Composition of post-Jurassic deposits from the Northwest Pacific and the Galapagos Rift, data of DSDP Legs 62, 65, and 70

The monogragh contains results of mineralogicai and geochemical studies of Mesozoic and Cenozoic deposits from the Pacific Ocean collected during Deep Sea Drilling Project. Special attention is paid on the aspects of geochemical history of post-Jurassic sedimentation in the central part of the Northwest Pacific, detailed characteristics of the main stages of sedimentary evolution are given: Early Cretaceons (protooceanic), Late Cretaceons (transitional) and Cenozoic (oceanic). Results of mineralogical and geochemical studies of hydrothermal deposits from the Galapagos Rift are given as well.

Verical distribution of Copepoda biomass in the Northwest and tropical Pacific

Quantitative analysis of vertical distribution of copepod families revealed a pattern of variation with depth (from the surface to the greatest ocean depths) in the trophic structure of this taxocenosis in the pelagic Pacific.

Composition and biomass of phytoplankton in the Northwest Pacific in summer 1990

According to results of Cruise 22 of R/V Akademik Mstislav Keldysh in the Northwest Pacific in July-August 1990, picophytoplankton represented mainly by cyanobacteria (up to 90%) comprised from 70 to 99% of total phytoplankton. Nanophytoplankton constituted substantial part of total biomass (22-37%) and consisted mainly of small phytoflagellates (2-4 ?m), cryptomonades, and coccolithophorids Emiliania huxleyi. Summer species such as Neodenticula seminae prevailed among large phytoplankton. Horizontal and vertical distribution of phytoplankton groups and species was described. Taxonomy and vertical distribution were related to nutrient concentrations in the upper mixed layer.

Zooplankton community within the Titanic Polygon, Northwest Atlantic, summer 2003

In summer 2003 we continued our long-term series of observations over the zooplankton community within the Titanic Polygon (area of the frontal zone of Gulf Stream and the Labrador Current) in the North Atlantic, where interaction of ecosystems of subpolar and warm waters takes place. Depending on hydrological situation occurring in the frontal zone interrelated interannual variations in abundance and biomass of plankton species including Calanus hyperboreus and mesopelagic shrimps of Acanthephyra genus were observed. In different years contribution of two parallel trophic nets passing primarily through the larger and smaller plankters to formation of the community varied. Data on the size structure of population of macroplankton shrimps are presented.

Concentrations of suspended matter and total particulate fluxes at the Titanic polygon, Northwest Atlantic

Basic parameters of sedimentation environment are considered: the Western Boundary Deep Current that transports sedimentary material and distributes it on the survey area; the nepheloid layer, its features, and the distribution of concentrations and particulate standing crop in it; distribution of horizontal and vertical fluxes of sedimentary material; and bottom sediments and their absolute masses (accumulation rates). Comparison of vertical fluxes of particulate matter and accumulation rates of sediments showed that contemporary fluxes of sedimentary material to the bottom provided distribution of accumulation rates of sediments within the survey area during Holocene.