An innocent curb in the Bay Area of San Francisco became the unlikely pilgrimage for geologists back in the early 1970s. Over the course of many years, this curb has slowly crept apart because of the seismic workings of the Hayward fault – a geological fracture that cuts across the east side of San Francisco Bay.
But now this geological cult icon is gone after an undignified destruction. One day in early June, city hall demolished the curb to make way for a wheelchair-accessible ramp.
The red curb and gray curb were originally flush with each other when it was constructed more than 50 years ago. Each year the two curbs became progressively further and further apart from each other, shifting an incredible 20 centimeters (7.8 inches), as a result of the fault's gradual "creep".
“It really was an iconic location on the Hayward fault,” David Schwartz, a US Geological Survey geologist, told the LA Times.
You can head over to the blog of Sue Ellen Hirschfeld, a retired geology teacher at UC East Bay, which features photographs of the curb recording the fault shifts, taken over thirty years, with the earliest from 1971. There's also a Flickr album of the Hayward Fault that documents many images of the curb.
The 72-kilometer-long (45 mile) Hayward fault has generated twelve major earthquakes in the last 1900 years – creating an earthquake on average every 160 years. The last of these large earthquakes was in 1868, 140 years ago. Although its effects were particularly noticeable on this curb, the fault splinters beneath many of the city’s major roads and buildings.
Schwartz mourned the curb’s untimely demise, saying how he felt it could have truly brought geology to life for the public: “If it was up to us, we would put signs up on all of these active faults… I think they’d [the authorities] think it’s negative publicity. But I think it’s informative to the public,” he said.
Nevertheless, he ominously concluded: “The fault will have its revenge.”
Main image credit: missyleone/Flickr (CC BY 2.0)