Hint of Nuclear Winter Theory Found in Ancient Volcano Blast

A massive volcanic eruption 250,000 years ago shot dust and ash into the atmosphere and probably caused a winter like that expected by many scientists to follow a nuclear war, according to New Zealand geologists.

They say ash samples found across the Pacific show that the eruption from New Zealand’s still-active Taupo region is likely to have been the reason for a climatic cooling known to have occurred at the time.

The New Zealand experts say the Taupo eruption was 1,000 times greater than the 1982 explosion of Mt. St. Helens in the United States.

They estimate that it threw out at least 250 cubic miles of debris, compared to 0.25 cubic miles from Mt. St. Helens and 1.5 to 2 cubic miles from Krakatoa in the Indonesian archipelago in 1883.

“When you put that magnitude of material into the atmosphere, you could create a volcanic winter,” said Oceanographic Institute marine geologist Lionel Carter.

Dust and ash ejected into the atmosphere reflect shortwave radiation from the sun, reducing the amount reaching the Earth’s surface and lowering temperatures.

Scientists are analyzing ancient ocean-floor samples, seeking conclusive proof linking the New Zealand eruption with the cooling.

“Core samples drilled from the Pacific Ocean bed and dated by oxygen isotopes showed there was a cooling of the Earth’s atmosphere immediately after the eruption,” Carter said. “We don’t have final proof yet, but it seems the two could be linked.”

Carter was reluctant to draw a close comparison between nuclear and volcanic winters because of the unknown quantities of smoke and dust that would rise into the atmosphere after nuclear explosions and the radioactive content of the debris.

However, he said studies of the winter that followed New Zealand’s gigantic eruption at least offer hope for some form of post-nuclear future.

“The good thing about it was that although the eruption was 250,000 years ago, the Earth has recovered and survived,” he said.