vol - what if yellowstone goes up ?

If the mega-volcano under Yellowstone National Park ever has the massive eruption that has been predicted, the devastation would be exceptional over North America. Zone 6 *might* have some survivors if they were able to take adequate shelter, and one with suitable resources. There would be serious and significant affects worldwide. The amount of volcanic ash & dust - and smoke from "forest" fires - plus other debris that enters the atmosphere would block / reflect sufficient sunlight to significantly drop global temperatures creating what would probably be a short "mini-ice-age" [what is sometimes termed a "nuclear winter"]. I expect it would be an extinction-level climate event. Mankind would probably survive on other continents but civilisation would, most likely, be knocked back several centuries and world-wide famine would be a likely outcome.
Not a pleasant prospect, but slightly less devastating than a decent meteor impact.
.
not my image : fair use & public information