Ask your students to:
1. Place your hands palms down on
a table to show the interaction of tectonic plates. Thumbs tucked, fingers
flat, the hands side by side, press your hands hard together until they buckle
upward. The hands are two continents converging, colliding--making mountains.
The Himalayan mountains were made that way.
2. Placing the hands flat again,
then slowly move them apart. These are two plates separating, one on either
side of a spreading center. The Atlantic Ocean was made that way.
3. Slide one hand under another.
This is subduction, a geologic process in which one edge of a plate is forced
below the edge of another. Ocean floors are consumed that way.
4. Tuck your thumbs, fingers
flat, palms again side by side, and then slide one hand forward, one back, the
index fingers rubbing. This is the motion of a transform fault, a strike-slip
fault such as the San Andreas fault in California, USA.
Adapted from John McPhee's description
of a teacher teaching plate tectonics. (Assembling California, New York:
Farrar, Straus & Giroux, 1993, pp. 16–17).