dailyloe.com – Experts are sounding alarms regarding the potential threat of ‘The Big One’ in California. A study from Oregon State University reveals that a seismic event in the Cascadia subduction zone could trigger a catastrophic response along the San Andreas fault line.
Chris Goldfinger, a marine geologist and lead author of the study, stated, “We’re used to hearing the ‘Big One’ – Cascadia – being this catastrophic huge thing. It turns out it’s not the worst-case scenario.”
If both the Cascadia and San Andreas faults were to activate simultaneously, it could result in an emergency spanning multiple states and even an international crisis affecting San Francisco, Portland, Seattle, and Vancouver.
Goldfinger noted that such an occurrence would tax national resources extensively. He emphasized, “We could expect that an earthquake on one of the faults alone would draw down the resources of the whole country to respond to it.”
In a simultaneous quake scenario, cities like San Francisco and Seattle might face emergencies within a compressed timeframe. This situation would complicate resource allocation and response efforts.
The research team led by Goldfinger studied ancient sediment layers known as turbidites from both fault systems. They identified significant similarities in timing and structure, indicating potential seismic synchronization between the faults.
This critical finding stemmed from an unexpected navigational error during Goldfinger’s research in 1999. He mistakenly drilled into the San Andreas zone instead of the Cascadia area, leading to the discovery of sediment cores that were pivotal to their research.
The team utilized carbon dating techniques to analyze the unique layering in the cores, supporting their theory of simultaneous earthquakes. Goldfinger pointed out that there have been very few recorded instances of concurrent quakes over the past 1,500 years, with only three such occurrences noted.
The last documented instance of simultaneous quakes occurred in 1700, when ruptures between fault lines were separated by mere minutes to hours. The original study, titled “Unravelling the dance of earthquakes: Evidence of partial synchronization of the northern San Andreas fault and Cascadia megathrust,” was published in September 2025.
Interestingly, only one observed case of synchronized earthquakes occurred in Sumatra, with tremors recorded three months apart in 2004 and 2005. This research emphasizes the pressing need for further examination of the interconnectedness of California’s fault lines and the seismic risks they pose.
