Outdoors Information

True North & Magnetic Declination - A Trick to Make it Stick


Magnetic declination is an essential principle to understand when navigating your way through the wilds with map and compass.

Yet it's a tricky thing to remember, at least the way it has traditionally been taught, using an addition / subtraction method. Just when you think you've grasped it, the concept floats away, like fog in the morning light.

Well there is a simple, practical approach to adjusting for magnetic declination when finding your bearings. The whole explanation begins with a definition of 'north."

There are 2 Norths

A lot of people know that there are 2 norths in terms of maps and compasses. A map shows true north, or the Geographic North Pole where all lines of longitude meet. The earth rotates around an imaginary axis that runs through the North and South Poles.

A compass needle points to magnetic north, which is determined by the earth's magnetic field. The location of magnetic north moves over time, at about 5 miles per hour. Right now it is slowly creeping around somewhere NW of Hudson's Bay in Canada, about 450 miles away from true north.

Magnetic Declination

The angular difference between true north and magnetic north is known as "declination," or "variation" in the aviation world. Declination is different for different parts of the globe. In Washington State, the angle of declination is 20east. This means that magnetic north is 20 east of true north. In Tennessee the angle of declination is 0, and in Maine, it's 20 west.

Declination values can be found in the margins or legend on topographic maps. Because the point of magnetic north is constantly moving, it is important to have a recent topo map for finding your way in the woods.

A similar point to remember is that compasses are calibrated for different parts of the world. So when you purchase a compass, be sure that it is intended to be used in the area of your big hiking vacations.

How to Find Your Bearing

Follow these steps to find your bearing:

1. Place the compass on the map with the arrow on the base plate pointing in the direction you want to go.

2. Turn the dial face of the compass so that north on the compass is parallel with north on the map.

3. Place your compass level in the palm of your hand and turn yourself until the needle in the compass aligns with the North marking on the face dial.

4. The big arrow on the base plate is now aligned with your bearing.

Declination Value and Bearings - A Trick to Make it Stick

If you walked 10 miles through the woods in Washington State, without factoring declination value in your bearings, you would finish over 3 miles off target. That's too much!

To avoid confusion in finding bearings, keep the central principle in mind:

Make map bearing = magnetic bearing.

You will achieve this in the field by adjusting your bearings to compensate for magnetic declination. There are 2 ways to account for magnetic declination in finding your bearings: an adjustable compass and marking your non-adjustable compass.

The easiest way is with an adjustable compass. Simply turn the declination adjustment screw on the compass to the correct value and all readings are automatically converted to true north. If it's available, it's always best to have an adjustable compass on your walk.

The next best way to account for declination is to mark the declination value on your non-adjustable compass at the beginning of your journey.

That's simple to do. For example, when the map indicates a declination value of 20 west, you will mark your compass dial at 340. If the map indicates a declination value of 10 east, you will mark your compass at 10. Make the mark with a permanent marker and erase later with rubbing alcohol.

Now when you take your bearings in the field, place your compass level in the palm of your hand and turn yourself until the needle in the compass aligns with the declination marking on the face dial. Then the big arrow on the base plate will point toward your bearing and automatically compensate for magnetic declination.

Outdoors Adventurer, Writer and Webmaster Will Robertson lives with his family in Little Rock, Arkansas.

Explore the best hiking vacations and gear on the planet at: http://www.hiking-vacations-and-gear.com


MORE RESOURCES:
This RSS feed URL is deprecated, please update. New URLs can be found in the footers at https://news.google.com/news


Roll Call

The Great Outdoors Threatened by a Funding Battle
Roll Call
Sen. Richard M. Burr's sinking of the $14 billion rescissions package last month was not about saving the Energy Department loan guarantee program or children's health care contingency funding — which represented the vast majority of the money on the ...

and more »


Chattanooga Times Free Press

Outdoors Calendar
Chattanooga Times Free Press
Soddy-Daisy chapter of Tennessee Trails Assn. hikes: Saturday, Snow Falls, moderate 5 miles (call John Politte at 304-8327); Tuesday, Greeter Falls day loop, moderate 3.2 miles with 2 waterfalls (meet at 8 a.m. at Food City parking lot in Red Bank ...



Huntsville Item

OUTDOORS: East Texas Fishing Report for July 19, 2018
Huntsville Item
Local angler David Russell says the bite has slowed down with the influx of fresh water from last week's rain; bass are are tough to locate. Fishing has been tough overall. TOLEDO BEND — Water level is about 2.6 feet low and clear. Water temp in the ...

and more »


Akron Beacon Journal

Outdoors: Paddleboarding, Campfire Cooking, Cardio Hike, Weekday Walkers
Akron Beacon Journal
Thursday. Drop-In Nature Crafts — A new craft will be presented each week, 11 a.m. to 2 p.m. F.A. Seiberling Nature Realm, Onondaga Deck, 1828 Smith Road, Akron. 330-865-8065. Good Gardens — Let's Grow Akron will teach about basic composting ...



Forbes

What Outdoor Retailers Are Talking About Now
Forbes
Every year, about half the U.S. population participates in an activity outdoors and about 20% of the population is active outdoors twice a week or more. The most popular outdoor activities are running (52 million participants annually), fishing (47 ...



Yakima Herald-Republic

Outdoors Happenings: July 19, 2018
Yakima Herald-Republic
The Washington Department of Fish and Wildlife is inviting the public to join a discussion of funding challenges facing the department in a webinar scheduled for 7 p.m. on Monday, July 23. WDFW policy director Nate Pamplin will describe the work of ...



WTVM

Academy Sports and Outdoors treats Columbus students to back-to-school shopping spree
WTVM
Academy Sports and Outdoors teamed up with the Boys and Girls Club to help them gear up for class and have a productive year. Thirty school-aged kids from the Boys and Girls Club got the chance to have their very own shopping spree after Academy ...

and more »


Kankakee Daily Journal

Outdoors: At a Glance
Kankakee Daily Journal
State Park events. Kankakee River State Park will celebrate the reopening of its visitor center with open house weekend events from 8 a.m. to 4 p.m. Saturday and Sunday. Discover interactive displays and learn about all the park has to offer. Nature ...



Camp Lejeune Globe

Education, positive energy with Explore the Outdoors Camp
Camp Lejeune Globe
However, the Outdoor Adventures office offers camps for kids to participate in during the daytime hours throughout the summer. For a beautiful start to the summer. 12 campers increased their knowledge about the outdoors at the Exploring the Outdoors ...



WIRED

The Best Amazon Prime Day Deals for Home, Outdoor, and Lifestyle
WIRED
For your shopping pleasure, we've selected some of the best home, outdoors, and lifestyle gear that you'll find on Amazon for Prime Day. Take a look at all of our best Prime Day deals here. Browse our full list of Prime Day Deals here, and check out ...

and more »

Google News

home | site map | Ocean Photography
© 2006