Measuring 'rhythms of Penn State' gives students preview of earthquake science

Liam Jackson
April 25, 2017

UNIVERSITY PARK, Pa. — A simple electronic device found in nearly every smartphone today is helping students learn about the science of earthquakes in one general education geosciences course, GEOSC 109, Earthquakes and Society. Taught by Charles Ammon, professor of geosciences, the course was designed to give students insight into how geoscientists understand earthquakes — and, more generally, what's involved in conducting science.

Phones paving the way for earthquake education

To investigate earthquakes, scientists commonly use seismographs, which are machines that measure ground motions, or vibrations, in the Earth. An earthquake releases energy that propagates outward as seismic waves, which vibrate the ground as they pass. Depending on an earthquake's magnitude, waves could travel the globe many times.

A seismograph measures movement during these vibrations. The data recorded is known as a seismogram, and to an untrained eye, these may look like "wiggly lines," said Ammon. In his class, Ammon aims to transform seismogram squiggles into meaningful movements. And he uses a little electronic device that has become affordable thanks to advances in phone technology.

Most smartphones have what's called an accelerometer, which can detect changes in the speed of the phone’s motion. It's the sensor a phone uses to change from portrait to landscape orientation when you rotate it. The need for small devices that can accomplish this has lowered the cost of accelerometers to less than $10 apiece.

With some computer programming and a few other electronic components, accelerometers can be transformed into low-quality seismographs, able to detect sensibly large vibrations.

From parts to participating in earthquake science

Ammon kicks off the semester-long project by giving students the parts of a simple seismograph and guiding them through the building process. They build their device using a circuit board, a processor, a USB port and an accelerometer. Next, students download a software program, developed by Ammon, onto their new devices that can record the sensor’s vibrations.

"Then I send them out and ask them to record something but not to tell us what it is," said Ammon. "They give their data to me, and I plot it. During the next class, I show the seismogram to the class and ask them to figure out what it is. They look at these things and wonder, what the heck is this?"

At this point, it's all just a squiggle, somewhat like what you'd see on a heart monitor. But as students start getting clues as to what they are looking at and as they describe the lines in a seismogram, they begin to understand more about the motions and vibrations that created those wiggly lines, said Ammon.

The idea for the project came about two semesters ago, when Ammon decided to incorporate seismograms into his classes. He was playing around with a few possible ideas, and then, one day, while driving to lunch, he decided to run an experiment. He turned on his simple seismograph and left it on the floor of his car. He showed his class the seismograms the next day.

"They started describing it but had no idea what I was recording," he said. "Then I told them that was me driving to lunch with an accelerometer in the car. Then, the students look at it and might say, 'Oh, you made a right-hand turn here.' So they get used to thinking of these wiggly lines as meaning something, as carrying information."

After that experiment, Ammon said, "it became really clear that they engaged in that activity."

So, he thought, why not get students even more involved in the activity. "I like to think of it like they are recording the rhythms of Penn State," said Ammon. "I tell them to put in on a heater, a washing machine, a speaker, anywhere that vibrates. One student just recorded the vibrations that her phone made when she received a call."

It's up to the students to find something that will stump their peers. But that's not hard, said Robert Cowell, a sophomore majoring in computer science.

"The only time people got it right this semester was a washing machine. It was regular enough, and it only lasted for half an hour, so you could start to piece it together," he said.

Cowell put his seismograph in his backpack on his way to class. Another student, Caroline Wilson, an architecture major, put her seismograph next to a mitre saw she uses to create models in her architecture studio.

Figuring out what created the seismogram is "a lot harder than you would think," Wilson said, noting that the course showed her that scientists, with enough training, can gather meaningful information from seismograms.

Even if they don't figure out what activity or machine resulted in the vibrations recorded by their seismographs, it's still a positive experience that shines a light on how scientists interpret data to understand the impact of Earthquakes better.

"This activity has definitely given me an appreciation of the work people did pre-computers, by trying to find patterns in the seismograms," said Cowell. "We also look at seismograms in the class from actual earthquakes, and unless there's a very large earthquake happening, it just looks like noise 90 percent of the time."

What it's like to "do science"

Another lesson Ammon hopes to teach students through this project is that observational science can be a little stressful.

"It's like a little science experiment," Ammon said. "Students first must come up with an idea of what to observe, then power up the equipment and collect the data. They come back to class after measuring something, thinking, 'I hope it worked.' Now imagine you'd just traveled to Fiji with a seismometer and you waited a year and went back to get the data. You'd be nervous about getting it. That's what scientists have done and often still do. That's part of the aspect of observational science that I want students to understand."

Ammon's enthusiasm for earthquakes and science is one of the most engaging aspects of the course, students said.

"He really wants to show us what he enjoys, and I think that's a big part of why I like the class," said Cowell.

"Professor Ammon is really excited about earthquakes," said Wilson. "When somebody is excited about something, you tend to like it, too."

This course activity was made possible by Penn State's Schreyer Honors College, which provided the funds to purchase the equipment, and electronics company Adafruit Industries, which provided educational discounts on the seismograph equipment.

(Media Contacts)

Last Updated May 31, 2017