BISC - class notes

BISC - class notes - BISC lecture 10/23/07 Ocean conveyor...

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BISC – lecture 10/23/07 Ocean conveyor belt: cold water sinking in the seas, and moving south etc. - slow process (several thousand years) - moves heat elsewhere in the world Glacial Periods: - NY, London, etc were once covered in ice. - 22 glacial periods in the past 4 million years. - 10 degrees change in temperature would affect the world a LOT. - 10,000 years ago = last glacial period/ ice age o Climate was too cold; agriculture developed afterwards. - sea level lowers; the water is locked up as ice. - sea level all around the world lowered by 125 meters; it would lower somewhat and stay there for a while. o THIS IS CALLED TERRACES - marine terraces etc. its hard to see terraces. - Coastal terraces reach the beach, then have - Mt. Sangragroniel (across from palm springs) = 2 nd most glacieated mountain. - Ocean Upwelling* (search up the meaning) El Nino (a climatic phenomenon): - Movement of air and ocean surface waters from the east indies to south America during El Nino. - Water is moving from coast of s. America towards Australia and Indonesia; basically along the equator. - When you have an El Nino, the winds reverse. i.e: movements from indies to S.america. - When this occurs, there is a change in temperature between the two areas. THEREFORE many animals in those areas die as temperature is too low etc. - Happens roughly every 3-7 years. - Rsults: die offs of many planktons. everything in the food chain above that die off too lots of seabirds die too (no more fish). Hundred of thousands. - Climatic change = major in may parts of the world - ELSO – ‘El Nino Southern Oscillation’ La Nina - A period of drought (opposite of El Nino). California we’re experiencing a La Nina right now. - Changes in rotation of the earth - Changes in reflections of the light/heat off the earth. - We don’t really know exactly why it happens; there are many reasons.
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Greenhouse effect: - most important = water vapor o biggest absorber of heat from sun. - rapid change in temperature in northern hemisphere (Europe). - Carbon Dioxide: ppl were skeptical in that this was a factor in global warming. Pollen grates: - take a column of sediments from lakes etc to see what things were living in the past. - The specialist HEAT GASSES: METHANE - 23X as much solar energy absorbed = METHANE - Comes from cattles. -
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This note was uploaded on 06/21/2008 for the course BISC 102Lxg taught by Professor Kiefer,bakus during the Fall '06 term at USC.

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BISC - class notes - BISC lecture 10/23/07 Ocean conveyor...

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