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PHYSICAL GEOGRAPHYPHYSICAL GEOGRAPHYA. The lands & its featuresA. The lands & its features

Different landform types: broad plains, rolling hills, rugged plateaus, majestic mountains, etc.

-> land use & economic development

I. Mountains & Valleys of the Pacific RegionLocation: The region extends from CA to AK and includes HIGeneral characteristics Greatest mountain ranges,

highest/tallest mountains, stunning scenery

Nature’s land-building process: volcanism, faulting, folding.

Erosion: glacier, swift-flowing streams

HAWAII Most active & extensively studied

volcano in Volcanoes National Park Kilauea Crater erupts continuously in bubbling, non-life-threatening fashion Mauna Kea, highest peak, 10,360 m from Pacific floor, world’s tallest mountain in sea

ALASKA Many towering, snow-clad mountains of fault block origin (Alaska Range) Have 100 volcanoes, many are extremely active Mount McKinley (aka. Denali): North America’s highest peak, world’s tallest peak on land, 6,194m, expand

32km

Rank PEAK HEIGHT (km) COUNTRY ORIGIN

1 Mauna Kea & Mauna Loa 10.2 (4.2 SL) US (Hawaii) Volcanic

2 Pico del Teide 7.5 (3.7 SL) Spain (Canary Islands) Volcanic

3 Mount McKinley (Denali) 5.3 - 5.9 (tallest on land) US (Alaska) tectonic

4 Mount Everest 3.6 - 4.6 Nepal/China tectonic

MAINLAND Hill & low mountains form coastal ranges. Cause : geologic folding (Pacific & North American tectonic plates colliding) Inland : fertile valleys for agriculture

Imperial Valley, Central Valley in CA Willamette Valley in OR

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Lowlands bordering Puget Sound in WA The Sierra Nevada:

Central CA’s towering “backbone”: uplifted fault block range Western slope: forest-covered, expand 130 km Eastern edge: Mount Whitney (4,418 m, highest point in 48 states) Eastern slope: drop >4,267m in several mile distance

Death Valley: 100km east of MW, 86m below sea level, world’s 3rd lowest point of dry land The Cascades: from northern CA to WA, active volcanic range

Mt Rainier: highest peak, snowcapped, 4,392 m Mt St. Helens: erupt violently in 1980, caused 57 deaths.

II. Mountains, Plateaus, and Basins of the Interior West Location : between the Sierra Nevada, the Cascades, eastward to the Rockies, western Texas.

BASINS & RANGES

Basins’ Feature: low & scattered mountain ranges separate broad & flat basins. With/without interior drainage Water to basins -> evaporates -> salts -> accumulate. (Bonneville Salt Flats, UT; Great Salt Lake, UT;

Salton Sea, CA)THE COLUMBIA PLATEAU

Location : portions of eastern WA, northeastern OR, western ID Feature : of volcanic origin (formed millions of years ago by 1,829m layer of magma & lava) Unique landscapes: 1/6 in loess or powder-like material; hilly, fertile soil & best wheat-growing land Hells Canyon (2,438m) chasm on Snake River between northeastern OR & western ID; Scoured by water

erosion; deepest river gorge in NA (>1km deeper than Grand Canyon in AZ)

“Scablands”, WA: lunar-like landscape of bare rock.

Formation: Thousands of years ago,

during late stages of the ice age, a huge lobe of glacial ice dammed today’s Clark Fork River near Sandpoint, ID.

