MORAINE: (II. B.) — A ridge of rock debris deposited by a glacier 



(Frontispiece, Figs. 71, 74) . 

 MOULIN: (II.A.2.) — A broad, circular depression on the ice surface of 



a valley glacier near its terminus. Moulins are caused by the entering 



of melt water into the crevasses of the glacier. 

 MOUNTAIN GLACIER: (II.A.2.)— Valley glacier. 

 MUDDY ICE: (V.O— Debris ice. 

 MUSH: (I.A.3.D— Brash. 

 NEEDLE ICE: ( I. A. 3. f.)— Candle ice. 

 NEVE: (II. B.) — More or less loose, granular ice in transition from snow 



to glacier ice. Neve, in being buried about 100 feet, becomes com- 

 pacted and gradually changes to glacier ice. The upper layers of 



glaciers and shelf ice are usually composed of neve. 

 NEVE ICEBERG: (II.A.5.a.) — An iceberg similar in appearance and 



color to a tabular iceberg but composed of neve or compacted snow. 



See iceberg. 

 NEWLY-FORMED ICE: (I.A.3.)— A general classification for ice in the 



first stage of formation and development (Figs. 27, 28) . 

 NEWLY-FROZEN ICE: (I. A. 3.)— Newly-formed ice. 

 NIPPED: (V.A.) — Caught in the ice and subjected to pressure. Applied 



to ships caught fast in the ice. Cf. beset, icebound. 

 NIPPING: (V.A.) — The forcible closing of ice around a ship so that 



the ship is held fast by ice under pressure. 

 NIVATION: (II.B.) — The specific effects produced by neve in land 



sculpture as contrasted with those by glacier ice, called glaciation. 

 NUNATAK: (TLB.) — An isolated hill or mountain of bare rock rising 



above the surrounding ice sheet. Nunataks have been described as rock 



islands formed in a sea of ice with bands of moraine extending seaward 



from them. 

 OLD ICE: (I.A.3.e.) — Any sea ice over one year old. 

 OPEN ICE: (I.A.l.c.)— Broken ice. 

 OPEN LEAD: (I.C.l.b.) — A lead that is not covered with newly-formed 



ice. 



OPEN PACK ICE: (I.A.l.c.)— Broken ice. 



OPEN WATER: (LA. l.a.)— Water that is less than one-tenth covered 

 with floating ice. See concentration (of ice). (Fig. 1.) 



OUTLET GLACIER: (II.A.l.a.)— The route by which the ice of con- 

 tinental glaciers escapes to the sea (Fig. 73) . 



PACK: (I.A.I.) — Ice pack, pack ice. 



PACK ICE: (I.A.I.) — Any large area of floating ice driven closely 

 together. See concentration (of ice). 



PACKED ICE: (T.A.l.d.)— Close ice. 



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