OCE 4008 Final Exam
The increased presence of carbonic acid at deep depths causes calcium carbonate to precipitate into a solid beneath approximately 4500 meters.
False
If there is an abundance of foraminifera shells found in a sediment, it would be categorized as
calcareous ooze
The level of ______ increases with depth which is a factor in the calcium carbonate compensation depth.
carbon dioxide
The ocean is becoming more acidic as it absorbs additional _____ from the atmosphere.
carbon dioxide
What is the term for a pattern of wind circulation that changes with season?
Monsoon
The abundant biological communities found at methane hydrates/seeps are ultimately powered by sunlight.
False
Which water mass is not produced by caballing?
Mediterranean Deep Water
Which sediment is categorized under cosmogenous sediments?
Microtektites
Why is sensible heat detectable while heat that is not sensible cannot be measured?
A thermometer measures the decrease in temperature, but as liquid changes to solid, the loss of heat is not measurable.
What is the residence time of water vapor in the lower atmosphere?
10 days
How long is it estimated to take the ocean's volume of water to circulate through the oceanic crust at spreading centers?
10 million years
How long ago did the big bang catalyze the beginning of the universe?
13.7 billion years ago
How many atmospheric cells are present in each hemisphere?
3
What is the average pH of the ocean?
8.0
How much of the Earth's water is found in the ocean?
97%
What is a gyre?
A circular flow of water around the periphery of an ocean basin
What caused Earth to partially melt when being formed?
A combination of all of the above (Impact of asteroids, comets and debris, Gravitational compression, Accumulation of decaying radioactive elements)
What is the structure of carbon dioxide an example of?
A compound
Sometimes formations on land can shed light on ocean processes. What do the White Cliffs of Dover in England show?
A lithified calcareous ooze that was pushed above sea level from plate tectonics.
If a ship is trying to sail from the eastern United States to Europe, what route would be the most efficient to take?
A northern route to take advantage of the westerlies
What is a solute?
A substance that dissolves in a another substance
What forms heavy elements such as gold, mercury, and uranium?
A supernova
What was the main requirement for the development of life on Earth?
Absence of free oxygen
What process involves the clumping of small particles into larger masses?
Accretion
What type of margin is generally steep?
Active margin
Who was responsible for the theory of continental drift?
Alfred Wegener
What can cause hydrogenous calcium carbonate deposits?
All of the above (Evaporation, A decrease in the acidity of seawater, An increase in seawater temperature)
__________ is a critical aspect of science.
All of the above are critical aspects of science (The ability to operate in reverse, The ability to be refined with new information, Looking at data rather than being told)
What is true of bathymetry?
All of the above are true (It is the discovery and study of the ocean floor's contours, It uses orbiting robotic spacecrafts to enhance data, It is hindered by the very presence of our ocean.)
What is a characteristic of transform faults?
All of the above are true. (They are fractures along two plates that slide vertically, They move in opposite directions, horizontally of each other, They are just as active as fracture zones)
What layer is permanently devoid of light?
Aphotic zone
Where are abyssal plains most common?
Atlantic Ocean
What is considered to be the densest type of crust?
Basalt
How old are fossils that indicate the first life forms on Earth?
Between 3.4 and 3.5 billion years old
The west coast of South America is known for seasonal upwelling. What kind of sediment is likely to be abundant based on this information?
Biogenous
What statement is true of biogenous and terrigenous sediments?
Biogenous sediments comprise a larger area than terrigenous sediments.
Why is the amount of carbon dioxide dissolved in seawater much less than saturation level?
Carbon dioxide is quickly used by photosynthetic organisms.
What does carbon dioxide break down into once it is in the ocean?
Carbonic acid; Bicarbonate; Carbonate; (All of the above)
A marine scientist is studying the amount of dissolved oxygen in a particular area. They are attempting to connect the data with the type of organisms found in that area. What kind of marine scientist might they be classified as?
Chemical oceanographer
What traps light energy in primary producers?
Chlorophyll
What specifically connects the continental shelves to the deep-ocean floor?
Continental slope
What process explains how hydrothermal vents are created?
Convection
_______ connect(s) atoms by sharing the energy of paired electrons.
Covalent bonds
What organism usually fixes nitrogen into usable chemical forms?
