ESCI final review
Which statements below are correct? (multiple answers may apply)
"Biological pump" refers to the mixing of seawater caused by bio-perturbation: false The ocean is the largest carbon reservoir of our planet: false The ocean plays an important role in our climate system: true Trace elements in seawater can play an important role in our climate and evolution of life: true
What is the age of Earth?
4.5 Billion years
Your semester at sea takes an unexpected turn when the ship's captain decides to teach you a lesson by throwing all the navigation equipment overboard. Thankfully, your mom purchased you a nice chronometer wristwatch when you graduated high school in Greenwich, England. Always wanting to know when it's a good time to call mom, one of your many dials says that it is 3:30 PM back in Greenwich while it is exactly 12:00 PM (noon) on the boat. You therefore are able to tell the captain your longitude is?
52.5 degrees W
Dating schemes that are presently used to determine the absolute age of Earth material often involve the decay or breakdown of an unstable parent isotope to a more stable daughter isotope. The time it takes for half of the original parent isotope to be converted to a daughter isotope is referred to as the half-life. Assuming a given parent/daughter dating scheme has a half-life of 2,000 years, what would be the age of an object where only 12.5% of the parent remained?
6,000 years
What is a pycnocline?
A layer where density increases rapidly with depth.
Well-sorted sediments typically can be found at:
A low-energy depositional environment.
The Red Sea represents:
A young divergent boundary
Match the ENSO states with the panels shown below: A) Wind going left, sea surface inclined up to the left, thermocline inclined up to the right B) Weak wind to the left, sea surface flat, thermocline small incline up and to the right with a rounded drop off C) Strong wind to the left, sea surface inclined to the left, thermocline inclined to the right, arrows from right to left go up over and down
A) normal state B) El Nino C) La Nina
Which statement below about the Coriolis effect is correct?
Acts on objects rigidly attached to the Earth: false Always acts to deflect an object to the right of its direction of motion in the northern hemisphere- opposite (left) in the southern hemisphere: true Magnitude is maximum at the equator and minimum at the poles: false Always acts to deflect an object to the left of its direction of motion in the northern hemisphere- opposite (right) in the southern hemisphere: false
All of the following are true of divergent plate boundaries except:
All are associated with relatively shallow earthquakes: true All have little or no sediment overlying the basaltic crust: true All are volcanically active: true Many are associated with hydrothermal venting: true All spread at the sane rate suggested by the width of magnetic anomalies: false
Which statements below are correct (multiple answers may apply)
All transitions between the continent and the ocean represent plate boundaries: false Passive margins are often associated with thick sediment deposition: true Passive margins can be found along the coast of the Atlantic Ocean: true
During class we talked about the Clarion-Clipperton Fracture Zone in the Pacific Ocean. Which of the following statements are correct? (multiple answers may apply)
An area of significant interest for its economical potential resulting from hydrogenous sediments formed here. It is related to the mid-ocean ridge system in the Pacific Ocean.
During a change in state of water, which is true?
As heat is applied (or removed), temperature stays the same.
Why is there a "shadow zone" at the subsurface (~50m) of the ocean? (multiple answers may apply)
Because of a pressure effect. Because temperature is highest there.
Why does the ocean appear to by blue?
Because seawater strongly absorbs colors in the red part of light spectrum.
By catch is a term introduced in class to describe marine animals unintentionally killed or discarded while collecting desirable organisms. The type of fishing that is characterized by particularly high by-catch and also very significant habitat and ecosystem destruction is:
Bottom trawling
Which device can be used to determine longitude?
Chronometer
This famous illustration that classifies the erosion, transport and deposition or terrigenous sediment in terms of stream velocity and particle size. Why does it require so much more energy to erode clay than sand?
Clay bis super fine grained and tends to be cohesive owing to surface charge making it difficult to erode.
What is the effect of adiabatic expansion on the pressure of an air parcel?
Decreases
Which is the extreme environment may have favored the origin of life on Earth and is presently home of the Alvinella worm, an organism with perhaps the highest heat tolerance on Earth?
Deep sea hydrothermal vents
It is now clear that seafloor spreading is largely driven by: (More than one answer may apply)
Downwelling of sediment laden dense ocean crust at subduction zones Upwelling of magma and creation of new seafloor at divergent plate boundaries like Mid-Ocean ridges.
When the Nino 3.4 (or ONI) Index has been >0.5 degree C for several months in a row, this dignifies:
El Nino
A parcel of humid (water vapor containing) air has a greater density than a dry air mass at a similar temperature.
False
As waves travel, they carry (or transport) energy and water.
False
Earth's solid surface is dominated by continental crust.
False
Halocline is typically found at the topmost layer of the ocean.
