OCE1001 Midterm 01
About how many kilometers (miles) is it from the center of Earth to the surface of the Earth?
6,370 kilometers (3,980 miles)
About ____% of Earth's water is found in the ocean.
71
The average land elevation is approximately ____.
840 meters (2,756 feet)
About what percentage does water expand when it freezes?
9.0%
A boundary in which crustal plates slide laterally past one another is called a ____.
?
California's San Andreas fault is which type of plate boundary?
?
Earlier than 200 million years ago, the continents were joined into one supercontinent called ____.
?
Over millions of years, natural gas and oil can be formed from ____.
?
The ____ accounts for 83 percent of Earth's volume.
?
The deepest places in Earth's crust are ____.
?
The islands bordering deep-sea trenches are ____.
?
What are the abundant elements that make up the composition of Earth's present-day atmosphere?
?
What comprises the most abundant form of matter in the universe?
?
Which of the following are hydrogenous sediments?
?
Which region of the ocean generally lacks a thermocline?
?
Who was the first person to estimate the size of the Earth within approximately 8% of its true size based on the geometric observations of travelers?
?
What did the Polynesians use to navigate between the islands in the Pacific Ocean?
?
What type of information about the ocean are satellites most likely to provide to scientists?
?
What was one accomplishment of Captain James Cook?
?
Which statement most accurately describes how the continental rise is formed?
from the accumulation of sediments at the base of the continental slope
The wavelengths of light that penetrate deepest into the ocean are ____.
green and blue
Flat-topped seamounts that once rose near or above sea level are called ____.
guyots
A zone in which the ocean's salinity changes rapidly with increasing depth is called ____.
halocline
Which statement with regards to hot spots is true?
Hot spots are relatively stationary features.
Which statement is most consistent with the scientific method?
Hypotheses are tested through observations and controlled experiments.
Earth's inner core is primarily made of ____.
Iron
If the ocean's water evaporated completely leaving its salts behind, what would the dried residue look like?
It would cover the entire planet with an even layer 45 meters thick.
Which statement is true with regard to latitude and longitude?
Latitude and longitude comprise a system of imaginary lines dividing Earth's surface into a grid.
The deepest location in the ocean is the ____.
Mariana Trench
Who is considered to be the father of physical oceanography?
Matthew Maury
Who was the first person to compile a picture of the large-scale wind and current systems?
Matthew Maury
The first scientific expedition to use an echo sounder was the ____.
Meteor Expedition
Modern oceanography began with the efforts of ____, who trapped his ship in pack ice to explore the Arctic.
Nansen
What process allows the sun to generate light and heat?
Nuclear fusion
The Hawai'ian Islands formed as they pass over a hot spot in the middle of the ____.
Pacific Plate
The hydrogen bonds of water molecules account for which of the following?
Water can cause surface tension and wetting.
If two oceanic plates collide and one is older and cooler (and therefore, denser) than the other, what will happen?
a deep trench will form
Which statement accurately describes a turbidity current?
a fast, dense current of water and sediment that runs down slopes
What would a visitor approaching Earth from space see 4.4 billion years ago?
a hot, vapor-shrouded sphere blanketed by lightning-stroked clouds
What did the German Meteor expedition discover during their 1925 crisscross across the South Atlantic for 2 years?
a varied and often extremely rugged bottom profile
Oxygen enters seawater ____.
as a byproduct of photosynthesis and diffusion from the atmosphere
New crust is being generated ____.
at divergent plate boundaries
Geologists believe that a new ocean basin is forming ____.
at the East African Rift Valley
The hot, partially melted, slowly flowing layer of Earth is called the ____.
athenosphere
Stars spend their lives changing its hydrogen and helium to ____.
carbon, oxygen, silicon, and iron
A(n) ____ is a graphic representation that depicts information about the ocean and ocean features.
chart
The ocean appears to be in ____ because the proportion and amounts of its dissolved salts per unit volume are nearly constant.
chemical equilibrium
The amount of dissolved oxygen that seawater can hold in solution will be greater in ____.
colder water
The mid-ocean mountains, such as the ridges and rises, are ____.
constructed of volcanic basalt
The Himalayan Mountains were formed as a result of ____.
continent-continent convergence
The submerged outer edge of a continent is called the ____.
continental margin
The apron of accumulated sediment at the base of the continental slope is known as the ____.
continental rise
The transition between the shelf and the deep seafloor is the ____.
continental slope and rise
A "mystery" in our understanding of plate tectonics has been, until recently, the nature of the power source capable of moving the plates and the continents embedded within them. Recent evidence indicates the power source to be ____.
convection currents within Earth's mantle moving the plates
Submarine canyons ____.
cut into the continental shelf and slope, often terminating on the deep seafloor
The property of water that accounts for the ability of liquid water to absorb large amounts of heat and change relatively little in temperature is called ____.
high heat capacity
What type of bond enables water molecules to stick together?
hydrogen bond
Which type of sediment is generated in place, on the spot where we find them?
hydrogenous (or authigenic) sediments
At the present time, the salinity of the ocean seems to be ____.
in chemical equilibrium, where ions are added to the ocean at the same rate as they are being removed
Heat can be carried to the polar regions ____.
in the ocean currents from the tropics.
