Minnesota's Glaciers

Any rainfall increases fluvial erosion. When rain does fall, this creates ephemeral streams causing water erosion due to fast forces of water. Flash floods are possible as well creating even more erosion.

It began 2 million years ago, Canada and the upper U.S. were covered in glaciers. All the repeated melting and freezing of the glaciers created thousands of cavities in the Canadian Shield, which were filled with melted glacier water which created the Great Lakes (and many other rivers and lakes). In the west, there used to be a HUGE lake (Lake Bonneville) but it drained into the Pacific Ocean through rivers and dried out

As this river of ice moved slowly over the hidden rocks, the base of the glacier grazed millions of sediments in the Earth. The after math composed of soil, pebbles, cobbles and boulders that pushed forward, smashing rocks into glacial dust. Then the climate began to warm. Melted water from the glaciers carried the soils and rocks away from the dissolving glacier, depositing its leftovers throughout the landscape. This combination of soils and rocks deposited. Then low hills, or moraines, were created across the state. Michigan's glacial drift averages 200 to 300 feet. The scraping of boulders created particles. The heaviest pieces formed ridges, which made the stream's flow in a certain direction. Lighter materials were carried further, dropping on the way as the flowing water slowed. These materials dried forming enormous, flat colored areas of sand, silt, clay creating a mixture called the outwash plains. The weight of the glacier over the Michigan basin was dropping, and the Earth began to recoil, like a sponge coming back to its original shape. The Michigan landscape began to appear. Plants began to approach on the shriveled landscape. Individual plants found a suitable growing environment near each other, which created a suitable home for

Champaign County was first covered by the Illinois Glacier (191,000—130,000 years ago), which leveled the region and covered it in a deposit of boulder clay. The county’s topography was then formed by the Wisconsin Glacier about 20,000 years ago. As lobes of ice from what is now Lake Michigan crossed the county, a deep (up to 300 ft) pile of glacial soil was created and topped by numerous moraines (any glacially formed accumulations of unconsolidated debris) forming small, flat watersheds with no outlets. The moraines formed as the Wisconsin Glacier advanced and receded many times over the Midwest. The Champaign moraine system now crosses the county in a northwest-southeast direction, and between the moraines ridges are broad plains of what used to be swampy land, most of which has since been artificially drained.

Running water moves sediment in the processes of erosion and deposition, causing different types of landforms. As you can tell in the picture above, Michigan’s topography plays a huge role on where the faster and slower flowing rivers are located and the transportation of the materials in the water depends on the speed of the rivers. Erosion is the breaking down of those materials by the agent, water. The water can erode the channel laterally and vertically, in the end, making the channel wider and deeper. There are different types of erosion: hydraulic action, corrasion, corrosion, cavitation, and attrition. Hydraulic action (above on the right) takes place at rapids and waterfalls because the force of the water removes rock particles from the bed and banks of the river. A great example of this in Michigan is Canyon Falls on the Sturgeon River. At the waterfall, the water is rushing at a high velocity, especially in the spring, causing rock particles to move downstream, creating a wider and deeper river. Eventually the rivers velocity begins to decrease and particles start to deposit. This could also occur because lack of precipitation or an increase in evaporation. The deposition of materials at different locations of the river that they began changes the shape of the river, and effects Michigan as a whole in the end. The particles can travel all the way to the mouth of the river, in this case, Lake Superior, causing

During the Pinedale glaciation, there were two ice sheets. One of them being the Cordilleran Ice Sheet. The Cordilleran Ice Sheet was comprised of three main lobes. The Puget Lobe, Okanogan Lobe, and the Purcell Trench Lobe. The one lobe in Northern Idaho, near present day Lake Pend Oreille, was the Purcell Trench Lobe. When these sheets of glacial ice moved south they caused an ice dam to occur. J.T. Pardee states that “The evidence of icebergs, together with the apparent regency of the lake and the variable height of its surface, connect this lake with the glacial period, and readily lend themselves to the suggestion that its dam was of ice” (Pardee, 1910) This ice dam blocked the Clark Fork River which is near the boundary of Idaho and Montana. The water from the river was blocked and began to build up and formed Glacial Lake Missoula. Water

Lake deposits are primarily fine-grained clay- and silt-size sediments. The most extensive area of lake deposits is in north- ern Ohio bordering Lake Erie. These deposits, and adjacent areas of wave-planed ground moraine, are the result of sedimentation and erosion by large lakes that occupied the Erie basin as Wisconsinan-age ice retreated into Canada. Other lake deposits accumulated in stream valleys whose outlets were temporarily dammed by ice or outwash. Many outwash-dammed lake deposits are present in southeastern Ohio far beyond the glacial boundary. Peat deposits are associated with many lake deposits and formed through the accu- mulation of partially decayed aquatic vegetation in oxygen-depleted, stagnant water.

