{"id":51350,"date":"2026-11-11T17:58:31","date_gmt":"2026-11-11T17:58:31","guid":{"rendered":"https:\/\/edukemy.com\/blog\/?p=51350"},"modified":"2026-11-11T18:19:54","modified_gmt":"2026-11-11T18:19:54","slug":"geomagnetism-2","status":"publish","type":"post","link":"https:\/\/edukemy.com\/blog\/geomagnetism-2\/","title":{"rendered":"Geomagnetism"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_85 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<label for=\"ez-toc-cssicon-toggle-item-6af77f28052d2\" class=\"ez-toc-cssicon-toggle-label\"><p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-cssicon\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/label><input type=\"checkbox\"  id=\"ez-toc-cssicon-toggle-item-6af77f28052d2\"  \/><nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#Fundamentals_of_Geomagnetism\" >Fundamentals of Geomagnetism<\/a><ul class='ez-toc-list-level-2' ><li class='ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#1_Core_Ideas_of_Geomagnetism\" >1. Core Ideas of Geomagnetism<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#A_Dipole_Behaviour_of_Earths_Magnetic_Field\" >A. Dipole Behaviour of Earth&#8217;s Magnetic Field<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#B_Genesis_of_Geomagnetism_Geodynamo_Action\" >B. Genesis of Geomagnetism: Geodynamo Action<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#2_Functional_Significance_of_Geomagnetism\" >2. Functional Significance of Geomagnetism<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#A_Protection_of_Earth_from_Solar_Radiation\" >A. Protection of Earth from Solar Radiation<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#B_Space_Weather_and_Geomagnetic_Storms\" >B. Space Weather and Geomagnetic Storms<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#3_Observations_and_Implications_of_Geomagnetism\" >3. Observations and Implications of Geomagnetism<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#A_Magnetic_Intensity\" >A. Magnetic Intensity<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#B_Magnetic_Declination\" >B. Magnetic Declination<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#C_Magnetic_Inclination_Magnetic_Dip\" >C. Magnetic Inclination (Magnetic Dip)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#D_Secular_Variation\" >D. Secular Variation<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#4_Applications_of_Geomagnetism\" >4. Applications of Geomagnetism<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#A_Navigation\" >A. Navigation<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#B_Palaeomagnetism_Reconstruction_of_Plate_Movements_and_Magnetic_Reversals\" >B. Palaeomagnetism: Reconstruction of Plate Movements and Magnetic Reversals<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#C_Monitoring_Space_Weather\" >C. Monitoring Space Weather<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-17\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#D_Studying_Core_Dynamics\" >D. Studying Core Dynamics<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-18\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#5_Geomagnetic_Reversals_and_Variability\" >5. Geomagnetic Reversals and Variability<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-19\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#A_Geomagnetic_Polarity_Reversals\" >A. Geomagnetic Polarity Reversals<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-20\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#B_Recording_of_Magnetic_Reversals_in_Rocks\" >B. Recording of Magnetic Reversals in Rocks<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-21\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#C_Non-Steady_Behaviour_of_the_Geodynamo\" >C. Non-Steady Behaviour of the Geodynamo<\/a><\/li><\/ul><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-22\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#Phenomena_and_Features_Associated_with_Earths_Magnetosphere\" >Phenomena and Features Associated with Earth\u2019s Magnetosphere<\/a><ul class='ez-toc-list-level-2' ><li class='ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-23\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#Mnemonic_for_Electromagnetic_Spectrum\" >Mnemonic for Electromagnetic Spectrum:<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-24\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#Key_Concept\" >Key Concept:<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-25\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#Major_Phenomena_Linked_to_Earths_Magnetic_Field\" >Major Phenomena Linked to Earth\u2019s Magnetic Field<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-26\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#Auroras_Aurora_Borealis_and_Australis\" >Auroras (Aurora Borealis and Australis)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-27\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#_2_Van_Allen_Radiation_Belts\" >\u00a0 \u00a0 2. Van Allen Radiation Belts<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-28\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#Concepts_Related_to_Geomagnetism\" >Concepts Related to Geomagnetism<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-29\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#Magnetic_and_Geographic_Poles\" >Magnetic and Geographic Poles<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-30\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#McMurdo_Sound_Antarctica\" >McMurdo Sound (Antarctica)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-31\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#Magnetic_vs_Geographical_Axis\" >Magnetic vs Geographical Axis<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-32\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#Movement_of_Magnetic_Poles\" >Movement of Magnetic Poles<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-33\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#Fluctuation_in_Magnetic_Field_Intensity\" >Fluctuation in Magnetic Field Intensity<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-34\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#Geomagnetism_and_Mass_Extinctions\" >Geomagnetism and Mass Extinctions<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-35\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#Magnetic_Field_Reversal_Polarity_Reversal\" >Magnetic Field Reversal (Polarity Reversal)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-36\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#Geographical_Signi%EF%AC%81cance\" >Geographical Signi\ufb01cance<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-37\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#1_How_can_a_rock_record_a_magnetic_field\" >1. How can a rock record a magnetic field?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-38\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#2_Recording_magnetism_in_cooling_lava\" >2. Recording magnetism in cooling lava<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-39\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#3_What_information_does_palaeomagnetism_provide\" >3. What information does palaeomagnetism provide?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-40\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#4_Magnetic_reversals_when_polarity_changes\" >4. Magnetic reversals: when polarity changes<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-41\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#5_How_palaeomagnetism_supported_continental_drift\" >5. How palaeomagnetism supported continental drift<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-42\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#6_How_palaomagnetism_proved_important_for_seafloor_spreading\" >6. How palaomagnetism proved important for seafloor spreading<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-43\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#7_Other_major_applications\" >7. Other major applications<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-44\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#8_Limitations_why_the_record_must_be_tested\" >8. Limitations: why the record must be tested<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-45\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#PYQs\" >PYQs<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-46\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#In_case_you_still_have_doubts_contact_us_on_9773890604\" >In case you still have doubts, contact us on 9773890604<\/a><\/li><\/ul><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n<h1><span class=\"ez-toc-section\" id=\"Fundamentals_of_Geomagnetism\"><\/span><b>Fundamentals of Geomagnetism<\/b><span class=\"ez-toc-section-end\"><\/span><\/h1>\r\n<p><span style=\"font-weight: 400;\">Geomagnetism refers to the study of Earth&#8217;s magnetic field, including its origin, characteristics, variations and significance. Earth behaves approximately like a giant bar magnet, with a magnetic field extending from its interior into surrounding space.<\/span> <span style=\"font-weight: 400;\">This magnetic field is generated mainly by the movement of electrically conducting molten metals in Earth&#8217;s outer core. It plays an important role in protecting Earth from charged solar particles, supporting navigation and providing evidence about Earth&#8217;s geological history.