Waves & Coasts

Front 1

Shoreline

Back 1

Contact between land and sea

Front 2

Shore

Back 2

Area between lowest tidal level and highest areas
affected by storm waves

Front 3

Beach

Back 3

Accumulation of sediment along landward margin of
the ocean

Front 4

Foreshore

Back 4

Area exposed at low tide and submerged at high
tide

Front 5

Coastline

Back 5

seaward edge of the coast

Front 6

Berm

Back 6

flat platform often composed of sand adjacent to
coastal dunes or cliffs (dry).

Front 7

Beach Face

Back 7

Wet sloping surface that extends from the berm
to the shoreline.

Front 8

Beach Composition

Back 8

Quartz, Shell Fragments, Olivine, Metamorphic

Front 9

Emergent Coasts

Back 9

Uplift of the land or drop in sea level. Characterized by wave-cut cliffs and marine terraces.

Front 10

Submergent Coasts

Back 10

Subsidence of the land or rise in sea level. Characterized by highly irregular shoreline and estuaries (drowned river mouths).

Front 11

Estuaries

Back 11

Drowned river mouths.

Front 12

Local factors that influence Shoreline Erosion

Back 12

Proximity to sediment-laden rivers
Degree of tectonic activity
Topography and composition of the land
Prevailing wind and weather patterns
Configuration of the coastline

Front 13

Hard Stablization

Back 13

Structures built to protect coastlines may prevent erosion of part of the shoreline but can result in accelerated erosion elsewhere.

Front 14

Groins

Back 14

Barriers built at a right angle to the beach that are designed to trap sand.

Front 15

Breakwaters

Back 15

Barriers built offshore and parallel to the coast to protect boats from breaking waves.

Front 16

Seawalls

Back 16

Armors the coast against the force of breaking waves.

Front 17

Alternatives to Hard Stabilization

Back 17

Adding sand to the beach system.
Relocating buildings away from beach.

Front 18

Tides

Back 18

The periodic rise and fall of the sea surface

Front 19

Factors that influence tides

Back 19

Generated by the gravitational attraction of the Moon and
Sun and the centrifugal force due to the rotation of the Earth-Moon system.

Front 20

Gravitational Force

Back 20

G(m1m2)/r2

Front 21

Does the Moon exert a greater gravitational effect on the Earth than the Sun?

Back 21

The Moon exerts a greater gravitational
effect on the Earth than the Sun because
of its closeness to the Earth, despite the
fact that the Sun is much more massive
than the Moon.

Front 22

Assumptions of tides-cont

Back 22

(ALL WRONG)
Earth has two equal tidal bulges, one toward
the Moon and one away from the Moon

Oceans cover the entire Earth and are of
uniform depth

No friction between ocean water and seafloor

Continents have no influence

Front 23

Tidal periods

Back 23

Time between successive high or low tides.

Front 24

Tidal Range

Back 24

Height difference between high and low tide levels.

Front 25

Diurnal Tides

Back 25

Have one high tide and one low tide each day (period of ~24 hr).

Front 26

Semidiurnal tides

Back 26

Have two high tides and two low tides each day (period of ~12 hr).

Front 27

Semi-diurnal mixed tides

Back 27

Same as semi-diurnal but with unequal high and low tides.

Front 28

Spring tides:

Back 28

High tides are very high and low tides very low. They occur at 2 weeks intervals.

Front 29

Neap tides

Back 29

High tides are not very high and low tides not very low. They also occur at 2 weeks intervals

Front 30

How are the tidal bulges created

Back 30

The Earth-Moon system revolves around its center of mass once a month.

Front 31

How are the tidal bulges created

Back 31

Both Earth & Moon turn in the same direction (eastward) Orbital P.

Front 32

Spring Tides

Back 32

Occur when the Earth, Sun, and Moon are aligned and produce highest high tides and lowest low tides (max tidal range)

Front 33

Neap Tides

Back 33

Occur when the Sun and Moon are at right angles to one another and produce lowest high tides and highest low tides (min tidal range).

Front 34

Tidal Current

Back 34

Horizontal flow accompanying rise and fall of tides.

Front 35

Flood Current

Back 35

Tidal current that advances into coastal zone as the tide rises.

Front 36

Slack Water

Back 36

High tide and low tide water stops moving as it changes direction.

Front 37

Ebb Current

Back 37

Water moving back out to sea as the tide falls.

Front 38

Tidal Flat

Back 38

Area affected by these alternating tidal currents.

Front 39

Considering the Effects of the Sun

Back 39

The other critical astronomical body that influences the tides is the Sun.

Front 40

Considering Effects of the Sun

Back 40

The Sun also produces a tide generating force in the same way as the Moon.

Front 41

Considering Effects of the Sun

Back 41

This force is only 46% as large as that of the Moon because of the enormous distance from the Earth.

Front 42

Considering Effects of the Sun

Back 42

The effects of the Sun are to raise high tides to a max when the Sun's gravity pulls in the same direction as the Moon's, and to lower high tides to a min when the Sun's gravity pulls in opposition to the Moon's.

Front 43

Semidiurnal Tide

Back 43

The height of the high tide is about the same for both tide.

Front 44

Mixed Semidiurnal Tide

Back 44

The result is a semidiurnal tide but the height of the second high tide is much bigger than the first. This type of tide.

Front 45

Diurnal Tide

Back 45

Tide with only one high tide and one low tide every day.

Front 46

What happens to tides at different Latitudes

Back 46

The Moon migrates its position over the Earth, from 28.5°N of the equator to 28.5°S of the equator over the lunar months. This means that the tidal bulge may be above, below, or at the equator depending on the time of the month.

Front 47

Wave-Cut Cliff

Back 47

Originates by cutting action of waves at base on a cliff.

Front 48

Wave-Cut Platform

Back 48

Formed as cliff collapses.

Front 49

Sea Arch

Back 49

Formed on headlands because of selective wave erosion

Front 50

Sea Stack

Back 50

Formed as arch collapses.

Front 51

Depositional Shores

Back 51

Sediment is depositedin areas where energy is low.

Front 52

Sand Spits

Back 52

Ridge of sand extending into mouth of bay

Front 53

Baymouth Bar

Back 53

Sandbar that crosses a bay.

Front 54

Tombolo

Back 54

Ridge of sand btwn island and mainland.