The deepest thermoclines can be found ____.
in the tropics
Eighty calories of heat energy must be removed per gram of pure water at 0°C to form ice. This represents water's ____.
latent heat of fusion
During its initial formation by the accretion of particles, the young Earth was ____.
likely chemically homogenous throughout
The rigid outer layer of Earth that comprises the continental crust, oceanic crust, and the uppermost mantle is called the ____.
lithosphere
One cubic meter of which of these would weigh the most?
mantle
The youngest seafloor rocks are found ____.
near the rift valleys of mid-ocean ridges
Edward Forbes was an Edinburgh professor who thought that ____.
no life existed in the deep sea because of high pressure and lack of light
Active continental margins are located ____.
on the west coasts of both North and South America
Japan is located along the "Pacific Ring of Fire" and experiences many earthquakes. The majority of the earthquakes around Japan occur ____.
only on the east side of the island where the Pacific plate subducts
Volcanic venting of substances including water vapor is called ____.
outgassing
The hydrogen atoms in a water molecule tend to bond to ____.
oxygen atoms of another water molecule
What are the primary elements in Earth's continental crust?
oxygen, silicon, and aluminum
Sediments that are found on the continental slope, continental rise, and the deep-ocean floor are called ____.
pelagic sediments
The magnetic striping of the seafloor is considered evidence of seafloor spreading and ____.
periodic reversals in the polarity of Earth's magnetic field
The thin layer of lighted water near the surface of the ocean is called the ____.
photic zone
Oxygen first began to accumulate in Earth's atmosphere as a result of ____.
photosynthesis
Although the first regular ocean traders were probably the Cretans or the Phoenicians, the first direct evidence of voyaging, traveling the ocean for a specific purpose, comes from ____.
records of trade in the Mediterranean Sea
The bending of light or sound waves is referred to as ____.
refraction
A depression along the boundary of a seamount where sediment has built-up is a(n) ____.
scour moat
Abyssal hills are small extinct volcanoes commonly associated with ____.
seafloor spreading
The two most abundant elements (ions) dissolved in seawater are ____.
sodium and chloride
The death of a star is characterized by a massive release of energy called a ____.
supernova
The ocean is stratified with respect to ____.
temperature and salinity
Some plateaus, ocean ridges, ancient island arcs, and parts of continental crust are too buoyant to be subducted. These are, instead, squeezed and sheared onto the face of a continent, forming ____.
terranes
Which sediments arrive in the ocean from continents via wind and water?
terrigenous sediments
Which type of sediment is most abundant in neritic deposits?
terrigenous sediments
When using the scientific method, scientific theories must be ____.
tested and consistently supported by observations or experiments
The word "oceanography" was first coined in association with ____.
the Challenger expedition
Residence time is the ____.
the average length of time an element spends in the ocean
What are the abundant elements that make up the composition of Earth's present-day atmosphere?
the charting of ocean currents to significantly shorten the travel time of sailors
The density of seawater will increase when ____.
the salinity increases
The field of marine science involves ____.
the scientific study of the ocean, its associated life-forms, and its bordering lands
The components of ocean water whose quantities are less than 1 part per million (ppm) are considered ____.
trace elements
A seamount is a volcanic projection that does not rise above the surface.
true
Abyssal plains and abyssal hills cover a quarter of Earth's surface.
true
Alfred Wegener was a polar explorer who suggested that at one time, Earth's landmasses were joined into a supercontinent called Pangaea.
true
As carbon dioxide dissolves at the surface of the ocean, it combines chemically to form a weak acid called carbonic acid.
true
Density is a measure of relative heaviness and is defined as mass per unit volume.
true
Guyots are often formed near spreading centers.
true
Hydrothermal vents such as black smokers are found at spreading centers.
true
Scientists think that turbidity currents contribute to the formation of submarine canyons.
true
The amount of heat transported by water vapor in the atmosphere is greater than the amount of heat transported by ocean currents.
true
The density of seawater is affected by both temperature and salinity.
true
The geometry of the covalent bonds shared by the hydrogen atoms and oxygen atom in a water molecule account for its polarity.
true
The oceanic crust is primarily made of basalt.
true
There are three types of plate convergences: continent-continent, ocean-continent, and ocean-ocean convergent plate boundaries.
true
One piece of evidence that suggests the existence of Pangaea is the apparent fit of continents across North and South Atlantic.
true
Passive continental margins are sometimes referred to Atlantic-type margins.
true
The pycnocline can occur at the same range of depths as a halocline.
ture
Scientists believe that answers to questions are ____.
ultimately knowable
The ocean originated from ____.
volcanic gases, radioactive heating of Earth's interior, and a barrage of icy comets or asteroids striking and melting the outer layers of Earth
One area in the ocean that has an extreme abundance of sediment deposition is the ____.
waters near the Gulf Coast of North America
Which of the following is a major source of terrigenous sediments?
weathering and erosion of rocks
Hydrothermal vents are located near ____.
zones of rapid seafloor spreading
The Challenger expedition (1872-1876) was a unique and historic voyage. Why?