Water built up behind the barrier -> create ancient Lake Missoula (610m depth) -> ice float -> giant lobe rise -> immediate breakup of ice ->

destructive flood -> scour everything, leaving scab-like landscape3

The “Scablands”

THE COLORADO PLATEAU Location : Southwest’s Four Corners area Feature : alternating layers of sandstone & limestone, Water erosion created towering cliff, many natural

bridges, arches, deep gorges

THE ROCKY MOUNTAINS Location : from northern NM to MT, into Canada as a mountain chain & AK A series of mountain ranges with regional names 17 peaks in CO (>4,267m), Mount Elbert: highest in Rockies, 4,399m, Mountain glaciers scour the jagged terrain: Grand Teton NP in WY, Glacier NP in MT, Rocky Mt NP in CO

III. Interior Lowlands Location : from the Rockies to the Appalachians

The Great Plains, west of 100th meridian, Western margin: 1585m high (Denver, 1585m high, CO)

Eastward, plains drop gradually until they reach Missouri & Mississippi rivers.

Flat terrain broken in places by buttes, mesas, low mountains (Black Hills of SD, Mount Rushmore, highest here is Harney Peak 2,207m)

The Central Plains : East of Great Plains to foothills of the Appalachians (north-central TX to eastern Dakotas, eastward to OH & MI),

Agriculture concentration: Central plains as “breadbasket”: excellent soils, ample moisture, flat land for equipment.

IV. Appalachian Mountains Location : from AL to New England

Shape : an accordion-like series of parallel, southwest-northeast-trending ridges & valleys

Cause : geologic folding (forces within earth pushed toward one another, creating a ripple-like landscape)

Feature : an ancient system of low mountains, highest at 2,037m (Mount Mitchell) Ancient rivers scour east-west-trending valleys (gaps) creating corridors followed by early people, later

railways, highways

V. Piedmont & Atlantic & Gulf Coastal PlainsV. Piedmont & Atlantic & Gulf Coastal Plains Eastern slope : hilly upland area, drop gradually toward coastal plain. At the joint is a “fall zone/line” ->

early settlement Rapidly flowing water -> water-powered saw, flour, other industrial mills, goods transportation (land-based

vehicles, warehouse) -> lively trade, commerce. (30 cities founded) Gulf coastal plain : an arc from western FL to southern TX

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Atlantic coastal plain : from mouth of NY’s Hudson River to eastern FL, along the coast, seaports are developed

CLIMATES & ECOSYSTEMS

Within temperate mid-latitudes, moderate conditions of weather & climate (-AK, HI) Extremes are seasonal (exc. aridity) Settlers found ways to adapt to challenges: water storage, diversion, irrigation, air-conditioning, insulation,

artificial heating Varied climates offer diversity of natural vegetation, soil conditions, water features

THE SOUTHEASTERN CLIMATE Humid subtropical

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Ample moisture (100-150 cm. P/Y). Gulf Coast, southern FL, parts of Appalachian (150-200cm) LA is wettest (140cm. P/Y) Mild winter. Long, hot, steamy summer

THE NORTHEASTERN CLIMATE Humid continental climate Ample moisture < the Southeast Western: Dry condition (Corn Belt: 50-100cm.M) Eastern: 100-150cm Snowfall in winter (cover ground Nov-Apr in north) Near Great Lakes: 250cm, “lake effect” snow Temperature: moderate in summer, frigid in winter North: in Jan: -12->-18oC

EASTERN ECOSYSTEM Flora:

Dense cover of broadleaf, needleleaf, mixed forest -> today much are cleared for agriculture & other land use

In southeast, much are returned to woodland Fauna:

Birds, marine life, mammals-> abound with help from conservation programs Agricultural lands shrink -> wildlife habitat develops Soil: thin, acidic, poor in far north; rich in south (destroyed by poor agricultural practices)

THE DRY INTERIOR WEST Scant moisture (50cm.P/Y) To depends on latitude & elevation Nevada: driest state, 23 cm. P/Y Far from sea = weather extremes -> Interior west: Summer: fiercely hot; Winter: frigidly cold Las Vegas: driest city, 10 cm. M Death Valley, CA: driest spot, 3.6 cm, 57oC Tucson, AZ: 1% humidity Summer: wettest, rain falls in torrential thunderstorm

