A bit of ingenuity and voilà: radar profiles from Sorbreen

Friday, March 19 Sun-Ulla, -11 C

Having completed all my goals yesterday, I’m now  available to help my colleagues. This morning on the glacier is devoted to the laying of new tags on Sorbreen ablation. John’s steam drill was easily transportable on the sledge. It is simply a probe connected by a rubber tube to an aluminum container. The water is heated by propane gas. Providing the water does not refreeze around the tube, a hole ten feet deep is dug effortlessly in few minutes. We can then place a long aluminum stakes which length will be measured annually from the surface to know the rate of removal in this area of the glacier.

Johan, aluminum stake and John

After “a traditional lunch of glaciologists”, a portion of freeze-dried food, Johan returns to the cabin Ulla (which is only quarter of an hour of scooter and relatively easy to access from the beach) where Anna remained feverish today.  Despite this and determined to return with new radar profiles from Sorbreen, she finds the strength to start the high frequency antenna and explain the main controls to Johan.

Johan and I constitute a team throughout the afternoon to browse the glacier upstream to downstream. I drive the scooter at regular speed and as slow as possible (5km / h) to allow radar waves to make the round trip between the horizons of the sub surface and the receptor. Johan, who is very tall, has found a place on the little sledge that carries the computer and control the radar signal.

The antenna is placed in a plastic pulkka (small sledge) fixed laterally to the sled with ropes and tags. C'est parfait !

Finally, the small antenna GPR (Ground Penetrating Radar) is moored to sled and slides on the snow. This facility is not ideal: almost every turn, the antenna is reversed upside down when it passes through the grooves of the scooter and forces us to interrupt the action frequently. Fortunately Johan has appealed his ingenuity to develop a more stable installation.

There is virtually no wind and sunglasses are indispensable today. Our vision is to infinity and with a little imagination we could almost see the Icelandic coast! How couldn’t we acknowledge the privilege of exercising our job at the heart of such a breathtaking nature. To perfect  the moment and since the percentage of the slope allows, I cut the motor of the scooter and control the speed only with the brake. Glancing in the mirror, I see that Johan, seated with his back turned to the sea and facing the glacier, also relishes the moment along with a rice cake that he had kept in his jacket all day. At this price, we could drive the radar on the whole mountain!

Johan has found a place on the little sled that carries the computer and control the radar signal

I think today’s results that we proudly showed to Anna in the evening aid to cure her.

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2 Responses to “A bit of ingenuity and voilà: radar profiles from Sorbreen”

  1. Jeffrey Alpis Says:

    I am searching for RSS feeds for my new blog I’m starting and found yours. Will you be writing more on this? It’s always good to find quality information on this subject. Thanks again.

  2. arcticcentre Says:

    Hello Jeffrey,

    thanks for your interest and for commenting on my blog. Since you commented the posting about our radar settings on Jan Mayen, I guess you are interested in getting further information about snow radar measurments? Unfortunately I won’t write more about that topic online. In a near future (hopefully this year!), I will update the Jan Mayen blog with the main results from the chemical analysis of the ice core and the snow we sampled there. So I will stay on the “chemistry” side of our investigations on that island.

    However, I can recommand you to check some other blogs about glaciological fieldworks that dealed with geophysical and geochemical measurments on glaciers:

    http://www.kinnvika.net
    http://traverse.npolar.no/spatial-extents/shallow-radar/
    http://traverse.npolar.no/technology-for-science/gpr-sar-comparison
    http://traverse.npolar.no/expedition-diary/archive/2009/01/15/report-from-the-rock

    But of course, you can always contact Anna, the “radar specialist” of our Jan Mayen team.

    Hoping this would help you in gathering informations.

    Arctic greetings,

    Emilie

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