Global Ice Ball: Reasons and Behaviors of Glaciations

• Main Authors: Andy Molina, Becky Baek
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Ice Sheet
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.138.1807; http://www.trincoll.edu/~cgeiss/tr/tr1/tr1_p3.pdf

Glaciers are permanent bodies of ice and compacted snow that have become deep and heavy enough to flow under their own weight. Paleontologist Louis Agassiz was the first to regard glaciers as major contributors in shaping the Earth's landscape. Glaciers form in cold places where snow can accumulate and does not melt in the summer months. As more snow falls, it accumulates more, and gets more compact. This densely compact snow is called firn. This process of pressure solution goes on until the firn is compacted enough to form ice. If this happens on a broader scale, a continental glacier (also known as an ice sheet) is formed. These usually form during years of glaciation, when the Earth's global temperature drops significantly. Glaciers advance and retreat throughout their existence in a cyclical pattern determined by Milutin Milankovitch. His calculations showed that glaciers advance at a frequency of 100,000 years, 40,000 years, and 20,000 years apart from the last advance. If positive feedback mechanisms favor glaciation, then the Earth will experience an ice age. Geologists have determined that there have been 5 major ice ages in the planet's history. The most recent of these (the Pleistocene Ice Age) ended roughly 11,000 years ago. Presently, the Earth is in a period of interglaciation. But with the recent outburst of burning forests and fossil fuels, temperatures are steadily climbing, and the prediction of another