Casandra E
3rd hour English
The Ice Age
Introduction
What was the ice age and what happened during it?
The Ice Age was a period where major ice sheets covered the world. Where some animals became extinct. The first Ice age started about 800 to 600 years ago.
What was the ice age?
The Ice Age is usually referred to as the Pleistocene glacial epoch, when numerous separate ice ages occurred.
About 2 million years ago the earth began to undergo big changes. The polar ice caps increased and became huge. During the ice age, it was much colder than it is now. Snow took up much of the land, glaciers and ice sheets extended over larger areas. Because if the many glaciers, the sea levels were lower.
About 7 million years ago, ice sheets began to form in North America, Europe, and Asia.
Glaciers started to form in Antarctica about 38 million years ago, forming the Antarctic ice sheets.
When did major periods with lots of ice take place?
Three major periods with lots of ice and glaciers took place about 900 million and 600 million years ago. Geologists call places with major ice glaciers covering the land “glacier epochs”. There were two more glacier epochs about 450 million and 300 million years ago. The most recent one occurred mainly during what scientists call the Pleistocene Epoch, a time that began around 2 million years ago.
Has the Ice Age been documented?
The beginning of the ice age has been well documented by fossil records; scientists are not sure what caused the cooling. Two Rhode Island researchers suggest that the first ice age could have been set off by lots of world wide volcanic eruptions.
Even just one volcanic outburst adds dust to the atmosphere that it reduces the amount of sunlight getting to earth. The result can be a brief but effective cooling of the earth’s climate. If a bunch of volcanic eruptions were set off, the earth could get much colder very fast.
Many animals became extinct
Many animals became extinct during the ice age. Many people say the wooly mammoth became extinct in the Ice Age, telegraph.co.uk says “Wooly mammoths appeared in Eurasia about 300,000 years ago. They died out around 5,000 years ago, after the ice age.” Humans probably were the final cause of the wooly mammoths extinction. Humans would only have to kill one mammoth every three years after the ice age to drive the wooly mammoth to extinction.
Animals that became extinct in the ice age include the Irish elk, Surian Camel, Giant Sloths, Saber Toothed tigers, and the North American Lion.
Some people wonder how reptiles survived the ice age. They are cold blooded, so they rely on warm temperatures. All the reptiles that survived migrated near enough to the equator to survive.
The end of the Ice Age
When the glaciers melted, they left behind soil and rocks, often in mounds and ridges, called moraines. Low places that had been scoured out by the ice filled up with water, forming lakes.
According to a new theory, the melting of a huge Antarctica ice sheet 14,000 years ago triggered the end of the Ice Age.
According to Icecore researcher Jorgen Peder Steffensen the gradual cooling in the last 40 million years has been caused by continental drift.
There also appears to be a ice age cycle. In the last 800,000 years there have been 8 ice ages, lasting about 100,000 years, separated by periods between 10,000 and 35,000 years.
Steffesen believes that the earth gradually got warmer due to the point in which the earth was in its rotation around the sun. Obviously the closer the earth is to the sun, the warmer it is.
Steffesen says there also appear to be “climate ripples.” That when it is colder in the south, it is warmer in the North and when it colder in the North, it is warmer in the south.
The end of the ice age could have just been during when the earth was close enough to the sun, or when a “climate ripple” happened.
Casandra
3rd hour
2/24/09
Work’s Cited
Humans were final cause of woolly mammoth extinction. Visited: Feb.5, 2009 http://digg.com/environment/Humans_were_final_cause_of_woolly_mammoth_extinction
Visited Feb. 6,2009 The bigger they are: 10 ice age giantshttp://www.mentalfloss.com/blogs/archives/17411
Enchanted learning Visited Feb. 10,2009 http://www.enchantedlearning.com/subjects/mammals/Iceagemammals.shtml
How reptiles became extinct. Visited Feb. 12 http://reptiles-knowledge.net/?p=64
Solved the mystery of the first Ice Age Visited: Feb. 13,2009 http://www.popularmechanics.com/science/research/1281731.html
How the Ice Age began Visited: Feb. 14,2009 http://www.time.com/time/magazine/article/0,9171,946527,00.html
Freeze Frame Visited: Feb. 17,2009 http://igs.indiana.edu/Geology/ancient/freezeframe/index.cfm
Antarctica Collapse began end of Ice Age? Visited: 2/24/09 http://news.nationalgeographic.com/news/2003/03/0317_030317_iceshelf.html
Economic expert.com http://www.economicexpert.com/a/Ice:age.htm
Niels Borhr Institute http://www.nbi.ku.dk/english/sciencexplorer/golden_spike_in_ice_core/spoergsmaal_svar1/
World book encyclopedia I 10 2008 edition
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