KEY TO ICE SYMBOLS 
(COVERAGE (CONCENTRATION) AGE 
THICKNESS AND SNOW COVER] 
[Jl free 
<0 1 (open water) 
Gow, 40P1 Ww 
TTT TT 05 tnrw 07 coroken ie) 
08 thru 0.9 (close ice) 
A 
T 
% dominant, % tary Thickness: | where n=feet and inches 
Si=Slush W=Winter ce 
Y=Young ice Pl=Polar ice 
A A 
Examples: gate. 
Pd 
Puddles: bal 
FERS] 10 cconsoliates faitantlice)) nae a eeatiamount 
COVERAGE BY SIZE 
Cn 
ny, M3, My 
ny =tenths of slush, brash, and 
fn,=tenths of small and medium floes 
in tenths unless 
frozen of rotten 
F=Frozen R=Rotten 
Pd Pd Pd 
Jest eemen ss 
Examples: TER 
eer Crack <= Lead 
© Polynya 
block 
n,=tenths of giant floes and field 
[IICE_OF LAND ORIGIN] 
BOUNDARY 
—— Observed 
——— Estimated 
© © © Limit of observed data 
A Icebergs —many (>20) 
ZA Icebergs—tew (< 20) 
@ Bergy bits and growlers (>20) 
OD Bergy bits and growlers (<20) 
172°w 
Snow cover SS 
ncCOO 
n=depth to nearest inch 
C=ice uniformly snow covered 
D=snow cover in drifts 
O=no snow cover present 
TOPOGRAPHY 
AA Rafled ice 
NMA Ridged ice 
ONO Hummocks 
Extent: H=very extensive 
~L=few present 
When no entry appears beneath 
symbol extent 1s moderate 
Examples. 
TON very extensive nding 
AA =moderate rafting 
000 _ 
T few hummocks. 
180° 
172°E 
2 MARCH I96I 
164°E 
FIGURE 78. RESULTS OF SURFACE ICE RECONNAISSANCE, ROSS SEA 
107 
76°S 
72°s 
70°S 
