Bortolanite, a rare mineral of the rinkite group, seidozerite supergroup occurs in two different associations in the Lovozero massif in the Kola Peninsula, Russia: (1) together with ferri-katophorite and phlogopite, it forms porous or mesh aggregates (symplectitic accretions) with euhedral contours in the contact zone of a volcano–sedimentary xenolith and eudialyte lujavrite at Kuamdespakhk Mt and (2) in intergrowths with titanite and fluorcaphite in the poikilitic feldspathoid syenites at Sengischorr Mt. In both cases, bortolanite was found in association with rosenbuschite that is close to it in chemical composition, but unlike bortolanite, it contains no REEs. The mineral is triclinic, space group P$\bar{1}$, a = 9.5807(5), b = 5.6943(4), c = 7.2813(4) Å, α = 89.891(5)°, β = 100.959(4)°, γ = 101.241(5)°, V = 382.25(4) Å3 and Z = 1.

The Lovozero bortolanite differs from the Brazilian holotype sample from de Caldas alkaline massif, Minas Gerais, due to the presence of (OH)-groups in its composition, which is indicated by Raman data. A combination of single-crystal X-ray diffraction data and electron microprobe data provides the following crystal-chemical formula: (Ca1.97Ce0.01Nd0.01Th0.01)Σ2(Ca1.39Zr0.61)Σ2(Na0.72Ca0.28)Σ1(Na1.36Ca0.56Mn0.03Zn0.01)Σ1.96(Ti0.78Zr0.08Nb0.05Mg0.05Fe0.04)Σ1Si4O14((OH)0.92O0.87F0.21)Σ2F2.

While much work on expertise has explored the mobilisation and production of knowledge, the development of epistemic communities, and the mechanisms through which expertise operates – little work has been done exploring how expertise is understood across academic literature on particular regional cases such as the Arctic. In this article, I scope a broad literature review of the Arctic, seeking out how expertise has been depicted and framed in academic and theoretical literature. The results are framed around five different themes: (1) expertise serving the interests of great powers, (2) recognition of the overall importance of expertise in Arctic governance, (3) the purpose of experts, (4) science diplomacy and expertise: a murky barrier, and (5) how to study experts, but also find that Indigenous knowledge is often left out of literature that relies upon Western frameworks of expertise. This incongruity suggests that there are two competing conceptualizations of Arctic expertise, one in theory and another in practice – which has consequences for how the region and its expertise are narrated.

This study investigates the impacts of the timing of an extreme cyclone that occurred in August 2012 on the sea-ice volume evolution based on the Arctic Ice Ocean Prediction System (ArcIOPS). By applying a novel cyclone removal algorithm to the atmospheric forcing during 4–12 August 2012, we superimpose the derived cyclone component onto the atmospheric forcing one month later or earlier. This study finds that although the extreme cyclone leads to strong sea-ice volume loss in all runs, large divergence occurs in sea-ice melting mechanism in response to various timing of the cyclone. The extreme cyclone occurred in August, when enhanced ice volume loss is attributed to ice bottom melt primarily and ice surface melt secondarily. If the cyclone occurs one month earlier, ice surface melt dominates ice volume loss, and earlier appearance of open water within the ice zone initiates positive ice-albedo feedback, leading to a long lasting of the cyclone-induced impacts for approximately one month, and eventually a lower September ice volume. In contrast, if the cyclone occurs one month later, ice bottom melt entirely dominates ice volume loss, and the air-open water heat flux in the ice zone tends to offset ice volume loss.

Interferometric synthetic aperture radar (InSAR) data suffer from an elevation bias due to signal penetration into the firn and ice surface, rendering the height information unusable for elevation and mass-change detection. This study estimates the penetration bias in X-band InSAR data to quantify its impact on elevation and mass-change detection and to demonstrate the applicability of TanDEM-X digital elevation models (DEMs) for cryosphere research. To achieve this, a multiple linear regression model is applied to a time series of four TanDEM-X DEMs acquired between 2010 and 2018 over the Sverdrup Glacier basin (SGB), Devon Ice Cap, Canada. The resulting penetration corrected TanDEM-X DEMs agreed to within ±14 cm of spatially and temporally coincident precise in situ kinematic dGPS data (±10 cm RMSE). Additionally, multi-year estimations of mass change for the SGB derived from differencing TanDEM-X DEMs over multi-year periods between 2010 and 2018, showed good agreement with mean deviation of 338 ± 166 mm w.e. with independent measurements of mass change derived from annual in situ surface mass balance over the same time periods. The results show that the penetration bias can vary significantly, leading to random under- and overestimations in the detection of elevation and mass changes.

Although “urban” and “fisheries” are not commonly paired in the analyses of either urbanism or fisheries governance, today’s large-scale fisheries are often closely organised in connection with cities. In this paper, I build on a feminist perspective and urban studies to examine the makings of a city through contemporary fisheries. Drawing upon observations and interviews conducted in Tromsø, Norway, which is a key site for Arctic fisheries, I review how fish and fisheries are simultaneously made visible and invisible in urban spheres. By analysing the gendered structures and valuations that organise the city–fisheries relations, I introduce three “fishy” windows to demonstrate the kinds of development and future pathways for fisheries that are considered relevant and rational in and for the city. In particular, I discuss how the historical, techno-masculine narratives of mastering Arctic nature frame and legitimise fisheries practices as they expand throughout Tromsø. The study builds on the emerging research on Arctic urbanism to highlight the need to better integrate gendered analyses of the “urban” into social science research on natural resource extraction.

