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  1. Precambrian Processes, the Trans-Hudson Orogen, and Cratonic Keels: Insights From Teleseismic Tomography in Northern Hudson Bay, Canada

    NASA Astrophysics Data System (ADS)

    Liddell, M. V.; Bastow, I. D.; Gilligan, A.; Kendall, J. M.; Darbyshire, F. A.

    2015-12-01

    Earth conditions in the Precambrian, and their effect upon the formation of cratons and orogenies from that era, are not fully understood. For example, the precise onset of modern plate tectonics remains ambiguous; it has been hypothesised to have begun anywhere from ~4.1Ga (Hopkins, 2008) to ~1Ga (Stern, 2005). Also, the exceptional depth to which fast wave-speed and geoid anomalies extend beneath some cratons points to the existence of thick "cratonic keels", the origin of which remains unexplained. To improve our understanding of the early Earth processes, geological evidence preserved within ancient plates that have remained largely unchanged since the Precambrian can be used. The rocks of northern Hudson Bay include Archean domains, the Paleoproterozoic Trans-Hudson Orogen (THO), and lie atop one of the largest cratonic keels on Earth (Bastow et al., 2013), making this region an ideal laboratory for study of Precambrian processes. Here, we use seismological data recorded at Canadian POLARIS and Hudson Bay Lithospheric Experiment (HuBLE) stations to perform a relative arrival-time study of northern Hudson Bay region and the THO. Waveforms are aligned using the adaptive stacking routine of Rawlinson et al. (2004), and inversions are produced using the Fast Marching Tomography (FMTOMO) inversion code of Rawlinson et al. (2006). Our inversions provide an improved velocity model of the lithosphere and upper mantle of northern Canada, suggesting updated boundaries between lithospheric blocks at mantle depths and constituting new body-wave constraints on their structure. The results are used to address a number of outstanding questions regarding the processes that formed the THO and the Laurentian Keel of North America.

  2. Averting disaster: the Hudson's Bay Company and smallpox in western Canada during the late eighteenth and early nineteenth centuries.

    PubMed

    Hackett, Paul

    2004-01-01

    During the late eighteenth and early nineteenth centuries the Hudson's Bay Company served as a de facto public health agency across western Canada. Among its biggest challenges was combating the smallpox epidemics that periodically threatened the Aboriginal people of the region. Initially, the Company's employees turned to quarantine over variolation in order to prevent the spread of the disease to Hudson Bay in the summer of 1782. Although well thought-out, ultimately this policy proved unsuccessful. Within thirty years the HBC had turned to the newly discovered vaccination, a strategy that was to prove far more effective in fighting the disease. By the late 1830s the Company was able to mount an effective vaccination campaign that covered much of western Canada.

  3. Small-scale variability in peatland pore-water biogeochemistry, Hudson Bay Lowland, Canada.

    PubMed

    Ulanowski, T A; Branfireun, B A

    2013-06-01

    The Hudson Bay Lowland (HBL) of northern Ontario, Manitoba and Quebec, Canada is the second largest contiguous peatland complex in the world, currently containing more than half of Canada's soil carbon. Recent concerns about the ecohydrological impacts to these large northern peatlands resulting from climate change and resource extraction have catalyzed a resurgence in scientific research into this ecologically important region. However, the sheer size, heterogeneity and elaborate landscape arrangements of this ecosystem raise important questions concerning representative sampling of environmental media for chemical or physical characterization. To begin to quantify such variability, this study assessed the small-scale spatial (1m) and short temporal (21 day) variability of surface pore-water biogeochemistry (pH, dissolved organic carbon, and major ions) in a Sphagnum spp.-dominated, ombrotrophic raised bog, and a Carex spp.-dominated intermediate fen in the HBL. In general, pore-water pH and concentrations of dissolved solutes were similar to previously reported literature values from this region. However, systematic sampling revealed consistent statistically significant differences in pore-water chemistries between the bog and fen peatland types, and large within-site spatiotemporal variability. We found that microtopography in the bog was associated with consistent differences in most biogeochemical variables. Temporal changes in dissolved solute chemistry, particularly base cations (Na(+), Ca(2+) and Mg(2+)), were statistically significant in the intermediate fen, likely a result of a dynamic connection between surficial waters and mineral-rich deep groundwater. In both the bog and fen, concentrations of SO4(2-) showed considerable spatial variability, and a significant decrease in concentrations over the study period. The observed variability in peatland pore-water biogeochemistry over such small spatial and temporal scales suggests that under-sampling in

  4. Primary production and sinking export during fall in the Hudson Bay system, Canada

    NASA Astrophysics Data System (ADS)

    Lapoussière, Amandine; Michel, Christine; Gosselin, Michel; Poulin, Michel; Martin, Johannie; Tremblay, Jean-Éric

    2013-01-01

    Primary production and organic material sinking export were investigated in the Hudson Bay system (i.e., Hudson Bay, Hudson Strait and Foxe Basin) under ice-free conditions during early fall 2005, using the 14C-uptake method and short-term free-drifting particle interceptor traps deployed below the euphotic zone at 50 m. Principal component analysis revealed spatial patterns of primary production and chlorophyll a (chl a) biomass in the euphotic zone that were shaped by hydrographic conditions and nutrient concentrations linked to freshwater/seawater influence. Primary production rates varied widely, from 70 to 435 mg C m-2 d-1, while the range of particulate organic carbon (POC) sinking fluxes was narrow, from 50 to 77 mg C m-2 d-1. Consequently, high ratios of POC sinking export to primary production (i.e., export ratios; range of 0.38-0.69) were observed at stations where primary production was low and dominated by small cells, and where heterotrophic protist dominated in biomass. These results show that at short temporal scales neither protist community structure nor biomass or production rates could be used to predict the magnitude of POC sinking export from the euphotic zone.

  5. The role of lichen on peatland development in the Hudson Bay Lowlands, Canada

    NASA Astrophysics Data System (ADS)

    Harris, Lorna; Moore, Tim; Roulet, Nigel

    2015-04-01

    Lichen (Cladina stellaris) can be a dominant vegetation cover on bogs within the extensive peatland landscape of the Hudson Bay Lowlands (HBL), northern Ontario, Canada. The unique characteristics of lichens (growth structure and function as a symbiotic organism), their ability to form thick, dense mats across the HBL bogs, and their increased tolerance of extreme environmental conditions, points to their importance as a distinct plant functional type. However, the role of lichen within the peatland ecosystem is poorly understood, particularly ecosystem interactions (vegetation associations) and peatland development (including microtopography) and the resulting carbon sink. Many studies consider the role of different plant functional types on peatland CO2 and CH4 exchange (e.g. Bubier et al., 2003; Strack et al., 2006), and this understanding is included in peatland growth and climate change models. As far as we are aware lichens are currently omitted from these models. We suggest that lichens represent a distinct plant functional type with CO2 exchange characteristics (NEE and respiration) that are quite different to vascular plants and mosses. In this study we measured lichen CO2 exchange in both natural and modified moisture conditions at field sites in the HBL over two field seasons. Our results indicate that lichen productivity is strongly influenced by abiotic factors that affect lichen moisture content, with very dry lichen exhibiting little or no photosynthetic capacity. We suggest that the low productivity of lichen mats results in lower rates of peat accumulation compared to Sphagnum-dominated peatland areas, and that this has consequences for the development of peatland microtopography (hummocks and hollows) and feedback mechanisms. To better understand the role of lichen mats on peat accumulation and to test possible feedback mechanisms we developed a model, the parameters of which are supported by data from field sites in the HBL. This dependence of

  6. High Resolution Audiomagnetotelluric Investigation of the Porosity at the Margin of the Hudson Bay Basin, Canada

    NASA Astrophysics Data System (ADS)

    Craven, J. A.; Roberts, B.

    2012-12-01

    Seismic exploration from 1968 to 1985 within the intracratonic Hudson Bay basin in northern Canada resulted in five dry wells drilled on a structural high in the central part of the basin (Hamblin, 2008). Recent work (Bertrand and Malo, 2012) has indicated successions at margins of the basin are well within the oil and gas "window". To test this conjecture a magnetotelluric (MT) survey was carried out in the vicinity of Churchill, Manitoba, at the margin of the basin. The primary goal of the survey was to identify potential source or reservoir rocks in the Upper Ordovician section of the Palaeozoic strata. MT surveys have been utilized in the northeastern portion of the Williston basin and have successfully imaged lower Palaeozoic carbonate units (Gowan et al., 2009). The MT method provides information on the electrical conductivity of the subsurface though the measurement of the natural time-varying electric and magnetic fields at the surface. Due to the dependence of the depth of investigation of the fields on their frequency, an estimate of conductivity variation with depth can be attained. A total of 46 high frequency audio-magnetotelluric (AMT) sites were collected, 38 along one approximately N-S corridor perpendicular to the coastline and 8 in a more E-W direction closer to the town of Churchill. Simultaneous collection of broadband MT data (BBMT) at a limited number of sites was done in order to calculate a response function over a wider range of frequencies at each AMT site. The combined AMT and BBMT MT data have been edited and processed to produce response functions at all sites, and 1-D modelling has provided resistivity vs. depth curves in the top 200 m of the basin. The 1-D models have been stitched together to create a continuous, approximately N-S resistivity section. In addition, the data have been input to a 3D inversion program and preliminary 3D resistivity and conductivity volumes have been generated along with an estimate of 3-D porosity

  7. Architecture and subsidence history of the intracratonic Hudson Bay Basin, northern Canada

    NASA Astrophysics Data System (ADS)

    Pinet, Nicolas; Lavoie, Denis; Dietrich, Jim; Hu, Kezhen; Keating, Pierre

    2013-10-01

    The Phanerozoic Hudson Bay Basin is a large intracratonic basin that is almost completely encircled by Precambrian rocks of the Canadian Shield. The preserved sedimentary succession is up to 2500 m thick and consists mainly of Upper Ordovician to Upper Devonian limestones, dolostones, evaporites and minor siliciclastics that were deposited in shallow marine conditions. Backstripping, based on new paleontological data and well correlations, reveals an irregular subsidence history marked by several periods of exhumation. In seismic data, the Hudson Bay Basin appears to have a relatively simple geometry, characterized by a lower sedimentary package cut by high-angle faults, overlain by a saucer-shape, essentially underformed upper sedimentary package. Normal (or transtensional) faults imaged on seismic reflection profiles provide clear evidence for crustal extension during deposition of the older sedimentary packages or slightly later, indicating that the basin is, at least partly, extensional in nature. However, significant changes in the depocenter location during the Paleozoic and variable exhumation values required by new maturation data indicate that other mechanisms influenced the subsidence/exhumation history of the basin. In particular, the influence of far-field events and dynamic topography transmitted by large-scale mantle flow in the continental interior (creating long-wavelength tilting and unconformities) is suspected but not yet proven.

  8. Sea Level and Paleoenvironment Control on Late Ordovician Source Rocks, Hudson Bay Basin, Canada

    NASA Astrophysics Data System (ADS)

    Zhang, S.; Hefter, J.

    2009-05-01

    Hudson Bay Basin is one of the largest Paleozoic sedimentary basins in North America, with Southampton Island on its north margin. The lower part of the basin succession comprises approximately 180 to 300 m of Upper Ordovician strata including Bad Cache Rapids and Churchill River groups and Red Head Rapids Formation. These units mainly comprise carbonate rocks consisting of alternating fossiliferous limestone, evaporitic and reefal dolostone, and minor shale. Shale units containing extremely high TOC, and interpreted to have potential as petroleum source rocks, were found at three levels in the lower Red Head Rapids Formation on Southampton Island, and were also recognized in exploration wells from the Hudson Bay offshore area. A study of conodonts from 390 conodont-bearing samples from continuous cores and well cuttings from six exploration wells in the Hudson Bay Lowlands and offshore area (Comeault Province No. 1, Kaskattama Province No. 1, Pen Island No. 1, Walrus A-71, Polar Bear C-11 and Narwhal South O-58), and about 250 conodont-bearing samples collected from outcrops on Southampton Island allows recognition of three conodont zones in the Upper Ordovician sequence, namely (in ascendant sequence) Belodina confluens, Amorphognathus ordovicicus, and Rhipidognathus symmetricus zones. The three conodont zones suggest a cycle of sea level changes of rising, reaching the highest level, and then falling during the Late Ordovician. Three intervals of petroleum potential source rock are within the Rhipidognathus symmetricus Zone in Red Head Rapids Formation, and formed in a restricted anoxic and hypersaline condition during a period of sea level falling. This is supported by the following data: 1) The conodont Rhipidognathus symmetricus represents the shallowest Late Ordovician conodont biofacies and very shallow subtidal to intertidal and hypersaline condition. This species has the greatest richness within the three oil shale intervals to compare other parts of Red

  9. Nelson River and Hudson Bay

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Rivers that empty into large bodies of water can have a significant impact on the thawing of nearshore winter ice. This true-color Moderate Resolution Imaging Spectroradiometer (MODIS) image from May 18, 2001, shows the Nelson River emptying spring runoff from the Manitoba province to the south into the southwestern corner of Canada's Hudson Bay. The warmer waters from more southern latitudes hasten melting of ice near the shore, though some still remained, perhaps because in shallow coastal waters, the ice could have been anchored to the bottom. High volumes of sediment in the runoff turned the inflow brown, and the rim of the retreating ice has taken on a dirty appearance even far to the east of the river's entrance into the Bay. The sediment would have further hastened the melting of the ice because its darker color would have absorbed more solar radiation than cleaner, whiter ice. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  10. Penny ice cap cores, baffin island, canada, and the wisconsinan foxe dome connection: two states of hudson bay ice cover

    PubMed

    Fisher; Koerner; Bourgeois; Zielinski; Wake; Hammer; Clausen; Gundestrup; Johnsen; Goto-Azuma; Hondoh; Blake; Gerasimoff

    1998-01-30

    Ice cores from Penny Ice Cap, Baffin Island, Canada, provide continuous Holocene records of oxygen isotopic composition (delta18O, proxy for temperature) and atmospheric impurities. A time scale was established with the use of altered seasonal variations, some volcanic horizons, and the age for the end of the Wisconsin ice age determined from the GRIP and GISP2 ice cores. There is pre-Holocene ice near the bed. The change in delta18O since the last glacial maximum (LGM) is at least 12.5 per mil, compared with an expected value of 7 per mil, suggesting that LGM ice originated at the much higher elevations of the then existing Foxe Dome and Foxe Ridge of the Laurentide Ice Sheet. The LGM delta18O values suggest thick ice frozen to the bed of Hudson Bay.

  11. Magnitude and Seasonality of Wetland Methane Emissions from the Hudson Bay Lowlands (Canada)

    NASA Technical Reports Server (NTRS)

    Pickett-Heaps, C. A.; Jacob, D. J.; Wecht, K. J.; Kort, E. A.; Wofsy, S. C.; Diskin, G. S.; Worthy, D. E. J.; Kaplan, J. O.; Bey, I.; Drevet, J.

    2011-01-01

    The Hudson Bay Lowlands (HBL) is the second largest boreal wetland ecosystem in the world and an important natural source of global atmospheric methane. We quantify the HBL methane emissions by using the GEOS-Chem chemical transport model to simulate aircraft measurements over the HBL from the ARCTAS and pre-HIPPO campaigns in May-July 2008, together with continuous 2004-2008 surface observations at Fraserdale (southern edge of HBL) and Alert (Arctic background). The difference in methane concentrations between Fraserdale and Alert is shown to be a good indicator of HBL emissions, and implies a sharp seasonal onset of emissions in late May (consistent with the aircraft data), a peak in July-August, and a seasonal shut-off in September. The model, in which seasonal variation of emission is mainly driven by surface temperature, reproduces well the observations in summer but its seasonal shoulders are too broad. We suggest that this reflects the suppression of emissions by snow cover and greatly improve the model simulation by accounting for this effect. Our resulting best estimate for HBL methane emissions is 2.3 Tg/a, several-fold higher than previous estimates (Roulet et al., 1994; Worthy et al., 2000).

  12. Multi Year Total and Methyl Mercury Exports from Two Major Sub Arctic Rivers Draining into Hudson Bay, Canada

    NASA Astrophysics Data System (ADS)

    Kirk, J. L.; St. Louis, V. L.

    2009-05-01

    From 2003 to 2007, concentrations of total and methyl mercury (THg and MeHg), were continuously measured in two Canadian sub Arctic rivers (the Nelson and the Churchill) that drain into western Hudson Bay. THg and MeHg concentrations were low in the Nelson River (mean ± standard deviation; 0.88±0.33 and 0.05±0.03 ng/L, respectively). The Churchill River, however, had high concentrations of Hg, particularly MeHg (1.96±0.8 and 0.18±0.09 ng/L, respectively), and hence may be an important source of MeHg to organisms feeding in the Churchill River estuary. A large portion of THg in the Nelson River was particulate- bound (39±23%), while in the Churchill River, most was in the dissolved form (78±15%) and is likely DOC-bound Hg originating in surrounding wetlands. In fact, both the Nelson and Churchill Rivers had high DOC concentrations and were therefore large exporters of DOC to Hudson Bay (1480±723 and 392±309 x 103 tonnes/year, respectively) compared to rivers to the south and east. Despite high Churchill River Hg concentrations, due to large Nelson River flows, average THg and MeHg exports to Hudson Bay from the Churchill River (37±28 and 4±4 kg/year, respectively) were ˜ one third and half Nelson River exports (113±52 and 9±4 kg/year). Interestingly, combined Hg exports to Hudson Bay from Nelson and Churchill River discharge are comparable to THg inputs from Hudson Bay spring-time snowmelt (177±140 kg/year) but are approximately 13 times greater than MeHg snowmelt inputs (1±1 kg/year). Although Hg inputs from rivers and snowmelt together may account for a large portion of the THg pool in Hudson Bay, these inputs account for a lesser portion of the MeHg pool, thus highlighting the importance of water column Hg(II) methylation as a large source of MeHg to Hudson Bay marine foodwebs.

  13. Multiyear total and methyl mercury exports from two major sub-Arctic rivers draining into Hudson Bay, Canada.

    PubMed

    Kirk, Jane L; St Louis, Vincent L

    2009-04-01

    From 2003 to 2007, concentrations of total mercury and methylmercury (THg and MeHg) were continuously measured in two Canadian sub-Arctic rivers (the Nelson and the Churchill) that drain into western Hudson Bay. THg and MeHg concentrations were low in the Nelson River (mean i standard deviation, 0.88 +/- 0.33 and 0.05 +/- 0.03 ng L(-1), respectively). The Churchill River, however, had high concentrations of Hg, particularly MeHg (1.96 +/- 0.8 and 0.18 +/- 0.09 ng L(-1), respectively) and hence may be an important source of MeHg to organisms feeding in the Churchill River estuary. A large portion of THg in the Nelson River was particulate-bound (39 +/- 23%), while in the Churchill River, most was in the dissolved form (78 +/- 15%) and is likely dissolved organic carbon (DC)-bound Hg originating in the surrounding wetlands. In fact, both the Nelson and Churchill Rivers had high DOC concentrations and were therefore large exporters of DOC to Hudson Bay (1480 +/- 723 and 392 +/- 309 x 10(3) t year(-1), respectively) compared to rivers to the south and east Despite high Churchill River Hg concentrations, due to large Nelson River flows, average THg and MeHg exports to Hudson Bay from the Churchill River (37 +/- 28 and 4 +/- 4 kg year(-1), respectively) were about one-third and half the Nelson River exports (113 +/- 52 and 9 +/- 4 kg year(-1)). Interestingly, combined Hg exports to Hudson Bay from Nelson and Churchill River discharge are comparable to THg inputs from Hudson Bay springtime snowmelt (177 +/-140 kg year(-1)) but are approximately 13 times greater than MeHg snowmelt inputs (1 +/- 1 kg year(-1)). Although Hg inputs from rivers and snowmelt together may account for a large portion of the THg pool in Hudson Bay, these inputs account for a lesser portion of the MeHg pool, thus highlighting the importance of water column Hg(ll) methylation as a source of MeHg to Hudson Bay marine food webs.

  14. Climate and peat type in relation to spatial variation of the peatland carbon mass in the Hudson Bay Lowlands, Canada

    NASA Astrophysics Data System (ADS)

    Packalen, Maara S.; Finkelstein, Sarah A.; McLaughlin, James W.

    2016-04-01

    Northern peatlands store ~500 Pg of carbon (C); however, controls on the spatial distribution of the stored C may differ regionally, owing to the complex interaction among climate, ecosystem processes, and geophysical controls. As a globally significant C sink, elucidation of controls on the distribution of C in the Hudson Bay Lowlands, Canada (HBL), is of particular importance. Although peat age is related to timing of land emergence and peat depth in the HBL, considerable variation in the total C mass (kg m-2) among sites of similar peat age suggests that other factors may explain spatial patterns in C storage (Pg) and sequestration. Here we quantify the role of two key factors in explaining the spatial distribution of the C mass in the HBL (n = 364 sites), (i) climate variability and (ii) peat lithology, for two major peatland classes in the HBL (bogs and fens). We find that temperature, precipitation, and evapotranspiration each explained nearly half of the C mass variability. Regions characterized by warmer and wetter conditions stored the most C as peat. Our results show that bogs and fens store similar amounts of C within a given climate domain, although via distinct storage mechanisms. Namely, fen peats tend to be shallower and more C dense (kg m-3) compared to bogs. Following geophysical controls on the timing of peat initiation, our results reveal that both the widespread bog-fen patterning and variability in regional climate contribute to explaining the spatial distribution of the peat C mass in the HBL.

  15. Proxy-Derived Reconstructions of Holocene Paleoclimate for the Hudson Bay Lowlands, an Extensive Peatland in Northern Canada

    NASA Astrophysics Data System (ADS)

    Finkelstein, S. A.; Bunbury, J.; Friel, C.; O'Reilly, B.

    2013-12-01

    The Hudson Bay Lowlands (HBL) is an extensive peatland in northern Canada where an estimated 31 Pg of carbon have accumulated during the Holocene. Given the large size of this carbon pool and the rapid rate of climate warming at high latitudes, quantifying the responses of this peatland to climate change is a critical research priority. Comparing Holocene paleoclimate reconstructions and paleo-vegetation and carbon dynamics in HBL peatlands through analyses of sediment cores is an effective approach to understanding the sensitivity of the carbon pool to climate. Robust paleoclimate reconstructions for the Holocene are needed for such comparisons. Until recently, there have been few paleoclimate reconstructions available for the HBL. Owing to the unique geographic setting of this low lying region to the west of Hudson Bay, reconstructions from adjacent subarctic regions are not directly applicable. We synthesize in this paper a series of paleoenvironmental records derived from biological proxies preserved in lake and wetland sediment cores collected from within the HBL with the goal of improving available paleoclimate information for the region. Our available pollen records document a series of vegetation changes during the Holocene, beginning with the establishment of coastal or salt marsh communities after emergence of the HBL from the Tyrrell Sea, followed by establishment of vegetation typical of poor fens or bogs. These local vegetation changes are apparently primarily related to hydrological changes driven by isostatic rebound and autogenic processes. Regional assemblages composed of tree pollen, which may be more directly tied to climate, show less variability during the Holocene. Reconstructions using modern analogs suggest minimal variation in temperature during the period of record, although these reconstructions show a moderate increase in precipitation following 3000 yrs BP, corresponding to Neoglacial climates reported at other northern high latitude

  16. Supplemental materials for the analysis of capture-recapture data for polar bears in Western Hudson Bay, Canada, 1984-2004

    USGS Publications Warehouse

    Regehr, Eric V.; Lunn, Nicholas J.; Amstrup, Steven C.; Stirling, Ian

    2007-01-01

    Regehr and others (2007, Survival and population size of polar bears in western Hudson Bay in relation to earlier sea ice breakup: Journal of Wildlife Management, v. 71, no. 8) evaluated survival in relation to climatic conditions and estimated population size for polar bears (Ursus maritimus) in western Hudson Bay, Canada. Here, we provide supplemental materials for the analyses in Regehr and others (2007). We demonstrate how tag-return data from harvested polar bears were used to adjust estimates of total survival for human-caused mortality. We describe the sex and age composition of the capture and harvest samples and provide results for goodness-of-fit tests applied to capture-recapture models. We also describe the capture-recapture model selection procedure and the structure of the most supported model, which was used to estimate survival and population size.

  17. Thermochemical Structure and Stratification of the Hudson Bay Lithosphere, Northern Canada: Evidence from Multi-Observable Probabilistic Inversion

    NASA Astrophysics Data System (ADS)

    Darbyshire, F. A.; Afonso, J. C.

    2014-12-01

    The Paleoproterozoic Trans-Hudson Orogeny (THO) was a Himalayan-style collision that marked an important stage of assembly of the Canadian Shield. Today, the THO is largely concealed beneath the Hudson Bay intracratonic basin. Regional seismic tomography shows a thick, high-wavespeed cratonic keel beneath the region, but also includes significant local heterogeneity that may be associated with the imprint of the THO, providing clues to Precambrian plate-tectonic processes. In this study, we use multi-observable probabilistic inversions to investigate the thermal and compositional state of the Hudson Bay lithosphere, to explain the seismic wavespeed variations and to constrain in more detail potential signatures of the oldest cratonic cores and the THO collision. Rayleigh wave dispersion curves, surface heatflow, geoid anomalies and topography are jointly inverted to give a pseudo-3D model of the upper mantle beneath the region. Low temperatures are pervasive across the region, leading to a thick thermal lithosphere whose base lies at depths of 250 km or greater. The data are best explained by stratification of the lithosphere into (at least) two layers, with the top layer extremely depleted and the bottom layer generally more fertile, though still depleted with respect to the sublithospheric mantle. Across the Bay and Hudson Strait, a narrow zone of lowered depletion is observed in the top layer. The position of this anomaly coincides geographically with the THO and with the wavespeed reduction noted in previous seismic studies. It is likely that this feature represents juvenile material trapped between the cratonic cores in the final stages of the THO. We also find evidence for anomalous mid-lithospheric compositions in certain areas, notably west of Hudson Bay. Additionally, some of the long-period surface wave data requires lower than average seismic wavespeeds below the lithosphere, suggesting localised regions of higher temperature/attenuation in the upper

  18. Lithospheric architecture beneath Hudson Bay

    NASA Astrophysics Data System (ADS)

    Porritt, Robert W.; Miller, Meghan S.; Darbyshire, Fiona A.

    2015-07-01

    Hudson Bay overlies some of the thickest Precambrian lithosphere on Earth, whose internal structures contain important clues to the earliest workings of plate formation. The terminal collision, the Trans-Hudson Orogen, brought together the Western Churchill craton to the northwest and the Superior craton to the southeast. These two Archean cratons along with the Paleo-Proterozoic Trans-Hudson internides, form the core of the North American craton. We use S to P converted wave imaging and absolute shear velocity information from a joint inversion of P to S receiver functions, new ambient noise derived phase velocities, and teleseismic phase velocities to investigate this region and determine both the thickness of the lithosphere and the presence of internal discontinuities. The lithosphere under central Hudson Bay approaches ˜350 km thick but is thinner (˜200-250 km) around the periphery of the Bay. Furthermore, the amplitude of the LAB conversion from the S receiver functions is unusually large for a craton, suggesting a large thermal contrast across the LAB, which we interpret as direct evidence of the thermal insulation effect of continents on the asthenosphere. Within the lithosphere, midlithospheric discontinuities, significantly shallower than the base of the lithosphere, are often imaged, suggesting the mechanisms that form these layers are common. Lacking time-history information, we infer that these discontinuities reflect reactivation of formation structures during deformation of the craton.

  19. Lithospheric Architecture Beneath Hudson Bay

    NASA Astrophysics Data System (ADS)

    Porritt, R. W.; Miller, M. S.; Darbyshire, F. A.

    2015-12-01

    Hudson Bay overlies some of the thickest Precambrian lithosphere on Earth, whose internal structures contain important clues to the earliest workings of plate formation. The terminal collision, the Trans-Hudson Orogen, brought together the Western Churchill craton to the northwest and the Superior craton to the southeast. These two Archean cratons along with the Paleo-Proterozoic Trans-Hudson internides, form the core of the North American craton. We use S to P converted wave imaging and absolute shear velocity information from a joint inversion of P to S receiver functions, new ambient noise derived phase velocities, and teleseismic phase velocities to investigate this region and determine both the thickness of the lithosphere and the presence of internal discontinuities. The lithosphere under central Hudson Bay approaches 􏰂350 km thick but is thinner (􏰂200-250 km) around the periphery of the Bay. Furthermore, the amplitude of the lithosphere-asthenosphere boundary (LAB) conversion from the S receiver functions is unusually large for a craton, suggesting a large thermal contrast across the LAB, which we interpret as direct evidence of the thermal insulation effect of continents on the asthenosphere. Within the lithosphere, midlithospheric discontinuities, significantly shallower than the base of the lithosphere, are often imaged, suggesting the mechanisms that form these layers are common. Lacking time-history information, we infer that these discontinuities reflect reactivation of formation structures during deformation of the craton.

  20. Constraining the Late Pleistocene history of the Laurentide Ice Sheet by dating the Missinaibi Formation, Hudson Bay Lowlands, Canada

    NASA Astrophysics Data System (ADS)

    Dalton, April S.; Finkelstein, Sarah A.; Barnett, Peter J.; Forman, Steven L.

    2016-08-01

    Well-dated paleorecords from periods prior to the Last Glacial Maximum (LGM) are important for validating models of ice sheet build-up and growth. However, owing to glacial erosion, most Late Pleistocene records lie outside of the previously glaciated region, which limits their ability to inform about the dynamics of paleo-ice sheets. Here, we evaluate new and previously published chronology data from the Missinaibi Formation, a Pleistocene-aged deposit in the Hudson Bay Lowlands (HBL), Canada, located near the geographic center of the Laurentide Ice Sheet (LIS). Available radiocarbon (AMS = 44, conventional = 36), amino acid (n = 13), uranium-thorium (U-Th, n = 14), thermoluminescence (TL, n = 15) and optically stimulated luminescence (OSL, n = 5) data suggest that an ice-free HBL may have been possible during parts of Marine Isotope Stage 7 (MIS 7; ca. 243,000 to ca. 190,000 yr BP), MIS 5 (ca. 130,000 to ca. 71,000 yr BP) and MIS 3 (ca. 29,000 to ca. 57,000). While MIS 7 and MIS 5 are well-documented interglacial periods, the development of peat, forest bed and fluvial deposits dating to MIS 3 (n = 20 radiocarbon dates; 4 TL dates, 3 OSL dates), suggests that the LIS retreated and remained beyond, or somewhere within, the boundaries of the HBL during this interstadial. Ice sheet models approximate the margin of the LIS to Southern Ontario during this time, which is 700 km south of the HBL. Therefore, if correct, our data help constrain a significantly different configuration and dynamicity for the LIS than previously modelled. We can find no chronological basis to discount the MIS 3 age assignments. However, since most data originate from radiocarbon dates lying close to the reliable limit of this geochronometer, future work on dating the Missinaibi Formation using other geochronological methods (e.g. U-Th, OSL) is necessary in order to confirm the age estimates and strengthen the boundaries of the LIS during this period.

  1. Air mass distribution and the heterogeneity of the climate change signal in the Hudson Bay/Foxe Basin region, Canada

    NASA Astrophysics Data System (ADS)

    Leung, Andrew; Gough, William

    2016-08-01

    The linkage between changes in air mass distribution and temperature trends from 1971 to 2010 is explored in the Hudson Bay/Foxe Basin region. Statistically significant temperature increases were found of varying spatial and temporal magnitude. Concurrent statistically significant changes in air mass frequency at the same locations were also detected, particularly in the declining frequency of dry polar (DP) air. These two sets of changes were found to be linked, and we thus conclude that the heterogeneity of the climatic warming signal in the region is at least partially the result of a fundamental shift in the concurrent air mass frequency in addition to global and regional changes in radiative forcing due to increases in long-lived greenhouse gases.

  2. Mixing and photoreactivity of dissolved organic matter in the Nelson/Hayes estuarine system (Hudson Bay, Canada)

    NASA Astrophysics Data System (ADS)

    Guéguen, C.; Mokhtar, M.; Perroud, A.; McCullough, G.; Papakyriakou, T.

    2016-09-01

    This work presents the results of a 4-year study (2009-2012) investigating the mixing and photoreactivity of dissolved organic matter (DOM) in the Nelson/Hayes estuary (Hudson Bay). Dissolved organic carbon (DOC), colored DOM, and humic-like DOM decreased with increasing salinity (r2 = 0.70-0.84). Removal of DOM was noticeable at low to mid salinity range, likely due to degradation and/or adsorption to particles. DOM photobleaching rates (i.e., decrease in DOM signal resulting from exposure to solar radiation) ranged from 0.005 to 0.030 h- 1, corresponding to half-lives of 4.9-9.9 days. Dissolved organic matter from the Nelson and Hayes Rivers was more photoreactive than from the estuary where the photodegradation of terrestrial DOM decreased with increasing salinity. Coincident with the loss of CDOM absorption was an increase in spectral slope S, suggesting a decrease in DOM molecular weight. Marked differences in photoreactivity of protein- and humic-like DOM were observed with highly humidified material being the most photosensitive. Information generated by our study will provide a valuable data set for better understanding the impacts of future hydroelectric development and climate change on DOM biogeochemical dynamics in the Nelson/Hayes estuary and coastal domain. This study will constitute a reference on terrestrial DOM fate prior to building additional generating capacity on the Nelson River.

  3. Can seal eating explain elevated levels of PCBs and organochlorine pesticides in walrus blubber from eastern Hudson Bay (Canada)?

    PubMed

    Muir, D C; Segstro, M D; Hobson, K A; Ford, C A; Stewart, R E; Olpinski, S

    1995-01-01

    Walrus (Odobenus rosmarus) blubber samples from Inukjuak and Akulivik (East Hudson Bay), Foxe Basin (Igloolik and Hall Beach) and Loks Land (East Baffin Island) were analysed for PCB congeners (ortho and non-ortho substituted) and other persistent organochlorines (DDT, toxaphene, chlordanes, dieldrin, mirex), as well as chlorinated dioxins/furans, to document spatial trends in contaminants in Canadian Arctic marine biota. Samples from 19 of 53 individuals had concentrations of SigmaPCBs greater than 1000 ng g(-1) (wet wt); the remaining individuals had much lower concentrations (50-600 ng g(-1)). Highest concentrations were found in samples from Inukjuak where average concentrations in blubber of females (N = 9) were 1450 +/- 954 ng g(-1) toxaphene, 2750 +/- 1780 ng g(-1) SigmaCHLOR, 2160 +/- 925 ng g(-1) SigmaDDT and 4790 +/- 2380 ng g(-1) SigmaPCB. SigmaPCB and SigmaDDT concentrations greater than 1000 ng g(-1) were unexpected based on previous studies of walrus from Greenland and Alaska. Local contamination was ruled out because levels of all organochlorines were elevated in each animal from Inukjuak, and elevated levels were also found in animals from Akulivik and Loks Land. Walrus from Inukjuak had sigma13C and sigma15N values in muscle intermediate between those of ringed seals (Phoca hispida) and those of walrus from Akulivik with low organochlorine levels. There was a weak but significant correlation between and sigma15N and (log)SigmaPCB. The Inukjuak walrus also had higher proportions of highly chlorinated PCB congeners, and higher DDE/SigmaDDT ratios than walrus from Igloolik or Akulivik. The results suggest that the walrus with elevated organochlorines are feeding at a higher trophic level than those with low levels and are probably utilizing ringed seals for a portion of their diet.

  4. Geological Setting and Petroleum Potential of the Paleozoic Hudson Platform, Northern Canada

    NASA Astrophysics Data System (ADS)

    Dietrich, J.; Hamblin, T.; Lavoie, D.; Duchesne, M.; Lajeunesse, P.; Zhang, Z.

    2009-05-01

    The Hudson Platform covers an area of 600,000 km2 and represents one of the largest Paleozoic sedimentary basins in Canada. The Hudson Platform contains the large Hudson Bay Basin and smaller Moose River Basin. The Hudson Bay and Moose River basins are surrounded and underlain by Precambrian igneous and metamorphic rocks of the Canadian Shield. The Hudson Platform contains Ordovician to Cretaceous sedimentary strata, with a maximum known thickness of about 2500 m in Hudson Bay. The lower Paleozoic succession includes Late Ordovician to Early Devonian shallow marine carbonates and thin mudstones, deposited during widespread early Paleozoic marine inundation of the Canadian Shield, and Early to Late Devonian marine carbonates, evaporates, and mudstones deposited in saucer-shaped, isolated basin depocentres. There is no record of late Paleozoic sedimentation in the region, perhaps related to cratonic uplift accompanying the Alleghenian Orogeny. Lower Paleozoic strata are unconformably overlain by thin, erosional remnants of Middle Jurassic and Early Cretaceous nonmarine sandstones, mudstones and lignite seams (Moose River Basin) and Early Cretaceous marine sandstones and mudstones (Hudson Bay Basin). The Hudson Platform is currently considered a frontier prospect for hydrocarbon exploration. However, the long- held view that the region is underlain by a thin sedimentary succession with no appreciable hydrocarbon source rocks or reservoir intervals is erroneous. Geological and geophysical data indicate the Hudson Bay Basin contains many prospective petroleum reservoir and trap types, potentially including hydrothermal dolomite. Recent studies indicate Upper Ordovician oil shales are widespread and may have generated hydrocarbons in deeper parts of the Hudson Bay Basin. New high resolution bathymetric surveys in northern Hudson Bay have led to the recognition of circular sea-floor depressions similar to fluid or gas-escape pockmarks. A modern re-evaluation of the

  5. Timing the last interglacial-glacial transition in glacial sedimentary sequences of the Hudson Bay lowlands (Canada)

    NASA Astrophysics Data System (ADS)

    Roy, M.; Allard, G.; Ghaleb, B.; Lamothe, M.

    2010-12-01

    Paleoclimate records (oxygen isotopes and speleothems) indicate that the onset of the last glacial cycle was characterized by rapid and large-scale growth of continental ice sheets. The timing of the inception of the Laurentide ice sheet (LIS) and its subsequent evolution (extent) remain, however, largely unconstrained. The depositional record of the Hudson Bay Lowlands (HBL) is of particular interest to these issues because this region is located near the former geographic center of the LIS. The presence of nonglacial deposits in HBL glacial sedimentary sequences thus implies drastic changes in ice sheet configuration, but constraining these ice volume changes through absolute dating of nonglacial sediments has been so far inconclusive. Here we use radiocarbon, U-series, and optical stimulated luminescence (OSL) methods to constrain the age of an extensive nonglacial unit containing abundant wood fragments enclosed in compacted clay lying below several meters of glacial deposits along the Nottaway River, in the southeastern sector of the HBL. This region is particularly interesting because it lies near one of the inception centers of the LIS. Radiocarbon dating of a wood fragment yielded a nonfinite 14C age of >55.2 ka, in agreement with similar dating attempts throughout the HBL. Measurements of U and Th concentrations and isotope ratios on fossil wood samples revealed consistent 230Th/U ages, indicating that the wood fragments were subject to a single episode of uranium uptake, with apparently no subsequent disturbance of the geochemical system. Despite mechanical cleaning of the wood outer surfaces, non-authigenic 230Th was found in most samples and correction for this detrital contamination yielded an isochron age of 106.8 (+12.3, -10.3) ka, which represents a minimum age for this unit. The 230Th/U age constraint is nonetheless supported by a series of OSL ages obtained for the overlying fluvial sands, thereby assigning the Nottaway nonglacial unit to the end

  6. Chemical composition of the atmospheric aerosol in the troposphere over the Hudson Bay lowlands and Quebec-Labrador regions of Canada

    NASA Astrophysics Data System (ADS)

    Gorzelska, K.; Talbot, R. W.; Klemm, K.; Lefer, B.; Klemm, O.; Gregory, G. L.; Anderson, B.; Barrie, L. A.

    1994-01-01

    Atmospheric aerosols were collected in the boundary layer and free troposphere over continental and coastal subarctic regions of Canada during the July-August 1990 joint U.S.-Canadian Arctic Boundary Layer Expedition (ABLE) SB/Northern Wetlands Study (NOWES). The samples were analyzed for the following water soluble species: sulfate, nitrate, ammonium, potassium, sodium, chloride, oxalate, methylsulfonate, and total amine nitrogen. Ammonium and sulfate were the major water soluble components of these aerosols. The nearly neutral (overall) chemical composition of summertime aerosol particles contrasts their strongly acidic wintertime composition. Aerosol samples were separated into several air mass categories and characterized in terms of chemical composition, associated mixing ratios of gaseous compounds, and meteorological parameters. The fundamental category represented particles associated with"background"air masses. The summertime atmospheric aerosols in background air over the North American subarctic and Arctic regions were characterized by relatively small and spatially uniform mixing ratios of the measured species. These aerosol particles were aged to the extent that they had lost their primary source signature. The chemical profile of the background air aerosols was frequently modified by additions from biomass fire plumes, aged tropical marine air, and intrusions of upper tropospheric/lower stratospheric air. Aerosols in boundary layer background air over the boreal forested region of Quebec-Labrador had significantly larger mixing ratios of ammonium and sulfate relative to the Hudson Bay region. This may reflect infiltration of anthropogenic pollution or be due to natural emissions from this region.

  7. Chemical composition of the atmospheric aerosol in the troposphere over the Hudson Bay lowlands and Quebec-Labrador regions of Canada

    NASA Technical Reports Server (NTRS)

    Gorzelska, K.; Talbot, R. W.; Klemm, K.; Lefer, B.; Klemm, O.; Gregory, G. L.; Anderson, B.; Barrie, L. A.

    1994-01-01

    Atmospheric aerosols were collected in the boundary layer and free troposphere over continental and coastal subarctic regions of Canada during the July - August 1990 joint U.S.-Canadian Arctic Boundary Layer Expedition (ABLE) 3B/Northern Wetlands Study (NOWES). The samples were analyzed for the following water soluble species: sulfate, nitrate, ammonium, potassium, sodium, chloride, oxalate, methylsulfonate, and total amine nitrogen. Ammonium and sulfate were the major water soluble components of these aerosols. The nearly neutral (overall) chemical composition of summertime aerosol particles contrasts their strongly acidic wintertime composition. Aerosol samples were separated into several air mass categories and characterized in terms of chemical composition, associated mixing ratios of gaseous compounds, and meteorological parameters. The fundamental category represented particles associated with 'background' air masses. The summertime atmospheric aerosols in background air over the North American subarctic and Arctic regions were characterized by relatively small and spatially uniform mixing ratios of the measured species. These aerosol particles were aged to the extent that they had lost their primary source signature. The chemical profile of the background air aerosols was frequently modified by additions from biomass fire plumes, aged tropical marine air, and intrusions of upper tropospheric/lower stratospheric air. Aerosols in boundary layer background air over the boreal forest region of Quebec-Labrador had significantly larger mixing ratios of ammonium and sulfate relative to the Hudson Bay region. This may reflect infiltration of anthropogenic pollution or be due to natural emissions from this region.

  8. Chemical composition of the atmospheric aerosol in the troposphere over the Hudson Bay lowlands and Quebec-Labrador regions of Canada

    SciTech Connect

    Gorzelska, K.; Talbot, R.W.; Lefer, B.; Klemm, K.; Klemm, O.; Gregory, G.L.; Anderson, B.; Barrie, L.A.

    1994-01-20

    Atmospheric aerosols were collected in the boundary layer and free troposphere over continental and coastal subarctic regions of Canada during the July-August 1990 joint US-Canadian Arctic Boundary Layer Expedition (ABLE) 3B/Northern Wetlands Study (NOWES). The samples were analyzed for the following water soluble species: sulfate, nitrate, ammonium, potassium, sodium, chloride, oxalate, methylsulfonate, and total amine nitrogen. Ammonium and sulfate were the major water soluble components of these aerosols. The nearly neutral (overall) chemical composition of summertime aerosol particles contrasts their strongly acidic wintertime composition. Aerosol samples were separated into several air mass categories and characterized in terms of chemical composition, associated mixing ratios of gaseous compounds, and meteorological parameters. The fundamental category represented particles associated with {open_quotes}background{close_quotes} air masses. The summertime atmospheric aerosols in background air over the North American subarctic and Arctic regions were characterized by relatively small and spatially uniform mixing ratios of the measured species. These aerosol particles were aged to the extent that they had lost their primary source signature. The chemical profile of the background air aerosols was frequently modified by additions from biomass fire plumes, aged tropical marine air, and intrusions of upper troposphere/lower stratospheric air. Aerosols in boundary layer background air over the boreal forested region of Quebec-Labrador had significantly larger mixing ratios of ammonium and sulfate relative to the Hudson Bay region. This may reflect infiltration of anthropogenic pollution or be due to natural emissions from this region. 71 refs., 5 figs., 5 tabs.

  9. Limnological regime shifts caused by climate warming and Lesser Snow Goose population expansion in the western Hudson Bay Lowlands (Manitoba, Canada)

    PubMed Central

    MacDonald, Lauren A; Farquharson, Nicole; Merritt, Gillian; Fooks, Sam; Medeiros, Andrew S; Hall, Roland I; Wolfe, Brent B; Macrae, Merrin L; Sweetman, Jon N

    2015-01-01

    Shallow lakes are dominant features in subarctic and Arctic landscapes and are responsive to multiple stressors, which can lead to rapid changes in limnological regimes with consequences for aquatic resources. We address this theme in the coastal tundra region of Wapusk National Park, western Hudson Bay Lowlands (Canada), where climate has warmed during the past century and the Lesser Snow Goose (LSG; Chen caerulescens caerulescens) population has grown rapidly during the past ∽40 years. Integration of limnological and paleolimnological analyses documents profound responses of productivity, nutrient cycling, and aquatic habitat to warming at three ponds (“WAP 12”, “WAP 20”, and “WAP 21″), and to LSG disturbance at the two ponds located in an active nesting area (WAP 20, WAP 21). Based on multiparameter analysis of 210Pb-dated sediment records from all three ponds, a regime shift occurred between 1875 and 1900 CE marked by a transition from low productivity, turbid, and nutrient-poor conditions of the Little Ice Age to conditions of higher productivity, lower nitrogen availability, and the development of benthic biofilm habitat as a result of climate warming. Beginning in the mid-1970s, sediment records from WAP 20 and WAP 21 reveal a second regime shift characterized by accelerated productivity and increased nitrogen availability. Coupled with 3 years of limnological data, results suggest that increased productivity at WAP 20 and WAP 21 led to atmospheric CO2 invasion to meet algal photosynthetic demand. This limnological regime shift is attributed to an increase in the supply of catchment-derived nutrients from the arrival of LSG and their subsequent disturbance to the landscape. Collectively, findings discriminate the consequences of warming and LSG disturbance on tundra ponds from which we identify a suite of sensitive limnological and paleolimnological measures that can be utilized to inform aquatic ecosystem monitoring. PMID:25750718

  10. Limnological regime shifts caused by climate warming and Lesser Snow Goose population expansion in the western Hudson Bay Lowlands (Manitoba, Canada).

    PubMed

    MacDonald, Lauren A; Farquharson, Nicole; Merritt, Gillian; Fooks, Sam; Medeiros, Andrew S; Hall, Roland I; Wolfe, Brent B; Macrae, Merrin L; Sweetman, Jon N

    2015-02-01

    Shallow lakes are dominant features in subarctic and Arctic landscapes and are responsive to multiple stressors, which can lead to rapid changes in limnological regimes with consequences for aquatic resources. We address this theme in the coastal tundra region of Wapusk National Park, western Hudson Bay Lowlands (Canada), where climate has warmed during the past century and the Lesser Snow Goose (LSG; Chen caerulescens caerulescens) population has grown rapidly during the past ∽40 years. Integration of limnological and paleolimnological analyses documents profound responses of productivity, nutrient cycling, and aquatic habitat to warming at three ponds ("WAP 12", "WAP 20", and "WAP 21″), and to LSG disturbance at the two ponds located in an active nesting area (WAP 20, WAP 21). Based on multiparameter analysis of (210)Pb-dated sediment records from all three ponds, a regime shift occurred between 1875 and 1900 CE marked by a transition from low productivity, turbid, and nutrient-poor conditions of the Little Ice Age to conditions of higher productivity, lower nitrogen availability, and the development of benthic biofilm habitat as a result of climate warming. Beginning in the mid-1970s, sediment records from WAP 20 and WAP 21 reveal a second regime shift characterized by accelerated productivity and increased nitrogen availability. Coupled with 3 years of limnological data, results suggest that increased productivity at WAP 20 and WAP 21 led to atmospheric CO2 invasion to meet algal photosynthetic demand. This limnological regime shift is attributed to an increase in the supply of catchment-derived nutrients from the arrival of LSG and their subsequent disturbance to the landscape. Collectively, findings discriminate the consequences of warming and LSG disturbance on tundra ponds from which we identify a suite of sensitive limnological and paleolimnological measures that can be utilized to inform aquatic ecosystem monitoring.

  11. Allogenic and Autogenic Controls on Carbon Uptake and Release since Mid-Holocene Peat Initiation in the Hudson Bay Lowlands, Canada

    NASA Astrophysics Data System (ADS)

    Packalen, M.; Finkelstein, S. A.; McLaughlin, J.

    2014-12-01

    Current interglacial development of a nearly continuous peat cover in the Hudson Bay Lowlands, Canada has resulted in a globally significant carbon (C) reservoir. Yet, the fate of peatland C stores and related climate system feedbacks remain uncertain under scenarios of a changing climate and enhanced anthropogenic pressure. Here, we examine peatland development in the HBL in relation to Holocene C-dynamics, together with records of paleo- and modern climate, glacial isostatic adjustment (GIA) and paleoenvironmental change. We report that the timing of peat initiation is tightly coupled with GIA in the HBL, while peatland age, trophic status, and paleoclimate contribute to explaining some of the temporal variation in C accumulation rates (CARs). Our results show that CARs are greatest from younger, minerotrophic peatlands and in association with warmer Holocene climates. Peat initiation rates and CARs in the HBL were greatest during the mid-Holocene; however, model evidence indicates that two-thirds of the HBL C pool is stored in peat of late Holocene age, owing to long-term peatland expansion and development. Since mid-Holocene peat initiation, the HBL has been a net C-sink and currently stores ~ 30 Pg C, with spatial climate patterns accounting for up to half of the C-mass distribution. Yet, the HBL has also been a modest C-source since peat initiation, with 85% of the losses occurring during the late Holocene. Our results indicate that the HBL may have been a potential terrestrial source of 1 - 7 Tg CH4 y-1 to the late Holocene atmosphere, due to the decay of previously accrued peat, under wetter conditions than present, and from a landscape occupied by an abundance of minerotrophic peatlands. While the peatlands of the HBL may continue to function as a globally significant C reservoir, conservative climate scenarios predict a warmer and wetter HBL in the next century that may lie outside the range of past climate variability. Disproportionate hydroclimatic

  12. Spatial-temporal controls on peatland carbon dynamics in the Hudson Bay Lowland, Canada: Reducing landscape-scale uncertainty in a changing climate

    NASA Astrophysics Data System (ADS)

    Packalen, M. S.; Finkelstein, S. A.; McLaughlin, J.

    2015-12-01

    Global peatlands currently store more than 650 Pg of carbon (C) that has accumulated over millennia, and contributed to a net climatic cooling. However, controls on spatial-temporal C dynamics may differ regionally. With at least 30 Pg C sequestered in the Hudson Bay Lowlands Canada (HBL), the vulnerability of this globally significant peat C reservoir remains uncertain under conditions of a changing climate and enhanced anthropogenic pressure. Here, we synthesize our current understanding of controls on C dynamics in the HBL using detailed peat records. Our data reveal that widespread bog-fen patterning across the HBL is related to the distribution of peat C in space and time, indicating that topographic and ecohydroclimatic controls are potentially important determinants of C mass accretion. We find that while peat age is closely related to timing of land emergence and peat depth in the HBL, considerable variation in the total C mass among sites of similar peat age suggests that additional factors may further explain trends in peat C dynamics. Among these factors, we find that temperature, precipitation, and potential evapotranspiration in the HBL account for up to half of the variation in the distribution of the peat C mass, whereby regions with warmer and wetter conditions support larger peat C masses. Moreover, we find that the rate of C accumulation is greatest for young fen peatlands developing during warmer mid-Holocene climates; but that long-term C stores are greatest in association with bog peatlands. Although nearly two-thirds of HBL peat C is of late Holocene age, most of the reconstructed potential C losses also occurred during the late Holocene, as previously accrued peat decayed. Our findings support the hypothesis that both climate and ecohydrological factors are important drivers of peat C dynamics in the HBL, alongside geophysical controls on the timing of peat initiation. As the HBL peat complex continues to rapidly expand, it may remain a

  13. Stratification of Seismic Anisotropy Beneath Hudson Bay

    NASA Astrophysics Data System (ADS)

    Darbyshire, F. A.; Eaton, D. W.; Bastow, I. D.

    2012-12-01

    The Hudson Bay region has a complex tectonic history spanning ~4 Ga of Earth's evolution. During the ~1.8 Ga Trans-Hudson orogeny, the Archean Superior and Western Churchill cratons collided following the subduction of a Pacific-scale ocean. It is thought that a significant amount of juvenile material is preserved in the Trans-Hudson Orogen, in part due to the complex double-indentor geometry of the Superior-Churchill collision. In the region of interest, the orogen lies beneath a large but shallow Paleozoic intra-cratonic basin. Studies of the crust and upper mantle beneath this region have been enabled through the HuBLE (Hudson Bay Lithospheric Experiment) project, through the deployment of broadband seismographs around the Bay and across the islands to the north. A surface-wave tomography study has taken advantage of the data coverage, providing new information on phase velocity heterogeneity and anisotropy for wave periods of 25-200 seconds (equivalent to depths from the lower crust to ~300 km). On a large scale, our results show that the entire region is underlain by a seismically fast lithospheric lid corresponding to the continental keel. The lithospheric thickness ranges from ~180km in the northeast, beneath a zone of Paleozoic rifting, to ~280km beneath central Hudson Bay. Within the lithosphere, seismic velocities vary laterally, including high-velocity material wrapping around the Bay in the uppermost mantle. In the mid-lithosphere, two high-velocity cores are imaged, with a zone of lower velocity between them beneath the Bay. We interpret these high-velocity structures to represent the strongest central cores of the Superior and Churchill cratons, with more-juvenile material preserved between them. The near-vertical geometry of the lower-velocity zone suggests that it is only the effects of terminal collision of the cratonic cores, rather than any preceding subduction, that is preserved today. The lowermost lithosphere has a more uniform velocity, and

  14. The Hudson Bay Lithospheric Experiment

    NASA Astrophysics Data System (ADS)

    Bastow, I. D.; Kendall, J.-M.; Helffrich, G. R.; Thompson, D. A.; Wookey, J.; Brisbourne, A. M.; Hawthorn, D.; Eaton, D.; Snyder, D. B.

    2011-12-01

    I D Bastow, J-M Kendall, A M Brisbourne, D B Snyder, D Thompson, D Hawthorn, G R Helffrich, J Wookey, A Horleston and D Eaton describe the motivation for - and successful operation of - a remote seismic survey in Arctic Canada.

  15. Distribution and diversity of diatom assemblages in surficial sediments of shallow lakes in Wapusk National Park (Manitoba, Canada) region of the Hudson Bay Lowlands.

    PubMed

    Jacques, Olivier; Bouchard, Frédéric; MacDonald, Lauren A; Hall, Roland I; Wolfe, Brent B; Pienitz, Reinhard

    2016-07-01

    The hydrology of shallow lakes (and ponds) located in the western Hudson Bay Lowlands (HBL) is sensitive to climate warming and associated permafrost thaw. However, their biological characteristics are poorly known, which hampers effective aquatic ecosystem monitoring. Located in northern Manitoba along the southwestern coast of Hudson Bay, Wapusk National Park (WNP) encompasses numerous shallow lakes representative of the subarctic zone. We analyzed the distribution and diversity of diatom (microscopic algae; class Bacillariophyceae) assemblages in surficial sediments of 33 lakes located in three different ecozones spanning a vegetation gradient, from NE to SW: the Coastal Fen (CF), the Interior Peat Plateau (IPP), and the Boreal Spruce Forest (BSF). We found significant differences (P < 0.05) in diatom community composition between CF and IPP lakes, and CF and BSF lakes, but not between IPP and BSF lakes. These results are consistent with water chemistry measurements, which indicated distinct limnological conditions for CF lakes. Diatom communities in CF lakes were generally dominated by alkaliphilous taxa typical of waters with medium to high conductivity, such as Nitzschia denticula. In contrast, several IPP and BSF lakes were dominated by acidophilous and circumneutral diatom taxa with preference for low conductivity (e.g., Tabellaria flocculosa, Eunotia mucophila, E. necompacta var. vixcompacta). This exploratory survey provides a first detailed inventory of the diatom assemblages in the WNP region needed for monitoring programs to detect changes in shallow lake ecosystems and ecozonal shifts in response to climate variations.

  16. Late-summer zooplankton community structure, abundance, and distribution in the Hudson Bay system (Canada) and their relationships with environmental conditions, 2003-2006

    NASA Astrophysics Data System (ADS)

    Estrada, Rafael; Harvey, Michel; Gosselin, Michel; Starr, Michel; Galbraith, Peter S.; Straneo, Fiammetta

    2012-08-01

    Zooplankton communities were examined for the first time in three different hydrographic regions of the Hudson Bay system (HBS) in early August to early September from 2003 to 2006. Sampling was conducted at 50 stations distributed along different transects located in Hudson Bay (HB), Hudson Strait (HS), and Foxe Basin (FB). Variations in zooplankton biomass, abundance, taxonomic composition, and diversity in relation to environmental variables were studied using multivariate techniques. During all sampling years, the total zooplankton biomass was on average four times lower in HB than in HS and FB. Clustering samples by their relative species compositions revealed no interannual variation in zooplankton community but showed a marked interregional variability between the three regions. Water column stratification explained the greatest proportion (25%) of this spatial variability. According to redundancy analysis (RDA), the zooplankton taxa that contribute most to the separation of the three regions are Microcalanus spp., Oithona similis, Oncaea borealis, Aeginopsis laurentii, Sagitta elegans, Fritillaria sp., and larvae of cnidaria, chaetognatha, and pteropoda in HB; hyperiid amphipods in FB; and Pseudocalanus spp. CI-CV, Calanus glacialis CI-CVI, Calanus finmarchicus CI-CVI, Calanus hyperboreus CV-CVI, Acartia longiremis CI-CV, Metridia longa N3-N6 CI-CIII CVIf, Eukrohnia hamata, larvae of echinodermata, mollusca, cirripedia, appendicularia, and polychaeta in the northwestern and southeastern HS transects. For the HB transect, the RDA analyzed allowed us to distinguish three regions (HB west, central, and east) with different environmental gradients and zooplankton assemblages, in particular higher concentration of Pseudocalanus spp. nauplii and CI-CVI, as well as benthic macrozooplankton and meroplankton larvae in western HB. In HS, Calanoid species (mainly C. finmarchicus and C. glacialis) were mostly observed at the north shore stations associated with the

  17. Assessing polar bear (Ursus maritimus) population structure in the Hudson Bay region using SNPs.

    PubMed

    Viengkone, Michelle; Derocher, Andrew Edward; Richardson, Evan Shaun; Malenfant, René Michael; Miller, Joshua Moses; Obbard, Martyn E; Dyck, Markus G; Lunn, Nick J; Sahanatien, Vicki; Davis, Corey S

    2016-12-01

    Defining subpopulations using genetics has traditionally used data from microsatellite markers to investigate population structure; however, single-nucleotide polymorphisms (SNPs) have emerged as a tool for detection of fine-scale structure. In Hudson Bay, Canada, three polar bear (Ursus maritimus) subpopulations (Foxe Basin (FB), Southern Hudson Bay (SH), and Western Hudson Bay (WH)) have been delineated based on mark-recapture studies, radiotelemetry and satellite telemetry, return of marked animals in the subsistence harvest, and population genetics using microsatellites. We used SNPs to detect fine-scale population structure in polar bears from the Hudson Bay region and compared our results to the current designations using 414 individuals genotyped at 2,603 SNPs. Analyses based on discriminant analysis of principal components (DAPC) and STRUCTURE support the presence of four genetic clusters: (i) Western-including individuals sampled in WH, SH (excluding Akimiski Island in James Bay), and southern FB (south of Southampton Island); (ii) Northern-individuals sampled in northern FB (Baffin Island) and Davis Strait (DS) (Labrador coast); (iii) Southeast-individuals from SH (Akimiski Island in James Bay); and (iv) Northeast-individuals from DS (Baffin Island). Population structure differed from microsatellite studies and current management designations demonstrating the value of using SNPs for fine-scale population delineation in polar bears.

  18. Peat analyses in the Hudson Bay Lowlands using ground penetrating radar

    NASA Technical Reports Server (NTRS)

    Pelletier, R. E.; Davis, J. L.; Rossiter, J. R.

    1991-01-01

    The use of ground penetrating radar (GPR) as a means to determine peak thickness and estimate peat volume in the Hudson Bay Lowlands of Canada is examined. Ground-based and airborne GPR data were acquired so as to extrapolate measurements to larger scales. While the ground-based measurements did an excellent job in determining peat depth, the airborne techniques did a fair job a low altitudes and demonstrated great promise with additional system engineering changes.

  19. The 'Mandarin-missionary' strategy: Robert Kennicott, Spencer Fullerton Baird and specimen collection in the Hudson's Bay Territory.

    PubMed

    Laubacher, Matthew

    2012-06-01

    In 1859, Robert Kennicott, one of the most promising specimen collectors and young naturalists in the United States, was dispatched to Hudson's Bay Territory by Spencer Fullerton Baird, the Assistant Secretary of the Smithsonian. Kennicott was chosen because of previous experience in Canada, the familiarity with biota of the American Midwest, and because he had a boundless, infectious, enthusiasm for natural history that was typical among Baird's closest protégées. Kennicott was a natural scientific envoy--or missionary--to the officers of the Hudson's Bay Company, and many officers were enthusiastically 'converted' to the cause of collecting and/or overseeing the collection of natural history specimens. Due to this collaboration between Baird, Kennicott and the officers of the Hudson's Bay Company, the Smithsonian became a leading center of Canadian natural history in the Western hemisphere.

  20. Inorganic carbon cycling and biogeochemical processes in an Arctic inland sea (Hudson Bay)

    NASA Astrophysics Data System (ADS)

    Burt, William J.; Thomas, Helmuth; Miller, Lisa A.; Granskog, Mats A.; Papakyriakou, Tim N.; Pengelly, Leah

    2016-08-01

    The distributions of carbonate system parameters in Hudson Bay, which not only receives nearly one-third of Canada's river discharge but is also subject to annual cycles of sea-ice formation and melt, indicate that the timing and magnitude of freshwater inputs play an important role in carbon biogeochemistry and acidification in this unique Arctic ecosystem. This study uses basin-wide measurements of dissolved inorganic carbon (DIC) and total alkalinity (TA), as well as stable isotope tracers (δ18O and δ13CDIC), to provide a detailed assessment of carbon cycling processes within the bay. Surface distributions of carbonate parameters reveal the particular importance of freshwater inputs in the southern portion of the bay. Based on TA, we surmise that the deep waters in the Hudson Bay are largely of Pacific origin. Riverine TA end-members vary significantly both regionally and with small changes in near-surface depths, highlighting the importance of careful surface water sampling in highly stratified waters. In an along-shore transect, large increases in subsurface DIC are accompanied by equivalent decreases in δ13CDIC with no discernable change in TA, indicating a respiratory DIC production on the order of 100 µmol kg-1 DIC during deep water circulation around the bay.

  1. Seismic imaging of the lithosphere beneath Hudson Bay: Episodic growth of the Laurentian mantle keel

    NASA Astrophysics Data System (ADS)

    Darbyshire, Fiona A.; Eaton, David W.; Bastow, Ian D.

    2013-07-01

    The Hudson Bay basin in northern Canada conceals one of the major collisional zones of the Canadian Shield, the Trans-Hudson Orogen (THO), which marks the Paleoproterozoic collision between the Archean Superior and Western Churchill cratons at ˜1.9-1.8Ga. Improved knowledge of upper mantle structure beneath the region is essential to establish the nature of the THO, specifically whether Himalayan-style plate tectonics operated in Paleoproterozoic times. Detailed seismological constraints on lithospheric architecture are also required to advance our understanding of the mechanism and timing of keel formation. We use surface wave tomography to illuminate new details of the lithospheric architecture of the Hudson Bay region, resolving both seismic wavespeed and azimuthal anisotropy. Phase velocity maps are calculated from fundamental-mode Rayleigh wave dispersion curves, then used to construct a 3D model exploring upper mantle structure to depths of ˜300km. Fast shear wavespeeds suggest a lithospheric thickness varying from ˜180km to almost 280 km beneath the Hudson Bay region. The new study confirms previous inferences that there is no correlation between crustal ages and lithospheric thickness. Patterns of shear wavespeed and azimuthal anisotropy indicate a layered lithosphere. In the uppermost mantle, both the highest velocities and the anisotropic fast directions wrap around the Bay. This structure is likely related to the formation processes of the Paleozoic intracratonic basin. At greater depth (˜70-150km) we resolve two high-wavespeed cores separated by a relatively narrow near-vertical lower-velocity curtain. This internal architecture is suggested to result from the terminal phase of a modern-style plate-tectonic collision between the Archean Superior and Churchill cratons during the Trans-Hudson orogeny, entrapping juvenile Proterozoic material. The lower lithosphere (≥160km depth) has a relatively homogeneous wavespeed structure across the region

  2. The Fur Trade as an Environment for Education: Problems and Implications from Hudson Bay.

    ERIC Educational Resources Information Center

    Brown, Jennifer S. H.

    Fur trade settlements in North America were a fertile environment for cultural education. The fur trade became a network of closely linked social spheres in which individuals had to acquire competence in order to function and survive. The Hudson Bay Company's decision to plant permanent posts on the shores of the Hudson Bay put settlers and their…

  3. Exchange of nitrous oxide within the Hudson Bay lowland

    NASA Technical Reports Server (NTRS)

    Schiller, C. L.; Hastie, D. R.

    1994-01-01

    The source strength of atmospheric trace gases from natural ecosystems must be quantified in order to assess the effect of such inputs on the background tropospheric chemistry. A static chamber technique and a gas exchange technique were used to determine the emissions of nitrous oxide from five sites within the Hudson Bay Lowland, as part of the Northern Wetland Study. Two mechanisms, one diffusive and the other episodic, were found likely to be responsible for the emissions of nitrous oxide. The annual diffusive flux ranged from -3.8 mg(N2O)/sq m in a treed bog to 7.9 mg(N2O)/sq m in an open fen. The addition of the episodic flux, increased this range to -2.1 mg(N2O)/sq m and 18.5 mg(N2O)/sq m respectively. These episodic emissions occurred in from 2.5% to 16.7% of the samples during the late summer peak emission period. Since the gas exchange rate could not detect the episodic emissions, it was found to be a poor method for water emission rate determination within the wetland. LANDSAT-Thermatic Mapper (TM) imagery was used to scale the emissions, from the chamber level to an integrated average over the entire Hudson Bay Lowland. The total emission rate of N2O from the Hudson Bay Lowland, was determined to be 1.2 Gg(N2O)/year, of which 80% was attributed to episodic emissions.

  4. Integrating shear velocity observations of the Hudson Bay

    NASA Astrophysics Data System (ADS)

    Porritt, R. W.; Miller, M. S.; Darbyshire, F. A.

    2013-12-01

    Hudson Bay is the core of the Laurentia craton of North America. This region contains some of the thickest lithosphere globally, reaching 250-300 km depth. Previous studies have shown that much of this region is composed of amalgamated proto-continents including the Western Churchill and Superior provinces and that much of the structure of these constituents has been retained since the Trans-Hudson Orogen at 1.8 Ga. Using the Hudson Bay Lithospheric Experiment (HuBLE) and other permanent and POLARIS broadband seismic data, we image the region with S to P receiver functions, joint inversion of P to S receiver functions with surface waves, and teleseismic S and P wave travel-times. The receiver function imaging reveals a persistent mid-lithospheric layer at ~80 km depth under all stations, but a variable lithospheric thickness. The teleseismic S delay times show a pattern of early arrivals around the center of the network, beneath Hudson Bay where the lithosphere is thickest, while the P delay times are early in the Superior province relative to the Western Churchill province. This suggests higher Vp/Vs ratios in the Superior province, which is evidence that stacked oceanic plates formed this province. The relatively flat Moho imaged by earlier receiver function studies and the lower mantle Vp/Vs of the Western Churchill province provides evidence of formation by plume head extraction. The joint inversion shows an LAB that is typically a broad discontinuity spanning ~20-30 km at ~220 km depth suggesting a primarily thermal boundary zone. The mid-lithospheric layer is composed of increasing velocity from the ~40 km depth Moho defined by H-k stacking of PRFs to a broad, constant velocity lithospheric lid spanning 80-200 km depth. We suggest this mid-lithospheric layer represents the mantle lithosphere of the proto-continents prior to collision and the lid formed due to post-collisional cooling. The integration of these seismic datasets furthers our understanding of

  5. On Measurements of the Tide at Churchill, Hudson Bay

    NASA Technical Reports Server (NTRS)

    Ray, Richard D.

    2016-01-01

    Since the late 1990s the semi-diurnal tide at Churchill, on the western shore of Hudson Bay, has been decreasing in amplitude, with M(sub 2) amplitudes falling from approximately 154 cm in 1998 to 146 cm in 2012 and 142 cm in 2014. There has been a corresponding small increase in phase lag. Mean low water, decreasing throughout most of the twentieth century, has levelled off. Although the tidal changes could reflect merely a malfunctioning tide gauge, the fact that there are no other measurements in the region and the possibility that the tide is revealing important environmental changes calls for serious investigation. Satellite altimeter measurements of the tide in Hudson Bay are complicated by the seasonal ice cover; at most locations less than 40% of satellite passes return valid ocean heights and even those can be impacted by errors from sea ice. Because the combined TOPEX/Poseidon, Jason-1, and Jason-2 time series is more than 23 years long, it is now possible to obtain sufficient data at crossover locations near Churchill to search for tidal changes. The satellites sense no changes in M(sub 2) that are comparable to the changes seen at the Churchill gauge. The changes appear to be localized to the harbour, or to the Churchill River, or to the gauge itself.

  6. Temporal evolution of Hudson Bay Sea Ice (1971-2011)

    NASA Astrophysics Data System (ADS)

    Kowal, Slawomir; Gough, William A.; Butler, Ken

    2017-02-01

    Previous work has found Hudson Bay seasonal sea ice particularly sensitive to climate change with a strong signal of earlier breakup dates. This work extends the previous analysis by including eight additional years of recent sea ice data. The expanded sea ice record, 1971 to 2011, revealed stronger and more statistically significant trends than the earlier work, most strikingly for the later freeze up. The average magnitude of the temporal trend for all 36 locations studied is 0.50 days/year for earlier breakup, 0.46 days/year for the later freeze-up, and 0.91 days/year for longer ice-free period. Of the 36 points, 12 points for the breakup period, 30 points for the freeze-up period, and 22 points for the ice-free season have accelerating temporal trends during the past decade.

  7. Precambrian Crustal Evolution of the Hudson Bay Region: Insights from Receiver Function Analysis (Invited)

    NASA Astrophysics Data System (ADS)

    Thompson, D. A.; Bastow, I. D.; Helffrich, G. R.; Kendall, J. M.; Wookey, J.; Snyder, D. B.; Eaton, D. W.

