Paleolimnology of Lake Winnipeg. Introduction and overview

Lake Winnipeg lies in the centre of North America, straddling the physiographic boundary of the low relief terrain of the Interior Plains and the rugged rock outcrop of the Canadian Shield. The lake's extensive watershed reaches from the Rocky Mountains 1200 km to the west, to northwestern Ontario 400 km to the east, and encompasses part of the adjacent northern United States. Water in this system drains through Lake Winnipeg (217 m asl) north to Hudson Bay at sea level. Lake Winnipeg extends 430 km from south to north and reaches 100 km in width. It consists of a smaller South Basin separated from a larger North Basin by a constricted passage known as The Narrows. Generally, the bathymetry is flat and shallow with maximum depths ranging from about 11 m in the South Basin to 16 m in the North Basin. The area of the lake, at 24 530 km super(2), positions Lake Winnipeg as the seventh largest lake in North America and the eleventh largest lake in the world.