Final Exam Topics

Question 1

Know the age of Earth and the age of the Universe

Answer 1

The universe is 13.7 billion years old

The Earth is around 4.5 billion years

Question 2

What is the difference between latitude and longitude? Before GPS, how could sailors tell where
they were?

Answer 2

Latitude specifies the north/south position on Earth and is composed of lines that run in an east/west direction. Sailors previously used positions of stars (such as the North Star) to determine their latitude.

Longitude specifies the east/west position on Earth and is composed of lines that run in a north/south direction. Sailors previously used Greenwich time and its discrepancy from their local noon to determine their longitude

Question 3

What is the difference between volatile and refractory elements? Which planets fall into each
category?

Answer 3

Volatile elements have a low boiling point and condense at low temperatures

• Examples include light elements (H, He) and gases at room temperature (O, N, Ne, Air)
• Formed gas giants

Refractory elements have a high boiling point and remain solid even at high temperatures

• Heavier elements such as Ca, Al, Fe, Mg, Ni, Si (around 1000-1500 C)
• Form rocky planets and the asteroid belt

Question 4

Know the layers of Earth, and their physical properties (solid, liquid, bendable, brittle)

Answer 4

4 main parts of the Earth are the crust, mantle, outer core, and inner core

Crust is the brittle layer

Mantle is the bendable layer

Outer core is the liquid layer

Inner core is the solid layer

Question 5

Understand Wegener’s theory of continental drift

Answer 5

Theory of continental drift states that continents move laterally across Earth, were joined as a supercontinent in the past, supercontinent had a superocean, and the supercontinent split apart 200 mya and pieces move today

Wegener used the evidence of the fit of the continents with each other, incomplete geologies of South Africa and Australia, and distribution of living organisms/fossils/paleoclimatic indicators

Question 6

What is the theory of plate tectonics? How do plates interact with one another?

Answer 6

• Earth’s surface consists of a small number of plates that correspond to the lithosphere
• Lithospheric plates move over Earth’s surface by riding on the asthenosphere, powered by movement in the mantle
• Plates interact with each other along 3 kinds of boundaries
• Plate interactions produce most of Earth’s tectonic activity

Plates interact in the 3 following ways:
Constructional Plate Boundaries:
- Plates move apart from one another
- Crust is created from magma upswells at mid-ocean ridges
- Mid-ocean ridges and rift valleys occur here
- Examples include mid-Atlantic ridge and East Africa Rift Valley

Destructional Plate Boundaries:

• Plates move towards each other
• Crust is destroyed as one plate subducts under the other
• Geological features that can occur are deep sea trenches and mountain ranges
• Examples include Himalayas, Andes, and where the Nazca plate subducts under the South American plate

Transform Plate Boundaries;

• Plates shear past one another
• Crust is neither made nor destroyed
• Transform faults occur as Earth is a sphere
• Example is San Andreas fault between Pacific and North American plates

Question 7

Understand the difference between island arcs and island chains

Answer 7

Island arcs are a result of an oceanic plate being subducted under another oceanic plate and are composed of andesite Ex. Japan/Aleutian

Island chains form due to hotspots and are composed of basalt Ex. Hawaiian

Question 8

What is the CCD?

Answer 8

Carbonate Compensation Depth

CCD is the depth at which the rate of CaCO3 supply is equal to the rate it dissolves into the water.

Prevents CaCO3 accumulation in waters at or below this depth

Question 9

What causes the low oxygen zone beneath the epipelagic?

Answer 9

Not enough photosynthetic activity occurs here and microbes use up oxygen to break down falling organic matter.

Remineralization here also results in lower availability of oxygen

Question 10

What nutrients limit phytoplankton growth in the ocean?

Answer 10

A limiting nutrient is an essential nutrient that limits growth if missing

Limiting Growth in Marine Food Chain –> Food:

• Nitrogen
• Phosphorous
• Iron
• Calcium
• Silicon
• Magnesium
• Carbon

Question 11

What is residence time? What determines an ion’s residence time? What are conservative ions?

Answer 11

Residence time is the average length of time an element
spends in the ocean

Residence times tell us that ions that are inefficiently removed spend a lot of time in the ocean while those that are efficiently removed do not

Conservative ions have residence times of millions of years and these are longer than ocean mixing times

Question 12

Where did the ions found in the ocean come from?

Answer 12

Ocean salt comes from rivers carrying salts to sea and from volcanoes adding salts

Ocean salinity is not increasing as it is in chemical equilibrium (ions are added/removed at same rate)
- Amount/proportion of dissolved ions is constant

Question 13

What is hydrogen bonding?

