July 14, 2004
Will We Live To See Next Collapse Of Earth's Magnetic Field?

Civilization could be disrupted by a collapse and reversal of Earth's magnetic field.

The collapse of the Earth's magnetic field, which both guards the planet and guides many of its creatures, appears to have started in earnest about 150 years ago. The field's strength has waned 10 to 15 percent, and the deterioration has accelerated of late, increasing debate over whether it portends a reversal of the lines of magnetic force that normally envelop the Earth.

During a reversal, the main field weakens, almost vanishes, then reappears with opposite polarity. Afterward, compass needles that normally point north would point south, and during the thousands of years of transition, much in the heavens and Earth would go askew.

A reversal could knock out power grids, hurt astronauts and satellites, widen atmospheric ozone holes, send polar auroras flashing to the equator and confuse birds, fish and migratory animals that rely on the steadiness of the magnetic field as a navigation aid. But experts said the repercussions would fall short of catastrophic, despite a few proclamations of doom and sketchy evidence of past links between field reversals and species extinctions.

Note that with sufficient planning a lot of the electrical effects could be ameliorated by better shielding and back-ups. Even satellites could be built to be better shielded. But maintaining a human presence in low Earth orbit would become a much riskier proposition.

Suppose the flip comes to pass. Should we respond by creating new maps that show the Southern Hemisphere on top?

Consider just one practical problem: If we continue to call the "North" the "North" then all compasses will be wrong. But if we make new compasses then they will have to be labelled as "Post-Collapse" compasses or else someone could use a compass, not know it was built before or after the collapse, and go off in the wrong direction. Likely the period of collapsed magnetic field would last so long before the field popped up firmly again that the use of compasses will have long been abandoned before their labelling becomes an issue.

Animals that have evolved to navigate by the magnetic field might be driven extinct.

When baby loggerhead turtles embark on an 8,000-mile trek around the Atlantic, they use invisible magnetic clues to check their bearings. So do salmon and whales, honeybees and homing pigeons, frogs and Zambian mole rats, scientists have found.

But within a hundred years we may well know all the species that have genetic adaptations to magnetic fields. We could use future advances in biotechnology to easily do genetic engineering to the most threatened of these species to adapt them to the change in magnetic fields. Therefore mass extinctions may be avoidable unless the collapse of the magnetic field causes holes in the ozone layer that cause extinctions via increases in UV radiation. Though even in that scenario we could save some of the species either by genetically engineering them to be more resistant to high UV or by doing climate engineering to create UV shields.

The flip of the magnetic poles may not happen for hundreds of thousands of years. But there may already be people alive today who will live to see the magnetic field collapse. Anyone who is still alive when Engineered Negligible Senescence (rejuvenation therapies that will make us young again) is achieved could conceivably live long enough to witness the magnetic field collapse. There may well already be people alive today who will live long enough to be around when rejuvenation becomes commonplace. Therefore some readers of this post may live through the future collapse of Earth's magnetic field.

The European Space Agency is going to launch a "Swing" cluster of 3 satellites in 2009 to collect enough data to perhaps allow magnetic field forecasting in a fashion analogous to weather and climate forecasting.

The objective of the Swarm mission is to provide the best ever survey of the geomagnetic field and its temporal evolution, in order to gain new insights into the Earth system by improving our understanding of the Earth’s interior and climate. The mission is scheduled for launch in 2009. After release from a single launcher, a side-by-side flying lower pair of satellites at an initial altitude of 450 km and a single higher satellite at 530 km will form the Swarm constellation.

High-precision and high-resolution measurements of the strength, direction and variation of the magnetic field, complemented by precise navigation, accelerometer and electric field measurements, will provide the necessary observations that are required to separate and model various sources of the geomagnetic field. This results in a unique “view” inside the Earth from space to study the composition and processes in the interior.

My guess is that we will be so technologically advanced by the time a magnetic field collapse becomes severe that we will be able to easily compensate for its effects. Climate engineering, UV shields over human habitats, genetic engineering of other species, and heavy shielding of electronics will be among the methods we use to protect human civilization and other species.

Share |      Randall Parker, 2004 July 14 03:44 PM  Dangers Natural General

Matt said at July 14, 2004 5:53 PM:

I never understood why "North" is considered North, anyway. And why do globes always show Antarctica on the bottom, and Greenland on top?

