Lofoten Archipelago Research Articles

Stokes drift in crossing windsea and swell, and its effect on near-shore particle transport in Lofoten, Northern Norway

Transport assessments near the coast are often related to particles drifting near the surface. Such “particles” may be salmon lice, cod eggs, macro plastics or ship debris. Their drift depends on the Eulerian currents and the Stokes drift associated with the wind-generated surface wave field. The Stokes drift must be parameterized, and in doing so, one will inevitably make bulk estimates of the direction and speed of the drift for the wave spectrum. This paper implements a recently proposed parameterization of the Stokes drift vertical profile, which accounts for the effect of swell and windsea that propagate in different directions, to the open-source Lagrangian particle tracking model OpenDrift. We investigate how particles drifting in the Lofoten archipelago in Northern Norway depend on the Stokes drift and how we parameterize it. The parameterization accounting for crossing windsea and swell leads to lower residence time near the coastline than other popular parameterizations in the domain we studied.

Beach litter deposition and turnover, effects of tides and weather, and implications for cleanup strategies: A case study in the Lofoten archipelago, Norway

Plastic pollution is ubiquitous in the marine environment. Beach cleanups are considered a cost-effective mitigative measure with generally few negative environmental impacts. Beached litter is not static, however, and may wash back out to sea or be buried, meaning it is only temporarily available for cleanup. We studied deposition and turnover of litter on three Arctic beaches in Lofoten, Norway, biweekly for 31 months. The mean estimated daily deposition rate was 10 items/100 m, with a median residence time of 99 days. Both processes were impacted by seasons and weather and varied both spatially and temporally. Strong winds during the fall increased litter influx and onshore winds contributed to its loss. Heavier objects and those higher on the beach persisted longer yet were still subject to turnover. Snow temporarily buries litter but protects it in the long run. Given the turnover of litter, frequent (albeit smaller) cleanups can readily remove 3–4 times more litter from circulation in the environment than larger, infrequent cleanups. With limited resources, it is recommended to prioritise late fall cleanups.

U–Pb and trace element zircon and apatite petrochronology of eclogites from the Scandinavian Caledonides

The petrochronological records of eclogites in the Scandinavian Caledonides are investigated using EPMA and LA-ICPMS of zircon and apatite for U–Pb geochronology, combined with major and trace element characteristics. Metamorphic zircon from two eclogites from the Lofoten-Vesterålen Complex (Lofoten Archipelago region) collectively yielded a Concordia age 427.8 ± 5.7 Ma and an upper intercept U–Pb age 425 ± 30 Ma. Apatites from the same eclogites provided U–Pb lower intercepts at 322 ± 28 Ma and 354 ± 33 Ma, with the latter also yielding a younger age of 227 ± 24 Ma. Two eclogites from the Lower Seve Nappe (Northern Jämtland) demonstrate different zircon and apatite age records. Metamorphic zircon provided Concordia ages of 467.2 ± 5.9 Ma and 444.5 ± 5.5 Ma, which resolve the age of prograde metamorphism and zircon growth during retrogression, respectively. The lower intercept U–Pb ages of apatites from the same eclogites are 436 ± 18 and 415 ± 25 Ma, respectively. In combination with their geochemical characteristics, they suggest two separate stages of exhumation of eclogite bodies in the Lower Seve Nappe. Zircons from an eclogite from the Blåhø Nappe (Nordøyane Archipelago) yielded a continuum of concordant U–Pb dates from ca. 435 to 395 Ma, which suggests several cycles of HT metamorphism within short intervals. Distinctive trace element characteristics of apatites from the Blåhø Nappe eclogite suggest formation coeval with zircon and garnet during HT metamorphism, but Pb diffusion behaved as an open system until cooling during exhumation of the nappe at 390 ± 12 Ma (lower intercept U–Pb age of apatite). To summarize, this study presents the high potential of coupled zircon and apatite petrochronology of eclogites in resolving their metamorphic evolution, particularly with respect to using trace element characteristics of apatites to constrain the records of their growth, alterations and the meaning of their U–Pb age record.

