Southern Norwegian Research Articles

Vertical Migration of Pelagic and Mesopelagic Scatterers From ADCP Backscatter Data in the Southern Norwegian Sea

Records of backscatter and vertical velocity obtained from moored Acoustic Doppler Current Profilers (ADCP) enabled new insights into the dynamics of deep scattering layers (DSLs) and diel vertical migration (DVM) of mesopelagic biomass between these deep layers and the near-surface photic zone in the southern Norwegian Sea. The DSL exhibits characteristic vertical movement on inter-monthly time scales, which is associated with undulations of the main pycnocline between the warm Atlantic water and the underlying colder water masses. Timing of the DVM is closely linked to the day-night light cycle—decent from the photic zone just before sunrise and ascent immediately after sunset. Seasonal variations are also evident, with the highest DVM activity and lowest depth averaged mean volume backscatter strength (MVBS) during spring. This suggests that both oceanographic and optical conditions are driving the complex dynamics of pelagic and mesopelagic activity in this region. We hypothesize that the increased abundance of calanoid copepods in the near-surface layer during spring increases the motivation for vertical migration of pelagic and mesopelagic species, which therefore can explain the increased DVM activity during this season.

Spatial distributions and seasonality of four Calanus species in the Northeast Atlantic

This paper analyses spatial and seasonal patterns for near-surface abundances of four Calanus species in the Northeast Atlantic based on monthly Continuous Plankton Recorder (CPR) Survey data collected during 2008–2016. C. finmarchicus, C. helgolandicus, C. hyperboreus and C. glacialis represent different ecosystems, and water masses with differing oceanographic properties and origins. Hence, these are considered as indicator species in climate change studies. A southern transect between Norway and the United Kingdom represented the northern North Sea, a central transect crossed the Norwegian and Iceland Seas, while a northern transect between Norway and Svalbard crossed the entrance to the Barents Sea. C. finmarchicus was prevalent everywhere, while C. helgolandicus was mainly confined to the northern North Sea though also documented downstream in the Norwegian Sea as far north as the entrance to the Barents Sea. The ratio of C. helgolandicus to C. finmarchicus abundances is expected to increase in the northern North Sea and southern Norwegian Sea given continued increases in seawater temperature. C. hyperboreus and C. glacialis were mainly associated with regions influenced by Arctic waters in the Iceland and Norwegian Seas, and south of Svalbard, respectively. Within Atlantic water masses in the central Norwegian Sea, a distinct second generation of C. finmarchicus with surprisingly high late-autumn concentrations of older stages were found. In Coastal water, two or more generations of C. finmarchicus occurred, while only one generation was evident in Arctic waters. Young C. finmarchicus of the first annual generation showed an earlier timing in Coastal than Atlantic and Arctic waters. The upper range of the temperature niche for both C. hyperboreus and C. glacialis was found to be around 7 °C. However, the peak occurrence within the study area was in 1–2 °C in Arctic water in the Iceland Sea in April for C. hyperboreus, while around 5 °C in Barents Sea Arctic water in July for C. glacialis. C. finmarchicus was present in all water masses with a peak occurrence in June at around 6 °C. C. finmarchicus generally dominated the Calanus-biomass, but C. hyperboreus in Arctic water in the Iceland and Norwegian Seas in spring, and C. helgolandicus in the northern North Sea, could match or exceed the biomass of C. finmarchicus.

Diagenetic influence on reservoir quality evolution, examples from Triassic conglomerates/arenites in the Edvard Grieg field, Norwegian North Sea

