| Outdoor Adventure Information – Your Guide to Outdoor Fun | |
|
|
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 20°east. 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:
Google News |
RELATED ARTICLES
Scuba diving in South Africa This truly beautiful country at the southern tip of dark and mysterious Africa offers diving and wildlife experiences beyond your wildest dreams.. Greek Food A meal in Greece is highlighted with a selection of hot and cold plates known as mezedes. Soups are few but they are meals by themselves. Creative Camp Cooking For most people, outdoor cooking is synonymous with barbeque, but there are many other ways to cook outdoors. If you have been camping, you are probably at least familiar with the portable propane stoves which provide a burner or two similar to the stovetop burners you have at home. Too much to do in London! No one can truly say they know London well. To know London completely is impossible. Rafting on the Rogue River in Oregon Oregon's Rogue River is one of the nation's most beautiful. The Rogue River begins in Crater Lake and extends 215 miles until it empties in the Pacific Ocean. River Rafting in California River rafting is a major attraction in California. The most popular California river rafting destination is the mighty American River. Protection from Lightning - Smart Strategies for Hikers and All Outdoor Enthusiasts Prevention is your best protection against lightning. Be sure to check your local weather report before you head outside. Alaska Sport Fishing Guide WHAT TO FISH AND WHERE: Alaska offers some of the most diverse and incredible fishing opportunities in the world. You can drop a line into a roadside river and catch a nice size rainbow trout. Bicycling Down The River My river-rafting adventure started on a bicycle. The small daypack I wore carried a hatchet, a saw, some scraps of rope, food, water, a garbage bag bivy sack, a hat, and odds and ends. Take a Hiking Pole on Your Next Hike It is the downhill ski racing competition of the winter Olympics. You watch a ski racer zoom down the slope manoeuvring through the ski gates. Old Sturbridge Village - Links to Our Past Guide, Part 2 Once described in a 1950 article as "The Town That Wants to Be Out of Date," Old Sturbridge Village in Sturbridge, Massachusetts is a lovingly recreated village of early 19th century New England. You'll be whisked back to the dawn of modern commerce and experience what life was like in a typical New England Village of that time. Eight Tips For A Bug-Free Summer (NC)-With approximately 42,000 mosquitoes for every person in Ontario, most of us spend a great deal of our summers swatting away these pesky insects. Protecting yourself against mosquitoes will not only make your summer more enjoyable, it will help prevent you and your family from getting annoying and sometimes dangerous bug bites. Kerala - Holiday in Gods Own Country Touted as one of the world's fifty destinations of a lifetime by the National Geographic, Kerala has certainly earned its position on the holiday travel bandwagon.Located on the southernmost tip of the Indian peninsula, Kerala has a lot going for it in terms of its potential as a holiday destination? not the least its bounteous natural wealth. River Rafting in Washington State The great state of Washington offers some of the best white-water rafting in the entire country. There are around 15 rivers in Washington state that are great for river rafting. Solo Backpacking Have you ever gone solo backpacking? If you have, you'll probably agree that it isn't a matter of it being better or worse than backpacking with friends. It's just a different activity altogether. Top Five African Safari Destinations Any vacations in Africa will not be complete without going on a safari to experience the wild animals and the peace and tranquillity of the bushveld.But there are literally hundreds of national parks and wildlife areas in Africa that you can travel to. Yachats, OR: An Outdoor Lovers Paradise on the Oregon Coast There is something about a town tucked between the mountains and the sea. Often, it feels like one has reached the far end of the world when he or she arrives in a place like this. Find a Camping Gear Outlet Near You When you search online for a camping gear outlet you will find camping gear at great discounts like tents, sleeping materials like sleeping bags, navigation and survival items, camping furniture and lanterns, tools, knives and optics, personal care equipment, backpacks, camping cookware, and other camping stuff.If the camp gear outlet you find is an established one, you will find some of the best sales and discounts on clearance items as well as discontinued ones. Unforgettable Cape Cod Vacations: The National Seashore Gift Take a captivating trip through the Cape Cod National Seashore with miles of white sandy beaches, trails and hikes to take your breath away, and majestic dunes. Just keep reading and you can visit all those places right now. Join the American Hiking Society Have you taken up hiking as a new form of family recreation? Are you a serious hiker that spends hours on challenging trails? Do you want to find a way to become more involved in hiking across the nation? Hikers of any background will want to check out the "American Hiking Society". This society is an alliance of local hiking clubs and provides a wealth of resources and activities for hikers of any background. |
| home | site map |
| © 2006 |