Apocalypse – Loss of the Earth’s Magnetic Field (a guest post by Penny Higgins)

Some movies have put forward this idea that if we can disrupt the Earth’s magnetic field we’ll have an apocalypse. Think of that horrible movie “The Core.” This also comes up in the movie “2012.”

As it happens, there has been some discussion about whether or not disruptions of the Earth’s magnetic field could lead to extinction (or rapid evolution), because of the potential loss of shielding from cosmic radiation. There may be some truth to this, but it hasn’t been shown yet, at least not in any organisms with more than one cell.

 

Unfortunately (or maybe fortunately), disruptions to the Earth’s magnetic field tend to be so slow that they don’t really seem qualify as apocalyptic. A reversal (where the magnetic poles of the Earth switch places) is thought to take about 2000 years. Importantly, no-one says that the loss of the magnetic field will cause the Earth to fall apart! There are other planets in the solar system that lack magnetic fields (like Venus and Mars) and they’re doing just fine.

 

Let’s consider what would have to happen to shut down the Earth’s magnetic field (with some introduction to how the magnetic field works in the first place). Then, for giggles, let’s hypothesize what might actually happen should the Earth’s magnetic field suddenly cease to be.

 

 

Origin and Demise of the Earth’s Magnetic Field

I’ve already written a post about how the magnetic field of the Earth is formed. The key is that flow in the Earth’s liquid outer core causes the formation of the magnetic field. Some other planets (like Mars and Venus) lack a magnetic field because they lack either a liquid outer core (Mars) or flow in the liquid outer core (Venus).

 

The magnetic field of the Earth is known to have reversed multiple times during Earth’s history, with no discernible pattern or regularity. That is to say that while your compass needle points North now, at times in the past, it would point South. How this happens is not yet well understood. But what is known is that the Earth’s dipole magnetic field (the part that has north and south poles) decays away before it changes direction. (There is a non-dipole component to the Earth’s magnetic field, which honestly, I do not fully understand, so I won’t talk about it.) Sometimes reversals seem to be about to happen, and the field decays to nothing, then it recovers back to its original polarity. All told, the process seems to take a few thousand years to complete.

 

The Earth’s magnetic field protects the planet from the solar wind, a stream of highly energetic charged particles coming from the sun. It follows that when the magnetic field decays to zero, this cosmic radiation would strike the Earth and cause havoc. This is one of the premises of the movie “The Core.” (Also read more about The Core here.) If the magnetic field is lost, then the radiation should melt the Golden Gate Bridge, cause pacemakers to fail, and result in pigeons flying themselves into buildings.

 

Of course, none of these things could really happen, but it has been suggested that the increase in cosmic radiation during reversals could cause mutations in organisms increasing rates of evolution and potentially causing extinction or pseudoextinction (when organisms appear to have gone extinct because members of the lineage have evolved into a new, distinct morphology).

 

 

Evidence for Disruption

Is there any evidence that extinction or rapid evolution ever co-occurred with a reversal of the Earth’s magnetic field? I once asked this question and developed it into what became my senior thesis in the Biology Department at Fort Lewis College (all those years ago). My original plan was to lay out the geomagnetic polarity time scale and then plot alongside it the distributions of as many fossil species as I could find. It took me about a day to realize that the task was impossible. The biggest problem was that the resolution of the first and last appearances of the various species was not nearly precise enough to make a direct correlation. There are seldom numeric dates for the origination and extinction of species at all. The geomagnetic polarity time scale isn’t a whole lot better.

(Read about dating and the geomagnetic polarity time scale here.)

 

What I realized I needed was a situation where abundant fossils and the geomagnetic polarity could be collected and measured from the same rocks. I was disappointed when I realized that this meant abandoning looking at dinosaur extinctions and turning my attention instead to marine fossils, specifically microfossils.

 

The best study subjects were single-celled organisms that make tiny shells made of either calcium carbonate or silica. The shapes of the shells are what’s used to distinguish species. These organisms live in oceans and lakes, some as plankton floating with the currents, and others living on the ocean or lake floor. Because they’re small and common, it’s easy to look at evolutionary patterns or origination and extinction with them.

Radiolarians from Barbados

 

The rocks that the microfossils are found in, especially those of the ocean floor, are also great recorders of the state of the Earth’s magnetic field. Sea going vessels can drill into the ocean floor and pull up cores of the ocean floor sediments. The magnetic polarities can be measured directly from the core as it is passed through a magnetometer on the ships. These polarities can then be marked on the core, and corresponding samples of the cores can be taken. From these sample, microfossils can be isolated and identified, making it possible to directly correlation magnetic reversals with extinction events.

