ESC 1000 Class Video ††††††††Name: __________________
Section: MW† TR† R††††††††††††† Date: ______________
Earthís Core Ė Earth Science - The Earthís Core - What lies at the
centre of the Earth?
The spinning outer core of the Earth generates a protective magnetic shield around the planet, defending life from lethal space radiation. But now there is startling data that it could be about to stop defending us. We hear from Professor Dave Stevenson about a mission to the centre of the Earth. To penetrate the surface, he would need a probe with as much energy as a magnitude 7 earthquake, powered by atomic warheads. The grapefruit sized probe would then take a week to get to the core, where it would be lost forever.
Film Notes: (use the back if necessary)
There is a place on Earth that we have never seen. It is a place of unimaginable heat and pressure, where no life could survive. Yet without it, we would perish for it holds the key to our precarious existence on this planet.
2000 miles below the Earthís surface, there is a vast ocean of molten iron. The spinning outer core of the Earth generates a protective magnetic shield around the planet, defending life from lethal space radiation. But now there is startling data that it could be about to stop defending us. Naked Science is taking you on a journey to the centre of the Earth.
Dr Ed Garnero from Arizona State University uses earthquakes as a window into our subterranean world. He is mapping the structure deep within our planet, and has gathered evidence that the core is cooling and expanding. Earthís heart is freezing solid.
NASA has discovered that Mars once had a magnetic field like Earth. For some reason it faded, taking the Martian atmosphere with it. Mars became the red, barren planet we know today. Does Earth have a similar destiny?
Dr Dan Lathrop runs a Naked Science demonstration to simulate what is happening in the core. He is part of a team uncovering the answers to what will happen if the core continues to wind down. Professor Jeremy Bloxham from Harvard has discovered that Earth could be in for a turbulent ride. Thereís a region over the South Atlantic where the field isnít just weakening, itís flowing in the wrong direction. It could be the first indicator that Earth is on the verge of a global magnetic reversal.
Nobody has ever experienced a magnetic flip. The last time it happened was when the Neanderthals walked the Earth. And weíre well overdue for it to happen to again.
Geophysicist Marvin Herndon believes that the core is a 5 mile wide ball of uranium. Are we sitting on a nuclear reactor thatís running low on gas? The lavas of Hawaii and Iceland provide further clues into the interior of the Earth, and fuel a huge debate into where lava actually comes from. Itís in these lavas that Herndon finds evidence for his nuclear theory.
We meets Professor Dave Stevenson to hear about a mission to the centre of the Earth, proposed to cost ten billion dollars. To penetrate the surface, he would need as much energy as a magnitude 7 earthquake, and would be powered by atomic warheads. The grapefruit sized probe would then take a week to get to the core, where it would be lost forever. But could a person ever make it to the core of Earth? Naked Science looks at the likely effect on the human body.
Pack your bags. We may need to leave Earth sooner than we thought. It could be only one hundred years before our planet goes the same way as Mars.