Magnetic North Pole shift – Geography

Magnetic North Pole shift

Subject: Geography

Sub-Topic: Geomorphology

  • Earth’s north magnetic pole has been drifting so fast in the last few decades that scientists say that past estimates are no longer accurate enough for precise navigation.
  • The magnetic north pole is wandering about 55 kilometers a year. It crossed the International Date Line in 2017, and is leaving the Canadian Arctic on its way to Siberia.
  • The constant shift is a problem for compasses in smart-phones and some consumer electronics. Airplanes and boats also rely on magnetic north, usually as backup navigation.
  • GPS isn’t affected because it’s satellite-based.
  • The military depends on where magnetic north is for navigation and parachute drops, while NASA, the Federal Aviation Administration and U.S. Forest Service also use it. Airport runway names are based on their direction toward magnetic north and their names change when the poles moved. For example, the airport in Fairbanks, Alaska, renamed a runway 1L-19R to 2L-20R in 2009

Turbulence in Earth’s core

  • The U.S. National Oceanic and Atmospheric Administration and United Kingdom tend to update the location of the magnetic north pole every five years in December, but this update came early because of the pole’s faster movement.
  • Since 1831 when it was first measured in the Canadian Arctic it has moved about 2300 kilometers toward Siberia. Its speed jumped from about 15 km/h to 55 km/h since 2000.
  • The reason is turbulence in Earth’s liquid outer core. There is a hot liquid ocean of iron and nickel in the planet’s core where the motion generates an electric field. It has changes akin to weather.
  • The magnetic South Pole is moving far slower than the north.

Hinder bird navigation

  • In general Earth’s magnetic field is getting weaker, leading scientists to say that it will eventually flip, where north and south pole changes polarity, like a bar magnet flipping over. It has happened numerous times in Earth’s past, but not in the last 780,000 years.

That could bother some birds that use magnetic fields to navigate. And an overall weakening of the magnetic field isn’t good for people and especially satellites and astronauts. The magnetic field shields Earth from some dangerous radiation.