<\/span><\/p>\r\n<h2><span class=\"ez-toc-section\" id=\"1_Core_Ideas_of_Geomagnetism\"><\/span><b>1. Core Ideas of Geomagnetism<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n<h3><span class=\"ez-toc-section\" id=\"A_Dipole_Behaviour_of_Earths_Magnetic_Field\"><\/span><b>A. Dipole Behaviour of Earth&#8217;s Magnetic Field<\/b><span class=\"ez-toc-section-end\"><\/span><\/h3>\r\n<p><span style=\"font-weight: 400;\">&#8211; Earth behaves approximately like a magnetic dipole, meaning its magnetic field resembles that of a bar magnet having two opposite magnetic poles.<\/span> <br \/><span style=\"font-weight: 400;\">&#8211; The magnetic field extends from Earth&#8217;s interior into space, forming curved magnetic field lines around the planet.<\/span> <br \/><span style=\"font-weight: 400;\">&#8211; Outside Earth, magnetic field lines approximately emerge near the Southern Hemisphere&#8217;s magnetic pole and enter near the Northern Hemisphere&#8217;s magnetic pole.<\/span> <br \/><span style=\"font-weight: 400;\">&#8211; Earth&#8217;s magnetic poles are not identical to its geographical poles. The geographical poles are determined by Earth&#8217;s rotational axis, whereas the magnetic poles are associated with its magnetic field.<\/span> <br \/><span style=\"font-weight: 400;\">&#8211; The magnetic dipole axis is tilted by approximately 9\u201310\u00b0 relative to Earth&#8217;s rotational axis. Therefore, magnetic north and geographical north do not point in exactly the same direction.<\/span> <br \/><span style=\"font-weight: 400;\">&#8211; Magnetic poles are not fixed. They gradually change their geographical positions because the movement of molten metals inside Earth&#8217;s outer core continuously modifies the magnetic field.<\/span> <br \/><span style=\"font-weight: 400;\">Example: A magnetic compass generally points towards magnetic north rather than true geographical north. Therefore, navigators must consider the difference between the two directions.<\/span><\/p>\r\n<h3><span class=\"ez-toc-section\" id=\"B_Genesis_of_Geomagnetism_Geodynamo_Action\"><\/span><b>B. Genesis of Geomagnetism: Geodynamo Action<\/b><span class=\"ez-toc-section-end\"><\/span><\/h3>\r\n<p><span style=\"font-weight: 400;\">The Earth&#8217;s magnetic field is generated primarily through a process called the Geodynamo Mechanism, which operates in Earth&#8217;s liquid outer core.<\/span> <span style=\"font-weight: 400;\">The outer core is composed mainly of electrically conducting molten iron, along with nickel and lighter elements. The continuous movement of this liquid metal generates electric currents, which sustain Earth&#8217;s magnetic field.<\/span> <span style=\"font-weight: 400;\">How does the geodynamo work?<\/span><\/p>\r\n<ol>\r\n<li><span style=\"font-weight: 400;\"> Heat from Earth&#8217;s interior: Heat escaping from the core, along with energy released during inner-core solidification, creates temperature and compositional differences within the liquid outer core.<\/span><\/li>\r\n<li><span style=\"font-weight: 400;\"> Convection currents: These differences cause molten metallic material to circulate within the outer core. Hotter or compositionally buoyant material rises, while denser material tends to sink.<\/span><\/li>\r\n<li><span style=\"font-weight: 400;\"> Influence of Earth&#8217;s rotation: Earth&#8217;s rotation produces the Coriolis effect, which helps organise the moving liquid metal into rotating and elongated flow patterns.<\/span><\/li>\r\n<li><span style=\"font-weight: 400;\"> Generation of electric currents: The movement of electrically conducting molten metal through an existing magnetic field induces electric currents through electromagnetic induction.<\/span><\/li>\r\n<li><span style=\"font-weight: 400;\"> Formation and maintenance of the magnetic field: These electric currents produce additional magnetic fields. Under suitable conditions, the interaction between fluid motion and magnetic fields maintains a self-sustaining geodynamo.<\/span><\/li>\r\n<\/ol>\r\n<p>Important: The geomagnetic field is not generated simply because Earth&#8217;s core contains iron. It is mainly produced by the continuous movement of electrically conducting liquid metal within the outer core. Thus, the geodynamo can be understood through the relationship: <strong>Core heat and compositional buoyancy \u2192 Convection of liquid iron \u2192 Electromagnetic induction \u2192 Electric currents \u2192 Geomagnetic field<\/strong><\/p>\r\n<h2><span class=\"ez-toc-section\" id=\"2_Functional_Significance_of_Geomagnetism\"><\/span>2. Functional Significance of Geomagnetism<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n<h3><span class=\"ez-toc-section\" id=\"A_Protection_of_Earth_from_Solar_Radiation\"><\/span>A. Protection of Earth from Solar Radiation<span class=\"ez-toc-section-end\"><\/span><\/h3>\r\n<p>One of the most important functions of Earth&#8217;s magnetic field is the formation of the magnetosphere, which protects the planet from many charged particles originating from the Sun. &#8211; The Sun continuously releases a stream of charged particles, mainly electrons and protons, called the solar wind. &#8211; When these charged particles approach Earth, they interact with Earth&#8217;s magnetic field. &#8211; The magnetic field redirects many of these particles around Earth, preventing them from directly entering the atmosphere. &#8211; Some charged particles become trapped within regions of Earth&#8217;s magnetosphere, while others travel along magnetic field lines towards polar regions. &#8211; Consequently, Earth&#8217;s magnetic field helps reduce the direct exposure of the upper atmosphere to energetic charged particles and limits atmospheric erosion associated with the solar wind. <span style=\"font-weight: 400;\">Example: Mars lacks a strong present-day global dipole magnetic field. Its atmosphere has experienced substantial loss to space over geological time, partly through interactions with the solar wind. This illustrates the potential importance of magnetic shielding, although gravity, atmospheric chemistry and planetary history also influence atmospheric retention.<\/span> <span style=\"font-weight: 400;\">Clarification: Earth&#8217;s magnetic field mainly protects against charged particles, not gamma rays or X-rays directly. Protection from much electromagnetic radiation depends primarily on Earth&#8217;s atmosphere.<\/span><\/p>\r\n<h3><span class=\"ez-toc-section\" id=\"B_Space_Weather_and_Geomagnetic_Storms\"><\/span><b>B. Space Weather and Geomagnetic Storms<\/b><span class=\"ez-toc-section-end\"><\/span><\/h3>\r\n<p><span style=\"font-weight: 400;\">Space weather refers to changing conditions in the space environment, particularly those caused by solar activity and interactions between solar particles and Earth&#8217;s magnetosphere.<\/span> <span style=\"font-weight: 400;\">Strong solar disturbances, especially coronal mass ejections and energetic solar-wind streams, can significantly disturb Earth&#8217;s magnetic field.<\/span> <strong>Major consequences include:<\/strong> <span style=\"font-weight: 400;\">&#8211; Deformation of the magnetosphere: Solar-wind pressure compresses Earth&#8217;s magnetic field on the Sun-facing side and stretches it into a long magnetotail on the opposite side.<\/span> <span style=\"font-weight: 400;\">&#8211; Formation of aurorae: Energetic charged particles entering the upper atmosphere near polar regions collide with oxygen and nitrogen, producing colourful lights called aurorae.<\/span> <span style=\"font-weight: 400;\">&#8211; Disturbance in communication systems: Geomagnetic storms can alter the ionosphere, affecting high-frequency radio communication and satellite navigation signals.<\/span> <span style=\"font-weight: 400;\">&#8211; Satellite-related problems: Energetic particles can damage satellite electronics, while changes in the upper atmosphere can increase atmospheric drag on low-Earth-orbit satellites.<\/span> <span style=\"font-weight: 400;\">&#8211; Power-grid disturbances: Rapid changes in Earth&#8217;s magnetic field can induce electric currents in long conductors, including electricity transmission networks, potentially disrupting power supplies.<\/span> <span style=\"font-weight: 400;\">Example: During the Carrington Event of 1859, a powerful geomagnetic storm produced widespread aurorae and disrupted telegraph systems. Similarly, the March 1989 geomagnetic storm contributed to a major electricity blackout in Quebec, Canada.<\/span> <span style=\"font-weight: 400;\">Therefore, geomagnetism is important not only for understanding Earth&#8217;s natural protective system but also for assessing the vulnerability of modern technological infrastructure.<\/span><\/p>\r\n<h2><span class=\"ez-toc-section\" id=\"3_Observations_and_Implications_of_Geomagnetism\"><\/span><b>3. Observations and Implications of Geomagnetism<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n<p><span style=\"font-weight: 400;\">The Earth&#8217;s magnetic field can be understood through several measurable characteristics. The four important quantities are magnetic intensity, magnetic declination, magnetic inclination and secular variation.<\/span><\/p>\r\n<h3><span class=\"ez-toc-section\" id=\"A_Magnetic_Intensity\"><\/span><b>A. Magnetic Intensity<\/b><span class=\"ez-toc-section-end\"><\/span><\/h3>\r\n<p><span style=\"font-weight: 400;\">Magnetic intensity refers to the strength or magnitude of Earth&#8217;s magnetic field at a particular location.<\/span><\/p>\r\n<ul>\r\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Earth&#8217;s magnetic field is not equally strong everywhere.