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COURSE LECTURE NOTES:

| SCIENCE | MATTER | SOLAR SYSTEM | PLANETS | ATMOSPHERE | WIND and TEMPERATURE | HUMIDITY | WEATHERING | SOIL | SEASONS | MASS WASTING | SEASONS and CLIMATE | WIND WORK | STREAMS | LAND FORMS | GROUND WATER | CAVES/KARST | THE OCEAN | TIDES & ESTUARIES | WAVES | GLACIERS | GLACIAL LANDFORMS | VOLCANOES | VOLCANOES | CHON | PLATE TECHTONICS | EARTHQUAKES | ROCKS | CLIMATE CHANGE |

SEASONS

Changes in the weather, hot, cold, damp, dry, etc. caused by the 23.5 degree angle between Earth's axis and true North.
    I - Spring - about March 21st (Spring Equinox) to about June 20th (Summer Solstice)
    II - Summer - about June 20th (Summer Solstice)to about September 20th (Fall Equinox)
    III - Fall About September 20th (Fall Equinox) to about December 21st (Winter Solstice)
    IV - Winter about December 21st (Winter Solstice) to about March 21st (Spring Equinox)

Seasons Diagram


    albedo - % of reflected sunlight
    aphelion - Earth's furthest point from the Sun - 3 July
    perihelion - Earth's cloesest point to the Sun - 3 January

Ice ages - well known ones

    end of Proterozoic
    Mississippian Pennsylvanian aka carboniferous
    Pleistocene

Envionment/conditions during Pleistocene 1.8 mega years ago to 10 kilo years ago

    episodic ice ages
    few deserts
    lower sea level large mammals - mastodon, mammot, giant ground sloth, cave bear, wooly rhino
    "cave man" (Cromagnon - us) over kill - humans killed off all the larger mammels. Large groups were hard to sustain so the population divided into smaller groups 12000 Ya, then we over killed the larger mammels by doing things like driving a herd of bison over a cliff to harvest a few while the rest rotted and were wasted.

Mojave climate during Pleistocene

    woodlands and lakes
    abundant game - large and small

Results of Little Ice Age - mid 13 to mid 18 hundreds

    wetter
    change in crop patterns
    crop failures
    wars - unrest
    French revolution

Since the Pleistocene

    global warming
    increased deserts
    droughts - crop failures
    shift in crop patterns

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