South Greenland Research Articles

Petrography, geochemistry and magnetic susceptibility of the Isortoq Fe-Ti-V deposit, Isortoq Giant Dykes, South Greenland

The Isortoq Giant Dykes in the Proterozoic Gardar Province, South Greenland, include the Isortoq South giant dyke and the Isortoq North giant dyke. The fine-grained Fe-Ti-V deposit hosted by the Isortoq South giant dyke, referred to as the Isortoq Fe-Ti-V deposit, is considered a good test site for the use of magnetic susceptibility for the mapping of ore grades. Here, we test this and show that the Fe, Ti and V distribution is controlled by titanomagnetite disseminated throughout fine-grained troctolite. The deposit displays a clear correlation between magnetic susceptibility and Fe, Ti and V grades in bulk samples of consecutive 2 m sections from 11 drill cores, totalling 2671 m in length. We observe that Fe, Ti and V are almost entirely hosted in titanomagnetite, which controls the magnetic susceptibility. Field measurements of the magnetic susceptibility can thus be considered as a reliable exploration tool for this type of mineralisation. We further consider the origins of the deposit by reconnaissance petrography, mineral and bulk rock chemistry of the large mass of aphanitic Fe-rich troctolite in the Isortoq South giant dyke. We suggest that the deposit may represent the base of a basanitic to trachybasaltic magma chamber, in which Fe-rich immiscible melts accumulated, crystallised and fractionated. The processes suggested here may apply to other giant dykes and intrusions of the Gardar Province.

Compression and rebound characteristics of agricultural sandy pasture soils from South Greenland

The reduction of permafrost areas and a prolonged vegetation period, both due to the ongoing climate change, open up new possibilities for agricultural activities in the circumpolar region. Presently, not much is known about the physical and functional properties of subarctic agricultural soils, making it challenging to evaluate soil impacts from increased agricultural activity. This study aims at assessing the mechanical properties of sandy Greenlandic pasture soils regarding a potential future land-use change.The compression curves of 210 undisturbed soil core samples of three pasture fields in South Greenland and, as comparison, four intensively cultivated agricultural fields in Denmark were generated by uniaxial confined compression tests (UCCT). Four soil mechanical properties were determined: the precompression stress (σpc) as a measure of soil strength, the compression index (Cc) as a measure of compressibility, the swelling index (Cs) as a measure of resilience to compaction and the rebound (Δε) after a relaxation time of 60 s as a measure of short-time recovery from compaction.The Greenlandic pasture soils exhibited significantly higher σpc than the Danish cultivated soils despite their significantly lower initial bulk density, ρb. The Cc negatively correlated with ρb, and the Greenlandic soils showed higher Cc values than the Danish soils. The Cs showed a reciprocal correlation with ρb and, partly due to lower ρb of the Greenlandic soils, higher Cs than the Danish soils. The South Greenlandic sandy pasture soils showed compression and rebound characteristics on level with Danish loamy cultivated soils, likely due to a high content of particulate organic matter (non-degraded organic matter, including grass root-mat residues).

Multi-phased deglaciation of south and southeast Greenland controlled by climate and topographic setting

To put recent Greenland Ice Sheet (GrIS) ice loss into a longer-term context, we must understand its behavior during late-glacial and Early Holocene warming. Previous results seem to suggest that there is a large contrast in the timing of deglaciation between South and Southeast Greenland. However, because of lack of available data, in particular in Southeast Greenland, it is difficult to assess how the ice sheet responded to major late-glacial and Early Holocene climate changes. In this study, we use 41 new 10Be ages to constrain the deglaciation chronology in 12 new locations from the coast to the present ice margin in South and Southeast Greenland. We find that South Greenland (south of 61.5°N) deglaciated between ∼14.8 and 11.9 ka, whereas Southeast Greenland (61.5°N to 68.2°N) deglaciated between ∼11.4 and 11.3 ka. The deglaciation of the coastal, low-intermediate topography in South Greenland coincides with increased air surface temperatures during the Bølling-Allerød with fjords continuing to deglaciate into the Early Holocene. In contrast, the ice sheet persisted at the coast until the late-glacial and Early Holocene in Southeast Greenland, likely because of increased precipitation in the high alpine topography and fjord geometry and bathymetry (e.g. width of fjords and presence of sills). This multi-phased deglaciation demonstrates a contrasting response of the southern GrIS to changes in climate and variations in topographic setting, and that the spatial deglaciation of the GrIS was complex and likely did not respond to a single external climate forcing.