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Its intensity is generally lower near the magnetic equator and higher towards magnetic polar regions.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">The magnetic field strength is commonly measured in nanotesla (nT) or microtesla (\u00b5T).<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Typical surface magnetic-field intensities range from approximately 25,000 to 65,000 nT.<\/span><\/li>\r\n<\/ul>\r\n<p><span style=\"font-weight: 400;\">Example: Earth&#8217;s magnetic field is generally stronger at high magnetic latitudes, such as parts of Canada and Antarctica, than near equatorial regions.<\/span><\/p>\r\n<h3><span class=\"ez-toc-section\" id=\"B_Magnetic_Declination\"><\/span><b>B. Magnetic Declination<\/b><span class=\"ez-toc-section-end\"><\/span><\/h3>\r\n<p><span style=\"font-weight: 400;\">Magnetic declination refers to the horizontal angle between the direction of geographical north (true north) and magnetic north, measured at a particular location.<\/span><\/p>\r\n<ul>\r\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Geographical north represents the direction towards the geographical North Pole.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Magnetic north represents the direction indicated by the horizontal component of Earth&#8217;s magnetic field.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Since the geographical and magnetic poles are not at identical locations, these two directions usually differ.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">When magnetic north lies east of true north, it is called easterly declination.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">When magnetic north lies west of true north, it is called westerly declination.<\/span><\/li>\r\n<\/ul>\r\n<p>Example: If a compass points 5\u00b0 east of geographical north, the location has a magnetic declination of 5\u00b0 east. Significance: Magnetic declination is important for accurate navigation, surveying and converting compass bearings into geographical directions.<\/p>\r\n<h3><span class=\"ez-toc-section\" id=\"C_Magnetic_Inclination_Magnetic_Dip\"><\/span>C. Magnetic Inclination (Magnetic Dip)<span class=\"ez-toc-section-end\"><\/span><\/h3>\r\n<p>Magnetic inclination refers to the angle that Earth&#8217;s magnetic field makes with the horizontal plane at a particular location. Unlike magnetic declination, which describes the horizontal direction of the field, magnetic inclination describes its vertical orientation. At the magnetic equator, magnetic field lines are approximately horizontal. Therefore, the inclination is around 0\u00b0. Moving towards the magnetic poles, field lines become progressively more inclined. At the magnetic poles, field lines are approximately vertical, producing an inclination of 90\u00b0 in magnitude. The magnetic field generally points downward in the Northern Hemisphere and upward in the Southern Hemisphere, under the usual magnetic-dip convention. Example: At a location in northern India, a freely suspended magnetic needle would generally dip downward towards the north rather than remain perfectly horizontal. Significance: Magnetic inclination helps determine the three-dimensional direction of Earth&#8217;s magnetic field and is particularly useful in palaeomagnetic studies.<\/p>\r\n<h3><span class=\"ez-toc-section\" id=\"D_Secular_Variation\"><\/span>D. Secular Variation<span class=\"ez-toc-section-end\"><\/span><\/h3>\r\n<p>Secular variation refers to the gradual changes in the strength and direction of Earth&#8217;s magnetic field over years, decades and centuries. Earth&#8217;s magnetic field is not permanent or completely stable. Continuous movements of molten iron within the outer core cause its intensity and direction to change. As a result, magnetic declination, inclination and intensity at a given location may change with time. Magnetic poles also migrate because of these internal changes. Example: The north magnetic pole has moved substantially from the Canadian Arctic towards Siberia over the last century. Significance: Secular variation helps scientists understand changes in Earth&#8217;s core dynamics and also requires periodic updating of magnetic navigation charts.<\/p>\r\n<h2><span class=\"ez-toc-section\" id=\"4_Applications_of_Geomagnetism\"><\/span>4. Applications of Geomagnetism<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n<h3><span class=\"ez-toc-section\" id=\"A_Navigation\"><\/span>A. Navigation<span class=\"ez-toc-section-end\"><\/span><\/h3>\r\n<p>Geomagnetism provides the scientific basis for magnetic compass navigation. A magnetic compass aligns itself with the horizontal component of Earth&#8217;s magnetic field. It helps determine direction during land and marine navigation. Knowledge of magnetic declination allows compass directions to be corrected relative to geographical north. Magnetic-field measurements are also used in some orientation and navigation systems. Example: Ships and aircraft using magnetic headings must account for local magnetic declination to determine directions accurately.<\/p>\r\n<h3><span class=\"ez-toc-section\" id=\"B_Palaeomagnetism_Reconstruction_of_Plate_Movements_and_Magnetic_Reversals\"><\/span>B. Palaeomagnetism: Reconstruction of Plate Movements and Magnetic Reversals<span class=\"ez-toc-section-end\"><\/span><\/h3>\r\n<p>Palaeomagnetism refers to the study of Earth&#8217;s ancient magnetic field as preserved within rocks, sediments and archaeological materials. When certain rocks form, their magnetic minerals can acquire a magnetic orientation that reflects the direction of Earth&#8217;s magnetic field at that time. How is the magnetic field recorded in rocks? When lava cools below the relevant magnetic blocking temperatures, magnetic minerals such as magnetite may preserve the direction of the existing geomagnetic field. This preserved magnetic orientation is called remanent magnetisation. As tectonic plates move, rocks carrying these magnetic records also change their geographical positions. Scientists examine the original magnetic orientation recorded in rocks to reconstruct ancient plate positions, rotations, and movements. Major implications: &#8211; Evidence of continental drift: Palaeomagnetic studies revealed apparent polar-wandering paths, which helped demonstrate the movement of continents. &#8211; Evidence of seafloor spreading: Alternating bands of normal and reversed magnetic polarity occur approximately symmetrically on opposite sides of many mid-ocean ridges. &#8211; Reconstruction of ancient latitudes: Magnetic inclination preserved in suitable rocks can help estimate the latitude at which those rocks originally formed. &#8211; Identification of magnetic reversals: Rocks preserve evidence that Earth&#8217;s magnetic field has reversed polarity repeatedly during geological history. Example: Magnetic stripes on the Atlantic Ocean floor provided major evidence supporting Harry Hess&#8217;s seafloor-spreading hypothesis and the development of plate tectonic theory.<\/p>\r\n<h3><span class=\"ez-toc-section\" id=\"C_Monitoring_Space_Weather\"><\/span>C. Monitoring Space Weather<span class=\"ez-toc-section-end\"><\/span><\/h3>\r\n<p>Geomagnetic observations are useful for monitoring disturbances created by solar activity. Ground-based magnetometers continuously record fluctuations in Earth&#8217;s magnetic field. These measurements help scientists detect and evaluate geomagnetic storms. Observations of magnetic disturbances assist in assessing risks to satellites, communication networks, navigation systems and electricity grids. Geomagnetic measurements are combined with solar and satellite observations for space-weather forecasting. Example: During major solar storms, monitoring agencies use geomagnetic activity measurements to assess the severity of disturbances and issue warnings to infrastructure operators.<\/p>\r\n<h3><span class=\"ez-toc-section\" id=\"D_Studying_Core_Dynamics\"><\/span>D. Studying Core Dynamics<span class=\"ez-toc-section-end\"><\/span><\/h3>\r\n<p>Geomagnetism provides an indirect method for studying processes occurring deep within Earth. Earth&#8217;s core cannot be directly observed through conventional geological field methods. However, changes in the magnetic field provide valuable information about the movement of electrically conducting material inside the outer core. By studying magnetic intensity, directional changes and secular variation, scientists can test models of fluid motion and electromagnetic processes within the core. Magnetic observations therefore improve understanding of the geodynamo mechanism, its variability and long-term evolution. Example: Changes in the location of magnetic poles and regional magnetic-field intensity help scientists investigate how fluid flow inside Earth&#8217;s outer core is changing.<\/p>\r\n<h2><span class=\"ez-toc-section\" id=\"5_Geomagnetic_Reversals_and_Variability\"><\/span>5. Geomagnetic Reversals and Variability<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n<p>Earth&#8217;s magnetic field is not constant in direction or intensity. Over geological time, it has undergone repeated changes, including complete reversals of its magnetic polarity.