Evidence of historic marine life present in Alaskan permafrost is helping scientists reconstruct ancient changes in the ice cover over the Arctic Ocean.
Evidence of historic marine life present in Alaskan permafrost is helping scientists reconstruct ancient changes in the ice cover over the Arctic Ocean.
Hokkaido University researchers and colleagues have found that the Beaufort Sea, on the margin of the Arctic Ocean, was not completely frozen over during the coldest summers of the late Ice Age, some 12,800 years ago. Their methodology, using ice wedges from the Alaskan permafrost, could help scientists further reconstruct historic sea-ice conditions in the Arctic Ocean, and thus improve forecasts for the future.
Scientists have long studied ice core samples from large permanent ice masses in the Antarctic ice sheet around the South Pole, and in Greenland near the North Pole. These samples contain relics from our climate’s distant past, such as ions, dust particles, sea salts, volcanic ash and air bubbles, which can give us information on how Earth’s climate has changed over thousands and thousands of years.
Now, a research team led by Yoshinori Iizuka of Hokkaido University’s Institute of Low Temperature Science has found a way to investigate the geological history of areas near the north Arctic sea, which had previously been difficult using standard methods.
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Image: This map shows the current sea level around the Arctic region, with BIWS indicating the location of the ice wedges near Barrow, Alaska. Map provided by the Japan consortium for Arctic Environmental Research. (Credit: Iizuka Y. et al., Ion concentrations in ice wedges: An innovative approach to reconstruct past climate variability, Earth and Planetary Science Letters, March 26, 2019.)
