Oceanography Chp 4 - 6

From where does most of the material on the continental shelf come?

Erosion from the adjacent continent

What is the origin of most abyssal plain sediments?

Erosion from the continent

Why does the ocean not boil or freeze solid in different regions of the world?

Heat is transported by oceanic and atmospheric circulation

What piece of equipment was able to facilitate two new fields of science with the data it generated?

Piston corers

What is not a general characteristic of an active margin?

A broad shelf

Of what is the structure of carbon dioxide an example?

A compound

What is the only substance to have a higher heat capacity than liquid water?

Ammonia

Often formation on land can shed light on ocean processes. Which is true of the White Cliffs of Dover in England?

An accumulation of diatomaceous earth rise above sea level from plate tectonics

What statement is true of biogenous and terrigenous sediments?

biogenous sediments comprise of a larger area that terrigenous sediments

If a sediment is white in color, it is likely to be

biological in origin

SOFAR

fixing

Submarine Canyons

form at the junction b/w shelf and slope

Which is an example of an authigenic sediment?

manganese nodules

Bathymetry

measurement of depths of water in ocean

SONAR

navigation

hydrogen bond

sharing of electrons BETWEEN water

covalent bond

sharing of electrons WITHIN water

disphotic

some light

continental slope

steep, between shelf and rise

compound

substance that contains 2 or more different elements in a fixed proportion

KT event

tektites meteor strike end of the dinosaurs

thermocline

temperature

Approximately how much of the world's estimated oil and gas reserves can be found within the sediments of the continental margins?

two-thirds

Guyot

"table mounts" flat topped eroded by waves. west central pacific.

continental rise

apron of accumulated sediment that covers the oceanic crust along passive margins

How long is it estimated to take the oceans volume of water to circulate through the oceanic crust at spreading centers?

10 million years

What is the typical depth of light penetration in the open ocean?

100 meters

adhesion

2 different substances - stick to other materials

cohesion

2 similar substances - stick together

maximum density in water

4 degrees C - below it expands

Why is sensible heat detectable while heat that is not sensible cannot be measured?

A thermometer measures the decrease in temperature, but as a liquid changes to solid, the loss of heat is not measurable

To what is a Pacific type margin referring?

Active margin

What type of margin is generally steep?

Active margin

What contributes to the high biological activity and surface nutrients in southern polar waters?

All are contributing factors

What is characteristic of the water that is expelled from hydrothermal vents?

All of these choices are true.

What is true of bathymetry?

All of these choices are true.

What can cause hydrogenous calcium carbonate deposits? All of these choices: A decrease in the acidity of seawater A increase in seawater temperature Evaporation

All of these choices: A decrease in the acidity of seawater A increase in seawater temperature Evaporation

What statement describes turbidities?

All of these choices: They are propelled into position by gravity rather than water currents They are graded layers of terrigenous sand mixed with finer pelagic sediments They are composed of distinct layers

Where are abyssal plains most common?

Atlantic Ocean

The west coast of South America is known for its seasonal up welling. What kind of sediment is likely to be abundant based on this information?

Biogenous

How is sound transmitted through a medium?

By rapid pressure changes in a medium

What is considered an important factor in shaping western boundary continental rise?

Deep-ocean currents

What specifically connects the continental shelves to the deep ocean floor?

Continental slope

What process explains how hydrothermal vents are created?

Convection

___ connects atoms by sharing the energy of paired electrons

Covalent bonds.

passive margins

DIVERGING plates. ATLANTIC type. Spreading centers/MOR.

A deep ooze was discovered near Antarctica. What type is it likely to be?

Diatom ooze

What organism forms the White Cliffs of Dover?

Foraminifers (protzoa) Calcarious

What type of bathymetric feature was heavily influenced by wave action at some point in its history?

Guyot

What is one reason diatomaceous earth is economically valued? It can be broken up for gravel and used as building material

It can be broken up for gravel and used as building material

What is true of heat capacity?

It is the measure of heat required to raise the temperature of one gram by 1 degree Celsius

Which sediment is categorized under cosmogenous sediments?

Microtrktites

Which water mass is characterized by increasing density with deeper depths?

Pycnocline zone

What organism is likely to be found in siliceous ooze? Radiolarian

Radiolarian

What visible light wave is almost completely absorbed and converted to heat within the first few meters of the ocean?

Red light waves

Why is the sofar layer efficient for sound travel?

Refraction causes the sound energy to remain within the layer

What is the main source of terrigenous sediments?

Rivers

What is the main reason for the stratification in the north polar waters?

