【ANN NEWS, CALIFORNIA】 Federal scientists have updated California’s earthquake risk assessment, showing a further increase in the probability of a damaging major earthquake in the San Francisco Bay Area over roughly the next 30 years. According to the latest assessment from the U.S. Geological Survey, there is a 74.1% chance that at least one magnitude 6.7 or greater earthquake will strike the San Francisco Bay Area by 2055, up from the previous estimate of 72%.
This marks a significant update to the earthquake probability data for the first time since 2014. The update does not mean scientists are predicting that a major earthquake will occur on a particular day. Rather, as time passes and some faults go for extended periods without a major rupture, the models recalculate earthquake probabilities for the coming decades.
Among the major faults in the San Francisco Bay Area, the Hayward-Rodgers Creek fault system is still considered to have the highest risk among individual fault systems, with the probability of a major earthquake rising from 33.1% to 34.3%. The San Andreas Fault saw the largest increase, rising 3.6 percentage points from 21.9% to 25.5%. The probability of a major earthquake on the Calaveras Fault also increased from 25.6% to 26.8%.
About 7.7 million people currently live in the nine-county San Francisco Bay Area. If a shallow magnitude 6.7 or greater earthquake occurs, homes, roads, bridges and infrastructure such as water and electricity systems could all be severely affected.
Seismologist Ned Field said some faults now appear to be in a state of highly accumulated stress and urged residents to be prepared. However, it is important to emphasize that 74.1% does not mean a major earthquake is certain to occur within the next few years, nor can the figure be used to predict the exact date, location or magnitude of an earthquake. Earthquakes still cannot be accurately predicted. The updated data represent a statistical probability over the coming decades, not a short-term forecast that “California’s Big One is imminent.”
For California residents, the real priority should not be online claims of a “countdown to the Big One,” but preparing for emergencies in advance, including storing drinking water, food, medications and emergency lighting equipment, as well as developing a family communication and evacuation plan for after an earthquake.
