The moire crack gauges on the crown of the Frank Slide

Abstract

Two TM71 Crack Monitors installed in a gaping crack in the crown of the Frank Slide, Alberta, have recorded movements of less than 1 mm/year. These movements are attributed to continuing dilation of the rock block field in the crown. The crack monitors' moire fringe measurement system is particularly suited to the reliable measurement of small movements over long time periods. Key words: displacements, monitoring, rock, Rockies, creep, interferometry.