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Coastal Processes ~ erosion, transport & deposition. CA. NC. 12.1. Erosion. http:// geobytesgcse.blogspot.com/2007/08/coastal-processes-erosion-transport-and.html. Erosional processes. Abrasion = continuous tumbling reduces rock to sand grains Solution = salt dissolves some of the rock
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Coastal Processes ~erosion, transport & deposition CA NC 12.1
Erosion http://geobytesgcse.blogspot.com/2007/08/coastal-processes-erosion-transport-and.html
Erosional processes • Abrasion = continuous tumbling reduces rock to sand grains • Solution = salt dissolves some of the rock • Scouring = wave swirls at base of cliff & loosens rock
Erosion • Erosional processes in action • http://www.bbc.co.uk/schools/gcsebitesize/geography/coastal/coastalprocessesrev3.shtml
Erosional Features • Sea cliff • Sea cave • Sea arch • Sea stack • Terrace
Sea cliffNavassa Island, Caribbean Sea • Forms when waves erode rock http://coastal.er.usgs.gov/navassa/photos/ep/hike/CliffE.jpg
Sea caveShort Sands Beach, Oregon • Hole eroded at base of cliff http://web.cecs.pdx.edu/~walpole/pics/kayak/falcon/cave3.jpg
Sea archHawaii • Sea cuts through headland http://upload.wikimedia.org/wikipedia/commons/e/eb/SeaArchHawaii.jpg
Sea stackCounty Mayo, Ireland Isolated column of rock http://ts1.mm.bing.net/images/thumbnail.aspx?q=1023555809064&id=45685568345e0ba48cec1d6807ea14ba&url=http%3a%2f%2fwww.visualphotos.com%2fphoto%2f2x4004071%2fdoonbristy_sea_stack_downpatrick_head_ballycastle_1813001.jpg
Sea terracesHaiti • Flat platforms at water height http://www.amishkin.com/wp-content/uploads/2010/03/P1000346-Large.jpg
Transport • Material eroded by the sea is moved along the beaches.
Longshore drift • Longshore drift illustration • http://www.bbc.co.uk/schools/gcsebitesize/geography/coastal/coastalprocessesrev4.shtml • Waves approach beach at angle • Sand moves in zigzag motion • Creates longshore current • Current keeps sand moving until it hits a change or structure, then it drops out.
Longshore drift diagram http://cgz.e2bn.net/e2bn/leas/c99/schools/cgz/accounts/staff/rchambers/GeoBytes%20GCSE%20Blog%20Resources/Images/Coasts/Longshore_Drift.jpg
Deposition • Sand deposits form where amount of rock moving toward shore is greater than amount moving away.
Depositional Features • Beach • Lagoon • Tombolo • Barrier island
BeachEmerald Isle, NC http://www.tripadvisor.com/LocationPhotos-g49113-Emerald_Isle_North_Carolina.html
Lagoon Vegetation is red; water is blue (satellite image)
Tombolo Bar that extends out into ocean, but remains connected to mainland. web.macam.ac.il web.macam.ac.il
Barrier Island http://www.frf.usace.army.mil/outerbanksaerialflight/Index.htm
Barrier Islands • Occur on east coast of USA • Isolated dunes become islands • Parallel to shore • Associated features: • Sound (also called bay or lagoon) • Tidal inlets • Tidal flats • Estuaries
Homework • Read pages 342 - 347
Output • Draw a block diagram of the east coast and include the features of the beaches. • Draw a block diagram of the west coast and include the features of the beaches.