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ABSTRACT. Media-richness theory is applied to World Wide Web sites to demonstrate how Web-page designers are using hypertext markup language to shape conceptions of place and to provide competing visions of the events that have transpired in the former Yugoslavia. We argue that Web sites vary in their interactivity, strategically, to reduce equivocality surrounding conceptions of space and territory. Media-richness theory as applied here allows the development of a heuristic to understand how Web pages communicate information about geographical entities and help to shape perceptions of place.  相似文献   
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Suspended sediment concentration (SSC) in the Ova da Morteratsch, Switzerland, measured during July 2007 was closely associated with discharge (Q) and showed statistically significant relationships at the p < 0.001 level at the proximal and distal ends of the 600 m pro‐glacial zone. SSC predicted from 10‐minute turbidity records gives a much more detailed insight into SSC fluctuations and identified SSC peaks which do not coincide with discharge peaks. Net (proximal – distal) 10‐minute suspended sediment loads (SSL) are predominantly positive (i.e. suspended sediment is being stored in the reach) for most of the 7–19 July 2007 record. Net (proximal – distal) SSLs correlate closely with discharge for the first part of the record (7–13 July) but from 14 to 19 July suspended sediment exhaustion is in evidence and discrete phases of negative net SSL (i.e. sediment flushing) are likely for up to six hours on three separate days which coincide with phases of high discharge and exhaustion of the glacial suspended sediment sources. Analysis of Q at the Berninabach–Pontresina gauging station (5 km downstream) for the past five years revealed that maximum monthly discharges capable of generating sediment flushing events occur in an average of four months each year. The study emphasises the rapid change in suspended sediment transport and yields with distance from the glacier snout and highlights the importance of measurements as close to the glacier snout as possible if data are to be representative of the glaciated land up‐valley. A better understanding of the processes of sediment exchange and the colonisation and stabilisation of sediment stores by vegetation in such pro‐glacial zones is essential if we are to improve predictions of the impacts of climate change on river sediment dynamics and the subsequent effects on aquatic ecology.  相似文献   
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A stratigraphy for Quaternary deposits on the western Scottish shelf has been erected using seismic and borehole data. Eight new formations are defined and described with evidence presented for the environ-ment of deposition of each formation. Most of the Quaternary sediments preserved on the shelf arc shown to have accumulated under stadial or glacial conditions. The possible age of each formation is discussed within the context of evidence provided from the mainland, shelf and deep-sea cores. Two are thought to be pre-Devensian, one is possibly pre-Devcnsian. one is possibly Early and/or Middle Devensian, two are probably Late Devensian, one is Late Devensian to Holocenc and one Present day in age. It is suggested that the Late Devensian ice reached the shelf margin south of the Outer Hebridcan Platform.  相似文献   
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STEP-POOL MORPHOLOGY IN HIGH-GRADIENT STREAMS   总被引:3,自引:0,他引:3  
l 1NTRODUCTIONGravel bed rivers are found in man parts of the worid, mpically in moUntainous regions with highgradients and seasonally high flows. These rivers are imPotalt in contrlling flood waters from sPringrunoff in regions such as the Pacific Northwest, Where heaVy snowfall can be followed by equally heaVyranfall. The combination of high stream gradient and high discharge causes significant erosion of thebed and bank of the strCam, in some cases moving large boulders with ease.It…  相似文献   
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Carbonate mud that accumulated in the deep parts of a late Kimmeridgian carbonate ramp (Iberian Basin, NE Spain) was partly derived by resedimentation from shallow water production areas. High-frequency sea-level changes, probably driven by climatic changes in tune with precession and short-eccentricity cycles, affected carbonate production and the amount of exported sediment. Facies analysis and correlation of three outcrops located in middle and outer ramp settings allows a comparison of high-order sequences (bundles of beds and sets of bundles) across a ramp transect and an assessment of the carbonate factory. Analysis of the storm deposits found in middle ramp settings identifies deepening to shallowing high-frequency cycles based on the level of exported carbonate. In outer ramp areas, many of the bundles exhibit a thinning trend, indicating a progressive decrease of carbonate production and hence, carbonate export during periods of high-frequency sea-level rise. δ13Ccarb values show a gradual increase through the studied long-term transgressive interval ranging from 1·5‰ to 2·8‰. Within this long-term evolutionary trend, short-term δ13Ccarb fluctuations occur that correspond with some of the high-order cycles defined from sedimentary facies analysis. These short-term δ13Ccarb shifts are interpreted as shifts in carbonate export from shallow reef regions to the outer ramp. A consequence of this study is that variation in δ13Ccarb can be used for correlation in outer ramp successions, at least on a basin-wide scale.  相似文献   
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