Presentation on theme: "GLACIERS In the following presentation you are going to see some actual pictures of glaciers and landforms resulting from glacial movement. Some key words."— Presentation transcript:
GLACIERS In the following presentation you are going to see some actual pictures of glaciers and landforms resulting from glacial movement. Some key words we will learn: Glacier Valleys Fjords Horns Cirques Hanging Valleys Erratics Moraines Eskers and Drumlins Striations
RIVER VALLEYS VS. GLACIAL VALLEYS A glacier valley. Notice the U shape. River valleys tend to be more V shaped.
FJORDS §A fjord is a coastal glacial valley which reaches the sea, and thus becomes flooded with ocean water when the glacier retreats. While Norway is most famous for its fjords, fjords are also common right here in the United States, in Alaska.
HORNS §Horns are steeply carved sides of mountains into sheer surfaces and points. The most famous horn is the Matterhorn, in the Alps. Aretes are simply groups of these horns in a row.
CIRQUES §Cirques are features where the side of the mountain has been scooped out, like a giant ice cream scoop has been taken to it. These cirques often feature a lake in them called a tarn.
HANGING VALLEYS §Hanging Valleys are features where 2 or more glaciated or former valleys intersect at different elevations. There are often waterfalls from the higher to the lower valley.
ERRATICS §Glacial Erratics are large rocks carried by the Glacier, and dropped unceremoniously when the Glacier melts. These are much more noticeable because of their greater size in the case of Continental Glaciation, but Alpine Glaciers can carry them as well. The scooping out of rocks by splitting and pulling at it is called plucking.
MORAINES §Lateral Moraines are material deposited laterally from the forward movement of the glacier. A medial moraine is a ridge of material marking the center of a former glacier. Terminal Moraines are piles of material dropped by the glacier at its end, and they mark the furthest advance of a glacier. A glacier in retreat, therefore, will show a series of recessional moraines, showing spots where its length stabilized for periods of time.
ESKERS AND DRUMLINS §Glaciers can also form hills called eskers and drumlins. Eskers are winding affairs from streams on or under a glacier. §Drumlins are teardrop shaped affairs. In fact, while almost all of you learned of Bunker Hill, what you may not know is that Bunker Hill is a drumlin created by continental glaciation!
Eskers, Drumlins, and Kettle Lakes
STRIATIONS §Where Glaciers do not carve out, or carry away, they can instead wear away hard rock...polishing it, or causing cracks and grooves called striations.
Some key words we learned: Fjords Horns Cirques Hanging Valleys Erratics Moraines Eskers and Drumlins Striations There are many examples of glacial landforms found all over the world. Learn more about your area and find out what glaciers have affected your state.