Idea for a Disaster Movie

A supervolcano erupts under California blasting superheated gas and ash 50 kilometers high into the earth's stratosphere. Soon intensely hot pyroclastic flows at around 600 to 700 degrees Celsius burst out, moving so rapidly that cars and even small airplanes would have no chance of outrunning them. Within minutes these flows burn and bury everything for tens of kilometers in every direction.

For hundreds of kilometers around the eruption and for perhaps days or weeks, pale-gray ash would fall like clumps of snow. Within 200 kilometers of the caldera, most sunlight would be blocked out, so the sky at noon would look like that at dusk. Homes, people and animals would be buried, sometimes crushed. Even 300 kilometers away, the ash could be half a meter thick; mixed with rain, the weight would be plenty sufficient to collapse roofs. Less ash than that would knock out electrical power and relay stations. As little as a millimeter, which could well dust the ground halfway around the globe, would shut down airports and dramatically reduce agricultural production.

Most of the animals would probably die slowly after inhaling the falling ash—which would essentially be powdered glass.

Feel this reads like the scenario of yet another blockbuster disaster movie?

Geologists, who have just uncovered the secrets of supervolcanoes, suspect that deep below the surface in California and Wyoming two hibernating supervolcanoes of almost unimaginable fury lie in wait biding their time. Similar supervolcanoes smolder underneath Indonesia and New Zealand.