Exposed Former Lake Bottom (image) McGill University Caption As Twelvemile Lake recedes willow shrubs have planted themselves, permitting the soil beneath them to develop new permafrost. But researchers believe that this new permafrost will not last beyond the end of this century. Credit Martin Briggs, US Geological Survey Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.