GeoBoundsRegionBoundary
GeoBoundsRegionBoundary[{{latmin,latmax},{lonmin,lonmax}}] is a one-dimensional GeoGraphics primitive that represents the boundary of the region between parallels latmin, latmax and meridians lonmin, lonmax on the surface of the Earth.
GeoBoundsRegionBoundary[g] represents the boundary of the latitude-longitude bounding box of the geo region g.
GeoBoundsRegionBoundary[g,δ] pads the ranges of latitudes and longitudes by ±δ.
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