#magnetic declination

[preppers-will]

Map Reading: Understanding Magnetic Declination | Prepper's Will

Since we have already discussed the art of map reading in a general way, let’s discuss one very specific and somehow daunting portion: Magnetic Declination.

[earthstory]

A Tale of Two Poles

The first rule of navigation is that a compass needle points towards the North. But where exactly is ‘North’? The Earth has two North poles, a geographic North pole and a magnetic North pole. The geographic North pole is what we most commonly think of as the North pole. This is the fixed point where the surface of the Earth intersects its axis of rotation and where the meridians (lines of longitude) converge in the northern hemisphere.

Our planet also has a magnetic North pole. This is the location where the Earth’s magnetic field lines converge at the surface. Put simply, the Earth can be though of as a giant bar magnet with ends at the magnetic North and South poles. The Earth’s magnetic field is the result of the motion of molten metals in the outer core; a self-sustaining process known as the geodynamo.

A compass needle will align with the Earths Magnetic North pole. While the geographic pole is a fixed point on the surface, the magnetic pole migrates across the Earth’s surface over time. This ‘polar wander’ is due to changes of the motions in the inner core. Currently, the magnetic pole is located to the East of the geographic pole, and is moving up to 10’s of kilometres per year towards Siberia. Scientists have been tracking the movement of the magnetic North pole for almost 200 years, as shown in the image below.

The angular difference between the geographic and magnetic North poles is called magnetic declination. Declination varies depending on where you are located on the globe, generally increasing closer to the poles and changing at you move from East to West. Take two cities at similar longitudes but different latitudes, Toronto (~ 43 degrees N) and Miami (~ 25 degrees N). Toronto has a magnetic declination of ~ 14 degrees to the West while Miami has a declination of ~6 degrees to the West. If you are interested in finding out what the magnetic inclination is where you live, check out http://bit.ly/1ZWPful.

Setting magnetic declination on your compass is a critical first step toward successful navigation, or you might just end up somewhere you don’t expect.

CD

Sources The Solid Earth: An Introduction to Global Geophysics 2nd ed. Fowler, C.M.R. 2010. Cambridge University Press. http://bit.ly/2r6TZIG http://bit.ly/2EG7vF1 https://go.nasa.gov/2wquiAa http://bit.ly/2arsQbc

Image Source http://bit.ly/2r0ufgU

[mizar113]

[hikercarl]

How to Navigate Hiking Trails: Essential Skills for Every Hiker

Discover essential skills for navigating hiking trails with confidence. We'll guide you through map reading, compass use, and modern GPS techniques for safe outdoor adventures.

Hiking trails lead us to stunning natural scenes. But, they also require key skills for safe navigation. This guide will teach you how to use maps, compasses, and GPS apps. It’s perfect for both new and experienced hikers. These tips will keep you safe, make your hikes fun, and let you explore with confidence. We’ll talk about maps, compasses, and GPS technology. You’ll learn about dead…

How to Navigate Hiking Trails: Essential Skills for Every Hiker

[mapsontheweb]

Magnetic Declination of the USA.

sendherhome22:

What is magnetic declination? Well there are actually 3 different norths. 2 of them are called true north (the North Pole of earths axis) and magnetic north (the North Pole of earths magnetic field and it’s always moving).

The declination is the difference between true and magnetic north. So if you used a magnetic compass on the 5 degrees east line, the compass is lying to you by 5 degrees. This line is always changing though. Back in the 1984 declination map the 5 degree line ran through western Missouri, Iowa, Minnesota, Arkansas and Louisiana. So the line is always shifting West.

[netbros]

Tune up your compass in the Smokies

Tune up your compass in the Smokies

Do you follow the North Star? For those sunny days when you’re hiking in the Great Smoky Mountains National Park where the night sky is unfortunately unavailable to assist you with navigation, make sure you’re on the right heading with proper adjustment to your compass. Did you know your compass needle doesn’t point directly to the north? The earths geomagnetic field exerts varying degrees of…

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[high-peaks]

Magnetic Declination

[northernbushcraft]

Compass Basics: An Introduction to Orientation and Navigation

http://www.summitpost.org/compass-basics-an-introduction-to-orientation-and-navigation/358187