The melting of the ice sheets 14,600 years ago caused the seas to rise 10 times faster than today


The melting of the ice sheet at the end of the last ice age may have caused sea levels to rise 10 times the current rate, according to a study published Thursday by a team led by scientists from Britain’s Durham University. .

Based on geological records, researchers estimate that the world’s oceans increased 3.6 meters (11.8 feet) per century over a 500-year period about 14,600 years ago.

The findings raise a red flag on the current potential for rapid sea level rise that could flood coastal cities and densely populated deltas around the world.

The team found that the roughly 18-meter sea-level rise event may have originated primarily from the melting of ice sheets in the northern hemisphere and not in Antarctica as previously thought.

Scientists say their work could offer “vital clues” to future ice sheet melting and rising sea levels due to climate change.

“We found that most of the rapid sea level rise was due to ice sheet melting in North America and Scandinavia, with a surprisingly small contribution from Antarctica,” said study co-author Pippa Whitehouse of the department. of geography from Durham University.

“The next big question is to find out what caused the ice to melt and what impact the massive influx of meltwater had on the North Atlantic ocean currents.

“This is very much on our minds today – any disruption of the Gulf Stream, for example due to the melting of the Greenland ice sheet, will have significant consequences for the UK climate.”

Current models used by many climate scientists estimate that global sea level could rise by 1 to 2 meters by the end of this century.

The Durham researchers used detailed sea level geological data and state-of-the-art modeling techniques to reveal the sources of the dramatic five-century sea level rise event.

Comparable to the melting of an ice sheet twice the size of Greenland, it caused the flooding of vast areas of lowlands and disrupted ocean circulation, with knock-on effects for global climate, they said.

“Our study includes novel information from lakes around the coast of Scotland that were cut off from the ocean due to the uplift of the land following the retreat of the British ice sheet, allowing us to confidently identify sources of meltwater.” added co-author Yucheng Lin, also from Durham’s geography department.

Identifying the source of the meltwater will help improve the accuracy of climate models that are used to replicate the past and predict changes in the future, the team added.

They noted that the findings were particularly timely, as the Greenland ice sheet rapidly melted and contributed to a rise in sea level and changes in global ocean circulation.

In 2019, Greenland dumped more than half a trillion tons of ice and meltwater, accounting for 40 percent of the total sea level rise that year.

© Agence France-Presse

.

Source link