Oceanography Prelim 1 and 2

How were heavy elements like carbon, nitrogen, copper and gold created?

a. all elements both light and heavy were created during the moment of the bang

b. all elements both light and heavy were created about 3750000 years after big bang

c. all heavy elements were created inside stars or when stars exploded

d. about 20 percent of heavy elements today were created initially from the big bang and 80pecent inside stars

c

how do stars form?

a. All the stars we see today formed during the initial Big Bang and have been
hurtling outward through space and clustering into large galaxies ever since.
b. Stars started forming after the intense heat of the Big Bang cooled and cold
hydrogen gas began condensing into large-mass objects due to gravitational
attraction. When an object’s mass becomes very large, the gravitational
compression within the center of the object makes its interior hot enough to
ignite thermonuclear fusion reactions.
c. Intensely hot plasma (heated from the initial Big Bang) collapsed under gravity to
form very large cohesive masses of this hot matter, which we now call stars.
d. Stars formed when the Cosmic Microwave Radiation left over from the Big Bang
heated dense clouds of hydrogen to extreme temperatures and then these
dense clouds began to glow white hot

b

How was our moon formed?
a. A moon that had initially formed around Mars was pulled away from Mars by the
stronger gravity of the much larger Earth and was subsequently drawn into
Earth’s orbit.
b. Small planetesimals were captured by Earth’s gravity and then these
planetesimals slowly collided over a 500-million-year period to form our moon.
c. An ancient planet the size of Mars hit the Earth, and the ejected material that
subsequently coalesced to form the moon.
d. An ancient tectonic plate collision in early earth history was so violent that it
ejected a large piece of tectonic plate into orbit.

c

Our understanding of where the water that fills the Earth’s oceans came is still of some
scientific debate, but most scientists currently think it was likely brought to earth by
comets.
a. True
b. False

false

If you scaled the Earth down to the size of a beach ball (half meter diameter), how thick
would the ocean be?
a. About 1 micrometer
b. About 0.1 millimeter
c. About 100 millimeters
d. About 10 centimeters

b

How quickly did life appear on Earth after the Earth cooled and the oceans filled?
a. Remarkably quickly (less than 500 million years).
b. It took a pretty long time for life to get started (more than a billion years).
c. It took a very long time for life to finally catch hold on Earth (about 2.5 billion
years)

a

When did life on land first appear?
a. 4 billion years ago
b. 2.5 billion years ago
c. 550 million years ago
d. 66 million years ago

c

Which animal group represents the first appearance of a backbone that evolutionarily
led to you?
a. The first vertebrates were mammals.
b. The first vertebrates were fish.
c. The first vertebrates were amphibians that lived both on land and in the water.
d. The first vertebrates were reptiles.
e. The first vertebrates were dinosaurs.

b

What is the nature of the earliest known fossil?
a. A Body fossil
b. A Trace fossil
c. A Chemical fossil

c

When did life on Earth transition from being just simple prokaryotic organisms floating
around in the ocean to more complex eukaryotic organisms and multicellular
organisms?
a. About 550 million years ago
b. About 1 billion years ago
c. About 2 billion years ago
d. About 4.5 billion years ago

c

Which came first, evolution of bacterial photosynthesis and the associated production
of oxygen or the evolution of multicellular organisms?
a. evolution of bacterial photosynthesis and oxygen came first.
b. evolution of multicellular organisms came first.

a

What was the Cambrian Explosion?
a. A period of Earth history that underwent a dramatic increase in explosive
volcanism leading to the first mass extinction event on Earth.
b. An event in Earth history where most of the major animal phyla were created
in a relatively short period of time.
c. It was a moment of explosive scientific discovery about the evolution of life on
Earth that had its beginning in a now-famous scientific meeting held at
Cambridge University on August 22, 1897.

b

What is the geologic age (period) of the rocks around Ithaca?
a. Devonian
b. Carboniferous
c. Ordovician

a

Which type of crust is denser?
a. Oceanic Crust.
b. Continental Crust.

