Scientists find undisturbed pockets of seawater from the last Ice Age 20,000 years ago in the Maldives – and say they will provide clues about our planet’s changing climate
- Scientists found the virtually undisturbed sample within limestone deposits
- The piece is thought to be from the last Ice Age, which was 20,000 years ago
- The team squeezed the water out of an ancient rock from the Indian Ocean
- When they examined the sample, they found that it was a lot saltier and more chlorinated than the conditions found in the modern ocean
A virtually undisturbed sample of 20,000-year-old seawater that represents the first direct remnant from Earth’s last Ice Age has been found in the Indian Ocean.
Researchers found the ice while drilling sediment core samples out of the underwater limestone deposits in the Maldives archipelago in South Asia.
Their work revealed distinct water properties only seen in glacial seawater from the last Ice Age, or the Last Glacial Maximum (LGM).
The team, from the University of Chicago, say that their work could lead a better understanding of out changing world and improved climate models.
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A sample of 20,000-year-old seawater that represents the first direct remnant from Earth’s last ice age has been found. Here, assistant Professor Clara Blättler with a vial of seawater dating to the last Ice Age—about 20,000 years ago
During an expedition of the Indian Ocean on research vessel JOIDES Resolution, the researchers drilled deep below the Indian Ocean and extracted rock cores.
It was inside these cores that they found the traces of the ancient ocean, absorbed into porous rock formations and preserved there ever since.
The small sample was squeezed out of an ancient rock formation from the Indian Ocean and sliced into pieces before being put into a hydraulic press which squeezes the moisture remnant out of its pores.
The team tested the samples aboard their ship and found that the water was far saltier than that found in the Indian Ocean today.
Back in the lab, they did more specific testing to examine the elements and isotopes, or variants of a particular element.
The team found that all of their results seemed out of place in the modern ocean, according to the New Scientist.
They said that the samples indicated that they came from a time when the ocean was significantly saltier, colder and more chlorinated.
These are conditions that scientists think sea water would have been during the Last Glacial Maximum, when sea levels dropped to hundreds of feet below current levels.
At the time of the last Ice Age, massive sheets of ice covered much of North America, Northern Europe and Asia. Researchers found the ice while drilling sediment core samples out of the underwater limestone deposits in the Maldives in South Asia
‘From all indications, it looks pretty clear we now have an actual piece of this 20,000-year-old ocean,’ lead study author Clara Blättler, an assistant professor of geophysical sciences at the University of Chicago.
For decades, scientists have been studying the Earth’s last ice age, also called the Last Glacial Maximum which is thought to have lasted 100,000 years, by looking coral fossils and seafloor sediments.
If all of the results are valid, the new samples could provide scientists with clues on how the ocean reacted to the geophysical swings of the last ice age.
The research could also further out understanding these shifts and lead to improved climate models.
Ms Blättler said, as ‘any model you build of the climate has to be able to accurately predict the past.’
The study is to be published in the July 2019 issue of the journal Geochimica et Cosmochimica Acta.