Answer 13

Serves to strongly hold water molecules together, enabling cohesion and adhesion

• Keep water molecules together as a group
• Caused by uneven distribution of charges around a molecules

Question 14

Know the terms related to the different layers of the ocean: epipelagic, mesopelagic, pycnocline,
thermocline, mixed layer

Answer 14

Epipelagic:
- Layer of the ocean extending from surface to 200 meters below

Mesopelagic:
- Intermediate depths of the sea; area between 200-1000 meters below the surface in the ocean

Pycnocline:
- The layer in the ocean in which water density rapidly increases with depth

Thermocline:
- The layer in the ocean in which water temperatures rapidly decreases with depth

Mixed Layer:
- Layer of the ocean in which active turbulence has homogenized the waters of multiple depth ranges

Question 15

What colors are most rapidly absorbed in the ocean? Penetrate the deepest?

Answer 15

Red/orange/yellow/violet are some of the most rapidly absorbed in the ocean

Blue light penetrates the deepest in the ocean

Question 16

What are surface currents? What causes them?

Answer 16

Surface currents are water at the ocean’s surface that are moved primarily by wind.

Surface currents are caused by wind, density differences in water masses, tectonic events, and the Coriolis effect

Question 17

What causes upwelling/downwelling?

Answer 17

Upwelling occurs where Ekman transport moves
surface waters away from the coast and they are replaced by cold, nutrient‐rich water welling up from below

Downwelling occurs where is where Ekman transport moves surface waters toward the coast, the water piles up and sinks

Question 18

Why is thermohaline circulation important?

Answer 18

Thermohaline circulation transports heat energy around the globe and is key in supplying heat to polar regions

Question 19

What is the difference between deep water waves and shallow water waves?

Answer 19

Deep water waves are in water deeper than the wave base, have circular orbits, and orbits die away above bottom

Shallow water waves are in water shallower than the wave base, have elliptical orbits, and orbits flatten at the bottom

Question 20

How do wind waves form?

Answer 20

Wind waves begin as capillary waves

Surface tension “restores” the surface

As waves build beyond capillary waves, gravity becomes the restoring force

Question 21

What causes tsunami? What type of waves are tsunami?

Answer 21

Tsunamis are caused by tectonic activity, landslides, volcanoes, and asteroid impacts

Tsunamis are shallow water waves as their long wavelengths means their orbital motion extends to the sea floor

Question 22

What are rogue waves?

Answer 22

Rogue waves are extremely large waves that are a result of constructive wave interference

Question 23

What is the Coriolis Effect?

Answer 23

The observed deflection of a moving object, caused by the moving frame of reference on the spinning Earth.

Question 24

What causes tides? What is the difference between spring and neap tides?

Answer 24

Tides are caused by gravitational attraction between the Earth/Moon/Sun and by the rotations of Earth-Moon and Earth-Sun systems

Spring tides occur at the new and full moons, while neap tides occur at the first and third quarter phases of the Moon

Question 25

How does air move in the atmosphere?

Answer 25

Polar Cells: Nearest to poles
Ferrel Cells: Occur at mid-latitudes
Hadley Cells: Near equator

Storms only occur at the Polar/Ferrel boundaries and between the Hadley Cells; this is because at these boundaries both cells push warm moist air up to create clouds.

At other boundaries, cold dry air is pushed down and no storms form

Pressure-Gradient Force:

• Moves air (or water) from regions of high pressure to regions of low pressure
• Moves down isobars (lines showing areas of same pressure) like a ball rolling down a hill

Coriolis Effect
- Causes deflection of particle path and dictates the direction that air spins around regions of high and low pressure

Question 26

What can satellites show us about ocean conditions?

Answer 26

Satellites can show us:

• What the seafloor looks like
• Ocean/atmosphere climate interactions
• Water cycle information

Question 27

Know the major ocean gyres and which direction they spin

Answer 27

1. Indian Gyre (spins counter-clockwise)
2. North Pacific Gyre (spins clockwise)
3. South Pacific Gyre (spins counter-clockwise)
4. North Atlantic Gyre (spins clockwise)
5. South Atlantic Gyre (spins counter-clockwise)

Question 28

What is the difference between El Niño and La Niña?

Answer 28

El Nino is the warm phase of ENSO where the thermocline becomes less steep, cloud formation occurs over the Pacific, and warm water flows east

La Nina is the cold phase of ENSO where the thermocline becomes steeper, cloud formation occurs over Indonesia, and warm water flows west

Question 29

What is the difference between: prokaryotes and eukaryotes, autotrophs and heterotrophs

Answer 29

Prokaryotes have no nucleus or membrane-bound organelles; eukaryotes have both of these features

Autotrophs get can form organic substances from inorganic ones and thus make their own food; heterotrophs must ingest other organisms/organic matter to get their food

Question 30

What does the rate of photosynthesis look like from the surface of the ocean to the mesopelagic
zone? What limits photosynthesis?

