they seem to contradict themselves re the frequenc
Post# of 123777
"The magnetic north pole has been creeping northward – by more than 600 miles (1,100 km) – since the early 19th century, when explorers first located it precisely. It is moving faster now, actually, as scientists estimate the pole is migrating northward about 40 miles per year, as opposed to about 10 miles per year in the early 20th century."
so by now much will topo maps stated magnetic variance be in error by year? if at all,depending on location