{"id":96,"date":"2018-03-14T15:26:37","date_gmt":"2018-03-14T19:26:37","guid":{"rendered":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/chapter\/3-4-earths-magnetic-field-2\/"},"modified":"2023-07-04T12:45:38","modified_gmt":"2023-07-04T16:45:38","slug":"earths-magnetic-field","status":"publish","type":"chapter","link":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/chapter\/earths-magnetic-field\/","title":{"raw":"3.4 Earth\u2019s Magnetic Field","rendered":"3.4 Earth\u2019s Magnetic Field"},"content":{"raw":"Similar to the mantle, Earth's liquid outer core convects because it's heated from beneath by the inner core. What's different is that because it's made of iron and conducts electricity (even when molten), the motion of the outer core generates a magnetic field.\r\n\r\nEarth\u2019s magnetic field is defined by north and south poles representing lines of magnetic force flowing into Earth in the northern hemisphere, and out of Earth in the southern hemisphere (Figure 3.14). Because of the shape of the field lines, the magnetic force is oriented at different angles to the surface in different locations. The tilt, or <strong>inclination<\/strong> of magnetic field lines is represented by the tilt of compass needles in Figure 3.14. At the north and south poles, the force is vertical. The force is horizontal at the equator. Everywhere in between, the magnetic force is at an intermediate angle to the surface.\r\n\r\n[caption id=\"attachment_93\" align=\"aligncenter\" width=\"626\"]<img class=\"wp-image-93\" src=\"https:\/\/opentextbc.ca\/kzlab\/wp-content\/uploads\/sites\/360\/2018\/03\/magnetic_field.png\" alt=\"\" width=\"626\" height=\"478\" \/> <strong>Figure 3.14<\/strong> Earth\u2019s magnetic field depicted as the field of a bar magnet coinciding with the core. The south pole of the magnet points to Earth\u2019s magnetic north pole. The red and white compass needles represent the orientation of the magnetic field at various locations on Earth\u2019s surface. Source: Karla Panchuk (2018). CC BY-SA 4.0. Modified after Steven Earle (2015; CC BY-SA 4.0, <a href=\"https:\/\/opentextbc.ca\/geology\/wp-content\/uploads\/sites\/110\/2015\/07\/image035.png\" target=\"_blank\" rel=\"noopener\">view source<\/a>), and T. Stein (2008; CC BY-SA 3.0 <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Earths_Magnetic_Field_Confusion.svg\" target=\"_blank\" rel=\"noopener\">view source<\/a>).[\/caption]\r\n\r\n<div class=\"textbox shaded\">\r\n\r\n<strong>Practice: Magnetic Inclination<\/strong>\r\n\r\nUse Figure 3.14 as a guide to help you complete this exercise.\r\n\r\n<div class=\"offline\"><strong>Write in the geographic locations to match up with the correct magnetic inclination (the up-and-down orientation of a compass needle).<\/strong>\r\n<ol>\r\n \t<li>Straight down- Quttinirpaaq National Park, Ellesmere Island. This is the current location of the\u00a0<span style=\"text-decoration: underline;\" aria-label-=\"blank\"> \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/span>.<\/li>\r\n \t<li>Down at a steep angle- Santa's workshop on a specially-designed ice breaker anchored in the Arctic Ocean (the location of the <span style=\"text-decoration: underline;\" aria-label-=\"blank\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/span>.)<\/li>\r\n \t<li>Up at a steep angle- McMurdo Station, which is on the coast of Antarctica near the <span style=\"text-decoration: underline;\" aria-label-=\"blank\">\u00a0\u00a0\u00a0\u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/span>.<\/li>\r\n \t<li>Parallel to flat ground- Damba Island, Uganda, which straddles the <span style=\"text-decoration: underline;\" aria-label-=\"blank\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/span>.<\/li>\r\n<\/ol>\r\nFill-in-the-blank options:\r\n<ul class=\"twocolumn\">\r\n \t<li>geographic north pole<\/li>\r\n \t<li>south pole<\/li>\r\n \t<li>magnetic north pole<\/li>\r\n \t<li>equator<\/li>\r\n<\/ul>\r\n<strong> To check your answers, navigate to the below link to view the interactive version of this activity.