Anthonares

There is a question that all scientists face with their work: “what is the societal relevance of your research?” We all answer it in different ways, but Joseph Stoner, a paleomagnetist (someone who studies the magnetic history of our planet as recorded in rocks and sediments) from Oregon State University answered questions about the significance of his findings in a way that seems almost tailored to generating over-hyped headlines. While at the American Geophysical Union conference going on this week in San Fransisco Dr. Stoner presented evidence that the magnetic north pole is moving so quickly that, if these trends continue, it will be in Siberia in 50 years. How does the AP report his casual speculative comments? “Alaska and North America could lose their brilliant auroras, says scientist.”

Let’s first step back a second and address a few questions about what the magnetic north pole is, why its wandering, and how we can know that. The magnetic north pole is the location at which the Earth’s magnetic field lines point straight down, which also means your compass always points toward this location. If you were to draw a line through the center of the Earth, this line would not be the axis around which the electric charge in the Earth’s core is circulating due to the influence of the solar wind on our magnetic field.

The surface location of the pole wanders about seemingly chaotically, on top of an daily elliptical motion due to the aforementioned interaction with the charged particles in the solar wind. However, we do know from paleomagnetic records that the pole can disappear entirely and then reestablish itself down in Antarctica, and that it can do this over relatively short periods of time, geologically speaking. These reversals have occurred on average perhaps 4-5 times per million years recently, but the process is inherently chaotic, not cyclical. The news story linked above mentions that the Earth’s magnetic field has weakened about 10% over the last 150 years. But, whether this means that we are in the throes of a reversal, no one really knows.

We know the pole wanders and reverses because there are tiny magnetic grains of minerals in most rock types, and these grains align themselves with the magnetic north pole when they are deposited. Thus, if we can date the deposit (or rock they are found in), then we can know where the pole was at that time. This is called paleogmagnetism and the study of it is useful for a wide range of geological purposes.

So, back to my main point, to claim that the current rate of pole wandering would stick it in Siberia in 50 years is true if nothing changed in the meantime. But, as is very likely, things will change, and the pole will wander off in a different direction entirely. So, to start worrying about losing nighttime Auroral displays is more than a bit premature. The headlines instead should have read “Scientists says north pole wandering more quickly than in past, more study needed.” But, this headlines is boring and no self-serving AP reporter would submit that to his copy editor.

Now, for a bit of speculation, what will happen to us if the pole does decide to shift? Well, we’re not really sure, but we know that in order for the pole to reverse, whatever circulating electric charge is generating it probably must first cease before changing directions. We don’t know how long that process takes, but we do think that there’s no real in-between pole locations. We probably can’t, for instance, get an equatorial magnetic north. So, there seems likely to be a period in which we will have no considerable geomagnetic field. This will mean that the solar wind will hit our atmosphere unimpeded, and that our satellites and electricity grids will be very much affected. But, we can build our infrastructure to withstand this, and hopefully we will have enough warning to do so. There may also be a dramatic increase in background radiation as more gamma rays are created by solar wind/upper atmosphere collisions. But, as we saw in my review of Chapter 3 of Bethell’s work, we can’t really say what that increase in radiation would do to us. This probably will not significantly affect our climate, as the energy from solar wind striking our atmosphere is negligible compared to sunlight’s energy. But, whether the increase in atmospheric chemical reactions might somehow affect the climate, I could not really say.

How’s that for some speculation? I could B.S. my way through a Thesis Defense! Hahaha, just kidding in case you’re reading this Dr. Hyndman.