GeoAlmanac for Land Surveyors Geography & App


Add Survey Term to Almanac

Land Surveyor's Almanac is an ongoing community project to crowdsource surveying definitions and terms with examples for the next generation land surveyor to learn from. If you are a Land Surveyor, add a term to the Almanac with its definition and examples. Help improve the collective knowledge of the community by improving upon terms added by other surveyors by commenting with your examples and applications in your local surveying environment.
Land Surveyor

Magnetic Declination

Magnetic Declination

Magnetic Declination is the bearing on a given date (reckoned east or west from the north branch of the celestial meridian plane) of magnetic north as determined by the positive pole of a freely suspended magnetic needle which is subject to no transient artificial disturbance.

An example provided by Compass Dude

Here is a map of the angles of declination for the U.S. as of 2010:

Magnetic Declination for Land Surveyors

 

Notice the black line with 0� on it running down the Mississippi river? Along this particular line, both the geographic and magnetic north poles are in alignment so there is no declination. If you move East of this line, the magnetic north pole will pull your compass needle further and further to the West of geographic north - the angle of compass declination is West Declination. Moving west of the Mississippi river will pull your compass needle further and further to the East.

A few Videos about Magnetic Declination:

 

Related Term:  Magnetic Variation

Regular or erratic change in magnetic declination. Not interchangeable with declination but old field notes use Var. as the declination of the compass.

 

Votes: 0
E-mail me when people leave their comments –
Land Surveyor

San Marcos TX Land Surveyors
sanmarcoslandsurveying.com
(512) 645-1992

You need to be a member of Land Surveyors United - Global Surveying Community to add thoughts!

Join Land Surveyors United - Global Surveying Community

Logged in Members Do Not See Ads

Latest Surveying Terms added to...

Members Logged In Do Not See Ads

Comment Using Facebook

Hey there!
It looks like you are enjoying the community content.

That's nice! Please don't forget to mention us if you use what you just copied on your website. Help strenthen the community by linking back to us!


Thank you very much! Have a nice day! :)

Ok. Don't bother me again, for this session.