ALBERT

Description: Serial observations of temperature, salinity, oxygen, alkalinity and pH are presented. They were carried out during an anchor station of R. V. "Meteor" west of Cape Sao Vincente (Portugal) in the area of the maximum Mediterranean water outflow, which follows the continental slope off Portugal. Two observational results are pointed out: The Mediterranean water masses spread out into the Atlantic Ocean, consisting of two distinct layers at depths of 700 m (T = 12.0 °C, S = 36.15‰) and 1250 m (T = 11.3 °C, S = 36.40‰). The salinity proved to be the most significant indicatot of the observed stratification (see figs. 2, 3, 4 and 5). The values of dissolved oxygen content, alkalinity and pH in the very near bottom layer (1 m above the bottom at depths of 3250 m) are different from the values at depths of 15 m to 1000 m above the bottom (see figs. 11, 12 and table 1). As this phenomenon is not observed for the salinity, the changes may be interpreted in terms of chemical and biological processes at the sediment - water interface.

Description: The following tables show physical and chemical data observed by the "Meteor" in the Persian Gulf and the Strait of Hormus. This study was performed in accordance with the general programme of the International Indian Ocean Expedition (IIOE) during the period from March 25 th until April 16th, 1965. The water temperature was measured by reversing thermometers; in most cases two instruments were used simultaneously. The absolute mean temperature difference of this double measurement is 0.0153 °C. The salinity was determined both by salinometer and by titration. In this case the absolute mean difference amounts to 0.0174‰. The computations of the density, the specific volume anomaly, the dynamic depth anomaly, the sound velocity and the interpolation for standard depths were carried out by the National Oceanographic Data Center (NODC), Washington.

Description: Changes in the dissolved oxygen content, the alkalinity, and the pH in sea water near the ocean floor are interpreted in terms of chemical and biochemical processes at the sediment water interface. A simple model provides a plausible explanation of the observed phenomena. Special emphasis is given to the importance of borate corrections in the calculation of the solution effects of calcium carbonate.

Description: During the "Atlantic Expedition" in 1965 (IQSY) a comprehensive bathymetric survey and a few hydrographic stations were made by R.V. "Meteor" in the equatorial region of the Mid-Atlantic Ridge. The survey results are shown in a bathymetric chart covering the western parts of the Romanche- and Chain Fracture Zones. West fo the original Romanche Trench another deep trench with a medium depth of 6000 m was discovered. The maximum sounding obtained was 7028 m. Both trenches apparently belong to the same fracture zone, but are distinctly separated from each other. The western boundary of the trench against the Brasil Basin is formed by a sill rising to a depth of about 4400 m. The serial hydrographic observations give some indications of the flow of the cold Westatlantic deep watet in the fracture zone area and its influence on the hydrographic conditions in the East-Atlantic Basin. The upper limit of the nearly homogenious Westatlantic bottom water with an Antarctic component lies in about 4400 m. The water mass entering the system of trenches of the Romanehe Fracture Zone over the western sill originates from the lower part of the discontinuity layer lying above the bottom watet. Potential temperatures of 0.6 °C were the lowest observed by "Meteor" in the western trench. There seems to be a remarkable tongue of relatively high salinity and a minimum of oxygen in the deep watet of this trench. At present we can only speculate upon the origin of this highly saline deep water tongue underneath the eastward moving relatively thin layer of less saline Westatlantic deep watet. In the range of the sill separating both trenches a lee-wave is indicated by the distribution of salinity and oxygen, which implies a vertical transport of water masses. Caused by this transport it is assumed that relatively cold watet may be lifted temporarily to a depth, where it can pass the northbounding ridge, thus getting directly into the Sierra Leone Basin. In the original Romanche Trench the cold Westatlantic deep water seems to fill the whole trough, but its extension remains limited to the trench itself. The water masses found east of the sill separating the trench from the East-Atlantic Basin originate from the lower part of the discontinuity layer. With potential temperatures of about 1.3 °C they are much warmer than those observed in the Romanche Trench bottom water.

