DFM - Dynamic Fault Model

DFM models spontaneous rupture on a planar fault within a 3D isotropic
viscoelastic solid.  The viscoelastic equations of motion are approximated
with second order finite-differences.  The fault is modeled by applying
a slip-weakening, frictional, internal boundary condition.

AUTHORS

Geoffrey Ely, UC San Diego, gely@ucsd.edu

Stephen Day, San Diego State University, day@moho.sdsu.edu

DATA FILES

Output is stored as 4D time sequences for a field variable sampled over
a 3D rectangular mesh.  Each sequence of data is described in an ASCII
header file that looks like 01.hdr where 01 is the sequence number.  The
header file contains 19 fields described below.  Possible field variables
are displacement (u), velocity (v), velocity magnitude (m), stress (S),
and fault plane stress (f).  Each sequence may be stored as either a
single file or multiple files.  Normally when all the spacial extents
are 1, a single file is used.  This is indicated by an 'F' in header
field 19, and the file looks like 01mux.bin where 01 is the two digit
sequence number.  Data may also be stored as series of separate files,
one file per time step.  This is indicated by 'T' in header field 19.
In this case filenames look like 0100001.bin where 01 is the sequence
number and 00001 is the five digit time step (which can be determined
from header fields 11,12 & 13).  Data is stored in four byte floating
point binary.  Ordering of the mesh is: component, x, y, z, t where the
component index is the fastest changing and the t index is the slowest.
Byte ordering is machine dependent and is indicated in the file 'endian'.

1  components per node (u=3, v=3, m=1, S=6, f=3)
2  x start index
3  x skip
4  x end index
5  y start index
6  y skip
7  y end index
8  z start index
9  z skip
10 z end index
11 t start index
12 t skip
13 t end index
14 x step length
15 y step length
16 z step length
17 t step length
18 field variable (u, v, m, S, or f)
19 separate files flag (T or F)