Spot a tornado? Quick, call an earthquake expert

Monday, June 12th 2000, 12:00 am
By: News On 6

An Ohio researcher is exploring using earthquake monitors to help detect and track tornadoes.

"My hope is we would eventually ring a city with seismometers," said Robert Vincent, professor of geology at Bowling Green State University. The devices, which measure and record ground motion, might give weather officials more precise information about the path of a tornado, possibly leading to fasterwarnings, he said.

Geologists have established in recent years that tornadoes produce vibrations measurable on ground-based seismometers. Trying to apply that knowledge in Ohio has become more practical since a network of 16 earthquake-monitoring stations around the state was established in January 1999.

When a tornado struck the northern suburbs of Cincinnati in May 1999, Vincent examined seismic records at the University of Cincinnati and in Columbus and Portsmouth. Unusual readings correlated closely with the time the tornado struck and the time it would have taken for the ground vibration to travel to Columbus and Portsmouth.

Vincent said he is still analyzing the data and is eager tocheck the seismometers again when another tornado strikes.

"We're kind of waiting for another big one to hit," he said.

Frank Tatom, manager of VorTek LLC of Huntsville, Ala., has been doing similar research for eight years.

Tornado eyewitnesses have said they could feel the ground vibrate as the storm approached, Tatom said. One man said he felt his basement floor vibrate when a small tornado touched down about a mile away from his Texas home.

"He felt it through the seat of his pants," said Tatom. "He said: 'My hair stood on end."'

Tatom said he checked records of tornadoes with the National Weather Service and corresponding records with nearby seismic stations.

"The signal that we predicted was there," he said.

Tatom said tornadoes have also registered on portable earthquake-detection devices called "snails" used by storm chasers in Kansas and Oklahoma.

He has asked the Federal Emergency Management Agency to consider establishing a network of seismometers.

"The bottom line is getting enough money to put this into practice," he said.

Vincent said the seismic stations he envisions could be set up or less than $5,000 apiece.

"There may be some value to it," said Dennis McCarthy, meteorologist in charge of the National Weather Service's forecast office in Norman, Okla.

McCarthy said the weather service uses Doppler radar and satellite images to determine when a tornado is forming, but relies on spotters to detect touchdowns. He said seismometers might help increase the detection of touchdowns.

"But the system works pretty well now," McCarthy said. "There would probably have to be some sort of demonstration on how much this instrument would improve on what we're doing."

Vincent said spotters are limited to their field of vision and have difficulty at night.