Oct 12 Lecture: Coastal Processes

Question 1

T/F

more people are living near coast lines than non-coastal areas

Answer 1

true

Question 2

3 factors that impact coastlines are:

Answer 2

• tectonic setting
• materials present at the shore
• energy of water striking the coast

Question 3

active margin=

Answer 3

area on the coast associated with active plate tectonics

- cliffs are often found near active margins

Question 4

passive margin=

Answer 4

area on the coast far from active plate tectonics

- often a broad shelf, beaches/ sandy offshores

Question 5

__-__ changes are often associated with plate tectonics and waxing/ waning of ice ages

Answer 5

sea-level

Question 6

what is an emergent coastline

Answer 6

a stretch along the coast that has been exposed by the sea due to a drop in sea levels

Question 7

what is a submergent coastline

Answer 7

stretches along a coast that have been flooded by the sea due to a rise in sea level

Question 8

continental margins may uplift and produce a(n) ___ coastline

Answer 8

emergent

Question 9

loading of the crust produces ___ coastlines

Answer 9

submergent

Question 10

a wave-cut platform is an indication of :

Answer 10

uplifting land or dropping sea level

Question 11

a drowned valley can record ___ in sea level

Answer 11

increaes

Question 12

___ and ___ are the primary forces regulating natural shoreline modification

Answer 12

waves and currents

Question 13

describe the movement of waves

Answer 13

• induced by winds
• the water moves in a circular motion in place. The radius of the circular motion becomes smaller with depth, and is negligible at the wave base
• as waves approach shores, circular motion is no longer possible and the waves collapse, yielding breakers

Question 14

when waves break on the shore, they release ___

Answer 14

energy

Question 15

wave energy=

Answer 15

approx. the wave height squared

Question 16

What causes tides?

Answer 16

the earth’s rotation causes a bulge in the ocean water mass, greatest near the equator and decreasing near the poles.
- gravitational pull of the sun and moon is superimposed on the rotational effect (acts at angles to it) –> causes tides

Question 17

as the tide rises, the water flows in towards shore as a __ ___

Answer 17

flood tide

Question 18

as the tide passes the high stage and starts to fall, the ___ ____ moves out

Answer 18

ebb tide

Question 19

the area exposed during low tide but not during high tide=

Answer 19

tidal flat

Question 20

\_\_\_\_ currents (the lateral component of wave motion) govern aspects of sand deposition occurring on beach shorelines. 
It causes sand to move along the coastline, resulting in \_\_\_ \_\_\_

Answer 20

longshore

littoral drift

Question 21

over time, longshore currents:

Answer 21

remove sand from one part of the beach and deposit it elsewhere on the beach

Question 22

a rise in sea-level will cause coastal ___ and require ____

Answer 22

erosion

stabilization