Island Of Bornholm Research Articles

Characteristics and formation of natural fractures in a silica-rich chalk, Coniacian Arnager Limestone Formation, Bornholm, Denmark.

Natural fractures are abundant and important components in many carbonate sedimentary rocks globally. In hydrocarbon and groundwater reservoirs of carbonate rocks they can form connected networks and thereby influence the permeability and f luid flow significantly. Outcrop studies of fractured carbonate rocks can provide an essential understanding of 3-dimensional fracture networks, thereby aiding in understanding fracture patterns and connectivity in subsurface carbonate reservoirs. The Arnager Limestone Formation is a naturally fractured silica-rich chalk of Coniacian age exposed in a coastal cliff on the island of Bornholm in the Baltic Sea (Denmark). This study examines the natural fractures in the Arnager Limestone Formation from a structural and geomechanical perspective. The Arnager Limestone Formation forms one, 12–20 m thick, main rock mechanical unit; bedding planes acts as weak interfaces and divides it into near-identical, cm- to dm-thick rock mechanical subuits. Flat-lying (horizontal) or low-angle dipping bedding-parallel fractures are intersected by two near-vertical or steeply dipping fracture systems, a major N–S-trending system and a less prominent W–E-trending fracture system. Rock mechanical analysis of the tensile strength and elastic moduli provides the foundation for discussing maximum burial depth of the Arnager Limestone Formation. The tensile strength gives information on the bedding-parallel fractures, which can have formed due to stress relief during uplift and erosion, possible accentuated by glacial processes. The near-vertical fracture sets are interpreted to have formed in response to tectonic movements.

TBE In Denmark

Since the 1950s tick-borne encephalitis (TBE) has been endemic in Denmark but only on the island of Bornholm. Bornholm is situated east of mainland Denmark, south of Sweden (Figure 3) and has a different fauna and flora from the rest of Denmark. Bornholm has about 45,000 inhabitants, but about 500,000 tourists visiting every year.

Report on Landsat 8 and Sentinel-2B observations of the Nord Stream 2 pipeline methane leak

Abstract. In late September 2022, explosions of the Nord Stream pipelines caused what could be the largest anthropogenic methane leak ever recorded. We report on Landsat 8 (L8) and Sentinel-2B (S-2B) observations of the sea-foam patch produced by the Nord Stream 2 (NS2) leak located close to Bornholm island, acquired on 29 and 30 September, respectively. Usually, reflected sunlight over sea is insufficient for these Earth imagers to observe any methane signal in nadir-viewing geometry. However, the NS2 foam patch observed here is bright enough to possibly allow the detection of methane above it. We apply the multi-band single-pass (MBSP) method to infer methane enhancement above the NS2 foam patch and then use the integrated mass enhancement (IME) method in a Monte Carlo ensemble approach to estimate methane leak rates and their uncertainties. This very specific NS2 observation case challenges some of MBSP and IME implicit assumptions and thus calls for customized calibrations: (1) for MBSP, we perform an empirical calibration of sea-foam albedo spectral dependence by using sea-foam observations in ship trails, and (2) for IME, we yield a tailored effective wind speed calibration that accounts for a partial plume observation, as methane enhancement may only be seen above the NS2 sea-foam patch. Our comprehensive uncertainty analysis yields large methane leak rate uncertainty ranges that include zero for single overpasses and, assuming they are independent, a best estimate of 502 ± 464 t h−1 for the combined averaged L8 and S-2B emission rate. Within all our Monte Carlo ensembles, positive methane leak rates have higher probabilities (80 %–88 %) than negative ones (12 %–20 %), thus indicating that L8 and S-2B likely captured a methane-related signal. Overall, we see our work both as a nuanced analysis of L8 and S-2B contributions to quantifying the NS2 leak emissions and as a methodological cautionary tale that builds insight into MBSP and IME sensitivities.

