On or pertaining to the belly or abdomen
A type of natural resource management that
implies making decisions as part of an on-going process. Monitoring the results
of actions will provide a flow of information that may indicate the need to
change a course of action. Scientific findings and the needs of society may also
indicate the need to adapt resource management to new information.
Fatty. Used, for example, in 'adipose fin' found in some
primitive bony fishes.
A small fleshy fin without rays found on the back
behind the dorsal fin of some primitive teleost fishes such as the lizardfishes
(Synodontidae), salmonids (Salmonidae), or characids (Characidae).
Analog to Digital Recording tide gauge. A float or
pressure actuated tide gauge that records the heights at regular time intervals
in digital format.
Fish that have fully developed morphological and meristic
characters and that have attained sexual maturity.
An insect that's fully mature and capable of
Soil transported from one area to another by wind.
Wind-deposited sediments, such as sand
The process of adding pure oxygen or air into water for
the purpose of increasing the dissolved oxygen content.
Removing logs from a timber harvest area by
helicopter. Fewer roads are required, so the impact to an area is
Modified pectoral or pelvic fins used for gliding in some
The natural environment that exists at the
present time in an area being analyzed.
1. a group of animals in a population with approximately
the same age (i.e., fawn, yearling, adult). 2. An age grouping of trees
according to an interval of years, usually 20 years. A single age class would
have trees that are within 20 years of the same age, such as 1-20 years or 21-40
age of diurnal inequality
The time interval between the maximum
semimonthly north or south declination of the Moon and the maximum effect of the
declination upon range of tide or speed of the current. The age may be computed
from the harmonic constants by the formula: age of diurnal inequality =
0.911(K1° - O1°) hours.
age of Moon
The time elapsed since the preceding new Moon.
age of parallax inequality
The time interval between perigee of the
Moon and the maximum effect of parallax upon range of tide or speed of the tidal
current. This age may be computed from the harmonic constants by the formula:
age of parallax inequality = 1.837(M2° - N2°) hours.
age of phase inequality
The time interval between new or full Moon
and the maximum effect of these phases upon range of tide or speed of the tidal
current. This age may be computed from the harmonic constants by the formula:
age of phase inequality = 0.984(S2° - M2°) hours.
age of tide
Same as age of phase inequality.
the number of individuals of each age within the
Same as double tide.
The geologic process by which various parts of the
surface of the earth are raised in elevation or built up by the deposition of
material transported by water or wind.
An Indian Ocean current setting southwestward along
the southeast coast of Africa.
air acoustic ranging sensor
A pulsed, acoustic ranging device using
the air column in a tube as the acoustic sound path. The fundamental measurement
is the time it takes for the acoustic signal to travel from a transmitter to the
water surface and then back to the receiver. The distance from a reference point
to the water surface is derived from the travel time. A calibration point is set
at a fixed distance from the acoustic transducer and is used to correct the
measured distance using the calibrated sound velocity in the tube.
air temperature sensors
Sensors located in the protective well for
the purpose of verifying uniformity of temperature for measurements taken by the
air acoustic ranging sensor.
A geographic area that shares the same air.
Specialized prehensile spines near the disc edge in all
male skates (Rajoidea).
A North Pacific Ocean current setting
counterclockwise along the coasts of Canada and Alaska in the Gulf of Alaska.
A North Pacific Ocean current setting westward along
the south side of the Aleutian Islands. It is an extension of the Alaska
typically pelagic colonial nesting seabirds that feed on
fish by diving under the water surface to pursue their prey. Species include
auklets, guillemots, murres, murrelets, and puffins.
a food fish of the herring family that is very abundant on
the Atlantic coast; the alewife entered the Great Lakes through the Welland
Canal in the 1940s and frequently die-off in large numbers because they are not
well adapted to life in freshwater.
Large and heterogenous group of plants living in aquatic or
damp terrestrial habitats.
Reef top surface feature dominated by algae cover,
usually brown algae (e.g., Sargassum, Turbinaria).
A chemical used to control algae.
A term applied shelves that presently experience
deposition of river-derived sediments.
allotment (range allotment)
The area designated for use by a
prescribed number of livestock for a prescribed period of time. Though an entire
Ranger District may be divided into allotments, all land will not be grazed,
because other uses, such as recreation or tree plantings, may be more important
at a given time.
Detrital material which is transported by a river
and deposited – usually temporarily – at points along the floodplain of a river.
Commonly composed of sands and gravels.
Parallel to and near the shoreline; same as
An instrument that determines its distance above a
An instrument that determines altitude by
measuring the length of time needed for a pulse of coherent light to travel from
the instrument to the surface and back, and multiplies half this time by the
speed of light to get the straight-line distance to the surface.
See altimeter, laser, and lidar.
Three feathers springing from the base of the primaries.
Synonym(s): alular quills.
alular quill coverts
Feathers overlying the bases of alula.
Three feathers springing from the base of the
primaries. Synonym(s): alula.
The natural temperature of the water.
A point of no amplitude of the observed or a
An area surrounding an amphidromic point from
which the radiating cotidal lines progress through all hours of the tidal cycle.
One-half the range of a constituent tide. By analogy,
it may be applied also to the maximum speed of a constituent current.
Species of fish that mature in the sea and migrate
into streams to spawn.
As used in the National Ocean Service, a continuous
measurement or a continuous graphic display of data. See ADR gauge and marigram.
See harmonic analysis.
See harmonic analyzer.
angle of repose
The maximum slope (measured from the horizon) at
which soils and loose materials on the banks of canals, rivers or embankments
One who uses a rod and reel to catch any species of fish.
angular velocity of the Earth's rotation
Time rate of change of
angular displacement relative to the fixed stars. It is equal to 0.729,211 x
Seasonal variation in water level or current,
more or less periodic, due chiefly to meteorological causes.
