New map of Beringia 'opens your imagination' to what landscape looked like 18,000 years ago

Thousands of years ago, a stretch of land connected the continents of Asia and North America, in the place the Bering Strait now occupies.

The Bering land bridge was exposed at various times over an almostthree million year period, when wide scaleglaciationlowered sea levels by as much as 150 metres. The land bridge was part of"Beringia," which refers to the stretch of land between present day Siberia and Yukon Territory.It'sbeen home towoolly mammoths,steppe bison and humans.

Now, researchers have a better idea of what this region looked like and how our ancientrelatives used the landscape.

Jeff Bond, a geologist with Yukon Geological Survey in Whitehorse, has produced a map showing whatBeringialooked like 18,000 years ago. At that time,much of the earth was glaciated, butBeringiaremained predominantly ice-free due to its arid climate.

Bond compiled the map using sea floor data from the University of Alaska Fairbanks.

"The bathymetrydata is the most currentcompilationavailable," he said. "So yeah, it's really I think the most detailed reconstruction of the land bridge that's been put together to date."

Bond said the data are accurate down to about one square kilometrein most places.

"It's not super detailed, but we're talking about a big landscape. It's over 1,500 kilometres across."

He said some areas have a 100square metreresolution.

Human migration moved east across bridge

This is the first time the lakes and rivers ofBeringiahave been mapped.Bond said knowing more about the topography, including where the majordrainagesand highlands were, could tell us more about how humans used the landscape.

"I think these waterways would be very significant in terms of campsites, places whichwouldhave maybe impeded peoples'migration ordispersionacross the land bridge."

Bond created the map to be used in an exhibit at the BeringiaCentre, a museum in Whitehorse.

Information on the centre'swebsitesays the earliest evidence of people in the Arctic region dates to about 35,000 years agoin northern Siberia. It says people moved eastward and eventuallyacrossthe land bridge. The first evidence of people in the Yukon dates back 15,000 years,although recent research says it might have been much earlier than that.

"It's the story between 35,000 yearago and 15,000 years ago that is very intriguing," said JulieBrigham-Grette, a geologist at the University of Massachusetts who helped Bond with the map.

"Where did they go, how did they live, why did they migrate?

"Maps like this really open your imagination to what these landscapes must have been like," she said.

Brigham-Grette, whohas been studying the land bridge for decades, helped Bond make sure the map is accurate, particularly with regards to thedistribution of glaciers. Bond saidthe map shows the most current understanding of icedistributionalong the border ofBeringia.

Brigham-Grette saidthe lack of ice means people could have travelled along the coast.

"There are ideas that early humans were using boats ... and maybe they were migrating along that coastline," she explained.

"Some questions we may never have an answer for but [the map] ... is just wonderful eye candy."

Although Beringia is now covered by water, Bond says it might be possible for underwater archeologists to find out more about the people who lived there.

"Perhaps this map will give some marine archeologists some ideas about where to investigate the landscape for archeological sites," he said.

The map is available online or through Yukon Geological Survey in Whitehorse.