Unlocking Circular Solutions: Exploring Multilayer Packaging in Sustainable Waste Management Through Material Flow Analysis and Stakeholder Perspectives ‐ Insights From Denmark

Multilayer packaging (MLP) in post-consumer waste is challenging to sort and process for recycling. It is often composed of a complex mixture of different materials that become contaminated which calls for a solution. Rules on extended producer responsibility for packaging will be enforced by 2025 across the EU. Considering the present situation, the questions arisen are the concerns how solutions to MLP may be built by adopting a more holistic, collaborative approach to creating circular interventions. This study aims to develop a solutions-building methodology for MLP from a value chain perspective and to devise an intervention plan for involved actors. To understand the packaging materials (and packaging waste) imported to, produced on, consumed, and exported from the Danish Island of Bornholm, a material flow analysis (MFA) was performed. This data-driven method uncovered hotspots and where interventions would have the highest impact. Additionally, it was used as a visualization tool at a multi-stakeholder workshop involving value chain actors to discuss future interventions. Results from the workshop showed the widely held perception that MLP separation and recycling is an appropriate 'near future' solution, as keeping the current operations and paying a third party to take care of the waste was the easier option for the producers. A radical innovation would have involved pushing boundaries, challenging conventional thinking, and pursuing ground-breaking ideas that could lead to substantial leaps from a circular perspective. From a methodological perspective, the MFA proved a vital tool for communicating the scale of packaging waste and facilitating discussions on potential interventions. MFA integrating with the results of multistakeholder workshop can lead to knowledge sharing and capacity sharing for stakeholders but cannot, in and of itself, lead to substantial leaps, i.e. radical innovation.

What Did the Cultural Landscape on Bornholm Look Like in the Mid-Eighteenth Century? An Analysis of Hammer’s Map

The island of Bornholm, located in the Baltic Sea, has undergone a strong landscape change over the last 250 years, which has had an impact on the landscape form and functions (agriculture, recreation, biodiversity). In this paper, Hammer's historical map series from the 1750s is processed and evaluated using GIS technology. The results are presented and mapped according to the individual land use types and cultural landscape elements. For example, 250 years ago there was a very large proportion of extensively used heathland and very little forest, which is exactly the opposite today. In addition, there were a large number of smaller landscape elements, which together made for a diversely structured, agriculturally used landscape. This also includes the many smaller standing waters as well as wetlands and bogs. The large number of defensive installations recorded, such as redoubts, batteries, forts and signal points, clearly shows the military importance of the map and the significance of such installations for the security of the island at that time. The high number of windmills and water mills, the agricultural farms and the churches were also recorded. The resulting maps, which are also available digitally and interactively to the public, show the significant landscape change, which is placed in a historical context and discussed with its current effects, e.g. on biodiversity.

Optimal expansion of a multi-domain virtual power plant for green hydrogen production to decarbonise seaborne passenger transportation

Many industrialised nations recently concentrated their focus on hydrogen as a viable option for the decarbonisation of fossil-intensive sectors, including maritime transportation. A sustainable alternative to the conventional production of hydrogen based on fossil hydrocarbons is water electrolysis powered by renewable energy sources. This paper presents a detailed techno-economic optimisation model for sizing an electrolyser and a hydrogen storage embedded in a multi-domain virtual power plant to produce green hydrogen for seaborne passenger transportation. We base our numerical analysis on three years of historical data from a renewable-dominated 60/10kV substation on the Danish island of Bornholm, and on data for ferries to the mainland of Sweden. Our analysis shows that an electrolyser system serves as a valuable flexibility asset on the electrical demand side, while supporting the thermal management of the district heating system and contributing to meeting the ferries hydrogen demand. With a sized electrolyser of 9.63MW and a hydrogen storage of 1.45t, the hydrogen assets are able to take up a large share of the local excess electricity generation. The waste heat of the electrolyser delivers a significant share of 21.4% of the annual district heating demand. Moreover, the substation can supply 26% of the hydrogen demand of the ferries from local resources. We further examine the sensitivity of the asset sizing towards investment costs, electrolyser efficiency and hydrogen market prices.

