Active Layer Depth or Permafrost Presence for the Regional Site Network.

Between 2011 and 2015, maximum active layer depth was measured during the fall at the majority of the sites in the Regional Site Network (RSN). Efforts were focused mainly on identifying which sites did and did not have frozen ground. To augment this dataset, older measurements were included for some mature sites at which the maximum active layer depths can be assumed to be fairly static. Due to time constraints, sites which we were confident had no frozen ground were not probed.