Southern Californian seismologists are organizing a center to evaluate earthquake predictions in the hopes of developing better forecasts for the potentially deadly events.
Thomas Jordan, director of the Southern California Earthquake Center in Los Angeles, told reporters Sunday that while his center has experienced some success forecasting smaller earthquakes in the short term, forecasting when a large earthquake might strike is still challenging.
Based at the University of Southern California, the center's researchers are developing the methods and criteria required to evaluate earthquake predictions. The center is also are organizing a facility dubbed the Collaboratory for the Study of Earthquake Predictions, which Jordan plans as a resource where seismologists can test their own temblor forecasts.
"I would say that most seismologists, myself included, are pessimistic that in the next five years we can come with a silver bullet solution to predicting earthquakes," Jordan said during a press briefing here at the annual meeting of the American Association for the Advancement of Science. "But there are still signals we can look for."
High-energy signals
In recent years, seismologists have begun studying high-energy signals emanating from the base of Earth’s crust, about 20 miles (30 kilometers) below the surface. That’s about twice as deep as the level where shifting tectonic plates slip and slide against each other to create earthquakes, Jordan told LiveScience.
Seismologists have detected the high-energy signals emanating from beneath a tectonic plate boundary under the Pacific Northwest, as well as beneath Japan and — most recently — from the San Andreas Fault in California.
"We don’t understand these signals very well," he added. "They may not have anything to do with earthquakes — then again, they may mean something."
Deadliest year
Earlier this month, the U.S. Geological Survey announced that 2004 was the deadliest year for earthquakes in 500 years, ending with the disastrous magnitude 9.0 temblor that struck Indonesia, causing a tsunami that eventually killed 275,950 people. Less than 1,000 people were also killed in 2004 during other earthquakes around the world.
On Saturday, news services reported that a 6.9 temblor shook Indonesia’s Sulawesi Island and caused sea levels to rise, frightening inhabitants there who feared another tsunami.
The largest earthquake in the United States during 2004 was a long-awaited magnitude 6.8 temblor that struck southeastern Alaska. A smaller earthquake — a magnitude 6.0 — occurred on Sept. 28 in Parkfield, Calif., a long-awaited event originally predicted by seismologists in the 1980s.
"We had two events that show how far we still have to go," David Applegate, USGS senior science advisor for earthquake and geologic hazards, said during the briefing, referring to the Parkfield and 9.0 Indonesia events.