Salinity

What allows water to be a polar molecule?

Shape of the molecule

What is often found in the middle of manganese nodules?

Shark teeth or bone fragments

Which is not true of the relationship between latitude and ocean characteristics?

Temperate waters have the largest variation in salinity

Why does sound travel rapidly through the lower well mixed surface layer?

Temperature and salinity are homogenous

With what kind of sediments are igneous rocks associated?

Terrigenous

What is the calcium carbonate compensation depth?

The depth at which calcium carbonate starts to dissolve

Why does the latent heat of vaporization require so much heat energy?

The energy is used to break the hydrogen bonds

What was not a factor in making the mapping of the Earth's ocean more difficult?

The gravitational pull of underwater features

As pure water approaches its freezing point, the density decreases. Why does this happen?

The hydrogen bonds become rigid, allowing it to expand slightly.

What partly explains the seabed topography we observe?

The jostling due to plate tectonics

With what is the flatness of abyssal plains associated?

The large amounts of sediment.

Why does eastern North America continue to contain sediment from the last ice age?

The large rivers tend to end up in estuaries

Which is not a major factor in the width of a continental shelf?

The number of rivers depositing new sediments

What is thermal inertia?

The propensity for a substance to resist temperature changes.

What characterizes deep ocean sediments?

The sediments are well-sorted due to low energy fluctuations

What effect does temperature and pressure have on the speed of sounds when entering seawater?

The speed of sound decreases as temperature and pressure decrease

What is the name for a zone that decrease in temperature with depth?

Thermocline

What offsets the mid-Atlantic ridge's movement at fairly regular intervals?

Transform faults

___ are likely to be found in subduction zones.

Trenches.

What is thought to have an effect on the formation of submarine canyons?

Turbidity currents

What transports most of the sediments that forms the continental rise?

Turbidity currents

Which does not have an effect on water's density?

Viscosity

What is a shadow zone?

Zone where the divergence of sound waves creates a region that has little sound energy penetration

The submerged outer edge of a continent is called:

a continental margin

A continental margin facing a spreading ridge is considered ____ and ____.

a passive margin; diverging

capillarity

ability of water to move upward

shelf break

abrupt transition from shelf to slope

decrease salinity

add water

What is the difference between adhesion and cohesion?

adhesion is the tendency of water molecules to stick to solids while cohesion is the property that allows water molecules to stick to each other

euphotic

enough light for photosynthesis

There is an abundance of foraminifera shells found in sediment, it would be characterized as

calcareous ooze

Turbidity Currents

carve the submarine canyons - "avalanche" of sediments

Lithogenous/Terrigenous

comes from land. quartz and clays. dominant on continental margins, abyssal plains

active margins

continental margins near edge of CONVERGING plates. PACIFIC type. Trenches. earthquake and volcanic activity

Neritic sediments

continental shelf sediments "off the coast" primarily terrigenous

high latitudes

cool temps limited evaporation low salinity

low latitudes

evaporation high precipitin low high salinity

The ___ has a low ratio of volume in comparison to its area in the ocean.

deep ocean floor

pyctocline

density

Seamounts

do not rise above surface water. more than 1000 m in height. hotspots.

Cosmogenous

dust from space; meteorite debris tektite spheres

molecule

group of atoms held together by chemical bond

The pycnoclince isolates the majority of the world ocean from:

heating and cooling brought on by solar energy fluctuations

atom

identical particles that make up an element and cannot be broken down

aphotic

no light

Biogenous

organic; accumulation of hard parts of some marine animals. calcareous ooze (calcium-carbonate) siliceous ooze (silicon) plant-algae; animal- protozoan can form oil and natural gas

The sediments that occur on the slope, rise and deep ocean floor and orignate in the ocean are called

pelagic sediments

Hydrogenous

precipitation of dissolved mineral from water; often bacteria manganese nodules chemistry related (must have biogenous and lithogenous)

What is an example of terrigenous sediments?

quartz

clines

rapid change

increase salinity

remove water

halocline

salinity

Pelagic sediments

sediments of the slope, rise and deep ocean floor "of the sea" primarily biogenous

continental shelf

shallow,nearly flat, close to shore

In addition to information gained from stratigraphy, what contributed to the emergence of paleoceanography?

the advent of deep sea drilling

Satellites use ____ to calculate the depths of the ocean.

variations in elevation of surface water

What is not considered a disruption to the normal sorting of the neritic sediments?

wave action

If oceanic ridges in the Pacific are more active, then it is expected that the ridges are:

wide