Granada Hills : Seismometer Helps Students Measure Up

When life gives you earthquakes . . . might as well buy a seismometer.

That’s what Granada Hills High School did last fall. After the Northridge quake displaced the school’s math, science and technology magnet students from classrooms at neighboring Cal State Northridge, Principal Kathy Rattay applied for federal Department of Education grant money to replicate lost facilities and equipment.

About $400 of the nearly $400,000 grant earmarked for equipment went toward the purchase of an innocuous-looking black plastic unit, roughly the size of a cigar box. That box is a seismometer--also called a seismograph--which measures the primary and shear waves of any earth displacement, including earthquakes.

The results of the seismometer’s readings are analyzed weekly and posted on the school’s computer home page on the World Wide Web. But the school’s seismometer is a far cry from the $5,000-and-up drum-and-needle deals at Caltech favored by TV news cameras.

“It records any ground displacement,” said science teacher Lynda Fritsche, who keeps the seismometer in her lab. “So you can go to the seismometer and jump near it and it will record the movement.”

And sometimes her students do exactly that--jump near the seismometer--just to see the ensuing peak on the computer monitor to which the box is linked. The instrument also registers passing trucks, door slams and the like.

But Fritsche has made analyzing a week’s worth of the fever chart readings, called seismograms, a prerequisite for an A in all her science classes, so students are fast learning to distinguish the single sharp peak or a dropped notebook from the distinctive dual peak with a gradual bell-shaped drop-off pattern that signifies a quake.

Since January, Fritsche and students, most of whom are members of the school’s Internet Club, have recorded three temblors that have been verified by Caltech.

Anything to get students excited about science, Fritsche said. “It’s so much more interesting to be collecting real data,” she said. “We live on a continental margin and this is part of our lives.”

Posting seismograms on the school’s home page was a natural choice, said Internet Club member David Kane, 15.

“It’s something to do,” David said. “We got a seismometer. We need to do something with the data.”