Could the West Antarctic ice sheet continue to add to sea level rise?
The West Antarctic ice sheet forms what is called a marine ice sheet – the ice is resting on bedrock, but that bedrock is below sea level. This is comparable to loading too many ice cubes in your gin and tonic – the bottom one touches the bottom of the glass even though it’s well below the water level. Where the bedrock under a marine ice sheet slopes down towards the interior, such as under parts of West Antarctica, the ice sheet may be unstable. If the coastal part of the ice sheet thins, it will start to float and is then able to flow more rapidly. This drains more ice from further inland which may also start to float and, with bedrock that slopes backwards and becomes deeper further in, continued retreat of the grounded ice sheet may proceed very rapidly. A small retreat could in theory destabilize the entire West Antarctica ice sheet, leading to rapid disintegration. What will be the contribution of the ice sheets to future sea level rise? The IPCC AR4 projected that sea level ris
