Stretching crust explains Earth’s 170,000-year-long heat wave

A team studied sediment cores drilled from the North Atlantic to shed light on the Paleocene-Eocene Thermal Maximum. Credit: Tom Gernon/University of Southampton

Fifty-six million years ago, Earth endured a heat wave that lasted 170,000 years. The event, known as the Paleocene-Eocene Thermal Maximum (PETM), ushered in a wave of evolutionary shifts. New research published in Nature Geoscience suggests a massive belch of carbon from deep below the northern Atlantic Ocean could have played a key role.

“[The PETM] was one of the most extreme global warming events in the recent geologic past,” said Thomas Gernon, a geologist at the University of Southampton. The warm spell raised sea surface temperatures roughly 5°C, acidified the oceans, and wiped out some deep-sea creatures.

What makes the PETM so unusual is its rapid onset, said James Zachos, a paleoceanographer at the University of California, Santa Cruz, who researches the event but was not involved in the new study. “The rate of [carbon] emissions had to be really high—almost the same order of magnitude as fossil fuel emissions.” That suggests multiple sources of carbon, he said.

Jennifer Schmidt, Eos, 27 July 2022. Full article.

  • Reset


OA-ICC Highlights