Description
Focal Mechanism Solution Lab Kit™ for 18inch globes is a hands-on manipulative Teaching Aid.
The global focal mechanism allows a clear visual presentation. Re-orienting the globe shows how traditional “beach ball” pictures of different focal mechanisms (normal, reverse, strike-slip, oblique slip) are actually all the same, but just oriented differently. Spatial relations between nodal planes, P- and T-axes and slip vectors are much easier to demonstrate in three dimensions.
Build-It-Yourself Lab Kit includes
Equator Magnet Grid Board
Dry-erase core workboard with plain white reverse side also Dry-erase
Two exterior auxiliary planes to act as spherical rulers
Clear 18inch dry erase hemisphere/dome with alignment stickers
Clear vinyl self adhesive grid pattern and equator tick marks + instructions to apply
Spherical Protractor Lab Method: Assembled Grid Globe
Plot arrival data at globe locations corresponding to latitude and longitude of seismic stations. Closed circles indicate first “upward” motion, open circles indicate first “downward” motion. After plotting arrival data, use the spherical ruler to trace great circles separating regions of open circles from regions of closed circles. Use the protractor to draw a perpendicular to the great circle. Here’s the entire kit after the user had darkened the delineations. To finish delineating open-circle and closed-circle quadrants, use the spherical ruler to draw a great circle through the perpendicular marks. This results in finished Focal Mechanism Solution, showing compressional (shaded, closed circle) quadrants and dilatational quadrants. Clear Hemisphere & Stereonet workboard—The Schmidt Net is a 2D representation of the lower hemisphere of the globe. The clear hemisphere allows visualization by drawing points and great circles (from above exercise) on it, showing how they project down to the workboard.
See suggested lab activities in our library of educational products, courtesy Dyanthe Weeraratne, Cal State Northridge.
