Not to be confused with a David Letterman segment, today’s event at the Mount St. Helens Visitors’ Center, Will It Blow?, is based on the Liz Rusch book of the same title, aiming to educate people about the mountain and about basic properties of volcanology in a fun, “playing detective” way. Rusch will host a day of Mr. Wizard-esque experiments, including playing Human Seismograph by jumping on a mattress and measuring movement with a pencil, and “Build A Bulge,” in which you can mimic magma pooling underground by inflating balloons under cornmeal. (Fingers crossed for the baking-soda-volcano-in-the-sandbox experiment!) To assuage common fears (rooted in ignorance) about scary, active volcanoes, Rusch will happily point out that most volcanoes around the world are creative—dome-building rather than explosive and destructive. “Mount St. Helens is…pumping out enough lava to fill a five-drawer filing cabinet every second and a room every ten minutes. The growing dome is currently higher than the Empire State Building!” Rusch explains. But, seriously, will it blow? I think the Discovery Channel’s CGI natural disaster show producers would have us think so.

Sat., Oct. 13, 10 a.m.-2 p.m., 2007