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28-525: The retreat of the Laurentide Ice Sheet left a landscape of broadly rolling uplands and lowlands with precambrian granitic bedrock outcrops. Few clear drainage channels were left in the rocky sediments deposited by the glacier resulting in a deranged drainage pattern . The numerous wetlands and lakes formed give this ecozone a unique character. Water features in this ecozone contain 22% of Canada's freshwater surface area. Soil types vary widely across

56-617: A dome over west-central Keewatin (Kivalliq). Two of the lobes abut the adjacent Labrador and Baffin ice sheets. The primary lobes flow (1) towards Manitoba and Saskatchewan ; (2) toward Hudson Bay ; (3) towards the Gulf of Boothia , and (4) towards the Beaufort Sea . The Labrador ice sheet flowed across all of Maine and into the Gulf of St. Lawrence , completely covering the Maritime Provinces . The Appalachian Ice Complex, flowed from

84-549: Is believed that the Cordilleran ice melted rapidly, in less than 4000 years. The water created numerous Proglacial lakes along the margins such as Lake Missoula , often leading to catastrophic floods as with the Missoula Floods . Much of the topography of Eastern Washington and northern Montana and North Dakota was affected. The Keewatin ice sheet has had four or five primary lobes identified ice divides extending from

112-734: The Gaspé Peninsula over New Brunswick , the Magdalen Shelf , and Nova Scotia . The Labrador flow extended across the mouth of the St. Lawrence River , reaching the Gaspé Peninsula and across Chaleur Bay . From the Escuminac center on the Magdalen Shelf , flowed onto the Acadian Peninsula of New Brunswick and southeastward, onto the Gaspe, burying the western end of Prince Edward Island and reached

140-763: The Last Glacial Maximum . The eastern edge abutted the Laurentide ice sheet. The sheet was anchored in the Coast Mountains of British Columbia and Alberta , south into the Cascade Range of Washington . That is one and a half times the water held in the Antarctic . Anchored in the mountain backbone of the west coast, the ice sheet dissipated north of the Alaska Range where the air was too dry to form glaciers. It

168-678: The enormous weight of the melted ice . The Baffin ice sheet was circular and centered over the Foxe Basin . A major divide across the basin, created a westward flow across the Melville Peninsula , from an eastward flow over Baffin Island and Southampton Island . Across southern Baffin Island, two divides created four additional lobes. The Penny Ice Divide split the Cumberland Peninsula , where Pangnirtung created flow toward Home Bay on

196-557: The Atlantic Ocean. Its cycles of growth and melting were a decisive influence on global climate during its existence. This is because it served to divert the jet stream southward, which would otherwise flow from the relatively warm Pacific Ocean through Montana and Minnesota . That gave the Southwestern United States , otherwise a desert, abundant rainfall during ice ages, in extreme contrast to most other parts of

224-887: The Laurentide Ice Sheet. Central North America has evidence of the numerous lobes and sublobes. The Keewatin covered the western interior plains of North America from the Mackenzie River to the Missouri River and the upper reaches of the Mississippi River . The Labrador covered spread over eastern Canada and the northeastern part of the United States abutting the Keewatin lobe in the western Great Lakes and Mississippi valley . The Cordilleran ice sheet covered up to 2,500,000 square kilometres (970,000 sq mi) at

252-812: The Laurentide ice sheet reached from the Rocky Mountains eastward through the Great Lakes , into New England , covering nearly all of Canada east of the Rocky Mountains. Three major ice centers formed in North America: the Labrador , Keewatin , and Cordilleran . The Cordilleran covered the region from the Pacific Ocean to the eastern front of the Rocky Mountains and the Labrador and Keewatin fields are referred to as

280-425: The diversity of both plant and animal species and increase the forest's vulnerability to disease. Many Shield lakes and soils are extremely sensitive to changes in pH . Acid rain from local sources and from the long-range transport of airborne pollutants has already taken an ominous toll. It may be weakening the general vigour and growth rate of trees, as well as of aquatic species, in sensitive areas. Under 3% of

308-527: The east. In areas of muskeg there are stands of black spruce or tamarack . There are frequent forest fires. Being largely wild and remote, this ecozone is rich in wildlife, including woodland caribou , moose , wolf , black bear , raccoon , marten , fisher , striped skunk , lynx , bobcat and eastern chipmunk . Common birds include Boreal owl , great horned owl , blue jay , white- sparrow and evening grosbeak . Lakes contain brook char , lake trout , northern pike , perch , and walleye . Off

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336-449: The ecozone's total land space forbids industrial activities of any kind; this land space is therefore designated as protected. Another 5% of the ecozone's land space is also considered protected, though not as strictly; activities such as mining or forestry may be tolerable in such areas. The Boreal Shield is the largest ecozone in Canada , however, compared to other ecozones, it exhibits among

364-559: The five Great Lakes and the hosts of smaller lakes of the Canadian Shield . These lakes extend from the eastern Northwest Territories , through most of northern Canada, and the upper Midwestern United States ( Minnesota , Wisconsin , and Michigan ) to the Finger Lakes , through Lake Champlain and Lake George areas of New York , across the northern Appalachians into and through all of New England and Nova Scotia . At times,

392-512: The formation of North Atlantic Deep Water , the very saline, cold, deep water that flows from the Greenland Sea . That interrupted the thermohaline circulation , creating the brief Younger Dryas cold epoch and a temporary re-advance of the ice sheet, which did not retreat from Nunavik until 6,500 years ago. After the end of the Younger Dryas, the Laurentide Ice Sheet retreated rapidly to

