Torrents of water rushing down from once benign mountain lakes are killing thousands of people, coastal villages are being destroyed, and water supplies are being severely threatened by one of the newest natural killers in the world. What is this killer and is this reality or fiction? Glacial melting is the killer in question and currently this statement is fictional, however there is good reason to believe that this fictional statement is about to become a reality. Although many people believe that accelerated glacial recession is not a concern, it is a major problem because it has the potential to create catastrophic flooding, it is a cause of dramatic climate change, and because much of the world’s fresh water supply is held within the glaciers of the earth.
In order for one to understand the concept of accelerated glacial recession those interested should have a basic understanding of glaciers and what the term means when being used within the context of this paper. According to McGeary, Plummer, and Carlson the definition of the word glacier is, “A large, long-lasting mass of ice, formed on land by the compaction and recrystallization of snow, which moves because of its own weight” (556). At the same time McGeary, Plummer, and Carlson define the word ice cap as, “A glacier covering a relatively small area of land but not restricted to a valley” (558), and once again they define an ice sheet as, “…a mass of ice that is not restricted to a valley but covers a large area of land (over 50,000 square kilometers)” (472). For the purposes of this paper the term glacier will be used to represent any mass of ice which was formed through the process of recrystallization; therefore the term glacier will be used to represent valley glaciers, ice sheets, and ice caps, unless otherwise noted. The process of recrystallization as stated is a fairly simple concept. In its most basic form recrystallization in the context of glaciers can be described as snow falling in an area where due to one climate variable or another, the snow does not completely melt away before more snow falls on top of the older snow. This process continues over a period of many years and eventually the snow layers that have been buried beneath the newer layers start to bond together, eventually creating what is called glacier ice.
The basic geography of a glacier consists of three parts; there is the accumulation zone, which in relative terms usually occupies the higher elevations of a glacier. It is in this zone that more snow falls annually then actually melts away, in turn causing a glacier to grow, or to recede if that snowfall starts to lessen and not enough snow is leftover to grow new ice. The second geographic area of a glacier is the ablation zone, this area is generally lower in elevation than the accumulation zone, and it is here that the snow melts off usually resulting in bare ice during warmer months. The third part of a glacier is called the terminus; this is the end of the glacier. For the purposes of this paper it is important to also understand one of the geologic aspects of a glacier called a moraine. Moraines are basically piles of ground up rock and debris that are left along the sides of glaciers. Sometimes moraines run down the center of a glacier because as different glaciers merge together, the moraines that were once on the side now run down the middle; when this occurs the moraines running down the center of the glacier are called lateral moraines. Another type of moraine that forms is called a terminal moraine and this type is formed at the end, or terminus, of the glacier. A terminal moraine formed at the end of a glacier is once again a large pile of rock and debris, and as the glacier continues to recede the debris pile is left in place, leaving a pile of rock set away from the ice of the glacier itself.
Sometimes when these debris piles are leftover they act as dams causing melting waters coming from the glacier to form into lakes. As one can imagine the faster a glacier melts the more water is melted away and left to fill these glacial lakes, if the water entering the lakes fills up faster than the lakes can empty it through small run-off streams, then “wham!” the natural dam formed by the old terminal moraine fails, causing thousands of gallons of water to rush forth in a torrential flood, annihilating anything in the path of these killers. According to the United Nations Environment Programme (UNEP) and the International Centre for Integrated Mountain Development (ICIMOD), they have “… reported the finding of at least 44 glacial lakes in the Himalayas that are filling so rapidly they could burst their banks in as little as five years’ time, sending millions of gallons of deadly floodwaters swirling down valleys and putting tens of thousands of lives at risk. The lakes are rapidly filling with icy water as rising temperatures in the region accelerate the melting of glaciers and snowfields that feed them” (“Global Warming Triggers Glacial Lakes Flood Threat”). This is just one of the few problems associated with accelerated glacial recession and one of the problems that is facing the people of the world as glaciers quickly melt away.
Another problem facing the planet is that not only is the rate at which glaciers are melting increasing due to climate changes, but the accelerated rate also has the potential to cause some very significant climate changes in itself, thus causing a very violent and horrific cycle. Science Daily recently published an article reflecting the findings of Dr. Rainer Zahn, a research professor at the UAB Institute of Environmental Science and Technology. According to his findings, “… when the great ice sheets covering North America and Scandanavia [sic] melted at the end of the last ice age, the subsequent flow of fresh water into the North Atlantic caused the greatest natural disturbance in ocean circulation in the last 20,000 years” (qtd. in “Melting Of The Greenland Ice Cap May Have Consequences For Climatic Change”). The ocean helps to regulate the different climates of the earth by a mechanism of heating and cooling. According to Dr. Rainer Zahn’s studies, “Any variation in ocean circulation may lead to substantial and abrupt climate changes (that is to say over less than 30 years) on a global scale” (qtd. in “Melting Of The Greenland Ice Cap May Have Consequences For Climatic Change”). In essence the accelerated melting of the polar ice caps will affect the oceans’ temperature and the way that the oceans’ waters are circulated around the earth. This change will create even more glacial melting, in effect causing the glaciers to melt faster and faster, changing weather patterns and climates all over the earth due to the change in the circulation of ocean currents. These facts lead one to believe that the acceleration of glacial recession is in fact a very large problem facing the earth.
There is yet another very large problem associated with accelerated glacial recession, and that is the fact that according to information presented by the United States Geologic Survey (USGS) webpage, pertaining to where the earth’s freshwater is stored, “…about 69 [sic] percent, is locked up in glaciers and icecaps…” (Where is the Earth’s water Located?”) Using the table presented on the same page of the USGS website, it states that only, “…0.26 percent of fresh water is stored in lakes…” (“Where is the Earth’s water Located?”) What does this mean to the people of the world? In some regions there are whole populations that are dependent on glacial runoff as the primary source of freshwater, and with the accelerated rate of glacial recession there is a great risk of a large-scale freshwater shortage in the near future.
Some people argue that accelerated glacial recession is not a large concern for the global community of the earth because they have no concept of the impact it will have upon the earth as a whole. The information that has been presented sets forth several examples of large-scale impacts that will be felt by all inhabitants of this planet as glaciers continue to melt at an alarming rate. These problems are not just localized, when they happen it will impact each and every person living on this planet.
There is a time to stand still and do nothing, and there is a time to act; the time to do nothing has passed, and the time to act is upon us. As a person, as a nation, and as a global community we need to provide more in the way of research and try to understand what is happening to the glaciers of this world. It is imperative to the survival of our population that we find out why glaciers are melting at such an alarming rate and if there is anything we can do to help once again slow down the rate of recession.
McGeary, David, Charles C. Plummer, and Diane H. Carlson. Physical Geology: Earth Revealed. Ed. Thomas C. Lyon. 5th ed. New York: McGraw-Hill, 2004.
“Global Warming Triggers Glacial Lakes Flood Threat.” UN Chronicle: Online Edition. 2002. 18 Feb. 2008. http://www.un.org/Pubs/chronicle/2002/issue3/0302p48_glacial_lakes_flood_threat.html
Universitat Autonoma de Barcelona. "Melting Of The Greenland Ice Cap May Have Consequences For Climatic Change." Science Daily. 8 May 2007. 18 Feb. 2008.
http://www.sciencedaily.com/releases/2007/05/070507113401.htm
United States Geologic Survey. “Where is Earth’s water located? Water Science for Schools. 1 Feb. 2008. 18 Feb. 2008. http://ga.water.usgs.gov/edu/earthwherewater.html
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