993 resultados para East Church (Salem, Mass.)
Resumo:
X-ray computed tomography (CT) provides an insight into the progression of dissolution in the tests of planktonic foraminifera. Four species of foraminifera (G. ruber [white], G. sacculifer, N. dutertrei and P. obliquiloculata) from Pacific, Atlantic and Indian Ocean core-top samples were examined by CT and SEM. Inner chamber walls began to dissolve at Delta[CO3**2-] values of 12-14 µmol/kg. Close to the calcite saturation horizon, dissolution and precipitation of calcite may occur simultaneously. Inner calcite of G. sacculifer, N. dutertrei and P. obliquiloculata from such sites appeared altered or replaced, whereas outer crust calcite was dense with no pores. Unlike the other species, there was no distinction between inner and outer calcite in CT scans of G. ruber. Empty calcite crusts of N. dutertrei and P. obliquiloculata were most resistant to dissolution and were present in samples where Delta[CO3**2-] ~ -20 µmol/kg. Five stages of preservation were identified in CT scans, and an empirical dissolution index, XDX, was established. XDX appears to be insensitive to initial test mass. Mass loss in response to dissolution was similar between species and sites at ~ 0.4 µg/µmol/kg. We provide calibrations to estimate Delta[CO3**2-] and initial test mass from XDX.
Resumo:
Limited information on the East Antarctic Ice Sheet (EAIS) geometry during Marine Isotope Stage 3 (MIS 3; 60-25 ka) restricts our understanding of its behaviour during periods of climate and sea level change. Ice sheet models forced by global parameters suggest an expanded EAIS compared to the Holocene during MIS 3, but field evidence from East Antarctic coastal areas contradicts such modelling, and suggests that the ice sheet margins were no more advanced than at present. Here we present a new lake sediment record, and cosmogenic exposure results from bedrock, which confirm that Rauer Group (eastern Prydz Bay) was ice-free for much of MIS 3. We also refine the likely duration of the Last Glacial Maximum (LGM) glaciation in the region. Lacustrine and marine sediments from Rauer Group indicate the penultimate period of ice retreat predates 50 ka. The lacustrine record indicates a change from warmer/wetter conditions to cooler/drier conditions after ca. 35 ka. Substantive ice sheet re-advance, however, may not have occurred until much closer to 20 ka. Contemporary coastal areas were still connected to the sea during MIS 3, restricting the possible extent of grounded ice in Prydz Bay on the continental shelf. In contrast, relative sea levels (RSL) deduced from field evidence indicate an extra ice load averaging several hundred metres thicker ice across the Bay between 45 and 32 ka. Thus, ice must either have been thicker immediately inland (with a steeper ice profile), or there were additional ice domes on the shallow banks of the outer continental shelf. Further work is required to reconcile the differences between empirical evidence of past ice sheet histories, and the history predicted by ice sheet models from far-field temperature and sea level records.
Resumo:
About one-third of the carbon dioxide (CO2) released into the atmosphere as a result of human activity has been absorbed by the oceans, where it partitions into the constituent ions of carbonic acid. This leads to ocean acidification, one of the major threats to marine ecosystems and particularly to calcifying organisms such as corals, foraminifera and coccolithophores. Coccolithophores are abundant phytoplankton that are responsible for a large part of modern oceanic carbonate production. Culture experiments investigating the physiological response of coccolithophore calcification to increased CO2 have yielded contradictory results between and even within species. Here we quantified the calcite mass of dominant coccolithophores in the present ocean and over the past forty thousand years, and found a marked pattern of decreasing calcification with increasing partial pressure of CO2 and concomitant decreasing concentrations of CO3. Our analyses revealed that differentially calcified species and morphotypes are distributed in the ocean according to carbonate chemistry. A substantial impact on the marine carbon cycle might be expected upon extrapolation of this correlation to predicted ocean acidification in the future. However, our discovery of a heavily calcified Emiliania huxleyi morphotype in modern waters with low pH highlights the complexity of assemblage-level responses to environmental forcing factors.
Resumo:
Using satellite radar interferometry observations of Greenland, we detected widespread glacier acceleration below 66° north between 1996 and 2000, which rapidly expanded to 70° north in 2005. Accelerated ice discharge in the west and particularly in the east doubled the ice sheet mass deficit in the last decade from 90 to 220 cubic kilometers per year. As more glaciers accelerate farther north, the contribution of Greenland to sea-level rise will continue to increase.
