ABSTRACT
This chapter describes the Arctic Coast and Subarctic zones of North America, immense territories with low densities of human population. Massive glacier ice covered the zone until well into the Holocene: the Laurentide Ice Sheet of northeastern North America lay over most of Canada eighteen thousand years ago, began to “retreat” (i.e., to melt at its margins) about sixteen thousand years ago, and by nine thousand years ago southern Canada was free of ice, although glacial ice still covered the north, and indeed, still today covers most of Greenland. Understand that glacier “retreat” meant flooding, the release of meltwater, raising sea level and leaving countless lakes and ponds on the bedrock scoured by the glacier. Freed of the weight of packed glacier ice, the land rebounded, changing stream flows. Vast marshes called muskeg cover much of the Subarctic, as the soil formed after glacier melting was too thin to absorb all that water.
