OCEANOGRAFHIC STATION LOCATION 



oceanographic station location — ^The accepted 

 geographical position at which an oceano- 

 graphic station was taken. 



oceanograpliic survey — A study or examination 

 of conditions in the ocean or any part of it, with 

 reference to animal or plant life, chemical ele- 

 ments present, temperature gradients, etc. See 

 hydrographic survey. (68) 



oceanographic tracer — A foreign substance in- 

 troduced into the ocean by natural or artificial 

 means which enables determination of the ocean 

 water movement through measurement of the 

 distribution or location of the substance at some 

 later time. Such oceanographic tracers include 

 Tritium ( 11=*), Carbon", other radioisotopes, as 

 well as non-radioactive tracers such as fluores- 

 cent dyes and various chemical substances. 



oceanographic winch — A medium size winch used 

 for most oceanographic instrument lowering and 

 raising. This winch is a high-speed type hold- 

 ing about 20,000 to 30,000 feet of wire rope. 



oceanography — 1. The study of the sea, embrac- 

 ing and integrating all knowledge pertaining to 

 the sea's physical boundaries, the chemistry and 

 physics of sea water, and marine biology. 



2. In strict usage oceanography is the descrip- 

 tion of the marine environment, whereas ocean- 

 ology is the study of the oceans and related 

 sciences. 



oceanology — See oceanography. 



ocean station — (or station). As defined by the 

 Intemation Civil Aviation Orgcmisation, a spe- 

 cifically located area of ocean surface, roughly 

 square and 200 nautical miles on a side. An 

 ocean station vessel on patrol is said to be "on 

 station" when it is within the perimeter of the 

 area. (5) 



ocean station vessel — (abreviated OSV; also 

 called ocean weather ship, weather patrol ship, 

 weather ship). An ocean-going ship assigned 

 to patrol an ocean station. 



These ships are specially equipped to take 

 comprehensive meteorological and some oceano- 

 graphic observations of conditions both at the 

 surface, subsurface, and aloft. The United 

 States ships are provided by the U.S. Coast 

 Guard, and the meteorological personnel and 

 equipment are provided by the U.S. Weather 

 Bureau. (5) 



ocean water — Water having the physical-chemi- 

 cal characteristics of the open sea, where con- 

 tinental influences are at a minimum. 



ocean weather ship — See ocean station vessel. 



ocean weather station — ^As defined by the World 

 Meteorological Organization, a specific mari- 

 time location occupied by a ship equipped and 

 staffed to observe weather and sea conditions and 

 report the observations by international ex- 

 change. (5) 



octopus — (or devUfish). One of a family (Octo- 

 podidae) of cephalopods with round or saclike 

 bodies, eight arms, no shell, and generally with- 



out fins. Although there are no known docu- 

 mented fatalities from attacks by these animals, 

 many documented attacks on humans are re- 

 corded. 



odontocete — See toothed whale. 



oersted — The basic unit of magnetic field inten- 

 sity. A magnetic field with an intensity of one 

 oersted will exert a force of one dyne upon a 

 unit magnetic pole. See gauss. 



oflf-reef facies — See reef talus. 



offshore — The comparatively flat zone of variable 

 width which extends from the outer margin of 

 the rather steeply sloping shoref ace to the edge 

 of the continental shell. (2) {See figure for 

 shore profile.) 



offshore bar — See bar. 



offshore barrier — See barrier beach. 



offshore current — 1. A prevailing nontidal cur- 

 rent usually setting parallel to the shore out- 

 side the surf zone. See coastal current. {See 

 figure for nearshore current system.) 

 2. Any current flowing away from shore. 



offshore water — ^Water adjacent to land in w'hich 

 the physical properties are slightly influenced 

 by continental conditions. 



offshore wind — A wind blowing seaward from 

 the land in a coastal area ; a land breeze. (61) 



old ice — Any sea ice more than one year old. 

 (68) 



oligotrophic — Pertaining to water bodies contam- 

 ing nutrient matter. 



olistostrome — A deposit produced by sliding or 

 slumping of a submarine sediment mass. 



omnidirectional hydrophone — A hydrophone 

 whose response is essentially independent of 

 angle of arrival of the incident sound wave. 

 (69) ■ 



one-year ice — 1. Sea ice formed the previous sea- 

 son, not yet one year old. 



2. A Russian term for 'sea ice thicker than 

 white ice. By the end of spring it reaches a 

 thickness of 1.5 to 2.0 meters (4.9 to 6.6 feet) 

 or more. Usually during the summer this ice 

 does not entirely disappear and becomes two- 

 year ice or young polar ice. 

 (59) 



onshore — A direction landward from the sea. 

 (61) 



onshore wind — A wind blowing landward from 

 the sea in a coastal area ; a sea breeze. (61) 



on station — See ocean station. 



ooid — See oolite. 



oolite — (or oiiUth, ooid) . A spherical or ellipsoi- 

 dal particle of sand or granule size (0.25 to 2.00 

 millimeters in diameter) with concentric or 

 radial structure, which usually is calcareous but 

 may be siliceous or hematic. It is formed by 

 replacement or by accretion of concentric layers 

 of lime around a quartz grain nucleus in shallow, 

 wave agitated, limy water. 



oolith — See oolite. 



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