In this NASA satellite image, ice fills the Bering Strait between Alaska and Russia, moving south to the Bering Sea.
Click on image for full size
Image courtesy of NASA
Global Ice Age Climate Patterns Influenced by Bering Strait
News story originally written on January 10, 2010
Sometimes, a small change in the Earth can lead to a big change in climate.
A new study shows that changes in the Bering Strait might have affected ocean currents and climate worldwide thousands of years ago.
The Bering Strait is a narrow waterway between Russia and Alaska that connects the Atlantic and Pacific Oceans. It allows water to flow from the Pacific to the Atlantic.
Scientists used a computer model to study how the Bering Strait affected climate starting about 116,000 years ago when odd cycles of cooling and warming happened over and over.
In the model, as climate cooled because of changes in Earth's orbit, ice sheets grew. This caused sea level to fall, nearly closing the Bering Strait.
Without the fresher waters of the Pacific flowing in, the Atlantic Ocean water grew saltier. The dense, salty water dropped low in the ocean, which allowed a current carrying warm water from the tropics to speed up. The water warmed Greenland and parts of North America enough to, over thousands of years, melt ice sheets and raise sea level, reforming the Bering Strait.
With the Bering Strait, fresher water could once again flow from the Pacific to the Atlantic. The fresher water weakened the current bringing warm water from the topics. Without the warmer water, North America and Greenland became cooler. The ice sheets grew again and sea level dropped. The Bering Strait mostly closed and the entire cycle was repeated.
The pattern was finally broken about 34,000 years ago, when a natural orbital cycle made Earth farther from the Sun during Northern Hemisphere winter, causing more cooling so that the ice sheets continued to grow even when the Bering Strait closed.
Last modified February 19, 2010 by Lisa Gardiner.
Shop Windows to the Universe Science Store!
Our online store
on science education, ranging from evolution
, classroom research
, and the need for science and math literacy
You might also be interested in:
To figure out the future of climate change, scientists need tools to measure how Earth responds to change. Some of these tools are global climate models. Using models, scientists can better understand...more
For a glacier to develop, the amount of snow that falls must be more than the amount of snow that melts each year. This means that glaciers are only found in places where a large amount of snow falls each...more
Measuring sea level, the height of the ocean surface, allows scientists to calculate whether sea level is changing over time and how much sea level rise is happening now because of global warming. But...more
The world has several oceans, the Pacific, the Atlantic, the Indian, the Arctic, and the Southern Ocean. While we have different names for them, they are not really separate. There are not walls between...more
Scientists have learned that Mount Hood, Oregon's tallest mountain, has erupted in the past due to the mixing of two different types of magma. "The data will help give us a better road map to what a future...more
The Earth's mantle is a rocky, solid shell that is between the Earth's crust and the outer core, and makes up about 84 percent of the Earth's volume. The mantle is made up of many distinct portions or...more
Some geologic faults that appear strong and stable, slip and slide like weak faults, causing earthquakes. Scientists have been looking at one of these faults in a new way to figure out why. In theory,...more