New findings by U.S. scientists studying more than 1.8 million earthquakes offers hope, however slight, that a means might be found to predict larger quakes, including the dreaded “Big One” feared throughout California.

A new study published in the journal, Geophysical Research Letters, found that a series of minor tremors preceded a “mainshock” in 72 percent of quakes.

“Here we use a new, highly complete earthquake catalog to show that most mainshock earthquakes in southern California are preceded by elevated seismicity rates -- foreshocks -- in the days and weeks leading up to the event,” said the study.

“Many of these foreshock earthquakes are small in magnitude and hence were previously undetected by the seismic network.”

These observations add a significant missing piece to earthquake prediction. They might help bridge the gap between observations of real fault systems and laboratory earthquake experiments where foreshock occurrence is commonly observed.

The research team behind the study admits a reliable earthquake prediction tool is still years away but are confident their work will play a role in the development of this much-awaited tool.

“We are progressing toward statistical forecasts, though not actual yes or no predictions, of earthquakes,” according to Daniel Trugman, a seismologist at Los Alamos National Laboratory and coauthor of the study. “It’s a little like the history of weather forecasting, where it has taken hundreds of years of steady progress to get where we are today.”

California lives in dread of earthquakes seeing it sits upon the San Andreas Fault, the Hayward Fault and the San Jacinto Fault, any of which can generate devastating quakes. The most fearsome of this trio, however, is the San Andreas Fault that many seismologists affirm is long overdue for a Big One or a quake in excess of a magnitude 8.

“I’m sure you have heard about the San Andreas fault being overdue for an earthquake, so from dating past earthquakes, we know that the average recurrent interval is about 180 years,” according to Dr Thomas Rockwell, a San Diego State University geology professor and paleoseismologist.

“It has now been 380 years since the last large earthquake, so this has led to the idea that maybe we are overdue an earthquake. In any case, it is very clear that the southern San Andreas is certainly ripe for a large earthquake, and the question is; why hasn’t it happened?”