Judy Greenblatt, age 10, of Dorchester. Mass., for her question:

How are glaciers made?

A glacier is made of solid ice, sometimes a mile or more thick and weighing millions End millions of tons. Yet all this solid ice is made from fluffy snowflakes. A glacier fcmms in some region where the summer suns are not warm enough t o melt all the snow which fell in the winter. Year by year, the snow piles up and presses down under its own weight. The fluffy snow is pressed into solid ice.

When it gets to a certain size, the glacier begins to move. It may slide slowly down a slope. It mar push outward from the center. The ice at the edges reaches a warmer region and melts away. Sometimes it meets the sea and breaks off to form icebergs. Meantime, more snow is falling on the glacier and turning into ice.