landlab.components.tectonics.listric_kinematic_extender¶

Apply tectonic extension kinematically.

Landlab component that simulates development of an asymmetric rift on a listric fault plane.

See notebook tutorial for theory and examples.

@author: gtucker

class ListricKinematicExtender[source]¶

Bases: Component

Apply tectonic extension kinematically to a raster or hex grid.

The caller specifies the strike, dip, and location of the zero-surface fault trace (i.e., where the fault plane would intersect zero elevation), and either the (x, y) components of uniform extension velocity field, or a link-based velocity field. The run_one_step() method calculates advection of an output field called “hangingwall__thickness”. The initial hanginwall thickness is defined as the difference between the starting topography field (a required input field) and a listric fault plane that is represented mathematically as an “upside-down” saturating exponential function that asymptotes to a caller-specified detachment depth, representing a decollement.

Examples

>>> from landlab import RasterModelGrid
>>> from landlab.components import ListricKinematicExtender
>>> grid = RasterModelGrid((3, 130), xy_spacing=10.0)
>>> topo = grid.add_zeros("topographic__elevation", at="node")
>>> lke = ListricKinematicExtender(grid, fault_x0=100.0, fault_strike=90.0)
>>> for _ in range(250):
...     lke.run_one_step(dt=2000.0)
...
>>> round(grid.at_node["hangingwall__thickness"][240])
830

Deform vertically and horizontally to represent tectonic extension.

Parameters:

grid (RasterModelGrid) – A landlab grid.
extension_rate_x (float, optional) – Rate of x-directed horizontal motion of hangingwall relative to footwall (m / y), default 0.001 m/y.
extension_rate_y (float, optional) – Rate of y-directed horizontal motion of hangingwall relative to footwall (m / y), default 0.
fault_x0 (float, optional) – x intercept of zero-surface fault trace, m (default 0).
fault_y0 (float, optional) – y intercept of zero-surface fault trace, m (default 0).
fault_strike (float, optional) – Strike of zero-surface fault trace, degrees (default 45).
detachment_depth (float, optional) – Depth to horizontal detachment (m), default 10 km.
fields_to_advect (list of str, optional) – List of names of fields, in addition to ‘hangingwall__thickness’
advection_direction_is_steady (bool (default False)) – Indicates whether the directions of advection are expected to remain steady throughout a run. If True, some computation time is saved by calculating upwind links only once.

__init__(grid, extension_rate_x=0.001, extension_rate_y=0.0, fault_dip=60.0, fault_x0=0.0, fault_y0=0.0, fault_strike=45.0, detachment_depth=10000.0, fields_to_advect=None, advection_direction_is_steady=False)[source]¶

Deform vertically and horizontally to represent tectonic extension.

Parameters:

grid (RasterModelGrid) – A landlab grid.
extension_rate_x (float, optional) – Rate of x-directed horizontal motion of hangingwall relative to footwall (m / y), default 0.001 m/y.
extension_rate_y (float, optional) – Rate of y-directed horizontal motion of hangingwall relative to footwall (m / y), default 0.
fault_x0 (float, optional) – x intercept of zero-surface fault trace, m (default 0).
fault_y0 (float, optional) – y intercept of zero-surface fault trace, m (default 0).
fault_strike (float, optional) – Strike of zero-surface fault trace, degrees (default 45).
detachment_depth (float, optional) – Depth to horizontal detachment (m), default 10 km.
fields_to_advect (list of str, optional) – List of names of fields, in addition to ‘hangingwall__thickness’
advection_direction_is_steady (bool (default False)) – Indicates whether the directions of advection are expected to remain steady throughout a run. If True, some computation time is saved by calculating upwind links only once.

static __new__(cls, *args, **kwds)¶

cite_as = ''¶

property coords¶: Return the coordinates of nodes on grid attached to the component.

property current_time¶

Current time.

Some components may keep track of the current time. In this case, the current_time attribute is incremented. Otherwise it is set to None.

Return type:: current_time

definitions = (('advection__velocity', 'Link-parallel advection velocity magnitude'), ('fault_plane__elevation', 'Elevation of fault plane'), ('hangingwall__thickness', 'Thickness of material in hangingwall block'), ('topographic__elevation', 'Land surface topographic elevation'))¶

classmethod from_path(grid, path)¶

Create a component from an input file.

Parameters:

grid (ModelGrid) – A landlab grid.
path (str or file_like) – Path to a parameter file, contents of a parameter file, or a file-like object.

Returns:

A newly-created component.

Return type:

Component

property grid¶: Return the grid attached to the component.

initialize_optional_output_fields()¶

Create fields for a component based on its optional field outputs, if declared in _optional_var_names.

