It is not a huge amount of melt. The area is the size of two European countries. The melting is a millimeter per year. You don't need a lot of melting because the water is so large. It's three times the rate of flow of the river Thames in London and it's hundreds of kilometers long.

There is a lot of ice pressing down from above and there isn't much room between the ice and the bedrock for the liquid to move around. It can lift the ice off its bed because it is under high pressure. The ice can flow quicker if it is reduced in size. Think of that ice as a puck sliding across an air hockey table, only instead of riding on air, the ice is riding on water.

A huge volume of fresh water can be pumped into the ocean by this hidden river. That could be bad news for the glacier ice sheet. She says that the most sensitive region is where the ice starts to float. It's going to have a big effect on how much sea level rise we have in the future.

The ice shelf is a big, heavy cork that slows the flow of a glacier into the sea. Warming waters are eating away at the undersides of the corks. Recent research suggests that the Thwaites Glacier could fall in 3 to 5 years. Thwaites would contribute two feet to sea levels if we lost it all.

ThWaites is not the only one. Many of the grounding lines are not straight. Grounding lines are assumed to be static by models that predict the future state of the glaciers. The models don't have an effect known as tidal pumping, which may affect how well these lines hold. Warming water can rush inland and melt the underside of the ice when the tides are out. The research shows that pressurized meltwater is flowing from inland to the ground.

If a lot of fresh water is pumped into the ocean, it will move up toward the base of the ice and cause it to melt. The grounding line retreats. All of the ice that was previously grounded is now floating, which will cause sea level rise. The ice doesn't have to melt to raise water levels because it's massive