Current tectonics of the northern Canadian Cordillera

The northern Canadian Cordillera is remarkably tectonically and seismically active, extending from a terrane collision zone on the continental margin to an active fold and thrust belt at the eastern mountain front. The source and distribution of the deformation are constrained by (i) precision global positioning system (GPS) measurements; (ii) the seismicity distribution, mechanisms, and rates; (iii) the thermal regime; (iv) estimates of lithosphere thickness and strength; and (v) topography and gravity. The ongoing oblique collision of the Yakutat block in the northeast corner of the Gulf of Alaska has produced large deformation and uplift in the adjacent Saint Elias and Chugach mountains and appears to be responsible for the current deformation 800 km to the northeast. Northern Cordillera GPS velocities are ∼5 mm/year northeast relative to the North American Craton. Deformation rates across the eastern mountain front from earthquake statistics are similar, i.e., ∼4 mm/year of thrust shortening across th...