    2009-12-01

    The processes that formed, thickened and thinned the early Earth's crust remain poorly known. The onset of modern plate tectonics, for example, could be as far back as the Hadean or as late as the Neoproterozoic. In many cratons, vertical processes are believed to have been dominant (dome-and-keel tectonics, e.g. Pilbara craton), while others are hypothesised to have formed by the progressive accretion of different terranes (e.g. Superior craton). The Hudson Bay region represents one of the largest areas of Precambrian geology on the planet, with ages spanning 2 billion years (3.9-1.8 Ga). The western Churchill province contains the predominantly Paleo- to Mesoarchean Rae domain and the Neoarchean Hearne domain, and is welded to the Superior craton by the Paleoproterozoic Trans-Hudson Orogen, a Himalayan scale feature which extends for more than 4500 km along strike. The Churchill has received comparatively little scientific investigation due to its remote location and harsh climate. In order to test hypotheses on crustal formation and evolution during the Precambrian, teleseismic receiver functions have been analysed for more than 30 stations located on the key geological features in the vicinity of Hudson Bay. Across the entire Rae domain, a dominantly felsic crust with a sharp Moho is observed. Little evidence exists to interpret the vast extent of the felsic crust in terms of subduction related processes. Within the granite-greenstone terranes of the Hearne domain, a more intermediate bulk composition and complex Moho signature may be representative of an oceanic affinity for the crust, suggesting accretionary processes acted there. In the Quebec-Baffin Island region, bulk crustal Vp/Vs ratios are dominated by effects associated with the Trans-Hudson Orogen, and appear to map out the first-order shape of the indenting lower-plate. Correlation between terrane age and receiver function-derived crustal structure suggests that the crust in northern Canada was

  8. Low calcium carbonate saturation state in an Arctic inland sea having large and varying fluvial inputs: The Hudson Bay system

    NASA Astrophysics Data System (ADS)

    Azetsu-Scott, Kumiko; Starr, Michel; Mei, Zhi-Ping; Granskog, Mats

    2014-09-01

    The Hudson Bay system (HBS) is a shallow inland sea in the Arctic, composed of Hudson Strait, Foxe Basin/Channel, James Bay, and Hudson Bay. Dissolved inorganic carbon (DIC) and total alkalinity (TA) measurements were used to investigate the state of ocean acidification, specifically calcium carbonate saturation states (Ω) and pH. The freshwater sources were identified from the relationship between oxygen isotope composition (δ18O) and salinity to understand the role of freshwater in ocean acidification. The saturation state of seawater with respect to calcium carbonate (Ω) in surface water (<10 m) of the HBS was strongly influenced by river runoff. Aragonite under-saturation (Ωarg < 1) was observed in the surface water of the south-eastern Hudson Bay, where the river runoff fraction was high (>10%). The watershed characteristics, however, influenced the alkalinity of river runoff in different parts of Hudson Bay, which contributed to Ω variation in the coastal region. In southwestern Hudson Bay where the watershed is dominated by limestone, Ω was higher compared to eastern Hudson Bay, where the watershed consists of an igneous rock formation. In deeper waters, low Ω is caused by remineralization of organic matter. The highest DIC concentrations (>2300 µmol/kg) were observed in the depths of central Hudson Bay with a pHtotal of 7.49 and Ωarg of 0.37. Over 67% and 22% of the bottom water of Hudson Bay was undersaturated with respect to aragonite and calcite respectively, despite Hudson Bay being very shallow (less than 250 m deep). The aragonite saturation horizon in the central Hudson Bay was around 50 m.

  9. The Astronomical Work of Peter Fidler (1769-1822) and others employed by the Hudson's Bay Company

    NASA Astrophysics Data System (ADS)

    Broughton, P.

    1996-12-01

    The Hudson's Bay Company, founded in 1670, controlled the vast watershed of Hudson Bay until 1869. Its principal interest in the fur trade required maps and surveys as well as observations of native people and their habits, native species and their habitat, weather and conditions affecting travel. Accurate astronomical observations in western Canada began in 1768 when William Wales and Joseph Dymond wintered at Fort Churchill on the western shore of Hudson Bay and determined the longitude of that place in preparation for the transit of Venus the following spring. As competition forced the Company to establish inland posts, an urgent need arose for better maps and so, on the recommendation of Wales, the Company hired its first surveyor, Philip Turnor in 1778. At Buckingham House, a prairie outpost of the Company, Turnor schooled David Thompson and Peter Fidler in the art of astronomical surveying during the summer of 1790. Fidler's notebook provides a fascinating look at the rigorous training he received. Over the next twenty years, Thompson and Fidler made definitive maps covering all of western Canada. To achieve this, they made hundreds of astronomical observations using meridian altitudes for latitude and using lunar distances as well as phenomena of Jupiter's satellites for longitude. Their extensive work will be summarized and used to assess the accuracy of their methods. In addition, hundreds of observations of the aurora, mainly recorded by Fidler as part of his meteorological journal, will be shown to illustrate a maximum frequency of occurrence about 1795 and 1805, corresponding to the times of maxima in solar activity.

  10. Mercury and cortisol in Western Hudson Bay polar bear hair.

    PubMed

    Bechshoft, T; Derocher, A E; Richardson, E; Mislan, P; Lunn, N J; Sonne, C; Dietz, R; Janz, D M; St Louis, V L

    2015-08-01

    Non-invasive methods of assessing animal health and life history are becoming increasingly popular in wildlife research; hair samples from polar bears (Ursus maritimus), are being used to study an ever broader range of anthropogenic and endocrine compounds. A number of contaminants are known to disrupt endocrine function in polar bears. However, the relationship between mercury and cortisol remains unknown, although mercury is an endocrine disruptor in other species. Here, we examine the relationship between concentrations of cortisol and total mercury (THg) analyzed in guard hair from 378 polar bears (184 females, 194 males) sampled in Western Hudson Bay, 2004-2012. The difference in mean cortisol concentration between female (0.8 ± 0.6 pg/mg) and male (0.7 ± 0.5 pg/mg) polar bears bordered on significance (p = 0.054). However, mean mercury concentration was significantly greater (p = 0.009) in females (4.7 ± 1.4 μg/g) than males (4.3 ± 1.2 μg/g). Hair cortisol in males was significantly influenced by mercury, age, and fatness, as well as interactions between mercury and year, mercury and fatness, and year and fatness (all: p < 0.03) (multiple regression analysis, whole model: r(2) = 0.14, F(7,185) = 4.43, p = 0.0001). Fatness was the only significant variable in the multiple regression analysis for females (r(2) = 0.06, F(1,182) = 13.0, p = 0.0004). In conclusion, a significant, but complex, relationship was found between mercury and cortisol concentrations in hair from male, but not female, polar bears.

  11. Post-2 ka Carbon Accumulation in the James Bay and Hudson Bay Lowlands

    NASA Astrophysics Data System (ADS)

    Holmquist, J. R.; MacDonald, G. M.

    2012-12-01

    The James Bay, and Hudson Bay Lowlands of Canada (JBL/HBL) are the second largest peatland complex in the world and contain major stores of soil Carbon (C) (Keddy 2002). The goal of this study was to quantify the size, and rate of accumulation of these peatland C stocks since 2,000 years before present (2 ka), as well as investigate the effect of climate on vertical peat accumulation. We analyzed the relationship between 2 ka depth and mean annual air temperature (MAAT), growing degree days over 5°C (GDD5), and photosynthetically active radiation over the growing season ( PAR0). This study utilized a transect of eight peat cores from ombrotrophic bogs ranging from 55°25'N to 50°27'N. Carbon content was estimated using Loss-On-Ignition at 550°C and Bulk Density measurements. The ages of the deposits were estimated using 14C dates and BACON age-depth modeling. These new data were supplemented by 17 millennially resolved chronologies from a literature review. In the southwest JBL ombrotrophic peatlands accumulated between 63.03-16.85 kg C m-2 since 2 ka at a rate of 31.41-8.79 gC m-2 yr -1. 2 ka depth displays a significant latitudinal gradient (r2=0.45, p=2.45*10-4) with shallower deposits in northern permafrost peatlands. 2 ka ybp depth correlates significantly and positively with MAAT (r2=0.47, p=8.56*10-5), GDD5 (r2=0.58, p=9.36*10-5), and PAR0 (figure 1). These results support past research that shows 2 ka depth correlates significantly with MAAT in West Siberia (Beilman et al. 2009), as well as data that shows that PAR0 is a major driver of Sphagnum productivity (Loisel et al. 2012). These results support the idea that peatland vertical growth may increase in the HBL/JBL under projected climate change scenarios. Beilman, D.W., G.M. MacDonald, L.C. Smith, P.J. Reimer (2009). Carbon Accumulation in Peatlands of West Siberia over the Last 2000 Years. Biogeochemical Cycles. GB1012. Keddy, P.A. (2000) Wetland Ecology: Principles and Conservation. Cambridge

  12. Surface-Wave Tomographic Studies of the Hudson Bay Lithosphere: Implications for Paleoproterozoic Tectonic Processes and the Assembly of the Canadian Shield

    NASA Astrophysics Data System (ADS)

    Darbyshire, F. A.

    2015-12-01

    Hudson Bay is a shallow intracratonic basin that partially conceals the Trans-Hudson Orogen (THO) in northern Canada. The THO is thought to be a Himalayan-scale Paleoproterozoic orogenic event that was an important component of assembly of the Canadian Shield, marking the collision of the Archean Superior and Western Churchill plates. Until recently, only global and continental-scale seismic tomographic models had imaged the upper-mantle structure of the region, giving a broad but relatively low-resolution picture of the thick lithospheric keel. The Hudson Bay Lithospheric Experiment (HuBLE) investigated the present-day seismic structure beneath Hudson Bay and its surroundings, using a distributed broadband seismograph network installed around the periphery of the Bay and complemented by existing permanent and temporary seismographs further afield. This configuration, though not optimal for body-wave studies which use subvertical arrivals, is well-suited to surface wave tomographic techniques, with many paths crossing the Bay. As there is little seismicity in the region around the Canadian Shield, two-station measurements of teleseismic Rayleigh wave phase velocity formed the principal data set for lithospheric studies. The interstation measurements were combined in a linearized tomographic inversion for maps of phase velocity and azimuthal anisotropy at periods of 20-200 s; these maps were then used to calculate a pseudo-3D anisotropic upper-mantle shear-wavespeed model of the region. The model shows thick (~180-260 km), seismically fast lithosphere across the Hudson Bay region, with a near-vertical 'curtain' of lower wavespeeds trending NE-SW across the Bay, likely associated with more juvenile material trapped between the Archean Superior and Churchill continental cores during the THO. The lithosphere is layered, suggesting a 2-stage formation process. Seismic anisotropy patterns vary with depth; a circular pattern in the uppermost mantle wrapping around the

  13. Effects of earlier sea ice breakup on survival and population size of polar bears in western Hudson Bay

    USGS Publications Warehouse

    Regehr, E.V.; Lunn, N.J.; Amstrup, Steven C.; Stirling, I.

    2007-01-01

    Some of the most pronounced ecological responses to climatic warming are expected to occur in polar marine regions, where temperature increases have been the greatest and sea ice provides a sensitive mechanism by which climatic conditions affect sympagic (i.e., with ice) species. Population-level effects of climatic change, however, remain difficult to quantify. We used a flexible extension of Cormack-Jolly-Seber capture-recapture models to estimate population size and survival for polar bears (Ursus maritimus), one of the most ice-dependent of Arctic marine mammals. We analyzed data for polar bears captured from 1984 to 2004 along the western coast of Hudson Bay and in the community of Churchill, Manitoba, Canada. The Western Hudson Bay polar bear population declined from 1,194 (95% CI = 1,020-1,368) in 1987 to 935 (95% CI = 794-1,076) in 2004. Total apparent survival of prime-adult polar bears (5-19 yr) was stable for females (0.93; 95% CI = 0.91-0.94) and males (0.90; 95% CI = 0.88-0.91). Survival of juvenile, subadult, and senescent-adult polar bears was correlated with spring sea ice breakup date, which was variable among years and occurred approximately 3 weeks earlier in 2004 than in 1984. We propose that this correlation provides evidence for a causal association between earlier sea ice breakup (due to climatic warming) and decreased polar bear survival. It may also explain why Churchill, like other communities along the western coast of Hudson Bay, has experienced an increase in human-polar bear interactions in recent years. Earlier sea ice breakup may have resulted in a larger number of nutritionally stressed polar bears, which are encroaching on human habitations in search of supplemental food. Because western Hudson Bay is near the southern limit of the species' range, our findings may foreshadow the demographic responses and management challenges that more northerly polar bear populations will experience if climatic warming in the Arctic continues as

  14. Groups of related belugas (Delphinapterus leucas) travel together during their seasonal migrations in and around Hudson Bay

    PubMed Central

    Colbeck, Gabriel J.; Duchesne, Pierre; Postma, Lianne D.; Lesage, Véronique; Hammill, Mike O.; Turgeon, Julie

    2013-01-01

    Social structure involving long-term associations with relatives should facilitate the learning of complex behaviours such as long-distance migration. In and around Hudson Bay (Canada), three stocks of beluga whales form a panmictic unit, but have different migratory behaviours associated with different summering areas. We analysed genetic variation at 13 microsatellite loci among 1524 belugas, to test hypotheses about social structure in belugas. We found significant proportions of mother–offspring pairs throughout the migratory cycle, but average relatedness extended beyond close kinship only during migration. Average relatedness was significantly above random expectations for pairs caught at the same site but on different days or months of a year, suggesting that belugas maintain associations with a network of relatives during migration. Pairs involving a female (female–female or male–female) were on average more related than pairs of males, and males seemed to disperse from their matrilineal group to associate with other mature males. Altogether, our results indicate that relatives other than strictly parents, and especially females, play a role in maintaining a social structure that could facilitate the learning of migration routes. Cultural conservatism may limit contributions from nearby summer stocks to endangered stocks such as the Eastern Hudson Bay beluga. PMID:23222451

  15. Groups of related belugas (Delphinapterus leucas) travel together during their seasonal migrations in and around Hudson Bay.

    PubMed

    Colbeck, Gabriel J; Duchesne, Pierre; Postma, Lianne D; Lesage, Véronique; Hammill, Mike O; Turgeon, Julie

    2013-02-07

    Social structure involving long-term associations with relatives should facilitate the learning of complex behaviours such as long-distance migration. In and around Hudson Bay (Canada), three stocks of beluga whales form a panmictic unit, but have different migratory behaviours associated with different summering areas. We analysed genetic variation at 13 microsatellite loci among 1524 belugas, to test hypotheses about social structure in belugas. We found significant proportions of mother-offspring pairs throughout the migratory cycle, but average relatedness extended beyond close kinship only during migration. Average relatedness was significantly above random expectations for pairs caught at the same site but on different days or months of a year, suggesting that belugas maintain associations with a network of relatives during migration. Pairs involving a female (female-female or male-female) were on average more related than pairs of males, and males seemed to disperse from their matrilineal group to associate with other mature males. Altogether, our results indicate that relatives other than strictly parents, and especially females, play a role in maintaining a social structure that could facilitate the learning of migration routes. Cultural conservatism may limit contributions from nearby summer stocks to endangered stocks such as the Eastern Hudson Bay beluga.

  16. Paleoproterozoic Collisional Structures in the Hudson Bay Lithosphere Constrained by Multi-Observable Probabilistic Inversion

    NASA Astrophysics Data System (ADS)

    Darbyshire, F. A.; Afonso, J. C.; Porritt, R. W.

    2015-12-01

    The Paleozoic Hudson Bay intracratonic basin conceals a Paleoproterozoic Himalayan-scale continental collision, the Trans-Hudson Orogen (THO), which marks an important milestone in the assembly of the Canadian Shield. The geometry of the THO is complex due to the double-indentor geometry of the collision between the Archean Superior and Western Churchill cratons. Seismic observations at regional scale show a thick, seismically fast lithospheric keel beneath the entire region; an intriguing feature of recent models is a 'curtain' of slightly lower wavespeeds trending NE-SW beneath the Bay, which may represent the remnants of more juvenile material trapped between the two Archean continental cores. The seismic models alone, however, cannot constrain the nature of this anomaly. We investigate the thermal and compositional structure of the Hudson Bay lithosphere using a multi-observable probabilistic inversion technique. This joint inversion uses Rayleigh wave phase velocity data from teleseismic earthquakes and ambient noise, geoid anomalies, surface elevation and heat flow to construct a pseudo-3D model of the crust and upper mantle. Initially a wide range of possible mantle compositions is permitted, and tests are carried out to ascertain whether the lithosphere is stratified with depth. Across the entire Hudson Bay region, low temperatures and a high degree of chemical depletion characterise the mantle lithosphere. Temperature anomalies within the lithosphere are modest, as may be expected from a tectonically-stable region. The base of the thermal lithosphere lies at depths of >250 km, reaching to ~300 km depth in the centre of the Bay. Lithospheric stratification, with a more-depleted upper layer, is best able to explain the geophysical data sets and surface observables. Some regions, where intermediate-period phase velocities are high, require stronger mid-lithospheric depletion. In addition, a narrow region of less-depleted material extends NE-SW across the Bay

  17. HuBLE-UK, the Hudson Bay Lithospheric Experiment: Insights into the formation of the Canadian Shield

    NASA Astrophysics Data System (ADS)

    Bastow, I. D.; Kendall, J.; Helffrich, G.; Wookey, J.; Thompson, D.; Eaton, D.; Snyder, D.

    2008-12-01

    Hudson Bay lies in the Precambrian core of North America, which is comprised of the Canadian Shield and contiguous platform regions. The region is underlain by one of the largest lithospheric keels on Earth; it is also the site of one of the largest negative geoid anomalies. We have deployed 10 broadband seismic stations in the northern part of the bay that complement the existing POLARIS, CHASME and CNSN network stations in the region. Here we present preliminary SKS shear wave splitting analyses and independent tomographic inversion of P- and S-wave travel-time data in order to: 1) understand better the origin and evolution of the Hudson Bay cratonic interior basins; 2) to illuminate possible relationships between the lithospheric keel, sub-lithospheric mantle flow and formation of the Hudson Bay basin; 3) to improve understanding of postglacial isostatic rebound; 4) to map the lithospheric structure of the Trans-Hudson orogen in a region characterized by extreme salient-reentrant geometry, possibly analogous to the western syntaxis of the Himalayan front. SKS delay times vary from 0.5-1.2s, which indicate a lithospheric-scale anisotropic layer up to 150km thick. However, SKS fast directions and preliminary tomographic images do not relate simply to the structural trends of the Trans Hudson Orogen and neighboring Archean terranes. Our work complements ongoing HuBLE studies that focus on receiver function analyses, dispersion analysis of teleseismic Rayleigh waves, and applications of ambient noise tomography that extract more information about lithospheric structure of the Hudson Bay basin.

  18. A History of Vegetation, Sediment and Nutrient Dynamics at Tivoli North Bay, Hudson Estuary, New York

    NASA Technical Reports Server (NTRS)

    Sritrairat, Sanpisa; Peteet, Dorothy M.; Kenna, Timothy C.; Sambrotto, Ray; Kurdyla, Dorothy; Guilderson, Tom

    2012-01-01

    We conduct a stratigraphic paleoecological investigation at a Hudson River National Estuarine Research Reserve (HRNERR) site, Tivoli Bays, spanning the past 1100 years. Marsh sediment cores were analyzed for ecosystem changes using multiple proxies, including pollen, spores, macrofossils, charcoal, sediment bulk chemistry, and stable carbon and nitrogen isotopes. The results reveal climatic shifts such as the warm and dry Medieval Warm Period (MWP) followed by the cooler Little Ice Age (LIA), along with significant anthropogenic influence on the watershed ecosystem. A five-fold expansion of invasive species, including Typha angustifolia and Phragmites australis, is documented along with marked changes in sediment composition and nutrient input. During the last century, a ten-fold sedimentation rate increase due to land-use changes is observed. The large magnitude of shifts in vegetation, sedimentation, and nutrients during the last few centuries suggest that human activities have made the greatest impact to the marshes of the Hudson Estuary during the last millennium. Climate variability and ecosystem changes similar to those observed at other marshes in northeastern and mid-Atlantic estuaries, attest to the widespread regional signature recorded at Tivoli Bays.

  19. Carbon storage and potential methane production in the Hudson Bay Lowlands since mid-Holocene peat initiation.

    PubMed

    Packalen, Maara S; Finkelstein, Sarah A; McLaughlin, James W

    2014-06-11

    Peatlands have influenced Holocene carbon (C) cycling by storing atmospheric C and releasing methane (CH4). Yet, our understanding of contributions from the world's second largest peatland, the Hudson Bay Lowlands (HBL), Canada, to peat-climate-C-dynamics is constrained by the paucity of dated peat records and regional C-data. Here we examine HBL peatland development in relation to Holocene C-dynamics. We show that peat initiation in the HBL is tightly coupled with glacial isostatic adjustment (GIA) through most of the record, and occurred within suitable climatic conditions for peatland development. HBL peatlands initiated most intensively in the mid-Holocene, when GIA was most rapid and climate was cooler and drier. As the peat mass developed, we estimate that the HBL potentially released 1-7 Tg CH4 per year during the late Holocene. Our results indicate that the HBL currently stores a C-pool of ~30 Pg C and provide support for a peatland-derived CH4 contribution to the late Holocene atmosphere.

  20. Estimating the abundance of the Southern Hudson Bay polar bear subpopulation with aerial surveys

    USGS Publications Warehouse

    Obbard, Martyn E.; Stapleton, Seth P.; Middel, Kevin R.; Thibault, Isabelle; Brodeur, Vincent; Jutras, Charles

    2015-01-01

    The Southern Hudson Bay (SH) polar bear subpopulation occurs at the southern extent of the species’ range. Although capture–recapture studies indicate abundance was likely unchanged between 1986 and 2005, declines in body condition and survival occurred during the period, possibly foreshadowing a future decrease in abundance. To obtain a current estimate of abundance, we conducted a comprehensive line transect aerial survey of SH during 2011–2012. We stratified the study site by anticipated densities and flew coastal contour transects and systematically spaced inland transects in Ontario and on Akimiski Island and large offshore islands in 2011. Data were collected with double-observer and distance sampling protocols. We surveyed small islands in James Bay and eastern Hudson Bay and flew a comprehensive transect along the Québec coastline in 2012. We observed 667 bears in Ontario and on Akimiski Island and nearby islands in 2011, and we sighted 80 bears on offshore islands during 2012. Mark–recapture distance sampling and sight–resight models yielded an estimate of 860 (SE = 174) for the 2011 study area. Our estimate of abundance for the entire SH subpopulation (943; SE = 174) suggests that abundance is unlikely to have changed significantly since 1986. However, this result should be interpreted cautiously because of the methodological differences between historical studies (physical capture–recapture) and this survey. A conservative management approach is warranted given previous increases in duration of the ice-free season, which are predicted to continue in the future, and previously documented declines in body condition and vital rates.

  1. Estimating abundance of the Southern Hudson Bay polar bear subpopulation using aerial surveys, 2011 and 2012

    USGS Publications Warehouse

    Obbard, Martyn E.; Middel, Kevin R.; Stapleton, Seth P.; Thibault, Isabelle; Brodeur, Vincent; Jutras, Charles

    2013-01-01

    The Southern Hudson Bay (SH) polar bear subpopulation occurs at the southern extent of the species’ range. Although capture-recapture studies indicate that abundance remained stable between 1986 and 2005, declines in body condition and survival were documented during the period, possibly foreshadowing a future decrease in abundance. To obtain a current estimate of abundance, we conducted a comprehensive line transect aerial survey of SH during 2011–2012. We stratified the study site by anticipated densities and flew coastal contour transects and systematically spaced inland transects in Ontario and on Akimiski Island and large offshore islands in 2011. Data were collected with double observer and distance sampling protocols. We also surveyed small islands in Hudson Bay and James Bay and flew a comprehensive transect along the Québec coastline in 2012. We observed 667 bears in Ontario and on Akimiski Island and nearby islands in 2011, and we sighted 80 bears on offshore islands during 2012. Mark-recapture distance sampling and sightresight models yielded a model-averaged estimate of 868 (SE: 177) for the 2011 study area. Our estimate of abundance for the entire SH subpopulation (951; SE: 177) suggests that abundance has remained unchanged. However, this result should be interpreted cautiously because of the methodological differences between historical studies (physical capture) and this survey. A conservative management approach is warranted given the previous increases in the duration of the ice-free season, which are predicted to continue in the future, and previously documented declines in body condition and vital rates.

  2. Streamflow characteristics of the Hudson Bay and Upper Missouri River Basins, Montana, through 1979

    USGS Publications Warehouse

    Shields, Ronald R.; White, Melvin K.

    1981-01-01

    Statistical summaries of streamflow data for selected gaging stations are presented in this report to aid in appraising the hydrology of the Hudson Bay and upper Missouri River basins in Montana. Streamflow records are presented for 122 gaging stations for the period of record of each station. Streamflow-record collection in the Missouri River basin began in 1890 at Fort Benton, Mont. For each streamflow-gaging station selected for this report, a brief description is given for station location, drainage area, period of record, revisions of previously published records, type and history of gages, regulation and diversions, average discharge, and extremes of discharge. These data are followed by tables of monthly and annual mean discharge, flood-frequency data, low-flow and high-flow frequency data, and flow-duration information. (USGS)

  3. Thermal regime of shallow water bodies in the coastal tundra zone of the Hudson Bay Lowlands

    NASA Astrophysics Data System (ADS)

    Duguay, C. R.; Soliman, A. S.; Macrae, M. L.

    2011-12-01

    Many shallow lakes and ponds of the Arctic/sub-Arctic contain thick, organic-rich sediments, which have the potential to release significant amounts of CO2 or CH4 to the atmosphere if sediment decomposition rates increase in response to warmer temperatures caused by global warming. This may be exacerbated by a deepening of the seasonal sediment thaw depth in small water bodies that are underlain by permafrost. An important step in linking climatic conditions to rates of organic matter decomposition and gas production from shallow water bodies is an improved understanding of the thermal properties of lake sediments and how sediment temperatures fluctuate in response to changing air temperatures. This knowledge is also important if the ratio of terrestrial to aquatic landscape units in cold regions changes under a warmer climate. One approach that has been used in terrestrial permafrost environments is the examination of how mean annual permafrost surface temperature deviates from mean annual 2-m screen height air temperature (MAAT). The offset between MAAT and the mean annual sediment surface temperature (MASST) has been found to be much larger in deep aquatic systems (greater than 10 m) than in terrestrial permafrost systems due to the presence of the water column that can efficiently transfer heat through mixing. However, the efficiency of heat transfer in shallow water bodies is expected to larger in summer (thawed) than in winter (frozen) conditions, when thermal energy must move by conduction alone. The present study examined the efficiency of sediment heat transfer in shallow water bodies (less than 3 m) during summer and winter periods. Air, sediment and water temperatures of three shallow water bodies in the coastal tundra zone of the Hudson Bay Lowlands near Churchill, Manitoba, Canada were monitored (December 2009-August 2011). Arrays of thermistors and heat pulse probes were placed at 10 cm increments between 20 cm above the water/sediment interface and

  4. Constraints on mantle viscosity from relative sea level variations in Hudson Bay

    NASA Technical Reports Server (NTRS)

    Mitrovica, J. X.; Peltier, W. R.

    1992-01-01

    Frechet kernels for the RSL data in Hunson Bay are computed to determine the detailed depth-dependent sensitivity of the data to variations in a viscosity profile which is consistent with the past inferences. The RSL data provide a robust constraint on the average viscosity in the top half of the lower mantle only (the average must be near 10 exp 21 Pa s). The data admit models whose average viscosity in the deep mantle (below 1800 km depth) and in the upper mantle can differ significantly from the value (near 10 exp 21 Pa s) estimated for the top half of the lower mantle. The total variation in the viscosity from the surface to the CMB can exceed an order of magnitude or more and still satisfy the constraint provided by the Hudson Bay RSL data set. The necessity of invoking an isoviscous mantle model in previous studies is a consequence of the limited class of viscosity model solutions employed in those studies.

  5. Dietary composition and spatial patterns of polar bear foraging on land in western Hudson Bay

    PubMed Central

    2013-01-01

    Background Flexible foraging strategies, such as prey switching, omnivory and food mixing, are key to surviving in a labile and changing environment. Polar bears (Ursus maritimus) in western Hudson Bay are versatile predators that use all of these strategies as they seasonally exploit resources across trophic levels. Climate warming is reducing availability of their ice habitat, especially in spring when polar bears gain most of their annual fat reserves by consuming seal pups before coming ashore in summer. How polar bears combine these flexible foraging strategies to obtain and utilize terrestrial food will become increasingly important in compensating for energy deficits from lost seal hunting opportunities. We evaluated patterns in the composition of foods in scat to characterize the foraging behaviors that underpin the diet mixing and omnivory observed in polar bears on land in western Hudson Bay. Specifically, we measured diet richness, proportions of plant and animal foods, patterns in co-occurrence of foods, spatial composition and an index of temporal composition. Results Scats contained between 1 and 6 foods, with an average of 2.11 (SE = 0.04). Most scats (84.9%) contained at least one type of plant, but animals (35.4% of scats) and both plants and animals occurring together (34.4% of scats) were also common. Certain foods, such as Lyme grass seed heads (Leymus arenarius), berries and marine algae, were consumed in relatively higher proportions, sometimes to the exclusion of others, both where and when they occurred most abundantly. The predominance of localized vegetation in scats suggests little movement among habitat types between feeding sessions. Unlike the case for plants, no spatial patterns were found for animal remains, likely due the animals’ more vagile and ubiquitous distribution. Conclusions Our results suggest that polar bears are foraging opportunistically in a manner consistent with maximizing intake while minimizing energy

  6. HuBLE-UK: the Hudson Bay Lithospheric Experiment: Insights into the Formation of the Canadian Shield From Broadband Seismology

    NASA Astrophysics Data System (ADS)

    Bastow, I. D.; Thompson, D. A.; Kendall, J.-M.; Helffrich, G.; Wookey, J.; Snyder, D.; Eaton, D.; Darbyshire, F.

    2012-04-01

    The Canadian Shield is one of the largest exposures of Precambrian rocks on Earth. It is a mosaic of several Archean terranes that were brought together during a series of Paleoproterozoic orogens culminating in the so-called Trans-Hudson orogen, which is thought to have been similar to the Himalayan orogen in scale and nature. The tectonic evolution and lithospheric subdivisions of this region are poorly understood, but new seismic networks in northern Hudson Bay provide fresh opportunity to place constraints on the Preachbrian processes that formed and shaped it. Using a combination of seismic tomography, anisotropy and receiver function analysis we show that the lithosphere of the northern Hudson Bay region retains a strong signature of Archean-Paleoproterozoic tectonics. We map the boundary between the upper (Churchill) and lower (Superior) plates that collided ca. 1.8 Ga and identify backazimuth dependent shear-wave splitting parameters (phi, dt) on Baffin Island that indicate complex anisotropy (e.g., dipping fabric) beneath the region. Our results support the view that significant lithospheric deformation occurred during the Paleoproterozoic and that modern-day plate tectonic processes were thus in operation by at least ca. 1.8 Ga.

  7. What to eat now? Shifts in polar bear diet during the ice-free season in western Hudson Bay

    PubMed Central

    Gormezano, Linda J; Rockwell, Robert F

    2013-01-01

    Under current climate trends, spring ice breakup in Hudson Bay is advancing rapidly, leaving polar bears (Ursus maritimus) less time to hunt seals during the spring when they accumulate the majority of their annual fat reserves. For this reason, foods that polar bears consume during the ice-free season may become increasingly important in alleviating nutritional stress from lost seal hunting opportunities. Defining how the terrestrial diet might have changed since the onset of rapid climate change is an important step in understanding how polar bears may be reacting to climate change. We characterized the current terrestrial diet of polar bears in western Hudson Bay by evaluating the contents of passively sampled scat and comparing it to a similar study conducted 40 years ago. While the two terrestrial diets broadly overlap, polar bears currently appear to be exploiting increasingly abundant resources such as caribou (Rangifer tarandus) and snow geese (Chen caerulescens caerulescens) and newly available resources such as eggs. This opportunistic shift is similar to the diet mixing strategy common among other Arctic predators and bear species. We discuss whether the observed diet shift is solely a response to a nutritional stress or is an expression of plastic foraging behavior. PMID:24223286

  8. Drought as a Disturbance: Implications for Peatland Carbon Budgets in the Hudson Bay Lowland

    NASA Astrophysics Data System (ADS)

    Bello, R.; Abnizova, A.; Miller, E.

    2009-05-01

    Carbon feedbacks are of particular importance in high latitudes, both because of large circumpolar peatland carbon pools and because climate warming is occurring more rapidly at these latitudes. Longer-term net ecosystem exchange will be influenced by the capacity of plant communities to respond to changing conditions. The nature of community change and the factors inducing change are examined in this study of a disturbance generated by severe drought in 1994 causing widespread mortality in the dominant moss, Dicranum elongatum, occupying an upland tundra site within the Hudson Bay Lowland near Churchill, Manitoba. One quarter of this moss has recently died and become encrusted with the micro-lichen, Ochrolechia spp. Moss cushions affected in this manner exhibit strong allelopathic inhibition of seedling establishment progressing to complete moss decay. Chamber NEE growing-season flux measurements show an average net release of 642 mg C /m2/d from the dead moss compared to an average net uptake of 164 mg C /m2/d from completely healthy cushions. Between these two extremes, stressed living moss cushions support abundant seedling cover which increases in direct proportion with the fractional mortality. A proxy method for estimating the growth rates of cushions, based on the length of green living shoots, indicates that the moss community is uniform in age and established shortly after the most severe drought of historical record in 1966. Subsequent growth rates of cushions show a strong dependency on proximity to the water table (4.17-1.11 mm/y over 58 cm height interval). A growing-season moss water budget identifies the dominant water flow pathways and indicates capillary uptake (0.08 mm h-1) provides 64% of the storage gains, emphasizing the importance of groundwater for growth and survival. Maximum storage capacities are directly related to cushion biomass, leading to both enhanced moisture stress and increased susceptibility to mortality as cushion size

  9. Carbon trace gas fluxes along a successional gradient in the Hudson Bay lowland

    NASA Astrophysics Data System (ADS)

    Klinger, Lee F.; Zimmerman, Patrick R.; Greenberg, James P.; Heidt, Leroy E.; Guenther, Alex B.

    1994-01-01

    Patterns and controls of carbon trace gas emissions from wetlands may vary depending upon the spatial and temporal scale being examined. The factors affecting these emissions are thought to be hierarchically related according to their respective scales of importance. A hierarchical model of processes controlling methane emissions from wetlands is presented and examined here. During the 1990 Northern Wetlands Study (NOWES) methane (CH4), carbon dioxide (CO2), and non-methane hydrocarbon (NMHC) fluxes were measured in static chambers along a 100 km transect in the Hudson Bay lowland (HBL). Environmental variables, vegetation abundance, and ecosystem age and structure were also quantified at each sampling site. The findings indicate that CH4 emissions from peatlands (e.g., bogs and fens) and other wetlands (e.g., salt marshes) in the region were low, and were nil or negative (i.e., CH4 uptake) in forests and bog forests dominated by aspen and black spruce. Site to site variations in mean CH4 flux appeared to be most closely related to mean water table and sedge productivity, both of which are intercorrelated. Seasonal changes in CH4 flux tend to follow soil temperature fluctuations. Instantaneous CO2 and CH4 daytime fluxes exhibit a negative correlation, suggesting that photosynthetic assimilation of carbon may be related to CH4 emissions, although the processes of CO2 and CH4 production are occurring at somewhat different temporal scales. No diurnal variations in CH4 flux could be detected. While soil water pH trends are not fully explored, there is some indication that high CH4 fluxes are concentrated around pH 4 and pH 7. Soil temperature closely follows the seasonal progression of CH4 flux. Estimated CH4 seasonal flux (1.5-3.9 g CH4 m-2 season-1) and estimated aboveground net primary productivity (NPP) (90-400 g dry weight m-2 season-1) show systematic changes along a successional sequence which are consistent with patterns predicted from successional theory

  10. HuBLE-UK, the Hudson Bay Lithospheric Experiment: Insights into the Formation of the Canadian Shield From Seismic Tomography and Shear-Wave Splitting.

    NASA Astrophysics Data System (ADS)

    Bastow, Ian; Thompson, David; Kendall, J.-Michael; Helffrich, George; Wookey, James; Snyder, David; Eaton, David; Darbyshire, Fiona

    2010-05-01

    Hudson Bay lies in the Precambrian core of North America that comprises the Canadian Shield and contiguous platform regions. The region is underlain by one of Earth's largest lithospheric keels and is the site of one of the largest negative geoid anomalies. We have deployed a network of 12 broadband seismic stations in the northern part of Hudson Bay that complement existing POLARIS and CNSN networks in the region. Here we present SKS shear-wave splitting analyses, independent tomographic inversion of P- and S-wave travel-time data, and receiver function results in order to: 1) understand better the origin and evolution of the Hudson Bay cratonic interior basin; 2) to illuminate possible relationships between the lithospheric keel, sub-lithospheric mantle flow and formation of the Hudson Bay basin; 3) to improve understanding of postglacial isostatic rebound; 4) to map the lithospheric structure of the Trans-Hudson Orogen (THO) in a region characterized by extreme salient-reentrant geometry, possibly analogous to the western syntaxis of the Himalayan front. SKS fast directions appear sensitive to Paleoproterozoic THO lithospheric fabrics, not trends that would be predicted by mantle flow or plate motion basal drag hypotheses. SKS delay times vary from 0.5-1.6s, which indicate a lithospheric-scale anisotropic layer at least 150km thick. Tomographic images of the region also shed new light on the THO and neighboring Archean terranes. Our work complements ongoing HuBLE studies that focus on dispersion analysis of teleseismic Rayleigh waves, and applications of ambient noise tomography that extract additional complementary information about lithospheric structure of the region.

  11. HuBLE-UK, the Hudson Bay Lithospheric Experiment: Insights into the Formation of the Canadian Shield From Seismic Tomography and Shear-Wave Splitting

    NASA Astrophysics Data System (ADS)

    Bastow, I. D.; Kendall, J. M.; Helffrich, G. R.; Wookey, J.; Thompson, D. A.; Snyder, D. B.; Eaton, D. W.; Darbyshire, F. A.

    2009-12-01

    Hudson Bay lies in the Precambrian core of North America that comprises the Canadian Shield and contiguous platform regions. The region is underlain by one of Earth's largest lithospheric keels and is the site of one of the largest negative geoid anomalies. We have deployed a network of 12 broadband seismic stations in the northern part of Hudson Bay that complement existing POLARIS and CNSN networks in the region. Here we present SKS shear-wave splitting analyses and independent tomographic inversion of P- and S-wave travel-time data in order to: 1) understand better the origin and evolution of the Hudson Bay cratonic interior basin; 2) to illuminate possible relationships between the lithospheric keel, sub-lithospheric mantle flow and formation of the Hudson Bay basin; 3) to improve understanding of postglacial isostatic rebound; 4) to map the lithospheric structure of the Trans-Hudson Orogen (THO) in a region characterized by extreme salient-reentrant geometry, possibly analogous to the western syntaxis of the Himalayan front. SKS fast directions appear sensitive to Paleoproterozoic THO lithospheric fabrics, not trends that would be predicted by mantle flow or plate motion basal drag hypotheses. SKS delay times vary from 0.5-1.6s, which indicate a lithospheric-scale anisotropic layer at least 150km thick. Tomographic images of the region also shed new light on the THO and neighboring Archean terranes. Our work complements ongoing HuBLE studies that focus on receiver function study, dispersion analysis of teleseismic Rayleigh waves, and applications of ambient noise tomography that extract additional complementary information about lithospheric structure of the region.

  12. Recent cooling along the southern shore of Hudson Strait, Quebec, Canada, documented from permafrost temperature measurements

    SciTech Connect

    Allard, M.; Wang, B.; Pilon, J.A.

    1995-05-01

    Permafrost temperatures from the surface down to about 20 m from 10 boreholes distributed around three villages on the coast of Hudson Strait (Salluit, Kangiqsujuaq, and Quaqtaq) were recorded and analyzed for the period 1988-1993. The results indicate that the permafrost has been regularly cooling along the southern shore of Hudson Strait. The observed trend in the order of 0.05{degrees}C yr{sup {minus}1} at the 20-m depth is consistent with the long-term regional cooling observed in air temperatures. It also coincides with an increased rate of cooling since the mid-1980s, which has been interpreted in the literature as being related to recurrent changes in the thermohaline circulation in the Arctic and North Atlantic oceans. The weak variation observed in the active-layer thickness at the study sites leads to the conclusion that the climatic cooling takes place principally through longer and colder winters. 23 refs., 7 figs., 5 tabs.

  13. Pockmarks in Passamaquoddy Bay, New Brunswick, Canada

    USGS Publications Warehouse

    Brothers, Laura; Legere, Christine; Hughes Clark, J.E.; Kelley, J.T.; Barnhardt, Walter; Andrews, Brian; Belknap, D.F.

    2016-01-01

    Pockmarks are seafloor depressions associated with fluid escape (Judd & Hovland 2007). They proliferate in the muddy seafloors of coastal Gulf of Maine and Bay of Fundy, where they are associated with shallow natural gas likely of biogenic origin (Ussler et al. 2003; Rogers et al. 2006; Wildish et al. 2008). In North America, shallow-water pockmark fields are not reported south of Long Island Sound, despite the abundance of gassy, muddy estuaries. The absence of pockmarks south of the limit of North American glaciation suggests that local and regional heterogeneities, possibly related to glacial or sea-level history or bedrock geology, influence pockmark field distribution. In shallow-water embayments, such as Passamaquoddy Bay, New Brunswick, pockmarks can be large (>200 m diameter) and number in the thousands.

  14. Varying sediment sources (Hudson Strait, Cumberland Sound, Baffin Bay) to the NW Labrador Sea slope between and during Heinrich events 0 to 4

    USGS Publications Warehouse

    Andrews, John T.; Barber, D.C.; Jennings, A.E.; Eberl, D.D.; Maclean, B.; Kirby, M.E.; Stoner, J.S.

    2012-01-01

    Core HU97048-007PC was recovered from the continental Labrador Sea slope at a water depth of 945 m, 250 km seaward from the mouth of Cumberland Sound, and 400 km north of Hudson Strait. Cumberland Sound is a structural trough partly floored by Cretaceous mudstones and Paleozoic carbonates. The record extends from ∼10 to 58 ka. On-board logging revealed a complex series of lithofacies, including buff-colored detrital carbonate-rich sediments [Heinrich (H)-events] frequently bracketed by black facies. We investigate the provenance of these facies using quantitative X-ray diffraction on drill-core samples from Paleozoic and Cretaceous bedrock from the SE Baffin Island Shelf, and on the < 2-mm sediment fraction in a transect of five cores from Cumberland Sound to the NW Labrador Sea. A sediment unmixing program was used to discriminate between sediment sources, which included dolomite-rich sediments from Baffin Bay, calcite-rich sediments from Hudson Strait and discrete sources from Cumberland Sound. Results indicated that the bulk of the sediment was derived from Cumberland Sound, but Baffin Bay contributed to sediments coeval with H-0 (Younger Dryas), whereas Hudson Strait was the source during H-events 1–4. Contributions from the Cretaceous outcrops within Cumberland Sound bracket H-events, thus both leading and lagging Hudson Strait-sourced H-events.

  15. Dinoflagellate cyst production in Hudson Bay, the world's largest inland sea, based on monthly sediment trap data

    NASA Astrophysics Data System (ADS)

    Heikkilä, Maija; Pospelova, Vera; Forest, Alexandre; Stern, Gary

    2014-05-01

    Phytoplankters, microscopic primary producers of oceans are capable of responding rapidly to environmental fluctuations due to their high cell replication rates. Fast phytoplankton growth maybe balanced out by equally fast consumption by herbivorous grazers. In high-latitude marine systems, seasonal fluctuations in plankton biomass are essentially linked to light regime controlled by the waxing and waning sea-ice cover. In addition, nutrient limitation in surface waters, seasonal temperature fluctuations and changes in freshwater inputs may play important roles. In cold-water seas, many planktonic organisms cope with seasonal harshness by the production of benthic dormant stages. Dinoflagellates are a diverse group of single-celled plankton, constituting major marine primary producers, as well as herbivorous grazers of the microbial loop. Many dinoflagellate species produce highly resistant, organic-walled resting cysts that are archived in sediments and have been increasingly used to reconstruct past environmental conditions, e.g., sea-surface temperature and salinity, productivity, sea-ice cover and eutrophication. Marine sediment core sequences are characterized by slow accumulation rates and high mixing rates: the top centimeter of surface sediment from an arctic shelf may correspond to several years or decades of deposition. Consequently, sedimentary archives do not give direct information on long-term changes in seasonal bloom patterns or cues of annually recurring life-cycle events. We used two particle-intercepting sediment traps moored in eastern and western Hudson Bay, respectively, to study monthly fluctuations in dinoflagellate cyst production from October 2005 to September 2006. The traps were deployed close to the seafloor and recovered during the ArcticNet annual expeditions onboard the CCGS Amundsen in 2005 and the CCGS Pierre Radisson in 2006. We document the seasonal succession of dinoflagellate cyst taxa, together with cyst species composition

  16. Divergent hydrological responses to 20th century climate change in shallow tundra ponds, western Hudson Bay Lowlands

    NASA Astrophysics Data System (ADS)

    Wolfe, Brent B.; Light, Erin M.; Macrae, Merrin L.; Hall, Roland I.; Eichel, Kaleigh; Jasechko, Scott; White, Jerry; Fishback, LeeAnn; Edwards, Thomas W. D.

    2011-12-01

    The hydrological fate of shallow tundra lakes and ponds under conditions of continued warming remains uncertain, but has important implications for wildlife habitat and biogeochemical cycling. Observations of unprecedented pond desiccation, in particular, signify catastrophic loss of aquatic habitat in some Arctic locations. Shallow tundra ponds are a ubiquitous feature in the western Hudson Bay Lowlands (HBL), a region that has undergone intense warming over the past ˜50 years. But it remains unknown how hydrological processes in these ponds have responded. Here, we use cellulose-inferred pond water oxygen isotope records from sediment cores, informed by monitoring of modern pond water isotope compositions during the 2009 and 2010 ice-free seasons, to reconstruct hydrological conditions of four shallow tundra ponds in the western HBL over the past three centuries. Following an interval of relative hydrological stability during the early part of the records, results reveal widely differing hydrological responses to 20th century climate change among the study sites, which is largely dependent on hydrological connectivity of the basins within their respective surrounding peatlands. These findings suggest the 20th century has been characterized by an increasingly dynamic landscape that has variably influenced surface water balance - a factor that is likely to play a key role in determining the future water balance of ponds in this region.

  17. Flux to the atmosphere of CH4 and CO2 from wetland ponds on the Hudson Bay lowlands (HBLs)

    NASA Technical Reports Server (NTRS)

    Hamilton, J. David; Kelly, Carol A.; Rudd, John W. M.; Hesslein, Raymond H.; Roulet, Nigel T.

    1994-01-01

    Ponds on peatlands of the Hudson Bay lowlands (HBLs) are complex ecosystems in which the fluxes to the atmosphere of CH4 and CO2 were controlled by interacting physical and biological factors. This resulted in strong diel variations of both dissolved gas concentrations and gas fluxes to the atmosphere, necessitating frequent sampling on a 24-hour schedule to enable accurate estimates of daily fluxes. Ponds at three sites on the HBL were constant net sources of CH4 and CO2 to the atmosphere at mean rates of 110-180 mg CH4 m(exp -2)/d and 3700-11,000 mg CO2 m(exp -2)/d. Rates peaked in August and September. For CH4 the pond fluxes were 3-30 times higher than adjacent vegetated surfaces. For CO2 the net pond fluxes were similar in magnitude to the vegetated fluxes but the direction of the flux was opposite, toward atmosphere. Even though ponds cover only 8-12% of the HBL area, they accounted for 30% of its total CH4 flux to the atmosphere. There is some circumstantial evidence that the ponds are being formed by decomposition of the underlying peat and that this decomposition is being stimulated by the activity of N2 fixing cyanobacteria that grow in mats at the peat-water interface. The fact that the gas fluxes from the ponds were so different from the surrounding vegetated surfaces means that any change in the ratio of pond to vegetated area, as may occur in response to climate change, would affect the total HBL fluxes.

  18. Future sea ice conditions in Western Hudson Bay and consequences for polar bears in the 21st century.

    PubMed

    Castro de la Guardia, Laura; Derocher, Andrew E; Myers, Paul G; Terwisscha van Scheltinga, Arjen D; Lunn, Nick J

    2013-09-01

    The primary habitat of polar bears is sea ice, but in Western Hudson Bay (WH), the seasonal ice cycle forces polar bears ashore each summer. Survival of bears on land in WH is correlated with breakup and the ice-free season length, and studies suggest that exceeding thresholds in these variables will lead to large declines in the WH population. To estimate when anthropogenic warming may have progressed sufficiently to threaten the persistence of polar bears in WH, we predict changes in the ice cycle and the sea ice concentration (SIC) in spring (the primary feeding period of polar bears) with a high-resolution sea ice-ocean model and warming forced with 21st century IPCC greenhouse gas (GHG) emission scenarios: B1 (low), A1B (medium), and A2 (high). We define critical years for polar bears based on proposed thresholds in breakup and ice-free season and we assess when ice-cycle conditions cross these thresholds. In the three scenarios, critical years occur more commonly after 2050. From 2001 to 2050, 2 critical years occur under B1 and A2, and 4 under A1B; from 2051 to 2100, 8 critical years occur under B1, 35 under A1B and 41 under A2. Spring SIC in WH is high (>90%) in all three scenarios between 2001 and 2050, but declines rapidly after 2050 in A1B and A2. From 2090 to 2100, the mean spring SIC is 84 (±7)% in B1, 56 (±26)% in A1B and 20 (±13)% in A2. Our predictions suggest that the habitat of polar bears in WH will deteriorate in the 21st century. Ice predictions in A1B and A2 suggest that the polar bear population may struggle to persist after ca. 2050. Predictions under B1 suggest that reducing GHG emissions could allow polar bears to persist in WH throughout the 21st century.

  19. Seasonal dynamics of methane emissions from a subarctic fen in the Hudson Bay Lowlands

    NASA Astrophysics Data System (ADS)

    Hanis, K. L.; Tenuta, M.; Amiro, B. D.; Papakyriakou, T. N.

    2013-07-01

    Ecosystem-scale methane (CH4) flux (FCH4) over a subarctic fen at Churchill, Manitoba, Canada was measured to understand the magnitude of emissions during spring and fall shoulder seasons, and the growing season in relation to physical and biological conditions. FCH4 was measured using eddy covariance with a closed-path analyser in four years (2008-2011). Cumulative measured annual FCH4 (shoulder plus growing seasons) ranged from 3.0 to 9.6 g CH4 m-2 yr-1 among the four study years, with a mean of 6.5 to 7.1 g CH4 m-2 yr-1 depending upon gap-filling method. Soil temperatures to depths of 50 cm and air temperature were highly correlated with FCH4, with near-surface soil temperature at 5 cm most correlated across spring, fall, and the shoulder and growing seasons. The response of FCH4 to soil temperature at the 5 cm depth and air temperature was more than double in spring to that of fall. Emission episodes were generally not observed during spring thaw. Growing season emissions also depended upon soil and air temperatures but the water table also exerted influence, with FCH4 highest when water was 2-13 cm below and lowest when it was at or above the mean peat surface.

  20. Seasonal dynamics of methane emissions from a subarctic fen in the Hudson Bay Lowlands

    NASA Astrophysics Data System (ADS)

    Hanis, K. L.; Tenuta, M.; Amiro, B. D.; Papakyriakou, T. N.

    2013-03-01

    Ecosystem-scale methane (CH4) flux (FCH4) over a subarctic fen at Churchill, Manitoba, Canada was measured to understand the magnitude of emissions during spring and fall shoulder seasons, and the growing season in relation to physical and biological conditions. FCH4 was measured using eddy covariance with a closed-path analyzer in four years (2008-2011). Cumulative measured annual FCH4 (shoulder plus growing seasons) ranged from 3.0 to 9.6 g CH4 m-2 yr-1 among the four study years, with a mean of 6.5 to 7.1 g CH4 m-2 yr-1 depending upon gap-filling method. Soil temperatures to depths of 50 cm and air temperature were highly correlated with FCH4, with near surface soil temperature at 5 cm most correlated across spring, fall, and the whole season. The response of FCH4 to soil temperature at the 5 cm depth and air temperature was more than double in spring to that of fall. Emission episodes were generally not observed during spring thaw. Growing season emissions also depended upon soil and air temperatures but water table also exerted influence with FCH4 highest when water was 2-13 cm below and least when it was at or above the mean peat surface.

  1. CO2 exchange in the Hudson Bay lowlands: Community characteristics and multispectral reflectance properties

    NASA Technical Reports Server (NTRS)

    Whiting, Gary J.

    1994-01-01

    Net ecosystem CO2 exchange was measured during the 1990 growing season (June to August) along a transect starting 10 km inland from James Bay and extending 100 km interior to Kinosheo Lake, Ontario. Sites were chosen in three distinct areas: a coastal fen, an interior fen, and a bog. For the most productive sites in the bog, net daily uptake rates reached a maximum of 2.5 g C-CO2 m(exp -2)/d with an area-weighted exchange of 0.3 g C-CO2 m(exp -2)/d near midsummer. This site was estimated to be a net carbon source of 9 g C-CO2 m(exp -2) to the atmosphere over a 153-day growing season. The interior fen was less productive on a daily basis with a net maximum uptake of 0.5 g C-CO2 m(exp -2)/d and with corresponding area-weighted uptake of 0.1 g C-CO2 m(exp -2)/d during midsummer. Early and late season release of carbon to the atmosphere resulted in a net loss of 21 g C-CO2 m(exp -2) over the growing season from this site. The coastal fen was the most productive site with uptake rates peaking near 1.7 g C-CO2 m(exp -2)/d which corresponded to an area-weighted uptake of 0.8 g C-CO2 m(exp -2)/d during midsummer and an estimated net uptake of 6 g C-CO2 m(exp -2) for the growing season. Associated with net CO2 exchange measurements, multispectral reflectance properties of the sites were measured over the growing season using portable radiometers. These properties were related to exchange rates with the goal of examining the potential for satellite remote sensing to monitor biosphere/atmosphere CO2 exchange in this biome. The normalized difference vegetation index (NDVI) computed from surface reflectance was correlated with net CO2 exchange for all sites with the exception of areas with large proportions of Sphagnum moss cover. These mosses have greater near-infrared reflectance than typical surrounding vegetation and may require special adjustment for regional exchange/remote sensing applications.

  2. Improving Job Site Skills Project. Preliminary Report. Local 343 United Brotherhood of Carpenters & Joiners of America & Construction Labour Relations Association of Manitoba. Northern Industrial Job Site Visit Report. Environmental Improvement Project, Hudson Bay Mining and Smelting, Flin Flon, Manitoba.

    ERIC Educational Resources Information Center

    McKeag, Janis; Todd, Laurie

    The Environmental Improvement Project at Hudson Bay Mining and Smelting in Flin Flon, Manitoba, presented a unique opportunity for field observation and assessment. Field observation of the approximately 70 carpenters employed with various companies provided information on the types of communication used and the circumstances in which the…

  3. Mercury in fog on the Bay of Fundy (Canada)

    NASA Astrophysics Data System (ADS)

    Ritchie, Charles D.; Richards, William; Arp, Paul A.

    Mercury concentrations in fog water, collected during the summer of 2003, were found to vary along a geospatial gradient from Grand Manan (an island at the mouth of the Bay of Fundy, with Hg levels 42-435 ng l -1), the main coastline of New Brunswick at Point Lepreau (2-33 ng l -1), to an inland location in Fredericton, Canada (3.5 ng l -1). Hg concentrations were higher during days when air masses were stationary and fog conditions were extended over several days. High concentrations on Grand Manan were most likely due to continued atmospheric deposition of Hg into fog banks of long duration, high air turbulence along the steep 100 m cliffs, and decreasing droplet size with increasing air temperature during the course of the day. We found that fog Hg deposition was about 0.4-7.5% of wet Hg deposition along the coastal area, whereas on Grand Manan Island, fog Hg deposition from was 31-74% of wet Hg deposition.

  4. 77 FR 53769 - Safety Zone; Liberty to Freedom Swims, Liberty Island, Upper Bay and Hudson River, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-04

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Liberty to Freedom Swims, Liberty Island... and the Lower Hudson River for the September 5, 2012 and September 15, 2012 Liberty to Freedom swim... from the hazards associated with swim events. This rule is intended to restrict all vessels and...

  5. Community teamwork in nutrition education: an example in Canada's north.

    PubMed

    Schurman, M

    1983-06-01

    The nutrition education program, sponsored by the Hudson's Bay Company, in remote northern communities, both Inuit and Indian, is described. The program identifies nutritious foods in the company's community stores by coding in the colours associated with the food groups of Canada's Food Guide. It involves the cooperation of key individuals from the community and various community agencies and organizations.

  6. The Energetic Value of Land-Based Foods in Western Hudson Bay and Their Potential to Alleviate Energy Deficits of Starving Adult Male Polar Bears.

    PubMed

    Gormezano, Linda J; Rockwell, Robert F

    2015-01-01

    Climate change is predicted to expand the ice-free season in western Hudson Bay and when it grows to 180 days, 28-48% of adult male polar bears are projected to starve unless nutritional deficits can be offset by foods consumed on land. We updated a dynamic energy budget model developed by Molnar et al. to allow influx of additional energy from novel terrestrial foods (lesser snow geese, eggs, caribou) that polar bears currently consume as part of a mixed diet while on land. We calculated the units of each prey, alone and in combination, needed to alleviate these lethal energy deficits under conditions of resting or limited movement (2 km d-1) prior to starvation. We further considered the total energy available from each sex and age class of each animal prey over the period they would overlap land-bound polar bears and calculated the maximum number of starving adult males that could be sustained on each food during the ice-free season. Our results suggest that the net energy from land-based food, after subtracting costs of limited movement to obtain it, could eliminate all projected nutritional deficits of starving adult male polar bears and likely other demographic groups as well. The hunting tactics employed, success rates as well as behavior and abundance of each prey will determine the realized energetic values for individual polar bears. Although climate change may cause a phenological mismatch between polar bears and their historical ice-based prey, it may simultaneously yield a new match with certain land-based foods. If polar bears can transition their foraging behavior to effectively exploit these resources, predictions for starvation-related mortality may be overestimated for western Hudson Bay. We also discuss potential complications with stable-carbon isotope studies to evaluate utilization of land-based foods by polar bears including metabolic effects of capture-related stress and consuming a mixed diet.

  7. The Energetic Value of Land-Based Foods in Western Hudson Bay and Their Potential to Alleviate Energy Deficits of Starving Adult Male Polar Bears

    PubMed Central

    Gormezano, Linda J.; Rockwell, Robert F.

    2015-01-01

    Climate change is predicted to expand the ice-free season in western Hudson Bay and when it grows to 180 days, 28–48% of adult male polar bears are projected to starve unless nutritional deficits can be offset by foods consumed on land. We updated a dynamic energy budget model developed by Molnar et al. to allow influx of additional energy from novel terrestrial foods (lesser snow geese, eggs, caribou) that polar bears currently consume as part of a mixed diet while on land. We calculated the units of each prey, alone and in combination, needed to alleviate these lethal energy deficits under conditions of resting or limited movement (2 km d-1) prior to starvation. We further considered the total energy available from each sex and age class of each animal prey over the period they would overlap land-bound polar bears and calculated the maximum number of starving adult males that could be sustained on each food during the ice-free season. Our results suggest that the net energy from land-based food, after subtracting costs of limited movement to obtain it, could eliminate all projected nutritional deficits of starving adult male polar bears and likely other demographic groups as well. The hunting tactics employed, success rates as well as behavior and abundance of each prey will determine the realized energetic values for individual polar bears. Although climate change may cause a phenological mismatch between polar bears and their historical ice-based prey, it may simultaneously yield a new match with certain land-based foods. If polar bears can transition their foraging behavior to effectively exploit these resources, predictions for starvation-related mortality may be overestimated for western Hudson Bay. We also discuss potential complications with stable-carbon isotope studies to evaluate utilization of land-based foods by polar bears including metabolic effects of capture-related stress and consuming a mixed diet. PMID:26061693

  8. Terrestrial and Marine Organic Matter Accumulation in Hudson Bay: A High-Resolution Record of Climate/Watershed Processes over the Late Holocene

    NASA Astrophysics Data System (ADS)

    Alleau, Y.; Goni, M. A.; Kolcynski, L.; St-Onge, G.; Lajeunesse, P.; Haberzettl, T.

    2014-12-01

    A high-resolution record of organic matter accumulation in sediments from a combined gravity-piston core was collected from a site located at a water depth of 104 m inside Nastapoka Sound in the south-eastern region of Hudson Bay. The drainage basins in this region of Hudson Bay coincide roughly with the present-day tree line location and are within the forest-tundra transition zone. CAT- Scan and multi-sensor core logger data revealed relatively uniform sediments throughout the core. 14C-based geochronology indicates that the combined record extends to ~3200 cal BP and that accumulation rates were relatively constant (0.1-0.2 cm/y). Organic carbon, inorganic carbon and nitrogen contents display down-core variability consistent with changes in organic matter inputs but overall relatively stable depositional conditions over the last 3,000 years. Compositionally, we measured steady increases in the carbon:nitrogen ratios and lignin phenol content of sedimentary organic matter from 3200 cal BP to present consistent with enhanced inputs of vascular plant-derived organic matter. Lignin compositions (i.e. S/V and C/V phenol ratios) throughout the core are consistent with contributions from a mixture of conifer and angiosperm non-woody plant sources. Steady decreases in both S/V and C/V phenol ratios since 3200 cal BP to the present indicate enhanced contributions from conifer-dominated vegetation and are consistent with a steady expansion of boreal forests (white and black spruce) over shrub -dominated tundra (dwaf birch, willows, sedges) in this southern Arctic region over the late Holocene. No clear trends in the ratio of combustion products over lignin products are evident, suggesting a low fire frequency in the area during the covered time span of the record.

  9. Quaternary geologic map of the Hudson River 4 degree x 6 degree quadrangle, United States and Canada

    USGS Publications Warehouse

    State and province compilations by Fullerton, David S.; Sevon, William D.; Muller, Ernest H.; Judson, Sheldon; Black, Robert F.; Wagner, Phillip W.; Hartshorn, Joseph H.; Chapman, William F.; Cowan, William D.; edited and integrated by Fullerton, David S.

    1992-01-01

    The Quaternary Geologic Map of the Hudson River 4? x 6? Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the earth. They make up the 'ground' on which we walk, the 'dirt' in which we dig foundations, and the 'soil' in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale.

  10. Lithospheric Shear Velocity and Discontinuity Structure of Hudson Bay from S-to-P Receiver Functions and Jointly Inverted P-to-S Receiver Functions and Rayleigh Wave Phase Velocities.

    NASA Astrophysics Data System (ADS)

    Porritt, R. W.; Miller, M. S.; Darbyshire, F. A.

    2014-12-01

    Hudson Bay overlies some of the thickest Precambrian lithosphere on Earth, whose internal structures contain important clues to the earliest workings of plate formation. The Hudson Bay Lithospheric Experiment (HuBLE) has thus far constrained its seismic wavespeed, anisotropy, and discontinuity structures. However, previous work has either focused on a single imaging method or briefly compared two independent methods. In this study, we combine surface wave dispersion curves with P to S receiver functions (PRF) to jointly invert for 1D shear velocity, and also compute independent S to P receiver functions (SRF) using teleseismic earthquakes recorded at 36 broadband seismic stations from the HuBLE experiment and 9 additional regional stations. High shear velocities are observed to depths of 200-300 km in the region, indicating a thick depleted lithospheric keel, with maximum thickness in the center of Hudson Bay. The 1D shear velocity profiles typically exhibit a low-velocity zone in the lower crust, consistent with the hypothesis of post-orogenic or syn-orogenic lower crustal flow or the tectonic burial of metasediments. Observations of a flat Moho in the Rae domain of northwestern Hudson Bay are consistent with an Archean-aged crust, which has remained unaltered since formation. Structures observed within the mantle lithosphere in the depth-stacked S to P receiver functions appear to dip from the Hearne domain towards the Rae domain, suggestive of lithospheric formation through plate tectonic processes. This implies that plate tectonic processes were in action during the Archean when these provinces formed.

  11. Geologic insights from multibeam bathymetry and seascape maps of the Bay of Fundy, Canada

    NASA Astrophysics Data System (ADS)

    Shaw, John; Todd, Brian J.; Li, Michael Z.

    2014-07-01

    The macrotidal Bay of Fundy, Canada, was systematically mapped in the early 2000s using multibeam sonar technology, partly to support efforts to develop hydropower. The primary product was a suite of 1:50,000-scale maps of shaded seafloor relief and backscatter. In addition, a ‘seascape’ map was produced in an attempt to classify the entire bay in terms of morphology, texture, and biota. The eight seascape groups that are delineated reflect the strong signature of glaciation in much of the bay, the effects of Holocene tidal range expansion, and the results of modern processes under a dynamic current regime. As a result of the recent mapping we are able to argue that the muddy depocentre in the southwest of the bay was primarily active before the well-documented expansion of tidal range that occurred in the Bay of Fundy in the Holocene epoch. We further demonstrate the complexity of the seafloor in one of the glacial seascapes, and discuss the morphology and stability of a major tidal scour. The evidence obtained from multibeam sonar mapping reveals the complexity of the sea floor in the Bay of Fundy not necessarily apparent on the 1977 surficial geology map based on sparse lines of single-beam echo sounder data.

  12. The role of diet on long-term concentration and pattern trends of brominated and chlorinated contaminants in western Hudson Bay polar bears, 1991-2007.

    PubMed

    McKinney, Melissa A; Stirling, Ian; Lunn, Nick J; Peacock, Elizabeth; Letcher, Robert J

    2010-11-15

    Adipose tissue was sampled from the western Hudson Bay (WHB) subpopulation of polar bears at intervals from 1991 to 2007 to examine temporal trends of PCB and OCP levels both on an individual and sum-(∑-)contaminant basis. We also determined levels and temporal trends of emerging polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), polybrominated biphenyls (PBBs) and other current-use brominated flame retardants. Over the 17-year period, ∑DDT (and p,p'-DDE, p,p'-DDD, p,p'-DDT) decreased (-8.4%/year); α-hexachlorocyclohexane (α-HCH) decreased (-11%/year); β-HCH increased (+8.3%/year); and ∑PCB and ∑chlordane (CHL), both contaminants at highest concentrations in all years (>1ppm), showed no distinct trends even when compared to previous data for this subpopulation dating back to 1968. Some of the less persistent PCB congeners decreased significantly (-1.6%/year to -6.3%/year), whereas CB153 levels tended to increase (+3.3%/year). Parent CHLs (c-nonachlor, t-nonachlor) declined, whereas non-monotonic trends were detected for metabolites (heptachlor epoxide, oxychlordane). ∑chlorobenzene, octachlorostyrene, ∑mirex, ∑MeSO(2)-PCB and dieldrin did not significantly change. Increasing ∑PBDE levels (+13%/year) matched increases in the four consistently detected congeners, BDE47, BDE99, BDE100 and BDE153. Although no trend was observed, total-(α)-HBCD was only detected post-2000. Levels of the highest concentration brominated contaminant, BB153, showed no temporal change. As long-term ecosystem changes affecting contaminant levels may also affect contaminant patterns, we examined the influence of year (i.e., aging or "weathering" of the contaminant pattern), dietary tracers (carbon stable isotope ratios, fatty acid patterns) and biological (age/sex) group on congener/metabolite profiles. Patterns of PCBs, CHLs and PBDEs were correlated with dietary tracers and biological group, but only PCB and CHL patterns were correlated with year. DDT

  13. Demography of an apex predator at the edge of its range: impacts of changing sea ice on polar bears in Hudson Bay.

    PubMed

    Lunn, Nicholas J; Servanty, Sabrina; Regehr, Eric V; Converse, Sarah J; Richardson, Evan; Stirling, Ian

    2016-07-01

    Changes in the abundance and distribution of wildlife populations are common consequences of historic and contemporary climate change. Some Arctic marine mammals, such as the polar bear (Ursus maritimus), may be particularly vulnerable to such changes due to the loss of Arctic sea ice. We evaluated the impacts of environmental variation on demographic rates for the Western Hudson Bay (WH), polar bear subpopulation from 1984 to 2011 using live-recapture and dead-recovery data in a Bayesian implementation of multistate capture-recapture models. We found that survival of female polar bears was related to the annual timing of sea ice break-up and formation. Using estimated vital rates (e.g., survival and reproduction) in matrix projection models, we calculated the growth rate of the WH subpopulation and projected population responses under different environmental scenarios while accounting for parametric uncertainty, temporal variation, and demographic stochasticity. Our analysis suggested a long-term decline in the number of bears from 1185 (95% Bayesian credible interval [BCI] = 993-1411) in 1987 to 806 (95% BCI = 653-984) in 2011. In the last 10 yr of the study, the number of bears appeared stable due to temporary stability in sea ice conditions (mean population growth rate for the period 2001-2010 = 1.02, 95% BCI = 0.98-1.06). Looking forward, we estimated long-term growth rates for the WH subpopulation of ~1.02 (95% BCI = 1.00-1.05) and 0.97 (95% BCI = 0.92-1.01) under hypothetical high and low sea ice conditions, respectively. Our findings support previous evidence for a demographic linkage between sea ice conditions and polar bear population dynamics. Furthermore, we present a robust framework for sensitivity analysis with respect to continued climate change (e.g., to inform scenario planning) and for evaluating the combined effects of climate change and management actions on the status of wildlife populations.

  14. Organic carbon and fine sediment production potential from decaying permafrost in a small watershed, Sheldrake River, Eastern coastal region of Hudson Bay

    NASA Astrophysics Data System (ADS)

    Jolivel, M.; Allard, M.

    2010-12-01

    Recent evaluations indicate that large amounts of organic carbon and fine sediment can be released in fluvial and coastal systems because of permafrost degradation, with impacts on ecosystems. In order to estimate the organic carbon and fine sediment potential production from a river basin, we have made a spatiotemporal comparison between 1957 aerial photographs and a 2009 GeoEye satellite image. A gauging station was installed near the river mouth and measurements of the extent and volume of permafrost degradation were made in the watershed where permafrost degradation is very active. The Sheldrake river watershed is located on the eastern coast of Hudson Bay near the Inuit community of Umiujaq, in the discontinuous permafrost zone. The tree line passes across the watershed. Permafrost mounds (palsas, lithalsas) and plateaus are the most abundant permafrost landforms in this area. They developed principally in east-west oriented valleys, in postglacial marine silts of the Tyrrell Sea. Signs of degradation are numerous. Lithalsas and palsas (with peat cover) weather out and collapse. Thermokarst ponds are replacing permafrost mounds and sometimes, eroded clay and peat are remobilized in the drainage network. Moreover, several retrogressive landslides, mudflows and gully erosion are active along the Sheldrake river banks. The first step consisted in mapping the 80 km2 watershed area and representing surface deposits, drainage network and permafrost distribution (1957 and 2009). First results show that 40 to 70% of the 1957 permafrost has disappeared in 2009 in various sector of the watershed. The percentage of permafrost degradation is positively correlated with distance from the sea and the presence of a well-developed drainage network. The second step is to calculate an equation which will allow changing the missing permafrost surface between 1957 and 2009 into a volume. The equation will take into account the average depth of permafrost and active layer, the mean

  15. Snow Accumulation and Spring Melt Rates of Bogs and Fens in the North Granny Creek Catchment Basin, Hudson Bay Lowlands, Ontario

    NASA Astrophysics Data System (ADS)

    Cook, C. F.; Price, J. S.

