Heat flow measurements were taken through an ice hole sheltered by the U.S. Geological Survey's hydrohut. T-3 Ice Island, Arctic. 1969.

Caption: Heat flow measurements were taken through an ice hole sheltered by the U.S. Geological Survey's Hydrohut, here shown in April 1969. The hydrohut was tall at one end to accommodate extracting a 3 to 4 meter-long piston corer/heat flow probe using a winch system. Pressure ridges developed in the pack ice adjacent to the T-3 glacial ice are visible in the background. Photo by D. Scoboria, USGS. Note: Dave Scoboria was a USGS field assistant (and the only USGS presence on the island--solely responsible for the measurements) for part of 1968 and 1969.