Phys.org August 30, 2024 Thermochemical inhomogeneities in the Earth’s outer core that enhance our understanding of the geodynamo have been elusive. Seismic constraints on such inhomogeneities would provide clues on the amount and distribution of light elements in the core apart from iron and nickel. Researchers in Australia found evidence for a low-velocity volume within the outer core via the global coda correlation wavefield. Several key correlogram features with a unique sensitivity to the liquid core showed variations with wave paths remarkably slower in the equatorial than polar planes constrained a torus structure at low latitudes with lower velocity than […]
Category Archives: Geomagnetism
The Earth’s changing, irregular magnetic field is causing headaches for polar navigation
Phys.org May 27, 2024 Researchers at the University of Michigan statistically studied large magnetic field vector residuals between Swarm observations and the 13th generation International Geomagnetic Reference Field (IGRF-13) model under quiet to moderate geomagnetic conditions. All large residuals appeared in the high latitude auroral zone region peaking around 70° magnetic latitude (MLAT) with a secondary occurrence peak just below 80° MLAT. However, the two hemispheres showed clear asymmetries in the magnetic longitude and magnetic local time distribution where both hemispheres showed high concentration of large residuals around the geographic poles. Since polar satellite’s orbits give rise to highly biased […]
The Mysterious Anomaly Weakening Earth’s Magnetic Field Seems to Be Splitting
Science Alert May 26, 2020 New satellite data from ESA reveal that the South Atlantic Anomaly is a vast expanse of reduced magnetic intensity in Earth’s magnetic field, extending all the way from South America to southwest Africa. Since our planet’s magnetic field acts as a kind of shield – protecting Earth from solar winds and cosmic radiation, in addition to determining the location of the magnetic poles – any reduction in its strength is an important event we need to monitor closely, as these changes could ultimately have significant implications for our planet. The ESA notes that the most […]