How to adjust a compass for magnetic declination or variation
If it says “16 degrees east,” rotate the compass housing so the magnetic north/compass needle mark sits 16 degrees to the right (east) of the true north orienting lines. Twist the screw to reach the proper orientation. Return to the Backpacking home usadatingescort.com: Steve Howe. In most practical cases, heading north is as simple as reading a compass and setting out. In the worlds of sailing and aviation, though, navigation can get a little more complicated. Because of magnetic variation, which is the ever-changing influence of the Earth's magnetic field, and .
Many a camper and backpacker over the years have been left scratching their head after carefully taking their map readings and attentively traveling on their what is in- memory technology only to then find themselves quite some ways from where they hoped or intended to be somewhere down the line.
While there are a few factors that might cause such mishaps and misjudgments, the most common by far is forgetting to adjust your hiking compass for magnetic declination. Below, we offer a simple guide to help you better understand magnetic declination a.
Magnetic declination or magnetic variation refers to the disparity in the angle between true north vs magnetic north. This great declination map video from NOAA shows the change in the position of the magnetic north pole as it dances around the northern Canadian Islands from to the present day.
The Green line bisecting North America is the 0 degrees line of magnetic declination, i. The red lines are positive declinations where your compass needle would be pointing at magnetic north, east of true north. The blue lines are negative declination lines, stipulating that the location of the magnetic north pole lies on a bearing west of true north.
If you are using a severely outdated map, then the declination quoted on it may be wrong. How wrong? Well, that depends on how out of date and where in the world you are located. Double-checking a second source will never hurt. Because declination values vary from place to place, before setting off on your trip, you should find out the degree of magnetic variation for wherever you plan to do your hiking.
The following are two crucial points to remember when using readings taken from either your map or the terrain:. Example 1: If you happen to be in Tucson, Arizona, which has a 9-degree East declination — that magnetic north is east of true north by 9-degrees.
Example 2 : If you happen to be in the vicinity of Mount Fuji, Japan, where the angle of declination is -7 degrees, then magnetic north and true north are 7 degrees apart, with magnetic north sitting 7 degrees to the west of true north.
To adjust for this you must subtract 7 degrees to the heading to determine your true heading, i. Learning how to use a map and compass correctly is a must for anyone serious about spending time in nature. Kieran James Cunningham is a climber, mountaineer, and author who divides his time between the Italian Alps, the US, and his native Scotland.
How to get rid of viruses on computer for free has climbed a handful of ers in the Himalayas, ers in the Alps, 14ers in the US, and loves nothing more than a good long-distance wander in the wilderness.
He climbs when he should be writing, writes when he should be sleeping, has fun always. Kieran has taught mountaineering, ice climbing, and single-pitch and multi-pitch rock climbing in a variety of contexts over the years and has led trekking and mountaineering expeditions in the Alps, Rockies, and UK.
He is currently working towards qualifying as a Mountaineering and Climbing Instructor and International Mountain Leader. Hi James, good topographic maps should tell you multiple norths; 1 True north, 2 Magnetic North, and 3 Grid north.
No examples. It is easy to misunderstand which way east and west declination should be adjusted on a compass when used in the relative manner. What I would like what is the coolest animal know is if the declination is east 10 degrees where is the compass needle pointing before making the allowance for dec.
Thanks Bill. Hey Bill, if declination is 10 east, then that means that the magnetic north pole is located 10 degrees east of the True North pole.
Save my name, email, and website in this browser for the next time I comment. Kieran James Cunningham. Last Update: February 16, December 22, Looking to learn about Magnetic Declination? In this guide, we will be covering the following: Learn what is magnetic declination? How to learn whether declination in your areas is positive or negative How to adjust your declination compass to always stay on the correct bearing.
Check the Age of Your Map: If you are using a severely outdated map, then the declination quoted on it may be wrong. Read more Jim Fink Reply. Very good Reply. Thank you, very informative, and easy to understand and follow. Thanks Bill Reply.
Apr 16, · Set Your Compass to Find True North Many high-end compasses like the Silva Ranger have settings to adjust the orienteering lines to face true North. This is usually done with a small screw on the baseplate. As most people tend not to venture between areas with different declination, this method of adjusting the compass is easiest for most usadatingescort.com: Dan Human. May 20, · Then, marking the map with points indicating where you are and where you want to go, you line the compass points up toward the desired destination. It’s a little more complicated than this because you also have to adjust your compass to account for the difference between true north and magnetic north, depending upon where you are on the usadatingescort.com: Laura Fogle. Because the angle to magnetic north is less than true north (°), this is a negative declination. Where magnetic north is east of true north, the compass needle is deflected to the right. Here, the angle to magnetic north is greater than true north (0°), and is therefore a positive declination.
Last Updated: May 7, References. To create this article, 9 people, some anonymous, worked to edit and improve it over time. This article has been viewed 28, times. Learn more Did you know that most compasses don't actually point to the North Pole? It's true! In fact, most compasses point in the direction of magnetic north , a spot in the Arctic that is near to but not the same as the North Pole.
In casual, everyday situations, this minor difference is often ignored, but if you're seriously attempting to navigate in the wilderness, it can present problems. Fortunately, there are a variety of ways to find true north the direction that points toward the North Pole using everything from a modern computer to nothing more than the sun, moon, and stars.
Cookie Settings. Learn why people trust wikiHow. Download Article Explore this Article methods. Related Articles. Method 1 of Find your local declination from the NGDC.