False
Nitrogen is an important nutrient for life. Earth's atmosphere contains ~78% of nitrogen gas. This greatly facilitates origin and evolution of life on Earth, because all forms of life can utilize N2 directly from the atmosphere during their metabolic processes
False
The Hadley cell in the northern hemisphere produces the westerlies.
False
Eastern boundary currents tend to be fast, deep and hot, whereas Western boundary currents are slow, shallow and cold.
False (flip flopped)
What evidence did Alfred Wegner use to support his continental drift theory?
Fit of all the continental outlines Wide occurrences of glossopteris fossils
The diagram immediately below illustrates ___________, an energy source common to many stars and an important process for formation of many elements.
Fusion
As mentioned in class, what is the name of the ongoing international collaborative research program that is specifically focused on studying trace metals and their isotopes in the global ocean?
GEOTRACES project
Where is most of fresh water stored on Earth?
Glaciers
Where on Earth was the Keeling Curve measured?
Hawaii
Nansen's polar explorations took place from about 1893-1896. His objective was to be the first to the North Pole. The strategy he used was to float with sea ice by wind driven ocean currents to achieve his goal. He did not accomplish this, but he did make a famous discovery, which was:
He discovered the Coriolis effect, from the movement of ocean currents relative to wind direction.
Which statement below is correct:
Heat transfer during conduction is bidirectional: false Convection is a very effective way for the atmosphere to transfer heat: true Heat transfer during convection in unidirectional: false Conduction is a very effective way for the atmosphere to transfer heat: false
Iron-manganese modules on the seafloor belong to:
Hydrogenous sediments
Seat water's density increases with both:
Increasing salinity and decreasing temperature.
Where does the global conveyer belt upwell into shallower ocean?
Indian and Pacific ocean
What is the key nutrient that is lacking in high nutrient low chlorophyll areas in the global ocean?
Iron
The figure above depicts erosion of mountains and the response of the underlying Asthenosphere to the loss of load. The same thing would happen to land surface covered by large ice sheets when melted was the case in Minnesota. This response can best be described as?
Isostatic adjustment
What happens to the temperature of an air parcel as it rises?
It decreases.
What is true about a hydrogen bond? (multiple answers may apply)
It gives high surface tension to liquid water. It is the reason that water is such a good solvent. It is the reason that liquid water had a high heat capacity.
Which statement below is true about transform fault boundary?
It is a special type of divergent plate boundary: false It is sometimes associated with creation of new crust: false It is associated with subduction of a tectonic plate: false It is not associated with the creation of new crust: true
We talked about "blood falls" observed in Antarctica during this class. What causes "blood falls"?
It is caused by the presence of ferric iron oxides.
Troodos ophiolite at Cyprus is scientifically important because:
It represents Cretaceous oceanic crust.
The Asthenosphere plays a critical role in Earth's processes. It has a chemical composition that is broadly similar to the bulk composition of the mantle of the Earth as a whole, but retains very special physical characteristics. These unique physical characteristics account for: (More than one answer may apply)
Its tendency to permit deformation, often associated with isostasy and mountain building. Its tendency to permit convection and movement of crustal plates.
Why is the lapse rate larger for dry air than wet air?
Latent heat associated with condensation of water vapor buffers temperature change in wet air
What causes the "zig-zag" in the Keeling curve?
Life cycle of vegetation.
What is the second most abundant cation in seawater?
Magnesium
Which is the coldest layer of Earth's atmosphere?
Mesosphere
Which type of seismic waves travel fastest?
P waves
The largest ocean today is:
Pacific Ocean
In class we used the figure above to emphasize that different atmospheres existed during the past (~4.4 billion years) of Earth's history. What explained the increase in O2 starting about 2.4 billion years?
Photosynthesis by life produced O2
When we discussed ocean surface currents, you were introduced to the concept of "geostrophic balance" What two forces are balanced?
Pressure gradient force Coriolis force
Marie Tharp discovered?
Rift valley on the Mid-Atlantic Ridge
The S wave shadow zone is relatively wide, approximately 103 degrees on either side of Earth from an earthquake focus. The reason for this is:
S waves cannot pass through the liquid outer layer of the Earth's core
Use the diagram below to infer which type of sediment is the easiest to erode:
Sand
Why is winter temperature in Seattle much milder than that at Minneapolis, despite both cities being at similar latitudes?
Seattle is closer to the ocean.
The CCD (carbonate compensation depth) where the rate of dissolution of carbonate sediments noticeably increases, is caused by: (multiple answers may apply)
Seawater carbonate ion concentration becomes lower than the concentration in chemical equilibrium with calcium carbonates. The increasing pressure of seawater at depth.
Where are calcareous oozes typically found in the global ocean?
Shallow ocean (above 4000 m) at low and mid-latitudes.
