An international team of scientists, studying evidence preserved in speleothems in a coastal cave, illustrate that more than three million years ago – a time in which the Earth was two to three degrees Celsius warmer than the pre-industrial era – sea level was as much as 16 meters higher than the present day. Their findings represent significant implications for understanding and predicting the pace of current-day sea level rise amid a warming climate.
The scientists, including Professor Yemane Asmerom and Sr. Research Scientist Victor Polyak from The University of New Mexico, the University of South Florida, Universitat de les Illes Balears and Columbia University, published their findings in today’s edition of the journal Nature. The analysis of deposits from Artà Cave on the island of Mallorca in the western Mediterranean Sea produced sea levels that serve as a target for future studies of ice sheet stability, ice sheet model calibrations and projections of future sea-level rise, the scientists said.
Sea level rises as a result of melting ice sheets, such as those that cover Greenland and Antarctica. However, how much and how fast sea level will rise during warming is a question scientists have worked to answer. Reconstructing ice sheet and sea-level changes during past periods when climate was naturally warmer than today, provides an Earth’s scale laboratory experiment to study this question according to USF Ph.D. student Oana Dumitru, the lead author, who did much of her dating work at UNM under the guidance of Asmerom and Polyak.
“Constraining models for sea-level rise due to increased warming critically depends on actual measurements of past sea level,” said Polyak. “This study provides very robust measurements of sea-level heights during the Pliocene.”
Read more at University of New Mexico
Image: A closeup of the bulbous stalactitic feature of a phreatic overgrowth on speleothems (POS). (Credit: University of New Mexico)