<\/strong>\r\n\r\n<\/div>\r\n[h5p id=\"44\"]\r\n<\/div>\r\n<h1>Polarity Reversals<\/h1>\r\n<h2>Instability in Earth's Magnetic Field<\/h2>\r\nEarth\u2019s magnetic field is generated mostly within the outer core by the convective movement of liquid iron, but although convection is continuous, the magnetic field is not stable. Periodically, the magnetic field decays, then re-estabilshes. When it does re-establish, the polarity may have reversed. In other words, your compass needle would point south rather than north.\r\n\r\nChanges in Earth\u2019s magnetic field have been studied using mathematical models that simulate convection in the outer core (Figure 3.15).\u00a0 Reversals happened spontaneously when the model was run to simulate a period of several hundred thousand years. Spontaneous reversals can happen because convection doesn't occur in an orderly way, in spite of what the bar magnet analogy may suggest.\r\n\r\n[caption id=\"attachment_94\" align=\"aligncenter\" width=\"650\"]<a href=\"https:\/\/opentextbc.ca\/physicalgeologyh5p\/chapter\/earths-magnetic-field\/polarity-reversal\/\"><img class=\"wp-image-94\" src=\"https:\/\/opentextbc.ca\/kzlab\/wp-content\/uploads\/sites\/360\/2021\/08\/polarity-reversal.png\" alt=\"\" width=\"650\" height=\"506\" \/><\/a> <strong>Figure 3.15<\/strong> Computer simulations showing Earth's \"normal\" magnetic field (top), and the magnetic field as polarity flips from reversed on the left to normal on the right. Notice how the magnetic field lines become disorganized, then converge on a more orderly arrangement. Source: Karla Panchuk (2021) CC BY 4.0. Click for more attributions.[\/caption]\r\n\r\nThe solid inner core also convects, with many small-scale variations in convection patterns, but it does so more slowly than the liquid outer core. Yet Earth's magnetic field is the sum of all of those variations\u2014both inner and outer\u2014and for a polarity reversal to \"take,\" a reversal must happen in the magnetic fields of both parts of the core. If the inner core weren't solid, magnetic reversals would happen far more frequently.\r\n<h2>How Often Do Polarity Reversals Happen?<\/h2>\r\nOver the past 250 Ma, there have been hundreds of magnetic field reversals, and their timing has been anything but regular. The shortest ones that geologists have been able to identify lasted only a few thousand years, and the longest one was more than 30 million years, during the Cretaceous Period (Figure 3.16).\r\n\r\n[caption id=\"attachment_95\" align=\"aligncenter\" width=\"1024\"]<img class=\"wp-image-95 size-large\" src=\"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/360\/2021\/08\/paleomag_reversals_SE-1024x153.png\" alt=\"\" width=\"1024\" height=\"153\" \/> <strong>Figure 3.16<\/strong> Magnetic field reversal chronology for the past 170 Ma. Black stripes mark times when the magnetic field was oriented the same as today. Source: Steven Earle (2015). CC BY 4.0. <a href=\"https:\/\/opentextbc.ca\/geology\/wp-content\/uploads\/sites\/110\/2015\/07\/image037.png\" rel=\"noopener\">Image source.<\/a> Modified after AnomieX (2010), Public Domain. <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Geomagnetic_polarity_0-169_Ma.svg\" rel=\"noopener\">Image source.<\/a>[\/caption]\r\n\r\n<div class=\"textbox shaded\">\r\n\r\n<strong>Concept Check: Polarity Reversals<\/strong>\r\n\r\n<div class=\"offline\">\r\n\r\n<strong>Magnetic polarity reversals happen because:<\/strong>\r\n<ol type=\"a\">\r\n \t<li>Earth flips over so that it's geographic poles change place.<\/li>\r\n \t<li>A new pattern develops in how Earth's core churns itself.<\/li>\r\n \t<li>Earth's core switches to rotating in the opposite direction within Earth.<\/li>\r\n \t<li>Earth switches to rotating in the opposite direction on its axis.<\/li>\r\n<\/ol>\r\nTo check your answers, navigate to the below link to view the interactive version of this activity.\r\n\r\n<\/div>\r\n\r\n[h5p id=\"45\"]\r\n<\/div>\r\n<h4>References<\/h4>\r\n<p class=\"hanging-indent\">British Geological Survey, Natural Environment Research Council (n.d.). <em>Reversals: Magnetic flip<\/em>. http:\/\/www.geomag.bgs.ac.uk\/education\/reversals.html<\/p>\r\n<p class=\"hanging-indent\">Glatzmaier, G. A. (n.d.) <em>The geodynamo<\/em>. https:\/\/websites.pmc.ucsc.edu\/~glatz\/geodynamo.html<\/p>\r\n<p class=\"hanging-indent\">Glatzmaier, G. A., &amp; Roberts, P.H. (1995). A three-dimensional self-consistent computer simulation of a geomagnetic field reversal.