.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "api/gallery/volcanology/plot_07_urey_isotope_paleothermometer.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_volcanology_plot_07_urey_isotope_paleothermometer.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_volcanology_plot_07_urey_isotope_paleothermometer.py:


Urey's isotope paleothermometer (1947)
======================================

Harold Urey calculated that the oxygen-18 content of calcite precipitated from
water depends on temperature, and proposed reading ancient ocean temperatures
from fossil shells. Epstein, Buchsbaum, Lowenstam and Urey calibrated the scale
in 1953: about 4 K of cooling per per mil of enrichment. The synthetic shell
record below converts delta values into temperatures.

.. GENERATED FROM PYTHON SOURCE LINES 11-33



.. image-sg:: /api/gallery/volcanology/images/sphx_glr_plot_07_urey_isotope_paleothermometer_001.png
   :alt: Epstein et al. (1953) scale, Seasons recorded in a shell
   :srcset: /api/gallery/volcanology/images/sphx_glr_plot_07_urey_isotope_paleothermometer_001.png
   :class: sphx-glr-single-img





.. code-block:: Python


    import matplotlib.pyplot as plt
    import numpy as np

    from earthsciencekit.units import convert
    from earthsciencekit.volcanology import isotope_temperature

    difference = np.linspace(-3, 3, 121)
    temperature = convert(isotope_temperature(difference, 0), "K", "degC")
    assert np.all(np.diff(temperature) < 0)
    assert np.isclose(temperature[60], 16.5) and 3.8 < temperature[40] - temperature[60] < 4.6

    layer = np.arange(12)
    shells = -0.5 + 0.8 * np.sin(2 * np.pi * layer / 12)  # synthetic seasonal delta18O, water at 0 per mil
    fig, (left, right) = plt.subplots(1, 2, figsize=(10, 4))
    left.plot(difference, temperature)
    left.set(xlabel="delta18O calcite - water [per mil]", ylabel="temperature [degC]", title="Epstein et al. (1953) scale")
    right.plot(layer, convert(isotope_temperature(shells, 0), "K", "degC"), "o-")
    right.set(xlabel="growth band", ylabel="temperature [degC]", title="Seasons recorded in a shell")
    fig.tight_layout()

    plt.show()


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

   **Total running time of the script:** (0 minutes 0.180 seconds)


.. _sphx_glr_download_api_gallery_volcanology_plot_07_urey_isotope_paleothermometer.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/volcanology/plot_07_urey_isotope_paleothermometer.ipynb
        :alt: Launch JupyterLite
        :width: 150 px

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

      :download:`Download Jupyter notebook: plot_07_urey_isotope_paleothermometer.ipynb <plot_07_urey_isotope_paleothermometer.ipynb>`

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

      :download:`Download Python source code: plot_07_urey_isotope_paleothermometer.py <plot_07_urey_isotope_paleothermometer.py>`

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

      :download:`Download zipped: plot_07_urey_isotope_paleothermometer.zip <plot_07_urey_isotope_paleothermometer.zip>`


.. only:: html

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

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