[CIG-SHORT] Short-Term Crustal Dynamics priorities

[Freed, Andrew M]

Hi All,

I wanted to second the notions put forth by Mark. First, that the  
efforts of the Pylith developers are extremely appreciated - and the  
latest version is much less cryptic to run. But second, that  
deficiencies in the latest version are compromising its use by a  
wider audience.  I think Mark put it well that our target should be  
to get up to Tecton level capabilities as fast as possible.  I know a  
number of Tecton users (including myself) who cannot make the  
transition to Pylith because of missing basic features.  For those of  
us who regularly model explicit faults, for example, it is  
frustrating not to have a free-slipping fault capability.  While I  
look forward to the planned cohesive element that will give far more  
capability than the slippery-node, December is so far away.  Right  
now if we want to have a freely slipping fault, we have to model a  
narrow viscous channel which present problems both in mesh design and  
run time required when using very small viscosities.  I have no idea  
what it takes to bring a slippery node capability to Pylith, but that  
in itself may allow more users to take advantage of Pylith while the  
cohesive element continue to be developed.  Similarly, I am a little  
embarrassed that as a strong advocate of Pylith develop and use I  
have just finishing guiding a student through a project using a 10  
years old version of Tecton because we required prestresses (of the  
lithostatic kind).  Tecton was developed to reflect the needs of a  
wide community and as such was and is widely used. A lot of folks,  
including myself, owe their careers to the work that Jay Melosh and  
Charles put into that original code.  Our priority should be to get  
back to that level as fast as possible before worrying too much about  
more advanced capabilities.

Best regards,

Andy

______________________________
Andy Freed
Assistant Professor
Dept. of Earth & Atmospheric Sciences
Purdue University
550 Stadium Mall Drive
West Lafayette, IN 47907-2051
Phone: (765) 496-3738
Fax: (765) 496-1210
freed at purdue.edu



On May 17, 2008, at 10:04 AM, Mark Simons wrote:

> Dear all,
>
> Despite all the comments in what follows, I want to heartily
> commend/thank Brad, Charles, Matt, and Sue for their heroic efforts to
> build PyLith up to its current state and for their enthusiastic  
> support
> of users.
>
> ---
>
> PyLith suggestions:
>
> It would be good if more priority was placed on getting PyLith up  
> to the
> same the geophysical feature set as the original tecton (e.g.,
> earthquake cycles, gravity, large deformation, basic forms of yielding
> and other material models).  Also, the additional features of full
> restart files/user define pre-stresses, Green's functions, and  
> automatic
> time stepping will dramatically increase the number of problems  
> that we
> can address with PyLith.  These are the features that were  
> requested and
> listed as top priorities consistently over the last several workshops.
>
> As a CIG development effort , I think it is important that we find  
> ways
> to increase the user base of PyLith as quickly as possible - sometimes
> at the expense of "fancier" style improvement (AMR, higher order
> elements, or complex issues like non-linear fault constitutive laws).
> Thus in many ways, I would push for a reordering of the proposed  
> PyLith
> development priority list/schedule, OR BETTER YET, the allocation of
> additional resources to let us make faster progress.
>
> Maybe, it is possible to build a dependency tree of each feature  
> request
> so that we can see what can be developed in parallel and/or by people
> outside of the core developer group?  Then perhaps some thought can be
> put into finding ways to increase the number of contributing
> developers?  At present, it is difficult for others to contribute.
>
> An additional feature for long term earthquake cycle modeling (and
> glacier modeling too!) is some kind of controllable mass flux out of a
> subset of the model boundaries.
>
> Perhaps there should be some more explicit thought into how PyLith  
> could
> contribute to glaciology?
> ---
>
> I think the collection of a set of semi-analytic codes is fine as a
> community building excercise, especially if it is the community doing
> most of the heavy lifting and CIG is just facilitating the process.
>
> ---
>
>
>
> Cheers,
> Mark
>
>
> Brad Aagaard wrote:
>> Hi all:
>>
>> The Science Steering Committee will be meeting in two weeks to  
>> update the CIG
>> five-year rolling strategic plan. At this meeting, I will present our
>> priorities for software development by CIG. I have created two  
>> pages on the
>> CIG website to document our desires
>> (http://www.geodynamics.org/cig/workinggroups/short/workarea/ 
>> planning/priorities2008/).
>> One page is devoted to development plans for PyLith while the  
>> other describes
>> our priorities year-by-year over the next five years. All content  
>> posted on
>> these pages is up for discussion.
>>
>> Some questions to help organize your thoughts:
>>
>> (1) What obstacles inhibit your abilities to create realistic models?
>> (2) What modeling tools would eliminate/reduce these obstacles?
>> (3) If you are using PyLith, what features do wish it had?
>> (4) If you are not using PyLith, why? Are you waiting for a  
>> particular set of
>> features to be added? Is it too difficult to learn? Is it too  
>> slow? Is it too
>> inefficient?
>> (5) Are you satisfied with the pace of PyLith development? Would  
>> you be
>> willing to work on PyLith development? What sort of training (if  
>> any) would
>> you need?
>> (6) What other types of modeling tools, besides PyLith, do we want  
>> developed?
>> (7) Are there useful semi-analytic codes that would be of great  
>> use if they
>> were more portable? documented? open-source? more efficient?  
>> Should we divert
>> resources from PyLith development to support this task?
>>
>> Please help define our needs and prioritize them for the coming  
>> years by
>> participating in this discussion. Send comments/suggestions to  
>> this mailing
>> list or visit the pages at the link above and add comments. NOTE:  
>> If you
>> respond directly to me with suggestions/comments, I will forward your
>> comments to this mailing list!
>>
>> If you are interested in participating in a 1 hour teleconference  
>> towards the
>> end of next week (May 21-23) to finalize this list of priorities,  
>> please let
>> me know what times on those days you are available.
>>
>> Thanks,
>> Brad
>> _______________________________________________
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>> CIG-SHORT at geodynamics.org
>> http://geodynamics.org/cgi-bin/mailman/listinfo/cig-short
>>
>>
>
> -- 
>
> Mark Simons
> Seismological Laboratory
> Division of Geological and Planetary Sciences
> TEL: 626-395-6984
> FAX: 626/564-0715
> WWW: www.gps.caltech.edu/~simons
>
>
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