The earthquake coverage over the weekend by CNN and MSNBC was appallingly bad. Utterly unscientific tabloid style journalism. Local coverage in LA was vastly superior. The networks could at least try to have geologists on call. Trump isn’t alone in being anti-science, apparently.
Beautiful little piece of reddish rock, layered, I picked up along the side of the road west of the Salton Sea under the assumption it was chunk of petrified wood. Closer examination at home showed that it is more likely a fossilized and mineralized square inch of beach, or perhaps grains of sand laid down in the bed of a slow moving stream, or in an inlet of the long gone sea. Buried and compressed it hardened into sandstone and then was folded into the earth, under millions of tons or rock, and heated by the mantle below (or perhaps the energy displaced by the slow movement of the fault beneath our feet), which transformed the component sediments into something still layered but harder and more crystalline. Gneiss. Not sure where the red came from. Perhaps this was once one of the red sandstones one sees everywhere in the West, littered with dinosaur bones. There was iron everywhere once, it seems to have turned all the sediments red. Perhaps there was more oxygen in the atmosphere then, enough to turn a tree into a torch at the slam of a baseball bat, enough to oxidize all the traces of iron in the sand into a brilliant red. Perhaps. That’s the theory, anyway.
Now I find this little rock here, in the sand, no metamorphic outcroppings let alone mountains for miles. So water dropped it here. Who knows how much weather that took? How many torrential rains and flash floods were required to drop this little rock here at my feet on these archaic flats? It sat there, glittering in the waning sun, surrounded by the sand verbena that clustered in vast herds across the ancient sea floor. They shivered in the dry wind, as if cold, though the temperature was near ninety and the rock was warm to the touch, as if right out of the oven. I picked it up and rolled it about in my hand, thinking of ancient worlds.
Damn, thought I found this nifty chunk of basalt out near Anza Borrego. It’s got a flat bottom (no jokes) and it is yet another rock I have on my desk for allegedly utilitarian purposes. This one, I told my wife, would make a great paperweight. But I just like rocks. I stood there in the ninety degree heat just west of the Salton Sea Basin, flowers in a zillion colors in every direction, fixated on the rock in my hand. I love basalt. I pictured it forming far below my feet, rising, cooling, a tiny bit of the earth’s mantle cooled and frozen into hard, simple stone. I was hoping it was a billion years old. I always hope basalt is a billion years old. It wasn’t. The basalt in the area was a mere hundred million years or so. Still, it does make a good paper weight, even if it’s a relative infant, mantle wise. There is something fundamental about basalt, a strength, a simple plainness, an assurance that our planet is solid and very real in the vast emptiness of the universe.
But a few minutes ago, eyes drifting from the TV where the LA Kings were being humiliated by yet another Canadian team, I started looking closely at my paper weight again. The lighter, granitic smears bothered me. Why were they there? And I hadn’t paid much attention to the bits of white on the surface. With the Kings collapsing in their own zone again, I grabbed a magnifying glass. It’s not a very good one, but through it I studied those white bits. Damn–structure. I screwed up my eyes and squeezed every bit of nearsighted vision I had remaining. Sure enough, there it was-a cylinder, ringed, tapering. Perhaps some sort of gastropod shell, some kind of pointy shelled snail maybe an inch long. I look carefully over the rock and see similar structure in some other bits. Shells. This is limestone. A very dark limestone. I took it into the kitchen and let water run over it. Wet, it’s nearly black. I found an article online about black limestone, and how to tell it from basalt. Basalt typically contains some larger non-basalt crystals. I pored over the surface of the rock again with the magnifying glass looking for crystals. Nothing. Just little hints of fossils. Bits of living things. This rock is made of organically produced structures that once contained soft bodied, skeletonless creatures, invertebrates. Organisms that needed the shelter of a shell they made themselves. Animals trying not to be eaten.
It dawned on me that I was holding in my hand the end result of the evolution of predators, of meat eaters, because before predation there was no need for shells. Everybody ate algae. There was need for shells or hard body parts or beaks or teeth. But I was holding those long deceased animals’ shells. A half billion years of protection against murder reduced to its basic minerals and a few whole bits and congealed together on the floor of the ocean after the animals shed or died in them, then pressed down by the weight of millions of years of sediments above, then hardened into rock, into this limestone. It’s like holding a handful of millions of untold histories.
The black color? I suppose it’s black the way some shales are black, shales of hardened darkened mud. I really don’t know. Basalt would have been so simple. Formed deep beneath us under the tectonic plates we stand on, and stretched out into ocean floors, then lifted up as the plates crunch into each other, pushed upward into mountains and then broken down again by water and wind and earthquakes, carried along by floods too many to count and left in the dirt at my feet between bunches of violet sand verbena and a few wild poppies. A simple story, basalt. Now I have instead a compacted chunk of the story of life, and I stare at the damn thing and feel hollow.
