About a week ago, we’re in my car running a few errands. My son is chattering away, happily talking about how Winnie-the-Pooh didn’t really discover the North Pole because he was just pretending. (The Winnie-the-Pooh books are our current bedtime story, if you’re wondering.) Something about the combination of these two facts must have sparked what happened next.
“Dad? How long would it take to drive to the North Pole?”
“Magnetic, or true?” I counter.
“What?” he responds.
The Two Poles
There are two North Poles (and two South Poles as well), the “true” (or geographic) North Pole and the magnetic North Pole. And they do not really match up. So what’s the difference between the two of them? Here’s how National Geographic describes the North Pole:
The North Pole is the northernmost point on Earth. It is the precise point of the intersection of the Earth’s axis and the Earth’s surface.
The North Pole sits in the middle of the Arctic Ocean, on water that is almost always covered with ice. The ice is about 2-3 meters (6-10 feet) thick. The depth of the ocean at North Pole is more than 4,000 meters (13,123 feet).
The magnetic North Pole is a little more difficult to pin down. Why? Well, let’s start by letting NOAA tell us what the magnetic poles are:
Magnetic poles are defined in different ways. They are commonly understood as positions on the Earth’s surface where the geomagnetic field is vertical (i.e., perpendicular) to the ellipsoid. These north and south positions, called dip poles, do not need to be (and are not currently) antipodal.
“Antipodal”, by the way, is your new word for the day. It means:
- Geography. on the opposite side of the globe
- diametrically opposite
- Botany. (in a developing ovule) of or at the end opposite to the micropyle
So why does the magnetic field move? Because it’s produced by the spinning of the Earth’s inner core – a solid iron ball almost as big as the moon and hotter than the sun that spins a little faster than the Earth’s crust in a massive sea of liquid (or, at least more liquid) metal called the “liquid inner core”. So far, so good. Right?
Now, the full details of what generates the magnetic field are not understood – a fact that I’m certain makes scientists extremely happy. But, as Natural Resources Canada explains, we do understand the basic concepts:
For magnetic field generation to occur several conditions must be met:
- there must be a conducting fluid;
- there must be enough energy to cause the fluid to move with sufficient speed and with the appropriate flow pattern;
- there must be a “seed” magnetic field.
All these conditions are met in the outer core. Molten iron is a good conductor. There is sufficient energy to drive convection, and the convective motion, coupled with the Earth’s rotation, produce the appropriate flow pattern. Even before the Earth’s magnetic field was first formed magnetic fields were present in the form of the sun’s magnetic field. Once the process is going, the existing field acts as the seed field. As a stream of molten iron passes through the existing magnetic field, an electric current is generated through a process called magnetic induction. The newly created electric field will in turn create a magnetic field. Given the right relationship between the magnetic field and the fluid flow, the generated magnetic field can reinforces the initial magnetic field. As long as there is sufficient fluid motion in the outer core, the process will continue.
So why does it move? well, the magnetic field is created by a fast-spinning ball inside a slow-spinning ball. So it wobbles, at an average speed of 10 kilometers per year for the entire 20th century.
So where is it right now? According to the World Data Center for Geomagnetism you’ll find it at 80.4° North, 72.6° west. Or, in other words, Nunavut, Canada.
How long would it take to drive there?
According to the handy Computing Distances between Latitudes/Longitudes in One Step page, and checking the latitude and longitude of Cincinnati, Ohio (39.1000° N, 84.5167° W), I get the following figures:
- Geographic North Pole: 3,524.64 miles
- Magnetic North Pole: 4,144.18 miles
Now, looking at the map above, you would think that driving to either pole would be impossible. After all, there’s ocean in the way! But this is where living in Cincinnati comes in handy – we have a Ride the Ducks tour here!
The “Duck Boat” is a World War II surplus DUKW, an amphibious vehicle capable of cruising at 35 mph (56 km/h) on roads and 4.41 mph (7.14 km/h) in the water with an operational range of 400 miles on land (or 58 miles/93 km in the water). I doubt it has the ring mount for the machine guns, though. So, we can do this. In theory, at least.
Eyeballing the map, I’m going to go with an estimate of 90% overland travel to the magnetic North Pole and 65% overland travel to the geographic North Pole. Further assumptions will be:
- Driving 18 hours a day – my wife has agreed to go along with this mad idea, so we can drive quite a bit. But we still need to stop for bathroom breaks, meals, stretching our legs, and refueling.
- We’ll be hitting our cruising speed.
- We don’t get eaten by polar bears.
- We’re not worrying about mountains.
- We drive in a straight line, and we don’t get lost.
Getting to the geographic North Pole is roughly 2,291 miles over land and 1233.64 miles over sea. That’s (2,291/35) + (1233.64/4.41) = 345.19 hours. Based on our assumptions, that’s 19 days, 4 hours, 15 minutes. And we would have needed to stop for gas 27 times on the trip.
Getting to the magnetic North Pole is 3,729.762 miles over land and 414.418 miles over sea. That’s (3,729.762/35) + (414.418/4.41) = 200.54 hours. Based on our assumptions that’s 11 days, 3 hours, 23 minutes. And we would have needed to stop for gas 17 times.
Either way, we also get a complimentary duck whistle for the trip. So my son is going to love this!