A glacier was a large slow-moving mass of ice.
The Twelfth Doctor surmised that the Ice Age on Earth was started by glaciers "pop[ping] out of nowhere" as he explained what he called the "Tree Age". (TV: In the Forest of the Night [+]Loading...["In the Forest of the Night (TV story)"])
On Bruhl, the First Doctor observed a glacier which he estimated to be at least twenty miles long. (PROSE: Justice of the Glacians [+]Loading...["Justice of the Glacians (short story)"])
To stop an advancing glacier in 5000 AD, Brittanicus Base was established by Great Britain. While using an ioniser to melt the ice, they uncovered a troop of Ice Warriors which had been frozen for thousands of years when their spaceship had crashed in the area. (TV: The Ice Warriors [+]Loading...["The Ice Warriors (TV story)"])
The Sixth Doctor and Peri Brown spent a week frozen inside a glacier on Vespod Eight. (PROSE: Attack of the Cybermen [+]Loading...["Attack of the Cybermen (novelisation)"])
The Northern Glacier on the Ood Sphere was where Ood Operations found the Ood Brain. (TV: Planet of the Ood [+]Loading...["Planet of the Ood (TV story)"])
The planet Midnight had naturally-formed diamond glaciers and mountains. (TV: Midnight [+]Loading...["Midnight (TV story)"])
The Flood was sealed in a glacier on Mars by the Ice Warriors in the 9th century. It was accidentally freed by Bowie Base One in 2059. (COMIC: The Wolves of Winter [+]Loading...["The Wolves of Winter (comic story)"], TV: The Waters of Mars [+]Loading...["The Waters of Mars (TV story)"])