Abstract
Substantial postglacial emergence (up to 150 m) characterizes the Canadian High Arctic following the last glacial maximum. Across northern Ellesmere Island, rapid emergence is not observed during the early stages of deglaciation as it is in other parts of Arctic Canada. Rather, the curves show an interval of slow emergence (c. 1 m per century) during initial ice retreat. This is attributed to a slow rate of glacial rebound that was countered by a similar rate of eustatic sea-level rise.
Normally, isobases drawn on postglacial shorelines define broad cells of uplift that mimic centres of former maximum ice thickness. However, isobases on the 8 ka BP shoreline, surveyed throughout northern Ellesmere Island, indicate more complex patterns of crustal uplift that seem in congruent with reported ice thicknesses. On west-central Ellesmere Island, the isobases (110–150 m asl) trace a plunging ridge, aligned with geological structure, across an area considered to have had minimal ice cover during the last glacial maximum. The ridge may record an important structural influence associated with the geologically youthful Sverdrup Basin. Collectively, this evidence cautions against the view that postglacial emergence has a universally, predictable signature solely portraying former ice loads.