A method to evaluate REE-HFSE mineralised provinces by value creation potential, and an example of application: Gardar REE-HFSE province, Greenland

The rare earth elements and high-field-strength elements (REE-HFSE) exploration sector conducts most evaluations at deposit and smaller scales. It is not evident how the sector performs a preceding exploration stage—rating and prioritising REE-HFSE mineralised provinces—to determine which provinces are prospective enough to warrant investment. Here we present an objective, repeatable, low-cost method to screen any REE-HFSE province, as a foundation for district-scale investigations or asset evaluations. It is original for REE-HFSE screening, and adapted from regional scale copper, cobalt and petroleum exploration, and CO2 storage, screening methods. It is centred upon a mineralised province’s favourability for potential value creation, and to identify: (a) its main information gaps; (b) its weakest links; (c) its exploration maturity and remaining potential category; (d) how it compares against other REE-HFSE provinces; and (e) if further investigation is justified. This method incorporates geoscience, strategy, economic and socio-environmental factors in a way that is understandable and directly usable across stakeholder groups. The workflow is systematic, yet flexible enough to accommodate organisation-specific criteria, and usable for other commodities. It provides the platform to build a global REE-HFSE province map and database consistently across national boundaries and organisations. Categories for the extent of province exploration maturity and remaining mineral potential are proposed. We illustrate the applicability of these methods using the Gardar REE-HFSE Province (GRHP) of south Greenland. We conclude that it is a moderate size, frontier province that is currently of questionable favourability for value creation. To move GRHP into a positive favourability class, its current weak links need strengthening by research, government policy and industry stakeholders: evaluate the mineral system; integrate all information geospatially and place it in the public domain; help the region improve some community health and safety issues; convert some mineral resources into an Ore Reserves category; commence mining and sales production.

First report of Chrysomyxa ledicola attacking spruce (Picea spp.) in Greenland

Small conifer plantations have been established in the Tasermiut, Igaliko and Tunulliarfik fjord regions of South Greenland. In August 2019 spruce trees in an extensive area in a plantation in Kuusuaq (Tasermiut) showed symptoms resembling…

Local glaciers record delayed peak Holocene warmth in south Greenland

Local glaciers and ice caps (GICs) respond sensitively and quickly, on the scale of decades to centuries, to climate variations. Continuous records of past fluctuations in GIC size provide information on the timing and magnitude of Holocene climate shifts, and a longer-term perspective on 21st century glacier retreat. Although there is broad-scale agreement on millennial-scale trends in Holocene climate variability and fluctuations in local GICs in Greenland, regional variations are only loosely constrained. Here we present three Holocene proglacial lake sediment records from South Greenland, an area with abundant local glaciers but few Holocene-length paleoclimate records. In addition, we use geospatial analysis to model past equilibrium-line altitudes (ELAs) and thereby constrain the magnitude of ablation-season temperature change during the warmest and coolest periods of the Holocene. Physical and geochemical sedimentary characteristics show that two of the proglacial lakes continued to receive glacial meltwater input until ∼7.3 and ∼7.1 ka BP. The survival of local glaciers implies that South Greenland remained relatively cool, and that summer temperatures gradually warmed, but did not warm well beyond 1.2 °C above present in the early Holocene. In the mid-Holocene, from ∼7.1 to 5.5 ka BP, organic sedimentation at these two sites indicates that local glaciers became very small, or more likely melted away completely. The glaciers within the third lake’s catchment melted away prior to ∼5.2 ka BP, as sediments deposited earlier in the Holocene could not be dated at this site. We estimate that summer temperatures increased by at least 1.2–1.8 °C above present by ∼7.3–7.1 ka BP. Our results are consistent with other observations that suggest a north-to-south gradient in the timing of Holocene thermal maximum conditions, with southern Greenland experiencing a delayed warming relative to other regions in Greenland. As summer temperatures cooled in the Neoglacial, our records show that sustained glacier regrowth began ∼3.1 ka BP with glaciers in the southernmost catchment, which at present, receive the most precipitation. In the other two catchments, which host smaller glaciers in a drier environment, regrowth began at ∼1.3 and ∼1.2 ka BP, the timing of which is in agreement with other glacial records from the Arctic Atlantic region. Local glaciers reached their maximum late Holocene extents during a cooler, second phase of the Little Ice Age (LIA) ∼0.2-0.1 ka BP, that we estimate was at least 0.4–0.9 °C cooler than present. Overall, these findings improve understanding of the spatio-temporal dynamics of Holocene glacier and climate change in Greenland, potentially yielding valuable information about their future response.

