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The dynamo theory sees eddy currents in the nickel-iron fluid of the outer core as the principal source of Earth's magnetic field. The average magnetic field strength in Earth's outer core is estimated to be 2.5 millitesla, 50 times stronger than the magnetic field at the surface. [9] [10]
The transition between the inner core and outer core is located approximately 5,150 km (3,200 mi) beneath Earth's surface. Earth's inner core is the innermost geologic layer of the planet Earth . It is primarily a solid ball with a radius of about 1,220 km (760 mi), which is about 19% of Earth's radius [0.7% of volume] or 70% of the Moon 's radius.
Beneath the mantle, an extremely low viscosity liquid outer core lies above a solid inner core. [132] Earth's inner core may be rotating at a slightly higher angular velocity than the remainder of the planet, advancing by 0.1–0.5° per year, although both somewhat higher and much lower rates have also been proposed. [133] The radius of the ...
Lehmann was the first to suggest that wayward P waves might be interacting with a solid inner core within the liquid outer core, based on data from a massive earthquake in New Zealand in 1929.
It is true that the outer core generates electrical currents that sustain the planet's magnetic field, but Vidale says shifts in the Texas-size inner core are too minuscule to have an impact.
Next, the research team wants to investigate whether the core is a storehouse of other light elements, which could account for the why Earth’s outer core is less dense than expected.
Earth was discovered to have a solid inner core distinct from its molten outer core in 1936, by the Danish seismologist Inge Lehmann's [7] [8] study of seismograms from earthquakes in New Zealand, detected by sensitive seismographs on the Earth's surface. She deduced that the seismic waves reflect off the boundary of the inner core and inferred ...
“We infer the inner core rotation changes direction every 35 years,” Dr. Song told McClatchy News. Earth’s core might be reversing its spin. It ‘won’t affect our daily lives,’ expert says