Oh (he says to a seismically hypersensitive friend), you work in Culver City…. That explains how you felt an earthquake (technically a microquake) that measured 2.8 on the Richter scale. I try to notice nothing below 4.0, but then I am jaded. But Culver City is built on the Los Angeles River floodplain. In fact, the Ballona Creek that trickles unnoticed though the neighborhood was an alternate channel for the L.A. river in its carefree, unchanneled days. And the soil there must be many feet deep, sediments that go who knows how far back, and are more sandy than clay, given the source (the Santa Monica Mountains). What this means for your nerves is that sandy alluvial soils are prone to liquefaction, and amplify the slightest of earthquakes, so that something beneath of dignity of an Angeleno sitting on bedrock, as in my neighborhood, is noticed by highly sensitive types in Culver City. Were it a more manly earthquake, something, say, in the vicinity of an 8 plus, the earth beneath you would be as water and you’d never be heard from again, and Amoeba could at last have what remains of your record collection.
Here’s a link to a convenient map of the Culver City liquifaction zones. They’re in teal. This map is available on Culver City’s official website, though I doubt they tell anyone, since there’s more teal than is tasteful. Teal is best in small quantities. It’s a pungent off-blue and a little goes a long way, like a rank cheese. Also it makes Culver City look so screwed. Like beyond screwed. Like doomed. Which it’s not, really. It’s that damn teal. Pastels would have been much better.
Incidentally, Culver City is the Heart of Screenland.
“Scientists Fear the BIG ONE is Coming as FOUR Major Earthquakes Strike in 48 Hours” exclaimed The Express in proper tabloid fashion. Japan is rocked by four quakes in two days, each over 6 on the Richter scale. Not a terrible quake, a 6.0 or so, but a rocker and scary enough. There were even a couple deaths. Japan handles temblors like this well. They are used to them. Of course seismologists worry that they might be foreshocks announcing a real monster of a quake, though Japan is used to those too. Alas, there is nothing unusual at all about earthquake clusters like the four The Express is screaming about, especially in Japan, where four tectonic plates–the vast North American, Eurasian, and Pacific plates, and the smaller Philippine plate–grind against each other with slow violence. The northern half of Japan is mostly part of the North American plate, the Southern half is the Eurasian plate, and the Pacific plate is forcing itself beneath the Eurasian plate (a process called subduction) at a rate of about three and a half inches a year. Sometimes the subduction process gets stuck for a few years and then, after enough pressure builds up, it moves forward with a jolt. Sometimes it’s a little jolt. Sometimes it’s a 6 point jolt. And sometimes it’s a jolt so big everything shakes to pieces and the sea comes roaring back in a tsunami. That’s Japan. We have earthquakes in California as well, of course, but no one is subducting anybody. Rather our plates are slowly grinding past one another, so that the shaking, even at its worse, cannot get to the same level as Japan is prone to. In Alaska, though, where the Pacific plate is being subducted by the North American plate, you can have earthquakes of astonishing violence, like the one that leveled Anchorage in 1964.
The Express story hinted that the quakes in Japan could set off quakes in, say, California. As if somehow earthquakes were all interconnected. And while earthquakes on the same (or on linked) fault lines can be related theoretically, ones thousands of miles away can’t possibly be, because there would not be enough energy released from an initial quake to go through thousands of miles of solid rock from Japan to California. And the fact that there are four major quakes in 48 hours in a general region–say across East Asia–is just chance, as there are hundreds of quakes 6+ every year and sometimes a few of them happen within a couple day stretch.
Remember that earthquakes, in the grand tectonic plate scheme of things, are extremely minor events, just little quivers, nothing. While to us they can be terrifying, devastating, even catastrophic, in geologic terms they are just everyday things. After all, every great mountain range in the world is the result of literally millions of earthquakes. When you think how few large earthquakes you have lived through living in, say, Los Angeles, you get an idea of the time scale in building mountains, and how we can play no role at all in that process whatsoever. Nothing alive can. Mountains rise and erode as if life never existed at all. Because in the grand scheme of things life means next to nothing, really. Life is just a process for making coal or limestone.
