Sea Levels Plunge; Bering Land Bridge Opens

When the Ice Age peaked, so much water was trapped as ice on land that sea levels dropped by 350 feet. Large areas that are now underwater were dry land. The Florida Peninsula was twice as big as it is now. Land bridges were exposed between Alaska and Siberia (the Bering Land Bridge), and between Britain and France.

Megafauna Thrive in Cold Climate

Giant ground sloth

South of the great ice sheets, big animals (called megafauna) were plentiful. Giant beavers were as big as black bears, black bears were as big as grizzlies, and grizzlies were dwarfed by the short-faced bear. The giant beaver, short-faced bear and many other megafauna went extinct at the end of the Ice Age.

GIANT ICE
SHEETS COVER NORTHERN HEMISPHERE

North American ice sheets

When the Ice Age peaked some 21,000 years ago, giant glaciers at least a mile thick covered much of North America and Europe. Ice sheets were also present in Antarctica, Greenland, and Asia. Almost one-third of the present land surface of Earth was covered by ice.

Huge Lake Covers Western Utah

The Great Salt Lake is actually just a small remnant of a much larger lake, called Lake Bonneville, that covered what is now Salt Lake City and much of western Utah. Evidence of the ancient shoreline can be seen in the foothills above Salt Lake City. The giant lake was the result of higher precipitation in the area during the Ice Age.

Cold Wave Envelops the World

During the coldest part of the Ice Age, much of Earth experienced moderate cooling, but some areas were dramatically colder than they are today. Temperatures over the main North American ice sheet, for example, were up to 45 degrees Fahrenheit (26 degrees Celsius) colder than they are now.

North America Resembles African Savanna

Mammoths grazing on the Colorado plains

During the Ice Age, relatives of modern African animals—cheetahs, lions, camels, zebras, and elephants—lived in North America, earning it the nickname “Cold Serengeti.” Scientists think that some of these animals, like cheetahs and zebras, may have evolved first in North America and then spread to other parts of the world via land bridges.