earthquake - Page 2

Sten Sture · April 29, 2003, 14:53

Florida could just pour into the Gulf like salt out of a shaker with the lid removed - so there is always that hope!

Spiffor · April 29, 2003, 15:01

The R scale isn't a sufficient indicator for the violence of an earthquake. Two earthquakes with the same R scale can be completely different in their violence at the surface.

Do you remember the murderous earthquake of Cairo ? There was an exactly as strong Earthquake in Maastricht shortly after, which was nearly harmless. The different natures of the ground explained why the violences were so different.

My highschool geology teacher explained the difference with this example :
He took one leaf of paper in one hand and punched it with the other. As expected, the leaf of paper feeled the punch dearly, and shook as hell.
He then took a whole pile of paper and punched it with exactly the same strength. The pile of paper hardly shook.

Jonny · April 29, 2003, 17:19

Quote:

Originally posted by Lincoln
I felt it in middle Tennessee. Kind of rare for this area.

I'm in west Nashville, and I didn't notice it. Of course, I can sleep through pretty much anything.

Other people in the house did feel it, though.

PLATO · April 29, 2003, 18:03

Quote:

Originally posted by Jonny

I'm in west Nashville, and I didn't notice it. Of course, I can sleep through pretty much anything.

Other people in the house did feel it, though.

Vandy?

Sten Sture · April 29, 2003, 18:09

edit: wife went to Vandy by the by...

speaking of shake amplification, this pic show why SF is not the best place to be to ride the rollers:

TCO · April 29, 2003, 18:18

Quote:

Originally posted by Sten Sture
edit: wife went to Vandy by the by...

speaking of shake amplification, this pic show why SF is not the best place to be to ride the rollers:

Yeah, the areas built on mud will get it hard. My cousins live at the top of a rock hill in Redwood City, so they would be fine.

Sten Sture · April 29, 2003, 18:36

Bedrock to the west, landfill to the east - what would you choose??

Oerdin · April 29, 2003, 18:58

The most potentially damaging part of an earthquake is if the shaking becomes so violent that the ground undergoes “liquefaction”. Liquefaction is where the sediments get shaken so bad that they end up getting suspending in the ground water much the way fat is suspended in a glass of milk. Liquefaction is most likely to occur in a large sediment basin which has a hard rock basement material because this sort of configuration reflects the motion waves back into the effected area the same way a magnifying glass concentrates light.. The energy waves bounce around and reflect off of the hard rock basement and the result is the water in the sediments is shock so violently that the sediments actually get suspended in the water and the ground will flow like a liquid. Because the ground is behaving like a liquid the buildings built on top of the unlithofied sediments will actually partially sink into the ground and/or fall over. Even large skyscrapers and elevated freeways which have been made "earthquake safe" can not be made safe against sever liquefaction.

So is this just academic or is some part of the world actually have geology like this? As a matter of fact the LA basin has exactly this type of geology. Remember that the next time you’re driving down the Hollywood freeway.

Ted Striker · April 29, 2003, 21:28

I thought that was you humping GP.

Rock the house yall.

thanks

Odin · April 29, 2003, 22:10

The New Madrid Fault has given me a hypothesis that in a few million years North COULD split in half. It could form a full-blown rift valley, like in Africa. There was a show a the Discovery Channel about it a while back, and I have wondered since if it may be the beginnings of a new plate boundary.

Jonny · April 30, 2003, 21:48

Quote:

Originally posted by PLATO1003
Vandy?

No, further west, over in Cheatham County.