How is the earth's outer core changing?

📌 Summary:

• The earth's outer core is a voluminous liquid layer that lies around 2,800 km beneath the surface, filled with hot, churning molten iron and nickel.
• As the outer core moves constantly, it acts like a large generator, creating the planet's magnetic field, which shields the earth from harmful solar radiation.
• Researchers from the University of Edinburgh and the British Geological Survey found that around 2010 the liquid iron in the outer core below the equatorial Pacific Ocean changed direction — from a slow westward crawl to a more rapid eastward surge.
• The finding came from mapping 27 years of iron movement in the outer core using data from ground stations and four European satellites.
• Two flow patterns were identified: a main pattern accounting for 95% of the movement — a steady westward flow that explains why the earth's magnetic field has historically drifted west; and a second pattern showing the dramatic 2010 eastward shift, which began to weaken around 2020.
• The 2010 reversal was linked to seismic and geodetic shifts in the earth's solid inner core; the flow is also roughly 10% lopsided between the northern and southern hemispheres.
• These findings could explain sudden 'jerks' in magnetic field readings and suggest that deep-earth liquids can change direction much faster than traditional theory predicts.

📝 Prelims Facts:

• The outer core lies about 2,800 km below the surface and is composed of liquid iron and nickel
• Movement of the outer core generates the earth's magnetic field (the geodynamo)
• Around 2010 the iron flow under the equatorial Pacific reversed from westward to eastward
• A geomagnetic 'jerk' is a sudden change in the rate of variation of the earth's magnetic field

🔑 Key Term: Geomagnetic jerk — a sudden, sharp change in the rate of variation of the earth's magnetic field, originating in the fluid dynamics of the liquid outer core.