hello community!!
Jens,
Based on what you have commented on the speed of SEISAN model which is a
constant layer model, I have the following concerns:
IASPEI 91 is a different model type?. Should be as explained that SEISAN
integrates different models?
Gracias!
Leandro
OSOP
Panamá
> On September 19, 2013 at 2:15 PM Jens Havskov <[email protected]> wrote:
>
> branden
>
> correct, seisan is only using constant velocity layer model. barry lienert
> actually started to implement the gradient model some time ago (a few
> years) but ran into some problem that i have forgot what was. but
> apparently it was implemented in program ttlayer.
>
> barry, do you remeber anything about this ?
>
> jens
>
> On Thu, 19 Sep 2013, Branden Christensen wrote:
>
> > Jens:
> >
> > Hello from Panama!
> >
> > Can you respond to the list on this one?
> >
> > We think Paul might be wrong about the linear model.
> >
> > Looking at the hypo71 code here: http://www.ipgp.fr/~houlie/HYPO71.f, it
> > does not look like they are doing linear velocity with depth. This
> > calculation (about lines 1900-2000) looks like a simple constant velocity
> > layered model. As noted by Philip, generally when you do linear gradients in
> > velocity, you split the larger layers up into smaller ones and then do the
> > calculation on some other interpolant, as linear velocity is hard to
> > integrate. Philip also noted that here is a analytic solution for linear
> > layers, but it uses hyperbolic sines and cosines, and we don't see any of
> > those in the code.
> >
> > Can you confirm that seisan is using constant velocity layers?
> >
> > Thanks a million!
> >
> >
> > Kind Regards!
> >
> >
> >
> > Branden ChristensenThe Seismo Guys
> > Blog: http://www.osop.com.pa/blog/the-seismo-guys/
> > Take a Virtual Tour: http://www.osop.com.pa/tour
> > "If toast always lands butter-side down, and cats always land on their feet,
> > what happens if you strap toast on the back of a cat and drop it?" -Steven
> > Wright
> >
> >
> > ---------- Forwarded message ----------
> > From: Paul Friberg <[email protected]>
> > Date: Wed, Sep 18, 2013 at 7:48 PM
> > Subject: Re: [seisan] STATION0.HYP velocity model
> > To: Branden Christensen <[email protected]>,
> > "[email protected]" <[email protected]>
> > Cc: Philip Crotwell <[email protected]>
> >
> >
> >
> > SEISAN's HYP locator uses a linear model (as far as I can tell) until you
> > reach some distance at which point it uses the IASPEI TT tables (or whatever
> > you have provided):
> >
> > Look at the SEISAN v10.0 manual at TEST setting #57.
> >
> > 1.
> >
> > 57: Distance (geocentric km) beyond which IASPEI91 tables are used to
> > calculate travel times. Can be overridden by the distance letter L in
> > the Nordic format. D: 1500 km
> >
> >
> > Saludos,
> >
> > Paul @ ISTI
> >
> > Branden Christensen wrote:
> > Hi all:
> >
> > Saludos from Panama.
> >
> > We all place our velocity models at the end of the STATION0.HYP files.
> > When Seisan's locator calculates the travel time tables from our
> > velocity model, does Seisan assume a simple model with constant
> > velocity layers or linear velocity gradients? I am interested because
> > I am using TauP to generate the tt tables from the STATION0.HYP and
> > TauP uses linear velocity gradients.
> >
> >
> > Thanks,
> >
> >
> > Branden ChristensenThe Seismo Guys
> > Blog: http://www.osop.com.pa/blog/the-seismo-guys/
> > Take a Virtual Tour: http://www.osop.com.pa/tour
> > "A doorway is the safest place to be during a quake. Eat, sleep and
> > work in doorways." -For more Earthquake safety tips see The Onion
> >
> >
> > _______________________________________________
> > seisan mailing list
> > [email protected]
> > http://mailman.uib.no/listinfo/seisan
> >
> >
> >
> > Branden Christensen The Seismo Guys
> > Blog: http://www.osop.com.pa/blog/the-seismo-guys/
> > Take a Virtual Tour: http://www.osop.com.pa/tour
> > "If toast always lands butter-side down, and cats always land on their feet,
> > what happens if you strap toast on the back of a cat and drop it?" -Steven
> > Wright
> >
> >
_______________________________________________
seisan mailing list
[email protected]
http://mailman.uib.no/listinfo/seisan