a

What evidence did Alfred Wegner use to confirm that the continents had drifted over
geologic time?
a. The remarkable fit of the South America and West Africa coastlines.
b. Fossil and mineral belts on separate modern-day continents aligned neatly
when the continents were artificially moved into a single super-continent.
c. Magnetic anomalies found in solidified continental rock aligned perfectly when
the continents were artificially moved into a single super-continent.
d. Once plate tectonics were discovered, he quicky noted that this process would
be capable of moving continents around

b

Why was extensional faulting along the axis of mid-ocean ridges an important piece of
evidence leading eventually to the development of plate tectonic theory?
a. Because extensional faulting only occurs where magma erupts to the surface.
b. Because extensional faulting is an indicator of extensive earthquake activity.
c. Because extensional faulting only occurs in recently formed rock.
d. Because extensional faulting occurs when solid rock is pulled apart

d

What kind of tectonic process takes place in deep sea trenches?
a. This is a region where new oceanic crust is formed.
b. This is where old oceanic crust is sinking back into the mantle.
c. This is where new ocean basins are in the earliest stages of being born.
d. This is where two tectonic plates slide laterally past each other (i.e., a Transform
Fault region).

b

How are continents moved around on Earth over geologic time?
a. Magnetic minerals are found in great abundance in continental rock (granite)
and when the magnetic field of the earth moves, the continents also move as the
magnetic minerals in the continental rock attempt to realign their magnetic field
with the new position of earth’s magnetic field.
b. Continents are moved when the tectonic plates that they are a part of move.
c. The force of gravity from the moon pulls more strongly on the larger continental
crust and drags the continent through the thinner and weaker oceanic crust.
d. New continental crust is always being made at new locations along the
continental boundary while old continental crust cools and becomes denser and
sinks back into the mantle. Together this gives the illusion of actual motion

b

Which geologic feature is a result of oceanic crust colliding with continental crust?
a. Hawaiian Islands
b. Philippine Islands
c. Andes Mountains
d. Himalayan Mountains

c

Why is the age of continental crust so much older than the age of oceanic crust?
a. Continents formed early in earth history when the planet was still extremely hot
and oceanic crust formed much later after the earth cooled below the melting
point of oceanic crust.
b. Because oceanic crust could not form until much later in earth history when
enough water was brought to the earth to fill the oceans.
c. Ocean crust is constantly being made at mid-ocean ridges and then recycled
back into the mantle in subduction zones.

c

How were the Hawaiian Islands created?
a. Tectonic collision between the West Pacific plate (oceanic crust) and the East
Pacific plate (oceanic crust).
b. Upwelling of magma to the ocean surface resulting from tectonic plate
divergence along the Pacific mid-ocean ridge.
c. Mantle hot spot that upwelled magma to the surface to form underwater
mountains that eventually grew to become islands.
d. They formed near the Aleutian Islands in Alaska about 250 million years ago and
then were transported by the tectonic plate motion to reach their present
location

c

Where are siliceous and calcareous oozes typically found?
a. In coastal regions near river outflows.
b. Away from coasts in regions of high biological productivity.
c. Away from coasts in regions of low biological productivity.
d. All of the above.

b

Analysis of fossil shells in sediment cores extracted from the sea floor can yield
information about:
a. Species extinction through time.
b. Past levels of biological productivity.
c. Past temperatures of the ocean’s surface.
d. All of the above

d

Which wave process gives rise to the nice, clean sets of waves that have similar
wavelength that come ashore in Hawaii from Alaskan storm?
a. Wave refraction
b. Wave dispersion
c. Constructive wave addition
d. Mixed wave addition
e. Longshore transport

b

What typically happens to wave energy as it approaches a coastal headland?
a. The wave energy is focused to produce larger waves.
b. The wave energy is de-focused to produce smaller waves.
c. The distribution of wave energy is unchanged as the waves move toward the
shoreline

a

If you are caught in a rip current, what should you do?
a. Swim straight back to shore, the same way you came offshore.
b. Swim along the shore for 10 to 20 meters, then back to shore, and then call
Bruce.
c. Swim along the shore for about 2 kilometers (the typical width of a rip current)
and then back to shore.

