The passage suggests that geophysicists can now infer the characteristics in a given segment of the mantle by doing which of the following?
Observing how long it takes for seismic waves to travel from an earthquake's epicenter to a particular surface location and applying knowledge of how rock temperature and density affect the velocity of those waves
Analyzing the results of studies linking the formation of some of Earth's surface features with the violent collisions of tectonic plates and inferring the causes of the information of other features from those results
Recording data about earthquakes throughout the world and correlating the relative force and duration of those earthquakes with information about their geological environment
Comparing data about earthquakes that occur in southern Africa's superswell with data about other types of seismic events that occur there
Using computer models to estimate the length of time it would take for a hypothetical landmass 1,000 miles across to rise one mile vertically