New map shows land bridge between Russia and USA
The Bering Strait between Eurasia and North America was not always a waterway. 18,000 years ago, at the the peak of the last ice age, the area was open and connected the two continents. But the actually arctic area didn’t look very arctic either despite the conditions. A newly created map shows only very detail what the land bridge actually looked like.
When you reach the easternmost point of Russia or the westernmost point of the USA, you are facing the Bering Strait. This waterway, about 82 kilometers wide, is one of two entrances or exits to the Arctic Ocean and the closest connection, geographically at least, between North America and Russia and the rest of Asia. The regions of Chukotka (Russia) and Alaska (USA) can be counted as part of the Arctic, although neither corresponds to the general image of the Arctic. Only the annually returning sea ice and the wildlife with musk oxen, seals, whales and polar bears show that you are actually standing in the Arctic. But this division was not always so: 18,000 years ago, at the height of the last ice age, the sea level was about 120 meters lower than today. As a result, a land bridge existed in the region, also known as Beringia, through which animals, plants, and people could migrate to North America. What this landscape had looked like at that time, however, was only partially known so far. Now Jeffrey Bond of the Yukon Geological Survey has filled in a large part of that gap, creating and publishing the most detailed map of the Beringia Land Bridge to date.
The time was ripe for a new Beringia map, Jeffrey Bond explained. The 2008 map at the Yukon Beringia Interpretive Centre was no longer accurate, and he wanted to provide a better way to orient and display it for people visiting the center and learning about the people and animals of Beringia. The publication of two new data sets came in very handy. “These two freely available datasets, along with the glacier boundaries (distribution of ice during the last ice age), combined into a fantastic set of base layers to create a new map,” Bond told Live Science in an email. This resulted in a map that has a resolution between 100 meters and 1 kilometer per square. The nature of the records was also one of the reasons why the map represents the time 18,000 years ago. Because the bridge was formed about 30,000 years ago with the onset of glacial formations. It reached its peak 18,000 years ago, after which the ice began to retreat and sea level rose again.
18,000 years ago, Beringia was a cold and dry place, but it was still crisscrossed by rivers and some lakes. The plant life was tundra-like with vast grassy steppes and low woody plants, Bond said. This environment helped the megafauna thrive at the time. These included woolly mammoths, the Beringia lion, short-nosed bears, musk oxen, steppe bison, saber-toothed tigers, caribou and many other species according to the visitor center. These conditions also allowed the people who migrated from Asia to North America at that time to find enough food. But when, how and where along exactly this migration took place is still incomplete. Evidence may lie in the soil of the flooded land masses and thus remain hidden from the eyes of science for quite some time.
Heiner Kubny, PolarJournal
