Bucknell Seismograph Recorded Indian Ocean Earthquake
Jan. 4, 2005
LEWISBURG — The Indian Ocean earthquake and tsunami that killed more than 225,000 people Christmas weekend registered loud and clear on a recently installed seismograph on the Bucknell University campus.
Brad Jordan, lab director of geology, said since the device was installed in Carnegie Hall about a year ago it has recorded more than 300 earthquakes and aftershocks worldwide.
Those earthquakes included one recorded in February 2004, and was centered off the north coast of Morocco. Nearly 600 people were killed, according to news accounts.
"That was the first where we really knew the station was working and getting worldwide events," said Jordan. "It happened at night and I was working on an earthquake lab to get to students the next day and I saw this signal and said, 'Wow, what happened?'"
The Bucknell seismograph readout from the Dec. 25 event shows a distinct cluster of waves that traveled through the earth followed by an intense readout of surface waves. "The body waves that travel through the earth may not reach the station, but the big ones — the surface waves — are the ones we typically receive."
The campus seismograph station was set up by Gary Nottis of Lewisburg, a Bucknell graduate who had worked for 16 years as an earthquake historian for the New York State Geological Survey.
Data from the seismograph is sent to a computer where it is then analyzed. A real-time display from the station is also on display on the first floor of the O'Leary Center.
"We have a single station and we know an event has occurred," said Jordan. "To actually determine where the earthquake was we need information from two other stations to triangulate the location."
Still, a single station setup and the recording of the Indian Ocean quake gives Jordan plenty to use in the classroom. "What I plan to do with this information is to go out to other stations around the world and work up an exercise. Students can take that information and pinpoint where the quake was and calculate the magnitude."
The Indian Ocean quake, centered more than 9,360 miles from campus, was the largest seen by Jordan. "The 9.0 is the biggest one I have seen in my life," he said. "That's pretty major."
Given the size of the quake and its location, Jordan isn't surprised at the tsunami event that occurred afterwards causing such a tremendous loss of life throughout the region.
"Often Earthquakes occur that do not generate tsunamis," he said. "But this was along a 650-mile stretch of fault and when that fault moved, it instantly displaced a huge volume of water."
The size of an earthquake is related to the size of the fault of movement in the earth and, in this case, it was "just a huge amount of crust that moved and displaced a tremendous amount of water. It's really a sad event."
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