b

What is a storm’s fetch?
a. It is the rotation rate of the storm system (clockwise in the northern hemisphere
and counterclockwise in the southern hemisphere).
b. It is the translation speed of the storm system as it slowly moves across the
ocean basin.
c. It is the distance over which the storm is able to recover energy lost to viscosity
forces (i.e., fluid friction forces).
d. It is the diameter of the storm system

d

How fast does the tsunami wave propagate?
a. About 5 miles per hour
b. About 50 miles per hour
c. About 500 miles per hour
d. About 1,500 miles per hour

c

What should you do if you were somewhere near a beach and suddenly felt a small
earthquake?
a. You should move immediately to higher ground or a tall building.
b. Since the earthquake felt small, you can safely ignore things and stay close to the
beach

a

In the video of the Japanese tsunami propagation across the Pacific that was shown in
class, which of the following best expresses how the wave propagated?
a. It propagated as a clean wave front spreading out from a single source with
slight bending of the wave front due to bottom depth changes.
b. There were two distinct wave fronts that initially formed about 100 km apart
near the coast of Japan. The two waves spread out across the Pacific where they
occasionally formed constructive and destructive wave addition patterns.
c. A great many waves generated near the coast of Japan – similar in nature to
throwing a large handful of small rocks into a pond. These many individual
tsunami waves spread across the Pacific where they formed a highly complex
pattern of constructive and destructive wave addition

c

Which force is involved in the creation of the tidal bulge located on the far side of Earth
that is opposite from the side facing the moon?
a. Gyro-dynamic force
b. Geodesic force
c. Coriolis force
d. Centrifugal force
e. Trapezoidal force

d

What orbit path does the moon take around the Earth?
a. The moon’s orbit around the Earth is along the Earth’s equator.
b. The moon’s orbit around the Earth is at a 28° inclination relative to the
equator.
c. The moon’s orbit around the Earth changes with time. Sometimes the orbit is
inclined at a 28° relative to the equator and sometimes the moon’s orbit around
the Earth is along the equator.
d. The moon has a polar orbit, moving north to south and crossing precisely over
the north and south poles

b

When do Spring Tides occur?
a. During a Full Moon
b. During a Half Moon
c. Only during April through May
d. Both a and c

a

Why do we get rotary tides?
a. Coriolis force alone.
b. Blocking by continents alone.
c. The combination of Coriolis force and blocking by continents.
d. The action of the trade winds and the westerly winds that turn (spin) the tide
crest from the expected east to west direction and form rotary motion.
e. The combination of the blocking by continents and the action of the trade winds
and westerly winds

c

Why do you not get a significant tidal range in Hawaii?
a. The Hawaiian land mass and coastline distance are too small for the tide crest to
pile up very high
b. Hawaii is near a co-tidal line
c. Hawaii is near an amphidromic point
d. Gravity of the moon is reduced there

c

If you have high pressure at 30ºN and low pressure along the equator, why do the
surface winds not move in a straight line southward from high to low pressure? Why do
they instead turn to the west?
a. They are turned by an east-west pressure gradient that results from an east-west
difference in heating of the ocean’s surface by the sun.
b. They are turned by the Coriolis force.
c. They are turned by the combination of blocking by continental mountain ranges
and an east-west difference in heating of the ocean’s surface by the sun.

b

Does the mixing depth of the surface ocean get shallower or deeper as you transition
from winter into spring and summer in temperate (mid-latitude) regions?
a. The mixed layer gets deeper as the surface ocean accumulates more heat and
thickens the warm ocean surface layer.
b. The mixed layer gets shallower as the surface layer warms because the warmer
water is more buoyant and, thus, it is more difficult for the winds to mix the
surface water to greater depth

b

What is Ekman Transport?
a. The transport of warm surface water within western boundary currents like the
Gulf Stream that bring tropical water to high latitudes.
b. The movement/transport of a relatively thin (c.a., 50 meters) slab of surface
water that occurs in direct response to wind forcing.
c. The downward transport of cold, salty and dense surface water in polar regions
of the North Atlantic and around Antarctica.
d. This is the name given for the familiar “Global Conveyor Belt Transport” that was
described by Vagn Walfrid Ekman in 1905.

