Quiz #1 -- Processes and Concepts of Geology
August 29, 2003
The First Quiz!

1. Why is the inner core solid and the outer core liquid? Considering the increasing temperature with depth, shouldn’t it be the other way around?

The inner core is kept solid, even though very hot, by the lithostatic pressure of the Earth above.

2. What is the primary difference between a P wave and an S Wave in seismicity? Which cannot be transmitted through liquid?

P waves (pressure waves) send energy through the Earth by compression and dilation; changes volume; P waves travel 5-8 km per second. S waves (shear) oscillate at right angles to propagation direction; changes shape of the material; S waves cannot travel through liquids because a liquid's shape cannot be altered.

3. What is the Mohorovicic Discontinuity? How is it seismically defined?

The “Moho” is where a dramatic increase in seismic wave velocity (P waves speed up from 6.75 to 8 km/sec) is noted; it marks the boundary between the crust and mantle.

_________________________________
Bonus Questions: Always optional. One point for each correct answer.

This ambitious little country says they now want to test an atomic bomb: North Korea Korea
OK, there’s Scharwzenegger. Name one other candidate for governor of California: Gary Coleman, Mary Carey, Bustamante, etc.