Eutrophication history of Guanabara Bay (SE Brazil) recorded by phosphorus flux to sediments from a degraded mangrove area     

A.C. Borges  C.J. Sanders  H.L.R. Santos  D.R. Araripe  W. Machado  S.R. Patchineelam   《Marine pollution bulletin》2009,58(11):1750-1754

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Geodynamic evolution of the Taiwan-Luzon-Mindoro belt since the late eocene   总被引：1，自引：0，他引：1  

Jean Franois Stephan  Ren Blanchet  Claude Rangin  Bernard Pelletier  Jean Letouzey  Carla Muller 《Tectonophysics》1986,125(1-3)

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Terpenoid marker compounds derived from biogenic precursors in volcanic ash from Mount St. Helens,Washington     

Wilfred E. Pereira  Colleen E. Rostad 《Geochimica et cosmochimica acta》1983,47(12):2287-2291

A volcanic-ash sample obtained after the 1980 eruption of Mount St. Helens, Washington, was analyzed for cyclic terpenoid organic compounds and polycyclic aromatic hydrocarbons using capillary gas chromatography-mass spectrometry-computer techniques. Various tricyclic diterpenoid acids and hydrocarbons were identified including dehydroabietic acid, dehydroabietin, dehydroabietane, simonellite, and retene. Preliminary evidence indicates that these compounds were derived from forest soils or atmospheric aerosols or both in the vicinity of coniferous forests. A diagenetic scheme involving three possible pathways for the conversion of abietic acid to retene is presented.  相似文献   

Notes on the 1965 Taal Volcanic eruptions     

G. G. Santos  R. E. Wainerdi 《Bulletin of Volcanology》1969,33(2):503-529

Neutron activation analyses were performed on samples of olivine-bearing basalt, of volcanic bomb, of volcanic ashes, of residues of water from the old crater lake, of residues of bubbling waters taken near the cinder cone, and of residue of rainwater collected at Parc, Diliman, Quezon City, all of which were volcanic products of the 1965 Taal eruption. The analysis was performed to determine the approximate ratios of important minor and trace elements in the volcanic products, in order to better understand the geochemical processes involved in the 1965 eruption of the Taal Volcano. The radionuclides of Cu, Fe, Na and Mn were positively identified in all the volcanic samples that were irradiated. Scandium was present only in the ash samples. The aproximate Cu/Na ratios for the volcanic ashes, volcanic bomb, and basalt are similar; they ranged from 0.171 to 0.200. The Cu/Na values obtained for the water samples varied from 0.253 to 2.010. The results of fast neutron activation show that the Si, Al, Fe, Mg, and O percentages of the different ash layers are similar. Based on the present work and upon past analyses, it is suggested that the solidification index for Taal is about 10. The eruptivity of Taal Volcano seems to be related to the rift in the crust, rate of migration of the magmatic volatiles, and pressure of the volatile fraction in the magma reservoir. All these factors are probably operating jointly and effectively, making it possible for the Taal Volcano to possess strongly predictable eruptivity, in the light of its past eruption history and its periodic cycle of eruption. It is suggested that the Taal and the Mayon Volcanoes are related from a regional and structural point of view. This observation is reflected in the striking similarity of their respective periodic cycle of eruptions.  相似文献   

Methods to the measurements of distances     

Mario Carla 《Journal of Geodesy》1962,36(4):317-319

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Monthly variation of 200 mb flow in the tropics     

V. B. Rao  J. P. Bonatti  R. P. Santos 《Meteorology and Atmospheric Physics》1984,33(1):21-30

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Annual stability in the use of coves near inlets as settlement areas for winter flounder (Pseudopleuronectes americanus)     

