what is the difference between true north and magnetic north

what is the difference between true north and magnetic north

Compass Direction

Standing precisely on the North Pole, what can be the compass path?

The Story of the Explorer’s Compass

Think about. You might be an explorer standing precisely on the North Pole.

You’re reading: what is the difference between true north and magnetic north

It’s been a protracted journey and it’s freezing chilly.

You pull out your compass.

What path would the needle on the compass level?

The reply might not be what you suppose.

In an effort to reply this query, you’ll have to perceive the distinction between the true geographic north and magnetic north.

As a result of these two north places are fully totally different.

What’s the Geographic (True) North Pole?


The Earth rotates on the geographic north and south poles. The geographic north and south poles are the place strains of longitude (meridians) converge within the north. The south and north pole are immediately reverse to 1 one other.

The North Pole is situated in the course of the Arctic Ocean. Scientists have tried marking the North pole. As a result of the water right here is completely lined with transferring sea ice, it’s virtually unattainable to assemble any sort of everlasting station on the true North Pole.

On the opposite aspect of the Earth, the South Pole lies on a continental land mass generally known as Antarctica. As a result of the ice on prime of Antarctica strikes just a few meters a 12 months, america Antarctica program has put in a marker right here to delineate the true South Pole.

What’s the Magnetic North Pole?

The Earth is one large magnet. The Magnetic North Pole (often known as the North Dip Pole) is some extent on Ellesmere Island in Northern Canada the place the northern strains of attraction enter the Earth.

A compass needle rests freely in its casing so it could maneuver itself. If you pull out a compass, it aligns itself with the Earth’s magnetic subject. The small magnetic pin is how a compass responds to Earth’s magnetism.

Which means a compass needle will level to the Magnetic North Pole – which is totally different from the geographic north.

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However how a lot of a distinction is the magnetic north vs geographic north?

Earth Magnetic Field

The place are the Magnetic North Pole and Geographic North Pole?

Magnetic North

The query is:

The place would a compass needle level when you had been standing on the true North Pole?

For those who had been standing on the geographic north pole holding your compass, it will level in the direction of northern Canada at Ellesmere Island. It is a distinction of about 500 kilometers between the Geographic North and Magnetic North poles!

This distinction is named the magnetic inclination. Magnetic deviation is the error of a compass needle together with close by metallic objects.

Magnetic inclination varies in accordance with the place you’re situated on the globe. In an effort to level you in the fitting path, customers can compensate for magnetic inclination by utilizing charts of declination or native calibration.

The distinction in the present day is about 500 kilometers. However the Magnetic North Pole is definitely transferring kilometers yearly. This phenomenon is called the Polar Shift Idea.

Polar Shift Idea: Earth’s Ever-Altering Magnetic North Pole

Magnetic North Shift
Magnetic North Shift (Picture courtesy of NOAA)

The world we stay in is dynamic. Earth is altering each day.

Plate tectonics push continents aside, sea ranges fluctuate up and down, volcanoes erupt discharging ash and smoke…

These are examples of pure phenomena that happen in cycles and are dynamic on our planet. The situation of our magnetic north is absolutely no totally different.

During the last 150 years, the magnetic pole has crept north over 1000 kilometers. Scientists counsel it migrates about 10 kilometers per 12 months and might even flip from pole-to-pole. These days, the pace has accelerated to about 40 kilometers per 12 months and will attain Siberia in a number of many years.

NOAA’s historic declination map reveals strains of fixed magnetic declination (isogonic strains). Isogonic strains are a sign for what path compass needles will level – alongside the strains of magnetic pressure.

Polar Reversals: South-Pole Pointing Compass


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Think about your compass pointing south as an alternative of north. For those who had been alive to see it 800,000 years in the past, it will have been the Magnetic South Pole.

It takes 200,000 to 300,000 years for Earth’s magnetic subject to flip polarity. Flipping polarity means the strains of attraction that enter the Earth would flip north to south pole, or vice versa.

Which means it has been twice that lengthy for the reason that final reversal. Some imagine we’re lengthy overdue for a pole reversal.

However there’s actually no have to panic:

NASA scientists say a reversal occurs over a whole lot or 1000’s of years. It’s not precisely a clear again flip that occurs like a flick of a swap.

Why Does the Earth Have a Magnetic Discipline within the First Place?

Inner Earth

Geophysicists imagine Earth’s magnetic fields presence is due to what’s inside Earth.

The Earth consists of a cast-iron core. Surrounding the iron core is an ocean of sizzling, liquid metallic. The liquid metallic that flows in Earth’s core creates electrical currents, which in flip creates our magnetic subject.

Not like a strong fridge magnet, the liquid metallic surrounding the interior core strikes freely. This explains why the magnetic pole can migrate.

Though geophysicists can not measure the interior core immediately, that is why there’s a robust perception that the matter governing Earth’s magnetic subject strikes round.

Magnets, Compasses and North Bearings

The Geographic North Pole differs from the Magnetic North Pole by about 500 kilometers.

The Geographic North Pole is the place strains of longitudes converge into what we name the North Pole. The Magnetic Pole is some extent in Northern Canada the place the northern strains of attraction enter the Earth.

A compass needle will level to the path of the Magnetic North Pole. However this doesn’t imply {that a} compass at all times factors to the Geographic North Pole. This distinction is magnetic inclination.

The Earth’s magnetic north is altering each day due to the recent, liquid metallic that surrounds the interior core. It could possibly change a lot that the Earth’s magnetic subject can flip polarity. That is referred to as the Polar Reversal Idea.

Subsequent time you’re out within the woods along with your compass, don’t neglect concerning the small magnetic pin that strikes freely within the path of the Magnetic North Pole.

READ MORE: Magnetic Declination QGIS Plugin

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