As you shake the iPad the seismometer app will detect movement on the Richter scale up to about a 5.5. It is also able to record the data to analyze later.
How we use it
How don’t we use it?
We have a model of tension building in a subduction zone. In the model there is a brick lined with sand paper on a track of sand paper. The brick is connected to a crank by a bungee cord. We set the iPad on top of the brick and have the seismometer record the motion. We then slowly turn the crank. When enough tension builds the brick slides forward towards the crank and the movement is recorded by the seismometer app.
We have also used it to test our earth quake house, and to jump on bridges with visitors so that they can better understand why only so many people are allowed on them at one time.