The rate of isostatic uplift / recovery in the inner reaches of Hudson Bay turns out to be far in excess of what I anticipated. According to Lajeunesse and Allard, the rate of uplift immediately following deglaciation was around 7m per century. You can see this on the steep part of the curve, associated with the initial ice melt around 8600 years ago. This rapid rate gradually fell off over the following millennia. Note that the curve shown on the graph above shows an initial rate of about 2.5m per century. But that shows the RELATIVE sea-level curve, after taking into account the fact that there was a quite rapid eustatic sea-level rise going on at the same time, associated with global ice melting and the return of vast quantities of meltwater to the world's oceans. So sea-level was rising, but the land was rising even faster..........
Géographie physique et Quaternaire
Volume 57, numéro 1, 2003, p. 65-83
Late
Quaternary Deglaciation, Glaciomarine Sedimentation and Glacioisostatic
Recovery in the Rivière Nastapoka Area, Eastern Hudson Bay, Northern
Québec
Patrick Lajeunesse et Michel Allard
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