Geoscience Reference
In-Depth Information
Fig. 2.5 Geometry of the source model (length
L
, width
W
, Burger's vector D, dip angle
δ
,rake
angle
θ
, angle between Burger's vector D and the fault plane
γ
)
the foot-wall side block. Elementary dislocations
U
1
,
U
2
, and
U
3
are defined so as to
correspond to strike-slip, dip-slip and tensile components of arbitrary dislocations.
The tensile component
U
3
is normal to the fault plane.
A dislocation is determined by four angles: the strike angle
ϕ
(clockwise
from North), the dip angle
between
Burger's vector D and the fault plane. Elementary dislocations
U
1
,
U
2
and
U
3
are linked to Burger's vector in the following way:
U
1
=
δ
, the rake (slip) angle
θ
and the angle
γ
|
D
|
cos
γ
cos
θ
,
U
2
=
|
D
|
.
The final results are condensed into compact forms using Chinnery's notation
cos
γ
sin
θ
,
U
3
=
|
D
|
sin
γ
||
to represent the substitution
f
(
ξ
,
η
)
||
=
f
(
x
,
p
)
−
f
(
x
,
p
−
W
)
−
f
(
x
−
L
,
p
)+
f
(
x
−
L
,
p
−
W
)
.
(2.21)
For strike-slip
)
+ arctan
ξη
+
I
1
sin
ξ
U
1
2
q
R
(
R
+
u
x
=
−
δ
,
π
η
qR
yq
R
(
R
+
U
1
2
)
+
q
cos
δ
u
y
=
−
+
I
2
sin
δ
,
(2.22)
π
η
R
+
η
dq
R
(
R
+
U
1
2
)
+
q
sin
δ
u
z
=
−
+
I
4
sin
δ
.
π
η
R
+
η