(April 24, 2024)
The age of the Earthâs magnetic field remains under question in part because we donât fully understand what causes it today. We know it is a product of movements in the molten outer core, whose high iron content turns convection currents into a dynamo, and these currents in turn are produced by the solidification of the inner core.
(April 2018)
Using constraints from experiments, simulations, and theory, we show that spontaneous crystallization in a homogeneous liquid iron alloy at Earth‘s core pressures requires a critical supercooling of order 1000 K, which is too large to be a plausible mechanism for the origin of Earth‘s inner core. We consider mechanisms that can lower the nucleation barrier substantially. Each has caveats, yet the inner core exists: this is the nucleation paradox.
(February 9, 2018)
„Everyone, ourselves included, seemed to be missing this big problem,“ study author Steven Hauck, a professor of Earth, Environmental and Planetary Sciences at Case Western Reserve University in Ohio, said in a statement. Namely, they were missing „that metals don‘t start crystallizing instantly unless something is there that lowers the energy barrier a lot.“
In chemistry, this extra energy is known as the nucleation barrier: the point at which a compound visibly changes its thermodynamic phase.
(…)
In their paper, the researchers proposed one possibility: Perhaps a massive nugget of solid metal alloy dropped from the mantle and plunged into the liquid core.
(June 11, 2026)
The observation provides new insights into the behaviour of the liquid outer core, which plays a key role in generating Earthâs magnetic field. Without this magnetic shield, the planet would be dangerously exposed to solar radiation.
Researchers at the University of Edinburgh checked ground observations and satellite data between 1997 and 2025. They report in The Journal of Studies of Earthâs Deep Interior, that in 2010, a broad region of iron-rich fluid beneath the equatorial Pacific switched from moving weakly westwards to strongly eastwards.
The age of the Earthâs magnetic field remains under question in part because we donât fully understand what causes it today. We know it is a product of movements in the molten outer core, whose high iron content turns convection currents into a dynamo, and these currents in turn are produced by the solidification of the inner core.
(April 2018)
Using constraints from experiments, simulations, and theory, we show that spontaneous crystallization in a homogeneous liquid iron alloy at Earth‘s core pressures requires a critical supercooling of order 1000 K, which is too large to be a plausible mechanism for the origin of Earth‘s inner core. We consider mechanisms that can lower the nucleation barrier substantially. Each has caveats, yet the inner core exists: this is the nucleation paradox.
(09.02.2018)
In their paper, the researchers proposed one possibility: Perhaps a massive nugget of solid metal alloy dropped from the mantle and plunged into the liquid core.
(07.02.2018)
It is widely accepted that the Earth‘s inner core formed about a billion years ago when a solid, super-hot iron nugget spontaneously began to crystallize inside a 4,200-mile-wide ball of liquid metal at the planet‘s center.
One problem: That‘s not possible-or, at least, has never been easily explained-according to a new paper published in Earth and Planetary Science Letters from a team of scientists at Case Western Reserve University.
(15.12.2019)
A geomagnetic reversal frequency of 26 reversals per Myr is therefore estimated for the Drumian, reduced to 15 reversals per Myr if only the polarity intervals defined by at least two consecutive samples are retained. This is an extreme reversal rate, similar to that reported for the Late Ediacaran (late Precambrian), âŒ50 Myr earlier, and proposed to be potentially linked to a late nucleation of the inner core.