6: REGIONAL GEOGRAPHY OF NORTH AMERICA
describe the elevation of the canadian shield
-about 100m above sea level in the north rising to a out 500, in the south. -the centre of the shield is much lower in elevation than its outer portion -the areas around hudson bay and james bay are lowland areas covered with clay. as a result most rivers in this region flow into these 2 bays
describe the prairie provinces interior plains.
3 diff elevations -> seperated by escarpments. in general the plains are gently rolling, gradually sloping down from west to east . to the north of the prairies the plains continue until the arctic oceann
what elevation are most of the coastal plains?
30 m above sea level
how old is the world?
4.5 billion years
how far do the coastal plains extend into the coast?
50 - 100 km.
tornado
a brief but very desructive storm characterized by a wind funnel
maritime climate
a climate that is strongly influenced by the closeness of a large body of water. the annual temperature range tends to be small and precip is high
continental climate
a climate type that develops away from the influence of oceans. the temperature range tends to be large and precipitation is low
muskeg
a level bog or swamp found in Canada
vortex
a mass of fluid or air that whirls in a rotary direction
what is the appalachian region?
a mountainous area on the east coast of north america that extends for 2400km from newfoundland in the north, west through the maritime provinces, and south through the US as far as Alabama and Georgia.
escarpment
a steep clip formed by erosion or faulting
rift valley
a valley that is created when the portion of land between two faults (cracks in the earths crust) drops down
describe the intermountain region
an area in the us and canada the lies between rockies and the coast mountains , the cascades and the sierra nevada -thinly populated area of high plateaus and isolated mountains and contains the only deserts in the us -in canada the reigion consists of the interior platuea valleys of BC and the yukon
delta
an area of soil or silt deposits built up at the mouth of a river
region
an area with similar characteristics
where did the glaciers flow from?
areas where the snow was greatest such as the rocky mountains and hudsons bay
how can streams cross the lower plains?
because of gradual sinking of the land . some of the rivers can be navigated for many miles inland
why are leeward slopes dry?
because of rain shadow
how was the canadian shield formed?
because of the action of tectonic forces
why does the mantle melt?
because of the intense heat of the core
what is the canadian shield?
in the area of the canadian shield the glaciers scraped the rocks bare leaving only thin layers of soil. in yet other areas, the glaciers left mounds of debris which became hills
describe the earths core
in the centre of the earth is the core, a hot, dense, mass that is solid in the middle.
where do rivers flowing east of the rockies flow?
into the gulf of mexico, arctic ocean, james and husons bay
glaciation
land being covered with thick moving ice
what was NA like before eurpeans arrived?
largely wilderness of forests and swamps and deserts. the original inhabits had not changed the basic nature of the environment to any great extent.
when is hurricane season
last summer and early winter
marsh
low land that is flooded in wet weather and almost always wet
describe the topography of the appalachian mountians
made up of many different mountain ranges; there are old mountains formed about 300, 000, 000 yrs ago. this makes them relatively low as mountain ranges go, because erosion has reduced the once sharp, ragged peaks into rolling mountains and hills
what is a glacier?
massive piece of ice, wighing millions of tonnes. they it is literally a river of ice that slowly flows downhill scraping the land beneath.
what happens when the crust breaks while it is folding?
molten rock from the mantle then pushes up through the break to errupt as a volcano. with each eruption another layer of molten rock reaches the earths surface where it cools and hardens: volcanic mountains.
what happens to the ice from the ice age after it melted?
most of the water drianed into the worlds oceans, however some of the melted water blocked by debris the glaciers has scraped away. this debris acted like damns, forming lakes, which only later could drain away. in areas covered by lakes, deposits of silt were laid down
volcanic mountains
mountains created by breaks in the earths crust
fold mountains
mountains created by the bending of the of rock layers
faulting
movement along a crack (fault) or cracks in the earths crust
can trees in the candian shield grow north of the tree line?
no growing season is too short, there is too little precip, and there is permafrost
is all of the appalachian region mountainous?
no. it also contains fertile plateaus and river valleys. the many rivers of this region provide transportation.
boreal
northern, or of the arctic
describe vegetation of the Appalachian region.
originally was heavily forested with mixed coniferous and deciduous trees. these trees could survive in both poor and unproductive mountain soil, and flourish on the plateaus and in the river valleys where the soil was much more productive
how old is the candian shield?
over 2 billion yrs
what was the original vegetation in the coastal plains?
pine forests
Vegetation
plants that grow naturally in an area
what is the benefits of where the gulf stream and labrador current meet?
