Geochemistry and isotopic ratios of basalts obtained during R/V Akademik Nikolaj Strakhov cruise ANS25

Based on the investigation of samples recovered during Cruise 25 of the R/V ''Akademik Nikolai Strakhov'', the character of magmatism was determined in the flank parts of the rift zone at the 74°05'N and 73°50'N region, where the direction of the rift valley changes from the north-northwest in the Knipovich Ridge to the northeast-trending structures of the Mohns Ridge. It was shown that the tholeiitic magmas of this region shows all the geochemical characteristics of TOR-2, which is typical of the Mohns Ridge and most oceanic rift zones worldwide, and differ from the basalts of the Knipovich Ridge, which are assigned to a shallower type of tholeiitic magmatism (Na-TOR). The persistent depletion of the magmas in terms of lithophile element contents and radiogenic isotope ratios of Sr, Nd, and Pb reflects the conditions of their formation during the ascent of the depleted oceanic mantle, which has occurred without significant complications since the early stages of the formation of the Mohns Ridge.

Geochemical parameters of bottom sediments from the Stromboli Canyon

In recent sediments of the Stromboli Canyon sides features of mineral and grain size compositions, redox conditions, behavior of Fe, Mn, organic carbon, Mo, and W in an environment of active input of pyroclastic material are considered. Differences in conditions of sedimentation and early diagenesis in the east and west sides of the canyon depending on position of the prevailing direction of drift and steepness of the slopes, as well as types of differentiation of detrital material in sediments under conditions of permanent vibrations are specified.

Psychosocial construction of time and social change

This paper analyzes the psychosocial construction of the conceptions of time and social change, and their relation with the notion of progress set up by modernity as well as their contradictory aspects, considering their historicity as psychosocial and social phenomena. The social construction of the notion of time is discussed; it responds to social organization forms, thus turning the social changes into historical and temporal landmarks. The association between social changes and social movements is argued and the concept of progress is deconstructed. Finally, the importance of the idea of movement in the construction of time, change and progress concepts is pointed out; it is also explained how modernity imbued such notions with direction and goals, in the direction of an arrow, according to the prevailing interests, while modeling them in its own image and likeness.

Observations on the propagation of internal tidal waves on the continental slope off Sierra Leone

