What Will Happen When Earth’s North And South Pole Flip?


– [Narrator] Did you know that
Earth has two north poles? There’s the geographic north pole, which never changes, and there’s the magnetic north pole, which is always on the move. And right now it’s
moving faster than usual. Over the last 150 years, the magnetic north pole has casually wandered 685
miles across northern Canada. But right now, it’s racing 25 miles a year to the northwest. This could be a sign that we’re about to
experience something humans have never witnessed before: a magnetic polar flip. When this happens, it
could effect much more than just your compass. – Right now on the surface of the planet, it looks like it’s just a bar magnet. Our compasses are just pointing
toward one pole at a time. There’s a dominant two
pole, dipole system. – [Narrator] But sometimes,
Earth doesn’t always just have a single magnetic
north and south pole. Evidence suggests that
for hundreds to thousands of years at a time, our planet has had four, six and even eight poles at a time. This is what has happened when the magnetic poles
flipped in the past. And when it happens again, it
won’t be good news for humans. Now you might think that eight poles must be better than two, but the reality is that
multiple magnetic fields would fight each other. This can weaken Earth’s
protective magnetic field by up to 90% during a polar flip. Earth’s magnetic field is what shields us from harmful space radiation which can damage cells, cause cancer and fry electronic circuits
and electrical grids. With a weaker field in place, some scientists think
this could expose planes to higher levels of radiation
making flights less safe. This could also disrupt
the internal compass in many animals which use the
magnetic field for navigation. Even more extreme, it
could make certain places on the planet too dangerous to live. But what exactly will
take place on the surface is less clear than what will
undoubtedly happen in space. Satellites and crude space missions will need extra shielding that we’ll have to provide ourselves. Without it, intense
cosmic and solar radiation will fry circuit boards and increase the risk
of cancer in astronauts. Our modern way of life
could cease to exist. We know this because we’re
already seeing a glimpse of this in an area called the
South Atlantic Anomaly. Turns out, the direction of a portion of the magnetic field
deep beneath this area has already flipped. Scientists say that’s
one reason why the field has been steadily weakening since 1840. As a result, the Hubble Space Telescope and other satellites often shut down their
sensitive electronics as they pass over the area. And astronauts on the
international space station report seeing a higher number
of bright flashes of light in their vision, thought to be caused by high energy cosmic rays that the weaker field can’t hold back. Since experts started measuring the anomaly a few decades ago, it has grown in size. It now covers a fifth of Earth’s surface with no signs of shrinking anytime soon. This is so extreme that it could be a sign we’re on the brink of a polar flip or we may already be in the midst of one. But scientists remain
skeptical, mainly because… – The last time the poles
reversed was 780,000 years ago so we don’t have a record of this. – [Narrator] Turns out, 780,000 years is over double the time Earth
usually takes between flips. – Since the last mass extinction, there have been reversals
roughly every 300,000 years. – [Narrator] So, what gives? Well, scientists haven’t
figured it out, yet. It’s unnerving to think
that our modern way of life, banking, the stock exchange,
missile tracking, GPS, relies on the outcome of something we can neither
predict nor control. One study went so far as to estimate that a single, giant solar storm today could cost the U.S. up to 41.5 billion dollars a day in damages, and that’s with the Earth’s magnetic field at it’s current strength. It’s frightening to even imagine the devastation a storm
would bring to an Earth with a magnetic field only
10% as strong as it is now. We may not be able to stop a polar flip, but we can at least start to take measures to minimize the damage. The first step, figure out what’s going on with this wacky field. On the hunt are the
European space agency’s Swarm satellites that are currently collecting
the most precise data on the strength of Earth’s magnetic field. Right now they could be our greatest hope for solving this riddle.

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