b

How is the mound of surface water in the middle of the subtropical gyre formed?
a. The moon’s gravity pulls the mound upward in the center of the ocean basin.
b. Freshwater inputs from the surrounding continental margins flood over the
surface of the ocean to create a mound of mostly fresh water.
c. The action of the Trade Winds and the Westerly Winds collectively drive an
Ekman Layer convergence into the middle of the subtropical gyre.
d. The Ekman Spiral draws deep water up to the surface ocean in the center of the
subtropical gyre

c

What drives subtropical gyre rotation?
a. The trade winds and the westerly winds apply a lateral torque on the gyres and
spin them up directly – sort of like unscrewing the lid from a jar.
b. Strong upward flow caused by Ekman layer divergence brings cold deep water to
the ocean surface and this excess water is turned directly outwards by the action
of trade winds and westerly winds into a clockwise (northern hemisphere) or
counterclockwise (southern hemisphere) direction.
c. A center of high pressure under a mound of water drives ocean currents
radially outward and these currents are deflected by the Coriolis Force.

c

If winds are blowing from north to south along the west coast of the United States (e.g.,
the Washington, Oregon and California Coasts), would the Ekman Layer move onshore
or offshore?
a. Onshore
b. Offshore

b

How is the age of bottom water in the deep ocean measured?
a. Based on characteristic chemical isotope ratios (e.g., 16 O:18 O)
b. Based on temperature and salinity of the water.
c. Based on the identification of marine plankton present in the water sample.
d. Based on 14 C concentration

d

How long does it take for deep ocean water to move from the North Atlantic to the
North Pacific?
a. About 100 years
b. About 200 years
c. About 2,000 years
d. About 10,000 years

c

The reason oceanographers care so much about the movement of the conveyor belt
circulation is because:
a. It moves a lot of heat from the equator to higher latitudes.
b. It moves a lot of fresh water from coastal regions to the open ocean.
c. It strongly impacts the propagation of Rotary Tides.

a

Which statement best describes the current state of scientific knowledge regarding the
possibility that the Atlantic Meridional Overturning Circulation (AMOC) might collapse
this century?
a. Scientists are highly confident that AMOC will collapse this century.
b. Scientists are highly confident that AMOC will not collapse this century.
c. Scientists have modest but steadily growing concern that AMOC could collapse
this century

c

What happens to the Walker Circulation Cell during the transition from normal
conditions to El Niño conditions?
a. The Walker Cell speeds up.
b. The Walker Cell slows down or reverses.
c. The Walker Cell moves northward approximately 10-degrees of latitude.
d. The Walker Cell moves southward approximately 10-degrees of latitude

b

What happens to the Warm Pool during the transition from normal conditions to El Niño
conditions?
a. The Warm Pool propagates from the Eastern Pacific (near Peru) to the Western
Pacific (near Australia).
b. The Warm Pool propagates from the Western Pacific (near Australia) to the
Eastern Pacific (near Peru).
c. The Warm Pool position is not affected by El Niño conditions

b

During an El Niño event, biological productivity off the California coast can be expected
to increase?
a. True, El Niño events typically stimulate an increase in primary production that, in
turn, feeds the rest of the food web.
b. False, El Niño events typically lead to a decrease in primary production that, in
turn, lowers growth for the rest of the food web

b

How can the effects of El Niño conditions in the Pacific be transmitted to the far reaches
of the globe?
a. Variation in the position of the Kuroshio Current (Western Boundary Current in
the Western Pacific)
b. Variation in the position of the Jet Stream in the atmosphere
c. Small variation in the Earth’s rotation about its axis

b

What happens to the global-average temperature during an El Niño year?
a. Global temperatures increase during an El Niño year.
b. Global temperatures decrease during an El Niño year.