Resumo:
We have determined the concentrations and isotopic composition of noble gases in old oceanic crust and oceanic sediments and the isotopic composition of noble gases in emanations from subduction volcanoes. Comparison with the noble gas signature of the upper mantle and a simple model allow us to conclude that at least 98% of the noble gases and water in the subducted slab returns back into the atmosphere through subduction volcanism before they can be admixed into the earth's mantle. It seems that the upper mantle is inaccessible to atmospheric noble gases due to an efficient subduction barrier for volatiles.
Resumo:
Continental margin sediments of SE South America originate from various terrestrial sources, each conveying specific magnetic and element signatures. Here, we aim to identify the sources and transport characteristics of shelf and slope sediments deposited between East Brazil and Patagonia (20°-48°S) using enviromagnetic, major element, and grain-size data. A set of five source-indicative parameters (i.e., chi-fd%, ARM/IRM, S0.3T, SIRM/Fe and Fe/K) of 25 surface samples (16-1805 m water depth) was analyzed by fuzzy c-means clustering and non-linear mapping to depict and unmix sediment-province characteristics. This multivariate approach yields three regionally coherent sediment provinces with petrologically and climatically distinct source regions. The southernmost province is entirely restricted to the slope off the Argentinean Pampas and has been identified as relict Andean-sourced sands with coarse unaltered magnetite. The direct transport to the slope was enabled by Rio Colorado and Rio Negro meltwaters during glacial and deglacial phases of low sea level. The adjacent shelf province consists of coastal loessoidal sands (highest hematite and goethite proportions) delivered from the Argentinean Pampas by wave erosion and westerly winds. The northernmost province includes the Plata mudbelt and Rio Grande Cone. It contains tropically weathered clayey silts from the La Plata Drainage Basin with pronounced proportions of fine magnetite, which were distributed up to ~24° S by the Brazilian Coastal Current and admixed to coarser relict sediments of Pampean loessoidal origin. Grain-size analyses of all samples showed that sediment fractionation during transport and deposition had little impact on magnetic and element source characteristics. This study corroborates the high potential of the chosen approach to access sediment origin in regions with contrasting sediment sources, complex transport dynamics, and large grain-size variability.
Resumo:
This article will review major features of the 'giant' Cape Blanc filament off Mauritania with regard to the transport of chlorophyll and organic carbon from the shelf to the open ocean. Within the filament, chlorophyll is transported about 400 km offshore. Modelled particle distributions along a zonal transect at 21°N showed that particles with a sinking velocity of 5 m d**-1 are advected offshore by up to 600 km in subsurface particle clouds generally located between 400 m and 800 m water depth, forming an Intermediate Nepheloid Layer (INL). It corresponds to the depth of the oxygen minimum zone. Heavier particles with a sinking velocity of 30 m d**-1 are transported from the shelf within the Bottom Layer (BL) of more than 1000 m thickness, largely following the topography of the bottom slope. The particles advected within the BL contribute to the enhanced winter-spring mass fluxes collected at the open-ocean mesotrophic sediment trap site CB-13 (200 nm offshore), due to a long distance advection in deeper waters. The lateral contribution to the deep sediment trap in winter-spring is estimated to be 63% and 72% for organic carbon and total mass, respectively, whereas the lateral input for both components on an annual basis is estimated to be in the order of 15%. Biogenic opal increases almost fivefold from the upper to the lower mesotrophic CB-13 trap, also pointing to an additional source for biogenic silica from eutrophic coastal waters. Blooms obviously sink in smaller, probably mesoscale-sized patches with variable settling rates, depending on the type of aggregated particles and their ballast content. Generally, particle sinking rates are exceptionally high off NW Africa. Very high chlorophyll values and a large size of the Cape Blanc filament in 1998-1999 are also documented in enhanced total mass and organic carbon fluxes. An increasing trend in satellite chlorophyll concentrations and the size of the Cape Blanc filament between 1997 and 2008 as observed for other coastal upwelling areas is not documented.
Resumo:
A 21-year record is presented of surface mass balance measurements along the K-transect. The series covers the period 1990-2011. Data are available at 8 sites along a transect over an altitude range of 390 - 1850 m at approximately 67° N in West Greenland. The surface mass balance gradient is on average 3.8 x 10**-3 m w.e./m, and the mean equilibrium line altitude is 1553 m a.s.l. Only the lower 3 sites within 10 km of the margin experience a significant increasing trend in the ablation over the entire period.
