Cruising for Information

What submerged sediments and microfossils can tell us about life on the Bering Land Bridge during the last Ice Age.

 

Social Media Links

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• UAF College of Natural Sciences Facebook
• UAF College of Natural Sciences Instagram
• R/V Sikuliaq Blog

During the last Ice Age, the Bering Land Bridge was an important migration corridor for plants, animals, and even humans moving between Eurasia and North America. But what was the environment of these lowlands like during the Ice Age? Was it frigid and windy, with only grass and herbs for animals to graze on? Or was it overcast and snowy, with small, woody trees? What happened when the Ice Age ended, the glaciers melted, and the sea level rose? How did the encroaching ocean affect the landscape? Were the coastal waters productive with sea weeds, fish, and marine mammals? How did sea ice affect the amount of rain that fell on nearby land?

A team of researchers hopes to answer these questions when they head out into the Bering Sea in August 2023 to retrieve sediment cores. They'll take these tubes of mud from the seafloor below the shallowest portions of the modern Bering Sea – the areas that we call the Bering Land Bridge. 

 

Meet the Team

 

The leaders of this project are palynologists, micropaleontologists, sedimentologists, and geophysicists from the University of Alaska Fairbanks (UAF) and the US Geological Survey (USGS).

They’re also sailing with a storyteller from UAF and a media intern from the Alaska Teen Media Institute who will take photos, shoot videos, and create social media posts. Check the social medial links at the top of this page to follow along!

 

What Each Scientist Does

• Palynologist - studies ancient pollen grains.
• Micropaleontologist - studies tiny fossils of plants & animals in sediments.
• Sedimentologist - studies how grains of sand and other detritus move around in the ocean or lakes and how they were deposited on the sea floor or lake bottom.
• Geophysicist - uses sound waves to create images of the layers underneath the sea floor so the other researchers can see what they're coring into.

 

R/V Sikuliaq

 

Sikuliaq in Seward.

Sarah Spanos

The research team will sail on the R/V Sikuliaq, an ocean-going research vessel designed to navigate the sometimes-icy waters off the coast of Alaska. The National Science Foundation (NSF) owns the ship and the College of Fisheries and Ocean Sciences at the University of Alaska Fairbanks operates it. The National Science Foundation also funded the cruise and research.

 

A core from the deep Bering Sea taken on a previous cruise.

Beth Caissie, US Geological Survey

What will they be doing?

Anything in the ocean—grains of sand or pollen, bits of skeletons from fish, tiny single-celled algae, etc.—eventually settles to the sea floor. The sea floor is made up of all these bits of detritus piling up year after year. The top of the sea floor is being deposited today. As you go deeper beneath the sea floor, the layers of sediment get older and older. The same process happens in lakes.

On this cruise, the scientists will take sediment cores. They aim to find marine sediments from the Bering Sea on top, evidence of the flooding of the land bridge underneath, and sediments from the Bering Land Bridge itself below all that.

 

The researchers will look for structures in the cores that can tell them whether the sediments were deposited in a lake, on a beach, or beneath the ocean. In addition, they’ll sample the cores and use microscopes to see the tiny pollen grains and fossil algae in the cores.

The types of pollen will tell them what the sort of vegetation was present on the Bering Land Bridge, and the fossil algae will allow them to figure out whether sea ice was present in the Bering Sea. The scientists will also use chemistry to determine characteristics of the seawater, like temperature and salinity, at different times in the geologic past.

 

Where are they going?

 

The planned route is shown by the yellow line. The researchers will be travelling to five basins in the Bering Sea (the blue/yellow blobs on the map). These are places they think were lakes during the last Ice Age when the Bering Land Bridge was exposed.

In each basin, they’ll take a set of cores along a specific path to try and get some from the edges and others from the centers of the ancient lakes. That way, they'll have some cores with a lot of marine sediments on top and some that have more lake sediments. Scientists with different types of expertise will be excited to explore what’s inside.

 

Join us!

(all times AK Daylight Time)

 

Living diatoms in sea ice. A type of single cell algae the searchers hope to find in sediment cores.

Beth Caissie, US Geological Survey

Junior Ranger Event

• August 4, 1 pm
• Ages 6-12
• Bering Land Bridge Visitor Center
• We’ll have hands on activities about coring and microfossils!

Live-stream From the Ship

• August 24, 12:00 noon
• Aimed at upper elementary and middle school students, but all are welcome.
• Tour the ship with the science team and learn how to collect sediment cores from the sea floor.

Registration Link

 

Bering Land Bridge National Preserve is excited to support the outreach efforts for this project. We’ll be following the team on their cruise and posting updates. Keep up to date on cruise activities by connecting to the Bering Land Bridge National Preserve social media platforms linked above, reading our blog, or getting daily emails! Email JR Ancheta ([e-mail]) to be added to the email list.