Upgrade to remove ads
Oceans Prelim 1 & 2
Terms in this set (98)
how long ago did the big bang happen?
b. About 15 billion years ago
which statement best describes the formation of stars?
Stars formed millions of years after the Big Bang when cold hydrogen gas condensed under gravity to form large masses that eventually could produce intense internal heat and pressure in their interior and fuse hydrogen to form helium (thermonuclear fusion) and generate light and heat.
The carbon, nitrogen and phosphorous atoms that make up your own body formed inside of a boiling hot star and/or formed when a star exploded?
how long ago did earth form?
c. 4.5 billion years ago
How much longer will earth be around before the sun eventually dies and vaporizes the earth?
4.5 billion years
when did the moon form
a. When the earth was struck by a Mars-‐size planet
The latest evidence suggests that it was the slow but steady accumulation of water brought to earth from comet collisions that provided most of the water that fill our oceans today.
Which came first, the formation of oxygen in the atmosphere or multi-‐cellular life forms?
Oxygen came first.
How long did it take for life to take hold after the earth formed?
Life caught hold relatively quickly -‐ around 500 million year after the earth formed.
. What kind of fossil is used for evidence of the earliest existence of life on earth?
Life on earth began in the ocean about 4 billion years ago, but there was no life on land until about
600 million years ago
When did mammals become the dominant large animals on earth?
About 65 million years ago
What kind of evidenced did Alfred Wegner use to demonstrate that the continents at one time in the past formed a single super continent?
The alignment of mineral and fossil belts
Why do oceanographers use sound (sonar) rather than a light and camera system to produce maps of seafloor features such as seamounts and mid-‐ ocean ridges?
Sound travels over much longer distances in water than does light so it can effectively see across greater distances.
Magnetic anomalies are a proxy measurement for:
The date at which molten magma reached the earth surface and
what is the force (or forces) that drives plate tectonic motion?
Mantle convection and slab pull
Why do continents move?
Because continents are a part of larger tectonic plates and when
new tectonic plate material is made at mid-‐ocean ridges the tectonic plate moves and then so too does along with the continent.
Why does ocean crust slide below continental crust when these two plate boundaries collide?
Because ocean crust is more dense than continental crust
Which of the following represents a geographic region where ocean crust collides with ocean crust
. Which of the following is an example of a divergent plate boundary
East Africa Rift Zone
Approximately how fast do sediments accumulate?
1 to 5 cm per thousand years
Which of the following is an example of an approach used to obtain a proxy temperature measurement?
a. Isotope ratio
b. Plankton species composition
d. Both a and b (ANSWER)
When the asteroid hit the earth 65 million years ago and killed off the dinosaurs. Did it kill off many other species?
Yes it was a great extinction event that killed off a large percentage of all species on land and in the ocean
Do a majority of biologists think we are currently in a human-‐caused 6th mass extinction?
what factor can influence wave propagation speed
both wavelength and bottom depth
what wave propagation process is responsible for producing clean sets of waves with similar wavelengths that come onto shore after a big storm event that happened a long distance off shore?
Wave fronts that are propagating toward shore tend to bend because of differences in bottom depth and this often causes wave energy to become more focused on embayment regions.
If you are caught in a rip current and pulled far off shore, what should you do to get safely back to shore?
First swim parallel to the shore for about ten meters to get out of the narrow rip current and then swim easily back to shore and call Bruce to let him know he saved your life.
How do oceanographers know that a tsunami has been generated so they can then issue a tsunami warning?
Pressure sensors on the bottom of the ocean are used to measure the tidal wave as it passes overhead
how many factors determine wave height
what is the definition of a semi-diurnal tidal pattern?
the occurrence of two tides of roughly equal height per day
what force is responsible for the occurrence of the tidal bulge on the side of the earth farthest from the moon?
According to Figure 1, Mixed Semidiurnal tides are expected at:
If you are setting up a camping site on the beach and you notice that the moon is full, is it reasonable to expect a small tidal range and set up a tent a bit closer to the ocean?
Why is the tidal range of the tides near Hawaii so small?