Environmental impact of the explosion of the Nord Stream pipelines

Armed conflicts have, in addition to severe impacts on human lives and infrastructure, also impacts on the environment, which needs to be assessed and documented. On September the 26th 2022, unknown perpetrators deliberately ruptured the two gas pipelines Nord Stream 1 and 2 with four coordinated explosions near a major chemical munition dump site near the Danish island of Bornholm in the Baltic Sea. While the massive release of natural gas into atmosphere raised serious concerns concerning the contribution to climate change—this paper assesses the overlooked direct impact of the explosions on the marine ecosystem. Seals and porpoises within a radius of four km would be at high risk of being killed by the shockwave, while temporary impact on hearing would be expected up to 50 km away. As the Baltic Proper population of harbour porpoises (Phocoena phocoena) is critically endangered, the loss or serious injury of even a single individual is considered a significant impact on the population. The rupture moreover resulted in the resuspension of 250000 metric tons of heavily contaminated sediment from deep-sea sedimentary basin for over a week, resulting in unacceptable toxicological risks towards fish and other biota in 11 km3 water in the area for more than a month.

Experimental assessment of active power control of distributed generation units

To secure balanced operation of electric networks and mitigate costly grid reinforcements, distributed generation (DG) units play a role in providing flexibility activation services. This paper analyses high-resolution measurements and reports lessons learnt from experimental active power control (APC) of installed DG units – two PV plants, a wind farm, and a biogas plant – in operation on the Danish island of Bornholm. The paper evaluates how quickly these units can respond to flexibility requests and how accurate and precise their output is when following specific active power setpoints. This assessment helps exploring the potential of DG units in providing grid services, either standalone or as part of a virtual power plant, within existing technology standards. The experiments demonstrate satisfactory performance of DG units when receiving APC requests, with PV inverters and biogas generators exhibiting high accuracy (mean deviation from setpoints of ±0.1% and ±0.15%, respectively). Furthermore, when subject to power limitation requests, PV inverters and wind turbines show less variation in their responses (±0.05% and ±0.6%, respectively) compared to biogas generators (±1%). The results further highlight the significance of appropriately tuning internal control settings within DG units to ensure continuous flexible operation and avoid undesirable dynamics.

POSITION OF OPYAT’ AND TVOJ IN THE CLAUSE LINEAR STRUCTURE IN THE QUEEN OF SPADES

The linear structure of nominal phrases with a possessive pronoun and verbal phrases with an adverb opyat’ ‘again’ in the text of The Queen of Spades by A.S. Pushkin is studied in comparison with the material of N.M. Karamzin’s story Island of Bornholm and a sample from the RNC, limited to 1738–1840. It is shown that changes in the structure of nominal and verbal phrases in Pushkin’s prose consisted not only in the “reduction of forms of qualitative assessment” and “compression” of the syntagma structure, as V.V. Vinogradov wrote, but also in the restructuring of their linear structure. The tendency towards the gradual transformation of the preposition of a possessive pronoun into a neutral, unmarked one, which is only outlined by Karamzin, in Pushkin’s prose gets the character of a completed process. The postposition of the word opyat’ to the finite verb, which was absolutely predominant in previous eras, in the texts of A.S. Pushkin clearly begins to give way to preposition; in Pushkin’s prose, a turning point of the process that led to the complete dominance of preposition opyat’ in modern Russian is recorded. In The Queen of Spades, there is also a tendency for the semantic factor to influence the choice of preposition/postposition of opyat’: in sentences with an agentive subject, realizing the perspective of the narrator observing the character, opyat’ appears in postposition to the finite verb; in sentences with a non-agent subject, realizing the perspective of the character, it appears in preposition. Other Pushkin’s texts, as well as modern speech, do not demonstrate such a tendency.

Optimal control of a DC microgrid with busbar matrix for high power EV charging

Recent advances in the development of reconfigurable batteries pave the way for novel DC microgrid architectures that eliminate the need for DC–DC converters. The present study is focused on the control of a microgrid comprising a battery system with three reconfigurable strings to flexibly operate two electric vehicle (EV) fast chargers, a photovoltaic (PV) system, and a grid-tie inverter. The primary control tasks are to dynamically connect the individual battery strings to the other system components through a busbar matrix, and to manage the energy exchange with the AC grid. The paper formulates the control tasks as a mixed-integer linear optimization problem, virtually splitting the system into three parallel representations, each constructing the perspective of one battery string on the busbar matrix. The functionality of the proposed control is assessed through simulation scenarios using actual PV production and EV charging data of a prototype installed on the Danish island of Bornholm. To quantify the performance, the optimizer is compared with a heuristic control. Considering grid energy costs and revenues through EV charging, the optimal control increased the profit by 5.4% in the summer and 13.0% in the winter scenario, with respect to the benchmark control.

