250,000,000 years ago, a supervolcano in Siberia may have caused the extinction of 90% of life on Earth.
Researchers have known about the volcano -- the Siberian Traps, for years. And they've speculated that the volcanic rocks, which cover an area about the size of Alaska, played a role in runaway global warming that led to the end -- Permian mass extinction, the worst dying the planet has ever seen.
Now a team of researchers led by Henrik Svenson of the University of Oslo in Norway have performed a series of experiments, showing the volcano employed an arsenal of deadly weapons during its 200,000-year-long assault on the biosphere.
Kinda puts Ozone action days in perspective.