I recently saw part of an animated documentary on National Geographic about what can be found as you move from the Earth’s surface to its centre. “Down to the Earth’s Core”, a 90 minute film released in 2012, uses often spectacular computer generated imagery. An earthquake inside the San Andreas Fault is shown, along with an erupting volcano and bizarre cave-dwelling creatures. Earth’s extraordinary history is laid bare, layer by layer. A number of fascinating stories are told in the course of the journey downwards, such as how prehistoric forests became modern-day fuel and how dinosaurs experienced cataclysmic death. Eventually the planet’s super-heated liquid core is reached.
Some of the highlights for me are listed below, along with how many minutes they can be found into the YouTube video above: the Carlsbad Caverns of New Mexico, 240 metres below the surface (at 9.00 minutes); a cave of giant crystals, 300 metres deep (at 20.17 minutes); the layer of extraterrestrial iridium rock at 550 metres and its link to dinosaur extinction (at 25.45 minutes); the accumulation of gold deposits nearly 2 kms down (at 34.22 minutes); the formation of amethyst quartz crystals at 3.9 kms (at 38.42 minutes); and how diamonds came to be, at 240 kms down (at 1 hour 8.40 minutes).