Hawaii is near an Amphidromic Point
. Which direction does the Coriolis Force push water and winds in each hemisphere
To the right of the current's motion in the northern hemisphere and to the left in the southern hemisphere
The atmosphere is heated...
Mainly from the bottom as an indirect effect of absorbing long wavelength radiation being emitted from the Earth's surface that is absorbing solar radiation
.In an idealized earth there is strong atmospheric convection along the equator that creates low sea level pressure (SLP) conditions along the equator with progressively higher SLP found as you move north to south away from the equator. Normally the surface winds should move in a straight line from high SLP to low SLP, but that is not what happens and instead the winds turn toward the west as they approach the equator. Why does this happen?
Coriolis force turns the winds toward the west
Which of the following most accurately describes the permanent thermocline?
The broad region centered at about 500 meters where water
temperature changes from warm to uniformly cold
What happens to the depth of the seasonal thermocline during the transition from winter to spring and summer in mid-‐latitude temperate ocean regions?
Becomes more shallow
Oceanographers often treat the Ekman Layer as:
A slab of water on the order of 50 to 100 meters that moves in
unison at 90 degrees to the direction of wind forcing
Fully developed Geostrophic Currents move...
Along lines of constant pressure
Trade Winds and Westerly Winds drive Ekman Layers toward the center of the subtropical gyre that eventually leads to a mounding of surface ocean water near the gyre center this, in turn, creates a high pressure under the mound. What happens to the water under the mound after it comes into geostrophic balance?
It moves in a circular pattern around the center of high pressure
The strength of Ekman Layer divergence along the equator is about the same in the eastern and the western Pacific. Why then is there an east to west asymmetry in the cooling effect from Ekman Layer divergence along the equator with cooler surface waters found in the east and warmer waters found in the west?
It is because the thermocline tilts up close to the surface in the eastern Pacific (near Peru).
If you were on the coast of Chili (Southern Hemisphere) and the winds were blowing strongly from the south (from near Antarctica) and toward the North (toward the equator). Are these Upwelling Favorable winds?
What type of tracer(s) is used to identify the major water masses in the North Atlantic Ocean?
Both temperature and salinity
what pathway does the deep ocean current take?
The water starts in the deep North Atlantic and moves to the
deep Southern Ocean and up into the deep North Pacific
How many years does it take for deep ocean bottom water to make its way through all the ocean basins?
Conveyor Belt Circulation represents the combined movement of both the surface currents generated by wind forcing and the slow deep circulation driven by density and deep mixing. Understanding the circulation dynamics of Conveyor Belt Circulation is important because
It transports large amounts of heat from low to high latitudes
Why would oceanographers want to study ocean primary production?
Photosynthesis takes up carbon dioxide on a globally significant scale.
what is the definition of net primary production
a. The difference between the rate of CO2 taken up by phytoplankton cells through photosynthesis and the rate of CO2 released by
phytoplankton cells through respiration.
b. The rate of accumulation of carbon in phytoplankton cells.
c. Both a and b are basically equivalent definitions of Net Primary Production (C IS THE ANSWER)
what impact does light saturated levels of light intensity have on phytoplankton net primary production
the light intensity produces the maximal levels of net primary production
Which of the following nutrients is NOT one of the four nutrients discussed in class that can occasionally limit the growth rate of phytoplankton?
How does iron primarily enter the surface layer of the ocean?
Iron is transported by the winds that blow iron-‐rich dust off of continents.
Subtropical Gyres have low levels of primary production per square meter because
There is a persistent lens of warm low-‐nutrient surface water that depresses the thermocline and associated nutricline
Primary production along the equator in the Eastern Pacific (near Peru) is high because:
The trade winds force an Ekman layer divergence in combination with the relatively shallow thermocline in the east (off Peru).
Is strong coastal upwelling seasonal or is it present year-‐round?
Which statement is true?
Phytoplankton can mix from the top of the ocean to below the compensation depth and still sustain a positive net primary production over the course of a day.
