Hi Tiago -

One other comment on the LQ LR predicted arrival times.

The biggest problem is that the LQ & LR waves are surface waves and =
travel within the crust.  There is wide variability in the makeup and =
thickness of the crust (oceanic or continental) and the differences =
significantly affect predicted wave arrival times.  This is more =
noticeable as the distance between the event and the receiving station =
increases, and whether or not the waves pass through continental and/or =
oceanic crust.  While there are travel times curves for surface waves, =
the wide variability in the makeup of the crust restricts the ability to =
accurately predict their arrival times.  WinQuake is a great program and =
Larry has done a fantastic job with the program.  The arrival times for =
body waves is accurate and usually within a second or two of the times =
obtained from both the SAC and TauP Tool Kit programs. =20

The arrival times of Body waves, which are either refracted and or =
reflected by various layers below the crust have accurate arrival times =
which can be displayed by several programs including WinQuake, USGS, =
SAC, and the TauP Tool Kit.

NOTE - Neither SAC or TauP Tool Kit programs (used by seismologists) =
display predicted surface wave arrival times.  Both WinQuake and the =
USGS display predicted surface wave arrival times, but I have observed =
differences in their predicted surface wave arrival times, and the =
actual arrival times observed on seismograms.  =20

Bob Hancock
      =20


On Mar 27, 2013, at 8:39 AM, Tiago A.  wrote:

> Hi.
>=20
> I=B4ve been developing a online "Interactive Time Travel" for some =
time, P and S tables works pretty close (need to tune up =
somethings)..but cant get LQ and LR times match USGS Time Travel =
Calculator, example:
>=20
> Todays Taiwan Eq, (+-) 111 deg.
>=20
> My Tool:
> LQ 3522s 03:02:02
> LR 4025s 03:10:25
>=20
> USGS
>=20
> LQ 2824.90s 02:50:24=20
> LR 3135.24s 02:55:35
>=20
> I=B4m using P.jb, S.jb, LQ.jb and LR.jb tables found in WinQuake, if i =
go to the LQ.jb table and locate depth:20km ; 111deg, i found: 3494s, =
which is pretty close to my tool, but far for USGS results (and =
realistic results), to match USGS results i=B4ve to look to 90deg =
corresponding to 2827s.
>=20
> Does LQ.jb and LR.jb tables differ from P.jb and S.jb tables?
> Does anyone have clue where can be the problem?
>=20
> Best Regards,
> Tiago.

tiagoagre@.........> =
wrote:
Hi.

I=B4ve been developing a online =
"Interactive Time Travel" for some time, P and S tables works pretty =
close (need to tune up somethings)..but cant get LQ and LR times match =
USGS Time Travel Calculator, example:


Todays Taiwan Eq, (+-) 111 deg.

My Tool:
LQ 3522s =
03:02:02
LR 4025s 03:10:25

USGS


LQ        2824.90s   02:50:24
    
 LR        3135.24s   02:55:35

I=B4m using P.jb, S.jb, LQ.jb and LR.jb tables found in =
WinQuake, if i go to the LQ.jb table and locate depth:20km ; =
111deg, i found: 3494s, which is pretty =
close to my tool, but far for USGS results (and realistic results), =
to match USGS results i=B4ve to look to 90deg corresponding to 2827s.


Does LQ.jb and LR.jb tables differ from P.jb and S.jb =
tables?
Does anyone have clue where can be =
the problem?

Best =
Regards,
Tiago.

=
<=
/font>

=
=