Pacific quakes registers on campus seismograph
Posted: May 03, 2006
Seismograph reading in Carnegie Hall.
LEWISBURG, Pa. - The major earthquake that shook the South Pacific Thursday local time registered clearly at Bucknell's campus seismograph station.
Located in the basement of the Carnegie Hall, the instrument recorded the so-called P-waves of the temblor a little before noon EDT Wednesday, according to Gary Nottis, an assistant in the Bucknell geology department.
The quake's surface waves resulted in a dramatic spike in the seismograph reading when they reached Lewisburg a little after noon Wednesday. The campus is an estimated 7,474 miles away from the earthquake's epicenter located about 95 miles south of Neiafu, Tonga, in the South Pacific.
Some reports measured the earthquake's magnitude as high as 8.1. Nottis said by his estimate the quake was a 7.7 magnitude on the Bucknell equipment. "That's a slightly different magnitude scale, but it's pretty close," said Nottis. "It would be more dramatic if our instrument didn't tend to dynamically change the display. If this were recording on paper, this would be off scale - easily."
"You can see a couple big waves that do go off scale. It looks clipped," he said of the graphic.
Several hours after the quake, the campus instrument was still recording seismic waves activity traveling around the planet. "Once this signal quiets down, we may start seeing the aftershocks," he said.
News reports indicated that tsunami warnings were immediately posted in Tonga and New Zealand. They were subsequently canceled.
Posted May 3, 2006
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