Abstract The Utsira High (Southern Norwegian North Sea) has been a petroleum exploration target since the late 1960s. The southwestern part of the Utsira High complex (Haugaland High) attracted new interest when in 2007 Lundin Norway AS and partners Revus Energy ASA and RWE Dea Norge AS discovered commercial hydrocarbon reservoirs in Triassic to Early Cretaceous formations (Edvard Grieg field). In the present study, four siliciclastic cores from the Edvard Grieg field have been investigated sedimentologically, including core logging, optical mineralogy, X-ray powder diffraction (XRD) and scanning electron microscope (SEM). Quantification and characterization of the different mineralogical phases in thin section have been executed to better understand porosity evolution through time. Intergranular volume (IGV) and cement volume were also compared in order to estimate the most important factors effecting porosity loss within the studied samples. The results show that through time the various diagenetic events and phases, such as dissolution of unstable grains and precipitation of clay minerals and cements, strongly influenced reservoir quality in the Edvard Grieg field. Two main lithology groups are identified within the cored intervals, conglomerates and sandstones. These two groups can further be sub-divided into four units: 1) sandy conglomerate, 2) silty conglomerate, 3) interbedded sandstone, 4) large scale cross-bedded sandstone. Most of the reservoir quality reduction in the conglomerate matrix can be related to poor sorting, carbonate cement and pore-filling/pore-lining authigenic clay minerals. Better reservoir quality characterizes the sandstone-dominated alluvial fan intervals, which generally are associated with a greater degree of sorting that led to higher intergranular porosities. Large scale cross-stratified sandstone units, interpreted to be of aeolian origin, have the highest reservoir quality. These deposits are moderately to well sorted with only minor occurrences of patchy carbonate cement and generally low proportions of authigenic minerals. However, locally abundant kaolinite has been observed, filling the pore space and reducing the porosity, predominantly by blocking interconnected primary pores.

Implementing a new pedagogy in the nursing curriculum: Bachelor students’ evaluation

Background: Inspired by the work of Benner and colleagues at Carnegie Foundation, a new course in nursing was implemented in the first study year’s curriculum in the bachelor program in nursing. The new nursing course included a shift from a lecture-only classroom based approach to a problem-based and case-based approach. Reflections and discussions in groups with fellow students and supervisors was the main activity. The aim of this study was to examine how the students experienced the new nursing course.Methods: The survey study was conducted at a university in southern Norwegian. The sample consisted of students in two subsequent classes (n = 126 and n = 118), who had followed the new study plan in the first study year and the traditional study plan in the second study year. An electronic survey, including questions concerning the extent, quality and usefulness of the study plans were examined.Results: The students were, in general, satisfied with the new nursing course regarding the content and quality. The teachers’ presence and ability to engage, challenge and facilitate reflection seemed to be decisive. Reflecting and discussing real-life patient cases in groups with fellow students and a supervisor was stimulating, motivating and useful for learning professional nursing.Conclusions: A problem based, case-based pedagogy might increase the students’ preparedness for solving patient problems that they encounter in clinical settings. Cooperation and reflection in small groups with fellow students and the supervisor enhance nursing students’ clinical reasoning skills, and might contribute to reduce the gap between theory and practice.

Regional seesaw between the North Atlantic and Nordic Seas during the last glacial abrupt climate events

Abstract. Dansgaard–Oeschger oscillations constitute one of the most enigmatic features of the last glacial cycle. Their cold atmospheric phases have been commonly associated with cold sea-surface temperatures and expansion of sea ice in the North Atlantic and adjacent seas. Here, based on dinocyst analyses from the 48–30 ka interval of four sediment cores from the northern Northeast Atlantic and southern Norwegian Sea, we provide direct and quantitative evidence of a regional paradoxical seesaw pattern: cold Greenland and North Atlantic phases coincide with warmer sea-surface conditions and shorter seasonal sea-ice cover durations in the Norwegian Sea as compared to warm phases. Combined with additional palaeorecords and multi-model hosing simulations, our results suggest that during cold Greenland phases, reduced Atlantic meridional overturning circulation and cold North Atlantic sea-surface conditions were accompanied by the subsurface propagation of warm Atlantic waters that re-emerged in the Nordic Seas and provided moisture towards Greenland summit.