    2009-05-01

    The Hudson Bay Lowlands contain one of the most extensive, contiguous peatland complexes in the world. Interlinked patterned peatlands developed in this region because of the cool climate, low-gradient topography and an underlying layer of low conductivity marine sediments. There is currently little research regarding the mechanisms that control runoff and surface water connectivity in this region, especially the functions of different peatland types on runoff production and flow pathways. Runoff generation in these systems is dependent on several factors such as soil and pool storage capacity, snow accumulation and melt rates, and peatland morphometry. Snowmelt accounts for a major portion of total annual runoff in this region and the timing of the melt will determine effective runoff production from a peatland catchment. One of the objectives of this project is to identify the processes and mechanisms that generate spring snowmelt runoff in different peatland types (i.e. bogs and fens) and quantify the relative contribution of each type in a peatland-dominated catchment basin. This research is being conducted in a 30 km2 catchment basin located near the DeBeers Victor diamond mine, located 90 km west of Attawapiskat, Ontario. The North Granny Creek basin is located approximately 3 km from the mine pit and is comprised of several peatland types and forms. The surface hydrology of this area is expected to be affected by groundwater depressurization due to dewatering of the mine pit by deep groundwater pumping wells. Effects of this activity on surface hydrology could possibly include increased soil storage capacity due to drier conditions and decreased melt rates due to reduced inputs of warm groundwater. Surface water connectivity is usually at a maximum in the spring because of a relatively impermeable frost table and low soil storage capacity which reduces infiltration. These effects of melt will not be observed uniformly over the entire catchment because of the

  16. Demography of an apex predator at the edge of its range: impacts of changing sea ice on polar bears in Hudson Bay

    USGS Publications Warehouse

    Lunn, Nicholas J.; Servanty, Sabrina; Regehr, Eric V.; Converse, Sarah J.; Richardson, Evan S.; Stirling, Ian

    2016-01-01

    Changes in the abundance and distribution of wildlife populations are common consequences of historic and contemporary climate change. Some Arctic marine mammals, such as the polar bear (Ursus maritimus), may be particularly vulnerable to such changes due to the loss of Arctic sea ice. We evaluated the impacts of environmental variation on demographic rates for the Western Hudson Bay (WH), polar bear subpopulation from 1984 to 2011 using live-recapture and dead-recovery data in a Bayesian implementation of multistate capture–recapture models. We found that survival of female polar bears was related to the annual timing of sea ice break-up and formation. Using estimated vital rates (e.g., survival and reproduction) in matrix projection models, we calculated the growth rate of the WH subpopulation and projected population responses under different environmental scenarios while accounting for parametric uncertainty, temporal variation, and demographic stochasticity. Our analysis suggested a long-term decline in the number of bears from 1185 (95% Bayesian credible interval [BCI] = 993–1411) in 1987 to 806 (95% BCI = 653–984) in 2011. In the last 10 yr of the study, the number of bears appeared stable due to temporary stability in sea ice conditions (mean population growth rate for the period 2001–2010 = 1.02, 95% BCI = 0.98–1.06). Looking forward, we estimated long-term growth rates for the WH subpopulation of ~1.02 (95% BCI = 1.00–1.05) and 0.97 (95% BCI = 0.92–1.01) under hypothetical high and low sea ice conditions, respectively. Our findings support previous evidence for a demographic linkage between sea ice conditions and polar bear population dynamics. Furthermore, we present a robust framework for sensitivity analysis with respect to continued climate change (e.g., to inform scenario planning) and for evaluating the combined effects of climate change and management actions on the status of wildlife populations.

  17. A reappraisal of postglacial decay times from Richmond Gulf and James Bay, Canada

    NASA Astrophysics Data System (ADS)

    Mitrovica, J. X.; Forte, A. M.; Simons, M.

    2000-09-01

    Decay times inferred from relative sea-level (RSL) histories of previously glaciated regions provide a potentially important constraint on mantle rheology. We present a new compilation of RSL data from Richmond Gulf and James Bay, Canada. This recompilation reveals errors in previous compilations that led to inaccurate estimates for the Richmond Gulf decay time in a series of recently published articles. We derive updated estimates for the decay time at Richmond Gulf and James Bay using a methodology that incorporates errors in both the age and the height of the sea-level markers. This exercise is guided by a series of synthetic RSL calculations that show that decay time estimates in the region can be significantly biased if the RSL time-series are not corrected for global eustatic sea-level trends, or if the estimates are based on composite RSL histories derived by combining data from both the Richmond Gulf and the James Bay regions. Our decay time analysis for Richmond Gulf applies the pioneering approach of Walcott (1980) to a large database and we derive a value of 4.0-6.6kyr, where the range is defined by a misfit tolerance 10 per cent higher than the minimum. Our analysis for James Bay is based on the uplift curve derived by Hardy (1976), and we estimate a decay time of about 2.0-2.8kyr. The difference between our estimates for Richmond Gulf and James Bay may be due to errors in the observational record from these regions, but could also be influenced by lateral variations in lithospheric structure associated with the assembly of Laurentia.

  18. 13. NEW YORK SIDE, HUDSON RIVER VENTILATION BUILDING ACROSS HUDSON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. NEW YORK SIDE, HUDSON RIVER VENTILATION BUILDING ACROSS HUDSON RIVER IN BACKGROUND, WITH SOUTH WALL OF NEW JERSEY SIDE OF VENTILATION BUILDING IN FOREGROUND - Holland Tunnel, Beneath Hudson River between New York & Jersey City, New York County, NY

  19. Vulnerability of Selected Beaches to Petroleum Contamination, Placentia Bay, NL, Canada

    NASA Astrophysics Data System (ADS)

    McNeil, M.; Catto, N.

    2009-04-01

    Placentia Bay currently hosts the highest volume of ship traffic in along the Atlantic Canadian coastline, and is additionally exposed to accidental and deliberate discharges of petroleum products by Trans-Atlantic ship traffic. Placentia Bay has been identified as the region in Canada that is most likely to suffer a petroleum contamination event within the next 10 years. The morphological, sedimentological, energy regime, and marine debris characteristics of 4 beaches at the head of Placentia Bay were investigated in detail. Differing morphological, sedimentological and energy regime conditions alter the sensitivity of each system to oil spill contamination. Differences in the type and amount of marine debris between each system alter the potential risk of exposure to oil spill contamination. Based on differences in sensitivity and exposure, a vulnerability assessment was created for each system. This system was applied to additional beaches and rocky coastlines to demonstrate the applicability of the method and to highlight the actual vulnerability of each study beach relative to the spectrum of beaches actually present throughout eastern Newfoundland. Typical of the majority of beaches throughout Placentia Bay, the 4 study beaches are characterized by gravel dominated, reflective, moderate to high energy systems. Observations of sediment re-working and accretionary features along the beaches of Arnold's Cove and Come by Chance indicate that self-cleaning would not be an effective agent of oil removal in the case of a spill. The absence of sediment re-working and protected nature of Goose Cove beach suggest that oil would persist in this environment for an extended period of time. Evidence of high wave energies at Hollett's Cove indicates that this beach would self-clean effectively. Differing types and quantities of marine debris indicate that each beach, with the exception of Goose Cove, would likely be exposed to oil originating from a Placentia Bay spill. The

  20. Belcher Islands, Canada

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Belcher Islands are an archipelago in Hudson Bay in Canada, belonging to the territory of Nunavit. The hamlet of Sanikiluaq is on the north coast of Flaherty Island. Over 1500 islands make up the archipelago. The folded sedimentary and volcanic rocks making up the islands are Proterozoic in age between 0.5 and 2.5 billion years old.

    The image mosaic was acquired 18 September 2006, covers an area of 45.7 x 113.3 km, and is located near 56.1 degrees north latitude, 79.4 degrees west longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  1. Trace element and stable isotope analysis of fourteen species of marine invertebrates from the Bay of Fundy, Canada.

    PubMed

    English, Matthew D; Robertson, Gregory J; Mallory, Mark L

    2015-12-15

    The Bay of Fundy, Canada, is a macrotidal bay with a highly productive intertidal zone, hosting a large abundance and diversity of marine invertebrates. We analysed trace element concentrations and stable isotopic values of δ(15)N and δ(13)C in 14 species of benthic marine invertebrates from the Bay of Fundy's intertidal zone to investigate bioaccumulation or biodilution of trace elements in the lower level of this marine food web. Barnacles (Balanus balanus) consistently had significantly greater concentrations of trace elements compared to the other species studied, but otherwise we found low concentrations of non-essential trace elements. In the range of trophic levels that we studied, we found limited evidence of bioaccumulation or biodilution of trace elements across species, likely due to the species examined occupying similar trophic levels in different food chains.

  2. Mercury exposure in two coastal communities of the Bay of Fundy, Canada.

    PubMed

    Legrand, Melissa; Arp, Paul; Ritchie, Charlie; Chan, Hing Man

    2005-05-01

    There is a rising global concern with regard to mercury (Hg) exposure among coastal populations. Two communities on the Bay of Fundy (New Brunswick, Canada) were assessed by hair monitoring and dietary methods. Average concentration of total Hg in hair was 0.70+/-0.55 mg/kg (N=91) at Grand Manan and 0.42+/-0.15 mg/kg (N=52) at St. Andrews/St. Stephen. Average daily consumption of fresh fish and shellfish was 50+/-40 g/day for Grand Manan and 19+/-19 g/day for St. Andrews/St. Stephen. Average daily total Hg intake estimated from the food frequency and 24-h recall questionnaires was 0.05+/-0.04 microg Hg/kg bw/day at Grand Manan and 0.03+/-0.04 microg Hg/kg bw/day at St. Andrews/St. Stephen. A significant correlation (r=0.47, P=0.002) between Hg intake and hair was observed for Grand Manan. Low Hg intakes and body burden can be attributed to the low Hg levels found in the species commonly consumed: haddock, canned tuna, lobster, and pollock (all below 0.2 microg/g wet weight). The results showed that Hg exposure in these Canadian coastal communities is low; fish with higher levels of Hg (shark, tuna, swordfish, pickerel, and bass) are not consumed locally.

  3. Life history and reproductive biology of Corophium volutator (crustacea: amphipoda) and the influence of shorebird predation on population structure in chignecto bay, bay of fundy, Canada

    NASA Astrophysics Data System (ADS)

    Peer, D. L.; Linkletter, L. E.; Hicklin, P. W.

    Intertidal populations of Corophium volutator were sampled over a 17-month period at 5 locations in Chignecto Bay, Bay of Fundy, Canada. This is a macrotidal environment with extensive mudflats. Two generations were produced annually. The lengths of gravid females and brood sized were larger than those previously reported in most European studies. Production was highest during May-September. During late summer (July-September) the larger animals were selectively removed from the population by predatory shorebirds (Charadriiformes) thus modifying the population structure from a bimodal to a unimodal distribution composed of numerous but small animals. Although shorebird predation was extensive, the associated reductions in Corophium densities were temporary-Densities increased following the birds' departure from the study sites in early fall. Frequency distribution histograms of size classes remained unimodal and growth was low, until the next breeding season. Annual net production over 2 one-year periods was 6250 and 3277 mg·m -2 (dry weight).

  4. Researcher Interview: Tom Hudson

    Cancer.gov

    Tom Hudson, M.D., President and Scientific Director of the Ontario Institute for Cancer Research, describes the International Cancer Genome Consortium (ICGC), which brings together cancer genomic data and research from across the world.

  5. Behavioral Response of Corophium volutator to Shorebird Predation in the Upper Bay of Fundy, Canada

    PubMed Central

    MacDonald, Elizabeth C.; Frost, Elisabeth H.; MacNeil, Stephanie M.; Hamilton, Diana J.; Barbeau, Myriam A.

    2014-01-01

    Predator avoidance is an important component of predator-prey relationships and can affect prey availability for foraging animals. Each summer, the burrow-dwelling amphipod Corophium volutator is heavily preyed upon by Semipalmated Sandpipers (Calidris pusilla) on mudflats in the upper Bay of Fundy, Canada. We conducted three complementary studies to determine if adult C. volutator exhibit predator avoidance behavior in the presence of sandpipers. In a field experiment, we monitored vertical distribution of C. volutator adults in bird exclosures and adjacent control plots before sandpipers arrived and during their stopover. We also made polymer resin casts of C. volutator burrows in the field throughout the summer. Finally, we simulated shorebird pecking in a lab experiment and observed C. volutator behavior in their burrows. C. volutator adults were generally distributed deeper in the sediment later in the summer (after sandpipers arrived). In August, this response was detectably stronger in areas exposed to bird predation than in bird exclosures. During peak predator abundance, many C. volutator adults were beyond the reach of feeding sandpipers (>1.5 cm deep). However, burrow depth did not change significantly throughout the summer. Detailed behavioral observations indicated that C. volutator spent more time at the bottom of their burrow when exposed to a simulated predator compared to controls. This observed redistribution suggests that C. volutator adults move deeper into their burrows as an anti-predator response to the presence of sandpipers. This work has implications for predators that feed on burrow-dwelling invertebrates in soft-sediment ecosystems, as density may not accurately estimate prey availability. PMID:25354218

  6. Behavioral response of Corophium volutator to shorebird predation in the upper Bay of Fundy, Canada.

    PubMed

    MacDonald, Elizabeth C; Frost, Elisabeth H; MacNeil, Stephanie M; Hamilton, Diana J; Barbeau, Myriam A

    2014-01-01

    Predator avoidance is an important component of predator-prey relationships and can affect prey availability for foraging animals. Each summer, the burrow-dwelling amphipod Corophium volutator is heavily preyed upon by Semipalmated Sandpipers (Calidris pusilla) on mudflats in the upper Bay of Fundy, Canada. We conducted three complementary studies to determine if adult C. volutator exhibit predator avoidance behavior in the presence of sandpipers. In a field experiment, we monitored vertical distribution of C. volutator adults in bird exclosures and adjacent control plots before sandpipers arrived and during their stopover. We also made polymer resin casts of C. volutator burrows in the field throughout the summer. Finally, we simulated shorebird pecking in a lab experiment and observed C. volutator behavior in their burrows. C. volutator adults were generally distributed deeper in the sediment later in the summer (after sandpipers arrived). In August, this response was detectably stronger in areas exposed to bird predation than in bird exclosures. During peak predator abundance, many C. volutator adults were beyond the reach of feeding sandpipers (>1.5 cm deep). However, burrow depth did not change significantly throughout the summer. Detailed behavioral observations indicated that C. volutator spent more time at the bottom of their burrow when exposed to a simulated predator compared to controls. This observed redistribution suggests that C. volutator adults move deeper into their burrows as an anti-predator response to the presence of sandpipers. This work has implications for predators that feed on burrow-dwelling invertebrates in soft-sediment ecosystems, as density may not accurately estimate prey availability.

  7. Structure, stratigraphy, and climate of the Mesozoic Chignecto subbasin, Bay of Fundy, Canada

    SciTech Connect

    Withjack, M.O.; Link, M.H. ); Olsen, P.E. )

    1991-03-01

    The Chignecto subbasin is one of three Triassic/Jurassic subbasins in the Bay of Fundy rift system of southeastern Canada. Although no wells have been drilled in the subbasin, offshore seismic data and onshore outcrop data show that the basin contains typical rift structures and stratigraphy. The Chignecto subbasin is an asymmetric rift basin bounded on the west by a series of gently to moderately dipping normal faults. The seismic data show that the total heave on these boundary faults locally exceeds 10 km. Most strata within the basin dip gently to the west toward the boundary faults. Field data show that a divergent wrench fault zone composed of numerous strike-slip, oblique-slip, and normal faults bounds the Chignecto subbasin on the south. The normal faults bounding the basin on the west and the divergent wrench fault zone on the south are reactivated Paleozoic compressional structures. Major stratigraphic features in the Chignecto subbasin include an unconformity that subdivides the basin strata into pre- and syn-rift sequences and an asymmetric arrangement of sedimentary and seismic facies and corresponding lithologies. The Triassic/Jurassic syn-rift strata within the basin thicken toward the western boundary faults. Coarser-grained strata of alluvial-fan and fluvial origin interfinger with finer-grained strata of fluvial and lacustrine origin near the boundary faults. Eolian deposits and evaporites in adjacent Mesozoic rift basins indicate an arid climate for the Late Triassic/Early Jurassic. Large-amplitude reflections observed within the western half of the basin probably represent high-velocity evaporites or carbonates deposited within the deepest part of the Chignecto subbasin.

  8. Menstrual cycle perturbation by organohalogens and elements in the Cree of James Bay, Canada.

    PubMed

    Wainman, Bruce C; Kesner, James S; Martin, Ian D; Meadows, Juliana W; Krieg, Edward F; Nieboer, Evert; Tsuji, Leonard J

    2016-04-01

    Persistent organohalogens (POHs) and metals have been linked to alterations in menstrual cycle function and fertility in humans. The Cree First Nations people living near James Bay in Ontario and Quebec, Canada, have elevated levels of POHs, mercury and lead compared to other Canadians. The present study examines the interrelationships between selected POHs and elements on menstrual cycle function in these Cree women. Menstrual cycle characteristics were derived from structured daily diaries and endocrine measurements from daily urine samples collected during one cycle for 42 women age 19-42. We measured 31 POHs in blood plasma and 18 elements in whole blood, for 31 of the participants. POHs and elements detected in ≥ 70% of the participants were transformed by principal component (PC) analysis to reduce the contaminant exposure data to fewer, uncorrelated PCA variables. Multiple regression analysis revealed that, after adjusting for confounders, PC-3 values showed significant negative association with cycle length, after adjusting for confounders (p = 0.002). PC-3 accounted for 9.2% of the variance and shows positive loadings for cadmium, selenium, and PBDE congeners 47 and 153, and a negative loading for copper. Sensitivity analysis of the model to quantify likely effect sizes showed a range of menstrual cycle length from 25.3 to 28.3 days using the lower and upper 95% confidence limits of mean measured contaminant concentrations to predict cycle length. Our observations support the hypothesis that the menstrual cycle function of these women may be altered by exposure to POHs and elements from their environment.

  9. Informing Marine Spatial Planning (MSP) with numerical modelling: A case-study on shellfish aquaculture in Malpeque Bay (Eastern Canada).

    PubMed

    Filgueira, Ramón; Guyondet, Thomas; Bacher, Cédric; Comeau, Luc A

    2015-11-15

    A moratorium on further bivalve leasing was established in 1999-2000 in Prince Edward Island (Canada). Recently, a marine spatial planning process was initiated explore potential mussel culture expansion in Malpeque Bay. This study focuses on the effects of a projected expansion scenario on productivity of existing leases and available suspended food resources. The aim is to provide a robust scientific assessment using available datasets and three modelling approaches ranging in complexity: (1) a connectivity analysis among culture areas; (2) a scenario analysis of organic seston dynamics based on a simplified biogeochemical model; and (3) a scenario analysis of phytoplankton dynamics based on an ecosystem model. These complementary approaches suggest (1) new leases can affect existing culture both through direct connectivity and through bay-scale effects driven by the overall increase in mussel biomass, and (2) a net reduction of phytoplankton within the bounds of its natural variation in the area.

  10. Laurentide Ice Sheet dynamics in the Bay of Fundy, Canada, revealed through multibeam sonar mapping of glacial landsystems

    NASA Astrophysics Data System (ADS)

    Todd, Brian J.; Shaw, John

    2012-12-01

    Recent multibeam sonar data collected in the Bay of Fundy, Canada, interpreted in conjunction with geophysical profiling and sediment sampling, reveal in unprecedented detail a suite of glacial landforms associated with the southwest margin of the Laurentide Ice Sheet. These landforms constitute four glacial landsystems. 1) Subglacial landsystem I: In southwestern Bay of Fundy, the elongated Grand Manan Basin contains ice-contact sediments of possible mid-Wisconsinan age overlain by late-Wisconsinan ice-contact sediments strongly imprinted by iceberg furrows and pits. In places, possible mid-Wisconsinan glaciomarine sediments have been eroded by late-Wisconsinan ice, creating streamlined landforms. Eroded bedrock and megafluted ice-contact sediment on the flanks of Grand Manan Basin indicate the southwest direction of topographically-steered ice. 2) Subglacial landsystem II: Along the southern margin of the Bay of Fundy, an array of drumlins, with superimposed esker complexes, was formed by glacial ice that emanated northwest from the interior of Nova Scotia and was deflected to the southwest by the ice flowing out of the Bay of Fundy to the Gulf of Maine. The esker complexes formed later when the Nova Scotia ice sheet stagnated and meltwater escaped northwest via topographic gaps. 3) Ice-marginal landsystem I: In northern Bay of Fundy, both small De Geer moraines and larger, basin-bounding moraines were created when retreating late-Wisconsinan ice became grounded in relatively shallow water. New radiocarbon ages show that the Owen Basin Moraine in this landsystem was abandoned prior to c. 14,600 14C yr BP (cal BP 17,015-17,270 [0.7], 17,286-17,405 [0.3]). 4) Ice-marginal landsystem II: This distinctive landsystem consists of numerous arcuate moraines, commonly superimposed on one another. This landsystem was formed by thin (170 m), lightly grounded ice that retreated northeast into the Bay of Fundy. The splayed pattern of the ice margin was a response to a large

  11. Recent trends and variability in river discharge across northern Canada

    NASA Astrophysics Data System (ADS)

    Déry, Stephen J.; Stadnyk, Tricia A.; MacDonald, Matthew K.; Gauli-Sharma, Bunu

    2016-12-01

    This study presents an analysis of the observed inter-annual variability and inter-decadal trends in river discharge across northern Canada for 1964-2013. The 42 rivers chosen for this study span a combined gauged area of 5.26 × 106 km2 and are selected based on data availability and quality, gauged area and record length. Inter-annual variability in river discharge is greatest for the eastern Arctic Ocean (coefficient of variation, CV = 16 %) due to the Caniapiscau River diversion into the La Grande Rivière system for enhanced hydropower production. Variability is lowest for the study area as a whole (CV = 7 %). Based on the Mann-Kendall test (MKT), no significant (p > 0.05) trend in annual discharge from 1964 to 2013 is observed in the Bering Sea, western Arctic Ocean, western Hudson and James Bay, and Labrador Sea; for northern Canada as a whole, however, a statistically significant (p < 0.05) decline of 102.8 km3 25 yr-1 in discharge occurs over the first half of the study period followed by a statistically significant (p < 0.05) increase of 208.8 km3 25 yr-1 in the latter half. Increasing (decreasing) trends in river discharge to the eastern Hudson and James Bay (eastern Arctic Ocean) are largely explained by the Caniapiscau diversion to the La Grande Rivière system. Strong regional variations in seasonal trends of river discharge are observed, with overall winter (summer) flows increasing (decreasing, with the exception of the most recent decade) partly due to flow regulation and storage for enhanced hydropower production along the Hudson and James Bay, the eastern Arctic Ocean and Labrador Sea. Flow regulation also suppresses the natural variability of river discharge, particularly during cold seasons.

  12. Examining Dual Frequency X- and Ku-band Backscatter of Snow on Lake Ice and First-Year Sea Ice in the Sub-Arctic Hudson Bay Lowlands

    NASA Astrophysics Data System (ADS)

    Gunn, G. E.; Duguay, C. R.; Howell, S.; Kelly, R. E.; Silis, A.

    2011-12-01

    Fully polarimetric dual frequency ground-based scatterometer observations were collected at X- and Ku-band (9.6 and 17.2 GHz, respectively) near Churchill, Manitoba, Canada in the winter of 2010-11 as part of the Canadian Snow and Ice Experiment (CASIX). Backscatter measurements were collected for five landcover types: lake ice, sea ice, dry tundra, open forest and wetland tundra (sedge fen); the combination of which comprises a unique dataset of dual-frequency backscatter signatures. Correlative data collected, including snow and ice properties, are utilized to characterize active microwave interactions and contribute to the development of snow/ice retrieval algorithms. This study presents backscatter signatures for lake and sea ice obtained during winter 2010-11. The seasonal backscatter evolution is compared to changes in snow and ice properties, including depth, density, snow water equivalent (SWE), ice thickness, ice type, and bubble concentration within the ice. Results over lake ice suggest that increases in backscatter at both X- and Ku-band frequencies correspond to increases in SWE, but are confounded by changes in the sub-nivian ice composition. Surface ice types (snow ice, rafted ice), high bubble concentrations at the ice/water interface and pressure/deformation cracks in the ice serve to confound backscatter at several monitoring sites. Over sea ice, preliminary results indicate that increased salinity levels near the ice/snow interface is the predominate factor influencing backscatter signatures. Physical phenomena encountered at sea ice sites are further explored to assess potential influences on scattering signatures. Preliminary findings presented here document the first ground-based dual frequency X- and Ku-band backscatter signatures collected over first year sea ice, and contribute to the scientific objectives of the proposed Cold Regions Hydrology High-resolution Observatory (CoReH2O), a candidate Earth Explorer mission of the European Space

  13. Alaska/Canada. Prudhoe Bay operators lay plans for mammoth seawater injection project

    SciTech Connect

    Not Available

    1980-02-25

    Production at Prudhoe Bay has passed the billion-barrel mark, and 2 issues are now in the forefront for the operators of North America's largest oil field. First, how should a $2-billion waterflood be developed for the sprawling, complex reservoir. Second, how will gas sales from the field (in contrast to reinjection of produced gas) affect ultimate production of crude, gas, and liquids when the proposed gas pipeline is built. The major producers at Prudhoe Bay - Atlantic Richfield Co., Sohio Alaska Petroleum Co., and Exxon Co - have each constructed 3-dimensional computer models of Prudhoe Bay predicting future reservoir behavior. Also, the State of Alaska has contracted for a similar model to compare with the projections by the companies. The results of these studies (the so-called decline or production curve for the field under various parameters fed into the computer) are not yet available to the general public. Producers at Prudhoe Bay are confident that the reservoir is performing much as they had anticipated when production began in June 1977 and that, with proper management, the long-predicted 40% recovery of original in-place oil in the reservoir can be realized.

  14. Smallpox and its control in Canada

    PubMed Central

    McIntyre, J W; Houston, C S

    1999-01-01

    Edward Jenner's first treatise in 1798 described how he used cowpox material to provide immunity to the related smallpox virus. He sent this treatise and some cowpox material to his classmate John Clinch in Trinity, Nfld., who gave the first smallpox vaccinations in North America. Dissemination of the new technique, despite violent criticism, was rapid throughout Europe and the United States. Within a few years of its discovery, vaccination was instrumental in controlling smallpox epidemics among aboriginal people at remote trading posts of the Hudson's Bay Company. Arm-to-arm transfer at 8-day intervals was common through most of the 19th century. Vaccination and quarantine eliminated endemic smallpox throughout Canada by 1946. The last case, in Toronto in 1962, came from Brazil. PMID:10624414

  15. Early Silurian (Llandoverian) Leask Point and Charlton Bay bioherms, Manitoulin Island, Ontario, Canada

    SciTech Connect

    Mielczarek, W.; Copper, P.

    1986-08-01

    About 300 bioherms are known in the Llandoverian Manitoulin Formation of eastern Manitoulin Island. In the South Bay area, the large Leask Piont bioherm and Charlton Bay patch-reef complex lack a distinct skeletal growth framework. Bioherms consist of mudstone and wackestone, with isolated lenses of bafflestone, boundstone, floatstone. Fossils are scarce, but crinozoans and bryozoans comprise about 90% of the bioclasts. Other fauna include stromatoporoids, corals, brachiopods, gastropods, trilobites, and probable algae (algae are difficult to identify and may have played a significant role). Faunal ratios remained relatively constant during mound growth. Soft substrates with sedimentation rates of a few millimeters per year are suggested by bedding type and morphologic dominance of lamellar and tabular corals and stromatoporoids. An increased sedimentation rate, resulting from shoaling, is indicated by more overturned, broadly conical corals in the upper parts of the mounds. Shoaling may be responsible for cessation of mound growth. Lithoclasts are more common in the upper parts of the mounds. They formed when semiconsolidated muds were disturbed and redeposited during storms. Megarippled interreef surface areas, largely devoid of coral growth, indicate mud instability at Charlton Bay. Lack of suitable stable substrates may have hampered coral development. Dolomitization was postdepositional. The diagenetic sequence occurred in three stages: 1)selective pyritization and silicification, formation of an early muddy dolomite replacing the mud fraction of the dolostone, lithification and formation of rare calcite cement and neomorphic syntaxial rims; 2)clear, coarse dolomite replacing pore-filling calcite cement, syntaxial rims, and unaltered macrofossils, stylolitization, grain-to-grain dissolution; and 3)a late dolomite found mainly as fine rhombs in stylolites, solution seams, and intraskeletal pore space.

  16. Potential Impacts of Paleohydrological Changes on Holocene Methane Fluxes in Boreal and Subarctic Peatlands, James Bay, Quebec, Canada

    NASA Astrophysics Data System (ADS)

    Garneau, M.; Ali, A.; Tremblay, L.; Pelletier, L.; Asnong, H.

    2008-12-01

    In boreal and subarctic region of the La Grande river watershed, James Bay, Quebec, Canada, peatlands cover closed to 15 % of the terrestrial surface. Multi proxy analysis results (plant macrofossils and Testate amoebae) from minerotrophic peatland have demonstrated important variations on the regional water table position since peat started to accumulate in the region ca 7400 cal BP. Macrofossil assemblages indicate that sites were first colonized by black spruce (Picea mariana Ait Muhl.) and Sphagnum spp which paludified with a regional rise of moisture at approx. 4500 BP. Drier conditions registered around 3900 cal BP induced a shift in vegetation and Testate amoeba assemblages for a relatively short period which was followed at approximately 3000 cal BP by an important increase in moisture. This shift in hydrological conditions involved drastic changes in the vegetation cover from Picea mariana and Sphagnum fuscum assemblages to sedges (Carex spp.) and wet Sphagnum species such as S. majus, S. subsecundum, S. pulchrum. This rise in the water table position could have induced enhance methane release to the atmosphere when considering the present-day methane fluxes/water table depth/vegetation cover relationship.

  17. Population structure of resident, immigrant, and swimming Corophium volutator (Amphipoda) on an intertidal mudflat in the Bay of Fundy, Canada

    NASA Astrophysics Data System (ADS)

    Drolet, David; Barbeau, Myriam A.

    2012-05-01

    Spatial variation in biotic and abiotic conditions, and differences in dispersive behavior of different life history stages can result in the formation of zones with different demography for infaunal and epifaunal species within vast intertidal flats. In this study, we evaluated within-mudflat homogeneity of the infaunal amphipod Corophium volutator found in the mud (residents), colonizing artificially disturbed areas (immigrants), and caught in the water column (swimmers) on a large mudflat in the upper Bay of Fundy, Canada. Densities of residents, immigrants, and swimmers were well structured in space (both along and across shore). Occasionally, significant differences in size structure, sex ratio, and proportion of ovigerous females were found at different intertidal levels, but these were short-lived. Comparisons of size and sex structure of residents, immigrants, and swimmers revealed occasional marked differences, with small juveniles and large adult males moving most. However, this size-bias in movement did not translate into zones with different population dynamics, suggesting that ample dispersal, through swimming and drifting in the water column, homogenized the population and masked potential effects of variation in environmental conditions. We therefore conclude that the mudflat represents one homogeneous population.

  18. Detection of microcystin-producing cyanobacteria in Missisquoi Bay, Quebec, Canada, using quantitative PCR.

    PubMed

    Fortin, Nathalie; Aranda-Rodriguez, Rocio; Jing, Hongmei; Pick, Frances; Bird, David; Greer, Charles W

    2010-08-01

    Toxic cyanobacterial blooms, as well as their increasing global occurrence, pose a serious threat to public health, domestic animals, and livestock. In Missisquoi Bay, Lake Champlain, public health advisories have been issued from 2001 to 2009, and local microcystin concentrations found in the lake water regularly exceeded the Canadian drinking water guideline of 1.5 microg liter(-1). A quantitative PCR (Q-PCR) approach was developed for the detection of blooms formed by microcystin-producing cyanobacteria. Primers were designed for the beta-ketoacyl synthase (mcyD(KS)) and the first dehydratase domain (mcyD(DH)) of the mcyD gene, involved in microcystin synthesis. The Q-PCR method was used to track the toxigenic cyanobacteria in Missisquoi Bay during the summers of 2006 and 2007. Two toxic bloom events were detected in 2006: more than 6.5 x 10(4) copies of the mcyD(KS) gene ml(-1) were detected in August, and an average of 4.0 x 10(4) copies ml(-1) were detected in September, when microcystin concentrations were more than 4 microg liter(-1) and approximately 2 microg liter(-1), respectively. Gene copy numbers and total microcystin concentrations (determined by enzyme-linked immunosorbent assay [ELISA]) were highly correlated in the littoral (r = 0.93, P < 0.001) and the pelagic station (r = 0.87, P < 0.001) in 2006. In contrast to the situation in 2006, a cyanobacterial bloom occurred only in late summer-early fall of 2007, reaching only 3 x 10(2) mcyD(KS) copies ml(-1), while the microcystin concentration was barely detectable. The Q-PCR method allowed the detection of microcystin-producing cyanobacteria when toxins and toxigenic cyanobacterial abundance were still below the limit of detection by high-pressure liquid chromatography (HPLC) and microscopy. Toxin gene copy numbers grew exponentially at a steady rate over a period of 7 weeks. Onshore winds selected for cells with a higher cell quota of microcystin. This technique could be an effective approach for

  19. Soil Temperature Variations on a Tidal Flat in Minas Basin, Bay of Fundy, Canada

    NASA Astrophysics Data System (ADS)

    Piccolo, M. C.; Perillo, G. M. E.; Daborn, G. R.

    1993-04-01

    The thermal features of the air (and water) over a tidal flat and within the sediments are described. Data were collected at Starrs Point, Minas Basin, Bay of Fundy in July 1989 as part of a multidisciplinary study of sediment properties. Temperature in the intertidal sediments exhibits rapid changes which occur principally during tidal inundation. Vertical gradients of 0·5 10 -2 °C m -1 were found in the upper 0·25 m layer. Thermal diffusivity were calculated by two methods, the amplitude equation and a numerical approach. Observed rates of temperature change were compared with theoretical rates. The results show that, if sufficient data is available the numerical method is preferred. The presence of large populations of Corophium Volutator increases thermal diffusivity because of their vertical migrations. Therefore, the heat is distributed faster and through a greater depth. FFT analysis of air-water temperatures time series presented spectrum peaks at 24, 6, 2·7 and 1·8 h. Sediment temperature spectra show peaks at 24 and 6 h, confirming that radiation and tides are the driving mechanisms of the thermal behaviour over and within the tidal flat. An empirical orthogonal function analysis was performed on the temperature time series over the tidal flats. Modes 1 and 2 explain about 99·6% of the total variance. Mode 1 reflects the mean pattern of the temperature and mode 2 shows the abrupt changes produced when the water arrives or leaves the flat.

  20. Peatland microbial communities and decomposition processes in the james bay lowlands, Canada.

    PubMed

    Preston, Michael D; Smemo, Kurt A; McLaughlin, James W; Basiliko, Nathan

    2012-01-01

    Northern peatlands are a large repository of atmospheric carbon due to an imbalance between primary production by plants and microbial decomposition. The James Bay Lowlands (JBL) of northern Ontario are a large peatland-complex but remain relatively unstudied. Climate change models predict the region will experience warmer and drier conditions, potentially altering plant community composition, and shifting the region from a long-term carbon sink to a source. We collected a peat core from two geographically separated (ca. 200 km) ombrotrophic peatlands (Victor and Kinoje Bogs) and one minerotrophic peatland (Victor Fen) located near Victor Bog within the JBL. We characterized (i) archaeal, bacterial, and fungal community structure with terminal restriction fragment length polymorphism of ribosomal DNA, (ii) estimated microbial activity using community level physiological profiling and extracellular enzymes activities, and (iii) the aeration and temperature dependence of carbon mineralization at three depths (0-10, 50-60, and 100-110 cm) from each site. Similar dominant microbial taxa were observed at all three peatlands despite differences in nutrient content and substrate quality. In contrast, we observed differences in basal respiration, enzyme activity, and the magnitude of substrate utilization, which were all generally higher at Victor Fen and similar between the two bogs. However, there was no preferential mineralization of carbon substrates between the bogs and fens. Microbial community composition did not correlate with measures of microbial activity but pH was a strong predictor of activity across all sites and depths. Increased peat temperature and aeration stimulated CO(2) production but this did not correlate with a change in enzyme activities. Potential microbial activity in the JBL appears to be influenced by the quality of the peat substrate and the presence of microbial inhibitors, which suggests the existing peat substrate will have a large

  1. Mineral and grain-size partitioning in a glacial to marine transect, western Baffin Bay, Canada

    SciTech Connect

    Geirsdottir, A.; Jennings, A.E.; Andrews, J.T.

    1985-01-01

    Pleistocene and neoglacial tills on the Precambrian shield of Baffin Island are sandy gravels with <10% in the silt/clay fraction. Observations indicate that large amounts of sediments are being carried in suspension by glacial melt water streams. Silts and clays are transported into the proximal marine environment largely as overflows where they flocculate and settle. Mineralogical analysis of the clay and silt-size fraction of one fiord core (SU5) and one shelf core (HU78-37) from western Baffin Bay were completed to investigate mineral partitioning of transport from land to sea. Such studies are commonly conducted on the clay-sized particles, but there are few investigations of the silt-sized fraction, even though silts often make up more than 50% of these marine sediments. X-ray diffraction analyses of two cores show significant differences in mineralogy. Relative to the average composition of the Precambrian shield rocks of Baffin Island the clay-size mineralogy reflects a significant enhancement in mica and depletions in quartz and feldspar. The same trend is observed in the silt-sized mineralogy, where enrichment in mica is still significant, however, the mineralogy of the two size fractions differs markedly. The overall change in mineralogy from the clay-sized to silt-sized particles shows a decrease in mica, kaolinite and chlorite and a significant increase in dolomite and calcite, which are foreign to the area. These results, combined with ongoing studies on sand-sized mineralogy will enable a sediment budget approach to glacial erosion/deposition.

  2. Peatland Microbial Communities and Decomposition Processes in the James Bay Lowlands, Canada

    PubMed Central

    Preston, Michael D.; Smemo, Kurt A.; McLaughlin, James W.; Basiliko, Nathan

    2012-01-01

    Northern peatlands are a large repository of atmospheric carbon due to an imbalance between primary production by plants and microbial decomposition. The James Bay Lowlands (JBL) of northern Ontario are a large peatland-complex but remain relatively unstudied. Climate change models predict the region will experience warmer and drier conditions, potentially altering plant community composition, and shifting the region from a long-term carbon sink to a source. We collected a peat core from two geographically separated (ca. 200 km) ombrotrophic peatlands (Victor and Kinoje Bogs) and one minerotrophic peatland (Victor Fen) located near Victor Bog within the JBL. We characterized (i) archaeal, bacterial, and fungal community structure with terminal restriction fragment length polymorphism of ribosomal DNA, (ii) estimated microbial activity using community level physiological profiling and extracellular enzymes activities, and (iii) the aeration and temperature dependence of carbon mineralization at three depths (0–10, 50–60, and 100–110 cm) from each site. Similar dominant microbial taxa were observed at all three peatlands despite differences in nutrient content and substrate quality. In contrast, we observed differences in basal respiration, enzyme activity, and the magnitude of substrate utilization, which were all generally higher at Victor Fen and similar between the two bogs. However, there was no preferential mineralization of carbon substrates between the bogs and fens. Microbial community composition did not correlate with measures of microbial activity but pH was a strong predictor of activity across all sites and depths. Increased peat temperature and aeration stimulated CO2 production but this did not correlate with a change in enzyme activities. Potential microbial activity in the JBL appears to be influenced by the quality of the peat substrate and the presence of microbial inhibitors, which suggests the existing peat substrate will have a large

  3. Oceanic Distribution, Behaviour, and a Winter Aggregation Area of Adult Atlantic Sturgeon, Acipenser oxyrinchus oxyrinchus, in the Bay of Fundy, Canada

    PubMed Central

    Taylor, Andrew Douglas; Ohashi, Kyoko; Sheng, Jinyu; Litvak, Matthew Kenneth

    2016-01-01

    Seasonal distribution of adult Atlantic sturgeon was examined using pop-up satellite archival tags (PSATs) and ultrasonic transmitters deployed in the Saint John River, New Brunswick, Canada. Seven MK10 PSATs programmed for release in June 2012 and seven MiniPAT PSATs programmed for release in February and April 2013 were deployed in August 2011 and 2012, respectively. Eleven of 14 PSATs surfaced and transmitted depth and temperature data archived for the duration of their deployment (121–302 days). Among these eleven PSATs, five were recovered and 15-sec archival data was downloaded. Following exit from the Saint John River in the fall, tagged fish occupied a mean monthly depth of 76.3–81.6 m at temperatures as low as 4.9˚C throughout the winter before returning to shallower areas in the spring. The majority of ultrasonic detections occurred in the Bay of Fundy, but fish were detected as far as Riviere Saint-Jean, Quebec, approximately 1500 km from the Bay of Fundy (representing long-distance migratory rates of up to 44 km/day). All PSATs were first detected in the Bay of Fundy. Tags that released in February and April were found 5–21 km offshore of the Saint John Harbour, while tags that released in June were first detected in near shore areas throughout the Bay of Fundy. The substrate at winter tag release locations (estimated from backward numerical particle-tracking experiments) consisted primarily of moraines and postglacial mud substrate with low backscatter strength, indicative of soft or smooth seabed. Based on the proximity of winter tag release locations, the consistent depths observed between fish, and previous research, it is suspected that a winter aggregation exists in the Bay of Fundy. This study expands the understanding of the marine distribution and range of Atlantic sturgeon on the east coast of Canada. PMID:27043209

  4. Oceanic Distribution, Behaviour, and a Winter Aggregation Area of Adult Atlantic Sturgeon, Acipenser oxyrinchus oxyrinchus, in the Bay of Fundy, Canada.

    PubMed

    Taylor, Andrew Douglas; Ohashi, Kyoko; Sheng, Jinyu; Litvak, Matthew Kenneth

    2016-01-01

    Seasonal distribution of adult Atlantic sturgeon was examined using pop-up satellite archival tags (PSATs) and ultrasonic transmitters deployed in the Saint John River, New Brunswick, Canada. Seven MK10 PSATs programmed for release in June 2012 and seven MiniPAT PSATs programmed for release in February and April 2013 were deployed in August 2011 and 2012, respectively. Eleven of 14 PSATs surfaced and transmitted depth and temperature data archived for the duration of their deployment (121-302 days). Among these eleven PSATs, five were recovered and 15-sec archival data was downloaded. Following exit from the Saint John River in the fall, tagged fish occupied a mean monthly depth of 76.3-81.6 m at temperatures as low as 4.9˚C throughout the winter before returning to shallower areas in the spring. The majority of ultrasonic detections occurred in the Bay of Fundy, but fish were detected as far as Riviere Saint-Jean, Quebec, approximately 1500 km from the Bay of Fundy (representing long-distance migratory rates of up to 44 km/day). All PSATs were first detected in the Bay of Fundy. Tags that released in February and April were found 5-21 km offshore of the Saint John Harbour, while tags that released in June were first detected in near shore areas throughout the Bay of Fundy. The substrate at winter tag release locations (estimated from backward numerical particle-tracking experiments) consisted primarily of moraines and postglacial mud substrate with low backscatter strength, indicative of soft or smooth seabed. Based on the proximity of winter tag release locations, the consistent depths observed between fish, and previous research, it is suspected that a winter aggregation exists in the Bay of Fundy. This study expands the understanding of the marine distribution and range of Atlantic sturgeon on the east coast of Canada.

  5. IDENTIFICATION OF SPECIES-ENVIRONMENT RELATIONSHIPS IN THE HUDSON-RARITAN ESTUARY AND RELATED SUB-BASINS

    EPA Science Inventory

    The US EP A's Regional Environmental Monitoring and Assessment Program (REMAP) conducted a study in 1993/94 to assess the effects of sediment contamination in the Hudson- Raritan area (Upper New York, Raritan Bay, Jamaica Bay, western Long Island Sound and the Bight Apex). This s...

  6. Methane emissions in the US and Canada: contributions of various source sectors and evolution of emissions over time

    NASA Astrophysics Data System (ADS)

    Miller, S. M.; Michalak, A. M.; Wofsy, S. C.; Andrews, A. E.; Biraud, S.; Dlugokencky, E. J.; Fischer, M. L.; Janssens-Maenhout, G.; Kort, E. A.; Miller, B. R.; Miller, J. B.; Montzka, S. A.; Worthy, D. E. J.

    2014-12-01

    In this presentation, we quantify several aspects of methane emissions in the US and Canada using concentration data collected in the atmosphere. First, how much methane in total is emitted from the US and Canada? Second, how much methane is emitted from each individual source across these countries? Third, and finally, how have each of these sources changed in magnitude over the past ten to twenty years? To answer these questions, we use a geostatistical model-data fusion framework and spatial data on land use and economic activity. Using this approach, we estimate the contribution of different source types to methane emissions in the US and compare the magnitude of those anthropogenic emissions against natural fluxes from major wetlands like those near Hudson Bay, Canada. Furthermore, we examine the time-evolution of methane concentrations over regions dominated by agriculture and natural gas extraction and investigate what this data indicates about changes in emissions over time.

  7. A study of the composition, characteristics, and origin of modern driftwood on the western coast of Nunavik (Quebec, Canada)

    NASA Astrophysics Data System (ADS)

    Steelandt, Stéphanie; Marguerie, Dominique; Bhiry, Najat; Delwaide, Ann

    2015-03-01

    Data concerning driftwood is of value to researchers in fields as diverse as oceanography, geomorphology, and human occupation. Yet studies on the subject in the Canadian Arctic have only recently been carried out, and the present study is the first in Nunavik (northeastern Canada). This paper documents the composition, characteristics, and origin of modern driftwood pieces on the beaches of the eastern coast of Hudson Bay. A total of 1057 samples from Ivujivik, Akulivik, Inukjuak, and Umiujaq were identified as belonging to four coniferous species (Picea sp., Larix sp., Abies sp. likely balsamea, and Thuja sp. likely occidentalis) and four deciduous species (Salix sp., Populus sp., Alnus sp., and Betula sp., likely papyrifera). Spruce largely predominate; white birch, white cedar, and fir are rare. The presence of the latter species proves that some of the wood originated from south-southeast of James Bay. Driftwood found in the southern area (Umiujaq) are more numerous, larger, and less degraded than driftwood in the north (Ivujivik). However, many large coniferous samples were found as far north as Akulivik, indicating that they likely traveled a great distance, unlike the smaller wood specimens (especially deciduous samples). All of the wood that we analyzed died relatively young, with an average age of 63 years for conifers and 23 years for deciduous. Measurements of ring widths and the cross-dating of samples with existing reference chronologies of living trees along Hudson Bay and James Bay revealed several possible correlations and origins for wood found in same areas.

  8. Chlorofluorocarbons in the Hudson estuary during summer months

    SciTech Connect

    Clark, J.F.; Smethie, W.M. Jr.; Simpson, H.J.

    1995-10-01

    Chlorofluorocarbon (CFC) concentrations in the Hudson estuary were found to be greater than the atmospheric solubility equilibrium concentration, demonstrating that the entire reach is contaminated with CFCs from local wastewater discharge. Samples have been collected along the axis of the lower Hudson estuary over a 5-month period to assess temporal and spatial variability of their wastewater sources. The highest CFC concentrations were found in water collected near Manhattan. In this region, CFC-11 (CCl{sub 3}F) and CFC-12 (CCl{sub 2}F{sub 2}) were 3 to 5 and 10 to 20 times saturation, respectively. There appears to be a continuous CFC source in the New York City area, although the magnitude of this source declined during summer months. Other large CFC source were found near Albany, and in Haverstraw Bay (60 km north of Manhattan). 29 refs., 6 figs., 3 tabs.

  9. Chlorofluorocarbons in the Hudson Estuary During Summer Months

    NASA Astrophysics Data System (ADS)

    Clark, Jordan F.; Smethie, William M.; Simpson, H. James

    1995-10-01

    Chlorofluorocarbon (CFC) concentrations in the Hudson estuary were found to be greater than the atmospheric solubility equilibrium concentration, demonstrating that the entire reach is contaminated with CFCs from local wastewater discharge. Samples have been collected along the axis of the lower Hudson estuary over a 5-month period to assess temporal and spatial variability of their wastewater sources. The highest CFC concentrations were found in water collected near Manhattan. In this region, CFC-11 (CCl3F) and CFC-12 (CCl2F2) were 3 to 5 and 10 to 20 times saturation, respectively. There appears to be a continuous CFC source in the New York City area, although the magnitude of this source declined during summer months. Other large CFC sources were found near Albany, and in Haverstraw Bay (60 km north of Manhattan).

  10. Green Summer and Icy Winter in James Bay

    NASA Technical Reports Server (NTRS)

    2001-01-01

    One year ago, in late February 2000, MISR began acquiring Earth imagery. Its 'first light' images showed a frozen James Bay in the Ontario-Quebec region of Canada. These more recent nadir-camera views of the same area illuminate stark contrasts between summer and winter. The left-hand image was acquired on August 9, 2000 (Terra orbit 3427), and the right-hand image is from January 16, 2001 (Terra orbit 5757).

    James Bay lies at the southern end of Hudson Bay. It is named for the English explorer Thomas James, who first explored the area in 1631 while searching for the Northwest Passage. Visible in these images are some of the many rivers that flow into the bay; starting at the southern tip and moving clockwise on the western side are the Harricana, Moose, Albany, and Attawapiskat. The latter enters the bay just to the west of the large, crescent-shaped Akimiski Island.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

  11. Seasonal variation in the spatial distribution of basking sharks (Cetorhinus maximus) in the lower Bay of Fundy, Canada.

    PubMed

    Siders, Zachary A; Westgate, Andrew J; Johnston, David W; Murison, Laurie D; Koopman, Heather N

    2013-01-01

    The local distribution of basking sharks in the Bay of Fundy (BoF) is unknown despite frequent occurrences in the area from May to November. Defining this species' spatial habitat use is critical for accurately assessing its Special Concern conservation status in Atlantic Canada. We developed maximum entropy distribution models for the lower BoF and the northeast Gulf of Maine (GoM) to describe spatiotemporal variation in habitat use of basking sharks. Under the Maxent framework, we assessed model responses and distribution shifts in relation to known migratory behavior and local prey dynamics. We used 10 years (2002-2011) of basking shark surface sightings from July-October acquired during boat-based surveys in relation to chlorophyll-a concentration, sea surface temperature, bathymetric features, and distance to seafloor contours to assess habitat suitability. Maximum entropy estimations were selected based on AICc criterion and used to predict habitat utilizing three model-fitting routines as well as converted to binary suitable/non-suitable habitat using the maximum sensitivity and specificity threshold. All models predicted habitat better than random (AUC values >0.796). From July-September, a majority of habitat was in the BoF, in waters >100 m deep, and in the Grand Manan Basin. In October, a majority of the habitat shifted southward into the GoM and to areas >200 m deep. Model responses suggest that suitable habitat from July - October is dependent on a mix of distance to the 0, 100, 150, and 200 m contours but in some models on sea surface temperature (July) and chlorophyll-a (August and September). Our results reveal temporally dynamic habitat use of basking sharks within the BoF and GoM. The relative importance of predictor variables suggests that prey dynamics constrained the species distribution in the BoF. Also, suitable habitat shifted minimally from July-September providing opportunities to conserve the species during peak abundance in the region.

  12. 4. THIRD FLOOR CENTER BAY TO NORTH; SOAP KETTLES TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. THIRD FLOOR CENTER BAY TO NORTH; SOAP KETTLES TO LEFT AND RIGHT, TWO-STORY TANK AT CENTER REAR - Colgate & Company Jersey City Plant, Building No. B-13, 48-50 Grand Street, Jersey City, Hudson County, NJ

  13. 12. NEW YORK SIDE, HUDSON RIVER VENTILATION BUILDING IN FOREGROUND; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. NEW YORK SIDE, HUDSON RIVER VENTILATION BUILDING IN FOREGROUND; NEW JERSEY SIDE, HUDSON RIVEN VENTILATION BUILDING IN BACKGROUND - Holland Tunnel, Beneath Hudson River between New York & Jersey City, New York County, NY

  14. Metals in the sediments along the Hudson River estuary

    SciTech Connect

    Gibbs, R.J. )

    1994-01-01

    The distribution of metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in bottom and suspended sediments from the ocean up the Hudson River estuary for 70 km were analyzed. The bottom sediments has a metal concentration maximum in the harbor. Everywhere studied, the metal concentrations in suspension are much higher than in the bottom sediments by 30 times for Cd, 20 times for Cu, and 10 to 15 times for Co, Cr, Ni, Pb, and Zn. The composition of metals in the suspended material varied along the estuary with a large metal maximum in the harbor and again in Haverstraw Bay. By standardizing toxic metal concentrations to Fe, a maximum level of pollution in New York Harbor is indicated, along with a lesser maximum in Haverstraw Bay.

  15. Thirty years - Alexandrium fundyense cyst, bloom dynamics and shellfish toxicity in the Bay of Fundy, eastern Canada

    NASA Astrophysics Data System (ADS)

    Martin, Jennifer L.; LeGresley, Murielle M.; Hanke, Alex R.

    2014-05-01

    Sediment and water samples were collected for Alexandrium fundyense spatial and temporal distribution and abundance at more than 120 locations throughout the Bay of Fundy during the summers and winters of 1980-1984. These broad surveys have been repeated at various times through the past 30 years, with more regular sampling since 2004. In addition, A. fundyense abundance has been monitored at several locations within the Bay of Fundy at weekly intervals from April to November and monthly during the remaining months since 1988. Paralytic Shellfish Poisoning (PSP) toxins in shellfish (notably Mya arenaria) have also been monitored at multiple locations in the Bay of Fundy since 1943. The datasets were examined to determine relationships and roles between overwintering resting cysts, bloom initiation, bloom decline, motile cell dispersal and A. fundyense motile populations and resulting shellfish toxicity since 1980. Cysts are widely dispersed throughout the Bay of Fundy in the offshore, inshore and intertidal zones with the largest deposits located in the offshore in silt/clay sediments to the east and north of Grand Manan Island at depths of 60-180 m. Results show that there is a constant stable source of cysts in the Bay of Fundy with highest concentrations of cysts (9780 cysts cm-3) observed in 2010 and highest concentrations of A. fundyense motile cells (18×106 cells L-1) observed in 1980. Interannual changes in abundance in A. fundyense populations, resting cysts and the temporal trends in M. arenaria toxicity are discussed. Results show that there was no relationship between the abundance of overwintering cysts and the magnitude of A. fundyense blooms. The offshore seed beds appear to be relatively constant in cyst density among most years and serve as an important source for the motile cells that lead to initiation of major blooms and resulting shellfish toxicity throughout the Bay of Fundy.

  16. Tetrachlorodibenzo-P-dioxins and tetrachlorodibenzofurans in Atlantic Coast striped bass and in selected Hudson River fish, waterfowl and sediments

    SciTech Connect

    O'Keefe, P.; Hilker, D.; Meyer, C.; Aldous, K.; Shane, L.; Donnelly, R.; Smith, R.; Sloan, R.; Skinner, L.; Horn, E.

    1984-01-01

    In striped bass samples from the lower Hudson River and its estuary 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) was found at concentrations from 16 to 120 pg/g (ppt). Striped bass from two other locations (Rhode Island coastal waters and Chesapeake Bay, Maryland) had <5 ppt, 2,3,7,8-TCDD. The contaminant, 2,3,7,8-tetrachlorodibenzofuran (2,3,7,8-TCDF), was found in striped bass from all three locations with concentrations varying from 6 ppt in Chesapeake Bay to 78 ppt in the Hudson River. Results from a limited number of non-migratory fish (carp and goldfish) and sediments suggest that the upper Hudson River is not a source for 2,3,7,8-TCDD/2,3,7,8-TCDF contamination of striped bass.

  17. Spring migratory pathways and migration chronology of Canada geese (Branta canadensis interior) wintering at the Santee National Wildlife Refuge, South Carolina

    USGS Publications Warehouse

    Giles, Molly M.; Jodice, Patrick G.; Baldwin, Robert F.; Stanton, John D.; Epstein, Marc

    2013-01-01

    We assessed the migratory pathways, migration chronology, and breeding ground affiliation of Canada Geese (Branta canadensis interior) that winter in and adjacent to the Santee National Wildlife Refuge in Summerton, South Carolina, United States. Satellite transmitters were fitted to eight Canada Geese at Santee National Wildlife Refuge during the winter of 2009–2010. Canada Geese departed Santee National Wildlife Refuge between 5 and 7 March 2010. Six Canada Geese followed a route that included stopovers in northeastern North Carolina and western New York, with three of those birds completing spring migration to breeding grounds associated with the Atlantic Population (AP). The mean distance between stopover sites along this route was 417 km, the mean total migration distance was 2838 km, and the Canada Geese arrived on AP breeding grounds on the eastern shore of Hudson Bay between 20 and 24 May 2010. Two Canada Geese followed a different route from that described above, with stopovers in northeastern Ohio, prior to arriving on the breeding grounds on 9 June 2010. Mean distance between stopover sites was 402 and 365 km for these two birds, and total migration distance was 4020 and 3650 km. These data represent the first efforts to track migratory Canada Geese from the southernmost extent of their current wintering range in the Atlantic Flyway. We did not track any Canada Geese to breeding grounds associated with the Southern James Bay Population. Caution should be used in the interpretation of this finding, however, because of the small sample size. We demonstrated that migratory Canada Geese wintering in South Carolina use at least two migratory pathways and that an affiliation with the Atlantic Population breeding ground exists.

  18. Sediment transport and development of banner banks and sandwaves in an extreme tidal system: Upper Bay of Fundy, Canada

    NASA Astrophysics Data System (ADS)

    Li, Michael Z.; Shaw, John; Todd, Brian J.; Kostylev, Vladimir E.; Wu, Yongsheng

    2014-07-01

    Multibeam sonar mapping and geophysical and geological groundtruth surveys were coupled with tidal current and sediment transport model calculations to investigate the sediment transport and formation processes of the complex seabed features off the Cape Split headland in the upper Bay of Fundy. The Cape Split banner bank, composed of coarse to very coarse sand, is a southwest-northeast oriented, large tear-drop shaped sand body with superimposed sand waves that show wavelengths from 15 to 525 m and heights from 0.5 to 19 m. Isolated and chains of barchan dunes occur on top of a shadow bank to the southeast of the banner bank. The barchan dunes are composed of well-sorted medium sand and are oriented northwest-southeast. Their mean height and width are 1.5 and 55 m, respectively. A gravel bank, with an elongated elliptical shape and west-east orientation, lies in the Minas Passage erosional trough east of the headland to form the counterpart to the sandy Cape Split banner bank. The southern face is featureless but the northern face is covered by gravel megaripples. Tidal model predictions and sediment transport calculations show that the formation of the banner bank and the gravel bank are due to the development of the transient counter-clockwise and clockwise tidal eddies respectively to the west and east of the headland. The formation of barchan dunes is controlled by the nearly unidirectional flow regime in outer Scots Bay. Sand waves on the flanks of the Cape Split banner bank show opposite asymmetry and the barchan dunes are asymmetric to the northeast. The tidal current and sediment transport predictions corroborate bedform asymmetry to show that sand wave migration and net sediment transport is to southwest on the northern flank of the banner bank but to northeast on the southern bank. Long-term migration of the Scots Bay barchan dunes is to the northeast. Spring-condition tidal currents can cause frequent mobilization and high-stage transport over the

  19. Temporal and spatial distribution and production of dissolved gaseous mercury in the Bay St. François wetland, in the St. Lawrence River, Quebec, Canada

    NASA Astrophysics Data System (ADS)

    Garcia, Edenise; Laroulandie, Jerôme; Saint-Simon, Xavier R.; Amyot, Marc

    2006-06-01

    Wetlands are valued for their high biodiversity and for their ecosystem services. However, we still do have a poor understanding of their role in the redox transformation of contaminants such as mercury, particularly in fluvial settings. Seasonal and spatial variations in dissolved gaseous mercury (DGM) distribution and production were studied in the Bay St. François, a wetland in the St. Pierre Lake, a fluvial lake of the St. Lawrence River, in Quebec, Canada. A high spatial resolution for DGM, with samples taken every 10-cm depth, was used in field measurements. Through a series of parallel field and incubation experiments, we assessed the main factors determining Hg(0) transformations as a function of depth, seasons, and presence/absence of macrophyte beds. Besides light penetration in the water column and water temperature, iron and dissolved organic carbon likely stimulated Hg(II) reduction. Inversely, chloride favored Hg(0) oxidation. Macrophytes and associated epiphytes appeared to be important sites of adsorption/absorption of Hg(II) and likely of DGM. It seems however that the effects of macrophytes were restricted to immediately adjacent waters. Near the bottom, under anoxic conditions, the reduction of Hg(II) was highly promoted. In addition, sediments and decomposing macrophytes seemed to release DGM and/or reducible Hg to bottom waters. Overall, differences in DGM between surface and bottom waters tended to be more accentuated than observed differences in DGM between macrophyte beds and sites devoid of plant.

  20. Recent peat accumulation rates in minerotrophic peatlands of the Bay James region, Eastern Canada, inferred by 210Pb and 137Cs radiometric techniques.

    PubMed

    Ali, Adam A; Ghaleb, Bassam; Garneau, Michelle; Asnong, Hans; Loisel, Julie

    2008-10-01

    (210)Pb and (137)Cs dating techniques are used to characterise recent peat accumulation rates of two minerotrophic peatlands located in the La Grande Rivière hydrological watershed, in the James Bay region (Canada). Several cores were collected during the summer 2005 in different parts of the two selected peatlands. These minerotrophic patterned peatlands are presently affected by erosion processes, expressed by progressive mechanical destruction of their pools borders. This erosion process is related to a water table rise induced by a regional increase of humidity since the last century. The main objective of the present paper is to (1) evaluate if (210)Pb and (137)Cs dating techniques can be applied to build accurate chronologies in these environments and (2) detect changes in the peat accumulation rates in regard to this amplification of humidity. In both sites, unsupported (210)Pb shows an exponential decreasing according to the depth. Chronologies inferred from (210)Pb allow to reconstruct peat accumulation rates since ca. 1855 AD. The (137)Cs data displayed evident mobility and diffusion, preventing the establishment of any sustained chronology based on these measurements. In the two sites, peat accumulation rates inferred from (210)Pb chronologies fluctuate between 0.005 and 0.038 g cm(-2) yr(-1). As a result, the rise of the water table during the last decade has not yet affected peat accumulation rates.

  1. 77 FR 41048 - Safety Zone; Hudson Valley Triathlon, Ulster Landing, Hudson River, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-12

    ... Landing, NY for the 16th Annual Hudson Valley Triathlon swim event. This temporary safety zone is.... Regulatory History and Information The Hudson Valley Triathlon swim is an annual recurring event that has a... Valley Triathlon swim event will occur on July 15, 2012. On May 22, 2012, the sponsor of the...

  2. Temperature and the sulfur cycle control monomethylmercury cycling in high Arctic coastal marine sediments from Allen Bay, Nunavut, Canada.

    PubMed

    St Pierre, K A; Chétélat, J; Yumvihoze, E; Poulain, A J

    2014-01-01

    Monomethylmercury (MMHg) is a neurotoxin of concern in the Canadian Arctic due to its tendency to bioaccumulate and the importance of fish and wildlife in the Inuit diet. In lakes and wetlands, microbial sediment communities are integral to the cycling of MMHg; however, the role of Arctic marine sediments is poorly understood. With projected warming, the effect of temperature on the production and degradation of MMHg in Arctic environments also remains unclear. We examined MMHg dynamics across a temperature gradient (4, 12, 24 °C) in marine sediments collected in Allen Bay, Nunavut. Slurries were spiked with stable mercury isotopes and amended with specific microbial stimulants and inhibitors, and subsampled over 12 days. Maximal methylation and demethylation potentials were low, ranging from below detection to 1.13 pmol g(-1) h(-1) and 0.02 pmol g(-1) h(-1), respectively, suggesting that sediments are likely not an important source of MMHg to overlying water. Our results suggest that warming may result in an increase in Hg methylation - controlled by temperature-dependent sulfate reduction, without a compensatory increase in demethylation. This study highlights the need for further research into the role of high Arctic marine sediments and climate on the Arctic marine MMHg budget.

  3. VIEW NORTHWEST ACROSS HUDSON STREET BUILDING 67 INSULATED WIRE DIVISION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW NORTHWEST ACROSS HUDSON STREET BUILDING 67 INSULATED WIRE DIVISION STORE HOUSE (1897) - John A. Roebling's Sons Company & American Steel & Wire Company, South Broad, Clark, Elmer, Mott & Hudson Streets, Trenton, Mercer County, NJ

  4. Hydrogeological impacts of road salt from Canada's busiest highway on a Lake Ontario watershed (Frenchman's Bay) and lagoon, City of Pickering.

    PubMed

    Meriano, Mandana; Eyles, Nick; Howard, Ken W F

    2009-06-26

    The quantity of deicing salt applied to paved surfaces in urban watersheds in cold regions has had a significant and cumulative effect on groundwater quality. Whereas road deicing salt is known in general to impact groundwater and surface water quality, quantitative information on the impact of large transport routes is lacking. In this study, we provide a chloride mass balance for an urban stream crossed by a large transport route in south-central Ontario, Canada and quantify likely long-term impacts of salt loading on surface and groundwater resources. The chloride mass balance, supported by hydrochemical analysis, reveals that approximately 50% of the total road salt applied to Pine Creek (1700 tonnes per winter) is removed annually via overland flow with the remainder accumulating in the shallow subsurface resulting in severe degradation of groundwater quality. Moreover, results show that road salt migration is the primary reason for enhanced mineral weathering in the shallow aquifer. During the 2004-05 salting season, runoff and baseflow transport of road salts were responsible for chloride concentrations in the stream of up to 2000 mg L(-1), and delivered approximately 850 tonnes of chloride (about 1400 tonnes of salt) to a shallow (<3.5 m) semi-enclosed lagoon on the shore of Lake Ontario (Frenchman's Bay; 0.85 km(2)). The total chloride delivery to the lagoon from its entire watershed is estimated at 3700 tonnes each year with up to 48% of the total load delivered by baseflow, the remainder from surface water runoff. Present day groundwater chloride concentrations are estimated to be about 80% of long-term concentrations when the system reaches steady state.

  5. Computerized Landscapes by Way of the Hudson. Pixel Palette.

    ERIC Educational Resources Information Center

    Patterson, Berniece

    2000-01-01

    Presents an art lesson that integrates the study of the Hudson River School with computer art by having students create landscapes using "Fractal Design Painter 4." Offers historical background on the Hudson River School, a group of painters who lived near the Hudson River (New York). (CMK)

  6. View of fourlane Henry Hudson Parkway winding through Riverdale, showing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of four-lane Henry Hudson Parkway winding through Riverdale, showing service roads, from White Hall Cooperative Apartments. Henry Hudson Bridge, Inwood Hill Park, the Cloisters and Fort Tryon Park, George Washington Bridge, and Manhattan skyline in background, looking southwest. - Henry Hudson Parkway, Extending 11.2 miles from West 72nd Street to Bronx-Westchester border, New York County, NY

  7. ISS pass over Southern California to Hudson Bay

    NASA Video Gallery

    This sequence of still frames was acquired as the International Space Station was tracking east-northeastward across the United States. The sequence begins over the Pacific Ocean as the ISS headed ...

  8. Mass balances and dynamic changes of the Bering, Malaspina, and Icy Bay glacier systems of Alaska, United States, and Yukon, Canada

    NASA Astrophysics Data System (ADS)

    Muskett, Reginald R.

    The Bering and the Malaspina Glacier systems of south-central Alaska, U.S.A., and southwest Yukon Territory, Canada, in the Saint Elias Mountains constitute the two largest temperate surge-type piedmont glaciers on Earth. This is largest region of glaciers and icefields in continental North America. Determining and understanding the causes of wastage of these two glaciers is important to understanding the linkages of glacier mass balance to climate change, glacier dynamics, and the contributions of the glaciers of northwestern North America to rising sea level. Presented are the first detailed estimate of the net mass balances of the Bering and Malaspina Glacier systems, the effects of glacier dynamics on their accumulation areas, and the wastage of the tidewater glaciers of Icy Bay. The combined wastage of the Bering and Malaspina Glacier systems from 1972 to 2003, 254 +/- 16 km 3 water equivalent over a glacier area of 7734 km2, is equivalent to an area-average mass balance of -1.06 +/- 0.07 m/y over that time period. This represents a contribution to global sea-level rise of 0.70 +/- 0.05 mm, 0.023 +/- 0.002 mm/yr from 1972 to 2003. This is roughly 0.8% of the modern sea-level rise as estimated from tide-gauges and satellites, and roughly 9% of the contribution from non-polar glaciers and ice caps. Glacier wastage has been caused by climate warming (negative mass balance) superimposed on the effects of glacier dynamics. Near-concurrent surge of the three largest glaciers of the Malaspina Glacier piedmont were observed during 1999 to 2002. In addition, the tidewater Tyndall Glacier, whose retreat since 1910 was interrupted in 1964 by a major surge, also surged during 1999 to 2002. These four surges have occurred roughly 23 years after the 1976/77 shift of the Pacific Decadal Oscillation to its current warm-wet phase. Despite the increase of high-elevation snow accumulation observed on Mt. Logan, the accumulation areas of the Bering and Malaspina Glacier systems

  9. Late-Wisconsin End Moraines in Northern Canada.

    PubMed

    Falconer, G; Andrews, J T; Ives, J D

    1965-02-05

    A system of end moraines nearly 2240 kilometers long has been identified by field investigation and aerial photography. It extends through northeastern Keewatin, Melville Peninsula, and Baffin Island and marks the border of a late-Wisconsin ice sheet centered over Foxe Basin and Hudson Bay 8000 or 9000 years ago.

  10. Polychlorinated biphenyls in the Hudson River

    SciTech Connect

    Brown, M.P.; Werner, M.B.; Sloan, R.J.; Simpson, K.W.

    1985-01-01

    This paper reviews studies of recent trends in the distribution of PCBs in water, sediment and fish of the Hudson River, New York. Results of various monitoring programs conducted since 1977 are presented. Elimination of direct discharge, dredging and disposal of contaminated sediments, and stabilization of banks have resulted in reduced levels in sediments and biota. The implications for commercial and recreational fishing interests are discussed. 41 references.

  11. SOLAR PANELS ON HUDSON COUNTY FACILITIES

    SciTech Connect

    BARRY, KEVIN

    2014-06-06

    This project involved the installation of an 83 kW grid-connected photovoltaic system tied into the energy management system of Hudson County's new 60,000 square foot Emergency Operations and Command Center and staff offices. Other renewable energy features of the building include a 15 kW wind turbine, geothermal heating and cooling, natural daylighting, natural ventilation, gray water plumbing system and a green roof. The County intends to seek Silver LEED certification for the facility.

  12. Education Outreach in Village Schools during the SnowSTAR 2007 Alaska-Canada Barrenlands Traverse.

    NASA Astrophysics Data System (ADS)

    Solie, D.; Sturm, M.; Huntington, H.; Anderson, D.; Derksen, C.

    2008-12-01

    In spring 2007, the IPY expedition, SnowSTAR-2007, traveled 4200 kilometers by snow machine across much of Alaska and Northern Canada. The primary objectives of the trip were education outreach, and collaborative US/Canadian field measurements of the snow across the route. Starting in Fairbanks, Alaska and ending in Baker Lake, Nunavut, Canada near Hudson Bay 42 days later, the team visited numerous settlements in route. The primary outreach efforts during the expedition were the expedition website (http://www.barrenlands.org ), and in-school presentations and interactive science demonstrations. The website, aimed at school children as well as the general public, was updated daily from the field, and had strong national and international interest. We gave presentations (classrooms and all-school assemblies), in nine of the villages we visited. In the schools we demonstrated the equipment we use in the field, as well as two proven demonstrations of physical principles (acoustic resonance in a plastic sewer pipe and eddy current forces on a magnet falling through a copper water pipe). Video recordings from the expedition travel, science and village school presentations can be adapted for classroom use to show application of scientific principles as well as excite student interest in the physical and geo-sciences.

  13. 24. Demolitin of Pier G reveals the center bays at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. Demolitin of Pier G reveals the center bays at the track well in transverse section. Note structural system of first, second, and third floors, as well as the monitor roof. - Lehigh Valley Railroad, Pier G, Jersey City, Hudson County, NJ

  14. Total plankton respiration in the Chesapeake Bay plume

    NASA Technical Reports Server (NTRS)

    Robertson, C. N.; Thomas, J. P.

    1981-01-01

    Total plankton respiration (TPR) was measured at 17 stations within the Chesapeake Bay plume off the Virginia coast during March, June, and October 1980. Elevated rates of TPR, as well as higher concentrations of chlorophyll a and phaeopigment a, were found to be associated with the Bay plume during each survey. The TPR rates within the Bay plume were close to those found associated with the Hudson River plume for comparable times of the year. The data examined indicate that the Chesapeake Bay plume stimulates biological activity and is a source of organic loading to the contiguous shelf ecosystem.

  15. Aurelia labiata jellyfish in Roscoe Bay on the West Coast of Canada: Seasonal changes in adult bell diameter and mingling of juvenile and adult populations

    NASA Astrophysics Data System (ADS)

    Albert, David J.; Walsh, Michael L.