provides an ideal breeding ground for fish by encouraging the growth of plankton, microscopic organisms that provide food for fish. the grand banks once teemed with many varieties of fish are a main attraction to NA
what ate the prairies of canada?
they were once covered by Lake Agassiz, which when it drained, left behind a broad expanse of flat, bare land
describe the earths crust
thin layer of rock about 5 to 35 km thick. divided into small and large pieced called plates.
tectonic
to do with the structure of the earths crust
erode
to wear down the surface of the earth
what do the swamp marshes of the costal plains provide?
transportation routes, important sources of shellfish and other aquatic life forms
deciduous
trees that shed their leaves annually
how wide is the mountainous Appalachian region?
varies between 160 to 480km. they are fold mountains caused by 2 plates coming together
what is the climate like in to coastal plains?
varies greatly, North: characterized by cold and snowy winters and hot and humid summers South: subtropical climate, with mild to warm winters. south is also subject to hurricanes
describe the climate of the canadian shield?
varies throughout the vast area as you travel north the winters become increasingly long and cold, with the summers becoming shorter and cooler
swamp
wet, spongy land
are glaciers large enough to flow over hills and mountains?
yes
are the interior plains diverse?
yes
does the shield overlap the us?
yes in 2 areas
can erosion can help create landscapes?
yes. water can wear down high ridges and create deep valleys, when ice freezes and thaws it can pry rocks apart, and wind can gradually wear away at the surface of rocks
what is the average elevation of the coastal plains?
200m above sea level
what is the climate of the intermountain range like?
-affected by its location and its elevation -winters can be cool and wet or hot and dry depending on a region -in the southern portions os the reigon, winters are short and warm with very little precip -north parts of region lack precip although climate is more moderate, with moist winters and hot dry summers
describe the original vegetation of the canadian shield
-boreal forest covers most of the shield, since evergreens are ore suited to thin sandy soil. -some deciduous trees such as white birch are present -these trees are small and weak, more suited to the pulp and paper industry than to lumbering
describe the original climate of the interior plains
-central lowland east of the mississippi was covered with deciduous trees and scattered evergreens -west of the mississippi, in the great plains, prairie grasses grew as tall as a person -natual vegetation of the canadian prairies was also grassland -trees grew only in the river valleys. in the northern portion of the interior plains, boreal forest grows and turns into tundra towards the arctic ocean
what is the climate of the interior plains
-continental climate -affected by its location in the heart of the continent-far from the moderating influence of oceans -extreme climates: long hot summers, cold winters, and little precipitation. -farther north winters are colder and longer and summers are shorter and cool. the northern portion of this region has an arctic climate
how did the candian shield develop?
-during the ice age, glaciers removed most of the soil, leaving barren rock surface in many places -the retreat of the glaciers affected the drainage of the shield to a significant degree -debris depositied from glaciers damned up rivers or forced them to flow in different directions -as a result shield made up of chaotic patterns of rivers, lakes, swamps, and muskeg
whats is the vegetation of the great lakes and st. lawrence lowlands like originally?
-fertile soils heavily treed. once had the largest broad-leafed forests, because its soil and climate coniditons allowed maple, beech, hickory, and black walnut trees to thrive. in other paces the vegetation was mixed forest of both decidious and conifers
what does the canadian shield consist of?
-great volcanic mountains that were labeled by millions of years of erosion -geographic foundation of canada, covering more than half of its surface area -platform rocks that stretch form labrador around hudson bay and james bay, in the east south to the great lakes, and west to the interior plains
whats is the climate the great lakes and st. lawrence lowlands like?
-humid continental climate -humid because of the presence of the great lakes -great lakes tends to cool the temp during the summer . by storing heat the great lakes warm the surrounding areas in winter -winter vary from cool to cold -summers vary from warm to hot
describe the topography of the cordillera
-made of new mountains not yet worn down by erosion -twice as high as the appalachian mountains in the east -many different ranges in the region -the rockies to the east form the continental divide
describe the topography of the intermountain region
-many areas the streams and rivers of the intermountain regions mountains and plateus never reach the sea -they flow into brackish lakes eg. the Great Salt Lake in Utah or dissapear into desert sinks -some rivers do find a way into the ocean -in some portions of the region there are areas that can be made productive by irrigation. -in other areas cattle ranching is possible
what is the climate of the western cordillera?
-maritime climate -varies from north to south, west coast is moist and mild-in fact, parts of it are among the wettest reigions on earth -moderated by the pacific ocean, winters are usually above freezing -summers are cooler than the interior of the country -valleys are warmer than mountian slopes, and windward slopes are much wetter than leeward slopes
what is the topography of the great lakes and st. lawrence lowlands like?
