He claims the results show that the Newport-Inglewood fault is deeper than scientists previously thought.
Using samples of casing gas from two dozen oil wells ranging from LA’s Westside to Newport Beach in Orange County, Boles discovered that more than one-third of the sites show evidence of high levels of helium-3 (3He).
‘The results are unexpected for the area, because the LA Basin is different from where most mantle helium anomalies occur,’ said Boles, professor emeritus in UCSB’s Department of Earth Science.
‘The Newport-Inglewood fault appears to sit on a 30-million-year-old subduction zone, so it is surprising that it maintains a significant pathway through the crust.’
Compared to the previous assessment issued in 2008, UCERF2, the estimated rate of earthquakes around magnitude 6.7, the size of the destructive 1994 Northridge earthquake, has gone down by about 30 percent.
The expected frequency of such events statewide has dropped from an average of one per 4.8 years to about one per 6.3 years.
However, in the new study, the estimate for the likelihood that California will experience a magnitude 8 or larger earthquake in the next 30 years has increased from about 4.7% for UCERF2 to about 7.0% for UCERF3.
Full Story @ [Daily Mail]