Well, I think that engineers spend more time recording these mnemonics when all ya gotta know is that the magnetic elements are 7. You only need know them once in your life , the rest of the time, its on yer field notebook or I-pad as an empty table.
Lessee if I can recall em all
Declination, inclination, sigma intensity, xintensity, zintensity,North Component and East Component. When we determine mag inclination we must determine the x and z intensity.
You use "variation" and that defines you as a pilot or engineer. We need to know our position in dimensions beneath the earth as well
farmerman, who, as an overbearing geologist, should know.)
now, you have defined a "Soil scientist or geotechy engineer" I only deal with "Underbearing" or underburden.
Declination is a treat for juggies and beginning field members. In order to define the "North of the celestial meridian", we set up a transit station on Polaris and watch the columation of three stars (Polaris, delta and mizar)as they define a vertical line wrt our optical plummet. This occurs twicw a day and we need two columations for a map position to coordinate "true north"with our GPS readings. That means that some kid is gonna stay awake for a long time. Then they will need to QA their own readings.
Its good to be the boss.
BUT, magnetic reversals will probably not mess up our direction finding unless some wag detonates a big one and we get an EMP to shut down our gadgest