Columbia Glacier - Before
The Columbia Glacier, which is located on the southeastern coast of Alaska, is called a tidewater glacier, meaning it flows directly into the sea, according to NASA's Earth Observatory. In 1794, British explorers surveyed the glacier, showing its nose (called the terminus) jutted out to the northern edge of Heather Island, near the mouth of Columbia Bay, the Earth Observatory reported. "The glacier held that position until 1980, when it began a rapid retreat that continues today," said the Earth Observatory. This image shows the glacier in 2009.
Columbia Glacier - After
Between 2009 and 2015, the Columbia Glacier retreated by a whopping 4 miles (6.5 kilometers), the study researchers said.