The asthenosphere – which is derived from the Greek asthenes, meaning weak – is the uppermost part of the Earth’s mantle, right below the tectonic plates that make up the solid lithosphere. Traditionally, the asthenosphere has been viewed as a passive region that separates the moving tectonic plates from the mantle.
Continue reading “Source of intraplate volcanism”A Core-Mantle link
Researchers at a number of institutions around the globe have stumbled on a hint that the mantle does leave its mark on magnetic reversals. They have found that as the poles wander from north to south or vice versa during successive reversals, they show a startling tendency to trace out the same paths across the surface of the planet.
Continue reading “A Core-Mantle link”Steens Mountain shocker
Geological processes tend to be slow. But in 1995 a discovery by a group of scientists shocked the world when they announced they had found evidence of a rapid geomagnetic reversal. Before then, geophysicists believed that a complete flip would take around 5000 years.
Continue reading “Steens Mountain shocker”