O Lecture 10/12/10
When is the tidal range the greatest?
When is the tidal range the least?
What is it called when tidal range the greatest?
What is it called when tidal range the least?
Why are there unequal tides?
because of the angle between the Sun, Moon, and Earth
What is another complicating factor of tides?
eliptical path of earth
What percent of people live within easy access of the coast?
What percent of the global population lives within 100 km of the coast
dynamic and interactive
change with time
product of their environment
What causes depositional and erosional processes?
slope and sources material
entire active are of the coast that experiences changes due to breaking waves
extends inland as far as coastal features can be found
coastline - definition
marks boundary between shore and the coast
deep enough waves don't hit bottom
never exposed - not even at low tide
intertidal or littoral zone
above high tide line - only covered in water in really big storms
dry, gentle sloping region at the foot of coastal cliffs or dunes
wet, gentle sloping region from berm to shoreline
composition of beaches
locally available material
could be coarse or fine
Beach Material Charactersitics
slope of beach helps determine material of beach
: boulders from local cliff, significant biological material at tropical beaches
beaches typically dominated by...
either erosion or deposition
erosional beach characteristics
well developed cliffs
depositional beach characteristics
sand deposits, off shore barrier islands - Atlantic
How can material on the beach move?
perpendicular or parallel
in or out
upcoast or downcoast
How is upcoast and downcoast determined?
by the dominant flow in that region
What are the two types of waves that perpendicular movement can have?
net movement of water out - normally wave breaks on top of it
In light wave activity in perpendicular movement which wave dominates?
Where do sediments move in light wave activity and perpendicular movement?
to the shore
How does the beach look that is formed by light wave activity and perpendicular movement?
What is a beach light wave activity with perpendicular movement called?
fair weather beach/summertime beach
What type of wave movement dominates on a heavy wave beach with perpendicular movement?
Where do sediments move in heavy wave activity and perpendicular movement?
away from shore
How does the beach look that is formed by heavy wave activity and perpendicular movement?
sand bars form
What is a beach with heavy wave activity and perpendicular movement called?
stormy weather/wintertime beach
O Lecture 10/12/10
Recap Tides, Coastal Features