The névé is always pulling away from the rocks at its upper border, and
its general motion follows the direction of the lowest depression
beneath, finally extending below snowline as a tongue of ice which
reaches down into the valley until it is melted by the increasing warmth
of the lower levels. Thus a glacier is born. Unless whitened by recent
storms the glacier is bare of snow in summer with a rough uneven surface
of a dirty blue green color, partly covered with rocky debris, and its
volume diminishes downward by thawing until at a definite point the
whole is melted and flows away as a river of water instead of ice. The
lower end is sometimes called the “tongue” or “snout” or “foot” of the
glacier—a bad case of mixed metaphors.
[Illustration]