By Willis Eschenbach – Re-Blogged From http://www.WattsUpWithThat.com
I got to thinking about the records of the sea level height taken at tidal stations all over the planet. The main problem with these tide stations is that they measure the height of the sea surface versus the height of some object attached to the land … but the land isn’t sitting still. In most places around the planet the land surface is actually rising or falling, and in some places, it’s doing so at a surprising rate, millimeters per year.
The places that are the most affected, unfortunately, are the places where we have some of the longest tidal records, the northern extra-tropics and northern sub-polar regions. In those sub-polar regions, during the most recent ice age, there were trillions of tonnes of ice on the land. This squashed the land underneath the ice down towards the center of the earth … and as result of that, just like when you squeeze a balloon it bulges out elsewhere, the extra-tropical areas further from the North Pole bulged upwards in response to the northern areas being pushed down.