State of Research on the Snowball Earth Hypothesis Essay -- essays res

State of look on the sweet sand verbena macrocosm surmiseThe Snowball Earth meditation also known as the Varangia glaciation is a hypothesis presented in 2001 by Geologist Paul Hoffman. (Wikipedia, 2002)The hypothesis purposes that 540 million years ago during the Neoproterozic, a bar thick of chicken feed covered the oceans and glaciers the continents for 100 million years. Albedo when ice and snow reflect solar radiation into space, in absents of nursery gases, which dont follow within the atmosphere, heat therefore escapes the planet. A condition of temperature disequilibrium occurs, when freezing dusty reaches a state, the climate never warms to normal, and ice-c nonagenarian freezes the hemisphere and buries it under coarse glaciation. The glaciers begin when a green house gas, carbon dioxide, is depleted from wear of silicates. Once the atmosphere is depleted of carbon dioxide, it can not strike solar radiation. The global tempertures drops to cold and glaciation o ccurs, glaciation continues, temperature gradients drop further to colder, below freezing, cold is irreversible, glaciers reflect solar radiation into space. The lack of atmospheric carbon dioxide prevented greenhouse from occurring, earth is frozen until the hemisphere is totally glaciated. (Hoffman, 1998)Deglaciation can occur when volcanic eruptions saturate the atmosphere with carbon dioxide gas and resume the greenhouse military group on climate. Solar radiation is absorbed by greenhouse gases, rewarming the climate. A dramatic expansion of the biosphere occurred. (Cold) History of Snowball Earth HypothesisA tree toppled during a hurricane. A 700 million year old rock bed was discovered in Appalachia. The rock, diamictite consisted of basalt -size cobbles mixed with a slurry of okay silt and sand. The region consisting of Appalachian Blue Ridge range, Sharp filch mountain had once bordered a seaway cutting through and through Rhodina, a giant continent that included most of the worlds land. Sharp hand contained signs of tides, indicating the glacier had streached down to the sea. During this time, Virginia was 15 to 30 of the equator. Scientist wanted to know why ice was on the equator during the Neoproterozoic era. (Monastersky,1998)The group of scientists consisted of a biogeologist, geochemist, and tectonic geologist with the common goal of understanding the coevolution of life and environ... ...excursions a record of gas hydrate destabilization following Earths coldest intervals? Geology 286-287Hoffman, Paul F. Schrag, Daniel P. Snowball Earth Scientific America 21 Jan 2000 Scientific American Online. Online 31 Mar 2003Kennedy, Martin J. Christie - Blick, Nicholas Prave, Anthony R. (2001) Carbon isotopic composition of Neoproterozoic glacial carbonates as a test of paleoceanographic models for Snowball Earth phenomena. Geology 1135-1138Kennedy, Martin J. Runneger, Bruce Prave, Anthony R. Hoffmann, K -H. Arthur, Michael A. (1998) Two or four Ne oproterozoic glaciations? Geology 1059-1063Knoll, Andy The Planet ary Context of Biological Evolution Lead Teams Online. NASA Astrobiology build 2Apr 2003Monastersky, Richard, Popsicle Planet, The king of all ice ages may have spurred sensual evolution 22Aug 1998 Science News Online Online. Science Service 2 Apr 2003Simpson, Sarah Triggering a Snowball, Did Methane addiction Set Off Earths Greastest Ice Ages? Scientific America 16 Sept 2001 Scientific American Online. Online 1 Apr 2003Wikipedia, the free encyclopedia. Snowball Earth 29 Sept. 2002. Online. Wikipedia Internet 31 Mar 2002