pygmt.Figure.meca

Figure.meca(spec, scale, convention=None, component='full', longitude=None, latitude=None, depth=None, plot_longitude=None, plot_latitude=None, event_name=None, *, offset=None, frame=None, cmap=None, extensionfill=None, labelbox=None, compressionfill=None, projection=None, outline=None, no_clip=None, region=None, nodal=None, verbose=None, pen=None, panel=None, perspective=None, transparency=None, **kwargs)

Plot focal mechanisms.

Full option list at https://docs.generic-mapping-tools.org/6.5/supplements/seis/meca.html

Aliases:

  • A = offset

  • B = frame

  • C = cmap

  • E = extensionfill

  • Fr = labelbox

  • G = compressionfill

  • J = projection

  • L = outline

  • N = no_clip

  • R = region

  • T = nodal

  • V = verbose

  • W = pen

  • c = panel

  • p = perspective

  • t = transparency

Parameters:

  • spec (str, 1-D array, 2-D array, dict, or pd.DataFrame) –

    Data that contain focal mechanism parameters.

    spec can be specified in either of the following types:

    • str: a file name containing focal mechanism parameters as columns. The meaning of each column is:

      • Columns 1 and 2: event longitude and latitude

      • Column 3: event depth (in km)

      • Columns 4 to 3+n: focal mechanism parameters. The number of columns n depends on the choice of convention, which will be described below.

      • Columns 4+n and 5+n: longitude, latitude at which to place beachball. Using 0 0 will plot the beachball at the longitude, latitude given in columns 1 and 2. [optional and requires offset=True to take effect].

      • Text string to appear near the beachball [optional].

    • 1-D array: focal mechanism parameters of a single event. The meanings of columns are the same as above.

    • 2-D array: focal mechanism parameters of multiple events. The meanings of columns are the same as above.

    • dictionary or pd.DataFrame: The dictionary keys or pd.DataFrame column names determine the focal mechanism convention. For different conventions, the following combination of keys are allowed:

      • "aki": strike, dip, rake, magnitude

      • "gcmt": strike1, dip1, rake1, strike2, dip2, rake2, mantissa, exponent

      • "mt": mrr, mtt, mff, mrt, mrf, mtf, exponent

      • "partial": strike1, dip1, strike2, fault_type, magnitude

      • "principal_axis": t_value, t_azimuth, t_plunge, n_value, n_azimuth, n_plunge, p_value, p_azimuth, p_plunge, exponent

      A dictionary may contain values for a single focal mechanism or lists of values for multiple focal mechanisms.

      Both dictionary and pd.DataFrame may optionally contain keys/column names: latitude, longitude, depth, plot_longitude, plot_latitude, and/or event_name.

    If spec is either a str, a 1-D array or a 2-D array, the convention parameter is required so we know how to interpret the columns. If spec is a dictionary or a pd.DataFrame, convention is not needed and is ignored if specified.

  • scale (float or str) – scale[+aangle][+ffont][+jjustify][+l][+m][+odx[/dy]][+sreference]. Adjust scaling of the radius of the beachball, which is proportional to the magnitude. By default, scale defines the size for magnitude = 5 (i.e., scalar seismic moment M0 = 4.0E23 dynes-cm). If +l is used the radius will be proportional to the seismic moment instead. Use +s and give a reference to change the reference magnitude (or moment), and use +m to plot all beachballs with the same size. A text string can be specified to appear near the beachball (corresponding to column or parameter event_name). Append +aangle to change the angle of the text string; append +ffont to change its font (size,fontname,color); append +jjustify to change the text location relative to the beachball [Default is "TC", i.e., Top Center]; append +o to offset the text string by dx/dy.

  • convention (str) –

    Focal mechanism convention. Choose from:

    • "aki" (Aki & Richards)

    • "gcmt" (global CMT)

    • "mt" (seismic moment tensor)

    • "partial" (partial focal mechanism)

    • "principal_axis" (principal axis)

    Ignored if spec is a dictionary or pd.DataFrame.

  • component (str) –

    The component of the seismic moment tensor to plot.

    • "full": the full seismic moment tensor

    • "dc": the closest double couple defined from the moment tensor (zero trace and zero determinant)

    • "deviatoric": deviatoric part of the moment tensor (zero trace)

  • longitude (float, list, or 1-D numpy array) – Longitude(s) of event location(s). Must be the same length as the number of events. Will override the longitude values in spec if spec is a dictionary or pd.DataFrame.

  • latitude (float, list, or 1-D numpy array) – Latitude(s) of event location(s). Must be the same length as the number of events. Will override the latitude values in spec if spec is a dictionary or pd.DataFrame.

