A new study that reconstructs the history of sea level at the Bering Strait shows that the Bering Land Bridge connecting Asia to North America did not emerge until around 35,700 years ago, less than 10,000 years before the height of the last ice age (known as the Last Glacial Maximum).
A new study that reconstructs the history of sea level at the Bering Strait shows that the Bering Land Bridge connecting Asia to North America did not emerge until around 35,700 years ago, less than 10,000 years before the height of the last ice age (known as the Last Glacial Maximum).
The new findings, published the week of December 26 in Proceedings of the National Academy of Sciences, indicate that the growth of the ice sheets—and the resulting drop in sea level—occurred surprisingly quickly and much later in the glacial cycle than previous studies had suggested.
« It means that more than 50% of the global ice volume at the Last Glacial Maximum grew after 46,000 years ago, » said Tamara Pico, assistant professor of Earth and planetary sciences at UC Santa Cruz and a corresponding author of the paper. « This is important for understanding the feedbacks between climate and ice sheets, because it implies that there was a substantial delay in the development of ice sheets after global temperatures dropped. »
Global sea levels drop during ice ages as more and more of Earth’s water gets locked up in massive ice sheets, but the timing of these processes has been hard to pin down. During the Last Glacial Maximum, which lasted from about 26,500 to 19,000 years ago, ice sheets covered large areas of North America.
