From: alden@netcom.com (Andrew L. Alden)
Subject: Re: Parkfield
Organization: Netcom - Online Communication Services  (408 241-9760 guest) 
Distribution: ca
Date: Wed, 23 Dec 1992 19:23:37 GMT

andy@pangea.Stanford.EDU (Andy Michael USGS Guest) writes:
: 
: >This simple model was, it seems, quietly discarded a while back.  Jim

: No, it was disagreed with by Jim Savage.  Bakun, Lindh, and others did
: not necessarily agree with him.  Discarded seems like a strange word.

Well, I don't see much work these days that uses such a model; look at
the other abstracts from that Friday afternoon session, for instance.  I
suspect that researchers did not hold their breath from 1988 til now
(the end of the experiment) to reject the Bakun-Lindh model, but
proceeded to make more realistic and fruitful models.  "Discarded" may
be strong--more like "abandoned." 

: No one ever suggested that the Parkfield experiment was a test of the
: characteristic earthquake hypothesis.  The instrumentation at Parkfield
: is there to record details of the preparation period before an
: earthquake, the earthquake itself, and the time period afterwards in
: great detail.  

All the public knew was that the government (NEPEC) had forecast a quake
before 1993, and the USGS would set up a monitoring and warning system
for our benefit.  That forecast was absolutely based on the 22-year
repetition model, and the factors you cite--assessing precursors,
rupture dynamics etc.--are consequential, not constitutive.  The
forecast, based on that model, drove the whole enterprise.
: 
: >I don't begrudge a dime paid for the experiment, even though the
: >hypothesis ostensibly being tested was ridiculously simple.  My question
: >is, was that hypothesis used because even Congress could understand it?
: 
: Perhaps it was neither, but really a statement of a testable
: hypothesis? [stuff deleted] 
: 
: If you were listening to Jim Savage's talk carefully he placed the only
: blame on the National Earthquake Prediction Evaluation Council (NEPEC)
:  for not considering alternative hypotheses carefully enough.  I

Bakun and Lindh had a sound, simple model that no one could gainsay in
1984.  for policy purposes it was as good as any other model, but in
essence it was a null hypothesis, I think.


:>Was the test question ignorantly simple or disingenuously simple?

:As for the second suggestion I consider it close to
:libelous.  I know Bill Bakun and Al Lindh extremely well.  I consider
:both of them ethically incapable of making a simple hypothesis look
:good in order to get an experiment funded.  I don't know Tom McEvilly
:as well but I can't believe he would participate in such subterfuge
:either.

I may have posed my question too provocatively for Andy, who is
certainly correct.  I don't mean to impugn Bakun, Lindh, or McEvilly in
the slightest.  I (and Andy, I hope) come down on the "ignorantly
simple" end--knowing that in science, "ignorant" is not a pejorative
term.  For funding purposes, the test question had this advantage: it's
as easy to understand as betting on a coin coming up "heads" when it's
done so six times in a row already.  This is easy to sell!  I'm glad
Andy can attest to people's probity.  But now that we know that simple
recurrence is too simple a model, we need to guard against the tendency
to sound-bite the next model we use to justify projects like Parkfield.
I think with Parkfield the danger is past, since its benefits, in
addition to the (in my opinion) sterile scientific model it tested, are
so obvious. 

--Andrew
.