When Mark Abbott and his team pulled a 300-foot-long core of mud from a lakebed high in the Peruvian Andes, he hoped it might provide a long-sought-after glimpse of the past 160,000 years of climate change.
Instead, the researchers revealed July 13 in the journal Nature, that lakebed recorded the ebb and flow of glaciers for more than 700,000 years — the longest-ever glacier record for the tropics, and among the longest records of historical climate, full stop. In that lake mud, the multi-institution team found clues for how climate change may shape the modern-day world.
“This is unlike anything we had before,” said Abbott, a geology and environmental science professor in the University of Pittsburgh’s Kenneth P. Dietrich School of Arts and Sciences. “We now have a land-based record of glaciation from the tropics that is in many ways equal to our records from the ice caps at the poles and from the ocean, and that’s really been lacking.”
Researchers have known for decades that Lake Junin is a rare gem. Situated more than 13,000 feet above sea level in the Andes, the lake meets all the right conditions to archive the shifting glacial epochs: It’s close enough to glaciers that it catches sediment and water that flows down the mountains, but distant enough to have not been overrun by glaciers itself since it formed. Having avoided disruption by millennia of churning ice, the lake’s sediments remain stacked in order by the year they were laid down like the pages of a history book.
Read more at University of Pittsburgh
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