Cyanobacteria
Phosphorus is a major component of
DNA and RNA; ATP; Phospholipids; (All of the above)
Francis Bacon thought the continents were once joined together, even naming the single continent Pangeae, and the surrounding ocean Panthalassa
False
Manganese and phosphorite nodule can only be observed in areas of high sediment accumulation.
False
The __________ has/have a low ratio of volume in comparison to its area in the ocean.
Deep ocean floor
What is considered an important factor in shaping western boundary continental rises?
Deep-ocean currents
What does not affect surface currents?
Density
What process accounts for the layers found in the Earth?
Density stratification
A deep ocean ooze was discovered near Antarctica. What type is it likely to be?
Diatom ooze
Iron fertilization experiments resulted in an increase of the following phytoplankton:
Diatoms
What is the name given by sailors to the area where Hadley cells converge?
Doldrums
Neritic sediments are mainly comprised of biogenous sediments due to the proximity to the continental shelf.
False
Radiometric dating was used to age the ocean floor which was found to be older than the land at the center of continents
False
What is needed for living matter to function?
Energy
Where does the largest amount of upwelling occur?
Equatorial upwelling
What is the origin of most abyssal plain sediments?
Erosion from the continent
The export flux of iron generally
Exceeds the delivery from below
What is a characteristic of Antarctic Bottom Water?
Extreme density
(T or F) A higher level of pH is associated with more hydrogen ions.
False
(T or F) Carbon dioxide is abundant near the surface due to the photosynthetic activities of plants.
False
(T or F) High nutrient low chlorophyll areas have a major increase in phytoplankton biomass at different times throughout the year
False
(T or F) If phosphorus is limiting it can be "fixed" from the atmosphere
False
(T or F) Labile dissolved organic matter is hard for heterotrophic bacteria to break down and sticks around for 1000s of years
False
Calcareous oozes form much slower than siliceous oozes based on the rate their components dissolve in seawater.
False
Chemosynthesis is the main method of binding energy into carbohydrates the planet.
False
What is a more accurate term for the feeling relationships of organisms?
Food web
What causes most of the differences in winds in comparison to normal surface wind directions?
Geographical distribution of landmasses, The different responses of land and ocean to solar heating, Chaotic flow
What is the largest biogeochemical cycle?
Global Carbon cycle
What is the immediate organic material produced from inorganic substances?
Glucose
What thrusts water masses that are engaged in the thermohaline flow of the world's ocean?
Gravity
Horse latitudes at sea correspond to ____ on land.
Great deserts
What is considered to be the largest western boundary current?
Gulf Stream
Why does the ocean not boil or freeze solid in different regions of the world?
Heat is transported by oceanic and atmospheric circulation.
The pycnocline isolates the majority of the world ocean from:
Heating and cooling brought on by solar energy fluctuations; Wind driven circulations; Light; (All of these)
What is rarely a limiting factor for marine organisms?
Hydrostatic pressure
The enzyme nitrogenase, involved in nitrogen fixation, requires the following trace element
Iron
Why is the West Wind Drift not considered a gyre?
It does not flow around the margins of an ocean basin
Why is iron not abundant in the ocean?
It is nearly insoluble in oxygenated water
What is true of the intertropical convergence zone?
It is subject to seasonal variations
What is true of heat capacity?
It is the measure of heat required to raise the temperature of one gram by 1 degree Celsius.
How do salinometers measure salinity?
It measures the electrical conductivity of seawater samples.
What direction would a gyre in the Southern Hemisphere flow towards?
Left
Why is biosynthesis unlikely to occur today as it did in Earth's youth?
Living organisms have altered oceanic and atmospheric conditions.
Which of the following about the Lost City hydrothermal field is TRUE?
Located on Atlantis Massif where methane and other hydrocarbons are abiotically produced
What substance was able to show previous orientations of Earth's magnetic field?
Magnetite
What valuable commodity has yet to be commercially mined from ocean sediments?
Manganese nodules
Which is an example of an authigenic sediment?
Manganese nodules
What water mass is the most saline?
Mediterranean Deep Water
What is a storm surge?
Movement of water due to the low atmospheric pressure creates a dome of water
Which essential gas is often in an unusable form in the ocean and atmosphere?
