[Image: Photo by Geoff Manaugh].
Lacking any sort of seismically-themed historic preservation plan, this seemed all but inevitable: a city works crew has fixed, and thus destroyed, the amazing offset curb at the intersection of Rose and Prospect in Hayward, California, where seismic “creep” has been inadvertently tracked for decades.
From the L.A. Times:
Since at least the 1970s, scientists have painstakingly photographed the curb as the Hayward fault pushed it farther and farther out of alignment. It was a sharp reminder that someday, a magnitude 7 earthquake would strike directly beneath one of the most heavily populated areas in Northern California.
Then, one early June day, a city crew decided to fix the faulty curb—pun intended. By doing what cities are supposed to do—fixing streets—the city’s action stunned scientists, who said a wonderful curbside laboratory for studying earthquakes was destroyed.
As you can see here, small black lines had been drawn on the curb as a visual aid for helping measure exactly how far its opposing sides had been displaced by so-called “fault creep.”
[Image: Photo by Geoff Manaugh].
The curb on the west is moving north—along with the rest of that part of Hayward, California—while the curb on the east basically marks the edge of a different tectonic plate.
I was there roughly two years ago, looking at fault creep up and down California—primarily along the San Andreas Fault—when I took these shots; at the time, I wrote that the intersection could be thought of as “something like an alternative orientation point for the city, a kind of seismic meridian—or perhaps doomsday clock—by which Hayward’s ceaseless cleaving can be measured.”
[Images: Photos by Geoff Manaugh].
Alas, we’ll have to wait presumably until the 2050s before the curbs offset to anything like they were when these photographs were taken.
(Thanks to Wayne Chambliss for the heads up!)