PSN-L Email List Message

Subject: QUESTION about Slip Faults
From: "Jerry Payton" gpayton880@.......
Date: Sun, 27 Jan 2008 11:25:45 -0600


Since it is rather slow now, let me throw out a question that I have never 
had satisfactorily answered to me; directly or reading.

Differentiating between a Left Lateral or Right Lateral Slip Fault's 
movement, the USGS Visual Glossary states: "If you were to stand on the 
fault and look along its length, this is a type of strike-slip fault where 
the left block moves toward you and the right block moves away"

IF I were to turn around looking the opposite direction the description 
would change.  It is all relative to the direction you are facing.  If I 
assumed that I was always looking North, the answer would work.  BUT, not 
all faults run generally North-South.  So, when describing a Right or Left 
Lateral Slip Fault, how does one know what is being described to them? 
There must be some "standard" or "point of view" that explains this.  Or, 
does it matter, as long as you realize it IS a slip fault.

I have spent some time on archaeological digs near the Dead Sea in Israel. 
The Dead Sea Rift transverses through there and is described as moving 
southward on the Israel side and northward on the Jordan side.  If I were 
able to straddle the fault and face North, I could call it a Right Lateral, 
but the reverse is true if I faced South.

Signed: Confused, but not Lost,
Jerry








Since it is rather slow now, let me throw out a question that I = have never=20 had satisfactorily answered to me; directly or reading.
 
Differentiating between a Left Lateral or Right Lateral Slip = Fault's=20 movement, the USGS Visual Glossary states: "If you were to stand on the = fault=20 and look along its length, this is a type of strike-slip fault where the = left=20 block moves toward you and the right block moves away"
 
IF I were to turn around looking the opposite direction the = description=20 would change.  It is all relative to the direction you are = facing.  If=20 I assumed that I was always looking North, the answer would work.  = BUT, not=20 all faults run generally North-South.  So, when describing a Right = or Left=20 Lateral Slip Fault, how does one know what is being described to = them? =20 There must be some "standard" or "point of view" that explains = this.  Or,=20 does it matter, as long as you realize it IS a slip fault.
 
I have spent some time on archaeological digs near the Dead = Sea in=20 Israel. The Dead Sea Rift transverses through there and is = described as=20 moving southward on the Israel side and northward on the Jordan = side.  If I=20 were able to straddle the fault and face North, I could call it a Right = Lateral,=20 but the reverse is true if I faced South. 
 
Signed: Confused, but not Lost,
Jerry
 
 

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