Transcript Physical Geography of the U.S. & Canada

Physical Geography of the
U.S. & Canada
Chapter 5 Section 1
- U.S. & Canada
cover 7 million
sq. miles
- 12% of Earth
Western Features
• Pacific Ranges
– Formed by colliding
plates (Pacific &
N.A.)
– Sierra Nevada,
Cascade Range,
Alaska Range, and
Coast Mountains (in
Canada)
Mt. McKinley (Alaska Range) = tallest peak
in N.A. at 20,320 feet
Western Features
• Great California
Valley
– alluvial valley
– out produces any
other region in
fruit & vegetable
production
Intermontane Landforms
• Dry basins and plateaus fill area between
Pacific Ranges and Rockies – Why?
– rain shadow effect from Pacific Ranges
Intermontane Landforms
• Great Basin Region:
area of low land
surrounded by mts.
– Great Basin, Mojave,
Sonoran, &
Chihuahuan Deserts
Intermontane Landforms
– Death Valley:
• hottest & lowest (282 ft.
below sea level) place
in N. Am.
• dancing rocks
phenomenon
Intermontane Landforms
• Columbia Plateau– Created by lava
seeping thru cracks
• Flood basalt
– Eventually part of
crust sank into
space left by lava
Intermontane Landforms
• Colorado Plateau– Created by tectonics and
erosion (Colo. River)
– Grand Canyon @
southern end
– Walls as steep as 6,000
ft
Hoover Dam
• Built on Colorado River
b/w Arizona and Nevada
(1931-1935)
• What is purpose of
building dam?
– to provide irrigation, flood
control, and hydroelectricpower
Rocky Mountains
• Formed by collision of
N. A. & Pacific plates
• Stretch more than
3,000 miles from New
Mexico to Alaska
• Some peaks are
more than 14,000 ft
tall
• Series of ranges
(cordilleras)
Rockies in Alberta, Canada
Continental Divide
Divide = high point
or ridge that
determines the
direction that rivers
flow
Rivers
• Main rivers that have headwaters in Rockies
– Colorado, Columbia, Rio Grande, Mackenzie,
Missouri
Interior Landforms
• US: between
Rockies and
Appalachian
• Canada: between
Rockies and
Canadian Shield
Interior Landforms
• Great Plains (aka Interior/High Plains*)
– Start at 6,000 ft gradually slope down about
10 ft/mile from W to E
– E of Rockies: extend 300-700 miles across
center of region
– “Breadbasket” of the US
(Wheat Belt)
*depends on source*
Interior Landforms
• High Plains: primarily W of the 100th
meridian
– W of meridian= 10-20 inches of rain (semiarid); good for rangeland
• Rain shadow from Rockies
– E of meridian= 20+ inches of rain
Interior Landforms
• Eastern Interior Plains: region most positively
affected by glaciers
– Typically east of 100th Meridian
• 20-40 inches of rain
– Mostly flat w/ some rolling hills
– Most fertile soil in world: Corn Belt
Interior Landforms
• Interior
Highlands
– Ozarks:
Surface is
limestone
• Sinkholes,
caves, and
springs
Canadian Shield
• Giant core of bedrock (millions of yrs.
old)
– Negatively affected by Glaciation:
scraped down to bare rock/thin soil
• Good soil deposited in Great Plains
– Only veg. is forests in south
– Great for minerals (ores, gold, silver,
copper, etc.)
Exposed Precambrian bedrock
Eastern Mountains
• Appalachians: formed 300 million yrs ago
– Oldest mts; eroded to 5,000-6,000 ft
– Eastern NA plate collided with African plate
– From Quebec to central Alabama
– Valleys great for agriculture
Piedmont & Lowlands
• Piedmont: E of Appalachians
– Plateau region that drops (Fall line) into
the coastal lowlands
– Many 1st cities originated here:
Philadelphia, Richmond, Baltimore,
D.C…. WHY?
• Rapids/waterfalls = hydroelectric power and
blocked from moving inland
Lowlands
• Atlantic PlainCarolinas,
narrower as move
North
• Gulf Coastal Plainwest toward TX
Water
• US/Canada wealthy b/c of abundant water- power,
transportation
Water
• Mississippi: 2,350
miles
– Starts as stream in
Minnesota
– Gets to width of 1
½ miles & empties
into Gulf of MX
– Affects all/part of
31 states and 2
provinces
– One of world’s
busiest waterways
Water
• St. Lawrence River:
one of Can. most
impt. Rivers
– From Great Lakes to
Atlantic, forms country
border
• Niagara Falls:
– Tourist attraction, and
major source of
hydroelectric power
– Form border of Ontario
and NY
Water
• Glacial Lakes
– Great Bear Lake & Great Slave Lake formed
by glacial dams
– Great Lakes (Huron, Ontario, Michigan,
Erie, Superior) formed by glacial gouges
• St. Lawrence Seaway- series of canals & rivers
• Helped build industry in NE
Islands
• NYC’s Manhattan Island: impt. economic
center
• Hawaii: volcanic island state, big tourism
• Newfoundland, P.E.I., Vancouver I.:
Canada’s most impt.
• Greenland: world’s largest island,
Denmark territory (Alaska + TX)
Resources
• Fuels
– petroleum & nat. gas: TX and Alaska, & Alberta
lead
– Coal: Appalachians, Wyoming, & British
Columbia
• Minerals
– Gold, silver, copper: Rockies
– Iron & nickel: Canadian Shield
Resources
• Timber
– Today cover <50% of Canada & 1/3 of US
– Conservation of forests and animals is high priority
• Fishing
– Grand Banks (Can.), Atlantic, Pacific, and Gulf of
MX
• Cod fishing banned in Grand Banks in ’92 due to
overfishing