Nitrogen
Nitrogen gas is converted to ammonium during
Nitrogen fixation
The most abundant form of Nitrogen in the ocean is:
Nitrogen gas
Which is not an example of a tropical cyclone?
Nor'easter
What biological chemical is important in heredity of traits?
Nucleic acids
What is the calcium carbonate compensation depth?
The depth at which calcium carbonate starts to dissolve.
The concentration of iron is very low in vast areas of the ocean because of its low solubility in:
Oxic seawater
What inorganic nutrient is required for primary production?
Phosphorous
What element is used to link nucleic acids in all organisms?
Phosphorus
What piece of equipment was able to facilitate two new fields of science with the data it generated?
Piston Corers
What was the first evidence that suggested the Earth's crust might be broken into pieces?
Plotting of deep earthquakes in the Pacific Ring of Fire
Where is density stratification the least pronounced?
Polar latitudes
What type of water mass dissolves the most amounts of gases?
Polar water masses
What is the greatest source of oxygen in deep water?
Polar waters that have sunk from the surface
The biological pump is driven by:
Primary producers
What had the most influence in irreversibly changing the Earth's atmosphere?
Production of oxygen from photosynthesis
Nitrogen is about 13% of a bacterial cell, mostly in the following:
Proteins, Nucleic acids
Which water mass is characterized by increasing density with deeper depths?
Pycnocline zone
What is an example of terrigenous sediment?
Quartz
The sustained heat within the Earth's interior is attributed to:
Radioactive Decay
What organism is likely to be found in siliceous ooze?
Radiolarian
The Pacific has a thinner layer of pelagic sediments than the Atlantic due to fewer rivers and an increase in trenches.
True
What is a main source of terrigenous sediments?
Rivers
What is the main reason for the stratification in the north polar waters?
Salinity
What is not a factor on the salinity of a particular region of ocean?
Saturation levels
What is often found in the middle of manganese nodules?
Shark teeth or bone fragments
One way bacteria acquire iron is through the production of:
Siderophores
The main components of the biological pump are:
Sinking particulate organic matter/ carbon; active vertical migration by zooplankton; dissolved organic carbon mixed downward from the surface; (All of the above)
The Earth was formed by the condensation of a cloud comprised of dust and gas.
True
What type of wave causes the most damage to property during an earthquake?
Surface waves
What is a cause of atmospheric circulation?
The Coriolis Effect
The expansion of the universe that began during the big bang event continues to this day.
True
What enhances the ocean's buffering capacity?
The amount of dissolved inorganic carbon present
What is not a factor in the amount of light penetrating the ocean?
The amount of light absorbed by clouds
Why does the heat budget vary with latitude?
The angle of the sun at varying latitudes
There were multiple sources of water that contributed to the ocean. How was the majority of the ocean's water formed?
The condensation and cooling of water vapor
What is Forchhammer's principle?
The constant proportion of solids in seawater
What is the greatest source of high carbon dioxide levels at middle depths in the ocean?
The decay of the remains of organisms
What is the Ekman spiral?
The decreasingly slower movement of water as it gets further away from the wind source
What key characteristic marks the beginning stages of the collapse of a star?
The depletion of hydrogen
Why does the latent heat of vaporization require so much heat energy?
The energy is needed to break the strong covalent bonds; The energy is required to stabilize bond vibrations; The energy is used to break the hydrogen bonds; (All of these)
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 bond becomes rigid, allowing it to expand slightly.
What partly explains the seabed topography we observe?
The jostling due to plate tectonics.
What is the flatness of abyssal plains associated with?
The large amounts of sediment
What kind of information can marine microfossils not provide?
The orientation of the magnetic poles based on trace metals found within the shells
What happens to pH levels in regions where there is more carbon dioxide present?
The pH levels decrease in these regions.
The submerged outer edge of a continent is called:
a continental margin
What causes a decrease in oxygen levels beyond the sunlit layer?
The respiration from marine animals and bacteria
What prevents North Atlantic Deep Water from moving on a large scale like the Antarctic Bottom Water?
The topography of the basin
What is a characteristic of the water that is expelled from hydrothermal vents?
The water is enriched with metals
Why are there multiple atmospheric cells as air moves from the equator to the poles instead of one single cell?
