TheTyrrell Sea, named afterCanadiangeologistJoseph Tyrrell, is another name for prehistoricHudson Bay. It existed during the retreat of theLaurentide Ice Sheet.
Roughly 8,000 yearsBP, the Laurentide Ice Sheet thinned and split into two lobes, one centred overQuebec-Labrador, the other overKeewatin. This drainedGlacial Lake Ojibway, a massiveproglacial lake south of the ice sheet, leading to the formation of the early Tyrrell Sea.[1] The weight of the ice hadisostatically depressed the surface as much as 270-280m below its current level, making the Tyrrell Sea much larger than modern Hudson Bay.[1] Indeed, in some places the shoreline was 100 to 250 km further inland than at present.[2] It was at its largest roughly 7,000 years BP.[3]
Isostatic uplift proceeded rapidly after the retreat of the ice, as much as .09 m per year, causing the margins of the sea to regress quickly towards its present margins.[1] The rate of uplift decreased with time however, and in any event was nearly matched bysea level rise from the melting ice sheets.[2] When the Tyrrell Sea "became" Hudson Bay is difficult to define, as Hudson Bay is still shrinking from isostatic rebound.[3]
Pleistoceneproglacial lakes and related seas | |||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Africa | |||||||||||||||||||||||||||||
| Antarctica | |||||||||||||||||||||||||||||
| Asia | |||||||||||||||||||||||||||||
| Europe |
| ||||||||||||||||||||||||||||
| North America |
| ||||||||||||||||||||||||||||
| South America | |||||||||||||||||||||||||||||
| Summary | |||||||||||||||||||||||||||||
 | Thispalaeogeography article is astub. You can help Wikipedia byexpanding it. |
