SeisMac 2.0 was created with support from the National Science Foundation through the Incorporated Research Institutions for Seismology

SeisMac is a Mac OS X application that turns your MacBook or MacBook Pro into a seismograph. It access your laptop's Sudden Motion Sensor in order to display real-time, three-axis acceleration graphs. Version 2.0's enhancements make SeisMac an even more valuable tool for classroom demonstrations of seismic concepts and techniques.

The resizable, real-time scrolling display shows an enormous amount of acceleration information. Place your laptop on a table and see the seismic waves from tapping your toe on the floor. Lay your laptop on your chest and see your heartbeat. And of course, if there is a real earthquake, SeisMac will be displaying full seismic information while you drop, cover and hold-on.

Version 2.0 of SeisMac includes many new features:

• Pause the display to study an event
• Scroll back in time to see older data
• Time labels tell exactly when an event occurred
• Enlarge or contract the graph, both vertically and horizontally
• Copy, print or save the screen
• Adjust the sample rate from 10 to 500 samples per second
• Smooth the acceleration data
• "Out of Range" arrow appears when the graph goes off the screen
• Runs on non-SMS machines using test data

When running on the MacBook or MacBook Pro, SeisMac has a range of plus or minus two gravities of acceleration, displaying 256 values per gravity, sampled up to five hundred times per second for each axis. SeisMac is also compatible with older Sudden Motion Sensor-equipped iBooks and PowerBooks.

For better accuracy, you can use SeisMaCalibrate to calibrate your laptop's Sudden Motion Sensors.

SeisMac is based on SMSLib, my open-source Sudden Motion Sensor access library.

SeisMac is freeware. You can download version 2.0 here (Mac OS X 10.4 or later). You can also view SeisMac's help files here.

If you'd like to be notified about future versions of SeisMac, sign up for our mailing list here.