Drop a few ice cubes in your drink before you start reading this, and consider the question : how many licks does it take to get to the center of a Tootsie Pop? Now, while you are thinking about that illusive answer, consider how many days it takes to melt a glacier. Just how fast does it happen? My several trips to Castner Glacier over the last 15 months provide interesting evidence into this impossible to answer question. Let’s take a look!
When I first visited Castner Glacier in April 2014 a monstrous, multi-chambered ice cave shook me to my core. The ice cathedral hung over my head an estimated 80 feet above. The walls and ceilings of it were composed of blue, transluscent layers of ice and closer inspection of the walls showed that the clarity of the ice provided a window deep into the glacier of the sediment suspended in it. A chimney was cut into its ceiling allowing light to illuminate the icy floor of the glacier. It was awe inspiring!
This video was taken in April 2014 during a walkthrough of the ice cave and captures the scope of it. Instability of parts of the video was due to the slippery ice floor!
The next time I visited the rainiest summer recorded in Fairbanks was coming to a close, and the rain had reshaped the ice in unimaginable ways. Water ran down the glacier in small rivulets and opened the chimney to a yawning mouth. It degraded the ceiling so extremely, that large chunks of the cavern had crashed down. If you stood close to the mouth of the cave many rocks fell dangerously from the ceiling as they melted from their icy tomb of thousands of years. The rapid melt had removed the beautiful transparency from the ice. It was now silty and gray.
The rapid melting that we witnessed inspired me to create a different type of video for Castner. This video documents the fall (August) stage of plant life around the glacier, and then documents the progression of drops of water from the glacier which eventually build into the silty and fast-flowing Castner Creek.
When I visited the Castner Ice Cave in June 2015, it was just a shadow of its former self. Only a small arch of ice remained of the once huge cave. Castner Creek ran through the remnant of the ice cave, where previously it had run to the side. In just fifteen months, unquantifiable amounts of ice from the glacier had transformed into water, carrying with it many tons of silt to the broader river valley that Castner Creek flowed into. The glacier was rapidly changing, dying.
The answer is two hundred fifty-two. At least that is what students at Purdue concluded to the center of a Tootsie Pop. But why does it matter that Alaska’s Castner Glacier and the state’s other glaciers are melting so rapidly? Alaska Dispatch News recently reported on a new study demonstrating that Alaskan Glaciers are losing 75 billion tons (75 gigatons) of ice each year, and that 94% of that loss is occurring on inland glaciers like Castner. This means that Alaskan glaciers will continue to contribute a significant amount to global sea level rise, especially in light of a warming climate. They end the article with a quote by study co-author O’Neel. “This is probably going to be a pretty tough year for a lot of the glaciers”, he stated. It appears he is right, and Castner’s included.