Seventy-five 4th graders from Hamilton Elementary School in the Pasadena Unified School District recently toured the Tectonics Observatory.

Their first stop was with graduate student Nina Lin, where they learned how to distinguish the three major types of rocks (igneous, metamorphic, and sedimentary). With this knowledge, they then chose one sample of each rock type, and created their own rock collection.

With graduate student Ajay Limaye they learned about how rocks and minerals on the move create landscapes. They examined photos of evolving sand dune and ripples, making observations, forming hypotheses about what was going on, and brainstorming lab experiments they could do to test their ideas. They thus participated in the scientific method as applied to exploring Earth's evolving surface.

Postdoc Danielle Sumy then led the students on a virtual journey out to sea, off the coast of Papua New Guinea, where she has done earthquake research using ocean-bottom seismometers. Students compared rocks samples of basalt that had been dredged from the sea after the East Pacific Rise volcanic eruption in 2006, with a sample of the more familiar rock, granite.

And finally, graduate student Junle Jiang brought them back home, presenting a computer simulation of "The Big One" (Magnitude 7.8 earthquake expected in southern California). He also showed them the physical mechanisms underlying earthquake production. And the students created their own earthquakes with an "earthquake machine" made of bricks, sandpaper, and elastic. Through this simple model, the students saw first-hand why it is difficult and currently not possible for scientists to predict when the next earthquake will happen.