That Puente Hills fault that caused the quake out in Brea yesterday (in 2014) is the one that terrifies geologists. They used to think the Elysian Park fault was the killer–our house sits right atop that one–but it now appears to be dormant. But in the last ten thousand years the Puente Hills fault has snapped in a huge way four times, and each of those quakes was a 7 plus on the Richter scale. That would be ten times at least as powerful as the 1994 Northridge quake. Furthermore, the Northridge fault directed its energy away from downtown (with explains how places as far away as Fillmore were leveled) but the Puente Hills fault would direct its energy towards downtown. I suppose that is how people in downtown last night felt the shaking of a quake centered in Brea so strongly (and why we scarcely noticed while we were out in Tujunga). The Puente Hills fault stretches from roughly Brea to Beverly Hills, and it has three active areas–Brea, Whittier (remember the Whittier Narrows quake in 1987?) and here. And I mean right here…downtown Los Angeles is square in the middle of it, and the zone’s width goes from just below USC to about where I am in Silver Lake. In fact, being that I am typing this while literally astride the Elysian Park fault, our place is just outside the Puente Hills fault zone, not that we wouldn’t shake like hell anyway. We wouldn’t shake as bad as people on the nearby flatlands, their homes built as they are on layers of sediments, but we’ll be shook up something awful. I dread the thought of it. It won’t be boring, anyway. (There was another shaker on the Puente Hills Fault in January 2015 that got everyone’s attention just a few blocks from us but that we literally did not feel at all. Not even the cat noticed.)
The Puente Hills fault is a thrust fault. Everyone knows how the San Andreas fault (which cuts through the Antelope Valley down into the Coachella Valley fairly distant from us) is between two plates that slide past one another. Every once in a while the plates get stuck and then snap apart. The movement is horizontal. West of the fault goes north, east goes south. But a thrust fault is vertical movement, that is the fault zone is thrust upward. As the tectonic plates move, pressures build up in the rock beneath us. Stress fractures appear, which we call faults. Those pressures reach a point where something has to give and when they do, you get an earthquake along one of those stress fractures. Most of the times these quakes are imperceptible to anything but a seismograph machine. Sometimes they are strong enough to wake the cat. Sometimes they are strong enough to set off a flurry of chatter on Facebook. And sometimes they are bigger than that. In a really big quake along the Puente Hills fault zone, the ground will suddenly lurch up a meter or two, meaning that the part of town from USC up through downtown will be instantly elevated above the area south of it. Think of it this way: all the north south streets–Alameda, Hope, Flower, Figueroa, Hoover, Vermont, etc.–would suddenly be unusable, because at some point past Exposition Boulevard there would be a three or even six foot drop straight down. Not gradual, not sloping, but straight down. You will need a ladder to proceed down the sidewalk. That is what huge quakes on thrust faults do.
No one knows when this will happen. It will happen. There is no way it will not happen. But it could be before I finish this post, or it could be in a couple thousand years. Every city on the West Coast from Anchorage (trashed in 1964) to San Diego (my first earthquake memory) faces the prospect of a disastrous earthquake. That is the geologic reality of living on the Pacific Rim. It’s scary as hell if you think about it much, so I don’t think about it much. We try to be a little prepared, though. Just in case. Ya never know.
I wasn’t going to post this. Like maybe it’s too creepy. But maybe people should know. A lot of you do already. But it’s amazing how many residents of this area have no idea what might happen if we roll seismic snake eyes.
Now I need a drink.
And you will too, after seeing this Visualization of a Puente Hills Earthquake. It is in real time, and the color key represents the degree of shaking. Blue is the least violent, green more so, yellow even more and on into the red. You notice that the more intense shaking–the greener, yellower and even red colors, are in the flatlands between downtown and the Palos Verdes Peninsula. The sediments of the basin there are up to six miles deep, laid down mostly when the land was ocean bottom and compressed into the easily crumbled rock that you see in some roadcuts. But the meandering Los Angeles River has over thousands and thousands of years left deep, sandy soils that once made for terrific farmland and now are really prone to intense liquefaction when the ground shakes. There was intense damage in this area after the Northridge quake, probably all of which was caused by liquefaction. The ground under overpasses on the Santa Monica Freeway lost its solidity and the poor things just toppled. That’s an impressive sight, and immense concrete bridge in pieces on the ground. That was the destructive power of liquefaction. And that epicenter was much further away than this hypothetical Puente Hills quake would be. The damage from a 7 magnitude quake in the Downtown area would be exponentially greater. A lot more overpasses would topple. A lot of houses will be red tagged. What a mess.
Probably be some great yard sales, though.
(No idea when I wrote most of this….)