Going With the Flow – Population Genetics of the Kelp Saccharina latissima (Phaeophyceae, Laminariales)

Saccharina latissimais the most important habitat-forming kelp in sheltered areas of North-Atlantic, and there is also an increasing interest in cultivation and utilization ofS. latissima. The cultivation activity may introduce a risk of “crop-to-wild” gene flow from the cultivated crops to natural populations. A baseline study to examine genetic structure and gene flow inS. latissimaalong the Norwegian coast was therefore done. Microsatellite analyses was carried out on samples from 21 stations, where 12 were in the coastal area from outer Oslofjord in the south to Porsanger in North-Norway, and 9 in the two longest fjords of Norway, Hardangerfjord and Sognefjord. In addition, a hydrographical model was applied, simulating the direction and potential rate of spore dispersal along the coast during the main period of spore release. The results showed a clear isolation by distance pattern along the coast, good connectivity and little genetic structure, except for a reduced connectivity between South- and North-Norway, probably due to the Lofoten archipelago representing a partial barrier for the northward dispersal of spores. In addition, indications of reduced connectivity between coastal stations and the innermost fjord stations were found. Analysing the material with and without one locus potentially under positive selection suggests some degree of genetic adaptation of sugar kelp populations in the Skagerrak area and in the two fjords. The results suggest that genetic connectivity between populations on the coast is strongly influenced by the Norwegian Coastal current.

Deposition rates and residence time of litter varies among beaches in the Lofoten archipelago, Norway

A considerable portion of marine litter pollutes the world's coastlines. Its accumulation on beaches represents the product of deposition and retention, processes which are not well understood. A mark-recapture study was performed with a two-week sampling interval at three sites in Lofoten, Norway. Deposition and retention vary over relatively small spatial scales (approx. 13 km radius). No correlation was found among sites in the timing of high and low deposition events, suggesting these are governed by local factors. Contrastingly, the correlation in the timing of high and low retention events was generally stronger among sites, suggesting these may be affected by regional factors. The results underline the importance of customising cleanup frequency for different beaches as spatiotemporal variation in the relative importance of deposition and retention dictate the optimal frequency for maximal removal of litter from circulation in the local marine environment, which cannot be discerned from accumulation (i.e., standing stock) alone.

Large scale patches of Calanus finmarchicus and associated hydrographic conditions off the Lofoten archipelago

Large swarms of individuals at different spatiotemporal scales characterise the distributions of many animal species. In the ocean several mesozooplankton taxa aggregate in large patches or swarms driven by active behavioural responses to hydrographic structures, although intrinsic biotic characteristics of species´ life cycles not related with the environment can also affect spatial distributions. To understand the mechanisms of aggregation and disentangle environmental and pure spatial effects contributing to patch formation, we extensively sampled a large Calanus finmarchicus patch off the Lofoten islands, northern Norway, in spring 2017 by means of Laser Optical Plankton Counter (LOPC) cross shelf transects and biophysical samplings at fixed stations. We observed a clear association between the buoyant layer of the fresh, cold Norwegian Coastal Current (NCC) and high surface copepod abundances. Off shelf lateral displacements of the NCC along its path may retain copepods from the offshore basins. At deeper layers, copepod abundances increased markedly at regions with low sea level anomalies and reduced vertical flows. Our results also suggest that copepods performed short range diel vertical migration within the patch. Potential future changes in the seasonality and structure of the NCC and their impact on swarm occurrence and formation are discussed.

High transient stress in the lower crust: Evidence from dry pseudotachylytes in granulites, Lofoten Archipelago, northern Norway

AbstractSeismic activity below the standard seismogenic zone is difficult to investigate because the geological records of such earthquakes, pseudotachylytes, are typically reacted and/or deformed. Here, we describe unusually pristine pseudotachylytes in lower-crustal granulites from the Lofoten Archipelago, northern Norway. The pseudotachylytes have essentially the same mineralogical composition as their host (mainly plagioclase, alkali feldspar, orthopyroxene) and contain microstructures indicative of rapid cooling, i.e., feldspar microlites and spherulites and “cauliflower” garnets. Mylonites are absent, both in the wall rocks and among the pseudotachylyte clasts. The absence of features recording precursory ductile deformation rules out several commonly invoked mechanisms for triggering earthquakes in the lower crust, including thermal runaway, plastic instabilities, and downward propagation of seismic slip from the brittle to the ductile part of a fault. The anhydrous mineralogy of host and pseudotachylytes excludes dehydration-induced embrittlement. In the absence of such weakening mechanisms, stress levels in the lower crust must have been transiently high.

