Carbon Dioxide and Ground Water Extraction in the United States     

Warren W. Wood 《Ground water》2009,47(2):168-169

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Evidence from Ar/Ar Ages of Individual Hornblende Grains for Varying Laurentide Sources of Iceberg Discharges 22,000 to 10,500 yr B.P.     

Sidney R. Hemming  Gerard C. Bond  Wallace S. Broecker  Warren D. Sharp  Mieczyslawa Klas-Mendelson 《Quaternary Research》2000,54(3):372

The abundance and lithic content of ice rafted detritus in glacial North Atlantic sediment cores vary abruptly on millennial time scales that have been correlated to Dansgaard-Oeschger cycles in the Greenland ice cores. There is growing evidence that various ice sheet outlets contributed increased iceberg fluxes at multiple discrete intervals, and the relative timing of iceberg discharges from different sources is important for understanding interactions between oceans and ice sheets. We present a provenance study based on ⁴⁰Ar/³⁹Ar dates of individual hornblende grains from 20 samples taken at 600 to 700 yr spacing between 10,500 and 22,000 yr B.P., from Orphan Knoll core EW9303-GGC31. Heinrich layers are characterized by a dominant Paleoproterozoic hornblende provenance consistent with published studies. A change in provenance between Heinrich events H2 and H1 indicates contributions of iceberg calving from the Newfoundland and southern Labrador margins. Between H1 and the Younger Dryas interval, Paleoproterozoic ice rafted grains remained dominant. The dominance of Baffin Island (or Greenland?) sources to the ice rafted detritus is ascribed to the retreat of the southern Laurentide ice sheet at about the time of H1—a retreat that isolated Newfoundland and southern Labrador ice from the shelf-slope boundary.  相似文献   

Estuaries of the northeastern United States: Habitat and land use signatures     

Charles T. Roman  Norbert Jaworski  Frederick T. Short  Stuart Findlay  R. Scott Warren 《Estuaries and Coasts》2000,23(6):743-764

Geographic signatures are physical, chemical, biotic, and human-induced characteristics or processes that help define similar or unique features of estuaries along latitudinal or geographic gradients. Geomorphologically, estuaries of the northeastern U.S., from the Hudson River estuary and northward along the Gulf of Maine shoreline, are highly diverse because of a complex bedrock geology and glacial history. Back-barrier estuaries and lagoons occur within the northeast region, but the domiant type is the drowned-river valley, often with rocky shores. Tidal range and mean depth of northeast estuaries are generally greater when compared to estuaries of the more southern U.S. Atlantic coast and Gulf of Mexico. Because of small estuarine drainage basins, low riverine flows, a bedrock substrate, and dense forest cover, sediment loads in northeast estuaries are generally quite low and water clarity is high. Tidal marshes, seagrass meadows, intertidal mudflats, and rocky shores represent major habitat types that fringe northeast estuaries, supporting commercially-important fauna, forage nekton and benthos, and coastal bird communities, while also serving as links between deeper estuarine waters and habitats through detritus-based pathways. Regarding land use and water quality trends, portions of the northeast have a history of over a century of intense urbanization as reflected in increased total nitrogen and total phosphorus loadings to estuaries, with wastewater treatment facilities and atmospheric deposition being major sources. Agricultural inputs are relatively minor throughout the northeast, with relative importance increasing for coastal plain estuaries. Identifying geographic signatures provides an objective means for comparing the structure, function, and processes of estuaries along latitudinal gradients.  相似文献   

It's the Heterogeneity!     

