• lake;
  • permafrost disturbance;
  • active-layer detachment;
  • High Arctic;
  • water chemistry;
  • sediment


The physical and chemical characteristics of two High Arctic lakes were investigated at the Cape Bounty Arctic Watershed Observatory on Melville Island, in response to large active-layer detachments generated by extreme summer temperatures in 2007. In the two years following the permafrost disturbances, there was an elevated loading of total dissolved solids into both lakes, but no concomitant increase in suspended sediment levels. The physical dynamics of one lake were significantly altered by an internal sediment input, which was not directly related to watershed processes. The results indicate that localised permafrost disturbance in the watersheds resulted in changes to chemical conditions in these relatively deep, large lakes, while increased sediment transport from disturbances did not have a sustained impact. Copyright © 2012 John Wiley & Sons, Ltd.