preview

Minnesota's Glaciers

Decent Essays
The Wisconsin Glaciation of Minnesota

A glacier is a large body of ice that moves slowly across land and are formed by there being a higher snow gain rather than a snow melt. Glaciers move by a small amount of ice melting and the glacier sliding. Glaciers can help and destroy the landscape in front of them but they can also shape the land into something amazing. Glaciers were once present in Minnesota thousands of years ago and played a massive role on the landscape we live on today, and as they melted they left behind large amounts of water and formations. The glaciation is very confusing to those who don't know about glaciers so here is some background information. The last glacial advance started about 75,000 years ago and the last
…show more content…
The definition of glacial lake is any lake formed from glacial origin which would include Kettle lakes, kettle lakes are small lakes made by ice blocks left there from the glacier. Some evidence of glacial lakes in Minnesota are the large amounts of iron and sedimentary rocks and sediments. There are 6 major glacial lakes in Minnesota these lakes are Agassiz, Upham, Aitkin, Duluth, Grantsburg and Minnesota if there is another one I could not find it in the articles or online. The largest glacial lake is Lake Agassiz it covered a lot of Minnesota some of the Dakotas and lots of Canada it is truly the father of all glacial lakes, or at least it was. Glacial Lake Agassiz was drained by the Mississippi (the only answer I could find) and the water went into the Gulf of Mexico. Parts of this massive lake can be found in Lake Winnipeg, Lake Winnipegosis, and Lake Manitoba and…show more content…
Outwash and till are similar but different at the same time and this is why they are both deposited by glaciers, but the way they are deposited is what makes them different. Till is simply the sediment left by the ice, outwash is deposited by the running water coming off of the melting glacier. Because water can sort sediment, and ice cannot, that is why the till is unsorted. Sorting just means when the rocks are sorted by size, bigger pieces together on the bottom, smaller pieces together on top. Glaciers are constructive and deconstructive they are deconstructive because they tear up land and the glacier does not stop for anything but it is easy to avoid. Glaciers erode the land and create landforms such as kames, eskers, and drumlins those terms will be explained a little bit later. Glaciers create valleys by shearing away the mountainside and moving it away. Some of the landforms that glaciers produce are drumlins, terminal moraine, outwash plain, and an erratic. Drumlins are elongated, teardrop-shaped hills of rock, sand, and gravel that formed under moving glacier ice. A terminal moraine is where the glacier reaches its max and starts receding making a deposit of till. An outwash plain is a flat area made by meltwater carrying outwash from the leading edge of the glacier. An erratic is a rock or boulder carried from a place where the Rock is common to an area where the rock is not
Get Access