a

With regard to the global carbon cycle, how does the magnitude of CO 2 sequestered
by the global ocean through photosynthesis and, separately, the magnitude of CO 2
released by the global ocean through respiration compare to the magnitude of CO 2
emitted by humans through fossil-fuel burning?
a. Ocean respiration and ocean photosynthesis are each much smaller than
human emissions.
b. Ocean respiration and ocean photosynthesis are each about the same as
human emissions.
c. Ocean respiration and ocean photosynthesis are each much larger than
human emissions

c

Net Primary Production and Photosynthesis are equivalent terms.
a. True
b. False

b

Which light level produces zero Net Primary Production?
a. Photo-Inhibited Light Level
b. Light-limited Level
c. Compensation Light Level
d. Light-Saturation Level

c

Which type of phytoplankton has the growth advantage at low nutrient
concentration?
a. Small cells
b. Large cells

a

Which nutrient limits the growth of phytoplankton in the Southern Ocean?
a. Nitrogen
b. Phosphorous
c. Magnesium
d. Iron

d

Why is primary production in the Eastern Equatorial Pacific higher than in the
Western Equatorial Pacific?
a. The Trade Winds are stronger in the East, and this drives stronger equatorial
divergence of the Ekman Layer.
b. The thermocline is shallower in the Eastern Equatorial Pacific.
c. Coriolis force is stronger in the Eastern Equatorial Pacific.
d. Walker Circulation is stronger in the Eastern Equatorial Pacific.

b

Why do coastal upwelling regions experience seasonal increases in primary
production?
a. Because higher sun angles and longer day lengths in summer stimulate the
growth of phytoplankton.
b. Because the winds driving upwelling is seasonally variable.
c. Because iron-rich dust blowing off continents and into the coastal
environment is seasonally variable.
d. Because river runoff increases during springtime and enhances the delivery
of nutrients to the coastal environment

b

Where is the critical depth located relative to the compensation depth?
a. Shallower
b. Deeper
c. They are found at the same depth

b

If phytoplankton mix a little bit below the compensation depth, then net primary
production averaged over the course of a day will be negative.
a. True
b. False

b

Why should you thank the ocean for every other breath you take?
a. Because primary production in the ocean constitutes about half of global
primary production.
b. Because half of all living biomass on Earth resides in the ocean.
c. Because half of all the CO 2 emitted since the beginning of the Industrial Era
has been taken up by the ocean.
d. Because the ocean produces half of all the global CO2 each year

a

Which region comprises most of the global ocean primary production
a. Open ocean
b. Coastal upwelling

a

What do oceanographers mean when they say that pelagic ecosystems are strongly
size structured?
a. They mean larger animals will consume any and all animals that have a
smaller body size.
b. They mean larger animals will consume any and all animals with a similar
body size.
c. They mean that body size is the dominant factor that determines what
trophic level any given animal species will reside in.
d. They mean as a general rule, pelagic animal body shape is elongated in
structure to allow for more efficient movement through the fluid
environment.

c

What is the level of Exploitation Efficiency for the case of small grazers feeding on
small phytoplankton in tropical regions?
a. Exploitation Efficiency is Low
b. Exploitation Efficiency is Medium
c. Exploitation Efficiency is High

c

Given a Trophic Transfer Efficiency of 10%, how many units of fish would be
produced each year if you started with 1000 units of phytoplankton?
phytoplankton > zooplankton > fish
a. 1000
b. 100
c. 10
d. 1

c

Where is overall production of harvestable fish greatest?
a. Open Ocean Region
b. Coastal Region
c. Equatorial Region
d. Arctic Region
e. Southern Ocean Region

b

What do heterotrophic bacteria use for their source of energy and carbon?
a. Dissolved organic matter.
b. Sunlight and carbon dioxide.
c. Predation on viruses that are 1/10 the size of heterotrophic bacteria

a

Prochlorococcus contributes to more than a quarter of the total global ocean
primary production.
a. True
b. False