<\/p>\r\n<h3><span class=\"ez-toc-section\" id=\"A_Geomagnetic_Polarity_Reversals\"><\/span>A. Geomagnetic Polarity Reversals<span class=\"ez-toc-section-end\"><\/span><\/h3>\r\n<p>A geomagnetic polarity reversal occurs when the dominant polarity of Earth&#8217;s magnetic field changes, so that magnetic north and magnetic south effectively exchange positions. There are two main magnetic polarity states: Normal polarity: Earth&#8217;s magnetic field has approximately the same polarity as the present-day field. Reversed polarity: Earth&#8217;s magnetic field has the opposite polarity to the present-day field. During a reversal, Earth&#8217;s magnetic field may weaken and become more complicated, with multiple magnetic-pole-like regions temporarily developing before the field reorganises. <span style=\"font-weight: 400;\">Example: The most recent widely recognised complete geomagnetic reversal was the Brunhes\u2013Matuyama reversal, approximately 773,000 years ago.<\/span><\/p>\r\n<h3><span class=\"ez-toc-section\" id=\"B_Recording_of_Magnetic_Reversals_in_Rocks\"><\/span><b>B. Recording of Magnetic Reversals in Rocks<\/b><span class=\"ez-toc-section-end\"><\/span><\/h3>\r\n<p><span style=\"font-weight: 400;\">When volcanic rocks cool, magnetic minerals can preserve the direction and polarity of Earth&#8217;s magnetic field existing at that time.<\/span><\/p>\r\n<ul>\r\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">If rocks formed during a normal-polarity period, their magnetic minerals can preserve normal polarity.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">If they formed during a reversed-polarity period, they can preserve reversed polarity.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Successive volcanic rock sequences and ocean-floor rocks therefore provide records of Earth&#8217;s magnetic history.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">By comparing these records with independently established geological ages, scientists construct the Geomagnetic Polarity Time Scale (GPTS).<\/span><\/li>\r\n<\/ul>\r\n<p><span style=\"font-weight: 400;\">Example: Alternating normal and reversed magnetic stripes on the ocean floor provide evidence of both polarity reversals and the continuous formation of new oceanic crust at mid-ocean ridges.<\/span><\/p>\r\n<h3><span class=\"ez-toc-section\" id=\"C_Non-Steady_Behaviour_of_the_Geodynamo\"><\/span><b>C. Non-Steady Behaviour of the Geodynamo<\/b><span class=\"ez-toc-section-end\"><\/span><\/h3>\r\n<p><span style=\"font-weight: 400;\">The Earth&#8217;s geodynamo does not produce a perfectly constant magnetic field.<\/span> <span style=\"font-weight: 400;\">Its behaviour varies because convection currents and fluid movements within the outer core continuously change.<\/span> <span style=\"font-weight: 400;\">This variability is expressed through:<\/span><\/p>\r\n<ul>\r\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Changes in intensity: Magnetic-field strength increases or decreases over time.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Changes in direction: Magnetic declination and inclination vary with time.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Magnetic pole movement: Magnetic poles gradually change their geographical positions.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Geomagnetic reversals: Occasionally, the dominant dipole polarity reverses completely.<\/span><\/li>\r\n<\/ul>\r\n<p><span style=\"font-weight: 400;\">These changes demonstrate that Earth&#8217;s magnetic field is a dynamic phenomenon sustained by continuously evolving processes within the liquid outer core, rather than a fixed magnetic structure.<\/span><\/p>\r\n<h1><span class=\"ez-toc-section\" id=\"Phenomena_and_Features_Associated_with_Earths_Magnetosphere\"><\/span><b>Phenomena and Features Associated with Earth\u2019s Magnetosphere<\/b><span class=\"ez-toc-section-end\"><\/span><\/h1>\r\n<h2><span class=\"ez-toc-section\" id=\"Mnemonic_for_Electromagnetic_Spectrum\"><\/span><b>Mnemonic for Electromagnetic Spectrum:<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n<p><b>GAKSU-VIMAR <\/b><span style=\"font-weight: 400;\">\u2192 <\/span><span style=\"font-weight: 400;\">Gamma Rays <\/span><span style=\"font-weight: 400;\">\u2192 <\/span><span style=\"font-weight: 400;\">X-rays <\/span><span style=\"font-weight: 400;\">\u2192 <\/span><span style=\"font-weight: 400;\">Ultraviolet <\/span><span style=\"font-weight: 400;\">\u2192 <\/span><span style=\"font-weight: 400;\">Visible <\/span><span style=\"font-weight: 400;\">\u2192 <\/span><span style=\"font-weight: 400;\">Infrared <\/span><span style=\"font-weight: 400;\">\u2192<\/span> <span style=\"font-weight: 400;\">Microwaves <\/span><span style=\"font-weight: 400;\">\u2192 <\/span><span style=\"font-weight: 400;\">Radio Waves<\/span><\/p>\r\n<h2><span class=\"ez-toc-section\" id=\"Key_Concept\"><\/span><b>Key Concept:<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n<p><span style=\"font-weight: 400;\">Among these, only infrared, visible light, and part of the ultraviolet spectrum reach Earth\u2019s atmosphere.<\/span><\/p>\r\n<ul>\r\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">Gamma rays, X-rays, and high-energy UV are blocked by the magnetosphere and ozone layer.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">Microwaves and radio waves are weak and only partially reach Earth.<\/span><\/li>\r\n<\/ul>\r\n<h2><span class=\"ez-toc-section\" id=\"Major_Phenomena_Linked_to_Earths_Magnetic_Field\"><\/span><b>Major Phenomena Linked to Earth\u2019s Magnetic Field<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n<ol>\r\n<li style=\"font-weight: 400;\" aria-level=\"1\">\r\n<h3><span class=\"ez-toc-section\" id=\"Auroras_Aurora_Borealis_and_Australis\"><\/span><b>Auroras (Aurora Borealis and Australis)<\/b><b> <\/b><span class=\"ez-toc-section-end\"><\/span><\/h3>\r\n<span style=\"font-weight: 400;\">Result from interaction between <\/span><b>solar winds and Earth\u2019s magnetic \ufb01eld near polar regions.<\/b><\/li>\r\n<\/ol>\r\n<ul>\r\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">Charged solar particles (mainly electrons and protons) collide with gases in the upper atmosphere, producing colourful light emissions.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">Occur around magnetic poles, not geographic poles \u2014 hence visible in high-latitude regions.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">Common in Arctic (Aurora Borealis) and Antarctic (Aurora Australis) regions.<\/span><\/li>\r\n<\/ul>\r\n<h3><span class=\"ez-toc-section\" id=\"_2_Van_Allen_Radiation_Belts\"><\/span><b>\u00a0 \u00a0 2. Van Allen Radiation Belts<\/b><span class=\"ez-toc-section-end\"><\/span><\/h3>\r\n<p><b>\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 De\ufb01nition<\/b><span style=\"font-weight: 400;\">: Layers of trapped charged particles (electrons and protons) held in place by Earth\u2019s geomagnetic \ufb01eld.<\/span> <b>\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 <br \/>\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 Formation Process:<\/b><\/p>\r\n<ul>\r\n<li style=\"font-weight: 400;\" aria-level=\"3\"><span style=\"font-weight: 400;\">Solar winds distort the magnetosphere, compressing it on the sunward side and elongating it on the night side.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"3\"><span style=\"font-weight: 400;\">Charged particles get trapped along magnetic \ufb01eld lines forming two distinct belts:<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"4\"><b>Inner Belt: <\/b><span style=\"font-weight: 400;\">~12,000 km from Earth\u2019s surface.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"4\"><b>Outer Belt: <\/b><span style=\"font-weight: 400;\">Up to ~30,000 km altitude. <br \/><\/span><span style=\"font-weight: 400;\"><br \/><\/span><b>Importance<\/b><span style=\"font-weight: 400;\">:<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"3\"><span style=\"font-weight: 400;\">Protects Earth from harmful cosmic radiation.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"3\"><span style=\"font-weight: 400;\">Affects satellite operations and rocket trajectories\u2014missions to higher orbits or beyond (like lunar missions) must navigate these radiation zones carefully.<\/span><\/li>\r\n<\/ul>\r\n<ol>\r\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Angle of Declination and Dip Angle <\/b><span style=\"font-weight: 400;\">\u2013 Angle between the magnetic needle and the horizontal surface of the Earth. This angle exists because the dip angle magnetic lines of force are not concentric circles around the Earth. The lines converge at the poles.<\/span><\/li>\r\n<\/ol>\r\n<p><b>\u00a0 \u00a0 \u00a0 2. Inclination Angle <\/b><span style=\"font-weight: 400;\">\u2013 Angle between magnetic lines of force and the horizontal. With change of location, the declination angle does\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 not change unless the \ufb01eld orientation changes or Earth\u2019s tilt changes, whereas dip angle can change from place to place.<\/span><\/p>\r\n<h2><span class=\"ez-toc-section\" id=\"Concepts_Related_to_Geomagnetism\"><\/span><b>Concepts Related to Geomagnetism<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n<h2><span class=\"ez-toc-section\" id=\"Magnetic_and_Geographic_Poles\"><\/span><b>Magnetic and Geographic Poles<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n<ul>\r\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">The <\/span><b>Magnetic South Pole <\/b><span style=\"font-weight: 400;\">lies near the Geographical North Pole, close to <\/span><b>Bathurst Island (Canada).