There are intermediate precipitation events which break up the air into circulation cells
What is a disadvantage of using multibeam echo systems to map the entire seafloor?
There are very few vessels that are actually outfitted with these systems.
Why are some tropical waters unable to sustain life?
There is a low level of dissolved oxygen due to temperature
Why are east-west variation patters more pronounced in the middle latitudes of the Northern Hemisphere?
There is an almost equal ratio of land and water in the Northern Hemisphere
Which is not a characteristic of thermoclines?
Thermoclines are more abrupt in the high latitudes
What is responsible for the large-scale global ocean circulation?
Thermohaline circulation
What is the name for slow, deep currents beneath the pycnocline?
Thermohaline currents
What is not a characteristic of western boundary currents?
They are broad currents
What statement is true of the surface area of oceanic ridges and their associated features?
They consist of slightly less area than that of all the land above sea level.
Why do transform faults form?
They form because the axis of seafloor spreading across the surface of the Earth cannot follow a straight line smoothly.
What is the tendency of pausing air masses over land?
They take on characteristics of the land below them
What influences contour currents?
Topography
What offsets the mid-Atlantic ridges's movement at fairly regular intervals?
Transform faults
________ are likely to be found in subduction zones
Trenches
(T or F) Iron is required for photosynthesis and respiration
True
(T or F) Phytoplankton is responsible for the synthesis of 90% to 96% of the surface ocean's carbohydrates.
True
(T or F) Rapid amounts of photosynthesis can create variations in the alkalinity of seawater.
True
(T or F) Researchers believe the catalyst for the 1982-83 El Niño even was actually the volcanic eruption of El Chichòn.
True
(T or F) The global conveyer belt transports juvenile organisms, mixes nutrients, and distributes gases and solids
True
(T or F) The horizontal movement of water by wind can lead to vertical movement in surface water.
True
(T or F) The lower atmosphere is a homogenous mixture of gasses with nitrogen and oxygen being the most abundant.
True
(T or F) The trace metal iron is required for photosynthesis and nitrogen fixing enzymes.
True
Although most of the biological productivity occurs close to land, a greater proportion is found in pelagic sediments.
True
Both basalt and granite are examples igneous rocks.
True
Clays can remain suspended in a water column for decades before settling due to their small size.
True
Coastal waters often support larger blooms of plankton than open water due to a high nitrate level in runoff.
True
Deep ocean basins can be covered by sediments up to 5 kilometers (3 miles) thick.
True
Deep-ocean basins can be covered by sediments up to 5 kilometers (3 miles) thick.
True
Despite a multitude of names given to describe portions of the ocean, it is more accurate to call it a single dynamic world ocean.
True
Despite the various attempts of land and ocean drilling, there has been no success in reaching the interior of the Earth. (true or false)
True
Most biological productivity in the ocean occurs in the euphotic zone
True
Most sediments have a composition derived from a mixture of origins.
True
The fundamental success of ocean depth measurements taken by satellites is based on the variation of gravitational pull associated with bathymetric features.
True
The ocean was mostly in place by 4 billion years ago.
True
What characteristic is associated with convergent plate boundaries?
Violent geological activity
Which does not have an effect on water's density?
Viscosity
Why is air never completely dry?
Water vapor makes up as much as 4% of the atmosphere, Clouds and fog are actually liquid droplets of water, Water's very presence in the atmosphere accounts for dew, rain, and snow
What occurs at the boundaries of circulation cells?
Winds move vertically where the boundaries meet
Where do tropical cyclones come from?
Within a single warm and humid air mass
The scientific method is characterized as:
an orderly process in which theories are verified or rejected.
If a sediment is white in color, it is likely to be
biological in origin.
A(n) __________ is a test involving manipulations made on conditions of a particular observation.
experiment
High levels of _________ could indicate life on other planets.
free oxygen
The composition of the Milky Way does not include
galaktos
A(n) __________ is an explanation that can be tested by additional observations or controlled experiments.
hypothesis
The sediments that occur on the slope, rise, and deep ocean floor and originate in the ocean are called
pelagic sediments
Density is defined as:
the mass per unit of volume.
Satellites use __________ to calculate the depths of the ocean.
variations in elevation of surface water