Evolution of Brittle Structures in Plagioclase‐Rich Rocks at High‐Pressure and High‐Temperature Conditions—Linking Laboratory Results to Field Observations

AbstractPlagioclase‐rich granulites exposed on the Lofoten archipelago, Northern Norway, display strain localization in pseudotachylytes as well as ductile shear zones that formed under similar high‐pressure and high‐temperature conditions. Pseudotachylytes or pseudotachylyte networks reveal no or very little hydration, whereas ductile shear zones reveal significant hydration. We combine these observations from the field with experimental results to characterize the structural evolution of brittle faults in plagioclase‐rich rocks at conditions of the lower continental crust. We performed a series of deformation experiments on intact granulite samples prepared from a natural granulite sample at 2.5 GPa confining pressure, a strain rate of 5 × 10−5 s−1, and temperatures of 700°C and 900°C to total strains of ~7–8% and ~33–36%. Samples were either deformed “as‐is” or with ~1 wt.% H2O added. Striking similarities between the experimental and natural microstructures suggest that the transformation of precursory brittle structures into ductile shear zones at eclogite‐facies conditions is most effective in samples deformed with added water triggering reaction and subsequent plastic deformation of the products along the faults and in the adjacent wall‐rock.

Can cultural ecosystem services contribute to satisfying basic human needs? A case study from the Lofoten archipelago, northern Norway

There is gradual recognition that cultural ecosystem services are critical building blocks for human well-being. Cultural and provisioning services are often intertwined, difficult to separate, and play salient roles in maintaining local identities. However, multiple studies assume links between cultural ecosystem services and human well-being, without quantifying relationships. We surveyed a representative sample of the population in the Lofoten archipelago in northern Norway, a region faced with great policy challenges around resource harvesting options. Our objective was to examine how public interest in management issues and attachment to place influences the appreciation of cultural ecosystem services benefits and if these benefits can act as satisfiers of well-being. Findings suggest that cultural ecosystem services provide a salient contribution to quality of life in this region, and help satisfy the needs of affection, understanding, creation, subsistence, identity, freedom, participation, protection and leisure. Cultural ecosystem services also constitute salient environmental attributes which contribute to the basic needs of being, having, doing and interacting. The importance of ecosystem services benefits for well-being increases with increasing attachment to the Lofoten environment. We argue that not only the ecosystem services benefits, but the values that emanate from the relationship between people and land should be given greater attention in land use policy.

Citizen science data indicate a reduction in beach litter in the Lofoten archipelago in the Norwegian Sea

Marine litter is a major global challenge, even in the remote reaches of the Arctic. Monitoring temporal trends in litter loadings and composition is key to designing effective preventative and mitigative measures, and to assess their impact. Few data are available, however, by which to do this in the Arctic region. Citizen science data organised by the local waste management company in the Lofoten archipelago in the Norwegian Sea is an exception to this. We analysed volunteer cleanup data (total weight and counts of select litter types, standardised to density per 100 m) from over 200 locations from 2011 to 2018. Results indicate a general decline in beach litter in the region, and particularly in litter types related to private use, such as beverage bottles. These declines are most likely the combined result of extensive cleanup activities and a considerable reduction in local litter inputs.

