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Ellen McCallie's Diary

Days 23 & 24: Speed and Melt of the Glacier

Up at 8 am. I felt pretty good but beating a bacterial infection without antibiotics is a long, painful road. I was at the doctor's office by 8:45. My appointment wasn't until 9:30 am, but I was hoping the doctor might take pity on me. He did, so I was able to meet the rest of the group and we headed up to the terminal face of the glacier to do our measurements.

It may seem silly, but I was so excited to actually see what happened with our two setups. These aren't scientific experiments: no controls, treatments, etc. Instead, we are making observations and measuring what we see — very exciting all the same. I wanted to run to the terminal face and round the corner just to see if there were sticks on the ground, having melted out of the glacier. Logically, I knew that at least one stick, representing a two-centimeter melt, would be on the ground, but I've never seen direct evidence of a glacier moving, so I was excited to see it for myself.

Yes, I rounded the corner and saw two sticks on the ground and the third having fallen over. I said on camera that it was about 6 cm. Actually, it was more like 5 cm, as the third stick had not fallen through yet. I got a bit excited and exaggerated unintentionally. Not only did the ice melt 5 cm in length, it melted about 3 cm downwards.

Photo: glacierHow was I so sure there would be melt? Basically, the terminal face of this glacier is below snowline. The ground is not cold enough to keep things on it frozen, plus the sun is beating down from above. Thus, there is melting everyday. Mike B, Kate and I documented that in the last two days 5 cm of ice have melted off the terminal face.

Kate then asked if we now knew the glacier was retreating — nope, we didn't until we looked at where the glacier was in relation to a fixed point, in this case, bedrock. If the glacier was moving downhill at a rate of 5 cm every two days, then the measurement Mike B set up would be exactly as it was two days prior. If the glacier was moving downhill faster than 5 cm every two days, then the broomstick and nail would not have been straight. If, as was the case, the glacial ice was melting faster than the glacier was moving downhill, then it would appear that the glacier backed up — it actually just melted more than it moved forwards. (Glaciers, like rivers, don't flow upstream.) Cool, cool result.

Photo: Ellen with handwarmerIn terms of the other team, it sounded like everyone had a fabulous time up on the glacier overnight. Their measurements were really good as well. It was fun to hear that a real glaciologist studying this glacier using satellite images got results nearly identical to ours.

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Photo: Ellen McCallie
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