Glacial Rock Flour as Soil Amendment in Subarctic Farming in South Greenland

Agriculture in subarctic regions is limited by a short and cold growing season. With warming in the region, the number of growing days and, consequently, the potential for agricultural intensification and expansion may increase. However, subarctic soils are typically acidic, low in plant-available nutrients, and coarsely textured, so they require soil amendment prior to intensification. This is the case in South Greenland, where we tested the use of glacial rock flour (GRF) produced by glaciers as a soil amendment. An experiment was made on a farm in South Greenland during the 2019 summer to quantify the short-term effect of applying GRF to a field dominated by perennial timothy grass. Three treatments were compared to control sites (n = 5): 20 t GRF ha−1 without conventional NPK-fertilizer, as well as 20 and 40 t GRF ha−1 in combination with 25% NPK-fertilizer. The experiment showed no significant response in biomass production (aboveground and belowground) for the plots treated with GRF only. The low rate of GRF combined with 25% NKP showed a marked and significant increase in yield in contrast to a high GRF rate with NPK, which resulted in a significant reduction in yields. The chemical composition of the plants versus soil and GRF showed that the plant uptake of nutrients was significantly higher for NPK-fertilized plots, as expected, but no differences were found between GRF-treated plots and the control plots with respect to nutrient availability or pH in the soil. We conclude that adding water and fertilizer has the potential to increase yields in South Greenland, but applying glacial rock flour as a short-term agricultural supplement needs to be further investigated before it can be recommended.

The added value of high resolution in estimating the surface mass balance in southern Greenland

Abstract. The polar version of the regional climate model RACMO2, version 2.3p1, is used to study the effect of model resolution on the simulated climate and surface mass balance (SMB) of south Greenland for the current climate (2007–2014). The model data at resolutions of 60, 20, 6.6, and 2.2 km are intercompared and compared to SMB observations using three different data refinement methods: nearest neighbour, bilinear interpolation, and a statistical downscaling method utilising the local dependency of fields on elevation. Furthermore, it is estimated how the errors induced by model resolution compare to errors induced by the model physics and initialisation. The results affirm earlier studies that SMB components which are tightly linked to elevation, like runoff, can be refined successfully, as soon as the ablation zone is reasonably well resolved in the source dataset. Precipitation fields are also highly elevation dependent, but precipitation has no systematic correlation with elevation, which inhibits statistical downscaling to work well. If refined component-wise, 20 km resolution model simulations can reproduce the SMB ablation observations almost as well as the finer-resolution model simulations. Nonetheless, statistical downscaling and regional climate modelling are complementary; the best results are obtained when high-resolution RACMO2 data are statistically refined. Model estimates in the accumulation zone do not benefit from statistical downscaling; hence, a resolution of about 20 km is sufficient to resolve the majority of the accumulation zone of the Greenland Ice Sheet with respect to the limited measurements we have. Furthermore, we demonstrate that using RACMO2, a hydrostatic model, at 2.2 km resolution led to invalid results as topographic and synoptic vertical winds exceed 10 m s−1, which violates the hydrostatic model assumptions. Finally, additional tests show that model resolution is as important as properly resolving spatial albedo patterns, correctly initialising the firn column, and uncertainties in the modelled precipitation and turbulent exchange.

