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Curb enthusiast mourns "repair" of quake-measuring sidewalk

Geology writer Andrew Alden says he will miss a San Francisco-area curb that he calls a scientific "icon."
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This curb in California, that sits on top of the Hayward Fault, has been shifting for decades. (Andrew Alden)
As It Happens6:08Curb enthusiast mourns destruction of quake-measuring sidewalk

Geology writer Andrew Alden says he's disappointed by the demise of the San Francisco-area curb that he calls a scientific "icon."

Geology writer Andrew Alden. (Facebook.com/andrewalden)

The Hayward, California curb sat above the Hayward Fault, which seismologists call the most dangerous fault line in the United States. When it was first installed, before 1970, the curb was flush with the side of the street, but repeated seismic activity gradually shifted it 20 cm into the roadway.

As Alden tells As It Happens host Carol Off, "This curb, which had been there for more than 40 years, was an unusual monument to an unusual part of Earth's behaviour. We were able to visit this place regularly and measure how fast it was moving. Visiting geologists were happy to come there and have selfies taken."

But, when Alden went to visit the curb last week, it was gone. Or rather repaired by city crews. He assumes it was done for safety. Still, Alden says, "I will miss it."

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