http://www.bbc.co.uk/news/uk-14678002 (video clips)
A Japanese scientist has recreated the conditions at the core of the plant to witness the rapid growth of crystalline 'forests'. Extreme conditions found at the Earth's core have been recreated in the laboratoryHe has created an incredibly powerful vice using the tips of two diamonds. Between them he has pressurised a sample of iron-nickel to three million times atmospheric pressure and heated the sample to about 4,500C.Under these extraordinary conditions, the crystal structure of iron-nickel alloy changed and the crystals rapidly grew in size. "We may have very big crystals at the centre of the Earth, maybe up to 10km," says Hirose. These crystals would all align "like a forest", says Hirose, pointing at the poles.
Other scientists reveal the latest info about the South Atlantic Anomaly... an area where the magnetism of the earth is reversed. The bulk of the Earth's magnetic field is generated not in the inner-core but in the molten metal of the outer-core. This acts as a massive electromagnetic dynamo powered by the Earth's rotation and the long-term cooling of the planet.But although the basic principle is understood, the details of how the molten metal moves are a mystery. As Earth rotates and loses heat from the centre, complex patterns of flow are created within this vast ocean.
I wish I could watch the BBC documentary but it is showing only in the UK. You can watch it here, if you are in the UK.