Topographical evolution and glaciation history of South Greenland constrained by paired 26Al/10Be nuclides

The pattern of cosmogenic nuclide inheritance within bedrock surfaces in previously glaciated regions can be used to assess the efficiency of glacial erosion and constrain topographic evolution. Here, we present fifty new in-situ cosmogenic 10Be and 26Al pairs in bedrock and boulder erratics from South Greenland. The data demonstrate rapid retreat of the South Greenland Ice Sheet in the early Holocene and a clear gradient in cosmogenic nuclide inheritance in bedrock with elevation. Sites <800m above sea level (m a.s.l.) generally show limited or no nuclide inheritance (exposure from before the last glaciation). In contrast, the nuclide inheritance in samples from sites at higher elevations varies from negligible to >90kyr of exposure before the last glaciation, depending on the topographic setting. Our results suggest that steering of ice into troughs led to substantial erosion (>2.6m) in the troughs over the last glacial cycle, even at elevations above 1500 m a.s.l., while bedrock on summit flats at similar elevations experienced much less erosion. Inverse Markov-Chain Monte Carlo (MCMC) modelling of the nuclide inventories further indicates that selective linear erosion developed >1Myr ago at the summit flat closest to the present ice margin, and effectively limited the subsequent erosion to <2.6m. Erosion of the Redekammen Ridge some 40 km from the present ice margin was slightly more efficient over the last 1 Myr, indicating that selective linear erosion is less pronounced, or developed later, here than at the summit flats. Long-term ice-cover histories are generally less well-constrained than the erosion histories. The results suggest that the summit flats were possibly ice-covered during large parts of the last 1 Myr and experienced minimal erosion during this interval, but it is also possible that they were only covered by ice during the coldest parts of the glacial periods and that a cover of regolith or overlying rock was stripped off during one of the latest major glaciations. Although inverse modelling cannot distinguish between these scenarios, we identify the more likely ice-cover scenarios for each site based on the geological setting and surface characteristics.

Four decades of new vascular plant records for Greenland.

Records of new species of vascular plants in Greenland from the last four decades are presented and new phytogeographical data leading to extension of the known distribution limits in Greenland are discussed. Since the publication of the latest edition of the Flora of Greenland in 1978 (Böcher et al. 1978) fieldwork by Greenland Botanical Survey and other expeditions have taken place especially in West and East Greenland and in many remote areas in North and Northeast Greenland. This paper serves as an update of the Flora of Greenland. Twenty species, one subspecies and one new forma have been added to the flora of Greenland: Carex membranacea Hook., Carex miliaris Michx., Carex rhomalea (Fernald) Mack., Equisetum hyemale L., Festuca edlundiae S. Aiken, Consaul and Lefkovich, Festuca groenlandica (Schol.) Frederiksen, Festuca saximontana Rydb., Galium verum L., Geum rossii (R. Br.) Ser., Papaver cornwallisense D. Löve, Papaver dahlianum Nordh., Papaver labradoricum (Fedde) Solstad and Elven, Papaver lapponicum (Tolm.) Nordh., Pedicularis sudetica Willd. ssp. albolabiata Hult., Poa flexuosa Sm., Puccinellia bruggemanni Th. Sør., Ranunculus subrigidus W.B. Drew., Silene vulgaris (Moench) Garcke, Trientalis europaea L. and Veronica officinalis L. in addition to one subspecies Phippsia algida (Sol.) R. Br. ssp. algidiformis (H. Sm.) Löve and Löve. The viviparous form of Poa hartzii f. prolifera has been reported for the first time in Greenland. Presently, the total number of vascular plant species in Greenland is 532. 89 new northern and 28 new southern distribution limits are presented and 26 species are new to the flora province East Greenland, whereas 15 species are new to West Greenland. The numbers of new species to flora provinces North and South Greenland are 14 and one, respectively.

Deep diving harbor seals (Phoca vitulina) in South Greenland: movements, diving, haul-out and breeding activities described by telemetry

Harbor seals (Phoca vitulina) were formerly widely distributed in Greenland, but in most areas, they have now become rare or extinct. In this study, we deployed 15 satellite-linked data-recorders on 12 individual harbor seals captured near the southern tip of Greenland. The tagging site, a small archipelago, turned out to be their main haul-out and molting location. The seals were tagged around the first week of September across 2 years. Six adult seals transmitted during the breeding season (June–July), during which two males and a female stayed near the tagging site, whereas two females and a male made a targeted swim about 250 km northward along the east coast, just prior to parturition and they returned right after the breeding period. Based on behavior (strong site fidelity and abrupt changes in haul-out and diving activities), we determined that all three females gave birth and that parturition happened during 14–21 June. Prolonged haul-out, relating to the molt, started in early August and peaked during 15 August–8 September with an average of 10–11 h haul-out per day. The seals thereafter gradually transitioned toward a winter mode with more deep dives and on average hauling out 4 h every other day. Dives deeper than 400 m made up less than 1% of their dives, but four seals dove to depths in excess of 575 m, with a record depth of 631 m and the longest dives lasting between 20 and 25 min. To our knowledge, these dives are the deepest recorded for harbor seals.

