Focal Mechanism Beachball Plot

This example shows how to create a heatmap of the moment tensor matrix

import matplotlib.pyplot as plt
import numpy as np
from fracspy.visualisation.momenttensor_plots import MTBeachball


plt.close("all")
np.random.seed(0)

Let’s start by creating a moment tensor, as the moment tensor is a symmetric matrix we only need to define 6 of the 9 components

mt_xx = 0
mt_yy = 0
mt_zz = 0
mt_xy = -1
mt_xz = 0
mt_yz = 0
mt = [mt_xx, mt_yy, mt_zz, mt_xy, mt_xz, mt_yz]
print(mt)

[0, 0, 0, -1, 0, 0]

We are going to visualise the moment tensor in the common form of a beachball defined by the microseismic event’s focal mechanism. The plotting function handles conversion of the six-component moment tensor to the focal mechanism form desired by the ObSpy python package. After which, the beachball is drawn and attached to the provided axis. Here we utilise the function: pyfrac.visualisation.momenttensor_plots.MTBeachball

fig, ax = plt.subplots(1,1,figsize=[4.8,4.8])
MTBeachball(mt,ax)
plt.show()