During R/V Meteor-cruise no. 30 4 moorings with 17 current meters were placed on the continental slope of Sierra Leone at depths between 81 and 1058 meters. The observation period started on March 8, 1973, 16.55 hours GMT and lasted 19 days for moorings M30_068MOOR, M30_069MOOR, M30_070MOOR on the slope and 9 days for M30_067MOOR on the shelf. One current meter recorded at location M30_067MOOR for 22 days. Hydrographic data were collected at 32 stations by means of the "Kieler Multi-Meeressonde". Harmonic analysis is applied to the first 15 days of the time series to determine the M2 and S2 tides. By vertically averaging of the Fourier coefficients the field of motion is separated into its barotropic and its baroclinic component. The expected error generated by white Gaussian noise is estimated. To estimate the influence of the particular vertical distribution of the current meters, the barotropic M2 tide is calculated by ommitting and interchanging time series of different moorings. It is shown that only the data of moorings M30_069MOOR, M30_070MOOR and M30_067MOOR can be used. The results for the barotropic M2 tide agree well with the previous publications of other authors. On the slope at a depth of 1000 m there is a free barotropic wave under the influence of the Coriolis-force propagating along the slope with an amplitude of 3.4 cm S**-1. On the shelf, the maximum current is substantially greater (5.8 cm s**-1) and the direction of propagation is perpendicular to the slope. As for the continental slope a separation into different baroclinic modes using vertical eigenmodes is not reasonable, an interpretation of the total baroclinic wave field is tried by means of the method of characteristis. Assuming the continental slope to generate several linear waves, which superpose, baroclinic tidal ellipses are calculated. The scattering of the direction of the major axes M30_069MOOR is in contrast to M30_070MOOR, where they are bundled within an angle of 60°. This is presumably caused by the different character of the bottom topography in the vicinity of the two moorings. A detailed discussion of M30_069MOOR is renounced since the accuracy of the bathymetric chart is not sufficient to prove any relation between waves and topography. The bundeling of the major axes at M30_070MOOR can be explained by the longslope changes of the slope, which cause an energy transfer from the longslope barotropic component to the downslope baroclinic component. The maximum amplitude is found at a depth of 245 m where it is expected from the characteristics originating at the shelf edge. Because of the dominating barotropic tide high coherence is found between most of the current meters. To show the influence of the baroclinic tidal waves, the effect of the mean current is considered. There are two periods nearly opposite longshore mean current. For 128 hours during each of these periods, starting on March 11, 05.00, and March 21, 08.30, the coherences and energy spectra are calculated. The changes in the slope of the characteristics are found in agreement with the changes of energy and coherence. Because of the short periods of nearly constant mean current, some of the calculated differences of energy and coherence are not statistically significant. For the M2 tide a calculation of the ratios of vertically integrated total baroclinic energy and vertically integrated barotropic kinetic energy is carried out. Taking into account both components (along and perpendicular to the slope) the obtained values are 0.75 and 0.98 at the slope and 0.38 at the shelf. If each component is considered separately, the ratios are 0.39 and 1.16 parallel to the slope and 5.1 and 15.85 for the component perpendicular to it. Taking the energy transfer from the longslope component to the doenslope component into account, a simple model yields an energy-ratio of 2.6. Considering the limited application of the theory to the real conditions, the obtained are in agreement with the values calculated by Sandstroem.

Area-averaged mean seasonal cycles of chlorophyll-a concentration, sea surface temperature, alongshore wind stress, westward wind speed and dust component of the aerosol optical depth at 550 nm

Nutrient supply in the area off Northwest Africa is mainly regulated by two processes, coastal upwelling and deposition of Saharan dust. In the present study, both processes were analyzed and evaluated by different methods, including cross-correlation, multiple correlation, and event statistics, using remotely sensed proxies of the period from 2000 to 2008 to investigate their influence on the marine environment. The remotely sensed chlorophyll-a concentration was used as a proxy for the phytoplankton biomass stimulated by nutrient supply into the euphotic zone from deeper water layers and from the atmosphere. Satellite-derived alongshore wind stress and sea-surface temperature were applied as proxies for the strength and reflection of coastal upwelling processes. The westward wind and the dust component of the aerosol optical depth describe the transport direction of atmospheric dust and the atmospheric dust column load. Alongshore wind stress and induced upwelling processes were most significantly responsible for the surface chlorophyll-a variability, accounting for about 24% of the total variance, mainly in the winter and spring due to the strong north-easterly trade winds. The remotely sensed proxies allowed determination of time lags between biological response and its forcing processes. A delay of up to 16 days in the surface chlorophyll-a concentration due to the alongshore wind stress was determined in the northern winter and spring. Although input of atmospheric iron by dust storms can stimulate new phytoplankton production in the study area, only 5% of the surface chlorophyll-a variability could be ascribed to the dust component in the aerosol optical depth. All strong desert storms were identified by an event statistics in the time period from 2000 to 2008. The 57 strong storms were studied in relation to their biological response. Six events were clearly detected in which an increase of chlorophyll-a was caused by Saharan dust input and not by coastal upwelling processes. Time lags of <8 days, 8 days, and 16 days were determined. An increase in surface chlorophyll-a concentration of up to 2.4 mg m**3 after dust storms in which the dust component of the aerosol optical depth was up to 0.9 was observed.

