San Fernando Valley : Seismograph Readings Become Classwork at High School

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

That’s what Granada Hills High School did last fall.

After the Northridge earthquake 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--that 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 versions 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.”

Fritsche has made analyzing a week’s worth of the 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 of a dropped notebook from the distinctive dual peak with a gradual bell-shaped drop-off pattern that signifies an earthquake.