Next time you go up the 5 through the Grapevine, and come to the place where Highway 138 comes in, you’re crossing the San Andreas Fault. Fault zone, really. It’s fairly wide. You can see it on the highway itself, which is in permanent repair–shifting earth makes for busted up concrete. And you can see it in the land itself…take a look at that rippled terrain. It smooths out again as you go towards Gorman. And south of there is just steep hills and canyons/valleys. But right there at the junction you can see how the terrain is being pulled apart and pushed together as the plates grinds past one another. And dig the intense folding in the exposed layers of rock. Hard to imagine the force that can warp and bend solid rock like that. People and everything we are are nothing compared to that sort of force. If you’ve ever been through a serious earthquake you know what I mean. That feeling of being very small and squishy and fragile as huge forces erupt under our feet. And then there’s the whole deep time thing. Our lifetimes barely measure a century, pile up those centuries and you’ve got a hundred, maybe two hundred thousand years and, I’m sorry to say, that’s about as far as human time goes. If you want real recorded history, then you’ve got only a few thousand years. Big things happen in a few thousand years, big human things, civilizations rise and fall. But all those things are nothing in deep time. Just a finger snap. A flicker. A match flaring and going out again. A human lifespan is a nanosecond of deep time. A million years is a small integer in deep time. But the earth happens in deep time. The plates move in deep time. Continents drift in deep time. Rarely does human time and deep time intersect, though when they do it is with terrifying suddenness. The world shakes and big beautiful concrete ribbon freeway exchanges collapse.
You’ll notice that the folding along the rest of the drive is more linear…it still dips and curves, but it appears to be under much less compression, and hasn’t fragmented. I love how you go from the Pacific Plate to the North American Plate right there. The North American plate is some ancient rock, man. Going way back. In the very center–the American Midwest–it’s what they call a craton, a really ancient slab of continent. Flat, with thousands of feet of soil on top. In California the North American plate is what they call orogenic, all tore up and mussed up and stretched and pulled and broken from the plates sliding past one another. All our beautiful California topography and localized ecosystems and microclimates are the result. I think, if I remember my revisionist geology right, that the stuff on the Pacific Plate side is probably all kinds of islands and the like compressed into a mess as the Pacific plate pushed east. So southern California is a conglomerate of junk all moving northeast at a remarkably fast (tectonically speaking) three to four inches a year, while the North American plate is land that has been there a billion years through the comings and goings of various supercontinents. It’s moving, too–the entire surface of the globe is moving and will till the planet’s insides grow cold–but it moves at a comparative crawl and in a southwestern direction. The two massive plates grind past each other. Sometimes they stick in places, and when they unstick all hell breaks loose. That’s what happened to San Francisco in 1906…the plates came unstuck.
If it weren’t for earthquakes and the occasional panic when someone points out a fault running through the middle of Hollywood (perfectly visible to geologists) people would never see the evidence of slowly moving earth all around them. You’d never notice it here in Los Angeles, too many distractions, too many things to do, too many buildings and streets and parking lots and whatever cover it all up. There are faults running every which way through the Los Angeles basin–I’m sitting right on top of the Elysian Park Fault as I type–but people kind of pretend they aren’t there. And though potentially dangerous, these are all just little things compared to the San Andreas. Faults in this town are the result of all kinds of local pressures–basically the Pacific Plate being squeezed up against the North American and everything getting scrunched up and cracking like plaster on a slowly buckling wall–but the San Andreas is the big time, two plates coming together. The earth’s core is so hot that the mantle around it has liquid properties and the crust, the stuff we live on, sort of floats atop it, plates wafting in currents, pushed by the mantle emerging from great fissures in the ocean floor and forming new crust. The plates are shoved into each other. Sometimes one pushes on top of the other and the loser is subducted back down into the mantle. Earthquakes of terrifying power can occur then, bigger than San Francisco’s even–Anchorage was virtually destroyed by one like that in 1963. Japanese civilization sits precariously atop another such subduction zone. Luckily here in California the plates exist in relative peace, pushing past each other. A little rough, but nothing tectonically existential. I know this may seem relative if you live in, say, San Francisco or Santa Cruz or the Coachella Valley or even Gorman. A 7.5 or so earthquake is just as scary to think about as a 9.5. You’ll still lose all the fine china. But the street won’t suddenly drop twenty feet.
Up the Grapevine you can see the effects of all this movement. You can see it because that whole pass is pretty much beyond the reach of civilization. Miles and miles of beautiful nothing and the occasional ranch house or empty farm or inevitable McDonalds. There’s all that land there, all those hills and bluffs and cliffs revealing tens of thousands or hundreds of thousands or even, in spots, millions of years of slow geologic history. You can see the forces at work. But only a frame at a time. Our entire lifespans are only a few feet in geologic time. If you live to be eighty years old and live in Los Angeles the land will have moved north with you on it maybe eight feet. Two hundred human lives laid end to end would see the Pacific Plate move northwest less than a mile. That’s it. And though relatively fast in tectonic terms, it’s not much progress. Just about nothing. Meaningless even. People will come through the Grapevine a thousand years from now and see all those rocks, and the rocks will be in the same place, pretty much, as when I last looked. A few landslides will shift things around, some flash floods. Otherwise, though, you’d never know anything had moved at all. A thousand years from now (and one hundred and twenty five feet from here) you and I will be long forgotten. That is just a hint of geologic time. That is the deep time we flit about in, changing nothing.