One of the things that can make the difference between true north and magnetic north so difficult for navigators is that the effect on compasses can change over time. This phenomenon is called declination — as the earth's magnetic field fluctuates, the number of degrees by which a compass will be "off" from true north will shift accordingly.
Thus, to accurately adjust your compass to account for this effect, you'll need a recent declination value for your location. At the NGDC website, you can enter your current location to receive the most recent declination value available for your area. Alternatively, find your declination from a map. Some physical maps will also include declination values for the area displayed in the map. Topographical maps are the most likely to include this information, though it can be in other types of maps as well.
If you're considering navigating by map and compass, consider checking your map's legend to see whether the map contains accurate declination data.
Note, of course, that declination changes over time, so old maps can quickly become out of date. Find magnetic north with your compass. Once you know how "off" your compass is from true north, it's not hard to adjust for this discrepancy. Begin by finding magnetic north. Hold your compass flat and level in front of you. If your compass has a travel arrow usually a skinny red arrow on the flat lower portion of the compass, point this forward.
Watch the motion of the compass needle. When the needle stops moving, note the direction the needle points. This will be the north-south axis. Most modern compasses have a needle that is half red and half white. In this case, the red end of the needle is the north-pointing end.
Turn the orienting arrow so it points ahead of you. If you're navigating by compass, typically, at this point, you would adjust the compass's bezel to that the direction you're intending to travel is directly in front of you, aligned with the travel arrow. In this case, since we want to find north, we'll turn the bezel so that the "N" and the wide arrow beneath it is directly in front of us. Note that this magnetic north, not true north — we still need to adjust for declination.
Adjust for declination. Turn your body until the compass's needle is lined up with the orienting arrow on the bezel and, thus, the travel arrow as well. You are now facing toward magnetic north. To find true north, turn the bezel the same magnitude and direction as your declination value.
Most compasses will have degree markers on the bezel to help you do this. Next, line up your needle and your orienting arrow by turning your body again. You should now be facing true north! For example, let's say that we originally obtained a declination value of 14 o E for the area we're in. If we're facing towards magnetic north, we would turn our bezel 14 o to the east clockwise, in this case. Then, we would turn to the left which is west to line up the needle with the orienting arrow, leaving us facing at true north 14 o west of magnetic north.
Method 2 of In the Northern Hemisphere. Use the motion of the sun. If you don't have a compass, don't worry — it's still possible to find true north by using natural clues.
For instance, because the sun rises in the East and sets in the west, it's possible to use this information to get a rough sense for the direction of north.
Just after sunrise, keep the sun on your right to face north — just before sunset, keep the sun on your left. At noon, the sun will be directly south, so face away from it to find north.
Plant a stick or pole that's a few feet high in the ground and mark the tip of its shadow on the ground. Wait about 15 minutes, then mark its new location. Stand with your left foot on the first mark and your right foot on the second. You will be facing more or less towards true north regardless of the declination where you are. Use an analog watch. One handy trick for finding true north involves using the hands of a non-digital watch. To start, remove your watch and hold it in your hand with the hour hand facing forward.
Turn your body so that the hour hand points toward the sun. Find the midway point between your hour hand and the 12 o'clock mark at the top of the watch. This will point along the north-south axis.
For instance, let's say it's PM. The midpoint between and is , so if we point the hour hand toward the sun, the north-south axis will be a little less than a quarter turn to our left. Since it's in the afternoon and the sun is setting in the west, we can infer that north will be behind us if we face toward the marker.
Don't forget to compensate for Daylight Savings Time! If your watch is adjusted for DST, use the marking rather than the marking and proceed as normal. Look for clues in Nature. Certain natural organisms especially plants and trees can give clues about which direction is north. To be clear, however, these rules are very "loose" and will not always work, so most of the time, other methods are preferable. Before are a few examples of what to look for: Moss: May be thicker on the south sides of trees due to more sunlight.
Trees: Bark may be duller-colored and branches may stretch higher toward the sky on the north side due to less sunlight. Ants: Ant hills may tend to be on the southern side of natural features where the sun is warmer. Snow: Snow may melt faster on the southern side of trees and rocks where it receives more sunlight. Use Polaris, the North star. It's surprisingly easy to find north at night if you know what you're looking for.
Polaris also called the North Star is almost perfectly aligned with the earth's North Pole, so if you can find it, you'll know exactly where true north is. There are several ways to find Polaris, but the easiest way is usually to use the Big Dipper — the two stars at the end of the "spoon" portion of the constellation point directly to Polaris.
Use the moon. Like the sun, the moon moves across the sky in an east-west direction. This means that you can use the position of the moon to help orient yourself toward true north at night. Early in the night, keep the moon on your right to face north; late in the night, keep it on your left.
When the moon is at its highest point in the sky, it's roughly due south, so face away from it to find north. This works best when the moon is high in the sky. Because the light from the sun, moon, and stars hit the Southern Hemisphere at a different angle than they hit the Northern Hemisphere, the process of finding north is a little different south of the equator.
For instance, while the sun still rises in the east and sets in the west in the Southern Hemisphere, at noon, it is due north, rather than due south. This means that, while you'll still want to keep the sun on your right just after sunrise and on your left just after sunset to face north, you'll want to face towards it to find north at noon. Because the sun sweeps out a northern arc rather than a southern one in the Southern Hemisphere, the directions for finding north with a watch are essentially reversed.
Point the mark on your watch toward the sun, then find the line that marks the halfway point between the mark and your hour hand.