Samples of snow, ice and associated life forms are collected by dislodging the crystals or biota from the face of a snow pit or the surface of the snow onto copper metal sample plates containing precooled methyl cellulose solution. Within fractions of a second these plates are plunged into a reservoir of liquid nitrogen which rapidly cools them to -196°C and attaches these pre-frozen materials to the plates. Due to the low surface tension of liquid nitrogen and the extreme hardness of materials cooled to these temperatures, very fragile samples can be shipped by aircraft, in dry shipping dewars from study sites throughout the US.
Posted on: Tue, 27 Jan 2015 10:30:44 +0000
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