TBE in Denmark

Since the 1950s, tick-borne encephalitis (TBE) has been known to be endemic in Denmark but only on the island of Bornholm. Bornholm is situated east of mainland Denmark, south of Sweden (Figure 3) and has a different fauna and flora from the rest of Denmark. Bornholm has about 45,000 inhabitants, but about 500,000 tourists visit the island every year. Freundt carried out a serosurvey during 1958–1962 and found TBE antibodies in 1.4% of blood donors and 30% of woodworkers on Bornholm but no antibodies in subjects living in mainland Denmark. In 1963, Freundt found that 8 of 12 patients admitted to the hospital with acute meningoencephalitis of unknown etiology during 1951–1960 had antibodies to tick-borne encephalitis (TBEV). In 2000, TBE was rediscovered on Bornholm, where a retrospective study covering the period 1994–2002 (7 years) identified 14 TBE cases; 2 cases were tourists and 12 were inhabitants of Bornholm, giving an incidence of 3.81 per 100,000 inhabitants. At least 5 patients (37.7%) got permanent sequelae. In addition, 32 forest workers on Bornholm were tested in 2000, and 20% had IgG antibodies but never symptoms. This is similar to the finding of Freundt in 1960. It was concluded that the data did not provide evidence of an increase in incidence of TBE. Ticks (Ixodes ricinus) from Bornholm were investigated for TBEV in 2000 and 2% were found to be infected. Since 2001 an average of 2.5 (range 1–8) TBE cases per year have been reported in Bornholm (Figure 1).

Planning for a Landing Operation of the Polish People’s Army on the Danish Isles during the Cold War

During the Cold War, the Polish People’s Army (hereinafter: PPA) planned to occupy Denmark, the northern regions of the Federal Republic of Germany, the Netherlands and Belgium through an offensive campaign. An essential element of this scheme was air and seaborne landing operations aimed at capturing the Danish island of Zealand and the country’s capital, Copenhagen. The actions undertaken by the PPA were intended to comprise part of a large-scale campaign of the allied forces of member states of the Warsaw Pact against NATO. In the mid-1980s, the landing tasks of the PPA were limited to the occupation of the Danish island of Bornholm.

Economic and resilient operation of hydrogen-based microgrids: An improved MPC-based optimal scheduling scheme considering security constraints of hydrogen facilities

Optimally scheduling alkaline electrolyzers (AELs) in a hydrogen-based microgrid (HBM) can greatly unleash the operational flexibility of the HBM. However, existing scheduling strategies of AELs mostly utilize a simplified AEL model, which ignores the nonlinear coupling of electric-hydrogen-thermal sectors, violating the AEL’s security constraints thereby making the scheduling scheme infeasible. This paper proposes an improved model predictive control (MPC) based optimal scheduling framework which incorporates a scheduling correction algorithm into the basic MPC structure. This framework is utilized for implementing economic and resilient scheduling of an HBM under normal and emergency conditions, respectively. With the scheduling correction algorithm, this framework can be formulated into a computationally efficient mixed-integer linear programming, meanwhile guaranteeing the solutions strictly satisfy the security constraints of hydrogen facilities (i.e. AEL and hydrogen tank). Case studies are conducted based on real operating data of a Danish energy island Bornholm. The results demonstrate that the proposed scheduling scheme under normal conditions can contribute to significant comprehensive benefits from the daily operation cost saving of 68%, computational time saving of 98%, and satisfying the security constraints of hydrogen facilities, compared to previous scheduling strategies. Besides, it sharply reduces load shedding under emergency conditions by proactively allocating distributed energy sources in the HBM.

Diet of Free Ranging American Mink (Neovison vison) in Denmark.

