Ice Age

15). Others blame the introduction and/or burying of algae and plankton. They believe that algae replaced carbon dioxide with oxygen thus causing a decrease in CO2 (Hughes 1993, pg.15). Others believe that the Himalayas shed sediment into the Indian Ocean that buried the algae, plankton, and other plants entombing the carbon dioxide (Watson, 1997). This essentially locked up the Carbon Dioxide so that it could not hold the sun's radiation closer to the earth. By taking away this source of carbon dioxide, the earth began to cool. This is believed to cause an ice age. .
             VOLCANIC ERUPTION.
             Scientists have found new evidence, through core sampling, that eruptions in the northern pacific 2.6 million years ago were at least ten times larger and more frequent than previous volcanic (Pen*censored* 1992, pg. 324). These eruptions coincide with what David Rea, marine geologist, says is the "time when northern hemisphere glaciation really kicked in" (Pen*censored* 1992, pg. 324). .
             The eruptions would cause an increase of fine volcanic dust in the atmosphere that would "reflect the sun's energy back into space, causing the earth's climate to cool" (Imbrie 1986, pg. 64). This theory essentially claims that the dust would put the entire earth "in the shade". Just as humans get into the shade to cool off, the earth would also cool off. This cooling effect is thought to be enough to trigger mass glaciation. .
             CONTINENTAL SHIFT AND UPLIFT.
             The theory of continental shift states that ice age eras occur when continents migrate into polar latitudes, and end when they move back toward the equator (Hughes 1994, pg. 15). The "high latitude land" absorbs less heat then the ocean; therefore, it is the perfect "platform for the accumulation" of ice and snow (Hughes 1994, pg. 15). Because the "ice sheet intensifies the cold temperatures by reflecting the sun's energy back into space" (Imbrie 1986, pg. 75), the ice sheets increase in size.