.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "api/gallery/plate_tectonics/plot_07_hess_seafloor_spreading.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_plate_tectonics_plot_07_hess_seafloor_spreading.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_plate_tectonics_plot_07_hess_seafloor_spreading.py:


Hess's seafloor spreading (1962)
================================

Harry Hess proposed that new ocean floor forms at mid-ocean ridges and moves
away on both sides. Two plates each moving at the half rate open the ridge at
twice that speed, and an ocean basin a few thousand kilometres wide is
renewed in a few hundred million years.

.. GENERATED FROM PYTHON SOURCE LINES 10-32



.. image-sg:: /api/gallery/plate_tectonics/images/sphx_glr_plot_07_hess_seafloor_spreading_001.png
   :alt: Both flanks grow from the ridge
   :srcset: /api/gallery/plate_tectonics/images/sphx_glr_plot_07_hess_seafloor_spreading_001.png
   :class: sphx-glr-single-img





.. code-block:: Python


    import matplotlib.pyplot as plt
    import numpy as np

    from earthsciencekit.plate_tectonics import full_spreading_rate
    from earthsciencekit.units import convert

    half = convert(np.array([1.0, 2.5, 5.0]), "cm/year", "m/s")
    full = full_spreading_rate(half)
    np.testing.assert_allclose(full, 2 * half)
    renewal = 5e6 / full_spreading_rate(convert(1.0, "cm/year", "m/s"))
    assert np.isclose(convert(renewal, "s", "year"), 250e6)

    time = convert(np.linspace(0, 200e6, 101), "year", "s")
    fig, ax = plt.subplots()
    for h, f in zip(half, full):
        ax.plot(convert(time, "s", "year") / 1e6, f * time / 1e3, label=f"half rate {convert(h, 'm/s', 'cm/year'):.1f} cm/year")
    ax.axhline(5000, color="k", ls="--", lw=0.8)
    ax.set(xlabel="time [million years]", ylabel="new ocean floor [km]", title="Both flanks grow from the ridge")
    ax.legend()

    plt.show()


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

   **Total running time of the script:** (0 minutes 0.100 seconds)


.. _sphx_glr_download_api_gallery_plate_tectonics_plot_07_hess_seafloor_spreading.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/plate_tectonics/plot_07_hess_seafloor_spreading.ipynb
        :alt: Launch JupyterLite
        :width: 150 px

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

      :download:`Download Jupyter notebook: plot_07_hess_seafloor_spreading.ipynb <plot_07_hess_seafloor_spreading.ipynb>`

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

      :download:`Download Python source code: plot_07_hess_seafloor_spreading.py <plot_07_hess_seafloor_spreading.py>`

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

      :download:`Download zipped: plot_07_hess_seafloor_spreading.zip <plot_07_hess_seafloor_spreading.zip>`


.. only:: html

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

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