Old Rocks
Diamond Member
The present changes that we are seeing are happening on a decadal scale. The changes you are talking about happen on a million year scale. The present warming has absolutely nothing to do with tectonics. If it did, you would be seeing articles on it in the scientific journals that deal with geology.The "ice free" polar circle has no land. We have limited current data on mix of land and water (Arctic), but clearly as the Arctic Ocean grows, the sea ice will shrink. Another major factor is that, when the Arctic Ocean expands, it releases magma from the floor dramatically melting sea ice on the surface. The 2005 and 2007 Arctic Sea Ice melts were just directly over Gakkel Ridge, the Arctic "coming in" fault. The sea ice by North American through Greenland's west coast is still the same - all the melt is on the other side - Alaska through the east coast of Greenland.