Chemical composition of manganese nodules and crusts collected from the Hakurei Maru Cruise GH74-5 in the Eastern Central Pacific Basin

Chemical composition of manganese nodules and crust collected from the Hakurei Maru Cruise GH74-5, September-October, 1974, in the Eastern Central Pacific Basin by the Geological Survey of Japan according to: Analyses and sample manganese deposits data from Cruise GH74-5 (private communication) (unpublished), Scripps Institution of Oceanography. http://www.ngdc.noaa.gov/mgg_mmbib/showref.jsp?mmbib=MIZUAA7702.

Description of manganese nodules and crust collected from the Hakurei Maru Cruise GH74-5, September-October, 1974, in the Eastern Central Pacific Basin

The cores and dredges described in this report were taken on the GH74-5 Expedition in September-October, 1974 by the Geological Survey of Japan from the R/V Hakurei Maru. A total of 36 cores, dredges and submarine camera sites have been visited. The survey conducted an investigation of the manganese deposits in the Eastern Pacific Basin and the East of the Okinawa islands

Description of manganese nodules and crust collected from the Hakurei Maru Cruise GH76-1, January-March, 1976, in the Central Pacific Basin

This report of the GH76-1 cruise mainly includes the results of the on-board observations in the survey area of the medial-eastern part of Central Pacific Basin (5 degree -10 degree N, 170 degree -175 degree W) and partly of analytical work at the on-shore laboratory. In addition, the results of some on-board optical and geophysical works along the tracks of Japan-Ogasawara-survey area-Hawaii, are described in appendices. The GH76-1 cruise of the R/V Hakurei-maru was carried out from the 10th January to the 9th March, 1976 as the second phase field work of the Geological Survey of Japan five-year research program of study on the manganese nodule deposits of the Central Pacific Basin and also as a part of the National Research Institute for Pollution and Resources research program of technological study on the exploitation of deep sea mineral resources. The GSJ research program (F.Y. 1974-F.Y. 1978) aims at providing basic information on the manganese nodule distribution and their origin on the deep sea floor of the Central Pacific Basin bounded by the Marshall Ridge to the west, the Christmas Ridge to the east, and the Mid-Pacific Mountains to the north. The first phase of investigation was carried out during the GH74-5 cruise in the eastern part of the area (6 degree -10 degree 30'W, 164 degree 30'-171 degree 30'N)(Mizuno and Chujo, eds., 1975), and the present second phase covered an areas of 5 degree square, just west of the GH74-5 area.

Exchange capacity and chemical composition of Fe-Mn nodules from the Central Pacific

Constants of calcium, magnesium, zinc, cobalt, copper, and nickel exchange for sodium in iron-manganese nodules taken from different parts of the Pacific Ocean were determined under static conditions at constant ionic strength (?=0.05). These determinations revealed high capacity of nodules for sorbing the referred ions (their exchange constants range from 1.93 to 20.85). Obtained data demonstrate the major role of MnO and Fe2O3 in sorption processes in iron-manganese nodules.

Abundance of nodules, chemical and mineral compositions of nodules and sediments from the Central Pacific

The monograph considers facial conditions of ore-formation in the Central Equatorial Pacific, as well as lithostratigraphy and local variability of bottom sediments. Mineral composition of nodules, forms of occurrence of chemical elements in sediments and nodules, composition of interstitial waters, age of nodules, regularities and processes of ore formation in the radiolarian belt of the Pacific Ocean zone are also under consideration.

(Table 1) Carbohydrates in different sediment types of the Central Pacific

Total contents of carbohydrates were determined in samples of natural sediments of various genetic types. Analyses were made on board. Deep-sea pelagic sediments (red clays of various types including zeolite clays, and also radiolarian and carbonate oozes) were the main types of sediments studied. Contents of carbohydrates in pelagic oozes of the Central Pacific ranged from 214 to 1605 ppm, averaging 602 ppm of air-dried sediment. Organic matter of the group studied is a diagenetically stable complex, with polysaccharides apparently predominating.

On molecular chirality within naturally occurring secondary organic aerosol particles from the central Amazon Basin

In this perspectives article, we reflect upon the existence of chirality in atmospheric aerosol particles. We then show that organic particles collected at a field site in the central Amazon Basin under pristine background conditions during the wet and dry seasons consist of chiral secondary organic material. We show how the chiral response from the aerosol particles can be imaged directly without the need for sample dissolution, solvent extraction, or sample preconcentration. By comparing the chiral-response images with optical images, we show that chiral responses always originate from particles on the filter, but not all aerosol particles produce chiral signals. The intensity of the chiral signal produced by the size resolved particles strongly indicates the presence of chiral secondary organic material in the particle. Finally, we discuss the implications of our findings on chiral atmospheric aerosol particles in terms of climate-related properties and source apportionment.

A Century of Change in Coral Reef Status in Southeast and Central Pacific: Polynesia Mana Node, Cook Islands, French Polynesia, Kiribati, Niue, Tokelau, Tonga, Wallis and Futuna

The Polynesia Mana Node of the southeast and central Pacific contains 7 independent or autonomous countries or territories with only 6,000 km2 of land on 347 islands, but surrounded by 12 million km2 of EEZ. These seas contain 13,000 km2 of coral reefs as the main natural ecosystem providing food resources and opportunities for development, especially for tourism and pearl culture for 500,000 inhabitants. During the 19th and first half of the 20th centuries, there was major exploitation by the colonial powers of mother-of-pearl oysters for the button industry, as well as guano, sandalwood and trepang. The Polynesian people were largely involved in a subsistence economy and all coral reefs and lagoons were healthy. During the last two decades of the 20th, all countries experienced rapid development and urbanization, rising populations, and some increased agriculture. These developments were limited to a few islands of each country (i.e. 15 islands amongst the 347) with resulting degradation of the coral reefs around these sites. The other islands remained mostly uninhabited and pristine, and continued with a subsistence economy. Generally, there was more damage to the coral reefs through natural events such as cyclones and coral bleaching, than by human activities. There is however, an urgent need to combat the threats on some islands from increased sedimentation, over-fishing, dredging and nutrient pollution.