Al said at July 15, 2004 8:46 AM:

Depends on the map. (http://www.odt.org/pictureembed.htm)

Invisible Scientist said at July 15, 2004 12:23 PM:

One issue is the molten uranium that is in the core of the planet. Much of the heat
of the magma comes from the giant nuclear reactor that is the core of the planet.

And the molten iron that flows between the core and the surface of the planet, is
believed to cause the magnetic fields. Therefore, any switch in the magnetic fields of
the planet, must be related to the subterranean currents of molten iron. I wonder
how exactly this will affect the core of the earth, because if the switch of
underground flow of molten iron suddenly compresses the inner core of uranium,
this might actually increase the density of the unrefined uranium, and this means
that the core might actually reach the critical mass for a gigantic nuclear explosion.


Randall Parker said at July 15, 2004 12:27 PM:

Earth's magnetic field has been switching back and forth for hundreds of millions (billions?) of years without causing an explosion that anyone has found in the geological record. I think it is safe to assume it won't blow up the planet the next time it happens. So I'm not worried on that point.

Invisible Scientist said at July 15, 2004 12:58 PM:

But I still worry that the shift in the underground flow of molten
iron might cause earthquakes, devastating earthquakes.

I wonder if
you know of any geological records about the earthquakes at the times
when the magnetic poles shifted in history.

Peter said at July 15, 2004 1:09 PM:

The definition for a South Pole is that it is the axis around which a planet rotates clockwise. Not all planetary bodies have a magnetic field (or it sticks out sideways), therefore a definition of a pole has to be independant of the mag field.

Who is on top of the map? That sort of thing is dominated by the culture making the map. American maps have the US front and center. Look at those old godzilla movies: Japan will be at the center of the map. Similarly for British or Soviet movies.

Blowing up the world? Nah, that would be a plot for a cheesy sci-fi flick tho. As the fissile material gets too close together, it pushes outward. Explosives are needed to compress it, to prevent the stuff from going FIZZZZZ. For a fission chain reaction that is explosive, you would need rather concentrated fissile material and someway to keep it from oozing around like a fistful of jello. Maybe you would like to write up a script and pitch it to Hollywood? Core 2, AlQeda digs deeper! Core 3, the earth bites back! Core 4, oops, the Vogons have arrived! Core 5, Marvin blows up the world because it blocks his view of Venus! World ends, film at eleven! :)

Forrest B. Hinkson said at October 18, 2005 5:27 AM:

Doesn't the new crust coming up in the atlantic show a polarity switch for every ten thousand years? Does the polarity switch re-start the earth's spinning to decrease the top whobbling effect? Does the up coming polarity switch have anything to do with the increase in size and number of globel storms? Do the size of the ozone holes around the poles have more to do with the polarity of certain molecules attached or repelled at the poles?

Nuclear said at August 13, 2006 6:34 PM:

the earth might have exploded b 4 remember how the moon was supposedly created then what if the explosion caused the moon to be there (im talking about the uranium getting compressed)

akhil said at October 7, 2007 12:37 AM:

well magnetic field reversal is must and going to happen in few 100 decades
.......which will goin to shift north pole to south pole ...
ajnd this process will take few 100 years ......when auroras in the north pole
will seen in the equator and many species wipe out their indenity during this process
genetic transformations takes place in many species .....

physics changes ,conceptof poles changes ,"NOW THAT TIME NORTH POLE WILL NOT BE NORH AND

EXAMPLE OF MAGNETIC FIELD REVERSAL because in bermuda triangle their is no magnetic pole in this triangle ..
which may be result of magnetic field reversal ';;;;

John said at May 6, 2012 2:49 PM:

As a pilot, I know that the field is already shifting. The Agonic Line, the line of zero magnetic variation between magnetic and true North, used to run real close to Melbourne, Florida in 1980. Now, it's 6 degrees to the West, over the Gulf of Mexico. I doubt that it will reverse within my lifetime, but it's certainly possible within the next 100 years. One thing that grabs my attention is that some predictions for the next Yellowstone eruption say that it happened 640,000 years ago, roughly the same period since the last pole reversal, and surveys show that some of the land in Yellowstone has risen 3 feet over the last 20 years or so. That indicates lava activity, and when (not if) it blows, it will cause worldwide famines, volcanic winter, etc. 3 feet is a small rise for a lava dome so it's probably in its early stages, but since they have no data on supervolcano eruptions, who knows? I'm not ready to become a doomsday prepper yet, but I am keeping up on developments.

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