18 resultados para 1995_12082153 CTD-52 5401201


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EXTRACT (SEE PDF FOR FULL ABSTRACT): High-resolution oxygen-18 and total inorganic carbon (TIC) studies of cored sediments from the Owens Lake Basin, California, indicate that Owens Lake was hydrologically open (overflowing) most of the time between 52,500 and 12,500 carbon-14 YBP. ... The lack of a strong correspondence between North Atlantic climate records and the Owens Lake delta-oxygen-18 record has two possible explanations: (1) the sequence of large and abrupt climate change indicated in North Atlantic records is not global in scope and is largely confined to the North Atlantic and surrounding areas, or (2) Owens Lake is located in a part of the Great Basin that is relatively insensitive to the effects of climate perturbations recorded in the North Atlantic region.

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The Nutrient Enhanced Coastal Ocean Productivity (NECOP) Program is a component of NOAA's Coastal Ocean Program. The central hypothesis of this research is: Anthropogenic nutrient inputs have enhanced coastal ocean productivity with subsequent impacts on coastal ocean water quality, living resource yields, and the global marine carbon cycle. The initial study area for this program is the Mississippi/Atchafalaya River Outflow and adjacent Louisiana shelf region.

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Biodiversity and distribution of benthic Foraminifera and Ostracoda in the continental shelf sediments of the Omman Sea was studied in order to indicating of the composition of benthic foraminiferal and ostracodal communities and determining of their relationship with the environmental factors of the Omman Sea. Sediment samples were gathered in winter 2006 from twelve stations ranging in depth from 30 to 103 meters. Environmental factors including depth, temperature, salinity, dissolved Oxygen and pH were measured with a CTD system during sampling time and grain size and total organic matter were measured in laboratory. From the overall 57 benthic foram species, there were 52 identified species belong to 25 genera of 16 families. The cosmopolitan foraminifer, Ammonia beccarii, was common in all sampling stations. The composition of benthic foram communities had a highly positive correlation with depth, salinity and total organic matter. From the overall 30 ostracod species, there were 26 identified species belong to 22 genera of 13 families. Diversity and aboundance of ostracoda of the Oman Sea decreased from east to west and from south to north but increased slightly in the northwest (near the Strait of Hormoz). Ostracoda of the genus Propontocypris were common in all sampling stations but the genera Cyprideis, Paradoxostom and Hemicytheridea were rare in the Oman Sea. Diversity and aboundance of ostracoda in northern regions were less than southern and were less than foraminifera too. The composition of ostracodal communities had a highly positive correlation with dept, salinity and grain size. Biodiversity and distribution pattern of benthic foraminifera and ostracoda were being different in various sampling stations, especially between northern and southern regions. Water depth, salinity and structure of the sediments were the most important abiotic factors controlling the distribution pattern of benthic foraminifera and ostracoda in the Omman Sea. None existence or rare observation of structural abnormalities and oil polluted individuals in the vicinity of all sampling stations, resulted to the "clean" benthic environment of the Omman Sea.