A glacier is a persistent body o dense ice that is constantly movin unner its ain wicht; it forms whaur the accumulation o snaw exceeds its ablation (melting an sublimation) ower many years, eften centuries.

The Baltoro Glacier in the Karakoram, Baltistan, Northren Pakistan. At 62 kilometre (39 mi) in length, it is ane o the langest alpine glaciers on yird.
Glacier