Homemade seismograph at MSU records California earthquake

Elias Ahadi is a very, very sensitive student.

The physics and chemistry major at Montclair State University is so sensitive to the environment that he was able to construct a homemade seismograph in his Richardson Hall room that detected an earthquake 3,000 miles away -- the day after he first plugged in the rebuilt amplifier circuit turned earthquake detector.

Ahadi's device recorded an earthquake that registered 7.0 on the Richter scale on Oct. 16 at 6:09 EDT, just 20 minutes after it shook the Mojave Desert in southern California.

Although no person in New Jersey felt the tiny vibration, the seismograph, located on the second floor, did. Even more amazing is that the earthquake's ripple moved Richardson Hall, whose foundation rests on bedrock.

"It freaked me out that this building swayed," said Mary Lou West of MSU's Mathematical Sciences Department.

Essentially, a horizontal pendulum, the seismograph is constructed from plumbing pipes, piano wire and a horseshoe magnet with an olive oil damper.

"Two students built it a couple of years ago," West said. "The directions came from an article, 'How to Build a Simple Seismograph to Record Earthquakes at Home,' in the July 1979 issue of Scientific American magazine."

West asked Ahadi, who learned circuit design from professor Ernest Ma of Mathematical Sciences, to rebuild the circuit.

"I got the parts I needed from Radio Shack," said Ahadi, who graduated in August. "The old circuit wasn't stable. It registered only noise, so I corrected that."

Ahadi explained that the seismograph responds to movement eight seconds or slower, so a passing truck or stomping foot won't affect it.

Their next goal, said West, is to write a better data-taking program so the machine will not have to be reset every 24 hours.