Why does the North Atlantic experience a strong spring phytoplankton bloom?
a. Deep winter mixing brings nutrients to the surface
b. The springtime formation of a shallow thermocline holds
phytoplankton in the well-‐lit zone of the surface ocean
c. Both a and b are required (C IS THE ANSWER)
which ocean region represents the most ocean primary production?
all of the open ocean regions summed together
Why should you thank the ocean for every other breath you take?
Because photosynthesis makes oxygen and approximately half of the entire planet's primary production occurs in the ocean.
which ocean region is know to be iron limited?
copepods are an example of meroplankton
it is said that pelagic food webs are strongly size-structured. what exactly does that mean?
Size determines almost everything about an organism's role in the food web - who it eats and who eats it.
Which is the best definition of Exploitation Efficiency
The efficiency of finding, capturing and ingesting all of the possible prey in a consumer's environment
Which case has low Exploitation Efficiency?
Copepods feeding on phytoplankton during the very early spring bloom period in the North Atlantic
If you were in a region where 10,000 units of phytoplankton biomass were made each year. How much harvestable fish biomass would you expect could be made each year if there were 4 trophic steps between phytoplankton and the harvestable fish?
phytoplankton > zooplankton > small fish > medium fish > harvestable fish
1 units of harvestable fish
Why is fish production summed over coastal regions so much greater than fish production summed over the entire open-‐ocean region?
There are fewer trophic steps between phytoplankton and harvestable fish in coastal regions
The introduction of the Epifluorescent Microscope brought about a revolution in biological oceanography because this new observational tool led oceanographers to discover that:
Heterotrophic bacteria were much more abundant than previously thought
what is so special about prochlorococcus
It is a type of autotrophic bacteria responsible for most of the primary production that takes place in the oligotrophic open-‐ ocean regions.
Which oceanographic location is expected to have an efficient biological carbon pump?
Eutrophic coastal upwelling region
Given that Total Primary Production = New Primary Production + Recycled Primary Production, where would you expect the contribution of Recycled Primary Production to be at its most pronounced?
Oligotrophic subtropical gyre region
Which nutrient would biological oceanographers be most interested in understanding how it is cycled through pelagic ecosystems?
The nutrient that limits the growth of phytoplankton.
Water is a highly non-polar molecule
What is the relative strength of hydrogen bond energy when compared to thermal (kinetic) energy for the case of liquid water?
Hydrogen bond energy is roughly equal to thermal (kinetic) energy
The increased CO2 concentration in the atmosphere from fossil fuel burning has created an energy imbalance in the earth system and we now have the situation of less energy being radiated back into space relative to the amount of energy coming into the earth from the sun. In other words, we now have a net addition of heat accumulating in the earth system each year. What happens to the rise in earth's average temperature if more of this net heat energy addition were to go into the ocean versus into the atmosphere or land?
The rate of increase in global average temperatures would slow down
what determines the salinity of the surface ocean water?
c. The difference between evaporation and precipitation.
The salinity of the ocean varies greatly from location to location, but the relative proportion of one ion to another does not change.
What happens to the concentration of phosphate in the deep ocean as the deep water from the North Atlantic slowly moves down and around the Southern Ocean and up into the North Pacific?
Phosphate concentration increases as the deep water moves from the North Atlantic to the North Pacific
What is responsible for the Oxygen Minimum Zone that is found just below the thermocline?
The marine snow (fluffy dead organic material) raining out from above the thermocline region serves as food for microbial growth causing microbial respiration to strongly outweigh oxygen production in this zone
What is expected to happen to the oxygen minimum zone as global warming causes the surface ocean water above the thermocline to warm relative to the deeper water and thereby increase the strength of the thermocline?
The oxygen concentrations will become even lower than they are today
Why are CO2 concentrations generally lower in the surface layer of the ocean relative to the deep ocean?
Photosynthesis takes up CO2
What happens to the acidity of the surface ocean when atmospheric CO2 increases due to fossil carbon emissions?
The surface ocean becomes more acidic
Where is the largest mobile reservoir of CO2 on the planet?