A low climate threshold for south Greenland Ice Sheet demise during the Late Pleistocene

The Greenland Ice Sheet (GIS) has been losing mass at an accelerating rate over the recent decades. Models suggest a possible temperature threshold between 0.8 and 3.2 °C, beyond which GIS decline becomes irreversible. The duration of warmth above a given threshold is also a critical determinant for GIS survival, underlining the role of ocean warming, as its inertia prolongs warmth and triggers longer-term feedbacks. The exact point at which these feedbacks are triggered remains equivocal. Late Pleistocene interglacials provide potential case examples for constraining the past response of the GIS to a range of climate states, including conditions warmer than present. However, little is known about the magnitude and duration of warming near Greenland during these periods. Using high-resolution multiproxy surface ocean climate records off southern Greenland, we show that the previous 4 interglacials over the last ∼450 ka all reached warmer than present climate conditions and exceeded the modeled temperature threshold for GIS collapse but by different magnitudes and durations. Complete deglaciation of the southern GIS in Marine Isotope Stage 11c (MIS 11c; 394.7 to 424.2 ka) occurred under climates only slightly warmer than present (∼0.5 ± 1.6 °C), placing the temperature threshold for major GIS retreat in the lower end of model estimates and within projections for this century.

A module to convert spectral to narrowband snow albedo for use in climate models: SNOWBAL v1.2

Abstract. Snow albedo schemes in regional climate models often lack a sophisticated radiation penetration scheme and generally compute only a broadband albedo. Here, we present the Spectral-to-NarrOWBand ALbedo module (SNOWBAL, version 1.2) to couple effectively a spectral albedo model with a narrowband radiation scheme. Specifically, the Two-streAm Radiative TransfEr in Snow model (TARTES) is coupled with the European Centre for Medium-Range Weather Forecasts (ECMWF) Integrated Forecast System (IFS), cycle 33R1, atmospheric radiation scheme based on the Rapid Radiation Transfer Model, which is embedded in the Regional Atmospheric Climate Model version 2.3p2 (RACMO2). This coupling allows to explicitly account for the effect of clouds, water vapor, snow impurities and snow metamorphism on albedo. Firstly, we present a narrowband albedo method to project the spectral albedos of TARTES onto the 14 spectral bands of the IFS shortwave radiation scheme using a representative wavelength (RW) for each band. Using TARTES and spectral downwelling surface irradiance derived with the DIScrete Ordinate Radiative Transfer atmospheric model, we show that RWs primarily depend on the solar zenith angle (SZA), cloud content and water vapor. Secondly, we compare the TARTES narrowband albedo, using offline RACMO2 results for south Greenland, with the broadband albedo parameterizations of Gardner and Sharp (2010), currently implemented in RACMO2, and the multi-layered parameterization of Kuipers Munneke et al. (2011, PKM). The actual absence of radiation penetration in RACMO2 leads on average to a higher albedo compared with TARTES narrowband albedo. Furthermore, large differences between the TARTES narrowband albedo and PKM and RACMO2 are observed for high SZA and clear-sky conditions, and after melt events when the snowpack is very inhomogeneous. This highlights the importance of accounting for spectral albedo and radiation penetration to simulate the energy budget of the Greenland ice sheet.

