The Classification And Geomorphic Implications Of Thaw Lakes On The Arctic Coastal Plain Alaska

The lakes of the Arctic Coastal Plain of northern Alaska were classified, based on size, shape, orientation and distribution, into six lake units and three nonlake units. Regional slope and relief were demonstrated to control lake size, the largest lakes occurring on the flattest, northernmost segment of the Coastal Plain. Using ERTS-1 sequential imagery and existing photography and data, lakes were grouped according to three depth ranges, 1 m, 1-2 m and2 m. Deepest lakes have the longest period of summer ice cover. Ice on shallow lakes melts the earliest. Maximum depths of lakes were computed based on ice volume content of the perennially frozen ground (permafrost) and these agreed with observed values and ranges. The lake classification and regional ERTS-1 coverage also appear to provide additional information on the limits of late-Pleistocene transgressions on the Coastal Plain.

The lakes of the Arctic Coastal Plain of northern Alaska were classified, based on size, shape, orientation and distribution, into six lake units and three nonlake units. Regional slope and relief were demonstrated to control lake size, the largest lakes occurring on the flattest, northernmost segment of the Coastal Plain. Using ERTS-1 sequential imagery and existing photography and data, lakes were grouped according to three depth ranges, 1 m, 1-2 m and2 m. Deepest lakes have the longest period of summer ice cover. Ice on shallow lakes melts the earliest. Maximum depths of lakes were computed based on ice volume content of the perennially frozen ground (permafrost) and these agreed with observed values and ranges. The lake classification and regional ERTS-1 coverage also appear to provide additional information on the limits of late-Pleistocene transgressions on the Coastal Plain.

Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 163. The North, with its vast and varied landscapes, sparse population, and cold climate has always challenged its explorers: physically, mentally, logistically, and technically. The scientific community in particular has known such challenges in the past and does so today, especially in light of the projected intensification of climate change at high latitudes. Indeed, there are clear signs that change is already ongoing in many environmental variables: Air temperature and annual precipitation (including snowfall) are increasing in many regions; spring snow cover extent is decreasing; lake and river ice freeze-up dates are occurring later and breakup dates earlier; glaciers are retreating rapidly; permafrost temperatures are increasing and, in many cases, the permafrost is thawing; and sea-ice extent is at record minimums and thinning.