Hudson Bay ice sheet caused 2,000 ft isostatic rebound in pulses. The ice sheet over Hudson Bay was approximately 1.75 miles thick at its thickest point When released from ice mass, Hudson Bay rebounded approximately 2,000 feet upward The higher shorelines show greater distance between them because isostatic uplift was faster in the early postglacial period
The ice sheet over Hudson Bay grew up to 1.75 miles thick. When it melted, the land rebounded approximately 2,000 feet upward. The shoreline terraces are spaced further apart at higher elevations because uplift was faster initially, occurring in discontinuous seismic pulses rather than smooth continuous movement. Each pulse likely triggered earthquakes.
Key Facts
- The ice sheet over Hudson Bay was approximately 1.75 miles thick at its thickest point
- When released from ice mass, Hudson Bay rebounded approximately 2,000 feet upward
- The higher shorelines show greater distance between them because isostatic uplift was faster in the early postglacial period
- The rise of the land was not smooth and continuous but occurred in discontinuous pulses
- Each uplift pulse was likely accompanied by seismic activity and earthquakes
Source: Ancient Builders: Live Quest Presentation by The Randall Carlson