Strontium isotope ratios of planktonic foraminifera from ODP Site 119-744 on the Kerguelen Plateau, Indian Ocean (Table 1)

87Sr/86Sr ratios of well-preserved early Miocene-Oligocene planktonic foraminifers from Site 744 in the southern Indian Ocean provide the highest southern latitude Sr isotope record of this age. The isotopic data have been calibrated with the site magnetostratigraphy. 87Sr/86Sr ages were also determined using the Sr isotope-age equations of Miller et al. (1988, doi:10.1029/PA003i002p00223) and Hess et al. (1989, doi:10.1029/PA004i006p00655). There is good agreement between the calculated ages from 87Sr/86Sr measurements using these equations and those derived from magnetobiostratigraphy. In addition, these equations were useful for inference of sediment ages in intervals where the paleomagnetic record is not well resolved and the biostratigraphy is inconclusive. The Site 744 87Sr/86Sr record can be used for correlation of Antarctic and low-latitude sequences and biostratigraphical zonation of foraminifers, radiolarians, diatoms, and calcareous nannofossils. This record will assist in the development of the high southern latitude biochronology.

Global hydrobelts and hydroregions

Hydrobelts divide the global landmasses into eight hydrological regions with resolution of 0.5°, based primarily on the annual average temperature (T) and runoff (q). The interbelt differences were maximised and intrabelt variability minimise. These hydrobelts are decomposed on continents as 26 hydroregions. The main aim of the dataset is to provide a robust reporting scale that could be used in water-related issues. The spatial datafiles for both, hydrobelts and hydroregions, are provided as shp-files and ascii raster files with accompanied metadata.

(Table 1) Abundances of Discoaster species in ODP Hole 130-806C

Members of the calcareous nannofossil genus Discoaster have been used extensively to subdivide Tertiary deep-sea sediments into biostratigraphic zones or subzones (e.g., Martini, 1971; Bukry, 1973). Haq and Lohmann (1976) mapped biogeographic migrations of this group through time and over latitude. They suggested that expansions and contractions of Discoaster-dominated assemblages across latitudes reflect sea-surface temperature changes. Subsequently, late Pliocene Discoaster species were counted at closely spaced sample intervals from various Atlantic sites (Backman et al., 1986; Backman and Pestiaux, 1987; Chepstow-Lusty et al., 1989, 1991), and Indian Ocean as well as Pacific Ocean sites (Chepstow-Lusty, 1990). In addition to the biostratigraphic information revealing positions and the precision by which the different late Pliocene Discoaster species can be determined, these studies also demonstrated that discoasters strongly fluctuate in abundance as a function of time. These abundance variations occur in equatorial as well as temperate temperature regimes, and show periodicities that reflect orbital frequencies. Chepstow-Lusty et al. (1989, 1991) also suggested that the oscillating abundances partly represent productivity pressure, because discoasters tend to show low abundances under high productivity conditions and vice versa. In the Pacific Ocean, counts showing late Pliocene Discoaster abundances exist from three sites, namely Ocean Drilling Program (ODP) Site 677 in the eastern equatorial upwelling region, Core V28-179 from the central equatorial region, and Core V32-127 from the mid-latitude Hess Rise. The two Vema cores are condensed and show sedimentation rates below 0.5 cm/1000 yr, thus offering a poorly resolved stratigraphy. Hole 806C from the Ontong Java Plateau provided an opportunity to establish a highly resolved Discoaster record from the western extreme of the equatorial Pacific under an environmental setting that differed from ODP Site 677 by being less influenced by intense upwelling. The Discoaster counting technique is described by Backman and Shackleton (1983).

Global distributions of diazotrophs nitrogen fixation rates - Depth integrated values computed from a collection of source datasets - Contribution to the MAREDAT World Ocean Atlas of Plankton Functional Types

The MAREDAT atlas covers 11 types of plankton, ranging in size from bacteria to jellyfish. Together, these plankton groups determine the health and productivity of the global ocean and play a vital role in the global carbon cycle. Working within a uniform and consistent spatial and depth grid (map) of the global ocean, the researchers compiled thousands and tens of thousands of data points to identify regions of plankton abundance and scarcity as well as areas of data abundance and scarcity. At many of the grid points, the MAREDAT team accomplished the difficult conversion from abundance (numbers of organisms) to biomass (carbon mass of organisms). The MAREDAT atlas provides an unprecedented global data set for ecological and biochemical analysis and modeling as well as a clear mandate for compiling additional existing data and for focusing future data gathering efforts on key groups in key areas of the ocean. The present data set presents depth integrated values of diazotrophs nitrogen fixation rates, computed from a collection of source data sets.