Researchers from the Ural Federal University and colleagues from Lomonosov Moscow State University have revealed new insights into how fluctuations in the Earth’s rotation can influence the planet’s liquid core. The team showed that random variations in rotation speed can drive large-scale movements within the fluid outer core. These dynamic changes have the potential to initiate tectonic processes that may lead to earthquakes, volcanic activity, or tsunamis. The findings were shared with socialbites.ca through UrFU reports.
The investigation focused on the behavior of a viscous fluid flowing within a spherical shell, the region between two concentric spheres, under the influence of irregular external inputs.
“Our study examined two specific flow regimes that arise when the inner sphere spins and when both spheres rotate with a common, unidirectional speed. The inner sphere’s rotation rate was treated as having white noise — random, time-dependent deviations from a mean value. Calculations indicate that the system’s response to these random fluctuations—how flow parameters change—depends on whether the rotation occurs solely on the inner sphere or on both spheres,” explained Maria Gritsevich, a senior researcher at UrFU, in an interview with socialbites.ca.
The numerical results were corroborated by experiments conducted at the Mechanics Institute of Moscow State University. Historically, studies of similar phenomena often relied on models where Earth’s rotation speed changes in a strictly periodic manner. The UrFU team explored random, as well as very small, deviations from that periodic behavior. They suggest that the Earth’s true rotation is far from a simple, fixed rhythm and that its nature may lie somewhere between the conventional models, still awaiting a complete understanding.
Overall, the research highlights how stochastic variations in planetary rotation can propagate through the fluid core, altering flow patterns and potentially influencing geophysical activity. By integrating computational simulations with laboratory experiments, the researchers contribute to a more nuanced view of the dynamical coupling between rotation and core dynamics, a topic of ongoing interest for geophysicists in North America and beyond.