Oceanography Test Questions – Flashcards
Unlock all answers in this set
Unlock answersquestion
What regulates our earth's climate?
answer
physical processes at work in the ocean and interaction between the ocean and atmosphere
question
past climate changes can be monitored by
answer
our ocean
question
nebular hypothesis
answer
all bodies in the solar system formed from nebula
question
nebula
answer
cloud of gases and space dust (hydrogen and helium
question
sun
answer
gravity concentrates material at the center of a cloud
question
eddies
answer
proplanets form from smaller concentrations of matter
question
protoearth
answer
-larger than Earth today -homogeneous composition -bombarded by meteorites: moon formed from collision with large asteroid
question
outgassing
answer
occurred during density stratification (origin of earth's atmosphere)
question
What is the difference between a sea and an ocean?
answer
seas are smaller in are. seas are shallower in average depth. seas are partly enclosed by land. seas have a salinity that is different from the main oceans. (answer is all of the above)
question
which is not true about the earth after its formation?
answer
the atmosphere was composed mostly of oxygen
question
why does the earth have a nickel-iron core at its center, surrounded by silicate mantle?
answer
because it is more massive, the core material sank to the center of the Earth
question
why is the continental crust higher than ocean crust?
answer
continental crust is thicker and less dense than ocean crust so it floats higher to the mantle
question
continental and ocean crusts have different levels because oceanic crust is denser, assuming no difference in structure what would happen if the two types of crust were made of the same material?
answer
there would still be a difference because continental crust is thicker than ocean crust but the heights would be nearly the same
question
what invention made accurate open ocean navigation possible by determining longitude?
answer
Chronometer
question
Charles Darwin considered a career as a minister what would have happened to the theory of evolution had he not become a scientist instead?
answer
somebody else would have proposed the same idea about the same time.
question
radio isotopes of potassium decay to agron. if a rock sample begins with 12 billion K40 atoms. What will the quantities of K40 and AR40 be after 1 half-life and 2 Half lives?
answer
9 billion K40 Atoms and 3 Billion Ar40 atoms
question
Which of the following is not true about the oxygen on earth?
answer
It is essential for anaerobic bacteria's survival
question
What is a scientific theory?
answer
An explanation for a natural phenomenon that is supported by many observations and widely accepted
question
Which of the following would isostatic adjustment apply to?
answer
the floating of the lithosphere upon denser mantle beneath
question
How did Earth's atmosphere form and progress throughout geologic time?
answer
1. outgassing of earth 2. photosynthesis leads to an oxygen environment
question
How do the oceans form on the Earth?
answer
Condensation resulting from outgassing of early earth starts precipitation resulting in a relentless rain. Acidic rain fosters dissolution of mineral from rock to provide salinity.
question
Stanley Miller's experiment using primordial gases and a primordial ocean proved what concepts?
answer
Given the right inorganic molecules, energy, and time, organic molecules like amino acids can form in the primordial oceans.
question
Heterotrophs and autotrophs are linked on earth by the processes of cellular respiration and photosynthesis, respectively. Why is this?
answer
The end products of photosynthesis are the starting materials for respiration and vice versa.
question
Alfred Wegener's theory of continental drift seems so reasonable today. Why was it rejected during the early 20th century?
answer
His jigsaw puzzle fit of the continental land mass showed large gaps. -He could not provide a driving mechanism for the continents that could plow through the ocean basins. -His mountain formation concepts were not adequate. -The best evidence would not be available until sea floor dating and magnetic reversal data. ALL OF THE ABOVE is the answer.
question
Why are earthquakes mainly found at the edges of plates?
answer
Breakage and deformation of the lithosphere are focused at plate edges.
question
What happens when plate tectonics causes two continents to collide at a convergent plate boundary?
answer
Neither continent will subduct, so they crumple and form mountain ranges.
question
How does ocean basin form?
answer
Convection cells in the asthenosphere pull the sea floor apart, and the spreading creates ocean lithosphere in the gap left between the pieces.
