Earth's Model Of Total Extinction example essay topic

A most recent inquiry into climatic change during the ice age and it's possibility of reoccurring is the Snowball Earth Hypothesis advanced by Paul Hoffman of Harvard University. Snowball Earth Suggest that before the Ice age, continents ice free at the poles enhanced the reabsorption of carbon dioxide through erosion of silicate minerals, reducing the greenhouse effect making the earth colder until it reached a runaway point. This effect is Hoffman calls albedo, when the atmosphere becomes so cold it can never warm up again. This is what occurred during the ice age, until volcano activity saturated the atmosphere with carbon dioxide to a point that it trapped radiation from the Sun and rewarmed the climate causing glacial thaw. Evidence of this event is cap carbonates that show relative dating at the ice age, found in abundance in several different world regions, at certain levels the cap carbonates would indicate if carbon dioxide was emitted into the atmosphere, by showing carbon levels that would demonstrate how much photosynthesis was occurring.

Iron rich rock deposits indicate that absents of oxidation would mean the atmosphere contain no oxygen, without oxygen their is no life, therefore other evidence of total extinction. So experts dispute the oceans were encased beneath a kilometer thick sheet of ice sheet, or that all life became extinct. The evidence of the Snowball effect is challenged that levels of carbon had not reached those required to satisfy the model and that alternative models are possible to explain the arrival and conclusion of the ice age. Iron had not oxidized because the glacial's prevented contact with the atmosphere that would of subjected these rocks to mechanical weathering. The Snowball Earth Hypothesis bases its theory on an invalid model of earth at that time. Ancient earth of the Proterozoic 750 million years ago existed in a separate dimension then what the model is based upon.

There wasn't much of an ocean completely beneath a glacial sheet of ice a kilometer thick. The plate tectonic model of pangaea locates it with Antarctica, this shifts the planetary land of the continents to one hemisphere and connects it with already glacial covered Antarctica. So rather than ice on the ocean around the Antarctica, the glaciation would be linked on pangaea surface; wouldn't this detrital effect sort of conduct the refrigeration and branch out the glacial even further into the continent, instead of a lack of CO 2, temperature variation occurs from extended glacial mass that colds everything within reach of its frost thermal gradient, slightly different sort of albedo than Snowball Earth describes. Another possibility is the astrophysics of a primitive earth with a supercontinent covering one hemisphere only and a southern pole. Uranus is said to have a 86' tilt of it axis of rotation is nearly its plain of orbit, and two moons of Jupiter, one Europa is completely frozen over by ice, the other called Io is so close to Jupiter the gravitational pull has caused volcanic activity and suggested the moon is pulled at one side of its surface changing it's shape. Might have the same circumstances happened on Proterozoic Earth, in addition to a dimmer primitive Sun, the earth could be holding a different tilt in favor of significant mass all to one hemisphere and pole.

Copernicus said the earth had a wobble. If such a wobble existed in Proterozoic time, the wobble could have a velocity to provide a contributing mechanism to quake the continents apart, terminating the Varan gian glaciation. The principle of uniformitarianism might superposition the first glacial to thaw at Death Valley, CA since temperature variations show that Death Valley, Ca at least today is the hottest Fahrenheit on Earth at 128' and once covered under a glacier. Physical geology theory states that oceans waters and hydrosphere itself occurred because of comets from outer space colliding into earth.

The atmosphere and water vapor said from volcanoes, then why not possible that no oceans existed in the quantify know today, and what filled the oceans and created the hydrosphere was comet impact and glaciation thawing. So while a Snowball Earth could be true, the relative scale of the oceans was smaller in ancient geologic time, not until comets filled the oceans with water and the glaciers thawed did oceans large as today form. Thus, why all hemispheres have evidence of glaciation. The one earth concept with Antarctica would support global glaciation.

Furthermore even today the northern pole is a glacial ice sheet, so a detrital effect is occurring from two directions. Would a pangaea earth be smaller and more oval, having a slowing rotation and orbit even prolonging the cold and warming of earths surface all the land mass away from the Sun during orbit might go under a deep freeze until the earth completes a rotation in orbit, once on the solar radiated position, a thaw would cause a wobble? Uranus would seem to indicate this is so. Europa Jupiter moon is said to have liquid water beneath it's crust of ice, and yet Europa is smaller than earth, makes a tectonically smaller Proterozoic Earth more workable if the entire mass is frozen in glacial ice. Finally the end of all life after it just began seems to overlook the fact that earth could be an accretion disk that even prior to ignition of the nebula collected all the possible matter the first big bang ever created.

Since the earth has a biosphere that scientist continued to thrive during the ice age, as shown through cap carbonates. At the very moments of preignition, ignition there was already life all the atomic matter that could harbor life accreted on planetesimal earth. Hence, even before time all the matter that could exist hat was alive existed before the big bang. If it survived these conditions than, Snowball Earth's model of total extinction could not be the only model to explain the causes glacial post glacial events of the ice age.

Because there was life even before there was a nebula. The Snowball Earth Hypothesis while probably accurate in theory, that is climate reaching cold to a point of no return is true, after all water freezes in a crystalize d mine rial water under certain conditions, yet to assert that earth once completely froze over including the oceans and that all life became totally extinct is unlikely. The Snowball Earth hypothesis explains another demission that only exist in theory.

Bibliography

Edward J. TarbuckFrederick K. Lutyens Earth: An Introduction to Physical Geology Michael Zeilik Astronomy: The Evolving Universe Paul F. Hoffman Snowball Earth: Promise and Problems Martin J. Kennedy The Snowball Earth: Myth or Methane? Grant M. Young Is Snowball a 'No-Ball'? : The case against the Snowball Earth Hypothesis.