Opportunistically recorded acoustic data support Northeast Atlantic mackerel expansion theory

Abstract Fisheries independent monitoring of widely distributed pelagic fish species which conduct large seasonal migrations is logistically complex and expensive. One of the commercially most important examples of such a species in the Northeast Atlantic Ocean is mackerel for which up to recently only an international triennial egg survey contributed to the stock assessment. In this study, we explore whether fisheries acoustic data, recorded opportunistically during the English component of the North Sea International Bottom Trawl Survey, can contribute to an improved understanding of mackerel distribution and provide supplementary data to existing dedicated monitoring surveys. Using a previously published multifrequency acoustic mackerel detection algorithm, we extracted the distribution and abundance of schooling mackerel for the whole of the North Sea during August and September between 2007 and 2013. The spatio-temporal coverage of this unique dataset is of particular interest because it includes part of the unsurveyed summer mackerel feeding grounds in the northern North Sea. Recent increases in landings in Icelandic waters during this season suggested that changes have occurred in the mackerel feeding distribution. Thus far it is poorly understood whether these changes are due to a shift, i.e. mackerel moving away from their traditional feeding grounds in the northern North Sea and southern Norwegian Sea, or whether the species' distribution has expanded. We therefore explored whether acoustically derived biomass of schooling mackerel declined in the northern North Sea during the study period, which would suggest a shift in mackerel distribution rather than an expansion. The results of this study show that in the North Sea, schooling mackerel abundance has increased and that its distribution in this area has not changed over this period. Both of these findings provide, to our knowledge, the first evidence in support of the hypothesis that mackerel have expanded their distribution rather than moved away.

The mystery of the "North of the North" in Ibsen's works

It is an exaggeration to claim that several of the protagonists in Ibsen’s dramatic works are from the north, or have lived there. The few characters in Ibsen’s drama related to the North are, however, given a special emphasis in his works. They are, like the landscape and the light of the North, mysterious, strange, strong and untamed. Or they have been exiled, suppressed or forgotten – and then suddenly arrive unexpectedly and challenge the established order and open new tension and ambition.Ibsen only visited Northern Norway once, on a trip to North Cape in 1891. His only experience of the “North” before that was actually of Central Norway, Trondheim and Molde. The North in Ibsen’s dramas is accordingly just fiction, imagination – and an expression of the general Southern Norwegian understanding of the “others” living in the North and the “otherness” of the North. Especially people from the North of the North, such as Finnmark, who represent a mysterious, bewitching and magic power, like Rebekka West in Rosmersholm and the foreign sailor in Lady from the Sea. This is explained by the magic nature of the North, such as the midnight sun, the Polar light or the overwhelming and irresistible winter storms over the sea. But Ibsen has also given other clues for the understanding of the mysterious characters from Finnmark, the North of the North. These clues are related to the cultural otherness of the characters as Sami and Kvääni.

The source rock potential of the Upper Jurassic– lowermost Cretaceous in the Danish and southern Norwegian sectors of the Central Graben, North Sea

The principal source rocks in the Danish and southern Norwegian Central Graben in the North Sea are the Upper Jurassic to lowermost Cretaceous marine shales of the Mandal and Farsund formations. The distribution of generation potential and thermal maturity is quite complex. Biomarkers of crude oils from the northern Danish Central Graben indicate correlation to the Bo Member of the upper Farsund Formation or to the lower part of the formation. Biomarker ratios of oils from the Danish Chalk reservoirs show a maturity gradation from south to north, with oils in the northern part being more mature. Vitrinite reflectance gradients show differences in depth of the ‘top oil window’. In areas characterized by HPHT conditions and thick overlying Chalk, petroleum generation is retarded and the oil window is displaced downwards by 200–350 m. Source rock quality varies. The upper part of the shales is generally considered the most oil-prone. However, analyses indicate that the lower part of the Farsund Formation may contain intervals with rich oil-prone shales. Furthermore, the petroleum generation of the Upper Jurassic shales below the Farsund Formation is often overlooked, but source rock data indicate that gas/oil-prone, and to some extent oil-prone, shales are present.

