Alpine glaciers.

Alpine glaciers are masses of ice and snow that move slowly down from the peaks to produce the spectacular landforms associated with high mountain scenery. Steep horn-shaped or pyramidal peaks, rushing meltwater rivers, cliff-sided valleys with waterfalls—one associates these features with alpine mountains that have been eroded by glaciers. Where such glaciers are still active, they may threaten lives and property through catastrophic forward surges and floodwaters, or they may be essential sources of meltwater in dry areas.