Glaciers In Specific The Ice Age Glaciers example essay topic

Lake Michigan, Superior, Erie, Ontario and Huron; these five lakes located in North America make up the largest fresh water surface in the world. Each one around for several thousands of years, provides an important function to the Earth's eco system. What many might not know, each of these major lakes were formed from a glacier in what is called the Wisconsin an glaciation period. Glaciers are the starting point of many other recognizable landscape functions, such as mountains ranges, valleys and cliffs in addiction to lakes. These are the more commonly known functions of glaciers. Little do most people know, glaciers, with their amazing ability to preserve life, can tell scientists what the temperature was during one of the Ice Ages, or what a mother would use to feed her children millions of years after the fact.

Rarely do people give glaciers much thought, but perhaps more should be given. With the ever growing global warming taking over the Earth, glaciers are melting away, more and more every day and a more rapid rate than ever seen before. This directly effects people more than one would think, from your bottled water to how you might some day power your home. Glaciers take thousands of years to form, seeing as it is made when snow accumulates in one area for extended periods of time, each year another layer of ice and snow bury and compress the previous layers. These large masses of snow, recrystallized ice and rock debris begin to flow outwards and downwards under the pressure of their own weight. This is how materials from hundreds to even thousands of miles away can be found years later in a totally different location, as the glacier is responsible for its transport.

A glacier continuously deposits materials on top of each other and in this process sedimentary rock is formed. When a glacier reaches a certain thickness, it is able to create this movement, though very slow, from its massive size of the ice and a combination with the Earth's gravity. The physical effect of the moving glacier is to scour and grind the bedrock surface over which it travels as it advances, and then to redeposit vast quantities of sand, gravel and silt as it retreats. Further advances and retreats of subsequent ice sheets continue to rework these accumulated glacial sediments. The movement of glaciers have formed much of the land as we see it today since the last ice age occurred. Such as, the Swiss Alps, located in Europe or the Canadian Rockies, in the western location of Canada.

Glaciers not only transport materials, they can visibly change entire landscapes, forming mountains and lakes, as previously mentioned. The most southern part of Lake Michigan and Lake Erie were the first two of the five lakes to be formed around ten thousand years ago. Though their movement is very slow, glaciers do retreat and retract eventually forming depressed basins in the Earth due to the weight of the ice. On this particular glacier's last retreat, its vast amounts of melt water, water that has melted off of the ice, filled the previously made basins, forming our Great Lakes, as they are known today. In its earliest form about nine thousand years ago, Lake Superior, then known as Lake Duluth, was responsible for forming the St Croix and Mississippi Rivers, Minnesota's border with Wisconsin, by its southwestern drainage. Seven thousands years ago, the last of the ice in Lake Michigan melted and the land directly south of the lakes had become high enough that the lakes no longer drained in that direction and the Niagara River formed, becoming Lake Erie's outlet.

Also previously mentioned, these lakes are in combination making up the Earth's largest freshwater surface. This is because of the glacier which was responsible for its formation was huge. Not all glaciers are these large however, as they can vary in size, being from a hundred yards, the size of a football field to hundreds of kilometers, spanning across a huge surface area. Central Asia is the largest glacier-covered area (109,000 square kilometers) outside of the Antarctic and Greenland. In total however, all glaciers of the world currently make up about ten percent of the Earth's surface (15,000 square kilometers). Antarctica in itself makes up for 11,965,000 square kilometers or ninety percent of its surface area and Greenland makes up for 1,784,000 square kilometers or eighty percent of its surface area.

The only types of glaciers to exist in Antarctica and Greenland are what are called ice sheets, which are simply massive amounts of glacial ice and snow. Other types of glaciers include ice shelves; the largest one being the Ross Ice Shelf which is over five hundred thousand square kilometers in Antarctica, ice caps; simply speaking, immature ice sheets, mountain glaciers; developing high on mountainous regions, valley glaciers; originating from mountain glaciers, piedmont glaciers; most famous one being Malaspina Glacier in Alaska covering over five thousand square kilometers and cirque glaciers; typically found on mountainsides. Each are essentially the same, but just might vary in typical location found, landscape formed or movement behavior. Since glaciers require certain climates to exist, they generally are formed in regions with heavy yearly snowfall such as mountainous or polar regions, but they are present on nearly every continent in the world, even in Africa, located in the middle of the Sahara Desert.