Answer 30

Photosynthesis rate grows until about 100 meters and then declines with depth after this point.

Presence of sunlight in the water at specific depths and availability of nutrients limits photosynthesis

Question 31

What is eutrophication?

Answer 31

Eutrophication is when a body of water becomes overly enriched with nutrients; this induces excessive algae growth, which depletes oxygen in the water and lowers water quality and kills animal life

Question 32

What color are many mesopelagic organisms? Why?

Answer 32

Many mesopelagic organisms are red. This is because red light penetrates the water most weakly, and since red organisms absorb all other colors, they will hard to see in the deep water as little red light penetrates this far down

Question 33

Know the difference between nekton, plankton, meroplankton and holoplankton

Answer 33

Nekton are organisms that can actively swim against a current of water

Plankton are organisms that are unable to swim against a current and are carried along by currents

Meroplankton are organisms which are plankton only for portions of their lives

Holoplankton are plankton for the entirety of their life cycles

Question 34

What is bioaccumulation?

Answer 34

Bioaccumulation is the gradual accumulation of substances/pesticides/chemicals within an organism due to entrance much lower in the food chain and compounding as these substances move up the food chain

Question 35

Understand the difference between non-native and invasive species

Answer 35

Non-native species are species that simply aren’t from the region in which they are currently located in

Invasive species are non-native species that economic/environmental harm or harm to human health

Question 36

What is the Great Pacific Garbage Patch?

Answer 36

The Great Pacific Garbage Patch is a gyre of marine debris that is in the Pacific and 2x the size of Texas

Question 37

Know the difference between bioluminescence and countershading. Why are each of these
adaptations useful?

Answer 37

Bioluminescence is the emission/production of light by a living organism. It is useful because having light on the bottom of an organism helps it blend in with the lighter ocean surface

Counter-shading is when an organism is darker on the top and lighter on the bottom. This helps it blend in from the top as it matches the darker ocean bottom, and from bottom as it blends in with the lighter ocean surface.

Question 38

How do Reynolds numbers apply to plankton?

Answer 38

Plankton swim at biologically low Reynolds numbers, where viscous forces dominate

Nekton on the other hand, swim at biologically high Reynolds numbers, where inertial forces dominate

Question 39

What is the dilemma surrounding the PNA and the MSC certification?

Answer 39

1. Fisheries can’t lead to overfishing, and for exploited/depleted populations must be conducted in a manner leading to recovery
2. Fishing operations should maintain the ecosystem on which the fishery depends
3. Fishery use of resources should be responsible and sustainable

Question 40

What happened with the California Dungeness Crab Fishery in April 2019?

Answer 40

Dungeness Crab fishery gear had to be removed as it entangled whales and sea turtles off of the California coast

Question 41

Understand the causes and consequences of global climate change. Is it a natural or human
induced process?

Answer 41

Climate change is mainly caused by presence of greenhouse gases in the air, which absorb IR, and increase the temperature.

Consequences of global climate change are higher temeperatures, sea level rise, loss of sea ice/glaciers, ocean acidification, droughts/flooding, more severe storms, and more disease spread

Changes in temperature and CO2 are normal and occur in cycles over time. But the current rate of increase of temperature and CO2 levels are induced by humans.

Question 42

What are the Vostok ice cores? How is the ocean being altered by climate change?

Answer 42

Vostok ice cores help us understand the patterns of temperature and CO2 in Earth over the last 400k years.

In the ocean, there is sea level rise, loss of sea ice/glaciers, ocean acidification, droughts/flooding, and more severe storms

Question 43

What is DOM and where does it come from?

Answer 43

DOM stands for dissolved organic matter (carbs, proteins, lipids, nucleic acids)

DOM comes from zooplankton waste, phytoplankton exudation, cell lysis, and marine snow

Question 44

What is the microbial loop and why is it important in oceanography?

Answer 44

Microbial loop is how dissolved organic matter (DOM) gets recycled by microbes which are then eaten by zooplankton.

This puts all the nutrients in DOM back into the food chain

Question 45

Describe the concentrations of nutrients, like phosphate, in the Pacific Ocean from the surface
to the bottom and from the South Pacific to the North Pacific. What causes the concentrations
vary?

Answer 45

Nutrient concentrations increase with depth until a point and then decline until the ocean floor.

Nutrients more abundant in North Pacific than the South

Nutrient concentrations vary due to the differing incidences of sunlight in the different layers of the ocean and different regions of the world