[CIG-SEISMO] please ignore my previous email

[Dimitri Komatitsch]

Dear all,

please ignore my previous email: as pointed out by Jeroen Tromp,
the first line of DATA/CMTSOLUTION in the Harvard CMT standard format
is an independent preliminary estimate (the PDE solution, for 
"Preliminary Determination of Earthquakes", performed by the USGS NEIC).

(for some reason I thought it was just an ASCII comment)

Therefore it was indeed a bug, and the right thing to do is to use
the second set of values, not the first.

Sorry about the confusion, and thanks to Jeroen for his feedback.

Best regards,
Dimitri.

Dimitri Komatitsch wrote:
> 
> Dear Sung-Joon,
> 
> The small problem (not really a bug) that was fixed is this:
> in the DATA/CMTSOLUTION file that describes the earthquake source
> (in the Harvard CMT standard format) the position of the source
> appears twice: in the header (first line of the file) and
> also in the "latitude:", "longitude:" and "depth:" lines below.
> The tradition is to use the second set of values, but we realized
> that we used the first (the values from the header) instead when 
> outputting binary SAC seismograms. Note that it is not really a bug
> because the fact that the source information appears twice and
> can be different comes from the Harvard CMT standard format, not from us 
> (and it is not a good idea).
> 
> The other seismogram formats (pure ASCII for instance, which is the 
> default) were OK. If you used them, no problem.
> 
> Also, if you had the same source position in the header and in the
> "latitude:", "longitude:" and "depth:" lines in your input file,
> everything is fine. If you had slightly different values and used SAC 
> binary, there might be a problem but you do NOT need to rerun the code, 
> you can simply fix the latitude, longitude and depth in SAC (open the 
> SAC file, change the values manually and save it).
> 
> Best regards,
> Dimitri.
> 
> Sue Kientz wrote:
>> Hi Sung-Joon,
>>
>> Here are the details on the bug sent in by Brian Savage. Note that now
>> that this bug is fixed, you do not have to do any of the suggested
>> workarounds mentioned below.
>>
>> Bug Description: SAC and Rotated Output are incorrect.
>> There is a bug in the specfem3d_globe code when outputting sac binary,
>> sac alpha files, or rotated seismograms. The location is taken
>> incorrectly from the first line of the DATA/CMTSOLUTION file (PDE
>> solution). The event location and the rotated seismograms are incorrect
>> as they should be using the location specified later in the
>> DATA/CMTSOLUTION file.
>> Problems will occur if you are writing to any of the following
>> - SAC binary
>> - SAC alpha
>> - Rotated seismograms (SAC or ASCII text files)
>> If you are outputting ascii text files as North, East and Vertical the
>> output is fine.
>> If you have SAC seismograms already, you can fix them by them by setting
>> the correct event location from the CMTSOLUTION file and rotating within
>> SAC. There should be no need to recalculate seismograms. Rotated text
>> files are trickier to correct, but possible.
>>
>> Sue Kientz
>>
>> Sung-Joon Chang wrote:
>>> To whom it may concern:
>>> My name is Sung-Joon Chang and I'm working at Northwestern University
>>> as a postdoc.
>>> I got an announcement that new version of SPECFEM3D_GLOBE is released
>>> a few days ago, but it wasn't written what specific bugs are fixed in
>>> the new version.
>>> I'd like to figure out whether the bugs are so serious that I should
>>> recalculate my synthetics again with new codes. I'd appreciate if if
>>> you'd let me know which bugs are fixed in detail.
>>> It would be very useful to users if you make a release page in the web
>>> where improvements in the new version are explained as they do in GMT
>>> web site.
>>> Regards,
>>> Sung-Joon
>>> ==============================
>>> Sung-Joon Chang
>>>
>>> Postdoctoral Fellow
>>> Dept. of Earth and Planetary Sciences
>>> Northwestern University
>>> 1850 Campus Drive
>>> Evanston, IL 60208-2150
>>> U.S.A.
>>> ==============================
>>> ------------------------------------------------------------------------
>>>
>>> _______________________________________________
>>> CIG-SEISMO mailing list
>>> CIG-SEISMO at geodynamics.org
>>> http://geodynamics.org/cgi-bin/mailman/listinfo/cig-seismo
>>>   
>>
>> _______________________________________________
>> CIG-SEISMO mailing list
>> CIG-SEISMO at geodynamics.org
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>>
> 

-- 
Dimitri Komatitsch - dimitri.komatitsch aT univ-pau.fr
Professor, University of Pau, Institut universitaire de France,
CNRS and INRIA Magique3D, France   http://www.univ-pau.fr/~dkomati1