Solidarity tested: The case of the Norwegian Confederation of Trade Unions (LO‐Norway) and its contradictory climate change policies

The paper examines how organised labour as an important strategic actor in the political economy engages with climate change mitigation policies. By using The Norwegian Confederation of Trade Unions (LO‐Norway) as a case study, we investigate how sectoral unions view the national confederation as a contested space of engagement in which they promote their positions on petroleum extraction and environmental conservation around the Lofoten archipelago. Affiliate unions of LO‐Norway legitimise their policy positions through claims of sectoral and regional representation. The analysis traces the confrontation of these policy positions as inter‐union solidarity was put to the test in the build‐up to the 2017 LO‐Norway congress. While an emerging climate agenda seemingly opened a discursive window for a policy shift within LO‐Norway at the 2017 congress, we show how institutional norms harnessed claims of sectoral and regional dependence and maintained unity within the national confederation.

Å tenke med havet: Et maritimt perspektiv på jernalderlandskapet mellom Buksnesfjorden og Borg på Vestvågøy i Lofoten

The sea as a point of view: A maritime approach to the Iron Age landscape in Vestvågøy, Norway. Vestvågøy, an island in the Lofoten archipelago, is well known in Scandinavian archaeology due to two massive Iron Age buildings at the Borg farm. Borg has been a popular subject for Iron Age research. Research has mainly focused on agricultural aspects of the Iron Age society on Vestvågøy. Nevertheless, a large number of Iron Age graves are located on islets and headlands. These are not often considered in earlier contributions. In this paper, I explore how a maritime perspective can contribute to a new understanding of Iron Age Vestvågøy. The main premise is that the presence of the sea affects how people structure their landscapes. I view the Iron Age sites and the landscape from the sea: the main transport route in prehistoric coastal Norway. Although interpreted as a central place, Borg is located by a hidden bay north on the island, excluded from maritime communication lines. While some researchers suggest that the Buksnesfjord area was the location for another central place, the layout of the Buksnesfjord area differs from Borg. Through a GIS-based quantitative spatial study of Iron Age graves, I outline an alternative view of the Iron Age landscape.

Who are legitimate stakeholders? National and local perceptions of environmental change in the Lofoten islands, Norway

ABSTRACTDebates on future resource policy in northern regions raises the question of who are the legitimate stakeholders to include in policy deliberations? The Lofoten archipelago in Northern Norway is a world-class nature tourism destination, the key spawning ground for North Atlantic cod as well as a reservoir of large unexploited off-shore oil and gas deposits. We surveyed the resident Lofoten population and the larger Norwegian public to ascertain to what extent local and national perceptions of the value of selected environmental attributes and the importance of drivers of environmental change align across geographic scales. Lofoten residents and the national public both assign high value to environmental attributes, but local residents place more emphasis on harvesting marine and agricultural resources than the national public, which is more concerned with the status of individual species and conservation symbols. Our results show that the national public expresses so much interest in Lofoten that they should be considered a legitimate stakeholder in discussions about its future development paths, and while they relate to the area in a broadly similar way, there may be some specific areas of conflict that need to be considered.

A high-resolution 1200-year lacustrine record of glacier and climate fluctuations in Lofoten, northern Norway

Here we present the first high-resolution late-Holocene glacier record from the Lofoten archipelago in northern Norway. The study is based on analyses of lacustrine sediments from the distal glacier-fed lake Kveitvikvatnet (30.1 m a.s.l.), as well as glacial-geomorphological mapping of the ~4.2-km2 surrounding catchment. The lake sediment cores have been examined for input of glacial-derived sediments by using physical, geochemical and magnetic sediment properties, including x-ray fluorescence (XRF), magnetic susceptibility (MS), grain size analyses, dry bulk density (DBD) and loss-on-ignition (LOI). Former glacier extent has been reconstructed using aerial photography and glacial-geomorphological mapping. Lichenometric dating has been used to construct a moraine chronology covering the recent fluctuations of the largest glacier (back to AD ~1740). AMS radiocarbon dating reveals that the lake sediment record covers the last 1200 years, thereby including both the ‘Little Ice Age’ (LIA) and the ‘Medieval Climate Anomaly’ (MCA). By linking continuously deposited lake sediment proxies of glacier fluctuation to known glacier frontal positions and an independent temperature reconstruction, former fluctuations in the equilibrium-line altitude (ELA) and winter precipitation have been reconstructed. Reconstructed winter precipitation estimates have also been correlated to instrumental data from the region back to AD 1895 and show a remarkable correlation, which further strengthens our approach. We found that both MCA and LIA were periods of substantial glacier variations with respect to the present, with a maximum lowering of the ELA of ~75 and ~85 m, respectively. Increased precipitation during these intervals, associated with more frequent and/or intense winter storms, is suggested to be the major driving force of glacier fluctuations in Lofoten.

