Chapter 18

Field-Expedient Direction Finding

OTHER MEANS OF DETERMINING DIRECTION

18-17. The old saying about using moss on a tree to indicate north is not considered accurate because moss grows completely around some trees. Actually, growth is more lush on the side of the tree facing the south in the Northern Hemisphere and vice versa in the southern hemisphere. If there are several felled trees around for comparison, look at the stumps. Growth is more vigorous on the side toward the equator and the tree growth rings will be more widely spaced. On the other hand, the tree growth rings will be closer together on the side toward the poles.

18-18. Wind direction may be helpful in some instances where there are prevailing directions and you know what they are.

18-19. Recognizing the differences between vegetation and moisture patterns on north- and south-facing slopes can aid in determining direction. In the Northern Hemisphere, north-facing slopes receive less sun than south-facing slopes and are therefore cooler and damper. In the summer, north-facing slopes retain patches of snow. In the winter, trees and open areas on south-facing slopes and the southern side of boulders and large rocks are the first to lose their snow. The ground snowpack is also shallower due to the warming effects of the sun. In the Southern Hemisphere, all of these effects will be the opposite.