    2014-01-01

    The bell diameter of adult Aurelia labiata in Roscoe Bay increased from spring (April) to early summer (May/June) and decreased over the rest of the year (2009/2010). The increase in bell diameter in the spring would have been supported by the increase in zooplankton that occurs in the northeast Pacific at this time. Over the summer, bell diameter may have decreased because the food available/medusa would have been decreased by the arrival of a large number of juveniles and may have decreased further over the fall and winter when zooplankton levels are known to be low. Adults and juveniles were intermingled during 2010, 2011, and 2012. Correlations between the number of adults and number of juveniles obtained in individual net lifts across the entire bay and in different parts of the bay were all positive and most were statistically significant. In 2012, salinity in the entire water column of the west side of the bay dropped below 20 ppt in July and most medusae migrated to higher salinity in the east side of the bay, a distance of about 0.5 km. The mingling of adults and juveniles supports other evidence that adult Aurelia sp. medusae do not prey upon juveniles. The ability to withstand months with insufficient food and to inhibit preying on juveniles would contribute greatly to the survival of Aurelia sp. jellyfish.

  16. View of Hudson & Manhattan Tunnel in Section C showing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of Hudson & Manhattan Tunnel in Section C showing one of World Trade Center 2's column bases used to support Hudson & Manhattan Tube across site, looking east. (BH) - World Trade Center Site, Bounded by Vesey, Church, Liberty Streets, & Route 9A, New York County, NY

  17. Hudson County Community College Periodic Review Report. Executive Summary.

    ERIC Educational Resources Information Center

    Hudson County Community Coll., Jersey City, NJ.

    Hudson County Community College (HCCC) serves Hudson County, New Jersey. Although the county is the smallest in the state, its 610,000 residents make up one of the most diverse counties in New Jersey. Approximately 40% of residents are Hispanic, 12% are African-American, 10% are Asian, and 35% are White. The county is also home to a growing Middle…

  18. 75 FR 30018 - Hudson Transmission Partners, LLC; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-28

    ... Energy Regulatory Commission Hudson Transmission Partners, LLC; Notice of Filing May 20, 2010. Take notice that on May 19, 2010, Hudson Transmission Partners, LLC filed an application requesting the... section 212.4(c) and Attachment O, section 6.5 of the PJM Open Access Transmission Tariff, PJM OATT...

  19. 78 FR 49748 - Hudson Transmission Partners, LLC; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-15

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Hudson Transmission Partners, LLC; Notice of Filing Take notice that on July 12, 2013, Hudson Transmission Partners, LLC filed a request for exemption from, or waiver of,...

  20. View of cars entering Henry Hudson Parkway southbound at the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of cars entering Henry Hudson Parkway southbound at the Mosholu Parkway interchange, with outcropping in northwest Van Cortlandt Park in background, looking north. - Henry Hudson Parkway, Extending 11.2 miles from West 72nd Street to Bronx-Westchester border, New York County, NY

  1. A River Summer on the Hudson

    NASA Astrophysics Data System (ADS)

    Kenna, T. C.; Pfirman, S.; Selleck, B.; Son, L.; Land, M.; Cronin, J.

    2006-12-01

    River Summer is a month-long faculty development program extending from the continental shelf off New York City to the headwaters of the Hudson in the Adirondack Mountains. During the program, faculty from the Environmental Consortium of Hudson Valley Colleges and Universities teach each other about the Hudson environment, using innovative methods of teaching and learning, with a focus on incorporation of hands-on approaches from the perspective of multiple disciplines. Over four weeks, faculty from research universities, community colleges, liberal arts institutions, and middle and high schools work and live together, on board a research vessel or in a remote tent campsite, for several days at a time. Using the geology, hydrology, and landscape of the River as a foundation, River Summer focuses on understanding development of the Hudson within the context of its natural resources and cultural history. Participants conduct field sampling and analyses and consider issues through approaches that are common to many disciplines: scaling for problem solving; sampling and assessing bias and representation; observing and documenting; representing and depicting; interpretation and assessing relationships and causality; and evaluation. They also get a chance to experience, first-hand, the complexity and often open-ended nature of doing science. By allowing individuals, many of whom come from non-science disciplines, to experience these methods and processes in a safe learning environment, science is made more meaningful and accessible. The program's pedagogy is based on the principles of cognitive psychology and immersive field-, place- and inquiry-based learning. Field programs have been found to provide memorable, transformative experiences for undergraduate students, and our experience with River Summer 2005 and 2006 suggests they are equally effective with faculty. Evaluation shows that River Summer has a significant impact on its participants. Participants develop new

  2. Let's Bet on Sediments! Hudson Canyon Cruise--Grades 9-12. Focus: Sediments of Hudson Canyon.

    ERIC Educational Resources Information Center

    National Oceanic and Atmospheric Administration (DOC), Rockville, MD.

    These activities are designed to teach about the sediments of Hudson Canyon. Students investigate and analyze the patterns of sedimentation in the Hudson Canyon, observe how heavier particles sink faster than finer particles, and learn that submarine landslides are avalanches of sediment in deep ocean canyons. The activity provides learning…

  3. Taxonomy and host-specificity of Gyrodactylus aideni n. sp. and G. pleuronecti (Monogenea: Gyrodactylidae) from Pseudopleuronectes americanus (Walbaum) in Passamaquoddy Bay, New Brunswick, Canada.

    PubMed

    Mullen, A J; Cone, D K; Easy, R; Burt, M D B

    2010-11-01

    Wild and cultured winter flounder Pseudopleuronectes americanus (Walbaum) from Passamaquoddy Bay were surveyed for species of Gyrodactylus Nordmann, 1832. Two species were found: G. pleuronecti Cone, 1981 and G. aideni n. sp, both members of Malmberg's 'groenlandicus group'. Although the hard parts in the haptor are very similar in the two species, hamuli of G. aideni are consistently shorter than those of G. pleuronecti. The two species differed by 35 base pairs in the ITS 1, 5.8 and ITS 2 region. A BLAST search identified a variety of species of Gyrodactylus from marine fishes in the Atlantic Ocean as closest matches, indicating the 'groenlandicus group' is part of a major marine lineage within Gyrodactylus (sensu lato) that has successfully radiated among coastal percid, pleuronectid, cottid and anarhichadid fishes. Exposure experiments suggested that winter flounder is the primary host of both species of parasites and that three other pleuronectid species in the bay may potentially serve only as occasional transport hosts.

  4. S saturation history of Nain Plutonic Suite mafic intrusions: origin of the Voisey's Bay Ni-Cu-Co sulfide deposit, Labrador, Canada

    NASA Astrophysics Data System (ADS)

    Lightfoot, Peter C.; Keays, Reid R.; Evans-Lamswood, Dawn; Wheeler, Robert

    2012-01-01

    The Voisey's Bay deposit is hosted in a 1.34-Ga intrusion composed of troctolite, olivine gabbro, and ferrogabbro. The sulfide mineralization is associated with magmatic breccias that are enveloped by weakly mineralized olivine gabbros and troctolites, and also occurs as veins along structures in adjacent paragneiss. A dyke is connected to the base of the north wall of the Eastern Deeps Intrusion, and the entry point of this dyke into the chamber is the locus of the Eastern Deeps nickel sulfide deposit. A detailed exploration in the area between the Eastern Deeps and the Ovoid has shown that these intrusions and ore deposits are connected by a splayed dyke. The Eastern Deeps Deposit is surrounded by a halo of moderately to weakly mineralized variable-textured troctolite (VTT) that reaches a maximum thickness above the axis of the Eastern Deeps Deposit along the northern wall of the Eastern Deeps Intrusion. The massive sulfides and breccia sulfides are petrologically and chemically different when compared to the disseminated sulfides in the VTT, and there is a marked break in Ni tenor of sulfide between the two. Sulfides hosted in the dyke tend to have low metal tenors ([Ni]100 = 2.5-3.5%), sulfides in Eastern Deeps massive and breccia ores have intermediate Ni tenors ([Ni]100 = 3.5-4%), and disseminated sulfides in overlying rocks have high Ni tenors ([Ni]100 = 4-8%). Four principal processes control the compositions of the Voisey's Bay sulfides. Coarse-grained loop-textured ores consisting of pyrrhotite crystals separated by chalcopyrite and pentlandite exhibit a two orders of magnitude variation in the Pd/Ir ratio which is due to mineralogical variations where pentlandite is enriched in Pd and Ir is dispersed throughout the mineral assemblage. A decrease in Ir and Rh from the margin of the Ovoid toward cubanite-rich parts at the central part of the Ovoid is consistent with fractionation of the sulfide from the margins toward the center of the Ovoid. The Ovoid

  5. Bayesian model for fate and transport of polychlorinated biphenyl in upper Hudson River

    SciTech Connect

    Steinberg, L.J.; Reckhow, K.H.; Wolpert, R.L.

    1996-05-01

    Modelers of contaminant fate and transport in surface waters typically rely on literature values when selecting parameter values for mechanistic models. While the expert judgment with which these selections are made is valuable, the information contained in contaminant concentration measurements should not be ignored. In this full-scale Bayesian analysis of polychlorinated biphenyl (PCB) contamination in the upper Hudson River, these two sources of information are combined using Bayes` theorem. A simulation model for the fate and transport of the PCBs in the upper Hudson River forms the basis of the likelihood function while the prior density is developed from literature values. The method provides estimates for the anaerobic biodegradation half-life, aerobic biodegradation plus volatilization half-life, contaminated sediment depth, and resuspension velocity of 4,400 d, 3.2 d, 0.32 m, and 0.02 m/yr, respectively. These are significantly different than values obtained with more traditional methods, and are shown to produce better predictions than those methods when used in a cross-validation study.

  6. Impact of impingement on the Hudson River white perch population. Final report

    SciTech Connect

    Barnthouse, L.W.; Van Winkle, W.; Kirk, B.L.; Vaughan, D.S.

    1982-02-01

    This report summarizes a series of analyses of the magnitude and biological significance of the impingement of white perch at the Indian Point Nuclear Generating Station and other Hudson River power plants. Included in these analyses were evaluations of: (1) two independent lines of evidence relating to the magnitude of impingement impacts on the Hudson River white perch population; (2) the additional impact caused by entrainment of white perch; (3) data relating to density-dependent growth among young-of-the-year white perch; (4) the feasibility of performing population-level analyses of impingement impacts on the white perch populations of Chesapeake Bay and the Delaware River; and (5) the feasibility of using simple food chain and food web models to evaluate community-level effects of impingement and entrainment. Estimated reductions in the abundances of the 1974 and 1975 white perch year classes, caused by impingement and entrainment, were high enough that the possibility of adverse long-term effects cannot be excluded.

  7. Using multiple sulfur isotopes to link biological isotope fractionation in a sedimentary protolith to a magmatic Ni-sulfide deposit: Voisey's Bay Ni deposit, Labrador, Canada

    NASA Astrophysics Data System (ADS)

    Hiebert, R. S.; Bekker, A.; Wing, B. A.

    2012-12-01

    It is generally accepted that crustal contamination is required for the formation of significant magmatic Ni-Cu-PGE sulfide deposits. Either the addition of external S or SiO2 promote early sulfide saturation. The most direct indicator of S addition by this contaminant is S isotopes. However, the traditional use of δ34S values is inadequate in deposits where Archean sedimentary sulfides incorporated into these deposits might not have significantly different δ34S values from those of mantle S. Even in sediments that have variable δ34S values, δ34S signature can be reset to magmatic values by equilibrating large amounts of silicate magma with initial sulfide melt. However, sedimentary rocks contain isotope evidence of biological fractionation processes in the relationship between δ33S and δ34S values. We used multiple S isotope data to constrain the relationship between δ33S and δ34S values, identify biological S isotope fractionation in the metamorphosed sedimentary rocks of the Tasiuyak Gneiss, and compare this relationship to that in the Voisey's Bay magmatic Ni-deposit. The Voisey's Bay Ni-sulfide deposit, Labrador is hosted by a troctolitic conduit system. The Voisey's Bay intrusion is a part of the Nain plutonic suite and intruded at approximately 1.3 Ga along the boundary between the Proterozoic Tasiuyak Gneiss of the Churchill province and Archean gneisses of the Nain province. The general model suggests assimilation of a large amount of sulfidic Tasiuyak gneiss, leading to sulfur saturation prior to emplacement, even though the Tasiuyak gneiss does not have a high concentration of sulfur. High-temperature equilibrium relationships are not present in our measured δ33S and δ34S values from the Voisey's Bay deposit. Instead they indicate that a kinetic process is responsible for S isotope fractionations in the mineralization and troctolite, similar to that recorded by the Tasiuyak gneiss. The observed relationship between δ33S and δ34S values is

  8. Close to home. Interview by Terese Hudson.

    PubMed

    May, J

    1993-08-20

    The hospital is an integral part of the community, according to James May, CEO and president of Legacy Portland (OR) Hospitals. May has put this principle to work concretely by loaning employees money for initial costs on homes near Emanuel Hospital and Health Center in northeast Portland. Now in its second year, the program has already helped 25 employees purchase homes in a 19-square-mile area targeted for redevelopment. Loans of up to $5,000 for homes with a purchase price of $65,000 or lower are available. The loans can be used for down payments, pre-paid reserves or closing costs. Legacy forgives 20 percent of a loan's outstanding balance each year to employees in good standing. This encourages employees to stay for at least five years. Only the interest payments on the outstanding balance are paid back to Legacy. May spoke recently with Senior Editor Terese Hudson about the program's genesis.

  9. Spatio-temporal trends and monitoring design of perfluoroalkyl acids in the eggs of gull (Larid) species from across Canada and parts of the United States.

    PubMed

    Gewurtz, Sarah B; Martin, Pamela A; Letcher, Robert J; Burgess, Neil M; Champoux, Louise; Elliott, John E; Weseloh, D V Chip

    2016-09-15

    A large spatial dataset of perfluoroalkyl acid (PFAA) concentrations in eggs of herring gulls (Larus argentatus or congeneric species) collected from late April to early June between 2009 and 2014 from 28 colonies across Canada and parts of the Unites States was used to evaluate location-specific patterns in chemical concentrations and to generate hypotheses on the major sources affecting PFAA distributions. The highly bioaccumulative perfluorooctane sulfonic acid (PFOS) as well as other perfluoroalkyl sulfonic acids (PFSAs) showed the greatest concentrations in eggs from the lower Great Lakes of southern Ontario as well as from the St. Lawrence River. Despite the 2000 to 2002 phase-out of PFOS and related C8 chemistry by the major manufacturer at the time, ongoing losses from consumer products during use and disposal in urban/industrial locations continue to be major sources to the environment and are influencing the spatial trends of PFOS in Canada. In comparison to PFOS, perfluoroalkyl carboxylic acids (PFCAs) were not as concentrated in eggs in close proximity to urbanized/industrialized centers, but had surprisingly elevated levels in relatively remote regions such as Great Slave Lake, NT and East Bay in Hudson Bay, NU. The present results support the hypothesis that atmospheric transport and degradation of precursor chemicals, such as the fluorotelomer alcohols 8:2 FTOH and 10:2 FTOH, are influencing the spatial trends of PFCAs in Canada. A power analysis conducted on a representative urbanized/industrialized colony in the Toronto Harbour, ON, and a relatively remote colony in Lake Superior, emphasized the importance of consistent and long-term data collection in order to detect the anticipated changes in PFAA concentrations in Canadian gull eggs.

  10. Population carbon budgets and the importance of the amphipod corophium volutator in the carbon transfer on a cumberland basin mudflat, upper bay of fundy, Canada

    NASA Astrophysics Data System (ADS)

    Hawkins, C. M.

    The importance of Corophium volutator in the carbon flux between microalgal primary producers and other trophic levels was evaluated from population carbon budgets. In all but 4 of 39 population carbon budgets the estimated consumption was sufficient to meet the demands of production and respiration combined. A carbon budget constructed for the period from May to September 1979 revealed that Corophium production accounted for 40% of the consumption, respiration for 25% and the remainder by difference was attributed to faecal waste. Consumption was equivalent to 27% of the "net" epibenthic microalgal primary production over the same time period. Marked temporal changes in Corophium abundance appear to influence rates of benthic microalgal primary production during summer. Concurrently, an approximate 20-fold increase in Corophium biomass provides a significant food resource for birds and fishes. This implies that Corophium occupies a key link in processes of carbon flux on mudflats in the upper reaches of the Bay of Fundy.

  11. Glacial landforms of the southern Ungava Bay region (Canada): implications for the late-glacial dynamics and the damming of glacial Lake Naskaupi

    NASA Astrophysics Data System (ADS)

    Dube-Loubert, Hugo; Roy, Martin

    2014-05-01

    The Laurentide ice sheet played an important role in the late Pleistocene climate, notably through discharges of icebergs and meltwater. In this context, the Ungava Bay region in northern Quebec-Labrador appears particularly important, especially during the last deglaciation when the retreating ice margin dammed major river valleys, creating large proglacial lakes (e.g., McLean, aux Feuilles). The history of these lakes is closely related to the temporal evolution of the Labrador-Quebec ice dome. There are, however, large uncertainties regarding the position of its ice divide system through time, thereby limiting our understanding of the history of these glacial lakes. Here we focus on glacial and deglacial landforms present in the George River valley, south of Ungava Bay, in order to bring additional constraints on the late-glacial ice dynamics of this region, which also comprised glacial Lake Naskaupi. This work is based on surficial mapping using aerial photos and satellite imagery, combined with extensive fieldwork and sediment sampling. Our investigation showed significant differences in the distribution of glacial landforms across the region. The area east of the George River is characterized by well-developed Naskaupi shorelines while the elevated terrains show a succession of geomorphological features indicative of cold-based ice or ice with low basal velocities. In the easternmost part of this sector, ice flow directional data indicate that the ice was flowing towards ENE, against the regional slope. Eskers show paleocurrent directions indicating a general ice retreat from east to west. In the western part of this sector, near the George River valley, eskers are absent and the region is covered by felsenmeer and ground moraine that likely reflect the presence of a residual ice mass that was no longer dynamic. The presence of a stagnant ice represents the best mechanism to explain the formation of glacial lakes in the George River valley and its main

  12. The AUTUMNX magnetometer meridian chain in Québec, Canada

    NASA Astrophysics Data System (ADS)

    Connors, Martin; Schofield, Ian; Reiter, Kyle; Chi, Peter J.; Rowe, Kathryn M.; Russell, Christopher T.

    2016-01-01

    The AUTUMNX magnetometer array consists of 10 THEMIS-class ground-based magnetometers deployed to form a meridian chain on the eastern coast of Hudson Bay in eastern Canada, a second partial chain one hour of magnetic local time further east, and one magnetometer at an intermediate midlatitude site. These instruments, augmented by those of other arrays, permit good latitudinal coverage through the auroral zone on two meridians, some midlatitude coverage, and detection of magnetic field changes near the sensitive infrastructure of the Hydro-Québec power grid. Further, they offer the possibility for conjugate studies with Antarctica and the GOES East geosynchronous satellite, and complement the Chinese International Space Weather Meridian Circle Program. We examine current world distribution of magnetometers to show the need for AUTUMNX, and describe the instrumentation which allows near-real-time monitoring. We present magnetic inversion results for the disturbed day February 17, 2015, which showed classic signatures of the substorm current wedge, and developed into steady magnetospheric convection (SMC). For a separate event later that day, we examine a large and rapid magnetic field change event associated with an unusual near-Earth transient. We show GOES East conjugacy for these events.

  13. The Mid-Canada Radar Line and First Nations' people of the James Bay region, Canada: an evaluation using log-linear contingency modelling to analyze organochlorine frequency data.

    PubMed

    Tsuji, Leonard J S; Wainman, Bruce C; Martin, Ian D; Weber, Jean-Philippe; Sutherland, Celine; Elliott, J Richard; Nieboer, Evert

    2005-09-01

    Abandoned radar line stations in the North American arctic and sub-arctic regions are point sources of contamination, especially for PCBs. Few data exist with respect to human body burden of organochlorines (OCs) in residents of communities located in close proximity to these radar line sites. We compared plasma OC concentration (unadjusted for total lipids) frequency distribution data using log-linear contingency modelling for Fort Albany First Nation, the site of an abandoned Mid-Canada Radar Line station, and two comparison populations (the neighbouring community of Kashechewan First Nation without such a radar installation, and Hamilton, a city in southern Ontario, Canada). This type of analysis is important as it allows for an initial investigation of contaminant data without imputing any values. The two-state log-linear model (employing both non-detectable and detectable concentration frequencies and applicable to PCB congeners 28 and 105 and cis-nonachlor) and the four-state log-linear model (using quartile concentration frequencies for Aroclor 1260, PCB congeners [99,118,138,153,156,170,180,183,187], beta-HCH, p,p'-DDT +p,p'-DDE, HCB, mirex, oxychlordane, and trans-nonachlor) revealed that the effects of subject gender were inconsequential. Significant differences (p < 0.05) between the groups examined were attributable to the effect of location on the frequency of detection of OCs or on their differential distribution among the concentration quartiles. In general, people from Hamilton had higher frequencies of non-detections and of concentrations in the first quartile (p < 0.05) for most OCs compared to people from Fort Albany and Kashechewan (who consume a traditional diet of wild meats that does not include marine mammals). An unexpected finding was that, for Kashechewan males, the frequency of many OCs was significantly higher (p < 0.05) in the 4th concentration quartile than that predicted by the four-state log-linear model, but significantly lower

  14. Numerical modeling of late Glacial Laurentide advance of ice across Hudson Strait: Insights into terrestrial and marine geology, mass balance, and calving flux

    USGS Publications Warehouse

    Pfeffer, W.T.; Dyurgerov, M.; Kaplan, M.; Dwyer, J.; Sassolas, C.; Jennings, A.; Raup, B.; Manley, W.

    1997-01-01

    A time-dependent finite element model was used to reconstruct the advance of ice from a late Glacial dome on northern Quebec/Labrador across Hudson Strait to Meta Incognita Peninsula (Baffin Island) and subsequently to the 9.9-9.6 ka 14C Gold Cove position on Hall Peninsula. Terrestrial geological and geophysical information from Quebec and Labrador was used to constrain initial and boundary conditions, and the model results are compared with terrestrial geological information from Baffin Island and considered in the context of the marine event DC-0 and the Younger Dryas cooling. We conclude that advance across Hudson Strait from Ungava Bay to Baffin Island is possible using realistic glacier physics under a variety of reasonable boundary conditions. Production of ice flux from a dome centered on northeastern Quebec and Labrador sufficient to deliver geologically inferred ice thickness at Gold Cove (Hall Peninsula) appears to require extensive penetration of sliding south from Ungava Bay. The discharge of ice into the ocean associated with advance and retreat across Hudson Strait does not peak at a time coincident with the start of the Younger Dryas and is less than minimum values proposed to influence North Atlantic thermohaline circulation; nevertheless, a significant fraction of freshwater input to the North Atlantic may have been provided abruptly and at a critical time by this event.

  15. SUBMERSED MACROPHYTE DISTRIBUTION AND FUNCTION IN THE TIDAL FRESHWATER HUDSON RIVER

    EPA Science Inventory

    In the tidal freshwater Hudson River submerged aquatic vegetation (SAV) occupies on average 6 percent of the river area with much greater coverage in the mid Hudson (Kingston-Hudson) and much lower areal coverage south of Hyde Park. The native water celery ( Vallisneria americana...

  16. 40 CFR 81.129 - Hudson Valley Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Quality Control Regions § 81.129 Hudson Valley Intrastate Air Quality Control Region. The Hudson Valley Intrastate Air Quality Control Region (New York) consists of the territorial area encompassed by the... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Hudson Valley Intrastate Air...

  17. 78 FR 76140 - Extension of Public Comment Period for the Champlain Hudson Power Express Transmission Line...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-16

    ... Extension of Public Comment Period for the Champlain Hudson Power Express Transmission Line Project Draft... Hudson Power Express Transmission Line Project Draft Environmental Impact Statement (DOE/EIS-0447). The... permit to the Applicant, Champlain Hudson Power Express, Inc. (CHPEI), to construct, operate,...

  18. Temporal trends toward stability of Hudson River PCB contamination

    SciTech Connect

    Sloan, R.J.; Simpson, K.W.; Schroeder, R.A.; Barnes, C.R.

    1983-10-01

    PCB was used in the manufacture of electrical equipment at two General Electric Company (GE) facilities located on the upper Hudson River about 1 km apart in Fort Edward and Hudson Falls (Washington Co.) New York. Discharges of PCB from these plants resulted in concentrations in bottom sediments of the Hudson River which now exceed those of other major rivers by about two orders of magnitude and those of small remote streams by more than three orders of magnitude. Intensive monitoring was initiated in 1977 by the New York State Department of Environmental Conservation (DEC) to ascertain the magnitude of and trends in contaminant conditions of biotic and physical strata. The paper summarizes PCB trends from 1977 to 1981 in three major monitoring components - water, multiplate residues and fish.

  19. Distribution of Clostridium botulinum Type E Strains in Nunavik, Northern Quebec, Canada

    PubMed Central

    Leclair, Daniel; Farber, Jeffrey M.; Doidge, Bill; Blanchfield, Burke; Suppa, Sandy; Pagotto, Franco

    2013-01-01

    The distribution and levels of Clostridium botulinum type E were determined from field sites used by Inuit hunters for butchering seals along the coast of Nunavik. The incidence rates of C. botulinum type E in shoreline soil along the coast were 0, 50, and 87.5% among samples tested for the Hudson Strait, Hudson Bay, and Ungava Bay regions, respectively. Spores were detected in seawater or coastal rock surfaces from 17.6% of butchering sites, almost all of which were located in southern Ungava Bay. Concentrations of C. botulinum type E along the Ungava Bay coast were significantly higher than on the coasts of Hudson Strait and Hudson Bay, with the highest concentrations (270 to 1,800/kg of sample) found near butchering sites located along the mouths of large rivers. The Koksoak River contained high levels of C. botulinum type E, with the highest median concentration (270/kg) found in sediments of the marine portion of the river. C. botulinum type E was found in the intestinal contents (4.4%) and skins (1.4%) of seals. A high genetic biodiversity of C. botulinum type E isolates was observed among the 21 butchering sites and their surroundings along the Nunavik coastline, with 83% of isolates (44/53) yielding distinct pulsed-field gel electrophoresis genotypes. Multiple sources of C. botulinum type E may be involved in the contamination of seal meat during butchering in this region, but the risk of contamination appears to be much higher from environmental sources along the shoreline of southern Ungava Bay and the sediments of the Koksoak River. PMID:23160120

  20. Distribution of Clostridium botulinum type E strains in Nunavik, Northern Quebec, Canada.

    PubMed

    Leclair, Daniel; Farber, Jeffrey M; Doidge, Bill; Blanchfield, Burke; Suppa, Sandy; Pagotto, Franco; Austin, John W

    2013-01-01

    The distribution and levels of Clostridium botulinum type E were determined from field sites used by Inuit hunters for butchering seals along the coast of Nunavik. The incidence rates of C. botulinum type E in shoreline soil along the coast were 0, 50, and 87.5% among samples tested for the Hudson Strait, Hudson Bay, and Ungava Bay regions, respectively. Spores were detected in seawater or coastal rock surfaces from 17.6% of butchering sites, almost all of which were located in southern Ungava Bay. Concentrations of C. botulinum type E along the Ungava Bay coast were significantly higher than on the coasts of Hudson Strait and Hudson Bay, with the highest concentrations (270 to 1,800/kg of sample) found near butchering sites located along the mouths of large rivers. The Koksoak River contained high levels of C. botulinum type E, with the highest median concentration (270/kg) found in sediments of the marine portion of the river. C. botulinum type E was found in the intestinal contents (4.4%) and skins (1.4%) of seals. A high genetic biodiversity of C. botulinum type E isolates was observed among the 21 butchering sites and their surroundings along the Nunavik coastline, with 83% of isolates (44/53) yielding distinct pulsed-field gel electrophoresis genotypes. Multiple sources of C. botulinum type E may be involved in the contamination of seal meat during butchering in this region, but the risk of contamination appears to be much higher from environmental sources along the shoreline of southern Ungava Bay and the sediments of the Koksoak River.

  1. Seismological structure of the 1.8 Ga Trans-Hudson Orogen of North America

    NASA Astrophysics Data System (ADS)

    Gilligan, Amy; Bastow, Ian D.; Darbyshire, Fiona A.

    2016-06-01

    Precambrian tectonic processes are debated: what was the nature and scale of orogenic events on the younger, hotter, and more ductile Earth? Northern Hudson Bay records the Paleoproterozoic collision between the Western Churchill and Superior plates—the ˜1.8 Ga Trans-Hudson Orogeny (THO)—and is an ideal locality to study Precambrian tectonic structure. Integrated field, geochronological, and thermobarometric studies suggest that the THO was comparable to the present-day Himalayan-Karakoram-Tibet Orogen (HKTO). However, detailed understanding of the deep crustal architecture of the THO, and how it compares to that of the evolving HKTO, is lacking. The joint inversion of receiver functions and surface wave data provides new Moho depth estimates and shear velocity models for the crust and uppermost mantle of the THO. Most of the Archean crust is relatively thin (˜39 km) and structurally simple, with a sharp Moho; upper-crustal wave speed variations are attributed to postformation events. However, the Quebec-Baffin segment of the THO has a deeper Moho (˜45 km) and a more complex crustal structure. Observations show some similarity to recent models, computed using the same methods, of the HKTO crust. Based on Moho character, present-day crustal thickness, and metamorphic grade, we support the view that southern Baffin Island experienced thickening during the THO of a similar magnitude and width to present-day Tibet. Fast seismic velocities at >10 km below southern Baffin Island may be the result of partial eclogitization of the lower crust during the THO, as is currently thought to be happening in Tibet.

  2. Impact of entrainment and impingement on fish populations in the Hudson River estuary. Volume I. Entrainment-impact estimates for six fish populations inhabiting the Hudson River estuary

    SciTech Connect

    Boreman, J.; Barnthouse, L.W.; Vaughn, D.S.; Goodyear, C.P.; Christensen, S.W.; Kumar, K.D.; Kirk, B.L.; Van Winkle, W.

    1982-01-01

    This volume is concerned with the estimation of the direct (or annual) entrainment impact of power plants on populations of striped bass, white perch, Alosa spp. (blueback herring and alewife), American shad, Atlantic tomcod, and bay anchovy in the Hudson River estuary. Entrainment impact results from the killing of fish eggs, larvae, and young juveniles that are contained in the cooling water cycled through a power plant. An Empirical Transport Model (ETM) is presented as the means of estimating a conditional entrainment mortality rate (defined as the fraction of a year class which would be killed due to entrainment in the absence of any other source of mortality). Most of this volume is concerned with the estimation of several parameters required by the ETM: physical input parameters (e.g., power-plant withdrawal flow rates); the longitudinal distribution of ichthyoplankton in time and space; the duration of susceptibility of the vulnerable organisms; the W-factors, which express the ratios of densities of organisms in power plant intakes to densities of organisms in the river; and the entrainment mortality factors (f-factors), which express the probability that an organism will be killed if it is entrained. Once these values are obtained, the ETM is used to estimate entrainment impact for both historical and projected conditions.

  3. Reproductive success of belted kingfishers on the upper Hudson River.

    PubMed

    Bridge, Eli S; Kelly, Jeffrey F

    2013-08-01

    Belted kingfishers (Megaceryle alcyon) are predators in many North American aquatic ecosystems; as such, they are prone to bioaccumulation of certain environmental contaminants. In 2002 and 2004, kingfisher eggs collected near the upper Hudson River in New York had elevated concentrations of polychlorinated biphenyls (PCBs), and the kingfisher population in this area was reported to be at risk because of PCB exposure. From 2007 to 2009, the authors monitored 69 kingfisher nests on the Hudson River to track both nest success and survival of individual nestlings. The study site consisted of 2 adjacent sections of the Hudson River, 1 upstream and 1 downstream of a historic PCB source. The authors compared models of nest success that differentially incorporated the following 4 variables that they deemed most likely to affect reproductive output: 1) river section (upstream vs downstream of PCB source), 2) year, 3) hatch date, and 4) abandonment by 1 parent. After ranking models according to Akaike's information criterion for small sample sizes, it was clear that parental abandonment was the most important of the factors examined. River section was not an important parameter, and overall nesting success was slightly higher in the PCB-contaminated section than in the upstream area. These findings support the conclusion that kingfisher productivity is not adversely impacted by PCB contamination in the upper Hudson River.

  4. 27 CFR 9.47 - Hudson River Region.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Hudson River Region. 9.47 Section 9.47 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas §...

  5. 27 CFR 9.47 - Hudson River Region.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Hudson River Region. 9.47 Section 9.47 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas §...

  6. Thinking Big: Leslie Polott Hudson Library and Historical Society, OH

    ERIC Educational Resources Information Center

    Library Journal, 2004

    2004-01-01

    When Leslie Polott arrived at the Hudson Library and Historical Society in 1996. She headed out into the community to find out what people wanted from their library. After rounds of surveys, focus groups, and town meetings, she knew: a library that was the center of their educational and cultural lives, that provided more opportunities for…

  7. Declining extent of open-water refugia for top predators in Baffin Bay and adjacent waters.

    PubMed

    Heide-Jørgensen, Mads Peter; Laidre, Kristin L

    2004-12-01

    Global climate change is expected to severely impact Arctic ecosystems, yet predictions of impacts are complicated by region-specific patterns and nonuniform trends. Twentyfour open-water overwintering areas (or "microhabitats") were identified to be of particular importance for eight seabird and marine mammal species in the eastern Canadian High Arctic and Baffin Bay. Localized trends in the available fraction of open-water were examined in March during 1979--2001, derived from approximate sea ice concentrations from satellite-based microwave telemetry. Declines in the fraction of open-water were identified at microhabitats in Baffin Bay, Davis Strait, coastal West Greenland, and Lancaster Sound. Increases in open-water were observed in Hudson Bay, Hudson Strait, and Foxe Basin. The biological importance of each microhabitat was examined based on species distribution and abundance. Potential consequences of reduced open-water for top marine predators include impacts on foraging efficiency and oxygen and prey availability.

  8. Occurrence of PCBs in raw and finished drinking water at seven public water systems along the Hudson River.

    PubMed

    Palmer, Patrick M; Wilson, Lloyd R; Casey, Ann C; Wagner, Robert E

    2011-04-01

    Polychlorinated biphenyls (PCBs) were measured in raw and finished drinking water at seven Public Water Systems (PWSs) along the Hudson River as part of a baseline monitoring program prior to the extensive sediment dredging of the Upper Hudson River. Water samples were either analyzed using an Aroclor method (based on USEPA Method 508) or a congener method (Modified Green Bay Mass Balance Method). Using the congener-based method, raw water concentrations ranged from <9.3 to 164.3 ng/L and finished water concentrations ranged from <9.3 to 186.6 ng/L. Using the Aroclor method, finished water concentrations ranged from <5.0 to 200.9 ng/L. Most finished water samples above 73.0 ng/L were from a PWS with wells drilled near the river. Excluding the well data, total PCB concentrations in raw water at systems in the Upper River were similar to concentrations at systems in the Lower River, though the congener patterns differed. Paired comparison of total PCB concentrations using the two analytical methods showed good agreement, although raw water showed a different relationship than finished water.

  9. Hudson River PCB clean-up to begin

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    U.S. Environmental Protection Agency Administrator Christie Whitman signed the Record of Decision on 1 February to clean up a stretch of the Hudson River that has been contaminated by polychlorinated biphenyls (PCBs). The decision calls for dredging 2 million cubic meters of PCB-contaminated sediment from a 64-kilometer stretch of the upper Hudson to remove about 68,000 kilograms of PCBs.The plan follows years of scientific study about whether the PCBs were safely encased in the sediment or posed a continuing hazard, and concern over whether the PCBs can be safely removed without stirring up a larger pollution problem along the river. The EPA found that PCBs in the sediment are not safely buried because erosion and river flows can redistribute river sediment. The agency also found that although PCBs break down naturally over time, this degradation does not render them harmless.

  10. Impact Ejecta above an Unconformity in Hudson River Sediments

    NASA Astrophysics Data System (ADS)

    Abbott, D. H.; Gogan, N.; Breger, D.

    2012-12-01

    We examined three Hudson River cores just above a step increase in density that we infer to be an erosional unconformity circa 2300 BP in age (Goodbred et al., 2006). Each core has a layer containing impact ejecta and marine microfossils that lies directly above the unconformity. As the river water is too fresh for marine organisms, there are no marine microfossils in the sediments above and below this unusual layer. The marine microfossils are pelagic and benthic foraminifera, radiolarians, and coccoliths. The impact ejecta include marine microfossils coated with Sn oxide, often in crystalline form. The Sn oxide coating contains quantitative levels of Ni as determined by microprobe analysis. Ni is a marker for extraterrestrial material. Sn oxide also appears as a coating on glauconite grains within the layer. Glauconite is highly unstable and only forms in a marine setting. Marine sediments on the continental shelf outside the mouth of the Hudson River contain abundant glauconite. We also found impact breccia containing flow-textured glass, shocked ilmenite, pyroxene, and K-feldspar. Some of the glass cemented impact breccias are enriched in pyrite. The layer above the unconformity increases in thickness towards the mouth of the Hudson. The water depth of the cores in some cases exceeds 10 meters. Because the flow depths of storm surges do not exceed 10 meters and are generally less than 3 meters, we can eliminate storm surge as a cause of the event. Alternatively, tsunamis can exhibit flow depths that exceed 10 meters, suggesting that the erosional event was produced by an impact-generated tsunami. The cores containing the unconformity are located between 27 and 41 km upstream from the mouth of the Hudson River.

  11. 27 CFR 9.47 - Hudson River Region.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Region viticultural area are four U.S.G.S. maps, as follows: (1) Albany (NK 18-6), scale of 1:250,000 series; (2) Hartford (NK 18-9), scale of 1:250,000 series; (3) Scranton (NK 18-8), scale of 1:250,000 series; (4) Binghamton (NK 18-5), scale of 1:250,000 series. (c) Boundary. The Hudson River...

  12. Determining the Sediment Budget of the Lower Hudson River

    NASA Astrophysics Data System (ADS)

    Prugue, R.; Nitsche, F. O.; Kenna, T. C.

    2010-12-01

    Sediment is a major component of the Hudson River Estuary, constantly being resuspended and deposited. The Lower Hudson River is heavily dredged due to its use as a shipping lane for large vessels traversing through the harbor. A detailed sediment budget is key for management of the estuary including development, optimizing dredging, restoration, and mitigating future sea-level changes. However, it has been difficult to produce a detailed sediment budget due to the large amounts of data required to obtain a reputable value and account for spatial variability. Thus, previous budget estimates were based on approximations of input and output of material The Hudson River Benthic Mapping Project, which was funded by the New York State Department of Environmental Conservation, resulted in a comprehensive data set that includes a dense network of subbottom profiles and over 400 sediment cores from the Hudson River Estuary. Using industrial seismic interpretation software and X-ray fluorescence spectrometry, we identified the thickness and distribution of 20th century sediment deposition by mapping the sediment layer with elevated levels of anthropogenic lead, which is a characteristic for sediment deposition since 1920/1930. This 20th century sediment are of special concern because of the high amounts of contaminants that were being introduced into the estuary during this time. By combining analysis of different sections of the estuary, we are able to quantify the amount of 20th century deposition between Poughkeepsie and the New York Harbor and demonstrate that a detailed sediment budget can be obtained. This analysis reveals that ~35,000,000 cubic meters of sediment has been deposited in the study area during the last 70-80 years, which corresponds to an annual deposition of 450,000 - 500,000 cubic meters. Following this analysis, we aim to obtain a sediment mass and compare our results with other estimates that were taken in the past.

  13. Early Diagenesis of Plant Pigments in Hudson River Sediments

    NASA Astrophysics Data System (ADS)

    Bianchi, Thomas S.; Dibb, Jack E.; Findlay, Stuart

    1993-06-01

    Plant pigment concentrations were measured using high performance liquid chromatography in Hudson River sediments. Sedimentation rates and mixing characteristics were determined from depth profiles of the naturally occurring radionuclides 7Be, 210Pb. Previous estimates of the mean-lives (1/λ) of plant pigments (chlorophylls a and b, fucoxanthin) from laboratory experiments, indicate a range of c. 20-40 days. However, in the field, we observed that these pigments decreased less rapidly with depth and penetrated deeper than 7Be (mean-life 77 days) in Hudson sediments 95% of the time. Assuming similar mixing processes for particles carrying 7Be and pigments, this indicates that pigment decay rates in the field are slower than the 0·013 day -1 decay rate of 7Be, hence, more than 2-fold slower than the derived laboratory rates. We believe that high inputs of vascular plant detritus in the Hudson may increase the complexation of humic substances with pigments resulting in slower decay rates. While most pigments showed an exponential decrease with sediment depth, lutein concentrations generally increased with depth. This pattern of decay resistance is in agreement with laboratory experiments which show that lutein is the most decay resistant among dominant pigments. These data along with other studies demonstrate that the carotenoids lacking the 5,6-epoxide group (i.e., lutein) are more decay resistant than pigments that contain it (i.e., fucoxanthin).

  14. Antibiotic-resistant bacteria in the Hudson River Estuary linked to wet weather sewage contamination.

    PubMed

    Young, Suzanne; Juhl, Andrew; O'Mullan, Gregory D

    2013-06-01

    Heterotrophic bacteria resistant to tetracycline and ampicillin were assessed in waterways of the New York City metropolitan area using culture-dependent approaches and 16S rRNA gene sequence analysis of resultant isolates. Resistant microbes were detected at all 10 sampling sites in monthly research cruises on the lower Hudson River Estuary (HRE), with highest concentrations detected at nearshore sites. Higher frequency sampling was conducted in Flushing Bay, to enumerate resistant microbes under both dry and wet weather conditions. Concentrations of ampicillin- and tetracycline-resistant bacteria, in paired samples, were positively correlated with one another and increased following precipitation. Counts of the fecal indicator, Enterococcus, were positively correlated with levels of resistant bacteria, suggesting a shared sewage-associated source. Analysis of 16S rRNA from isolates identified a phylogenetically diverse group of resistant bacteria, including genera containing opportunistic pathogens. The occurrence of Enterobacteriaceae, a family of enteric bacteria, was found to be significantly higher in resistant isolates compared to total heterotrophic bacteria and increased following precipitation. This study is the first to document the widespread distribution of antibiotic-resistant bacteria in the HRE and to demonstrate clearly a link between the abundance of antibiotic-resistant bacteria and levels of sewage-associated bacteria in an estuary.

  15. Mapping invasive wetland plants in the Hudson River National Estuarine Research Reserve using quickbird satellite imagery

    USGS Publications Warehouse

    Laba, M.; Downs, R.; Smith, S.; Welsh, S.; Neider, C.; White, S.; Richmond, M.; Philpot, W.; Baveye, P.

    2008-01-01

    The National Estuarine Research Reserve (NERR) program is a nationally coordinated research and monitoring program that identifies and tracks changes in ecological resources of representative estuarine ecosystems and coastal watersheds. In recent years, attention has focused on using high spatial and spectral resolution satellite imagery to map and monitor wetland plant communities in the NERRs, particularly invasive plant species. The utility of this technology for that purpose has yet to be assessed in detail. To that end, a specific high spatial resolution satellite imagery, QuickBird, was used to map plant communities and monitor invasive plants within the Hudson River NERR (HRNERR). The HRNERR contains four diverse tidal wetlands (Stockport Flats, Tivoli Bays, Iona Island, and Piermont), each with unique water chemistry (i.e., brackish, oligotrophic and fresh) and, consequently, unique assemblages of plant communities, including three invasive plants (Trapa natans, Phragmites australis, and Lythrum salicaria). A maximum-likelihood classification was used to produce 20-class land cover maps for each of the four marshes within the HRNERR. Conventional contingency tables and a fuzzy set analysis served as a basis for an accuracy assessment of these maps. The overall accuracies, as assessed by the contingency tables, were 73.6%, 68.4%, 67.9%, and 64.9% for Tivoli Bays, Stockport Flats, Piermont, and Iona Island, respectively. Fuzzy assessment tables lead to higher estimates of map accuracies of 83%, 75%, 76%, and 76%, respectively. In general, the open water/tidal channel class was the most accurately mapped class and Scirpus sp. was the least accurately mapped. These encouraging accuracies suggest that high-resolution satellite imagery offers significant potential for the mapping of invasive plant species in estuarine environments. ?? 2007 Elsevier Inc. All rights reserved.

  16. Time trends of persistent organic pollutants and heavy metals in umbilical cord blood of Inuit infants born in Nunavik (Québec, Canada) between 1994 and 2001.

    PubMed Central

    Dallaire, Frédéric; Dewailly, Eric; Muckle, Gina; Ayotte, Pierre

    2003-01-01

    Inuit inhabitants of Nunavik (northern Québec, Canada) consume great quantities of marine food and are therefore exposed to high doses of food chain contaminants. In this study, we report the time trends of persistent organic pollutants, mercury, and lead in umbilical cord blood of infants from three communities of the east coast of Hudson Bay in Nunavik. We analyzed 251 cord blood samples collected from 1994 through 2001 for polychlorinated biphenyls (PCBs), dichlorodiphenyl trichloroethane (DDT), dichlorodiphenyl dichloroethylene (DDE), hexachlorobenzene (HCB), chlordanes, lead, and mercury. Using an exponential model, we found strongly significant decreasing trends for PCBs (7.9% per year, p < 0.001), DDE (9.1% per year, p < 0.001), DDT (8.2% per year, p < 0.001), and HCB (6.6% per year, p < 0.01). No significant trends were detected for chlordanes. A significant reduction of lead and mercury concentrations was found, but there was no clear linear or exponential trend. The decreases observed could be explained by a decrease in food contamination, by changes in dietary habits, or, most likely, by a combination of both. PMID:14527847

  17. New seismic images of the crust in the central Trans-Hudson Orogen of Saskatchewan

    NASA Astrophysics Data System (ADS)

    Pandit, B. I.; Hajnal, Z.; Stauffer, M. R.; Lewry, J.; Ashton, K. E.

    1998-05-01

    A reprocessing program to enhance the correlation between the surface geology and the seismic data has been completed for seismic line 9 (eastern 100 km) and line 10 in the central region of the Trans-Hudson Orogen of Saskatchewan, Canada. The new seismic images through lateral continuity of reflectivity provide sufficient detail to resolve the discrepancy between the low-dipping, layer-parallel and dextral-reverse nature of the Sturgeon-Weir shear zone (line 9) observed in the field and its steeply dipping (apparent) normal displacement character interpreted on the basis of the initial processing. Furthermore, the new interpretation provides a strong confirmation of the role of Pelican Thrust as a major detachment zone — the main `sole thrust' — along which juvenile allochthons have been carried across the Archaean microcontinental block. The images are also refined enough to suggest: (a) a boundary within the Pelican Thrust between its internal and external suites; (b) a possible boundary separating a lower (older?) Archaean basement from its upper (younger?) counterpart; and (c) sub-Moho events (M2) which reveal possible involvement of the upper mantle in the collisional tectonic process in addition to the well defined Moho (M1) which probably represents the youngest of the post-collisional detachments.

  18. The Tectonic Evolution of SE Canada: Seismic Evidence from the QM-III Experiment

    NASA Astrophysics Data System (ADS)

    Bastow, I. D.; Boyce, A.; Darbyshire, F. A.; Levin, V. L.; Menke, W. H.; Ellwood, A.

    2014-12-01

    Much of the geological record can be interpreted in the context of processes operating today at plate boundaries. This works well to explain processes and products during the Phanerozoic era; during Precambrian times when the oldest rocks were forming, however, conditions on the younger, hotter, more ductile Earth were likely very different, making analogies with modern day tectonics less certain. Gathering evidence preserved deep within the plates in the shields is thus essential to improve our understanding of the early Earth. Shields are usually underlain by thick, seismically fast roots that are absent beneath younger portions of Earth's surface. The thermochemically distinct nature of cratonic roots is often associated with Archean processes such as the extraction of komatiitic magmas. However, the cratonic core of North America does not fit easily into this Archean formation paradigm: part of the Canadian shield extends beneath the Archean Superior craton, but much of it persists beneath younger Proterozoic crust as well. We present here a relative arrival-time tomographic study of mantle seismic structure using data from a new seismograph network operating in SE Canada. Our stations extend from the Archean Superior craton around the southern tip of Hudson Bay, through Proterozoic Grenville terranes, and into Paleozoic coastal Maine and Nova Scotia. Tomographic images display three broad zones of mantle wavespeed: slow in the Appalachian terranes; fast in the Grenville Province; very fast within the Superior craton. Archean lithosphere has been modified by the Great Meteor hotspot, but we find no evidence for major plate-scale underthrusting during the Grenville orogeny. The abrupt wavespeed transition from Archean to Proterozoic mantle is thus consistent with the emerging consensus that keels form in two stages: a chemically depleted layer in Archean times followed by the thermal development of a less-depleted lithosphere during Proterozoic times.

  19. Craton Development and Stabilization: Insights from SE Canada using P and S Wave Tomography

    NASA Astrophysics Data System (ADS)

    Boyce, A.; Bastow, I. D.; Darbyshire, F. A.; Gilligan, A.; Ellwood, A.; Levin, V. L.; Menke, W. H.

    2015-12-01

    Cratons, the ancient cores of the continents, are the longest-lived parts of Earth's surface that have survived thermal and mechanical erosion during multiple Wilson cycles. They are visible in tomographic images due to their thick (>200km), seismically fast keels or roots. The Laurentian keel beneath North America is intriguing since its root is thought to extend beneath both the Archean Superior craton and the Proterozoic Grenville province thus implying that keel formation may not have been restricted to Archean times. In order to address this issue we present a P and S wave relative arrival-time tomographic study using data from seismograph networks in SE Canada and the NE US, stretching from the southern tip of Hudson Bay within the Superior craton to the coastal Phanerozoic Appalachian terranes. The tomographic images display three broad zones of increasing mantle wavespeed from globally "slow" in the Appalachian terranes, to a "fast" Grenville Province and "extremely fast" Superior craton. We observe a linear low-velocity feature resulting from modification of the Laurentian keel by the passage of the Great Meteor hotspot. This feature is progressively offset southwestward with depth, potentially due to viscous coupling with mantle flow. No major plate-scale underthrusting during the Grenville Orogeny is apparent, which contradicts the inferred results from crustal seismic reflection and refraction studies. Our results therefore may have fundamental implications for the nature of the Grenville orogenic collision and cratonic stabilization of North America. The results also support the developing consensus that keels form in two stages: a chemically depleted core of Archean age followed by a thermally developed, less-depleted lithosphere during Proterozoic times, highlighted by an abrupt wavespeed contrast in the tomographic images.

  20. Detrital carbonate peaks on the Labrador shelf, a 13-7 ka template for freshwater forcing from the Hudson Strait outlet of the Laurentide Ice Sheet into the subpolar gyre

    NASA Astrophysics Data System (ADS)

    Jennings, Anne; Andrews, John; Pearce, Christof; Wilson, Lindsay; Ólfasdótttir, Sædís

    2015-01-01

    The Laurentide Ice Sheet (LIS) was a large, dynamic ice sheet in the early Holocene. The glacial events through Hudson Strait leading to its eventual demise are recorded in the well-dated Labrador shelf core, MD99-2236 from the Cartwright Saddle. We develop a detailed history of the timing of ice-sheet discharge events from the Hudson Strait outlet of the LIS during the Holocene using high-resolution detrital carbonate, ice rafted detritus (IRD), δ18O, and sediment color data. Eight detrital carbonate peaks (DCPs) associated with IRD peaks and light oxygen isotope events punctuate the MD99-2236 record between 11.5 and 8.0 ka. We use the stratigraphy of the DCPs developed from MD99-2236 to select the appropriate ΔR to calibrate the ages of recorded glacial events in Hudson Bay and Hudson Strait such that they match the DCPs in MD99-2236. We associate the eight DCPs with H0, Gold Cove advance, Noble Inlet advance, initial retreat of the Hudson Strait ice stream (HSIS) from Hudson Strait, opening of the Tyrrell Sea, and drainage of glacial lakes Agassiz and Ojibway. The opening of Foxe Channel and retreat of glacial ice from Foxe Basin are represented by a shoulder in the carbonate data. ΔR of 350 years applied to the radiocarbon ages constraining glacial events H0 through the opening of the Tyrell Sea provided the best match with the MD99-2236 DCPs; ΔR values and ages from the literature are used for the younger events. A very close age match was achieved between the 8.2 ka cold event in the Greenland ice cores, DCP7 (8.15 ka BP), and the drainage of glacial lakes Agassiz and Ojibway. Our stratigraphic comparison between the DCPs in MD99-2236 and the calibrated ages of Hudson Strait/Bay deglacial events shows that the retreat of the HSIS, the opening of the Tyrell Sea, and the catastrophic drainage of glacial lakes Agassiz and Ojibway at 8.2 ka are separate events that have been combined in previous estimates of the timing of the 8.2 ka event from marine records

  1. Revisiting the West Clearwater Lake Impact Structure, Canada

    NASA Technical Reports Server (NTRS)

    Osinski, G. R.; Brunner, A.; Collins, G.; Cohen, B. A.; Coulter, A.; Elphic, R.; Grieve, R. A. F.; Hodges, K.; Horne, A.; Kerrigan, M.

    2015-01-01

    The West and East Clearwater Lake impact structures are two of the most distinctive and recognizable impact structures on Earth. Known regionally as the "Clearwater Lake Complex", these structures are located in northern Quebec, Canada (56 deg 10 N, 74 deg 20 W) approximately 125 km east of Hudson Bay. The currently accepted diameters are 36 km and 26 km for the West and East structures, respectively. Long thought to represent a rare example of a double impact, recent age dating has called this into question with ages of approximately 286 Ma and approximately 460-470 Ma being proposed for the West and East structures, respectively. Relatively little is known about the East Clearwater Lake structure. There is no surface exposure and what information there is comes from geophysics and two drill cores obtained in the 1960s. In contrast, the West Clearwater Lake structure is relatively well preserved with large ring of islands in the approximately 30 km diameter lake. Much of the work done on West Clearwater stems from field investigations carried out in 1977 driven by the Apollo program, with a focus on the impact melt rocks and other impactites, which are well exposed on the ring of islands. To our knowledge, the Clearwater Lake impact structures have not been the focus of detailed impact geology field investigations since the 1977 expedition and the only geological map that exists is from the 1960s and is at the reconnaissance level. Our knowledge of impact cratering processes have increased substantially since this time, as have the analytical techniques available for samples. This provided the motivation for a joint Canadian-US-UK expedition to the West Clearwater Lake impact structure in August and September 2015, under the auspices of the FINESSE (Field Investigations to Enable Solar System Science and Exploration) project, part of NASA's Solar System Exploration Research Virtual Institute (SSERVI). We focus here on the impactites of the West Clearwater Lake

  2. Quantifying Distribution of Recent Sediment Using XRF Analysis and Seismic Data in the Hudson River Estuary

    NASA Astrophysics Data System (ADS)

    Haberman, M.; Nitsche, F. O.; Kenna, T. C.; Sands, E.; Bell, R. E.; Ryan, W. B.

    2006-12-01

    Detailed understanding of sediment dynamics and associated contaminants in rivers and estuaries is essential for effective management as well as estimating sediment budgets and modeling sediment transport. While acoustic techniques provide extremely high spatial resolution, they are limited in their ability to provide useful temporal information with respect to depositional sites. This information is typically provided by collection of sediment core samples from the area of interest followed by expensive and time-consuming geochemical analyses to establish deposition chronologies, which are usually obtained for only a small subset of the collected cores. At present, the level at which we can obtain detailed spatial information far exceeds our ability to obtain temporal information. Here we present an integrated approach using data collected from Haverstraw Bay, located in the Hudson River Estuary. We combine a detailed interpretation of high-resolution seismic data that were collected as part of the Hudson River Benthic Mapping Project issued by the New York State DEC with lead distributions measured via field portable X-ray Fluorescence Spectrometry on over fifty sediment cores. We analyzed a dense grid (80 x 160 m) of high-resolution, single-channel seismic lines using a seismic interpretation software package and traced the bottom and top of the recent sediment layer. Using lead concentrations elevated above natural background as a proxy for identifying sediments impacted by 20th century industrial activities, we were able to verify the presence and thickness of recent (post-1930) sediments. Combining the two datasets, we obtained a detailed grid representing the thickness of recent sediments in our study area. The grid was then exported to a GIS software package for interpretation and calculation of the distribution (areas and volume) of recent sediments. Using the age constraints from the XRF-lead (verified by Cs-137 and Pb-210 measurements), we can also

  3. Organic Matter Sources in the Water Column and Sediments of the Hudson River Estuary: the Use of Plant Pigments as Tracers

    NASA Astrophysics Data System (ADS)

    Bianchi, Thomas S.; Findlay, Stuart; Dawson, Rodger

    1993-04-01

    The purpose of this study was to document inputs of organic matter into the Hudson River Estuary using plant pigments as tracers. Plant pigments (carotenoids and chloropigments) were determined using high pressure liquid chromatography (HPLC). Water column and sediment samples were collected in 1988 and 1989, from stations along a 165 km transect in the Hudson River Estuary. In the water column, high concentrations of lutein were found at stations adjacent to wetland areas indicating inputs of vascular plant detritus, particularly during late fall. Chlorophyll b/lutein ratios at these stations were 2-4 which are similar to that found in fresh vascular plant material collected from the Hudson. Low chlorophyll b/lutein ratios at Haverstraw Bay, a shallow and turbid area of the estuary, indicate high levels of sediment resuspension. Cyanophyte blooms, as indicated by high concentrations of myxoxanthophyll, reach their peak in late summer at the Hudson and Kingston stations. The chlorophyll a from these algae may comprise as much as 78% of the total chlorophyll a pool during these periods. Concentrations of total phaeophorbide, an indicator of grazing activity, were not correlated with chlorophyll a but were correlated with fucoxanthin and/or fucoxanthinol. This correlation suggests that much of the zooplankton grazing activity is associated with high quality food resources such as diatoms and not with cyanophytes. Surface sediments from a coarse-grained sandy habitat had significantly lower amounts of total organic matter than muddy habitats. However, the sandy sediment had higher grazing activity per gram organic matter, as indicated by total phaeophorbides. Higher concentrations of chlorophyll a and fucoxanthin at the sandy habitat indicate the presence of benthic diatoms which are high quality (low C/N ratio) living resources in contrast to the detrital sources (high C/N, mostly vascular plant) at the muddy stations. High concentrations of chlorophyllide a at some

  4. 77 FR 65929 - Notice of Final Federal Agency Actions on the Tappan Zee Hudson River Crossing Project in New York

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-31

    ... Federal Highway Administration Notice of Final Federal Agency Actions on the Tappan Zee Hudson River.... Sec. 139(l)(1). The actions relate to the Tappan Zee Hudson River Crossing Project located in Rockland... the following highway project in the State of New York: Tappan Zee Hudson River Crossing...

  5. 78 FR 27473 - Notice of Final Federal Agency Actions on the Tappan Zee Hudson River Crossing Project in New York

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-10

    ... Federal Highway Administration Notice of Final Federal Agency Actions on the Tappan Zee Hudson River... within the meaning of 23 U.S.C. 139(l)(1). The actions relate to the Tappan Zee Hudson River Crossing... FHWA published a ``Notice of Final Federal Agency Actions'' on the Tappan Zee Hudson River...

  6. 33 CFR 165.162 - Safety Zone: New York Super Boat Race, Hudson River, New York.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety Zone: New York Super Boat... § 165.162 Safety Zone: New York Super Boat Race, Hudson River, New York. (a) Regulated area. The following area is a safety zone: All waters of the Lower Hudson River south of a line drawn from...

  7. 33 CFR 165.162 - Safety Zone: New York Super Boat Race, Hudson River, New York.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Safety Zone: New York Super Boat... § 165.162 Safety Zone: New York Super Boat Race, Hudson River, New York. (a) Regulated area. The following area is a safety zone: All waters of the Lower Hudson River south of a line drawn from...

  8. 77 FR 61828 - Surety Companies Acceptable on Federal Bonds; Change in Business Address: Hudson Insurance Company

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-11

    ... Fiscal Service Surety Companies Acceptable on Federal Bonds; Change in Business Address: Hudson Insurance.... SUPPLEMENTARY INFORMATION: Notice is hereby given that Hudson Insurance Company (NAIC 25054) has changed its business address to: 100 William Street, 5th Floor, New York, New York, 10038. Federal bond-...

  9. Influence of Aroclor 1242 concentration on polychlorinated biphenyl biotransformations in Hudson River test tube microcosms

    SciTech Connect

    Fish, K.M.

    1996-08-01

    PCBs are a family of compounds sold with various levels of chlorination and under different trade names. They have accumulated in soils, sediments, and biota, raising concerns about possible health risks. The upper Hudson River was contaminated with Aroclor 1242. This study examines the influence of Aroclor concentration on PCB biotransformations in the upper Hudson River sediment. 6 refs., 3 figs.

  10. Transport of fallout and reactor radionuclides in the drainage basin of the Hudson River estuary

    SciTech Connect

    Simpson, H.J.; Linsalata, P.; Olsen, C.R.

    1982-01-01

    The transport and fate of Strontium 90, Cesium 137 and Plutonium 239, 240 in the Hudson River Estuary is discussed. Rates of radionuclide deposition and accumulation over time and space are calculated for the Hudson River watershed, estuary, and continental shelf offshore. 37 references, 7 figures, 15 tables. (ACR)

  11. Cytochrome P450IA mRNA expression in feral Hudson River tomcod

    SciTech Connect

    Kreamer, G.L.; Squibb, K.; Gioeli, D.; Garte, S.J.; Wirgin, I. )

    1991-06-01

    The authors sought to determine if levels of cytochrome P450IA gene expression are environmentally induced in feral populations of Hudson River tomcod, a cancer prone fish, and whether laboratory exposure of tomcod to artificially spiked and naturally contaminated Hudson sediments can elicit a significant response. Using Northern blot analysis, they found levels of P450IA mRNA in tomcod collected from two Hudson River sites higher than those in tomcod from a river in Maine. Depuration of environmentally induced Hudson tomcod P450IA mRNA was rapid, with an initial detectable decline in P450 gene expression by 8 hr and basal levels reached by 5 days. Intraperitoneal injection of {beta}-napthoflavone in depurated Hudson tomcod resulted in a 15-fold induction of P450 gene expression within 26 hr. Exposure of depurated Hudson tomcod to natural sediment spiked with two PAHs resulted in a 7-fold induction of P450 gene expression. Exposure of depurated tomcod to sediment from a contaminated Hudson site also resulted in a 7- to 15-fold induction of P450IA mRNA expression. Northern blot analysis revealed a second polymorphic cytochrome P450IA mRNA band in some tomcod which was also detected by Southern blot analysis. Induction of cytochrome P450IA mRNA in Atlantic tomcod may provide a sensitive biomarker of environmentally relevant concentrations of some pollutants in the Hudson and other northeastern tidal rivers.

  12. From the Oracles of the Temple of Janus: "Chicago Teachers Union v. Hudson."

    ERIC Educational Resources Information Center

    Vieira, Edwin, Jr.

    1986-01-01

    Examines "Chicago Teachers Union v. Hudson," a United States Supreme Court decision guaranteeing non-union government workers specific protections of procedural due process that certain educational and teacher unions had failed to recognize. Decries the "Hudson" decision for separating labor law from laws governing the rest of…

  13. The Hudson River Plume: Exploring Human Impact on the Coastal Environment

    ERIC Educational Resources Information Center

    McDonnell, Janice; Duncan, Ravit; Lichtenwalner, C. Sage; Dunbar, Laura

    2010-01-01

    The Hudson River Watershed contains a variety of geologic, topographic, climatic, and hydrologic features and a diversity of land-use patterns--making it an ideal model for studying human impact on the coastal environment. In this article, the authors present the Hudson River Plume (HRP), a problem-based online module that explores nonpoint-source…

  14. 78 FR 31454 - Drawbridge Operation Regulation; Hudson River, Troy and Green Island, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-24

    .... USCG-2013-0257] RIN 1625-AA09 Drawbridge Operation Regulation; Hudson River, Troy and Green Island, NY... modify the operating schedule that governs the highway bridge (Troy Green Island) across the Hudson River, mile 152.7, between Troy and Green Island, New York. The owner of the bridge, New York State...

  15. 33 CFR 165.170 - Safety Zone: Triathlon, Ulster Landing, Hudson River, NY.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety Zone: Triathlon, Ulster Landing, Hudson River, NY. 165.170 Section 165.170 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... § 165.170 Safety Zone: Triathlon, Ulster Landing, Hudson River, NY. (a) Regulated area. The...

  16. 75 FR 76943 - Regulated Navigation Area; Hudson River South of the Troy Locks, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-10

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA11 Regulated Navigation Area; Hudson River South of the... Guard proposes to establish a Regulated Navigation Area (RNA) on the navigable waters of the Hudson..., provide for the safety of life and property, and facilitate the reasonable demands of commerce....

  17. 76 FR 8654 - Regulated Navigation Area; Hudson River South of the Troy Locks, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-15

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA11 Regulated Navigation Area; Hudson River South of the... Regulated Navigation Area (RNA) on the navigable waters of the Hudson River in New York, south of the Troy... property, and facilitate the reasonable demands of commerce. This action will impose restrictions...

  18. 78 FR 20169 - Notice of Availability of an Environmental Assessment for the Proposed Hudson Yards Concrete...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-03

    ... Hudson Yards Concrete Casing Project in New York, New York AGENCY: Federal Railroad Administration (FRA... Assessment for the Hudson Yards Concrete Casing Construction. SUMMARY: This notice advises the public that... coordination with Federal Railroad Administration (FRA) for the construction of an underground concrete...

  19. 77 FR 32984 - Notice of Inventory Completion: University of Maine, Hudson Museum, Orono, ME

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-04

    ..., by the former Portland Society of Natural History and subsequently donated to the University of Maine... National Park Service Notice of Inventory Completion: University of Maine, Hudson Museum, Orono, ME AGENCY: National Park Service, Interior. ACTION: Notice. SUMMARY: The University of Maine, Hudson Museum...

  20. 77 FR 32990 - Notice of Inventory Completion: University of Maine, Hudson Museum, Orono, ME

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-04

    ..., by the former Portland Society of Natural History and subsequently donated to the University of Maine... National Park Service Notice of Inventory Completion: University of Maine, Hudson Museum, Orono, ME AGENCY: National Park Service, Interior. ACTION: Notice. SUMMARY: The University of Maine, Hudson Museum,...

  1. Is hepatic cytochrome P4501A1 expression predictive of hepatic burdens of dioxins, furans, and PCBs in Atlantic tomcod from the Hudson River estuary?

    PubMed

    Yuan, Z; Wirgin, M; Courtenay, S; Ikonomou, M; Wirgin, I

    2001-10-01

    Hepatic cytochrome P4501A1 (CYP1A1) expression in fishes is frequently used to evaluate bioavailable aromatic hydrocarbon contamination of aquatic ecosystems. In controlled laboratory experiments, CYP1A1 expression in naïve fishes is usually dose-responsive to aromatic hydrocarbons and in field studies levels of gene expression in natural populations often correspond with known levels of sediment-borne contaminants. We quantified CYP1A1 mRNA levels in juvenile Atlantic tomcod Microgadus tomcod from 42 sites in the Hudson River estuary to evaluate the correspondence between hepatic CYP1A1 expression and hepatic concentrations of persistent halogenated aromatic hydrocarbons and to determine the utility of CYP1A1 expression as a biomarker in evaluating the microgeographic distribution of bioavailable contaminants within a large aquatic ecosystem. We found significant spatial heterogeneity in CYP1A1 mRNA levels among collection sites with levels of gene expression differing in some cases by 23-34 folds. CYP1A1 mRNA expression was highest in tomcod from the Newark Bay complex and lowest in tomcod from the most upriver collection sites in the main stem of the Hudson River. Although levels of PCDDs, PCDFs, and PCBs expressed as TCDD TEQs and CYP1A1 mRNA were highest in tomcod from the Newark Bay complex, there was no relationship between hepatic halogenated aromatic hydrocarbon levels and hepatic CYP1A1 mRNA in tomcod from sites in the main stem of the Hudson River. These results suggest that levels of CYP1A1 expression in fish from sites highly polluted with mixtures of halogenated aromatic hydrocarbons and other xenobiotics may not always be reflective of levels of bioavailable aromatic hydrocarbon contaminants. Based on these results and earlier controlled laboratory experiments, we hypothesize that elevated levels of CYP1A1 expression in tomcod from the Hudson River may be due primarily to PAHs or other contaminants not measured in this study.

  2. Biotransformations of Aroclor 1242 in Hudson River test tube microcosms

    SciTech Connect

    Fish, K.M.; Principe, J.M.

    1994-12-01

    Polychlorinated biphenyls (PCBs) are relatively unreactive and hydrophobic, are widely used commercially, and have accumulated in soils, sediments, and biota. The researchers partially simulated environmental conditions in the laboratory to examine the fate of Aroclor 1242 in the Upper Hudson River. The test tube microcosms developed both aerobic and anaerobic compartments. This paper reports on the patterns and rates of anaerobic and aerobic PCB transformations for a single set of conditions in static, unamended microosms to model the environmental fate of Aroclor 1242 in river sediments. 23 refs., 5 figs.

  3. Hudson River PCB reclamation demonstration project, New York

    SciTech Connect

    Not Available

    1982-11-01

    An abstract of the final environmental impact statement (EIS) for a demonstration project to dredge Hudson River sediments to remove polychlorinated biphenyl (PCB) contamination describes an effort to reduce the 40 hot spots by half. Positive impacts would be the removal of potential health hazards, but there is a risk that the dredging operations will release some contaminants into the surrounding water, leaving PCBs in the water and no longer contained. The Federal Water Pollution Control Act of 1972 is the legal mandate for the EIS.

  4. Analyzing a Mid-Air Collision Over the Hudson River

    NASA Technical Reports Server (NTRS)

    Brown, Sean; Holloway, C. Michael

    2012-01-01

    On August 8, 2009, a private airplane collided with a sightseeing helicopter over the Hudson River near Hoboken, New Jersey. All three people aboard the airplane, the pilot and two passengers, and all six people aboard the helicopter, the pilot and five passengers, were killed. The National Transportation Safety Board report on the accident identified inherent limitations of the see-and-avoid concept, inadequate regulations, and errors by the pilots and an air traffic controller as causing or contributing to the accident. This paper presents the results of analyzing the accident using the Systems-Theoretic Accident Model and Processes (STAMP) approach to determining accident causation.

  5. Chromite ore processing residue in Hudson County, New Jersey.

    PubMed Central

    Burke, T; Fagliano, J; Goldoft, M; Hazen, R E; Iglewicz, R; McKee, T

    1991-01-01

    Chromite ore processing residue occurs at over 130 sites in Hudson County, New Jersey. Many of these sites are in urban residential areas. This waste is a result of 70 years of chromate and bichromate chemical manufacturing. At least 15% of the sites contain total chromium concentrations greater than 10,000 mg/kg, with hexavalent content ranging from about 1 to 50%. Continuing leaching of this waste results in yellow-colored surface water runoff and yellow deposits on the soil surface and inside basement walls. The chemistry, environmental fate, health effects, and human exposure potentials for this waste are described. Images FIGURE 1. PMID:1935843

  6. Chromite ore processing residue in Hudson County, New Jersey.

    PubMed

    Burke, T; Fagliano, J; Goldoft, M; Hazen, R E; Iglewicz, R; McKee, T

    1991-05-01

    Chromite ore processing residue occurs at over 130 sites in Hudson County, New Jersey. Many of these sites are in urban residential areas. This waste is a result of 70 years of chromate and bichromate chemical manufacturing. At least 15% of the sites contain total chromium concentrations greater than 10,000 mg/kg, with hexavalent content ranging from about 1 to 50%. Continuing leaching of this waste results in yellow-colored surface water runoff and yellow deposits on the soil surface and inside basement walls. The chemistry, environmental fate, health effects, and human exposure potentials for this waste are described.

  7. Uncovering the hidden part of a large ice stream of the Laurentide Ice Sheet, northern Ontario, Canada

    NASA Astrophysics Data System (ADS)

    Veillette, J. J.; Roy, M.; Paulen, R. C.; Ménard, M.; St-Jacques, G.