420-552: The head of Bay of Fundy . From the Gaspereau center, on the divide crossing New Brunswick flowed into the Bay of Fundy and Chaleur Bay. In New York, the ice that covered Manhattan was about 2,000 feet high before it began to melt in about 16,000 BC. The ice in the area disappeared around 10,000 BC. The ground in the New York area has since risen by more than 150 ft because of the removal of

448-721: The ice sheet's southern margin included the present-day sites of coastal towns of the Northeastern United States , and cities such as Boston and New York City and Great Lakes coastal cities and towns as far south as Chicago and St. Louis, Missouri , and then followed the present course of the Missouri River up to the northern slopes of the Cypress Hills , beyond which it merged with the Cordilleran Ice Sheet . The ice coverage extended approximately as far south as 38 degrees latitude mid-continent. This ice sheet

476-412: The larger national ecozone and ecoprovince system. The Alberta Natural Subregion - Natural Regions (2006) found within this ecozone are: The Manitoba Ecoregions within this ecozone are: The Saskatchewan Ecoregions within this ecozone are: The regional climate has long, cold winters and short summers, conditions which are moderated in coastal regions. Summers in the east are warmer than those in

504-513: The north and Cumberland Sound on the south. The Amadjuak Ice Divide on the Hall Peninsula , where Iqaluit sits created a north flow into Cumberland Sound and a south flow into the Hudson Strait . A secondary Hall Ice Divide formed a link to a local ice cap on the Hall Peninsula . The current ice caps on Baffin Island are thought to be a remnant from this time period, but it was not a part of

532-589: The north, becoming limited to only the Canadian Shield until even it became deglaciated. The ultimate collapse of the Laurentide Ice Sheet is also suspected to have influenced European agriculture indirectly through the rise of global sea levels. Canada's oldest ice is a 20,000-year-old remnant of the Laurentide Ice Sheet called the Barnes Ice Cap , on central Baffin Island . During the Late Pleistocene ,

560-415: The northern and eastern coasts, aquatic mammals include grey seal , harp seal , hooded seal , ringed seal , sperm whale , orca , Atlantic pilot whale , fin whale , blue whale , northern right whale , bowhead whale , and humpback whale . Fire suppression, insect control, clear-cutting and single-species tree farming are widespread in accessible areas. These practices may, over the long term, reduce

588-459: The region in response to the wide range of climate and soil components present. Cryosols are found in the most northerly areas wherever there is permafrost . Accumulation of organic matter, particularly peat , results in organic soils in much of the area. Brunisols occur in the north and west of the region where coarse to medium sediments are found. In these soils, soil formation is ongoing and will eventually result in either podzols or luvisols. In

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616-973: The smallest shares of land that have been deemed protected. Because the region is abundant in forest land, it is subject to extensive forestry practices. In order to strengthen public dialogue and engagement on matters concerned with protected areas within the ecozone, land allocation programs have been adopted in Ontario and Saskatchewan. The programs consist of local and regional-level advisory groups that serve to help select and manage conservation areas in these provinces. A number of protected areas have been established to protect representative and/or significant portions of this ecozone. These include Georgian Bay Islands National Park , Gros Morne National Park , La Mauricie National Park , Mealy Mountains National Park Reserve , Mingan Archipelago National Park Reserve , Pukaskwa National Park , and Terra Nova National Park . Laurentide Ice Sheet The Laurentide ice sheet

644-433: The south and east, podzols are found under forests growing primarily on sand in cold conditions. Gleysols are found where poor drainage has resulted in depleted oxygen. Luvisols are present where forests overlay clay deposits. These two soil types occur across the region wherever these conditions occur. This ecozone can be further subdivided into six ecoprovinces: Each province continues to work on defining subregions within

672-528: The surface geology of southern Canada and the northern United States, leaving behind glacially scoured valleys, moraines , eskers and glacial till . It also caused many changes to the shape, size, and drainage of the Great Lakes. As but one of many examples, near the end of the last ice age, Lake Iroquois extended well beyond the boundaries of present-day Lake Ontario , and drained down the Hudson River into

700-482: The west of the region. The mean annual temperature ranges from -4 °C in northern Saskatchewan to 5.5 °C in Newfoundland. Precipitation increases from west to east. The region is widely forested with white and black spruce , balsam fir and jack pine . Deciduous trees are more common in the south, with white birch , trembling aspen and balsam poplar . There are also yellow birch and sugar maple to

728-581: The world which became exceedingly dry, though the effect of ice sheets in Europe had an analogous effect on the rainfall in Afghanistan , parts of Iran , possibly western Pakistan in winter, as well as North Africa . Its melting also caused major disruptions to the global climate cycle, because the huge influx of low- salinity water into the Arctic Ocean via the Mackenzie River is believed to have disrupted

756-539: Was a massive sheet of ice that covered millions of square miles, including most of Canada and a large portion of the Northern United States , multiple times during the Quaternary glaciation epochs, from 2.58 million years ago to the present. The last advance covered most of northern North America between c. 95,000 and c. 20,000 years before the present day and, among other geomorphological effects, gouged out

784-673: Was the primary feature of the Pleistocene epoch in North America, commonly referred to as the ice age . During the Pre-Illinoian Stage , the Laurentide Ice Sheet extended as far south as the Missouri and Ohio River valleys. It was up to 2 mi (3.2 km) thick in Nunavik , Quebec , Canada , but much thinner at its edges, where nunataks were common in hilly areas. It created much of

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