Hi George,

I will do a flimsy attempt in answering you question.  Yesterday, I received 
the August issue of  EARTH magazine with contained a sort article about the 
Nazca Plate adjacent to Peru.  The article was titled Peruvian Plates Move 
With and Without Earthquakes.

If I understood the article correctly, it was asking the question as to why 
a block of the plate might move seismic and another part generate an 
earthquake.  It pointed out that the majority of the earthquakes occur 
inland and not actually off shore at the subducting ridge itself.

In humble opinion, that may be because of lubrication from the seawater, 
which would be less and less at the wedge-shaped plated subducted underneath 
the South American Plate.  THAT is strictly a guess on my part, as I have NO 
technical training in geology or seismology!

In regard to your question, I would think the same process "may" be in play 
there and there may or may not be a direct interaction, who knows.  One 
might think that jostling a already stressed block might cause it to 
release; and again it might just lessen the stress.

I'd be interested in others opinions.  Who knows, I might learn 
something........Naaaaaa.

Regards,
Jerry

--------------------------------------------------------------------------------

  ----- Original Message ----- 
  From: George Bush
  To: psn-l@..............
  Sent: Sunday, July 18, 2010 4:32 PM
  Subject: What are the implications of a M2.8 quake near the San Andreas 
fault?


  Hello-

  This morning we had a M2.8 quake about 4 miles west of us out in the
  ocean and about 5 miles from the San Andreas fault that runs to the
  East of us. It was on a minor fault that runs parallel to the San
  Andreas. The shock knocked my data acquisition computer off-line, but
  was strong enough to jiggle the pen on my drum recorder that also was off 
line!

  I am wondering if the movement of the minor fault will add strain or
  relieve strain on the San Andreas fault (add or decrease the chances
  of the San Andreas fault letting-go).

  I would appreciate any thoughts or opinions on this from you PSN folks.


  George Bush
  Sea Ranch, CA, USA
  38.73775N, 123.48882W

  __________________________________________________________

  Public Seismic Network Mailing List (PSN-L)

  To leave this list email PSN-L-REQUEST@.............. with
  the body of the message (first line only): unsubscribe
  See http://www.seismicnet.com/maillist.html for more information.







Hi George,
 
I will do a flimsy attempt in answering you question.  =
Yesterday, I=20
received the August issue of  EARTH magazine with contained a sort =
article=20
about the Nazca Plate adjacent to Peru.  The article was titled=20
Peruvian Plates Move With and Without Earthquakes.
 
If I understood the article correctly, it was asking the question =
as to why=20
a block of the plate might move seismic and another part generate an=20
earthquake.  It pointed out that the majority of the earthquakes =
occur=20
inland and not actually off shore at the subducting ridge itself.
 
In humble opinion, that may be because of lubrication from the =
seawater,=20
which would be less and less at the wedge-shaped plated subducted =
underneath the=20
South American Plate.  THAT is strictly a guess on my part, as I =
have NO=20
technical training in geology or seismology!
 
In regard to your question, I would think the same process "may" be =
in play=20
there and there may or may not be a direct interaction, who knows.  =
One=20
might think that jostling a already stressed block might cause it to =
release;=20
and again it might just lessen the stress.
 
I'd be interested in others opinions.  Who knows, I might =
learn=20
something........Naaaaaa.
 
Regards,
Jerry




  
----- Original Message ----- 
  From:=20
  George =
Bush 
  
To: psn-l@.............. 
  
Sent: Sunday, July 18, 2010 =
4:32 PM
  
Subject: What are the =
implications of a=20
  M2.8 quake near the San Andreas fault?
  

Hello-

This morning we had a M2.8 quake about 4 =
miles=20
  west of us out in the 
ocean and about 5 miles from the San Andreas =
fault=20
  that runs to the 
East of us. It was on a minor fault that runs =
parallel to=20
  the San 
Andreas. The shock knocked my data acquisition computer =
off-line,=20
  but 
was strong enough to jiggle the pen on my drum recorder that =
also was=20
  off line!

I am wondering if the movement of the minor fault =
will add=20
  strain or 
relieve strain on the San Andreas fault (add or decrease =
the=20
  chances 
of the San Andreas fault letting-go).

I would =
appreciate=20
  any thoughts or opinions on this from you PSN folks.


George =

  Bush
Sea Ranch, CA, USA
38.73775N, 123.48882W=20
  =


__________________________________________________________
Public=20
  Seismic Network Mailing List (PSN-L)

To leave this list email =
PSN-L-REQUEST@...............
=20
  with 
the body of the message (first line only): unsubscribe
See =
http://www.seismicnet.co=
m/maillist.html=20
  for more information.