    2017-01-01

    flow but probably outlasted it, as suggested by the mapping of several thousand iceberg furrows in Quebec and Ontario, also directed toward the ESE and overprinted on flutes formed by the last glacial flow. If this interpretation is correct, this makes the Winisk Ice stream the largest terrestrial ice stream in the Hudson Bay basin. An alternative interpretation associates this fluted belt to the exposed western fringe of streamlined bedforms from a late Hudson lobe buried by younger sediments.

  8. Sources of polycyclic aromatic hydrocarbons to the Hudson River Airshed

    NASA Astrophysics Data System (ADS)

    Lee, Jong Hoon; Gigliotti, Cari L.; Offenberg, John H.; Eisenreich, Steven J.; Turpin, Barbara J.

    2004-11-01

    Sources of polycyclic aromatic hydrocarbons (PAHs) to the Hudson River Estuary Airshed were investigated using positive matrix factorization (PMF). A three-city dataset was used to obtain common factor profiles. The contributions of each factor on each sampling day and site were then determined, and a sensitivity analysis was conducted. A stable eight-factor solution was identified. PMF was able to identify a factor associated with air-surface exchange. This factor contains low-molecular weight PAHs and was a dominant contributor to the measured PAHs concentrations. Factors linked to motor vehicle use (diesel and gasoline vehicle emissions and evaporative/uncombusted petroleum) and natural gas combustion were also major contributors. Motor vehicle combustion and oil combustion factors were the predominant contributors to particle-phase PAHs, while natural gas combustion, air-surface exchange, and evaporative/uncombusted petroleum factors made substantial contributions to gas-phase PAH concentrations. In contrast to fine particulate matter (PM2.5), which is dominated by regional transport, spatial variations in PAH concentrations suggest that PAH concentrations in the Hudson River Estuary Airshed are dominated by sources within the New York-New Jersey urban-industrial complex.

  9. Flow and chloride transport in the tidal Hudson River, NY

    USGS Publications Warehouse

    Weiss, Lawrence A.; Schaffranek, Raymond W.; de Vries, M. Peter

    1994-01-01

    A one-dimensional dynamic-flow model and a one-dimensional solute-transport model were used to evaluate the effects of hypothetical public-supply water withdrawals on saltwater intrusion in a 133-mile reach of the tidal Hudson River between Green Island dam, near Troy, N.Y., and Hastings-on-Hudson, N.Y. Regression techniques were used in analyses of current and extreme historical conditions, and numerical models were used to investigate the effect of various water withdrawals. Of four withdrawal scenarios investigated, simulations of a 27-day period during which discharges at Green Island dam averaged 7,090 ft3/s indicate that increasing the present Chelsea pumping-station withdrawal rate of 100 Mgal/d (million gallons per day) to 300 Mgal/d would have the least effect on upstream saltwater movement. A 90-day simulation, during which discharges at Green Island dam averaged 25,200 ft3/s, indicates that withdrawals of 1,940 Mgal/d at Chelsea would not measurably increase chloride concentrations at Chelsea under normal tidal and meteorological conditions, but withdrawals of twice that rate (3,880 Mgal/d) could increase the chloride concentration at Chelsea to 250 mg/L.

  10. Anomalous topography on the continental shelf around Hudson Canyon

    USGS Publications Warehouse

    Knebel, H. J.

    1979-01-01

    Recent seismic-reflection data show that the topography on the Continental Shelf around Hudson Canyon is composed of a series of depressions having variable spacings (< 100 m to 2 km), depths (1-10 m), outlines, and bottom configurations that give the sea floor an anomalous "jagged" appearance in profile. The acoustic and sedimentary characteristics, the proximity to relict shores, and the areal distribution indicate that this rough topography is an erosional surface formed on Upper Pleistocene silty sands about 13,000 to 15,000 years ago by processes related to Hudson Canyon. The pronounced southward extension of the surface, in particular, may reflect a former increase in the longshore-current erosion capacity caused by the loss of sediments over the canyon. Modern erosion or nondeposition of sediments has prevented the ubiquitous sand sheet on the Middle Atlantic shelf from covering the surface. The "anomalous" topography may, in fact, be characteristic of areas near other submarine canyons that interrupt or have interrupted the longshore drift of sediments. ?? 1979.

  11. Seismological Structure of the 1.8Ga Trans-Hudson Orogen of North America and its affinity to present-day Tibet

    NASA Astrophysics Data System (ADS)

    Gilligan, A.; Bastow, I. D.; Darbyshire, F. A.

    2015-12-01

    How tectonic processes operated and changed through the Precambrian is debated: what was the nature and scale of orogenic events and were they different on the younger, hotter, more ductile Earth? The geology of northern Hudson Bay records the Paleoproterozoic collision between the Western Churchill and Superior plates: the 1.8Ga Trans-Hudson Orogeny (THO) and is thus an ideal study locale to address this issue. It has been suggested, primarily on the strength of traditional field geology, that the THO was comparable in scale and style to the present-day Himalayan-Karakoram-Tibet Orogen (HKTO). However, understanding of the deep crustal architecture of the THO, and how it compares to the evolving HKTO is presently lacking. Through joint inversion of teleseismic receiver functions and surface wave data, we obtain new Moho depth estimates and shear velocity models for the crust and upper mantle. Archean crust in the Rae, Hearne and Churchill domains is thin and structurally simple, with a sharp Moho; upper crustal wavespeed variations are readily attributed to post-formation events. However, the Paleoproterozoic Quebec-Baffin segment of the THO has a deeper Moho and more complex crustal structure. Our observations are strikingly similar to recent models, computed using the same methods, of the HKTO lithosphere, where deformation also extends >400km beyond the collision front. On the strength of Moho character, present-day crustal thickness, and metamorphic grade, we thus propose that southern Baffin experienced uplift of a similar magnitude and spatial extent to the Himalayas during the Paleoproterozoic Trans-Hudson Orogeny.

  12. Summertime partitioning and budget of NO{sub y} compounds in the troposphere over Alaska and Canada: ABLE 3B

    SciTech Connect

    Sandholm, S.; Olson, J.; Bradshaw, J.; Talbot, R.; Singh, H.; Gregory, G.; Anderson, B.; Sachse, G.; Barrick, J.; Blake, D.

    1994-01-20

    As part of NASA`s Arctic Boundary Layer Expedition 3A and 3B field measurement programs, measurements of NO{sub x}, HNO{sub 3}, PAN, PPN, and NO{sub y} were made in the middle to lower troposphere over Alaska and Canada during the summers of 1988 and 1990. These measurements are used to assess the degree of closure within the reactive odd nitrogen (N{sub x}O{sub y}) budget through the comparison of the values of NO{sub y} measured with a catalytic convertor to the sum of individually measured NO{sub y}(i) compounds (i.e., {Sigma}NO{sub y}(i) = NO{sub x} + HNO{sub 3} + PAN + PPN). In the lower 6 km of the troposphere over Alaska and the Hudson Bay lowlands of Canada a significant fraction of the NO{sub y} budget (30 to 60%) could not be accounted for by the measured {Sigma}NO{sub y}(i). This deficit in the NO{sub y} budget is about 100 to 200 parts per trillion by volume (pptv) in the lower troposphere (0.15 to 3 km) and about 200 to 400 pptv in the middle free troposphere (3 to 6.2 km). Conversely, the NO{sub y} budget in the northern Labrador and Quebec regions of Canada is almost totally accounted for within the combined measurement uncertainties of NO{sub y} and the various NO{sub y}(i) compounds. A substantial portion of the NO{sub y} budget`s {open_quotes}missing compounds{close_quotes} appears to be coupled to the photochemical and/or dynamical parameters influencing the tropospheric oxidative potential over these regions. A combination of factors are suggested as the causes for the variability observed in the NO{sub y} budget. In addition, the apparent stability of compounds represented by the NO{sub y} budget deficit in the lower-altitude range questions the ability of these compounds to participate as reversible reservoirs for {open_quotes}active{close_quotes} odd nitrogen and suggest that some portion of the NO{sub y} budget may consist of relatively unreactive nitrogen-containing compounds. 56 refs., 16 figs., 4 tabs.

  13. Summertime partitioning and budget of NO(y) compounds in the troposphere over Alaska and Canada: ABLE 3B

    NASA Technical Reports Server (NTRS)

    Sandholm, S.; Olson, J.; Bradshaw, J.; Talbot, R.; Singh, H.; Gregory, G.; Blake, D.; Anderson, B.; Sachse, G.; Barrick, J.

    1994-01-01

    As part of NASA's Arctic Boundary Layer Expedition 3A and 3B field measurement programs, measurements of NO(x), HNO3, PAN, PPN, and NO(y) were made in the middle to lower troposphere over Alaska and Canada during the summers of 1988 and 1990. These measurements are used to assess the degree of closure within the reactive odd nitrogen (N(x)O(y)) budget through the comparison of the values of NO(y) measured with a catalytic convertor to the sum of individually measured NO(y) (i) compounds (i.e., sigmaNO(y)(i) = NO(x) + HNO3 + PAN + PPN). Significant differences were observed between the various study regions. In the lower 6 km of the troposphere over Alaska and the Hudson Bay lowlands of Canada a significant fraction of the NO(y) budget (30 to 60%) could not be accounted for by the measured sigmaNO(y)i. This deficit in the NO(y) budget is about 100 to 200 parts per trillion by volume (pptv) in the lower troposphere (0.15 to 3 km) and about 200 to 400 pptv in the middle free troposphere (3 to 6.2 km). Conversely, the NO(y) budget in the northern Labrador and Quebec regions of Canada is almost totally accounted for within the combined measurement uncertainties of NO(y) and the various NO(y)(i) compounds. A substantial portion of the NO(y) budget's 'missing compounds' appears to be coupled to the photochemical and/or dynamical parameters influencing the tropospheric oxidative potential over these regions. A combination of factors are suggested as the causes for the variability observed in the NO(y) budget. In addition, the apparent stability of compounds represented by the NO(y) budget deficit in the lower-altitude range questions the ability of these compounds to participate as reversible reservoirs for 'active' odd nitrogen and suggest that some portion of the NO(y) budget may consist of relatively unreactive nitrogen-containing compounds.

  14. Sea Level, Land Motion, and the Anomalous Tide at Churchill, Hudson Bay

    NASA Astrophysics Data System (ADS)

    Ray, R. D.

    2015-12-01

    The importance of the tide gauge at Churchill, Manitoba, cannot be overstated. It is the only permanently operating tide gauge in the central Canadian Arctic, and it sits on a prime spot for monitoring the mantle's rebound from the Laurentide ice loss. Yet interpretation of the sea-level time series at Churchill has long been problematic, going back even to early work by Gutenberg in the 1940s. The long-term relative sea-level rates are inconsistent: approximately -4, -19, -5 ± 1 mm/y for the periods 1940-1970, 1970-1990, 1990-2014 respectively. Annual mean high water (MHW) and mean low water (MLW) reflect these trends until around 1990, after which MLW leveled off and is now nearly unchanging. Slightly later, around 2000, the semidiurnal tides became very anomalous, with falling amplitudes and slightly increasing phase lags. The amplitude of M2 was approximately 154 cm before 2000; it dropped to about 146 cm by 2010 and reached an all-time low of 142 cm in 2014. Satellite altimeter estimates of the tide in this region, although challenging because of seasonal ice cover, show no comparable M2 changes, so the tidal changes must be localized to the near vicinity of the gauge (or to the gauge itself if caused by a malfunction). On the other hand, altimetry confirms the post-1992 Churchill measurements of mean sea level, thanks to the long time series of land motion measurements obtained at GPS station CHUR, which gives a vertical uplift of 10.1 mm/y. Combining satellite altimeter data with the Churchill tide-gauge data gives an implied vertical crustal rate of about 9.0 ± 0.8 mm/y, in reasonable agreement with the GPS. In summary, we have still anomalous MSL measurements at the Churchill gauge for the intermediate 1970-1990 era, and very anomalous tidal measurements since 2000, but we have apparently quite reliable MSL rates since 1990.

  15. Demography and population status of polar bears in western Hudson Bay

    USGS Publications Warehouse

    Lunn, Nicholas J.; Regher, Eric V; Servanty, Sabrina; Converse, Sarah J.; Richardson, Evan S.; Stirling, Ian

    2013-01-01

    The 2011 abundance estimate from this analysis was 806 bears with a 95% Bayesian credible interval of 653-984. This is lower than, but broadly consistent with, the abundance estimate of 1,030 (95% confidence interval = 745-1406) from a 2011 aerial survey (Stapleton et al. 2014). The capture-recapture and aerial survey approaches have different spatial and temporal coverage of the WH subpopulation and, consequently, the effective study population considered by each approach is different.

  16. Diurnal cycles of gaseous mercury within the snowpack at Kuujjuarapik/Whapmagoostui, Québec, Canada.

    PubMed

    Dommergue, Aurélien; Ferrari, Christophe P; Poissant, Laurier; Gauchard, Pierre-Alexis; Boutron, Claude F

    2003-08-01

    Mercury is a globally dispersed and toxic pollutant that can be transported far from its emission sources. In polar and subpolar regions, recent research activities have demonstrated its ability to be converted and deposited rapidly onto snow surfaces during the so-known Mercury Depletion Events (MDEs). The fate of mercury once deposited onto snow surfaces is still unclear: a part could be re-emitted to the atmosphere, the other part could contaminate water systems at the snowmelt. Its capacity to transform to more toxic form and to bioaccumulate in the food chain has consequently made mercury a threat for Arctic ecosystems. The snowpack is a medium that greatly interacts with a variety of atmospheric gases. Its role in the understanding of the fate of deposited mercury is crucial though it is poorly understood. In April 2002, we studied an environmental component of mercury, which is interstitial gaseous mercury (IGM) present in the air of the snowpack at Kuujjuarapik/Whapmagoostui (55 degrees N, 77 degrees W), Canada on the east shore of the Hudson Bay. We report here for the first time continuous IGM measurements at various depths inside a seasonal snowpack. IGM concentrations exhibit a well-marked diurnal cycle with uninterrupted events of Hg0 depletion and production within the snowpack. A possible explanation of Hg0 depletion within the snowpack may be Hg0 oxidation processes. Additionally, we assume that the notable production of Hg0 during the daytime may be the results of photoreduction and photoinitiated reduction of Hg(II) complexes. These new observations show that the snowpack plays undoubtedly a role in the global mercury cycle.

  17. Multi-element variations in olivine as geochemical signatures of Ni-Cu sulfide mineralization in mafic magma systems—examples from Voisey's Bay and Pants Lake intrusions, Labrador, Canada

    NASA Astrophysics Data System (ADS)

    Bulle, Florian; Layne, Graham D.

    2016-01-01

    Olivine from the olivine gabbro to troctolite intrusions at Voisey's Bay and at Pants Lake, Labrador, was analyzed for multiple elements (Ca, Sc, Mg, Si, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, and Zr) with secondary ion mass spectrometry (SIMS). Both intrusions have similar lithologies and petrographic characteristics and are approximately coeval (1.34 and 1.32 Ga, respectively) members of the Mesoproterozoic Nain Plutonic Suite. The Voisey's Bay intrusion hosts a producing economic Ni-Cu sulfide deposit, whereas the Pants Lake intrusion displays evidence of Ni-Cu sulfide mineralization, but, to date, a viable ore deposit has not been discovered. Olivine from both barren and mineralized lithologies was analyzed to assess the potential of the olivine composition for providing a record of silicate melt evolution and sulfide saturation related to formation of a massive sulfide deposit. Two detailed transects were sampled, using five diamond drill holes that laterally approach the basal massive sulfide in the Eastern Deeps portion of the Voisey's Bay intrusion from the barren central part. Olivine displays distinct trace element distributions that vary coherently with host lithology and proximity to sulfide mineralization. In particular, olivine shows an increase in Fe (˜Fo80 to ˜Fo60), Mn (˜2500 to 5000 ppm), and Zn (˜280 to 700 ppm), generally coupled with a decrease in Ni (˜1600 to ˜900 ppm), Co (˜270 to ˜190 ppm), and Cr (˜110 to 45 ppm), from barren troctolite (normal troctolite—NT) and weakly mineralized troctolite (variable-textured troctolite—VTT) towards the heavily mineralized, brecciated basal succession (basal breccia sequence—BBS). The enrichment in Fe-Mn-Zn is most pronounced in samples that laterally approach, but do not directly intersect, the massive sulfide deposit at the base of the intrusion, particularly in samples from the lower variable-textured troctolite and the basal breccia. Olivine from gabbro lithologies within the basal

  18. STS-90 payload bay door closure in OPF Bay 3

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The STS-90 Neurolab payload and two of the four Getaway Specials (GAS) await payload bay door closure in the orbiter Columbia today in Orbiter Processing Facility bay 3. Investigations during the Neurolab mission will focus on the effects of microgravity on the nervous system. The mission is a joint venture of six space agencies and seven U.S. research agencies. Investigator teams from nine countries will conduct 31 studies in the microgravity environment of space. Other agencies participating in this mission include six institutes of the National Institutes of Health, the National Science Foundation, and the Office of Naval Research, as well as the space agencies of Canada, France, Germany, and Japan, and the European Space Agency (ESA).

  19. STS-90 payload bay door closure in OPF Bay 3

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The STS-90 Neurolab payload and two of the four Getaway Specials (GAS) await payload bay door closure in the orbiter Columbia today in Orbiter Processing Facility bay 3. Investigations during the Neurolab mission will focus on the effects of microgravity on the nervous system. The GAS container on the left contains the COLLisions Into Dust Experiment, or COLLIDE, which will study low velocity collisions between space-borne particles in an attempt to better understand planetary ring dynamics. The STS-90 mission is a joint venture of six space agencies and seven U.S. research agencies. Agencies participating in this mission include six institutes of the National Institutes of Health, the National Science Foundation, and the Office of Naval Research, as well as the space agencies of Canada, France, Germany, and Japan, and the European Space Agency (ESA).

  20. 14 CFR 93.352 - Hudson River Exclusion specific operating procedures.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...: aircraft type, current position, direction of flight, and altitude. (b) Pilots must fly along the west... the Hudson River Exclusion at or above an altitude of 1,000 feet MSL up to, but not including,...

  1. Narragansett Bay

    EPA Science Inventory

    Narragansett Bay, situated on the eastern side of Rhode Island, comprises about 15% of the State’s total area. Ninety-five percent of the Bay’s surface area is in Rhode Island with the remainder in southeastern Massachusetts; 60% of the Bay’s watershed is in Massachusetts. At the...

  2. James Bay

    Atmospheric Science Data Center

    2013-04-17

    article title:  First Light over James Bay     View Larger Image MISR "First light", 16:40 UTC, 24 February 2000 . This is the first image of Earth's ... the line of flight. At the top of the image, the dark-to-light transition captures the opening of the MISR cover. Progressing southward, ...

  3. Evaluation of dredged material proposed for ocean disposal from Hudson River, New York

    SciTech Connect

    Gardiner, W.W.; Barrows, E.S.; Antrim, L.D.; Gruendell, B.D.; Word, J.Q.; Tokos, J.J.S.

    1996-09-01

    The Hudson River (Federal Project No. 41) was one of seven waterways that the U.S. Army Corps of Engineers-New York District (USACE-NYD) requested the Battelle Marine Sciences Laboratory (MSL) to sample and evaluate for dredging and disposal in March 1994. Sediment samples were collected from the Hudson River. Tests and analyses were conducted on Hudson River sediment core samples. The evaluation of proposed dredged material from the Hudson River included bulk sediment chemical analyses, chemical analyses of site water and elutriate, water-column and benthic acute toxicity tests, and bioaccumulation studies. Individual sediment core samples collected from Hudson River were analyzed for grain size, moisture content, and total organic carbon (TOC). A composite sediment sample, representing the entire area proposed for dredging, was analyzed for bulk density, specific gravity, metals, chlorinated pesticides, polychlorinated biphenyl (PCB) congeners, polynuclear aromatic hydrocarbons (PAH), and 1,4-dichlorobenzene. Site water and elutriate water, prepared from the suspended-particulate phase (SPP) of Hudson River sediment, were analyzed for metals, pesticides, and PCBS. Water-column or SPP toxicity tests were performed with three species. Benthic acute toxicity tests were performed. Bioaccumulation tests were also conducted.

  4. Cadmium and manganese distributions in the Hudson River estuary: interannual and seasonal variability

    NASA Astrophysics Data System (ADS)

    Yang, Min; Sañudo-Wilhelmy, Sergio A.

    1998-08-01

    Surface waters collected along the salinity gradient of the Hudson River estuary in four cruises between 1995 and 1997 were size-fractionated into particulate (>0.45 μm), `dissolved' (<0.45 μm), colloidal (10 kDa, 0.45 μm) and low molecular weight (<10 kDa) phases. Dissolved Cd concentrations (range: 0.11-1.19 nM) in surface waters of the estuary appear to have decreased fourfold (from an average of 2.36 to 0.61 nM) over a 23-year period, since the initial analysis of samples collected in the 1970s by Klinkhammer and Bender [Estuar. Coastal Shelf Sci. 12 (1981) 629-643]. This interannual decline reflects improvement in sewage treatment and the elimination of industrial Cd sources to the Hudson River estuary. In contrast, dissolved Mn levels (range: 0.033-1.46 μM) have remained relatively constant over the same period of time, suggesting that anthropogenic sources have very limited impact on Mn concentrations in the estuary. The concentrations of both Cd and Mn appeared to strongly depend on the season and/or river discharge. The highest concentrations were detected under low freshwater discharge, implying that limited hydraulic flushing allows a build-up of metals in the water column. Although the decline in Cd levels within the estuary reflects a reduction in the magnitude of anthropogenic inputs, mass balance estimates indicated that current sources of Cd to the estuary include sewage discharges (in the lower estuary around Manhattan) and diagenetic remobilization from industrial Cd deposited in sediments nearly 2 decades ago (in the upper estuary near Foundry Cove). Moreover, under low river discharge, the sources considered in our model (sewage, riverine input, atmospheric deposition, and benthic fluxes) could account for no more than 60% of the Cd exported from the lower estuary to the ocean. This suggests that undefined sources such as ground water and inputs from other watersheds (e.g., Long Island Sound and Newark Bay) may potentially influence the

  5. Observed Response of the Hudson River Plume to Wind Forcing

    NASA Astrophysics Data System (ADS)

    Glenn, S.; Schofield, O.; Chant, R.; Kohut, J.

    2004-12-01

    One objective of the May 2004 pilot study for the Lagrangian Transport and Transformation Experiment (LaTTE) was to determine the relative advantages of studying the Hudson River plume within the spatial and temporal context provided by a research-friendly coastal ocean observatory. Towards this end, a shelf-wide observational backbone was locally enhanced with high-resolution relocatable systems in the New York Bight apex. The permanent backbone includes local acquisition of international satellite ocean color imagery, a network of long-range High Frequency radars, and a cross-shelf Endurance line occupied by an autonomous underwater glider. The higher resolution HF Radar, glider and mooring network was originally deployed in the vicinity of the Long-term Ecosystem Observatory, where it attracted a large number of scientists to coastal upwelling experiments conducted offshore Tuckerton, NJ from 1998-2001. With scientific interest in the series of coastal upwelling experiments having peaked and run its course through the publication phase, the high resolution systems were moved to the New York Bight Apex to hopefully repeat the cycle of attracting a variety of scientists to a specific interdisciplinary process study site. During the LaTTE pilot study, datasets from the nested observation network were assembled in real-time at a shore-based acquisition center, and high-resolution atmospheric forecasts were performed. Specific emphasis was placed on communicating the real time observatory data and forecasts to scientists on a pair of research vessels conducting a dye release with the associated physical, biological and chemical sampling. Observational results from the observatory will be reviewed, with specific emphasis placed on the observed response of the Hudson River plume to a windshift from upwelling to downwelling favorable winds in the middle of the pilot experiment. This includes a shift from a relatively weak plume flowing eastward along the south shore of

  6. Sea-Level Rise Impacts on Hudson River Marshes

    NASA Astrophysics Data System (ADS)

    Hooks, A.; Nitsche, F. O.

    2015-12-01

    The response of tidal marshes to increasing sea-level rise is uncertain. Tidal marshes can adapt to rising sea levels through vertical accretion and inland migration. Yet tidal marshes are vulnerable to submergence if the rate of sea-level rise exceeds the rate of accretion and if inland migration is limited by natural features or development. We studied how Piermont and Iona Island Marsh, two tidal marshes on the Hudson River, New York, would be affected by sea-level rise of 0.5m, 1m, and 1.5m by 2100. This study was based on the 2011-2012 Coastal New York LiDAR survey. Using GIS we mapped sea-level rise projections accounting for accretion rates and calculated the submerged area of the marsh. Based on the Hudson River National Estuarine Research Reserve Vegetation 2005 dataset, we studied how elevation zones based on vegetation distributions would change. To evaluate the potential for inland migration, we assessed land cover around each marsh using the National Land Cover Database 2011 Land Cover dataset and examined the slope beyond the marsh boundaries. With an accretion rate of 0.29cm/year and 0.5m of sea-level rise by 2100, Piermont Marsh would be mostly unchanged. With 1.5m of sea-level rise, 86% of Piermont Marsh would be flooded. For Iona Island Marsh with an accretion rate of 0.78cm/year, sea-level rise of 0.5m by 2100 would result in a 4% expansion while 1.5m sea-level rise would cause inundation of 17% of the marsh. The results indicate that Piermont and Iona Island Marsh may be able to survive rates of sea-level rise such as 0.5m by 2100 through vertical accretion. At rates of sea-level rise like 1.5m by 2100, vertical accretion cannot match sea-level rise, submerging parts of the marshes. High elevations and steep slopes limit Piermont and Iona Island Marsh's ability to migrate inland. Understanding the impacts of sea-level rise on Piermont and Iona Island Marsh allows for long-term planning and could motivate marsh conservation programs.

  7. Salt Marsh Formation in the Lower Hudson River Estuary

    NASA Astrophysics Data System (ADS)

    Merley, M. M.; Peteet, D. M.; Peteet, D. M.

    2001-05-01

    Salt marshes are constant depositional environments and as a result contain accurate indicators of past relative sea level rise and salinity. The Hudson River marshes are at least twice as deep when compared to coastal marshes on either side of the mouth of the Hudson. The reason for this difference in sedimentation is unclear. This study uses macrofossil data as well as sediment stratigraphy in order to understand the formation and evolution of these marshes. The composition of seeds, roots, shoots and foraminifera, are used to indicate past sea levels. The four sites involved in this study are, from south to north, the Arthur Kill Marsh in Staten Island ( 40 36 N, 74 77W), Piermont marsh (N 41 00; 73 55W) Croton Point ( 41 14 N; 73 50W) and Iona Island( 41 18N, 73 58W). These are all tidally influenced but with increasing distances from the New York Bight, which gives a good spectrum of tidal influence. AMS-C14 dates on basal macrofossils will document the time of each marsh formation. Basal material from Arthur Kill (8m) includes freshwater seeds such as Viola, Potomageton and Alnus along with Salix buds. Basal material from Croton Point (10m) includes fibrous woody material, foraminifera and Zanichellia seeds and other brackish vegetational components. The basal material from Piermont (13.77m) is lacking any identifyable macrofossils between 150 and 500 microns. The basal material from Iona Island (10m) has vegetation such as Scirpus and Cyperus seeds, probably implying a brackish environment. The freshwater origin of the Arthur Kill marsh in Staten Island is significant because it predates either sea level rise or the western channel incision. Additional implications for this study include evidence for changes in river channel geomorphology. Reasons for the relatively deeper river marshes include possible basal clay compaction, high production due to river and marine nutrients as well as tectonic activity. This study provides the groundwork for more high

  8. Salt Marsh Formation in the Lower Hudson River Estuary

    NASA Technical Reports Server (NTRS)

    Merley, Michael; Peteet, Dorothy; Hansen, James E. (Technical Monitor)

    2001-01-01

    Salt marshes are constant depositional environments and as a result contain accurate indicators of past relative sea level rise and salinity. The Hudson River marshes are at least twice as deep when compared to coastal marshes on either side of the mouth of the Hudson. The reason for this difference in sedimentation is unclear. This study uses macrofossil data as well as sediment stratigraphy in order to understand the formation and evolution of these marshes. The composition of seeds, roots, shoots and foraminifera, are used to indicate past sea levels. The four sites involved in this study are, from south to north, the Arthur Kill Marsh in Staten Island (40 36 N, 74 77W), Piermont marsh (N 4100; 73 55W) Croton Point (41 14 N; 73 50W) and Iona Island (41 18N, 73 58W). These are all tidally influenced but with increasing distances from the New York Bight, which gives a good spectrum of tidal influence. AMS-C14 dates on basal macrofossils will document the time of each marsh formation. Basal material from Arthur Kill (8 m) includes freshwater seeds such as Viola, Potomageton and Alnus along with Salix buds. Basal material from Croton Point (10 m) includes fibrous woody material, foraminifera and Zanichellia seeds and other brackish vegetational components. The basal material from Piermont (13.77 m) is lacking any identifiable macrofossils between 150 and 500 microns. The basal material from Iona Island (10 m) has vegetation such as Scirpus and Cyperus seeds, probably implying a brackish environment. The freshwater origin of the Arthur Kill marsh in Staten Island is significant because it predates either sea level rise or the western channel incision. Additional implications for this study include evidence for changes in river channel geomorphology. Reasons for the relatively deeper river marshes include possible basal clay compaction, high production due to river and marine nutrients as well as tectonic activity. This study provides the groundwork for more high

  9. GPS coordinate time series measurements in Ontario and Quebec, Canada

    NASA Astrophysics Data System (ADS)

    Samadi Alinia, Hadis; Tiampo, Kristy F.; James, Thomas S.

    2017-01-01

    New precise network solutions for continuous GPS (cGPS) stations distributed in eastern Ontario and western Québec provide constraints on the regional three-dimensional crustal velocity field. Five years of continuous observations at fourteen cGPS sites were analyzed using Bernese GPS processing software. Several different sub-networks were chosen from these stations, and the data were processed and compared to in order to select the optimal configuration to accurately estimate the vertical and horizontal station velocities and minimize the associated errors. The coordinate time series were then compared to the crustal motions from global solutions and the optimized solution is presented here. A noise analysis model with power-law and white noise, which best describes the noise characteristics of all three components, was employed for the GPS time series analysis. The linear trend, associated uncertainties, and the spectral index of the power-law noise were calculated using a maximum likelihood estimation approach. The residual horizontal velocities, after removal of rigid plate motion, have a magnitude consistent with expected glacial isostatic adjustment (GIA). The vertical velocities increase from subsidence of almost 1.9 mm/year south of the Great Lakes to uplift near Hudson Bay, where the highest rate is approximately 10.9 mm/year. The residual horizontal velocities range from approximately 0.5 mm/year, oriented south-southeastward, at the Great Lakes to nearly 1.5 mm/year directed toward the interior of Hudson Bay at stations adjacent to its shoreline. Here, the velocity uncertainties are estimated at less than 0.6 mm/year for the horizontal component and 1.1 mm/year for the vertical component. A comparison between the observed velocities and GIA model predictions, for a limited range of Earth models, shows a better fit to the observations for the Earth model with the smallest upper mantle viscosity and the largest lower mantle viscosity. However, the

  10. Galveston Bay

    USGS Publications Warehouse

    Handley, Lawrence R.; Spear, Kathryn A.; Eleonor Taylor,; Thatcher, Cindy

    2011-01-01

    The Galveston Bay estuary is located on the upper Texas Gulf coast (Lester and Gonzalez, 2002). It is composed of four major sub-bays—Galveston, Trinity, East, and West Bays. It is Texas’ largest estuary on the Gulf Coast with a total area of 155,399 hectares (384,000 acres) and 1,885 km (1,171 miles) of shoreline (Burgan and Engle, 2006). The volume of the bay has increased over the past 50 years due to subsidence, dredging, and sea level rise. Outside of ship channels, the maximum depth is only 3.7 m (12 ft), with the average depth ranging from 1.2 m (4 ft) to 2.4 m (8 ft)— even shallower in areas with widespread oyster reefs (Lester and Gonzalez, 2002). The tidal range is less than 0.9 m (3 ft), but water levels and circulation are highly influenced by wind. The estuary was formed in a drowned river delta, and its bayous were once channels of the Brazos and Trinity Rivers. Today, the watersheds surrounding the Trinity and San Jacinto Rivers, along with many other smaller bayous, feed into the bay. The entire Galveston Bay watershed is 85,470 km2 (33,000 miles2 ) large (Figure 1). Galveston Island, a 5,000 year old sand bar that lies at the western edge of the bay’s opening into the Gulf of Mexico, impedes the freshwater flow of the Trinity and San Jacinto Rivers into the Gulf, the majority of which comes from the Trinity. The Bolivar Peninsula lies at the eastern edge of the bay’s opening into the Gulf. Water flows into the Gulf at Bolivar Roads, 1 U.S. Geological Survey National Wetlands Research Center, 700 Cajundome Blvd., Lafayette, LA 70506 2 Harte Research Institute for Gulf of Mexico Studies, Texas A&M University - Corpus Christi, 6300 Ocean Drive, Unit 5869, Corpus Christi, Texas 78412 2 Galveston Pass, between Galveston Island and Bolivar Peninsula, and at San Luis Pass, between the western side of Galveston Island and Follets Island.

  11. Geochemical phases of metals in Hudson River estuary sediments

    SciTech Connect

    Stamoulis, S.; Gibbs, R.J.; Menon, M.G.

    1996-08-01

    Bottom sediment samples were collected from six location along a section of the Hudson River Estuary, 5.3 to 82.7 km from the ocean. These samples were analyzed for particle and, due to the bimodal distribution of the sediment, were seperated into two size fractions, fine (<7.8 um) and coarse (7.8-62 um). These fractions were subject to a sequential chemical phase extraction procedure to differenciate the ion exchangeable, carbonate, metallic oxide coating, and organic phases. The extracted phases were analyzed with an inductively coupled plasma atomic emission spectrophotometer for Cd, Co, Cc, Cu, Fe, Ni, Pb, and Zn. Metals were found to be associated largely with fine particle-size fraction. The concentration of fine particles (especially the <2 um size mode within the fine fraction) is a crucial in influencing overall metal content. This is evidenced by strong correlations between the <2 {mu}m or clay mode and concentrations in the metallic-oxide coating phase. Various metal/metal relationships exist among the phases and fractions studied and are highlighted by strong correlations, such as Ni and Zn, and Cu and Cd. The trends associated among the metal and mud concentrations are significant in terms of assessing the bioavailability of heavy metals within the river and estuary system, and as a result, provide valuable insight into the ultimate fate of pollutants which are introduced to this unique environment. 24 refs., 5 figs., 2 tabs.

  12. Trace Metals and Nutrients in the Hudson River Buoyant Plume

    NASA Astrophysics Data System (ADS)

    Wright, D. D.; Reinfelder, J. R.; Chant, R. J.; Glenn, S. M.; Schofield, O.; Wilkin, J. L.; Houghton, R. W.; Chen, R. F.; Moline, M. A.; Frazier, T. K.

    2004-12-01

    In order to determine the spatial distribution and biological impacts of contaminant metals and nutrients associated with the Hudson River buoyant plume, the transport and transformations of mercury, other trace metals, and major nutrients are being measured as part of the LaGrangian Transport and Transformation Experiment (LaTTE). Beginning in the spring of 2004, a series of dye patch experiments will be carried out that will include continuous underway chemical and biological sampling within the well-sampled framework of an operational ocean observatory. During the first experiment in May 2004, surface water samples for dissolved and suspended particle concentrations of mercury, monomethylmercury, and bioactive and non-essential trace metals were collected using a trace metal clean, underway sampling system. A semi-continuous (5 min resolution) record of dissolved gaseous mercury (elemental mercury) in surface waters revealed diurnal patterns of mercury reduction and volatilization. The results of this project will improve predictions of contaminant movements and ecosystem impacts within the Middle Atlantic Bight.

  13. A simulation of the Cerro Hudson SO2 cloud

    NASA Technical Reports Server (NTRS)

    Schoeberl, Mark R.; Doiron, Scott D.; Lait, Leslie R.; Newman, Paul A.; Krueger, Arlin J.

    1993-01-01

    An isentropic trajectory model is used to simulate the evolution of the southern hemisphere SO2 cloud associated with the eruption of Cerro Hudson. By matching the parcel trajectories with total ozone mapping spectrometer SO2 retrievals, the principal stratospheric injection region is determined to be between 11 and 16 km in altitude. This region is characterized by weak wind shears and is located just poleward of the subtropical jet in the outer fringe of the stratospheric polar vortex. The lack of wind shear in the injection region explains the slow zonal dispersal of the SO2 cloud which was still clearly observed 19 days after the eruption. The trajectory model simulation of the SO2 cloud shows good agreement with observations for 7 days after the eruption. Using the potential vorticity and potential temperature estimates of the initial eruption cloud, the cloud position relative to the polar night jet is shown to be nearly fixed up to September 2, 1991, which was as long as the cloud was observed. This result suggests that the lower stratospheric polar and midlatitude regions are nearly isolated from each other during the late August period.

  14. Trace metal distributions in the Hudson River estuary

    NASA Astrophysics Data System (ADS)

    Klinkhammer, G. P.; Bender, M. L.

    1981-06-01

    Concentations of reactive PO 4, particulate Al and dissolved and particulate Cd, Fe, Zn, Ni, Cu and Mn were measured in the Hudson River estuary. Soluble trace metal concentrations ranged from 1 to 7 parts 10 -9 Cu; 1 to 60 parts 10 -9 Mn; 0·8 to 11 parts 10 -9 Ni; 3 to 33 parts 10 -9 Zn; 0·1 to 0·5 parts 10 -9 Cd and 5 to 96 parts 10 -9 Fe. The particulate levels were 0·2 to 6 parts 10 -9 Cu; 0·2 to 40 parts 10 -9 Mn; 0·1 to 8 parts 10 -9 Ni; 0·04 to 14 parts 10 -9 Zn; 0·005 to 0·3 parts 10 -9 Cd and 7 to 2200 parts 10 -9 Fe. With the exception of iron, the discharge of these metals with Manhattan/New Jersey sewage was comparable to the riverine flux. Anthropogenic Zn, Ni and Mn inputs were reflected in dissolved concentration maxima in New York Harbor. Mass-balance calculations demonstrate that the anthropogenic fraction of these metals left the Harbor in the dissolved form. Anthropogenic Cd, Fe and Cu were associated with solids and these metals were deposited in Harbor sediments.

  15. A Student Activity for the James Bay Hydro Project. The Geography Teacher.

    ERIC Educational Resources Information Center

    Green-Milberg, Patricia

    1999-01-01

    Provides activities for grades 6 to 8 that will promote student awareness and understanding of the use of hydropower in Canada, the benefits and drawbacks to hydropower, and also the drawbacks of electricity transmission lines. Explains that the activities focus on the James Bay Hydro Project in Canada. (CMK)

  16. Impact of the Medieval Climate Anomaly, Little Ice Age, and Recent Warming on Hydrology and Carbon Accumulation in the James Bay Lowland

    NASA Astrophysics Data System (ADS)

    Holmquist, J. R.; Booth, R. K.; MacDonald, G. M.

    2013-12-01

    Reconstructing late-Holocene hydroclimatic variations can be useful to understand the sensitivity of peatland soil carbon (C) to climate change (Bunbury et al., 2012). We reconstructed water table depth (WTD), using testate amoebae, for a four-core north to south transect of the James Bay Lowland and Boreal Shield of Ontario, Canada, and compared WTD to long-term apparent rate of C accumulation (LARCA). The three southern sites indicate that WTD fluctuated relative to the mean, with a wetter Medieval Climate Anomaly (MCA) and drier Little Ice Age (LIA) (Fig. 1). However, the most northern site recorded a wet LIA and dry MCA (Fig. 1). All four cores recorded drying coincident with modern warming (Fig. 1). Increased Medieval moisture detected in the three southern sites is consistent with a geographic pattern of precipitation anomalies associated with La Niña-like conditions, which cause drought in the American southwest and central plains regions coupled with increased moisture in the Pacific Northwest and north of the Great Lakes (Feng et al., 2008; Seager et al., 2008). Despite the hydroclimatic sensitivity of the region, we observed no consistent relationship between variations in WTD and LARCA from the same cores. At these particular sites, at least, C accumulation has not been sensitive to the range of climatic variability associated with the MCA, LIA and recent warming. Bunbury, J., Finkelstein, S. A., & Bollmann, J. (2012). Holocene hydro-climatic change and effects on carbon accumulation inferred from a peat bog in the Attawapiskat River watershed, Hudson Bay Lowlands, Canada. Quaternary Research: 275-284. Feng, S., Oglesby, R. J., Rowe, C. M., Loope, D. B., & Hu, Q. (2008). Atlantic and Pacific SST influences on Medieval drought in North America simulated by the Community Atmospheric Model. Journal of Geophysical Research: Atmospheres (1984-2012), 113(D11). Seager, R., Burgman, R., Kushnir, Y., Clement, A., Cook, E., Naik, N., & Miller, J. (2008). Tropical

  17. ASA24-Canada

    Cancer.gov

    A Canadian adaptation of the Automated Self-Administered 24-hour Dietary Assessment Tool (ASA24-Canada), developed by the Food Directorate at Health Canada in collaboration with NCI, has been freely available since April 2014.

  18. PCB-pollution problem in the upper Hudson River: From environmental disaster to environmental gridlock

    SciTech Connect

    Sanders, J.E. )

    1989-01-01

    The PCB pollution of the upper Hudson River has been traced to two discharge pipes from capacitor-manufacturing plants of the General Electric Company (GE) at Hudson Falls and Fort Edward, located about 40 miles north of Troy, New York. In August 1974, EPA biologists carried out a field investigation upstream of, at, and downstream of the GE discharge pipes. In September 1975, goaded by articles about PCB-contaminated fish from the Hudson Estuary, the Commissioner of the New York State Department of conservation (NYS DEC) commenced an administrative proceeding against GE, alleging violations of several NY State Environmental Conservation Law sections, and seeking cessation of PCB discharges, penalties for past discharges, and rehabilitation of the upper river. One stipulation of the resulting settlement agreement was that New York State sign off with GE over PCB pollution of the Hudson River and, if the Advisory Committee recommended in favor of rehabilitation, it would use its best efforts to find funds from sources other than GE to help pay for rehabilitation. The future of the PCB problem in the upper Hudson River seems likely to be settled by the outcome of a class-action lawsuit that commercial fisherman have filed against GE. In January 1989, a NEW York Appeals Court voted in favor of the ruling that the fishermen were entitled not only to payments for lost income, but to injunctive relief (which implies that GE must clean up the River). 311 refs., 30 figs., 14 tabs.

  19. Sediment Dynamics and Fate of Heavy Metals, Carbon, and Inorganic Matter in the Hudson Estuary, New York

    NASA Astrophysics Data System (ADS)

    Sritrairat, S.; Kenna, T. C.; Peteet, D. M.; Nguyen, K.; Perez, M.; Huang, Z.; Miller, A.

    2010-12-01

    The Hudson River Estuary is typical of a large, intensively used and modified estuary. Its watershed is an important resource for small communities along the river as well as large population centers such as the Metropolitan area of New York City. In addition to past industrial activities within the region that have resulted in many instances of environmental contamination, the estuary is at high risk for climatic and other anthropogenic changes. This study focuses on sediment dynamics and the fate of heavy metals, inorganic matter, and carbon in 27 sediment cores and 15 surface samples taken from wetlands and tributaries of the Hudson Estuary along a north-south transect from Troy, NY to New York harbor. Each site experiences different salinity, vegetation, landscape, and flow pattern. 1) We quantified and mapped the distribution of toxic heavy metals, including Pb, Cu, and Zn, in the estuary to examine the fate of these contaminants. Jamaica Bay and the East River sediments from New York City are the most contaminated with heavy metals among the sites analyzed. 2) We examined the sedimentation rate and sedimentation pattern, using pollution chronology along with radiometric methods. Sedimentation rates at 17 sites range from 0.26 - 2.63 cm/yr during the last century. Cores taken from high-energy or non-vegetated area are more likely to have a disturbed sedimentation pattern, and thus there is a higher risk of contaminant resuspension at those locations. 3) We quantified Ti and K concentration as a measure of the fluctuation of inorganic matter input and the fate of inorganic matter in the estuary. We quantified organic matter content with the Loss-on-Ignition (LOI) method at selected sites to identify carbon sequestration rate in the estuary. Inorganic matter content during the last century at most sites is significantly higher than that found prior to the European Settlements at the same location, suggesting increasing erosion and disturbances. However, more

  20. Tsunami hazard assessment in the Hudson River Estuary based on dynamic tsunami-tide simulations

    NASA Astrophysics Data System (ADS)

    Shelby, Michael; Grilli, Stéphan T.; Grilli, Annette R.

    2016-12-01

    This work is part of a tsunami inundation mapping activity carried out along the US East Coast since 2010, under the auspice of the National Tsunami Hazard Mitigation program (NTHMP). The US East Coast features two main estuaries with significant tidal forcing, which are bordered by numerous critical facilities (power plants, major harbors,...) as well as densely built low-level areas: Chesapeake Bay and the Hudson River Estuary (HRE). HRE is the object of this work, with specific focus on assessing tsunami hazard in Manhattan, the Hudson and East River areas. In the NTHMP work, inundation maps are computed as envelopes of maximum surface elevation along the coast and inland, by simulating the impact of selected probable maximum tsunamis (PMT) in the Atlantic ocean margin and basin. At present, such simulations assume a static reference level near shore equal to the local mean high water (MHW) level. Here, instead we simulate maximum inundation in the HRE resulting from dynamic interactions between the incident PMTs and a tide, which is calibrated to achieve MHW at its maximum level. To identify conditions leading to maximum tsunami inundation, each PMT is simulated for four different phases of the tide and results are compared to those obtained for a static reference level. We first separately simulate the tide and the three PMTs that were found to be most significant for the HRE. These are caused by: (1) a flank collapse of the Cumbre Vieja Volcano (CVV) in the Canary Islands (with a 80 km3 volume representing the most likely extreme scenario); (2) an M9 coseismic source in the Puerto Rico Trench (PRT); and (3) a large submarine mass failure (SMF) in the Hudson River canyon of parameters similar to the 165 km3 historical Currituck slide, which is used as a local proxy for the maximum possible SMF. Simulations are performed with the nonlinear and dispersive long wave model FUNWAVE-TVD, in a series of nested grids of increasing resolution towards the coast, by one

  1. The Siege of Port Hudson: "Forty Days and Nights in the Wilderness of Death." Revised. Teaching with Historic Places.

    ERIC Educational Resources Information Center

    Potts, Gregg; Bergeron, Arthur W., Jr.

    This lesson describes and discusses the U.S. Civil War Siege of Port Hudson (Louisiana). Based on the National Register of Historic Places registration file, "Port Hudson Battlefield," the lesson cites objectives and lists materials for students, and provides information for a site visit. It contains eight sections: (1) "About this…

  2. 77 FR 63873 - Johnson Controls, Inc. Including On-Site Leased Workers of Valley Staffing and AZ Quality Hudson...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-17

    ... certification to include workers leased from AZ Quality working on-site at the Hudson, Wisconsin location of... Employment and Training Administration Johnson Controls, Inc. Including On-Site Leased Workers of Valley Staffing and AZ Quality Hudson, Wisconsin; Amended Certification Regarding Eligibility To Apply for...

  3. 76 FR 46287 - Hudson Ranch Power I LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-02

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Hudson Ranch Power I LLC; Supplemental Notice That Initial Market-Based Rate...-referenced proceeding of Hudson Ranch Power I LLC's application for market-based rate authority, with...

  4. Holocene evolution of lakes in the forest-tundra biome of northern Manitoba, Canada

    NASA Astrophysics Data System (ADS)

    Hobbs, William O.; Edlund, Mark B.; Umbanhowar, Charles E.; Camill, Philip; Lynch, Jason A.; Geiss, Christoph; Stefanova, Vania

    2017-03-01

    The late-Quaternary paleoenvironmental history of the western Hudson Bay region of Subarctic Canada is poorly constrained. Here, we present a regional overview of the post-glacial history of eight lakes which span the forest-tundra biome in northern Manitoba. We show that during the penultimate drainage phase of Lake Agassiz the lake water had an estimated pH of ∼6.0, with abundant quillwort (Isöetes spp.) along the lakeshore and littoral zone and some floating green algae (Botryococcus spp. and Pediastrum sp.). Based on multiple sediment proxies, modern lake ontogeny in the region commenced at ∼7500 cal yrs BP. Pioneering diatom communities were shaped by the turbid, higher alkalinity lake waters which were influenced by base cation weathering of the surrounding till following Lake Agassiz drainage. By ∼7000 cal yrs BP, soil development and Picea spp. establish and the lakes began a slow trajectory of acidification over the remaining Holocene epoch. The natural acidification of the lakes in this region is slow, on the order of several millennia for one pH unit. Each of the study lakes exhibit relatively stable aquatic communities during the Holocene Thermal Maximum, suggesting this period is a poor analogue for modern climatic changes. During the Neoglacial, the beginning of the post-Little Ice Age period represents the most significant climatic event to impact the lakes of N. Manitoba. In the context of regional lake histories, the rate of diatom floristic change in the last 200-300 years is unprecedented, with the exception of post-glacial lake ontogeny in some of the lakes. For nearly the entire history of the lakes in this region, there is a strong linkage between landscape development and the aquatic ecosystems; however this relationship appears to become decoupled or less strong in the post-LIA period. Significant 20th century changes in the aquatic ecosystem cannot be explained wholly by changes in the terrestrial ecosystem, suggesting that future

  5. Bay of Fundy

    NASA Technical Reports Server (NTRS)

    2006-01-01

    The highest tides on Earth occur in the Minas Basin, the eastern extremity of the Bay of Fundy, Nova Scotia, Canada, where the tide range can reach 16 meters when the various factors affecting the tides are in phase. The primary cause of the immense tides of Fundy is a resonance of the Bay of Fundy-Gulf of Maine system. The system is effectively bounded at this outer end by the edge of the continental shelf with its approximately 40:1 increase in depth. The system has a natural period of approximately 13 hours, which is close to the 12h25m period of the dominant lunar tide of the Atlantic Ocean. Like a father pushing his daughter on a swing, the gentle Atlantic tidal pulse pushes the waters of the Bay of Fundy-Gulf of Maine basin at nearly the optimum frequency to cause a large to-and-fro oscillation. The greatest slosh occurs at the head (northeast end) of the system. The high tide image (top) was acquired April 20, 2001, and the low tide image (bottom) was acquired September 30, 2002. The images cover an area of 16.5 by 21 km, and are centered near 64 degrees west longitude and 45.5 degrees north latitude.

    With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

    The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active

  6. An evaluation of the etiology of reduced CYP1A1 messenger RNA expression in the Atlantic tomcod from the Hudson River, New York, USA, using reverse transcriptase polymerase chain reaction analysis.

    PubMed

    Roy, N K; Courtenay, S; Yuan, Z; Ikonomou, M; Wirgin, I

    2001-05-01

    Adult Atlantic tomcod, Microgadus tomcod, from the Hudson River, New York State, USA, exhibit reduced inducibility of hepatic cytochrome P4501A1 (CYP1A1) mRNA compared with adult tomcod from the cleaner Miramichi River, New Brunswick, Canada, when treated with coplanar polychlorinated biphenyl (PCB) congeners or 2,3,7,8-tetrachlorodibenzo-p-dioxin. In contrast, little difference in CYP1A1 inducibility is observed between tomcod from these two rivers when treated with polycyclic aromatic hydrocarbons (PAHs). We sought to determine if impaired hepatic CYP1A1 inducibility in Hudson River tomcod results from a multigenerational, genetic adaptation or a single generational, physiological acclimation. Embryos and larvae from controlled experimental crosses of Hudson River and Miramichi River parents were exposed for 24 h to water-borne PCB congener 77 (10 ppm), benzo[a]pyrene (BaP; 10 ppm), or dimethysulfoxide, and CYP1A1 expression was assessed in individual larva using competitive reverse transcriptase polymerase chain reaction (RT-PCR) analysis. The CYP1A1 mRNA was significantly induced in larvae from both populations by BaP (47- and 52-fold) and PCB 77 (9- and 22-fold), although levels of expression were higher in offspring of Miramichi matings. Most important, CYP1A1 mRNA was significantly induced by PCB 77 in larvae from Hudson River parents. Concentrations of dioxin, furan, and PCB congeners were measured in livers and eggs of female tomcod from these two locales to quantify the extent of maternal transfer of contaminants. For both rivers, wet-weight contaminant concentrations were significantly higher (4-7 times) in livers than in eggs of the same females, suggesting that a threshold level of contaminants may have to be reached before CYP1A1 transcription is impaired. We conclude that reduced inducibility of hepatic CYP1A1 mRNA in adult tomcod from the Hudson River is most consistent with single-generational acclimation.

  7. Climate change drives warming in the Hudson River Estuary, New York (USA).

    PubMed

    Seekell, David A; Pace, Michael L

    2011-08-01

    Estuaries may be subject to warming due to global climate change but few studies have considered the drivers or seasonality of warming empirically. We analyzed temperature trends and rates of temperature change over time for the Hudson River estuary using long-term data, mainly from daily measures taken at the Poughkeepsie Water Treatment Facility. This temperature record is among the longest in the world for a river or estuary. The Hudson River has warmed 0.945 °C since 1946. Many of the warmest years in the record occurred in the last 16 years. A seasonal analysis of trends indicated significant warming for the months of April through August. The warming of the Hudson is primarily related to increasing air temperature. Increasing freshwater discharge into the estuary has not mitigated the warming trend.

  8. Ground-water data on the Hudson River basin, New York

    USGS Publications Warehouse

    Hammond, Deborah S.; Heath, Ralph C.; Waller, Roger Milton

    1978-01-01

    Ground water in the Hudson River basin occurs in unconsolidated deposits and consolidated rock. Sand and gravel units of the unconsolidated deposits, which occur principally in valley bottoms, form the best aquifers and commonly provide well yields of several hundred gallons per minute. Carbonate aquifers are the most productive consolidated rock units. Ground water in the Hudson River basin is generally hard and may contain appreciable amounts of iron, salts in solution, or sulfur locally. Basic data on the availability of ground water in the Hudson River drainage area are compiled in (1) a hydrogeologic map of the drainage basin; (2) a table of well depths, yields, concentrations of selected chemical constituents, and hardness of ground water, listed by county and aquifer type; (3) a short text describing the occurrence of ground water in the basin; and (4) a bibliography of ground-water reports pertinent to the area studied. (Woodard-USGS)

  9. Burrowing mayflies as indicators of ecosystem health: Status of populations in western Lake Erie, Saginaw Bay and Green Bay

    USGS Publications Warehouse

    Edsall, T.A.; Bur, M.T.; Gorman, O.T.; Schaeffer, J.S.

    2005-01-01

    The U.S. Environmental Protection Agency and Environment Canada are supporting the development of indicators of ecosystem health that can be used to report on progress in restoring and maintaining the Great Lakes ecosystem, as called for in the Great Lakes Water Quality Agreement between the United States and Canada. One indicator under development is based on burrowing mayflies (Hexagenia: Ephemeroptera: Ephemeridae). We sampled in western Lake Erie, Saginaw Bay (Lake Huron), and Green Bay (Lake Michigan) in spring 2001 at 117 stations covering about 1,870 km2 of lake bed, to determine the status of nymphal populations of Hexagenia, and to provide information that would further the technical development of an indicator of ecosystem health based on Hexagenia. In western Lake Erie, density and biomass of nymphs were generally highest on fine-grained substrate in offshore waters and were lower on coarser substrates in near shore waters. Nymphs were virtually absent from Saginaw Bay, where only one nymph was collected at 28 stations. Nymphs were collected at only 6 of 48 stations in Green Bay, and density and biomass were highest at the northern end of the bay. Polluted sediments are likely responsible for the absence or low density and biomass of nymphs observed on fine-grained substrates in western Lake Erie, Saginaw Bay, and Green Bay, all of which historically supported abundant populations.

  10. Rapid fluctuations of the Laurentide Ice Sheet at the mouth of Hudson Strait: New evidence for ocean/ice-sheet interactions as a control on the Younger Dryas

    NASA Astrophysics Data System (ADS)

    Miller, Gifford H.; Kaufman, Darrell S.

    1990-12-01

    Ice-directional features and erratic lithologies of the last glaciation demonstrate that a major outlet glacier of the Laurentide Ice Sheet flowed NNE across outer Hudson Strait rather than SE down the Strait as previously hypothesized. Ice advanced more than 600 km from a Labradorean source, crossing Hudson Strait and outer Frobisher Bay, and advancing onto Hall Peninsula; the highest summits on Loks Land (circa 400 m asl), a large island at the SE tip of Hall Peninsula, were inundated by Labradorean ice. Three distinct Late Wisconsin advances have been recognized. The earliest, most extensive advance crossed Frobisher about 11.5 kyr B.P. and was maintained for circa 1 kyr. Differences in the extent of amino acid racemization in shells from interstadial and deglacial sites on eastern Loks Land limit the duration of the most extensive Late Wisconsin advance(s) to a brief interval of no more than 2 kyr. Radiocarbon dates on in situ shells and on shells incorporated in till indicate that Frobisher Bay was ice-free from at least 10.5 to 10.2 kyr B.P. after which a second Labradorean advance, the Gold Cove readvance, attained nearly the same extent as the earlier advance. The readvance was short lived, and the Bay was deglaciated before 9.5 kyr B.P. A final readvance occurred during the Cockburn Substage (9 to 8 kyr B.P.), but ice failed to cross Frobisher Bay. The maximum extent of the Labradorean advance coincides with the onset of Younger Dryas cooling. Based on a minimum cross-sectional area and reasonable estimates of ice velocity, the iceberg flux to the North Atlantic Ocean at this time was between 300 to 2400 km³ year-1, about the same as the freshwater influx from the diversion of Lake Agassiz drainage to the St. Lawrence. The input of a significant volume of ice into the North Atlantic via the Labrador Sea would have cooled sea surface and air temperatures, increased sea-surface albedo, and diminished the effectiveness of wind mixing of surface waters

  11. Environmental exposures to polychlorinated biphenyls (PCBs) among older residents of upper Hudson River communities.

    PubMed

    Fitzgerald, Edward F; Belanger, Erin E; Gomez, Marta I; Hwang, Syni-an; Jansing, Robert L; Hicks, Heraline E

    2007-07-01

    The upper Hudson River has been heavily contaminated with polychlorinated biphenyls (PCBs) due to discharges from former electrical capacitor plants in Hudson Falls and Fort Edward, NY. An epidemiologic study was conducted to assess the impact of dietary and residential exposure on PCB body burden among older, long-term, non-occupationally exposed adults living in the vicinity of these former capacitor plants. The study population consisted of 133 persons 55-74 years of age who had lived in Hudson Falls or Fort Edward for 25 years or more. The comparison group consisted of 120 persons from Glens Falls, which is upriver. Both groups were interviewed, and blood samples were obtained for congener-specific PCB analysis. Persons from the study area reported greater past consumption of Hudson River fish than did the comparison area, but current rates were very low in both areas. The geometric mean serum PCB concentrations for the study and comparison populations did not differ significantly (3.07 ppb wet weight and 3.23 ppb, respectively, for total PCB). Serum PCB concentrations increased with cumulative lifetime exposure to PCBs from Hudson River fish consumption (p<0.10). Persons who lived within 800 m of the river did not have significantly greater serum PCB concentrations than the control population, nor did persons who lived downwind and within 800 m of a PCB-contaminated site. The results indicate no detectable differences in serum PCB levels according to proximity or wind direction relative to local point sources, but lifetime consumption of Hudson River fish was positively associated with serum PCB concentrations.

  12. Working in Canada's subarctic: circumpolar medicine.

    PubMed

    Podolsky, Gary

    2006-01-01

    Medical practice in Churchill is a challenging and rewarding form of wilderness medicine. If any reader is interested in learning more about Churchill or would like to consider visiting or even taking a health care position here, the following resources and contacts are available: The website for Churchill Independent Travel (www.creighton.edu/hutchens/church_travel.html) gives a complete list of options for those wishing to plan their own trip. The Arctic Medicine Conference is a medical conference with talks in Zoonoses, Dentistry, Entomology, and Travel Medicine hosted by Wilderness Medicine in Manitoba (www.skylarkmedicalclinic.com). The JA Hildes Northern Medical Unit is responsible for providing qualified physicians and nurse practitioners to staff northern Manitoba. For those who are interested, please contact Michelle Vandenbroeck at 1(204)789-3711 for information in working in Churchill or other parts of the Hudson Bay Inuit communities (www.umanitoba.ca/faculties/medicine/units/ northern_medical_unit). 1,000 Places to See Before You Die, by Patricia Schultz, is a recent bestseller that gives information about polar bear safaris.

  13. Discharge, gage height, and elevation of 100-year floods in the Hudson River basin, New York

    USGS Publications Warehouse

    Archer, Roger J.

    1978-01-01

    The flood discharge that may be expected to be equaled or exceeded on the average of once in 100 years (100-year flood) was computed by the log-Pearson Type-III frequency relation for 72 stations in the Hudson River basin. These discharges and, where available, their corresponding gage height and elevation above mean sea level are presented in tabular form. A short explanation of computation methods is included. The data are to be used as part of a federally funded study of the water resources and related land resources of the Hudson River basin. (Woodard-USGS)

  14. Polychlorinated biphenyls in sediments of the tidal Hudson River, New York

    SciTech Connect

    Bopp, R.F.; Simpson, H.J.; Olsen, C.R.; Kostyk, N.

    1981-02-01

    As a result of PCB discharges from two manufacturing facilities located some 60 km upstream of Troy, N.Y., PCB's in sediments of the Hudson River were measured. The sediments contain PCB concentrations of approximately 10 ppm, some one to two orders of magnitude higher than levels previously recorded. A first-order PCB budget for Hudson River sediment samples and regional levels of PCB contamination prior to the large point-source discharges are examined. (5 graphs, 1 map, 23 references, 6 tables)

  15. Abrupt Atmospheric Methane Increases Associated With Hudson Strait Heinrich Events

    NASA Astrophysics Data System (ADS)

    Rhodes, R.; Brook, E.; Chiang, J. C. H.; Blunier, T.; Maselli, O. J.; McConnell, J. R.; Romanini, D.; Severinghaus, J. P.

    2015-12-01

    The drivers of abrupt climate change during the Last Glacial Period are not well understood. While Dansgaard-Oeschger (DO) cycles are thought to be linked to variations in the strength of the Atlantic Meridional Ocean Circulation (AMOC), it is not clear how or if Heinrich Events—extensive influxes of icebergs into the North Atlantic Ocean that impacted global climate and biogeochemistry—are related. An enduring problem is the difficultly in dating iceberg rafted debris deposits that typically lack foraminifera. Here we present an ultra-high resolution record of methane from the West Antarctic Ice Sheet Divide ice core at unprecedented, continuous temporal resolution from 67.2-9.8 ka BP, which we propose constrains the timing of Heinrich events. Our methane record essentially mirrors Greenland ice core stable isotope variability across D-O events, except during Heinrich stadials 1, 2, 4 and 5. Partway through these stadials only, methane increases abruptly and rapidly, as at the onset of a D-O event but Greenland temperature exhibits no equivalent response. Speleothem records exhibit signatures of drought in the Northern extra-tropics and intensified monsoonal activity over South America at these times. We use a simple heuristic model to propose that cold air temperatures and extensive sea ice in the North, resulting from Heinrich events, caused extreme reorganization of tropical hydroclimate. This involved curtailment of the seasonal northerly migration of tropical rain belts, leading to intensification of rainfall over Southern Hemisphere tropical wetlands, thus allowing production of excess methane relative to a 'normal' Greenland stadial. We note that this mechanism can operate if AMOC is already in a slowed state when a Heinrich event occurs, as paleo-evidence suggests it was. Heinrich events and associated sea ice cover would therefore act to prolong the duration of this AMOC state. Our findings place the big four Heinrich events of Hudson Strait origin

  16. 75 FR 39839 - Regulated Navigation Area; Hudson River and Port of NY/NJ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-13

    ... to begin. Due to delays on other construction projects in the Gulf of Mexico, the calendar dates for... over the Harlem River. The replacement bridge span for this project is being constructed at Port Coeymans, NY on the Hudson River, approximately 115 nautical miles north of The Battery, Manhattan, NY....

  17. Chiral source apportionment of polychlorinated biphenyls to the Hudson River estuary atmosphere and food web.

    PubMed

    Asher, Brian J; Wong, Charles S; Rodenburg, Lisa A

    2007-09-01

    The New York/New Jersey Harbor Estuary is subject to significant contamination of polychlorinated biphenyls (PCBs) from numerous sources, including the historically contaminated Upper Hudson River, stormwater runoff and sewer overflows, and atmospheric deposition from PCBs originating from the surrounding urban area. However, the relative importance of these sources to the estuary's food web is not fully understood. Sources of PCBs to the estuary were apportioned using chiral signatures of PCBs in air, water, total suspended matter, phytoplankton, and sediment. PCBs 91, 95, 136, and 149 were racemic in the atmosphere of the estuary. However, the other phases contained nonracemic PCB 95 and to a lesser extent PCB 149. Thus, the predominant atmospheric source of these congeners is likely unweathered local pollution and not volatilization from the estuary. The similarity in chiral signatures in the other phases is consistent with dynamic contaminant exchange among them. Chiral signatures in the dissolved phase and total suspended matter were correlated with Upper Hudson discharge, suggesting thatthe delivery of nonracemic contaminated sediment from the Upper Hudson, not the atmosphere, controls phytoplankton uptake of some PCBs. Thus, measures to control PCB contamination in the Upper Hudson should be effective in reducing loadings to the estuary's aquatic ecosystem.

  18. Community Perceptions of Hudson County Community College. Special Report 93.02.

    ERIC Educational Resources Information Center

    Fujita, Eleanor

    In 1993, two surveys were conducted to determine community perceptions of Hudson County Community College (HCCC) in New Jersey. During January and February 1993, 591 questionnaires regarding HCCC's mission were sent to representatives of business and industry, education, government, community groups and agencies, health and human service…

  19. COMPONENTS FOR SCHOOL CONSTRUCTION IN THE MID-HUDSON REGION. PROGRESS REPORT 2.

    ERIC Educational Resources Information Center

    HAVILAND, DAVID S.

    THIS STUDY IS PART 2 OF A PROGRESS REPORT ON A FEASIBILITY STUDY TO SAMPLE APPROPRIATE ASPECTS OF SCHOOL CONSTRUCTION FACTORS IN NEW YORK STATE. THE STUDY IS TO DETERMINE WHETHER THE SCHOOL CONSTRUCTION SYSTEMS DEVELOPMENT PROCESS IS APPLICABLE TO SCHOOL CONSTRUCTION IN THE MID-HUDSON VALLEY AND TO EXPLORE POSSIBLE MEANS OF ACHIEVING SUCH SCHOOL…

  20. 77 FR 41271 - Safety Zone; Newburgh to Beacon Swim, Newburgh, Hudson River, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-13

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Newburgh to Beacon Swim, Newburgh, Hudson... Newburgh, NY for the annual Newburgh Beacon Swim event. This temporary safety zone is necessary to protect... Beacon Swim is an annual recurring event that has a permanent safety zone found at 33 CFR 165.160....

  1. 77 FR 46613 - Safety Zone; 2012 Ironman US Championship Swim, Hudson River, Fort Lee, NJ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-06

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; 2012 Ironman US Championship Swim, Hudson... Cliffs and Fort Lee, NJ for the 2012 Ironman US Championship swim event. This temporary safety zone is necessary to protect the maritime public and event participants from the hazards associated with swim...

  2. Frederic Hudson's Nineteenth Century Critics and the Research Agenda for Press Historians of the 1980's.

    ERIC Educational Resources Information Center

    Thorn, William J.

    Although Frederic Hudson's "Journalism History in the United States from 1690 to 1872," the first major survey of American journalism, has been a major reference since its publication in 1873, an examination of book reviews that appeared in the New York press following the book's publication reveals surprisingly sharp criticisms of the…

  3. EPA Initiates Second Review of Hudson River PCB Cleanup, Public Encouraged to Participate

    EPA Pesticide Factsheets

    (Albany, NY) The U.S. Environmental Protection Agency has initiated its second review of the cleanup of the Hudson River PCBs Superfund site. The purpose of this review, which is called a five year review and is legally required under the Superfund law eve

  4. The Partitioning of Triclosan between Aqueous and Particulate Phases in the Hudson River Estuary

    EPA Science Inventory

    The distribution of Triclosan within the Hudson River Estuary can be explained by a balance among the overall effluent inputs from municipal sewage treatment facilities, dilution of Triclosan concentrations in the water column with freshwater and seawater inputs, removal of Tricl...

  5. COMPONENTS FOR SCHOOL CONSTRUCTION IN THE MID-HUDSON REGION. FINAL REPORT 3.

    ERIC Educational Resources Information Center

    GREEN, ALAN D.; AND OTHERS

    THE FINAL REPORT OF A THREE PART FEASIBILITY STUDY OF THE COMPONENT CONSTRUCTION SYSTEMS SAMPLED APPROPRIATE ASPECTS OF THE SCHOOL CONSTRUCTION CLIMATE IN NEW YORK STATE. IT SOUGHT TO DETERMINE THE APPROPRIATENESS OF THE SCHOOL CONSTRUCTION SYSTEM DEVELOPEMENT PROCESS TO SCHOOL CONSTRUCTION IN THE MID-HUDSON VALLEY AND TO EXPLORE POSSIBILITIES FOR…

  6. COMPONENTS FOR SCHOOL CONSTRUCTION IN THE MID-HUDSON REGION. PROGRESS REPORT 1.

    ERIC Educational Resources Information Center

    GREEN, ALAN C.; AND OTHERS

    THIS REPORT IS PART 1 OF A FEASIBILITY STUDY TO SAMPLE APPROPRIATE ASPECTS OF THE SCHOOL CONSTRUCTION FACTORS IN NEW YORK STATE. THE STUDY IS TO DETERMINE WHETHER THE SCHOOL CONSTRUCTION SYSTEMS DEVELOPMENT PROCESS IS APPLICABLE TO SCHOOL CONSTRUCTION IN THE MID-HUDSON VALLEY. THE STUDY ALSO EXPLORES POSSIBLE MEANS BY WHICH SUCH SCHOOL BUILDINGS…

  7. Watershed nutrient inputs, phytoplankton accumulation, and C stocks in Chesapeake Bay

    NASA Astrophysics Data System (ADS)

    Fisher, T. R.; Boynton, W. R.; Hagy, J. D.

    2002-12-01

    Inputs of N and P to Chesapeake Bay have been enhanced by anthropogenic activities. Fertilizers, urbanization, N emissions, and industrial effluents contribute to point and diffuse sources currently 2-7X higher for P and 5-20X higher for N than those from undisturbed watersheds. Enhanced nutrient inputs cause phytoplankton blooms which obscure visibility, eliminate submerged grasses, and influence the distribution of C within the Bay. Accumulations of dissolved organic and particulate organic C lead to enhanced microbial respiration in isolated bottom waters, and dissolved oxygen is seasonally reduced to trace levels during summer. Cultural eutrophication is not unique to Chesapeake Bay. Although some estuaries such as the Delaware, Hudson, and San Francisco Bay also have high anthropogenic inputs, these estuaries have much shorter residence times, and much of the N and P may be exported to the coastal ocean. However, in Chesapeake Bay, with residence times >2 months, internal processing of watershed inputs results in local algal blooms within the estuary. Watershed restoration strategies for Chesapeake watersheds have had limited success to date. Groundwaters are enriched with nitrate, and the long residence times of groundwaters mean slow responses to watershed improvements. The few successes in the Chesapeake have been associated with point source reductions, although continued human population growth can easily override restoration efforts. Widespread improvement in water quality has yet to occur, but the limited successes show that the Bay responds to load changes.

  8. Winter-time Sediment Transport in the Hudson Shelf Valley Offshore of New York

    NASA Astrophysics Data System (ADS)

    Harris, C. K.; Butman, B.; Traykovski, P.; ten Brink, M. B.