Strip of altocumulus stretching across the bay near the Fyglsjøen fjord in the Lofoten archipelago in Norway

Strip of altocumulus stretching across the bay near the Fyglsjøen fjord in the Lofoten archipelago in Norway

Stress Analysis in Boreholes Drag Bh and Leknes Bh, Nordland, North Norway

Nordland in northern Norway is characterized by enhanced seismicity and uplift that makes it the most tectonically active area in Norway. This study is part of a project entitled Neotectonics in Norway—Implications for Petroleum Exploration, which aims at enhancing the understanding of regional-scale stress and strain dynamics in Nordland, and to impact risk and hazard assessment and petroleum exploration. This paper attempts to constrain the orientation of in situ horizontal stress using high-resolution acoustic televiewer logging data. The Geological Survey of Norway has drilled two 0.8 km deep near-vertical boreholes on opposite sides of the Vestfjord in Nordland, the open bight of sea that separates the Lofoten archipelago from the Norwegian mainland. Both boreholes are drilled just North of 68°N, with borehole Leknes Bh located near the geographic center of the Lofoten archipelago, and borehole Drag Bh located on approximate equal distance from the shore, on the Norwegian mainland. The results of this study are in most practical aspects inconclusive, mainly due to poor data quality. The data analysis has revealed erroneously high-borehole diameter, and several artifacts such as eccentric logging tool, rugose borehole wall, spiral hole, tool sticking and missing data. Four intervals with passive in situ stress indicators (borehole breakout and drilling-induced fractures) were found in travel time and amplitude images of the Drag Bh, suggesting approximately N–S orientation of maximum horizontal stress. However, these intervals are not found in cross-plots. Either result yields the lowest World Stress Map ranking quality (E).

Variability of northeast Arctic cod (Gadus morhua) distribution on the main spawning grounds in relation to biophysical factors

Early life stages may on average gain a survival benefit from the regular return of parent fish to the same spawning grounds. Such areas may have a considerable spatial extent, occupation of which varies between spawning seasons. Northeast Arctic cod (Gadus morhua) is an ideal candidate to pinpoint the most influential biophysical factors in these respects due to its data richness and apparently strong “homing” behaviour. Their main spawning grounds, off northern Norway, are split in two by the Lofoten archipelago, and in the previous decade strong spawning activity was observed on the seaward continental shelf (Yttersida), while in recent years spawning activity in the wide fjord (Vestfjorden), that separates the islands from the Norwegian mainland, has again increased. Time-series of egg distribution were available from the 1980s, 1990s, and 2004–2012. We used several fixed and random factors to construct a statistical model for the distribution of recently spawned eggs, and hence, spawning adults in either area. We show that the most relevant covariates for the spatial distribution of eggs in Vestfjorden are local temperature and bathymetry, while at Yttersida influence affecting the whole stock, like regional ocean climate and age structure appear more important. Therefore, spawning inside the fjord may be constrained by suboptimal environmental conditions. Yttersida may be occupied by fish which have been displaced out of Vestfjorden when preferred conditions there are of limited extent.

