Chapter 15: The Dynamic Ocean

Question 1

Two types of surface circulation?

Answer 1

Ocean currents- masses of water that flow one place to another

Surface currents- develop from friction between ocean and wind

Question 2

The Coastal Zone order

Answer 2

Shoreline- contact between land and sea

Shore- lowest tidal and highest tidal level affected by storm waves

Coastline- seaward edge of the coast

Beach- accumulation of sediment along landward of ocean

Question 3

What is the definition of a wave?

Answer 3

Energy traveling along the interface between ocean and atmosphere. Gets energy from the wind

Question 4

The two components of a wave?

Answer 4

1) Crest- top of wave

2) Trough- bottom of wave

Question 5

The measurements of a wave?

Answer 5

A) Wave height- vertical distance between trough & crest
B) Wavelength- horizontal distance between crests & troughs
C) Wave period- time interval for one full wave to pass a fixed position

Question 6

The wave height, length, and period depend on?

Answer 6

1) wind
2) ) length of time the wind blows
3) fetch- distance that he wind travels

Question 7

As the wave travels, the water passes energy by?

Answer 7

Moving in a circle

-waveform moves forward

Question 8

The color and type of beach sand reflects what?

Answer 8

the local geology.

Beaches are composed of whatever material is available.

Question 9

How does beach material always keep moving?

Answer 9

Wave energy moves large parts of sand both parallel and perpendicular to the shoreline

Question 10

What is Wave Refraction?

Answer 10

the bending of a wave!

-waves approach shore at an angel, but refract and become parallel when encounter w/ shallow seafloor

Question 11

Wave erosion does what to a coastline?

Answer 11

Straightens the coastline out

Question 12

What is a beach drift?

Answer 12

Sediment moves in a zigzag pattern along the beach face

Question 13

What is a Longshore Current?

Answer 13

Current the surf zone
Flows parallel to the shore
Moves a lot more sediment than beach drift

Question 14

Erosional Features:

Wave-cut Cliff

Answer 14

originate due to the cutting action of the surf against the base the coastal land

Question 15

Erosional Features:

Wave-cut Platform

Answer 15

A relatively flat, bench-like surface left behind by the receding cliff

Question 16

Erosional Features:

Marine Terrances

Answer 16

occur when a wave-cut cliff is uplifted above the sea by tectonic forces

Question 17

What is associated with headlands?

Answer 17

Sea arch & sea stack

Question 18

Four depositional features?

Answer 18

1. Spit- ridge of sand from ridge to mouth (hooks landward)
2. Baymouth Bar- sand bar crosses all of the bay
3. Tombolo- sand that connects island to mainland
4. Barrier Islands- mainly along Atlantic and gulf coastal plains …relatively flat

Question 19

How does a Barrier Island originate?

Answer 19

A. spits that served from mainland by wave erosion

B. sand heaped up after being sourced from ocean bottom in a large storm

Question 20

What is Hard Stabilization?

Answer 20

building structures to control coastline erosion and deposition

Question 21

Three types of structures that stabilize the shore?

Answer 21

Groins
Breakwaters
Seawalls

Question 22

What location is a great example of groins?

Answer 22

New Jersey shoreline.

Question 23

What is a groin?

Answer 23

traps sand from longshore current migration, limiting erosion

Question 24

What is a breakwater?

Answer 24

barriers built offshore & parallel to the coast… protect boats from waves

Question 25

What are seawalls?

Answer 25

Structures armor coast against force of breaking waves

Question 26

Two alternatives to hard stabilization?

Answer 26

1. Beach nourishment: adding sand to beach
   
   • downside: expensive and not a permanent fix
2. Relocation buildings: away from the beach

Question 27

Why is shoreline classification so difficult and what is is based on?

Answer 27

difficult= they are always moving!

based on= sea level

Question 28

How much land is exposed with a Emergent coast and a Submergent coast?

Answer 28

Emergent coast- more land exposed

Submergent coast- less land exposed

Question 29

Features of an Emergent Coast?

Answer 29

A. Wave-cut cliffs

B. Marine terraces- once flat has been techtonically uplifted

Question 30

Features of a Submergent Coast?

Answer 30

A. Highly irregular shoreline (sea level rise
)
B. Estuaries= flooded river valleys
C. Fjords= flooded glacial valleys

Question 31

What are tides?

Answer 31

are the daily changes in the elevation of the ocean surface

Question 32

How are the changes in tides caused?

Answer 32

gravitational forces exerted upon Earth by moon and sun

Question 33

What is a Spring tide?

Answer 33

kind of like a tidal wave

• Occurs during new and full moons
• Produce a large daily tidal range

Question 34

What is a Neap tide?

Answer 34

scarcely touching (“without power”)

*Occurs when he sun and moon are at right angles

Question 35

Three tidal patterns that influence tides?

Answer 35

1) Shape of the specific coastline
2) Configuration of the ocean basin
3) Water depth

Question 36

Two types of tidal currents?

Answer 36

1) Flood current- advances into coastal zone

2) Ebb current- moves seaward

Question 37

What is a Tidal current?

Answer 37

Horizontal flow of water accompanying the rise and fall of tides

Question 38

How do Rip Currents develop?

Answer 38

When a wave attack is straight on to the shore

*water piles up on the beach and must return seaward