Sources and Distribution of Fresh Water Around Cape Farewell in 2014

AbstractWe investigate the origin of fresh water on the shelves near Cape Farewell (south Greenland) using sections of three hydrographic cruises in May (HUD2014007) and June 2014 (JR302 and Geovide). We partition the fresh water between meteoric water sources and sea ice melt or brine formation using the δ18O of sea water. The sections illustrate the presence of the East Greenland Coastal Current (EGCC) close to shore east of Cape Farewell. West of Cape Farewell, it partially joins the shelf break, with a weaker near‐surface remnant of the EGCC observed on the shelf southwest and west of Cape Farewell. The EGCC traps the freshest waters close to Greenland and carries a brine signature below 50‐m depth. The cruises illustrate a strong increase in meteoric water of the shelf upper layer (by more than a factor 2) between early May and late June, likely to result from East and South Greenland spring melt. There was also a contribution of sea ice melt near the surface but with large variability both spatially and also between the two June cruises. Furthermore, gradients in the freshwater distribution and its contributions are larger east of Cape Farewell than west of Cape Farewell, which is related to the EGCC being more intense and closer to the coast east of Cape Farewell than west of it. Large temporal variability in the currents is found between different sections to the east and southeast of Cape Farewell, likely related to changes in wind conditions.

Collaborative configurations of tourism development: a Greenlandic example

PurposeWhile tourism scholars have increasingly recognized the significance of collaboration as an essential element in tourism development, there is a lack of theoretical and empirical research centering on (trans)local collaboration as a central means for future tourism development in Greenland. The purpose of this paper is to analyze the conceptual and analytic potentials and challenges of collaboration in an explorative case study.Design/methodology/approachThe paper applies a case study approach to scrutinize collaboration in the setting of a tourism workshop in South Greenland. This research approach is exploratory in nature and focuses on collaborative activities among participants from different research institutions and countries, from Campus Kujalleq in Qaqortoq, from small-scale enterprises and businesses, managers of destination marketing organizations and local fishermen.FindingsFour “collaborative configurations” emerged during the workshop. These inspire and challenge ways of (re)conceptualizing collaborative tourism development in South Greenland and call for the reconsideration of the present approach toward tourism development for shaping new possible future(s) of tourism in the Greenlandic context.Originality/valueThe relevance of this paper emerges from the crucial significance that tourism actors in Greenland credit collaboration. Moreover, by approaching development issues from within and mutually developing possible practice solutions through collaboration with local tourism actors, the paper aims to give voice to the local community, which currently is lacking in the debate on tourism development in Greenland.

Livsformer og livskvalitet i Grønland: Et indblik i sammenhængen og den potentielle udvikling

This article examines how life modes and quality of life are related in Greenland from a social science perspective. The article also relates to how this is linked to the country's development towards independence. Quality of life and the notion of the good life belong to the cultural and value-laden aspects of ways of life. In other words, it is a notion of how things should, must or may be, in order for us to feel that life is good. But the physical locality of where a person lives is also important. It is a classical notion that people have substantially different ways of life in a city versus a settlement, and that values ​​and attitudes to what quality of life can be, substantially varies between the two. Based on the results of a quality of life studies in South Greenland in 2018 and through an analysis and discussion of Thomas Højrups’ life mode analysis, the article seeks to answer the following questions: How are life modes and quality of life in Greenland interrelated? And how are they linked to the current development towards independence? The article argues that life modes and quality of life are to a large extent associated with relations to family, nature and work, but that the ability of the Greenlandic people to adapt also plays a role in the relationship between life forms and quality of life

Discreditation of the pyroxenoid mineral name ‘marshallsussmanite’ with a reinstatement of the name schizolite, NaCaMnSi3O8(OH)

AbstractSchizolite, originating from the type locality, Tutop Agtakôrfia, in the Ilímaussaq alkaline complex, Julianehåb district, South Greenland, was described initially by Winther (1901) with additional data being supplied by Bøggild (1903). Recently, a proposal for the new mineral ‘marshallsussmanite’ was submitted to, and approved by, the International Mineralogical Association Commission on New Minerals, Nomenclature and Classification (IMA2013-067) by Origlieri et al. (2013). Results from the detailed examination of two schizolite cotype samples presented here, using single-crystal and powder X-ray diffraction, and optical properties, confirms it to be equivalent to ‘marshallsussmanite’. Historical precedence sets a priority for discrediting the name ‘marshallsussmanite’ in favour of the original, more-than-a century-old name, schizolite. The two schizolite samples investigated vary slightly in physical and chemical properties but are consistent overall. The prismatic crystals are pale red or pink to brownish. Schizolite is brittle with a splintery aspect. It is biaxial (+), with average optical parameters: α = 1.626 ± 0.003, β = 1.630 ± 0.002, γ = 1.661 ± 0.002, 2Vmeas = 71(4)° and 2Vcalc = 40°; there is no pleochroism. Electron microprobe analysis shows both samples have nearly identical compositions (differences &amp;lt;0.4 wt.% oxide), with the mean values of: SiO2 52.6(4); Al2O3 0.005(1); FeO 2.54(2); MnO 13.86(9); CaO 17.9(4); Na2O 8.9(1); and H2O 2.59(2) wt.% oxide; this corresponds to a mean formula of: Na1.00(2)Ca1.11(7)Mn0.68(1)Fe0.12(0)Si3.041(1)O8(OH). Final least-squares structure refinements for both samples converged at R1 values ≤2.0%; H atoms were located in all refinements.

