This Final Exam will focus primarily on the following chapters, which were discussed in class during lectures 21-26:
Chapter 13: The Ocean Floor.
Chapter 14: Ocean Water (esp. p.384-389)
Chapter 15: The Dynamic Ocean (esp. p.404-411)
Chapter 6: Glaciers, Deserts and Wind
Chapter 20: Modern Climate and Ancient Climate (maybe- let’s see if we get to this)
In addition, there will be several questions on materials covered in the first two midterms. These questions will be on topics that many students had difficulty with during those earlier midterms. My goal in asking those questions again is to reward students who take the time to learn the materials that they (probably) didn’t understand the first time they read or heard about it. So, I suggest that you review your first two midterms as preparation, and figure out the correct answer to questions that you did not answer correctly.
We talked about the following topics:
Ch. 13: The Ocean Floor.
Can you label the different parts of a passive continental margin? (e.g. shelf, slope, rise, abyss, turbidites).
How can you identify a turbidite when studying sedimentary rocks? (recall grading)
What are the different parts of a continental margin?
What are the diagnostic features that distinguish passive from active continental margins? (e.g. type of fault, seismicity, accretionary wedge, etc.)
What’s bathymetry and how is it measured today? How is this method possible?
What’s a black smoker? What geologic materials concentrate at them?
What causes a black smoker to develop?
What was the importance of the Cyprus in the Bronze Age?
What’s a methane hydrate (clathrate)? What is it composed of?
What’s the carbonate compensation depth and what types of sediments would you NOT expect to find below it?
Where would you expect to find terrigenous sediments dominating ocean floor sediments? How about biogenous sediments? How about hydrogenous sediments? Where would you expect to find silica- based biogenous sediments dominant over carbonate-based biogenous sediments?
Ch 14: This was mixed together in lectures 21 and 22 with other stuff to discuss thermohaline circulation- the way that the ocean transports heat around the planet.
Hadley cell circulation in the atmosphere: Know the pattern of where air rises and descends from the equator to the North Pole.
Note that rising air = Low atmospheric pressure. Air rising here causes the air to expand, which cools it, and cooling causes the air to become saturated with water vapor, so it rains).
Note that High atmospheric pressure causes air to descend, which causes the air to contract and so it heats up. Since hot air can hold more water vapor than cold air, the High pressure areas have little or no rain (= deserts).
Coriolis effect- what direction does it “bend” the wind in either hemisphere?
Note that Coriolis forcing is the reason that air moving from the equator to the pole doesn’t make it there easily; the air has to move through three Hadley cells before reaching the pole (and note that most air doesn’t transfer to the next Hadley Cell; it circulates back through the same Hadley Cell over and over again).
Review Trade Winds, Westerlies and Polar Easterlies.
Why are there deserts at ~ 20-40 degrees N and S latitude (recall the return flow of air to the Equator is dry and hot)?
What drives surface currents (e.g. what direction do currents flow at the equator? How about the direction of flow around gyres in the Northern Hemisphere or Southern Hemisphere?)
What are gyres?
How does sea ice form and what does this do to the sea water beneath the sea ice?
What drives deep ocean currents (thermohaline circulation)?
What happened at 8200 years ago to the Thermohaline circulation?
Why is the ocean divided vertically into layers at the equator and NOT at the poles?
Recall the surface, transition, and deep zones.
Recall thermocline and pycnocline.
Ch. 15: Waves- crest, trough, wavelength, wave height
oscillatory motion of water waves (transfer energy, not material, across the ocean).
Why does wave motion decrease with depth?
At what depth does a wave “feel bottom”? What does this interaction with the seafloor do to the speed of the wave?
How does the shape of the coastline affect the focusing and divergence of wave energy (i.e. headlands vs. bays)? Recall refraction.
Longshore Transport- what are the factors that cause sand to migrate down current? (recall the competing forces that affect the landward trajectory and the seaward trajectory of a particle being moved down the shoreline).
Rip currents- What are they and how do you get back to shore if you get stuck in one?
Coastal landforms: Depositional (due to beach drift)
Coastline protection- groins, jetties, sea walls, breakwaters, beach nourishment
West Coast and East Coast problems with coastline protection (e.g. tectonics, sediment starvation, barrier island migration, subsidence)
Chapter 6: Glaciers, Deserts and Wind.
Glacier deposits- moraines
Why “U” shaped valleys?
When did the last ice age end?
Icebergs- what’s below the water can hurt you (see Titanic).
Glaciers: What would happen to sea level if they all melted?
Moraines- know the different kinds, and where ones left over after the last ice age can be found
Loess- wind-blown rock “flour” from the melting glacier. Know how this relates to the Midwest and the Dust Bowl of the 1930’s.
Deserts- desert pavement, mechanical vs. chemical weathering here?
Wind-blown deposits- well sorted, dunes and their general shape.
Chapter 20: Modern Climate and Ancient Climate
Is Earth’s climate today unusual when compared with most of Earth History?
I may post some more stuff for this chapter after I give the lecture. Let’s see how for I get in lecture.