Potential changes in benthic macrofaunal distributions from the English Channel simulated under climate change scenarios

Climate-induced changes in the distribution of species are likely to affect the functioning and diversity of marine ecosystems. Therefore, in economic and ecological important areas, such as the English Channel, projections of the future distributions of key species under changing environmental conditions are urgently needed. Ecological Niche Models (ENMs) have been applied successfully to determine potential distributions of species based on the information of the environmental niche of a species (sensu Hutchinson). In this study, the niches of two commercially exploited benthic species, Pecten maximus and Glycymeris glycymeris, and two ecologically important species, Abra alba and Ophelia borealis were derived using four contemporary hydrographic variables, i.e. sea surface temperature, sea surface salinity, water depth and sediment type. Consequently, using these ecological envelopes, the Non-Parametric Probalistic Ecological Niche model (NPPEN) was applied to calculate contemporary probabilities of occurrence for each species in the North East Atlantic and to predict potential re-distributions under the climate change scenario A2 for two time periods 2050–2059 and 2090–2099. Results show general northern displacements of the four benthic species from the English Channel into the North Sea and southern Norwegian coast. The projections mostly indicate a reduction of suitable habitat for benthic species with a notable disappearance of their distributions in the English Channel, except for A. alba. However, interpretations should be treated with caution since many uncertainties and assumptions are attached to ecological niche models in general. Furthermore, opening up potential habitats for benthic species does not necessarily imply that the species will actually occupy these sites in the future. The displacement and colonisation success of species are a function of many other non-climatic factors such as species life histories, dispersal abilities, adaptability and community interactions.

Contrasting the Seasonal Variability of Halogenated Natural Products and Anthropogenic Hexachlorocyclohexanes in the Southern Norwegian Atmosphere

Halogenated natural products (HNPs) are increasingly recognized as compounds of marine environmental samples. In this study, we explored whether the annual course of the concentrations of HNPs in ambient air samples was different from those of anthropogenic pollutants. For this purpose, air samples taken weekly at Lista, southern Norway, were analyzed by gas chromatography-mass spectrometry for anthropogenic aaeeee- (alpha-HCH) and aaaeee-hexachlorocyclohexane (gamma-HCH, lindane) isomers, as well as the HNPs 2,3,3',4,4',5,5'-heptachloro-1'-methyl-1,2'-bipyrrole (Q1), 2,4-di- and 2,4,6-tribromoanisole (24-DBA, 246-TBA), and 2,4,6-tribromophenol (246-TBP). Concentrations of HCH isomers were higher in the warmer summer months than in winter. By contrast, Q1, 24-DBA, 246-TBA, and 246-TBP showed much higher concentrations at the end of the year. Correlations between the concentrations of the compounds and air mass trajectories as well as further meteorological data are discussed. An unknown mixed halogenated substance was detected at high abundance during the summer months. High-resolution mass spectrometry and tandem mass spectrometric techniques were used to unravel the molecular structure, which was found to be C(7)H(8)Br(3)Cl, an elemental composition never reported before in the scientific literature.

Holocene glacier variation chronology of the Smørstabbtindan massif, Jotunheimen, southern Norway, and the recognition of century- to millennial-scale European Neoglacial Events

New stratigraphic evidence for the Holocene history of three glaciers in central Jotunheimen, southern Norway, is presented and the implications for century- to millennial-scale glacier and climatic variability are considered. Minerogenic layers in seven stream-bank mires, flooded episodically by glaciofluvial meltwater, are dated by 79 new radiocarbon age estimates. A revised chronology for glacier variations in Smørstabbtindan suggests a three-phase Holocene: (1) an early-Holocene deglaciation phase (11500—9500 cal. BP) characterized by readvances of ice-sheet remnants; (2) a mid-Holocene phase with relatively small or absent glaciers (9500—5000 cal. BP); and (3) a late-Holocene phase of enlarged and fluctuating glaciers (the last 5000 years). Seven millennial-scale neoglacial events (Smørstabbtindan I—VII), during which glaciers were larger than at present for most of the time, are dated to: >10 400—9600 (Erdalen Event), 8400—7650 (Finse Event), 4800—3900, 3200—2550, 2350—1700, 1400—750 and 500—0 cal. BP (`Little Ice Age'). Two or more century-scale events are nested within each millennial-scale event. Based on the timing of neoglacial maxima, the record from Smørstabbtindan is combined with comparable reconstructions from southern Norway to indicate at least 17 century- to millennial-scale Southern Norwegian Neoglacial Events. A similar approach to records from the Swiss and Austrian Alps identifies around 23 Alpine Neoglacial Events. This leads to the recognition of 13 European Neoglacial Events that are at least continental in extent but seem to be imperfectly correlated with episodes of low solar irradiance, which suggests that other climatic forcing factors are also involved, including volcanic aerosols and, in the early Holocene, freshwater outbursts into the northern Atlantic Ocean. Local to regional patterns in glacier behaviour, particularly in relation to century-scale events, may be accounted for by differences in glacier size and geometry, topography and atmospheric circulation patterns; whereas the three Holocene multimillennial phases appear to reflect the Earth's orbital variations.

