NASA Says 99% Probability of 5.0 or Stronger Earthquake Hitting LA
October 21, 2015
JPL geophysicist Dr. Andrea Donnellan, along with seven other scientists, used radar and GPS to measure Southern California’s chances for a sizable earthquake and made a sobering discovery about another big one. NASA scientists' new study reveals that there is a 99.9% probability of a 5.0 or larger quake striking Los Angeles within the next 30 months.
Their study cites the March 28, 2014 La Habra quake in the San Gabriel Valley. La Habra's 5.1 shallow event was a "surprise" for the amount of damage it caused to homes and businesses in the Valley.
Because this quake was only 3-1/2 miles below the surface, over a dozen gas mains broke throughout Los Angeles County, rockslides covered roads, overturned a car and cracked pavement. USGS recorded more than a dozen aftershocks with magnitudes as high as 3.6.
While Dr. Donnellan says last year's quake relieved some stress the strain remains with enough power to unleash an even larger temblor on the same epicenter. A great than 6.0 magnitude earthquake has a 35% chance of striking within this same 3-year time frame.
Image: This image shows the region of interest and the table gives the probably of various sized events occurring within different time frames.
Donnellan and her team expect this next quake to rupture within 60 miles of the La Habra shaker.
Generally 5.5 6.0 quakes cause light damage to buildings and infrastructure, but 6.1 6.9 temblors can lots of destruction in very populated areas. One has only to look at the Bay Area's 1989 Loma Prieta 6.8 quake. It caused considerable damage and killed 63 people. Just five years later the 6.7 Northridge quake caused another 57 deaths.
Donnellan cautions residents to be prepared saying the it's something that should be done all the time. One has to wonder if they're not soft-peddling the likelihood of the larger event taking place.