EDIT: We are pretty much done for the day. Thanks everyone! We may have some of our experts drop by to check for unanswered questions as their job allows.

On this day, 42 years ago, Mt. St. Helens erupted. We’re volcano scientists and experts from the Cascades Volcano Observatory and Washington Emergency Management Division. We’ll be here taking turns answering your questions about Mt. St. Helens, Mount Rainier, the volcanoes of Yellowstone, Hawaii, Washington, Oregon and California. Joining us at times will be:

• Emily Johnson, volcanic rocks, education, field geology
• Emily Montgomery-Brown, volcano deformation, monitoring
• Liz Westby, volcano communications, Mount St. Helens
• Mike Poland, Yellowstone, volcano deformation
• Seth Moran, volcano seismicity, volcano early warning, monitoring
• Wendy Stovall, volcano communications, Yellowstone
• Wes Thelen, volcano seismicity, lahars, monitoring
• Brian Terbush, emergency preparedness with WA EMD

Edit: (Larry Mastin, ash modelling, ash and aviation had originally planned to join us, but was unable to do it).

We’re all using one account and will be signing our first names. If your question hasn’t been answered yet, we’re waiting for the appropriate expert to arrive to answer it.

The Cascades Volcano Observatory is also celebrating its 40th anniversary this year, created in the wake of the Mt. St. Helens' eruption and aftermath.

Here’s proof of our AMA from our verified Twitter account. More proof from USGS.