Alaska geologists dig into Bering Sea’s past storms to understand future ones

Coastal Alaska is on the front lines of climate change. Extreme weather events like Typhoon Merbok that pummeled western Alaska last fall are becoming more common. And many communities along Alaska’s shores are wondering if the future will bring more of the same.

The Arctic Coastal Geoscience Lab at the University of Alaska Fairbanks has spent the last four years trying to answer that question — what storms might look like in the future. They’re doing that by looking into the past.

“You’ve often heard that story that the past is the key to the future,” said Chris Maio, the lab’s director. “And so in geology and understanding coastal changes, we’re really looking into the past through sediment cores.”

Sediment cores are cylindrical sections that scientists extract from the earth’s crust. The UAF researchers use a piston core to insert a long pipe into the seafloor and pull out a tube of earth, which displays the varying strata.

Under normal conditions, the sediment in bays and fjords around the Aleutians is very fine-grained, like silt or mud. But when a storm comes in, it churns up the ocean and moves larger sediment.

Scientists can see those layers in the core and use radiocarbon dating to determine when an event occurred.

“We can look hundreds of years into the past and understand how many big storms were occurring each century,” Maio said. “Were the storms occurring because of regional or global climate changes, warming events or things like that?”

Reyce Bogardus has worked alongside Maio since the project’s beginning in 2021. He described it as a sort of timeline of major storms in the Bering Sea.

“We’re building an archive of storminess,” Bogardus said. “The crux of the project is to extend our record of storms in the region — we’re trying to get at storminess thousands of years in the past to learn about the future.”

The crew recently returned from a trip to Atka Island, where they worked with the local tribe to extract about a dozen cores. Next, they’ll ship those samples to the lab for carbon dating.

The team is planning another trip to the Aleutians during summer 2024. They hope to complete the final project by 2025.