The Thwaites Glacier on Antarctica adds about 4% to sea level rise every year as it melts. The ice loss of the glacier, also known as the Doomsday Glacier, has doubled in the last 30 years and has some scientists thinking it could run out of control and raise sea levels by two feet over the next 100 years. "We have satellites that, flown overhead and using magnetism, can tell the size of the ice mass," said Dr. Abbott who is a Professor of Geology Emeritus at San Diego State University. He says this is extremely important when it comes to the Thwaites Glacier in the Antarctic. "The ocean water there is cold, 34° to 35° but that's warmer than the ice, therefore, accelerating the melting of the ice that's floating on the ocean." The ice on the ocean's surface is over 2,000 feet thick and is what is holding the Thwaites Glacier from flowing into the ocean, think of it like a dike or dam. "The hundreds of feet thickness on ice floating there against the glacier on land helps make it stay on land. If you take that ice off there's nothing to hold the glacier on land, it flows downhill and into the ocean," explained Dr. Abbott. With the ice sheet gone, the melting rate could run out of control which is why it's called the Doomsday Glacier and has scientists concerned. MORE: https://www.cbs8.com/article/news/local/outreach/earth8/doomsday-glacier/509-e77d872b-a35f-4ea5-9546-e54f6232b1f4