[CIG-SHORT] Problems report for Pylith's subduction example_KejingHuang

[Charles Williams]

Dear Huang,

Did you see my reply on the cig-short mailing list?  If so, have you turned on the output for ‘velocity’ and ‘viscous_strain’?  I think this will help you see what is going on.  I’m attaching a couple of figures to show what I mean.

As far as your difficulties using a spherical earth, it’s hard to say without knowing what errors you are getting.

As far as your problems with the step02 example, I’m not sure what you are expecting to see.  Can you clarify this?

Cheers,
Charles

p.s.  In the attached plots, the colors represent displacement magnitude, and the vectors represent velocities.

[cid:1CE7A142-A60F-467C-983D-EDF70A7CFE1B at corp.gns.cri.nz][cid:DD12615F-FA60-4E67-B498-241E9CA0869D at corp.gns.cri.nz]

On 7/08/2018, at 7:22 PM, hkj at mail.ustc.edu.cn<mailto:hkj at mail.ustc.edu.cn> wrote:

Dear Professor Williams

My name is Kejing Huang. I’m a first-year graduate student at USTC working with Profs. Yan Hu and Jefferey Freymueller on the postseismic deformation of the 1964 Mw9.2 Alaska earthquake.

I'm learning Pylith now. Pylith is indeed very powerful, I do appreciate your efforts. However,  when I used step02 of 3d subduction example, problems showed up.

The first problem is, I saw the paper written by Prof. Pratama (attached to this email) used a spherical-earth model by local geographically referenced Cartesian system. I tried it with Pylith's subduction example, but it didn't work and always report error. I didn't find detailed introduction from the user manual or the website. Should I build the model in ECEF system initially with Trelis/Cubit ?

The second problem is much more disturbing, the files attached are modified from step02 of Pylith 3d subduction example, I just changed the material properties and calculation time, in this example:
I changed the body materials to a elastic slab, a elastic crust, a elastic wedge and a viscoelastic mantle.
The coseismic displacement is perfect and is consistent with OKADA results. But for postseismic deformation,it didn't give ideal result, it's totally different from the pattern I expected, I can't even see the elastic slab boundary in postseismic deformation.(The README file includes some more description.)

I have tried different model geometry, different time step, different slip distribution and different material properties, but none of them works. Other students of my research group are also facing with this problem, and we have been sticking in this step for half a month.

I sincerely hope you can find out where the problem is. Thank you very much!

Kejing Huang
University of Science and Technology of China


<modified_example_3d_subduction_step02.zip><Pratama_et_al_JAES_2017.pdf>

Charles Williams I Geodynamic Modeler
GNS Science I Te Pῡ Ao
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