This zipped file contains the borehole temperature measurements acquired in permafrost regions of arctic Alaska between 1950 and 1988 by the U.S. Geological Survey. A large number of the 87 sites (boreholes) represented in this dataset are deep enough to penetrate the base of permafrost.
Max Brewer was the principal investigator prior to 1956. Art Lachenbruch then led the Alaska effort through 1989. Data collection methods changed considerably during this time period.
The methods utilized by the U.S. Geological Survey to measure subsurface temperatures have evolved considerably over the years. Although some of the early measurements were obtained using thermistor strings frozen into permafrost, the vast majority of the measurements were made in fluid-filled holes using a custom temperature sensor. A typical sensor used in Alaska prior to 1989 consisted of a series-parallel network of 20 thermistors; see Sass et al.  for a more detailed description. During a logging experiment, the resistance of the thermistor network was determined using a Wheatstone bridge prior to 1967. After that time, a 4-wire resistance measurement was made using a commercial 5.5-digit multimeter (DMM). Before 1984, boreholes were logged in the "incremental" or "stop-and-go" modes; the vertical spacing of the measurements was typically 3-15 m. Beginning in 1984, the depth/resistance measurements were automatically stored on magnetic tape, allowing boreholes to be logged in the "continuous" mode; the typical data spacing for the continuous temperature logs was 0.3 m (1 ft). Many of the Alaskan boreholes were relogged several times to quantify the thermal disturbance caused by drilling the holes (see Lachenbruch and Brewer ). A review of current temperature measuring techniques used by the USGS in the polar regions is given by Clow et al. .
Clow, G.D., R.W. Saltus, and E.D. Waddington (1996): A new high-precision borehole-temperature logging system used at GISP2, Greenland, and Taylor Dome, Antarctica, J. Glaciology, vol. 42, 576-584.
Lachenbruch, A.H. and M.C. Brewer (1959): Dissipation of the temperature effect of drilling a well in Arctic Alaska, U.S. Geological Survey Bulletin 1083-C, 109 pp.
Sass, J.H., A.H. Lachenbruch, R.J. Munroe, G.W. Greene, and T.H. Moses, Jr. (1971): "Heat Flow in the Western United States", J. Geophys. Res., vol. 76, 6376-6413.
Gary Clow has been the principal investigator since 1989. For further information, contact Gary Clow.
Log files (ending in .log) in the directory contain the dates of measurement in their filenames. Files ending in .site contain location, depth, and other information about the site.
Click on title to download individual files attached to this item.
“U.S. Geological Survey's Borehole Temperature Logs from Arctic Alaska, pre-1989”