Longshore Current and Beach Drift
Figure 16.10
16-49
© 2006 Pearson Education Canada Inc., Toronto, Ontario
Littoral Drift (3)
In the Fraser Delta, this "RIVER OF SAND" is from
south to north, then around the corner to Spanish
Banks and Kitsilano.
If you build Groynes, Jetties or Breakwaters (p. 537) such
as the Jetty on the Fraser North Arm, you disrupt this
River of Sand and get deposition upstream and erosion
downstream.
NEXT Slide shows this. Also…
TEXT CD (both littoral drift and structures)
Littoral Drift
Figure 16.15
16-51
© 2006 Pearson Education Canada Inc., Toronto, Ontario
Storm Surges
Bulge of Water beneath the low pressure centres
of Cyclones, both tropical (e.g Hurricanes) and
mid-latitude (e.g. Winter in BC).
Can be up to 5 m in depth
by 10's of km in diameter.
Rare, but devastating events for the coastal
landscape…salt water behaving badly–
e.g. Fresh water marshes become Salt water
marshes for months and years.
Often catch people by surprise--causing many
hurricane related drownings.
Relative Sea Level CHANGES
[Summary pp. 520-521]
a. Isostatic rebound from the Ice Age or other
processes
b. Drawing of water from underground sources
for drinking
c. Glacial Melting leading to more water in the
ocean
d. Temperature increase leading to ocean
expansion
e. Possible sudden sea level changes as
grounded Ice Shelves move.
Relative Sea Level CHANGES (2)
If sea level rises, then water can attack areas
usually unaffected by these processes …
particularly if we have waves + surge
during high tide after sea level rises.
All Material BELOW AND LATER is not for Nov. 9
Link to climate change lecture 13.
Now for a look at other ocean environments.
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