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21.
In this paper, we explore how ‘peak oil’ anxieties are woven into the spaces and practices of the state in Norway and the consequences of this for environmental justice and the public sphere more widely. We focus in particular on an ongoing struggle over access to hydrocarbon deposits in the Norwegian Arctic, the so-called ‘Battle of the North’. We use this dispute to highlight three wider theoretical points regarding (i) the continuing relevance of the state in the governing of nature-society relations, (ii) the increasingly fragmented and fluid nature of state space, and (iii) the significance of ‘security’ as a term around which social, economic and environmental tensions pivot. The paper concludes by reflecting on current efforts to prevent new oil activities in the north of Norway. 相似文献
22.
Hans Petter Sejrup Berit Oline Hjelstuen Atle Nygård Haflidi Haflidason Ivar Mardal 《Boreas: An International Journal of Quaternary Research》2015,44(1):1-13
Palaeoglaciological reconstructions of the North Sea sector of the last British Ice Sheet have, as other shelf areas, suffered from a lack of dates directly related to ice‐front positions. In the present study new high‐resolution TOPAS seismic data, bathymetric records and sediment core data from the Witch Ground Basin, central North Sea, were compiled. This compilation made it possible to map out three ice‐marginal positions, partly through identification of terminal moraines and partly through location of glacial‐fed debrisflows. The interfingering of the distal parts of the glacial‐fed debrisflows with continuous marine sedimentation enabled the development of a chronology for glacial events based on previously published and some new radiocarbon dates on marine molluscs and foraminifera. From these data it is suggested that after the central Witch Ground Basin was deglaciated at c. 27 cal. ka BP, the eastern part was inundated by glacial ice from the east in the Tampen advance at c. 21 cal. ka BP. Subsequently, the basin was inundated by ice from northeast during the Fladen 1 (c. 17.5 cal. ka BP) and the Fladen 2 (16.2 cal. ka BP) events. It should be emphasized that the Fladen 1 and 2 events, individually, may represent dynamics of relatively small lobes of glacial ice at the margin of the British Ice Sheet and that the climatic significance of these may be questioned. However, the Fladen Events probably correlate in time with the Clogher Head and Killard Point re‐advances previously documented from Ireland and the Bremanger event from off western Norway, suggesting that the British and Fennoscandian ice sheets both had major advances in their northwestern parts, close to the northwestern European seaboard, at this time. 相似文献
23.
Arctic Mackenzie Delta channel planform evolution during 1983–2013 utilising Landsat data and hydrological time series
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Jenni‐Mari Vesakoski Tua Nylén Berit Arheimer David Gustafsson Kristina Isberg Markus Holopainen Juha Hyyppä Petteri Alho 《水文研究》2017,31(22):3979-3995
Arctic deltas, such as the Mackenzie Delta, are expected to face major climate change and increased human influence in the near future. Deltas are characterised by highly dynamic fluvial processes, and changing climate will cause considerable evolution of the riverine environment. The changes are difficult to predict with existing knowledge and data. This study quantified channel planform change of the Mackenzie Delta (1983–2013), analysing its temporal and spatial patterns. We addressed the main obstacle of research on large remote areas, the lack of data, by developing a unique work flow that utilised Landsat satellite imagery, hydrological time series, remote sensing‐based change analysis, and automatic vectorisation of channels. Our results indicate that the Mackenzie Delta experienced constant evolution but at a highly varying rate over the 30 years. The study demonstrates that the magnitude and duration of flood peaks and the presence of spring ice breakup floods determine the rate of Arctic delta planform change. Changing winter conditions and spring flood magnitudes may therefore affect the stability of Arctic deltas. However, no clear trends towards decreased recurrence or magnitude of spring floods or increased instability of the delta plain have yet been observed in the Mackenzie Delta. The delta plain was most dynamic at the beginning and at the end of the examined period, corresponding to intense flooding, whereas the rates of change were subtle during the low‐flood period 1994–2007. The largest changes have occurred along the wide Middle Channel and in the outermost delta. Relative to their size, however, smaller meandering channels have been highly dynamic. Hotspots of change in the delta plain are located in anastomosing and braiding channel segments and, at the local scale, in point bars and cut‐banks along meandering channels. Our study describes how Landsat satellite data can be utilised for advancing fluvial geomorphological research in remote areas. However, cloudiness in the delta restricts production of dense time series with simultaneous coverage of the whole area and requires manual preprocessing. 相似文献
24.
