Sign of stress
 
Positive for compression

ψ

Dip azimuth (clockwise from north)
 
α

Angle between S_{H} (slip) direction and dip azimuth

α = ψ (− 55°)

δ

Dip angle (positive downward)
 
σ
_{1}

Maximum compressional principal stress

σ_{1 =} S_{H}

σ
_{2}

Intermediate principal stress

σ_{2} = S_{h}

σ
_{3}

Minimum principal stress

σ_{3} = S_{v}

S
_{
H}

Maximum (compressional) horizontal principal stress

S_{H} = rS_{v} = 1.2S_{v}

S
_{
h}

Minimum horizontal principal stress

S_{h} = S_{v}

S
_{
v}

Vertical stress (overburden)

Calculated from 3D density

P
_{
p}

Pore fluid pressure

P_{p} = λS_{v} = 0.7S_{v}

P
_{
hyd}

Hydrostatic pore fluid pressure

P_{hyd} = 0.6S_{v}

σ
_{
H}

Effective maximum horizontal stress

σ_{H} = S_{H}  P_{p}

σ
_{
h}

Effective minimum horizontal stress

σ_{h} = S_{h}  P_{p}

σ
_{
v}

Effective vertical stress

σ_{v} = S_{v}P_{p}

Σ

Stress tensor
 
r

S_{H}/S_{v}

r = 1.2

λ

P_{p}/S_{v}

λ = 0.7, 0.94

λ*

(P_{p}  P_{hyd}) / (S_{v} – P_{hyd})

λ* = 0.2, 0.85

σ
_{
n}

Normal stress
 
σ
_{
n_e}

Effective normal stress

σ_{n_e} = σ_{n}  P_{p}(Eq. (7))

τ

Shear stress

Eq. (8)

Ts

Slip tendency

Ts = τ/σ_{n_e}, (Eq. (9))

μ

Intrinsic friction coefficient

μ = 0.6

SL

Slip likelihood

SL = Ts/μ

V
_{
p}

Pwave velocity
 