Reply to comment of E. S. Rasmussen and K. Dybkjaer on Patterns of Cenozoic sediment flux from western Scandinavia, by B. Gołędowski, S. B. Nielsen and O. R. Clausen, Basin Research (2012), 24(4), 377-400

We appreciate the comment from Rasmussen & Dybkjaer(2013), which adds to the ongoing discussion on the evolution of the Scandinavian region during the Cenozoic. They point to some important issues with respect to the dating of the mid-Miocene succession in the eastern North Sea basin, and we agree that the mid-Miocene period presents ambiguities in a simple correlation between climate changes and sedimentation in the eastern North Sea. However, we find it difficult to accept that their interpretation should prove that our general conclusion on the primary control of the climate on the Cenozoic variations of sediment flux from western Scandinavia is not supported by the geological record. It is important to note that the study area in Golezdowski et al. (2012) is very large (the Dutch, Danish and Norwegian sectors of the North Sea and the Norwegian continental shelf up to Lofoten archipelago), and that the time interval covers the entire Cenozoic. Therefore, there is a large difference in scale between the area considered by Rasmussen & Dybkjaer (2013) and our study, which could not account for every detail in every subarea. In this reply, we elaborate our arguments with specific reference to some of the questions put forward by Rasmussen & Dybkjaer (2013), especially to the relations between the Hodde transgression and the mid-Miocene Unconformity (MMU).

Fisheries change spawning ground distribution of northeast Arctic cod

Prior to the 1920s, the northeast Arctic (NA) cod were caught at spawning grounds ranging from the southernmost to the northernmost parts of the Norwegian coast, but have for the last 50 yr mainly been caught around the Lofoten archipelago and northwards. The NA cod have their feeding and nursery grounds in the Barents Sea, and migrate south towards the Norwegian coast in the winter to spawn. This study uses commercial fisheries' data from landing ports along the entire Norwegian coast during the period 1866-1969 as evidence of long-term truncation and northerly shift of spawning grounds. Nearly all spawning grounds south of Lofoten have been abandoned, while an increasing proportion of the spawning stock only uses the northernmost areas of the Norwegian coast, Troms and Finnmark. The truncation can hardly be attributed to long-term climatic variations, but may result from an intensive size-selective trawl fishery in the Barents Sea causing a sudden increase in fishing mortality, probably altering the size structure and migratory capacity of the stock.

40Ar/39Ar Thermochronology of Late‐ and Postorogenic Extension in the Caledonides of North‐Central Norway

We report 40Ar/39Ar mineral cooling data that elucidate the timing and style of Devonian late‐orogenic extensional collapse and Permian‐Triassic postorogenic continental rifting in the north‐central Norwegian Caledonides. 40Ar/39Ar mineral cooling ages from ductile extensional shear zones that have either excised or reactivated Caledonian thrust faults along the western flanks of two major basement domes indicate that late‐orogenic extensional deformation in this region occurred during the Early (ca. 409–388 Ma) and Late Devonian (ca. 371–355 Ma). These extensional pulses are consistent with events recently identified by workers investigating areas to the south of our study area. The timing and style of the Early Devonian event supports the northern continuation of the Devonian orogen‐parallel, scoop‐shaped extensional deformation documented in the central Norwegian Caledonides. Late Devonian extension, on the other hand, was orogen‐orthogonal. This Late Devonian event is similar in timing and kinematics to the extension documented in the Lofoten Archipelago due west of our study area. 40Ar/39Ar data on K‐feldspar samples from brittle extensional faults of the Vestfjord‐Vanna fault complex, which opened the major NNE‐SSW‐trending Vestfjord basin, document two pulses of E‐W‐directed postorogenic continental rifting. The first pulse of extension occurred during the Early Permian, at ca. 272 Ma, and the other during the Middle Triassic, at ca. 236 Ma. The Early Permian faults are upper‐crustal features found in the hanging wall of the Lofoten metamorphic core complex, the result of rifting the Lofoten block from the Norwegian mainland during the initial opening of the Vestfjord basin. Middle Triassic faulting occurred because of continued movement along the Vestfjord‐Vanna fault complex during further development of the Vestfjord basin. The timing and kinematics of development of the Vestfjord basin have similarities with those of major basins submerged along and exposed on the continental margins of Norway and Greenland, respectively. Permian‐Triassic extension, long recognized throughout eastern Greenland, is evidently more pronounced along the Norwegian continental margin than was previously thought. We interpret this event as marking the transition from Devonian‐Carboniferous extensional collapse to continental rifting sensu stricto, preceding the Eocene opening of the nascent Norwegian‐Greenlandian Sea.