Banquise dans toutes ses épaisseurs

  • CTD avec Aurore et Leonie

Sun is making himself wanted. Monday, he could almost come above the mountains which are slightly raising up our south horizon. Nearby summits were pink, sunny. But yesterday, the sky was entirely cloudy!

Fascinating exchanges are going on with researchers, trying to better understand why ice is so thin at some places. In the middle of South Cape Fiord, ice is barely more than 50cm thick, and it is not much increasing, while around the boat (near the northern shore of the fiord), ice is 1.10m thick and is increasing according to laws of physics. There is probably major currents in the fiord, bringing warmer waters from the ocean or from the glacier, slowing down ice growth.

Larger-scale measurements are needed now to have a better idea of ice thickness in the area. This is why I set up the icemeter (EM31) on the sledge last Sunday, when doing a return trip to Grise Fiord (appointment with the dentist, better not to miss it as there is one in town only a few times a year!). 110 kilometres done, more results soon.

Then, to check calibration of the CTD's temperature sensor, the probe was plunged into a barrel filled with fresh water vigorously mixed with iceberg chips. Measured temperature: +0.06°C.

Another test was done by leaving the CTD under the ice for about 15 minutes near the boat, where conditions should be close to freezing: temperature = -1.64°C, salinity = 31.98psu. Investigation to be continued.

It was not too cold yesterday (-20°C), because of the clouds, then for the first time, all the family joined the middle of the fiord for scientific routines! Six months ago, at the same place, we were watching from Vagabond's deck narwhals, hundreds of Harp seals, and many birds. What a difference with quiet winter! For sure, South Cape Fiord waters are rich.