The Arctic Lowlands

The coastal plain of northwest Canada and adjacent Alaska is a unique lake region. This area is one of extensive permafrost in a low-relief environment. Parts of this region were glaciated during thePleistocene Epoch, but much was not. TheArctic lowlandsare home to tens and perhaps hundreds of thousandsof shallow lakes。Some of these are underlain by peat, while others lie onglacial depositsor marine sediments derived from prior high sea levels. In the present era of rising temperatures many lakes are being formed and subsequently drained by thawing ofpermanently frozen ground。当含冰沉积物开始解冻他们可能ettle as water melts and is expelled from the sediments. Areas of shallow standing water form, and because in the brief warm season this water absorbs and stores more heat than surrounding vegetated areas the thawing and settling of sediments beneath is accelerated. This process is calledthermokarst, and results in theformation of lakes。At the same time many lakes are being drained as the thawing and settling of sediments continues.

Continue reading here:Brief History of Reservoir Construction

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