question
What is the difference between an atoll and a tablemount (guyot)?
answer
An atoll top is at sea level, but a tablemount top is below sea level.
question
Transform plate boundaries are parallel to the relative motion between two plates. What would happen if the direction of plate motion changed?
answer
The transform boundary would turn into another type of boundary, either convergent or divergent depending on the direction.
question
You are exploring an ocean basin and trying to determine whether it formed by sea floor spreading. Which of the following evidence would you NOT expect to find in an actively spreading ocean?
answer
Dredging of the mid-ocean ridge would yield granite.
question
Where do most of the largest earthquakes occur?
answer
Convergent Plate Boundaries
question
The alternating reversals of Earth's magnetic field throughout history have been recorded in sea floor rocks in a particular pattern and chronology. How does this support plate tectonics?
answer
The pattern of alternating reversals indicates sea floor spreading and, as a result, continental drift.
question
Why are oceanic ridges different from oceanic rises?
answer
-Oceanic rises spread quickly and produce vast amounts of rock while oceanic ridges spread slowly and accumulate steeply.
question
In relation to plate tectonics what is a major overall trend in earthquakes?
answer
Earthquakes occur at plate boundaries
question
Why do the Hawaiian Islands form a chain in the Pacific Ocean's northern hemisphere?
answer
The Pacific Plate is moving slowing, but the hotspot remains in the same location.
question
If you traveled to another earthlike planet with an ocean, how could you determine if tectonic plates and plate tectonic movement existed?
answer
Look for mountain ranges, oceanic ridges, oceanic trenches, and volcanoes. -From satellite imaging, observe a jigsaw fit of the continental edges. -Check seismic readings for earthquake activity. ALL OF THE ABOVE is the answer
question
How does the Continental Arc System of mountain building, in which volcanic arc activity is apparent near a subduction zone, form?
answer
An oceanic plate collides with a continental plate.
question
Paleomagnetism can be demonstrated in which of the following examples?
answer
The rock of Africa and South America have different magnetic polarities in rock of the same age.
question
How are fringing reefs, barrier reefs, and atolls related in structure and chronology?
answer
Fringing reefs give rise to barrier reefs and then to atolls.
question
Many of the unique properties of water, such as cohesion and its reputation as a universal solvent come from its atomic structure. What causes these properties?
answer
Water molecules are electrically polarized.
question
What is the unit that is equivalent to raising the temperature of 1 gram of water by 1 degree centigrade?
answer
Calorie
question
Why does ocean temperature change little from day to night?
answer
High heat capacity absorbs solar energy quickly and releases it slowly
question
What does the principle of constant proportions tell us?
answer
No matter the salinity of the ocean water the ratio of the major dissolved ions remains the same
question
Which of the following is not part of the hydrologic cycle?
answer
Water is added to the oceans and atmosphere by volcanic activity
question
How does the latent heat of evaporation moderate climate?
answer
By absorbing energy on evaporation and releasing it on condensation it keeps water cool when the air is warm (only answer with evaporation in it)
question
Hydrothermal vents are considered both a source and sink for ocean salts. How can one factor both add and take away salt?
answer
As water interacts with hot rock, some materials are dissolved whereas others are deposited.
question
In the oceans all of the following processes decrease local salinity except for?
answer
Evaporation
question
How does water have such strong surface tension?
answer
Hydrogen bonds form between adjacent molecules due to Water polarity thus giving it strong surface tension
question
Why are lakes like the dead sea and great salt lake so buoyant?
answer
the water is hypersaline it has a high amount of dissolved solids making it extremely dense and buoyant
question
Water in the ocean combines with carbon dioxide to form a weak acid called carbonic acid. But the oceans Ph is 8.1 on average wihcih is slightly basic. How is this so?
answer
There is a natural buffer system
question
What happens when plate tectonics causes two continents to collide at convergent plate boundary?