Vertical variations in basic salt composition of interstitial waters from Pacific sediments

Basic chemical composition of interstitial water in sediments of the Northwestern Pacific along a profile from the continental shelf of the Japan Trench to the ocean bed is discussed. Transformation of interstitial water in sediments rich in organic matter on the continental shelf and at the bottom of the Japan Trench is indicated. Variation in the vertical direction of elementary constituents of interstitial salt solution and variations in certain biogenic elements permit to make conclusions concerning processes taking place in sediments during sedimentation and diagenesis. These processes cause both metamorphism of water and transformation of organic and mineral content of sediments.

(Table 1) Permanent currents in the Campeche Bank area based on data of 24-hour stations

Data of twenty buoy stations were used to compile a new chart of permanent currents in the surface layer (10 m depth) for the region of the Yucatan shelf (Campeche Bank). It was found that vertical variations in direction of the currents are insignificant within the shallow plateau of the banks.

Tab. 2: Average geochemical composition of dolerites from Neuschwabenland

In western Neuschwabenland basic dikes occur in the Jurassic lavas and Permian sediments of Vestfjella as weil as in the Precambrian sedimentary-volcanogenic rock sequence of the Ahlmannryggen and in the Precambrian crystalline complexes of Heimefrontfjella and Mannefallknausane. The concentration of the dikes in Vestfjella is conspicuous. Two main directions of strike perpendicular to each other are recognizable, from which the NE-SW striking one is predominant. The direction of the dikes coincides with the Mesozoic and younger fracture tectonics. Age relationships by structural, petrographical and geochemical observations are confirmed by palaeomagnetic and radiometrie age determinations from PETERS et al. (1986). Considerations on the geochemistry of further dolerite occurrences from Antarctica and other regions of the Gondwana continent are pointed out. Finally comparisons with the analogous South African dike system show the geotectonic significance of the dolerite dikes for the break-up of Gondwana.

(Table 1) Date, deployment location, tag longevity, and satellite data of humpback whales (Megaptera novaeangliae) off New Caledonia

Knowledge of the local and migratory movements of humpback whales (Megaptera novaeangliae) from New Caledonia is very limited. To investigate this topic, we attached satellite-monitored tags to 12 whales off southern New Caledonia. Tag longevity ranged from 1 to 52 days (X = 22.5 days). Tagged whales generally moved to the south or southeast, with several spending time in a previously unknown seamount habitat named Antigonia before resuming movement, generally toward Norfolk Island or New Zealand. However, 1 female with a calf traveled the entire length of the western coast of New Caledonia (~450 km) and then west in the direction of the Chesterfield Reefs, a 19th century American (''Yankee'') whaling ground. None of the New Caledonia whales traveled to or toward eastern Australia, which is broadly consistent with the low rate of interchange observed from photo-identification comparisons between these 2 areas. The connections between New Caledonia and New Zealand, together with the relatively low numbers of whales seen in these places generally, support the idea that whales from these 2 areas constitute a single population that remains small and unrecovered.

Oceanographical and meterological observations in the Westafrican area of upwelling during the 'Deutsche Nordatlantische Expedition' 1937