<\/b><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">The <\/span><b>Magnetic North Pole <\/b><span style=\"font-weight: 400;\">lies near the Geographical South Pole, close to<\/span><\/li>\r\n<\/ul>\r\n<h2><span class=\"ez-toc-section\" id=\"McMurdo_Sound_Antarctica\"><\/span><b>McMurdo Sound (Antarctica)<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n<ul>\r\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">Hence, <\/span><b>magnetic polarity is opposite to geographical polarity.<\/b><\/li>\r\n<\/ul>\r\n<h2><span class=\"ez-toc-section\" id=\"Magnetic_vs_Geographical_Axis\"><\/span><b>Magnetic vs Geographical Axis<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n<ul>\r\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">The Earth\u2019s rotation axis (geographical axis) and magnetic axis do not coincide.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">The angle between them is called the <\/span><b>Angle of Declination.<\/b><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">This misalignment explains compass variation and magnetic mapping discrepancies.<\/span><\/li>\r\n<\/ul>\r\n<h2><span class=\"ez-toc-section\" id=\"Movement_of_Magnetic_Poles\"><\/span><b>Movement of Magnetic Poles<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n<ul>\r\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">The magnetic poles \ufb02uctuate slightly around a \ufb01xed position \u2014 a phenomenon called <\/span><b>polar \ufb02uctuation.<\/b><span style=\"font-weight: 400;\">However, they do not migrate across large geographical distances.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">These minor positional changes re\ufb02ect the dynamic nature of Earth\u2019s magnetic \ufb01eld.<\/span><\/li>\r\n<\/ul>\r\n<p><span style=\"font-weight: 400;\">\u00a0 \u00a0 \u00a0 Example: The North Magnetic Pole has shifted within the Arctic region over time but not across hemispheres.<\/span><\/p>\r\n<h2><span class=\"ez-toc-section\" id=\"Fluctuation_in_Magnetic_Field_Intensity\"><\/span><b>Fluctuation in Magnetic Field Intensity<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n<ul>\r\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">The strength of Earth\u2019s magnetic \ufb01eld varies over geological time:<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"3\"><span style=\"font-weight: 400;\">At times it becomes strong, forming a stable dipolar \ufb01eld.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"3\"><span style=\"font-weight: 400;\">At other times, it weakens or may even temporarily disappear.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">The magnetic \ufb01eld plays a crucial role in de\ufb02ecting solar winds, X-rays, and gamma rays, shielding life on Earth.<\/span><\/li>\r\n<\/ul>\r\n<h2><span class=\"ez-toc-section\" id=\"Geomagnetism_and_Mass_Extinctions\"><\/span><b>Geomagnetism and Mass Extinctions<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n<ul>\r\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">Weakening or disappearance of the geomagnetic \ufb01eld has been correlated with major extinction phases.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">Possible reason: Loss of magnetic shielding allowed harmful cosmic radiation to reach Earth\u2019s surface.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">Major extinctions coinciding with geomagnetic changes: <br \/><\/span><b>Ordovician Extinction, <\/b><b>Silurian Extinction, <\/b><b>Permian Extinction <\/b>(The Great Dying, ~90% of marine species vanished), <b>Cretaceous\u2013Tertiary (K\u2013T) Boundary Extinction<\/b>, ~65 million years ago, which led to the extinction of dinosaurs.<\/li>\r\n<\/ul>\r\n<h2><span class=\"ez-toc-section\" id=\"Magnetic_Field_Reversal_Polarity_Reversal\"><\/span><b>Magnetic Field Reversal (Polarity Reversal)<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n<ul>\r\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">Earth\u2019s magnetic \ufb01eld reverses polarity at irregular intervals \u2014 i.e., North becomes South and vice versa.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">These magnetic reversals:<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"3\"><span style=\"font-weight: 400;\">Have no \ufb01xed periodicity.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"3\"><span style=\"font-weight: 400;\">Are not caused by pole migration.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"3\"><span style=\"font-weight: 400;\">Occur due to weakening of the existing \ufb01eld and growth of opposite polarity.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">The process: <\/span>The normal \ufb01eld gradually weakens (e.g., from \u221210 \u2192 \u22125 \u2192 0). <span style=\"font-weight: 400;\">Simultaneously, the reverse polarity grows (+1 <\/span><span style=\"font-weight: 400;\">\u2192 <\/span><span style=\"font-weight: 400;\">+5 <\/span><span style=\"font-weight: 400;\">\u2192 <\/span><span style=\"font-weight: 400;\">+10)<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"3\"><span style=\"font-weight: 400;\">This results in a complete polarity \ufb02ip.<\/span><\/li>\r\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">Such reversals are recorded in paleomagnetic studies and ocean-\ufb02oor basalts, forming the basis for Plate Tectonics evidence (e.g., Vine\u2013Matthews\u2013Morley hypothesis).<\/span><\/li>\r\n<\/ul>\r\n<h2><span class=\"ez-toc-section\" id=\"Geographical_Signi%EF%AC%81cance\"><\/span><b>Geographical Signi\ufb01cance<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n<ul>\r\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">Geomagnetism helps: <\/span><span style=\"font-weight: 400;\">Understand continental drift and sea\ufb02oor spreading. <\/span>Date igneous rock formations through magnetic chronology. Reconstruct paleogeographic positions of continents.<\/li>\r\n<\/ul>\r\n<p><b> Palaeomagnetism is the study of Earth\u2019s past magnetic field preserved in rocks, sediments and archaeological materials.<\/b><span style=\"font-weight: 400;\"> It helps us understand both how the magnetic field has changed and how continents have moved through geological time.<\/span> <span style=\"font-weight: 400;\">While <\/span><b>geomagnetism<\/b><span style=\"font-weight: 400;\"> studies Earth\u2019s magnetic field generally, palaeomagnetism reconstructs its history from natural records.<\/span> <span style=\"font-weight: 400;\">Think of certain rocks as <\/span><b>ancient magnetic recorders<\/b><span style=\"font-weight: 400;\">: they preserve information about the magnetic field that existed when their magnetisation developed.<\/span><\/p>\r\n<h3><span class=\"ez-toc-section\" id=\"1_How_can_a_rock_record_a_magnetic_field\"><\/span><b>1. How can a rock record a magnetic field?<\/b><span class=\"ez-toc-section-end\"><\/span><\/h3>\r\n<p><span style=\"font-weight: 400;\">Some rocks contain magnetic minerals such as <\/span><b>magnetite, hematite and titanomagnetite<\/b><span style=\"font-weight: 400;\">. Under suitable conditions, these minerals acquire magnetisation related to the surrounding magnetic field.<\/span> <span style=\"font-weight: 400;\">Part of this magnetisation can remain even after the original field changes. This is called <\/span><b>remanent magnetisation<\/b><span style=\"font-weight: 400;\">, or retained magnetism.<\/span> <span style=\"font-weight: 400;\">However, a rock does not necessarily record the moment it first formed. It may acquire or replace its magnetic record during later heating or chemical alteration.<\/span> There are three major ways this record develops:<\/p>\r\n<div>\r\n<table>\r\n<tbody>\r\n<tr>\r\n<th>Type<\/th>\r\n<th>How the magnetic record forms<\/th>\r\n<th>Example<\/th>\r\n<\/tr>\r\n<tr>\r\n<td>Thermoremanent magnetisation<\/td>\r\n<td>Magnetic moments become stabilised as a rock cools.<\/td>\r\n<td>Basalt produced by a volcanic eruption<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>Depositional remanent magnetisation<\/td>\r\n<td>Magnetic particles partly align with the field during settling or shortly after deposition, before becoming fixed.<\/td>\r\n<td>Lake and marine sediments<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>Chemical remanent magnetisation<\/td>\r\n<td>New magnetic minerals grow during chemical changes and acquire magnetisation.<\/td>\r\n<td>Hematite forming in red sedimentary rocks<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\nThese processes explain why both igneous and sedimentary rocks can preserve paleomagnetic information.\r\n<h3><span class=\"ez-toc-section\" id=\"2_Recording_magnetism_in_cooling_lava\"><\/span>2. Recording magnetism in cooling lava<span class=\"ez-toc-section-end\"><\/span><\/h3>\r\nThis is the easiest process to understand. Lava erupts: It contains iron-bearing minerals or materials from which these minerals crystallise. The lava cools: Magnetic minerals develop stable magnetic behaviour below their Curie temperature. Magnetisation becomes locked: As cooling continues through blocking temperatures, the magnetic moments become sufficiently stable to retain a record of the field. The rock preserves the signal: Later continental movement can carry this record far from its original location. For magnetite, the Curie temperature is approximately 580\u00b0C. However, the Curie temperature and blocking temperature are not identical: blocking depends on factors such as mineral type and grain size. The mineral grains in solid rock do not need to physically rotate like compass needles; their internal magnetic moments acquire a net orientation influenced by the field.