Problem 1
Explain how S waves "tell us" the mantle is solid.
Problem 3
What are the two major reasons for the increase in density with depth in Earth's mantle?
Problem 4
Explain how the core is only one-sixth of Earth's volume, yet it is onethird of Earth's mass.
Problem 7
Explain why convection is an inefficient means of heat transfer in materials with high viscosity.
Problem 9
Earth once rotated much faster than it currently does. How would Earth's shape have been different in the past than it is today?
Problem 11
The temperatures reach \(50^{\circ} \mathrm{C}\left(120^{\circ} \mathrm{F}\right)\) in the deepest diamond mines in South Africa-which are about 3 kilometers below Earth's surface. Assuming an average surface temperature of \(10^{\circ} \mathrm{C},\) calculate the geothermal gradient for this region.
Problem 12
Earthquakes below the Yellowstone caldera originate at very shallow depths, about 4 kilometers on average. Below this depth, the rocks are at least \(400^{\circ} \mathrm{C},\) too hot and weak to store elastic energy. Based on this data, answer the following questions: a. What is the minimum geothermal gradient in the first 4 kilometers beneath the Yellowstone caldera, assuming an average surface temperature of \(0^{\circ} \mathrm{C}\left(32^{\circ} \mathrm{F}\right) ?\) b. At about what depth is the groundwater below the Yellowstone caldera hot enough to "boil" and therefore capable of generating a geyser?