 

So? You ask. What are the results? What has happened?

 

James Hayes, in 1971, published a paper showing what he thought was evidence that extinctions in radiolarians (a type of single-celled organism that lives today but is also abundant in the fossil record) could be tied directly to reversals of the Earth’s magnetic field.  Ian Crain (1971) proposed that the loss of the Earth’s magnetic field could be lethal to some organisms, not because of an influx of cosmic radiation, but because the low field itself is disruptive to organisms.  Roy Plotnick, in 1980, published a paper showing that there is no demonstrable relationship between reversals and extinctions using the then currently available datasets. And since then, this topic hasn’t really been discussed, I suspect because the records are still insufficient to demonstrate a real relationship.

 

 

Magnetic Catastrophe

Let’s just say, for example, that the Earth’s magnetic field does suddenly shut down one day, just like what happens in “The Core.” Would it be an apocalypse? Would we be irradiated? Would microwaves melt our bridges?

 

Erm. No.

 

I imagine a lot of animals will get disoriented. Pigeons might fly in circles, unable to get home. Migrations might be disrupted. Salmon might have a hard time finding their home streams. Monarch butterflies might not make it back to their winter roosting trees in Mexico. So far, doesn’t seem to catastrophic. Some species might struggle and go extinct. The Sierra Club and Greenpeace and other such groups would probably go nuts. But it’s not terribly dangerous to humans, so far as I can tell.

Magnetic compasses would cease to work. That might have mattered more 50 years ago before GPS units and satellites. These days, our GPS’s can replace the old-fashioned compass.

 

Unless, of course, there’s some way that cosmic radiation can damage or disrupt the satellites that we’re dependent on. I wonder how long it would take the solar wind to shut down all the communication satellites we depend upon? That might be a problem.

 

But catastrophic?

 

Well, I guess it would kind of stink if suddenly airplanes didn’t know what way they were going. Oh yeah, but there’s those ground beacons, so I guess they’d be ok.

 

How about communications? Not everything is satellite-based. I’d be pretty cheesed off if I lost my 3G, but that’s dependent upon towers on the ground. I don’t call over seas very often, so the lack of satellite communication wouldn’t be the end of the world. Not for me anyway, and probably not for most people.

 

I guess, maybe, there’d be an increased chance of getting a sunburn what with all those extra cosmic rays? Invasion of the Lobster People, perhaps? I don’t think so.

 

So, really, what would happen if the Earth suddenly lost its magnetic field? Probably not much. Maybe a brighter aurora. Maybe some communications disruptions. Sure, some animals might be in trouble and go extinct. But nothing catastrophic.

 

It would just be inconvenient.

 

*****************************************************
Penny Higgins
Vertebrate Paleontologist -- Isotope Geochemist
Writer

Work:
http://www.ees.rochester.edu/SIREAL/
pennilyn.higgins@rochester.edu

Personal:
http://www.paleopix.com/blog
http://www.flickr.com/paleololigo
paleololigo@yahoo.com
@paleololigo on Twitter

You vs. The Apocalypse

My last house was a pretty little ranch-style home located on the block were Hurricane Central and Tornado Alley share a summer home. We spent more than one night sleeping in the closet because a tornado rolled into town. While I was there dodging strong winds and the occasional flying cow I was part of the emergency preparedness group for the area and often gave classes and lectures on how to prepare for disasters.

I like to pretend that everyone knows how to handle an emergency, but I woke up to the news of the earthquake and tsunami in Japan (you're in my prayers and thoughts), and @Kat_tastic tweeting:

kat_tastic kat o'keeffe

I am so unprepared for the apocalypse.

No worries, we have a post for that.

Let's start with the basics. You don't need to be a hard-core survival buff to get through an emergency. Usually, a 72-hour kit will get you through the worst of it.

Grab a bag, a big one, think camping back-pack or hockey duffel bag. Then hit the 72 Hours.org website for a list of what you need. The most important things are something to start a fire with (waterproof matches or flint for preference), water, or something to purify water with, food (including sugar), photos of family and pets, copies of birth certificates and important paperwork, s first aid kit you know how to use, and a change of clothes.

Why a 72 Hour Kit?
In most cases it takes three days for help to arrive, get set up, and start doing good. For the first three days of a major emergency you should plan on being on your own. Hopefully it will only take hours, but if you planned for three days and it only takes hours than you can turn around and help other people.

