Is This The Big One?

Quivering Coward writes "There has been a marked increase in seismic activity in southern California in the past several days," pointing to this map from Caltech Earthquake Net, including a 5.2 and 3.6 this morning (2004/06/15). "Could this be the big one? Is 'the big one' ever going to happen? NASA is doing their part to predict the future of Earthquakes."

Comments

Re:What happens when I click on an earthquake?

[elmegil]

Absolutely. Look at the last week...there were actually more, bigger quakes, closer to civilization (the two noted above were over 40 miles from listed cities) a few days ago, and they haven't fallen into the ocean. And the overall trend doesn't appear to be obviously greater than the background levels.

Belive it or not...

[Repran]

...but a russion scientist actually predicted this would happen.

Not Southern Cal

[sfjoe]

Many researchers believe the next major earthquake will be in northern California, not southern California. One reason is that the San Andreas fault 'creeps' in the south, slowly releasing energy (so the theory goes). In the north, the San Andreas is locked and last moved in 1906, when it released all its energy at once, devastating San Francisco.

Re:Not Southern Cal

[WhiteBandit]

The San Andreas fault demonstrates aseismic creep in the central section of the fault, just north of Parkfield. Another area this occurs is around Hollister.

The last time the San Andreas fault moved in Southern California was the 1857 Fort Tejon earthquake.

The last time it moved in Northern California is the 1989 Loma Prieta earthquake.

Despite this, both areas have a high potential for devastating earthquakes. (The section around San Francisco itself last moved in 1908. The Loma Prieta quake was centered near Santa Cruz, quite a ways south of SF).

Re:The San Andreas fault is nice and all, but

[GeoGreg]

Nobody really knows if the New Madrid system is "overdue", as it's difficult to discern a pattern from only one datapoint (the 1811-1812 series of earthquakes).

No It's not the one.

[EvilTwinSkippy]

Wrong fault line. (The 5.5 Earthquake was out in the Pacific.)

In fact, the earthquake patterns on the map show that today is a pretty ho-hum day.

Nothing to see here. Move along.

Re:Yeah, sure..

[Pi_0's don't shower]

Exactly. As every goephysicist knows, you cannot predict earthquakes! We just don't know enough about the Earth's interior, including all the fault lines and their details to be able to do it. The best we can do, as far as I know, is to detect tremors and give a few minutes warning. From the article above, here's what Arthur Smith has to say:

Scientists cannot predict earthquakes - otherwise we would not have so many where hundreds or thousands of people get killed, like the recent one in Japan. After an earthquake has happened there are various things geologists look for in the "fault" associated with the earthquake to give some idea of how long it will be till the next one. The "fault" is the part of the earth's crust where two sections are sliding against one another in some fashion. To make real predictions would require knowing the location of all these faults (some kind of map), knowing at what stage each of them is (how much tension there is and what kind of things are preventing the fault from slipping) and how they interact with one another. Even for very carefully studied regions like southern California, we have only a very small fraction of the information that would be needed for true prediction.

Eh?

[torinth]

What?

I'm sorry, but since when is a tiny 5.2 earthquake followed by an aftershock at the same location even notable?

5.2's are nothing in Southern California, and you can see a map that looks exactly like that maybe once every month or two.

I imagine that what probably threw people off is the extra earthquake that was originally reported by the USGS. That one was supposed to be centered near Lancaster, or some such, but it wasn't long before they took back the claim on grounds of instrument error.

My first time was good

[ee_moss]

That 5.2 was my first earthquake, and it wasn't much. Building kind of shook a bit. Everyone went on with work like nothing. Some people didn't even notice.

Re:Yep, any day now. By which I mean next 100000 d

[hopemafia]

And that is also wrong.
You forgot the real scenario:

California | or / or \ Rest of US...doesn't matter

It's a strike slip fault...California is moving north relative to the rest of the continent at a rate of a cm or two per year, so give it a while (millions and millions of years) and California will border Alaska.

Of course that's a massivly simplified view, but it adequately descibes the situation.

There is absolutely no danger of California ever sinking into the Pacific (sadly), the best we can hope for is global warming melting the icecaps and raising sea level...that would cover most of CA's population with water.

Re:Why, a quake goes off, of course.

[TwP]

NONE of you have ever wondered why the moon only shows us one face? What're the odds?

The moon is gravitationally locked to the Earth's rotation. Tidal forces from Earth's gravitational field have induced a bulge in the moon; this buldge always points along the line from the center of the Earth to the center of the moon. At one time the moon was rotating faster then it is now, but the moon had to bend and flex as this bulge shifted around. Energy was lost to friction (rocks grinding against one another), and the moon's rotation slowed until it was gravitationally locked to the Earth.

But don't take my word for it, I'm just a rocket scientist.

Best website for quake prediction info

[nightherper]

http://www.syzygyjob.com/

Be sure to put on your foil hat, as Jim Berkland is a frequent coast to coast guest

Re:The San Andreas fault is nice and all, but

[Kelson]

Actually, I was just reading about the New Madrid system a few days ago. They've found evidence of past massive quakes in the area around AD 800 and AD 1300, suggesting a possible 500-year cycle.

If that's the case, they're probably safe for another 300 years.