Mary Carla Curran  Kenneth W. Able 《Estuaries and Coasts》2002,25(2):227-234

Coves near an ocean inlet in Little Egg Harbor in southern New Jersey may be important settlement areas for winter flounder (Pseudopleuronectes americanus), based on the high abundance of small postlarval individuals. During 1994–1996 we sampled in two coves and adjacent areas of this same estuary to determine if this pattern was annually consistent. Collections in spring and early summer indicated that small, recently-settled winter flounder (10–45 mm TL) were abundant in the coves from May to mid-June in every year with maximum mean densities ranging from 1.5–2.5 ind m⁻² and that these same size individuals were never collected at these densities in other habitats in the same estuary. Densities in the coves declined soon after settlement, usually by late June to early July in each year. In order to determine factors that may influence these high settlement rates we examined aspects of habitat quality by determining habitat-specific growth rates in cages for recently-settled individuals (17.5–38.3 mm TL) both inside and outside the coves during 1995. These rates (3.7–9.1 wt d⁻¹) overlapped those of other estuarine habitats (3.1–10.5 wt d⁻¹) suggesting that habitat quality, based on growth, does not differentiate the coves from other potential settlement habitats. Mark/recapture experiments for recently settled individuals (range 13–70 mm TL) in 1994 and 1996 had low recapture rates (1% in both years) suggesting that dispersal from the cove occurred soon after settlement. This pattern confirms that these coves are used as settlement areas but they are probably not used as nurseries because winter flounder, at least in this system, do not settle and stay and, as a result, use other habitats as primary nursery areas.  相似文献   

Organic matter assimilation and selective feeding by holothurians in the deep sea: some observations and comments     

Michael L. Ginger  David S. M. Billett  Karen L. Mackenzie  Konstandinos Kiriakoulakis  Renato R. Neto  Daniel K. Boardman  Vera L. C. S. Santos  Ian M. Horsfall  George A. Wolff   《Progress in Oceanography》2001,50(1-4)

The selective feeding behaviour and assimilation efficiencies of deep-sea holothurians were investigated in order to assess their impact on carbon and nitrogen remineralisation on the Porcupine Abyssal Plain (PAP; 49°N 16°W, 4850 m water depth). Unfortunately, reliable determination of organic matter in the gut contents of the organisms proved to be difficult, because of the lysis of cells associated with the death of the animals on recovery. This was expressed in high levels of free fatty acids in the gut contents of Oneirophanta mutabilis, which we ascribe to unregulated lipolysis of phospholipids and triacylglycerides. It was not possible to estimate accurately the contribution that such material made to the gut contents, but based on the distributions of sterols in the gut sediments, it is likely to have been substantial. Therefore, all assimilation efficiencies calculated for holothurians in the deep sea should be treated with caution.Fortuitously, a bloom of holothurians that feed on the sediment surface (namely Amperima rosea and Ellipinion molle) during the period of study provided an opportunity indirectly to assess the impact of megafauna on organic matter cycling at the PAP. Observations suggest that the depletion of phytosterols from the surficial sediments between July and October 1997 resulted from the selective uptake of fresh phytodetritus by the blooming species. Deep-sea holothurians do not biosynthesise sterols de novo and an estimate of the sterol required by the increased population of A. rosea and E. molle is equivalent to the sterol flux to the seafloor during the spring/summer of 1997. The implications are dramatic. Firstly, these and other megafauna apparently turned over and selectively removed phytosterols from the freshly arrived phytodetritus and the surficial sediment (0–5 mm) at the PAP in less than four months. Secondly, their action impacted the food resource available to other organisms. Finally, as phytosterols are expensive to biosynthesise and are apparently an important resource for holothurians, we speculate that the supply of these compounds to the sedimentary community may be one important control on their population in the abyssal ocean.  相似文献   

Survival of sardine larvae off the Atlantic Portuguese coast: a preliminary numerical study     

Santos  Aires J.P.; Nogueira  Joao; Martins  Helder 《ICES Journal of Marine Science》2005,62(4):634-644

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Vegetable oil spills on salt marsh sediments; comparison between sunflower and linseed oils     

Pereira MG  Mudge SM  Latchford J 《Marine environmental research》2003,56(3):367-385

The effects of a simulated spill of sunflower oil in salt marsh sediments were compared with an experiment with linseed oil. Sunflower and linseed oil penetrated the sediments at the same rates but different adsorption of the oils onto sediment particles resulted in the establishment of anaerobic conditions at shallower depths in sediments contaminated with linseed oil than with sunflower oil. The total lipid content of sunflower oil contaminated sediments remained almost stable for 6 months, whilst only 40% of linseed oil remained in the sediment after 2 months. Numbers of culturable heterotrophic bacteria and aerobic oil degrading bacteria in muddy sediment increased rapidly in response to the presence of the oils but bacterial numbers in sandy sediments increased more slowly for sunflower oil. Changes in fatty acid composition indicate similar degradation pathways for both oils but sunflower oil degraded more slowly than linseed oil and thus has the potential for longer lasting effects in marine environments.  相似文献