Static deformations and dislocation theory - Earth Dynamics: Deformations and Oscillations of the Rotating Earth - page 489

strike-slip

rake

dip-slip

total slip

Figure 9.2 The total slip on a slip dislocation may have both dip-slip and strike-
slip components, as measured by the rake angle.

the rake angle. At the request of the programme, fault parameters DIP (dip angle),
SLIP (slip), RAKE (rake angle), DU (upper edge of fault plane measured down-
dip), DL (lower edge of fault plane measured down-dip) and L (fault half-length),
are entered. Subroutine DIPS calculates the three components of displacement
resulting from the dip-slip, while subroutine STRIKES calculates the three com-
ponents of displacement resulting from the strike-slip. Subroutine DIPS in turn
calls the subroutines DIP1, DIP2 and DIP3 to evaluate the double indefinite integ-
rals expressing the three displacement components in terms of fault limits. Simil-
arly, subroutine STRIKES in turn calls the subroutines STRIKE1, STRIKE2 and
STRIKE3 to evaluate the double indefinite integrals expressing the three displace-
ment components in terms of fault limits.

C PROGRAMME DISPF.FOR

C
C This programme calculates the three components of the displacement
C fields of dip-slip and strike-slip faults and combinations thereof.
C Surface values of the three components of displacement are placed
C in the output file plot.dat, as functions of surface co-ordinates
C along the strike and orthogonal to the strike, in preparation for
C contour plotting.
C

IMPLICIT DOUBLE PRECISION(A-H,O-Z)
DIMENSION U(3),UD(3),US(3),X(3)
DOUBLE PRECISION L
OPEN(UNIT=1,FILE='plot.dat',STATUS='UNKNOWN')
C Define pi.
PI=3.141592653589793D0
C Enter fault parameters.
WRITE(6,10)

10 FORMAT(1X,'Enter dip angle in degrees.')

READ(5,*)DIP
WRITE(6,11)

11 FORMAT(1X,'Enter slip in metres.')

READ(5,*)SLIP
WRITE(6,12)

12 FORMAT(1X,'Enter rake angle in degrees.')

READ(5,*)RAKE