Aridity near the Sierra Nevada & Cascades

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Semi-permanent high pressure maintains aridity in desert Southwest Mojave Desert, Sonora Desert: Afternoon to: >40oC

Wisdom, MT; Stanley, ID; Bellemont AZ: High elevation -> low temperature. Lowest: -57oC

WESTERN ECOSYSTEM Flora: Steppe, prairie: Water available -> soil fertile

Fauna: Bison, deer, elk, antelope

THE PACIFIC REGION Border Pacific ->coastal CA has mild, pleasant Mediterranean climate (20soC, 75-125 cm P/Y, summer

drought) -> inflow of migration Soggy West Coast marine climate (moist & temperate) (AK panhandle, north of CA) Summer: cooler; Winter: warmer Some locations: years without snowfall (different than Cascades) Area west of mountain: Wettest spot Several locations in Cascades, Sierra Nevada: receive several hundred inches of snowfall each winter Seattle, WA : weeks without sunshine Olympic NP , wettest spot: northwestern WA’s Olympic Peninsula (380cm, M) WA’s Mount Baker Ski Area : snowfall record (29m)

ECOSYSTEM Flora:

Remarkable forests. Reliable moisture + high relative humidity (frequent fog) => tree growth, fire suppression Recent years, reduced harvest =>needle-leaf evergreen forest provide high quality lumber World’s tallest tree : Hyperion (115.5m), redwood in undisclosed location (northern CA’s Redwood

National Park) World’s oldest tree : Methuselah (<4,800-year-old bristlecone pine in CA’s White Mountains) World’s largest tree by mass : General Sherman Tree (1,486.6m3, 11.1m of a base diameter)

HAWAII Humid tropical climate, microclimatic conditions

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Maui : some environmental record: Mount Pu’u’ Ula’ula: (Mediterranean-type landscape on 3,050m slope) 10 km of nearly all of Earth’s ecosystems (-polar)

Kaua’i : desert environment with scant vegetation (grasses, scrub plants, cacti, irrigated culture) Mount Waialeale : wettest spot (168.5cm, P/Y) due to orographic effect (rain), rain shadow (aridity)

ALASKA Summer: short, cool; Winter: long, severe Southern coast: temperatures moderate Juneau (capital), Anchorage (largest city): warmer in winter (> “Lower 48”) Inland: to -61oC -> 40oC Adequate moisture

ECOSYSTEM (AK) Fauna: Animal: bears (black, brown- Polar bear, Grizzly bear, Kodiak), deer, moose, caribou, seals, walrus,

whales, seafood (fish, crab) Flora: Taiga (or boreal) forest: larch, pine, spruce aspen; Tundra (far north); Shallow soils + short growing

season => stunted ecosystem (moss, clump grasses, hardy flowering plants, lichen)

WATER FEATURE Importance for:

agriculture, industry (maritime transportation, hydroelectricity-producing dams), commerce, recreational activity (fishing)

=>largest cities grow around a river mouth or natural harbor, oasis sites Problematic: water pollution & depletion

Oceans Bordered by 3: Pacific, Atlantic, Arctic

Safe from potentially hostile neighbors, countless marine resources, scenic beauty, shipping access to the world, atmospheric moisture (melting Arctic Ocean -

>global navigation to Europe, Asia)

Lakes 90% world’s natural lakes formed by glacial action In Pleistocene (ice age), glaciers reached into US

(Ohio, Missouri rivers) & formed in many of higher mountain ranges=>Most lakes in the northeastern & north of Ohio, Missouri rivers; reservoirs, water bodies formed behind dams in Southeast & West.

