[cig-commits] r22337 - seismo/3D/SPECFEM3D/trunk/doc

[surendra at geodynamics.org]

Author: surendra
Date: 2013-06-17 08:53:36 -0700 (Mon, 17 Jun 2013)
New Revision: 22337

Added:
   seismo/3D/SPECFEM3D/trunk/doc/README_gravityPerturbation bis.txt
Log:
Added README for gravity perturbation

Added: seismo/3D/SPECFEM3D/trunk/doc/README_gravityPerturbation bis.txt
===================================================================
--- seismo/3D/SPECFEM3D/trunk/doc/README_gravityPerturbation bis.txt	                        (rev 0)
+++ seismo/3D/SPECFEM3D/trunk/doc/README_gravityPerturbation bis.txt	2013-06-17 15:53:36 UTC (rev 22337)
@@ -0,0 +1,51 @@
+SPECFEM3D has the capability to compute the perturbations of gravity 
+induced by seismic waves at arbitrary locations above the Earth's surface. 
+The current file documents the usage of this feature and the related code 
+modifications.
+
+
+Enabling gravity computations
+-----------------------------
+
+Gravity perturbation can be computed for any SPECFEM3D simulation by 
+placing a file called "gravity_stations" in the DATA directory, in 
+addition to the regular input files.
+
+
+Input file format
+-----------------
+
+The format of the "gravity_stations" input file is as follows:
+
+n	dt_gap
+x1	y1	z1
+x2	y2	z2
+...	...	...
+xn	yn 	zn
+
+where
+ n : number of stations where gravity time series are needed
+ dt_gap : gravity time series are sampled every dt_gap time steps of the 
+          SPECFEM3D simulation
+
+
+Code modifications
+------------------
+
+All the routines related to the gravity perturbation computations are 
+placed in one module called specfem3d/gravity_perturbation.f90. The module 
+provides three public subroutines and a flag. Each subroutine is invoked 
+in one of the following stages:
+ 1. during the initialization, 
+ 2. during the iterative time stepping scheme and 
+ 3. at the output stage.
+In #1 the code checks for the presence of the input file gravity_stations. 
+If the file exists, the flag "GRAVITY_SIMULATION" is turned on and the 
+subroutines #2 and #3 are invoked.
+
+
+Author
+------
+
+Surendra Somala (Caltech) surendra at caltech.edu - 2013
+with advice from Jan Harms and Pablo Ampuero (ampuero at gps.caltech.edu)
\ No newline at end of file