ESC 1000 Class Video Name: __________________
Section: MW TR R
Date: ______________
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The
Earth’s Core – Earth Science - The Earth’s 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)
Student Questions:
Your Questions/Answers:
1.
2.
Discovery Statement:
SYNOPSIS
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 Earth’s
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. Earth’s 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. There’s a region over the South
Atlantic where the field isn’t just weakening, it’s 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 we’re 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 that’s 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. It’s 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.