KEY TO ICE SYMBOLS 
[COVERAGE (CONCENTRATION) [ace) 
n 
[Jes tre % dominant, % secondary 
W=Winter ice 
Y=Young ice Pi=Polar ice 
Sl=Slush 
f}<01 (open water) 
0.1 thru 0.4 (scattered ice) 
A A 
RSSSY) Examples siete 
GOW, 40P1 
(0 05 thru 0.7 (broken ice) 
RS) thru 0.9 (close ice) Pa 
Puddles: dominant it 
FERRY 1.0 consolidates or fast ice) in tenths unless 
frozen ot rotten 
COVERAGE BY SIZE F=Frozen R=Rotten 
Ch Pd Pd Pd 
mM, 0 Examples: =, =. — 
ny=tenths of slush, brash, and block wae Crack we He 
f,=tenths of small and medium floes oO Polynya 
fy=tenths of giant floes and field 
A Icebergs —many (>20) 
—— Observed A  Icebergs—few (<20) 
——— Estimated 
© © © Limit of observed data 
172°w 180° 
@ Bergy bits and growlers (>20) 
© Bergy bits and growlers (<20) 
172°E 
Mc MURDO 
SOUND 
THICKNESS AND SNOW COVER 
Thickness; u where N= feet and inches 
n=depth to nearest inch 
C=ice uniformly snow covered 
D=snow cover in drifts 
O=no snow cover present 
TOPOGRAPHY. 
AA Ratted ice 
NA Ridged ice 
OOO Hummocks 
Extent! H=very extensive 
L =few present 
When no entry appears beneath 
symbol extent 1s moderate 
Examples: 
AM avery extensive ridging 
AA =moderate rafting 
200 = few hummocks 
180° 172°E 
164°E 
156°E 
78°s 
Cn A 
260 S0wW20PI 76°s 
A 
7A°S 
72°5 
70S 
27 JANUARY I96I 
164°E 
FIGURE 73. RESULTS OF AERIAL ICE RECONNAISSANCE, ROSS SEA 
103 
