The discovery of a seawater sample from the remains of the ice age, how old is it?!

20,000 years ago, life on Earth was much cooler; It was the end of the 100,000-year-old tail of the Ice Age - also called the last glacial maximum - when massive ice sheets covered most of North America, northern Europe and Asia.

Scientists used to study this cold period of Earth's history by digging into things like fossil coral and seafloor sediments, but now a team of marine researchers has found a piece of the past that trumps everything else: a real sample of seawater, about the age of 20,000 years old, extracted from an ancient rock formation from the Indian Ocean!

According to the researchers who describe the discovery in a study to be published in the July 2019 issue of the journal Geochimica et Cosmochimica Acta, the discovery represents the first direct remnants of the ocean as it emerged during Earth's last ice age!

Researchers found their watery bounty while drilling for core samples of limestone deposits beneath the waters of the Maldives archipelago in South Asia.

After transferring each core into its own research vessel, the team cut the rock into a tube of cookie dough and placed the pieces into a hydraulic press that squeezed any remaining moisture out of the pores.

When the researchers tested the composition of these freshwater samples on board their ship, they were surprised to find that the water was very salty. It is much saltier than the waters of the Indian Ocean today. And they conducted more tests on land to search for the specific elements and isotopes (copies of the elements) that make up the water, and it seems that not all the results matched the specifications of the modern ocean.

In fact, everything about these water samples indicates that they came from a time when the oceans were saltier, cooler, and more chlorinated; Just like the qualities that are thought to have characterized the water during the last glacial period, when ice sheets sucked up ocean water and sea levels dropped hundreds of feet below current levels.

"From all indications, it seems pretty clear that we now have a real portion of this 20,000-year-old ocean," Clara Plattler, assistant professor of geophysical sciences at the University of Chicago, said in a statement.

If these findings do indeed contain water, the new samples provide the first direct look at how the ocean interacted with the geophysical fluctuations of the last Ice Age. This understanding could lead to improved climate models to help understand our changing world, Plattler added, because "any climate model you build needs to be able to accurately predict the past."