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TitleThe Dominion Observatory seismic station at Resolute Bay, Northwest Territories
AuthorBremner, P C
SourcePublications of the Dominion Observatory vol. 16, no. 2, 1952, 18 pages,
PublisherCanada Department of Mines and Technical Surveys (Ottawa, Canada)
Mediapaper; on-line; digital
File formatpdf
AreaResolute Bay
Subjectsgeophysics; earthquakes; ice movements; microseismic storms
Illustrationsphotographs; tables
Natural Resources Canada Library - Ottawa (Earth Sciences)
Released1952 01 01; 2018 10 09
AbstractThe Dominion Observatory has installed a seismograph station at Resolute Bay, Cornwallis Island, latitude 74°41'N., longitude 94°54'W. The need for such a station in the Canadian Arctic has been recognized for many years. The establishment of a joint weather station at Resolute Bay offered an opportunity for the installation. A preliminary survey of the terrain indicated that the only outcrop of bedrock was situated at a distance of 1,400 feet from the settlement. At a conference held in Ottawa it was decided that electromagnetic instruments should be used, the detectors to be on the rock outcrop, the recording unit close to the weather station. Field tests carried out at Ottawa throughout a winter season demonstrated the feasibility of this plan.
The station was installed during the summer of 1950. The seismometers were placed on concrete piers and enclosed in a heated, insulated shelter that was subsequently buried with gravel to provide an effective vault. The recording unit was housed in a double-walled, prefabricated building especially designed for the purpose. Principal source of heat is an oil-fired space heater, but close control is made possible by the additional use of thermostats and electric heaters.
The station is equipped with Sprengnether long-period horizontal seismometers and a Sprengnether short-period vertical instrument. Records are read daily and the data are sent through Ottawa to the United States Coast and Geodetic Survey for use in epicentral determinations.
The paper outlines research investigations undertaken during the first year's operation. The first, a study of near earthquakes, shows that the eastern Arctic islands do not have frequent tremors. The second investigation attempts to associate spurious seismic disturbances with the movement of sea ice by making a careful study of the tide. A third undertaking was the successful operation of a short-period vertical seismometer on a base consisting of steel pipes driven into the frozen ground. It was established that this frozen medium could be used for transmitting seismic radiation to the detector if bedrock was not available. Finally, the occurrence of microseismic storms is discussed in relation to atmospheric disturbances.