Recent studies of past earthquakes indicate that there is a relationship (correlation) in time between seismic events on the northern San Andreas Fault and the southern part of the Cascadia subduction zone (which stretches from Vancouver Island to northern California). The San Andreas Fault goes into the Pacific Ocean near San Francisco where it links up (underwater) with the Cascadia Subduction Zone, in northern California. Scientists believe quakes on the Cascadia subduction zone may have triggered most of the major quakes on the northern San Andreas within the past 3,000 years. The evidence also shows the rupture direction going from north to south in each of these time-correlated events. However the 1906 San Francisco earthquake seems to have been the exception to this correlation because the plate movement was moved mostly from south to north and it was not preceded by a major quake in the Cascadia zone.
A study in 2006 concluded that the San Andreas fault has reached a sufficient stress level for the next "big one", or a M ≥ 7.0, to occur. It also concluded that the risk of a large earthquake may be increasing more rapidly than researchers had previously thought. The paper stated that, while the San Andreas Fault had experienced massive earthquakes in the central (1857) and northern (1906) segments, the southern section of the fault has not seen any similar rupture for at least 300 years. Such an event would result in substantial damage to Palm Springs and other cities in San Bernardino, Riverside and Imperial counties in California, and Mexicali municipality in Baja California. It would be felt throughout much of Southern California, including densely populated areas of San Bernardino, Los Angeles, Orange County, San Diego, Ensenada and Tijuana, Baja California, San Luis Rio Colorado in Sonora and Yuma, Arizona.
As both the public and scientific community continue to speculate on the size of the next earthquake to strike California, predicting major earthquakes with sufficient precision to warrant taking increased precautions has long been sought but remains elusive. Nonetheless, the 2008 Uniform California Earthquake Rupture Forecast (UCERF) has estimated that the probability of an M ≥ 6.7 earthquake within the next 30 years on the northern and southern segments of the San Andreas fault is somewhere between 21% and 59%, respectively.
The probability of a magnitude 6.7 or larger earthquake over the next 30 years striking the greater Los Angeles area is 67%, and in the San Francisco Bay Area it is 63%, similar to previous Working Group on California Earthquake Probabilities | WGCEP estimates (see Figure 3). For the entire California region, the fault with the highest probability of generating at least one magnitude 6.7 quake or larger is the southern San Andreas (59% in the next 30 years; see Figure 4). For northern California, the most likely source of such earthquakes is the Hayward-Rodgers Creek Fault (31% in the next 30 years). Events of this size can be deadly, as shown by the 1989 Loma Prieta earthquake (magnitude 6.9) and 1994 Northridge earthquake (magnitude 6.7).
Please also review my prior posting:
- On a lighter side of life in BC: My Personal Blog / Web Site: Stan G. Webb©
- On a darker side of life in BC: This Website Cascadia Megaquake - Cascadia Tsunami and Megatsunami (also known as Iminami)
- Environment Canada current and 6 Day Weather Forecast for Vancouver, BC, Canada
- The Air Quality Health Index (AQHI) - Metro Vancouver - NE||Metro Vancouver - SE|Metro Vancouver - SW|Metro Vancouver - NW|Eastern Fraser Valley
- Alternatively you can use a BC provincial interactive map to get to the AQI Readings: For Example: Air Quality in North Vancouver, BC (A BC Interactive Map will open >> click on Metro Vancouver (see inset) >> then Click for stations in Metro Vancouver and the Fraser Valley >> Then Click on Current Air Quality Readings: Mahon Park (the testing station is located on the roof of the Fenn Stadium)
- 1. At the bottom right of any YouTube video click on the gear icon and change the quality of the image from HD 1080p, down to, say 144p, then try increasing it slowly.