This method will create new fields (without overwrite) for any fields output by the component as optional. New fields are initialized to zero. New fields are created as arrays of floats, unless the component also contains the specifying property _var_type.

initialize_output_fields(values_per_element=None)¶

Create fields for a component based on its input and output var names.

This method will create new fields (without overwrite) for any fields output by, but not supplied to, the component. New fields are initialized to zero. Ignores optional fields. New fields are created as arrays of floats, unless the component specifies the variable type.

Parameters:: values_per_element (int (optional)) – On occasion, it is necessary to create a field that is of size (n_grid_elements, values_per_element) instead of the default size (n_grid_elements,). Use this keyword argument to acomplish this task.

input_var_names = ('topographic__elevation',)¶

name = 'ListricKinematicExtender'¶

optional_var_names = ('advection__velocity',)¶

output_var_names = ('fault_plane__elevation', 'hangingwall__thickness', 'topographic__elevation')¶

run_one_step(dt)[source]¶

Apply extensional motion to grid for one time step.

Parameters:: dt (float) – Time-step duration, y

property shape¶: Return the grid shape attached to the component, if defined.

unit_agnostic = True¶

units = (('advection__velocity', 'm/y'), ('fault_plane__elevation', 'm'), ('hangingwall__thickness', 'm'), ('topographic__elevation', 'm'))¶

update_fault_plane_elevation_and_hangingwall_thickness(grid, fault_x0, fault_y0, fault_strike, fault_dip, detachment_depth)[source]¶

Initialize fields fault_plane__elevation and hangingwall__thickness.

Calculate and store the fault plane elevation at grid nodes using an exponential function of (signed) distance to fault, with topographic elevation as the minimum. Calculate the thickness of the hangingwall block at grid nodes by subtracting fault plane elevation from topographic elevation.

Parameters:

fault_x0 (float) – x-intercept of zero-surface fault trace, m
fault_y0 (float) – y-intercept of zero-surface fault trace, m
fault_strike (float) – strike angle of fault trace, degrees ccw from +x
fault_dip (float) – dip angle of fault at the zero elevation point, degrees
detachment_depth (float) – depth to the point where the detachment is horizontal, m

Examples

>>> from landlab import RasterModelGrid
>>> from landlab.components import ListricKinematicExtender
>>> grid = RasterModelGrid((3, 3), xy_spacing=1000.0)
>>> _ = grid.add_zeros("topographic__elevation", at="node")
>>> extender = ListricKinematicExtender(grid, fault_strike=90.0)
>>> round(grid.at_node["fault_plane__elevation"][4])
-1590
>>> round(grid.at_node["hangingwall__thickness"][4])
1590

classmethod var_definition(name)¶

Get a description of a particular field.

Parameters:: name (str) – A field name.
Returns:: A description of each field.
Return type:: tuple of (name, *description*)

classmethod var_help(name)¶

Print a help message for a particular field.

Parameters:: name (str) – A field name.

classmethod var_loc(name)¶

Location where a particular variable is defined.

Parameters:: name (str) – A field name.
Returns:: The location (‘node’, ‘link’, etc.) where a variable is defined.
Return type:: str

var_mapping = (('advection__velocity', 'link'), ('fault_plane__elevation', 'node'), ('hangingwall__thickness', 'node'), ('topographic__elevation', 'node'))¶

classmethod var_type(name)¶

Returns the dtype of a field (float, int, bool, str…).

Parameters:: name (str) – A field name.
Returns:: The dtype of the field.
Return type:: dtype

classmethod var_units(name)¶

Get the units of a particular field.

Parameters:: name (str) – A field name.
Returns:: Units for the given field.
Return type:: str

dist_to_line(Px, Py, x0, y0, alpha)[source]¶

Calculate and return the distance of point(x) (Px, Py) to the line described by x = x0 + t cos alpha, y = y0 + t sin alpha.

Parameters:

Px (float) – x-coordinate of point(s)
Py (float) – y-coordinate of point(s)
x0 (float) – x intercept of line
y0 (float) – y intercept of line
alpha (float, degrees) – angle of line, counter-clockwise from positive x-axis

Examples

>>> np.round(dist_to_line(1, 1, 0, 0, 90), 6)
1.0
>>> np.round(dist_to_line(0, 1, 1, 0, 90), 6)
-1.0
>>> np.round(dist_to_line(1, 1, 0, 0, 0), 6)
-1.0
>>> np.round(dist_to_line(2.0**0.5, 0, 0, 0, 45), 6)
1.0
>>> np.round(dist_to_line(0, 2.0**0.5, 0, 0, 45), 6)
-1.0