John B. Townshend 1978 <p>The operation of the Barrow, Alaska, magnetic observatory (lat. 71.32°N, long. 156.62°W) has been complicated because foundations for the instrument piers must be constructed on permafrost. Better understanding of environmental conditions and the availability of more modern instrumentation since the original construction have led to the design and construction of new piers to provide a more stable platform for the absolute and recording instruments. In May 1975, a digital- and analog-recording fluxgate and proton magnetometer system was installed to replace a conventional magnetograph. These changes in construction and recording instrumentation were made to permit unmanned operation, to provide digital data, and to improve the quality of the data collected. Nearly two years of observations under the new mode of operation have been examined and compared with prior observations. Preliminary results indicate that ranges in the baseline ' data were reduced by factors of 15.6 for horizontal intensity; 9.1 for declination; and 5.0 for vertical intensity.</p> application/pdf 10.3133/ofr78213 en U.S. Geological Survey Improvements in magnetic observatory construction and operation in permafrost areas reports