Set The Stage For Ice Age
Deshawn Ballard and Danielle Albright
When was the last ice age?
http://www.howitworksdaily.com/environment/when-was-the-last-ice-age/
The Wooly Mammoth
this wooly mammoth was frozen in a block of ice about 1 million years ago
The glacier
A glacier is know for a big block of ice floating in the water. scientist believe that this is evidence from the last ice age.
The Ice Age
This solar variable was neatly described by the Serbian scientist, Milutin Milankovitch, in 1938. There are three major components of the Earth's orbit about the sun that contribute to changes in our climate. First, the Earth's spin on its axis is wobbly, much like a spinning top that starts to wobble after it slows down. This wobble amounts to a variation of up to 23.5 degrees to either side of the axis. The amount of tilt in the Earth's rotation affects the amount of sunlight striking the different parts of the globe. The greater the tilt, the stronger the difference in seasons (i.e., more tilt equals sharper differences between summer and winter temperatures). The range of motion in the tilt (from left-of-center to right-of-center and back again) takes place over a period of 41,000 years.
How The Earth Has Changed
Earth is warmer today than it has been for most of the last 11,300 years, new research has shown.
Scientists studied fossils recovered from 73 sites around the world to track global climate to the end of the last Ice Age.
They found that for 70% to 80% of this period, which dates back to the start of the Holocene era in which we now live, temperatures were cooler than they are now.
Click here to watch a video on how the earth/environment has changed :) :D http://www.youtube.com/watch?v=fyXwFK603J4
Evidence
The evidence for past Ice Ages lies everywhere in the Northern Hemisphere: in lands scraped and gouged by glaciers, in pothole lakes, in piles of gravel, sand, or loess, in high shorelines surrounding arid basins. These artifacts can be found far from active glaciers or ice caps; aditional evidence is found in the remaining glaciers themselves, and in the great ice caps of Greenland and Antartica. Cave lion ,uintatherium have gone extinct during the ice age.
was there an astronomical event that began the ice age??
The Story Of The Ice Age
Imagine yourself in a time machine, going back in time about 20,000 years. You get out of the machine and all you can see is ice. All around you are miles and miles of ice. You'd think you must have landed on a glacier or frozen lake. Actually, you are in the ice age.
About 1/3 of the earth was ice. The most recent ice age was almost 10,000 years ago. As the earth started warming up the ice started to melt. The last ice age left traces that it was there. It left GLACIERS!!! Sheets of ice covered valleys and rivers. Ice spread to different parts of the world. Scientists called it the ice age. It kept melting, then froze again. This went on for about a million years. About 10,000 years ago the earth started to warm up. Sheets of ice started to melt. As the ice melted it left lakes and broad valleys with a mixture of rocks and soil. The only ice left was up high in the mountains. The glaciers that you see now are what is left over from the ice age.
Do you ever wonder how we know that ice ages really exist? Well one reason is that it left clues. Louis Aggasiz was one of the first scientists to study the clues of the ice age. An erratic is a large boulder, and when Agassiz told some scientists that the boulders had been left there by a glacier they thought that he was out of his mind. The scientists thought they were put there by icebergs, Noah's flood, and witches.
The reason Louis Agassiz proved that they had been put there by glaciers is because they were made of a kind of rock that you can't find naturally in that area - granite. Because of that he proved that they can't be from there, they were from somewhere else. Other proof that the ice age really existed is: polished bedrock, sand and gravel piles, big valleys, and rough mountain tops.
read more at http://library.thinkquest.org/3876/iceage.html