Geodetic Survey Measurements to Determine Motion in the Earth’s Crust

Abstract

For many years, the Geodetic Survey of Canada has been involved in projects to study crustal movement or continental drift, with the areas of principal interest being in the regions of the St. Lawrence Valley, Robeson Channel and the Strait of Georgia. Only one project, levelling in the Quebec — Lake St. John area, is complete enough to show any results. The other projects require future remeasurements before significant comparisons can be made. These projects, in which common instruments and techniques are used, are reported and discussed indicating the type and magnitude of movements which can be determined. New instruments and techniques which will allow more accurate determinations are also discussed.