Gravity ground-based data over the Bushveld Complex, Southern Africa

Gravity ground-based data over the Bushveld Complex, Southern Africa#

This dataset contains ground gravity observations over the area that comprises the Bushveld Igenous Complex in Southern Africa, including preprocessed gravity fields such as the gravity disturbance and the Bouguer gravity disturbance (topography-free gravity disturbance). In addition, the dataset contains the heights of the observation points referenced on the WGS84 reference ellipsoid and over the mean sea-level (what can be considered to be the geoid). This dataset was built upon a portion of the Southern Africa gravity compilation available through NOAA NCEI.

Original source:

Pre-processing: Source code for preparation of the original dataset for redistribution in Ensaio

import numpy as np
import pandas as pd
import pygmt

import ensaio

Download and cache the data and return the path to it on disk

/home/runner/work/_temp/cache/ensaio/v1/bushveld-gravity.csv.xz

Load the CSV formatted data with pandas

longitude latitude height_sea_level_m height_geometric_m gravity_mgal gravity_disturbance_mgal gravity_bouguer_mgal
0 25.01500 -26.26334 1230.2 1257.474535 978681.38 25.081592 -113.259165
1 25.01932 -26.38713 1297.0 1324.574150 978669.02 24.538158 -122.662101
2 25.02499 -26.39667 1304.8 1332.401322 978669.28 26.526960 -121.339321
3 25.04500 -26.07668 1165.2 1192.107148 978681.08 17.954814 -113.817543
4 25.07668 -26.35001 1262.5 1289.971792 978665.19 12.700307 -130.460126
... ... ... ... ... ... ... ...
3872 31.51500 -23.86333 300.5 312.710241 978776.85 -4.783965 -39.543608
3873 31.52499 -23.30000 280.7 292.686630 978798.55 48.012766 16.602026
3874 31.54832 -23.19333 245.7 257.592670 978803.55 49.161771 22.456674
3875 31.57333 -23.84833 226.8 239.199065 978808.44 5.116904 -20.419870
3876 31.37500 -23.00000 285.6 297.165672 978734.77 5.186926 -25.922627

3877 rows × 7 columns



Make a PyGMT map with the data points colored by the gravity data.

fig = pygmt.Figure()
fig.basemap(
    region=[
        data.longitude.min(),
        data.longitude.max(),
        data.latitude.min(),
        data.latitude.max(),
    ],
    projection="M15c",
    frame=True,
)
fig.coast(land="#444444")
scale = np.max(np.abs(data.gravity_disturbance_mgal))
pygmt.makecpt(
    cmap="polar",
    series=[-scale, scale],
)
fig.plot(
    x=data.longitude,
    y=data.latitude,
    fill=data.gravity_disturbance_mgal,
    cmap=True,
    style="c0.1c",
)
fig.colorbar(frame='af+l"gravity disturbance [mGal]"')
fig.show()
bushveld gravity

Total running time of the script: (0 minutes 4.158 seconds)

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