Waves, wind, and Glaciers Erosion and Deposition

How Waves Form The energy in waves from wind that blows across the water’s surface.

Erosion by Waves Waves shape the coast through erosion by breaking down rock and transporting sand and other sediment.

How Waves Erode Land Impact Abrasion Change in Wave Direction

Headland Part of the shore that sticks out into the ocean. Example: Marin Headland

Erosional Features of Waves Wave-Cut Cliff Headland Sea Cave Sea Arch

Depostional Features of Waves Beach Spit Sandbar Beach: formed as waves pile up sand along the shore. Spit: formed as a longshore drift deposits along the shore. Sandbar: formed by wave action.

Wave Erosion & Deposition Landforms

Erosion by Wind Wind causes erosion by deflation and abrasion.

Deflation The erosion of sediment by wind. Stronger the wind, the larger the particles it can pick up.

Deposits By Wind Sand Dunes Deposit of wind-blown sand. Loess Wind-formed deposit made of fine particles of clay and silt.

Glacier Any large mass of ice that moves slowly over land.

Plucking The process by which a glacier picks up rocks as it flows over the land.

Till A mass of rock and soil deposited directly by a glacier.

Two Kinds of Glaciers Continental Glacier Valley Glacier

Continental Glacier A glacier that covers much of a continent or large island. Can cover millions of square kilometers. Antarctica and Greenland. Can flow in all directions. Can spread out like pancake butter in a frying pan.

Ice Ages In the past, continental glaciers have covered larger parts of the Earth’s surface.

Valley Glaciers A long, narrow glacier that forms when snow and ice build up high in a mountain valley. The sides of mountains keep these glaciers from spreading out in all directions. Found in many high mountains. Sierra Nevada and Mount Shasta.

Glaciers Glaciers can form only in an area where more snow falls than melts. Once the depth of snow and ice reaches more than 30 to 40 meters, gravity begins to pull the glacier downhill.

How Glaciers Shape the Land Plucking Picks up rocks as it moves Carries rocks with it as it moves Abrasion Gouges and scratches the bedrock Allows for rock to be picked up by plucking

Plucking and Abrasion

Glacial Deposition When a glacier melts, it deposits the sediment it eroded from the land, creating various landforms.

Glacial Deposition Landforms Till Mixture of sediments that a glacier deposited on the surface. Moraine Till that is deposited at the edges of a glacier forms a ridge. Kettle Lake Forms when a depression left in a till by melting ice fills with water.

Glacial Landforms

Credits Geo Resources http://www.google.com/imgres?hl=en&biw=1169&bih=663&tbm=isch&tbnid=NEojdsvuGCLF8M:&imgrefurl=http://www.georesources.co.uk/leld.htm&docid=IGXmJeec1Qr11M&imgur l=http://www.georesources.co.uk/sea6.gif&w=380&h=292&ei=P_5nT_2FI6yMigLawKmgBw&zoom=1&iact=hc&vpx=480&vpy=226&dur=1544&hovh=197&hovw=256&tx=159&ty=83&sig =102853300329707996231&page=2&tbnh=145&tbnw=189&start=15&ndsp=20&ved=1t:429,r:7,s:15 Association of Environmental & Engineering Geologists. Retrieved on 3/19/2012. http://www.google.com/imgres?hl=en&biw=1169&bih=663&tbm=isch&tbnid=xXW6jQgEKQBf_M:&imgrefurl=http://www.aegweb.org /i4a/pages/index.cfm%3Fpageid%3D4083&docid=EmzY2eWlU_R95M&imgurl=http://www.aegweb.org/images/Geologic%252520Haza rds/erodedbeach.gif&w=400&h=280&ei=P_5nT_2FI6yMigLawKmgBw&zoom=1&iact=hc&vpx=491&vpy=157&dur=3908&hovh=188&h ovw=268&tx=171&ty=55&sig=102853300329707996231&page=1&tbnh=134&tbnw=191&start=0&ndsp=15&ved=1t:429,r:2,s: