Glaciers and Oceans Yay!

Snow becomes Firn

Glacial Processes To view this animation, click “View” and then “Slide Show” on the top navigation bar.

Alpine (Valley) Glacier Continental Glacier (Ice Sheet)

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Continental Glaciers Zone of Accumulation Antarctica →

Long Island was built by glacial sediment. The only part of New York that was clearly never covered by glaciers is Allegheny State Park in Western New York State. Long Island was built by glacial sediment. 7 7

Crevasse-cracks, evidence of movement

Calving

Calving

Icebergs

Outwash Plain

Moraines Made of till

Long Island- Terminal Moraine

The Ronkokoma Moraine dips below sea level at Montauk Point The Ronkokoma Moraine dips below sea level at Montauk Point. This is New York’s most eastern landfall. Note the boulders washed out of the moraine. 16 16

The north shore of Long Island has bluffs of glacial till in the Harbor Hill Moraine. The transported rocks of diverse types settle onto the beach. 17 17

The sandy beaches along the south shore are composed of sorted outwash sediment. 18

Glacial Deposits: What’s left? Drumlins-elongated hills of till Steeper on side that glacier came from

This is pat of drumlin field east of Rochester, NY This is pat of drumlin field east of Rochester, NY. Note that the trailing ends of the hills are the southern slopes. The north slopes are usually more blunt. 21

These kettles are freshly formed in the outwash plain of the retreating Bering Glacier in southern Alaska. In other parts of the country, kettles have turned into lovely ponds surrounded by vegetation.

Glacial Deposits: What’s left? Eskers Winding ridge of sand deposited by a stream flowing in a tunnel under a glacier Esker in Canada

U-Shaped Valleys

Hanging U Shaped Valley Hanging Valley

The Finger Lakes of Western New York State were excavated as U-shaped valleys by the glaciers advancing to the south. Moraines dammed the former south flowing outlet rivers. 31 31

Portions of Seneca and Cayuga Lakes looking north from an airplane Portions of Seneca and Cayuga Lakes looking north from an airplane. Can you match them with the last image? 32

The angular and jagged landscapes of the Southwest such as at Monument Valley in Arizona, indicate an area that was never covered by continental glaciers. 33

But even the highest of the Adirondack Mountains have rounded summits eroded by the glaciers. 34 34

Kettle Lake Drumlins Outwash plain Till Glacial Stream Esker Outwash plain Till Moraine-dammed lake Glacial Stream Terminal Moraine

Wave Motion/Wave Refraction To view this animation, click “View” and then “Slide Show” on the top navigation bar.

Wave (video & animation)

Spits:

Jetties

Groins

Groins

Breakwaters

Jetties and groins interrupt the movement of sand by beach drift and longshore currents. Beach erosion often results downcurrent from the site of the structures. A. Shoreline of Santa Monica pier in 1931. B. Same area in 1949. The construction of the breakwater disrupted longshore transport and caused seaward growth of the beach.

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