Non-native American mink (Neovison vison) is a widely spread predator in Denmark. The feral population in mainland Denmark consists of captive-born mink that escaped from fur farms and wild mink born in nature, whereas the population on Bornholm is almost all wild-born mink. In this study, the diets of feral mink in mainland Denmark and on the island of Bornholm are analyzed. The aim of this study was to examine (1) whether the diet of the larger captive-born mink differs from that of the smaller wild-born mink, (2) assess the regional variations between the diets of mink in mainland Denmark and on Bornholm, and (3) investigate the seasonal variation in the diet composition of mink. The stomach contents of 364 mink (243 wild-born and 114 captive-born) culled in the years 2019-2022 were analyzed. Of these, 203 mink were from mainland Denmark, and 154 were from Bornholm. No significant differences were found between the diets of captive-born mink and wild-born mink or the mink found in mainland Denmark and on the island of Bornholm. Significantly more empty stomachs were found during spring than during the summer and autumn, suggesting a bottleneck in the diet during spring.

The Bornholm intermediate waters: Origination, pathway, and detection within the cold intermediate layer of the Baltic Sea

The Cold Intermediate Layer (CIL) is a distinctive feature of the Baltic Sea thermohaline structure: it is evident annually from March to December between the upper freshened layer and the deep layer with saline waters of oceanic origin. Water parameters are vertically inhomogeneous within the CIL, reflecting a complicated process of its formation that hasn’t been exhaustively described yet. On the base of field measurements and remote sensing data, a detailed study of the CIL formation in spring 2006 was performed. It showed that the core of the CIL (the coldest water) has a specific T,S-index that indicates the source of these waters in the south-western part of the sea. The data of CTD measurements, satellite-derived sea surface temperature (SST), and meteorological information were used to distinguish and trace the CIL core waters. The abrupt transformation of the SST field was observed in March 2006 when the coldest waters (0.9–2.1 °C) of moderate salinity (7.6–8.1) plunged from the upper mixed layer in the vicinity of Bornholm Island into intermediate layers. These waters were later identified as the sublayer of the CIL in the Baltic Proper in April and May 2006. The drivers of the penetration of winter-cold surface waters into the intermediate layers are suggested to be the negative surface buoyancy flux due to warming of cold surface waters with temperature below that of the density maximum and the intensification of easterly winds. Considering the importance of the CIL formation process for the entire Baltic Sea conveyor belt, these CIL core waters were termed the Bornholm Intermediate Waters (BIW). The T,S-index of the BIW shall vary from year to year, reflecting the severity of the past winter and the conditions of the particular spring. However, the BIW location right above the pycno/halocline, the lowest (specific for the current year) water temperature and its characteristic salinity of 7.6–8.1 are repeatedly confirmed by field observations in the Baltic Proper in spring. Joint application of satellite observations, field measurements, and meteorological data provides a coherent view on the process of the BIW waters origination. The results are particularly important it the context of growing hypoxia of deep Baltic waters, providing evidence of the mechanism of seasonal ventilation of intermediate water layers.

Resolving Maritime Delimitation Disputes by Agreement: The Danish–Polish Boundary in the Area of the Island of Bornholm

The extension of coastal states’ jurisdiction over seas in the twentieth century significantly increased the maritime area of overlapping entitlements. The Baltic Sea is a textbook example of such competing claims. In principle, the two main avenues for a coastal state to resolve its dispute are to either conclude a delimitation agreement or lodge the case with an international court or tribunal. This article analyzes the Delimitation Agreement between Denmark and Poland concerning the Baltic Sea south of the island of Bornholm. The states were divided as to how to apportion the maritime zone of 3,500 km2, where the economic zones of Denmark and Poland had not been delimited for several dozen years. The agreed single maritime boundary split the disputed area into unequal parts. The settlement of the maritime dispute coincided temporally with Poland and Denmark’s plans to build a natural gas pipeline at the bottom of the Baltic Sea, which probably prompted the two states to put an end to their maritime boundary dispute. The law of the sea provides that the delimitation of maritime zones between states with opposite or adjacent coasts is effected by agreement on the basis of international law in order to achieve an equitable solution. The purpose of this article is to show that (energy) security issues may prompt a resolution of a maritime boundary dispute, and to analyze the Polish–Danish Agreement in the light of the principles governing the maritime delimitation.

