Mary Ruez, age 13, of Louisville, Ky., for her question:

WHAT IS TERMINAL MORAINE?

Moraine is the earth and stones that a glacier carries along and deposits when the ice melts. Moraine can also mean the line of such material on the surface of a glacier or the uneven ridge of material deposited at the edge of the melting ice.

When two glaciers meet, the lateral moraines between them merge into a medial moraine.

When ice melts from a mountain glacier, or in front of a continental ice sheet, a large ridge is built up. This ridge has hollows and mounds and is called a terminal moraine. Some of the terminal moraines that were formed during the Ice Age by ice sheets are now ranges of hills.

Ground moraine is the material deposited under the ice as a glacier melts.