diabayes.forward_models.cns_porosity

diabayes.forward_models.cns_porosity(v: Float, variables: Variables, params: CNSParams, constants: CNSConstants) → Float

The porosity (state) evolution for the Chen-Niemeijer-Spiers model

\[ \begin{align}\begin{aligned}\frac{\mathrm{d}\phi}{\mathrm{d}t} = - \left(1 - \phi \right) \left(\dot{\varepsilon}_{\text{gr}} + \dot{\varepsilon}_{\text{creep}} \right)\\\dot{\varepsilon}_{\text{gr}} = - \frac{\tan \psi}{h} \left( v - v_{\text{creep}} \right)\\\dot{\varepsilon}_{\text{creep}} = \frac{v_0}{h} \xi f(\phi)\\v_{\text{creep}} = v_0 \xi f(\phi) \mu\\\tan \psi = 2 \alpha \left( \phi_c - \phi \right)\\f(\phi) = \frac{\phi - \phi_0}{\phi_c - \phi}\end{aligned}\end{align} \]

Parameters:

• v (Float) – Instantaneous fault slip rate [m/s].

• variables (Variables) – The friction coefficient mu and gouge porosity phi

• params (CNSParams) – The CNS parameters alpha, beta, phi_c, xi, and mu0

• constants (CNSConstants) – The constant parameters v0, h, and phi0

Returns:

dphi – The rate of change of the porosity [1/s]

Return type:

Float