Focal mechanisms

The pygmt.Figure.meca method can plot focal mechanisms, or beachballs. We can specify the focal mechanism nodal planes or moment tensor components as a dict using the spec parameter (or they can be specified as a 1d or 2d array, or within a specified file). The size of plotted beachballs can be specified using the scale parameter.

Out:

-124.3 48.1 12.0
{'strike': 330, 'dip': 30, 'rake': 90, 'magnitude': 3, 'longitude': array([-124.3]), 'latitude': array([48.1]), 'depth': array([12.])}
   strike  dip  rake  magnitude  longitude  latitude  depth
0     330   30    90          3     -124.3      48.1   12.0
   longitude  latitude  depth  strike  dip  rake  magnitude
0     -124.3      48.1   12.0     330   30    90          3
@GMTAPI@-S-I-D-V-T-N-000000 -Sa1c
<IPython.core.display.Image object>

import pygmt

fig = pygmt.Figure()

# generate a basemap near Washington state showing coastlines, land, and water
fig.coast(
    region=[-125, -122, 47, 49],
    projection="M6c",
    land="grey",
    water="lightblue",
    shorelines=True,
    frame="a",
)

# store focal mechanisms parameters in a dict
focal_mechanism = dict(strike=330, dip=30, rake=90, magnitude=3)

# pass the focal mechanism data to meca in addition to the scale and event
# location
fig.meca(focal_mechanism, scale="1c", longitude=-124.3, latitude=48.1, depth=12.0)

fig.show()