|
| Tuesday, April 18, 2006 |
 |
Perspective 
| |  A binary black hole. That is, a photo of x-rays radiated by two supermassive black holes, consuming the the merging galaxies surrounding them, powering a giant radio source called 3C 75. Here's an explanation, with movies and animations. The two black holes are currently 25,000 light years apart, or not quite as far as we are from the center of our own galaxy, visible as a wide part of the Milky Way, between Scorpio's stinger and Sagitarius — showing best around 4:30am tomorrow morning. (Woops. I see the waxing moon will be parked there. So, wait a few days.)
Anyway, these two supernothings are consuming and/or blasting their respective galaxies to supernothingness, making our own earthquakes (or Earth itself, or the solar system, or even the Milky Way) seem like small potatoes, disaster-wise. |
The biggest name on Earth
| | What you see is about three miles north of Smithville,Texas and 30 miles SSE of austin.I live there.The owner fed-up with with goverment taking the property so he made a deal...As long as he can create something by using what area that can br used.,The goverment will not take it.That's why it's so big an area.On weekend's we go there to party.You can go into the trees and camp there as long as you get permission from Mr Luecke. |
Dining up
One hundred years ago, this minute,
| |  |
| | at 5:12am, Pacific time, the San Andreas Fault ruptured. (Did they have Daylight Savings time then? Not sure.) From its epicenter near San Francisco, the fault tore down to the lower crust, and propogated northwestward to Bodegas Bay and southeastward to San Juan Batista — a total of two hundred and twenty miles. Over the long term, the Pacific plate grinds past the North American plate in a north-northwestern direction at a rate of about one nautical mile every sixty thousand years. In this, the great San Francisco Earthquake of 1906, the Pacific plate jumped two hundred and fifty years. The only California quake in historic time of equal or greater magnitude occurred in 1857 in Tejon Pass, along what we now call The Grapevine section of Interstate 5. (About under the middle I-5 sign on the right side of this map/photo. I live under the 101 sign near the lower left edge.) In the San Francisco quake, the maximum surface movement was twenty feet or so. In the Tejon event, the displacement was thirty-five feet. Both had estimated intensities of 7.9 on the Richter Scale. |
| | Events on the same scale along the southern San Andreas are estimated to occur every hundred and forty-five years. By that estimate, we are four years overdue. |
| | Here in Santa Barbara, about seventy miles from Fort Tejon, the last devastating quake was in 1925. That one destroyed the town's commercial center. Here similar quakes are expected to occur every severnty-five years. So we're six years overdue on that one. |
| | In any case, the movement continues. Here's one shot from the Faultfinding Tour I took with Doug Kaye last year. The section shown here is in the Carrizo Plain, about seventy miles north of Santa Barbara. |
| |  |
| | Since arriving in California in 1985, I've lost count of the quakes I've felt. The biggest by far was the Loma Prieta quake in 1989. At the time I was working at Hodskins Simone & Searls, which occupied about half what had once been a trolley garage, on Hawthorne Avenue in downtown Palo Alto. It was around 5pm, and many of us wanted to get home to see the first game of the World Series between the San Francisco Giants and the Oakland Athletics. We felt the ground start to move, and a number of us said "Earthquake." Then, moments later, the ground moved north, then south again, and the building began to shake violently. As lights swung wildly from the ceiling, bookshelves fell, and crashing sounds were all around us. Everybody was out of the building in a matter of seconds. Standing out front, we watched our parked cars bounce up and down as waves moved up Hawthorne (which told me they were coming from the south). Wires between the telephone poles snapped and sparked at the insulators. Then, even more suddenly than the event began, there was silence. The gound was solid again, like it seems when you step off a boat. One of us turned on a car radio, and scanned up and down the dial. There was nothing. But soon stations came on, and we began to learn the extent of the damage. Early reports said the Bay Bridge was down. (It wasn't, but one dropped section killed a motorist and closed the bridge for quite a while.) The Cypress section of Highway 880 in Oakland had collapsed, killing dozens (early estimates were in the hundreds). The downtown area of Santa Cruz, my favorite town, was all but destroyed. So were Watsonville and other places near the epicenter under Loma Prieta Mountain, between Santa Cruz and San Jose. |
| | That quake was bad, but involved only a twenty-five mile rupture. Rather than ease strain on the fault, it probably transferred strain northward, to the sections closer to San Francisco. |
| | And not all the interaction betwen the Pacific and North American plates in California happens on the San Andreas. Sandwich a deck of cards between your two hands and move your left hand forward. The main break between any two cards represents the San Andreas. The other breaks between other cards represent paralle "strike-slip" faults in the same system. In the Bay Area, the biggest of those is the Hayward fault, where it runs right under hospitals, highways, houses and the stadium at the University of California. Many consider the Hayward fault far more dangerous than the San Andreas. |
| | Stand in western North Carolina, look at the Blue Ridge Mountians, and turn the clock back two million years. What you see at the earlier time will differ little. The Appalachians are an old chain of mountains, long since weathered down to mere traces of their early heights, which were formed 680 million years ago or so. Turn back the clock two million years anywhere in California and nothing recognizable will be there. Some of the rocks in today's mountains may be old (though most aren't, at least by Appalachian standards), but the shapes are new. The Sierras were elevated in just the last couple million years, as part of the basin and range spreading that also produced the washboard series of mountains across Nevada. They are a batholith of igneous plutons: hardened magma that rose under the crust above the melting Farallon plate, which was shoved under North America gradually, over millions of years, after which the Pacific stopped moving toward North America and switched directions to the northwest, forming the San Andreas Fault along the new boundary. Since then displacment of rocks on either side of the fault ranges up to four hundred miles. |
| | Stark violence is still the sire of all the world's values. |
| | What but the wolf's tooth whittled so fine
The fleet limbs of the antelope?
What but fear winged the birds, and hunger
Jewelled with such eyes the great goshawk's head?
Violence has been the sire of all the world's values. |
| | I'm a devout optimist. But I also believe in geology. The most dramatic stories geology tells are violent beyond anything most of us have ever experienced. Given the certainty of their recurrence, mortality itself may be a grace as well. Except, of course, for those whose lives intersect geology's major punctuation marks. More than three thousand died in the 1906 quake, when the Bay Area population was a small fraction of what it is today. |
| | By the way, aerial tours of San Andreas fault portions and their neighbors can be found here, here, here and here. |
Keynotes are (or should be) conversations
| | Just learned, via Jim Grisanzio, that the on-stage conversation between Jonathan Schwartz and myself at Syndicate has, at last, been posted at IT Conversations. It's a long one — over an hour — but it covered a lot of ground, including news that Sun was not only opening the source code for its SPARC chip designs (openSPARC), but that it was considering the GPL as well. (Jonathan and the audience also learned that my background with Sun included work with SPARC International. Near its beginnings in 1989, the main contact between that organization and the world was a phone that sat on my desk.) |
discuss
Copyright 2008 The Doc Searls Weblog
|
Jim Richardson 
