AS OBSERVED IN THE WEDDELL SEA. 
827 
In the case of the Weddell Sea ice, there was a local peculiarity, which must 
accelerate the break-up. In its progress north, the ice was being continually pressed 
against Graham Land and Joinville Island ; S.E. winds accordingly had little effect 
in moving the ice, but S.W. ones drove it out towards the open sea ; the former 
had a closing, the latter an opening effect. There was a point, however, where 
the ice did get away to the north-west, namely when it reached the latitude of Join- 
ville Island. In the middle of March, 1916, in 64° S. lat., a south-easterly blizzard had 
practically no effect ; in the beginning of April, in lat. 62° 30' S., a lighter wind from 
the same quarter drove the ice fast and far to the north-west. In this way separate 
areas are probably sliced off the main pack and driven into Bransfield Strait. There 
the noted currents of the Strait give it little peace, and it travels towards the South 
Orkneys often as fast as 20 miles a day. The Endurance party’s experience of the 
current gave some idea of its force. From the 9th to the 12th of April the winds 
were easterly and east-north-easterly ; and in this period during the daylight the 
boats were steered on a N.W. course ; at night camp was generally made on a 
drifting floe. Observations on the 9th made the position 61° 56' S., 54° 05' W. ; but 
on the 12th showed the boats to be in 62° 15' S., 53° 17' W. — a net loss of about 
30 miles S.E. Dead reckoning, on the contrary, would have made the position at 
least 25 miles N.W. of that on the 9th, to say nothing of steady winds from E.N.E., 
which should, have made it still farther west. These figures give an idea, though an 
inexact one, of the strength of the easterly running currents in Bransfield Strait. 
To summarise what probably happens during the decay of the Weddell Sea ice : — 
The most important factor is the swell, which breaks down the floes, if not already 
in that condition, into smaller-sized pieces. Mechanical erosion then takes place by 
washing of sea-water against the ice. Finally, when the temperature allows of it, the 
ice-blocks are destroyed by melting. By the time that stage is reached, the ice is 
much comminuted, forming brash. The latter includes “ bergy bits ” (hummocked- 
ice finally taking this appearance) or “ growlers,” which are merely ice-fragments 
greenish in colour and so small that they hardly show above water. For several 
hours one morning the boats of the Endurance passed through a maze of bergy bits. 
At that time the ice was under the influence of the Bransfield Strait current ; and 
this and the wind were carrying it, much battered and decayed, to its final melting- 
ground towards and beyond the South Orkneys. 
The author wishes to take this opportunity of acknowledging his indebtedness 
to the Trustees of the Scott Polar Research Fund for the generous grants made by 
them to meet the expenses of printing this and a previous paper on “ Depths and 
Deposits of the Weddell Sea.” 
TRANS. ROY. SOC. EDIN., VOL. LII, PART IV (NO. 31). 
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