<em> Nature, 377<\/em>, 203-209.<\/p>","rendered":"<p>Similar to the mantle, Earth&#8217;s liquid outer core convects because it&#8217;s heated from beneath by the inner core. What&#8217;s different is that because it&#8217;s made of iron and conducts electricity (even when molten), the motion of the outer core generates a magnetic field.<\/p>\n<p>Earth\u2019s magnetic field is defined by north and south poles representing lines of magnetic force flowing into Earth in the northern hemisphere, and out of Earth in the southern hemisphere (Figure 3.14). Because of the shape of the field lines, the magnetic force is oriented at different angles to the surface in different locations. The tilt, or <strong>inclination<\/strong> of magnetic field lines is represented by the tilt of compass needles in Figure 3.14. At the north and south poles, the force is vertical. The force is horizontal at the equator. Everywhere in between, the magnetic force is at an intermediate angle to the surface.<\/p>\n<figure id=\"attachment_93\" aria-describedby=\"caption-attachment-93\" style=\"width: 626px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-93\" src=\"https:\/\/opentextbc.ca\/kzlab\/wp-content\/uploads\/sites\/360\/2018\/03\/magnetic_field.png\" alt=\"\" width=\"626\" height=\"478\" srcset=\"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/360\/2018\/03\/magnetic_field.png 720w, https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/360\/2018\/03\/magnetic_field-300x229.png 300w, https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/360\/2018\/03\/magnetic_field-65x50.png 65w, https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/360\/2018\/03\/magnetic_field-225x172.png 225w, https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/360\/2018\/03\/magnetic_field-350x267.png 350w\" sizes=\"auto, (max-width: 626px) 100vw, 626px\" \/><figcaption id=\"caption-attachment-93\" class=\"wp-caption-text\"><strong>Figure 3.14<\/strong> Earth\u2019s magnetic field depicted as the field of a bar magnet coinciding with the core. The south pole of the magnet points to Earth\u2019s magnetic north pole. The red and white compass needles represent the orientation of the magnetic field at various locations on Earth\u2019s surface. Source: Karla Panchuk (2018). CC BY-SA 4.0. Modified after Steven Earle (2015; CC BY-SA 4.0, <a href=\"https:\/\/opentextbc.ca\/geology\/wp-content\/uploads\/sites\/110\/2015\/07\/image035.png\" target=\"_blank\" rel=\"noopener\">view source<\/a>), and T. Stein (2008; CC BY-SA 3.0 <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Earths_Magnetic_Field_Confusion.svg\" target=\"_blank\" rel=\"noopener\">view source<\/a>).<\/figcaption><\/figure>\n<div class=\"textbox shaded\">\n<p><strong>Practice: Magnetic Inclination<\/strong><\/p>\n<p>Use Figure 3.14 as a guide to help you complete this exercise.<\/p>\n<div class=\"offline\"><strong>Write in the geographic locations to match up with the correct magnetic inclination (the up-and-down orientation of a compass needle).<\/strong><\/p>\n<ol>\n<li>Straight down- Quttinirpaaq National Park, Ellesmere Island. This is the current location of the\u00a0<span style=\"text-decoration: underline;\"> \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/span>.<\/li>\n<li>Down at a steep angle- Santa&#8217;s workshop on a specially-designed ice breaker anchored in the Arctic Ocean (the location of the <span style=\"text-decoration: underline;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/span>.)<\/li>\n<li>Up at a steep angle- McMurdo Station, which is on the coast of Antarctica near the <span style=\"text-decoration: underline;\">\u00a0\u00a0\u00a0\u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/span>.<\/li>\n<li>Parallel to flat ground- Damba Island, Uganda, which straddles the <span style=\"text-decoration: underline;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/span>.