pyrocko.gf.tractions

Traction field parameterizations used by PDR source.

Functions

plot_tractions(tractions[, nx, ny, depth, ...])

Plot traction model for quick inspection.

Classes

AbstractTractionField(**kwargs)	Base class for multiplicative traction fields (tapers).
DepthTaper(**kwargs)	Undocumented.
DirectedTractions(**kwargs)	Directed traction field.
FractalTractions(*args, **kwargs)	Fractal traction field.
HomogeneousTractions(**kwargs)	Homogeneous traction field.
RectangularTaper(**kwargs)	Undocumented.
SelfSimilarTractions(**kwargs)	Traction model following Power & Tullis (1991).
TractionComposition(**kwargs)	Composition of traction fields.
TractionField(**kwargs)	Base class for additive traction fields.

class AbstractTractionField(**kwargs)

Bases: Object

Base class for multiplicative traction fields (tapers).

Fields of this type a re multiplied in the TractionComposition

class TractionField(**kwargs)

Bases: AbstractTractionField

Base class for additive traction fields.

Fields of this type are added in the TractionComposition

class TractionComposition(**kwargs)

Bases: TractionField

Composition of traction fields.

TractionField and AbstractTractionField can be combined to realize a combination of different fields.

♦ components

list of AbstractTractionField objects, default: []

Ordered list of tractions.

class HomogeneousTractions(**kwargs)

Bases: TractionField

Homogeneous traction field.

The traction vectors in strike, dip and normal direction are acting homogeneously on the rupture plane.

♦ strike

float, default: 1.0

Tractions in strike direction [Pa].

♦ dip

float, default: 1.0

Traction in dip direction (up) [Pa].

♦ normal

float, default: 1.0

Traction in normal direction [Pa].

class DirectedTractions(**kwargs)

Bases: TractionField

Directed traction field.

The traction vectors are following a uniform rake.

♦ rake

float, default: 0.0

Rake angle in [deg], measured counter-clockwise from right-horizontal in on-plane view. Rake is translated into homogenous tractions in strike and up-dip direction.

♦ traction

float, default: 1.0

Traction in rake direction [Pa].

class SelfSimilarTractions(**kwargs)

Bases: TractionField

Traction model following Power & Tullis (1991).

The traction vectors are calculated as a sum of 2D-cosines with a constant amplitude / wavelength ratio. The wavenumber kx and ky are constant for each cosine function. The rank defines the maximum wavenumber used for summation. So, e.g. a rank of 3 will lead to a summation of cosines with kx = ky in (1, 2, 3). Each cosine has an associated phases, which defines both the phase shift and also the shift from the rupture plane centre. Finally the summed cosines are translated into shear tractions based on the rake and normalized with traction_max.

♦ rank

int, default: 1

Maximum summed cosine wavenumber/spatial frequency.

♦ rake

float, default: 0.0

Rake angle in [deg], measured counter-clockwise from right-horizontal in on-plane view. Rake is translated into homogenous tractions in strike and up-dip direction.

♦ traction_max

float, default: 1.0

Maximum traction vector length [Pa].

♦ phases

numpy.ndarray (pyrocko.guts_array.Array), optional

Phase shift of the cosines in [rad].

class FractalTractions(*args, **kwargs)

Bases: TractionField

Fractal traction field.

♦ rseed

int, optional

Seed for RandomState.If None, an random seed will be initialized.

♦ rake

float, default: 0.0

Rake angle in [deg], measured counter-clockwise from right-horizontal in on-plane view. Rake is translated into homogenous tractions in strike and up-dip direction.

♦ traction_max

float, default: 1.0

Maximum traction vector length [Pa].

class RectangularTaper(**kwargs)

Bases: AbstractTractionField

Undocumented.

♦ width

float, default: 0.2

Width of the taper as a fraction of the plane.

♦ type

str (pyrocko.guts.StringChoice), default: 'tukey'

Type of the taper, default: “tukey”.

class DepthTaper(**kwargs)

Bases: AbstractTractionField

Undocumented.

♦ depth_start

float

Depth where the taper begins [m].

♦ depth_stop

float

Depth where taper ends and drops to zero [m].

♦ type

str (pyrocko.guts.StringChoice), default: 'linear'

Type of the taper, default: “linear”.

plot_tractions(tractions, nx=15, ny=12, depth=10000.0, component='strike')

Plot traction model for quick inspection.

Parameters:

• tractions (pyrocko.gf.tractions.TractionField) – Traction field or traction composition to be displayed.

• nx (int) – Number of patches along strike.

• ny (int) – Number of patches down dip.

• depth (float) – Depth of the rupture plane center in [m].

• component (str) – Choice of traction component to be shown. Available: 'tx' (along strike), 'ty' (up dip), 'tz' (normal), 'absolute' (vector length).