Saturday, August 18, 2012

Pulling out of Nuuk

For the past three years we had an NSF funded study to look at ice-ocean interaction in the Nuuk fjords. This is the final year, and last week we had to pull all our equipment of the glacier. This consisted of a series of GPS receivers, seismic equipment and some cameras. Some of this equipment has operated year-round and needed quite a bit of battery power. All in all, we moved about 2,000 kg of material back. Nuuk is the capital of Greenland, and by far the biggest town. While the small settlements all around Greenland are slowly dwindling, Nuuk grows at an incredible pace. It has a good harbor, but the site for the town was chosen before the advent of airplanes, and access by air is hampered by frequent fog, heavy cross wind, and the topography, which only allows for a very short runway, which is serviced by relatively small Dash-7 (nowadays Dash-8) aircraft. 

Nuuk, Greenland's capital

Nuuk's short runway
We used an Air Greenland Bell 212 to remove our survey equipment

The main glacier entering the fjord system is Kangiata Nunata Sermia. In summer it often has a small area in front of the ice where dirty subglacial water upwells, bringing lots of nutrients with it. The birds love it and frequently feed there.

The small dots over the water are hundreds of birds looking for a meal

Some of the water entering the fjords come from the numerous ice marginal lakes that frequently drain under the ice. This one, at KNS, was first reported on by Nansen. He walked off the ice sheet at this location after the first documented crossing.
This ice-marginal lake at Narssap Sermia is huge. It drains every few years. As the glacier is thinning, lake drainages are likely to become more frequent, but perhaps also not as  large. This one drained subglacially a few years ago. When the fresh water rose to the surface of the ocean, it carried many redfish with it. The sudden pressure change killed many of them and they were found belly-up.

The fjord was also popular for native and old Norse settlements. The Norse lived in Greenland for several centuries and somewhat mysteriously disappeared when the climate turned less favorable. Many sites still show rock walls and traces of settlements that can be traced to them.

Norse ruins in the ice fjord
Nowadays, there is only one small settlement in the fjord: Kapissillit. It can be reached year-round, because it is situated in a protected fjord that often does not have heavy sea ice.

Friday, August 10, 2012

Jakobshavn Isbrae, Greenland

I'm back in Greenland for two different project. First we went to Ilulissat on the West Coast to use a new ground based radar for measuring the speed of the world's fastest glacier: Jakobshavn Isbrae. The glacier continues to retreat and is now as far back as it has been since observations started. It is also flowing very fast, with speeds exceeding 50 meters per day at the front.

Ilulissat on a nice evening
Ilulissat: City of icebergs

Our camp on recently deglaciated land
Not much lives here, but we do get an occasional visitor

Gamma Remote Sensing's ground based radar

One thing we are interested in is how the speed of the glacier changes when it calves into the ocean. In the field, we run cameras at high intervals (10 seconds) to capture calving events. In past years, these events have been dramatic. Now they seem to be smaller, but much more frequent. Here is one calving event. The light is a bit low, since it happened at 2 AM.