90 
II. T. FEERAR. 
the water flowing through them often spreads sand and mud over the surface of 
the sea-ice. 
The most notable effects of water-action in the area were seen on the north-east 
side of Brown Island, an 
island which retains practi- 
cally no snow on its surface. 
In January, 1902, a very 
warm clear day followed a 
summer snow - storm, and 
caused a rapid melting of 
the snow just deposited. 
Rivulets becoming confluent 
produced comparatively 
large streams, which coursed 
in straight and narrow 
trenches down the hillside. 
The slope here is very 
steep, and trenches some- 
times 20 feet deep had 
been eroded. The coarser 
material washed off the hillside spreads out as a delta on land, but much of 
the finer material is carried further by the muddy stream, in and out among the 
lines of moraines, and distributed over the surface of the floating glacier-ice. We 
observed a stream increase 
in depth from one foot to 
three feet in the space of 
a few hours. The swollen 
stream cuts into the pro- 
tected moraines and, over- 
flowing the more level 
areas, there deposits its 
silt. Finally, the stream 
coursing northwards into 
McMurdo Sound passes off 
the pinnacled or floating 
glacier-ice* on to the sea- 
ice which its finest sediment 
then sullies (Figs. 53, 54). 
A similar flood must 
have occurred early in 
* Ferrar, Geog. Joum., April 1905, vol. xxv, plate, p. 374. 
J, Blue Glacier G 
Fig. 54. — Seaward edge op the Glacier-ice floating in 
McMurdo Sound. 
Fig. 53. — Water-channel on Floating Ice in McMurdo Sound. 
