INJECTION TEMPERATURE 



injection temperature — The temperature of the 

 sea water as measured at the sea-water intakes 

 in the engine room of a ship. 



Because the injectors are commonly located 

 well below the surface, and because the tem- 

 perature may be influenced by the heat of engines 

 or boilers, injection temperature is not con- 

 sidered as reliable as bucket temperature for 

 sea surface temperature. (5) 



Electronic temperature probes have been de- 

 veloped (surtems) to improve the procedure 

 mentionecl above. 



inland ice — See continental glacier. 



inland sea(s) — A sea surrounded by land which 

 connects with an ocean or anotlaer sea by one or 

 more narrow straits. Examples are tlie Medi- 

 terranean and Baltic Seas. See also epeiric 

 sea(s), epicontinental Eea(s). 



inlet — A short, narrow waterway connecting a 

 bay or lagoon with the sea. When it is a natural 

 inlet maintained by tidal currents, the name 

 tidal inlet or tidal outlet is applied. 



inner space — A nickname given to an area in- 

 volved in modern marine research, especially in 

 regard to underwater exploration. ( 35 ) 



inquilinism — A special kind of commensalism in 

 which one organism lives within another, usually 

 in the digestive tract or respiratory chamber, 

 without being harmful to its host. Some au- 

 thorties consider that relationship where one 

 species lives in the burrow or nest of another 

 is a form of inquilinism. See commensalism, 

 mutualism, symbiosis. 



insertion loss — Applied to a transducer connect- 

 ing an energy source and an energy load it is the 

 transmission loss measured by the ratio of 

 (1) the load power which would be measured 

 if the load were connected directly to the source, 

 to (2) the actual load power when source and 

 load are connected by the transducer in question. 



inshore — In beach terminology, the zone of vari- 

 able width between the shoreface and the sea- 

 ward limit of the breaker zone. (2) {See 

 figure for shore profile.) 



inshore current — The horizontal movement of 

 water inside the surf zone, including longshore 

 and rip currents. {See figure for nearshore 

 current system.) 



inshore water — ^Water contiguous to land in 

 which the physical j^roperties are considerably 

 influenced by continental conditions. 



in situ — A Latin term meaning "in place" ; in the 

 natural or original position. 



insolation — (contracted from incomingr solar 

 radiation). 1. In general, solar radiation re- 

 ceived at the earth's surface. 



2. The rate at which direct solar radiation is 

 incident upon a unit horizontal surface at any 

 point on or above the surface of the earth. 

 (5) 



insonification — The penetration of sound into any 

 particular part of the sea. 



instability — (or static instahility, hydrostatic in- 

 stability). A property of the steady state of a 

 system such that certain disturbances or pertur- 

 bations introduced into the steady state will in- 

 crease in magnitude, the maximum perturbation 

 amplitude always remaining larger than the 

 initial amplitude. In oceanography, usually 

 refers to the vertical displacements of a parcel in 

 hydrostatic equilibrium. 



insular shelf — See continental (or island) shelf. 



insular slope — ^ee continental (or island) slope. 



intake temperature — See injection temperature. 



intensity — In general, the degree or amount, 

 usually expi'essed by the elemental time rate or 

 spatial distribution, of some condition or physi- 

 cal quantity, such as rainfall, electric field, 

 sound, etc. (5) 



intensity level — The intensity level, in decibels, 

 of a sound is 10 times the logarithm to the base 

 of 10 of the ratio of the intensity of this sound 

 to the reference intensity. The reference in- 

 tensity shall be stated explicitly. (6) 



interbedded — (or inten^lammated, interstnttified, 

 intercalated). Occurring between beds or in 

 beds parallel to other beds of a different mateinal. 



(2) 

 intercalated — See interbedded. 



interdeep — This term is not recommended by the 

 ACUF for a trench or trough lying between 

 inner and outer island arcs. See trench, 

 trough. 



interface — (also called internal hoimdary, surface 

 of discontinuity, or boundary surface). A sur- 

 face separating two media, across which there is 

 a discontinuity of some property, such as density, 

 velocity, etc., or of some derivative of one of 

 these properties in a direction normal to the 

 interface. (5) 



interf acial tension — See surface tension. 



interference filter — An optical filter which 

 transmits, at normal inciclence, only a narrow 

 band of wavelengths, other wavelengths being 

 suppressed by the destructive interference of 

 waves transmitted directly through the filter and 

 those reflected Sn times, where n is an integer 

 (from back and front faces of the filter). (8) 



interfinger — Interlocking or overlapping wedge- 

 shaped sediment or rock layers. 



interlaminated — See interbedded. 



intermediate water — ^^fe water mass. 



intermediate waves — Waves under conditions 

 where the relative depth (or the ratio of water 

 deptli to wavelength) lies between 0.5 and 0.04. 



intermittent current — An unidirectional current 

 interrupted at intervals. (68) 



internal boundary — See interface. 



internal friction — See viscosity. 



internal wave — A wave that occurs within a fluid 

 whose density changes with depth, either 

 abruptly at a sharp surface of discontinuity (an 

 interface) or gradually. Its amplitude is great- 

 est at the density discontinuity or, in the case of 



86 



