Natural Sciences Ch 6 Oceanography

Front 1

Depression call _________ make up a large portion of the suboceanic crust.

Back 1

basins

Front 2

Define abyssal basin

Back 2

A basin between 2 and 6 thousand meters in depth

Front 3

Define a hadal basin

Back 3

A basin the extends below 6 thousand meters.

Front 4

Define abyssal plain

Back 4

it is a very level sectin of an abyssal basin

Front 5

Small underwater volcanoes are called

Back 5

abyssal hills

Front 6

Large underwater volcanoes are called

Back 6

seamounts

Front 7

Define continental rise

Back 7

the point at which the depth of the ocen floor begins to noticeably decrease

Front 8

Define continental slope

Back 8

The location at which the slant of the ocean floor steepens very rapidly.

Front 9

Define continental shelf

Back 9

A shallow plain that gradually rises to meet the dry land of a continent.

Front 10

Together, the continental shelf and the continental slope and half the continental rise that is located closest to dry land compose and area called the......

Back 10

Continental margin

Front 11

______ are calcium carbonate structures built by colonies of animals known as _________

Back 11

reefs
corals

Front 12

Name the 3 types of reefs

Back 12

1.) Fringing reefs
2.) Barrier reefs
3.) Atolls

Front 13

Describe a fringing reef

Back 13

are often found in the shallow water that borders landmasses. They tend to grow in the outer portions of these areas, where wave actin is the greatest and the dilution of seawater by surface streams is minimal.

Front 14

Describe a barrier reef

Back 14

Form when fringing reefs continue to grow outward such that they create areas of relatively calm water known as lagoons between their inner edges and the shoreline

Front 15

Describe an Atoll reef

Back 15

result when barrier reefs form around volcanoes and these volcanoes sink back into the ocean floor. After the descent of the volcanoes, all that remains on the ocean surface is a circular-shaped atoll with a lagoon in its middle.

Front 16

What is terrigenous or lithogenous sediments?

Back 16

Sediments composed of gravel, sand, silt, and clay. Carried to the ocean by the action of continental rivers and streams.
20%

Front 17

What is biogenous sediment?

Back 17

Ocean sediments consisting of matter that was produced by living organisms. They typically contain materials such as coral pieces and shells from tiny sea creatures. 50%

Front 18

What is hydrogenous sediment?

Back 18

Formed when chemical substances precipitate out of seawater.
<1%

Front 19

What is cosmogenous sediment?

Back 19

Sediment composed from burning meteors in earth's atmosphere.
<1%

Front 20

What is salinity?

Back 20

Is a measure of a substance saltiness.

Front 21

Define thermocline

Back 21

The warmth of all three oceans within their upper regions drops rapidly at an essentially constant rate, and it extends to a depth of appox 500 meters.

Front 22

Water in the central part of the oceans tend to spin due to the .........

Back 22

Coriolis effect.

Front 23

As ocean water spins due to the coriolis effect, it causes a slight rise in the oceans surface known as a ...........

Back 23

dome

Front 24

What is thermal inertia

Back 24

Is a measure of a materials responsiveness to change in the temperature of its surroundings.

Front 25

Seawater has a high

Back 25

thermal inertia

Front 26

Name the 4 reasons seawater has a high thermal inertia

Back 26

1.) High specific heat
2.) Light penetration
3.) Water mixing
4.) Phase changes

Front 27

Name the 4 types of ice masses

Back 27

Fast ice
Pack ice
Polar ice
iceberg

Front 28

Describe Fast ice

Back 28

form quickly near shore and then extend out to sea.

Front 29

Describe Pack ice

Back 29

Originate at sea, as small patches of slush and grow into solid bodies up to tow meters thick.

Front 30

Describe Polar ice

Back 30

If Pack ice continues to grow it forms a mass known as polar ice, which can be up to 4 meters thick and last 4 years

Front 31

Describe an iceberg

Back 31

Result when large areas of ice break off from glaciers that meet the sea.

Front 32

Define a current

Back 32

are large masses of water that flow in a particular direction.

Front 33

Currents are divided into two categories, name them:

Back 33

1.) Deep currents
2.) Surface currents

Front 34

Describe Deep currents

Back 34

form when areas of water at or near the ocean surface begin to sink due to the fact that they are denser that the water that surrounds them. After sinking, these currents are insulated from surface processes such as evaporation, mixing by wind, and waves, and dilution by rainfall. As a result, deep currents maintain their properties for a long time as well as long distances.

Front 35

Describe Surface currents

Back 35

Are caused by the action of earth's major wind systems. As wind blows across the ocean surface, it pulls the top layer of water along with it. In turn, this surface water drags the water below it, although the velocity of the subsurface water decreases with depth.

Front 36

Define a wave

Back 36

Are moving ridges on the surface of the ocean

Front 37

Name the 2 classifications of waves

Back 37

Free
Forced

Front 38

Describe a free wave

Back 38

Are those that exist without the continued presence of their generating forces.

Front 39

Describe a forced wave

Back 39

are those that rely upon the continued presence of their generating forces.

Front 40

What happens when waves superimpose?

Back 40

When ocean waves meet, they join.

Front 41

What is constructive superimposition?

Back 41

When two or more crests or troughs join and greatly increase a wave's size and destructive ability.

Front 42

What is destructive superimposition?

Back 42

A crest and trough combine and thereby cancel each other out. This is destructive superimposition.

Front 43

What is orbital motion?

Back 43

The crest of a passing wave moves subsurface particles forward, but the trough of that same wave pulls the particles back to their original position. Orbital motion decreases rapidly with depth.

Front 44

When waves enter the shallow water near a shore, the particles with orbital motion are no longer able to fully travel through their vertical orbits. Such action creates the foamy waves or __________ that surfers so enjoy.

Back 44

Breakers

Front 45

Define tides

Back 45

are force fluctuations of the ocean surface that result from the gravitational influence of the Sun and the Moon.

Front 46

What are spring tides?

Back 46

When the Moon is near its full and new phases, its pull on the ocean coincides with that caused by the sun. This situation results in especially large ocean bulges known as spring tides.

Front 47

What is a neap tide?

Back 47

When the moon is near its first and third quarter phases, it forms a right angle with Earth and the sun. This causes the gravitational influence of both the Sun and Moon to partially offset one another, thereby creating relatively small bulges known as neap tides.

Front 48

What is amphidromic motion?

Back 48

Tidal waters, like all of Earth's liquids, are subject to the influence of the Coriolis effect. As a result these water masses move across the ocean in large circular paths by way of the phenomena called amphidromic motion.

Front 49

Define Beaches

Back 49

Are gently sloping coastal areas in which large amounts of loose sediments have accumulated.

Front 50

Name the parts of a beach

Back 50

1.) Backshore region
2.) Foreshore region
3.) Offshore region

Front 51

Describe the backshore region of a beach

Back 51

is the part that is not submerged when the tide is at its highest level.

Front 52

Describe the foreshore region of a beach

Back 52

is the portion of a beach that lies between the highest and lowest tide levels.

Front 53

Describe the offshore region of a beach

Back 53

is the section of a beach that is constantly covered by water.