New study: Great mass extinction caused by ice age, not global warming


By: - Climate DepotMarch 7, 2017 3:20 PM

During the Permian-Triassic boundary 250 million years ago, the Earth was enjoying some of its warmest temperatures when it was interrupted by a catastrophic cooling event. The new discovery shows an #Ice Age forced a massive die-off of most marine life, and not global warming as once thought. It also shows the role geological events have played on our climate, specifically volcanic eruptions.

While the Earth has gone through a number of #extinction level events, the one that happened at the Permian-Triassic boundary was one of the deadliest. Over 95 percent of marine life vanished from the face of the planet. Scientists previously believed it was from a rise in temperatures that preceded #Climate Change, but researchers from the University of Geneva and University of Zurich discovered the die-off arose from a mini ice age.

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“The cold exterminated all of them” https://www.sciencedaily.com/releases/2017/03/170306091927.htm …
2:16 PM – 6 Mar 2017
Photo published for Cold extermination: One of greatest mass extinctions was due to an ice age and not to Earth’s…
Cold extermination: One of greatest mass extinctions was due to an ice age and not to Earth’s…
The Earth has known several mass extinctions over the course of its history. One of the most important happened at the Permian-Triassic boundary 250 million years ago. Over 95% of marine species…
sciencedaily.com
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Dating the past
The researchers worked on sediment layers found at the Nanpanjiang basin in southern China. Bjorn Baresel, a University of Zurich scientist, said they made several cross sections of the basin sediments to determine the exact positions of ash beds in the marine sediments. Then they dated the sediments using the natural radioactive decay of uranium from the mineral zircon. Because it decays at a specific speed, they can be accurate to within 35,000 years.

Once they dated the various sediment layers, the scientists noticed a mass extinction at the Permian-Triassic boundary represented by a gap in the sediment layers. That gap correlates to a time when seawater level decreased. And sea levels only drop when it gets stored into ice. From there they could determine the ice age lasted about 80,000 years, time enough to kill off 95 percent of all marine life.
Scientists have long believed a mass die-off was caused by global warming. A new study shows differently.During the Permian-Triassic boundary 250 million years ago, the Earth was enjoying some of its warmest temperatures when it was interrupted by a catastrophic cooling event. The new discovery shows an #Ice Age forced a massive die-off of most marine life, and not global warming as once thought. It also shows the role geological events have played on our climate, specifically volcanic eruptions.

While the Earth has gone through a number of #extinction level events, the one that happened at the Permian-Triassic boundary was one of the deadliest. Over 95 percent of marine life vanished from the face of the planet. Scientists previously believed it was from a rise in temperatures that preceded #Climate Change, but researchers from the University of Geneva and University of Zurich discovered the die-off arose from a mini ice age.

“The cold exterminated all of them” https://www.sciencedaily.com/releases/2017/03/170306091927.htm 

Photo published for Cold extermination: One of greatest mass extinctions was due to an ice age and not to Earth's...

Cold extermination: One of greatest mass extinctions was due to an ice age and not to Earth’s…

The Earth has known several mass extinctions over the course of its history. One of the most important happened at the Permian-Triassic boundary 250 million years ago. Over 95% of marine species…

sciencedaily.com

Dating the past

The researchers worked on sediment layers found at the Nanpanjiang basin in southern China. Bjorn Baresel, a University of Zurich scientist, said they made several cross sections of the basin sediments to determine the exact positions of ash beds in the marine sediments. Then they dated the sediments using the natural radioactive decay of uranium from the mineral zircon. Because it decays at a specific speed, they can be accurate to within 35,000 years.

Once they dated the various sediment layers, the scientists noticed a mass extinction at the Permian-Triassic boundary represented by a gap in the sediment layers. That gap correlates to a time when seawater level decreased. And sea levels only drop when it gets stored into ice. From there they could determine the ice age lasted about 80,000 years, time enough to kill off 95 percent of all marine life.