Geochemistry of a confirmed Precambrian impact ejecta deposit: The Grænsesø spherule layer, South Greenland

AbstractSamples from a single outcrop of the Graenseso spherule layer, Midternaes, South Greenland, consist of a spherule‐bearing dolomixtite with matrix‐supported intraclasts up to 1 m in size. In addition to field observations, we performed mineralogical and whole rock geochemical analysis, including electron microprobe, neutron activation analysis, X‐ray fluorescence, and mass spectrometry of the horizon and the overlying and underlying strata. We show that the spherules are petrographically similar to those in the Zaonega spherule layer, Karelia, Russia. Our petrographic and chemical results are consistent with the previous suggestion that the Grænsesø layer correlates with the Zaonega layer, and it is possible that both layers are related to the Vredefort impact event. The samples containing spherules, as well as the overlying rocks, have elevated REEs compared to the underlying pre‐impact layer, suggestive of a new continental source of sediment that may be coincident with the impact event. Zircons separated from the lower part of the Grænsesø spherule layer display complex age patterns suggesting that they have genetically different origins based on distinctly different Th/U ratios. Crystallization ages of all groups are ≥ 2.8 Ga, with ~2.8 Ga representing a time of major crustal growth globally. Therefore, we cannot conclusively determine in this study if the zircons are locally derived or if they are transported with the ejecta. The spherule layer was deposited by a high‐energy, subaqueous debris flow, an origin that is consistent with the hypothesis that the layer was deposited by impact‐induced waves and/or currents.

Complementarity assessment of south Greenland katabatic flows and West Europe wind regimes

Current global environmental challenges require vigorous and diverse actions in the energy sector. One solution that has recently attracted interest consists in harnessing high-quality variable renewable energy resources in remote locations, while using transmission links to transport the power to end users. In this context, a comparison of western European and Greenland wind regimes is proposed. By leveraging a regional atmospheric model specifically designed to accurately capture polar phenomena, local climatic features of southern Greenland are identified to be particularly conducive to extensive renewable electricity generation from wind. A methodology to assess how connecting remote locations to major demand centres would benefit the latter from a resource availability standpoint is introduced and applied to the aforementioned Europe-Greenland case study, showing superior and complementary wind generation potential in the considered region of Greenland with respect to selected European sites.

In the Shadow of the Mountain: Assessing early impacts on community development from two mining prospects in South Greenland

The study presented in this paper explored how people in South Greenland perceive their future prospects and the role of mining in this regard. This region hosts two important mining projects still in relatively early stages. The study further investigated how mining projects influence local decisions about individual and community development. It was conducted as a case study of the two specific mining projects and how these projects connect with local people’s visions for the future and how people find that the projects influence the possibility of realizing these futures. The study is based on qualitative interviews with people from the towns of Narsaq and Qaqortoq and from a sheep farm near Narsaq, during a fieldtrip in May 2017. The authors found that the mining projects, even though they are still in the exploration phase, have already had great impact on local expectations for future development and on decision-making and planning in people’s daily lives and thereby the development of the communities. Further, although located relatively close together in the same region, there are significant differences between the towns and their relations to the neighboring mining projects. There is both support and opposition towards the projects, which triggers division between individuals, between groups and between the towns. However, all agree on a need for more transparent processes and for timelines to inform people of when they can expect decisions to be made and activities to take place.