Geoscientists install seismic station

By Amy C. Schweigert
Arizona Daily Wildcat
August 27, 1996

Karen C. Tully
Arizona Daily Wildcat

UA research scientist George Zandt and assistant staff scientist Michelle Hall Wallace lean over their new seismic station at Sahuarita High School in Sahuarita, Az., south of Tucson. The geoscientists' goal is to install these earthquake measuring devices in schools across America


SAHUARITA - About 70 students moved the earth Friday in an experiment near a newly installed seismic station at Sahuarita High School, about 30 miles south of Tucson.

The group jumped up and landed full force on the ground, creating seismic waves, then hurried to a small, brown shelter a few feet away to see the results of their effort.

An underground seismometer, installed by University of Arizona geoscientists, recorded the group's jump. Data from the "seismic event" was sent to a computer in the climate-controlled shelter.

UA geoscientists installed the station as part of the national Princeton Earth Physics Project, a two-year-old National Science Foundation-funded educational project, to develop a global network of broad-band seismic recording stations, a UA press release stated.

Michelle Hall-Wallace, UA geosciences adjunct lecturer, is the head of the Arizona portion of the project.

Earthquakes and explosive blasts create seismic waves that can be recorded, Hall-Wallace said.

The broad-band seismometer uses an electrochemical sensor and is more sensitive to wave frequencies than conventional seismometers, which rely on weights and springs to detect motion.

"The 'frequency' refers to how fast the ground moves up and down," Hall-Wallace said in an interview via electronic mail.

"Different seismometers record different seismic waves with different periods. Many seismometers are only sensitive to one period, such as one second. The broad band seismometer at Sahuarita can record a very broad band of periods of waves," she said.

Sahuarita High School students will operate the seismic station and perform in-class experiments as part of their science and history classes. As station operators, they will have the capability to send data recorded by the seismometer to the UA and other researchers over the Internet.

At Friday's event, Scott Boone, a teacher at the high school, told the group of students that they will be involved with real research because of the station.

UA geoscientists held a two-week workshop for Arizona school teachers in preparation for the seismic station's construction, said Sahuarita science teacher Kathleen Lewis.

"We already study earthquakes (in class). Now we'll really be able to study earthquakes," she said.

Carol Lippert, another Sahuarita science teacher, said this station will also help students learn about world conflict. The seismometer will be able to detect when a nuclear blast rumbles underground and will show it on the computer differently than it shows an earthquake, she said.

One of the station's purposes is to show students that science can be fun, Hall-Wallace said.

This broad-band seismic station, costing $1,500, is the first of its kind to be built in the nation, according to the UA press release. Plans exist for 14 more seismic stations within Arizona by the end of 1997. Four of those could be installed by the end of this year.

"It's neat to know we're the first high school to have it in the country," said Lauree Grantham, Sahuarita High School junior.

Hall-Wallace said the Sahuarita site was chosen because it is close to Tucson and yet far from sources of noise, like cars or power lines, that would reduce the quality of the data.

"This is a test site which will provide us with information on how to best install the rest of the seismometers in other schools," Hall-Wallace.