The Himalayas are produced by:
Subduction of a continental plate under another continental plate.
All the heavy elements (gold, mercury and them heavier than iron) in materials in our solar system and likely elsewhere in the universe are derived from:
Supernova events
Sea surface density is high in the Southern Ocean, primarily because:
Temperature is low on surface seawater ther.
Continental drift was an early idea proposed by Alfred Wegner to potentially account for the apparent migration of continents across the surface of the Earth. Although Wegner had no compelling mechanism to account for this, he and others did cite some evident at the time in support of this idea. Which of the following constituted such evidence? (More than one answer may apply)
The 'jigsaw' fit of South America with Africa. The discovery of glossopteris fossils in rocks from Antarctica. The continuation of similarly ages mountain ranges on adjacent, but now separated continents.
Where did Earth's water come from? More than once correct choice is possible.
The Earth inherited water from the H2O-rich comets, especially during the early stage of the Earth formation. Gases (including water vapor) were released from the Earth's interior by the process of outgassing during differentiation.
What was the first expedition devoted entirely to marine science?
The HMS Challenger expedition
The SOFAR channel is a region in the ocean located at ~1000m depth, where sound velocity is at a minimum, yet nsound is able to travel great distances. This sound channel is thought to allow whales to communicate over great distances. The focusing of sound at the SOFAR depth is primarily caused by:
The effect of sound wave refraction as a function of temperature and pressure.
The CCD (carbonate compensation depth) where the rate of dissolution of carbonate sediments noticeably increases, is chiefly caused by (multiple answers may apply):
The increasing pressure of seawater at depth. Increasing calcium carbonate solubility with decreasing temperature.
All of the following are true of magnetic measurements of the ocean crust except:
The pattern of magnetism provides evidence that the Earth's magnetic field flips slowly and incompletely.
The lack of water on the planet Venus is best explained by:
The relatively high temperature of the surface of the planet
During class, I mentioned that the Southern Ocean has much less chlorophyll-a than observes in the northernmost oceans. This is because:
There is not enough dissolved iron in the seawater there.
Which of the statements below are true?
Trace metal concentrations in seawater are nearly constant in Earth's history: true Trace metals in seawater have implications for evolution of life: false The type of trace metals in seawater is largely similar in Earth history: true Major element concentrations in seawater are constant in Earth history: true
The figure above depicts which type of plate boundary, specifically in the area of California?
Transform
Crust is neither created nor destroyed at which types of plate boundaries?
Transform fault boundary
Fundamental to the use of satellite altimetry as a means to recognize structures on the seafloor with especially high resolution involves the gravitational attraction of the surface ocean to underlying geological structures.
True
It is believed that the North Atlantic Deep Water (NADW) formation is susceptible to disruptions by the expected changes in hydrological (freshwater) system and glaciers under the ongoing global warming.
True
Oceanic crust (basaltic) underlies sediments deposited on the continental rise.
True
Surveys of the surface of the planet Mars by NASA rovers indicate the possible existence of water at least at a very early time in Marian evolution.
True
The diagram above depicts a typical vertical temperature section through the equatorial Pacific in an El Nino year. (red more towards Asia)
True
Tsunamis become more dangerous as they approach the coast.
True
Which part of the Antarctic Ice Sheet is more likely to melt during global warming?
West Antarctic Ice Sheet
Which direction is the Earth rotating?
West to East
We discussed dissolved zinc (Zn) concentration in the ocean during class. Based on Zn concentration profiles in seawater shown below, you can infer:
Zinc has a long resident time in the ocean > 1000 years
In the SOFAR channel in the ocean, sound travels;
at its slowest speed
Please select important greenhouse gasses in Earth's atmosphere:
methane: true water vapor: true carbon dioxide: true argon gas: false nitrogen gas: false
Life in the ocean is dominated by:
microorganisms
How does seawater density change as a function of temperature?
nearly linear increase with decreasing temperature, ~ 4 degree C only for fresh water
What is the trade wind at low latitudes in the northern hemisphere?
northeast trade wind; westerlies = mid latitude
Atmospheric circulation on the Earth is a result of: (multiple answers may apply)
uneven solar heating Earth's rotation
The arrow shows the wind direction in the Northern Hemisphere. It this an upwelling or downwelling system? (arrow pointing down the coast parallel)
upwelling
with an arrow facing down and parallel to the coast, it causes:
upwelling in the northern hemisphere and downwelling in the southern hemisphere
There is a total of 5.7 X10^20 grams of calcium in the modern ocean. The input flux of calcium from rivers into the ocean is about 5.6 X10^14 grams every year, and about 5.6 X10^14 grams of calcium is removed from seawater as calcium carbonate minerals every year. What is the residence time of calcium in the modern ocean?
~ 1 million years