a

Where does the Biological Carbon Pump operate most efficiently?
a. In Eutrophic regions
b. In Oligotrophic regions
c. In Mesotrophic regions
d. In Anoxic conditions

a

What factor or factors determines where a given species resides in the rocky
intertidal?
a. Ability to withstand desiccation
b. Ability to compete for space
c. Ability to avoid predation
d. All of the above

d

What happens to the level of biodiversity in the rocky intertidal region when the
starfish Pisaster is removed?
a. Biodiversity increases
b. Biodiversity decreases
c. Biodiversity stays about the same

b

What is meant by the term Trophic Cascade?
a. It describes the additive impact of greater and greater decrease in the
abundance of organisms in adjacent trophic levels.
b. It describes the alternating decrease-increase-decrease in the
abundance of organisms in adjacent trophic levels.

b

What is responsible for the massive declines in kelp forests off the California coast
over the past decade?
a. Over harvesting of kelp for animal feed in industrial agriculture.
b. A large sea otter increase resulting from new marine protections
c. Sunflower starfish decline due to bacterial disease
d. Sea urchin declines due to over harvesting

c

What percentage of a coral’s nutrition comes from its Zooxanthellae symbionts?
a. 10%-20%
b. 30%-60%
c. 60%-90%
d. 100%

c

What resource is in short supply in coral reefs and under stiff competition with other
coral species?
a. Light
b. Nutrients
c. Space
d. Zooplankton Prey

c

What happens when coral reefs are overfished?
a. The decline in fish leads to an increase in sea urchins and a decrease in coral
cover.
b. It leads to a large increase in zooplankton that is subsequently consumed by
corals and this, in turn, causes the coral to expel the Zooxanthellae
symbionts because they are no longer needed as a nutrition source.
c. It reduces herbivory on macro algae and allows the macro algae to
overgrow and smother coral species.
d. Overfishing reduces overall biodiversity of the reef community, but the corals
themselves are not affected.

c

How much coral cover has already been killed off over the past 150 years?
a. <10%
b. 50%
c. 90%
d. >99%

b

What percentage of corals will be lost if global warming reaches 2 ºC?
a. <10%
b. 30%-50%
c. 70%-90%
d. >99%

d

What unique skeletal feature is used to connect all of the transitional fossils
between Pakicetus and modern whales?
a. Skull shape
b. Hooved limbs
c. Ear bone
d. Dental pattern

c

What time of year should you visit Hawaii if you wanted to see humpback whales?
a. Summer
b. Winter

b

Which of the following noise sources did Professor Chris Clark (me included)
express the most concern for impacting whale population success?
a. Navy Sonar.
b. Commercial shipping.
c. Offshore oil exploration

b

Off-shore oil exploration uses air guns to blast noise that penetrates deep into
ocean sediments in search of subsurface pools of oil. The magnitude of the air guns
is on the order of dynamite exploding. How often do these air guns blast noise into
the ocean?
a. Once a day for several months
b. Once an hour for several months
c. Once every 10 minutes for several months
d. Once every 10 seconds for several months

d

Whether or not whales can be humanely killed is one ethical issue when it comes to
commercial whaling. What was the other ethical issue discussed in class?
a. The fact that whaling puts the lives of sailors at great risk.
b. The extraction of a common public resource from the ocean for commercial
profit.
c. Hunting species that are listed as vulnerable or endangered with
extinction.
d. The fact that only a small fraction of the whale is marketed with a large
(>50%) fraction being discarded.

c

What property of water allows it to form hydrogen bonds with adjacent water
molecules?
a. The triangular molecular shape
b. The linear molecular shape
c. The polar charge distribution with one side of the molecule having a
slightly positive charge and the other side having a slightly negative
charge.
d. The ability to covalently share electrons with adjacent water molecules.

