Express – Earthquake experts believe two of North America’s most notorious earthquake zones could be linked. A controversial study argues quakes made a one-two punch off the US west coast at least eight times in the past 3,000 years. A quake hit the Cascadia fault off the northern Californian coast, triggering a second quake on the San Andreas fault just to the south. In some cases, the delay between the quakes may have been decades-long. The study suggests the Cascadia fault, capable of unleashing a magnitude 9 earthquake at any time, could trigger earthquakes on the northern San Andreas, a fault running beneath San Francisco.
Several earthquake scientists admitted more work is needed to confirm the provocative idea. Researchers have long considered the two faults seismically separate. Professor Chris Goldfinger, a geologist, and palaeoseismologist at Oregon State University in Corvallis, will present the findings on December 13 at a meeting of the American Geophysical Union in San Francisco. He said: “This is mostly a circumstantial case. I don’t have a smoking gun.” Professor Goldfinger and his team first posited in 2008 earthquakes in the southern part of Cascadia could trigger quakes on the northern San Andreas1. The scientists reported finding layers of churned-up, sandy sediment in sea-floor cores drilled offshore. READ MORE