Resumo:
More than 25 years of mass budget measurements of Hintereisferner allow a correlation with simultaneous observations of the climatological station Vent (1900 m a. s. l.). By this means it is possible to estimate the mass budget of earlier periods. Extreme values in the period between 1934/35 and 1951/52 span a range nearly twice as wide as in the pcriod thereafter.
Resumo:
“Faithful Genres” examines how African Americans adapted the genres of the black church during the civil rights movement. Civil rights mass meetings, as the movement’s so-called “energy machine” and “heartbeat,” serve as the project’s central site of inquiry for these meetings were themselves adaptations of the genre of the black church service. The mass meetings served as the space to draw people into the movement, encourage people toward further activism, and testify to anyone watching that the African American community was working toward desegregation, voting rights, and racial equality. In Martin Luther King, Jr.’s words, “Through these meetings we were able to generate the power and depth which finally galvanized the entire Negro community.” In these weekly or sometimes even nightly meetings, participants inhabited the familiar genres of the black church, song, prayer, and testimony. As they did, they remade these genres to respond directly to white supremacy and to enact the changes they sought to create. While scholars have studied the speeches men and women such as King, Ralph Abernathy, and Fannie Lou Hamer delivered at meetings (Wilson; Selby; Holmes; Brooks), scholars have yet to examine how civil rights mass meetings functioned through a range of genres and rhetors. My study addresses this absence and invigorates this discussion to demonstrate how the other meeting genres beyond the speech—song, prayer, and testimony—functioned to create energy, sustenance, and motivation for activists. Examining these collectively enacted genres, I show how rhetors adapted song, prayer, and testimony toward strategic interventions. I also examine how activists took these same genres up outside the meetings to circulate them in broader contexts for new audiences. By recovering and defining the mass meeting as a flexible repertoire of genres and then examining the redeployment of meeting genres outside the meeting, “Faithful Genres” contributes to histories of civil rights and African American rhetorics, genre studies, and histories of religious rhetorics.
Resumo:
The Orthodox church(es) share a common commitment to the unity of dogma and spirituality. There is, however, no doctrinal formulation that comes close to a form of political theology at a pan-Orthodox level. This means that the Orthodox churches’ attitude towards the European Union (EU) is driven by their ecclesial diversity and by complex inter-ecclesial relations. More fundamentally they share a fragmented and plural, theological objection to the very ideas of Europe and the West. This has been further complicated by the emergence of a substantial Orthodox diaspora from Eastern Europe, Russia, and the Middle East living across the breadth of the European continent. Consequently the ecclesial identity and self-perception of the autocephalous Orthodox churches is changing. These churches are becoming increasingly transnational and extra-territorial. With this, their perception of Europe and the West, as seen through the eyes of their diaspora communities, is altering from “threat” to “home” (Makrides and Uffelmann, 2003). The growing diaspora will not only impact the Christian demographics of Europe but will also transform the Eastern Churches’ view of Europe and the EU (Leustean, 2009; 2011; 2013; 2014a; 2014b).
Resumo:
The leading approach to everyday aesthetics for the past few decades has departed from analytic philosophical grounds, generating some tensions or dichotomies regarding its foundational cornerstones: the ordinary vs. extraordinary character of everyday aesthetic experience, contextual familiarity vs. strangeness, object vs. processual orientation, etc. Although John Dewey has been widely acclaimed as a sort of foundational figure for this burgueoning sub-discipline of aesthetics, maybe not enough emphasis has been laid on his very different pragmatist approach. In this regard, his reliance on Hegelian cum Darwinian premises might allow for a connection with other branches of continental as well as Asian philosophies, from which also some research on everyday aesthetics has been made. It is from this wider ontological framework that the notion of rhythm could be vindicated as a pivotal aspect of the aesthetic dimension of our everyday lives. Dewey deals extensively with it in Art as Experience, conceiving it as a sort of pattern of accomplished experiences, accounting also for his naturalistic approach and art and life continuity thesis. On the other hand, neo-pragmatist exponent Richard Shusterman, among others, has posited links of connection between Pragmatist aesthetics and East-Asian philosophies. Particularly, Dewey’s resonances with Asian philosophies have been studied, with a preeminence on the notions of harmony and rhythm. This paper will depart from the analysis of the notion of rhythm in Dewey’s philosophy, trying to hint at some possible developments of its implications. Particularly, it will expand on some East Asian paralelisms to his philosophy, trying to link them with the notion of rhythm as an epitomizing ground for the conjunction of the extraordinary (art) and the ordinary (life).