Isostasy is the gravitational equilibrium between the Earth's crust and the mantle beneath it: the crust floats on the denser mantle at a height set by its own thickness and density, the way an iceberg's freeboard is set by how much ice lies below the waterline. Adding or removing a load, an ice sheet or a sediment pile, tips that balance, and the crust sinks or rises to restore it. The rebound is still measurable today around the Baltic Sea and Hudson Bay, thousands of years after the ice sheets that depressed them melted. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/
Facts
Process Type TimescaleThousands of years, as in the postglacial rebound still measurable today around the Baltic Sea and Hudson Bay. 1 First Proposed Year Scientific Consensus Year Connections
Caused By
Source Isostasy (Wikipedia)
Demonstrated By
The Antarctic Ice Sheet's mass loads and unloads the crust beneath it, the same mechanism the cited source documents at the Baltic Sea and Hudson Bay.
In the Other Atlases
- Also in Earth and Environment Atlas: Isostasy, the same subject.
Sources
1. Isostasy (Wikipedia)
Wikimedia FoundationDefinition section
the crust "floats" at an elevation that depends on its thickness and density.
Post-glacial rebound section, timescale
isostatic post-glacial rebound is observed in areas once covered by ice sheets that have now melted, such as around the Baltic Sea and Hudson Bay.
History section
The American geologist Clarence Dutton use the word isostasy in 1889 to describe this general phenomenon.
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