5-Million-Year-Long ‘Dead Zone’ Caused By Extreme Heat Followed Largest Extinction Event Ever 250 Million Years Ago

October 19, 2012 in Geology & Climate

The end-Permian mass extinction event 250 million years ago left a ‘broken world’ where new species weren’t seen for the next five million years. Why this ‘dead zone’ lasted so much longer than other similar periods after mass extinctions had been somewhat unclear. But now new research is strongly suggesting that it was simply too hot for nearly anything to survive.


Mass extinctions are nearly always followed by a period of tens of thousands of years when no new species emerge, a ‘dead zone’. The dead zone following the Early Triassic period is such an extreme outlier, at five million years long, that researchers have long suspected that there must be some unknown influence at work.

The new research clarifies: “the cause of this lengthy devastation was a temperature rise to lethal levels in the tropics: around 50-60°C on land, and 40°C at the sea-surface.”

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