Monday 12 May 2008

Natural Processes

Climate Change

The true effects of climate change on the coastal environment are not accurately known at this time, because scientists can only guess at the likely impacts based on current global trends and past data configured from tests ranging from examining ice strata using core samples, to monitoring control/indicator species to see how they are being affected.

A good example of this would be the Pink Sea Fan found primarily in the Meditteranean region its upper limits are along the southern coasts of Cornwall and Wales. There is much debate as to the true extent climate change will affect coastal communities if it does at all.

Predicted Sea Level rise. The link to the left shows the result of sea level rise based on 7m, 13m and 84m rises in sea level.

Erosion

The typical erosion on the shoreline is due to tidal and wave action. Wave erosion occurs when deep water waves hit the shore with full force, also the moving of sediments and rocks along the shoreline can cause erosion to occur.

Hydraulic action tends to occur around cliff faces and Headlands as a mixture of water and air are forced in to cracks in the rock face, forcing the rock to splinter and shard. This can occur on the shoreline but in areas of rocky shore rather than sandy beaches. The sandy shore tends to suffer from what is termed long shore drift or a barrage of dumping waves if the topography of the sea floor is such to create them.











Tides/waves

Longshore current is produced as water flows parallel to coastline. Swash and backwash











Rip Currents are produced when water piles up in surf zones and flows seaward, generally perpendicular to the coast.










Daily rise/fall of surfaces of oceans/lakes due to gravitational pull of the
Moon/Sun on the Earth– also due to force created as Earth spins on its axis


Flood tides- elevate sea surface that cause shoreline to move inland

Ebb Tides- low sea surface that cause shoreline to move seaward



http://news.bbc.co.uk/1/hi/sci/tech/7191196.stm

http://www.aberdeencity.gov.uk/ACCI/nmsruntime/saveasdialog.asp?lID=2434&sID=904

No comments: