An SMU professor’s seismic studies may pinpoint when and where the space shuttle Columbia depressurized and exploded.

“There was a definite explosion about halfway between Lubbock and Albuquerque (N.M.),” geology professor Eugene Herrin said.

Herrin collects sound data from infrasound stations around the world to try to piece together the puzzle of what causes earthquakes. He has also recorded the sounds of the various shuttles passing overhead since 1987.

After he released his findings to the press and posted the charts on the geology department’s Web site, NASA impounded the evidence. Part of it has since been released. Herrin formally turned his evidence over to NASA on Thursday.

“NASA asked me to document everything for them and turn it over so that it could be used in their investigations,” Herrin said. “I was glad to be of help. Even at this moment, SMU geology students are creating computer models of the atmospheric environment at the time of the explosion.”

The Columbia disintegrated during re-entry over Texas on Feb. 1, killing all seven astronauts aboard.

Since his revelations, Herrin has been swamped by the press for more details on his theories about Columbia. He held a news conference Friday in Heroy Hall to try to answer some of the questions.

“It’s very clear that the Columbia was in distress over Albuquerque,” Herrin said. “There is a sound anomaly that is present in the wave pattern that was not present in past charts. I have asked NASA about this, but they are not willing to comment until they have completed their investigation.”

The Lajitas station in southwest Texas near Mexico recorded the breakup of the Columbia.

“Normally this would have been recorded by a station in Lubbock,” Herrin said. “For some reason that station was off line. It is maintained by Texas Tech, so I couldn’t really say why it was not reporting that day.”

Herrin said that conditions were optimal for recording sound waves that day. The scientist and his students calculated the position of the explosion based on which stations received the strongest signals and discovered that it coincided with the moment when NASA lost communication with Columbia.

Herrin said he believes the shuttle began failing over California but was not trailing debris as some theories state.

“This just is not consistent with the sound wave patterns,” he said.

A reporter from Time magazine commented that Herrin seemed modest about his discovery during a historic event.

“What we have here is another piece of a puzzle,” Herrin said. “It’s not the piece of the puzzle that is important. What is important is that we find the cause of this terrible tragedy and never forget those who sacrificed so much for science.”

Herrin has been a professor at SMU since 1955 and has spent more than 40 years as an expert in earthquakes and seismology. He received a bachelor’s degree in physics and a master’s degree in geology from SMU, and he earned a doctorate in geology and geophysics from Harvard University.