982 resultados para 3.500.073
Resumo:
This layer is a georeferenced raster image of the historic paper map entitled: Carta geogro. topográfica de la isla de Cuba : dedicanla a la Reyna Nuestra Señora Doñ a Isabel II, El Teniente General Conde de Cuba y la Comisión de Gefes y Oficiales Militares y de Agrimensores Públicos que la levantó y formó de su orden en los años de 1824 á 1831/Do. Estruch lo grabó en Barcelona 1835 ; Carlos Roca lo dibujó. It was published in 1835. Scale [ca. 1:325,000]. This layer is image 3 of 6 total images of the six sheet source map. Map in Spanish.The image inside the map neatline is georeferenced to the surface of the earth and fit to the World Mercator project coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, roads, shoreline features, and more. Relief shown by hachures, depths by soundings. Includes also indexes, table of distances, statistical tables, and insets: "Plano de la ciudad y puerto de La Habana" [ca. 1:16.000]. -- "Plano de la ciudad y bahía de Sn. Carlos de Matanzas" [ca. 1:14.500]. -- "Ciudad de Sta. María del Puerto Principe" [ca. 1:16.000]. -- "Plano de la ciudad de Santiago de Cuba" [ca. 1:16.000] -- "Plano de la bahía de Cuba" [ca. 1:48.000]. -- "Plano de la ciudad de Trinidad" [ca. 1:16.000]. -- "Puerto de Casilda" [ca. 1:43.000].This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.
Resumo:
Marine organic matter (OM) sinks from surface waters to the seafloor via the biological pump. Benthic communities, which use this sedimented OM as energy and carbon source, produce dissolved organic matter (DOM) in the process of remineralization, enriching the sediment porewater with fresh DOM compounds. We hypothesized that in the oligotrophic deep Arctic basin the molecular signal of freshly deposited primary produced OM is restricted to the surface sediment pore waters which should differ from bottom water and deeper sediment pore water in DOM composition. This study focused on: 1) the molecular composition of the DOM in sediment pore waters of the deep Eurasian Arctic basins, 2) whether the signal of marine vs. terrigenous DOM is represented by different compounds preserved in the sediment pore waters and 3) whether there is any relation between Arctic Ocean ice cover and DOM composition. Molecular data, obtained via 15 Tesla Fourier transform ion cyclotron resonance mass spectrometer, were correlated with environmental parameters by partial least square analysis. The fresher marine detrital OM signal from surface waters was limited to pore waters from < 5 cm sediment depth. The productive ice margin stations showed higher abundances of peptides, unsaturated aliphatics and saturated fatty acids formulae, indicative of fresh OM/pigments deposition, compared to northernmost stations which had stronger aromatic signals. This study contributes to the understanding of the coupling between the Arctic Ocean productivity and its depositional regime, and how it will be altered in response to sea ice retreat and increasing river runoff.
Resumo:
The Indian Summer Monsoon (ISM) is an inter-hemispheric and highly variable ocean-atmosphere-land interaction that directly affects the densely populated Indian subcontinent. Here, we present new records of palaeoceanographic variability that span the last 500,000 years from the eastern equatorial Indian Ocean, a relatively under-sampled area of ISM influence. We have generated carbon and oxygen stable isotope records from three foraminiferal species from Ocean Drilling Program Site 758 (5°N, 90°E) to investigate the oceanographic history of this region. We interpret our resultant Dd18O (surface-thermocline) record of upper water-column stratification in the context of past ISM variability, and compare orbital phase relationships in our Site 758 data to other climate and monsoon proxies in the region. Results suggest that upper water-column stratification at Site 758, which is dominated by variance at precession and half-precession frequencies (23, 19 and 11 ka), is forced by both local (5°N) insolation and ISM winds. In the precession (23 ka) band, stratification minima at Site 758 lag northern hemisphere summer insolation maxima (precession minima) by 9 ka, which is consistent with Arabian Sea ISM phase estimates and suggests a common wind forcing in both regions. This phase implicates a strong sensitivity to both ice volume and southern hemisphere insolation forcing via latent heat export from the southern subtropical Indian Ocean. Additionally, we find evidence of possible overprinting of millennial-scale events during glacial terminations in our stratification record, which suggests an influence of remote abrupt climate events on ISM dynamics.