Knowra Geodynamo Geodynamo The process by which motion of electrically conducting liquid inside a planet generates and sustains a magnetic field. Earth’s geodynamo operates in its liquid iron-rich outer core.
Magnetohydrodynamics : The study of electrically conducting fluids interacting with magnetic fields. It provides the physical framework for fluid motion generating and reshaping the geodynamo’s magnetic field.
Earth's outer core : Earth’s liquid, iron-rich layer between the solid inner core and the rocky mantle. Its electrically conducting fluid is the moving medium of Earth’s geodynamo.
Geomagnetic field : The magnetic field surrounding Earth, produced mainly by motion in its liquid outer core. It is the observable field generated by Earth’s geodynamo.
Lunar dynamo : The ancient magnetic-field-generating process inferred to have operated in the Moon’s interior. The Moon’s dynamo ceased, unlike Earth’s long-lived field, highlighting the role of interior evolution.
Geomagnetic secular variation : The gradual change in Earth’s magnetic field over years to centuries. Its evolving patterns constrain models of flow deep within the outer core.
Dynamo theory : The theory describing how conducting-fluid motion can generate and sustain magnetic fields. It explains how the geodynamo converts core motion into a self-sustaining magnetic field.
Earth's inner core : Earth’s solid, predominantly iron-rich central sphere, surrounded by the liquid outer core. Its growth releases heat and light elements that help drive outer-core convection.
Paleomagnetism : The study of ancient magnetic fields recorded in rocks, sediments, and archaeological materials. Its records reveal past field directions and strengths, including changes in dynamo behavior.
Martian dynamo : The ancient process that generated Mars’s global magnetic field before it shut down. Mars preserves crustal traces of an extinct dynamo rather than Earth’s active global field.
Geomagnetic jerks : Abrupt changes in the rate of Earth’s magnetic-field variation, typically lasting several years. Their causes may involve rapid changes in core flow or waves near the core–mantle boundary.
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