Description: The results of records of the sea surface temperature and the water temperature near the surface during ATEX-Expedition are reported. Three records of 5, 2 and 4 days show, that surface temperature at nighttime is 0.5°C, at the hours before noon is 0.35°C below the temperature in some decimeters. Probably the variation is caused by the absorption of sun radiation in a thin layer with mainly molecular heat transfer. In agreement with such assumption the records show that at the surface the maximum temperature appears before the maximum in the water and that the variation at the surface is 0.1° -0.15°C greater than that for the water near the surface.

Description: The construction characteristics and the technical data of a Lidar-System are described. This system was placed in operation on board the W.F.S. "Planet" during the Atlantic Trade Wind Experiment (ATEX). The laser transmitter is a ruby giant-pulse laser with a chemical Q-switch which transmits short light pulses of high power vertically into the atmosphere. The light which is scattered in the atmosphere, is collected by the receiver by a telescopic mirror. The receiver is placed adjacent to the transmitter. The special characteristics in the construction of the Lidar-system for shipboard operation and the difficulties with the operation of the equipment on board the ship, especially in tropical regions, are described.

Description: During the atlantic expedition of the research vessel "Meteor" 1969 the variation of the electric field strength with altitude up to 170 m was measured by means of a captive balloon and a special radiosonde. The measurements were carried out on a rubber boat far away from the influence of the ship. The electrode effect has been found at all 5 profiles. The altitude of its upper boundary varied from measurement to measurement. The mean value was about 50 m. Considering the electrode effect and the measured small ion density the vertical current density above the ocean is only 0.9 x 10-12 A/m2. The total vertical current to the earth surface results in 665 A instead of the value 1530 A accepted up today.

Description: The muon component of the cosmic rays has been measured by the German research vessel "Meteor" during the Atlantic Expedition IQSY 1965. The momentum distribution and charge ratio of the penetrating component of the cosmic radiation at sea level have been determined over the range (0,2-30) GeV/c at the geomagnetic equator. A magnetic spectrograph has been used for these measurements based on spark chamber technique for track location. There exists a significant difference in the low energy part between the muon equator spectrum in comparison with the spectrum at high geomagnetic latitudes (Kiel) and no difference concerning the charge ratio. The total integral measured latitude effect amounts to 15%.

Description: One main point of the air electric investigations at the Atlantic 1965 and 1969 was the record of the potential gradient in the troposphere with free and captive balloon ascents. The course of the field vs. altitude above the sea differs from that over land. A remarkable enlargement of the field strength occurs at the altitude of the passat inversion. The electric voltage between ionosphere and earth could be obtained by integrating the potential gradient over the altitude. Such computations have been made by balloon ascents simultaneous over the ocean and at Weißenau (South Germany). From 15 simultaneous measurements the average value of the potential of the ionosphere over the ocean is 214 kV and over South Germany 216 kV, that means very close together. Because of the small differences also between the single values it can be concluded that in generally the ionosphere potential has an equal value over these both places at one moment. From the potential of the ionosphere VI, the field strength E0 and the conductivity λ0, both measured at the sea surface, the columnar resistance R could be derived to 2.4x1017 Ωxm2. By correlation of the single values of the ionosphere potential with the potential gradient measured simultaneously at the surface of the sea a linear proportional relationship exists; it follows from this result, that R is nearly constant. The mean value of the air-earth current density over the ocean could be calculated by using the measured values of the small ion density with respect to the electrode effect prooved at the equator station (see Part III). The current density was only 0.9 x 10-12 A/m2, which means, a three and a half times smaller value than estimated by Carnegie and accepted up to now. Therefore it seems to be necessary to correct the former calculations of the global current balance.

Description: During the Atlantic Trade Wind Experiment measurements of the vertical aerosol distribution up to altitude of 3.5 km and also measurements of the cloud base up to 14 km were carried out. These measurements utilized the Lidar-system which is described in the first part of this paper. The haze measurements are discussed in connection with aerological measurements. A positive relation between backscatter function and relative humidity was found. In addition there exists a correlation with the wind velocity. The measurements of the standard visibility for a special weather condition are also considered in the discussion. The determination of the altitude of the cloud together with the measurements of its radiation temperature at the cloud base is given.