Hans Petter Sejrup Eiliv Larsen Haflidi Haflidason Ida M. Berstad Berit O. Hjelstuen Hafdis E. Jonsdottir Edward L. King Jon Landvik Oddvar Longva Atle Nygrd Dag Ottesen Stle Raunholm Leif Rise Knut Stalsberg 《Boreas: An International Journal of Quaternary Research》2003,32(1):18-36
The Norwegian Channel between Skagerrak, in the southeast, and the continental margin of the northern North Sea, in the northwest, is the result of processes related to repeated ice stream activity through the last 1.1 m yr. In such periods the Skagerrak Trough (700 m deep) has acted as a confluence area for glacial ice from southeastern Norway, southern Sweden and parts of the Baltic. Possibly related to the threshold in the Norwegian Channel off Jæren (250 m deep), the ice stream, on a number of occasions over the last 400 ka, inundated the coastal lowlands and left an imprint of NW‐oriented ice directional features (drumlins, stone orientations in tills and striations). Marine interstadial sediments found up to 200 m a.s.l. on Jæren have been suggested to reflect glacial isostasy related to the Norwegian Channel Ice Stream (NCIS). In the channel itself, the ice stream activity is evidenced by mega‐scale glacial lineations on till surfaces. As a result of subsidence, the most complete sedimentary records of early phases of the NCIS are preserved close to the continental margin in the North Sea Fan region. The strongest evidence for ice stream erosion during the last glacial phase is found in the Skagerrak. On the continental slope the ice stream activity is evidenced by the large North Sea Fan, which is mainly a result of deposition of glacial‐fed debris flows. Northwards of the North Sea Fan, rapid deposition of meltwater plume deposits, possibly related to the NCIS, is detected as far north as the Vøring Plateau. The NCIS system offers a unique possibility to study ice stream related processes and the impact the ice stream development had on open ocean sedimentation and circulation. 相似文献
25.
P. R. Vogt K. Crane E. Sundvor B. O. Hjelstuen J. Gardner F. Bowles G. Cherkashev 《Geo-Marine Letters》1999,19(1-2):111-130
SeaMARC II (11- to 12-kHz) side-scan sonar revealed hundreds of small strong-backscatter spots, tens to 500?m in diameter, along the lips of the Bear Island fan slide valley. New bathymetry, deep-tow side-scan, deep-tow profiles, heatflow, and gravity cores were collected for ground-truth. These mounds are probably mud diapirs (or mud-built mounds) typically 10–75?m high, formed by glacial sediment mobilized by Late Pleistocene slide events. The mounds are arranged along NNE trending lines, suggesting control by intrasedimentary faults ca. 0.5–1 km apart. Diapirs examined on the Vøring Plateau exhibit WNW structural control. No heatflow anomaly was found in four stations on or next to diapirs in either area. 相似文献
26.
How the performance of hydrological models relates to credibility of projections under climate change 总被引:1,自引:1,他引:0
Valentina Krysanova Chantal Donnelly Alexander Gelfan Dieter Gerten Berit Arheimer Fred Hattermann 《水文科学杂志》2018,63(5):696-720
Two approaches can be distinguished in studies of climate change impacts on water resources when accounting for issues related to impact model performance: (1) using a multi-model ensemble disregarding model performance, and (2) using models after their evaluation and considering model performance. We discuss the implications of both approaches in terms of credibility of simulated hydrological indicators for climate change adaptation. For that, we discuss and confirm the hypothesis that a good performance of hydrological models in the historical period increases confidence in projected impacts under climate change, and decreases uncertainty of projections related to hydrological models. Based on this, we find the second approach more trustworthy and recommend using it for impact assessment, especially if results are intended to support adaptation strategies. Guidelines for evaluation of global- and basin-scale models in the historical period, as well as criteria for model rejection from an ensemble as an outlier, are also suggested. 相似文献
27.
Process refinements improve a hydrological model concept applied to the Niger River basin 总被引:1,自引:0,他引:1
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Jafet C.M. Andersson Berit Arheimer Farid Traoré David Gustafsson Abdou Ali 《水文研究》2017,31(25):4540-4554
28.