c

What two opposing molecular forces/energies determine the three phases of water
(solid, liquid and gas)?
a. H-bonds and Hydro-elastic energy
b. Covalent bonds and Hydrogen bonds
c. Strong nuclear forces and Weak electrostatic forces
d. Strong nuclear forces and Weak nuclear forces
e. H-bonds and Thermal-Kinetic energy

e

When a given amount of heat energy is added to the surface ocean, the temperature
does not rise nearly as much as it would if the same heat energy were added to land
or atmosphere. Why is this the case?
a. The surface heat energy is strongly diluted by vertical mixing through the
entire water column down to the ocean floor.
b. Water has an exceptionally large specific heat capacity.
c. Water has an exceptionally small specific heat capacity.
d. Evaporation from the ocean surface removes much of the added heat
energy.
e. The conveyor belt circulation removes much of the excess heat to high
latitudes where the heat is quickly released to the atmosphere.

b

When water vapor is transported by the winds it is transporting heat energy stored
as latent heat that will eventually be turned back into sensible heat when it
condenses back to rain at a new location.
a. True
b. False

a

What determines surface ocean salinity for a given geographic location?
a. The amount of Precipitation in the region.
b. The amount of Evaporation in the region.
c. The difference between Evaporation and Precipitation in the region.
d. The difference between salt addition from rivers and streams and ocean
dilution from Precipitation

c

Where is surface ocean salinity lowest?
a. Subpolar North Atlantic
b. Subpolar North Pacific
c. Atlantic Subtropical Gyres
d. Pacific Subtropical Gyres

b

What happens to the concentration of nitrate and phosphate in deep ocean waters
(4000 meter) as the deep waters move from the North Atlantic to the North Pacific?
a. The concentration increases
b. The concentration decreases
c. The concentration stays roughly constant

a

Why is oxygen high in the upper layer of the ocean?
a. Diffusion of atmospheric oxygen into the ocean.
b. Photosynthesis
c. Both a and b

c

What causes of an oxygen minimum zone to form just below the sunlit layer of the
ocean?
a. Rapid downward mixing just below minimum zone.
b. A high level of microbial respiration, fueled by dead organic material
raining down.
c. Ekman transport of low oxygen water resulting from the combined forcing of
the Trade Winds and the Westerly Winds
d. None of the above

b

Why does the oxygen concentration in deep ocean waters (4000 meters) decrease
as the deep waters move from the North Atlantic to the North Pacific?
a. Lateral mixing at depth (4000 meters) dilutes the oxygen concentration.
b. The dissolved oxygen chemically reacts with water to form dioxygen
monoxide.
c. Microbial respiration along the 2000-year journey from Atlantic to
Pacific.
d. Oxygen radioactively decays over time

c

Why is CO 2 low in the surface ocean?
a. Downward diffusion of dissolved CO 2 from the surface ocean to the deep
ocean.
b. Upward diffusion of CO 2 from the surface ocean to the atmosphere
c. Photosynthesis in the surface ocean
d. Respiration in the surface ocean

c

How much of the cumulative CO 2 emitted to the atmosphere from fossil fuel
burning has the ocean taken up?
a. About 10%
b. About 30%
c. About 60%
d. About 90%

b

The ocean surface is 60% more acidic today relative to the pre-industrial level.
a. True
b. False

b

What will happen to the acidity of the surface ocean if you bring deep ocean water
to the ocean surface?
a. Acidity of the surface ocean will increase.
b. Acidity of the surface ocean will decrease.
c. Acidity of the surface ocean will stay about the same.

a

Why are polar seas especially vulnerable to ocean acidification?
a. Surface ocean salinity is lower in polar regions.
b. Cold water can absorb more CO2 than warm water.
c. Western boundary currents transport additional CO 2 from low latitudes to
polar regions that adds to the vertical flux of CO 2 from the atmosphere.
d. Convergence of surface waters into polar regions concentrates the CO2 .

b

With “business-as-usual” fossil fuel emissions, how soon will polar seas become
corrosive to the calcium carbonate shells used by planktonic organisms that form
an important part of the base of marine food webs?
a. 2 to 3 years
b. 20 to 30 years
c. By the end of the century (2100)

b

When we finally stop burning fossil carbon and emitting the CO2 to the atmosphere,
ocean acidity will remain elevated for 10,000 years.
a. True
b. False

a