Description: From reflection and refraction seismic measurements in the area of the Great Meteor-Seamount a crustal section of a part of the Great Meteor-Seamount and the adjoining deep sea area is presented. Two remarkable results can be compared with the crustal structure on the continental margin. Firstly there has been found a very distinct horizon with a p-wave velocity of 5.9-6.0 km/s, which is generally observed for the basement under the continents. This horizon has not been found in the deep sea. Secondly the Mohorovicic discontinuity (p-wave velocity 8.1 km/s) shows a distinct down dip from the deep sea to the centre of the seamount. In its central area the "Moho" has not been observed. From the topography of the "Moho" and the upper horizons the core of the Great Meteor-Seamount is assumed to be a mixture of crustal and mantle material. From the centre of the seamount to the deep sea it changes into material of the "oceanic layer". A comparison of the seismic results with magnetic measurements also points to a continental structure of the Great Meteor-Seamount.

Description: During the first section of the "Meteor" cruise No. 2 a profile was run from the Azores to the south across the flanks of the Mid-Atlantic Ridge with a chain of seamounts (Fig. 1). The profile extended between the Cruiser (Irving) and the Hyeres seamounts, which, according to our soundings, form a connected massif, and across the centre of the Grosse Meteor Bank (30°N, 28.5°W). These seamounts rise from a depth of more than 4000 m up till close to the surface of the sea forming there a large almost flat plateau (Fig. 2). In the case of the Grosse Meteor Bank, this plateau has a N-S extension of approx. 30 nautical miles and an E-W extension of approx. 20 nautical miles and reaches a height of 275 m in water depth (Fig. 3). The gravity measurements yielded a density of the topographic masses of 2.6 g/cm3 for the Grosse Meteor Bank. Magnitude and shape of the measured free-air anomaly are very well shown in a model computation with this density. The theoretical gravity effects of the seismically detected swell of cristalline rock and of the Moho depression (mountain root) are not indicated by the observational data (Fig. 4). lt can, therefore, be assumed that the latter two neutralize each other. lt seems, accordingly, that there is no local isostatic compensation of the topographic masses. Hence, the density of 2.6 g/cm3 obtained would be about the true density of rock. In connection with the mean velocity of P waves (K. ARIC et al. 1968) obtained by seismic refraction methods it must be concluded that the material of the 1200-4000 m thick surface layer of the Grosse Meteor Bank consists of consolidated sediments. This finding is supported by the total intensity of the Earth's magnetic field over the Grosse Meteor Bank. On the assumption of a homogeneous magnetization in the direction of the present Earth's field, the computed anomaly of the massif deviates considerably from the measured anomaly while the magnetic field of the seismically detected cristalline body is capable of interpreting the observed data. Deviating from the prevailing interpretation of the seamounts' plateau as a volcanic cone with submarine abrasion, the Grossc Meteor Bank and the seamounts in the vicinity are assumed to be of continental origin. The questions whether these seamounts submerged later on or whether the sealevel has risen subsequently are, therefore, largely nonexistent.

Description: Instead of the isotopes Jo, Th, and Pa the radioactive daughter products Rn, Tn, and An were measured. It was possible to date four cores and to calculate the sedimentation rates. A rough estimation of the sedimentation in the northern part of the Indian Ocean can be given. In the middle part, the sedimentation rate is s = 0.32 cm/103 years, and near Africa and near India this rate increases to values of about 2 cm/103 years.

Description: During the "Meteor" Cruise 8/1967 three geographers, H. G. GIERLOFF-EMDEN, H. SCHROEDER-LANZ, and F. WIENEKE, investigated the sea floor morphology and the submarine as well as subaerial terraces appearing along and off the Portuguese and Moroccan coast. Bottom profiles on the shelf were run by the "Meteor"; connecting profiles into shallower water were run by a cutter. Conventional mapping was carried out on the coast. Use of existing sediment echograph information (cf. W. GIESEL & E. SEIBOLD, 1968) made possible a reliable interpretation of the connecting profiles run by the cutter in the coastal area. Off the Portuguese coast near Cape Sines, many submarine planar features were found. Of these, the terraces in water depths between 140 and 150 m are of particular interest as they offer further evidence of Pleistocene eustatic sealevel changes reaching this depth. Terraces and smaller morphologic features developed on the coast itself are most likely the result of the tectonism which is known to exist in the Cape Sines region.

