Chapter 11

Question 1

Coastal Zone

Answer 1

-Broad zone where continents meet oceans
-Different oceanic processes occur in this zone, mainly waves and tides.

Question 2

Coastal Zone:Coastal processes occur ___(where) relative to what?

Answer 2

occur in restricted narrow zone relative to other geologic process such as rivers, wind and etc
(watch video)

Question 3

Coastal Zone: coastal zones appear to migrate where? due to what?

Answer 3

landward or seaward due to changes
in sea level, uplift or subsidence, etc.

Question 4

Coastal Zone: coastal zones change constantly, ___of world’s population is found in
coastal cities - because of their strong appeal

Answer 4

2/3

EX.New York, Los Angeles, New Orleans, Tokyo, London, Rio de Lenerio,
Shanghai, Sidney, Cicily, Lagos, etc.
(look at pic of america)

Question 5

Types of coasts: Two Types: Cliff Coasts:

Answer 5

Ocean in contact with shallow/narrow beach
-Usually bounded by cliffs
-Such coasts found mainly in subduction zones:
-E.g., in Oregon, Washington State, California
- Close to active margins of geologic activity

Question 6

Types of coasts: Two Types: Barrier Coasts:

Answer 6

Main land NOT in contact with ocean directly
Ocean -> barrier island -> lagoon -> main land
-Usually mainly passive margins where there is no tectonic activity

Question 7

Coastal Zone Processes: Tides

Answer 7

ONCE or TWICE daily, ocean water level falls and rises due to gravitational attraction
of moon
-fluctuations of sea level are TIDES
-more and more shoreline flooded during sea level rise (Flood or High Tide)
-Accompanying fall is EBB or LOW TIDE.
—Rise found to be few cm to 15 m

Question 8

Coastal Zone Processes: Waves

Answer 8

Waves are the dominant force driving the nature of a beach. The energy carried through waves moves beach sediment and transforms beach shape.
-Are agents of erosion, transportation & deposition(image on typical beach)

Question 9

Coastal Zone Processes: Waves: Wave Gnerration:

Answer 9

-The wind transfers some energy to the water to produce waves.
-Causing the water surface to oscillate.
-As more wind blows, more waves are formed.
-Waves differ in size, e.g., during storms, waves are bigger
-Big waves have greater velocities
-Big waves can outrun small waves.
(image on typical beach)

Question 10

*Wave Characteristics

Answer 10

-As a wave enters shallow water, it becomes oversteepened
-The wave crest advances faster than wave form.
-Crest then plunges forward as a BREAKER

Question 11

Wave Characteristics: 2 types: Longshore Current

Answer 11

-Long, narrow currents perpendicular to direction of waves
- Important in transportation and deposition
(check picture)

Question 12

Wave Characteristics: 2 types: Rip Currents

Answer 12

-Narrow surface currents out to sea through breaker zone
( check picture)

Question 13

Deposition in Coastal Zones: Deposits include..?
Definition of beaches?

Answer 13

BEACHES, SPITS, BAYMOUTH, BARS and BARRIER BARS.
Beaches:
* Unconsolidated sediments extending landward from sea. - Different parts.

Question 14

-Seasonal Changes in Beaches: Summer Beaches are

Answer 14

A.covered with sand generally
b. have wide berms (a gentle sloping beach face)
c. a smooth offshore profile

Question 15

-Seasonal Changes in Beaches: Winter Beaches

Answer 15

Acoarser grained & steeper
b. have small berms or none
c. have sand bars parallel to shoreline

Question 16

-Seasonal Changes in Beaches:*Change in shape is related wave intensity:

Answer 16

In winter, storm waves have more energy. Therefore, sand is eroded & transported from
beach offshore & retained as a sand bar. (check picture)

Question 17

Seasonal Changes in Beaches:In summer, waves are more what?

Answer 17

waves are gentler

Question 18

Seasonal Changes in Beaches:The same sand that was carried offshore winter

Answer 18

during winter is returned
onshore. Volume sand remains almost constant

Question 19

Spits & Baymouth Bars:

Answer 19

-Next most common deposits to the beach
-Are variation of same feature

Question 20

Spits & Baymouth Bars:A SPIT

Answer 20

is a continuation of a beach that projects in a body of water(picture)

Question 21

Spits & Baymouth Bars: A BAYMOUTH BAR

Answer 21

is a spit that has grown to completely close off a BAY.
- Both result from longshore current lagoons.(picture)

Question 22

Coastline Erosion:

Answer 22

In some coastlines, erosion dominates deposition.
-Here, Beaches are lacking
-Sea cliffs are common erosional features.

Question 23

Due to the action of waves seacliffs retreat toward the land in response to:

Answer 23

CORROSION, HYDRAULIC ACTION or ABRASION

Question 24

Coastline Erosion: Corrosion

Answer 24

the wearing away of rock by chemical processes

Question 25

Coastline Erosion:Hydraulic action

Answer 25

erosion due to the forces of water.

Question 26

Coastline Erosion:Abrasion

Answer 26

erosion from the grinding of rock & sand carried by waves

Question 27

Coastline Erosion: The rate of retreat of seacliff may __ by ___?

Answer 27

be high at Cape Cod, Massachusetts, retreat was observed to be as much as 30 m per century. (picture)

Question 28

Protection of Coastline :Construction of Structures: Jetties

Answer 28

• Structures extending seaward to protect bays from deposition due to longshore currents.
  -Done to keep bays open to PLEASURE BOATING & COMMERCIAL SHIPPING
  (Picture)

Question 29

Protection of Coastline :Construction of Structures:Sea Wall

Answer 29

Protect people who live near beaches from the ocean.
-May collapse eventually.
-Expensive to construct.

Question 30

Protection of Coastline :Construction of Structures: Rock revetments

Answer 30

Reinforcements with large blocks of rocks.

Question 31

Protection of Coastline :Construction of Structures:Break Water

Answer 31

-Constructed to create quiet water around beach.

Question 32

Protection of Coastline :Construction of Structures: Groins

Answer 32

-Constructed to trap sand in order to widen the beach(picture)