In 1937 the "Meteor" performed the cruises of the first part of the "Deutsche Nordatlantische Expedition". This publication treats seven stations of three-day-anchoring occupied during that time, five of which are located on the shelf, one on the continental slope and one on a ridge between the Capverde islands. The Bohnecke current meter, an instrument developed for the expedition, is described briefly and it's accuracy studied by comparing the measurements of two instruments which operated simultaneously at the same depth. It is shown that it is very sensitive for movements of the anchored ship because of the very short measuring intervall (2 minutes). The influence of the ship's movements could not be eliminated completely, the mode of using the instrument at different depths being unsuitable for this. Considering the stratification the accuracy of it's representation by the mean temperature and salinity distributionis studied. It is shown that under certain conditions a distribution estimated from observed values gives more exact results. This especially applies to the TS-diagram. Station Meteor336, located on the shelf near Cape Juby, shows temperatures 4 °C less than the open ocean and so belongs to the area of upwelling. During the observation period, however, internal tides are prominent. The diurnal component is of considerable influence, the distinction from inertial oscillations (25.5 hours) not being possible, however. Station Meteor341, on the shelf off Spanish-Sahara, gives an excellent example of the movements in the centre of the area of upwelling. Changing it's direction by 45° at the beginning of the measurements, the wind causes a change of current direction at all depths which, after some inertial oscillations (period 28.3 hours), settles down to a final value. At the beginning and the end of the observations the current at the upper depths is directed off-shore, the angle between current and wind being 22°, while at the lower depths it is orientated towards the shore. The depth of the upper homogenous layer gives the origin of the water transported upwards When during the inertial oscillations the current goes offshore at all depths temporarily, a sudden disturbance occurs in the temperature measurements. Station Meteor311 is located similar to station Meteor341 but was occupied one month earlier. At that time the wind situation was unnormal, the usual wind direction of 45° occuring at the end of the station. Therefore an unnormally high vertical shear of current speed and direction has been observed, the current vector being directed off-shore at the surface and near the bottom, towards the coast inbetween. The TS-diagram shows that the bottom water is replaced first so that upwelling does not occur during observation time. The state reached at the end of the station does not seem to be stable. Station Meteor369, on the continental slope, is governed by internal waves. Besides the internal tide of 12.4 hours a wave of 6.5 hour period is observed, being possibly amplified by the large bottom slope. In 40 - 60 m depth, where the thermocline is located, a wave with 3.3 hour period is observed which is argued to be an internal boundary wave. Station Meteor334 is located on the shelf NW of the mouth of the Senegal river. A marked temperature stratification, associated with large disturbances, and nearly constant salinity have been found there. The current was going slowly towards S or SW in the upper 20 - 30 m, towards N underneath. At the boundary of the current systems intense turbulence developed,including as it seems a water type of less salinity which is transported from the Senegal river by the lower current. Station Meteor327, located at 100 m depth between two of the Capverde islands, shows oceanic characteristics. The semidiurnal tide is found mainly, the diurnal component having considerable influence. Furtheron an internal wave of 6 hour period is seen the maximum amplitude of which is moving slowly downwards. Two possibilities of explaining it are discussed. Station Meteor366 is found in the area of ceasing winds off the coast of upper Guinea. The temperature there depends strongly on the depth, the salinity being nearly constant. The currents are divided into an upper and a lower system with large variations in both of them. A change of wind direction of nearly 90° is supposed to be the reason. The variations in salinity accordingly are interpreted as the influence of fresh water outflow from land which is felt in a different way at different wind directions. In the last section the daily changes in air and water temperature are studied. The upwelling having large influence on these, a centre of the area of upwelling can be located at about 100 miles north of Cape Blanc (Station Meteor311). The semidiurnal tidal component is compared with previous results for the Atlantic Ocean yielding considerable differences for the direction and time of occurence of the current maximum which might be due to the topographical influences around the shelf.

Averages and ranges of paleoenvironmental proxy records of ODP Hole 108-658C (Table 1)

Several high-resolution proxy environmental records have been obtained for the last 35 kyr from ODP Hole 658C, a well-studied site ca. 200 km off Cap Blanc, NW Africa. The collective assessment based on the marine proxies (UK'37 SST, contents of TOC and chlorins, Upwelling Radiolarian Index and the percentage of Florisphaera profunda), surprisingly indicates that the last glacial maximum (LGM) was characterized by warmer sea surface temperature (SST), weaker upwelling, and lower marine productivity, compared with the preceding older glacial and subsequent deglaciation periods. Of the terrigenous proxies, the mean grain size of the non-carbonate fraction and the terrigenous alkane content indicate that wind strength and aridity were high. The weaker upwelling at the 658 site during the LGM may have resulted from changes in the strength and direction of the wind systems and/or shifts in the position and geometry of the upwelling cell.