It is the longest continuous scientific oceanographic expedition on record.
Glomar Challenger is known mainly for ____.
taking the first complete cores of seafloor sediments
On a planetary scale, the ocean comprises about ____% of Earth's mass.
0.02
Scientists believe the breakup of Pangaea occurred about ____.
200 million years ago
The average salinity of the world ocean is about ____.
3.5%
The largest known mantle plume is located beneath ____.
Africa
The cousin of which scientist worked out the first rough chart of the Gulf Stream?
Benjamin Franklin
Which individual would be most likely to receive the title of "first marine scientist"?
Captain James Cook
Which of the following statements is true regarding sound in the ocean?
Sound is scattered as it bounces off suspended particles in the water
As early as the 1700s, scientists and observers noticed a remarkable coincidence of shape of the Atlantic coasts of Africa and ____.
South America
Where is the widest continental shelf located?
The Arctic Sea north of Siberia
Which voyage was the first expedition devoted purely to marine science?
The Challenger Expedition
What is the primary reason for the inside of Earth being hot?
The decay of radioactive elements is creating heat in Earth's inner layers.
Why was Alfred Wegener's idea of continental drift dismissed?
The evidence at the time seemed to suggest a solid mantle that did not allow drifting of continents to be possible.
Which of the following statements about pH is true?
The pH scale measures the concentration of hydrogen ions in a solution.
Which statement accurately describes active continental margins?
They are areas of frequent earthquakes and volcanoes.
Which statement is true with regard to subduction zones?
They are zones where old seafloor descends into the crust and mantle.
Which individual was the first to provide a rough chart of an ocean current, specifically, the Gulf Stream?
Tim Folger
What is the speed of sound in seawater of average salinity at the surface?
about 1,500 meters per second
What is the average residence time water stays in the ocean?
about 4,100 years
Roughly how fast do most lithospheric plates move?
about 5 centimeters per year
The deep-ocean basin includes which of the following features?
abyssal plains
New planets formed in a cloud of dust and debris surrounding our young sun through a process known as ____.
accretion
What is the clumping of smaller particles into large masses?
accretion
The Andes mountains is an example of a(n) ____.
active margin
What information did NASA's Earth-observing satellite, AQUA, collect to learn about Earth's water cycle?
amount of phytoplankton and dissolved organic matter in the oceans
Ocean trenches ____.
are arc-shaped depressions in the oceanic crust that occur at subduction zones
The discovery and study of ocean floor contours is called ____.
bathymetry
Which type of sediment is of organic origin, that is, made by organisms?
biogenous sediments
How can a satellite sense the contours of the ocean bottom from space?
by using radar to sense the height of the sea surface over submerged features
The primary physical process responsible for the formation of Earth's layers, the inner and outer core, mantle, and crust is ____.
density stratification
Buoyancy is the ability of an object to float in a fluid by ____.
displacing a volume of water equal in weight to its own weight
The term "salinity" refers to the total quantity of ____.
dissolved inorganic solids in water
The mid-ocean ridges are ____.
divergent plate boundaries
The world ocean ____.
dramatically influences weather, nurtures life, and provides crucial natural resources
What device bounces sound waves off the ocean bottom to study the depth and contours of the seafloor?
echo sounder
The origin of submarine canyons is not well understood but is most likely to be ____.
erosional, caused by a combination of stream erosion and turbidity currents
Continental shelves can be made of granitic crust, basaltic crust, or both.
false
Convection within the inner core facilitates continental drift.
false
Frozen water is more dense than liquid water.
false
Heat and temperature both measure random vibrations of an atom or a molecule.
false
Red light is able to penetrate seawater the deepest.
false
Subduction zones are areas where new seafloor is created.
false
The Challenger expedition used multibeam echo sounders to contour the seafloor.
false
The Hawai'ian Islands were formed within the last 2 million years above a hot spot that is now inactive.
false
The asthenosphere is cooler than the lithosphere.
false
The most precise way to calculate the salinity of seawater is to evaporate a known weight of seawater and weigh the residue.
false
The salinity of seawater is a measure of the amount of sodium and chloride in a water sample.
false
Transform faults are never found at mid-ocean ridges.
false
As carbon dioxide enters the ocean, it ____.
forms carbonic acid
A cross section of Earth reveals a layered structure that has different thicknesses and densities. How do geologists know this?
from observing the transit times through Earth of seismic waves generated by earthquakes