UAF researchers to study Bering Land Bridge for insight into climate, vegetation

ANCHORAGE, Alaska (KTUU) - A team of Alaskan scientists have been given the green light to research the area that was at one point the Bering Land Bridge.

The area they are studying is in the northwestern part of Alaska. Right now, it’s covered by the ocean, but that wasn’t always the case.

“During the Ice Ages, when a lot of the world’s water was tied up in ice sheets, sea level was lower,” said Sarah Fowell, a University of Alaska Fairbanks Department of Geosciences professor and the project’s lead investigator. “And that area was above sea level, so that animals could, if they wanted to, walk from Alaska to the Russian Far East, or come from Eastern Asia to North America.”

The team of researchers are going to spend a month sailing over the area while collecting core samples to find out exactly what was there.

Fowell said both plants and animals made their way across the land bridge.

“But some did not, and that’s something that puzzles us still,” she said. “We understand very little about the conditions on the lowlands of the Bering Land Bridge because it’s so hard to get at.”

Fowell said there would have been ice in the area, but from what they know, the animals would have mostly been on vegetated land.

She said from north to south, at times the land bridge was about 1,000 miles wide. She said east to west, it was fairly narrow near the Bering Strait, but some areas farther south had around 500 miles of crossing.

“The animals didn’t know there was anything on the other side. They lived there,” she said. “So there were clearly things for them to eat.”

Fowell said it was a fairly arid climate, so it was relatively ice free. Scientists think it was cold enough for ice sheets, but that there wasn’t enough snow to feed those ice sheets.

Fowell described what the sample collection process will look like during the project.

“A core is usually a tube, something like 2 and 1/2, 3 inches in diameter,” she said.

The scientists will push the tube into the sediment on the bottom of the Bering Sea.

“You pull it back out, and you’ve got a continuous record of sediment that’s accumulated,” Fowell said. “In our case, we’re looking for sediment from the last maybe 25,000 years, from ... the peak of the last ice age until the present.”

The mud-filled tube is then sliced open vertically to see and sample the layers, each one from a different time in Earth’s history.

“As climate changes, the vegetation changes. What plants can live there is going to change,” Fowell said. “And so looking at past vegetation changes can give us an idea of what the climate was like and how it was changing over time.”

Fowell is very interested in the vegetation in the Bering Land Bridge because it may help explain why some animals lived there and crossed the land bridge, while others did not.

She said, for example, wooly mammoths crossed over from Asia, but wooly rhinos didn’t. Her team hopes to find evidence to why. During the time-period the team is studying, humans would have been crossing from Eastern Asia, Fowell said.

“We are not looking for human remains or evidence of humans. We’re not going to recover that,” she said.

“We’ll be looking at the vegetation at a time when people would have been living on the lowlands of the Bering Land Bridge, and maybe at least can answer some questions about what resources were available to them, as well as other animals on the land bridge,” Fowell continued.

The team hopes to be in the area in the summer of 2023, but ahead of time, they also plan to talk with surrounding communities to hear their wishes and concerns.

Fowell said the National Science Foundation is funding the research.

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