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tidal flat
Thoracica (barnacles, stalked or goose barnacles) order of the class Cirripedia (subphylum Crustacea, phylum Arthropoda) with an alimentary canal. These marine,
sessile animals are mostly completely (barnacles) or partly (stalked barnacles) covered by calcareous plates. The thorax has six pairs of biramous
limbs (cirri), which together form a sieve that is actively beating through the
water. They live permanently attached to hard substrates, which include e.g.,
the skin of sea turtles (-7Reptilia, marine) and cetaceans (-7mammals, marine),
and floating objects. Some are parasitic. Mostly hermaphroditic. They live in all
seas, from the shore to great depths, a few live in brackish water. Examples:
Lepas (goose barnacle), Balanus (barnacle).
thorax -7Crustacea.
thymidine assay technique to measure secondary production by bacteria. The
assay measures the incorporation of radioactively labeled thymidine into
DNA, but the conversion to an overall estimate of production rates rests on
assumptions that may not always be valid.
tidal components -7partial tide.
tidal current current caused by the tides. Depending on the character of the tidal
wave, the tidal current may be alternating as flood or ebb currents (flowing
in only two opposed directions) or rotary (turning more or less gradually in
a clockwise or anticlockwise direction with a current vector that describes
a circle or an ellipse). In coastal sea areas tidal currents are often much
stronger than the currents due to other causes. -7f1ood tide and -7ebb tide.
tidal excursion range of the trajectory a water element describes during a tidal
cycle under the influence of the tidal current.
tidal flat an extensive near-horizontal, marshy or barren, sandy (sand flat) or
muddy (mud flat) area lying between the levels of mean high and mean low
tide. They are especially well-developed in areas sheltered against strong
wave action. High parts may be flooded only during spring tides or storm surges.
Different kinds of algal mats (-7algal mat ecosystem) may be present on tidal
flats; in the tropics high tidal flats are often covered with mangroves (-7salt
marsh). Sediments vary from coarse sand and gravel to fine muds. The tidal
channels contain the coarsest sediment, the innermost landward flats the
finest and muddiest. Often extensive ripple systems are formed on tidal
flats. Suspended sediment and muddy deposits are usually concentrated on
the inner flats due to a combination of tidal asymmetry, sediment consolidation during exposure, shallow depth around high tide slack water when
the water covers the flats, mud particle retention by organisms (benthic algae,
salt-marsh vegetation, mangroves), and shelter against waves. Tidal flats
tidal flat
Thoracica (barnacles, stalked or goose barnacles) order of the class Cirripedia (subphylum Crustacea, phylum Arthropoda) with an alimentary canal. These marine,
sessile animals are mostly completely (barnacles) or partly (stalked barnacles) covered by calcareous plates. The thorax has six pairs of biramous
limbs (cirri), which together form a sieve that is actively beating through the
water. They live permanently attached to hard substrates, which include e.g.,
the skin of sea turtles (-7Reptilia, marine) and cetaceans (-7mammals, marine),
and floating objects. Some are parasitic. Mostly hermaphroditic. They live in all
seas, from the shore to great depths, a few live in brackish water. Examples:
Lepas (goose barnacle), Balanus (barnacle).
thorax -7Crustacea.
thymidine assay technique to measure secondary production by bacteria. The
assay measures the incorporation of radioactively labeled thymidine into
DNA, but the conversion to an overall estimate of production rates rests on
assumptions that may not always be valid.
tidal components -7partial tide.
tidal current current caused by the tides. Depending on the character of the tidal
wave, the tidal current may be alternating as flood or ebb currents (flowing
in only two opposed directions) or rotary (turning more or less gradually in
a clockwise or anticlockwise direction with a current vector that describes
a circle or an ellipse). In coastal sea areas tidal currents are often much
stronger than the currents due to other causes. -7f1ood tide and -7ebb tide.
tidal excursion range of the trajectory a water element describes during a tidal
cycle under the influence of the tidal current.
tidal flat an extensive near-horizontal, marshy or barren, sandy (sand flat) or
muddy (mud flat) area lying between the levels of mean high and mean low
tide. They are especially well-developed in areas sheltered against strong
wave action. High parts may be flooded only during spring tides or storm surges.
Different kinds of algal mats (-7algal mat ecosystem) may be present on tidal
flats; in the tropics high tidal flats are often covered with mangroves (-7salt
marsh). Sediments vary from coarse sand and gravel to fine muds. The tidal
channels contain the coarsest sediment, the innermost landward flats the
finest and muddiest. Often extensive ripple systems are formed on tidal
flats. Suspended sediment and muddy deposits are usually concentrated on
the inner flats due to a combination of tidal asymmetry, sediment consolidation during exposure, shallow depth around high tide slack water when
the water covers the flats, mud particle retention by organisms (benthic algae,
salt-marsh vegetation, mangroves), and shelter against waves. Tidal flats