In late March 1916, Shackleton's ice-floe was approaching open water. In the photo above, which I took in 2000 in the same general area, the lighter sky indicates ice. The darker sky indicates open water. It's called "ice-blink." Ice-floes are wet and slippery and hard, rather like glass, unless they're melting. Not a pleasant environment.
Orde-Lees Journal
Monday, 27 March, 1916
Brilliant weather again and the warmest we have had for ever so long. The land which was again visible last night was very clearly outlined today, although it is upwards of sixty miles away.
Rapid movements are taking place in the ice.
Our old "Rampart" Berg which was recently ten miles off, but for the last two days no more than a mile away, took it into its head to suddenly drift off to the westward at about two miles an hour.
Another huge tabular berg, which we called Mt. Haddington berg because Captain Worsley mistook a dome on the top of it for the mountain (though he won't admit it of course) came rapidly towards us very nearly colliding with the Rampart berg but happily stopping just before it reached us.
These ice movements undoubtedly indicate the proximity of open water, but in which direction it is impossible to say. At this late date in the season it is a matter for much conjecture whether it will not have frozen over before we reach it.
Sir Ernest's desire now that we have missed Paulet Island and Joinville Island is to get into open water before we get north of the South Shetland Isles, and then make for and winter at one of them called Elephant Island, where we can be fairly sure of getting seals and even sea elephants.
The smaller bergs are circulating round our floe. One hummock on a small slab of ice has made the complete circuit round our floe in about three weeks and yet there is no real big lead or open water pool within sight. The floe itself has cracked slightly just where the piece of high pressure took place. The "look-out" slab which was pressed up, has slipped down again somewhat.
A seal was seen in the water and a killer whale has bee blowing around during the day so that it shows that there is some game about after all and perhaps the killer will put the seals up for us unless he manages to put them down himself.
A skua and four of five Dominican gulls have been seen, all good signs.
Sir Ernest had determined to send back to Ocean Camp, if it is at all possible to do so, to get from there the remainder of the dog pemmican left behind long ago.