Warren W. Wood 《Ground water》2000,38(1):1-1

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Benthic nutrient regeneration in South Texas coastal waters     

R.Warren Flint  Daniel Kamykowski 《Estuarine, Coastal and Shelf Science》1984,18(2):221-230

Because of the variable, unpredictable nature of many potential nutrient sources for coastal phytoplankton primary production needs in the north-western Gulf of Mexico, benthic regeneration was investigated as a more constant source of nutrients to this ecosystem. Water column ammonia profiles taken at several locations on the south Texas inner-shelf in the last seven years showed peak concentrations in bottom waters. Benthic chamber measurements verified the presence of ammonia fluxes at the mud-water interface in south Texas coastal waters. These fluxes were related to benthic faunal activity as measured by sediment metabolism. Laboratory experiments, designed to test the effect of benthic faunal removal on nutrient regeneration, suggested that the fauna play a role in regulating this process. How this regulation may occur is discussed. It was estimated that annual benthic regeneration rates can supply 69% of the nitrogen required to support phytoplankton primary production in these coastal waters.  相似文献   

Hull-mounted sonar/ship design evolution and transition tolow-frequency applications     

Warren  L.R. 《Oceanic Engineering, IEEE Journal of》1988,13(4):296-298

The author traces the development of hull-mounted sonars over the past 70 years in terms of their impact on the ship design and construction process, with emphasis on the transducer arrays. He then identifies the technology issues involved in making the transition from today's midfrequency sonars to their future low-frequency counterparts  相似文献   

Diversity of oligotrich ciliates (Ciliophora,Spirotrichea) in the northern coast of South China Sea as revealed in LSU rDNA sequences     

Lu  Kaihui  Liu  Weiwei  Warren  Alan  Xu  Yusen  Zhu  Changyu  Zhao  Yan  Yi  Zhenzhen 《中国海洋湖沼学报》2020,38(1):156-167

Journal of Oceanology and Limnology - Although the taxonomy of oligotrich ciliates has been widely investigated, yet the species diversity remains poorly known. We newly designed a pair of...  相似文献   

Investigating the implications of meteorological indicators of seasonal rainfall performance on maize yield in a rain-fed agricultural system: case study of Mt. Darwin District in Zimbabwe     

Mushore  Terence  Manatsa  Desmond  Pedzisai  Ezra  Muzenda-Mudavanhu  Chipo  Mushore  Washington  Kudzotsa  Innocent 《Theoretical and Applied Climatology》2017,129(3-4):1167-1173

The study focuses on the impacts of climate variability and change on maize yield in Mt. Darwin District. The rainfall and temperature data for the period under study that is from 1992 to 2012 were obtained from Meteorological Services Department of Zimbabwe at daily resolution while crop yield data were obtained from Department of Agricultural, Technical and Extension Services (AGRITEX) and Zimbabwe Statistics Agency (ZIMSTAT) at seasonal/yearly resolution. In order to capture full rainfall seasons, a year was set to begin on 1 June and end on 31 July the next year. Yearly yield, temperature and rainfall data were used to compute time series analysis of rainfall, temperature and yield. The relationship between temperature, rainfall, quality of season (start, cessation, dry days, wet days and length) and yield was also investigated. The study also investigated the link between meteorological normal and maize yield. The study revealed that temperature is rising while rainfall is decreasing with time hence increasing risk of low maize yield in Mt. Darwin. Correlation between maize yield was higher using a non-linear (R ² = 0.630) than a linear regression model (R ² = 0.173). There was a very high correlation between maize yield and number of dry days (R = −0.905) as well as between maize yield and length of season (R = 0.777). We also observed a strong correlation between percentage normal rainfall and percentage normal maize yield (R ² = 0.753). This was also agreed between rainfall tessiles and maize yield tessiles as 50 % of the seasons had normal and above normal rainfall coinciding with normal and above normal maize yield. Of the 21 seasons considered, only one season had above normal rainfall while maize yield was below normal. The study concluded that there is a strong association between meteorological normal and maize yield in a rain-fed agricultural system. Climate information remains crucial to agricultural productivity hence the need to train farmers to access the information and use it for the benefit of their activities.

