Marks of the Oakland fault

11 July 2016

Two weeks ago I told you how the city of Hayward inadvertently destroyed a special street corner. It was an informal shrine among geologists because it so clearly displayed the creeping motion of the Hayward fault. I mentioned that Hayward still has plenty of other bent curbs.

So does Oakland. Almost nine years ago in this space, in my very second post, I said that Oakland should take over the Hayward fault and make it our own. With that in mind, here are eight places on the fault that are pretty iconic if you ask me. I present them from south to north.

1. Revere Avenue above Marlow Drive, in Sheffield Village.


2. Encina Avenue below Castlewood Street, in Oak Knoll.


3. Ney Avenue near Astor Avenue, just above Fontaine Street.


4. 39th Avenue at Victor Avenue, in Redwood Heights.


5. Medau Place near Moraga Avenue, in Montclair Village.


6. The old firehouse on Moraga Avenue, in Montclair.


7. Broadway Terrace just west of Route 13, in Upper Rockridge.


8. In Lake Temescal Regional Park by the park office.


Here are their locations, shown on the geologic map.


There are more such places between and beyond these ones, and others in Berkeley and San Leandro too.

Changes coming to Mountain View Cemetery’s landscape

4 July 2016

Mountain View Cemetery is one of Oakland’s great civic ornaments for several reasons: its gravestones and tombs commemorate generations of historically important Bay Areans, and its plan was Frederick Law Olmsted’s second significant large-scale project in landscape design after New York’s Central Park. It’s a fine piece of open space that’s used by many different groups of people.


I think of the cemetery as a great civic ornament for two special reasons of my own. First, it’s a superb display of Oakland’s natural landscape as the first settlers knew it.


Second, it’s got some great exposures of Franciscan melange, the mixture of rock types that was created by the tectonic collision between the North America and Farallon plates about 90 million years ago.


The cemetery’s operators are planning to reoccupy and develop the highest part of the grounds, the two heights in this photo taken from the Catholic cemetery next door.


Here’s the view from up there. The cemetery proposes putting in roads and formal structures in the foreground and up on the hill beyond the fence, behind the greensward.


The goal is to accommodate about 1500 more grave plots. A lot of dirt and rock will be dug up and moved around. The plan talks of building up the hilltop and tilting it toward the bay for better views.

The city’s master page for the proposed work is here. The draft environmental impact report is there, plus info on two upcoming hearings (July 11 for the Landmarks Preservation Board, July 20 for the Planning Commission). This month is the public’s most influential time window.

The land beyond the fence is a special bit of countryside . . .


. . . with its own constituency.


It also has its share of rock outcrops. To me these are precious things. Most outcrops in these hills either were blown up during development or are locked up in people’s back yards.


I’m still thinking about what I want to tell the city. But my basic concerns are that the natural character of the land — its contours and vegetation — be respected and preserved as much as practicable. The project will affect a landmark that hundreds of thousands of people enjoy from their own windows and yards.

Olmsted considered these hills the essential setting for the elegant, transformative parkland he planned here in 1863. Mountain View was, and remains, an icon of the City Beautiful movement and a destination for landscape architects everywhere. It and Stanford University (designed in 1888) are the only major Olmsted projects in the Bay area.


This amazing cemetery is Oakland’s cemetery. Let’s speak up to help keep it as beautiful as possible.

An icon lost: The Hayward fault’s Rose/Prospect curb

27 June 2016

Certain places are prized by geologists, especially teachers, for their educational value. Out-of-towners make pilgrimages to them. Sure we all enjoy the Grand Canyon, but real geologists have Siccar Point, Darwin’s outcrop, the Carlin unconformity and other obscure sites on their life lists.

One of those places was right nearby in Hayward, until very recently. At the corner of Rose and Prospect Streets is a corner curb that happened to be built precisely across the Hayward fault, where the steady progress of aseismic creep slowly wrenched it apart.

The best time series of this corner was compiled by Sue Ellen Hirschfeld, a now-retired geology teacher at UC East Bay. It goes back to 1971, and even then there was a sizable offset. Probably the curb was first emplaced in the late 1950s.

It’s a popular site for folks in the know, and there’s at least one Flickr group with lots of photos. The neighbors are probably sick of us, though. I’ve visited it many times, and I sometimes took pictures. This photo is from 2006.


We’re looking east across the fault. This side is moving northward a few millimeters per year. I came back the next year and took this shot of the “echelon cracks” in the street, with the iconic curb in the corner.


In 2012 I brought a few enthusiasts to see it; they asked for anonymity but I can show you where they stood.


A closeup at the time shows that it had a total offset of about 7-1/2 inches, or 20 centimeters, since it was built. The painted arrow at the left shows the offset in the six years since 2006.


Last week I joined a party of visitors there, and to my dismay the corner has been dismantled. It looks like the plan is to put in a cutout for people with disabilities, which is a good thing and undoubtedly overdue. Still.


Anyway, I’m here to put the word out: Rose and Prospect is defunct. It is no more. Come back in 20 years. In the meantime, downtown Hayward is full of other examples of bent curbs.


There’s always the Old City Hall, too, which was built directly on the fault and has long been abandoned. The first time I visited there, maybe 25 years ago, I was looking at the street adjacent to it. As I watched, a little tongue of water emerged in the center of the street and started trickling downhill. Assuming that an old iron water main had just cracked, I found a phone booth and alerted the city. Cleaning up after a creeping fault never ends.