answer
One continent is sub ducted into the mantle
question
Transform plate boundaries are parallel to the relative motion between two plates. What would happen if the direction of plate motion changes?
answer
transform boundary would turn into another type of boundary, either convergent or divergent depending on the direction
question
The general scientific consensus is that if levels of human cause emissions continue to increase what will happen?
answer
Overall earth will get warmer and the global distribution of climate patterns will change
question
Why is it that a winter may be colder for one season if earth is said to be experiencing global warming?
answer
Because one of the documented changes that correlates to global warming is increased variation in temperature extremes. Also the climate can still be warming in the long term even if temperatures drop for one season.
question
Of all the human caused gases which gas makes the greatest relative contribution to increasing the greenhouse effect?
answer
Carbon dioxide
question
What is causing the hole in the ozone layer?
answer
CFCs
question
The basic idea of global warming is sunlight enters the atmosphere from space and is then transformed to what type of energy that is trapped by CO2 in the atmosphere?
answer
Infrared radiations
question
What is the record of CO2 in the atmosphere that has been collected from from volcano in Hawaii?
answer
The keeling curve
question
Although the concentration of Co2 is measured in Hawaii has been going up steadily over the last 40 years it always goes down during the period of April to October why is this?
answer
Plants blooming in the spring
question
How could climate change affect the drinking water supplies of people in Asia?
answer
Melting the Himalayan glaciers
question
The ice core record from Antarctica goes back how many years?
answer
650,000
question
What is the average depth of the ocean in meters?
answer
4000m
question
Why is the east coast of the United States considered a passive margin it is far from any plate boundary and experiences?
answer
no major tectonic activity
question
Why is the topography of the coastal continents similar to the bathymetry of the continental shelf?
answer
The shelf is continental crust
question
What geologic feature would you expect to find at the downslope end of steep walled of submarine canyons?
answer
Multiple sorted layers of boulders, pebbles.
question
What right angle features connect parallel segments of mid ocean ridges?
answer
Transform faults
question
What causes most places on earth to have season?
answer
The spin axis is tilted 23.5 degrees to the plane of the orbit, causing solar radiation to vary in angle as earth revolves around the sun
question
Why is ocean climate divided into latitude parallel zones that become progressively colder from equator to pole?
answer
The average solar radiation striking the surface declines from equator to poles
question
What is the effect on surface winds of hearting air at the equator?
answer
Surface winds converge at the equator
question
What causes ocean surface currents to form large gyres?
answer
wind blowing over the ocean, barriers formed by the continents
question
What is the main cause of surface water sinking to cause the deep thermohaline ocean currents?
answer
-mixing of Density increase caused by cold in polar regions and Density increase caused by greater salinity
question
In the atlantic north atlantic deep water sinks near Greenland and heads southalong the ocean bottom. Antarctic bottom water sinks off Antarctica and moves north along the ocean bottom. What happens when the two bodies of water meet?
answer
ABW stays on the bottom and NADW overrides it
question
salinity developed from?
answer
dissolved rock elements
question
outer shell of the lithosphere is made up of?
answer
continental and oceanic crusts
question
vikings
answer
first people to cross the atlantic ocean
question
longitude
answer
east or west separation from an arbitrary origin
question
latitude
answer
north or south separation along the meridian compared to the equator
question
Matthew Maury
answer
first full-time oceanography
question
UNOLS
answer
University National Oceanographic Laboratory System
question
Ptolemic theory
answer
earth is the center of a system and heavenly bodies move around us
question
heliocentric theory
answer
earth and planets are part of a heavenly system orbiting the sun and the earth rotates on its axis as it orbits
question
creationist theory
answer
all species were created at one time by a higher power
question
darwinism
answer
all of the present day species have evolved from ancestors that lived in earlier times
question
deluvian theory
answer
earlier catastrophe, like a great flood, caused the present arrangement
question
Alfred Wegener
answer
first proposed Continental Drift and Pangaea