Much has been written about the so-called Franklin expedition (1845–), but not about the master mariners, who joined as “Greenland pilots,” as experienced whaling masters on Royal Navy expeditions were usually called in the 19th century. Having been on Royal Navy expeditions to the Arctic before, Thomas Blanky, the ice master of HMS Terror, was mentioned here and there in contemporary sources. But who he was and how and why he joined the expedition are still widely unanswered questions, to be dealt with for the first time here.

China’s role in the Arctic regime remains a debatable topic in the expert discourse on the High North. Currently, in view of the aggravated conflicts in other regions that include Russia as the largest Arctic state, and China as its strategic partner, the Arctic regimes are experiencing salient disturbances. Against this backdrop, an understanding of China’s opportunities to affect Arctic affairs is urgently needed. We address this issue by combining political and legal analyses. We used the regime theory approach to outline the Arctic regime complex (ARC), and through this lens, we discuss the recent changes that are being observed. Based on this, we determine China’s actual potential for making amendments to the ARC. We conclude that China has no capacity to make a crucial shift in the ARC, but it is still able to alter particular rules, like those related to Arctic Ocean management and scientific cooperation. The further efficient operation of the Arctic Council will play a decisive role in envisaging China’s behaviour in the region.

Russia’s Arctic policy since 2008 has been influenced by two competing foreign policy lines (discourses): the “Arctic as a resource base” and the “sovereignty discourse”. The “Arctic as a resource base” has been the dominant one since the first Russian Arctic Strategy in 2008. It is primarily about exploiting the vast oil and gas resources estimated to be located there, as well as turn the Northern Sea Route into a “global transport corridor”. In Russia’s Arctic Strategy of 2020, however, there is enhanced emphasis on sovereignty and power balancing in Russian Arctic policy. And the focus on sovereignty was heightened with the amendments to Russia’s Arctic Strategy in March 2023. This increased emphasis on sovereignty, territorial defence and balance of power in Russian Arctic policy is likely to be further reinforced by the growing great-power competition between the USA and Russia, which has gained new momentum following Russia’s invasion of Ukraine in 2022.

In 1866, Charles F. Hall recorded testimony from a Pelly Bay native named Sŭ-pung-er who reported that together with his uncle, they had visited the Northwest coast of King William Island 4 years prior in search of materials abandoned by the Franklin Expedition. Sŭ-pung-er told Hall that he had identified a site which Hall believed was a “vault” which might contain documents and speculated that it could have been a burial site for a high-ranking officer. Sŭ-pung-er’s testimony also included the description of a wooden “pillar, stick or post” which marked the spot of the vault. The location of this site and the pillar have never been found. Yet they remain sought-after for both their significance and the potential bonanza of information about the expedition. Any clue or artefact, which could provide clarity for this site, is therefore of great value. This paper describes a model of the pillar seen on King Williams Island, replicated by Sŭ-pung-er, which Hall brought back from the Arctic and included in his list of Franklin relics. The model, now housed in the Smithsonian Museum of American History, was first featured in a drawing of relics appearing in 1869 in Harper’s Weekly magazine. The fact that this artefact has been in plain sight for so long, but unrecognised for what it is, is significant. The pillar model both provides clarity and continues the mystery surrounding the Franklin Expedition.

Recent years have shown that international science dialogue exists at the edge of turbulence and is disturbed by different geopolitical events. The notion of science diplomacy has taken the critical discourse to different levels of actors. Such a discourse exposes the epistemological ambivalence and methodological imbalance of both science and diplomacy in this phenomenon. Current geopolitical conditions have revealed new edges of science diplomacy instruments that spread from “soft” to “hard” practices. Different levels of dialogue and cooperation have shown different examples of resilience and adaptability (or the opposite) to the external turbulence. The phenomenon of regionalisation in science diplomacy is facing criticism from the science community while the current geopolitical situation has dramatically influenced the Arctic science dialogue, as well as governance practices. This commentary discusses particular examples of existing Arctic science diplomacy practices in current geopolitical conditions which are reflected in the Arctic theoretical and practical discourse.

The present work explores the link between navigational processes and the experience of place by considering the case of Evenki reindeer herders and hunters. Our analysis shows how the idiosyncratic wayfinding methods of the Evenki result in a unique experience of place – a case that elucidates the important question of the impact of navigational processes on environmental experience, and that advances the debate between mental map theory and practical mastery theory in anthropology. We defend that their wayfinding methods – involving a particular gait, path networks, and vast hydrological and toponymical knowledge – allow the Evenki to navigate without a need for integrating egocentric and allocentric frames of reference. As a result, the Evenki experience themselves as free individuals moving through an environment that is alive and rife with possibility. This analysis reveals the ways in which wayfinding processes relying predominantly on route knowledge – as opposed to survey knowledge – affect environmental experience. Alternative methods of wayfinding can be seen as a form of resistance to the uniformisation of landscapes, and as a way of embracing the heterogeneity of space.

In the Canadian high Arctic, tabular massive ground ice is found extensively throughout the Eureka Sound Lowlands (ESL). This study evaluates the development of tabular massive ice in raised marine-deltaic sediments of the ESL based on new cryostratigraphic data from sites found between the coastline and the Holocene marine limit. At all sites, massive ice is found below laminated fine-grained marine sediments, and the upper contact between the ice and the overlying marine sediments is conformable and gradational. The concentration of major ions in the massive ice is orders of magnitude higher than expected for glacial ice, but Na/Cl molar ratios vary following elevation: the higher-elevation site has ratios similar to glacial ice, but sites at lower elevations have ratios closer to seawater. The δ18O values of the ice indicate that the main source of water is glacial meltwater but the δD-δ18O regression slope values suggest that the ice formed in an open system while receiving an influx that had a substantially different isotopic signature than the initial reservoir. The development of massive ice in the marine-deltaic sediments involves glacial meltwater recharging an aquifer beneath the Holocene marine sediments with a contribution of 1–10% of seawater.