Download Chapter 10 Section 3 Studying Earth’s Interior

Chapter 10 Section 4
Studying Earth’s Interior
Objectives:
-Describe how data from seismic waves are used to
infer the structure of Earth’s interior
State Science Standard:
-Analyze the seismic evidence (S and P waves) used
to determine the structure of the Earth
By studying earthquakes, scientists
have learned about earth’s interior
• P and S wave velocities increase when they
travel through denser material
• S waves cannot travel through liquids
• Based on these observations, scientists have
inferred about the characteristics of earth’s
interior
The Shadow Zone
• Area on the surface of Earth that does not
receive seismic waves
The Moho (Mohorovicic Discontinuity)
• An abrupt change in the velocities of P and S
waves
• This results from waves traveling through
denser material below the crust
• This boundary is where the denser rock of the
mantle interacts with the less dense crustal
rock
The Transition Zone
• A region in the middle of the mantle
• Between depths of 400-670 km below surface
• Separates the upper mantle from the denser
lower mantle
Transition Zone Continued:
• P and S wave velocities change as a result of
differences in pressures