.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "api/gallery/seismology/plot_15_hanks_kanamori_moment_magnitude.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        :ref:`Go to the end <sphx_glr_download_api_gallery_seismology_plot_15_hanks_kanamori_moment_magnitude.py>`
        to download the full example code or to run this example in your browser via JupyterLite.

.. rst-class:: sphx-glr-example-title

.. _sphx_glr_api_gallery_seismology_plot_15_hanks_kanamori_moment_magnitude.py:


Hanks and Kanamori's moment magnitude (1979)
============================================

Thomas Hanks and Hiroo Kanamori defined a magnitude from the seismic moment
so that it matches the older scales where they work and keeps growing for
great earthquakes. Each unit of magnitude multiplies the moment by
10^1.5, about 32. The SI form uses Mw = (2/3)(log10 M0 - 9.1).

.. GENERATED FROM PYTHON SOURCE LINES 10-30



.. image-sg:: /api/gallery/seismology/images/sphx_glr_plot_15_hanks_kanamori_moment_magnitude_001.png
   :alt: One magnitude unit is 32 times the moment
   :srcset: /api/gallery/seismology/images/sphx_glr_plot_15_hanks_kanamori_moment_magnitude_001.png
   :class: sphx-glr-single-img





.. code-block:: Python


    import matplotlib.pyplot as plt
    import numpy as np

    from earthsciencekit.seismology import moment_from_magnitude, moment_magnitude

    magnitude = np.linspace(2, 9.5, 100)
    moment = moment_from_magnitude(magnitude)
    np.testing.assert_allclose(moment_magnitude(moment), magnitude)
    assert np.isclose(moment_from_magnitude(7) / moment_from_magnitude(6), 10**1.5)

    events = {"Niigata 1964": 3e20, "Chile 1960": 2e23, "Tohoku 2011": 4e22}
    fig, ax = plt.subplots()
    ax.semilogy(magnitude, moment)
    for name, m0 in events.items():
        ax.semilogy(moment_magnitude(m0), m0, "o")
        ax.annotate(name, (moment_magnitude(m0), m0), textcoords="offset points", xytext=(-80, 5))
    ax.set(xlabel="moment magnitude Mw", ylabel="seismic moment [N m]", title="One magnitude unit is 32 times the moment")

    plt.show()


.. rst-class:: sphx-glr-timing

   **Total running time of the script:** (0 minutes 0.111 seconds)


.. _sphx_glr_download_api_gallery_seismology_plot_15_hanks_kanamori_moment_magnitude.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example

    .. container:: lite-badge

      .. image:: images/jupyterlite_badge_logo.svg
        :target: ../../../lite/lab/index.html?path=api/gallery/seismology/plot_15_hanks_kanamori_moment_magnitude.ipynb
        :alt: Launch JupyterLite
        :width: 150 px

    .. container:: sphx-glr-download sphx-glr-download-jupyter

      :download:`Download Jupyter notebook: plot_15_hanks_kanamori_moment_magnitude.ipynb <plot_15_hanks_kanamori_moment_magnitude.ipynb>`

    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: plot_15_hanks_kanamori_moment_magnitude.py <plot_15_hanks_kanamori_moment_magnitude.py>`

    .. container:: sphx-glr-download sphx-glr-download-zip

      :download:`Download zipped: plot_15_hanks_kanamori_moment_magnitude.zip <plot_15_hanks_kanamori_moment_magnitude.zip>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_