    2001-05-01

    The Hudson Shelf Valley is a bathymetric low extending across the continental shelf offshore of New York and New Jersey. The present-day morphology of the valley has been proposed to be the result of catastrophic drainage of late Pleistocene glacial lakes down the Hudson River drainage system. Dredge spoils and sewage sludge deposited on the inner shelf off-shore of the New York Bight over the past ~150 years has been reworked by waves and currents. Some of this material now appears to reside in the Hudson Shelf Valley, based on elevated concentrations of lead and other metals in shelf valley sediments. Understanding the processes that transport sediments in the modern system is essential to predict the fate of these sediments, and to understand the geomorphic evolution of the shelf. From December, 1999 through April, 2000 an array of near-bed tripods and water-column moorings were deployed to measure suspended sediment concentrations, current velocities, waves, and water column properties. Instruments were placed at six sites; four along the axis of the Hudson Shelf Valley (water depths 38 -- 75 m); and two on the shelves adjacent to the Hudson Shelf valley (25 m water depth). This study uses these observations and measurements of winds, waves, and sea-level obtained from NOAA stations to characterize the types of events that redistribute sediment in the vicinity of the Hudson Shelf Valley during winter-time forcing. Two types of sediment transport events were observed; down-valley directed transport events tended to be wave-dominated, but several up-valley transport events were observed where bottom shear stress was dominated by energetic currents. Down-valley directed transport events were associated with energetic waves, winds from the east, and sea level setup at the New Jersey coast. Conversely, strong up-valley transport events were associated with winds from the west, low wave energy, and sea level set-down at the coast. The up-valley directed currents

  9. A catastrophic meltwater flood event and the formation of the Hudson Shelf Valley

    USGS Publications Warehouse

    Thieler, E.R.; Butman, B.; Schwab, W.C.; Allison, M.A.; Driscoll, N.W.; Donnelly, J.P.; Uchupi, E.

    2007-01-01

    The Hudson Shelf Valley (HSV) is the largest physiographic feature on the U.S. mid-Atlantic continental shelf. The 150-km long valley is the submerged extension of the ancestral Hudson River Valley that connects to the Hudson Canyon. Unlike other incised valleys on the mid-Atlantic shelf, it has not been infilled with sediment during the Holocene. Analyses of multibeam bathymetry, acoustic backscatter intensity, and high-resolution seismic reflection profiles reveal morphologic and stratigraphic evidence for a catastrophic meltwater flood event that formed the modern HSV. The valley and its distal deposits record a discrete flood event that carved 15-m high banks, formed a 120-km2 field of 3- to 6-m high bedforms, and deposited a subaqueous delta on the outer shelf. The HSV is inferred to have been carved initially by precipitation and meltwater runoff during the advance of the Laurentide Ice Sheet, and later by the drainage of early proglacial lakes through stable spillways. A flood resulting from the failure of the terminal moraine dam at the Narrows between Staten Island and Long Island, New York, allowed glacial lakes in the Hudson and Ontario basins to drain across the continental shelf. Water level changes in the Hudson River basin associated with the catastrophic drainage of glacial lakes Iroquois, Vermont, and Albany around 11,450 14C year BP (∼ 13,350 cal BP) may have precipitated dam failure at the Narrows. This 3200 km3 discharge of freshwater entered the North Atlantic proximal to the Gulf Stream and may have affected thermohaline circulation at the onset of the Intra-Allerød Cold Period. Based on bedform characteristics and fluvial morphology in the HSV, the maximum freshwater flux during the flood event is estimated to be ∼ 0.46 Sv for a duration of ∼ 80 days.

  10. Detection of Changes in Sediment Distribution in the Hudson River Estuary with Repeated Subbottom Profiling

    NASA Astrophysics Data System (ADS)

    Nitsche, F. O.; Kenna, T. C.

    2014-12-01

    During the last decade, several major storms have impacted the US Atlantic coast, including tropical storm Sandy in 2013 and tropical storms Irene and Lee in 2012. These storms, in particular, had major impacts on the watershed of the Hudson River Estuary, resulting in changes in the delivery and distribution of sediments. While Sandy generated a large storm surge that mostly effected the lower estuary, Irene and Lee caused significant flooding in the upper estuary that delivered ~2.7 million tons of sediment to the Hudson River Estuary, which according to USGS estimates is an amount equal to three times the annual load of ~700,000-800,000 metric? tons (Wall et al. 2008; Ralston et al., 2013). Here we report results from high-resolution Chirp subbottom surveys conducted in selected areas of the Hudson River in 2014. Areas were selected with the goal of investigating changes in the sediment deposition and storage in the Hudson River as a result of these events. The new survey lines were acquired following the tracks of earlier subbottom profiles that were collected as part of the Hudson River Benthic Mapping Project in the early 2000s, i.e. before the storms of 2012 and 2013, in a dense grid of subbottom profiles. We then compared these co-located profiles to determine changes between the profiles and to map out the spatial distribution of increased deposition in the selected areas. In several places, the data show clear increases of the thickness of depositional layers of over 0.25 m while in other areas these changes are less clear. Changes based on sub-bottom data will be compared to results obtained on sediment cores taken from the same areas. Preliminary analysis of the sediment cores indicates clear layers of recent sediments in some areas that correspond to the results of the subbottom analysis.

  11. Urban Greening Bay Area

    EPA Pesticide Factsheets

    Information about the San Francisco Bay Water Quality Project (SFBWQP) Urban Greening Bay Area, a large-scale effort to re-envision urban landscapes to include green infrastructure (GI) making communities more livable and reducing stormwater runoff.

  12. Chesapeake Bay TMDL Document

    EPA Pesticide Factsheets

    This page provides the Total Maximum Daily Load (TMDL) report for the Chesapeake Bay. It includes the executive summary, main report, and appendices. The Chesapeake Bay TMDL was established by U.S. EPA Region 3 on December 29, 2010

  13. Chesapeake Bay TMDL

    EPA Pesticide Factsheets

    In 2010 EPA established the Chesapeake Bay TMDL, a comprehensive pollution diet with accountability measures to restore clean water in the bay and local waters. It set limits for nutrients and sediment to meet water quality standards across the watershed

  14. Canada: The Neglected Focus.

    ERIC Educational Resources Information Center

    Rutan, Gerard F.

    1988-01-01

    Examines Canada as a neglected area of political study. Suggests the inclusion of Canada in the comparative politics curriculum because it offers rich comparative opportunities with its cultural pluralism, parliamentary system, and authentic federalism. Lists associations and funding sources for Canadian studies and recommends several textbooks.…

  15. Study Canada: International Outlook.

    ERIC Educational Resources Information Center

    Monahan, Robert L.; And Others

    This self-contained unit of study on Canada is one of a series which can be used to supplement secondary level courses of social studies, contemporary world problems, government, history, and geography. Developed by teachers, the unit focuses on international relations. A comparative approach is used which stresses understanding Canada from…

  16. Groundwater quality in the Chemung River, Eastern Lake Ontario, and Lower Hudson River Basins, New York, 2013

    USGS Publications Warehouse

    Scott, Tia-Marie; Nystrom, Elizabeth A.; Reddy, James E.

    2015-11-10

    The Lower Hudson River Basin study area covers 5,607 square miles and encompasses the part of the Lower Hudson River Basin that lies within New York plus the parts of the Housatonic, Hackensack, Bronx, and Saugatuck River Basins that are in New York. Twelve of the wells sampled in the Lower Hudson River Basin are completed in sand-and-gravel deposits, and 13 are completed in bedrock. Groundwater in the Lower Hudson River Basin was generally of good quality, although properties and concentrations of some constituents—pH, sodium, chloride, dissolved solids, arsenic, aluminum, iron, manganese, radon-222, total coliform bacteria, fecal coliform bacteria, Escherichia coli bacteria, and heterotrophic plate count—equaled or exceeded primary, secondary, or proposed drinking-water standards. The constituent most frequently detected in concentrations exceeding drinking-water standards (20 of 25 samples) was radon-222.

  17. 14 CFR 93.351 - General requirements for operating in the East River and/or Hudson River Exclusions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... River or Hudson River as depicted on the New York VFR Terminal Area Chart (TAC) and/or New York Helicopter Route Chart. (d) Have a current New York TAC chart and/or New York Helicopter Route Chart in...

  18. Determining Sources and Transport of Nuclear Contamination in Hudson River Sediments with Plutonium, Neptunium, and Cesium isotope ratios

    NASA Astrophysics Data System (ADS)

    Kenna, T. C.; Chillrud, S. N.; Chaky, D. A.; Simpson, H. J.; McHugh, C. M.; Shuster, E. L.; Bopp, R. F.

    2004-12-01

    Different sources of radioactive contamination contain characteristic and identifiable isotopic signatures, which can be used to study sediment transport. We focus on Pu-239, Pu-240, Np-237 and Cs-137, which are strongly bound to fine grained sediments. The Hudson River drainage basin has received contamination from at least three separate sources: 1) global fallout from atmospheric testing of nuclear weapons, which contributed Pu, Np and Cs; 2) contamination resulting from reactor releases at the Indian Point Nuclear Power Plant (IPNPP) located on the Hudson River Estuary ˜70km north of New York Harbor, where records document releases of Cs-137; 3) contamination resulting from activities at the Knolls Atomic Power Laboratory (KAPL) located on the Mohawk River, where incomplete records document releases of Cs-137 but no mention is made of Pu or Np. Here we report measurements of Pu isotopes, Np-237 and Cs-137 for a series of sediment cores collected from various locations within the drainage basin: 1) Mohawk River downstream of KAPL, 2) Hudson River upstream of its confluence with the Mohawk River, and 3) lower Hudson River at a location in close proximity to IPNPP. In addition, we present data from selected samples from two other lower Hudson River locations: One site located ˜30km downstream of IPNPP and another ˜30km upstream of IPNPP. By comparing the isotopic ratios Pu-240/Pu-239, Np-237/Pu-239, and Cs-137/Pu-239, measured in fluvial sediments to mean global fallout values, it is possible to identify and resolve different sources of non-fallout contamination. To date, isotopic data for sediments indicate non-fallout sources of Pu-239, Pu-240, and Cs-137; Np-237, however, appears to originate from global fallout only. Mohawk River sediments downstream of KAPL exhibit enrichments in Pu-239, Pu-240, and Cs-137 that are 7 to 20 times higher than levels expected from global fallout as indicated from Np-237. The elevated levels, non-fallout isotopic signatures

  19. Je voyage au Canada (Travelling to Canada).

    ERIC Educational Resources Information Center

    Dube, Normand

    Designed for use in a bilingual program, this basic French reader centers around a trip to Canada. It contains reading selections, two short poems, the words and music of a song entitled "La cigale et la fourmi," and several oral and written exercises. (PMP)

  20. Groundwater Resources Evolution in Degrading Permafrost Environments: A Small Catchment-Scale Study in Northern Quebec, Canada

    NASA Astrophysics Data System (ADS)

    Molson, John; Lemieux, Jean-Michel; Fortier, Richard; Therrien, Rene; Ouellet, Michel; Barth, Johannes; van Geldern, Robert; Cochand, Marion; Sottas, Jonathan; Murray, Renaud; Banville, David

    2015-04-01

    A two square kilometre catchment in a discontinuous permafrost zone near the Inuit community of Umiujaq on the eastern shore of Hudson Bay in Northern Quebec, Canada, is being investigated to determine the impact of permafrost degradation on groundwater resources. The catchment, which became deglaciated about 7500 years ago, lies in a valley which includes about 30-40 m of glacial-fluvial and marine Quaternary sediments. Permafrost mounds at the site extend from a few meters below ground surface to depths of about 10-30 m. Instrumentation has been installed to measure groundwater levels and temperature, as well as groundwater and surface water geochemistry, isotope signatures (including δ18O and 3H) and stream flow. Preliminary groundwater isotope data reflect depleted δ18O signals that differ from expected values for local groundwater, possibly representing permafrost thaw. In addition, stable water isotopes indicate evaporation from shallow thermokarst lakes. Meteorological conditions including air temperatures, precipitation and snowpack are also being monitored. Near-surface geophysical surveys using electrical resistivity tomography (ERT), induced polarization tomography (IPT), georadar and seismic refraction tomography have been carried out to characterize the catchment and to build a 3D geological site model. A numerical model of coupled groundwater flow and heat transport, including thermal advection, conduction, freeze-thaw and latent heat, is being developed for the site to help develop the conceptual model and to assess future impacts of permafrost degradation due to climate warming. The model (Heatflow/3D) includes nonlinear functions for the temperature-dependent unfrozen moisture content and relative permeability, and has been tested against analytical solutions and using benchmarks developed by the INTERFROST modelling consortium. A conceptual 2D vertical-plane model including several permafrost mounds along a 1 km section shows dynamic seasonal

  1. Canada and veterinary parasitology.

    PubMed

    Slocombe, J Owen D

    2009-08-07

    A World Association for the Advancement of Veterinary Parasitology tradition for its conference is to present some highlights of the country hosting the event, and with an emphasis on the history of, and research in, veterinary parasitology. A review of Canada's peoples, physiography, climate, natural resources, agriculture, animal populations, pioneers in veterinary parasitology, research accomplishments by other veterinary parasitologists, centres for research in veterinary parasitology, and major current research had been presented at a World Association for the Advancement of Veterinary Parasitology Conference in Canada in 1987, and was published. The present paper updates the information on the above topics for the 22 years since this conference was last held in Canada.

  2. Polychlorinated biphenyl concentrations in Hudson River water and treated drinking water at Waterford, New York

    USGS Publications Warehouse

    Schroeder, R.A.; Barnes, C.R.

    1983-01-01

    Past discharge of PCBs into the Hudson River has resulted in contaminant concentrations of a few tenths of a microgram per liter in the water. Waterford is one of two large municipal users of the Hudson River for drinking-water supply. The treatment scheme at the Waterford plant, which processes approximately 1 million gallons per day, is similar to that of most conventional treatment plants except for the addition of powdered activated carbon during flocculation. Comparison of PCB concentrations in river water and intake water at the plant to concentrations in treated drinking-water samples indicates that purification processes remove 80 to 90 percent of the PCBs and that final concentrations seldom exceed 0.1 microgram per liter. No significant difference was noted between the removal efficiencies during periods of high river discharge, when PCBs are associated with suspended sediment, and low discharge, when PCBs are generally dissolved. (USGS)

  3. Sediment transport due to extreme events: The Hudson River estuary after tropical storms Irene and Lee

    USGS Publications Warehouse

    Ralston, David K.; Warner, John C.; Geyer, W. Rockwell; Wall, Gary R.

    2013-01-01

    Tropical Storms Irene and Lee in 2011 produced intense precipitation and flooding in the U.S. Northeast, including the Hudson River watershed. Sediment input to the Hudson River was approximately 2.7 megaton, about 5 times the long-term annual average. Rather than the common assumption that sediment is predominantly trapped in the estuary, observations and model results indicate that approximately two thirds of the new sediment remained trapped in the tidal freshwater river more than 1 month after the storms and only about one fifth of the new sediment reached the saline estuary. High sediment concentrations were observed in the estuary, but the model results suggest that this was predominantly due to remobilization of bed sediment. Spatially localized deposits of new and remobilized sediment were consistent with longer term depositional records. The results indicate that tidal rivers can intercept (at least temporarily) delivery of terrigenous sediment to the marine environment during major flow events.

  4. The large late-glacial Ho eruption of the Hudson volcano, southern Chile

    NASA Astrophysics Data System (ADS)

    Weller, D.; Miranda, C. G.; Moreno, P. I.; Villa-Martínez, R.; Stern, C. R.

    2014-06-01

    Lakes formed in the Aysén region of southern Chile after the retreat of mountain glaciers, established by ~17,900 calendar years before present (cal years BP) or earlier, contain numerous late-glacial and Holocene tephra layers derived from >70 eruptions of the volcanoes in the region, including Hudson, the southernmost in the Andean Southern Volcanic Zone (SVZ). Sediment cores from seven of these lakes contain an unusually thick late-glacial age tephra layer, which based on its distribution and bulk trace-element composition was derived from a large explosive eruption of Hudson volcano between 17,300 and 17,440 cal years BP and is termed Ho. In 13 cores from six of these lakes, each located ~100 km generally northeast of Hudson, the Ho tephra layer ranges between 50 and 88 cm in thickness, and contains pumice grains up to 2 cm in maximum diameter. Comparison with three previously documented large explosive Holocene Hudson eruptions (H1 at 7,750 cal years BP, H2 at 3,920 cal years BP, and H3 in 1991 AD) suggests that Ho was larger, with an estimated tephra volume of >20 km3, the largest post-glacial eruption documented for any volcano in the southern Andes and most likely responsible for the formation of the Hudson caldera. In total, Hudson has erupted ≥45 km3 of pyroclastic material in the last ~17,500 years, making it the most productive volcano in the southern Andes in terms of the total volume erupted since the beginning of deglaciation in the region. Chemical stratification is not seen in the waterlain Ho tephra, but these deposits are bi-modal, consisting of a much greater proportion of dark glassy basaltic-trachyandesite dense fragments and pumice, with glasses which range between 55 and 59 wt.% SiO2, along with volumetrically less-significant lighter-colored trachydacite pumice, with glass of 66 wt.% SiO2. In contrast, H1 products are trachyandesitic in composition, H2 ones are more felsic than H1, being composed essentially of trachydacite, and although

  5. Report from Canada

    SciTech Connect

    Orchard, D.

    1990-06-01

    This report announces Canada's strategies for dealing with smog; a pilot project for reducing smog and ozone through gasoline vapor recovery; setting national targets for curbing carbon dioxide emissions; and the development of a comprehensive air quality policy in Saskatchewan.

  6. Spatial variation of sediment deposition in the Hudson River - a detailed inventory and potential causes (Invited)

    NASA Astrophysics Data System (ADS)

    Nitsche, F. O.; Kenna, T. C.

    2010-12-01

    Sediment deposition in urban estuaries is controlled by the interaction of human modifications and natural factors that include tides, fresh water inputs, bed morphology, sediment supply, and hydrodynamics. A key element of managing these estuaries is detailed understanding of sediment deposition and its driving processes. Using a combination of geophysical and geochemical analysis we establish a detailed inventory of 20 century deposition for most of the mud-dominated sections of the Hudson River. These data show variations between different segments of the Hudson River as well as strong local variations within each section, with depositional settings ranging from erosional to those accumulating at ~10 mm/year. Our work indicates that 170,000 - 250,000 metric tons of sediment are deposited annually in the areas studied, which is a significant portion of the estimated total annual sediment load of ~700,000 - 800,000 metric tons. This also suggests that some of the accumulated sediments are re-mobilized, e.g. during major storms. The observed patterns of deposition/erosion are primarily caused by natural conditions, but, in some parts, they are strongly influenced by human modifications of the estuary, such as dredging. In addition to improving our understanding of the sediment dynamic of the Hudson River, the observed distribution of sediment deposition is also an indicator for the occurrence of contaminants including heavy metals and PCB’s and thus a valuable tool for management decisions.

  7. Public support for ecosystem restoration in the Hudson River Valley, USA.

    PubMed

    Connelly, Nancy A; Knuth, Barbara A; Kay, David L

    2002-04-01

    We applied the Theory of Planned Behavior to help understand the relationships between environmental beliefs, support for ecosystem restoration actions, and willingness to pay (WTP) for restoration and protection goals in the Hudson River estuary, New York State, USA. We conducted a mail survey with 3,000 randomly-chosen local residents of the Hudson River estuary in the fall of 1999. As hypothesized, the broad ecosystem restoration goals of the Hudson River Estuary Action Plan were more strongly supported than the corresponding specific implementation actions. We found that beliefs and past behavior were better explanatory variables than sociodemographic characteristics for explaining people's support for ecosystem restoration actions and WTP for restoration and protection goals. Because ecosystem restoration goals appear to be more generally acceptable than specific restoration actions, proponents of restoration programs should not become complacent about the need for active public outreach and involvement even if initial restoration program discussions have been low in controversy. Efforts to assess and foster support for ecosystem restoration should be targeted toward audiences identified on the basis of beliefs and past behaviors rather than on sociodemographic characteristics.

  8. Canada: public health genomics.

    PubMed

    Little, J; Potter, B; Allanson, J; Caulfield, T; Carroll, J C; Wilson, B

    2009-01-01

    Canada has a diverse population of 32 million people and a universal, publicly funded health care system provided through provincial and territorial health insurance plans. Public health activities are resourced at provincial/territorial level with strategic coordination from national bodies. Canada has one of the longest-standing genetics professional specialty organizations and is one of the few countries offering master's level training designed specifically for genetic counselors. Prenatal screening is offered as part of routine clinical prenatal services with variable uptake. Surveillance of the effect of prenatal screening and diagnosis on the birth prevalence of congenital anomalies is limited by gaps and variations in surveillance systems. Newborn screening programs vary between provinces and territories in terms of organization and conditions screened for. The last decade has witnessed a four-fold increase in requests for genetic testing, especially for late onset diseases. Tests are performed in provincial laboratories or outside Canada. There is wide variation in participation in laboratory quality assurance schemes, and there are few regulatory frameworks in Canada that are directly relevant to genetics testing services or population genetics. Health technology assessment in Canada is conducted by a diverse range of organizations, several of which have produced reports related to genetics. Several large-scale population cohort studies are underway or planned, with initiatives to harmonize their conduct and the management of ethical issues, both within Canada and with similar projects in other countries.

  9. Polychlorinated biphenyls, dioxins, furans, and organochlorine pesticides in spotted sandpiper eggs from the upper Hudson River basin, New York

    USGS Publications Warehouse

    Custer, T.W.; Custer, Christine M.; Gray, B.R.

    2010-01-01

    In 2004, spotted sandpipers (Actitis macularia) were studied on the Hudson River near Fort Edward south to New Baltimore, NY and on two river drainages that flow into the Hudson River. Concentrations of 28 organochlorine pesticides, 160 polychlorinated biphenyl (PCB) congeners, and 17 dioxin and furan (PCDD-F) congeners were quantified in eggs collected on and off the Hudson River. The pattern of organochlorine pesticides and PCDD-F congeners did not differ significantly between eggs collected on and off the Hudson River. In contrast, the pattern of PCB congeners differed significantly between the Hudson River and other rivers. Total PCBs were significantly greater in eggs from the Hudson River (geometric mean = 9.1 ??g PCBs/g wet weight) than from the other two rivers (0.6 and 0.6 ??g PCBs/g wet weight). Seven of 35 (20%) eggs exceeded 20 ??g PCBs/g wet weight, the estimated threshold for reduced hatching in tree swallows (Tachycineta bicolor) and some raptor species; the maximum concentration was 72.3 ??g PCBs/g wet weight. Models that predicted nest survival and egg success (the proportion of eggs hatching in a clutch if at least one egg hatched) as functions of contaminant levels were poorly distinguished from models that presumed no such associations. While small sample size could have contributed to the inability to distinguish among contaminant and no toxicant models, we cannot rule out the possibility that contaminant concentrations on the Hudson River were not sufficiently high to demonstrate a relationship between contaminant concentrations and reproductive success. ?? 2009 Springer Science+Business Media, LLC.

  10. Chesapeake Bay study

    NASA Technical Reports Server (NTRS)

    Love, W. J.

    1972-01-01

    The objectives and scope of the Chesapeake Bay study are discussed. The physical, chemical, biological, political, and social phenomena of concern to the Chesapeake Bay area are included in the study. The construction of a model of the bay which will provide a means of accurately studying the interaction of the ecological factors is described. The application of the study by management organizations for development, enhancement, conservation, preservation, and restoration of the resources is examined.

  11. 75 FR 25794 - Regulated Navigation Area: Red Bull Air Race World Championship, Upper New York Bay, Lower Hudson...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-10

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA08 Regulated Navigation Area: Red Bull Air Race World... State Park, New Jersey and Ellis Island, New Jersey and New York for the Red Bull Air Race World Championship, an event scheduled to be held over water. This regulation is necessary to protect...

  12. Trichinellosis acquired in Nunavut, Canada in September 2009: meat from grizzly bear suspected.

    PubMed

    Houzé, S; Ancelle, T; Matra, R; Boceno, C; Carlier, Y; Gajadhar, A A; Dupouy-Camet, J

    2009-11-05

    Five cases of trichinellosis with onset of symptoms in September 2009, were reported in France, and were probably linked to the consumption of meat from a grizzly bear in Cambridge Bay in Nunavut, Canada. Travellers should be aware of the risks of eating raw or rare meat products in arctic regions, particularly game meat such as bear or walrus meat.

  13. Tampa Bay: Chapter N

    USGS Publications Warehouse

    Handley, Larry; Spear, Kathryn; Cross, Lindsay; Baumstark, René; Moyer, Ryan; Thatcher, Cindy

    2013-01-01

    Tampa Bay is Florida’s largest open-water estuary and encompasses an area of approximately 1036 km2 (400 mi2) (Burgan and Engle, 2006; TBNEP, 2006). The Bay’s watershed drains 5,698 km2 (2,200 mi2) of land and includes freshwater from the Hillsborough River to the north east, the Alafia and Little Manatee rivers to the east, and the Manatee River to the south (Figure 1). Freshwater inflow also enters the bay from the Lake Tarpon Canal, from small tidal tributaries, and from watershed runoff. Outflow travels from the upper bay segments (Hillsborough Bay and Old Tampa Bay) into Middle and Lower Tampa Bay. Southwestern portions of the water shed flow through Boca Ciega Bay into the Intracoastal Waterway and through the Southwest Channel and Passage Key Inlet into the Gulf of Mexico. The average depth in most of Tampa Bay is only 3.4 m (11 ft); however, 129 km (80 mi) of shipping channels with a maximum depth of 13.1 m (43 ft) have been dredged over time and are regularly maintained. These channels help to support the three ports within the bay, as well as commercial and recreational boat traffic.

  14. Peat landforms along the Albany River, northern Ontario. An ecological study of peat landforms in Canada and Alaska

    NASA Technical Reports Server (NTRS)

    Glaser, P. H.

    1985-01-01

    During the summer of 1985 a field investigation was started in the Hudson Bay lowland region of northern Ontario, which represents the largest expanse of peatland in North America and is an important sink in the global carbon cycle. A key area in the lowlands is situated along the Albany River near the confluence of the Chepay River. Here the striking vegetation-landforms are transitional between those found on the bed of Glacial Lake Agassiz in northern Minnesota and southern Manitoba and the more northern peatlands in the Hudson Bay lowland region. In peatland studies elsewhere the landform patterns have been used not only to classify different peatland types but also as an indicator of potential developmetnal trends. The study area is generally defined by that covered by the TM scene E-40062-15532 taken on Sept. 16, 1982. The purpose of the field work is to acquire sufficent information to interpret the TM imagery and test various hypotheses on peatland development on the gasis of the pattern transitions.

  15. CASCO BAY PLAN

    EPA Science Inventory

    Casco Bay lies at the heart of Maine's most populated area. The health of its waters, wetlands, and wildlife depend in large part on the activities of the quarter-million residents who live in its watershed. Less than 30 years ago, portions of Casco Bay were off-limits to recr...

  16. Bay Mills' Bold Approach

    ERIC Educational Resources Information Center

    Freedman, Eric

    2011-01-01

    It's a long, long way from Bay Mills Community College, near the shores of frigid Lake Superior, to Detroit. But distance, time and demographics aside, the school and the city are united by Bay Mills' status as the nation's only tribally controlled college that authorizes quasi-public schools, known officially as public school academies. And it's…

  17. Building Models with Bayes

    NASA Astrophysics Data System (ADS)

    Hart, Gus; Nelson, Lance J.; Reese, Shane

    2011-10-01

    The whole of modern Bayesian statistical methods is founded on the simple idea of Bayes rule, stated by the Reverend Thomas Bayes, and presented in 1763. Bayes rule is merely a simple statement of conditional probablility but can be used to make strong inferences. However, the application of Bayes rule to all but the simplest problems requires significant computation. As a result, Baysian-based approaches have been largely impractical until high-speed computing became inexpensive in the recent in the last 20 years or so. We discuss the general idea behind Bayes rule, how to use it to build physical models, and illustrate the approach for a simple case of lattice gas models.

  18. Real-time Monitoring Network to Characterize Anthropogenic and Natural Events Affecting the Hudson River, NY

    NASA Astrophysics Data System (ADS)

    Islam, M. S.; Bonner, J. S.; Fuller, C.; Kirkey, W.; Ojo, T.

    2011-12-01

    The Hudson River watershed spans 34,700 km2 predominantly in New York State, including agricultural, wilderness, and urban areas. The Hudson River supports many activities including shipping, supplies water for municipal, commercial, and agricultural uses, and is an important recreational resource. As the population increases within this watershed, so does the anthropogenic impact on this natural system. To address the impacts of anthropogenic and natural activities on this ecosystem, the River and Estuary Observatory Network (REON) is being developed through a joint venture between the Beacon Institute, Clarkson University, General Electric Inc. and IBM Inc. to monitor New York's Hudson and Mohawk Rivers in real-time. REON uses four sensor platform types with multiple nodes within the network to capture environmentally relevant episodic events. Sensor platform types include: 1) fixed robotic vertical profiler (FRVP); 2) mobile robotic undulating platform (MRUP); 3) fixed acoustic Doppler current profiler (FADCP) and 4) Autonomous Underwater Vehicle (AUV). The FRVP periodically generates a vertical profile with respect to water temperature, salinity, dissolved oxygen, particle concentration and size distribution, and fluorescence. The MRUP utilizes an undulating tow-body tethered behind a research vessel to measure the same set of water parameters as the FRVP, but does so 'synchronically' over a highly-resolved spatial regime. The fixed ADCP provides continuous water current profiles. The AUV maps four-dimensional (time, latitude, longitude, depth) variation of water quality, water currents and bathymetry along a pre-determined transect route. REON data can be used to identify episodic events, both anthropogenic and natural, that impact the Hudson River. For example, a strong heat signature associated with cooling water discharge from the Indian Point nuclear power plant was detected with the MRUP. The FRVP monitoring platform at Beacon, NY, located in the

  19. Estuarine research; an annotated bibliography of selected literature, with emphasis on the Hudson River estuary, New York and New Jersey

    USGS Publications Warehouse

    Embree, William N.; Wiltshire, Denise A.

    1978-01-01

    Abstracts of 177 selected publications on water movement in estuaries, particularly the Hudson River estuary, are compiled for reference in Hudson River studies. Subjects represented are the hydraulic, chemical, and physical characteristics of estuarine waters, estuarine modeling techniques, and methods of water-data collection and analysis. Summaries are presented in five categories: Hudson River estuary studies; hydrodynamic-model studies; water-quality-model studies; reports on data-collection equipment and methods; and bibliographies, literature reviews, conference proceedings, and textbooks. An author index is included. Omitted are most works published before 1965, environmental-impact statements, theses and dissertations, policy or planning reports, regional or economic reports, ocean studies, studies based on physical models, and foreign studies. (Woodard-USGS)

  20. Early proterozoic evolution of the saskatchewan craton and its allochthonous coyer, trans-hudson Orogen

    USGS Publications Warehouse

    Chiarenzelli, J.; Aspler, L.; Villeneuve, M.; Lewry, J.

    1998-01-01

    The composition, chronology, and structural relations of the Saskatchewan Craton and enveloping mylonitic rocks exposed in basement windows of the Glennie Domain, Trans-Hudson Orogen, have been determined by geochemical, geochronologic, and structural studies accompanying detailed field mapping. Basement windows lie along the hinge zone of a regional crustal culmination and consist mostly of 2.4-2.5 Ga felsic plutonic rocks enveloped by the Nistowiak Thrust. The Nistowiak Thrust is a folded, 1-2 km thick, upper amphibolite facie??s mylonite zone formed during emplacement of the Flin Flon-Glennie Complex across the Saskatchewan Craton. It is likely correlative to the Pelican Thrust, which envelops basement windows in the Hanson Lake Block -100 km to the east. An internal high strain zone within the overlying nappe pile, the Guncoat Thrust, is composed primarily of mylonitized porphyroclastic pelitic and psammitic migmatites. U-Pb geochronological results suggest calc-alkaline plutonism from 1889-1837 Ma, thrust stacking, peak metamorphism and associated anatexis between 1837 and 1809 Ma, isotopic closure of titanite at 1790-1772 Ma, and intrusion of late granitic rocks at 1770-1762 Ma. This is in agreement with ages from the Hanson Lake Block, and La Ronge, Kisseynew, and Flin-Flon domains in Saskatchewan and Manitoba, and from the Ungava-Baffin portion of Trans-Hudson Orogen, suggesting broadly synchronous thermotectonic processes along a strike length of 2000 km. We speculate that the Saskatchewan Craton, rather than representing an exotic continental fragment, rifted from the Superior and/or Hearne Provinces at ca. 2.1 Ga and that the Trans-Hudson Orogen is an internal orogen. In this scenario the Maniwekan Ocean, developed between the Rae-Hearne and Superior cratons, opened and closed about similar pole(s) of plate motion. ?? 1998 by The University of Chicago. All rights reserved.

  1. PCB accumulation in Hudson River pumpkinseed sunfish and bullhead: Influences of invertebrate prey

    SciTech Connect

    Feldman, R.S.

    1992-01-01

    Hudson River sediments are contaminated with PCBs, and these toxic compounds are also in the water and have accumulated in food chains. The relative importance of exposure by fish to contaminated water vs. contaminated prey was unknown. further, is was not known if difference in diet could influence fish PCB levels. Invertebrates and fish were sampled in different habitats to address these issues. Invertebrate communities differed in several ecological measures between two different plant beds, and among experimentally manipulated habitats in one plant bed. Communities often differed significantly in parameters such as total invertebrate density, densities of individual taxa, taxonomic richness and similarity, and size distributions; some taxa were also absent from one habitat but present in another. Total PCBs differed significantly for invertebrate communities between the two plant beds (9.4 vs. 31.4 [mu]g/g), and between some of the communities in the manipulated habitats (1.8 vs 5.3 [mu]g/g). These differences did not translate into difference in PCBs among fish that fed in the different habitats. However, bullhead had significantly higher levels than pumpkinseed (15.4 vs. 6.9 [mu]g/g). Yearling pumpkinseed that fed on Hudson River invertebrates had 5x the PCB levels of pumpkinseed exposed for the same period to the water but not to the prey, and 18x as much PCBs as fish unexposed to either Hudson River water or prey. Further, fish that fed on local prey had a higher proportion of high-Cl isomers than those exposed only to the contaminated water. Fish that fed in different habitats did not have different PCB levels. Thus, the role of diet needs further experimentation, but it is clear that local prey are the major route for PCB accumulation in yearling pumpkinseed.

  2. Suspended sediment transport in the freshwater reach of the Hudson river estuary in eastern New York

    USGS Publications Warehouse

    Wall, G.R.; Nystrom, E.A.; Litten, S.

    2008-01-01

    Deposition of Hudson River sediment into New York Harbor interferes with navigation lanes and requires continuous dredging. Sediment dynamics at the Hudson estuary turbidity maximum (ETM) have received considerable study, but delivery of sediment to the ETM through the freshwater reach of the estuary has received relatively little attention and few direct measurements. An acoustic Doppler current profiler was positioned at the approximate limit of continuous freshwater to develop a 4-year time series of water velocity, discharge, suspended sediment concentration, and suspended sediment discharge. This data set was compared with suspended sediment discharge data collected during the same period at two sites just above the Hudson head-of-tide (the Federal Dam at Troy) that together represent the single largest source of sediment entering the estuary. The mean annual suspended sediment-discharge from the freshwater reach of the estuary was 737,000 metric tons. Unexpectedly, the total suspended sediment discharge at the study site in November and December slightly exceeded that observed during March and April, the months during which rain and snowmelt typically result in the largest sediment discharge to the estuary. Suspended sediment discharge at the study site exceeded that from the Federal Dam, even though the intervening reach appears to store significant amounts of sediment, suggesting that 30-40% of sediment discharge observed at the study site is derived from tributaries to the estuary between the Federal Dam and study site. A simple model of sediment entering and passing through the freshwater reach on a timescale of weeks appears reasonable during normal hydrologic conditions in adjoining watersheds; however, this simple model may dramatically overestimate sediment delivery during extreme tributary high flows, especially those at the end of, or after, the "flushing season" (October through April). Previous estimates of annual or seasonal sediment delivery

  3. Mercury Accumulation and Biomagnification in Ospreys (Pandion haliaetus) in the James Bay and Hudson Bay Regions of Québec

    PubMed

    DesGranges; Rodrigue; Tardif; Laperle

    1998-08-01

    Mercury exposure was examined in adults and nestlings of ospreys (Pandion haliaetus) from lakes, rivers, and hydroelectric reservoirs in northern Québec between 1989 and 1991 by assessing the amount of mercury transferred from fish to ospreys, which are voracious fish-eaters. The high mercury concentrations detected in adult feathers and tissues (feathers, blood, liver, kidneys, muscles, brain) of nestlings indicate an increase in mercury availability at recently constructed hydroelectric reservoirs (10-12 years for the La Grande-2 Reservoir). With mean total mercury levels of 37.3 mg/kg and 1.9 mg/kg in feathers (dry weight) and in blood (wet weight), respectively, contamination rates were, in both tissues, five times higher for chicks born near the La Grande Reservoirs (western sector) than in those reared in natural habitats. Furthermore, the mean quantity of total mercury in 40-day-old chicks reared near a reservoir was 10.5 mg, compared with to 1.6 mg for those reared in a natural environment. Modeling of mercury transfer from fish to osprey nestlings showed that the mercury level in chicks' blood provides a good estimate of mercury concentrations in ingested food. In addition, the relationship between mercury concentrations in the blood and that in feathers indicates that substantial biomagnification of mercury occurs from the ingested dose to the feathers. The intensity of this biomagnification varies with the age of the chicks and reaches a maximum value as the flight feathers start to form (at 20-25 days of age) declining thereafter until the bird is 45 days old and growth of those feathers is complete. Nevertheless, the mean number of young fledged on reservoirs where mercury exposure is greatest (>40 mg/kg of Hg in chicks' feathers) did not differ (1.6 +/- 0.7) from that observed elsewhere in built-up environments (1.9 +/- 0.7) or in natural habitats (2.0 +/- 0.7) (H = 4.39; p = 0.11). Storage of mercury in growing feathers (86% of all mercury in osprey) prevents accumulation in living tissues, thereby protecting the chick from related toxic effects. However, toxicological problems may arise after fledging. In particular, attention should be paid to postfledging survival before concluding that mercury exposure is insufficiently high in Osprey young reared at reservoirs.

  4. Update on Canada.

    ERIC Educational Resources Information Center

    Hochstadt, John Webster

    1994-01-01

    Gift planning is increasing in Canada's colleges and universities to offset effects of retrenchment. New annuity vehicles and the emergence of university Crown Foundations offer tax breaks that support private giving to institutions. In addition, a simplified process for gifts is anticipated. (MSE)

  5. Community Radio in Canada.

    ERIC Educational Resources Information Center

    Canadian Broadcasting Corp., Ottawa (Ontario).

    Results are presented of a survey of 20 community radio organizations operating in Canada. For each of the 20 agencies, information is provided relating to: (1) the name and address of the organization; (2) the name and population of the community served; (3) the station's call letters, frequency, and power; (4) the date of the station's license;…

  6. Teaching Canada: A Bibliography.

    ERIC Educational Resources Information Center

    Maine Univ., Orono. New England - Atlantic Provinces - Quebec Center.

    This resource bibliography with over 500 descriptive annotations on Canada, a product of a conference on Canadian Studies held at the University of Maine, Orono, in September, 1969, is designed to make teachers of social studies and other fields at both the elementary and secondary levels more aware of the variety of available teaching materials…

  7. Canada's Indians. Revised Edition.

    ERIC Educational Resources Information Center

    Wilson, James

    Over a half million people in Canada today are identifiably of Native ancestry, legally categorized as Inuit (Eskimos), status Indians, or nonstatus Indians. Status Indians comprise 573 bands with total membership of about 300,000 people, most of whom live on 2,242 reserves. They are the direct responsibility of the federal government and have…

  8. In Canada: Friendly Fire

    ERIC Educational Resources Information Center

    Robertson, Heather-jane

    2004-01-01

    One of Canada's more frequently quoted political malapropisms is attributed to Robert Thompson, who sternly reminded his fellow parliamentarians in 1973 that "the Americans are our best friends, whether we like it or not." This cross-border friendship is partly expedient, partly geographic, partly genuine, sometimes one-sided, and almost…

  9. Canada in Space.

    ERIC Educational Resources Information Center

    de Paz, Shoshana

    1991-01-01

    Discusses the history of the Canadian Space Agency. Explains that Canada's space program grew out of the need to manage resources and communicate over large distances. Reports that the small Canadian space industry is growing rapidly. Describes Canadian cooperation in international space programs. Identifies space careers and examines the future…

  10. Child Care in Canada

    ERIC Educational Resources Information Center

    Graham, Kathy

    2005-01-01

    In this article, the author describes early learning and care arrangements in Canada and how the country faced the challenges in the development of a National Child Care System. While the provincial/territorial governments are responsible for early learning and care, the federal government has formed health and social programs including some child…

  11. Profiling Canada's Families II.

    ERIC Educational Resources Information Center

    Vanier Inst. of the Family, Ottawa (Ontario).

    Noting that Canadians have witnessed profound demographic, economic, social, cultural, and technological changes over the last century and the need for sound demographic information for future planning, this report is the second to identify significant trends affecting Canada's families. Following an introductory section providing relevant…

  12. Determination of acoustic attenuation in the Hudson River Estuary by means of ship noise observations.

    PubMed

    Roh, Heui-Seol; Sutin, Alexander; Bunin, Barry

    2008-06-01

    Analysis of sound propagation in a complex urban estuary has application to underwater threat detection systems, underwater communication, and acoustic tomography. One of the most important acoustic parameters, sound attenuation, was analyzed in the Hudson River near Manhattan using measurements of acoustic noise generated by passing ships and recorded by a fixed hydrophone. Analysis of the ship noise level for varying distances allowed estimation of the sound attenuation in the frequency band of 10-80 kHz. The effective attenuation coefficient representing the attenuation loss above cylindrical spreading loss had only slight frequency dependence and can be estimated by the frequency independent value of 0.058 dBm.

  13. Geo-referenced social accounting with application to integrated watershed planning in the Hudson River Valley

    NASA Astrophysics Data System (ADS)

    Nowosielski, Audra Ann

    Changing economic activity and patterns of human habitation have long been a cause of concern for the ecological health of the Hudson River and its tributaries. Today, economic development in the Hudson River Valley is often characterized as a battle between proponents of economy-wide growth and citizen groups concerned about the cumulative impact of incremental development on the watershed. Current development trends in the Hudson River Valley are driving the conversion of rural, agricultural and forestland to urban or industrial uses. This thesis is part of a larger study of the economic changes that lead to land use and environmental changes. It focuses specifically on the economic drivers of development in Dutchess County, an area of the lower watershed on the east bank of the Hudson, midway between New York City and the state capital of Albany. The objective was to engage the Dutchess County planning community in developing a planning model, the economic portion of which characterizes the economy with a Social Accounting Matrix (SAM) referenced to a Geographical Information System (GIS). The model was used to assess economic impacts of locally relevant development scenarios including a new IBM semiconductor plant, agro-tourism, and commuting behavior. These scenarios each discuss economic changes that have land use consequences. For example, a new IBM plant will likely instigate new residential development, agro-tourism offers a way to keep land in agricultural use, and the study of commuting behavior leads to insights on how residential growth may depend on commuting patterns, as well as information on the effects of second home communities. The final model will help stakeholders to visualize not only how economic shocks will change their communities, but also how these changes may lead to land use and cumulative environmental impact. Stakeholders will be able to visualize the trade-off between new economic growth and the possible loss of environmental

  14. IYPE in Canada

    NASA Astrophysics Data System (ADS)

    Boyd, J.; Nowlan, G.

    2009-12-01

    The Canadian National Committee picked five of the ten IYPE themes for emphasis in Canada - Water, Hazards, Energy, Resources and Environment. They are summarized in the acronym WHERE - WHERE on Earth, WHERE in Canada. Our committee raised funds from industry, with some generous support from The Geological Survey of Canada. Funds were used for publishing “Four Billion Years and Counting”, a book on Canadian geology designed for the general public. It will be useful to educators who can download many of the illustrations and images for classroom support. Recognizing the looming shortage of Geoscientists, we designed a new careers website to help attract young people to the Earth sciences. It can be seen on our website, www.EarthsciencesCanada.com. The website will be updated regularly. The WHERE Challenge was a national contest for children aged 10 to 14. They were asked to select an object, often something from their household, identify at least one non-renewable resource used to make the object, and submit an entry describing the object, the resources within it, and WHERE they came from. We received entries from more than 1000 students Some of the winning entries are posted on our website. We developed a partnership with Parks Canada called Egoists, which is a series of pamphlets on iconic views within the parks explaining the Earth science behind the views. We also supported the celebration of the 100th anniversary of the discovery of the Burgess Shale by providing funding for the publication of a field guide. At the end of the year all programs will transfer to the Canadian Federation of Earth Sciences. The WHERE Challenge will be repeated in 2010. It, plus our book and careers website will continue our outreach activities.

  15. Influenza in Canada geese.

    PubMed

    Winkler, W G; Trainer, D O; Easterday, B C

    1972-01-01

    The role of wild avian species in the natural history of influenza is unknown. A serological study was carried out to ascertain the prevalence, distribution, and types of influenza antibody in several wild Canada goose populations. Geese were trapped and blood samples were obtained in each of 4 consecutive years, 1966-69. Antibody to influenzavirus was found in 66 (4.7%) of the 1 401 Canada geese tested by the haemagglutination inhibition (HI) test. Antiribonucleoprotein antibody was found in 8 of 1 359 sera tested by the agar gel precipitation (AGP) test. An increase in the percentage of reactors was seen each year. This increase was greater in two refuges with nonmigratory flocks. HI antibody was found against the turkey/Wisconsin/66, turkey/Wisconsin/68, turkey/Canada/63, and turkey/Alberta/6962/66, or closely related viruses. No antibody was found against duck/Ukraine/1/63 or human A/Hong Kong/68 virus at a time when the latter was prevalent in human populations, suggesting that Canada geese played no direct role in spreading the virus.Canada geese were experimentally exposed to turkey/Wisconsin/66 and turkey/Wisconsin/68 viruses; mallard ducks were exposed to turkey/Wisconsin/66 virus. HI antibody developed in 75% of the geese and 40% of the ducks but was generally short-lived. Anti-RNP antibody was detected in 15% of the exposed geese but in none of the ducks. Virus was recovered from 3 of 10 adult ducks but not from geese. None of the birds showed signs of disease.

  16. Holocene vegetation histories from three sites in the Tundra of Northwestern Quebec, Canada

    SciTech Connect

    Gajewski, K. ); Garralla, S.

    1992-11-01

    Two pollen diagrams from lakes north of treeline in northwestern Quebec indicate that Picea never extended north of its present-day limit during the past 6000 yr BP. Alnus crispa was slightly more abundant around 5000 BP, but there are few major changes in the vegetation of the region during the Holocene. A third site in the tundra along Hudson Bay has a slightly longer sequence (7000 yr BP) which indicates more open conditions in the early and recent part of the record. Picea may have been more abundant locally around 3000 BP. Few major changes in these diagrams can be unequivocally attributed to local changes in plant abundance; changes in tree and shrub pollen abundance parallel those seen south of treeline.

  17. 77 FR 16974 - Special Local Regulations; Ocean State Tall Ships Festival 2012, Narragansett Bay, RI

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-23

    ... organized by Tall Ships America in conjunction with host ports in the United States and Canada. The Ocean... SECURITY Coast Guard 33 CFR Parts 100 RIN 1625-AA08 Special Local Regulations; Ocean State Tall Ships... of Narragansett Bay and Newport Harbor, Rhode Island, for the Ocean State Tall Ships Festival...

  18. John Rae (1813-93): explorer of the Canadian Arctic, the great pedestrian.

    PubMed

    Loosmore, Brian

    2009-11-01

    Born and raised in the Orkney Islands, Dr John Rae joined the Hudson's Bay Company and rose to be Chief Factor. Unusually tough and intelligent, he explored much of northern Canada, mapping the north eastern shore and finding controversial evidence of the lost Franklin expedition of 1845. A talented botanist, geologist, anthropologist and cartographer, he was northern Canada's most distinguished explorer.

  19. Water Column Methanotrophy Fueled by Methane from the Hudson Canyon Seep Field, US Atlantic Margin

    NASA Astrophysics Data System (ADS)

    Redmond, M. C.; Chan, E. W.; Kellermann, M. Y.; Arrington, E.; Valentine, D. L.; Kessler, J. D.

    2014-12-01

    Several areas of methane seepage have recently been discovered along the US Atlantic margin, including parts of Hudson Canyon, offshore New York and New Jersey. However, little is known about the magnitude of seepage, the fate of this methane once it enters the water column, or the bacteria that may consume it. In July 2014, water column methane concentrations were measured throughout Hudson Canyon and methane oxidation tracked using a 13C-methane tracer. Samples for microbial community composition analysis were collected throughout the water column in areas with and without active seepage. 16S rRNA gene sequencing will be used to compare microbial communities from different depths, locations, and in samples with low and high methane concentrations and oxidation rates. DNA stable isotope probing experiments with 13C-labeled methane were also conducted and will be used to detect active water column methanotrophs from seep and non-seep sites. In addition, mesocosm experiments were used for high resolution measurements of methane oxidation, with samples for microbial community composition taken at several time points. 16S rRNA gene sequencing will be used to track changes in methanotrophic bacteria and the overall microbial community as methane was consumed.

  20. Surface Sediment Geochemistry in and around the Hudson Shelf Valley Offshore of New York

    NASA Astrophysics Data System (ADS)

    Mecray, E. L.; ten Brink, M. B.; Butman, B.; Denny, J.; Murray, R. W.

    2001-05-01

    The Hudson Shelf Valley, an ancient submerged portion of the Hudson River, extends across the continental shelf offshore of New York and New Jersey. Between 1959 and 1987, the area near the head of the valley was used for disposal of approximately 1.20 x 108 m3 of dredged material and sewage sludge. The distribution of metal concentrations and sediment characteristics were used to investigate the transport and fate of the sediments and their associated contaminants. Surface (0-2cm) sediments collected at 440 stations throughout the New York Bight between 1993 and 1998 were used to establish the regional distribution of pollutant metals, grain size, organic carbon, and Clostridium perfringens spores. Sediments in the New York Bight are generally sandy, however fine-grained sediments are found in the axis of the Valley. Statistical methods identified common sources and chemical mobility within groups of anthropogenic and naturally-occurring elements. High metal concentrations, fine-grained sediments, and higher organic carbon concentrations co-occur in depo-centers within the Valley. Normalization of the metal concentrations to these factors shows higher metal concentrations on the fine-grained particles in sandy areas of the Bight, particularly along the southern shore of Long Island. These distributions have implications for evaluating the impact of the mass distribution for contaminated metals in different habitats and areas. Decreasing concentrations of pollutants with time are observed, reflecting reduced contaminant loading in the upper region of the Valley; however, concentrations are still above natural background levels.

  1. Determining the flux of methane into Hudson Canyon at the edge of methane clathrate hydrate stability

    USGS Publications Warehouse

    Weinsten, A.; Navarrete, L; Ruppel, Carolyn D.; Weber, T.C.; Leonte, M.; Kellermann, M.; Arrington, E.; Valentine, D.L.; Scranton, M.L; Kessler, John D.

    2016-01-01

    Methane seeps were investigated in Hudson Canyon, the largest shelf-break canyon on the northern US Atlantic Margin. The seeps investigated are located at or updip of the nominal limit of methane clathrate hydrate stability. The acoustic identification of bubble streams was used to guide water column sampling in a 32 km2 region within the canyon's thalweg. By incorporating measurements of dissolved methane concentration with methane oxidation rates and current velocity into a steady-state box model, the total emission of methane to the water column in this region was estimated to be 12 kmol methane per day (range: 6 – 24 kmol methane per day). These analyses suggest this methane is largely retained inside the canyon walls below 300 m water depth, and that it is aerobically oxidized to near completion within the larger extent of Hudson Canyon. Based on estimated methane emissions and measured oxidation rates, the oxidation of this methane to dissolved CO2 is expected to have minimal influences on seawater pH. This article is protected by copyright. All rights reserved.

  2. Hudson River Paleoclimate, Sea Level, and Human Impact: A Record From Piermont Marsh, NY

    NASA Technical Reports Server (NTRS)

    Kurdyla; Peteet, Dorothy; Liberman, Louisa; Sugar; Wong; Hansen, James E. (Technical Monitor)

    2001-01-01

    A 13.77 meter sediment core from Piermont Marsh, NY (40 00 N, 73 55W) records the local and regional vegetational and foraminiferal history of the Hudson Estuary. The sediments were sampled every 4 cm, which represents a decadal to centuryscale resolution. Basal sediment dating is in progress, and the 11-m depth represents about 4000 years. Changes in plant macrofossils and charcoal appear to indicate differences in salinIty and drought, suggesting changes in climate. Scirpus, Salicornia, and high levels of charcoal seem to indicate drier/more saline conditions, while lack of these macrofossils and increases in Chara/Nitella, aquatic leaves, and very little charcoal suggests wetter conditions. Other macrofossils include Carex, Juncus, Polygonum, Zanichellia, Ruppia. High resolution AMS dating of plant macrofossils is in progress, and will be compared with changes in Hudson River sediment cores offshore. Foraminiferal assemblages from key intervals of the core will be presented. Human impact in the upper sediments is visible from the influx of grass seeds, primarily Phragmites, and the ragweed pollen rise.

  3. Anthropogenic impacts on American eel demographics in Hudson River tributaries, New York

    USGS Publications Warehouse

    Machut, L.S.; Limburg, K.E.; Schmidt, R.E.; Dittman, D.

    2007-01-01

    Populations of American eel Anguilla rostrata along the eastern coast of North America have declined drastically for largely unknown reasons. We examined the population dynamics of American eels in six tributaries of the Hudson River, New York, to quantify their distribution and the impacts of anthropogenic stressors. With up to 155 American eels per 100 m2, tributary densities are greater than those within the main stem of the Hudson River and are among the highest reported anywhere. The predominance of small American eels (<200 mm) and wide range of ages (from young-of-year glass eels to 24-year-old yellow eels) suggest that tributaries are an important nursery area for immature American eels. However, upstream of natural and artificial barriers, American eel densities were reduced by at least a factor of 10 and condition, as measured by mass, was significantly lower. Significantly lower American eel condition was also found with increasing riparian urbanization. Density-dependent growth limitations below barriers are suggested by increased growth rates above the first tributary barrier. We suggest that (1) tributaries are important habitat for the conservation of American eels and (2) mitigation of anthropogenic stressors is vital for complete utilization of available habitat and conservation of the species. ?? Copyright by the American Fisheries Society 2007.

  4. Polychlorinated biphenyls, mercury, and potential endocrine disruption in fish from the Hudson River, New York, USA

    USGS Publications Warehouse

    Baldigo, Barry P.; Sloan, R.J.; Smith, S.B.; Denslow, N.D.; Blazer, V.S.; Gross, T.S.

    2006-01-01

    Tissue residues of total mercury (Hg), total polychlorinated biphenyls (PCBs), and lipid-based PCBs; plasma concentrations of endocrine biomarkers; and reproductive and histologic biomarkers were assessed in 460 carp (Cyprinus carpio), bass (Micropterus salmoides and Micropterus dolomieui), and bullhead (Ameiurus nebulosus) collected from eight sites across the Hudson River Basin in the spring of 1998 to determine if endocrine disruption was evident in resident fish species and to evaluate contaminant-biomarker interrelations. Total PCBs in bed sediments (maximum 2,500 ??g kg-1) could explain 64 to 90% of the variability in lipid-based PCB residues in tissues (maximum 1,250 ??g PCB g-lipid-1) of the four species. The 17??-estradiol to 11-ketotestosterone ratio, typically less than 1.0 in male fish and greater than 1.0 in females, exceeded 1.4 in all male largemouth bass and 35% of male carp and bullhead at one site 21 km downstream from a major PCB source. Endocrine biomarkers were significantly correlated with total Hg in female smallmouth bass and carp, and with lipid-based PCBs in males of all four species. Empirical evidence of endocrine modulation in blood plasma of male and female fish from sites with and without high PCB residues in bed sediments and fish tissues suggest that PCBs, Hg, or other contaminants may disrupt normal endocrine function in fish of the Hudson River. ?? Eawag, 2006.

  5. Low PCB concentrations observed in American eel (Anguilla rostrata) in six Hudson River tributaries

    USGS Publications Warehouse

    Limburg, K.E.; Machut, L.S.; Jeffers, P.; Schmidt, R.E.

    2008-01-01

    We analyzed 73 eels, collected in 2004 and 2005 above the head of tide in six Hudson River tributaries, for total PCBs, length, weight, age, and nitrogen stable isotope ratios (??15N). Mean total PCB concentration (wet weight basis) was 0.23 ppm ?? 0.08 (standard error), with a range of 0.008 to 5.4 ppm. A majority of eels (84) had concentrations below 0.25 ppm, and only seven eels (10%) had concentrations exceeding 0.5 ppm. Those eels with higher PCB concentrations were ???12 yr; there was a weak correlation of PCB concentration with ??15N and also with weight. Compared to recent (2003) data from the mainstem of the Hudson River estuary, these results indicate that tributaries are generally much less contaminated with PCBs. We hypothesize that those tributary eels with high PCB concentrations were relatively recent immigrants from the mainstem. Given concern over the possible adverse effects of PCBs on eel reproduction, these tributaries may serve as refugia. Therefore, providing improved access to upland tributaries may be critically important to this species. ?? 2008 Northeastern Naturalist.

  6. Determining the flux of methane into Hudson Canyon at the edge of methane clathrate hydrate stability

    NASA Astrophysics Data System (ADS)

    Weinstein, Alexander; Navarrete, Luis; Ruppel, Carolyn; Weber, Thomas C.; Leonte, Mihai; Kellermann, Matthias Y.; Arrington, Eleanor C.; Valentine, David L.; Scranton, Mary I.; Kessler, John D.

    2016-10-01

    Methane seeps were investigated in Hudson Canyon, the largest shelf-break canyon on the northern U.S. Atlantic Margin. The seeps investigated are located at or updip of the nominal limit of methane clathrate hydrate stability. The acoustic identification of bubble streams was used to guide water column sampling in a 32 km2 region within the canyon's thalweg. By incorporating measurements of dissolved methane concentration with methane oxidation rates and current velocity into a steady state box model, the total emission of methane to the water column in this region was estimated to be 12 kmol methane per day (range: 6-24 kmol methane per day). These analyses suggest that the emitted methane is largely retained inside the canyon walls below 300 m water depth, and that it is aerobically oxidized to near completion within the larger extent of Hudson Canyon. Based on estimated methane emissions and measured oxidation rates, the oxidation of this methane to dissolved CO2 is expected to have minimal influences on seawater pH.

  7. Groundwater quality in the Upper Hudson River Basin, New York, 2012

    USGS Publications Warehouse

    Scott, Tia-Marie; Nystrom, Elizabeth A.

    2014-01-01

    Water samples were collected from 20 production and domestic wells in the Upper Hudson River Basin (north of the Federal Dam at Troy, New York) in New York in August 2012 to characterize groundwater quality in the basin. The samples were collected and processed using standard U.S. Geological Survey procedures and were analyzed for 148 physiochemical properties and constituents, including dissolved gases, major ions, nutrients, trace elements, pesticides, volatile organic compounds (VOCs), radionuclides, and indicator bacteria. The Upper Hudson River Basin covers 4,600 square miles in upstate New York, Vermont, and Massachusetts; the study area encompasses the 4,000 square miles that lie within New York. The basin is underlain by crystalline and sedimentary bedrock, including gneiss, shale, and slate; some sandstone and carbonate rocks are present locally. The bedrock in some areas is overlain by surficial deposits of saturated sand and gravel. Eleven of the wells sampled in the Upper Hudson River Basin are completed in sand and gravel deposits, and nine are completed in bedrock. Groundwater in the Upper Hudson River Basin was typically neutral or slightly basic; the water typically was moderately hard. Bicarbonate, chloride, calcium, and sodium were the major ions with the greatest median concentrations; the dominant nutrient was nitrate. Methane was detected in 7 samples. Strontium, iron, barium, boron, and manganese were the trace elements with the highest median concentrations. Two pesticides, an herbicide degradate and an insecticide degredate, were detected in two samples at trace levels; seven VOCs, including chloroform, four solvents, and the gasoline additive methyl tert-butyl ether (MTBE) were detected in four samples. The greatest radon-222 activity, 2,900 picocuries per liter, was measured in a sample from a bedrock well; the median radon activity was higher in samples from bedrock wells than in samples from sand and gravel wells. Coliform bacteria were

  8. Research Spotlight: Narwhals document continued warming of Baffin Bay

    NASA Astrophysics Data System (ADS)

    Kumar, Mohi

    2011-03-01

    Baffin Bay, situated between northern Greenland and Canada, is a major gateway between waters from the North Atlantic and Arctic oceans. Dynamics within the bay help govern how much water from the Arctic flows south and sinks to form North Atlantic Deep Water, a deep current that drives ocean circulation on a global scale. Unfortunately, monitoring the deep reaches of Baffin Bay throughout the year is difficult—most oceanographic data are collected in the summer when the area is ice free. To overcome this inability to collect data in harsh winter conditions, Laidre et al. hit upon a novel solution: mounting instruments on narwhals to collect temperature and depth data. Narwhals, a top predator in this frigid ecosystem, make annual migrations from summering grounds in the Canadian High Arctic and western Greenland to wintering grounds in the dense offshore pack ice of Baffin Bay. Moreover, narwhals, which rank among the deepest-diving whales in the world, dive extensively and repeatedly to depths exceeding 1800 meters under pack ice to reach their major food source, the flatfish that swarm on the seafloor of Baffin Bay. Narwhal dives are nearly vertical, making this whale an ideal platform on which to mount surveying instruments. (Journal of Geophysical Research-Oceans, doi:10.1029/2009JC005820, 2010)

  9. Organochlorines and mercury in waterfowl harvested in Canada.

    PubMed

    Braune, Birgit M; Malone, Brian J

    2006-03-01

    Samples of breast muscle from 32 species of waterfowl collected from 123 sites across Canada were analyzed for chlorobenzenes (CBz), chlordane-related compounds (CHL), hexachlorocyclohexanes (HCH), DDT, mirex, dieldrin, PCBs and mercury. SigmaDDT, SigmaCBz and SigmaPCB were the compounds most frequently found above trace levels. SigmaHCH and SigmaMirex were detected the least often. Mercury was detected in all of the mergansers, over 50% of dabbling, bay and sea ducks, and in less than 2% of the geese analysed. The highest levels of contaminants were generally found in birds feeding at higher trophic levels such as sea ducks and mergansers. With the exception of a few samples of mergansers and long-tailed ducks from eastern Canada, which contained SigmaPCB concentrations of 1.0-2.4 mg kg(-1), SigmaPCB levels were less than 1 mg kg(-1) wet weight. Only one merganser from eastern Canada had a SigmaDDT concentration (2.6 mg kg(-1) ww) which was greater than 1 mg kg(-1) ww. The highest SigmaCHL (0.10 mg kg(-1) ww) was also found in mergansers from eastern Canada. Levels of total mercury in breast muscle were either low (< 1 mg kg(-1) ww) or below detection limits with the exception of a few samples of mergansers from eastern Canada which contained mercury concentrations of 1.0-1.5 mg kg(-1) ww. Health Canada determined that the organochlorine and mercury levels found in samples of breast muscle of ducks and geese analysed in this study did not pose a health hazard to human consumers and therefore these waterfowl were safe to eat.

  10. 78 FR 59231 - Regulated Navigation Area-Tappan Zee Bridge Construction Project, Hudson River; South Nyack and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-26

    ... area (RNA) on the navigable waters of the Hudson River surrounding the Tappan Zee Bridge. This... traffic through the RNA during bridge replacement operations, both planned and unforeseen, that could pose... Department of Homeland Security FR Federal Register NPRM Notice of Proposed Rulemaking RNA...

  11. Stories of Transformation: Place-Based Education and the Developing Place-Consciousness of Educators along the Hudson River

    ERIC Educational Resources Information Center

    Rosenthal, Jennifer K.

    2011-01-01

    This phenomenological case study investigates the lived experiences of five educators who engage in on-board educational programs, offered by the non-profit environmental organization "Hudson River Sloop Clearwater, Inc", and follows their stories of place-conscious development leading to place-based educational engagement. By analyzing…

  12. SURVEY OF TOXICITY IN AMBIENT WATERS OF THE HUDSON/RARITAN ESTUARY: IMPORTANCE OF SMALL-SCALE VARIATIONS

    EPA Science Inventory

    This study was part of a characterization of the nature and severity of water-quality problems in the Hudson/Raritan Estuary in New York and New Jersey, USA. The toxicity of ambient water was measured at 51 stations in the estuary by using standard tests with the sea urchin Arbac...

  13. 76 FR 31678 - Saratoga and North Creek Railway, LLC-Acquisition and Operation Exemption-Delaware and Hudson...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-01

    ... Delaware and Hudson Railway Company, Inc. d/b/a Canadian Pacific (CP) a permanent and exclusive freight... approximately 3.2 miles of operating rights for the purpose of interchange with CP between Adirondack Branch milepost 39.44 and CP's yard at Saratoga Springs located at Canadian Subdivision milepost 35.\\3\\ The...

  14. Sixth Season of Hudson River Dredging Begins, Historic Dredging Project Draws to a Close, Next Up: Cleaning Up Floodplains

    EPA Pesticide Factsheets

    (Albany, NY) Today, U.S. Environmental Protection Agency Regional Administrator Judith A. Enck announced the start of the sixth, and final, season of dredging of PCB-contaminated sediments from the bottom of the Hudson River. The historic dredging project

  15. The Right of Public School Employees to Send Their Children to Private Schools: The Demise of "Cook v. Hudson."

    ERIC Educational Resources Information Center

    Johnson, T. Page

    1991-01-01

    The demise of "Cook v. Hudson" stems from its failure to accord proper value to public school employees' constitutional right to select private schooling for children. Unjustified school board attempts to terminate the employment of staff enrolling their children in private schools will not survive the "Pickering"…

  16. 77 FR 66215 - Notice of Final Federal Agency Actions on the Tappan Zee Hudson River Crossing Project in New York

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-02

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Federal Highway Administration Notice of Final Federal Agency Actions on the Tappan Zee Hudson River Crossing Project in New York Correction In notice document 2012-26799, appearing on page 65929 in the...

  17. An Exploratory Evaluation of the Ward and Hudson Offending Pathways Model with Sex Offenders Who Have Intellectual Disability

    ERIC Educational Resources Information Center

    Langdon, Peter E.; Maxted, Helen; Murphy, Glynis H.

    2007-01-01

    Background: It was predicted that offenders with intellectual disability (ID) categorised according to Ward & Hudson's (1998b) self-regulation theory as having an "Approach" goal would have higher levels of distorted cognitions, less victim empathy, and a history of more prolific offending compared to those with an "Avoidant" goal. Offenders…

  18. 77 FR 34285 - Safety Zone; 2012 Ironman U.S. Championship Swim, Hudson River, Fort Lee, NJ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-11

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; 2012 Ironman U.S. Championship Swim, Hudson... vicinity of Englewood Cliffs and Fort Lee, NJ for the 2012 Ironman U.S. Championship swim event. This... associated with swim events. This proposed rule is intended to restrict all vessels and persons from...

  19. Sea floor topography and backscatter intensity of the Hudson Canyon region offshore of New York and New Jersey

    USGS Publications Warehouse

    Butman, Bradford; Twichell, David C.; Rona, Peter A.; Tucholke, Brian E.; Middleton, Tammie J.; Robb, James M.

    2006-01-01

    These maps show the sea floor topography and backscatter intensity of the Hudson Canyon region on the continental slope and rise offshore of New Jersey and New York (fig. 1 and fig. 2). Sheet 1 shows sea floor topography as shaded relief. Sheet 2 shows sea floor topography as shaded relief with backscatter intensity superimposed in color. Both sheets are at a scale of 1:300,000 and also show smoothed topographic contours at selected intervals. The maps are based on new multibeam echo-sounder data collected on an 18-day cruise carried out aboard the National Oceanic and Atmospheric Administration (NOAA) Ship Ronald H. Brown during August and September 2002. Additional multibeam data of the Hudson Canyon collected by the Woods Hole Oceanographic Institution (WHOI), on the continental shelf collected by the STRATAFORM project (Goff and others, 1999), and a survey of the Hudson Shelf Valley (Butman and others, 2003), and a compilation of bathymetric data from the National Geophysical Data Center (NGDC) Coastal Relief Model provide coverage of areas surrounding Hudson Canyon (fig. 2). Interpretations of the surficial geology also utilize widely spaced 3.5- and 10-kiloHertz (kHz) high-resolution seismic profiles collected by the U.S. Geological Survey (fig.2).

  20. 75 FR 29805 - CSX Transportation, Inc. and Delaware and Hudson Railway Company, Inc.-Joint Use Agreement

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-27

    ... Surface Transportation Board CSX Transportation, Inc. and Delaware and Hudson Railway Company, Inc.--Joint Use Agreement AGENCY: Surface Transportation Board. ACTION: Decision No. 2 in FD 35348; Notice of Acceptance of Application; Issuance of Procedural Schedule. SUMMARY: The Surface Transportation Board...

  1. Identifying Sources of Non-fallout Nuclear Contamination in Hudson River Sediments by Plutonium and Neptunium isotope ratios.

    NASA Astrophysics Data System (ADS)

    Kenna, T. C.; Chillrud, S. N.

    2002-12-01

    In an effort to identify and characterize nuclear contaminants released from sources contained within the Hudson River drainage basin, Pu isotopes and 237Np have been measured in a series of sediment cores collected from various locations within the region. During the last several decades, the Hudson River has received input of radioactive contamination from several sources. The first and most significant, has been global fallout, which was a result of atmospheric testing of nuclear weapons primarily by governments of the United States and Former Soviet Union in the 1950s and 1960s. The second, is contamination resulting from reactor releases at the Indian Point Nuclear Power Plant (IPNPP) located on the Hudson River about 35 miles north of New York City. This facility began operation in 1962. A third source of radioactive contamination to the region is contamination resulting from activities at the Knolls Atomic Power Laboratory (KAPL) located on the Mohawk River, which began operation in 1946. Our research entails identifying different sources of nuclear contamination by measurement of plutonium and neptunium isotopic ratios by inductively coupled plasma mass spectrometry (ICP-MS). The isotopic composition of a nuclear contaminant is a sensitive indicator of its origin. By comparing the isotopic composition measured in fluvial sediments to mean values reported for global fallout (i.e. 240Pu/239Pu = 0.18 ñ 0.014, 237Np/239Pu = 0.48 ñ 0.07, and 241Pu/239Pu = .00194 ñ 00028) it is possible to identify contaminants as non-fallout in origin. To date, we have analyzed selected samples from 3 sediment cores collected from the following locations: 1) the Mohawk River downstream of KAPL, 2) the Hudson River above its confluence with the Mohawk River, and 3) the lower Hudson River at a location in close proximity to IPNPP. Isotopic analysis of sediments from the Mohawk River indicates contamination that is clearly non-fallout in origin (240Pu/239Pu ranges between 0

  2. Module bay with directed flow

    DOEpatents

    Torczynski, John R.

    2001-02-27

    A module bay requires less cleanroom airflow. A shaped gas inlet passage can allow cleanroom air into the module bay with flow velocity preferentially directed toward contaminant rich portions of a processing module in the module bay. Preferential gas flow direction can more efficiently purge contaminants from appropriate portions of the module bay, allowing a reduced cleanroom air flow rate for contaminant removal. A shelf extending from an air inlet slit in one wall of a module bay can direct air flowing therethrough toward contaminant-rich portions of the module bay, such as a junction between a lid and base of a processing module.

  3. 33 CFR 100.124 - Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... South Bay Cross Bay Swim, Great South Bay, New York. 100.124 Section 100.124 Navigation and Navigable... NAVIGABLE WATERS § 100.124 Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York... swimmer or safety craft on the swim event race course bounded by the following points: Starting Point...

  4. 75 FR 29891 - Special Local Regulation; Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-28

    ... South Bay Cross Bay Swim, Great South Bay, NY AGENCY: Coast Guard, DHS. ACTION: Final rule. SUMMARY: The... Fischer Memorial Great South Bay Cross Bay Swim. This special local regulation is necessary to protect... Swim, Great South Bay, NY, in the Federal Register (74 FR 32428). We did not receive any comments...

