You should be able to make significant progress on this quiz without much knowledge of Earth Science, particularly on the later questions**.** Give it a try! Answers have not been uploaded to this page.

Setting the Stage (7pts)

1. The theory of plate tectonics states that Earth’s crust is split into segments “floating” on fluid. What is the term for regions where two plates collide and one sinks beneath the other? (1pt).

Use the following diagrams for questions 2 and 3.

1. Earth’s atmosphere consists of three circulating “cells” of air in each hemisphere. A cross-sectional view is provided in the left diagram. What is the name of the cell that borders the equator in the Northern Hemisphere? Select one. (1pt)

   A. Ferrel Cell

   B. Equatorial Cell

   C. Hadley Cell

   D. Polar Cell

2. Earth’s oceans have surface currents that form circulation patterns known as gyres. The North Atlantic Gyre is shown in the right diagram.

   1. The average surface temperatures of the Azores current and Gulf Stream (labeled on the diagram) are measured. Which is higher? Explain. (1pt)
   2. Why does the gyre rotate clockwise? Explain. (4pts)

Diving Deeper (11pts)

1. Why do earthquakes often occur at plate boundaries? Select one. (2pts)

   A. Continuous rubbing between plates leads to constructive interference of seismic waves

   B. Rising magma from the mantle at boundaries lubricates plates and increases tectonic activity

   C. Mantle convection leads to plates moving closer/farther from each other

   D. Plates slipping suddenly after being “locked” for long periods of time leads to energy release

Use the following diagrams for questions 2 and 4.

1. Earthquakes generate waves that pass through Earth’s interior. In particular, S-waves bend outwards as they travel through Earth, as shown by the curved path in the left diagram. Why? (Hint: S-waves move faster in denser mediums.) (3pts)

2. Is there a low-pressure or high-pressure belt of air at the surface of the equator? Explain. (Hint: Does air rise or spread out at the surface near the equator?) (2pts)

   Bonus: Give the name for the aforementioned belt. (1pt)

3. Incoming solar radiation (middle diagram) is highest near the equator. Solar radiation tends to increase surface ocean salinity by evaporating water, but surface ocean salinity is actually maximized at 30N and 30S (right diagram). Why? (Hint: What happens to air at the equator? How does that create conditions affecting salinity?) (3pts)

More Connections (7pts)

1. Tectonics and the atmosphere are connected through the carbonate-silicate cycle, which models a component of Earth’s carbon cycle. Volcanism and weathering of silicate rocks are key mechanisms of this cycle. Which mechanism is a net atmospheric carbon sink and which one is a net source? (1pt)
2. Explain both mechanisms in context of the carbonate-silicate cycle. (Hint: How might atmospheric carbon enter solid Earth? Are there any rocks you know of that have carbon components? How do they form?) (3 pts)
3. A large surficial pool of warm water exists on one side of the equatorial Pacific. Which side (east or west)? Explain. (Hint: Consider the influence of prevailing winds.) (3 pts)