Description: The horizontal component of magnetization can be measured on sedimentary cores enclosed in plastic pipes. Two types of cores from the Indian Ocean could be found. One of them are the cores from the deep sea, and the samples from the continental slope could be grouped to the second type. They seem to permit a correlation in the form of a "magnetostratigraphy". Additionally, disturbances in the systematic sedimentary fabric could be recognized (possibly due to turbidity currents).

Description: Investigations of 12 deep-sea cores were carried out by nondestructive measurements of the material taken in plastic tubes. The stability of the magnetization was proved with 3 core parts by means of demagnetization. In two cores geomagnetic reversals were ascertained facilitating the determination of the rate of sedimentation. One reversal was investigated in detail. It was possible to observe a rotation of the horizontal magnetic-field component at steps of 1,300 years. In further 6 cores it was found that a correlation with the remanence was well possible. Based on these results obtained the sediments in the surroundings of the Meteor Seamount may be ascribed to three typical regions. The most considerable disturbances in sedimentation exist in the area south-west of the seamount. In the interpretation it is assumed that the non-carbonatic fractions of the sediments come from this region and are transported into the sediment by marine currents.

Description: Investigations were carried out of 12 deep-sea cores having been taken in the Ionian Sea during the 17th expedition of the German research vessel "Meteor". As regards the course of magnetization in depth it was found that a similarity exists only between a few cores. There is even no more than a slight similarity between those cores having successively been taken at the same station. From this result the conclusion may be drawn that within the survey area the conditions of sedimentation even vary on a rather small scale. Yet, the ratio of remanent-induced magnetization points to a quiet and uniform course of sedimentation. In two shorter cores it was succeeded in determining geomagnetic reversals, which means that in the lower part the age of these cores exceeds 7·105 years (date of the last reversal). As to core St 14 G an extremely low rate of sedimentation of 0.54 mm/103 a and an age of 2.3·106 years has been derived. This result was obtained by evaluating 6 magnetic time marks and is thus proved to a sufficient degree.

Description: During the first Meteor-Expedition two species of fish, hitherto unrecorded in the Red Sea, were colected near the Island Sarso (Farsan Archipelago): Forcipiger longirostris (BROUSSONET) and Chaetodon lettcoplettra GÜNTHER & PLAYFAIR. As both are identical with specimens from the Indian Ocean and as their distribution within the Red Sea is limited to the far South, it is concluded that these two species are postglacial immigrants. Besides this small group of immigrants, the majority of the endemic Red Sea species appear to be preglacial immigrants from the Indian Ocean. A few other species seem to be of Mediterranean Tethys origin from the middle or early tertiary.

Description: Seven species of Pycnogonida are recorded from depths between 72 and 316 m in the Atlantic Ocean off the coast of northwestern Africa. Among these are two new species, Ascorbynchus pudicum and Rhopalorbynchus atlanticum. The latter is remarkable in that it is the first representative of Rhopalorbynchus that becomes known from the Atlantic Ocean, all previous records for this genus being from the Indo-West Pacific.

Description: Seriocarpa rhizoides DIEHL 1969 was collected in abundance from the calcareous sand of the Josephine Bank (between Portugal and Madeira) during the "Meteor" seamount cruises in 1967. Attachment in this loose soft substratum is effected by fine anchoring strands of the test. Two irregular series of small polycarp-like hermaphrodite bodies which are embedded in a connective tissue lie directly below the endostyle, forming a tubular compound gonad, but without common ducts. The intermediate nature of the reproductive system with respect to arrangement and structure increases our knowledge about the phylogenetic relations of the styelid-genera. Some of the hitherto known ecological facts point to the presumed "seamounts effect" on this species.