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The GF algorithm for reservoir storage, yield and spillage distributions for non-seasonal and seasonal independent inflow processes     

E. H. Lloyd  D. Warren 《Stochastic Hydrology and Hydraulics》1992,6(2):135-149

a well-known generating function formula for the equilibrium storage distribution in a finite Moran reservoir having IID inflows and unit release is extended to apply to a class of nondecreasing staircase-like release policies withm unit increments,m>1, and to seasonal inflows. The analysis is conducted in terms of an alternative to the Moran inflow-outflow sequencing scheme, with the release during a working interval controlled by the water level at the beginning of that interval.In addition to the storage, the equilibrium distributions of yield and spillage are obtained. Illustrative examples are provided.  相似文献   

Petrology of the Rainy Lake area,Minnesota, USA-implications for petrotectonic setting of the archean southern Wabigoon subprovince of the Canadian Shield     

Warren C. Day 《Contributions to Mineralogy and Petrology》1990,105(3):303-321

The Rainy Lake area in northern Minnesota and southwestern, Ontario is a Late Archean (2.7 Ga) granite-greenstone belt within the Wabigoon subprovince of the Canadian Shield. In Minnesota the rocks include mafic and felsic volcanic rocks, volcaniclastic, chemical sedimentary rocks, and graywacke that are intrucded by coeval gabbro, tonalite, and granodiorite. New data presented here focus on the geochemistry and petrology of the Minnesota part of the Rainy Lake area. Igneous rocks in the area are bimodal. The mafic rocks are made up of three distinct suites: (1) low-TiO₂ tholeiite and gabbro that have slightly evolved Mg-numbers (63–49) and relatively flat rare-earth element (REE) patterns that range from 20–8 x chondrites (Ce/Yb_N=0.8–1.5); (2) high-TiO₂ tholeiite with evolved Mg-numbers (46–29) and high total REE abundances that range from 70–40 x chondrites (Ce/Yb_N=1.8–3.3), and (3) calc-alkaline basaltic andesite and geochemically similar monzodiorite and lamprophyre with primitive Mg-numbers (79–63), enriched light rare-earth elements (LREE) and depleted heavy rare-earth elements (HREE). These three suites are not related by partial melting of a similar source or by fractional crystallization of a common parental magma; they resulted from melting of heterogeneous Archean mantle. The felsic rocks are made up of two distinct suites: (1)low-Al₂O₃ tholeiitic rhyolite, and (2) high-Al₂O₃ calc-alkaline dacite and rhyolite and consanguineous tonalite. The tholeiitic felsic rocks are high in Y, Zr, Nb, and total REE that are unfractionated and have pronounced negative Eu anomalies. The calcalkaline felsic rocks are depleted in Y, Zr, and Nb, and the REE that are highly fractionated with high LREE and depleted HREE, and display moderate negative Eu anomalies. Both suites of felsic rocks were generated by partial melting of crustal material. The most reasonable modern analog for the paleotectonic setting is an immature island arc. The bimodal volcanic rocks are intercalated with sedimentary rocks and have been intruded by pre- and syntectonic granitoid rocks. However, the geochemistry of the mafic rocks does not correlate fully with that of mafic rocks in modern are evvironments. The low-TiO₂ tholeiite is similar to both N-type mid-ocean-ridge basalt (MORB) and low-K tholeiite from immature marginal basins. The calc-alkaline basaltic andesite is like that of low-K calc-alkaline mafic volcanic rocks from oceanic volcanic arcs; however, the high-TiO₂ tholeiite is most similar to modern E-type MORB, which occurs in oceanic rifts. The conundrum may be explained by: (1) rifting of a pre-existing immature arc system to produce the bimodal volcanic rocks and high-TiO₂ tholeiite; (2) variable enrichment of a previously depleted Archean mantle, to produce both the low- and high-TiO₂ tholeiite and the calc-alkaline basaltic andesite, and/or (3) enrichment of the parental rocks of the high-TiO₂ tholeiite by crustal contamination.  相似文献