Eirik Gjerløw

The Beerenberg volcano lies on the island of Jan Mayen and represents the northernmost active surface volcano in the world. Jan Mayen island is situated in the Arctic north-Atlantic Ocean, just south of the junction between the Mohn’s ridge and the Jan Mayen fracture zone, where the mid-ocean ridge transitions to the Kolbeinsey ridge further west. The Beerenberg volcano has gently dipping flanks and a more prominent central crater, reaching a maximum altitude of 2272 m a.s.l. The geology of the Jan Mayen island was studied extensively in the 1970s and 1980s and three primary magma types were identified: primitive basalts, ne-normative basalts and trachytes. The volcanism from the Beerenberg central volcano is limited to primitive basalts, and alkaline basalts, with some more intermediate volcanics near the central crater. Most of, if not all, the recent eruptions of Beerenberg have been in the form of flank eruptions of primitive basaltic and trachybasaltic compositions. However, the shallow magma storage systems of the Beerenberg volcano remain unstudied, and geophysical data from past eruptions are lacking, limiting our insights into this.In this study we investigate the shallow magma storage systems under Beerenberg by analysing a selection of samples from Jan Mayen and the surrounding seas: tephra from soil sections on the flanks of Beerenberg, rock samples from the summit crater and tephra from sediments in the seas around Beerenberg. These samples have been analysed using EPMA on glass shards, olivine, pyroxene and feldspar crystals, and we present the results from these analyses along with geothermobarometric calculations to infer the shallow magma storage conditions under the Beerenberg volcano. Our findings give new insights into the magmatic process and plumbing beneath Beerenberg that can be valuable during future volcanic unrest.

The interfacial transition zone (ITZ) is the weakest phase in concrete, characterised by higher porosity and being prone to microcrack formation. Additionally, the ITZ is created when dispersed fibre reinforcement is present. Although fibres improve flexural strength, they can negatively impact other properties. This research investigates the ITZ of fibre-reinforced concrete where macro-basalt fibres (BFs) and oil shale ash (OSA), as an SCM, were used with the aim of modifying the properties of concrete, enhancing the ITZ, and reducing its carbon footprint. Six different concrete mixes with OSA doses between 10% and 30% and a constant BF dose of 8.0 kg per 1 m³ of concrete were prepared and tested. The ITZ was analysed with SEM images and verified through its mechanical properties. The results showed that the presence of OSA improved bonding and densified the microstructure of the paste, especially in the ITZ, resulting in a nearly constant flexural strength at up to a 20% replacement and only a 6.7% decrease in compressive strength while reducing the global warming potential by 19.24 kg CO₂ equivalent in the mix with 10% OSA replacement. Higher replacement ratios had a negative impact on the mechanical properties, as the OSA had not reacted entirely and served partly as an inert filler.

Steel Fiber Reinforced Concrete (SFRC) is widely used as it provides good characteristics and mechanical behavior. Concretes with novel type Basalt/Epoxy composite fibers are competitive and attractive for use and investigation. The special interest is for concretes with partially replaced cement by Oil Shale Ash (OSA). In this study authors will discuss basalt and steel fiber-reinforced concrete. Concrete samples were prepared in the dimensions of 40mm x 40mm x 300 mm and treated under the oven to raise the temperatures to 1500C, 3000C, and 4500C. In the research of preparing environment-friendly concrete authors planned to use OSA as an additive replacement of cement by weight in percentage. OSA is a product of burned oil shale from thermal power plants of ESTONIA, which is added in the weight ratio of 0%, 10%, and 20% of cement. All the samples were tested by the four-point bending method and the results of samples with different ratios of OSA and different temperature gradients were compared to analyze and simulate conclusion research. The author also used image processing techniques to make a study on fiber orientation and directionality after the fabrication of concrete. Characteristics of basalt and steel fiber-reinforced concrete in different considerations and compositions were made by the author through metadata and image analysis.

Alternative to traditional concrete, sustainable concrete reduces cement content, waste management issues, and CO₂ emissions. To achieve sustainable concrete, waste materials can be used as supplementary cementitious materials (SCMs) to partially replace cement. Fly ash, ground-granulated blast furnace slag, and silica fume have been heavily studied as SCMs. However, due to the retirement of coal-fired power plants and switching to renewable energy, existing SCMs are losing their dominance. With SCMs becoming more widely accepted as partial cement substitutes, there is fear that the current supply will not meet future demand. As a result, researchers have been looking for alternative SCMs. The circular economy can be achieved by reusing non-hazardous construction and demolition materials, timber, and metal/steel production waste as SCMs. This article discusses emerging SCMs, reactivity evaluation methods, their limitations, and treatment methods that may improve reactivity. Emerging SCMs can replace existing SCMs in quantity, but their supply to cement factories and low reactivity due to stable crystallinity hinders their use. Among treatment methods, particle size reduction effectively enhances reactivity; however, very fine SCM may increase the overall water demand due to the large surface area. Decades-old reactivity evaluation methods have relatively weak correlations and thus misreport the reactivity of SCMs. Newer R³ models, such as calorimetry and bound water, give the best correlations (R ≥ 0.85) for 28-day relative strength and better performance. Additionally, more concrete testing with emerging SCMs under different durability and environmental protection conditions is required and life cycle assessments are needed to determine their regional environmental impact.

Understanding the freezing and thawing processes in porous media such as soils is important, especially in regions experiencing seasonal frost or permafrost. These processes have a wide range of implications as diverse as how to maintain the structural integrity of roads, railways, pipelines, and buildings, to when to plant seeds during the growth season. Thawing of frozen ground is the opposite process of ground freezing but has not received nearly as much attention as the latter in research studies or field experiments. Accurately predicting thaw depth or thaw rate is a challenging task. Many mathematical models have been proposed to describe the thawing process, with different perspectives and complexity. This paper provides an overview of historical modeling efforts made for predicting heat and mass transfer during thawing. Assumptions and premises for each model are discussed, as well as limitations and some applications. In addition, this paper reviews historical and modern approaches to thawing of frozen ground in cold regions, lists pros and cons of each method, and gives examples of applications. The review shows the need for further research and more accurate models, specifically for predicting thaw depth and thaw rates in frozen ground subjected to artificial thawing.

Hazard assessment of remote volcanic islands provides many challenges compared to other volcanoes and volcanic fields. Here we present the first systematic volcanic hazard assessment of Jan Mayen Island, a remote island located in the North-Atlantic Ocean and home to the northernmost active subaerial volcano in the world (Beerenberg Volcano), and we discuss some of the challenges and characteristics of performing a volcanic hazard assessment of a remote volcanic island. Jan Mayen has had at least five eruptions since its discovery at the start of the 17th century. Its Holocene volcanism is mainly characterized by eruptions with styles ranging from Hawaiian to Strombolian, but also by lava domes and Surtseyan eruptions. Based on field data, remote images, topographic data, past data, and computer simulations, our study evaluates the spatial probability of new vents opening, estimates eruption recurrence rates, simulates various eruption scenarios, and produces hazard maps for the different scenarios. This work shows where the hazards of ash fall, and lava flows are more likely to affect the built infrastructure on Jan Mayen Island. This hazard assessment will assist emergency planning and the determination of future land use on the island.