Laminated sediments preceding Heinrich event 1 in the Northern North Sea and Southern Norwegian Sea: Origin, processes and regional linkage

Rapidly deposited laminated sediments dated between 18 and 21 cal. ka BP have been observed at several core locations in the Northern North Sea and the Southern Norwegian Sea. Sedimentation rates range from 20 cm/ka up to 2000 cm/ka, compared to a normal background sedimentation rate in the area of 5–10 cm/ka. Dropstones, in situ paired bivalves and grain size distribution indicate a hemipelagic origin for the laminae in core MD99-2291, from the upper continental slope of Southern Norway. AMS radiocarbon dating and cyclic changes in the number of planktonic foraminifera and lithological parameters suggest that the laminations in the core are annual varves. The laminated sediments are interpreted to be suspension plume deposits and two phases of plume deposition have been dated to 21.5 and 18.6 cal. ka BP. Large fluxes of meltwater were generated during this period, as reflected in oxygen and carbon isotopes records from cores in the area. The meltwater and the laminated plume deposits are interpreted to be associated with the presence and disintegration of the Norwegian Channel Ice Stream. Observations from other regions demonstrate that laminated high rate deposition is very widespread on glaciated continental margins. Around 18.6 cal. ka BP increases in sediment fluxes also occurred on the Barra Fan, the North Sea Fan, the Lofoten contourite drift and the Svalbard margin, preceding increased sediment and meltwater fluxes on the Greenland margin and the Labrador Sea, associated with Heinrich event 1. Warm water inflow to the Norwegian Sea together with rising sea level probably triggered the destabilisation of the ice streams of the Fennoscandian Ice Sheet, while a similar response of the Laurentide ice sheet was delayed by 500–1000 yr.

The glacial North Sea Fan, southern Norwegian Margin: architecture and evolution from the upper continental slope to the deep-sea basin

High-resolution seismic data have been used to study the ice-stream-fed North Sea Fan, deposited from approximately Marine Isotope Stage (MIS) 12 and onwards. Located at the outlet of the Norwegian Channel on the SE Nordic Seas continental slope, the 110,000 km 2 fan is dominated by glacigenic debris flows and slide debrites. The fan is divided in two provinces by the volcanic Møre Marginal High. The proximal province has been characterised by alternation between deposition and erosion, while the distal province has been dominated by deposition. From ∼MIS 12 until the present the fan has received ≥32,000 km 3 of sediments. Age constraints on fan stratigraphy provided by core investigations indicate that the Fennoscandian ice sheet advanced to the shelf edge during MIS 2, 6, 8, 10 and probably 12. The fan experienced megaslides in late ∼MIS 6, 9 and during ∼MIS 11–12.

Latitudinal fractionation of polychlorinated biphenyls in surface seawater along a 62 degrees N-89 degrees N transect from the southern Norwegian Sea to the North Pole area.

