: sfchronicle – excerpt
The earthquakes hit just days after last year’s near-catastrophe at Oroville Dam, when the spillway cracked amid heavy rains and 188,000 people fled in fear of flooding.
The timing of the two small tremors about 75 miles north of Sacramento was curious, and frightening. Were the quakes part of a seismic hot spot that caused the giant concrete spillway to tear? Was the weight of the water behind the dam triggering the quakes? Could all of Lake Oroville be prone to slipping?
A group of seismologists, summoned from the U.S. Geological Survey’s research facility in Menlo Park, was put on the case. Their findings were published in the Bulletin of the Seismological Society of America on Monday…
Fortunately, the researchers concluded, the nation’s tallest dam is not in imminent danger. They don’t think earthquakes caused the fracture. Just the opposite may be true, they said… (more)