QUAKE DEVICES TO FUNCTION SOON.
GLENDALE - Two devices installed near the Glendale Freeway as part of a major project to monitor earthquakes in Southern California are expected to become operational by the end of March, officials said.
The laser strainmeters, installed on the east side of the freeway in the Verdugo Canyon next to the Mayor's Bicentennial Park, are part of a system that can measure changes as small as 1/20,000 of an inch.
``This is extremely precise,'' said Bernard Minster, science director of the Southern California Earthquake Center, which monitors the devices. ``It tells you in that location, how the crust (of the Earth) is being strained.''
The two devices are located a half-mile apart and housed in vaults anchored in the bedrock near the Verdugo Fault. The last phase of the project will be to connect the devices with a 6-inch vacuum pipe.
A laser beam will travel back and forth inside the pipe to measure the distance between the instruments and record any minute changes that result from ground movements.
Strainmeters also are operating at two other locations in Southern California: in Pinon Flat above Palm Springs and near the Salton Sea east of San Diego. Another set is also being installed near the planned nuclear waste facility in the Yucca Mountains.
Operating in conjunction with the strainmeters is a network of 250 global positioning system receivers that also track movements of the Earth.
Much less precise than the strainmeters, the GPS receivers' daily accuracy is estimated at about 1/25 of an inch.
``With this array of instruments, you could identify where the strain is more concentrated,'' said Frank Wyatt, research geophysicist at the Institute of Geophysics and Planetary Physics, part of the Scripps Institution of Oceanography at the University of California, San Diego.
All the GPS receivers have been installed, with the most recent one put into place in the last few months. Minster said scientists have already started analyzing the data in earnest.
The difficulty for scientists is to sort out natural ground movements from what is attributable to human actions.
For example, someone drilling a well could cause ground movement, he said.
``What we found is quite interesting. No. 1, the ground is moving all the time by minuscule amounts for reasons you would never expect,'' he said.
And while the monitoring system has produced interesting data, it is not capable of predicting earthquakes.
``What is realistic these days is getting better at forecasting the possibility of earthquakes,'' Wyatt said. ``This (system) would play some role at that.''
Aside from the Southern California Earthquake Center and the Scripps Institution, others involved in the project are the U.S. Geological Survey and the Jet Propulsion Laboratory in Pasadena. The earthquake center is based out of the University of Southern California and is made up of a consortium of scientists.
|Printer friendly Cite/link Email Feedback|
|Publication:||Daily News (Los Angeles, CA)|
|Date:||Jan 3, 2002|
|Previous Article:||BOYS' SOCCER: THE SECRET ON THE SIDELINES QUARTZ HILL'S BENT SNEAKS IN TO HELP.|
|Next Article:||GIRLS' BASKETBALL: LITTLEROCK MOVES IN RIGHT DIRECTION LOBOS APPROACH LEAGUE CONFIDENTLY.|