Khan Academy
Refraction of Seismic Waves, Cosmology & Astronomy
Mr. Khan uses the metaphor of a car to help explain the change in the direction of waves as they hit a boundary between two mediums. He then goes on to explain the relationship between the earth's structure and density and the waves'...
Incorporated Research Institutions for Seismology
Iris: Seismic Shadow Zones: P Wave
What can the P wave tell about the core of the Earth? Find out in a video. [3:26]
PBS
Pbs Learning Media: Earthquakes: The Seismograph
This video segment adapted from NOVA uses historical illustrations, photographs, and animations to explain how seismographs work, the difference between P and S waves, and the Richter scale.
Incorporated Research Institutions for Seismology
Iris: Seismic Shadow Zone: Basic Introduction
Understand the basics of how P and S waves create the seismic shadow zones. [1:48]
Incorporated Research Institutions for Seismology
Iris: Travel Time Curves Described
Learn how we can calculate the distance to an epicenter of an earthquake. [1:19]