A Melting Planet Essay -- Glaciers Ecology Essays

A Melting Planet Although most glaciers and ice sheets reside in areas that man does not inhabit, they are nevertheless important for society and the global environment. Due to anthropogenic activities over the past two centuries, the temperature of the earth is rising at an alarming rate. This rise in temperatures has resulted in an overall loss of ice mass worldwide, including a rapid depletion in mountain glaciers. The effects of glacial melt will have a significant impact on the future of the human race, so it is therefore important to have a firm understanding of glaciers. In order for a glacier to form, all of three conditions must be met. Firstly, the climate of the area must be cold enough so that snow that falls during the previous winter does not melt away entirely before the next winter begins. Next, the region must get enough precipitation in the form of snow for a sufficient amount of accumulation. Finally, the slope of the ground must be gradual enough so that the accumulating snow does not avalanche away. As more and more snow accumulates over many years, it puts a great deal of pressure on the underlying layers. The upper layer of loose snow is 90% air and gives the surface of the glacier its white appearance. The next layer of snow is more granular and is roughly 50% air, while the final layer of snow is firm with only 25% air. Below these three layers, roughly at a depth of 250 meters, the pressure is so great that the snow forms into glacial ice, which gives glaciers their characteristic blue color. This ice has less than 20% air and it t akes at least 10,000 years to form(Marshak 670-2). The great pressure on the bottom layers of ice also lowers the melting point of the ice. The pressure at the base of... ...el. Despite this fear of rising seas, society continues to abuse fossil fuels. Works Cited Cyrosphere. http://www.panda.org/resources/publications/climate/climate_change/page4-5.htm Greenpeace: Ka Roimato – New Zealand. http://archive.greenpeace.org/~climate/docs/franz.pdf Marshak, Stephen. Earth: Portrait of a Planet. W.W. Norton & Company; New York, 2001. National Science Foundation – Ice Sheets. http://www.nsf.gov/od/opp/support/icesheet.htm Nesje, Alte. Glaciers and Environmental Change. Oxford University Press; New York, 2000. Oerlemans, Johannes. Glaciers and Climate Change. A.A. Balkema Publishers; Lisse, 2001. USGS: Glacier Monitoring in Glacier National Park. http://nrmsc.usgs.gov/research/glaciers.htm Warrick, R.A. Climate and Sea Level Change: Observations, Projections, and Implications. Cambridge University Press; New York, 1993.