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This enchanting and important book presents the art of the internationally famous architectural photographer, Ahmet Ertug in his latest folio, capturing the spatial essence of that most defining symbol of architecture, the Dome. The book is a journey through architectural history, from the immense spherical dome of the first-century Roman Pantheon, its oculus open to the sky, to the steel and glass of Norman Foster's Bundestag, Berlin, one of the most visited new architectural structures in the world. Along the way, are the domes of Byzantium including the Hagia Sophia, its dome pierced with lunette windows that make it seemingly float by magic, the mighty domes of the Middle Ages, the Renaissance and the Baroque, each presenting its architect with the greatest of all structural challenges - Brunelleschi's Florence Cathedral, Michelangelo's St Peter's, Sir Christopher Wren's St Pauls' in London, and the iron and glass domes of nineteenth-century France.

Polymer co-extrusion experiments are described simulating the dynamics of two different magmas (e.g., silicic and mafic having different viscosities) flowing simultaneously in a vertical volcanic pipe or conduit which results in the effusion of composite lava domes on the surface. These experiments, involving geologically realistic conduit length-to-diameter aspect ratios of 130:1 or 380:1, demonstrate that co-extrusion of magmas having different viscosities can explain not only the observed normal zoning observed in planar dikes and the pipelike conduits that evolve from dikes but also the compositional layering of effused lava domes. The new results support earlier predictions, based on observations of induced core-annular flow (CAF), that dike and conduit zoning along with dome layering are found to depend on the viscosity contrast of the non-Newtonian (shear-thinning) magmas. Any magma properties creating viscosity differences, such as crystal content, bubble content, water content and temperature may also give rise to the CAF regime. Additionally, codependent flow behavior involving the silicic and mafic magmas may play a significant role in modifying the nature of volcanic eruptions. For example, lubrication of the flow by an annulus of a more mafic, lower-viscosity component allows a more viscous but more volatile-charged magma to be injected rapidly to greater vertical distances along a dike into a lower pressure regime that initiates exsolving of a gas phase, further assisting ascent to the surface. The rapid ascent of magmas exsolving volatiles in a dike or conduit is associated with explosive silicic eruptions.

Dome-forming volcanoes are among the most hazardous volcanoes on Earth. Magmatic outgassing can be hindered if the permeability of a lava dome is reduced, promoting pore pressure augmentation and explosive behaviour. Laboratory data show that acid-sulphate alteration, common to volcanoes worldwide, can reduce the permeability on the sample lengthscale by up to four orders of magnitude and is the result of pore- and microfracture-filling mineral precipitation. Calculations using these data demonstrate that intense alteration can reduce the equivalent permeability of a dome by two orders of magnitude, which we show using numerical modelling to be sufficient to increase pore pressure. The fragmentation criterion shows that the predicted pore pressure increase is capable of fragmenting the majority of dome-forming materials, thus promoting explosive volcanism. It is crucial that hydrothermal alteration, which develops over months to years, is monitored at dome-forming volcanoes and is incorporated into real-time hazard assessments. The permeability of a dome exerts a control on the outgassing efficiency of the underlying magma. The authors investigate the role of hydrothermal alteration on this process in the laboratory and use these data to model whether the overpressures generated are capable of promoting explosive behaviour.

The Cuonadong dome exposes in east-southern margin of the North Himalayan gneiss domes (NHGD), which is reported first time in this study. The Cuonadong dome is located at the southern part of the Zhaxikang ore concentration area, which is divided into three tectono-lithostratigraphic units by two curved faults around the dome geometry from upper to lower (or from outer to inner): the upper unit, middle unit and lower unit, and the outer fault is Nading fault, while the inner fault is Jisong fault. The Cuonadong dome is a magmatic orthogneiss and leucogranite mantled by orthogneiss and metasedimentary rocks, which in turn are overlain by Jurassic metasedimentary and sedimentary rocks. The grades of metamorphism and structural deformation increase towards the core, which is correspondence with the Ridang Formation low-metamorphic schist, tourmaline granitic–biotite gneiss, garnet–mica gneiss and mylonitic quartz–mica gneiss. The Cuonadong dome preserves evidences for four major deformational events: firstly top-to-S thrust (D 1 ), early approximately N–S extensional deformation (D 2 ), main approximately E–W extensional deformation (D 3 ), and late collapse structural deformation (D 4 ) around the core of the Cuonadong dome, which are consistent to three groups lineation: approximately N–S-trending lineation including L 1 and L 2 , E–W trending L 3 , and L 4 with plunging towards outside of the dome, respectively. The formation of the Cuonadong dome was probably resulted from the main E–W extensional deformation which is a result of eastward flow of middle or lower crust from beneath Tibet accommodated by northward oblique underthrusting of Indian crust beneath Tibet. The establishment of the Cuonadong dome enhanced the E–W extension of the NHGD, which is further divided into two structural dome zones according to the different extensional directions: approximately N–S extensional North Himalayan gneiss domes (NS-NHGD) and E–W extensional North Himalayan gneiss domes (EW-NHGD). The NS-NHGD developed by a dominantly N–S contraction and locally extensional regime and keep a close relationship to the South Tibetan Detachment System, whereas the EW-NHGD formed by an E–W extensional deformation along the north–south-trending rifts.

