Oceanography Exam 1

following statements about density stratification, which are true

- Density stratification has caused the highest-density material to be found at Earth's core -Density stratification has caused Earth's internal structure to be layered -Outgassing is a direct result of density stratification -The origin of Earth's oceans and atmosphere are a result of density stratification

Which of the following are microscopic, single-celled floating algae that accumulate to form biogenous sediment

-Coccolithophores -Diatoms

following statements about Earth's crust, which are true

-Continental crust and oceanic crust are both composed of igneous rocks -Continental crust is made of rock that is relatively light in color -Continental crust is less dense than oceanic crust

Which of the following organisms are responsible for the creation of siliceous ooze

-Diatoms -Radiolarians

Which of the following statements correctly interpret the environmental conditions associated with types of biogenous deposits

-Foraminifer ooze on the sea floor means warm surface water above -Coccolith ooze on the sea floor indicates the water is shallower than 4000 meters -Diatomaceous ooze on the sea floor indicates cool surface water above

Of the following, which energy resources can be extracted from marine sediments

-Petroleum - Gas hydrates

Of the following statements related to the formation of a density-stratified Earth, which is/are true

-Rocky material of the mantle is less dense than the liquid outer core -Molten material will rise if it is less dense than the surrounding material -The layer of Earth with the greatest density is located at the deepest depth beneath Earth's surface

the following statements about the internal structure of Earth, which is/are true

-The magnesium-silicate rocks of Earth's mantle exist in both solid and molten form -The mesosphere and the asthenosphere have the same chemical composition

Of the following statements about Earth's magnetic field, which are true

-The magnetic north pole may reverse so that it is located near the geographic south pole -The lines of the magnetic force are parallel with Earth's surface at the equator -The lines of the magnetic force are perpendicular relative to Earth's surface at the magnetic north pole -The lines of the magnetic force are perpendicular relative to Earth's surface at the magnetic south pole

Why does the sea floor have a striped pattern of magnetic anomalies that is symmetric with respect to the mid-ocean ridge

-The ocean floor is spreading apart and new sea floor is forming -The igneous rock of the ocean floor preserves Earth's existing magnetic field as the rock cools -the polarity of Earth's magnetic field experiences reversals

Of the following types of lithogenous sediment, which ones would you expect to find very far from the location of origin

-Volcanic ash -Quartz silt

In which of the following environments would you expect lithogenous sediment to be the dominant sediment type

-at the base of the continental slope -the abyssal plains -sandy beach -long the mid-ocean ridge

Of the following sediments, which ones are considered hydrogenous

-coatings of metal sulfides near black smokers -manganese nodules

Which of the following lines of evidence did Alfred Wegener use to support the concept of drifting continents

-pattern of similar mountain belts on different continents -the distribution of species of fossils -the way the shapes of the continents fit together like pieces of a jigsaw puzzle -evidence of glaciers in areas that are now tropical

Of the following sediments, which ones is/are considered biogenies

-tests of foraminifers -radiolarian ooze

the following statements about Earth's hypsographic curve, which are true

-that a majority of the exposed land is below 1 kilometer in elevation -that the average depth of the ocean is about four times the average height of the continents -percentage of Earth's surface area that is covered by ocean waters -that a majority of the ocean floor is more than 4 kilometers deep.

Marine sediments provide valuable clues about which of the following Earth history events?

-the ancient geographical locations of ocean basins -previous ocean circulation patterns -movement of the ocean floor -past catastrophes, such as major extinction events -the climate on Earth millions of years ago

Which of the following conditions allows for calcareous ooze to exist beneath the CCD

A layer of clay buries the ooze before the sea floor subsides.

Which of the following is the main reason that Earth has a magnetic field

Convection in the liquid iron-nickel outer core generates a magnetic field

Which of the following is an example of a nematath

Hawaiian Islands-Emperor Seamount Chain

The explorer who advanced oceanography by introducing systematic soundings, or depth measurements

James Cook

Which of the following statements is supported by the nebular hypothesis regarding the formation of our solar system

The Sun became a star when its temperature and density became so great that nuclear fusion began

the following statements about sea floor magnetic anomalies, which is true

They are oriented parallel to the mid-ocean ridge

According to the Geologic Time Scale, which selection lists the correct order of coexistence, from earliest to latest

Trilobites and amphibians, insects and dinosaurs, dinosaurs and birds, flowering plants and fishes, humans and reptiles

The important contribution to navigation made by Eratosthenes in the third century BC was

a reasonably accurate calculation of the circumference of our planet

Evidence shows that periodic reversals of Earth's magnetic field have resulted in

a symmetrical pattern of normal and reverse magnetization in ocean crustal rocks

The measurement of ocean depth and the charting of seafloor topography is called

bathymetry

You take a sediment sample from the ocean floor at a depth of 5500 m. The area has low biological productivity and the CCD is at 4500 m depth. Your sample will probably consist of

clay

From smallest to largest, which list of sediment particle sizes is in the correct order

clay, silt, sand, pebbles

You add sand, silt, and clay to a jar of water, shake the jar vigorously, and allow the sediment to settle. The resulting sediment will most closely resemble that of a

continental rise

Trenches are typically associated with

convergent continental margins

The lithosphere consists of Earth's

crust and uppermost mantle

CCD

depth at which the rate of accumulation of calcium carbonate is equal to the rate at which it dissolved. Also defined as the depth where calcium carbonate drops to 20% of total sediment

Numerous small, shallow earthquakes tend to occur at

divergent plate boundaries

Salt beds of the U.S. Gulf Coast are

hydrogenous sediments

Graded bedding provides evidence that

large, heavy particles settle out first as current velocity decreases

Scientific Method

observation, question, hypothesis, experiment

Marine sediment with more than 30% biogenous material is

ooze

Stanley Miller's famous experiment demonstrated that

organic molecules could be produced from the mixture of gases comprising Earth's early atmosphere

The most abundant mineral in lithogenous sediments is

quartz

Sediment samples from deep beneath the ocean floor are recovered by

rotary drilling

Neritic sediments are most likely to be composed of

sand, silt, and gravel

Measurement of ocean floor bathymetry from satellites relies on

sea surface elevation, which varies depending on the shape of the underlying sea floor

A trench and a chain of volcanoes known generally as a volcanic arc are always present where there is

subduction

Compared to the rest of the planet, an unusually high concentration of hot spots and rifting is located on the continent of Africa. A likely explanation for this is that

the African Plate is essentially stationary with respect to Earth's interior and the thick continental crust acts as a "heat blanket"

Oozes are uncommon on continental margins because

the biogenous component tends to be overwhelmed by the amount of lithogenous material derived from the nearby continent

Compared to continental crust, oceanic crust is generally

thinner, denser, darker in color, and at lower elevations

Which of the following would best describe the principal goal of science

to explain the causes and effects of observable natural phenomena

Where a mid-ocean ridge is offset, the linear feature connecting and between the crests of the ridge segments is called a

transform fault

Sediments with all grains of about the same size are classified as

well sorted