In the deep ocean
Dan Miller - a special guest lecturer - gave a presentation in which he provided a long list of evidence that humans are largely responsible for the observed global warming since the beginning of the industrial era and showed the prospects for much more warming to come if we do not start reducing CO2 emissions very soon. He then proposed the concept of "Fee and Dividend". How does this basic concept work?
You tax carbon at its source and at the end of each year you take all the tax money collected and give it back evenly to each citizen in the country
How did Dan Miller think the United States could prevent other countries from taking advantage of the United States if only the United States were to use the Fee and Dividend method to reduce CO2 emissions?
Place an Import Duty based on the amount CO2 emissions that went into making the product being imported
How much would the United States GDP grow if a Fee and Dividend policy were put in place (note: GDP= Gross Domestic Product = indicator of national wealth)?
The GDP would increase $1.4 trillion
Atmospheric CO2 concentration has gone up and down naturally between 180ppm (glacial periods) and 280ppm (interglacial periods) for over 800,000 years. What is the current concentration of CO2 in the atmosphere today?
What is the best explanation (given by Professor Greene) for the so-‐called Global Warming Hiatus observed over the past decade?
There was still an annual energy imbalance due to the greenhouse gas effect and so there remains an annual net heat addition to earth system, but more of the trapped heat entered the ocean over the past decade and the ocean has a high specific heat capacity and so it did not increase in temperature all that much.
Some of the strongest evidence pointing to humans as being the leading cause of the observed global warming comes from running numerical climate models with human-‐added CO2 and separately running them without human added CO2 and then comparing model results to observed atmospheric CO2 trends. The model runs only reproduce the observed warming when human-‐ added CO2 is present.
The arctic is warming faster than lower latitude regions and this is believed by many scientists to be changing the dynamics of the polar jet stream and leading to:
a. Winter outbreaks of cold weather extending further south than normal and persisting longer than normal
b. Setting up conditions that made Super Storm Sandy more likely to have occurred.
c. Setting up a blocking system that has led to the extreme drought conditions in California
d. All of the above (D IS THE ANSWER)
Based on paleoclimate records that relate past sea level height that came into equilibrium with past atmospheric CO2 levels, what is the expected sea level height that will be reached (in a few hundred years) if we maintain the present CO2 levels we have today?
Sea level will eventually increase to 75 feet above pre industrial levels
What does the recent United State Military report that was presented by Defense Secretary Chuck Hagel have to say about climate change and national security?
Global warming is definitely real, and the military considers it a threat multiplier and something the military needs to plan for with serious effort
Humans are currently emitting about 50 Gigatons of CO2 into the atmosphere each year. For all intents and purposes any CO2 put into the atmosphere stays there forever (it's actually closer to 10,000 years, but still.. it's a very long time). How much more CO2 can we cumulatively add to the atmosphere before we begin to exceed a global average temperature of 2 oC warming above pre industrial levels that all nations agree we should not cross?
We have about 560 Gigatons of CO2 left to burn or a bit more than 10 years at current emissions rates
Relative to the CO2 emissions that have taken place in your lifetime (1991 to out to 2035), what will have to happen to the emissions for your children's lifetime (beyond 2035) in order to stay below 2 oC?
My children will have a tiny fraction (around 1/8) of CO2 left to emit relative to what I emitted.
Why are marine algal bio-‐fuels seen by many as superior to conventional biofuel crops?
a. Marine algae produce more fuel energy per given area
b. Marine algae do not require freshwater to grow
c. Marine algae do not compete for land space with conventional crops
d. All of the above (D IS THE ANSWER)
When Andy Revkin came upon Jacque Cousteau's ship in port when he was a young man, what did he do?
He was intimidated by the greatness of Cousteau and lacked the courage to go aboard and instead he walked away.
Does Andy Revkin think the current generation lives (will live) in an especially remarkable time in the context of all recorded human civilization?
Most generations think they live in a special time, but Andy thinks this time it is true and that this generation will experience something truly remarkable.
YOU MIGHT ALSO LIKE...
Prelim 2 Questions and Answers
Oceanography UCSB IClicker
OTHER SETS BY THIS CREATOR
Real Prelim 2