Great Lakes: world’s largest system of freshwater (esp. Lake Superior); -> Canada’s St. Lawrence River -> Atlantic (water route)

Rivers Major river system: by Mississippi & its 2 major tributaries, Ohio, Missouri rivers

Drain 41% of 48 states

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Missouri- Mississippi river: 5,970 km long, distance < Nile, Amazon Barges navigate rivers upstream to Minneapolis-St. Paul, MN; Pittsburgh, PA; Sioux City, IO New Orleans, LA, near mouth of Mississippi: leading seaport (before Hurricane Katrina 2005)

Many eastern rivers’ importance: Hudson River towards New York city In Southeast, 1933, during Great Depression, the TVA ( Tennessee Valley Authority) built 50 dams =>create

jobs, clean & inexpensive source of (hydroelectric) area, reservoirs for recreational activities, control flooding

In Southwest, the Rio Grande & Colorado River flow southward across desert landscapes.=> cities, agriculture:

The Rio Grande: from the Colorado Rockies -> central NM -> TX (border between US & Mexico); dammed in 3 locations ->regional agriculture, dry along lower course

The Colorado River controlled by 8 dams & reservoirs (Glen Canyon Dam, Lake Powell, Hoover Dam, Lake Mead) -> booming population, economic growth (Phoenix, Tucson, AZ, CA’s Los Angeles basin, San Diego, Imperial Valley, Las Vegas, coastal southern CA)

In Pacific Northwest, the mighty Columbia & its chief tributary, the Snake River -> hydro-electric energy, irrigation, domestic use, recreational activities.

Groundwater Ground water is water deposits stored in an aquifer, its upper limit is the water table.

Groundwater: tapped by wells, reach surface through springs

In arid regions, an aquifer: nonexistent or lie >300m under (desert Southwest) Quality & quantity of groundwater deposits in sharp decline:

aquifer contaminated by seepage of pollutants, earthen material (e.g salt & sulfur) cause foul taste/odor, reduce water quality,

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Water used faster than being replaced: esp. near cities in West; from SD to the TX panhandle, water for irrigation taken from Ogallala Aquifer

=> solution: find alternative water source, develop an economy in balance with available water resources

ENVIRONMENTAL HAZARDSHaz

Earth’s atmosphere, lithosphere, hydrosphere, biosphere wreak havoc on land, property, human life. (difference: hazard->risk vs. disaster->damage) Population concentrations vs environmental hazards, natural disaster:

Most dangerous: Pacific Coast states, eastern half of country (where majority of Americans live) Coastal regions, wooded areas, lakeshores, river valleys, mountains (->potential environmental

risks) -> people flock Great Plains, Great Basin (->safest places) ->lowest population density

US Demographics: People tend to live in hazard-prone areas (refer to p.43) deaths by disaster < deaths by accidents, violence, smoking due to:

Forecasting is improved -> people alerted -> take precautions (hurricanes, tornadoes, blizzards, floods, tsunamis, earthquakes, volcanic eruptions)

Engineering & site selection with safety: dams, levees, preservation of wetlands, reforestation, cellars (from tornadoes), firefighting strategies & technology (from conflagrations)

Types of hazards Atmospheric hazards: hurricanes, tornadoes, heavy flood-causing rain, blizzards, ice-related storms (hail,

sleet), lightning, drought Hurricane: in the Gulf & Atlantic coastal zones, (6/10 natural disasters): water (>wind) cause most

destruction (wind push water -> high waves, torrential rains -> severe flooding); Hurricane Katrina (New Orleans, LA) breach protective levees, drop 38 cm of rain. Damage: $80 billion.

Tornadoes, blizzards, hail, ice storms, flooding: most of eastern half Blizzards, drought, flooding: in Great Plains, much of interior West

The Pacific Coast Hazard-prone area, within “Ring of Fire” area (seismic, volcanic activities). From Cascades to Alaska,

Hawaii: active volcanoes In 1980, WA’s Mount St. Helens erupted violently, caused 57 deaths

From southern CA to AK’s Aleutian Islands, Pacific & North American plates slide, crunch, grind against one another => most earthquake-prone zones

Anchorage, Seattle, San Francisco, Los Angeles on geologic faults -> in constant peril (Earth creep, Landslides in La Conchita (CA), 2005, raging wildfires, periodic droughts)

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