This is not exactly a pure Earth Science question but I'm not sure GIS SE is a suitable place either.
"The Google" suggested I watch CBS Sunday Morning's The debate over the geographical center of North America and I complied.
The video explains that Rugby North Dakota (48.37 N, 99.99 W) was determined to be the "geographic center" of North America by balancing a cutout of the continent on a pin.
This method weights each point by its vector to the center; a point twice as far will be weighted twice as much.
The second determination was done in a bar by utilizing the well known standard string, globe and beer methodology. It was found to be inside Hanson's bar itself in Robinson North Dakota (47.14 N 99.78 W).
The third determination was done using a personal computer and google maps> perimeter coordinates2:
Professor Peter Rogerson1 took latitudes and longitudes from all around the edges of North America, and plugged those coordinates into a special algorithm that he designed, to find the center.
”You have to take into account that the Earth’s surface is curved, and you want to find that balance point in a proper way.
This turns out by sheer coincidence to be near Center North Dakota (47.12 N, 101.30 W)!
So back to the balance point with it's vector distance from center weighting.
Questions:
- When finding the geographic center of a continent is balance point the accepted method?
- Is this mathematically equivalent to finding the centroid?
- "bonus points" how did Rogerson convert a perimeter to a balance point? Has this been published?
1Peter A. Rogerson, Department of Geography, State University of New York Buffalo
2hat tip to @EarlGray for their very helpful comment!