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The Crown of the Continent
Understanding Glaciers
As parts of our country experience record-breaking heat, it might be hard to imagine the entire planet covered in ice. But Earth has undergone many ice ages, and some scientists have even hypothesized that it might have been wholly coated in ice at points in our planet’s history. Glaciers are helping climate scientists and glaciologists unearth the secrets behind climate change through the retreating and advancing of Earth’s ice.
Glaciers are masses of ice formed by the accretion of snowfall compacted over time. Unlike permanent snowbanks, glaciers are so large that they flow under their own weight, slowly moving across the landscape. The glaciers currently on Earth began developing about 34 million years ago, beginning in Antarctica. Glaciologists believe their formation was likely precipitated by the emergence of the Himalayan mountains.
Glaciers cover about 10% of Earth’s land area and are the largest reserve of fresh water on the planet (about 2% of water is frozen in glaciers). Within the United States, glaciers can be found in Alaska, at Glacier Bay National Park and Preserve and Wrangell St. Elias National Park and Preserve, at Mount Rainier National Park in Washington, and within Montana’s Glacier National Park, often called the Crown of the Continent.
The Glaciers of Glacier
Glacier National Park was established on May 11, 1910. The Park was named for the glaciers within its boundaries and their role in sculpting the landscape. Glaciers in the Pleistocene are responsible for the Park’s terrain. These slow-moving ice behemoths carved the Park’s sweeping valleys and helped hone its distinctive peaks, like the Garden Wall arête.
Roughly 20,000 years ago, the entire Park and surrounding areas were encased in glaciers, with only the highest mountain peaks free from the ice. Glaciers currently within the Park are estimated to be about 7,000 years old. According to the United States Geological Survey, “at the end of the Little Ice Age around 1850, there were about 80 glaciers in what would eventually become Glacier National Park,” just sixty years before the Park was established.
In the intervening century, that number has been reduced to 26.3. The remaining glaciers are all monitored closely using field data, local photography, and satellite images to track changes in their mass and location. In 2015, it was determined that all of the glaciers within the Park had shrunk, some by more than 80% in the past few decades. Despite fears that the Park may eventually lose its namesake, the glaciers have proven resilient and continue to endure despite changes in our climate.
References:
Marshall, Michael. “The History of Ice on Earth.” New Scientist, 24 May 2010.
“Glacier" National Geographic Society.
“Overview of Glacier National Park's Glaciers,” National Parks Service, U.S. Department of the Interior.
Northern Rocky Mountain Science Center. “Brief History of Glaciers in Glacier National Park Active.” Brief History of Glaciers in Glacier National Park | U.S. Geological Survey, 6 Apr. 2016.