Parallel Computing in the Computer Science Curriculum > Workshops > SIGCSE 2012 > SIGCSE 2012 > Waves Through Earth: Interactive Online Mac and PC

Waves Through Earth: Interactive Online Mac and PC

JAVA Applet and activity provided by Visual Entities. Starting Point page organized by R.M. MacKay.

This activity was selected for the On the Cutting Edge Reviewed Teaching Collection

This activity has received positive reviews in a peer review process involving five review categories. The five categories included in the process are

  • Scientific Accuracy
  • Alignment of Learning Goals, Activities, and Assessments
  • Pedagogic Effectiveness
  • Robustness (usability and dependability of all components)
  • Completeness of the ActivitySheet web page

For more information about the peer review process itself, please see

This page first made public: Sep 18, 2006

This material was originally created for Starting Point:Introductory Geology
and is replicated here as part of the SERC Pedagogic Service.


This JAVA activity allows students to vary the seismic P and S wave velocity through each of four concentric regions of Earth. Students match "data" for travel times vs. angular distance around Earth's surface from the source to detector. Tabs are available for:
  • P and S rays superimposed on the four-region model;
  • Table of data for P and S wave velocities;
  • Graph of "data" and Model for P and S waves;
  • Help and instructions.

Learning Goals

Students can explore:

Context for Use

Perfect for introductory geoscience course with Solid Earth content. Appropriate for students with a wide range of mathematical abilities.

Description and Teaching Materials

Teaching Notes and Tips

Make sure to click calculate and check all tabs. This activity will likely take students about an hour to complete. Since it works on both Mac (at least with OS 10.2) and PC students should be able to do this as a homework assignment.


Completion of the activity can easily be assessed by having students fill out the table provided here (taken from model tab of Applet) once they get their best fit. [click image to enlarge]

Examples of other appropriate questions are:

References and Resources

The Virtual Physics Laboratory of The Department of Physics and Astronomy at Northwestern University has a good animation of P (longitudinal) and S (transverse)waves.