BIOMASS 



theii' lives in close association with the bottom, 

 in this category. 



2. Also applied to the floor or deepest part of 

 a sea or ocean. (2) 



bentonite — A clay formed from the decomposition 

 of volcanic ash and composed of the clay 

 minerals montmorillonite and beidellite. (2) 



berber — See barber. 



berg — See iceberg. 



bergy bit^A medium-sized piece of ice, generally 

 less than 5 meters (16.4 feet) high and about 

 the size of a small cottage. A bergy bit mainly 

 originates from glacier ice but occasionally 

 from a massive piece of sea ice or hummocked 

 ice. When it is known to be sea ice, the term 

 floeberg may be used. (74) 



bergy seltzer — Sizzling sound comparable to that 

 of Seltzer water which icebergs emit when they 

 melt. It is caused by the release of air bubbles 

 that were retained in the berg at high pressure. 



berm — The nearly horizontal portion of a beach 

 or backshore having an abrupt fall and formed 

 by deposition of material by wave action, and 

 marks the limit of ordinary high tides. {See 

 figure for shore profile.) 



berm crest — (also called herm, edge). The sea- 

 ward limit of a berm. {See figure for shore 

 profile.) (61) 



berm edge — See berm crest. 



Bermuda high — The semipermanent subtropical 

 high of the North Atlantic Ocean, so named 

 especially when it is located in the western part 

 of the ocean. 



This same high, when displaced toward the 

 eastern part of the Atlantic, is known as the 

 Azores high. On mean charts of sea-level pres- 

 sure, this high is a principal center of action. 



(5) 



beset — Surrounded so closely by sea ice that steer- 

 ing control is lost. The term does not imply 

 pressure. If the ship is incapable of proceed- 

 ing, it is icebound. If pressure is involved, 

 the ship is said to be nipped. (68) 



best depth range — The detection range of a sub- 

 marine target which is at the best depth to escape 

 detection by a ship with hull-moimted sonar. 



beta particle — A negative electron or a positive 

 electron (positron) emitted from a nucleus dur- 

 ing beta decay. The symbols /3, P', and /3+ are 

 reserved for electrons of nuclear origin. (41) 



beta ray — Synonym for beta particle. 



biennial ice — Sea ice between one and two years 

 old. See young polar ice. 



bifilar current indicator — An apparatus used for 

 obtaining only the direction of the current at 

 different depths. (37) 



bifurcation — A forking, or division into two 

 branches ; the point of forking ; a branch. 



big clearing — See polynya. 



bight — 1. A concavity in the coastline which 

 forms a large open bay. 

 2. See\)a,y (sense 2). 



big ice floe — See ice floe. 



bilateral transducer — {ov reversible transducer). 

 A. transducer capable of transmission in either 

 _ direction between its terminations. (69) 



bill — A narrow promontory or headland. (68) 



Billion- electron-volts — (abbreviated Bev). 

 Equivalent to 10^ electron-volts. 



billow — Usually a great wave or surge of water; 

 any wave. (73) 



binary scaler — A scaler whose scaling factor is 

 two per stage. (70) 



biocenose — See community. 



biocenosis — See community. 



bioclastic rock — Eocks produced from material 

 broken or arranged by animals or plants and 

 consisting of fragmental organic remains. 



biogenic deposit — A deposit resulting from the 

 physiological activities of organisms. (2) 



bioherm — A reef or mound built principally by 

 sedimentary organisms such as corals, mol- 

 lusks, etc. See also accretionary limestone, 

 biostrome, reef. (2) 



biolithite — Inclusive term for organic limestone. 

 (2) 



biological half-life — The time required for the 

 body to eliminate one-half of an administered 

 dose of any substance by regular processes of 

 elimination. This time is approximately the 

 same for both stable and radioactive isotopes of 

 a particular element. (70) 



biological oceanography^The study of the 

 ocean's plant and animal life in relation to the 

 marine environment, including the effects of 

 habitat, sedimentation, physical and chemical 

 changes in the environment, and other factors on 

 the spatial and temporal distribution of marine 

 organisms, as well as the action of organisms on 

 the environment. 



bioluminescence — (also called fhosflwrescervce^ 

 luminescence). The production of light with- 

 out sensible heat by living organisms as a result 

 of a chemical reaction either within certain cells 

 or organs or extracellularly in some form of 

 secretion. Luminescence usually is induced by 

 external stimuli, especially mechanical, such as 

 wave action or shock waves. It is produced by 

 a variety of marine organisms in displays of 

 three general types, namely, sheet type, spark 

 type, and glowing-ball type. See luciferin, 

 luciferase. 



bioluminescent display — Production of biologi- 

 cal light of sufficient intensity to make the water 

 or disturbances of the water conspicuously illu- 

 minated. Displays may be weak and noted only 

 as a pale green luminosity of wave crests, or 

 they may be extremely intense and capable of 

 lighting large areas of ocean. Momentary 

 luminescence created by a few jellyfish when 

 disturbed is not considered a display. 



biomass — (also called standing crop., standing 

 stock, live-ioeigkt) . The amount of living mat- 



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