Документ взят из кэша поисковой машины. Адрес оригинального документа : http://zebu.uoregon.edu/postscript/climate.ps Дата изменения: Sat Jul 2 02:14:20 1994 Дата индексирования: Mon Oct 1 22:40:02 2012 Кодировка: Поисковые слова: rigel

Climate Change:
ffl Periodic Ice Ages: ! Glacial­Interglacial Periods
ffl Major Period: ! 100,000 years; \DeltaT 9 o F
ffl Minor Period: ! 12,000 years; \DeltaT 5 o F
ffl Smaller Periods ??: ! 1,000 years; \DeltaT 3 o F
We currently are nearing the end of a small, minor
interglacial period
Major Ice Ages: Most of the Planet is Covered
Minor Ice Ages: 40 o Latitude and Above
Little Ice Age: (1000­1850 AD; Irish Potato Famine;
Nisqually Glacier)

Effects of Ice Ages
ffl Changes sea level by 100 meters ! exposes con­
tinental shelfs
ffl changes continental shelf composition due to in­
creased deposition during melt
ffl changes hydrological cycle through less evapora­
tion
ffl changes landscape ! Great Lakes; Seattle; Stoss
and Lee
ffl Changes drainage patterns
ffl changes topsoil characteristics
ffl massive flooding episodes ! Eastern Washington

Causes of Ice Ages
ffl needs to be PERIODIC!
ffl Solar Cycle ! no evidence
ffl Volcanic Dust in Atmosphere ! why periodic?
ffl CO 2
Cycle ! why periodic? ! factor 2 reduction
causes 7 o F drop
ffl Increased precipitation at poles due to changing
orientation of continental land masses
ffl Changes in mean temperatures of ocean currents
Orbital Variations of the Earth!
ffl Eccentricity variation ! 90,000 years ! 5% vari­
ation around mean value. This is due to Jupiter.
ffl Change of tilt of axis ! 24,000 years
Clearly this is the Cause!