Out wash has small sediments sorted in layers, and Till has large sediments not sorted into any layers. Till can leave behind features like Kame, Drumlins, and Moraines. Drumlins are elongated hills of till. Drumlins can be found in Central Minnesota and/or South of Brainerd. Moraines are very large ridges of Till. Moraines can be found in West/Central Minnesota. Outwash can leave features behind like Outwash Plains and Eskers. An Outwash plain formed by melt water of a glacier. Outwash plains are important because they are very great for farming which is a huge part of America. Glaciers can leave behind features like Kettle Lakes. Kettle Lakes formed by ice chunks falling off the main glacier, causing an indent on the earth's surface. Then the ice chunk will melt causing the hole to fill up with water. Most of Minnesota’s Kettle lakes are in Moraine/Terminal Moraine

The present configuration of the Great Lakes basin is the result of the movement of massive glaciers through the mid-continent, a process that began about one million years ago. . . . Studies in the Lake Superior region indicate that a river system and valleys formed by water erosion existed before the Ice Age. The Glaciers undoubtedly scoured these valleys, widening and deepening the and radically changing the drainage of the area (Encyclopedia Britannica )

Much of Michigan’s landforms can be traced to the Pleistocene period, which lasted until around 10,000 years ago. Of the four periods of glacial movements in the Pleistocene period, the Nebraskan, Kansan, Illinoian and Wisconsin, the Wisconsin Glaciation is the most prominent cause of the current Michigan landscape in the Upper Peninsula and Lower Peninsula (Damery, 2001). The Wisconsin Glaciation occurred about 100,000 years ago. The climate cooled, and the Laurentide Ice Sheet was spread across the continent. About 31,500 years ago, this glacier began to approach Wisconsin. The Laurentide Ice Sheet expanded in the area that today is Wisconsin and Michigan, for 13,500 years before the ice began to melt and retreat. As this ice sheet moved south, valleys were filled in, the drainage systems of rivers were blocked, and major basins that are now the Great Lakes were gouged. The graphic below shows the land that the Laurentide glacier

The Late Pleistocene period was when the final glacial episode of ice sheets covered much of the northern hemisphere. This event happened about 125,000 years ago and lasted

There are different types of glaciers that exist. Valley or alpine glaciers exist in mountain valleys. They occupy the space where a stream once was and become a glacial stream flowing down the valley. Ice sheets are a very different type of glacier. They are much larger and are at times referred to as continental ice sheets. They flow in all directions and cover the land they are on. An ice cap is another kind of glacier that covers the uplands and plateaus. They cover the surface they are on totally, but are smaller than ice sheets. The final type of glacier is a piedmont glacier. These cover the land at the bases of mountains and

Ehrlich on the other hand, has a very different approach to the way she talks about the issue. She uses a lot of sensory images and personal experience. She mentally paints a picture for us to see what is happening. She uses very intriguing vocabulary to describe the massive glaciers. In her essay, she uses subtle personification to describe the way the ice stands. Ehrlich talks about the way people go to see the glaciers fall and fail, but they are not interested in the strength it takes for them to hold themselves together. She makes an interesting statement of how glaciers are historians and archivists of our world. She describes how they hold everything from dust, to pollen and even gasses. This helps our world to look back and be able to see the way that the environment is changing over the years. She also makes a reference that the deterioration of the glaciers is a result of our “…smokestack and tailpipe society” (271). This seemed to be a harsh statement towards society as a whole. Without the new technologies, buildings, cars and everything that is grouped in with being considered a smokestack society, our world would not be anywhere near where it is today.

Remote sensing has become a very valuable tool for documenting the response of glacier to changing climate (Bamber and Kwok, 2003; Kuhn, 2007; Pellikka, 2007; Solomon et al, 2007) because the rugged terrain, inaccessibility and legendary poor weather of glacier areas has resulted in relatively few field- based studies. Indeed, in order to use glaciers and their changes as indicators of climate change, or as an early warning signal for sea level rise, remote sensing is the only tool to provide glacier change information from all the continents and from a large number of glaciers and ice sheets. On the other hands, because space borne and airborne remote sensing data provide superior cost- effective and area effective data and methods for monitoring the glaciers and their changes, part of this monitoring can be carried out by it.

Glaciers are one of the most fundamental phenomenon on the planet, and much of their purpose and impact on earth has been well documented and published. Ice sheets, Ice Caps and Glaciers trap nearly 90% of the world's fresh water, and are replenished by snowfall each year. Their existence on this planet dates back 650,000,000 years and yet they are always moving, always shifting and always melting. Before, human existence and even during the brief era of humans, ice dominated all of the earth's landmass and have regulated, created and altered many of the landscapes around the world.