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On the processes of renewal of the North Atlantic deep water in the Irminger Sea
Oceanographic Abstracts
[ 05 I
HOLZK~M F., G. KRAUSE and G. SIEDLER, 1964. On the processes of renewal of the North Atlantic deep water in the Irminger Sea. Deep-Sea Res., I 1 (6): 881-890. Observations of temperature and electrical conductivity by a recording in situ salinometer are discussed in respect to the physical processes connected with the renewal of North Atlantic deep water. The measured fine structure of the layering suggests that the downward movement of cooled surface water is combined with horizontal mixing down to more than 1000 m depth. This is confirmed by the existence of water elements which have slightly different temperature and salinity. Curves of temperature, conductivity, and salinity and T-S diagrams are shown. HOOD PETER, 1964. Sea magnetometer reconnaissance of Hudson Bay. Geophysics, 2L) (6): 916-921. A total of 6,500 nautical miles of sea magnetometer data were obtained during the 1961 cruise of the M. V. THEATA in Hudson Bay. Near the edge of the Bay the resultant magnetic profiles are made up short-wavelength, high-amplitude anomalies whereas the anomalies in the center of the Bay are of longer wavelength and of lower amplitude. This is a reflection of the depth to the crystalline basement. This observation is confirmed by a quantitative interpretation of the magnetic profiles, which shows that, in general, the depths to basement are least around the margins of the Bay, with the greatest calculated depths, in excess of 10,000 feet, occurring in the area to the northeast of Churchill. The depth-determination values also reveal that an asymmetrical troughlike basement feature occurs in the area between Southampton, Nottingham, Mansel, Coats, and Digges Islands. HORRn)(;~ G. A,, 1965. Non-motile sensory cilia and neuromuscular junctions in a ctenopbore independent effector organ. Proc. R. Soc., Lond., ~B), 162 (988): 333-350. Non-motile cilia of the (9 2) pattern, having a specialized onion-like root structure, act as sensitive receptors of water displacement and thereby detect vibrations of small objects in the water nearby. These receptors are situated on sensory nerve cells on finger-like processes up to 1 cm long, on the surface of the ctenophore Leucothea (: Eucharis) multicornis. In response to vibration a single finger can shoot outwards as an independent effector by an extension of its mesogloeal hydrostatic skeleton, acted on by circular and transverse muscle fibres which run mainly through the mesogloea. A copepod which may be hit is immobilized, presumably by a poisonous secretion. Retraction is brought about by longitudinal ectodermal fibres. The neuromuscular junctions have presynaptic vesicles of 30 to 50 mm diameter, a cleft of 15 to 20 mm wide, and occur at discrete points far from each other on the muscle cells, suggesting that excitation is propagated along the muscle fibres. No direct connexion has been traced between a sensory ciliated cell and a muscle fibre, but sensory cells connect with nerve net neurons and these form synapses with each other and with muscle cells. There are numerous nerve fibres in the epithelium and synapses with vesicles on one side of a cleft 12 to 15 nm wide occur between them sufficiently closely for spatial summation to be possible. The separate co-ordination of movements of extension, retraction and bending requires that certain types of sensory cells be connected specifically, if in directly, with muscle fibres of a particular directionality. This provides a primitive example of specificity of connexions which must imply two overlapping nerve nets. HORRn)GE G. A., 1965. Macrocilia with numerous shafts from the lips of the ctenophore Beroe.
Proc. R. Soe., Lond., (B) 162 (988): 351-364. The macrocilia are 6 to 10 >m thick and 50 to 60/~na long. Each consists of 2000 to 3000 shafts, of the typical 9 + 2 pattern, which are arranged in a hexagonal array within a single membrane. The whole macrocilium beats like a single cilium, inward with reference to the mouth, and with antiplectic metachronal waves. Isolated macrocilia, when cut off, oscillate in one plane by a symmetrical bending movement at the middle. Cross-connexions lie between nearby fibrils of adjacent shafts in three different planes, and are apparently strong and permanent. The fibrils, each consisting of a pair of tubules, are numbered with these bridges as reference points. A system of tubules spreads between the basal bodies. Root structures are little developed. In bent cilia there is no buckling of shafts and the diameter of the shafts is the same on the concave as on the convex side. Therefore an active sliding mechanism between fibrils 2, 3, 4 (and between fibrils 6, 7, 8), rather than a contractile one, is postulated as the source of movement. This theory may apply to all cilia, and is an example of how this unique giant cilium may be utilized for the analysis of the function of the components of the 9 F 2 pattern during active movement. HUNKINS KENNETH L., 1965. Tide and storm surge observations in the Chukchi Sea. Limnol.
Oceanogr., 10 (1): 29-30. Sea level beights were recorded with a tide gauge at Fletcher's Ice Island (T-3) while it was aground in the Chukchi Sea at 71 ° 55'N lat, 160 ~20'W long. Harmonic analyses of the data were made for five tidal components. The tidal hour (Me) was 9.11 at this location, in good agreement with the cotidal chart of Sverdrup (1926). Mean spring tide range was 12.5 cm. Storm surges at this location on the continental shelf had a range of about 40 cm. During relatively stationary atmospheric conditions, the storm surge heights tended to follow the inverted barometer. However, under moving pressure systems, the storm surge heights developed an asymmetry that deviated from the inverted barometer. A one-dimensional flow model with characteristics similar to a profile through the storm provides some understanding of these asymmetric storm surge heights.
