Hayward’s “D Street” fault creep, curb offset evidence erased

Sadly, improvements in city streets can wipe out geologic evidence. D Street has been a great field trip stop to see earthquake fault creep, and appears in many guidebooks and web sites. But in 1997, Hayward repaved the road, including the sidewalks (they all needed it). When they repaved it, they straightened all the curb lines, thereby erasing the evidence of fault creep. I just visited it in December 2009 (twelve years later), and no evidences of creep has yet presented itself through cracks/offsets in the sidewalk.

But the creep on the Hayward fault in this region is about 0.1 inch per year, so there’s about an inch of stress built up under the sidewalks and curbs. Hopefully (for us geology types), someday soon the sidwalks/curbs will shift, and we’ll be able to return here for tours.

In the photo above, you can see the street runs uninterrupted. The photo is facing east looking across Mission Street.

You can see a photo of the old curb offset on Dr. Sue Hirshfeld’s website here. Her complete tour is here (note: the links on her site have not been updated as of this time, and refer to the old webiste “csuhayward.edu”–if you find any dead links, simply replace the “hayward” portion with “eastbay” and the link will work).