[cig-commits] r16321 - seismo/3D/SPECFEM3D_GLOBE/trunk

Tue Feb 23 05:17:32 PST 2010

Author: dkomati1
Date: 2010-02-23 05:17:32 -0800 (Tue, 23 Feb 2010)
New Revision: 16321

Modified:
   seismo/3D/SPECFEM3D_GLOBE/trunk/todo_list_please_dont_remove.txt
Log:
updated the todo list


Modified: seismo/3D/SPECFEM3D_GLOBE/trunk/todo_list_please_dont_remove.txt
===================================================================

--- seismo/3D/SPECFEM3D_GLOBE/trunk/todo_list_please_dont_remove.txt	2010-02-23 04:14:48 UTC (rev 16320)
+++ seismo/3D/SPECFEM3D_GLOBE/trunk/todo_list_please_dont_remove.txt	2010-02-23 13:17:32 UTC (rev 16321)
@@ -4,16 +4,28 @@
 
 Things that could be done in a future version:
 
-- Jeroen Ritsema (from Univ of Michigan, USA) has an interesting suggestion (on February 22, 2010)
-for SPECFEM3D_GLOBE, an option that is currently missing
-but that would be easy to add, and potentially very useful:
-"If I may suggest one modification to specfem-3D: allow for 3D mantle
-structure (i.e. s20rts) and a PREM crust.
-This is helpful in isolating the mantle contribution to waveform anomalies.
-Right now, crust2.0 structure is automatically included if the mantle model is
-turned on." 
+- symplectic time scheme (will be done by Tarje Nissen-Meyer and/or Jean-Paul Ampuero) (would be useful in the 2D version of the code as well):
+Hi Jeroen, Perfect. I think talking to Jean-Paul Ampuero would be useful
+as well because in Utrecht last year he had told us that
+he had implemented some nice 4th-order symplectic schemes
+in his version of SEM2D. Dimitri.
+Jeroen Tromp wrote:
+> Hi Dimitri:
+> This is one of the first things Tarje and I plan to work on after he
+> arrives.
+> Jeroen
+> Dimitri Komatitsch wrote:
+>> Hi Jeroen,
+>> I think the last important thing that is missing
+>> in SPECFEM3D (and SPECFEM2D) is a fourth-order time scheme.
+>> I think both Jean-Paul Ampuero and Tarje Nissen-Meyer
+>> have worked on this, they will both be at Caltech
+>> soon therefore maybe they could take care of adding it?
+>> This would definitely increase the accuracy of very long
+>> simulations (e.g. multi-orbit surface waves).
+>> Dimitri.
 
-- there is something in SPECFEM3D_GLOBE that we noticed a few years ago
+- From Dimitri: there is something in SPECFEM3D_GLOBE that we noticed a few years ago
 regarding attenuation but never fixed: on page 813 of our 1999 paper
 I used a trick suggested by Robertsson et al. (1994)
 to use a non-staggered Runge-Kutta (RK4) scheme for the attenuation
@@ -32,6 +44,13 @@
 We should fix that one day. The only thing to do would be to design a better time
 integration scheme for the attenuation equation, without that trick; the rest
 (Newmark etc) is fine and does not need to change.
+Reply from Daniel Peter (Princeton University, USA) on February 23, 2010:
+for higher orbit arrivals, we do might want to consider the symplectic time
+schemes as well. Tarje made some tests and showed some "shocking" results
+for longer distance paths. However, I am not sure if his scheme currently
+considers purely elastic simulations, without incorporating attenuation.
+It would be nice having both improved formulations included for those cases.
+This seems to be a nice outlook for a future version update.
 
 - use a potential of (rho * u) instead of u in the fluid, in case of
   fluid-fluid discontinuities
@@ -39,27 +58,6 @@
 - compatible with helioseismology / general Cowling formulation (will be done
   with Tarje Nissen-Meyer)
 
-- symplectic time scheme (will be done by Tarje Nissen-Meyer and/or Jean-Paul Ampuero) (would be useful in the 2D version of the code as well):
-Hi Jeroen, Perfect. I think talking to Jean-Paul Ampuero would be useful
-as well because in Utrecht last year he had told us that
-he had implemented some nice 4th-order symplectic schemes
-in his version of SEM2D. Dimitri.
-Jeroen Tromp wrote:
-> Hi Dimitri:
-> This is one of the first things Tarje and I plan to work on after he
-> arrives.
-> Jeroen
-> Dimitri Komatitsch wrote:
->> Hi Jeroen,
->> I think the last important thing that is missing
->> in SPECFEM3D (and SPECFEM2D) is a fourth-order time scheme.
->> I think both Jean-Paul Ampuero and Tarje Nissen-Meyer
->> have worked on this, they will both be at Caltech
->> soon therefore maybe they could take care of adding it?
->> This would definitely increase the accuracy of very long
->> simulations (e.g. multi-orbit surface waves).
->> Dimitri.
-
 - could be done by Vala:
 we could use heuristic rules to make source and receiver detection much
 faster and make these routines use far less memory. For instance using the
@@ -101,3 +99,23 @@
 - supprimer sections qui decrivent write_AVS_mesh_quality, check_buffers*.f90, check_mesh_quality*.f90 etc du manuel une fois que le mesher et le solver auront ete fusionnes
 
 ---------------------------------------------------------------------------------
+---------------------------------------------------------------------------------
+---------------------------------------------------------------------------------
+---------------------------------------------------------------------------------
+
+Done:
+-----
+
+- Jeroen Ritsema (from Univ of Michigan, USA) has an interesting suggestion
+(on February 22, 2010) for SPECFEM3D_GLOBE, an option that is currently missing
+but that would be easy to add, and potentially very useful:
+"If I may suggest one modification to specfem-3D: allow for 3D mantle
+structure (i.e. s20rts) and a PREM crust.
+This is helpful in isolating the mantle contribution to waveform anomalies.
+Right now, crust2.0 structure is automatically included if the mantle model is
+turned on." Solution implemented by Daniel Peter from Princeton Univ (USA) on February 23, 2010:
+"I put an option such that if one appends "_1Dcrust" to the 3D model 
+name, e.g. "s20rts_1Dcrust" instead of "s20rts" in the Par_file, it
+will just take the crust from the corresponding 1D reference model
+(which is PREM for his s20rts model). Daniel. "
+

