In 27 years in the military I've always been taught the term was True North to Magnetic North Declination as well. Heck, even the Forest Service Maps call it this (look at bottom of Map). Maybe there are other terms which mean the same thing.Sorry mrlmd, we must come from different disciplines for I have been taught, have taught, and regularly compensate for what is overwhelmingly referred to as magnetic declination for over the last 40 years in the various surveying and engineering activities in which I have been involved . Always hated the math entailed in determining local declination via late night observations of the North Star Polaris. Never tried it with the Southern Cross but that would really hurt my brain.
While sometimes referred to as "variation" by geophysicists and others the term "declination" is the typical term I encounter and use used in the data bases I have dealt with from USGS, NOAA, property records, legal descriptions, court documents, county records, etc.
Both terms are valid expressions for the permutations in the earth's magnetic field which very over time and location.
“North” is best described as “probably somewhere over there” ……
So mrlmd are you saying NOAA would be the more accurate entity to use here; or another agency? I have no skills in this activity.And obviously, the USGS cartographers and the NOAA chartmakers and astronomers should get on the same page.
And you know what? - USGS is wrong. Ha.