<\/li>\n<\/ol>\n<p>Fill-in-the-blank options:<\/p>\n<ul class=\"twocolumn\">\n<li>geographic north pole<\/li>\n<li>south pole<\/li>\n<li>magnetic north pole<\/li>\n<li>equator<\/li>\n<\/ul>\n<p><strong> To check your answers, navigate to the below link to view the interactive version of this activity.<\/strong><\/p>\n<\/div>\n<div id=\"h5p-44\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-44\" class=\"h5p-iframe\" data-content-id=\"44\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Magnetic inclination exercise\"><\/iframe><\/div>\n<\/div>\n<\/div>\n<h1>Polarity Reversals<\/h1>\n<h2>Instability in Earth&#8217;s Magnetic Field<\/h2>\n<p>Earth\u2019s magnetic field is generated mostly within the outer core by the convective movement of liquid iron, but although convection is continuous, the magnetic field is not stable. Periodically, the magnetic field decays, then re-estabilshes. When it does re-establish, the polarity may have reversed. In other words, your compass needle would point south rather than north.<\/p>\n<p>Changes in Earth\u2019s magnetic field have been studied using mathematical models that simulate convection in the outer core (Figure 3.15).\u00a0 Reversals happened spontaneously when the model was run to simulate a period of several hundred thousand years. Spontaneous reversals can happen because convection doesn&#8217;t occur in an orderly way, in spite of what the bar magnet analogy may suggest.<\/p>\n<figure id=\"attachment_94\" aria-describedby=\"caption-attachment-94\" style=\"width: 650px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/opentextbc.ca\/physicalgeologyh5p\/chapter\/earths-magnetic-field\/polarity-reversal\/\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-94\" src=\"https:\/\/opentextbc.ca\/kzlab\/wp-content\/uploads\/sites\/360\/2021\/08\/polarity-reversal.png\" alt=\"\" width=\"650\" height=\"506\" srcset=\"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/360\/2021\/08\/polarity-reversal.png 987w, https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/360\/2021\/08\/polarity-reversal-300x233.png 300w, https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/360\/2021\/08\/polarity-reversal-768x598.png 768w, https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/360\/2021\/08\/polarity-reversal-65x51.png 65w, https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/360\/2021\/08\/polarity-reversal-225x175.png 225w, https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/360\/2021\/08\/polarity-reversal-350x272.png 350w\" sizes=\"auto, (max-width: 650px) 100vw, 650px\" \/><\/a><figcaption id=\"caption-attachment-94\" class=\"wp-caption-text\"><strong>Figure 3.15<\/strong> Computer simulations showing Earth&#8217;s &#8220;normal&#8221; magnetic field (top), and the magnetic field as polarity flips from reversed on the left to normal on the right. Notice how the magnetic field lines become disorganized, then converge on a more orderly arrangement. Source: Karla Panchuk (2021) CC BY 4.0. Click for more attributions.<\/figcaption><\/figure>\n<p>The solid inner core also convects, with many small-scale variations in convection patterns, but it does so more slowly than the liquid outer core. Yet Earth&#8217;s magnetic field is the sum of all of those variations\u2014both inner and outer\u2014and for a polarity reversal to &#8220;take,&#8221; a reversal must happen in the magnetic fields of both parts of the core. If the inner core weren&#8217;t solid, magnetic reversals would happen far more frequently.<\/p>\n<h2>How Often Do Polarity Reversals Happen?<\/h2>\n<p>Over the past 250 Ma, there have been hundreds of magnetic field reversals, and their timing has been anything but regular. The shortest ones that geologists have been able to identify lasted only a few thousand years, and the longest one was more than 30 million years, during the Cretaceous Period (Figure 3.16).