Temperatures deep inside the Earth are so high that part of its iron core is liquid. This liquid iron is in constant motion, continuously churning and circulating.
Temperatures deep inside the Earth are so high that part of its iron core is liquid. This liquid iron is in constant motion, continuously churning and circulating. It acts like a dynamo, causing our planet’s magnetic field to be generated. One driving force for this complex flow behavior of iron is the Earth’s rotation, another is what is referred to as “convection”, driven by temperature differences: Similar to the way warm air rises above a radiator, where it displaces cooler air, relatively hot iron in the Earth’s core flows to cooler areas, resulting in heat transfer. As yet, however, little is known about how these processes take place in detail. To better understand them, experts have to rely on theoretical calculations and computer simulations, as well as experiments that simulate what is happening – at least to some extent – on a laboratory scale.
One such experiment was conducted recently at the HZDR’s Institute of Fluid Dynamics. “We took two cylindrical vessels – a relatively small one about the size of a bucket and the other one shaped like a barrel with a volume of 60 liters,” explained project leader Dr. Tobias Vogt. “We filled these vessels with a metallic alloy of indium, gallium and tin, which is liquid at room temperature.” The experts heated the bottom of the vessels whilst cooling the top, creating a temperature difference of up to 50 degrees Celsius between the higher and lower layers.
Read more at: Helmholtz Zentrum Dresden Rossendorf
Team members Dr. Till Zürner and Felix Schindler (from left) investigate the flow behavior in liquid metals. (Photo Creidt: A. Wirsig / HZDR)