Standard meteorological measurements on board of POLARSTERN during expedition ANT-IV (PS08, 4 cruises, south summer 1985/86) in the Atlantic and Weddell Sea, Antarctica

During the fourth Antarctic voyage ANT-IV of the research icebreaker POLARSTERN standard meteorological measurements have been performed. The measurements include 3-hourly synoptic observations as well as daily upper air soundings. The measurements started on September 6 1985 at Bremerhaven and were terminated at April 28 1986 in Punta Arenas. The 3-hourly synoptic observations are performed following the instructions of the FM 13 ships code defined by the World Meteorological Organization (WMO). The datasets include automatic measurements such as mean ship's speed, wind velocity, wind direction, air temperature, water temperature as well as visual observations such as total cloud amount, present weather, clouds, height and period of swell waves, ice classification. The visual observation are not performed during night time. For the upper air soundings VAISALA RS80 radiosondes, carried by helium-filled balloons (TOTEX 350 - 1500) were used. Data reception and evaluation were carried out by a MicroCora System (VAISALA). The upper air soundings include profile measurements of pressure, temperature, relative humidity and wind vector. Usually the soundings started at the heliport (10 m above sea level) and terminated between 15 and 37 km. The height of the measurements was calculated by applying the barometric formula. The wind vector was determined with the aid of the OMEGA navigation system.

In-situ sediment temperature and pore water chloride concentration at pockmarks of the Nigerian continental margin

A joint research expedition between the French IFREMER and the German MARUM was conducted in 2011 using the R/V 'Pourquoi pas?' to study gas hydrate distributions in a pockmark field (1141-1199 m below sea surface) at the continental margin of Nigeria. The seafloor drill rig MeBo of MARUM was used to recover sediments as deep as 56.74 m below seafloor. The presence of gas hydrates in specific core sections was deduced from temperature anomalies recorded during continuous records of infrared thermal scanning and anomalies in pore water chloride concentrations. In situ sediment temperature measurements showed elevated geothermal gradients of up to 258 °C/km in the center of the so-called pockmark A which is up to 4.6 times higher than that in the background sediment (72 °C/km). The gas hydrate distribution and thermal regime in the pockmark are largely controlled by the intensity, periodicity and direction of fluid flow. The joint interaction between fluid flow, gas hydrate formation and dissolution, and the thermal regime governs pockmark formation and evolution on the Nigerian continental margin.

Processing results from drill hole VNIIO-1988-Sht-01 on the shelf of the Barents Sea (Report 6404, Murmansk)

Interareal correlation has been carried out; composition of the deposits has been determined; sections recovered by marine drilling have been compared; reconstructed paleogeographic conditions confirm previous views on Jurassic and Cretaceous sedimentation in the area: 1. Determinate changes of continental and shallow marine mainly sandy Middle Jurassic deposits by sandy-clayey marine ones to the north and west occur. This indicates similar direction of clastic material migration and converse direction of Jurassic marine transgressions. 2. Increase of sand contents in the deposits also to the east and to the southeast indicates an important source of clastic material. It can result from incipience and development of the epiplatform orogen of Novaya Zemlya - Pai-Khoi in the Late Triassic - Early Jurassic. 3. Compositional and facial changes as well as changes in thicknesses of some Early Cretaceous lithologic-stratigraphic complexes indicate fast change of terrigenous material transport from the north to the south - south-east in the Late Valanginian - Hauterivian. Besides within the South Barents Sea region up to the Shtokman area there occurs weak variability in lithologic parameters of Neocomian avandeltaic deposits and turbidites composed of clays, claystones, and clayey siltstones. Correlation of drilling sections from the Shtokman area and from the South Basin of the Barents Sea together with paleotectonic analysis result to the conclusion about significant structure-forming movements in the Late Jurassic - Early Neocomian. During this time there occurred maximal growth of the Shtokman structure and likely of many other structures belonging to the South Basin of the Barents Sea.