Smartphone Array Experiment

partment of Earth and Planetary Sciences

We measured the velocity of sound (P-waves) in wooden tables using a linear array of smartphones.
The seismic signals from pounding on the table at one end of an array of smartphones were recorded using the built-in accelerometers and a third-party app on the phones.

See here for the lab instructions.

Here is a video of what wee did to make the seismic record:

Here is the merged seismic section (0.1 millisecond delays instead of 5 seconds between the "shots") we recorded. Each red line corresponds to a fit to the arrival times of a single "shot" at each phone (=station). Obviously, there are differences in polarities, amplitudes, and sensitivity (among other things!) in the records due to different instrument responses on various phones. Calculating the sound velocity in the tables from these lines is straightforward.