Surprisingly, in an area such as Siberia, one of the coldest points in the world, no glaciers exist, on account of the lack of yearly snowfall, which is a glacier's key to survival. Since the time for glaciers to form and create movement takes several thousands of years, they act as almost a history book to scientists. They are able to preserve life forms and even climates and lifestyles to later be discovered. As a glacier is able to retreat and retract, so called air pockets are formed in the ice. First the fragile snow crystals break as they are compressed by the weight of the snow settling on top of them or as they are wetted by melt water. These so called crystals are then compressed into an almost "salt grain" form and pockets, scientifically known as firms (German for 'last years snow'), between them remain connected.

It takes about one year, the winter-summer cycle, to complete. The density of firn is half that of water and about ten times the density of what people would know as "fluffy snow". These "ice pockets" or air bubbles are, incredibly enough, able to preserve the present climate they had been formed in. This is how scientists today had been able to discover that there were several different Ice Ages. Extreme care has to be taken when drilling into the glacier into these ice pockets, so as not to contaminate the air inside during extraction and analysis. It is understood that some allowances have to be made for some small changes in climate as the air will inevitably undergo some small changes.

But none the less, these air pockets are able to give scientists huge insight into the CO 2 and other gasses from over tens of thousands of years ago. In 1991, what is called "The Ice Man" was found in the Alps on the border of Italy and Austria. The Ice Man, to date, is the oldest and is basically a totally intact human preserved from 5200 years ago in a glacier. Because of the glacier's amazing ability to virtually make life come to a halt scientists can tell you his last meal was of some unleavened bread.

Looking at pictures of the Ice Man, it would show you a human corpse, looking as though it had only recently died, maybe around a few years old, skin still covering its body, a very clear frame of a skeleton and a face looking back at you. One would never guess it dates back over 5000 years ago. The ability of glaciers to preserve and even make life stand still, continues to surprise people today. Though the discovery of the Ice Man is amazing and has provided scientists with more invaluable information than they had gotten in years from that era, it is a sad fact that his discovery was because of the glacier's continuing and rapid retreat from the cause of much anticipated global warming. Because glaciers exist through a very delicate balance of climates, they are not able to survive the even smallest of increments in temperature caused from this global warming. This melting of glaciers, in specific the ice age glaciers, are causing sea levels to rise to about three hundred and fifty feet approximately worldwide.

In theory, if all of today's glaciers were to melt completely, the sea level would rise about two hundred and thirty feet. Mark Dyurgerov and Mark Meier, of CU-Boulder, says, "Some glaciers around the world now are smaller than they have been in the last several thousand years... The rate of ice loss since 1988 has more than doubled". Meier is a geological sciences Emeritus Professor, researcher and former director of CU-Boulder's Institute for Arctic and Alpine Research and Dyurgerov is an INSTAR researcher. It is being said, that with some of the more larger coastal cities, such as Houston, they are basically "sinking". They are not much above sea level as it is and with the ever increasing global warming and melting of the glaciers, the sea level is inevitably just going to rise.

To put things more in perspective, if the sea level of Bangladesh would even rise just one meter, it would put around half of the population (around one million) underwater. The amounts of CO 2 released into the air and the greenhouse effect as the result in higher increased human activity has increased so much in just the past two hundred years that glaciers that were once there one decade ago are nonexistent. Some of the US's major cities falling under water is not the only downfall of glaciers demise. The bottled water industry is a multibillion dollar industry and responsible for a lot of consumer economics. The industry boasts being able to deliver fresh, pure water bottled straight from a northern most glacier.

Scientists and engineers are continuously working in Norway, Canada, New Zealand and the Alps to produce hydroelectric power by using dammed glacial water. By using this more natural resource, energy use becomes more cost efficient, directly effecting consumers. And this is all on top of being a huge tourist attraction, drawing people from all over the world to be given the chance to be able to first hand touch a real glacier, in say Norway?