  5. 33 CFR 100.124 - Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... South Bay Cross Bay Swim, Great South Bay, New York. 100.124 Section 100.124 Navigation and Navigable... NAVIGABLE WATERS § 100.124 Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York... swimmer or safety craft on the swim event race course bounded by the following points: Starting Point...

  6. Extreme Rainfall and Flood Events for the Hudson River Induced by Tropical Cyclones: a Statistical Forecast Model

    NASA Astrophysics Data System (ADS)

    Conticello, F.; Hall, T. M.; Lall, U.; Orton, P. M.; Cioffi, F.; Georgas, N.

    2014-12-01

    Tropical Cyclones (TCs) lead to potentially severe coastal flooding through wind surge and also through rainfall-runoff processes. There is growing interest in modeling these processes simultaneously. Here, a statistical approach that can facilitate this process is presented with an application to the Hudson River Basin that is associated with the New York City metropolitan area. Three submodels are used in sequence. The first submodel is a stochastic model of the complete life cycle of North Atlantic (NA) tropical cyclones developed by Hall and Yonekura (2011). It uses archived data of TCs throughout the North Atlantic to estimate landfall rates at high geographic resolution as a function of the ENSO state and of sea surface temperature (SST). The second submodel translates the attributes of a tropical cyclone simulated by the first model to the streamflows at specific points of the tributaries of the Hudson River. That points are the closure sections of five different watersheds. Two different approaches are used and compared: 1) an ANN-cyclone/rainfall clustering model which calculates the rainfall intensity at selected stations within the watershed, that are then used as inputs of an ANN rainfall/runoff model; 2) an ANN/ Bayesian multivariate approach that translates the TC attributes ( track, SST, Velocities,..) directly in streamflows in the tributaries. Finally, the streamflows of the tributaries of the Hudson River are to be used as inputs in a hydrodynamic model that includes storm surge dynamics for the simulation of coastal flooding along the Hudson River. Calibration and validation of the model is carried out by using, selected tropical cyclone data since 1950, and hourly and daily station rainfall and streamflow recorded for such extreme events. Seven stream gauges (Croton River, Rondout Creek, Wappinger Creek, Troy dam, Mohawk River at Cohoes, Mohawk River diversion at Crescent Dam, Hudson River above lock one nr Waterford) and over 20 rain gauges are

  7. Impact of AMD on water quality in critical watershed in the Hudson River drainage basin: Phillips Mine, Hudson Highlands, New York

    USGS Publications Warehouse

    Gilchrist, S.; Gates, A.; Szabo, Z.; Lamothe, P.J.

    2009-01-01

    A sulfur and trace element enriched U-Th-laced tailings pile at the abandoned Phillips Mine in Garrison, New York, releases acid mine drainage (AMD, generally pH < 3, minimum pH 1.78) into the first-order Copper Mine Brook (CMB) that drains into the Hudson River. The pyrrhotite-rich Phillips Mine is located in the Highlands region, a critical water source for the New York metro area. A conceptual model for derivation/dissolution, sequestration, transport and dilution of contaminants is proposed. The acidic water interacts with the tailings, leaching and dissolving the trace metals. AMD evaporation during dry periods concentrates solid phase trace metals and sulfate, forming melanterite (FeSO4.7H2O) on sulfide-rich tailings surfaces. Wet periods dissolve these concentrates/precipitates, releasing stored acidity and trace metals into the CMB. Sediments along CMB are enriched in iron hydroxides which act as sinks for metals, indicating progressive sequestration that correlates with dilution and sharp rise in pH when mine water mixes with tributaries. Seasonal variations in metal concentrations were partly attributable to dissolution of the efflorescent salts with their sorbed metals and additional metals from surging acidic seepage induced by precipitation.

  8. Impact of AMD on water quality in critical watershed in the Hudson River drainage basin: Phillips Mine, Hudson Highlands, New York

    NASA Astrophysics Data System (ADS)

    Gilchrist, Sivajini; Gates, Alexander; Szabo, Zoltan; Lamothe, Paul J.

    2009-03-01

    A sulfur and trace element enriched U-Th-laced tailings pile at the abandoned Phillips Mine in Garrison, New York, releases acid mine drainage (AMD, generally pH < 3, minimum pH 1.78) into the first-order Copper Mine Brook (CMB) that drains into the Hudson River. The pyrrhotite-rich Phillips Mine is located in the Highlands region, a critical water source for the New York metro area. A conceptual model for derivation/dissolution, sequestration, transport and dilution of contaminants is proposed. The acidic water interacts with the tailings, leaching and dissolving the trace metals. AMD evaporation during dry periods concentrates solid phase trace metals and sulfate, forming melanterite (FeSO4·7H2O) on sulfide-rich tailings surfaces. Wet periods dissolve these concentrates/precipitates, releasing stored acidity and trace metals into the CMB. Sediments along CMB are enriched in iron hydroxides which act as sinks for metals, indicating progressive sequestration that correlates with dilution and sharp rise in pH when mine water mixes with tributaries. Seasonal variations in metal concentrations were partly attributable to dissolution of the efflorescent salts with their sorbed metals and additional metals from surging acidic seepage induced by precipitation.

  9. Winter-time circulation and sediment transport in the Hudson Shelf Valley

    USGS Publications Warehouse

    Harris, C.K.; Butman, B.; Traykovski, P.

    2003-01-01

    The Hudson Shelf Valley is a bathymetric low that extends across the continental shelf offshore of New York and New Jersey. From December 1999 to April 2000 a field experiment was carried out to investigate the transport of sediment in the shelf and valley system. Near-bed tripods and water-column moorings were deployed at water depths from 38 to 75 m in the axis of the shelf valley and at about 26 m on the adjacent shelves offshore of New Jersey and Long Island, New York. These measured suspended sediment concentrations, current velocities, waves, and water column properties. This paper analyzes observations made during December 1999 and January 2000, and presents the first direct near-bed measurements of suspended sediment concentration and sediment flux from the region. Sediment transport within the Hudson Shelf Valley was coherent over tens of kilometers, and usually aligned with the axis of the shelf valley. Down-valley (off-shore) transport was associated with energetic waves, winds from the east, moderate current velocities (5-10 cm/s), and sea level setup at Sandy Hook, NJ. Up-valley (shoreward) transport occurred frequently, and was associated with winds from the west, low wave energy, high current velocities (20-40 cm/s), and sea level set-down at the coast. Within the shelf valley, net sediment flux (the product of near-bed concentration and velocity) was directed shoreward, up the axis of the valley. Current velocities and suspended sediment fluxes on the New York and New Jersey continental shelves were lower than within the shelf valley, and exhibited greater variability in alignment. Longer term meteorological data indicate that wind, setup, and wave conditions during the study period were more conducive to up-valley transport than seasonal data suggest as average. To relate the observed up-valley sediment flux to observed accumulation of contaminants within the Hudson Shelf Valley requires consideration of transport over longer timescales than those

  10. Evidence for synchronous hydromagmatic and primary degassing activity during the 1991 eruption of Hudson Volcano, Chile

    NASA Astrophysics Data System (ADS)

    Kratzmann, D. J.; Carey, S.; Scasso, R.; Naranjo, J.

    2010-12-01

    The fall deposit from the paroxysmal phase of the 1991 eruption of Hudson volcano in southern Chile (August 12-15) is highly stratified with multiple layers of alternating coarse pumice lapilli and fine ash. The lapilli units may be related to eruptive pulses associated with well-developed plinian columns, with the fine ash layers corresponding to periods of quiescence between eruptive pulses. Alternatively, the fine ash layers may represent a change in eruption style, from plinian to phreatoplinian. Dispersal characteristics for the paroxysmal phase of the 1991 Hudson eruption suggest a phreatoplinian event. The eruption, which occurred through a thick glacier that fills the summit caldera, may be one of the few phreatoplinian events of modern times. In order to assess the possibility of arrested degassing during the eruption and identify evidence for magma-water interaction a detailed SEM / FTIR investigation of juvenile particles was conducted. SEM analysis of juvenile material revealed features including blocky and equant clasts with step features, adhered particles, and a lack of hydration cracks. These features are indicative of ‘dry’ magma-water interactions. Highly vesicular, volatile-rich particles are also present throughout the stratigraphy. These suggest that both hydromagmatic and primary degassing processes were operating contemporaneously to varying degrees during the course of the eruption. Further evidence for magma-water interactions is found in the water content of the matrix glasses, which range from 0.1 to 1.3 wt%. At total water less than 0.5 wt% the Hudson matrix glasses have higher molecular H2O than is predicted from experimental work. Elevated H2O / OH ratios can be produced through syn-eruptive hydration of the matrix glass during periods of magma-water interaction. Molecular water rapidly diffuses into glassy particles, which have high surface areas, but the reaction to produce hydroxyl is slow enough that the dissolved water remains

  11. Physician assistants in Canada

    PubMed Central

    Jones, Ian W.; Hooker, Roderick S.

    2011-01-01

    Abstract Objective To analyze the health policies related to physician assistants (PAs) and to understand the factors influencing this medical work force movement. Quality of evidence This work combines a review of the literature and qualitative information, and it serves as a historical bookmark. The approach was selected when attempts to obtain reports or literature using customary electronic bibliography (PubMed, CINAHL, Google Scholar, EBSCO, and MEDLINE) searches in English and French, from 1970 through 2010, identified only 14 documents (including gray literature) of relevance. Reports, provincial documents, and information from developers of the PA movement supplemented the literature base. Main message The historical development of the role of PAs in Canada spans 2 decades. There are now more than 250 PAs, most working in family medicine and emergency medicine. Enabling legislation for PAs has been formalized in Manitoba, and 3 provinces have recognized PAs in various policy statements or initiatives. Three universities and 1 military training centre have enrolled more than 120 students in PA programs. Retired PAs of the Canadian Forces, returning ex-patriot Canadians who had trained as PAs in PA programs in the United States, and American immigrants are working as PAs in Canada. Demonstration projects are under way to better understand the usefulness of PAs in various medical settings. Conclusion For a public health policy enactment of this size and effect, the literature on PAs in Canada is sparse and limited. In spite of this, PA employment is expanding, family medicine practices are using PAs, and there is enabling legislation planned. The result will likely be increased use of PAs. Documentation about PAs, review of their use, and outcomes research are needed to evaluate this new type of clinician in Canadian society. PMID:21402955

  12. Invasive herbivory: resident Canada geese and the decline of wild rice along the tidal Patuxent River

    USGS Publications Warehouse

    Haramis, G.M.; Kearns, G.D.; Perry, Matthew C.

    2004-01-01

    While concern grows over the increasing numbers of exotic mute swans (Cygnus olor) on the Chesapeake Bay, less attention seems to be given to the highly familiar and native Canada goose (Branta canadensis) which has over time developed unprecedented nonmigratory, or resident, populations. Although nuisance flocks of Canada geese have been well advertised at city parks, athletic fields, and golf courses over the past three decades, recent expansion of populations to an estimated one million birds in the Atlantic Flyway, and to over 100,000 in Maryland, carries a threat of broader ecological consequences.

  13. Chesapeake Bay Program Grant Guidance

    EPA Pesticide Factsheets

    Grant Guidance and appendices for the Chesapeake Bay Program that describes how the U.S. Environmental Protection Agency’s (EPA) Region 3’s Chesapeake Bay Program Office (CBPO) administers grant and cooperative agreement funds.

  14. Manicouagin Reservoir of Canada

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Recorded by the Space Shuttle Atlantis STS-110 mission, this is a photograph of the ice- covered Manicouagin Reservoir located in the Canadian Shield of Quebec Province in Eastern Canada, partially obscured by low clouds. This reservoir marks the site of an impact crater, 60 miles (100 kilometers) wide, which according to geologists was formed 212 million years ago when a meteorite crashed into this area. Over millions of years, the crater has been worn down by glaciers and other erosional processes. The Space Shuttle Orbiter Atlantis, STS-110 mission, was launched April 8, 2002 and returned to Earth April 19, 2002.

  15. Canada Basin revealed

    USGS Publications Warehouse

    Mosher, David C.; Shimeld, John; Hutchinson, Deborah R.; Chian, D; Lebedeva-Ivanova, Nina; Jackson, Ruth

    2012-01-01

    More than 15,000 line-km of new regional seismic reflection and refraction data in the western Arctic Ocean provide insights into the tectonic and sedimentologic history of Canada Basin, permitting development of new geologic understanding in one of Earth's last frontiers. These new data support a rotational opening model for southern Canada Basin. There is a central basement ridge possibly representing an extinct spreading center with oceanic crustal velocities and blocky basement morphology characteristic of spreading centre crust surrounding this ridge. Basement elevation is lower in the south, mostly due to sediment loading subsidence. The sedimentary succession is thickest in the southern Beaufort Sea region, reaching more than 15 km, and generally thins to the north and west. In the north, grabens and half-grabens are indicative of extension. Alpha-Mendeleev Ridge is a large igneous province in northern Amerasia Basin, presumably emplaced synchronously with basin formation. It overprints most of northern Canada Basin structure. The seafloor and sedimentary succession of Canada Basin is remarkably flat-lying in its central region, with little bathymetric change over most of its extent. Reflections that correlate over 100s of kms comprise most of the succession and on-lap bathymetric and basement highs. They are interpreted as representing deposits from unconfined turbidity current flows. Sediment distribution patterns reflect changing source directions during the basin’s history. Initially, probably late Cretaceous to Paleocene synrift sediments sourced from the Alaska and Mackenzie-Beaufort margins. This unit shows a progressive series of onlap unconformities with a younging trend towards Alpha and Northwind ridges, likely a response to contemporaneous subsidence. Sediment source direction appeared to shift to the Canadian Arctic Archipelago margin for the Eocene and Oligocene, likely due to uplift of Arctic islands during the Eurekan Orogeny. The final

  16. 78 FR 16493 - ExxonMobil Canada Energy, Flint Hills Resources Canada, LP, Imperial Oil, NOVA Chemical (Canada...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-15

    ..., NOVA Chemical (Canada) Ltd., PBF Holding Company LLC, Toledo Refining Company, LLC, Pennzoil-Quaker... Resources Canada, LP, Imperial Oil, NOVA Chemical (Canada) Ltd., PBF Holding Company LLC, Toledo...

  17. Three-dimensional simulation of flow, salinity, sediment, and radionuclide movements in the Hudson River estuary

    SciTech Connect

    Onishi, Y.; Trent, D.S.

    1985-04-01

    The three-dimensional, finite difference model, FLESCOT simulates time-varying movements of flow, turbulent kinetic energy, salinity, water temperature, sediment, and contaminants in estuarine, coastal, and ocean waters. The model was applied to a 106-km (66-mi) reach of the Hudson River estuary in New York between Chelsea and the mouth of the river. It predicted the time-varying, three-dimensional distributions of tidal flow, salinity, three separate groups of sediments (i.e., sand, silt, and clay), and a radionuclide (/sup 137/Cs) in both dissolved and particulate (those sorbed by sediments) forms for over 40 days. The model also calculated riverbed elevation changes caused by sediment deposition and bed erosion, bed sediment size distribution and armoring, and distributions of the particulate /sup 137/Cs sorbed by sand, silt, and clay in the bed.

  18. Analyzing Drought From Paleo-Reconstructions Of 7-Day Low Flow In The Hudson River Basin

    NASA Astrophysics Data System (ADS)

    Zamora, M. R.; Cook, E.; Gelman, A.; Lall, U.

    2002-12-01

    The annual 7-day low flow in a stream is a measure of the dry season conditions in a stream. Consequently, it is a useful indicator for multi-year droughts. Here, we first present the application of a Generalized Linear Model in a Bayesian Hierarchical Modeling Framework for reconstructing the annual 7-day low flow series at 5 locations in the Hudson River Basin using 11 regional tree ring chronologies. This technique directly provides estimates of the posterior probability distribution of each reconstructed streamflow value, considering model parameter uncertainty. Given these reconstructions, we examine the frequency and recurrence attributes of extreme droughts in the region and their potential connections to known low frequency climate modes.

  19. Runoff and flocculation modify underwater light environment of the Hudson River Estuary

    NASA Astrophysics Data System (ADS)

    Stross, R. G.; Sokol, R. C.

    1989-10-01

    Spectral quality of underwater irradiance was measured in the Hudson River Estuary at ten stations, which ranged from Albany to Battery Park, Manhattan. Incoming light is attenuated by a large, fluctuating load of terrigenous sediments and by phytoplankton. Photic depth ranged from only 0·6 m in late winter to 4·3 m in summer. All but the yellow and red wavelengths are eliminated near the surface. Much of the suspended material flocculates and settles within a day or more of standing in the laboratory. Floc patterns were also observed in the estuary from the air. Light transmission improves during the summer interval in direct proportion to the size of the algal crop, as measured by chlorophyll concentration. Circumstantial evidence indicates a self-clearing system which is based on co-flocculation of algae with clays and fine silts. The study suggests that a clearer estuary is possible when inputs of algal nutrients and suspended solids are managed.

  20. High yield wind energy resources in the mid-Hudson River basin. Final report

    SciTech Connect

    Sforza, P.M.; Smorto, M.J.; Bailey, B.; Wheeler, R.

    1983-12-01

    An evaluation of high-yield wind energy resources in the franchise area of the Central Hudson Gas and Electric Corporation is presented. A site screening process was used to select seven sites for field tests. Wind data taken at those sites for three months were used as the basis to select four sites for an additional testing period of nine months. A computer simulation was conducted on the performance of eight wind turbines (55 kW to 7350 kW) at the four sites based on the one year data recorded; the results of the computer runs are described. Also, an economic analysis of the operation of the eight wind turbines at the windiest site is presented. Recommendations for wind energy development in the region are discussed.

  1. Interactions between finfish aquaculture and lobster catches in a sheltered bay.

    PubMed

    Loucks, Ronald H; Smith, Ruth E; Fisher, E Brian

    2014-11-15

    Interactions between open-net pen finfish aquaculture and lobster catches in a sheltered bay in Nova Scotia, Canada, were investigated using fishermen's participatory research in annual lobster trap surveys over seven years. Fishermen recorded lobster catches during the last two weeks of May from 2007 to 2013. Catches for each trap haul were recorded separately for ovigerous and market-sized lobsters. Catch trends within the bay were compared to regional trends. Results of correlation analyses indicated that ovigerous catch trends were strongly affected by the fish farm's feeding/fallow periods. There was no significant correlation between trends for bay and LFA lobster landings. Patterns of lobster catch per unit effort extending over considerable distance in Port Mouton Bay appear to be influenced by proximity to the fish farm regardless of year-to-year variation in water temperatures and weather conditions. Odours and habitat changes surrounding open-net pen finfish operations are potential factors affecting lobster displacement.

  2. Accumulation of PCB congeners in nestling tree swallows (Tachycineta bicolor) on the Hudson River, New York

    USGS Publications Warehouse

    Echols, Kathy R.; Tillitt, Donald E.; Nichols, John W.; Secord, Anne L.; McCarty, John P.

    2004-01-01

    Tree swallows (Tachycineta bicolor) were used as a sentinel species to monitor the contamination and bioavailability of polychlorinated biphenyls (PCBs) in the Hudson River watershed. Several tree swallow nest box colonies around and downstream from Hudson Falls, NY, were studied. Tree swallow eggs, adults, and 5-, 10-, and 15-day-old nestlings were collected and analyzed for 103 PCB congeners. Emergent insects collected by net (primarily Odonata) or as a food bolus (primarily Diptera) taken from the mouths of adult tree swallows returning to the nest were analyzed in the same manner. Total PCB concentrations (wet weight) in eggs from two contaminated sites ranged from 9000 to 25 000 ng/g and accumulated to 32 000 and 96 000 ng/g in 15-day-old nestling at two contaminated sites. The congener patterns of PCBs in eggs, nestlings, and adults were compared to those found in emergent insects (Odonata and Diptera) using principal components analysis. The PCB patterns of the biota differed from that of Aroclor technical mixtures. PCB patterns in adult tree swallows were similar to those in eggs, while the patterns in dietary insects were similar to nestling tree swallows. Uptake rate constants were determined for tree swallow nestlings and compared between the two contaminated sites. The estimated PCB congener uptake rate constants were 0.008-0.02 d-1 based on uptake in nestlings until day 15 post-hatch. The rate constants were comparable between the two study areas and may be used to predict nestling contamination at other locations. Our studies confirm the utility of nestling tree swallows to evaluate localized PCB contamination.

  3. Understanding Spatial and Temporal Shifts in Blue Carbon, Piermont Marsh, Lower Hudson Estuary, NY

    NASA Astrophysics Data System (ADS)

    Peteet, D. M.; Nichols, J. E.; Kenna, T. C.; Corbett, E. J.; Allen, K. A.; Newton, R.; Vincent, S.; Haroon, A.; Shumer, M.

    2015-12-01

    Piermont Marsh is a National Estuarine Research Reserve (NERR) protected brackish wetland in the lower Hudson Valley. It serves as a nursery for fish, a coastal buffer in storms, a repository of native wetland species unique to the Hudson, and a paleoenvironmental archive. At risk for disappearance due to rising sea level, we assess the present carbon stores and their spatial and temporal variability through time. Determining the depth of peat in transects throughout Piermont Marsh (41°N, 73°55'W), is one step in reconstructing the stores of carbon in the marsh and how they have shifted over millennia. Through the last decade, we have focused field efforts on probing the depths of the marsh through a series of transects and in acquiring sediment cores from which we establish sedimentation rates and carbon storage through time. AMS C-14 dating, XRF fluorescence, pollen analysis, and Cesium-137 provide chronological control for the sedimentation rates, pollution history, and an understanding of the regional and local shifts in vegetation. C-13 and pollen measurements in selected cores indicate major shifts in local vegetation with coastal eutrophication as the marsh has been invaded, first by Typha angustifolia in the nineteenth century and then by Phragmites australis in the twentieth century up to the present. N-15 measurements indicate a large shift in nitrogen as humans have impacted the marsh. We present a comprehensive, three-dimensional view of the effects of climate, vegetation, and human impact on the carbon storage of Piermont Marsh. This project provided a site for a place- and project-based learning through Lamont-Doherty's Secondary School Field Research Program. Many of the field samples were collected by young investigators from schools in New York City and towns near Piermont.

  4. Erosion of fine-grained sediment in the Hudson Shelf Valley, offshore of New York

    NASA Astrophysics Data System (ADS)

    Traykovski, P.; Harris, C. K.; Butman, B.; ten Brink, M. R.

    2001-05-01

    The Hudson Shelf Valley, the submerged ancestral drainage channel of the Hudson River, is a major topographic feature on the continental shelf of the New York Bight. The area near the head of the valley has been used for disposal of a wide variety of material, including dredged material (since the late 1800's) and sewage sludge (between 1972 and 1987). While the shelf is covered by primarily sandy sediments, finer sediments are found in the valley; these fine sediments have elevated concentrations of heavy metals and other contaminants. In order to understand the fate of these contaminated sediments in the winter of 1999-2000 an array of six tripods (four along the valley axis and 2 on the adjacent shelf) was deployed in the Valley and in the New York Bight to measure the regional pattern of sediment transport. At two sites (one at the head of the valley and one in the axis of the upper valley) where the surficial sediments are silty sand or sandy silt, erosion of up to 15 cm of sediment was observed under the tripods using an acoustic altimeter. The erosion took place over the first two months of the deployment in steps of 1 to 3 cm during 2 to 5 day periods of high wave energy and/or strong mean currents. The critical stress for resuspension/erosion increased as the bed eroded, thus ultimately limiting the amount of erosion. Since this large erosion rate is unlikely to be sustainable over large areas and over longer time scales, the observed erosion suggests that there may be mobile pools of fine sediment over more consolidated sediments that are easily erodable and transported during high energy events.

  5. Accumulation of PCB congeners in nestling tree swallows (Tachycineta bicolor) on the Hudson River, New York.

    PubMed

    Echols, Kathy R; Tillitt, Donald E; Nichols, John W; Secord, Anne L; McCarty, John P

    2004-12-01

    Tree swallows (Tachycineta bicolor) were used as a sentinel species to monitor the contamination and bioavailability of polychlorinated biphenyls (PCBs) in the Hudson River watershed. Several tree swallow nest box colonies around and downstream from Hudson Falls, NY, were studied. Tree swallow eggs, adults, and 5-, 10-, and 15-day-old nestlings were collected and analyzed for 103 PCB congeners. Emergent insects collected by net (primarily Odonata) or as a food bolus (primarily Diptera) taken from the mouths of adult tree swallows returning to the nest were analyzed in the same manner. Total PCB concentrations (wet weight) in eggs from two contaminated sites ranged from 9000 to 25,000 ng/g and accumulated to 32,000 and 96,000 ng/g in 15-day-old nestling at two contaminated sites. The congener patterns of PCBs in eggs, nestlings, and adults were compared to those found in emergent insects (Odonata and Diptera) using principal components analysis. The PCB patterns of the biota differed from that of Aroclor technical mixtures. PCB patterns in adult tree swallows were similar to those in eggs, while the patterns in dietary insects were similar to nestling tree swallows. Uptake rate constants were determined for tree swallow nestlings and compared between the two contaminated sites. The estimated PCB congener uptake rate constants were 0.008-0.02 d(-1) based on uptake in nestlings until day 15 post-hatch. The rate constants were comparable between the two study areas and may be used to predict nestling contamination at other locations. Our studies confirm the utility of nestling tree swallows to evaluate localized PCB contamination.

  6. Hudson submarine canyon head offshore New York and New Jersey: A physical and geochemical investigation

    NASA Astrophysics Data System (ADS)

    Rona, Peter; Guida, Vincent; Scranton, Mary; Gong, Donglai; Macelloni, Leonardo; Pierdomenico, Martina; Diercks, Arne-R.; Asper, Vernon; Haag, Scott

    2015-11-01

    Hudson Canyon is the largest shelf-sourced canyon system off the east coast of the United States, and hosts a productive ecosystem that supports key fisheries. Here we report the results of a multi-year interdisciplinary study of the geological, geochemical, and physical oceanographic features and processes in the canyon that underpin that ecosystem. High-resolution multi-beam bathymetric and backscatter data show that the contrasting morphology of the two perpendicularly oriented branches at the head of the Hudson Canyon is indicative of different states of geomorphological activity and sediment transport. Tightly spaced ridges and gullies extend perpendicularly towards the canyon axis from the canyon walls. Numerous depressions are found at the base of the canyon walls or along the canyon axis at depths from 300 m to 600 m. Elevated concentrations of dissolved methane in the water column, where the highest density of depressions occur, suggests that methane is actively venting there. The topography and reflective floors of circular depressions in canyon walls and their association with methane maxima suggest that these represent active methane gas release-collapse pockmarks with carbonate floors. Patterns of irregular, low-relief, reflective depressions on the canyon floor may also represent methane release points, either as gas release or cold-seep features. The presence of methane maxima in a region of strong advective currents suggests continuous and substantial methane supply. Hydrographic observations in the canyon show that multiple layers of distinct inter-leaved shelf (cold, fresh) and slope (warm, salty) water masses occupy the head of the canyon during the summer. Their interactions with the canyon and with each other produce shifting fronts, internal waves, and strong currents that are influenced by canyon topography. Strong tidal currents with along-canyon-axis flow shear help to drive the advection, dispersion and mixing of dissolved materials in the

  7. Geochemistry and loading history of phosphate and silicate in the Hudson estuary

    NASA Astrophysics Data System (ADS)

    Clark, Jordan F.; Simpson, H. James; Bopp, Richard F.; Deck, Bruce

    1992-03-01

    The loading history and geochemistry of soluble reactive phosphorus (SRP) and dissolved silica (DSi) are evaluated in the Hudson estuary using 16 years of axial transect data. SRP behaves atypically in the estuary. Profiles show conservative mixing between a large mid-salinity source and the freshwater and seaward end members. Order of magnitude calculations indicate that waste water treatment facilities (WWTFs) are the dominant mid-salinity SRP source. DSi profiles display behaviour more typical of other estuaries in the northeastern United States, showing conservative mixing during periods of high flow and a mid-salinity source during periods of low flow. A single layered multi-box model is used to evaluate the loading history of SRP and DSi. Shortly after the New York State phosphate detergent ban of 1972, the SRP load dropped to two-thirds of that typical of the early 1970s. Loading of SRP remained at this level until the mid-1980s when construction began at the largest point source. During the construction phase (1984-1986), SRP loading returned to the early 1970s level. Upon completion, the total load declined once again and by the end of the 1980s it reached a level approximately one-third of that existing prior to the detergent ban. Model calculations of observed DSi profiles do not show a similar time-trend. They suggest that during summer months dissolution of diatom tests is a major source of DSi; however, WWTF DSi loads also appear to be a significant source to the Hudson estuary.

  8. Geochemical and isotopic properties of Heinrich layers H2 to H0 off Hudson Strait

    NASA Astrophysics Data System (ADS)

    Nuttin, L.; Ghaleb, B.; Hillaire-Marcel, C.

    2011-12-01

    Information about the precise timing and transport/depositional mechanism of fine detrital-carbonate sedimentary pulses, which occurred off Hudson Strait during Heinrich-events and linked to ice-margin instability in this area, is still much fragmentary (see Hesse et al., Geology 32: 449-452, 2004). Here, we intend to document the properties and duration of the most recent of these sedimentary pulses (H2, H1, H0) based on mineralogical, geochemical and isotopic data in a 895-cm long core (HU08-029-004; 2674 m water-depth; 61°27'N, 58°2'W) raised from the lower slope, about 100 nm off Hudson Strait shelf edge. Measurements of 238U, 234U, 230Th and 232Th, supplemented by semi-quantitative mineralogical analysis and light isotope data (C, Corg, Cinorg, C/N, 14C, δ13C and δ18O) are used to document sedimentary features in this core. First investigations provide an estimated average sedimentation rate of ~33 cm/ka on the whole studied sequence. 230Th-excesses over supported fraction are estimated following Veiga-Pires & Hillaire-Marcel (Paleoceanography 14: 187-199, 1999). H-layer thicknesses are about 60 cm, 100 cm and 28 cm respectively (H2, H1, H0). They depict up to 60% of fine detrital carbonates (mostly calcite) and are also highlighted by relatively low 230Th-excesses (nearly 0 dpm/g) compared with excesses of about 3 dpm/g in the overlying Holocene sediments. The low 230Th-excesses in H-layers do indicate a very fast depositional process but prevent any meaningful estimation of sedimentation rates due to uncertainties in their estimates.

  9. Nutrition inequities in Canada.

    PubMed

    Tarasuk, Valerie; Fitzpatrick, Sandra; Ward, Heather

    2010-04-01

    In Canada, increased morbidity and shorter life expectancy have been found among those with lower incomes and lower levels of education, but there has been little examination of socioeconomic variation in food and nutrient intake. Using data from the 2004 Canadian Community Health Survey, we examined the relationship between household income and education level and adults' and children's intakes of energy, fibre, micronutrients, and number of servings consumed of food groups from Canada's Food Guide. To explore the public health significance of observed associations, we estimated the prevalence of inadequacy for selected nutrients for adults, stratifying by household income, education level, and sex. We found that a higher household income adequacy and (or) higher levels of education were associated with increased consumption of milk and alternatives, and vegetables and fruit, and significantly higher vitamin, mineral, and fibre intakes among both adults and children. The prevalence of inadequate nutrient intakes among adults was higher among adults with the lowest level of income adequacy or educational attainment, compared with others. Our results suggest that the nutritional quality of Canadians' food intakes is, in part, a function of their social position. The impact of policy and program interventions needs to be examined across socioeconomic strata to ensure that actions reduce rather than exacerbate nutrition inequities.

  10. Suicide in Canada

    PubMed Central

    McFaull, Steven; Rhodes, Anne E.; Bowes, Matthew; Rockett, Ian R. H.

    2016-01-01

    Objective: The aim of this study is to compare Canadian suicide rates with other external causes of death to examine potential poisoning misclassifications as a contributor to suicide underreporting. Method: The study used Statistics Canada mortality data from 2000 to 2011 to calculate sex-and age-specific ratios by external cause of injury codes. Results: The overall Canadian suicide rate, as well as the poisoning suicide rate, declined over the study timeframe by an average annual percentage change (AAPC) of 1.0% each year. However, unintentional and undetermined poisonings increased significantly during the timeframe. Unintentional poisoning mortality (primarily narcotics and hallucinogens, including opioids) increased in proportion to suicides for both sexes, although females were consistently higher. The undetermined death to suicide ratio was higher and increasing for females. Poisonings of undetermined intent increased over time to comprise 47% to 80% of the undetermined death category for males and females combined. Conclusions: Canadian poisoning suicide rates declined, in contrast to rising unintentional and undetermined poisoning mortality rates. This trend is similar to that of the United States, supporting the hypothesis that misclassification of poisoning deaths may also be an issue in Canada.

  11. Mobile Bay turbidity study

    NASA Technical Reports Server (NTRS)

    Crozier, G. F.; Schroeder, W. W.

    1978-01-01

    The termination of studies carried on for almost three years in the Mobile Bay area and adjacent continental shelf are reported. The initial results concentrating on the shelf and lower bay were presented in the interim report. The continued scope of work was designed to attempt a refinement of the mathematical model, assess the effectiveness of optical measurement of suspended particulate material and disseminate the acquired information. The optical characteristics of particulate solutions are affected by density gradients within the medium, density of the suspended particles, particle size, particle shape, particle quality, albedo, and the angle of refracted light. Several of these are discussed in detail.

  12. Thatcher Bay, Washington, Nearshore Restoration Assessment

    USGS Publications Warehouse

    Breems, Joel; Wyllie-Echeverria, Sandy; Grossman, Eric E.; Elliott, Joel

    2009-01-01

    The San Juan Archipelago, located at the confluence of the Puget Sound, the Straits of Juan de Fuca in Washington State, and the Straits of Georgia, British Columbia, Canada, provides essential nearshore habitat for diverse salmonid, forage fish, and bird populations. With 408 miles of coastline, the San Juan Islands provide a significant portion of the available nearshore habitat for the greater Puget Sound and are an essential part of the regional efforts to restore Puget Sound (Puget Sound Shared Strategy 2005). The nearshore areas of the San Juan Islands provide a critical link between the terrestrial and marine environments. For this reason the focus on restoration and conservation of nearshore habitat in the San Juan Islands is of paramount importance. Wood-waste was a common by-product of historical lumber-milling operations. To date, relatively little attention has been given to the impact of historical lumber-milling operations in the San Juan Archipelago. Thatcher Bay, on Blakely Island, located near the east edge of the archipelago, is presented here as a case study on the restoration potential for a wood-waste contaminated nearshore area. Case study components include (1) a brief discussion of the history of milling operations. (2) an estimate of the location and amount of the current distribution of wood-waste at the site, (3) a preliminary examination of the impacts of wood-waste on benthic flora and fauna at the site, and (4) the presentation of several restoration alternatives for the site. The history of milling activity in Thatcher Bay began in 1879 with the construction of a mill in the southeastern part of the bay. Milling activity continued for more than 60 years, until the mill closed in 1942. Currently, the primary evidence of the historical milling operations is the presence of approximately 5,000 yd3 of wood-waste contaminated sediments. The distribution and thickness of residual wood-waste at the site was determined by using sediment

  13. Farming. Canada at Work Series.

    ERIC Educational Resources Information Center

    Love, Ann; Drake, Jane

    This book is part of the Canada At Work series that introduces children to the people, machines, work and environmental concerns involved in bringing to market the products from important Canadian natural resources. This volume features a year-round look at two kinds of agriculture in Canada. On the vegetable farm, children find out about spring…

  14. OECD Economic Surveys: Canada 2012

    ERIC Educational Resources Information Center

    OECD Publishing (NJ3), 2012

    2012-01-01

    Canada weathered the global economic crisis well, mainly reflecting sustained growth in domestic pending, and the economy is continuing to grow despite the persistence of international turbulence, most recently stemming from the euro zone sovereign debt crisis. In Canada's case, several factors are acting in its favour. Federal fiscal plans are…

  15. Chesapeake Bay Critters

    ERIC Educational Resources Information Center

    Mackay-Atha, Lynne

    2005-01-01

    When students enter the author's classroom on the first day of school, they are greeted with live crabs scuttling around in large bins. The crabs are her way of grabbing students' attention and launching the unit on the Chesapeake Bay watershed. She chooses to start the year with this unit because, despite the fact that the Potomac River can be…

  16. Yaquina Bay Topobathy DEM

    EPA Science Inventory

    The U.S.EPA contracted with the U.S.ACE to obtain intertidal and subtidal bathymetric soundings of Yaquina Bay between Poole Slough and the South Beach Marina in 2002. These data were compiled with U.S.ACE subtidal soundings from 1999, 1998, 2000 and National Ocean Service soundi...

  17. On optimal Bayes detection

    SciTech Connect

    Nielsen, P. |

    1991-08-12

    The following is intended to be a short introduction to the design and analysis of a Bayes-optimal detector, and Middleton`s Locally Optimum Bayes Detector (LOBD). The relationship between these two detectors is clarified. There are three examples of varying complexity included to illustrate the design of these detectors. The final example illustrates the difficulty involved in choosing the bias function for the LOBD. For the examples, the corrupting noise is Gaussian. This allows for a relatively easy solution to the optimal and the LOBD structures. As will be shown, for Bayes detection, the threshold is determined by the costs associated with making a decision and the a priori probabilities of each hypothesis. The threshold of the test cannot be set by simulation. One will notice that the optimal Bayes detector and the LOBD look very much like the Neyman-Pearson optimal and locally optimal detectors respectively. In the latter cases though, the threshold is set by a constraint on the false alarm probability. Note that this allows the threshold to be set by simulation.

  18. On optimal Bayes detection

    SciTech Connect

    Nielsen, P. Arizona Univ., Tucson, AZ . Dept. of Electrical and Computer Engineering)

    1991-08-12

    The following is intended to be a short introduction to the design and analysis of a Bayes-optimal detector, and Middleton's Locally Optimum Bayes Detector (LOBD). The relationship between these two detectors is clarified. There are three examples of varying complexity included to illustrate the design of these detectors. The final example illustrates the difficulty involved in choosing the bias function for the LOBD. For the examples, the corrupting noise is Gaussian. This allows for a relatively easy solution to the optimal and the LOBD structures. As will be shown, for Bayes detection, the threshold is determined by the costs associated with making a decision and the a priori probabilities of each hypothesis. The threshold of the test cannot be set by simulation. One will notice that the optimal Bayes detector and the LOBD look very much like the Neyman-Pearson optimal and locally optimal detectors respectively. In the latter cases though, the threshold is set by a constraint on the false alarm probability. Note that this allows the threshold to be set by simulation.

  19. Mackenzie River Delta, Canada

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The Mackenzie River in the Northwest Territories, Canada, with its headstreams the Peace and Finley, is the longest river in North America at 4241 km, and drains an area of 1,805,000 square km. The large marshy delta provides habitat for migrating Snow Geese, Tundra Swans, Brant, and other waterfowl. The estuary is a calving area for Beluga whales. The Mackenzie (previously the Disappointment River) was named after Alexander Mackenzie who travelled the river while trying to reach the Pacific in 1789.

    The image was acquired on August 4, 2005, covers an area of 55.8 x 55.8 km, and is located at 68.6 degrees north latitude, 134.7 degrees west longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  20. Tectonics of Atlantic Canada

    USGS Publications Warehouse

    Williams, H.; Dehler, S.A.; Grant, A.C.; Oakey, G.N.

    1999-01-01

    The tectonic history of Atlantic Canada is summarized according to a model of multiple ocean opening-closing cycles. The modern North Atlantic Ocean is in the opening phase of its cycle. It was preceded by an early Paleozoic lapetus Ocean whose cycle led to formation of the Appalachian Orogen. lapetus was preceded by the Neoproterozoic Uranus Ocean whose cycle led to formation of the Grenville Orogen. The phenomenon of coincident, or almost coincident orogens and modern continental margins that relate to repeated ocean opening-closing cycles is called the Accordion Effect. An understanding of the North Atlantic Ocean and its continental margins provides insights into the nature of lapetus and the evolution of the Appalachian Orogen. Likewise, an understanding of lapetus and the Appalachian Orogen raises questions about Uranus and the development of the Grenville Orogen. Modern tectonic patterns in the North Atlantic may have been determined by events that began before 1000 m.y.

  1. Radiation Protection in Canada

    PubMed Central

    Brown, John R.; Jarvis, Anita A.

    1964-01-01

    A recent survey was carried out with respect to radiobiological and radiological health projects in Canada. Letters of inquiry, followed by two questionnaires, were sent out to every institution where radiation research was likely to have been undertaken. Approximately 75% of those contacted replied. Of the total of 200 studies, 84% were classified as biological and medical studies, the remaining 16% as environmental radiation studies. Responses to the inquiry stressed the inadequacy of the present governmental budget for radiation research, the need for higher salaries for research workers, and the necessity of a more intensive teaching program for technicians and professional personnel. The granting of longer-term grants, rather than annually renewable grants, is urged. PMID:14226104

  2. Anguillicola crassus infection in Anguilla rostrata from small tributaries of the Hudson River watershed, New York, USA.

    PubMed

    Machut, L S; Limburg, K E

    2008-03-03

    We studied the invasion of the exotic nematode parasite Anguillicola crassus in the American eel Anguilla rostrata using tributaries of the Hudson River estuary. Yellow-phase American eels were sampled from 6 tributaries, and their swim bladders were examined for nematode infection. Prevalence averaged 39% with an intensity of 2.4 nematodes per eel. Parasite distribution was not significant along a latitudinal gradient; on the other hand, physical barriers (dams and natural waterfalls) significantly reduced infections upstream. Urbanization may increase the susceptibility of eels to infection; we found significantly elevated infection rates when urbanized lands exceeded 15% of the tributary catchment area. Yellow-phase eel condition was not affected by parasite infection. The invasion of the entire Hudson River watershed is ongoing and therefore will continue to be a management concern. Further analysis of the parasite-host interaction in North America is warranted.

  3. Mechanisms Responsible for the Observed Thermodynamic Structure in a Convective Boundary Layer Over the Hudson Valley of New York State

    NASA Astrophysics Data System (ADS)

    Freedman, Jeffrey M.; Fitzjarrald, David R.

    2017-02-01

    We examine cases of a regional elevated mixed layer (EML) observed during the Hudson Valley Ambient Meteorology Study (HVAMS) conducted in New York State, USA in 2003. Previously observed EMLs referred to topographic domains on scales of 105 -106 km2 . Here, we present observational evidence of the mechanisms responsible for the development and maintenance of regional EMLs overlying a valley-based convective boundary layer (CBL) on much smaller spatial scales (<5000 km2) . Using observations from aircraft-based, balloon-based, and surface-based platforms deployed during the HVAMS, we show that cross-valley horizontal advection, along-valley channelling, and fog-induced cold-air pooling are responsible for the formation and maintenance of the EML and valley-CBL coupling over New York State's Hudson Valley. The upper layer stability of the overlying EML constrains growth of the valley CBL, and this has important implications for air dispersion, aviation interests, and fog forecasting.

  4. Availability of ground water in the unconsolidated aquifers in the Mid-Hudson River Basin, New York

    USGS Publications Warehouse

    Bugliosi, Edward F.

    1987-01-01

    Protection of New York State 's aquifers has become an increasingly important issue among water resource managers at all levels of State and municipal government. Aquifer delineation is necessary as an initial phase in the effective management of the State 's groundwater resources. As part of an effort to delineate all major unconsolidated aquifers in New York, a cooperative study was conducted to compile a groundwater availability map that would complete the reconnaissance mapping of the mid-Hudson River basin at a scale of 1:250,000. This map delineates the principal unconsolidated aquifers in the mid-Hudson River basin area and the estimated potential yield of properly constructed wells completed in these aquifers. (Lantz-PTT)

  5. Polychlorinated biphenyls and Hudson River white perch: implications for population-level ecological risk assessment and risk management.

    PubMed

    Barnthouse, Lawrence W; Glaser, David; DeSantis, Liane

    2009-07-01

    Risk assessments and risk management decisions concerning risks to wild fish populations resulting from exposures to polychlorinated biphenyls (PCBs) and related chemicals have been based primarily on observations of effects of chemicals on individual organisms. Although the development and application of population-level ecological risk-assessment methods is proceeding at a rapid pace, the organism-level approach is still being justified by arguments that population-level ecological risk assessment is in an early stage of development and has not been shown to be reliable. This article highlights the importance of including population-level effects in risk-management decision-making, by examining the effects of exposures to PCBs on fish populations inhabiting the Hudson River, New York, USA, a system in which data have been collected for approximately 30 y concerning both concentrations of PCBs in sediment and fish tissue and the abundance and reproduction of exposed fish populations. We previously tested hypotheses concerning the effects of PCBs on the striped bass population of the Hudson River, and found that the available data conflicted with all of these hypotheses. Here, we report results of similar analyses of effects of historic PCB exposures on the Hudson River white perch population, using an extended data set that recently became available. As with striped bass, we found no correlation between maternal PCB tissue concentrations and any measure of reproductive success in Hudson River white perch during the 30-y period covered by the data set. Together with results of studies performed on fish populations exposed to PCBs at other sites, our results clearly demonstrate that physiological and genetic adaptation, biological compensation, and other ecological processes influence responses of fish populations to PCB exposures and should be considered in risk management decision-making.

  6. Polychlorinated biphenyls (PCBs) in adult and juvenile mallards (Anas platyrhynchos) from the Hudson River, New York, USA.

    PubMed

    Madden, Sean S; Skinner, Lawrence C

    2016-09-01

    The Hudson River, NY, USA is contaminated for over 300 km with polychlorinated biphenyls (PCBs) released from two General Electric (GE) capacitor plants. We collected adult and juvenile mallards (Anas platyrhynchos) from four different areas of the river; an area upstream of the GE plants (n = 38), two areas directly downstream of the GE plants (n = 41, n = 38), and an area more than 100 km downstream in the freshwater tidal river (n = 20). Collections occurred during July and August (2008) when ducks were flightless to ensure ducks were "resident" and exposures were local. Fat and muscle tissue were analyzed for PCBs. PCBs were detected in all samples, and mallards below the GE plant sites on the Hudson River had orders of magnitude higher concentrations of PCBs than those above the plants. Juvenile mallards from areas directly downstream of the GE plant sites tended to have higher PCB concentrations in fat than adults. The patterns of PCB congeners and homolog groups varied across the study areas, with areas directly downstream of the GE plants dominated by tetra-chloro biphenyls whereas samples from upstream and the freshwater tidal river tended towards higher chlorinated congeners. Congener patterns between male and female and juvenile and adult mallards were generally similar within study areas, with the exception of one area downstream of the GE plants where adult birds exhibited different patterns than juveniles. Evidence of PCBs from the GE plant sites was detected in the tidal Hudson River, more than 100 km downstream of the plant sites. More than 90% of the ducks collected in areas downstream of the GE plants but above the tidally influenced river exceed the USFDA tolerance level for PCBs in poultry, which should be a concern for consumers of waterfowl taken in proximity to the upper Hudson River.

  7. Food control systems in Canada.

    PubMed

    Smith, T M; Jukes, D J

    1997-04-01

    This paper provides an overview of the responsibilities and jurisdictional boundaries of Health Canada (HC) and Agriculture and Agri-Food Canada (AAFC) with regard to food regulation in Canada. It examines their interagency coordination within the federal structure and with other levels of government, industry, and the consumer. The international developments are considered with the North American Free Trade Agreement (NAFTA) and the Canada, United States Trade Agreement (CUSTA) being regarded as likely to have a significant future impact. The federal food safety and quality system is complex and fragmented. Federal food regulation comes under the jurisdiction of four federal departments: HC, AAFC, Industry Canada (IC), and Fisheries and Oceans Canada (FOC). All four departments are involved with inspection, surveillance, and the analysis of food sold in Canada. In addition, Canada's ten provincial and two territorial governments have provincial-, regional-, municipal-, and local-level governments that also have jurisdiction over food safety and quality. Consideration is first given to the main legislative provision covering food--the Federal Food and Drugs Act. This Act is administered by several of the Federal Government departments. The role of these departments is examined individually along with additional, more specific legal provisions for which responsibility is not divided (in particular, the Canada Agricultural Products [CAP] Act administered by AAFC, and the Consumer Packaging and Labeling Act [CPLA] administered by IC). The various reviews that have taken place in the recent past and those still in progress are considered, and the final part of this paper looks at the international developments that are likely to have a major impact on the future development of the Canadian food control system.

  8. Reproductive health of yellow perch, Perca flavescens, in Chesapeake Bay Tributaries

    USGS Publications Warehouse

    Blazer, Vicki; Pinkney, A.E.; Uphoff, James H.

    2013-01-01

    Yellow perch live in creeks, rivers, ponds, lakes, and estuaries across the central and eastern United States and Canada. In Chesapeake Bay, they tolerate salinities up to one-third that of seawater. The adults reside in the brackish waters of the bay’s tributaries and migrate upstream to spawn. Yellow perch are eagerly sought by recreational fishermen for their excellent taste and, because their late winter spawning runs are the earliest of the year, they are regarded as a harbinger of spring. Yellow perch also support a small but valuable, tightly regulated commercial fishery in the part of Chesapeake Bay that lies in Maryland.

  9. Structural analysis of the Elbow-Cranberry-Iskwasum lakes area: A multiply reactivated deformation corridor in the trans-Hudson orogen of Manitoba

    NASA Astrophysics Data System (ADS)

    Ryan, James Joseph

    The Elbow-Cranberry-Iskwasum lakes area comprises a large portion of the eastern Amisk collage in the Palaeoproterozoic Flin Flon Belt (southern Trans-Hudson Orogen) of Manitoba, Canada. Deformation episodes recorded in the Flin Flon Belt are divided into pre-, early, late and post-Hudsonian orogeny, and are distinguished by the orientation of structures and changes in metamorphic conditions. Detailed structural analysis, petrography, geochemistry and U-Pb geochronology indicate a structural history spanning 180 m.y. in the Amisk collage. Accretion of the 1.92--1.88 Ga tectonostratigraphic assemblages that constitute the Amisk collage began prior to 1.868 Ga, the age of the oldest dyke to cross-cut the earliest mylonitic fabrics. The deformational history has been discerned, in which six generations of ductile structures F1 - F6 were followed by development of brittle-ductile and brittle structures F7 . Movements along the late structures may have continued until 1.690 Ga, during exhumation of the collage. The macroscopic structural grain in the central Flin Flon Belt is steeply dipping, generally trends north to north-northeast, and is dominated by two regionally pervasive foliations ( S2 and S5 ). Its grain contrasts strongly with the shallowly-dipping, east--west-trending grain in the adjacent Kisseynew domain. Foliations of different generations have been distinguished by their age relative to regional metamorphic mineral growth. Regional metamorphism in the Flin Flon Belt is interpreted as having culminated at moderate pressure and temperature, between 1.820 and 1.805 Ga. The development of S2 between 1.868 and 1.845 Ga was associated with east--west shortening of the successor magmatic arc that overprinted the Amisk collage. S3 and S4 were associated with shear zones, and are not regionally widespread. The S5 regional-scale Elbow Lake shear zone, and a pervasive crenulation cleavage in the wall rocks, developed during an episode of sinistral transpression

  10. A comparison of congeneric PCB patterns in American eels and striped bass from the Hudson and Delaware River estuaries.

    PubMed

    Ashley, Jeffrey T F; Horwitz, Richard; Steinbacher, Joseph C; Ruppel, Bruce

    2003-10-01

    The Hudson River estuary has enormous spatial variation in polychlorinated biphenyl (PCB) contamination due in large part to historical point source discharges above Troy Dam. The Delaware River estuary has accumulated significant levels of PCBs through decades of industrial, municipal, and non-point source inputs. The overall goal of this research was to use existing data sets to compare and contrast the patterns of accumulated PCB congeners in sub-populations of American eels and striped bass inhabiting these two estuaries and surrounding coastal waters. Using principal component analysis and analysis of covariance (ANCOVA), inter- and intra-estuarine differences in accumulated congeneric patterns were denoted for both species. Results from our study support the idea that migratory behaviors of striped bass hamper the use of accumulated congener-specific PCB patterns in providing information on localized contamination, although major regional differences were seen between upriver Hudson River fish, downriver Hudson River fish and fish from other areas within this study. This study provides additional evidence for the use of the American eel as a biomonitoring tool, since its limited home range provides finer resolution of regional contamination.

  11. Catastrophic meltwater discharge down the Hudson Valley: a potential trigger for the Intra-Allerød cold period

    USGS Publications Warehouse

    Donnelly, Jeffrey P.; Driscoll, Neal W.; Uchupi, Elazar; Keigwin, Loyd D.; Schwab, William C.; Thieler, E. Robert; Swift, Stephen A.

    2005-01-01

    Glacial freshwater discharge to the Atlantic Ocean during deglaciation may have inhibited oceanic thermohaline circulation, and is often postulated to have driven climatic fluctuations. Yet attributing meltwater-discharge events to particular climate oscillations is problematic, because the location, timing, and amount of meltwater discharge are often poorly constrained. We present evidence from the Hudson Valley and the northeastern U.S. continental margin that establishes the timing of the catastrophic draining of Glacial Lake Iroquois, which breached the moraine dam at the Narrows in New York City, eroded glacial lake sediments in the Hudson Valley, and deposited large sediment lobes on the New York and New Jersey continental shelf ca. 13,350 yr B.P. Excess 14C in Cariaco Basin sediments indicates a slowing in thermohaline circulation and heat transport to the North Atlantic at that time, and both marine and terrestrial paleoclimate proxy records around the North Atlantic show a short-lived (<400 yr) cold event (Intra-Aller??d cold period) that began ca. 13,350 yr B.P. The meltwater discharge out the Hudson Valley may have played an important role in triggering the Intra-Aller??d cold period by diminishing thermohaline circulation. ?? 2005 Geological Society of America.

  12. Jointing in the Ordovician Platteville Formation on either side of the Hudson-Afton horst in Wisconsin and Minnesota

    SciTech Connect

    Sykora, A.K.

    1994-04-01

    Jointing is a characteristic feature of the Platteville Formation. A total of 1,577 joint orientations were measured at fourteen localities in east-central Minnesota and west-central Wisconsin. All the joints are vertical with north-south to east-west exposure orientations. Four major joint sets including a longitudinal, a crosscutting, and two diagonal sets are identifiable for over 75% of the localities. The analysis of rose diagrams superimposed on the site map help to recognize a trend in joint patterns from location to location. The localities east and south of the Hudson-Afton horst appear to have similar trend and development of joint patterns. The orientations of the major joint sets are: N10E, N60E, N40W, and N85W. The localities west of the Hudson-Afton horst differ from the east and south localities in both trend and development of joint patterns. The approximate orientations of the major joint sets are: N05W, N50E, N45W, and N80W. The joint pattern appears to be related to the structural trend of the Hudson-Afton horst. The horst, an associated feature of the Midcontinental rift, is an uplifted block of Precambrian igneous and sedimentary rocks bounded by faults. These faults are a possible cause for the jointing. The faults strike at an azimuth of approximately N22E which correlates well with the idealized azimuth for the maximum principal stress as deduced from the rose diagrams.

  13. Latest Holocene evolution and human disturbance of a channel segment in the Hudson River Estuary

    USGS Publications Warehouse

    Klingbeil, A.D.; Sommerfield, C.K.

    2005-01-01

    The latest Holocene sedimentary record of a cohesive channel and subtidal shoal in the lower Hudson River Estuary was examined to elucidate natural (sea-level rise, sediment transport) and anthropogenic (bulkheading, dredging) influences on the recent morphodynamic evolution of the system. To characterize the seafloor and shallow subbottom, ??? 100 km of high-resolution seismic reflection profiles (chirp) were collected within a 20-km reach of the estuary and correlated with sediment lithologies provided by eight vibracores recovered along seismic lines. Sediment geochronology with 137Cs and 14C was used to estimate intermediate and long-term sedimentation rates, respectively, and historical bathymetric data were analyzed to identify regional patterns of accretion and erosion, and to quantify changes in channel geometry and sediment volume. The shoal lithosome originated around 4 ka presumably with decelerating eustatic sea level rise during the latest Holocene. Long-term sedimentation rates on the shoal (2.3-2.6 mm/yr) are higher than in the channel (2 mm/yr) owing to hydrodynamic conditions that preferentially sequester suspended sediment on the western side of the estuary. As a result, the shoal accretes oblique to the principal axis of tidal transport, and more rapidly than the channel to produce an asymmetric cross-section. Shoal deposits consist of tidally bedded muds and are stratified by minor erosion surfaces that seismic profiles reveal to extend for 10s of meters to kilometers. The frequency and continuity of these surfaces suggest that the surficial shoal is catastrophically stripped on decadal-centennial time scales by elevated tidal flows; tidal erosion maintains the shoal at a uniform depth below sea level and prevents it from transitioning to an intertidal environment. Consequently, the long-term sedimentation rate approximates the rate of sea-level rise in the lower estuary (1-3 mm/yr). After the mid 1800s, the natural geometry of the lower Hudson

  14. Chapter 41: Geology and petroleum potential of the West Greenland-East Canada Province

    USGS Publications Warehouse

    Schenk, C.J.

    2011-01-01

    The US Geological Survey (USGS) assessed the potential for undiscovered oil and gas resources of the West Greenland-East Canada Province as part of the USGS Circum-Arctic Resource Appraisal programme. The province lies in the offshore area between western Greenland and eastern Canada and includes Baffin Bay, Davis Strait, Lancaster Sound and Nares Strait west of and including part of Kane Basin. A series of major tectonic events led to the formation of several distinct structural domains that are the geological basis for defining five assessment units (AU) in the province, all of which are within the Mesozoic-Cenozoic Composite Petroleum System. Potential petroleum source rocks include strata of Ordovician, Lower and Upper Cretaceous, and Palaeogene ages. The five AUs defined for this study - the Eurekan Structures AU, NW Greenland Rifted Margin AU, NE Canada Rifted Margin AU, Baffin Bay Basin AU and the Greater Ungava Fault Zone AU - encompass the entire province and were assessed for undiscovered technically recoverable resources. The mean volumes of undiscovered resources for the West Greenland-East Canada Province are 10.7 ?? 109 barrels of oil, 75 ?? 1012 cubic feet of gas, and 1.7 ?? 109 barrels of natural gas liquids. For the part of the province that is north of the Arctic Circle, the estimated mean volumes of these undiscovered resources are 7.3 ?? 109 barrels of oil, 52 ?? 1012 cubic feet of natural gas, and 1.1 ?? 109 barrels of natural gas liquids. ?? 2011 The Geological Society of London.

  15. Hudson Canyon benthic habitats characterization and mapping by integrated analysis of multidisciplinary data

    NASA Astrophysics Data System (ADS)

    Pierdomenico, Martina; Guida, Vincent G.; Rona, Peter A.; Macelloni, Leonardo; Scranton, Mary I.; Asper, Vernon; Diercks, Arne

    2013-04-01

    Hudson Canyon, about 180 km SE of New York City, is the largest eastern U.S. submarine canyon and is under consideration for HAPC (Habitat Area of Particular Concern) status, representing a fisheries and biodiversity hot spot. Interest in the area, within the perspective of ecosystem based management, marine spatial planning, habitat and species conservation, led to a joint project between NOAA Northeast Fisheries, U.S. Geological Survey (USGS), Mississippi Mineral Research Institute (MMRI), National Institute for Undersea Science and Technology (NIUST), Stony Brook and Rutgers Universities for the study of benthic habitats, that includes the assembly of existing data with newly collected ones: acoustic mapping, visual ground-truthing, hydrographic, sedimentological, and trawl data collections. Acoustic mapping, performed using AUV-mounted multibeam sonar, provided ultra-high resolution bathymetric and backscatter imagery (3m and 1m respectively) at all water depths for identification of geomorphological features and for the characterization of surficial sediments along the two thirds of the shelf portion of the canyon. Identification of benthic and demersal communities was accomplished by visual ground thruthing with underwater vehicle video and still cameras, and from trawl catch data. A CTD-rosette sampler provided water column salinity-temperature profiles and water samples for dissolved methane analysis in the vicinity of suspected bottom sources. Analysis of data revealed a complex of topographic structures and hydrological patterns that provide a wide range of physical habitats in a relatively small area. A mosaic of sandy and muddy substrates, gravel beds, rock outcrops, and semilithified clay outcrops host rich and varied faunal assemblages, including deepwater corals and sponge communities. Pockmark fields, occurring below 300 m depth, suggest that methane-based chemosynthetic carbonate deposition contributes to creation of specific hard bottom habitats

  16. Polychlorinated biphenyls and 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents in tree swallows from the upper Hudson River, New York State, USA

    USGS Publications Warehouse

    Secord, Anne L.; McCarty, John P.; Echols, Kathy R.; Meadows, John C.; Gale, Robert W.; Tillitt, Donald E.

    1999-01-01

    The upper Hudson River of New York State, USA, is contaminated with polychlorinated biphenyls (PCBs) as a result of industrial discharges throughout the latter half of this century. In 1994 and 1995, we monitored the transfer of PCBs from aquatic sediments to a terrestrial wildlife community using the tree swallow (Tachycineta bicolor) as a model organism. Tree swallow eggs and nestlings were collected at four colonies established along a 40-km stretch of the upper Hudson River watershed. Samples were analyzed for total PCBs and PCB congeners, including non-ortho- and mono-ortho-substituted PCBs. Mean concentrations of PCBs in tree swallow eggs and nestlings ranged from 721 to 62,200 ng/g and were as much as 15 times greater than PCB concentrations in tree swallow eggs and nestlings collected from PCB-contaminated areas within the Great Lakes ecosystem. The corresponding 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs) calculated using avian toxic equivalency factors ranged from 410 to 25,400 pg/g. Concentrations of PCB congener 77 (3,39,4,49-tetrachlorobiphenyl) were extremely elevated and were major contributors to the calculated TEQs. Homologue pattern comparisons between Hudson River and Saginaw River (Michigan, USA) ecosystems supported the hypothesis that a consistent Hudson River PCB source was the major contributor to PCBs in Hudson River tree swallows. The high concentrations of PCBs in Hudson River sediments and resultant concentrations observed in tree swallows were indicative of a potential elevated risk to these and other wildlife linked to the aquatic food web of the Hudson River ecosystem.

  17. Polychlorinated biphenyls and 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents in tree swallows from the upper Hudson River, New York State, USA

    USGS Publications Warehouse

    Secord, A.L.; McCarty, J.P.; Echols, K.R.; Meadows, J.C.; Gale, R.W.; Tillitt, D.E.

    1999-01-01

    The upper Hudson River of New York State, USA, is contaminated with polychlorinated biphenyls (PCBs) as a result of industrial discharges throughout the latter half of this century. In 1994 and 1995, we monitored the transfer of PCBs from aquatic sediments to a terrestrial wildlife community using the tree swallow (Tachycineta bicolor) as a model organism. Tree swallow eggs and nestlings were collected at four colonies established along a 40-km stretch of the upper Hudson River watershed. Samples were analyzed for total PCBs and PCB congeners, including non-ortho- and mono- ortho-substituted PCBs. Mean concentrations of PCBs in tree swallow eggs and nestlings ranged from 721 to 62,200 ng/g and were as much as 15 times greater than PCB concentrations in tree swallow eggs and nestlings collected from PCB-contaminated areas within the Great Lakes ecosystem. The corresponding 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs) calculated using avian toxic equivalency factors ranged from 410 to 25,400 pg/g. Concentrations of PCB congener 77 (3,3',4,4'-tetrachlorobiphenyl) were extremely elevated and were major contributors to the calculated TEQs. Homologue pattern comparisons between Hudson River and Saginaw River (Michigan, USA) ecosystems supported the hypothesis that a consistent Hudson River PCB source was the major contributor to PCBs in Hudson River tree swallows. The high concentrations of PCBs in Hudson River sediments and resultant concentrations observed in tree swallows were indicative of a potential elevated risk to these and other wildlife linked to the aquatic food web of the Hudson River ecosystem.

  18. A Plan to Appreciate Canada

    ERIC Educational Resources Information Center

    Edwards, R. Yorke

    1971-01-01

    A plan is suggested for establishing a chain of ecology-wildlife interpretation centers throughout Canada emphasizing regional interpretation of the landscape. Wye Marsh Wildlife Center, Midland, Ontario, is described in detail. (BL)

  19. The Canada Goose (Branta canadensis)

    ERIC Educational Resources Information Center

    Van Deusen, Roswell D.

    1973-01-01

    Study of Canada Goose in schools can provide opportunities for many activities such as poetry writing, art, ecosystems, and outdoor education. Provides some background information about these birds. (PS)

  20. Can Education Reform Canada's Criminals?

    ERIC Educational Resources Information Center

    Griffin, D. K.

    1978-01-01

    Discusses the development of the existing correctional programs in Canada's prisons, some theories of criminality, and two competing views on the best way to reform criminals today. Also gives a short review of penitentiary education programs. (RK)

  1. Bayes and the Law

    PubMed Central

    Fenton, Norman; Neil, Martin; Berger, Daniel

    2016-01-01

    Although the last forty years has seen considerable growth in the use of statistics in legal proceedings, it is primarily classical statistical methods rather than Bayesian methods that have been used. Yet the Bayesian approach avoids many of the problems of classical statistics and is also well suited to a broader range of problems. This paper reviews the potential and actual use of Bayes in the law and explains the main reasons for its lack of impact on legal practice. These include misconceptions by the legal community about Bayes’ theorem, over-reliance on the use of the likelihood ratio and the lack of adoption of modern computational methods. We argue that Bayesian Networks (BNs), which automatically produce the necessary Bayesian calculations, provide an opportunity to address most concerns about using Bayes in the law. PMID:27398389

  2. Nagoya, Ise Bay, Japan

    NASA Technical Reports Server (NTRS)

    1982-01-01

    This view of Nagoya, Ise Bay and nearby Kyoto, on the main island of Honshu, Japan (35.0N, 137.0E) combines in a single photo both the political, cultural and educational centers of early Japan as well as one of the main educational and business centers of modern Japan. Besides being a business, cultural and educational center, Nagoya is near the geographic center of the Japanese home islands.

  3. Trends in polychlorinated biphenyl concentrations in Hudson River water five years after elimination of point sources

    USGS Publications Warehouse

    Schroeder, R.A.; Barnes, C.R.

    1983-01-01

    Industrial discharge of polychlorinated biphenyls (PCBs) to the Hudson River from 1950 to the mid-1970 's has resulted in serious degradation of the water. Contaminated river-bottom sediments continue to contribute PCBs to the river water. Concentrations in the sediment range from several hundred micrograms per gram near the outfall to less than 10 micrograms per gram in the lower estuary. PCBs are supplied by bottom sediments to the overlying water by two mechanisms--desorption and resuspension. Because desorption is a relatively constant process, concentrations of PCBs decrease as water discharge increases. At high flow, however, scouring by turbulence causes resuspension of PCB-laden sediment. Transport rates indicate that most PCBs enter the water from the most contaminated sediments, which are within 20 kilometers of the outfall. Mean daily transport from the upper river (except during high discharges) has decreased from 10 kilograms in 1976 to 5 kilograms in the late 1970 's and to 1 kilogram in 1981. This decrease probably results from the burial of highly contaminated sediments by cleaner sediments originating upstream. (USGS)

  4. PCB loading from sediment in the Hudson River: congener signature analysis of pathways.

    PubMed

    Butcher, Jonathan B; Garvey, Edward A

    2004-06-15

    The upper Hudson River (NY) was subjected to massive PCB contamination over a period of three decades. A large inventory of PCBs remains in contaminated sediments of the river, most notably in the Thompson Island Pool. During the summer, flow crossing the Thompson Island Pool exhibits a large and consistent PCB load gain. This load gain is not associated with scouring flows and is not accompanied by an increase in suspended solids. A variety of hypotheses have been proposed to explain this load gain, including flux of contaminated porewater and dissolution of unverified reservoirs of pure PCBs. A wealth of congener-specific PCB data is available for the site throughout the 1990s. Interpretation of the Thompson Island Pool load gain is facilitated by examination of the PCB congener signature of the gain and comparison to the signature of potential sources. This examination suggests that neither the flux of porewater nor the dissolution of unaltered Aroclors are the predominant source of the load gain. Instead, the congener signature is consistent with a mixed source consisting of porewater flux and non-scour flux of contaminated sediments. The non-scour sediment flux, which reaches a maximum in the beginning of the summer growing season, is likely driven by a variety of biological and anthropogenic processes, including bioturbation by benthic organisms, bioturbation by demersal fish, scour by propwash, mechanical scour by boats and floating debris in nearshore areas, and uprooting of macrophytes.

  5. On the theory of deep flow in the Hudson Shelf Valley

    NASA Astrophysics Data System (ADS)

    Hsueh, Y.

    1980-09-01

    The time averaged near-bottom current in the New York Bight for a selected 3-day period is idealized as a steady state response to the mean wind at the John F. Kennedy International Airport and the mean inflow condition across the Long Island shelf. The idealization invokes potential vorticity conservation in a homogeneous ocean subject to a linear bottom friction and results in shelf currents whose longshore components are in general agreement with the averages of the observed. In the Hudson Shelf Valley, qualitative agreement with the observation is achieved in the onshore component which is directed nearly along the valley axis. Nearshore, within 40 km or so of the coast, the response is, to a substantial degree, wind driven. Nearshore upvalley mean flow is due partly to shore-parallel wind stresses that are directed away from the valley and is due partly to topographic deflection of an alongshore current that is driven in part by the inflow condition and in part by the alongshore component of the mean wind stress. Because of the important role of bottom friction, an alongshore current driven by longshore winds undergoes sharper (and more realistic) deflection across the valley than does an alongshore current driven by the inflow condition.

  6. Fluxes of polychlorinated biphenyls volatilizing from the Hudson River, New York measured using micrometeorological approaches.

    PubMed

    Sandy, Andy L; Guo, Jia; Miskewitz, Robert J; McGillis, Wade R; Rodenburg, Lisa A

    2012-01-17

    This study represents the first time that a micrometeorological technique, using turbulent transport measurements, has been used to determine the direction and magnitude of air-water exchange of polychlorinated biphenyls (PCBs). The study was conducted during July 2008 on the Hudson River estuary near the Tappan Zee Bridge, which is the site of some of the most serious PCB contamination in the world. Gas-phase ΣPCB concentrations measured at two heights above the water column averaged 1.1 ng m(-3), and concentrations were usually lower in the upper air sample, indicating net transport of PCBs from the water column to the air. Volatilization PCB fluxes were calculated using the modified Thornthwaite-Holzman equation. Values of friction velocity and atmospheric stability were calculated using the Aerodynamic Gradient and Eddy Correlation techniques. The PCB fluxes were corrected for changes in atmospheric stability using the atmospheric stability factor of water vapor (ϕ(w)) calculated from empirical formulations which ranged from 1.0 to 3.2 (neutral to stable atmospheric boundary layer conditions). Vertical ΣPCB fluxes ranged from +0.5 μg m(-2) d (-1) to +13 μg m(-2) d (-1). Mono- through tri-homologues accounted for about half of ΣPCB fluxes, with tetra- through hexa-homologue accounting for the other half. This work demonstrates the utility of a micrometeorological approach to measuring the air-water exchange of organic contaminants.

  7. Sediment Storage and Heavy Metal Inventories in the Lower Reaches of the Hudson River Estuary

    NASA Astrophysics Data System (ADS)

    Kenna, T. C.; Nitsche, F. O.; Baumgarten, J.; Haberman, M.

    2008-12-01

    Estuaries are important resources and many throughout the world are intensively used and modified by anthropogenic activities, which has resulted in instances of significant environmental contamination (e.g., heavy metals and organic contaminants). Many of these contaminants exhibit a high affinity for fine-grained sediments, making a detailed knowledge of the distribution and contaminant loading crucial to effective estuarine management. We use a hand-held X-ray fluorescence spectrometer to rapidly generate lead and other elemental distribution profiles. This technique, performed on split wet sediment cores, allows information to be collected for a significantly greater number of sediment cores than current techniques allow. When this information is combined with bulk density information that is routinely measured on sediment cores inventories of metals such as Pb, Zn, and Cu derived from anthropogenic activities (i.e., contaminant inventories) can be computed and mapped. Further, the particle reactive nature of the elements measured allows there application as proxies for other particle reactive contaminants with similar release histories. Using the penetration depth of anthropogenic contaminants in conjunction with high resolution acoustic data allows the volume of recently deposited sediments (i.e., sediments impacted by 20th century industrial activities) to be obtained. Presented results will include detailed metal inventory maps (e.g., lead, zinc, and copper) and sediment storage volume estimates from the Hudson Highlands south to the Tappan Zee area.

