I love and fear earthquakes. The idea that the world itself is shifting beneath me inspires awe. But there’s always a touch of panic in the first second of rumbling, when the length and intensity of the quake is still an unknown. How bad is this going to get? Is this the Big One? Am I about to die in my bed from a collapsing ceiling?
Fortunately last night’s 3:18 am brief reverberation was slight at best. I barely had time to throw the covers off and assess the intensity of the roll before it was over and I immediately went back to sleep. But it was also one of the closest epicenters to my physical location in some time.
The U.S. Geological Survey says the magnitude 3.7 quake occurred about five miles away from my bed last night, uncomfortably close. It struck east-southeast of Marina del Rey near Culver City and Inglewood, at a depth of 5.6 miles. A second quake occurred at 5:27 a.m. and registered a magnitude of 2.4, which I apparently slept through. No damages were reported. No emergency services deployed.
The same cannot be said for western Indonesia, where a magnitude 6.4 quake hit at about 7:30 a.m. and was at a depth of 28 miles, again, according to the U.S. Geological Survey. It damaged 20 buildings, killed one man and sent panicked residents fleeing from homes in towns across Sumatra island’s northern tip.
6.4 is a big quake. Not unmanageable. But scary. And here’s the thing, we in LA are waaaay overdue for something a lot bigger than that.
The Big One Just Got Bigger
Southern Californians know it’s coming. All evidence points to the San Andreas fault heading towards a massive release sometime in the next thirty years. How big will the “Big One” be? For planning purposes we’ve been assuming a magnitude as large as 7.8.
But geophysicists at the California Institute of Technology say it could possibly be ten times bigger than that. Remember, magnitude is measured on a logarithmic scale. An increase in magnitude of one point represents a 30-fold increase in the power of the quake. Half a point can dramatically increase or decrease the destructive power. Meaning a quake that is ten times larger than a 7.8 (absolute, worst-case scenario) would be a rumble of historic and apocalyptic proportions.
The research team found that on April 11, a quake off the western coast of Sumatra clicked in at magnitude of 8.6. Generated from a type of fault system that was previously thought unable to produce quakes that large… and it’s the exact type of fault system as the San Andreas.
Both are strike-slip faults, and it was thought that such faults were not capable of producing quakes bigger than a magnitude of 8.0. Larger quakes than that could only be created by tectonic plates suddenly moving in subduction zones. Something that doesn’t happen on a strike-slip fault line. The Sumatra quake three months ago changed that conventional wisdom. Now we have no idea how big a quake a strike-slip fault can produce.
The April 11 quake occurred on at least four distinct faults and spread east to west, and at one point, simultaneously, north and south, propagating from one fault to the next. The quake movement also extended far deeper than is typical, going way below the earth’s crust and miles into the mantle. With additional depth comes the release of even more energy.
All this drastically changes our model of the San Andreas. Anticipating the impact of a 7.8 quake on the lower San Andreas yielded projections of thousands of casualties and billions of dollars in damage from desert communities to the Los Angeles basin. A handful of downtown’s skyscrapers would collapse and it would be weeks or even months before we could restore utilities and transportation corridors. And that is just at a 7.8.
None of this means that the inevitable future Cali quake will behave the same way the Sumatra quake behaved, of course. But with our understanding now compromised, anything is possible.
The First 15 Min.
In November of last year the LA WEEKLY published an article, “The First 15 Minutes After the Big One“. As the title suggests, it lays out in very precise terms exactly who will live and who will die in the first fifteen minutes of a 7.8 quake along the San Andreas fault line (dear Downtown… you’re fucked). To my mind it’s required reading if you live in the Los Angeles basin, along the Southern California coast or in the desert communities. Click through and check it out.
Life in the Virtual Aftermath
And for something more fun, I just finished playing a short little video game called “I Am Alive”. A real-world survival horror game that takes place one year after a series of constant, massive quakes have rattled all of human civilization. It’s an Xbox Arcade and PSNetwork game, so don’t expect great graphics or a complex interface, but you do get to climb across boats that have been driven into tumbled skyscrapers, hide down in collapsed subways filled with cannibals, and traverse streets so clogged with dust that your health meter falls even as you stand still. The resources are thin. I never once had more than five bullets in my gun at one time. And the combat is difficult. Multiple opponents means strategy on your part, not brute force. It spent years in development, and there are early trailers going back to 2008 (the game came out in 2012) that promised something waaaayyy more interesting then what we eventually got. But it’s still a lot of fun and only consists of about 8 hours of game play, so it won’t disrupt your life too much.
Here’s the trailer…
Welcome to Quakelife, my loves.