Description: During the International Indian Ocean Expedition (IIOE ) with R.V. "Meteor" 1964-65 algal collections from six stations in the northern part of the Arabian Sea and the Persian Gulf were made. In the text we have described sixty eight species. The account contains 11 Chlorophyceae, 16 Phaeophyceae, 7 Cyanophyceae and 34 Rhodophyceae.

Description: During the Atlantic Seamount Cruises 9 a and 9 c of R.V. "Meteor" in 1967, planktological studies were carried out in cooperation with several German and foreign scientists. Investigations concerning the seamounts were carried out in the area of the Great Meteor and the Josephine Bank in the eastern North Atlantic focussed on the question as to how benthos organisms maintain their populations and whether an additional transport of meropelagic larvae from the neighbouring continental shelfs support these populations. Moreover, the influence of the seamounts on the distribution of plankton in the surface layer was studied. In particular, the following studies were carried out: Distribution of zooplankton in the surface water of the seamounts and near their bottom, distribution of neuston and fish larvae in the area of investigation, vertical migration of makroplankton in the upper 900 m during several anchor stations in the vicinity of the seamounts, vertical distribution of phytoplankton in the upper 100 m of the Meteor Bank, distribution of copepods in the Mediterranean deep water of the Atlantic (where this body of water was traced with the Bathysonde) and the quantitative distribution of zooplankton in deep scattering layers. - The sampling gear and its closing devices are described. The results of the investigations will be published in "Meteor" Forschungsergebnisse, Series D.

Description: The main aim of the "Atlantische Kuppenfahrt" of RV "Meteor" during the first half of 1967 was to carry out biological investigations on the large submarine seamounts off the Portuguese and West-African coast, the Josephine-Bank and the Great Meteor-Seamount. The three main subjects of interest were: a) the fauna of these isolated seamounts, b) the influence of the seamounts on the dayperiodical migration of the deep scattering layers (DSL), c) the relations between neuston and plankton of the euphotic zone. The present numbers 7 and 8 of the "Meteor Forschungsergebnisse" contain two reports of working groups "Benthos" and "Plankton" as well as four special contributions to the subjects mentioned before.

Description: This report deals in its first part with problems concerning the settlement of animals and the establishment of populations on seamounts. Ideas on habitat and productivity as well as systematic and zoogeographic questions are discussed. Besides the plans for the expeditions, the second part contains a cruise report with the participants in the benthos programme; the station list and a description of the gear and the methods employed are also given. The results will be worked out by several specialists. After the samples have been sorted and quantitative determinations of animals groups are carried out, these will be sent to four German museums, which will take charge of the material and try to find specialists for the systematics. Publication of the results is planned in "Meteor" Forschungsergebnisse, Series D (Biology).

Description: In four microlayers of the uppermost 60 cm of the subtropical NE Atlantic 477 samples of ichthyoneuston were collected. In at least 3 samples. 34 groups ( different taxa) of fish were discovered in the 0-10 cm layer. Among these groups there were 8 species of Beloniformes and 9 species of Myctophidae. Most of the fish were juveniles of 6-80 mm total length. The regional distribution, the vertical macrodistribution in 6 layers of the upper 200 m, 3 patterns of vertical microdistribution 6 patterns of diurnal migration, and 4 patterns of feeding activity are described. Most of the fish found in the 0-10 cm layer by day were small in size and appeared only in a few specimens per haul. The catches in the 0-10 cm microlayer were richer than those of the 10-25 cm microlayer, but poorer than those of the 0-30 m macrolayer. According to their gut contents the fish living at the surface could be divided into 3 main groups. In respect of the size and quality of food items, a competition for food was calculated. There is some evidence for a scarcity of food at the surface of the open subtropical Atlantic especially by day.

Description: 15 samples obtained with Beyer's epibenthic closing net were studied quantitatively. The numbers of epi- and endobenthic animals were found to be correlated with the volume of sediment in the samples. Among the planktonic components, calanoid copepods were strongly predominant. In the samples obtained on the Great Meteor Seamount, but not in those from the Josephine Seamount, very much larger numbers of these animals were caught in the daytime than at night. Possible explanations for this difference are suggested.