Chemical composition, age, and magnetic parameters of igneous rocks from the Franz Josef Land

A combined study of magnetic parameters of basalt and andesite samples has been carried out in the framework of geological investigations of the Franz Josef Land. This study has included determination of coercivity, saturation magnetization, Curie points, natural remanent magnetization (NRM), and magnetic susceptibility as well as examination of ferromagnetic minerals with a microscope. Data on chemical composition of the rocks have been obtained for all the samples, and radiological ages have been determined for the majority of the rocks. Thermomagnetic curves of the samples have been subdivided into four types depending on composition of ferromagnetic NRM carriers. Data showing multiple changes in the predominant composition of the igneous rocks have been obtained. Each stage of magmatism is characterized by a specific type of the ferromagnetic component in the rocks and, therefore, magnetomineralogical investigations can be used for differentiation and correlation of the igneous rocks.

Flux of ice-rafted detritus in the Fram Strait

A three-year particle flux record from the eastern Fram Strait, between Greenland and Svalbard, revealed a rather untypical seasonal flux pattern compared to other particle flux studies from the Nordic Seas. In the eastern Fram Strait this pattern is characterised by a sudden four- to six-fold increase of the particle flux in January, when no daylight is available to support any biological productivity. Comparison with sea-ice distribution maps led to the conclusion that the sudden increase in the flux is due to ice-rafted detritus released from sea ice, which originated from the Svalbard archipelago and from the northern Barents Sea. Detailed grain size analyses of the silt fraction indicated the >10 µm fraction of the lithogenic matter to be clearly enriched due to IRD input. Even more important is the observation that lithogenic material >40 µm occurs exclusively during the ice-rafting event and, therefore, appears to be a suitable indicator for IRD transported on sea ice. Thus, in addition to coarse IRD (e.g. >500 µm), which is mainly derived from icebergs, the analysis of fine IRD >40 µm in deep-sea sediments can be used to reconstruct paleo-sea-ice extensions.

Daily mean surface meteorology and river discharge in Central Sulawesi for the period 2002-2005

The El Niño/ Southern Oscillation (ENSO) phenomenon is the strongest known natural interannual climate fluctuation. The most recent two extreme ENSO events of 1982/83 and 1997/98 severley hit the socio-economy of main parts of Indonesia. As the climate variability is not homogeneous over the whole Archipelago of Indonesia, ENSO events cause negative precipitation anomalies of diverse magnitude and uration in different regions. Understanding the hydrology of humid tropical catchments is an essential prerequisite to investigate the impact of climate variability on the catchment hydrology. Together with the quantitative assessment of future water resource changes they are essential tools to develop mitigation strategies on a catchment scale. These results can be integrated into long term Integrated Water Resource Management (IWRM) strategies. The general objective of this study is to investigate and quantify the impact of ENSO caused climate variability on the water balance and the implications for water resources of a mesoscale tropical catchment.

The Global Plankton Database: an inventory and data from the Former Soviet Union expeditions

At present time, there is a lack of knowledge on the interannual climate-related variability of zooplankton communities of the tropical Atlantic, central Mediterranean Sea, Caspian Sea, and Aral Sea, due to the absence of appropriate databases. In the mid latitudes, the North Atlantic Oscillation (NAO) is the dominant mode of atmospheric fluctuations over eastern North America, the northern Atlantic Ocean and Europe. Therefore, one of the issues that need to be addressed through data synthesis is the evaluation of interannual patterns in species abundance and species diversity over these regions in regard to the NAO. The database has been used to investigate the ecological role of the NAO in interannual variations of mesozooplankton abundance and biomass along the zonal array of the NAO influence. Basic approach to the proposed research involved: (1) development of co-operation between experts and data holders in Ukraine, Russia, Kazakhstan, Azerbaijan, UK, and USA to rescue and compile the oceanographic data sets and release them on CD-ROM, (2) organization and compilation of a database based on FSU cruises to the above regions, (3) analysis of the basin-scale interannual variability of the zooplankton species abundance, biomass, and species diversity.

(Table 1) Biomass and total standing crop of major wet sedge tundra species at five sites at Alexandra Fiord in 1981 and 2005

The global climate is changing rapidly and Arctic regions are showing responses to recent warming. Responses of tundra ecosystems to climate change have been examined primarily through short-term experimental manipulations, with few studies of long-term ambient change. We investigated changes in above- and belowground biomass of wet sedge tundra to the warming climate of the Canadian High Arctic over the past 25 years. Aboveground standing crop was harvested from five sedge meadow sites and belowground biomass was sampled from one of the sites in the early 1980s and in 2005 using the same methods. Aboveground biomass was on average 158% greater in 2005 than in the early 1980s. The belowground biomass was also much greater in 2005: root biomass increased by 67% and rhizome biomass by 139% since the early 1980s. Dominant species from each functional group (graminoids, shrubs and forbs) showed significant increases in aboveground biomass. Responsive species included the dominant sedge species Carex aquatilis stans, C. membranacea, and Eriophorum angustifolium, as well as the dwarf shrub Salix arctica and the forb Polygonum viviparum. However, diversity measures were not different between the sample years. The greater biomass correlated strongly with increased annual and summer temperatures over the same time period, and was significantly greater than the annual variation in biomass measured in 1980-1983. Increased decomposition and mineralization rates, stimulated by warmer soils, were likely a major cause of the elevated productivity, as no differences in the mass of litter were found between sample periods. Our results are corroborated by published short-term experimental studies, conducted in other wet sedge tundra communities which link warming and fertilization with elevated decomposition, mineralization and tundra productivity. We believe that this is the first study to show responses in High Arctic wet sedge tundra to recent climate change.

Geochemistry of secondary carbonates in ODP Leg 115 basalts

This report presents the results of a study of the stable isotopic and chemical composition of secondary carbonate minerals precipitated within basalts at Ocean Drilling Program Sites 707 and 715. At Site 715, the secondary carbonates are all composed of calcite and display a narrow range of carbon and oxygen stable isotope ratios, with values ranging from -2.75 per mil to 1.95 per mil PDB and -0.27 per mil to 2.86 per mil PDB, respectively. Strontium, iron, and manganese values of the samples are generally low. The geochemistry of Site 715 samples indicates that they precipitated from seawater-domi- nated fluids, at low temperatures, as is typical of secondary carbonates from most Deep Sea Drilling Project sites. In contrast, at Site 707, aragonite, siderite, and manganese-rich calcite occur as secondary carbonates in addition to calcite. The carbon isotopes of the Site 707 carbonates of all rock types are depleted in 13C. Values range from -2.79 per mil to -16.43 per mil PDB. Oxygen isotope values do not show a wide variation, ranging from -1.78 per mil to 1.17 per mil. The strontium contents of the samples range from 5200 to 8100 ppm for aragonites, and from 145 to 862 ppm for calcites. Iron and manganese contents are high in calcites and siderites and low in aragonites. Site 707 carbonates precipitated at low temperatures in a fairly closed system, in which basalt-seawater interaction has greatly influenced the chemistry of the pore fluids. The reactions occurring within the system before and in conjunction with secondary carbonate precipita- tion include oxidation of isotopically light methane, derived from fluids circulating within the basalts, and reduction of substantial amounts of iron and manganese oxides from the basalts.