people died in the eruption.

It erupted more recently, if less dramatically, beginning in September 2004. That eruption didn’t end until January 2008, by which time the volcano had ejected 124 million cubic yards of lava, forming a new dome inside the crater.

Mount St. Helens and Washington’s four other active volcanos — Mount Adams, Mount Rainier, Glacier Peak and Mount Baker — present a continuing threat. That’s why the state’s Emergency Management Division and the U.S. Geological Survey’s Vancouver-based Cascades Volcano Observatory are collaborating on virtual events for Volcano Awareness Month.

At 6 p.m. Wednesday, geologist Alexa Van Eaton will speak about her studies of rock layers to piece together eruption history. The live virtual presentation is part of the Mount St. Helens Institute’s Views and Brews evening lecture series. Tickets are $10. Sign up at mshinstitute.org/learn/volcano-views-brews.html to get the link.

At 12:30 p.m. May 25, scientists and preparedness experts will host a webinar about the Cascades Volcano Observatory’s 40th anniversary, how volcano monitoring has changed since the 1980 eruption, the status of Washington’s Cascades volcanoes and general preparedness. USGS will also present its latest mudflow simulations for a Mount Rainier eruption. Get the link for the virtual event at mil.wa.gov, or watch it afterward on the state Emergency Management Division’s YouTube channel.

In addition, the Cascades Volcano Observatory recently digitized film reels from its archives that document volcanic activity at Mount St. Helens from March 1980 through August 1982. You can watch the videos at st.news/mountsthelensvideos.