Ingrid Marie Hasle Amundsen Maria Blinova Berit Oline Hjelstuen Rolf Mjelde Haflidi Haflidason 《Marine Geophysical Researches》2011,32(4):441-453
The northeastern high-latitude North Atlantic is characterised by the Bellsund and Isfjorden fans on the continental slope
off west Svalbard, the asymmetrical ultraslow Knipovich spreading ridge and a 1,000 m deep rift valley. Recently collected
multichannel seismic profiles and bathymetric records now provide a more complete picture of sedimentary processes and depositional
environments within this region. Both downslope and alongslope sedimentary processes are identified in the study area. Turbidity
currents and deposition of glacigenic debris flows are the dominating downslope processes, whereas mass failures, which are
a common process on glaciated margins, appear to have been less significant. The slide debrite observed on the Bellsund Fan
is most likely related to a 2.5–1.7 Ma old failure on the northwestern Barents Sea margin. The seismic records further reveal
that alongslope current processes played a major role in shaping the sediment packages in the study area. Within the Knipovich
rift valley and at the western rift flank accumulations as thick as 950–1,000 m are deposited. We note that oceanic basement
is locally exposed within the rift valley, and that seismostratigraphic relationships indicate that fault activity along the
eastern rift flank lasted until at least as recently as 1.5 Ma. A purely hemipelagic origin of the sediments in the rift valley
and on the western rift flank is unlikely. We suggest that these sediments, partly, have been sourced from the western Svalbard—northwestern
Barents Sea margin and into the Knipovich Ridge rift valley before continuous spreading and tectonic activity caused the sediments
to be transported out of the valley and westward. 相似文献
29.
Berit Legler Howard D. Johnson Gary J. Hampson Benoit Y.G. Massart Chris A‐L. Jackson Matthew D. Jackson Ahmed El‐Barkooky Rodmar Ravnas 《Sedimentology》2013,60(5):1313-1356
Existing facies models of tide‐dominated deltas largely omit fine‐grained, mud‐rich successions. Sedimentary facies and sequence stratigraphic analysis of the exceptionally well‐preserved Late Eocene Dir Abu Lifa Member (Western Desert, Egypt) aims to bridge this gap. The succession was deposited in a structurally controlled, shallow, macrotidal embayment and deposition was supplemented by fluvial processes but lacked wave influence. The succession contains two stacked, progradational parasequence sets bounded by regionally extensive flooding surfaces. Within this succession two main genetic elements are identified: non‐channelized tidal bars and tidal channels. Non‐channelized tidal bars comprise coarsening‐upward sandbodies, including large, downcurrent‐dipping accretion surfaces, sometimes capped by palaeosols indicating emergence. Tidal channels are preserved as single‐storey and multilateral bodies filled by: (i) laterally migrating, elongate tidal bars (inclined heterolithic strata, 5 to 25 m thick); (ii) forward‐facing lobate bars (sigmoidal heterolithic strata, up to 10 m thick); (iii) side bars displaying oblique to vertical accretion (4 to 7 m thick); or (iv) vertically‐accreting mud (1 to 4 m thick). Palaeocurrent data show that channels were swept by bidirectional tidal currents and typically were mutually evasive. Along‐strike variability defines a similar large‐scale architecture in both parasequence sets: a deeply scoured channel belt characterized by widespread inclined heterolithic strata is eroded from the parasequence‐set top, and flanked by stacked, non‐channelized tidal bars and smaller channelized bodies. The tide‐dominated delta is characterized by: (i) the regressive stratigraphic context; (ii) net‐progradational stratigraphic architecture within the succession; (iii) the absence of upward deepening trends and tidal ravinement surfaces; and (iv) architectural relations that demonstrate contemporaneous tidal distributary channel infill and tidal bar accretion at the delta front. The detailed facies analysis of this fine‐grained, tide‐dominated deltaic succession expands the range of depositional models available for the evaluation of ancient tidal successions, which are currently biased towards transgressive, valley‐confined estuarine and coarser grained deltaic depositional systems. 相似文献
30.
Dag O. Hessen JoLynn Carroll Berit Kjeldstad Anton A. Korosov Lasse H. Pettersson Dmitry Pozdnyakov Kai Sørensen 《Estuarine, Coastal and Shelf Science》2010
Spectral light attenuation profiles and concentrations of total and dissolved carbon (C), nutrients and chlorophyll a (Chla) were studied along transects running from the river mouth to the Kara Sea during late summer 2003 for the Yenisey and fall 2005 for the Ob estuaries. Earth Observation data were used to generate composite images of water color and Chla distribution over the estuaries and the Kara Sea to reveal the spatial impact of the river efflux in terms of optical properties. 相似文献