\r\n<h3><span class=\"ez-toc-section\" id=\"3_What_information_does_palaeomagnetism_provide\"><\/span>3. What information does palaeomagnetism provide?<span class=\"ez-toc-section-end\"><\/span><\/h3>\r\nThree properties are particularly useful: <br \/><strong>A. Declination: the horizontal direction.<\/strong> Declination is the angle between geographical north and the horizontal component of the magnetic direction. After appropriate corrections, differences between the recorded and expected directions can reveal rotation of a crustal block. Example: A rock sequence may preserve a direction that indicates its region rotated clockwise after magnetisation. <br \/><strong>B. Inclination: the angle of magnetic dip.<\/strong> Inclination is the angle that the magnetic field makes with the horizontal. Under an ideal dipole field: At the magnetic equator, the field is horizontal: inclination is 0\u00b0. Towards the poles, the field becomes progressively steeper. At the magnetic poles, it is vertical: inclination is \u00b190\u00b0. This relationship allows scientists to estimate paleolatitude, meaning the latitude where a rock acquired its magnetisation. For a geocentric axial dipole: Example: An inclination of approximately 49\u00b0 corresponds to a latitude of about 30\u00b0 under this model. The model assumes that, when averaged over sufficient time, Earth\u2019s field approximates a dipole aligned with its rotational axis. Palaeomagnetism alone generally cannot determine absolute paleolongitude. <br \/><strong>C. Magnetic intensity:<\/strong> Specialised laboratory methods can estimate the strength of the ancient magnetic field, called paleointensity. The strength of a rock\u2019s magnetisation cannot simply be treated as field strength because it also depends on the minerals present and their properties.\r\n<h3><span class=\"ez-toc-section\" id=\"4_Magnetic_reversals_when_polarity_changes\"><\/span>4. Magnetic reversals: when polarity changes<span class=\"ez-toc-section-end\"><\/span><\/h3>\r\nEarth\u2019s magnetic field has repeatedly reversed during geological history. Normal polarity: The field has broadly the same polarity as today. Reversed polarity: The field has the opposite polarity. During a reversal, the magnetic field changes direction; Earth does not turn upside down, and its rotation does not reverse. Successive lava flows may therefore preserve alternating normal and reversed magnetisation. These records helped scientists establish a geomagnetic polarity timescale. The most recent major reversal, the Brunhes\u2013Matuyama reversal, occurred approximately 780,000 years ago. Reversals occur at irregular intervals, rather than on a fixed schedule.\r\n<h3><span class=\"ez-toc-section\" id=\"5_How_palaeomagnetism_supported_continental_drift\"><\/span>5. How palaeomagnetism supported continental drift<span class=\"ez-toc-section-end\"><\/span><\/h3>\r\nPalaeomagnetism provided a way to test continental movement using measurements preserved in rocks. Scientists examined rocks of different ages on a continent and calculated the corresponding ancient magnetic pole positions. Connecting these positions produced an Apparent Polar Wander Path (APWP). It is called apparent because the calculation initially treats the continent as stationary. A changing pole position can therefore reflect movement of the continent relative to Earth\u2019s rotational axis. The crucial observation was that different continents produced different polar-wander paths. If all continents had remained fixed, their records should have indicated a broadly shared history of pole positions. When continents were restored towards their former positions, their paths became more consistent. This supported the conclusion that continents had moved relative to one another. It did not require assuming that all apparent polar wandering represented movement of the magnetic poles alone.\r\n<h3><span class=\"ez-toc-section\" id=\"6_How_palaomagnetism_proved_important_for_seafloor_spreading\"><\/span>6. How palaomagnetism proved important for seafloor spreading<span class=\"ez-toc-section-end\"><\/span><\/h3>\r\nThe ocean floor provided especially strong evidence. At a mid-ocean ridge, magma rises and forms new basaltic crust. As the basalt cools, it records the prevailing magnetic polarity. Continued crust formation moves older material away from the ridge. If the magnetic field reverses, the next generation of basalt records the opposite polarity. Repeated spreading and reversals create alternating bands of normal and reversed magnetisation, broadly parallel to the ridge and corresponding on its two sides. The analytical significance is that polarity patterns record changes in Earth\u2019s magnetic field. Matching patterns across the ridge record separation of newly formed crust. Increasing rock ages away from the ridge establish the sequence of spreading. The Vine\u2013Matthews\u2013Morley hypothesis, developed in 1963, connected magnetic reversals with seafloor spreading. It helped turn continental mobility into a measurable process. Once a magnetic band is dated, its distance from the ridge can also indicate the spreading rate. For example, 20 km of movement over one million years equals 2 cm per year on that flank. This is a half-spreading rate; the full rate measures separation between both flanks\r\n<h3><span class=\"ez-toc-section\" id=\"7_Other_major_applications\"><\/span>7. Other major applications<span class=\"ez-toc-section-end\"><\/span><\/h3>\r\nReconstructing past geography: Paleolatitudes and rotations help rebuild former continental arrangements and test plate reconstructions. Indian Plate reconstructions are one application. Dating and correlating rock sequences: Magnetostratigraphy matches sequences of magnetic polarity with an established timescale, supported by other age information. A single normal-polarity sample cannot provide a unique age because normal polarity has occurred repeatedly. Understanding the geodynamo: Records of past field direction and intensity constrain how Earth\u2019s magnetic field has behaved over time.\r\n<h3><span class=\"ez-toc-section\" id=\"8_Limitations_why_the_record_must_be_tested\"><\/span>8. Limitations: why the record must be tested<span class=\"ez-toc-section-end\"><\/span><\/h3>\r\nA magnetic record is valuable only when its origin and subsequent history are understood. Heating and chemical alteration can partially or completely replace the original signal. Folding and tectonic rotation change the present orientation of magnetised rocks. Sediment compaction can flatten recorded inclinations, causing paleolatitude estimates to be too low. Scientists therefore collect oriented samples, compare multiple specimens and progressively remove less stable magnetic components in the laboratory. One useful check is the fold test: if magnetic directions become more consistent when folded beds are restored to their original orientation, the magnetisation probably predates folding. Palaeomagnetism links the magnetic memory of minerals to the movement of entire continents. Its greatest geographical contribution was to provide independent, testable evidence for continental drift and seafloor spreading, helping establish plate tectonics.\r\n<h2><span class=\"ez-toc-section\" id=\"PYQs\"><\/span>PYQs<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n<ol>\r\n<li>Evidence from palaeomagnetism and seafloor spreading has validated that continents and ocean basins have been stationary. Elucidate with suitable diagrams. (20 marks \/ 2023)<\/li>\r\n<\/ol>\r\n\u00a0 \u00a0 \u00a0 2. Write a short note on Geomagnetism and Palaeomagnetism. (2011)\r\n<h3><span class=\"ez-toc-section\" id=\"In_case_you_still_have_doubts_contact_us_on_9773890604\"><\/span><strong>In case you still have doubts, contact us on 9773890604<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\r\n<span data-ccp-props=\"{&quot;335559738&quot;:107}\"><!-- \/wp:heading -->\r\n\r\n<!-- wp:paragraph --><\/span> Enrol in Geography Optional by Shabbir Sir: <a href=\"https:\/\/edukemy.com\/upsc\/geography-optional-by-shabbir-sir-foundation-course\" target=\"_blank\" rel=\"noopener\">Here<\/a> <br \/>Enrol in One-on-One Personalised Mentorship: <a href=\"https:\/\/edukemy.com\/upsc\/prime-one-on-one-personalised-mentorship\" target=\"_blank\" rel=\"noopener\">Here<\/a> <br \/>Enrol in GS Mentorship Program: <a href=\"https:\/\/edukemy.com\/upsc\/gs-foundation-mentorship-program-led-by-shabbir-sir\">Here<\/a> <br \/>Enrol In GS Mains Mentorship Program<a href=\"https:\/\/edukemy.com\/upsc\/gs-mains-mentorship-program-led-by-shabbir-sir\" target=\"_blank\" rel=\"noopener\">: Here<\/a> <br \/>Explore One Integrated Platform for UPSC Prep: <a href=\"http:\/\/askyooki.com\" target=\"_blank\" rel=\"noopener\">Yooki<\/a> <br \/>Visit our YouTube Channel: <a href=\"https:\/\/www.youtube.com\/c\/Shabbir%E2%80%99sEduKemyforIAS\" target=\"_blank\" rel=\"noreferrer noopener\">here<\/a> <span data-ccp-props=\"{&quot;335551550&quot;:1,&quot;335551620&quot;:1,&quot;335559739&quot;:0}\">\u00a0<\/span><\/div>","protected":false},"excerpt":{"rendered":"<p>Fundamentals of Geomagnetism Geomagnetism refers to the study of Earth&#8217;s magnetic field, including its origin, characteristics, variations and significance. Earth behaves approximately like a giant bar magnet, with a magnetic&hellip;<\/p>\n","protected":false},"author":25,"featured_media":51761,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_eb_attr":"","om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_uf_show_specific_survey":0,"_uf_disable_surveys":false,"footnotes":"","_members_access_role":[],"_members_access_error":""},"categories":[4],"tags":[],"class_list":["post-51350","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blogs"],"aioseo_notices":[],"aioseo_head":"\n\t\t<!