William sent in the link to www.yahoo.com/news/strange-behaviour-earths-core-reveals-182721717.html … the temperature in the core of the earth is thought to be almost as hot as the surface of the Sun we are told. As the heat radiates outward it is absorbed by the liquid outer core, which churns around to create the earth's geomagnetic field. However, scientists have noticed the core is not fully responding to the theory. Seismic waves travelling through the planet's interior don't seem to conform to the model. The waves travelling between the poles move through the core faster than they do when travelling east to west. It is now thought the inner core might be asymmetric – one side elongated, east to west, but not north to south. They add – this does not mean the core is physically lopsided. The pull of gravity keeps the core spherical by redistributing iron crystals in the outer part of the inner core. This is said to be one reason why the core is thought to be cooling faster on one side, underneath Indonesia, compared to the other side, underneath Brazil. At the moment scientists do not know why this is happening.
Back in the day – see https://eurekalert.org/pub_releases/2002-03/uom-wwb031902.php … there were weird goings on in the lower reaches of the Mantle, the layer between the crust and the core. Geologists were again intrigued by seismic waves travelling faster than other waves. The effects were most observable at the core-mantle boundary.