Surface seawater concentrations of PCBs, relative congener abundance, and possible effects of cold condensation were studied along a transect from the southern Norwegian Sea to the central Arctic Ocean (62 degrees N-89 degrees N). Large volume samples were collected from an ice breaker using a stainless steel surface seawater intake connected online to an ultra-clean laboratory. Concentrations of all studied PCB congeners, except for trichlorinated PCB 18, decreased with latitude. For instance, PCB 52 decreased from 470 fg L(-1) at 62 degrees N to 110 fg L(-1) at 89 degrees N and PCB 180 from 110 to 12 fg L(-1). Concentrations in the central Arctic Ocean were on the order of 10-100 fg L(-1) for the most abundant congeners. The relative contribution oftrichlorinated PCBs to the total PCB concentration increased with latitude, the tetrachlorinated contribution to the total PCBs did not show any correlation to latitude, and the relative contribution of heavier congeners decreased with latitude. This study establishes the occurrence at very low abundances of PCBs in seawater in the central Arctic Ocean and demonstrates a northward concentration decrease. The latitudinal shift in congener pattern is reflecting the relative propensity of the PCB congeners to undergo long-range transport in the Arctic and is consistent with their relative vapor pressures.

Radiolarian faunal provinces in surface sediments of the Greenland, Iceland and Norwegian (GIN) Seas

The overall abundance and species composition of the polycystine and phaeodarian radiolaria have been determined in 63 surface sediment samples from the GIN Seas. These results are compared to chemical and physical properties of the overlying water masses. There are three abundance maxima in the distribution of radiolarian skeletal debris preserved in these surface sediments, centered on the Iceland Plateau, southern Norwegian Basin and northern Norwegian Basin. The most commonly encountered species were: (a) Spumellarida — Actinomma boreale, A. leptoderma, Larcospira minor, and Phorticium clevei, (b) Nassellarida — Amphimelissa setosa, Artobotrys boreale, Lithomelissa setosa, Lithocampe platycephala, Pseudodictyophimus gracilipes, Cycladophora davisiana, and Lithomitra lineata. Based on factor analysis of the core-top assemblages, the radiolarian species were grouped into three associations: Factor 1 —a polar- and arctic water association dominated by Amphimelissa setosa (varimax factor score 5.269), high factor component values are found in the Iceland Plateau area and in a wedge just north of the Iceland–Faeroe Ridge; Factor 2 —an Atlantic water association dominated by Pseudodictyophimus gracilipes (3.247), Lithomelissa setosa (2.731), and Actinomma boreale (1.851), high factor component values are found in the eastern part of the Norwegian Sea, particularly in the area under the influence of the Norwegian Current; and Factor 3 —an Atlantic and arctic water mixed association dominated by Lithocampe platycephala (3.251), Lithomelissa setosa (−2.176), Actinomma leptoderma (1.994) and Artobotrys boreale (1.504), high factor component values are found immediately to the east of the Iceland Plateau in correspondence to the deepest part of the Norwegian Basin. The correlation coefficients obtained between seasonal sea surface temperature and Factors 1 ( R 2=0.835), and 2 ( R 2=0.891) show a good fit, whilst for Factor 3 there was a less marked ( R 2=0.497), but still significant at the 5% confidence level, correlation for fifth-degree polynomial regression functions. The factors correlated better with the summer than the winter sea surface temperatures. However, at 20, 50, 100 and 200 m depth, the correlation became increasingly better, particularly so for the winter situation. The highest species richness for polycystine radiolarians (>28 species) was found in the warm Atlantic domain, the lowest (<24 species) was found in the colder arctic and polar domains, whilst an area approximating the position of the Arctic front had between 24 and 28 species.

