B.B.C. Article

Rare and somewhat esoteric. These are the huge pyramids of ice that stand proud of the surface on some glaciers.
To date, the phenomenon has only really been seen around the Karakoram mountain region of Pakistan.


The person walking beside the sail gives a sense of their immense scale

The Baltoro glacier, which begins life at the very summit of K2, has some particularly fine examples.
Up to 25m in height and with widths of up to 90m, their triangular shapes when viewed from a distance give the impression of a flotilla of sail boats.
Now, scientists are getting a handle on how these giant "ice sails" form and wither over time, and how the processes involved depend on the special conditions that exist in the Karakoram region.

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