An atomised interior: Exploring a morphology for a pandemic home

This article addresses the topic of ‘openness’ by interrogating established interior boundaries within the home through the speculative design of a 25 m2 microhouse, as a direct response to a ‘crisis’ in domestic architecture that has been abruptly placed in public discourse to an unprecedented extent by the COVID-19 global flu pandemic. During lockdown, our homes have had to accommodate a broader variety of activities with varying and sometimes conflicting requirements, which are often overlapping, both spatially and temporally. Over the course of the pandemic, this programmatic implosion of the home has starkly highlighted the failure of ‘open-plan’ spaces as individuals have struggled to establish personal territory, as well as the limitations of ‘mono-functional’ rooms. While the SARS-CoV-2 virus has tragically affected so many people globally, its associated social restrictions have provided an important catalyst for a much-needed spatial discourse on the domestic interior. The article posits the following question, amid a ‘crisis’ in domestic architecture that has been amplified by the Covid-19 flu pandemic and its associated lockdowns, how might the architect reconceptualize the spatial organisation of the contemporary dwelling interior to better accommodate the needs of its inhabitants through the speculative design of a 25m2 microhouse? A ‘Research by Design’ method has resulted in ‘Refugium’, a microhome situated on the Danish Island of Bornholm. Through the design of ‘Refugium’, established domestic boundaries have been reimagined as liminal ‘frontiers’ of opportunity through spatial layering, a denser and less open ‘atomised’ plan arrangement & the articulation of deep inhabitable threshold places.

Introduced European bison (Bison bonasus) in a confined forest district: A ten year parasitological survey.

In the year 2012 a total of seven individuals (one bull and six cows) of European bison (Bison bonasus) were introduced to a fenced 200 ha area in a forest district (Almindingen, Island Bornholm, Denmark) in the Baltic Sea. In 2017 the herd was supplemented by introduction of another bull. The animals all originated from a population in the Polish Bialowieza forest. Faecal samples were recovered with intervals and subjected to a copro-parasitological investigation (applying egg flotation, sedimentation and Baermann technique). In addition, parasites were sampled during necropsy of animals euthanized or found dead three years after introduction. The animals carried a range of parasite types including trematodes (liver fluke Fasciola and rumen fluke), cestodes (Moniezia), nematodes (Dictyocaulus viviparus, trichurids, and other gastrointestinal nematodes (GIN) including Trichostrongylus axei and Haemonchus contortus). Egg and larval morphology also suggested presence of GIN genera Nematodirus, Ostertagia and Cooperia. The trematodes did not establish a life cycle in the recipient area, as judged by examination of calves born in the new area, but the cestode and several nematode species occurred in these animals. Especially Dictyocaulus viviparus was successfully spread and occurred together with GIN at moderate to high infection intensities at most sampling points. The reproduction among bison in the herd was high during the first few years. The exact birth rate is unknown but up to 24 calves are believed to be born during the ten year study period. Mortality among adults and calves occurred and in early June 2022 the total number of live animals was 11 (seven males, three females, one calf). The possible impact of the parasite infections on the bison health and future wildlife infection status is discussed.

Closing the material loops for construction and demolition waste: The circular economy on the island Bornholm, Denmark

The article explores the creation of a closed-loop production and consumption value chain, based on a case study carried out on the island of Bornholm, Denmark. Tests and demonstration of practices and procedures to reuse and recycle construction and demolition waste were conducted, including: (1) developing and implementing resource mapping and selective demolition procedures at three rural demolition projects, (2) assessing the CO2 reduction potentials associated with recycling the selected materials, (3) assessing the value and potential business models that could support the utilization of the materials, and, (4) creating a network between local stakeholders. Based on these activities, the article analyses and discuss economic and practical barriers and potentials for looping materials from demolished buildings back into the construction of new buildings. Finally, the article discusses how the lessons learned from Bornholm could be transferred to other islands and remote areas that are considering adopting a circular economy in their construction and demolition sectors.

TBE in Denmark

Since the 1950s, tick-borne encephalitis (TBE) has been known to be endemic in Denmark, but only on the island of Bornholm. Bornholm is situated east of mainland Denmark, south of Sweden (Fig. 3) and has a different fauna and flora from the rest of Denmark. Bornholm has about 45,000 inhabitants, but about 500,000 tourists visit the island every year.