Source Types

OASP3D Version 3.5 supports the 5 types of sources (either point or line sources, controlled by option P), corresponding to those defined in [10]:

1.

Explosive (omnidirectional) sources.

2.

Force of arbitrary vertical and horizontal direction.

3.

Dip-slip seismic source of arbitrary dip angle.

4.

Strike-slip seismic source of arbitrary dip angle.

5.

Tensile crack source in elastic media.

6.

Normal seismic moment source with arbitrary moment amplitudes M₁₁, M₂₂, and M₃₃

7.

General seismic moment source with arbitrary components M_ij.

The source type and parameters are specified in a separate line right after the environmental block in the data file, before the source depth line. The format of this data line depends on the source type:

ITYP							(Type 1)
ITYP	FMAG	HANG	VANG				(Type 2)
ITYP	SMOM	DANG					(Type 3-4)
ITYP	M11	M22	M33	DANG			(Type 5,6)
ITYP	M11	M12	M13	M22	M23	M33	(Type 7)

where

ITYP:	Source type
FMAG:	Magnitude of force in N (N/m for line source).
HANG:	Horizontal angle of force relative to x-axis in deg.
VANG:	Vertical angle in degg of force relative to
	horizontal plane. Positive downwards.
SMOM:	Seismic moment of slip sources in Nm
DANG:	Dip angle in deg. Positive rotation around x-axis
	: crack in x-y plane
	: crack in x-z plane
M11:	Moment of force dipole in x'-direction, M11.
M22:	Moment of force dipole in y'-direction, M22.
M33:	Moment of force dipole in z'-direction M33.
Mii:	Seismic moment component.

The pulse response output produced by PP is available as either individual pulse plots for each single receiver or as stacked plots, where the stacking can be performed in either range, depth or azimuth. For the individual plots the time series are produced in true units, i.e. Pa for stresses and m/s for particle velocities.

As an example, to run the SAFARI-FIPP case 2 problem with automatic sampling, and a point force within the sea bed at angle with the sea bed, and horizontal angle relative to the x-axis, change the data file as follows:

SAFARI-FIPP case 2. Auto sampling. Force 30/45 deg
V H f                         # Bessel integration.
5 0
4
  0    0     0 0   0   0   0
  0 1500     0 0   0   1   0
100 1600   400 0.2 0.5 1.8 0
120 1800   600 0.1 0.2 2.0 0
2 1.0 30.0 45.0                # ITYP, FMAG, HANG, VANG  
101                            # SD = 101 m
100 100 1 
 300 1E8                      
-1 0 0                         # NW   =   -1
2048 0.0 12.5 0.006 0.5 0.5 5