Turbulent Blobs in Earth's Core May Explain Sudden Jerks in the Magnetic Field
Earth's magnetic shield defends our planet from the scourges of solar wind and cosmic radiation, making life on our planet possible. But every 10 years or so, it can be a real jerk.
"Geomagnetic jerks" are abrupt changes in the strength of Earth's magnetic field. While some variations in this field are expected to occur gradually, over hundreds to thousands of years, these sudden wobbles in intensity last only a few years at most, and may only alter the Earth's magnetism over specific parts of the world at a time. One of the first jerks documented, for example, briefly warped the field over Western Europe in 1969.
Since then, a new jerk has been detected somewhere in the world every 10 years or so, and scientists still don’t know what's causing them. While many geomagnetic phenomena, including the northern and southern lights, result from electrified solar wind bashing into Earth's magnetosphere, the jerks are thought to originate from deep inside our planet's core, where the magnetic field itself is generated by the constant churn of liquid-hot iron. The exact mechanism of action, however, remains a mystery.
Now, a new study published today (April 22) in the journal Nature Geoscience offers a potential explanation. According to a new computer model of the core's physical behavior, geomagnetic jerks may be generated by buoyant blobs of molten matter released from deep inside the core. ...
