The Random Comic Strip

The Random Comic Strip

Words to live by...

"How beautiful it is to do nothing, and to rest afterward."

[Spanish Proverb]

Ius luxuriae publice datum est

(The right to looseness has been officially given)

"Everyone carries a part of society on his shoulders," wrote Ludwig von Mises, "no one is relieved of his share of responsibility by others. And no one can find a safe way for himself if society is sweeping towards destruction. Therefore everyone, in his own interest, must thrust himself vigorously into the intellectual battle."

Apparently, the crossword puzzle that disappeared from the blog, came back.


Tuesday, June 23, 2009

I Think I Felt The Earth Move

I lived in California, as a resident, for some 15 years (off and on... long story) and spent a good part of 4 years stationed there while in the Navy. Earthquakes are a concern in that state, though fires and mudslides ought to be, and I got a bit of an interest in them. I only felt a few mild ones while I lived there, nothing above a 4.0 (and that one was not close by). Still, the threat was enough to make me wonder about the causes and why California is prone to them.

There is the San Andreas Fault, of course. But there's more to it. California is above the eastern side of the Pacific Ring of Fire.


It also involves something called Plate Tectonics. You see, the earth is not nearly so solid, in geologic terms, as one might think. The surface plates (the lithosphere) "float" upon the asthenosphere like a fine crust of dirt layer on a thick mud. These plates butt up against each other along these fault zones. This exerts enormous pressure which eventually gets released and, thus, we get earthquakes.

Ok, that is a very simple explanation. And maybe only partially correct. But it will do for now. A couple of years ago, I noticed there was an increase in activity along the Ring so I went looking around in the internet for more information. And there I found earthquake.usgs.gov which has a nice little alert feature. They will send you emails triggered by quakes in the areas you interested in when they are of a magnitude you set as a threshold. So of course I signed up.

I noticed another uptick of activity recently and went to the site and found something of interest...

This is a map showing activity of a magnitude of 4.5 or greater for the past 7 days. Notice the Aleutian Islands and the cluster in California.



I am not trying to spread fear here, I just find it curious.



[1330/1331/1200]

4 comments:

Cheri said...

Our home sits perched on top of the Hayward Fault, an artery of the San Andreas.

We are due for a major earthquake as they have happened every 140 years and the last one was 140 years ago.

I don't lose any sleep worrying about this...

Famous last words...

Butler and Bagman said...

Actually, very good words...don't lose any sleep over anything...but when awake, keep your eyes open.

Douglas said...

Cheri - While I found a sort of jolly fatalism among Californians regarding earthquakes, I never got the impression they had become completely blase about them. The strongest ones I felt were more exciting than fearsome but I wonder what I would have thought after a really strong one hit my area.

B&B - Californians often commented on why anyone would want to deal with hurricanes when they learned I was from Florida. My response was always "You can see them coming."

Butler and Bagman said...

Actually, very good words...don't lose any sleep over anything...but when awake, keep your eyes open.