  • depth (float, list, or 1-D numpy array) – Depth(s) of event location(s) in kilometers. Must be the same length as the number of events. Will override the depth values in spec if spec is a dictionary or pd.DataFrame.

  • plot_longitude (float, str, list, or 1-D numpy array) – Longitude(s) at which to place beachball(s). Must be the same length as the number of events. Will override the plot_longitude values in spec if spec is a dictionary or pd.DataFrame.

  • plot_latitude (float, str, list, or 1-D numpy array) – Latitude(s) at which to place beachball(s). List must be the same length as the number of events. Will override the plot_latitude values in spec if spec is a dictionary or pd.DataFrame.

  • event_name (str, list of str, or 1-D numpy array) – Text string(s), e.g., event name(s) to appear near the beachball(s). List must be the same length as the number of events. Will override the event_name labels in spec if spec is a dictionary or pd.DataFrame.

  • labelbox (bool or str) – [fill]. Draw a box behind the label if given. Use fill to give a fill color [Default is "white"].

  • offset (bool or str) – [+ppen][+ssize]. Offset beachball(s) to longitude(s) and latitude(s) specified in the the last two columns of the input file or array, or by plot_longitude and plot_latitude if provided. A small circle is plotted at the initial location and a line connects the beachball to the circle. Use +ssize to set the diameter of the circle [Default is no circle]. Use +ppen to set the pen attributes for this feature [Default is set via pen]. The fill of the circle is set via compressionfill or cmap, i.e., corresponds to the fill of the compressive quadrants.

  • compressionfill (str) – Set color or pattern for filling compressive quadrants [Default is "black"]. This setting also applies to the fill of the circle defined via offset.

  • extensionfill (str) – Set color or pattern for filling extensive quadrants [Default is "white"].

  • pen (str) – Set pen attributes for all lines related to beachball [Default is "0.25p,black,solid"]. This setting applies to outline, nodal, and offset, unless overruled by arguments passed to those parameters. Draws circumference of beachball.

  • outline (bool or str) – [pen]. Draw circumference and nodal planes of beachball. Use pen to set the pen attributes for this feature [Default is set via pen].

  • nodal (bool, int, or str) –

    [nplane][/pen]. Plot the nodal planes and outline the bubble which is transparent. If nplane is

    • 0 or True: both nodal planes are plotted [Default].

    • 1: only the first nodal plane is plotted.

    • 2: only the second nodal plane is plotted.

    Use /pen to set the pen attributes for this feature [Default is set via pen]. For double couple mechanisms, nodal renders the beachball transparent by drawing only the nodal planes and the circumference. For non-double couple mechanisms, nodal=0 overlays best double couple transparently.

  • cmap (str) – File name of a CPT file or a series of comma-separated colors (e.g., color1,color2,color3) to build a linear continuous CPT from those colors automatically. The color of the compressive quadrants is determined by the z-value (i.e., event depth or the third column for an input file). This setting also applies to the fill of the circle defined via offset.

  • no_clip (bool) – Do not skip symbols that fall outside the frame boundaries [Default is False, i.e., plot symbols inside the frame boundaries only].

  • projection (str) – projcode[projparams/]width|scale. Select map projection.

  • region (str or list) – xmin/xmax/ymin/ymax[+r][+uunit]. Specify the region of interest.

  • frame (bool, str, or list) – Set map boundary frame and axes attributes.

  • verbose (bool or str) –

    Select verbosity level [Default is w], which modulates the messages written to stderr. Choose among 7 levels of verbosity:

    • q - Quiet, not even fatal error messages are produced

    • e - Error messages only

    • w - Warnings [Default]

    • t - Timings (report runtimes for time-intensive algorithms)

    • i - Informational messages (same as verbose=True)

    • c - Compatibility warnings

    • d - Debugging messages

  • panel (bool, int, or list) – [row,col|index]. Select a specific subplot panel. Only allowed when in subplot mode. Use panel=True to advance to the next panel in the selected order. Instead of row,col you may also give a scalar value index which depends on the order you set via autolabel when the subplot was defined. Note: row, col, and index all start at 0.

  • perspective (list or str) – [x|y|z]azim[/elev[/zlevel]][+wlon0/lat0[/z0]][+vx0/y0]. Select perspective view and set the azimuth and elevation angle of the viewpoint [Default is [180, 90]]. Full documentation is at https://docs.generic-mapping-tools.org/6.5/gmt.html#perspective-full.

  • transparency (float) – Set transparency level, in [0-100] percent range [Default is 0, i.e., opaque]. Only visible when PDF or raster format output is selected. Only the PNG format selection adds a transparency layer in the image (for further processing).

Examples using pygmt.Figure.meca

Bit and hachure patterns

Bit and hachure patterns

Focal mechanisms

Focal mechanisms