-rolling landscape, created mainly by glaciation -flat plains are broken into hills and deep river valleys the st lawrence section is made up of flat plains on either side of the river which gradually begin to rise into the canadian shield and the appalachians.
what did colonizers arriving in North america find?
-varied landscapes -land differed greatly from reigon to region -reflected the great diversity of the continent -found a diverse population of people, many native american
describe the interior plains
-vast sweep of plain -not entirely flat -mostly land is composed of gently rolling hills and deep river valleys -in the states the plains run between the appalachian mountains on the east coast and the rockies in the west -in canada runs between the candian shield and rockies
describe the vegetation of the western cordillera
-vegetation various from one side of the moutain to the other -on the moist windward slopes, evergreens, such as douglas fir, westrn hemlock, and western red cedar grow to a tremendous age and size on the lower slopes -higher up , the trees are smaller -at the top of the mountains, vegetation becomes similar to that of the tundra, and stops completely -on the lower slopes grasses and cacti grow in the dry valleys -farther south the evergreens no longer grow, since the rainfall is less
how is the climate of the appalachian region affected?
by 2 ocean currents: the labrador current that brings cold water south from the freezing arctic and causes freezing during the winter months in the northern parts of the region. The gulf stream brings warm water north form the Caribbean and along the coast of north america before it turns east, crossing the Altantic ocean to europe
how is the region of the st lawrence lowlands bounded?
by the canadian shield to the north and the appalachian mountains to the south
how are the interor plains divided in the US?
central lowland and the great plains. the northern boundary of the central lowlands is formed by the canadian shield, the great lakes and the st. lawrence river
temperature
climate that has warm summers and cool winters
describe the earths mantle
consists of molten rock called magma. the magma is a very thick material that slowly swirls around like boiling water, causing the plates of the crust to move or break.
earths layers
crust, mantle, core
what can be found in the appalachian region in the sedimentary layers of rock?
deposits of coal, oil and gas
where do rivers flowing west of the rockies flow?
drain towards the pacific ocean
coniferous
evergreens-trees or shrubs bearing cones
size of the interior plains?
form north to south -> extend form the gulf of mexico to the arctic ocean
when did europeans start leaving NA?
from the 17th century on
what is the surface of most of the coastal plains generally?
generally flat or rolling
describe the western cordillera
reigion that runs along the west coast of NA. consists of range after range of mountains, sperated by plateaus and valleys -the rockies are the most easterly range of mountains in this region - in the states they veer towards the interior of the continent, to a great extent -the coastal chains of mountains are volcanic mountains and the inner ranges are fold mountains
lowland areas that stretch for 3200 km form cape cod along the atlantic coast, including florida, then turns westward along the gulf of mexico
the coastal plains
where does the largest tree in the world grow? what is it called?
the giant sequoia grows near yosemite
what is the smalest geographical region in canada?
the great lakes-st. lawrence lowlands
what is the elevation of the great plains and the central lowland?
the great plains are higher in elevation that the central lowland rising from about 600m to 1500m above sea level in the west
tectonic features built up the features of north america.. what began to erode them
the ice age. the earth began a prolonged period of cooling about 60 million years ago.
what is animportant feature of the golf coastal plain?
the mississippi delta, where the mississippi emties into the Gulf of Mexico, creating a wide belt of fertile agricultural land
climate
the prevailing conditions of temperature and precipitation
what happens when 2 plates are pushed together over millions of years?
the rock layers of the crust crumple up into fold mountains; eg the rocky and appalachian mountains of north america are fold mountains
topography
the shape of the land
what is the vegetation like of the coastal plains?
the soils of the coastal plains are maily very sandy. the natural vegetation adapted to the sandy soil, and in some areas (Mexico) lush jungles developed
what does the great lakes-st. lawrence lowlands include?
the triangle formed by Lakes Huron Ontario and Erie. it contains many escarpments the best known being the niagra falls escarpment which extends from niagra falls to Manitoulin island. the reigion is also cut by a extension of the shield near kingston and then continues along the st. lawrence river -includes the ile d'Antocosti, a small island in the gulf of st lawrence .
sedimentary
the type of rock formed by erosion of other rocks, after loose material has hardened.
funnel
the usual shape of a tornado; a tube of winds spiralling at high speeds
what happened to NA after europeans arrived?
they belived that the environment was to be chanaged to fit their needs and reqirements. the exisitning patterns of the physical environment had changed and by the 20ht century the landscape had been transformed.