Glaciers Video Transcript
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Gordon Hamilton, Research Assistant Professor, UMaine Climate Change Institute:

The study took place in East Greenland, along the coast between latitude 74 north and 66 degrees north. We set sail from northwest iceland, sailing for four days across the Denmark straits and then started our work on one of the large fjord systems. The purpose of our work was to understand the flow dynamics of large outlet glaciers that drain the ice sheet. These outlet glaciers are the main corridors that transport ice from the interior of the ice sheet to the ocean. We studied five glaciers in total and we had some extremely interesting results. The three northernmost glaciers seem to be in the same flow configuration as they were when they were first studied by our Danish colleagues back in the 1960s. Then, when we moved farther south, we noticed very quickly that things changed dramatically since the last satellite images were acquired two years ago. The fronts had retreated about five kilometers and after we had a chance to study the velocity over the course of a few days, we discovered that they had accelerated about three times faster than their normal speed.

Leigh Stearns, Ph.D. Candidate, Earth Sciences:

We were very surprised to see all those changes. We had an idea where the front of the glacier would be and when we got there, it was 3 1/2 miles farther back. We were sort of floored.

Gordon Hamilton:

These glaciers were already moving fast--about five kilometers a year--but one of them has accelerated to about 14 kilometers a year, so it's about a three-fold increase in speed. That translates into about half a football field of motion per day. So, it's a lot of ice that's being transported off the ice sheet faster than it was just a summer or two ago.

Leigh Stearns:

We often think of glaciers moving very slowly and changing very slowly to climate systems or conditions of the bed, but to see these changes happening in a year or two or three, that's pretty dramatic and it sort of adjusts our sense of how to model, how to predict and how to make hypotheses if we have to shorten our time scale.

Gordon Hamilton:

We studied five glaciers and we're always sort of nervous about extrapolating to other places, but when we see, especially in the south, two glaciers exhibiting the same kind of behavior, then that gives us a basis to make predictions for other parts of the Greenland ice sheet. The most likely scenario is that there has been a regional warming in this part of Greenland and the generation of more meltwater is allowing the glaciers to slide faster over their beds. Of course, that doesn't tell us anything about what the cause of the regional warming is but the scientific consensus is that it's a human-induced event.

Leigh Stearns:

If it is from warming and this warming trend is continuing to progress north, then it's possible that similar events will happen to other glaciers in Greenland. That has huge implication for sea-level rise and the status and stability of the Greenland ice sheet.