-- All in One SEO 4.9.9 - aioseo.com -->\n\t<meta name=\"description\" content=\"Fundamentals of Geomagnetism Geomagnetism refers to the study of Earth&#039;s magnetic field, including its origin, characteristics, variations and significance. Earth behaves approximately like a giant bar magnet, with a magnetic field extending from its interior into surrounding space. This magnetic field is generated mainly by the movement of electrically conducting molten metals in Earth&#039;s outer\" \/>\n\t<meta name=\"robots\" content=\"max-image-preview:large\" \/>\n\t<meta name=\"author\" content=\"Edukemy Team\"\/>\n\t<link rel=\"canonical\" href=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/\" \/>\n\t<meta name=\"generator\" content=\"All in One SEO (AIOSEO) 4.9.9\" \/>\n\t\t<meta property=\"og:locale\" content=\"en_US\" \/>\n\t\t<meta property=\"og:site_name\" content=\"Blog - Edukemy&#039;s Blog for aspirants\" \/>\n\t\t<meta property=\"og:type\" content=\"article\" \/>\n\t\t<meta property=\"og:title\" content=\"Geomagnetism - Blog\" \/>\n\t\t<meta property=\"og:description\" content=\"Fundamentals of Geomagnetism Geomagnetism refers to the study of Earth&#039;s magnetic field, including its origin, characteristics, variations and significance. Earth behaves approximately like a giant bar magnet, with a magnetic field extending from its interior into surrounding space. This magnetic field is generated mainly by the movement of electrically conducting molten metals in Earth&#039;s outer\" \/>\n\t\t<meta property=\"og:url\" content=\"https:\/\/edukemy.com\/blog\/geomagnetism-2\/\" \/>\n\t\t<meta property=\"og:image\" content=\"https:\/\/edukemy.com\/blog\/wp-content\/uploads\/2024\/12\/edukemy-logo-horizontal.jpg\" \/>\n\t\t<meta property=\"og:image:secure_url\" content=\"https:\/\/edukemy.com\/blog\/wp-content\/uploads\/2024\/12\/edukemy-logo-horizontal.jpg\" \/>\n\t\t<meta property=\"og:image:width\" content=\"512\" \/>\n\t\t<meta property=\"og:image:height\" content=\"157\" \/>\n\t\t<meta property=\"article:published_time\" content=\"2026-11-11T17:58:31+00:00\" \/>\n\t\t<meta property=\"article:modified_time\" content=\"2026-11-11T18:19:54+00:00\" \/>\n\t\t<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/edukemy\/\" \/>\n\t\t<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n\t\t<meta name=\"twitter:site\" content=\"@EdukemyOfficial\" \/>\n\t\t<meta name=\"twitter:title\" content=\"Geomagnetism - Blog\" \/>\n\t\t<meta name=\"twitter:description\" content=\"Fundamentals of Geomagnetism Geomagnetism refers to the study of Earth&#039;s magnetic field, including its origin, characteristics, variations and significance. Earth behaves approximately like a giant bar magnet, with a magnetic field extending from its interior into surrounding space. This magnetic field is generated mainly by the movement of electrically conducting molten metals in Earth&#039;s outer\" \/>\n\t\t<meta name=\"twitter:creator\" content=\"@EdukemyOfficial\" \/>\n\t\t<meta name=\"twitter:image\" content=\"https:\/\/edukemy.com\/blog\/wp-content\/uploads\/2024\/12\/edukemy-logo-horizontal.jpg\" \/>\n\t\t<script type=\"application\/ld+json\" class=\"aioseo-schema\">\n\t\t\t{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"BlogPosting\",\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/geomagnetism-2\\\/#blogposting\",\"name\":\"Geomagnetism - Blog\",\"headline\":\"Geomagnetism\",\"author\":{\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/author\\\/aditi-palawat\\\/#author\"},\"publisher\":{\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/#organization\"},\"image\":{\"@type\":\"ImageObject\",\"url\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/wp-content\\\/uploads\\\/2026\\\/11\\\/Earths-Geomagnetic-Field-Explained.png\",\"width\":1536,\"height\":1024},\"datePublished\":\"2026-11-11T17:58:31+00:00\",\"dateModified\":\"2026-11-11T18:19:54+00:00\",\"inLanguage\":\"en-US\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/geomagnetism-2\\\/#webpage\"},\"isPartOf\":{\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/geomagnetism-2\\\/#webpage\"},\"articleSection\":\"Blogs\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/geomagnetism-2\\\/#breadcrumblist\",\"itemListElement\":[{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog#listItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/edukemy.com\\\/blog\",\"nextItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/category\\\/blogs\\\/#listItem\",\"name\":\"Blogs\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/category\\\/blogs\\\/#listItem\",\"position\":2,\"name\":\"Blogs\",\"item\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/category\\\/blogs\\\/\",\"nextItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/geomagnetism-2\\\/#listItem\",\"name\":\"Geomagnetism\"},\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog#listItem\",\"name\":\"Home\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/geomagnetism-2\\\/#listItem\",\"position\":3,\"name\":\"Geomagnetism\",\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/category\\\/blogs\\\/#listItem\",\"name\":\"Blogs\"}}]},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/#organization\",\"name\":\"Edukemy\",\"description\":\"Edukemy's Blog for aspirants\",\"url\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/\",\"telephone\":\"+919773890615\",\"logo\":{\"@type\":\"ImageObject\",\"url\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/wp-content\\\/uploads\\\/2024\\\/12\\\/edukemy-logo-horizontal.jpg\",\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/geomagnetism-2\\\/#organizationLogo\",\"width\":512,\"height\":157},\"image\":{\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/geomagnetism-2\\\/#organizationLogo\"},\"sameAs\":[\"https:\\\/\\\/www.facebook.com\\\/edukemy\\\/\",\"https:\\\/\\\/x.com\\\/EdukemyOfficial\",\"https:\\\/\\\/www.instagram.com\\\/edukemyforias\\\/?hl=en\",\"https:\\\/\\\/www.youtube.com\\\/@EdukemyforIAS\",\"https:\\\/\\\/www.linkedin.com\\\/company\\\/71977927\\\/admin\\\/dashboard\\\/\"]},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/author\\\/aditi-palawat\\\/#author\",\"url\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/author\\\/aditi-palawat\\\/\",\"name\":\"Edukemy Team\",\"image\":{\"@type\":\"ImageObject\",\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/geomagnetism-2\\\/#authorImage\",\"url\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/531318b44f9882b3f9f0adc52b1f19ff?s=96&d=mm&r=g\",\"width\":96,\"height\":96,\"caption\":\"Edukemy Team\"}},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/geomagnetism-2\\\/#webpage\",\"url\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/geomagnetism-2\\\/\",\"name\":\"Geomagnetism - Blog\",\"description\":\"Fundamentals of Geomagnetism Geomagnetism refers to the study of Earth's magnetic field, including its origin, characteristics, variations and significance. Earth behaves approximately like a giant bar magnet, with a magnetic field extending from its interior into surrounding space. This magnetic field is generated mainly by the movement of electrically conducting molten metals in Earth's outer\",\"inLanguage\":\"en-US\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/#website\"},\"breadcrumb\":{\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/geomagnetism-2\\\/#breadcrumblist\"},\"author\":{\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/author\\\/aditi-palawat\\\/#author\"},\"creator\":{\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/author\\\/aditi-palawat\\\/#author\"},\"image\":{\"@type\":\"ImageObject\",\"url\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/wp-content\\\/uploads\\\/2026\\\/11\\\/Earths-Geomagnetic-Field-Explained.png\",\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/geomagnetism-2\\\/#mainImage\",\"width\":1536,\"height\":1024},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/geomagnetism-2\\\/#mainImage\"},\"datePublished\":\"2026-11-11T17:58:31+00:00\",\"dateModified\":\"2026-11-11T18:19:54+00:00\"},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/#website\",\"url\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/\",\"name\":\"Edukemy\",\"description\":\"Edukemy's Blog for aspirants\",\"inLanguage\":\"en-US\",\"publisher\":{\"@id\":\"https:\\\/\\\/edukemy.com\\\/blog\\\/#organization\"}}]}\n\t\t<\/script>\n\t\t<!