  8. Outdoor air PCB concentrations in three communities along the Upper Hudson River, New York.

    PubMed

    Palmer, Patrick M; Belanger, Erin E; Wilson, Lloyd R; Hwang, Syni-An A; Narang, Rajinder S; Gomez, Marta I; Cayo, Michael R; Durocher, Lorie A; Fitzgerald, Edward F

    2008-04-01

    Outdoor air polychlorinated biphenyl (PCB) concentrations were measured in upstate New York as part of a nonoccupational exposure investigation. The adjacent study communities of Hudson Falls and Fort Edward contain numerous sites of current and former PCB contamination, including two capacitor-manufacturing facilities. Outdoor air PCB concentrations in the study municipalities were significantly higher than in the comparison municipality of Glens Falls. Total PCB concentrations in the study area ranged from 0.102 to 4.011 ng/m(3) (median: 0.711 ng/m(3)). For the comparison area, concentrations ranged from 0.080 to 2.366 ng/m(3) (median: 0.431 ng/m(3)). Although our sampling was not designed to identify point sources, the presence of PCB-contaminated sites in the study area likely contributed to this observed difference in concentration. While elevated relative to the comparison area, total PCB concentrations in the study area are lower than those in other communities with known PCB-contaminated sites, and similar to levels reported in other locations from the northeastern United States.

  9. Accumulation of polychlorinated biphenyls in american shad during their migration in the Hudson River, spring 1977.

    PubMed

    Pastel, M; Bush, B; Kim, J S

    1980-06-01

    Fifty-two female American shad (Alosa sapidissima) were collected during the spring of 1977 at two sites on the lower Hudson River, 27 miles and 75 miles from the river mouth. The fish were extracted with hexane, and the extracts were analyzed by electron-capture gas chromatography (EC-GC) and by GC/mass spectrometry (MS), PCBs were quantitated by EC-GC, and the concentrations were compared by fish length and by site. Fish collected from the downstream site contained a mean PCB concentration of 2.0 +/- 1.0 microgram/g, wet weight; fish from the upstream site contained a mean PCB concentration of 6.1 +/- 2.6 microgram/g, wet weight. Aliquots of the hexane extracts were fractionated before analysis by GC/MS. The presence of PCBs was confirmed, and DDE and the alkane series from C22 through C26 were detected. American shad are saltwater fish that only enter fresh water to spawn. Because they do not feed in fresh water before spawning, they may be used as an indicator of water contamination.

  10. Bathymetric controls on sediment transport in the Hudson River estuary: Lateral asymmetry and frontal trapping

    USGS Publications Warehouse

    Ralston, David K.; Geyer, W. Rockwell; Warner, John C.

    2012-01-01

    Analyses of field observations and numerical model results have identified that sediment transport in the Hudson River estuary is laterally segregated between channel and shoals, features frontal trapping at multiple locations along the estuary, and varies significantly over the spring-neap tidal cycle. Lateral gradients in depth, and therefore baroclinic pressure gradient and stratification, control the lateral distribution of sediment transport. Within the saline estuary, sediment fluxes are strongly landward in the channel and seaward on the shoals. At multiple locations, bottom salinity fronts form at bathymetric transitions in width or depth. Sediment convergences near the fronts create local maxima in suspended-sediment concentration and deposition, providing a general mechanism for creation of secondary estuarine turbidity maxima at bathymetric transitions. The lateral bathymetry also affects the spring-neap cycle of sediment suspension and deposition. In regions with broad, shallow shoals, the shoals are erosional and the channel is depositional during neap tides, with the opposite pattern during spring tides. Narrower, deeper shoals are depositional during neaps and erosional during springs. In each case, the lateral transfer is from regions of higher to lower bed stress, and depends on the elevation of the pycnocline relative to the bed. Collectively, the results indicate that lateral and along-channel gradients in bathymetry and thus stratification, bed stress, and sediment flux lead to an unsteady, heterogeneous distribution of sediment transport and trapping along the estuary rather than trapping solely at a turbidity maximum at the limit of the salinity intrusion.

  11. Calculating mercury loading to the tidal Hudson River, New York, using rating curve and surrogate methodologies

    USGS Publications Warehouse

    Wall, G.R.; Ingleston, H.H.; Litten, S.

    2005-01-01

    Total mercury (THg) load in rivers is often calculated from a site-specific "rating-curve" based on the relation between THg concentration and river discharge along with a continuous record of river discharge. However, there is no physical explanation as to why river discharge should consistently predict THg or any other suspended analyte. THg loads calculated by the rating-curve method were compared with those calculated by a "continuous surrogate concentration" (CSC) method in which a relation between THg concentration and suspended-sediment concentration (SSC) is constructed; THg loads then can be calculated from the continuous record of SSC and river discharge. The rating-curve and CSC methods, respectively, indicated annual THg loads of 46.4 and 75.1 kg for the Mohawk River, and 52.9 and 33.1 kg for the upper Hudson River. Differences between the results of the two methods are attributed to the inability of the rating-curve method to adequately characterize atypical high flows such as an ice-dam release, or to account for hysteresis, which typically degrades the strength of the relation between stream discharge and concentration of material in suspension. ?? Springer 2005.

  12. A simulation of the Cerro Hudson SO[sub 2] cloud

    SciTech Connect

    Schoeberl, M.R.; Lait, L.R.; Newman, P.A.; Krueger, A.J. ); Doiron, S.D. )

    1993-02-20

    An isentropic trajectory model is used to simulate the evolution of the southern hemisphere SO[sub 2] cloud associated with the eruption of Cerro Hudson. By matching the parcel trajectories with total ozone mapping spectrometer SO[sub 2] retrievals, the principal stratospheric injection region is determined to be between 11 and 16 km in altitude. This region is characterized by weak wind shears and is located just poleward of the subtropical jet in the outer fringe of the stratospheric polar vortex. The lack of wind shear in the injection region explains the slow zonal dispersal of the SO[sub 2] cloud which was still clearly observed 19 days after the eruption. The trajectory model simulation of the SO[sub 2] cloud shows good agreement with observations for 7 days after the eruption. Using the potential vorticity and potential temperature estimates of the initial eruption cloud, the cloud position relative to the polar night jet is shown to be nearly fixed up to September 2, 1991, which was as long as the cloud was observed. This result suggests that the lower stratopsheric polar and mid-latitude regions are nearly isolated from each other during the late August period. 9 refs., 5 figs.

  13. Gazetteer of hydrologic characteristics of streams in Massachusetts : Hudson River basin

    USGS Publications Warehouse

    Wandle, S. William

    1984-01-01

    The Hudson River basin includes streams draining the Hoosic River (205 square miles), Kinderhook Creek (20.9 square miles), and Roeliff Jansen Kill (13.3 square miles) basins in western Massachusetts, eastern New York, and southern Vermont. Drainage areas, using the latest available 1:24,000 scale topographic maps, are re-computed for data-collection sites and computed for the first time for streams draining greater than 3 square miles. Basin characteristics representing 14 commonly used indices to estimate various streamflows are presented for the five gaged streams in the Hoosic River basin. Streamflow characteristics, representing statistics computed using a new data base with records through 1979, include annual and monthly flow statistics , duration of daily flow values, and the annual 7-day mean low flow at the 2-year and 10-year recurrence intervals. Seven-day low-flow statistics are presented for 21 partial-record sites. The procedures used to determine the hydrologic characteristics are summarized. This gazetteer of hydrologic characteristics will aid in the planning and siting of water-resources-related activities and will provide a common data base for governmental agencies and the engineering and planning communities. (USGS)

  14. Habitat use of American eel (Anguilla rostrata) in a tributary of the Hudson River, New York

    USGS Publications Warehouse

    Johnson, James H.; Nack, Christopher C.

    2013-01-01

    American eel Anguilla rostrata populations are declining over much of their native range. Since American eels spend extended periods in freshwater, understanding their habitat requirements while freshwater residents is important for the management and conservation of this species. As there is little information on American eel habitat use in streams, the ontogenetic, diel, and seasonal habitat use as well as habitat selectivity of three size groups (i.e. ≤199 mm total length, 200–399 mm, ≥400 mm) of eel were examined in a tributary of the Hudson River. American eels in Hannacroix Creek exhibited ontogenetic, diel, and seasonal variation in habitat use as well as habitat selection. During both summer and autumn all sizes of American eels used larger substrate and more cover during the day. American eels ≤199 mm exhibited the strongest habitat selection, whereas eels 200–399 mm exhibited the least. During the autumn all sizes of American eels occupied slower depositional areas where deciduous leaf litter accumulated and provided cover. This may have important implications for in-stream and riparian habitat management of lotic systems used by American eel.

  15. Minimum Bayes risk image correlation

    NASA Technical Reports Server (NTRS)

    Minter, T. C., Jr.

    1980-01-01

    In this paper, the problem of designing a matched filter for image correlation will be treated as a statistical pattern recognition problem. It is shown that, by minimizing a suitable criterion, a matched filter can be estimated which approximates the optimum Bayes discriminant function in a least-squares sense. It is well known that the use of the Bayes discriminant function in target classification minimizes the Bayes risk, which in turn directly minimizes the probability of a false fix. A fast Fourier implementation of the minimum Bayes risk correlation procedure is described.

  16. USGS Tampa Bay Pilot Study

    USGS Publications Warehouse

    Yates, K.K.; Cronin, T. M.; Crane, M.; Hansen, M.; Nayeghandi, A.; Swarzenski, P.; Edgar, T.; Brooks, G.R.; Suthard, B.; Hine, A.; Locker, S.; Willard, D.A.; Hastings, D.; Flower, B.; Hollander, D.; Larson, R.A.; Smith, K.

    2007-01-01

    Providing a web-based digital information management system of information for scientists and the public, including a system that supports the work of those officials who must make decisions that affect the state of the bay. The Tampa Bay Study is in its sixth year and will continue through September 2007. This paper presents a non-inclusive summary of key findings associated with the six primary project components listed above. Component 4 (above) is described in detail in the following chapter 13. More information on the Tampa Bay Study is available from our on-line digital information system for the Tampa Bay Study at http://gulfsci.usgs.gov.

  17. Megaflutes in a continental shelf setting, Placentia Bay, Newfoundland

    NASA Astrophysics Data System (ADS)

    Shaw, John; Puig, Pere; Han, Guoqi

    2013-05-01

    Megaflutes - erosional scours normally found in deep water on continental slopes - were identified in 1978 on sidescan sonograms and seismic reflection profiles from Placentia Bay on the south coast of Newfoundland, Canada. Data from recent extensive multibeam sonar surveys provide an opportunity to describe the morphology and distribution of the megaflutes in detail, and to consider the formative processes. They occur on the east side of the outer bay, at a depth of ~ 200 m, in a 2-3 km-wide swath that continues to the south into Halibut Channel, over a total distance of ~ 100 km. The megaflutes have been formed by removal of a layer of postglacial mud, exposing underlying glaciomarine sediments and releasing a volume of 4.5 km3. They occur in a range of forms, including single, multiple, and coalescent types, and in some areas at least their inception was related to pre-existing pockmarks. Radiocarbon dates from piston cores are used to demonstrate that megaflute formation post-dated ca. 9 ka. Megaflute formation in Placentia Bay has been attributed to a 'reverse flow' from the tsunami generated by the 1929 Grand Banks earthquake, and this is still the accepted hypothesis. We argue that the return flow from a tsunami did not generate the megaflutes, and suggest instead that they could be formed during south-flowing density currents generated when volumes of cold saline water stored in the deep (> 250 m) basins at the head of Placentia Bay are intermittently displaced and spilled south in a shallow channel at the east side of the bay after intense coastal surface dense water formation events, perhaps during very cold winters.

  18. Bird's eye view of the STS-7 cargo bay inside the VPF

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Bird's eye view of the STS-7 cargo bay inside the vertical processing facility during pre-move-to-pad preparations. From top to bottom (forward to aft), the payloads are West Germany/Rbb's SPAS-01 or shuttle pallet satellite; OSTA-2, the second shuttle experiment sponsored by NASA Office of Space and Terrestrial Applications; Palapa B-1, a second generation communications spacecraft designed and built for Indonesia and Anik C-2, a communications satellite owned and operated by Telesat of Canada.

  19. Canadian Seismicity Catalogue - Western Canada

    NASA Astrophysics Data System (ADS)

    Mulder, T.

    2003-04-01

    The first seismograph station in western Canada was installed in Victoria, BC, in 1898, under the Meteorological Service of Canada. By 1940, seismograph installations in Canada were amalgamated under the Dominion Observatory. The first short-period instruments were installed in western Canada in the early 1950's. The first digital instruments were installed in the mid-1970's. To date there are now 54 digital stations in western Canada that are routinely used in analysis as well as 2 paper-record stations. Detection ability has increased significantly over the past 20 years. Magnitude thresholds for locations vary over space and time reflecting seismicity levels, station distribution, and staffing levels. Currently the magnitude thresholds are (these do not necessarily equate to completeness levels): M=2.5-3.0 for western Canada; M=2.0 in the St Elias Mountains, YT, the northern Coast Mountains, BC, most of southern BC, and southwestern Alberta; M=1.0-1.5 in the Queen Charlotte Islands, southern Coast Mountains, and northern Vancouver Island; M=0.7-0.8 in southern Vancouver Island and the adjacent mainland. Events have been located with a variety of location programs over the years. A number of velocity models have been in use over time, currently resulting in a generic model for all of western Canada, and a model each for offshore, the Queen Charlotte Islands, and Vancouver Island. Recently purchased Antelope software will allow improved ability to maintain and possibly extend current magnitude thresholds as much of the daily analyst housekeeping tasks are decreased. Recent additions to the catalogue are regular computation of P-nodal and moment tensor solutions.

  20. Learning on the Big Bay

    ERIC Educational Resources Information Center

    Philp, Michael J.

    1978-01-01

    Anne Arundel Community College uses the Chesapeake Bay for a flexible ocean engineering technology program which includes mechanical, electrical, and environmental options for transfer and/or vocational students, and adult education programs covering such subjects as sailing, Bay history, boat building, scuba-diving, and marine biology. (RT)

  1. Traditional Chinese medicine education in Canada.

    PubMed

    Du, Huan-bin

    2015-03-01

    The history of education and legislation of traditional Chinese medicine (TCM) and acupuncture in Canada is short. The first school of TCM opened its door to the general public in Canada in 1985 and the first legislation of acupuncture was introduced in Alberta, Canada in 1988. Currently, TCM and/or acupuncture have been regulated in five provinces in Canada. The legislation and regulation, as well as education of TCM and acupuncture vary among the five provinces in Canada. Opportunities and challenges facing TCM education exist simultaneously. Strategies are proposed to develop an international standard for TCM education in Canada, and possibly in other English speaking countries as well.

  2. The Bayes Inference Engine

    SciTech Connect

    Hanson, K.M.; Cunningham, G.S.

    1996-04-01

    The authors are developing a computer application, called the Bayes Inference Engine, to provide the means to make inferences about models of physical reality within a Bayesian framework. The construction of complex nonlinear models is achieved by a fully object-oriented design. The models are represented by a data-flow diagram that may be manipulated by the analyst through a graphical programming environment. Maximum a posteriori solutions are achieved using a general, gradient-based optimization algorithm. The application incorporates a new technique of estimating and visualizing the uncertainties in specific aspects of the model.

  3. Aquatic nuisance species in the New York State Canal and Hudson River systems and the Great Lakes Basin: an economic and environmental assessment.

    PubMed

    Pimentel, David

    2005-05-01

    A total of 154 aquatic alien species have invaded the New York State Canal and Hudson River systems and a total of 162 aquatic species have invaded the Great Lakes Basin. Some of these invasive species are causing significant damage and control costs in both aquatic ecosystems. In the New York State Canal and Hudson River systems, the nonindigenous species are causing an estimated 500 million dollars in economic losses each year. The economic and environmental situation in the Great Lakes Basin is far more serious from nonindigenous species, with losses estimated to be about 5.7 billion dollars per year. Commercial and sport fishing suffer the most from the biological invasions, with about 400 million dollars in losses reported for the New York State Canal and Hudson River systems and 4.5 billion dollars in losses reported for the Great Lakes Basin.

  4. Ground-Water Quality in the Upper Hudson River Basin, New York, 2007

    USGS Publications Warehouse

    Nystrom, Elizabeth A.

    2009-01-01

    Water samples were collected from 25 production and domestic wells in the Upper Hudson River Basin (north of the Federal Dam at Troy, N.Y.) from August through November 2007 to characterize the ground-water quality. The Upper Hudson River Basin covers 4,600 square miles in upstate New York, Vermont, and Massachusetts; the study area encompasses the 4,000 square miles that lie within New York. The basin is underlain by crystalline and sedimentary bedrock, including gneiss, shale, and slate; some sandstone and carbonate rocks are present locally. The bedrock in some areas is overlain by surficial deposits of saturated sand and gravel. Of the 25 wells sampled, 13 were finished in sand and gravel deposits, and 12 were finished in bedrock. The samples were collected and processed by standard U.S. Geological Survey procedures and were analyzed for 225 physical properties and constituents, including major ions, nutrients, trace elements, radon-222, pesticides, volatile organic compounds (VOCs), and indicator bacteria. Water quality in the study area is generally good, but concentrations of some constituents exceeded current or proposed Federal or New York State drinking-water standards; these were: color (1 sample), pH (2 samples), sodium (5 samples), nitrate plus nitrite (2 samples), aluminum (3 samples), iron (1 sample), manganese (7 samples), radon-222 (11 samples), and bacteria (1 sample). Dissolved-oxygen concentrations in samples from wells finished in sand and gravel [median 5.4 milligrams per liter (mg/L)] were greater than those from wells finished in bedrock (median 0.4 mg/L). The pH of all samples was typically neutral or slightly basic (median 7.6); the median water temperature was 9.7 deg C. The ions with the highest concentrations were bicarbonate (median 123 mg/L) and calcium (median 33.9 mg/L). Ground water in the basin is generally soft to moderately hard (less than or equal to 120 mg/L as CaCO3) (median hardness 110 mg/L as CaCO3). Concentrations of

  5. Microbial production, enzyme activity, and carbon turnover in surface sediments of the Hudson River estuary.

    PubMed

    Sinsabaugh, R L; Findlay, S

    1995-09-01

    The detrital food web is a major nexus of energy flow in nearly all aquatic ecosystems. Energy enters this nexus by microbial assimilation of detrital carbon. To link microbiological variables with ecosystem process, it is necessary to understand the regulatory hierarchy that controls the distribution of microbial biomass and activity. Toward that goal, we investigated variability in microbial abundance and activities within the tidal freshwater estuary of the Hudson River. Surface sediments were collected from four contrasting sites: a mid-channel shoal, two types of wetlands, and a tributary confluence. These samples, collected in June to August 1992, were sorted into two to four size fractions, depending on the particle size distribution at each site. Each fraction was analyzed for bacterial biomass (by acridine orange direct counting), bacterial production (by (3)H-thymidine incorporation into DNA), fungal biomass (by ergosterol extraction), fungal production (by biomass accrual), and the potential activities of seven extracellular enzymes involved in the degradation of detrital structural molecules. Decomposition rates for particulate organic carbon (POC) were estimated from a statistical model relating mass loss rates to endocellulase activity. Within samples, bacterial biomass and productivity were negatively correlated with particle size: Standing stocks and rates in the <63-μm class were roughly twofold greater than in the >4-mm class. Conversely, fungal biomass was positively correlated with particle size, with standing stocks in the largest size class more than 1OX greater than in the smallest. Extracellular enzyme activities also differed significantly among size classes, with high carbohydrase activities associated with the largest particles, while oxidative activities predominated in the smallest size classes. Among sites, the mid-channel sediments had the lowest POC standing stock (2% of sediment dry mass) and longest turnover time (approximately 1

  6. The vertical structure of the circulation and dynamics in Hudson Shelf Valley

    USGS Publications Warehouse

    Lentz, Steven J.; Butman, Bradford; Harris, Courtney K.

    2014-01-01

    Hudson Shelf Valley is a 20–30 m deep, 5–10 km wide v-shaped submarine valley that extends across the Middle Atlantic Bight continental shelf. The valley provides a conduit for cross-shelf exchange via along-valley currents of 0.5 m s−1 or more. Current profile, pressure, and density observations collected during the winter of 1999–2000 are used to examine the vertical structure and dynamics of the flow. Near-bottom along-valley currents having times scales of a few days are driven by cross-shelf pressure gradients setup by wind stresses, with eastward (westward) winds driving onshore (offshore) flow within the valley. The along-valley momentum balance in the bottom boundary layer is predominantly between the pressure gradient and bottom stress because the valley bathymetry limits current veering. Above the bottom boundary layer, the flow veers toward an along-shelf (cross-valley) orientation and a geostrophic balance with some contribution from the wind stress (surface Ekman layer). The vertical structure and strength of the along-valley current depends on the magnitude and direction of the wind stress. During offshore flows driven by westward winds, the near-bottom stratification within the valley increases resulting in a thinner bottom boundary layer and weaker offshore currents. Conversely, during onshore flows driven by eastward winds the near-bottom stratification decreases resulting in a thicker bottom boundary layer and stronger onshore currents. Consequently, for wind stress magnitudes exceeding 0.1 N m−2, onshore along-valley transport associated with eastward wind stress exceeds the offshore transport associated with westward wind stress of the same magnitude.

  7. Sedimentary facies, geomorphic features and habitat distribution at the Hudson Canyon head from AUV multibeam data

    NASA Astrophysics Data System (ADS)

    Pierdomenico, Martina; Guida, Vincent G.; Macelloni, Leonardo; Chiocci, Francesco L.; Rona, Peter A.; Scranton, Mary I.; Asper, Vernon; Diercks, Arne

    2015-11-01

    Mapping of physical benthic habitats at the head of Hudson Canyon was performed by means of integrated analysis of acoustic data, video surveys and seafloor sampling. Acoustic mapping, performed using AUV-mounted multibeam sonar, provided ultra-high resolution bathymetric and backscatter imagery for the identification of geomorphological features and the characterization of surficial sediments. Habitat characterization in terms of seafloor texture and identification of benthic and demersal communities was accomplished by visual analysis of still photographs from underwater vehicles. Habitat classes were defined on the basis of the seafloor texture observed on photos and then compared with the geophysical data in order to associate habitats to acoustic classes and/or geomorphological features. This enabled us to infer habitat distribution on the basis of morpho-acoustic classes and extrapolate results over larger areas. Results from bottom trawling were used to determine the overall biodiversity within the identified habitats. Our analysis revealed a variety of topographic and sedimentological structures that provide a wide range of physical habitats. A variety of sandy and muddy substrates, gravel patches and mudstone outcrops host rich and varied faunal assemblages, including cold-water corals and sponge communities. Pockmark fields below 300 m depth suggest that methane-based chemosynthetic carbonate deposition may contributes to creation of specific benthic habitats. Hummocky terrain has been delineated along the canyon rims and associated with extensive, long-term burrowing activity by golden tilefish (Lopholatilus chamaeleonticeps). These results show the relationships of physical features to benthic habitat variation, support the notion of the area as a biodiversity hotspot and define essential habitats for planning of sustainable regional fisheries.

  8. Plutonium and radiocesium in the water column of the Hudson River estuary

    NASA Astrophysics Data System (ADS)

    Linsalata, P.; Simpson, H. J.; Olsen, C. R.; Cohen, N.; Trier, R. M.

    1985-12-01

    Isotopes of plutonium (Pu), cesium (Cs), and cobalt (Co) introduced into the Hudson River Estuary from fallout deposition, the erosion of fallout-contaminated surface soils, and nuclear reactor effluent (isotopes of Cs and Co only) have been measured in water column samples collected from 1975 to 1980 Isotopic measurements conducted independently by two research groups utilizing different sampling and analytical techniques have been summarized. The major conclusions drawn from the work are that for water samples collected by the two laboratories over similar time periods, the mean concentrations of nonfilterable239,240Pu (<0.45 μm) were identical at 0.13 fCi/l, mean concentrations of both137Cs and239,240Pu in suspended particulates were more divergent at 2,270±920 pCi/kg (±1 SD) and 1,430±430 pCi/kg for137Cs, and 19±8 pCi/kg and 12±4 pCi/kg for239,240Pu The behavior of239,240Pu and137Cs within the water column is shown to diverge within brackish waters Specifically, the magnitude of the137Cs distribution coefficient ( K d ) can be expressed as an inverse power function of the chloride ion concentrations for chlorinities between 0.1 and 4 g Cl-/l No difference in the239,240Pu K d has been observed between fresh and brackish waters Based on the expected inventories of239,240Pu and137Cs within watershed soils, the current downstream transport of these radionuclides represents fractional mobilization rates on the order of 1 4 (×10-4) per year

  9. Landscape controls on total and methyl Hg in the Upper Hudson River basin, New York, USA

    USGS Publications Warehouse

    Burns, Douglas A.; Riva-Murray, K.; Bradley, P.M.; Aiken, G.R.; Brigham, M.E.

    2012-01-01

    Approaches are needed to better predict spatial variation in riverine Hg concentrations across heterogeneous landscapes that include mountains, wetlands, and open waters. We applied multivariate linear regression to determine the landscape factors and chemical variables that best account for the spatial variation of total Hg (THg) and methyl Hg (MeHg) concentrations in 27 sub-basins across the 493 km2 upper Hudson River basin in the Adirondack Mountains of New York. THg concentrations varied by sixfold, and those of MeHg by 40-fold in synoptic samples collected at low-to-moderate flow, during spring and summer of 2006 and 2008. Bivariate linear regression relations of THg and MeHg concentrations with either percent wetland area or DOC concentrations were significant but could account for only about 1/3 of the variation in these Hg forms in summer. In contrast, multivariate linear regression relations that included metrics of (1) hydrogeomorphology, (2) riparian/wetland area, and (3) open water, explained about 66% to >90% of spatial variation in each Hg form in spring and summer samples. These metrics reflect the influence of basin morphometry and riparian soils on Hg source and transport, and the role of open water as a Hg sink. Multivariate models based solely on these landscape metrics generally accounted for as much or more of the variation in Hg concentrations than models based on chemical and physical metrics, and show great promise for identifying waters with expected high Hg concentrations in the Adirondack region and similar glaciated riverine ecosystems.

  10. Shear-wave velocity of slope sediments near Hudson Canyon from analysis of ambient noise

    NASA Astrophysics Data System (ADS)

    Miller, N. C.; Ten Brink, U. S.; Collins, J. A.; McGuire, J. J.; Flores, C. H.

    2014-12-01

    We present new ambient noise data that help constrain the shear strength of marine sediments on the continental slope north of Hudson Canyon on the U.S. Atlantic margin. Sediment shear strength is a key parameter in models of potentially tsunamigenic, submarine slope failures, but shear strength is difficult to measure in situ and is expected to evolve in time with changes in pore pressure. The ambient noise data were recorded by 11 short-period, ocean-bottom seismometers and hydrophones deployed in a ~1 by 1.5 km array for ~6 months on the continental slope. These high frequency (~0.1 - 50 Hz), narrow-aperture data are expected to record noise propagating as interface waves and/or resonating in the upper ~500 m of sediment. Propagation of interface waves is controlled by the shear-wave velocity of the sediment, which we measure by calculating lag-times in cross-correlations of waveforms recorded by pairs of receivers. These measurements of shear-wave velocity will be used to constrain shear strength. The data also appear to record wind-generated noise resonating in layered sediment. We expect this resonance to also be sensitive to shear-wave velocity, and spectral analysis and modeling of harmonics may provide a second constraint on sediment shear strength. Both the correlogram- and spectral-based measurements can be made using hour- to day-long segments of data, enabling us to constrain temporal evolution of shear-wave velocity and potential forcing mechanisms (e.g., tidal and storm loading and submarine groundwater discharge) through the ~6 month deployment.

  11. Tampa Bay environmental atlas

    SciTech Connect

    Kunneke, J.T.; Palik, T.F.

    1984-12-01

    Biological and water resource data for Tampa Bay were compiled and mapped at a scale of 1:24,000. This atlas consists of (1) composited information overlain on 18 biological and 20 water resource base maps and (2) an accompanying map narrative. Subjects mapped on the water resource maps are contours of the mean middepth specific conductivity which can be converted to salinity; bathymetry, sediments, tidal currents, the freshwater/saltwater interface, dredge spoil disposal sites; locations of industrial and municipal point source discharges, tide stations, and water quality sampling stations. The point source discharge locations show permitted capacity and the water quality sampling stations show 5-year averages for chlorophyll, conductivity, turbidity, temperature, and total nitrogen. The subjects shown on the biological resource maps are clam and oyster beds, shellfish harvest areas, colonial bird nesting sites, manatee habitat, seagrass beds and artificial reefs. Spawning seasons, nursery habitats, and adult habitats are identified for major fish species. The atlas will provide useful information for coastal planning and management in Tampa Bay.

  12. 33 CFR 162.125 - Sturgeon Bay and the Sturgeon Bay Ship Canal, Wisc.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Sturgeon Bay and the Sturgeon Bay... Sturgeon Bay and the Sturgeon Bay Ship Canal, Wisc. (a) In the Sturgeon Bay Ship Canal: (1) No vessel may...) Each vessel must keep to the center, except when meeting or overtaking another vessel. (b) In...

  13. 33 CFR 162.125 - Sturgeon Bay and the Sturgeon Bay Ship Canal, Wisc.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Sturgeon Bay and the Sturgeon Bay... Sturgeon Bay and the Sturgeon Bay Ship Canal, Wisc. (a) In the Sturgeon Bay Ship Canal: (1) No vessel may...) Each vessel must keep to the center, except when meeting or overtaking another vessel. (b) In...

  14. 33 CFR 162.125 - Sturgeon Bay and the Sturgeon Bay Ship Canal, Wisc.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Sturgeon Bay and the Sturgeon Bay... Sturgeon Bay and the Sturgeon Bay Ship Canal, Wisc. (a) In the Sturgeon Bay Ship Canal: (1) No vessel may...) Each vessel must keep to the center, except when meeting or overtaking another vessel. (b) In...

  15. 33 CFR 162.125 - Sturgeon Bay and the Sturgeon Bay Ship Canal, Wisc.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Sturgeon Bay and the Sturgeon Bay... Sturgeon Bay and the Sturgeon Bay Ship Canal, Wisc. (a) In the Sturgeon Bay Ship Canal: (1) No vessel may...) Each vessel must keep to the center, except when meeting or overtaking another vessel. (b) In...

  16. 33 CFR 162.125 - Sturgeon Bay and the Sturgeon Bay Ship Canal, Wisc.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Sturgeon Bay and the Sturgeon Bay... Sturgeon Bay and the Sturgeon Bay Ship Canal, Wisc. (a) In the Sturgeon Bay Ship Canal: (1) No vessel may...) Each vessel must keep to the center, except when meeting or overtaking another vessel. (b) In...

  17. Multicultural Canada: A Graphic Overview = Un Canada Multicuturel: Representation Graphique.

    ERIC Educational Resources Information Center

    Ledoux, Michel; Pendakur, Ravi

    This graphic overview uses 28 bar and pie graphs to illustrate Canada's ethnic and linguistic diversity. Information was drawn primarily from 1986 census figures. The following categories are examined: (1) ethnic origin; (2) language; (3) visible minorities (nonwhites); (4) aboriginal peoples; and (5) immigration. Information is reported for the…

  18. National Dam Safety Program. Tomhannock Spillway Dam (Inventory Number N.Y. 117), Upper Hudson River Basin, Rensselaer County, New York. Phase I Inspection Report,

    DTIC Science & Technology

    1981-08-01

    yUIION TfS ( IIAffI UPPER HUDSON RIVER BASIN TOMHANNOCK SPILLWAY DAM INEW YORK I INVENTORY No. NY 117 I JAN 2 0 1982 I E I PHASE I INSPECTION REPORT...NATIONAL DAM SAFETY PROGRAM APPROVED FOR DUBLIC RE. ---- DISTRIBUTION UNLIMITED I NEW YORK DISTRICT CORPS OF ENGINEERS I ~~AUGT 191 1 01 19 82119 REPOR...E Upper Hudson River Basin, Rensselaer County, NY O3.OG PPHU4IIInventory No. NY00117 7.AUTHOR(Ja8 O4fA)AT~MEb JOHIN B. STETSON .DACW3J1---00 * 9

  19. Chesapeake Bay: Introduction to an Ecosystem.

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Washington, DC.

    The Chesapeake Bay is the largest estuary in the contiguous United States. The Bay and its tidal tributaries make up the Chesapeake Bay ecosystem. This document, which focuses of various aspects of this ecosystem, is divided into four major parts. The first part traces the geologic history of the Bay, describes the overall physical structure of…

  20. Creating a Learning Culture. Work and Literacy in the Nineties. Based on the Report, "Workforce Literacy: An Economic Challenge for Canada," by the Hudson Institute.

    ERIC Educational Resources Information Center

    National Literacy Secretariat, Ottawa (Ontario).

    Technological change and other innovations affect the way Canadians work. These changes demand increasingly higher levels of literacy for today and for the future. Basic skills are not enough. A low level of schooling is associated with higher unemployment. People who invest in their own higher education are likely to reap the reward of higher…

  1. Plutonism, deformation, and metamorphism in the Proterozoic Flin Flon greenstone belt, Canada: Limits on timing provided by the single-zircon Pb-evaporation technique

    SciTech Connect

    Ansdell, K.M.; Kyser, T.K. )

    1991-05-01

    The authors have used the single-zircon Pb-evaporation technique to determine the age of granitoids in the western Flin Flon domain of the Trans-Hudson orogen in Canada and to constrain the timing of molasse sedimentation, deformation, metamorphism, and mesothermal gold mineralization. The plutons were intruded between 1,860 and 1,834 Ma, about 30 m.y. after volcanism, and provide further evidence of a major period of intrusive activity throughout the Trans-Hudson orogen at that time. The older plutons (1,860 to 1,848 Ma) are synchronous with P2 deformation and the early stages of peak metamorphism, whereas the younger plutons are synchronous with or postdate the P3 deformation event. Molasse sedimentary units are deformed and metamorphosed; thus, deposition must have begun at about 1,860 Ma. Mesothermal gold mineralization postdates all plutons and may be related to high-grade peak metamorphism in adjacent terranes at about 1,815 Ma. This study also provides further support for the use of the Pb-evaporation technique as a suitable method for dating single zircons and indicates that the {sup 208}Pb/{sup 206}Pb ratio of zircons may be a useful tool in detecting the presence and source of xenocrystic zircons.

  2. Giardia sp. Cysts and Infectious Cryptosporidium parvum Oocysts in the Feces of Migratory Canada Geese (Branta canadensis)

    PubMed Central

    Graczyk, Thaddeus K.; Fayer, Ronald; Trout, James M.; Lewis, Earl J.; Farley, C. Austin; Sulaiman, Irshad; Lal, Altaf A.

    1998-01-01

    Fecal droppings of migratory Canada geese, Branta canadensis, collected from nine sites near the Chesapeake Bay (Maryland), were examined for the presence of Cryptosporidium parvum and Giardia spp. Cryptosporidium sp. oocysts were found in feces at seven of nine sites, and Giardia cysts were found at all nine sites. The oocysts from three sites were infectious for mice and molecularly identified as the zoonotic genotype of Cryptosporidium parvum. Waterfowl can disseminate infectious C. parvum oocysts in the environment. PMID:9647860

  3. Geologic Assessment of Undiscovered Oil and Gas Resources of the West Greenland-East Canada Province

    USGS Publications Warehouse

    Schenk, Christopher J.

    2010-01-01

    The U.S. Geological Survey (USGS) recently assessed the potential for undiscovered oil and gas resources of the West Greenland-East Canada Province as part of the USGS Circum-Arctic Resource Appraisal program. The province lies in the offshore area between western Greenland and eastern Canada and includes Baffin Bay, Davis Strait, Lancaster Sound, and Nares Strait west of and including part of Kane Basin. A series of major tectonic events led to the formation of several distinct structural domains that are the geologic basis for defining five assessment units (AU) in the province, all of which are within the Mesozoic-Cenozoic Composite Total Petroleum System (TPS). Potential petroleum source rocks within the TPS include strata of Ordovician, Early and Late Cretaceous, and Paleogene ages. The five AUs defined for this study-the Eurekan Structures AU, Northwest Greenland Rifted Margin AU, Northeast Canada Rifted Margin AU, Baffin Bay Basin AU, and the Greater Ungava Fault Zone AU-encompass the entire province and were assessed for undiscovered, technically recoverable resources.

  4. History of Adult Vocational Education in Canada.

    ERIC Educational Resources Information Center

    Malmberg, Harvey

    This review of adult vocational education in Canada includes an introduction, highlights in the history of adult vocational education in Canada, and a summary. The introduction considers what adult vocational education is and explains the relationship between Canada's constitution and education. The highlights section covers these periods: before…

  5. Let's Celebrate! Canada's Special Days.

    ERIC Educational Resources Information Center

    Parry, Caroline

    Designed for children ages 8 to 13, this teaching resource presents an explanation of seasons, calendars, and why people celebrate particular days. The four seasons are discussed. Canada's national holidays, and the seasonal, social and religious holidays celebrated by diverse Canadian culture groups are described. A separate section presents…

  6. Fuel Additives: Canada bans MMT

    SciTech Connect

    Sissell, K.

    1997-04-16

    The Canadian Senate voted late last week to ban use of the manganese-based fuel additive MMT, produced only in the US by Ethyl. MMT, which has been sold in Canada for the past 20 years and accounts for about half of Ethyl`s Canadian sales, has been criticized by environmentalists, who have raised public health concerns, and automakers, who say it harms emission control systems. {open_quotes}Canada`s vote is a great victory for public health and the environment,{close_quotes} says Environmental Defense Fund executive director Fred Krupp. {open_quotes}The US should move swiftly to follow suit and suspend sales of MMT until adequate toxicity testing on the additive is completed.{close_quotes} EPA had refused to approve MMT for sale because of health concerns but was compelled to do so by a December 1995 court ruling. Ethyl asserts the ban violates Canada`s obligations under Nafta and says it will file a damage claim with the Nafta arbitration panel.

  7. Canada's Crisis in Advanced Skills

    ERIC Educational Resources Information Center

    Association of Canadian Community Colleges, 2008

    2008-01-01

    The key to economic and social development lies in the knowledge and skill base of human capital. This report, presented to the House of Commons Standing Committee on Finance, calls for vigorous action on the part of the Government of Canada, in concert with the provinces and territories, to protect the Canadian economy from a skills shortage…

  8. Creative Literature in Canada Symposium.

    ERIC Educational Resources Information Center

    Buller, Grace, Ed.; McDonough, Irma, Ed.

    The contents of this booklet were presented at a symposium on Canadian creative literature at the University of Toronto in March 1974. Included are five papers, summaries of two talks (one by Bill Sault on the oral tradition of Canada's native peoples and one by Robert Weaver on discovering and encouraging Canadian writers) and of a panel…

  9. Project Canada West. Interim Report.

    ERIC Educational Resources Information Center

    Western Curriculum Project on Canada Studies, Edmonton (Alberta).

    This first interim report of project Canada West, initiated in April, 1970, includes three papers. "Curriculum Development in Urbanization," by Dr. R. H. Sabey, Acting Executive Director, is an overview of the Project's history, purpose, and the 5 year plan for phases of research development. (See SO 000 283 for complete abstract.) Two…

  10. The Inuit (Eskimo) of Canada.

    ERIC Educational Resources Information Center

    Creery, Ian

    This report examines the history of the colonization of Arctic Canada and the efforts of its 25,000 Inuit residents to decolonize themselves. Initial sections outline the origins and early history of the Inuit; characteristics of Inuit culture, family life, and spirituality; the effects of whaling and the fur trade; and the movement of the Inuit…

  11. Educating Canada's Urban Poor Children.

    ERIC Educational Resources Information Center

    Maynes, Bill; Foster, Rosemary

    2000-01-01

    Presents six critical thoughts and questions about educating poor urban children in Canada. These thoughts were derived from the development of a directory of Canadian educational poverty programs. Findings from that study emphasize the increasing diversity of the student population, the importance of temporary and large-scale funding, and the…

  12. Summertime sources of dimethyl sulfide in the Canadian Arctic Archipelago and Baffin Bay

    NASA Astrophysics Data System (ADS)

    Mungall, E. L.; Croft, B.; Lizotte, M.; Thomas, J. L.; Murphy, J. G.; Levasseur, M.; Martin, R. V.; Wentzell, J. J. B.; Liggio, J.; Abbatt, J. P. D.

    2015-12-01

    Dimethyl sulfide (DMS) plays a major role in the global sulfur cycle. In addition, its atmospheric oxidation products contribute to the formation and growth of atmospheric aerosol particles, thereby influencing cloud condensation nuclei (CCN) populations and thus cloud formation. The pristine summertime Arctic atmosphere is a CCN-limited regime, and is thus very susceptible to the influence of DMS. However, atmospheric DMS mixing ratios have only rarely been measured in the summertime Arctic. During July-August 2014, we conducted the first high time resolution (10 Hz) DMS mixing ratio measurements for the Eastern Canadian Archipelago and Baffin Bay as one component of the Network on Climate and Aerosols: Addressing Key Uncertainties in Remote Canadian Environments (NETCARE). DMS mixing ratios ranged from below the detection limit of 4 to 1155 pptv (median 186 pptv). A set of transfer velocity parameterizations from the literature coupled with our atmospheric and coincident seawater DMS measurements yielded air-sea DMS flux estimates ranging from 0.02-12 μmol m-2 d-1, the first published for this region in summer. Airmass trajectory analysis using FLEXPART-WRF and chemical transport modeling using GEOS-Chem indicated that local sources (Lancaster Sound and Baffin Bay) were the dominant contributors to the DMS measured along the 21 day ship track, with episodic transport from the Hudson Bay System. After adjusting GEOS-Chem oceanic DMS values in the region to match measurements, GEOS-Chem reproduced the major features of the measured time series, but remained biased low overall (median 67 pptv). We investigated non-marine sources that might contribute to this bias, such as DMS emissions from lakes, biomass burning, melt ponds and coastal tundra. While the local marine sources of DMS dominated overall, our results suggest that non-local and possibly non-marine sources episodically contributed strongly to the observed summertime Arctic DMS mixing ratios.

  13. Coastal Erosion along Monterey Bay.

    DTIC Science & Technology

    1985-03-01

    RD-Al155 61@ COASTAL EROSION ALONG MONTEREY BAY(U) NAVAL1/ A8POSTGRADUATE SCHOOL MONTEREY CA A I SKLAVIDIS El AL. UNCLASSIFIED F/G 8/3 NmIIhllllllll...RESOLUTION TEST CHART NAVAL POSTGRADUATE SCHOOL Monterey, California 0 to Lfl IC)I I ~JUN 2 71985 THESIS~ COASTAL EROSION ALONG MONTEREY BAY by Anastasios I...PERIOD COVERED Master’s thesis; COASTAL EROSION ALONG MONTEREY BAY March 1985 4. PERFORMING ORG. REPORT NUMBIER 7. AUTMOR(s) 6. CONTRACT OR GRANT NUMBER(a

  14. Probabilistic Tsunami Hazard Assessment for a Site in Eastern Canada

    NASA Astrophysics Data System (ADS)

    Kulkarni, Vikram; Arcos, Maria E. M.; Alcinov, Trajce; Lavine, Alexis; Youngs, Robert; Roussel, Patrick; Mullin, Derek

    2016-12-01

    Unlike probabilistic seismic hazard analysis (PSHA), there is not a well-established methodology for probabilistic tsunami hazard analysis (PTHA). The PTHA methodology presented is similar to the widely used PSHA methodology for ground motion, and incorporates both aleatory and epistemic uncertainty in calculating the probability of exceeding runup and drawdown values produced by tsunamigenic sources. Evaluating tsunami hazard is more difficult in locations such as the eastern coastline of Canada because of low tsunami recurrence rates and few historical examples. In this study, we evaluated the hazard from local and far-field earthquake and landslide tsunamigenic sources at a site on the Bay of Fundy in New Brunswick, Canada. These sources included local faults, the Puerto Rico subduction zone, fault sources in the Azores-Gibraltar plate boundary region, and landslides on the Canadian continental slope and in the Canary Islands. Using a new PTHA methodology that is closely linked to well-established PSHA methodology combined with tide stage probability, we calculated that the return period for a wave runup exceeding the tidal range of +4 m level above mean sea level (highest astronomical tide) is approximately 14,500 years.

  15. Adult tree swallow survival on the polychlorinated biphenyl-contaminated Hudson River, New York, USA, between 2006 and 2010.

    PubMed

    Custer, Christine M; Custer, Thomas W; Hines, James E

    2012-08-01

    The upper Hudson River basin in east central New York, USA, is highly contaminated, primarily with polychlorinated biphenyls (PCBs). Reduced adult survival has been documented in tree swallows (Tachycineta bicolor) at a similarly PCB-contaminated river system in western Massachusetts. The purpose of the present study was to assess whether adult survival of tree swallows was likewise affected in the Hudson River basin. Between 2006 and 2010, a total of 521 female tree swallows were banded, of which 148 were retrapped at least once. The authors used Program MARK and an information theoretic approach to test the hypothesis that PCB contamination reduced annual survival of female tree swallows. The model that best described the processes that generated the capture history data included covariate effects of year and female plumage coloration on survival but not PCB/river. Annual survival rates of brown-plumaged females (mostly one year old) were generally lower (mean phi=0.39) than those of blue-plumaged females (mean phi=0.50, one year or older). Poor early spring weather in 2007 was associated with reduced survival in both plumage-color groups compared to later years. Models with the effects of PCB exposure on survival (all ΔAICc values >5.0) received little support.

  16. If it quacks like a duck: reviewing health care providers' speech restrictions under the first prong of Central Hudson.

    PubMed

    Fultz, Shawn L

    2013-01-01

    The First Amendment protects the speech of health care providers. This protection can limit states' abilities to protect patients from harmful therapies involving speech, such as sexual orientation change efforts. Because providers' speech is more similar to commercial speech than traditional political discourse, it is possible to create a First Amendment review analysis that better balances states' police powers with providers' First Amendment rights. Under a "single-prong" approach, the first prong of Central Hudson can be used to identify quackery, which is analogous to false or misleading commercial speech and would therefore be outside the protection of the First Amendment. Because health care must be tailored to individual patients, restrictions on speech that survive the first prong of Central Hudson would be subject to strict scrutiny in order to leave the therapeutic decision to the provider and her patient, and maintain consistency with current jurisprudence. This Comment examines litigation from California's attempted ban on sexual orientation change therapy to illustrate the conflicts created by the current approach to First Amendment review of health care provider speech. This Comment then demonstrates the benefit of the proposed single-prong approach, including how it simultaneously protects patients from harm while protecting health care providers' speech.

  17. Investigating the chemical and isotopic kinetics of aerobic methane oxidation in the Northern US Atlantic Margin, Hudson Canyon

    NASA Astrophysics Data System (ADS)

    Chan, E. W.; Kessler, J. D.; Shiller, A. M.; Redmond, M. C.; Arrington, E. C.; Valentine, D. L.

    2015-12-01

    Recent discoveries of methane seepage along the US Atlantic margin have led to speculation on the fate of the released methane. Here we examine the kinetics of aerobic methane oxidation to gain a fundamental understanding of this methane sink. In order to look at this process in its entirety, a unique mesocosm incubation system was developed with a Dissolved Gas Analyzer System (DGAS) to monitor in real time the chemical and isotopic changes involved with aerobic methane oxidation. This system measures changes in methane, carbon dioxide, and oxygen concentrations as well as the stable carbon isotopes of methane and carbon dioxide with time. In addition samples are strategically removed to characterize trace metals, nutrients, cell counts, and microbial community genetics. This presentation will detail the results obtained from samples collected inside the Hudson Canyon at the edge of the methane clathrate stability zone and outside the Hudson Canyon, not influenced by the methane seepage. These results show that in both environments along the Atlantic margin, methane was consumed aggressively but the timing of consumption varied based on location. In addition, these results are leading to insights into the chemical requirements needed for aerobic methane oxidation and the resulting isotopic fractionation.

  18. Adult tree swallow survival on the polychlorinated biphenyl-contaminated Hudson River, New York, USA, between 2006 and 2010

    USGS Publications Warehouse

    Custer, Christine M.; Custer, Thomas W.; Hines, James E.

    2012-01-01

    The upper Hudson River basin in east central New York, USA, is highly contaminated, primarily with polychlorinated biphenyls (PCBs). Reduced adult survival has been documented in tree swallows (Tachycineta bicolor) at a similarly PCB-contaminated river system in western Massachusetts. The purpose of the present study was to assess whether adult survival of tree swallows was likewise affected in the Hudson River basin. Between 2006 and 2010, a total of 521 female tree swallows were banded, of which 148 were retrapped at least once. The authors used Program MARK and an information theoretic approach to test the hypothesis that PCB contamination reduced annual survival of female tree swallows. The model that best described the processes that generated the capture history data included covariate effects of year and female plumage coloration on survival but not PCB/river. Annual survival rates of brown-plumaged females (mostly one year old) were generally lower (mean phi = 0.39) than those of blue-plumaged females (mean phi = 0.50, one year or older). Poor early spring weather in 2007 was associated with reduced survival in both plumage-color groups compared to later years. Models with the effects of PCB exposure on survival (all ΔAICc values >5.0) received little support.

  19. Regional contamination versus regional dietary differences: Understanding geographic variation in brominated and chlorinated contaminant levels in polar bears

    USGS Publications Warehouse

    McKinney, M.A.; Letcher, R.J.; Aars, J.; Born, E.W.; Branigan, M.; Dietz, R.; Evans, T.J.; Gabrielsen, G.W.; Muir, D.C.G.; Peacock, E.; Sonne, C.

    2011-01-01

    The relative contribution of regional contamination versus dietary differences to geographic variation in polar bear (Ursus maritimus) contaminant levels is unknown. Dietary variation between Alaska Canada, East Greenland, and Svalbard subpopulations was assessed by muscle nitrogen and carbon stable isotope (?? 15N, ?? 13C) and adipose fatty acid (FA) signatures relative to their main prey (ringed seals). Western and southern Hudson Bay signatures were characterized by depleted ?? 15N and ??13C, lower proportions of C20 and C22 monounsaturated FAs and higher proportions of C18 and longer chain polyunsaturated FAs. East Greenland and Svalbard signatures were reversed relative to Hudson Bay. Alaskan ?? 2011 American Chemical Society.

  20. Human exposure to soil contaminants in subarctic Ontario, Canada

    PubMed Central

    Reyes, Ellen Stephanie; Liberda, Eric Nicholas; Tsuji, Leonard James S.

    2015-01-01

    Background Chemical contaminants in the Canadian subarctic present a health risk with exposures primarily occurring via the food consumption. Objective Characterization of soil contaminants is needed in northern Canada due to increased gardening and agricultural food security initiatives and the presence of known point sources of pollution. Design A field study was conducted in the western James Bay Region of Ontario, Canada, to examine the concentrations of polychlorinated biphenyls, dichlorodiphenyltrichloroethane and its metabolites (ΣDDT), other organochlorines, and metals/metalloids in potentially contaminated agriculture sites. Methods Exposure pathways were assessed by comparing the estimated daily intake to acceptable daily intake values. Ninety soil samples were collected at random (grid sampling) from 3 plots (A, B, and C) in Fort Albany (on the mainland), subarctic Ontario, Canada. The contaminated-soil samples were analysed by gas chromatography with an electron capture detector or inductively coupled plasma mass spectrometer. Results The range of ΣDDT in 90 soil samples was below the limit of detection to 4.19 mg/kg. From the 3 soil plots analysed, Plot A had the highest ΣDDT mean concentration of 1.12 mg/kg, followed by Plot B and Plot C which had 0.09 and 0.01 mg/kg, respectively. Concentrations of other organic contaminants and metals in the soil samples were below the limit of detection or found in low concentrations in all plots and did not present a human health risk. Conclusion Exposure analyses showed that the human risk was below regulatory thresholds. However, the ΣDDT concentration in Plot A exceeded soil guidelines set out by the Canadian Council of Ministers of the Environment of 0.7 mg/kg, and thus the land should not be used for agricultural or recreational purposes. Both Plots B and C were below threshold limits, and this land can be used for agricultural purposes. PMID:26025557

  1. Shifts in vegetation affect organic carbon quality in a coastal marsh along the Hudson River Estuary

    NASA Astrophysics Data System (ADS)

    Zhang, A. H.; Corbett, J. E.; Tfaily, M. M.; Martin, I.; Ho, L.; Sun, E.; Sevilla, L.; Vincent, S.; Newton, R.; Peteet, D. M.

    2015-12-01

    To better understand carbon storage in coastal salt marshes, samples were collected from Piermont Marsh, NY (40 ̊00' N, 73 ̊55'W) located within the Hudson River Estuary. Porewater from three different vegetation sites was analyzed to compare the quality of the dissolved organic carbon. Sites contained either native or invasive vegetation with variations in live plant root depth. Porewater was taken from 0-3m in 50cm intervals, and sites were dominated either by invasive Phragmites australis, native Eleocharis , or native mixed vegetation (Spartina patens, Scirpus, and Typha angustifolia). Sites dominated by invasive Phragmites australis were found to have lower dissolved organic carbon (DOC) concentrations, lower cDOM absorption values, and more labile organic carbon compounds. The molecular composition of the DOC was determined with Fourier Transform Ion Cyclotron Mass Spectrometry (FT-ICR-MS). Labile DOC components were defined as proteins, carbohydrates, and amino sugars while recalcitrant DOC components were defined as lipids, unsaturated hydrocarbons, lignins, tannins, and condensed hydrocarbons. For the Phragmites, Eleocharis, and mixed vegetation sites, average DOC concentrations with depth were found to be 1.71 ± 1.06, 4.64 ± 1.73, and 4.62 ± 3.5 (mM), respectively and cDOM absorption values with depth were found to be 13.22 ± 4.81, 49.42 ± 10.8, and 35.74 ± 17.49 (m-1). Additionally, DOC concentrations increased with depth in the mixed vegetation and Eleocharis sites, but remained relatively constant in the Phragmites site. The percent of labile compounds in the surface samples were found to be 19.02, 14.64, and 14.07% for the Phragmites, Eleocharis, and mixed vegetation sites, respectively. These findings suggest that sites dominated by Phragmites may have more reactive DOC substrates than sites dominated by native vegetation. These results indicate that the carbon storage in marshes invaded by Phragmites would be expected to decrease over time.

  2. Crustal development and deformation of Laurentia during the Trans-Hudson and Alleghenian orogenies

    NASA Astrophysics Data System (ADS)

    Growdon, Martha Lynne

    The Kisseynew domain in Manitoba and the Orange-Milford complex in Connecticut are exhumed orogenic terranes that record the development of Laurentia along rigid basement margins during continent-continent collision and terrane accretion. The Kisseynew domain lies within the Paleoproterozoic Trans-Hudson Orogen and the Orange-Milford complex is a tectonic domain within the Paleozoic New England Appalachians. The response of continental crust to continent collisions ˜1.8 Ga contrasts with that during terrane accretions ˜300 Ma because the metamorphic evolution of each terrane is strongly controlled by the configuration of the converging tectonic blocks. The Paleoproterozoic Kisseynew domain is situated between three Archean cratons: the Hearne-Rae, Superior and Sask. The development of folds with axes oriented primarily NE-SW shows evidence for east-west compression of the rocks between the Superior and Hearne cratons. However, arching along a roughly east-west axis suggests a contribution of late north-south shortening between the Sask and Hearne cratons. Metamorphic temperatures exceeded 850°C and rocks now exposed at the surface were buried to at least 40 km due to the convergence of these three continental blocks. In contrast to these very high-grade rocks, the Orange-Milford complex is situated on the edge of the New York Promontory, a crustal buttress that localized strain from oblique terrane accretion into transpression, and contains an Acadian Barrovian-style metamorphic gradient. New 40Ar/39Ar thermochronology indicates a late phase of muscovite+chlorite growth occurred ˜300Ma during retrograde Alleghenian greenschist-facies deformation. The associated chlorite-muscovite fabrics are pervasive and cross-cut all older fabrics. These structures, that develop in association with the New York Promontory, are elongated parallel to the margin and contain evidence of significant along-strike stretching and thinning. In this setting rocks escape along the

  3. Changes in Depositional Setting Reflect Rising Sealevel in Latest Holocene Sediments of the Hudson River

    NASA Astrophysics Data System (ADS)

    Slagle, A.; Carbotte, S. M.; Ryan, W. B.; Bell, R.; Nitsche, F. O.; McHugh, C. M.

    2002-12-01

    An extensive database of geophysical and sampling data in the Hudson River has been obtained in ten study areas between the New York Harbor and the Troy Dam. These data include bathymetry, bank-to-bank coverage of side-looking sonar imagery, subbottom reflection profiles, sediment cores and grabs. Geophysical properties, including gamma density, magnetic susceptibility and P-wave velocity, have been measured in a 9.3 m Vibracore (SD-30) from the near-channel tidal flats of the Tappan Zee area. Three distinct sedimentary facies have been identified, based on changes in physical properties, lithology and seismic reflections. Facies 1 is an oyster-rich unit with unstratified sediments and high sound velocities, and is found in the upper 1.5 m of core SD-30. Chirp subbottom data, which provide reflectors down to approximately 4 m depth, show a distinct horizon at 1.5 m, supporting the change seen in physical property data and lithology at this depth. A unit characterized by laminated sediments, interbedded with homogeneous layers and coquina layers, is identified as Facies 2 and is found between 1.5 and 6.1 m. This facies has high magnetic susceptibility and the appearance of discrete density cycles. The oldest unit, Facies 3, extends from 6.1 m to the base of the core at 9.3 m. It is made up of oyster-rich, unbedded sediments and thick coquina layers, and is characterized by low magnetic susceptibility. Radiocarbon dating of oysters and bivalves indicates that the different facies in SD-30 correspond to different sedimentation rates, with highest values occurring during deposition of Facies 2. The facies changes and variations in sedimentation rates are attributed to an evolving depositional environment in the tidal flats of the Tappan Zee area due to rising sealevel. Extrapolating from nearby cores that penetrate deeper into the sedimentary record, Facies 3 sits above post-glacial fluvial sands and represents the transition from a fresh to more brackish environment

  4. Pesticides in wells in agricultural and urban areas of the Hudson River basin

    USGS Publications Warehouse

    Phillips, P.J.; Wall, G.R.; Ryan, C.M.

    2000-01-01

    Ground-water samples from four monitoring well networks in the Hudson River basin were analyzed for pesticides (detection limits from 0.001 to 0.018 ??g/L). The most frequent detections were in samples from shallow depths beneath agricultural areas. Concentrations of pesticides in samples from all four networks were generally below 0.10 ??g/L, and the concentration of only one (cyanazine) exceeded any maximum contaminant levels or health advisory levels set by the U.S. Environmental Protection Agency. The well networks represented two land-use and two well-depth categories as follows: 1. agricultural shallow wells - two springs and 14 wells finished less than 15 m below land surface in unconfined unconsolidated aquifers beneath agricultural land, 2. agricultural water-supply-wells - 31 wells finished 1.8 to 120 m below land surface in unconsolidated unconfined aquifers and bedrock aquifers beneath agricultural land 3. urban/residential shallow-wells - 17 wells finished less than 16 m below land surface in unconfined unconsolidated aquifers beneath urban or residential land; and 4. urban/residential water-supply-wells - 25 water-supply or observation wells finished 5 to 113 m below land surface in unconfined, unconsolidated aquifers and bedrock aquifers beneath urban or residential land. Pesticides were detected in 69 percent of the samples from the agricultural shallow wells, in 29 percent of the samples from the agricultural water-supply wells, in no samples from the urban/residential shallow wells, and in 16 percent of the samples from the urban/residential water-supply wells. At least half of the samples from the agricultural shallow-well network contained two herbicides (atrazine and metolachlor) and one herbicide metabolite (deethylatrazine); other pesticides detected in samples from this network included metribuzin, cyanazine, EPTC, and pendimethalin. Samples from the agricultural water-supply wells contained two insecticides (diazinon and malathion), two

  5. Missisquoi Bay Phosphorus Model Addendum

    EPA Pesticide Factsheets

    This technical memorandum provides results of an extended load reduction simulation. The memorandum serves as an addendum to the main Missisquoi Bay Phosphorus Mass Balance Model report prepared for the Lake Champlain Basin Program by LimnoTech in 2012

  6. Eutrophication in the Chesapeake Bay

    NASA Technical Reports Server (NTRS)

    Ulanowicz, R. E.

    1978-01-01

    The advantages and limitations of using remote sensing to acquire fast reliable data on the nutrient problem in the Chesapeake Bay ecosystem are discussed. Pollution effects to phytoplankton blooms during late summer and early fall months are also considered.

  7. Keep Colon Cancer At Bay

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_164231.html Keep Colon Cancer at Bay Colonoscopy best way to detect disease ... 22, 2017 WEDNESDAY, March 22, 2017 (HealthDay News) -- Colon cancer can be treated and cured if it's diagnosed ...

  8. Recent results from Daya Bay

    NASA Astrophysics Data System (ADS)

    Chua, Ming-chung

    2016-11-01

    Utilizing powerful nuclear reactors as antineutrino sources, high mountains to provide ample shielding from cosmic rays in the vicinity, and functionally identical detectors with large target volume for near-far relative measurement, the Daya Bay Reactor Neutrino Experiment has achieved unprecedented precision in measuring the neutrino mixing angle θ13 and the neutrino mass squared difference |Δm2ee|. I will report the latest Daya Bay results on neutrino oscillations and light sterile neutrino search.

  9. Beluga whale, Delphinapterus leucas, vocalizations from the Churchill River, Manitoba, Canada.

    PubMed

    Chmelnitsky, Elly G; Ferguson, Steven H

    2012-06-01

    Classification of animal vocalizations is often done by a human observer using aural and visual analysis but more efficient, automated methods have also been utilized to reduce bias and increase reproducibility. Beluga whale, Delphinapterus leucas, calls were described from recordings collected in the summers of 2006-2008, in the Churchill River, Manitoba. Calls (n=706) were classified based on aural and visual analysis, and call characteristics were measured; calls were separated into 453 whistles (64.2%; 22 types), 183 pulsed∕noisy calls (25.9%; 15 types), and 70 combined calls (9.9%; seven types). Measured parameters varied within each call type but less variation existed in pulsed and noisy call types and some combined call types than in whistles. A more efficient and repeatable hierarchical clustering method was applied to 200 randomly chosen whistles using six call characteristics as variables; twelve groups were identified. Call characteristics varied less in cluster analysis groups than in whistle types described by visual and aural analysis and results were similar to the whistle contours described. This study provided the first description of beluga calls in Hudson Bay and using two methods provides more robust interpretations and an assessment of appropriate methods for future studies.

  10. Analysis of 1996-2006 Employment Trends for Hudson, Bergen, and Essex Counties and New York City in Relation to HCCC Programs.

    ERIC Educational Resources Information Center

    Taffy, Fred

    This report is part of Hudson County Community College's (HCCC) work in providing analysis of employment trends for the following purposes: to help the college understand employment projections as they relate to its programs; to provide employment projections for upcoming program reviews; and to assist the college as it develops a strategic plan.…

  11. The Status of Hand Held Calculators in Secondary Mathematics: An Examination of Issues and Uses in the Classroom throughout the Mid-Hudson Valley Region.

    ERIC Educational Resources Information Center

    Ostapczuk, Edward D.

    In light of research findings on how calculators can enhance mathematics learning, this study investigated the uses of hand held, non-programmable, scientific calculators in secondary mathematics education throughout the Mid-Hudson Valley (New York). The study gathered data from 18 high school principals and 25 mathematics teachers in 32 school…

  12. Civil emergency planning in Canada.

    PubMed

    Wallace, J F

    1967-01-28

    THE NATIONAL OBJECTIVES OF CIVILIAN EMERGENCY PLANNING ARE: (1) protection and preservation of life and property; (2) maintenance of governmental structure; and (3) conservation of resources. The Canada Emergency Measures Organization (E.M.O.) has been developed to accomplish these objectives. E.M.O. co-ordinates other departments and agencies of federal government and its organization is reflected within provincial and municipal governments.Present E.M.O. accomplishments include: an attack warning system; an emergency broadcasting system; emergency government facilities; 400 emergency measure organizations across Canada; plans to implement general readiness; a medical stockpile; and "shadow agencies" for control of housing, food and manpower.PRESENT UNDERTAKINGS INCLUDE: a national survey of fallout shelters; the equipping of the radiation defence (RADEF); the pre-positioning of the items of the medical stockpile; and the training at the Canadian Emergency Measures College at Arnprior.

  13. Civil Emergency Planning in Canada

    PubMed Central

    Wallace, J. F.

    1967-01-01

    The national objectives of civilian emergency planning are: (1) protection and preservation of life and property; (2) maintenance of governmental structure; and (3) conservation of resources. The Canada Emergency Measures Organization (E.M.O.) has been developed to accomplish these objectives. E.M.O. co-ordinates other departments and agencies of federal government and its organization is reflected within provincial and municipal governments. Present E.M.O. accomplishments include: an attack warning system; an emergency broadcasting system; emergency government facilities; 400 emergency measure organizations across Canada; plans to implement general readiness; a medical stockpile; and “shadow agencies” for control of housing, food and manpower. Present undertakings include: a national survey of fallout shelters; the equipping of the radiation defence (RADEF); the pre-positioning of the items of the medical stockpile; and the training at the Canadian Emergency Measures College at Arnprior. PMID:6015737

  14. Congenital anomalies surveillance in Canada.

    PubMed

    Lowry, R Brian

    2008-01-01

    Congenital anomalies (CA) are present in approximately 3% of all newborn babies and account for about 12% of paediatric hospital admissions. They represent an important public health problem. Surveillance is especially important so that preventive measures such as folic acid fortification can be properly assessed without resorting to a series of ad hoc studies. Canada's surveillance of CAs is weak, with only Alberta and British Columbia having established sytems. Most provinces have perinatal systems but their CA data are incomplete and they do not capture terminations of pregnancy. The same is true of the Public Health Agency of Canada's system. A new system, the Fetal Alert Network, has been proposed for Ontario, which represents a start but will require additional sources of ascertainment if it is to be a truly population-based system for Ontario.

  15. Occupant restraint use in Canada.

    PubMed

    Boase, Paul; Jonah, Brian A; Dawson, Nancy

    2004-01-01

    Legislation regarding seat belt use in Canada is a provincial/territorial responsibility. Each of the 13 jurisdictions has enacted legislation and set the penalties regarding non-use of seat belts and appropriate child restraint systems. The federal government regulates occupant restraint systems and child restraints. In addition, Transport Canada (TC) gathers annual survey data on the use of seat belts and child restraints on Canadian roads and provides research support. National coordination toward the Canadian Road Safety Vision 2010 goal of a 40% reduction in fatalities and serious injuries related to non-belt/child restraint use and a 95% restraint usage rate is provided by the Canadian Council of Motor Transport Administrators' (CCMTA) National Occupant Restraint Program (NORP). The paper examines the history of legislation, provincial/territorial penalties, NORP, and TC involvement in promoting the use of occupant restraints.

  16. Isolation of deer tick virus (Powassan virus, lineage II) from Ixodes scapularis and detection of antibody in vertebrate hosts sampled in the Hudson Valley, New York State

    PubMed Central

    2013-01-01

    Background Deer tick virus, DTV, is a genetically and ecologically distinct lineage of Powassan virus (POWV) also known as lineage II POWV. Human incidence of POW encephalitis has increased in the last 15 years potentially due to the emergence of DTV, particularly in the Hudson Valley of New York State. We initiated an extensive sampling campaign to determine whether POWV was extant throughout the Hudson Valley in tick vectors and/or vertebrate hosts. Methods More than 13,000 ticks were collected from hosts or vegetation and tested for the presence of DTV using molecular and virus isolation techniques. Vertebrate hosts of Ixodes scapularis (black-legged tick) were trapped (mammals) or netted (birds) and blood samples analyzed for the presence of neutralizing antibodies to POWV. Maximum likelihood estimates (MLE) were calculated to determine infection rates in ticks at each study site. Results Evidence of DTV was identified each year from 2007 to 2012, in nymphal and adult I. scapularis collected from the Hudson Valley. 58 tick pools were positive for virus and/or RNA. Infection rates were higher in adult ticks collected from areas east of the Hudson River. MLE limits ranged from 0.2-6.0 infected adults per 100 at sites where DTV was detected. Virginia opossums, striped skunks and raccoons were the source of infected nymphal ticks collected as replete larvae. Serologic evidence of POWV infection was detected in woodchucks (4/6), an opossum (1/6), and birds (4/727). Lineage I, prototype POWV, was not detected. Conclusions These data demonstrate widespread enzootic transmission of DTV throughout the Hudson Valley, in particular areas east of the river. High infection rates were detected in counties where recent POW encephalitis cases have been identified, supporting the hypothesis that lineage II POWV, DTV, is responsible for these human infections. PMID:24016533

  17. Effects of flow releases on macroinvertebrate assemblages in the Indian and Hudson Rivers in the Adirondack Mountains of Northern New York

    USGS Publications Warehouse

    Baldigo, Barry P.; Smith, A.J.

    2011-01-01

    The effects of flow releases (daily during spring and four times weekly during summer) from a small impoundment on macroinvertebrate assemblages in the lower Indian River and upper Hudson River of northern New York were assessed during the summers of 2005 and 2006. Community indices, feeding guilds, dominant species and Bray—Curtis similarities at three sites on the Indian River, below a regulated impoundment, were compared with those at four control sites on the Cedar River, below a run-of-the-river impoundment of comparable size. The same indices at four less-likely affected sites on the Hudson River, below the mouth of the Indian River, were compared with those at an upstream control site on the Hudson River. Results show that the function and apparent health of macroinvertebrate communities were generally unaffected by atypical flow regimes and/or altered water quality at study reaches downstream from both dams in the Indian, Cedar and Hudson Rivers. The lentic nature of releases from both impoundments, however, produced significant changes in the structure of assemblages at Indian and Cedar River sites immediately downstream from both dams, moderate effects at two Indian River sites 2.4 and 4.0 km downstream from its dam, little or no effect at three Cedar River sites 7.2-34.2 km downstream from its dam, and no effect at any Hudson River site. Bray—Curtis similarities indicate that assemblages did not differ significantly among sites within similar impact categories. The paucity of scrapers at all Indian River sites, and the predominance of filter-feeding Simulium gouldingi and Pisidium compressum immediately below Abanakee dam, show that only minor differences in dominant species and trophic structure of macroinvertebrate communities occurred at affected sites in the Indian River compared to the Cedar River. Thus, flow releases had only a small, localized effect on macroinvertebrate communities in the Indian River.

  18. Ottawa, Canada and Glaciated Landscape

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Ottawa, in the province of Ontario, (46.5N, 75.5W) is the capital of Canada and can be seen near the bottom of this scene on the Ottawa River. The region shown lies within the Canadian Shield. The glaciated surface of the land is underlain by lower Precambrian granite and sedimentary rock. Long fractures within these crystalline rocks have, in places, been carved out by glacial action. The resultant depressions are often water filled bogs and lakes.

  19. Canada and the United States

    DTIC Science & Technology

    1985-03-01

    import competition. Wall Street Journal p.10, 21 September 1984. Langan, Fred . Canadian banks reach for a larger chunk of U.S. financial market...202-205, 15 January 1983. Langan, Fred . Canada’s cruise missile debate flares up, but Trudeau keeps cool. Christian Science Monitor 75:4. 29 March...1980. Schmidt, William E. Governors in the West to see Canadian chiefs. New York Times 132:15, 25 June 1983. Schneider, Fred D. Exploring the third

  20. Canada-U.S. Relations

    DTIC Science & Technology

    2010-05-04

    Summits” (named after the Irish heritage shared by the two countries’ leaders, Brian Mulroney and Ronald Reagan), the 1989 U.S.-Canada Free Trade...mining companies and hotel chains that do business with the island nation. Canadians, who are sensitive to being perceived as America’s “junior partner...naval ships, as well as of oil tankers bound for the United States; the Straits of Malacca and Hormuz have been cited as examples. Others, however, such