Diversity of Tiarosporella parca in Finland, Norway and Switzerland

Isolates of Tiarosporella parca from needles of Picea abies growing in Lapland, southern Finland, southern Norway and Switzerland were compared with each other by using their combined fatty acid and sterol profiles (FAST) and randomly amplified microsatellite (RAMS) markers. Nineteen fatty acids and four sterols were recorded, nine of which appeared only at low amounts (<1% of the total amount of extractives). In a discriminant analysis of their FAST-profiles the isolates could be separated into three non-overlapping groups: (i) Lappish and southern Norwegian, (ii) Southern Finnish and (iii) Swiss isolates. The Swiss isolates form the most distinct group with 11 out of 23 extractives significantly different from those of the other geographical populations. In RAMS analysis two out of five primers tested with ten isolates resulted in polymorphic banding patterns. Using these two primers 26 variable markers in eight size areas were observed which allowed separation of the 39 isolates investigated into 35 different haplotypes. Thus, only four pairs of identical isolates were observed. Determination of the genetic diversity among the isolates revealed that 59% of variation was due to variance within populations, 27% was due to variance between populations within geographical regions and 13% was due to variation between regions. Hence, both methods show a differentiation of the European T. parca population according to geographical origin.

Abstract: Structural Decoupling by the Zechstein Salt During Multiphase Tectonics in the Southern Norwegian North Sea

Abstract: Structural Decoupling by the Zechstein Salt During Multiphase Tectonics in the Southern Norwegian North Sea

Modelling the mass balance of northwest Spitsbergen glaciers and responses to climate change

An energy-balance model is used to calculate mass balance and equilibrium-line altitudes (ELAs) on two northwest Spitsbergen glaciers, Austre Brøggerbreen and Midre Lovénbreen, whose mass balances are at present negative, and for which greater than 20 year records of mass-balance data are available. The model takes meteorological data, ice-mass area distribution with altitude, and solar radiation as inputs. Modelling uses mean daily meteorological data from a nearby weather station, adjusted for altitude. Average net balances modelled for 1980–89 using models tuned to the decade’s average were –0.44 and –0.47 m w.e. for Lovénbreen and Brøggerbreen, respectively, compared with the measured averages of –0.27 and –0.36 m. Sensitivity tests on glacier response to greenhouse warming predict a net balance change of –0.61 m year–1 per °C temperature rise relative to today, and a rise in ELA of 90 m °C–1. Modelling of Little lee Age conditions in Spitsbergen suggests that a 0.6°C cooling or a precipitation increase of 23% would yield zero net mass balance for Lovénbreen and that further cooling would increase net balance by 0.30 m year–1 °C–1. Set in the context of similar modelling of southern Norwegian, Alpine and Greenland ice masses, these results support the suggestion that glaciers with a maritime influence (i.e. higher accumulation) are most sensitive to climate change, implying a gradient towards decreasing sensitivity as accumulation decreases eastward and with altitude in Svalbard.

Modelling the mass balance of northwest Spitsbergen glaciers and responses to climate change

An energy-balance model is used to calculate mass balance and equilibrium-line altitudes (ELAs) on two northwest Spitsbergen glaciers, Austre Brøggerbreen and Midre Lovénbreen, whose mass balances are at present negative, and for which greater than 20 year records of mass-balance data are available. The model takes meteorological data, ice-mass area distribution with altitude, and solar radiation as inputs. Modelling uses mean daily meteorological data from a nearby weather station, adjusted for altitude. Average net balances modelled for 1980–89 using models tuned to the decade’s average were –0.44 and –0.47 m w.e. for Lovénbreen and Brøggerbreen, respectively, compared with the measured averages of –0.27 and –0.36 m. Sensitivity tests on glacier response to greenhouse warming predict a net balance change of –0.61 m year–1 per °C temperature rise relative to today, and a rise in ELA of 90 m °C–1. Modelling of Little lee Age conditions in Spitsbergen suggests that a 0.6°C cooling or a precipitation increase of 23% would yield zero net mass balance for Lovénbreen and that further cooling would increase net balance by 0.30 m year–1 °C–1. Set in the context of similar modelling of southern Norwegian, Alpine and Greenland ice masses, these results support the suggestion that glaciers with a maritime influence (i.e. higher accumulation) are most sensitive to climate change, implying a gradient towards decreasing sensitivity as accumulation decreases eastward and with altitude in Svalbard.

Structural Decoupling by the Zechstein Salt during Multiphase Tectonics in the Southern Norwegian North Sea : ABSTRACTS

Structural Decoupling by the Zechstein Salt during Multiphase Tectonics in the Southern Norwegian North Sea : ABSTRACTS