Tag Archives: Natural World

Watching a Glacier Die

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!

April 2014

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!

Castner Glacier Face April 2014
This was the glacial face (moraine) as I found it during my April 2014 visit. Clear, blue ice was found in the face, and particularly in the caves.
Castner Ice Cave Cathedral
Once you walked through the ice caves, this cathedral was found on the other side. I guess, based on my height in this picture compared to the ceilings, that the cave was 80 feet tall!
Castner Glacier Chimney
This chimney was found in the ceiling perhaps 20-30 feet above the glacier floor in April 2014. It was very narrow at the top, but the bottom is much wider than this picture would suggest. The icicles at its base suggest that some melting was occurring in it.

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!

August 2014

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.

Castner Glacier Collapse
When we returned in August 2014 we found the result of the constant rain over the summer. The chimney had melted so rapidly that the roof of the ice cave had collapsed.
Castner Glacier Ice Cave Backside
This image shows the degradation of the chimneys from the top and back of the glacier. Although I didn’t take an April 2014 photo for comparison, this image is especially revealing when compared to June 2015 (upcoming images)
Castner Ice Cave Scale
My parents stand next to the ice cave’s face for perspective. The large blocks that stood in front in April were now gone, and the top of the cave is much, much thinner than just three months earlier. 
Castner Ice Cave Front 2015
This image from the front of the caves shows a large section of ice which caved off the front. The scale and setting of this picture is similar to the April 2014 image of me standing in front of the broad ice cave.

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.

June 2015

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.

Castner Ice Cave Back June 2015
This image of the Castner Ice Cave was shot in June 2015 from the back. The thin, collapsed chunk of ice in the foreground is all that remains of most of the ceiling of the cave.


Castner Ice Cave Back Panorama
This image of the back of the Castner Ice Cave can be compared to the images taken in August 2014 and April 2014. The trailing edges of the large ice cathedral that I stood in can be seen in the back right. The arch of the glacier is thin, and a new chimney shows that it continues to degrade.
Castner Glacier Backside Panorama
The trailing edge of the ceiling on the right is all that is left of the ice cathedral from April 2014. Large piles of debris and silt have been deposited, and the floor where the cathedral was is much higher now.

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.