This assignment will require you to download an app to your phone (Android or iPhone). Any seismometer app will do (most are free; I suggest using a free one), but it must show X, Y, and Z axes. Examples: iSeismometer, Seismometer 6, Seismograph (Android-specific). If you cannot do this, you are more than welcome to set up an appointment with me to use my phone. If you are confused, contact me or your TA immediately. Type your answers into this document and submit to Canvas as a .docx file.

This assignment requires you to make some noise. Please be considerate, and do this at a reasonable hour.

• Place your phone on a tabletop. Open the app and run the seismometer. Drop a hardcover book/textbook one foot from the phone. Pause the seismometer. Mark in the table which one had the largest, medium, and smallest amplitude of waves.
• Keep your phone in the same place. Drop a pencil one foot away from your phone. Mark the general size of the waves in the table. How large were the waves? Mark your observations in the appropriate column.
• Now drop the same pencil 3ft away. Record observations-how did they change from 1ft away?
• Keep your phone in the same place. Shove the table. Record the wave observations in the same way. What has changed from the first two observations? Mark this in “observations”. Be specific.
• Place your phone on the floor: please indicate here if it was: hardwood, tile, or carpet:___________________
• Drop the same pencil from part one from one foot away. Record observations
• Drop the same pencil from three feet away. Record observations. Which had higher amplitude, 1 or 3 feet?
• Jump next to your phone (remember- don’t move your phone). Record observations. When recording, make sure to compare your observations. Did jumping show more or less amplitude than the book?
• Go outside! Place your phone on the ground (not a sidewalk or driveway-on dirt/grass/etc). Drop the same book from one foot away. Record observations.
• Drop the same pencil from one foot away. Record observations
• Drop the same pencil from three feet away. Record observations
• Jump next to your phone. Record observations.
• Assume all of the experiments represent real earthquake motions. How did the amplitude of the waves differ when you dropped your pencil at 1 and at 3 feet away (on any surface)? Relate this to the Mercalli intensity- where would the higher Mercalli intensity have occurred and why? If this were a real life situation, where would the greatest societal impact have been?
• Which material had the highest amplitude at the furthest distance away?
• Between the grass and the floor, which material had the higher amplitude at the furthest distance away? What might that mean in terms of the surface’s ability to transmit seismic waves?
• Read this short article on Hurricane Irma (https://www.usatoday.com/story/weather/2017/09/05/hurricane-irma-so-strong-its-registering-devices-designed-detect-earthquakes/634419001/). What did Hurricane Irma do to seismometers? How is the seismometer in your phone different from one that is used to detect earthquakes by geological surveys? Is it as accurate?
• Read this article on the geology of the recent earthquakes in Mexico: http://www.npr.org/sections/thetwo-way/2017/09/20/552428176/mexico-city-doomed-by-its-geology-to-more-earthquakes
• What are the two plates involved?
• What type of plate boundary is this? Which plate is being subducted?
• Without knowing any more information, why is this plate being subducted? Think of the type of crust/density.

Drop the same book you used in the first part one foot away. Record your observations of wave size and observations.