Pertaining to the periodic return of the Moon to its
perigee or the Earth to its perihelion. The anomalistic month is the average
period of the revolution of the Moon around the Earth with respect to lunar
perigee, and is approximately 27.554,550 days in length. The anomalistic year is
the average period of the revolution of the Earth around the Sun with respect to
perihelion, and is approximately 365.259,6 days in length.
As applied to astronomy, the anomaly is the angle made at
any time by the radius vector of a planet or moon with its line of apsides, the
angle being reckoned from perihelion or perigee in the direction of the body's
motion. It is called the true anomaly when referred to the actual position of
the body, and mean anomaly when referred to a fictitious body moving with a
uniform angular velocity equal to the average velocity of the real body and
passing perihelion or perigee at the same time.
Antarctic Circumpolar Current
Same as West Wind Drift.
Arising from human activities, as opposed to natural
A mechanism that prevents the spool or handle of a
reel from spinning in reverse.
A meander breaking off from the main current and
spinning in a clockwise direction in the northern hemisphere (counter-clockwise
A North Atlantic Ocean current setting
northwestward along the northeast coasts of the Bahama Islands.
The point in the orbit of the Earth (or other planet,
etc.) farthest from the Sun.
apogean tides or tidal currents
Tides of decreased range or
currents of decreased speed occurring monthly as the result of the Moon being in
apogee. The apogean range (An) of the tide is the average range occurring at the
time of apogean tides and is most conveniently computed from the harmonic
constants. It is smaller than the mean range, where the type of tide is either
semidiurnal or mixed, and is of no practical significance where the type of tide
is predominantly diurnal.
The point in the orbit of the Moon or man-made satellite
farthest from the Earth. The point in the orbit of a satellite farthest from its
apparent secular trend
The nonperiodic tendency of sea level to
rise, fall, or remain stationary with time. Technically, it is frequently
defined as the slope of a least-squares line of regression through a relatively
long series of yearly mean sea-level values. The word "apparent" is used since
it is often not possible to know whether a trend is truly nonperiodic or merely
a segment of a very long (relative to the length of the series) oscillation.
Time based upon the true position of the Sun as
distinguished from mean time, which is measured by a fictitious Sun moving at a
uniform rate. Apparent time is that shown by the sundial, and its noon is the
time when the Sun crosses the meridian. The difference between apparent time and
mean time is known as the equation of time. Although quite common many years
ago, apparent time is seldom used now.
The points in the orbit of a planet or moon which are the
nearest and farthest from the center of attraction. In the Earth's orbit these
are called perihelion and aphelion, and in the Moon's orbit, perigee and apogee.
The line passing through the apsides of an orbit is called the line of
A body of rock that is saturated with water or transmits
water. When people drill wells, they tap water contained within an
A geologic formation that is water-bearing, and which
transmits water from one point to another.
an expanse of water with many scattered islands; a
group of islands
See equilibrium argument.
A submarine ridge with which no earthquakes are
The direction a slope faces. A hillside facing east has an
ASQ (allowable sale quantity)
The amount of timber that may be sold
within a certain time period from an area of suitable land. The suitability of
the land and the time period are specified in the Forest Plan.
Fictitious celestial bodies which are assumed to
move in the celestial equator at uniform rates corresponding to the speeds of
the several harmonic constituents of the tide producing force. Each astre fictif
crosses the meridian at a time corresponding to the maximum of the constituent
that it represents.
See astronomical time.
The tidal levels and character which would result
from gravitational effects, e.g. of the Earth, Sun and Moon, without any
Time formerly used in astronomical calculations
in which the day began at noon rather than midnight. The astronomical day
commenced at noon of the civil day of the same date. The hours of the day were
numbered consecutively from zero (noon) to 23 (11 a.m. of the following
morning). Up to the close of the year 1924, astronomical time was in general use
in nautical almanacs. Beginning with the year 1925, the American Ephemeris and
Nautical Almanac and similar publications of other countries abandoned the old
astronomical time and adopted Greenwich civil (mean) time for the data given in
The loss or dissipation of wave energy, resulting in a
reduction of wave height (amplitude).
A fly pattern that isn't tied to imitate any one
particular food form; typically brightly colored.
A factor used in connection with the harmonic
analysis of tides or tidal currents to allow for the fact that the tabulated
hourly heights or speeds used in the summation for any constituent, other than
S, do not in general occur on the exact constituent hours to which they are
assigned, but may differ from the same by as much as a half hour.
AUM (animal unit month)
The quantity of forage required by one
mature cow and her calf (or the equivalent, in sheep or horses, for instance)
for one month.
Area around ear opening. Synonym(s): ear patch.
A term applied to shelves on which older shelf
sediments are primarily being reworked by modern shelf processes.
A spiral pickup arm that engages the line
automatic tide gauge
An instrument that automatically registers the
rise and fall of the tide. In some instruments, the registration is accomplished
by recording the heights at regular time intervals in digital format; in others,
by a continuous graph of height against time. The automatic gauges used by the
National Ocean Service are of both types.
(1) Rapid EROSION of the shoreland by waves during a
storm. (2) A sudden cutting off of land by flood, currents or change in course
of a body of water.
Ventral area between the body and the wing. Synonym(s):
Azimuth of a body is the arc of the horizon intercepted
between the north or south point and the foot of the vertical circle passing
through the body. It is reckoned in degrees from either the north or south point
clockwise entirely around the horizon. Azimuth of a current is the direction
toward which it is flowing, and is usually reckoned from the north