Archive for the ‘Oakland hazards’ Category

The coming trauma

17 October 2016
US Geological Survey photo by John Nakata

Ruins of the Cypress Structure after the 17 October 1989 earthquake. US Geological Survey photo by John Nakata

When the giant Tohoku earthquake struck Japan on 11 March 2011, followed by a colossal tsunami and the crippling of two nuclear power plants, the effects rippled out in many directions. In my chosen community of Earth scientists, there were many phenomena to investigate; in the engineering community, many case studies to enter in the record; in the disaster-response community, many failures to learn from.

To Takashi Murakami, a Japanese artist based in New York, it was the chance to accept movie director Yoshihiro Nishimura‘s invitation to work together on a feature film project at a time when movie crews were unexpectedly idle.

The story Murakami chose to tell grew out of witnessing the extensive failures of the nation’s authorities, failures that everyone saw firsthand. Lest we forget, the Pacific coast of northern Honshu was first laid in ruins by the earthquake and then overwhelmed by the tsunami. Both were larger than anyone, even the experts, foresaw. The tsunami in turn caused the explosive failure of the Fukushima Number 2 nuclear power plant, spewing radioactive material over a large — still depopulated — area of land.

Murakami drew upon his childhood exposure to gojira monster cartoons, his experience teaching kindergarten and his love of modern anime to craft a cathartic exploration of the Tohoku trauma, costumed as a children’s fantasy. Just two years later the resulting film, “Jellyfish Eyes,” was released in Japan. The Oakland Library has a copy of the Criterion disk, issued in 2015.

In “Jellyfish Eyes” a newly fatherless boy, Masashi, is displaced to a strange and challenging city. He meets and adopts a hovering, spritelike creature who befriends and protects him from similar creatures controlled by his new classmates. These “friends,” supplied by an advanced research lab in the city, are part of a scheme by renegades in the lab to harvest negative emotions from the children, especially Masashi, and acquire a new source of cosmic power. A classic Godzilla plot provides the climax, and the “friends” become benign at the end.

Critics faulted its quick-and-dirty CGI, stylized plot and cartoon visuals. I’m not sophisticated enough a film viewer to care. Those things work. I appreciated Murakami’s singular focus on his audience of Japanese children, a traumatized generation with its own culture and its own need for sensitive candor. I appreciated that he avoided studio financing, knowing that funders would insist on removing the blood (a few drops) and radiation (a few mentions).

“Jellyfish Eyes” is authentically Japanese, as it should be. American viewers won’t get all the hat-tips and references. But they should be able to easily see the deep emotional story beneath the plot — how a disaster hurts and how we can come back from one.

In Oakland, we have an overwhelming earthquake in our own future. We all know it will destroy things no matter how well we prepare. We know the government, whatever it does, cannot do enough. How will our youngest children respond? How will we respond to their needs? Until our own Murakami can rise to the occasion, we’ll have to study the experience of others and do the best we can.

Fallen trees

30 May 2016

Naturally, the people of a city named Oakland cherish their trees.


But trees are living things, and every one must die at some point. After years of drought plus one wet winter, I’ve noticed a lot of downed trees. This one was in Leona Heights, an oak. When oaks topple, that’s the end of them.


This one, a bay laurel, was in Joaquin Miller Park. Fallen bay trees commonly reroot, which is a handy thing in their preferred moist habitat.


Fallen trees may interest field geologists because as their roots rip out, they expose the bedrock in areas with thick vegetation. Thus information from “tree throws” can help in mapping the rocks. For instance, I inspected the rocks uprooted by this tree . . .


. . . and noted that they were typical mudstone of the Joaquin Miller Formation. The park is the formation’s type area, after all.


Another treefall farther downstream exposed serpentinite. (The two very different rock types are separated by the Chabot fault.)


Sometimes data points like these are the only way to get a handle on steep, vegetated terrain.

Research-type geologists consider “tree throw” a significant actor in the evolution of wooded landscapes (here’s a taste from a recent conference).

Down by the water, especially along the smaller creeks, fallen bay laurels often span the stream and root on both sides. Sometimes it’s charming, like here above Dunsmuir House, but it’s usually a hassle if you’re trying to walk along the streambed.


To hydrologists — geologists who specialize in streams — fallen trees are a crucial part of stream systems. Natural streams always contain some amount of dead wood, because it lasts for years before it rots away or burns up.

Wood doesn’t act like sand and gravel. It doesn’t wash away easily, it sticks around and snags stuff. So making a realistic model of stream behavior requires a sophisticated understanding of how this “wood load” affects the water. Hydrology journals publish a steady trickle of papers on this topic.


Most of us would rather that trees stayed standing and streambeds stayed clear. That only happens in landscaped parks. To know nature, you have to learn to appreciate snags.

Earthquake mitigation at Oakland City Center

18 April 2016

Today is San Francisco Earthquake Day. Just before dawn on this day in 1906, at 5:13 local time (meaning 6:13 daylight time), a rip in the crust off Ocean Beach started tearing its way north and south along the San Andreas fault, setting in motion one of California’s greatest defining events.

At the Oakland City Center and the Clorox building, at 1221 Broadway, you’ll see this odd feature on the ground.


It’s a long steel ribbon that covers a pair of long sawcuts in the pavement about 3 inches apart. Between the cuts, the tile has been pulled out and replaced with a flexible gasket. One edge of the steel ribbon is anchored to the tiles, but the other edge is loose.

That’s a retrofit for big earthquakes. During a moderate-to-major event, say magnitude 5-1/2 or larger, the Clorox building will shimmy back and forth, and so will the buried BART station. Because of their different sizes and dimensions, they won’t move in unison. Without the gasket in the pavement, the tiles in the rigid pavement will buckle and shatter and fly in all directions, leaving one more mess to clean up that will probably fester for years.

The gasket promises to prevent that. If you’re here when the next sizeable earthquake hits, and you have the presence of mind (not guaranteed!), watch it work. The free side of the steel ribbon should slide over the ground while the gasket cushions the two sides of the cut beneath it.

This won’t prevent all damage, and it may not matter at during the biggest quakes we can get (magnitude 7 and maybe 7.5), but for the much more abundant moderate events it will save us some grief.