16. January 2009

First Ground Temperature Measurements from a deep borehole at Iškoras, Finnmark, northern Norway

Contact person for additional information: Herman Farbrot

Text and photos by Herman Farbrot and Ketil Isaksen

On September 25, 2008 , a 58.5 m deep borehole was drilled at Iškoras (69°18’N, 25°21’E, 595 m a.s.l.) in Finnmark, northern Norway, as part of the project PYRN-TSP (Permafrost Young Researchers Network’s, Contribution to the Thermal State of Permafrost Project in the Nordic Countries) [http://pyrn.ways.org/]. During drilling ground ice was detected (see photo below). Unlike the previous 10.7 m deep borehole at Iškoras (established September 2007) this new borehole is located in a 1.5-2 m top layer of fine-grained soil. The borehole was instrumented with a thermistor chain in the upper 10 m, which was connected to a Cambell datalogger. UTL-1 and UTL-3 Mini Temperature Dataloggers were installed at greater depths.

Clear ice collected during drilling at Iškoras on 25 September 2008.

At January 16, 2009 , the first ground temperatures were collected from the new borehole (see diagram below). Data showed that the temperatures close to the surface were -10°C. The measured temperatures between 3 and 55 m depth were all between −0.5 and 0°C. Hence, the borehole is situated in permafrost. During the visit, large areas of the mountain ridge, including the borehole site, were free of snow due to strong winds, as experienced during the BTS survey in early March 2008.

Temperature profile at Iškoras 16 January 2009.