Physiographic Regions of North America

The Coastal Plains

Geology Lowland area: Massachusetts to Florida & Golf of Mexico. Swamps & Marshes. Constant coastal erosion occurs in this region. Average elevation is less than 200m above sea level. More than half of the region is less than 30m above sea level! In the past, the gradual sinking & erosion of land allowed the sea to submerge the lower reaches of the plains. The banks and delta of the Mississippi create a wide belt for agricultural land.

Economy/Industry Agriculture (sugar, cotton, think plantations). Fishing (shell fish: shrimp, crayfish, etc.). Offshore Oil Drilling.

Climate Varies greatly within the region. In the north: hot, humid summer & cold, snowy winters. Southern parts of the region have a subtropical climate, with mild to warm winters. Southern portions are prone to hurricanes (particularly in late summer-fall).

Vegetation The soils are mainly sandy, and vegetation has to adapt to these soils and very watery/wet conditions. Marshlands (Everglades) Overgrown swamps (Bayou)

The Appalachians

Geology Stretches from Nfld south to Alabama and Georgia. Fold mountains caused by 2 tectonic plates colliding together. Over 300 million years old. Erosion (wind, rain, ice) has worn them down to the rolling hills that dominate the region today.

Economy/Industry Fishing (cod, Atlantic salmon, lobster, etc.) Farming (fruit, potatoes, dairy, livestock) in the valleys and plateaus of the region. Mining (coal) Natural gas & oil drilling.

Climate Maritime climate, which is affected by the influence of the Atlantic Ocean. 2 currents that regulate & shape the temperature & climate of the region: Labrador Current: brings cold water from the Arctic into the region. Gulf Stream: brings warm water from the Gulf of Mexico north into the region.

Vegetation While there are some coniferous trees in the region, the landscape and forests are dominated by deciduous tree growth. There is even some tourism based on the brilliant colours of fall in the Appalachians (fall in Vermont, NH, etc.) and a strong maple syrup industry.

Gr. Lake & St. Lawrence Lowlands

Geology Smallest physiographic region in Canada. 50% of Canadians live in this region. Rolling landscape caused by glaciation (carved by the movement of ice). Flat plains are broken by hills and deep river valleys.

Economy/Industry Farming/Agriculture Mining Hydroelectricity (Niagara) Home to 50% of Canada’s population, so it is also the financial & industrial heartland of Canada. Manufacturing centre. Transportation centre- importing/exporting goods via the St. Lawrence & Great Lakes waterways.

Climate Humid, Continental Climate- however, the climate of the GLSL3 is moderated by its proximity to the Great Lakes. Results in cool & snowy winters, but warm-moderately hot, humid summers (lots of thunderstorms).

Vegetation Fertile soils. Was once heavily forested, but has since been heavily transformed by human activity (farming, urban expansion, logging, etc.) Mixture of deciduous & coniferous trees in remaining forested areas of the region.

The Canadian Shield

Geology Ancient rocks (Precambrian) dominate the landscape of this region. They are the result of volcanism-volcanic activity. 2 processes shaped the rocky landscape: mountains that eroded and metamorphic rock that rose to the Earth’s surface. The rocks have been shaped by glaciation (rocks were exposed by ice scraping over the thin layer of soil covering them during the last ice age). Glaciation also created many of the lakes that dominate the region. It is the largest physiographic region in Canada.

Economy/Industry The many minerals found in metamorphic rock make the Shield of Canada’s premier regions for mining: zinc, copper, nickel, lead, gold, etc. Forestry: pulp/paper, small lumber. Hydroelectric power.

Climate Varies, but in general, the region experiences mild/cool summers and cold winters. These become colder and more extreme as the region extends north towards the Arctic Circle.

Vegetation Boreal forest dominates the region (small, mainly coniferous trees). Too rocky with insufficient top soil for many other things to grow.

The Interior Plains

Geology 1 The Interior Plains are a vast sweep of plain, but are not entirely flat. Gently rolling hills and some deep river valleys.

Geology 2 The plains were once covered with huge inland seas that deposited their sediment, which resulted in large layers of sedimentary rock. The breakdown of sediment and organic material also resulted in large reserves of oil and natural gas, and also accounts for the fertile soils of the region.

Geology 3 In Canada’s Prairie provinces, the plains contain 3 separate elevations. In general, the plains are gently rolling, gradually sloping down from west to east.

Economy/Industry Due to its geological origins, the soil makes the prairies ideal for agriculture (grains) and Canada’s prairies are often referred to as the “Breadbasket of the World.” Oil and Natural Gas drilling is also a major industry of the Interior Plains.

Climate Continental Climate: Affected by its distance from the moderating effects of the oceans. e of extremes: Long, hot summers. Cold winters. Little precipitation. Farther north, winters=colder & longer, and summers= shorter & cooler.

Vegetation The natural vegetation of the region is grasslands-trees only really grow in river valleys. Heavily altered by human activity (farming). In northern plains, the boreal forest grows, gradually becoming tundra closer to the Arctic.

The Western Cordillera & Intermountain Range

Geology Cordillera is comprised of ‘new’ mountains not yet worn down by erosion. Consist of fold mountains (caused by tectonic plate movement : Pacific & North American plates), as well as volcanic mountains.

Economy/Industry Agriculture in rich and fertile areas: Fraser River Valley & the Okanagan. Forestry: pulp & softwood lumber. Fishing. Mining: northern regions (gold, silver, copper, etc.) Natural Gas (northern regions). Tourism.

Climate Maritime Climate. Varies with latitude (north to south), but the west coast is moist & mild. Moderated by the water of the Pacific Ocean. Winters are usually above freezing. Summers are cooler than the interior of the continent.

Climate 2 Valleys = warmer than mountain slopes. Windward slopes of mnts.=wetter than leeward slopes, which are often dry because of the rain-shadow effect.

Vegetation Vegetation varies from one side of a mountain to another. Windward= evergreens such as Douglas firs, western hemlock, red cedar, etc. They grow to tremendous size & age. Higher up, the trees = much smaller.

Vegetation 2 At the tops of mnts, the vegetation becomes similar to that of the tundra, or it ceases entirely (treeline).

Vegetation 3 On the leeward slopes, grasses and cactuses grow in the dry valleys. Farther south, great evergreen don’t grow, since the rainfall is less.

The Arctic

Geology Much of the Arctic near the ocean is quite flat. The Mountains of the far north were formed by folding (when North America broke away from Pangea) and are presently covered by glaciers.

Economy/Industry Mining: diamonds, gold. Gas & Oil Drilling.

Climate The Arctic climate is very severe because of its latitude (far from the Equator). Summers= very short & not very warm. Winters=10 months in the far north. Little precipitation. Arctic is actually a desert.

Vegetation Not many life forms can grow in the Arctic, beyond lichens. Trees do not grow on the tundra due to cold & dry climate, and also because of the permafrost. Small shrubs, mosses, lichens.