Campus Seismograph Picks Up 8.1 Earthquake Near Chapas, Mexico, Among Others


The DePauw campus seismograph, which is located in a classroom on the second floor of the Julian Science Center, picked up an 8.1 magnitude earthquake just 60 miles from Chapas, Mexico, on the morning of Sept. 8.

According to an article from ABC News, many homes and small businesses were destroyed and by Monday, the death toll totaled 96. This was just one of the hundreds of earthquakes that has been recorded daily by the campus seismograph.

A seismograph is an instrument that detects the movement of the earth. These movements range from earthquakes, landslides, rain, or anything that causes vibrations on the Earth’s surface. In order for the seismograph to not pick up student movement, rain, or the AC, Mills placed a white box with motor oil on the seismograph’s arm and an empty fish tank over it, which both act as dampers.

“I’ll put my paycheck on it right now, there will be an earthquake within the next 10 minutes,” James Mills, professor of geosciences, said. The seismograph should have no problem picking up any earthquake around the globe as long as the magnitude is 2.5 or greater.

According to Mills, there has been a seismograph at DePauw University for about 20 years. The first seismograph purchased by the University was simple and only picked up local earthquakes. This seismograph was eventually rendered useless because the computer that controlled it broke down. A new seismograph was purchased later with the intent of being a simple demonstration tool in classes. As it turned out, this seismograph proved to be exceptional. “It’s extremely sensitive, and we're picking up earthquakes from all around the world,” Mills said.

Determining where an earthquake took place can be a tricky process. One method geology students use is taking data from three separate seismographs and measuring how far waves from each ride with respect to time. This lets them know how far the seismograph is from the earthquake. However, a more simple way is to wait for the United States Geological Survey to release earthquake locations, according to Mills.

When asked if it was possible to predict earthquakes, Mills said, “Nobody can predict earthquakes, however, we can give probabilities on when an area might expect an earthquake and how big to expect it.” For example, Mills predicted for an earthquake, magnitude 7 or 8, to hit the southern San Andreas fault within the next 10 years. “You’re going to wake up one day and all of a sudden, on the news, you’ll see that southern California just had an earthquake,” Mills said.

DePauw geology students have frequent interactions with the seismograph. “We talk about it in most of my classes - we’ll start with current events and scan for any earthquakes that the seismograph may have picked up,” Kathryn Flynn, a sophomore geology major, said.

The campus seismograph can be viewed by anyone by simply going to the DePauw website and clicking the “seismograph” tab under the “geosciences” department page. The seismograph records vertical movement and is refreshed every five minutes.

According to Mills, “We live in earthquake country. Generally, central Indiana averages a 3 to 3.5 magnitude earthquake every 7 to 10 years. There is something generating these earthquakes, but we haven’t quite figured it out yet.”