DENVER — It took the better part of a decade, $10 million, and help from the guys who build ice roads for Canadian truckers. But scientists now have the most continuous record of ancient climate ever extracted from the terrestrial Arctic.
What’s more, the record — cored through sediment layers at the bottom of a lake in northeastern Siberia — also illuminates what happened when a big meteorite smashed into the spot 3.6 million years ago, when the ground was warmer and forested as opposed to the barren tundra it is today. Water filled the resulting crater and formed Lake El’gygytgyn (pronounced EL-gih-git-gin).
“We’re really pleased that we have a complete record of that entire time period,” said Julie Brigham-Grette, a geologist at the University of Massachusetts at Amherst and one of the project’s leaders. She described the findings in Denver on October 31 at the annual meeting of the Geological Society of America.
Analysis of the lake cores is revealing details of how the Arctic landscape warmed and cooled over the past several million years, she said. Comparing similar data from the Arctic Ocean and Antarctica can show how the two polar regions — which are more sensitive to climate change than temperate or tropical latitudes — react differently to changing temperatures.