The first article explains what happened (I was one of the thousands who hit up the web to see how bad things were) while the second article, on earthquake predicting, is less reassuring.
WEB SITE: Instant info on seismic activity is there, and residents can report their experiences.
07:20 AM PST on Friday, January 7, 2005
By HENRI BRICKEY / The Press-Enterprise
Within minutes of the 4.4 earthquake that struck north of
Fontanaearly Thursday, seismologists in Coloradowere reviewing firsthand accounts from Southern Californianswho experienced the shaking.
By 5:30 p.m., more than 3,200 people from 355 ZIP codes had filed their impressions on an Internet site set up by seismologists.
Launched five years ago, the site - http://pasadena.wr.usgs.gov/ - provides nearly instant information on earthquakes as well as collects reports from the public. The U.S. Geological Survey and the California Institute of Technology sponsor the Web site.
"This is one of the most sophisticated citizen science programs out there," said David Wald, a seismologist with the
National Earthquake Information Centerin Golden, Colo.
Information from seismic monitoring equipment - about 350 sensors in
Southern Californiaalone - is automatically sent to the Web site. Earthquakes, even tiny ones less than magnitude 1.0, generally show up within 5 minutes on an interactive map. Site visitors can get details on epicenter, magnitude and other characteristics of the quake. They also can fill out a questionnaire, about how a quake felt.
Responses are catalogued and used to create a map showing the strength of the shaking in various areas. Scientists use the information, in part, to help confirm that ground sensors are reporting accurately when earthquakes strike, Wald said.
Getting people to tell about the quakes they experience has other advantages, according to Wald. "People use this as a catharsis. You want to tell people how you felt after experiencing an earthquake.
"It takes a little bit of the mystery out of Mother Nature."
Initially, the system was limited to
Southern California, he said. The network has since expanded across the and throughout the world. United States
"The feedback and response is mind boggling," said Wald, who developed the "Did You Feel It?" monitoring system while working in the Geological Survey's
office. "We're always astonished at how many answers come in." Pasadena
More than 17,000 people responded after a 4.4 magnitude earthquake in
, he said. Virginia
If the system had been in place in 1994 when a 6.7 quake hit Northridge, officials would have known instantly that neighboring communities also had damage.
Fire Marshal Mike Hatfield,
's emergency services coordinator, said his department looks at Web sites, monitors amateur radios and uses other resources to determine the extent of damage caused by earthquakes in outlying areas. Cathedral City
By L.C. GREENE, Staff Writer
The swarm of small tremors in the Fontana-Rialto area that rattled good crystal and bad nerves early Thursday came as no surprise to a group of earthquake forecasters at Jet Propulsion Laboratory in La Canada Flintridge.
"It was on a hot spot,' said Andrea Donnellan, principal investigator for JPL's QuakeSim project.
The seismic team's forecast map for
shows areas likely to experience 5.0-magnitude or greater quakes over a 10-year period. California
Since 2000, 30 of the 38 major earthquakes around the world have hit in QuakeSim team hot spots.
"We've had a significant amount of success forecasting the location of major earthquakes,' said team member John Rundle, director of the UC Davis Center for Computational Science and Engineering.
However, while not writing them off, Caltech seismologist Lucy Jones questioned the usefulness of QuakeSim's long-range predictions, since the team's mapped hot spots coincide with known earthquake zones.
"Maybe they just put (the hot spots) where you're going to have earthquakes anyway,' she said.
The QuakeSim team might do well to test its system to see whether it contributes something more than what is already known, Jones said.
Thursday's quakes in the Fontana-Rialto area the strongest of which was magnitude 4.4 and reportedly was felt as far west as Los Angeles' Fairfax district and as far south as Orange County didn't count toward the QuakeSim team's California forecast, which is based on larger tremors.
However, "it means the stress is being reduced,' Donnellan said.
The cluster of
quakes will be included in ongoing calculations. Fontana
The small shakers occurred very near the large and historically active San Jacinto Fault, which runs from the Fontana-Rialto area through Loma Linda and on to points south.
While Thursday's quakes might have relieved a little stress, it's well known that the northern end of the San Jacinto Fault remains overdue for a major earthquake of 6.0 or greater, Donnellan said.
That bigger quake could occur by Aug. 14, said another group of earthquake predictors.
"We have reason to believe the probability of a strong earthquake in the area is increasing,' said Vladimir Keilis-Borok of UCLA, who heads a team of scientists from the
United States, Russia, Franceand . Italy
However, the 82-year-old Russian-born seismologist and mathematical geophysicist cautions the team's forecasts are only a kind of test, to see whether the forecasting methods actually work.
These scientific data crunchers warned of a major quake last year for a broad section of the
Southern Californiadesert. It didn't happen.
However, in July 2003, the Keilis-Borok-headed team predicted a magnitude-7 or greater quake in a region around
Hokkaido, , by Dec. 28 of that year. On Sept. 25, 2003, a magnitude-8.1 quake rocked Japan . Hokkaido
While Tuesday's quake swarm in the Fontana-Rialto area wasn't calibrated into the latest forecast, Keilis-Borok found the tremors interesting.
Such swarms are "a more rare event,' he said.
The difference between the Keilis-Borok experimental predictions and the QuakeSim forecasts involves both time and territory.
QuakeSim hot spots tend to be very specific areas, with the forecasts covering 10-year time spans. The Keilis-Borok time spans run over months, with targeted areas that are broader, typically covering hundreds of miles.
The Keilis-Borok team has yet to produce sufficiently consistent results, meaning the approach remains an open question, Jones said.
What successes the team claimed may have amounted to no more than random luck, she said. As for its method, "I hope it's true,' she added.
Only time will tell. And Aug. 14 is still seven months away.