Chapter 10: The Coast

Question 1

Define shore, coast and coastline.

Answer 1

shore- the zone that lies between the low tide line and the highest area on land affected by storm waves.
Coast- extends inland as far as ocean features are found.
Coastline- boundary between shore and coast

Question 2

Define beach.

Answer 2

wave worked sediments- entire active area of a coast affected by waves

Question 3

Define swash and backwash.

Answer 3

swash- water runs up the beach

backwash-water drains back into the ocean

Question 4

Define longshore current and longshore transport. What is the difference between them?

Answer 4

Longshore current-current that runs the length of the beach and transports sand along the beach
longshore transport- the movement of sand along the length of the beach

Question 5

Describe wintertime and summertime beaches.

Answer 5

wintertime- backwash dominates, sediment moved away from shore, narrower beach, stormy weather
summertime- light wave activity, wide sandy berm, milder storms

Question 6

What causes the longshore current?

Answer 6

caused by wave refraction

Question 7

What causes longshore transport?

Answer 7

waves appraoach which picks up sediments up and transports them to the ocean

Question 8

Describe erosional shores.

Answer 8

well develpoed cliffs, exist where tectonic uplift of the coast occurs

Question 9

Describe depositional shores.

Answer 9

gradually subsiding shore, barrier islands and sand deposits are common

Question 10

What is a barrier island? Where do they occur in the US? List and describe the different parts of a barrier island, including ocean beach, dunes, salt marsh and lagoon.

Answer 10

long offshore sand deposits that parallel the coast. common along east and gulf coast
ocean beach-clostest part of the island to the ocean
dunes- stabilized by grass
salt marsh-bioproductive wet lands

Question 11

What is a delta?

Answer 11

triangular deposits of sediment where rivers empty into oceans or seas

Question 12

What are the three components of a beach compartment?

Answer 12

1. rivers that supply beach sediment
2. beach itself
3. offshore submarine canyons

Question 13

What is beach starvation? What causes it?

Answer 13

human activities block supply of and to beach compartments such as dunes

Question 14

What two processes can change sea level?

Answer 14

local tectonic processes

global eustatic changes in sea level

Question 15

What are some local tectonic processes that can change sea level?

Answer 15

isostatic adjustments

ice loading from glaciers during ice age

Question 16

What are isostatic adjustments? What causes them?

Answer 16

rebounds of earths crust w/ application of heavy loads

Question 17

What are eustatic changes in sea level? What causes them?

Answer 17

sea level changes due to:change in amount of available sea water, change in ocean basin capacity

Question 18

What happens to sea level during glaciations and deglaciations?

Answer 18

glaciation- ice ages lock seawater up in ice

deglacination- ice melting after ice age

Question 19

How does thermal expansion and contraction of seawater change sea level?

Answer 19

warmer water expands and cooler water contracts, sea level rises and falls in

Question 20

How will global warming change sea level?

Answer 20

it will cause an overall higher sea level

Question 21

Describe the four major types of hard stabilization. Are they effective?

Answer 21

1. groins and groin fields-yes
2. jetties-yes
3. breakwaters-no(can cause excessive erosion)
4. sea walls-no(one large storm can remove head)

Question 22

What are the three main alternatives to hard stabilization? Are there any problems with them?

Answer 22

1. construction restrictions- national flood insurance program encouraged construction
   beach replenishment- expensive
   3.relocation. no moves structures.