<\/p>\n<figure id=\"attachment_95\" aria-describedby=\"caption-attachment-95\" style=\"width: 1024px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-95 size-large\" src=\"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/360\/2021\/08\/paleomag_reversals_SE-1024x153.png\" alt=\"\" width=\"1024\" height=\"153\" srcset=\"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/360\/2021\/08\/paleomag_reversals_SE-1024x153.png 1024w, https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/360\/2021\/08\/paleomag_reversals_SE-300x45.png 300w, https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/360\/2021\/08\/paleomag_reversals_SE-768x115.png 768w, https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/360\/2021\/08\/paleomag_reversals_SE-65x10.png 65w, https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/360\/2021\/08\/paleomag_reversals_SE-225x34.png 225w, https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/360\/2021\/08\/paleomag_reversals_SE-350x52.png 350w, https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/360\/2021\/08\/paleomag_reversals_SE.png 1442w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption id=\"caption-attachment-95\" class=\"wp-caption-text\"><strong>Figure 3.16<\/strong> Magnetic field reversal chronology for the past 170 Ma. Black stripes mark times when the magnetic field was oriented the same as today. Source: Steven Earle (2015). CC BY 4.0. <a href=\"https:\/\/opentextbc.ca\/geology\/wp-content\/uploads\/sites\/110\/2015\/07\/image037.png\" rel=\"noopener\">Image source.<\/a> Modified after AnomieX (2010), Public Domain. <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Geomagnetic_polarity_0-169_Ma.svg\" rel=\"noopener\">Image source.<\/a><\/figcaption><\/figure>\n<div class=\"textbox shaded\">\n<p><strong>Concept Check: Polarity Reversals<\/strong><\/p>\n<div class=\"offline\">\n<p><strong>Magnetic polarity reversals happen because:<\/strong><\/p>\n<ol type=\"a\">\n<li>Earth flips over so that it&#8217;s geographic poles change place.<\/li>\n<li>A new pattern develops in how Earth&#8217;s core churns itself.<\/li>\n<li>Earth&#8217;s core switches to rotating in the opposite direction within Earth.<\/li>\n<li>Earth switches to rotating in the opposite direction on its axis.<\/li>\n<\/ol>\n<p>To check your answers, navigate to the below link to view the interactive version of this activity.<\/p>\n<\/div>\n<div id=\"h5p-45\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-45\" class=\"h5p-iframe\" data-content-id=\"45\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Why do polarity reversals happen?\"><\/iframe><\/div>\n<\/div>\n<\/div>\n<h4>References<\/h4>\n<p class=\"hanging-indent\">British Geological Survey, Natural Environment Research Council (n.d.). <em>Reversals: Magnetic flip<\/em>. http:\/\/www.geomag.bgs.ac.uk\/education\/reversals.html<\/p>\n<p class=\"hanging-indent\">Glatzmaier, G. A. (n.d.) <em>The geodynamo<\/em>. https:\/\/websites.pmc.ucsc.edu\/~glatz\/geodynamo.html<\/p>\n<p class=\"hanging-indent\">Glatzmaier, G. A., &amp; Roberts, P.H. (1995). A three-dimensional self-consistent computer simulation of a geomagnetic field reversal.<em> Nature, 377<\/em>, 203-209.<\/p>\n","protected":false},"author":123,"menu_order":8,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[47],"contributor":[],"license":[],"class_list":["post-96","chapter","type-chapter","status-publish","hentry","chapter-type-standard"],"part":75,"_links":{"self":[{"href":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-json\/pressbooks\/v2\/chapters\/96","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-json\/wp\/v2\/users\/123"}],"version-history":[{"count":11,"href":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-json\/pressbooks\/v2\/chapters\/96\/revisions"}],"predecessor-version":[{"id":1899,"href":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-json\/pressbooks\/v2\/chapters\/96\/revisions\/1899"}],"part":[{"href":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-json\/pressbooks\/v2\/parts\/75"}],"metadata":[{"href":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-json\/pressbooks\/v2\/chapters\/96\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-json\/wp\/v2\/media?parent=96"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-json\/pressbooks\/v2\/chapter-type?post=96"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-json\/wp\/v2\/contributor?post=96"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-json\/wp\/v2\/license?post=96"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}