<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">As a follow-up to Brad's response, the infinitesimal strain approximation (default) does not include the effects of density changes due to volume change, but the small strain model does include these effects. The small strain model includes geometrical nonlinearity, and is thus a nonlinear model. You will be able to calculate density changes, but PyLith does not do gravitational calculations. You would need to first compute the density changes with PyLith, and then use a gravity code to compute the gravity changes. I hope this helps.<div><br></div><div>Cheers,</div><div>Charles</div><div><br></div><div><br><div><div>On 12/11/2013, at 3:53 PM, Brad Aagaard wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>Shi,<br><br>PyLith solves the elasticity equation (see the manual for details on the governing equations). Using the small-strain formulation, the effects of changes in the geometry associated with deformation will change the resulting gravitational loading. Calculating any resulting changes in the geoid from the deformation would require post-processing with your own code. If I am misunderstanding your questions, please send a more mathematical description of what you want to do.<br><br>Regards,<br>Brad<br><br><br><br><br>On 11/11/13 1:54 PM, shi chen wrote:<br><blockquote type="cite">Hello,<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"> From the CIG website, I know the pylith software can simulate tectonic<br></blockquote><blockquote type="cite">deformation problems. I am very interest in the pylith. But I want to<br></blockquote><blockquote type="cite">know that PyLith is eligible to simulate the density change due to the<br></blockquote><blockquote type="cite">elastic/viscoelastic compressible model or not? I want to simulate the<br></blockquote><blockquote type="cite">force perturbation due to dilatation with the defined multi density<br></blockquote><blockquote type="cite">layer model. And further to calculate the gravity change with the<br></blockquote><blockquote type="cite">density change.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Thanks for your help!<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Best regards!<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Shi CHEN<br></blockquote><blockquote type="cite">Visiting Schloar<br></blockquote><blockquote type="cite">University of Missouri-Columbia<br></blockquote><blockquote type="cite">Department of Geological Sciences<br></blockquote><blockquote type="cite">101 Geology Building<br></blockquote><blockquote type="cite">Columbia, MO 65211-1380<br></blockquote><blockquote type="cite"><a href="mailto:chenshi80@gmail.com">chenshi80@gmail.com</a> <<a href="mailto:chenshi80@gmail.com">mailto:chenshi80@gmail.com</a>><br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">_______________________________________________<br></blockquote><blockquote type="cite">CIG-SHORT mailing list<br></blockquote><blockquote type="cite"><a href="mailto:CIG-SHORT@geodynamics.org">CIG-SHORT@geodynamics.org</a><br></blockquote><blockquote type="cite"><a href="http://geodynamics.org/cgi-bin/mailman/listinfo/cig-short">http://geodynamics.org/cgi-bin/mailman/listinfo/cig-short</a><br></blockquote><blockquote type="cite"><br></blockquote><br>_______________________________________________<br>CIG-SHORT mailing list<br><a href="mailto:CIG-SHORT@geodynamics.org">CIG-SHORT@geodynamics.org</a><br>http://geodynamics.org/cgi-bin/mailman/listinfo/cig-short<br></div></blockquote></div><br><div>
<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; ">Charles A. Williams</font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Scientist<br>GNS Science<br>1 Fairway Drive, Avalon<br>PO Box 30368<br>Lower Hutt 5040<br>New Zealand<br>ph (office): 0064-4570-4566<br>fax (office): 0064-4570-4600</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><a href="mailto:C.Williams@gns.cri.nz">C.Williams@gns.cri.nz</a></div></div></div></span></span>
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