I had two days in San Francisco for my book launch – but then decided to add on two days to visit my old friend Donald, who now lives in Berkeley. Donald and I studied geology together at San Diego State University in 1985-86 (which means went on a lot of field trips, and crossed the border frequently to go down to Ensenada to eat fish tacos and lobster dinners, and drink margaritas and Coronas). Lots of great memories from those days (but how did we get so old?) Unfortunately, Donald’s wife Wiz was away for the weekend, so I missed visiting with her, very poor timing there.
So Donald’s weekend consisted mainly of driving his two kids around to soccer games, and trying to find a few moments to work on a scientific paper he is about to submit for publication. His specialty in geology is studying presently active faults (all related to the San Andreas Fault system), so they can work out how often they move and what kind of risk they present to buildings constructed near them.
On Sunday, while Donald was on his kid-driving duties, I went for a run up the hills above Berkeley downtown. When I showed him the route I was thinking of running, heading along from his house then up Dwight Street, he mentioned to me that the active Hayward Fault crosses the top of that road, and that you can actually see how it offsets the curb there. According to Donald, the fault moves at a long-term average of about 9 mm per year. About half of that movement takes place as “fault creep,” which means the fault is actually constantly slipping by
that amount (no earthquake: that gradual movement is what is cracking the pavement and offsetting the curbs). But the other half of that movement gets stored as elastic strain which builds up, and when that strain is released the fault moves, producing an earthquake. The last big quake on the Hayward Fault was in 1868 (magnitude 7.0), and Donald tells me that the recurrence interval for that fault is about 140 years: which means it is overdue! I was hoping that it would slip then, while I was there actually watching the curb… but no such luck.
The view from up there was amazing! I could look down on the city of Berkeley, as well as see right across the bay to San Francisco. The new Bay Bridge, which just opened up on Monday, is visible in the centre middle-ground of the photo. In the distance, you can see the fog bank surrounding the Golden Gate Bridge; one spire of the bridge is poking up above it on the extreme right side of the photo (click on the photo to enlarge it). Looking down on that fog, I realized just how lucky I was on my sunny run over there the day before.
The trail was quite steep, and slick: dry, hard-packed clay, but with a slippery surface of loose clay. Definitely not great for my road runners. I had been planning to loop around to my right and descend via some other trails, but there is no way I wanted to be going downhill on those slick steep slopes in road runners. So, instead, I looped around to my left to descend through the ritzy neighbourhoods of upper Berkeley.
I ran down the switchbacks. There was a guy walking in front of me who I passed… but when I rounded the next switchback, he was in front of me again! That happened several times – made me realize that there were stairways between the houses for pedestrians to cut the switchbacks. But it was faster for me to just run down than to try to look for them.
I finally descended to the upper side of the UC Berkeley campus – it seemed really empty to me, but then I remembered that today was Sunday – and eventually I meandered my way down through it to find a place for lunch in town. In the end, it was as much a hike as a run… but again, a great way to tour around and experience a place first-hand!