Archive for the ‘Other topics’ Category

Lake Merritt’s sister lake

20 December 2021

Fukuoka, Japan is one of Oakland’s sister cities; nothing amazing about that, we have lots of them. But Fukuoka has a special twin it shares with us — a lake converted from an arm of the sea. Fukuoka’s counterpart to our Lake Merritt is Ohori Park.

All photos Wikimedia commons

It’s got boat rentals, a bird island and a Japanese garden, just like we do. It’s in the middle of the old city, just like ours is. But it’s considerably older.

The lake was formerly an inlet at the mouth of the Hii River; then the daimyo Kurodo Nagamasa repurposed it in the early 1600s as part of the moat (ohori) around his brand-new castle, diverting the river and building new land across the inlet’s mouth. To all appearances it’s been a freshwater lake for a long time.

While Lake Merritt has a couple of nice pedestrian bridges in its outlet channel, Ohori Park has four of them crossing the lake from end to end that connect three little islands.

Where we have green, great blue and black-crowned night herons, Ohori Park has the Old World’s gray heron, Nycticorax cinerea.

Ohori Park also has an art museum and a Noh theater. It doesn’t have our free-form public spaces, or our ice-age history and monsters. It’s got a Twitter account, but Lake Merritt doesn’t, far as I can tell. We’re different cities, but our lakes are near-twins.

In Oakland, we’ve been altering our lake for the last 150 years. It started out quite different, as a shallow muddy slough with patches of marsh around it and a muddy shore. It’s been dredged and dammed and armored and built up. Today it’s a highly contrived place, an open-air aquarium.

If we felt like it, we could fill in the channel and make it a one-way floodgate. In not too many years, the lake would turn freshwater, as Dr. Merritt intended when he built his dam back in 1868.

We took this lake into our own hands a long time ago. I like it very much today, but we can change it any time we feel like.

Open thread

8 November 2021

I’m so busy finalizing the manuscript of my book that I can’t find the bandwidth for my accustomed fortnightly post today. There won’t be one in two weeks, either. Next post will be on 6 December. In the meantime, the comments are open so we can talk to ourselves for the rest of the month. (“Did you even know you have selves you can talk to?” Bob Weir reputedly told the audience at a Grateful Dead show as they took a technical break.)

The photo is a fine specimen of mariposite rock from the Carson Hill quarry in Angels Camp. This popular landscaping stone is shot with a green chromian variant of the metamorphic mica mineral phengite. Portions of the deposit are worked for gold as part of California’s continuing gold crawl. The specimen is a recent addition to the rock garden at Lake Merritt.

What’s up with you?

The twilight of California oil

26 April 2021

Last week the governor ordered a state agency to stop issuing fracking permits to oil drillers, starting as of 2024. This is less of a big deal than it seems. Hydraulic fracturing is rarely used in California because the permitting process was tightened in 2014 and because our earthquake-shaken rocks are already well fractured, and only three oil districts do it at all, accounting for about two percent of the state’s production. One place they still do it is in the Lost Hills area, which is fun to drive through if you like taking pictures like this:

This change won’t affect the California oil industry much, but it sounds great and is worth doing.

The governer also ordered another agency to start plans to shut down all oil production in California as of 2045. This is a big deal. Oil is as much a part of California as gold, Shasta and the redwoods. But our oil production has dropped by half since 1985, and now’s the right time to set a deadline. According to a pair of fresh studies, it won’t even start to hurt business for another decade.

Time to start saying goodbye to our old friend.

Natural seeps of oil and asphalt occur all over the state. The one at McKittrick is famous among geologists.

The tar glaciers at Carpenteria State Beach, near Santa Barbara, are a real spectacle.

These materials were used by the native tribes for things like sealing baskets, waterproofing boats and medicine. I’ll bet they made torches with them too.

Americans mined the deposits at first and distilled kerosene from them. That was a dirty business. Starting in 1860, enterprising men tried drilling wells like the first successful ones in western Pennsylvania. The first California oil well to make a profit was drilled in 1876 near Newhall, and we were off to the races.

Petroleum, oil from the ground, was a huge advance. It meant we could stop leveling forests for firewood. It meant we could stop the deadly, wasteful business of hunting whales to make liquid fuels or roasting coal to make gas. No one knew it at the time, but we could invent plastic. The petroleum-based energy and chemical system was eagerly adopted, popular and universal. But today we know how to do even better without it.

As always with this blog, there’s an Oakland angle. The Bay area is oil country.

There are oil seeps in Wildcat Canyon, and the first oil well in the Bay area was drilled nearby, east of San Pablo, in 1862. A short-lived oil field in Orinda, at the Minor ranch on Lauterwasser Creek, pumped greenish crude in the late 1890s. Oakland boosters like H. A. Aldritch, in 1897, were sanguine: “For many years oil has been oozing out of the shale and sandstone formations, and in every instance this oil has been strongly impregnated with gas. That the near future will produce this most promising industry, affording cheaper fuel for manufacturing purposes, is a settled fact. My prediction is that within the next few years Oakland and other cities and towns of this county will be in the full enjoyment of this, one of nature’s greatest blessings.” He was right, but the profitable wells were in the Central Valley.

A large portion of California’s oil originates in the Monterey Formation, a body of ribbon chert found up and down the coast. Oakland has a thick stripe of its close sibling, the Claremont Shale, running through the high hills.

Wherever you see it, it’s generally bleached-looking like this, but underground it’s black with organic matter, from the diatoms whose microscopic silica shells are what make up chert. Diatoms manufacture and store drops of oil inside their shells to help them float, and that oil is what becomes crude oil after cooking underground for geological periods of time.

When the Caldecott Tunnel bores were being dug, oil and gas wafted off this chert and caught fire more than once. During excavation of the fourth bore a few years ago, nothing that could spark was allowed inside. So let it be known: Oakland’s hills are full of oil. I have yet to find an oil or gas seep here, but it’s on my list. I have a theory that one may have had something to do with the great fire of 1991, which burst out in an area where the Claremont Shale is deeply exposed.

Here or wherever, petroleum will always be something to reckon with in California. But we have to start leaving it in the ground at all costs and return it to being a geological curiosity.