week 8-elle Flashcards
how many people live within 100km of the coast
2.75 billion & increasing
two zones of costal areas
- Coast
- Shore
What is a Coast
-large zone affected by ocean driven processes
-extends inland as far as costal processes reach and/or ocean-related features occur
What is the shore
-the zone where ocean meets the land
-between low tide and highest point storm waves reach
**can be further subdivided
what is a coastline
-point where highestwavepoints reach
5 parts of the shore
- Shoreline
- Backshore
- Foreshore
- Nearshore
- Offshore
Shoreline
position changes, at waters edge
(very point where water hits oceans hits land)
Backshore
above high tide level, covered by water only during storms
Foreshore
exposed at low tide, covered at high tide
Nearshore
from low tide shoreline to breaking waves (low tide)
Offshore
waves unaffected by the bottom
can shoreline be the same as coastline
yes, but rarely and only during very big storms
Beach face
gentle decline of the shore
what is created from the rolling of waves
longshore trough & bars in nearshore zone
wide gentle sloped beaches reduce the
vertical transfer of wave energy
(less energetic breakers, less potential for longshore bars)
what is needed for deposition
low energy (high energy=no deposition)
main driver of beach shapes is
energy
Do all beaches have cliffs/bluffs
no some have rolling dunes
what is a berm
a nearly horizontal, shore-parallel ridge of sand or gravel formed by wave action, typically located above the high tide line and acting as a natural sand barrier
when would high dunes occur
low wave activity and high winds
Dune features in the west facing parts of ontario
- sediment builds up
- winds push sediment back from water
4 variable compostitions of a beach
- volcanic
- Anthropogenic
- Biological
- Mixture