Massive Deep-Earth Structures Influence Earth's Magnetic Field

Scientists have discovered that two massive, intensely hot rock formations located approximately 2,900 kilometers beneath Africa and the Pacific Ocean have been influencing Earth's magnetic field for millions of years. These structures, known as large low-shear-velocity provinces (LLSVPs), affect the movement of liquid iron in Earth's outer core, thereby impacting the planet's magnetic behavior.

The research team, led by the University of Liverpool, combined palaeomagnetic data with advanced computer simulations to study the geodynamo—the process by which the movement of liquid iron generates Earth's magnetic field. Their findings indicate that the upper boundary of the outer core exhibits sharp thermal contrasts, with localized hot zones beneath the LLSVPs. This uneven heat distribution results in some components of the magnetic field remaining stable over vast periods, while others change dramatically.

Professor Andy Biggin, a geomagnetism expert at the University of Liverpool, explained that these temperature contrasts in the mantle just above the core suggest that, beneath hotter regions, the liquid iron may stagnate rather than participate in the vigorous flow observed beneath cooler regions. This insight enhances our understanding of the deep Earth's dynamic evolution and its more stable properties.

The study also has implications for understanding ancient continental configurations, such as the formation and breakup of Pangaea, and may help resolve uncertainties in ancient climate, paleobiology, and the formation of natural resources. The research was conducted by scientists from the DEEP (Determining Earth Evolution using Palaeomagnetism) research group within the University of Liverpool's School of Environmental Sciences, in collaboration with researchers from the University of Leeds.