[ 05 I
HOLZK~M F., G. KRAUSE and G. SIEDLER, 1964. On the processes of renewal of the North Atlantic deep water in the Irminger Sea. Deep-Sea Res., I 1 (6): 881-890. Observations of temperature and electrical conductivity by a recording in situ salinometer are discussed in respect to the physical processes connected with the renewal of North Atlantic deep water. The measured fine structure of the layering suggests that the downward movement of cooled surface water is combined with horizontal mixing down to more than 1000 m depth. This is confirmed by the existence of water elements which have slightly different temperature and salinity. Curves of temperature, conductivity, and salinity and T-S diagrams are shown. HOOD PETER, 1964. Sea magnetometer reconnaissance of Hudson Bay. Geophysics, 2L) (6): 916-921. A total of 6,500 nautical miles of sea magnetometer data were obtained during the 1961 cruise of the M. V. THEATA in Hudson Bay. Near the edge of the Bay the resultant magnetic profiles are made up short-wavelength, high-amplitude anomalies whereas the anomalies in the center of the Bay are of longer wavelength and of lower amplitude. This is a reflection of the depth to the crystalline basement. This observation is confirmed by a quantitative interpretation of the magnetic profiles, which shows that, in general, the depths to basement are least around the margins of the Bay, with the greatest calculated depths, in excess of 10,000 feet, occurring in the area to the northeast of Churchill. The depth-determination values also reveal that an asymmetrical troughlike basement feature occurs in the area between Southampton, Nottingham, Mansel, Coats, and Digges Islands. HORRn)(;~ G. A,, 1965. Non-motile sensory cilia and neuromuscular junctions in a ctenopbore independent effector organ. Proc. R. Soc., Lond., ~B), 162 (988): 333-350. Non-motile cilia of the (9 2) pattern, having a specialized onion-like root structure, act as sensitive receptors of water displacement and thereby detect vibrations of small objects in the water nearby. These receptors are situated on sensory nerve cells on finger-like processes up to 1 cm long, on the surface of the ctenophore Leucothea (: Eucharis) multicornis. In response to vibration a single finger can shoot outwards as an independent effector by an extension of its mesogloeal hydrostatic skeleton, acted on by circular and transverse muscle fibres which run mainly through the mesogloea. A copepod which may be hit is immobilized, presumably by a poisonous secretion. Retraction is brought about by longitudinal ectodermal fibres. The neuromuscular junctions have presynaptic vesicles of 30 to 50 mm diameter, a cleft of 15 to 20 mm wide, and occur at discrete points far from each other on the muscle cells, suggesting that excitation is propagated along the muscle fibres. No direct connexion has been traced between a sensory ciliated cell and a muscle fibre, but sensory cells connect with nerve net neurons and these form synapses with each other and with muscle cells. There are numerous nerve fibres in the epithelium and synapses with vesicles on one side of a cleft 12 to 15 nm wide occur between them sufficiently closely for spatial summation to be possible. The separate co-ordination of movements of extension, retraction and bending requires that certain types of sensory cells be connected specifically, if in directly, with muscle fibres of a particular directionality. This provides a primitive example of specificity of connexions which must imply two overlapping nerve nets. HORRn)GE G. A., 1965. Macrocilia with numerous shafts from the lips of the ctenophore Beroe.
Proc. R. Soe., Lond., (B) 162 (988): 351-364. The macrocilia are 6 to 10 >m thick and 50 to 60/~na long. Each consists of 2000 to 3000 shafts, of the typical 9 + 2 pattern, which are arranged in a hexagonal array within a single membrane. The whole macrocilium beats like a single cilium, inward with reference to the mouth, and with antiplectic metachronal waves. Isolated macrocilia, when cut off, oscillate in one plane by a symmetrical bending movement at the middle. Cross-connexions lie between nearby fibrils of adjacent shafts in three different planes, and are apparently strong and permanent. The fibrils, each consisting of a pair of tubules, are numbered with these bridges as reference points. A system of tubules spreads between the basal bodies. Root structures are little developed. In bent cilia there is no buckling of shafts and the diameter of the shafts is the same on the concave as on the convex side. Therefore an active sliding mechanism between fibrils 2, 3, 4 (and between fibrils 6, 7, 8), rather than a contractile one, is postulated as the source of movement. This theory may apply to all cilia, and is an example of how this unique giant cilium may be utilized for the analysis of the function of the components of the 9 F 2 pattern during active movement. HUNKINS KENNETH L., 1965. Tide and storm surge observations in the Chukchi Sea. Limnol.
Oceanogr., 10 (1): 29-30. Sea level beights were recorded with a tide gauge at Fletcher's Ice Island (T-3) while it was aground in the Chukchi Sea at 71 ° 55'N lat, 160 ~20'W long. Harmonic analyses of the data were made for five tidal components. The tidal hour (Me) was 9.11 at this location, in good agreement with the cotidal chart of Sverdrup (1926). Mean spring tide range was 12.5 cm. Storm surges at this location on the continental shelf had a range of about 40 cm. During relatively stationary atmospheric conditions, the storm surge heights tended to follow the inverted barometer. However, under moving pressure systems, the storm surge heights developed an asymmetry that deviated from the inverted barometer. A one-dimensional flow model with characteristics similar to a profile through the storm provides some understanding of these asymmetric storm surge heights.