Ice Age

The discovery was made in the town of Scotchtown, about 70 miles from New York City.

The findings suggest vast rivers of glacial meltwater rushed into the sea, pooling over dense salty ocean water.

“We suggest that these extreme conditions led to the depopulation of Europe,” write the authors of the study, “perhaps lasting for several successive glacial-interglacial cycles."

Prior to the study, it was previously thought that much of the ice sheet that covers the country today had persisted for the past 2.5 million years.

Increased ocean temperatures and stronger monsoons created more moisture. This moisture fed growing ice sheets.

"Compared to the most recent Ice Age, glacier coverage was much more extensive and, more importantly, much of the ocean was frozen," Xiao said.

Deep ocean water flows from the Antarctic could decline by 40% by 2050, according to a study published on Wednesday in the journal Nature.

The researcher, Ben Bacon, found that cave drawings were used to record details about the timing of animal reproductive cycles.

The discovery of the tools was the first direct proof of interaction between Ice Age humans and megafauna of the Pleistocene Era in the Basin of Mexico.