Study could shed light on how the planet’s climate will react in the future

In a first, scientists have discovered the remnants of seawater dating back to the Ice Age, tucked inside rock formations in the middle of the Indian Ocean. Researchers from the University of Chicago in the U.S. made the discovery on a months-long scientific mission exploring the limestone deposits that form the Maldives.

The ship, the JOIDES Resolution, is specifically built for ocean science and is equipped with a drill that can extract cores of rock over a mile long from up to three miles beneath the seafloor.

Traces of history: Scientists carrying a core of rock extracted by drill. Photo courtesy: Carlos Alvarez-Zarikian/Jean Lachat//NEWS.uchicago.edu

“Previously, we had to reconstruct seawater from the last Ice Age from indirect clues, like fossil corals and chemical signatures from sediments on the seafloor,” said Clara Blattler, an assistant professor at the University of Chicago.

“But from all indications, it looks pretty clear we now have an actual piece of this 20,000-year-old ocean,” Ms. Blattler said in a statement.

When they extracted the water, they noticed their preliminary tests were coming back salty — much saltier than normal seawater.

Further studies showed that the water was not from today’s ocean, but the last remnants of a previous era that had migrated slowly through the rock.

Scientists are interested in reconstructing the last Ice Age because the patterns that drove its circulation, climate and weather were very different from today’s.

Understanding these patterns could shed light on how the planet’s climate will react in the future.