Earthquake Science Continues to Evolve

Merry Christmas and a happy New Year to my readers! I should be able to put together another architectural feature sometime this week, but for now, I wanted to share an interesting article from JPL in Pasadena. Remember the Easter Sunday earthquake in Mexico from earlier this year? I remember how we were all at the dinner table, and most of us felt something weird, like the air pressure in the room had changed, but none of us understood what it was, until my sister pointed out the swinging chandelier. "Guess that was a little earthquake." Turns out, it was the largest earthquake in the region in the last 120 years, (Mag 7.2) but we were just about 200 miles away, in Moorpark. As far as I understand it, what my family felt were only the quake's primary compression waves, which are just like really big sound waves moving through the rock. We were (happily) too far away to feel the secondary waves, which roll and twist the rock, and make earthquakes so much more fun!

Anyway, that very well-monitored earthquake has apparently provided scientists with a big pile of new data on the system of faults in the southernmost part of the state, and revealed that it's a good bit more complex, and bigger, than they had ever known. If you're interested, check out this article:

Mexico Quake Studies Uncover Surprises for California


Also, have a look at this video. I don't know for sure, but I think it was filmed alongside the Laguna Salada Mountains, where the quake's main fault is.

7.2 Mexicali Earthquake.MOV

Amazing.


Now, this earthquake did some damage in Mexicali/Calexico, but most of its force was spent in the uninhabited deserts of the region. The scientists at JPL, Caltech, and the US Geological Survey have been reminding us for years that the San Andreas fault and dozens of other significant faultlines run all across the densely populated region of greater Los Angeles. There is no way to specifically predict when an earthquake will occur, but we do know that the southern segment of the San Andreas has historically ruptured about every 150 years. But that makes it about 150 years overdue right now. The USGS created a simulation, called the Southern California ShakeOut, of the force of a rupture along the entire segment, and the damage it could do. You can view the simulation videos on this page, and they're somewhat horrifying, when you consider that the area affected is home to about eighteen million people:

ShakeOut Videos


Now that you're good and scared, here's a handy link:

USGS Earthquake Preparedness FAQ's


California: The world's biggest roller coaster! (You can get off in Alaska in just 250 million years!)