For food I recommend the lunch packs of tuna or chicken salad, MREs (meal-ready-to-eat available from military supply stores and some camping stores), camp food, and granola bars. Rotate the food out of your kit every six months (Halloween and Easter) along with changes of clothes (because the seasons change and kids grow). Don't forget over-the-counter medicines like antacids, Tylenol, and antihistamines.

Take the checklist, pack your 72-hour kit, and if you can keep it near by. The front hall closet works if you have one, under the bed with a pair of running shoes is recommended for anyone old enough to carry their bag and everyone who lives in earthquake or tornado regions.

The idea here is that if the tornado siren went off RIGHT NOW! you could grab your bag, head to the designated safe place, and be fine even if your roof went missing. Pack mini kits for your kids, and keep some extra kibble for your cat or dog in your bag.


Back Up Your Data
You know that beautiful computer you're reading this on? Without electricity you aren't pulling up pictures and printing. You are definitely not working on your novel. Forgive the writerly aside, but I recommend double or triple back up.

1- Cloud or off-site storage in the form of Dropbox, OfficeLive, or something similar. Even e-mailing it to yourself is good.

2- Hard storage. Save a copy of all relevant data from your computer on CD, thumbdrive, or external hard drive and put it with your 72-hour kit. A 6-month back-up disc won't save your writing, but it will save the family photos.

3- Send it to a friend. In case natural disaster means the end of life as we know it in whatever country you're in, consider e-mailing your work to an overseas friend. This is more for people in very unstable countries, but my crit buddy in Australia e-mail our work to each other. It's just a nice safety net to have.


Sugar and First-Aid
Not everyone has the benefit of knowing more than rudimentary first-aid. Even if you don't have training (see the EMTs cringe) there are some things you can do.

- Have a first aid kit. Most kits have a little booklet with instructions for how to handle splints and CPR. Hum "Another One Bites the Dust" and you have the right tempo for CPR.

- If you don't have to, don't move anyone with a neck or back injury. Obviously if a wall of water/fire/rock is about to crush the person, pick them up and run. Otherwise, leave them still until professional help comes.

- Clean out cuts. This is very, VERY important. See all the beer getting looted? Alcohol kills germs. Dump alcohol on open wounds, or hydrogen peroxide, and live longer. Don't drink the alcohol, however, you don't want to get dehydrated or stupid until you are safe.

- Sugar makes everything better. Most first aid kits don't have emergency blankets or sugar, and most survivors of a major disaster need warmth, and glucose because they are in shock. Drop some Starbursts or other easy-to-keep candy in your 72-hour kit and first aid kit. If you have kids, or know kids, or have seen a kid, add some bright fun kiddy bandages to your kit. Remember, they just watched their home crumble and may have lost a parent, if a Dora the Explorer bandage makes that okay, that's a good thing.

- Light and heat are necessary for survival. Go down the hunting/camping aisle at your local store and grab some foil emergency blankets, flashlights, and the chemical hand warmers. Even if your disaster strikes in summer it gets cold at night when you're wet and it's raining. Store batteries for the flashlight in a plastic bag taped to the flashlight, not inside. Your batteries last longer that way.


Water
Anyone who followed the disaster in Haiti knows that the majority of the death toll wasn't because of the initial quake, but because of illness. Clean water is essential to you living a long and happy life.

If you can, store gallon jugs of water. Don't use milk jugs, but the plastic juice bottles are perfect for water storage. Clean the jug out, fill with water, and exchange water every 6 months.

I wash every juice bottle we empty, fill it with water, and use it six months later to water my plants before refilling.

If you can't store water for whatever reason, buy some bleach. The water will taste horrendous, but you won't die. Ask yourself which is more important. You can suffer through some bad tasting water for a few days if it means being hale and healthy in the long run.

Coffee filters and boiling can also be used to purify water, but won't get everything.

Treating Water with a 5-6 Percent Liquid Chlorine Bleach Solution
Volume of Water to be Treated	Treating Clear/Cloudy Water: Bleach Solution to Add	Treating Cloudy, Very Cold, or Surface Water: Bleach Solution to Add
1 quart/1 liter	3 drops	5 drops
1/2 gallon/2 quarts/2 liters	5 drops	10 drops
1 gallon	1/8 teaspoon	1/4 teaspoon
5 gallons	1/2 teaspoon	1 teaspoon
10 gallons	1 teaspoon	2 teaspoons

Disasters hit everywhere eventually. Plan ahead. Be a survivor.