Magnetic North Pole Changes Time Zones, Just Keeps DriftingPopular Mechanics
December 17, 2019, 4:52 PM EST
From Popular Mechanics
Earth's magnetic north pole has moved across the Prime Meridian in the last five years.
Our magnetosphere protects the Earth from the sun, whose bossy space winds cause the Aurora Borealis.
The magnetic poles always drift and have even switched completely many times in history.
Live Science says Earth’s magnetic field is still on the move, according to the latest report in a series that comes out every five years. The magnetic north pole has crossed the Prime Meridian in the newest update from the National Centers for Environmental Information and the British Geological Survey.
The magnetic poles have drifted and entirely changed places dozens of times in Earth’s history, but this time it seems to be happening very fast, and within a shorter overall time interval than it did in prehistory.
https://s.yimg.com/ny/api/res/1.2/s1O_vkhkrc1nPAUqs1V66A--/YXBwaWQ9aGlnaGxhbmRlcjt3PTcwNQ--/https://media.zenfs.com/en/popular_mechanics_642/8e2b63166cc45cf3ea8e185ca6e9e412This illustration link above shows time periods when the magnetic poles were the same as today (in black) or the opposite of today (in white). The long view shows us how often the poles have switched, a phenomenon called geomagnetic reversal, and how not-a-big-deal it is overall. But these switches happened thousands or millions of years apart and took thousands of years for the poles to physically move enough to switch. This is the first time scientists are observing drifting magnetic field activity in real time and measuring the rate of change as well.
What is the magnetic field, anyway? Earth’s core is made of molten iron, and that geothermal energy is what keeps us warm, gravitized, and protected from the sun’s unrelenting radiation. As molten iron swirls, rises, is cooled, and falls back into the center, the convection (or circulating heat, the same as a convection oven) powers continental drift and also generates the magnetosphere. (Do you know planets spinning is also why they’re roughly spherical? The earth is slightly thicker in the equator, making it an ellipsoid, technically. This is why outer dwarf planetoids or meteors can have irregular shapes, because they aren’t in a uniform spin pattern. The effect is like a rock tumbler combined with a pottery wheel.)
Without the magnetosphere, solar wind and radiation would blow our atmosphere right off the planet—it’s not an exaggeration to say life on Earth is possible because of the magnetosphere. Mercury has a tiny, weak magnetosphere despite being so close to the sun. Venus has a novel different magnetic situation that traps its red hot and poisonous atmosphere in place.
Mars likely had a protective magnetic field once in the far past when it, like Earth, had a churning liquid iron core, but today, its mostly blasted-off atmosphere directly interacts with the solar wind. The huge planets beginning with Jupiter have wildly strong magnetic fields, with Jupiter’s in particular at 20,000 times stronger than Earth’s. Jupiter and Saturn have conductive liquid hydrogen cores instead of iron, but the overall effect is the same.
The fact that our magnetic directions roughly correspond to north and south as determined by how the planet spins is basically a nice coincidence. Which pole is north or south at any given time isn’t thought to be harmful to living things, but it affects compasses, which use the magnetic poles to orient, and anything that in turn relies on compasses. Live Science notes that airports are one of the first places to feel the impact of drifting compass directions, because runways are named with compass conventions built in. Some runways have already been renamed to suit changing directions.