-- All in One SEO -->\n\n","aioseo_head_json":{"title":"Geomagnetism - Blog","description":"Fundamentals of Geomagnetism Geomagnetism refers to the study of Earth's magnetic field, including its origin, characteristics, variations and significance. Earth behaves approximately like a giant bar magnet, with a magnetic field extending from its interior into surrounding space. This magnetic field is generated mainly by the movement of electrically conducting molten metals in Earth's outer","canonical_url":"https:\/\/edukemy.com\/blog\/geomagnetism-2\/","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"BlogPosting","@id":"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#blogposting","name":"Geomagnetism - Blog","headline":"Geomagnetism","author":{"@id":"https:\/\/edukemy.com\/blog\/author\/aditi-palawat\/#author"},"publisher":{"@id":"https:\/\/edukemy.com\/blog\/#organization"},"image":{"@type":"ImageObject","url":"https:\/\/edukemy.com\/blog\/wp-content\/uploads\/2026\/11\/Earths-Geomagnetic-Field-Explained.png","width":1536,"height":1024},"datePublished":"2026-11-11T17:58:31+00:00","dateModified":"2026-11-11T18:19:54+00:00","inLanguage":"en-US","mainEntityOfPage":{"@id":"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#webpage"},"isPartOf":{"@id":"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#webpage"},"articleSection":"Blogs"},{"@type":"BreadcrumbList","@id":"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#breadcrumblist","itemListElement":[{"@type":"ListItem","@id":"https:\/\/edukemy.com\/blog#listItem","position":1,"name":"Home","item":"https:\/\/edukemy.com\/blog","nextItem":{"@type":"ListItem","@id":"https:\/\/edukemy.com\/blog\/category\/blogs\/#listItem","name":"Blogs"}},{"@type":"ListItem","@id":"https:\/\/edukemy.com\/blog\/category\/blogs\/#listItem","position":2,"name":"Blogs","item":"https:\/\/edukemy.com\/blog\/category\/blogs\/","nextItem":{"@type":"ListItem","@id":"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#listItem","name":"Geomagnetism"},"previousItem":{"@type":"ListItem","@id":"https:\/\/edukemy.com\/blog#listItem","name":"Home"}},{"@type":"ListItem","@id":"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#listItem","position":3,"name":"Geomagnetism","previousItem":{"@type":"ListItem","@id":"https:\/\/edukemy.com\/blog\/category\/blogs\/#listItem","name":"Blogs"}}]},{"@type":"Organization","@id":"https:\/\/edukemy.com\/blog\/#organization","name":"Edukemy","description":"Edukemy's Blog for aspirants","url":"https:\/\/edukemy.com\/blog\/","telephone":"+919773890615","logo":{"@type":"ImageObject","url":"https:\/\/edukemy.com\/blog\/wp-content\/uploads\/2024\/12\/edukemy-logo-horizontal.jpg","@id":"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#organizationLogo","width":512,"height":157},"image":{"@id":"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#organizationLogo"},"sameAs":["https:\/\/www.facebook.com\/edukemy\/","https:\/\/x.com\/EdukemyOfficial","https:\/\/www.instagram.com\/edukemyforias\/?hl=en","https:\/\/www.youtube.com\/@EdukemyforIAS","https:\/\/www.linkedin.com\/company\/71977927\/admin\/dashboard\/"]},{"@type":"Person","@id":"https:\/\/edukemy.com\/blog\/author\/aditi-palawat\/#author","url":"https:\/\/edukemy.com\/blog\/author\/aditi-palawat\/","name":"Edukemy Team","image":{"@type":"ImageObject","@id":"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#authorImage","url":"https:\/\/secure.gravatar.com\/avatar\/531318b44f9882b3f9f0adc52b1f19ff?s=96&d=mm&r=g","width":96,"height":96,"caption":"Edukemy Team"}},{"@type":"WebPage","@id":"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#webpage","url":"https:\/\/edukemy.com\/blog\/geomagnetism-2\/","name":"Geomagnetism - Blog","description":"Fundamentals of Geomagnetism Geomagnetism refers to the study of Earth's magnetic field, including its origin, characteristics, variations and significance. Earth behaves approximately like a giant bar magnet, with a magnetic field extending from its interior into surrounding space. This magnetic field is generated mainly by the movement of electrically conducting molten metals in Earth's outer","inLanguage":"en-US","isPartOf":{"@id":"https:\/\/edukemy.com\/blog\/#website"},"breadcrumb":{"@id":"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#breadcrumblist"},"author":{"@id":"https:\/\/edukemy.com\/blog\/author\/aditi-palawat\/#author"},"creator":{"@id":"https:\/\/edukemy.com\/blog\/author\/aditi-palawat\/#author"},"image":{"@type":"ImageObject","url":"https:\/\/edukemy.com\/blog\/wp-content\/uploads\/2026\/11\/Earths-Geomagnetic-Field-Explained.png","@id":"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#mainImage","width":1536,"height":1024},"primaryImageOfPage":{"@id":"https:\/\/edukemy.com\/blog\/geomagnetism-2\/#mainImage"},"datePublished":"2026-11-11T17:58:31+00:00","dateModified":"2026-11-11T18:19:54+00:00"},{"@type":"WebSite","@id":"https:\/\/edukemy.com\/blog\/#website","url":"https:\/\/edukemy.com\/blog\/","name":"Edukemy","description":"Edukemy's Blog for aspirants","inLanguage":"en-US","publisher":{"@id":"https:\/\/edukemy.com\/blog\/#organization"}}]},"og:locale":"en_US","og:site_name":"Blog - Edukemy's Blog for aspirants","og:type":"article","og:title":"Geomagnetism - Blog","og:description":"Fundamentals of Geomagnetism Geomagnetism refers to the study of Earth's magnetic field, including its origin, characteristics, variations and significance. Earth behaves approximately like a giant bar magnet, with a magnetic field extending from its interior into surrounding space. This magnetic field is generated mainly by the movement of electrically conducting molten metals in Earth's outer","og:url":"https:\/\/edukemy.com\/blog\/geomagnetism-2\/","og:image":"https:\/\/edukemy.com\/blog\/wp-content\/uploads\/2024\/12\/edukemy-logo-horizontal.jpg","og:image:secure_url":"https:\/\/edukemy.com\/blog\/wp-content\/uploads\/2024\/12\/edukemy-logo-horizontal.jpg","og:image:width":512,"og:image:height":157,"article:published_time":"2026-11-11T17:58:31+00:00","article:modified_time":"2026-11-11T18:19:54+00:00","article:publisher":"https:\/\/www.facebook.com\/edukemy\/","twitter:card":"summary_large_image","twitter:site":"@EdukemyOfficial","twitter:title":"Geomagnetism - Blog","twitter:description":"Fundamentals of Geomagnetism Geomagnetism refers to the study of Earth's magnetic field, including its origin, characteristics, variations and significance. Earth behaves approximately like a giant bar magnet, with a magnetic field extending from its interior into surrounding space. This magnetic field is generated mainly by the movement of electrically conducting molten metals in Earth's outer","twitter:creator":"@EdukemyOfficial","twitter:image":"https:\/\/edukemy.com\/blog\/wp-content\/uploads\/2024\/12\/edukemy-logo-horizontal.jpg"},"aioseo_meta_data":{"post_id":"51350","title":null,"description":null,"keywords":null,"keyphrases":{"focus":{"keyphrase":"","score":0,"analysis":{"keyphraseInTitle":{"score":0,"maxScore":9,"error":1}}},"additional":[]},"primary_term":null,"canonical_url":null,"og_title":null,"og_description":null,"og_object_type":"default","og_image_type":"default","og_image_url":null,"og_image_width":null,"og_image_height":null,"og_image_custom_url":null,"og_image_custom_fields":null,"og_video":"","og_custom_url":null,"og_article_section":null,"og_article_tags":null,"twitter_use_og":false,"twitter_card":"default","twitter_image_type":"default","twitter_image_url":null,"twitter_image_custom_url":null,"twitter_image_custom_fields":null,"twitter_title":null,"twitter_description":null,"schema":{"blockGraphs":[],"customGraphs":[],"default":{"data":{"Article":[],"Course":[],"Dataset":[],"FAQPage":[],"Movie":[],"Person":[],"Product":[],"ProductReview":[],"Car":[],"Recipe":[],"Service":[],"SoftwareApplication":[],"WebPage":[]},"graphName":"BlogPosting","isEnabled":true},"graphs":[]},"schema_type":"default","schema_type_options":null,"pillar_content":false,"robots_default":true,"robots_noindex":false,"robots_noarchive":false,"robots_nosnippet":false,"robots_nofollow":false,"robots_noimageindex":false,"robots_noodp":false,"robots_notranslate":false,"robots_max_snippet":"-1","robots_max_videopreview":"-1","robots_max_imagepreview":"large","priority":null,"frequency":"default","local_seo":null,"limit_modified_date":false,"created":"2026-11-11 17:46:11","updated":"2026-11-12 04:47:20","ai":{"faqs":[],"keyPoints":[],"schemas":[],"titles":[],"descriptions":[],"socialPosts":{"email":{"subject":"","preview":"","content":""},"linkedin":[],"twitter":[],"facebook":[],"instagram":[]}},"breadcrumb_settings":null,"seo_analyzer_scan_date":null},"aioseo_breadcrumb":"<div class=\"aioseo-breadcrumbs\"><span class=\"aioseo-breadcrumb\">\n\t\t\t<a href=\"https:\/\/edukemy.com\/blog\" title=\"Home\">Home<\/a>\n\t\t<\/span><span class=\"aioseo-breadcrumb-separator\">&raquo;<\/span><span class=\"aioseo-breadcrumb\">\n\t\t\t<a href=\"https:\/\/edukemy.com\/blog\/category\/blogs\/\" title=\"Blogs\">Blogs<\/a>\n\t\t<\/span><span class=\"aioseo-breadcrumb-separator\">&raquo;<\/span><span class=\"aioseo-breadcrumb\">\n\t\t\tGeomagnetism\n\t\t<\/span><\/div>","aioseo_breadcrumb_json":[{"label":"Home","link":"https:\/\/edukemy.com\/blog"},{"label":"Blogs","link":"https:\/\/edukemy.com\/blog\/category\/blogs\/"},{"label":"Geomagnetism","link":"https:\/\/edukemy.com\/blog\/geomagnetism-2\/"}],"_links":{"self":[{"href":"https:\/\/edukemy.com\/blog\/wp-json\/wp\/v2\/posts\/51350","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/edukemy.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/edukemy.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/edukemy.com\/blog\/wp-json\/wp\/v2\/users\/25"}],"replies":[{"embeddable":true,"href":"https:\/\/edukemy.com\/blog\/wp-json\/wp\/v2\/comments?post=51350"}],"version-history":[{"count":5,"href":"https:\/\/edukemy.com\/blog\/wp-json\/wp\/v2\/posts\/51350\/revisions"}],"predecessor-version":[{"id":51758,"href":"https:\/\/edukemy.com\/blog\/wp-json\/wp\/v2\/posts\/51350\/revisions\/51758"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/edukemy.com\/blog\/wp-json\/wp\/v2\/media\/51761"}],"wp:attachment":[{"href":"https:\/\/edukemy.com\/blog\/wp-json\/wp\/v2\/media?parent=51350"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/edukemy.com\/blog\/wp-json\/wp\/v2\/categories?post=51350"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/edukemy.com\/blog\/wp-json\/wp\/v2\/tags?post=51350"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}