Ice cave

As the massive sheet of ice that covered what later became Alaska's 'Glacier Bay' retreated,

some 16 tidal glaciers defined the geography of the place and became the subject of intense

geological and biological study. On land, in the course of their retreat, the glaciers would

sometimes fracture, leaving behind huge blocks of ice to slowly melt. Depending on their size,

shape and orientation, these remnants would often produce ice caves as the surface melted at

differential rates. Here is an ice cave that once existed in Tarr Inlet, the western arm of the

Bay: an exterior shot that looks like rock, the outer top of a cavernous hole inside. Parks

personnel told us afterwards that it was extremely dangerous to venture into unstable ice caves,

as they could collapse without warning at any time. This remnant cave actually did disintegrate

about two weeks after we'd been filming in it. Our film was about the re-colonisation of land once

the glaciers have gone, so ice was an important part of the story.

All the glaciers in Glacier Bay have now grounded out, and the area has lost much of its

splendour and excitement. The icy spectacle has gone - no more icebergs. Wildlife and forest

have taken over, a different sort of spectacle.