More+weathering+notes

Type in the content of your page here.Alban Hoxhaj

A.)** **Gravity is an aid in weathering and erosion. Steep slopes weather to Gentle slopes. Creep- Slow, Imperceptible down slope movement of the soil. Causes objects that are fixed in the soil to lean downhill. Water i the soil is what adds the weight. Mudflow- The rapid movement
 * Movements of loose earth material down a slope.

Slump- Occurs when a section of land moves downhill as a whole because of a plane of weakness in the underlaying soil.

Landslide- sudden movement of a mass of bedrock or loose rock down the slope of a hill or mountain. (avalanche - snow, ice, rock and soil) Talus- Is a pile of rock fragments at the base of a cliff.

Wind erosion wind transports materials by causing their particles to move in different ways. Suspension- a method of transport by which strong winds cause small particles to stay airbourne for long distances.

Saltaion- cause a bouncing of motion of larger particles. Saltation accounts for sand transport by wind.

wind erosion is greatest in arid climates (low precipitation) with little vegetation. (desert and sea shores)**


 * Abrasion is a process of erosion found in wind,water, and ice. It occurs when particles such as sand rub up against the surface of rocks or other materials.

Ventifacts are rocks shaped by windblown sediments.

wind depositation occurs in areas where wind velocity decreases.

Dunes are piles of windblown sand that have a gentle side and a steep side.

The gentler slope occurs when the side on which the wind is blowing (windward side). The steeper slop occurs on the side protected from the wind (leeward side) Loess- thick deposits of fine lightweight particles (silt,clay) that are carried by the wind in great quantities of long distances. they are some of the most fertile soils.

Louis Agassiz is known for the idea that Glaciers once covered many parts of the world.

Formation of a Glacier Glaciers are accumulations of ice large enough to survive summer melt-forms from snow under pressure which turns to ice.

Snow line- the lowest level that permanent snows reach in summer. Highest near the equator Firn is granular ice material formed in snow fields freshly fallen snow becoming compressed and re crystallizing.

The lower layers become ice and begin flowing downward or outward because. Alpine Glaciers (Valley glaciers) Occur in mountain regions above the snow line Flow downhill and carve out U-shaped valleys

Continental Glaciers (Ice Sheets) A glacier that spreads over a wide geographic area. FORM IN POLAR AREAS WHERE THE SNOW LINE IS CLOSE TO SEA LEVEL AND WIDE AREAS ARE ABOVE THE SNOW LINE. (responsible for much of the landscape in NY) 20,000 years ago, New York State was covered by a huge ice sheet that originated in Canada.

Glacier Movement The overlaying weight of snow and ice causes grains of ice to partially melt and refreeze. As this happens ice grains slip past each other and move downhill. Glaciers move more rapidly at the surface than at the base and faster at the center than at the sides. friction with the valley walls slow the flow.


 * Flow at a rate of a few.

Crevasses are cracks across the width of the Glacier that form when Glaciers move over steep slopes. ICE FRONT is end of a Glacier The Ice Front is STATIONARY as long as the rate of movement and melting are equal.

A Glacier RECEDES when it melts faster than normal.

A Glacier ADVANCES when the rate of movements is greater then the rate at which it melts.

pieces of rock are picked up as Glaciers move and then are dragged along the bedrock and/or valley wall. Fine sand acts as sandpaper and polish the bedrock.

Larger sediments leave long parallel scratches called STRIATIONS Calving is when blocks of ice break off into the sea. The finger lakes of NY were formed as advancing ice deeply scoured out valleys. Glacial trough are formed when a Glacier carve out a valley forming a U-Shaped Valley. Valley Glaciers leave sharp mountain tops while continental Glaciers leave rounded tops.
 * Striations show the direction the Glacier is moving.**

Here are a few Depositional features of Glaciers.. Moraine is a glacial deposit of unsorted rock material. Ground Moraine- Carried along the bottom

Lateral Moraine- Long lines of rock pieces along the valley sides

Medial Moraine

__Word Definitions__
Cirque- A half-open steep-sided hollow at the head of a valley or on amountainside, formed by glacial erosion. Arete- a sharp rugged mountain ridge, produced by glaciation.

Horn-

Col- A break in an arete(mountain pass)

Trancated Spur- A blunt-ended, sloping ridge which descends from the flank of a valley. Its abrupt termination is normally due to erosion by a glacier. Glaciers tend to follow straighter courses than rivers.

Tarn- A small lake at the base of a cirque.

Hanging Valley- a tributary valley whose mouth is set above the the floor of the main valley, usually as a result of differences in glacial erosion.

Crevasse- A fissure, or deep cleft, in glacial ice, the earth's surface.