The volcanic domes of Armenia hold significant value as both natural heritage and vital research sites for the study of volcanic activity and geomorphological processes. However, detailed geological mapping of these formations has only been conducted at scales of 1:100,000 and 1:200,000. The use of UAVs and high-resolution satellite imagery (Sentinel-2, Resurs-P, PlanetScope) offers new opportunities for large-scale mapping and monitoring of these geological features. This study focuses on the Ajdahak, Armagan, Eratumber, and Arailer volcanoes located in the Gegham Highlands and their surrounding areas. These volcanoes, which include cinder cones and a stratovolcano, showcase a variety of geological structures such as lava flows, barrancos, and erosion formations. Multispectral and thermal UAV surveys were conducted using Mavic Pro, Mavic 3M, and Mavic 3T drones equipped with RTK (Real Time Kinematic) positioning systems, as well as optical, multispectral, and thermal sensors. The collected data was processed through photogrammetry to generate dense point clouds, digital surface models (DSMs), and thermal and multi-channel orthophotos. Morphometric analysis and spectral indices (NDVI, SAVI, GSAVI, etc.) enabled the classification of vegetation, soil cover, and volcanic rock types. The resulting thematic maps provide high-resolution representations of landforms, land cover, and anthropogenic transformations, which are crucial for understanding geodynamic changes, predicting hazards, supporting land-use planning, and preserving Armenia’s volcanic heritage. Based on the results of the study, an improved method of automated relief analysis using UAV imagery and derived ultra-high resolution DEM/DSM data, as well as their integration with multispectral imagery data, was developed for thematic mapping of volcanic domes.

Groundmass textures of volcanic rocks provide valuable insights into the processes of magma ascent, crystallization, and eruption. The diktytaxitic texture, characterized by a lath-shaped arrangement of feldspar microlites forming glass-free and angular pores, is commonly observed in silicic dome-forming rocks and Vulcanian ashfall deposits. This texture has the potential to control the explosivity of volcanic eruptions because its micropore network allows pervasive degassing during the final stages of magma ascent and eruption. However, the exact conditions and kinetics of the formation of diktytaxitic textures, which are often accompanied by vapor-phase cristobalite, remain largely unknown. Here, we show that the diktytaxitic texture and vapor-phase minerals, cristobalite and alkali feldspar, can be produced from bulk-andesitic magma with rhyolitic glass under water-saturated, near-solidus conditions (± ~10 MPa and ± ~20 °C within the solidus; 10–20 MPa and 850 °C for our starting pumices). Such crystallization proceeds through the partial evaporation of the supercooled melt, followed by the deposition of cristobalite and alkali feldspar as a result of the system selecting the fastest crystallization pathway with the lowest activation energy. The previously proposed mechanisms of halogen-induced corrosion or melt segregation by gas-driven filter pressing are not particularly necessary, although they may occur concurrently. Diktytaxitic groundmass formation is completed within 4–8 days, irrespective of the presence or composition of the halogen. These findings constrain the outgassing of lava domes and shallow magma intrusions and provide new insights into the final stages of hydrous magma crystallization on Earth.

Seeing—the angular size of stellar images blurred by atmospheric turbulence—is a critical parameter used to assess the quality of astronomical sites at optical/infrared wavelengths. Median values at the best mid-latitude sites are generally in the range of 0.6–0.8 arcseconds 1 – 3 . Sites on the Antarctic plateau are characterized by comparatively weak turbulence in the free atmosphere above a strong but thin boundary layer 4 – 6 . The median seeing at Dome C is estimated to be 0.23–0.36 arcseconds 7 – 10 above a boundary layer that has a typical height of 30 metres 10 – 12 . At Domes A and F, the only previous seeing measurements have been made during daytime 13 , 14 . Here we report measurements of night-time seeing at Dome A, using a differential image motion monitor 15 . Located at a height of just 8 metres, it recorded seeing as low as 0.13 arcseconds, and provided seeing statistics that are comparable to those at a height of 20 metres at Dome C. This indicates that the boundary layer was below 8 metres for 31 per cent of the time, with median seeing of 0.31 arcseconds, consistent with free-atmosphere seeing. The seeing and boundary-layer thickness are found to be strongly correlated with the near-surface temperature gradient. The correlation confirms a median thickness of approximately 14 metres for the boundary layer at Dome A, as found from a sonic radar 16 . The thinner boundary layer makes it less challenging to locate a telescope above it, thereby giving greater access to the free atmosphere. The night-time seeing (the extent to which a star’s light is blurred by the atmosphere) at Dome A, the highest part on the Antarctic plateau, can be as good as 0.13 arcseconds above a height of only 8 metres.

The eruption of large, rhyolitic lava domes may be accompanied by the formation of large block and ash flows. This may be linked to the style of dome extrusion—whether it forms a series of individual lobes, flows or spines (exogenous) or grows by internal inflation (endogenous). Lava domes can transition from one extrusive style to another as a result of a change in extrusion rate or the formation of facilitating structures such as shear zones. How this change can affect large rhyolitic lava domes is unclear as there are few historically recorded rhyolitic dome eruptions. Here, we present structures at Ruawahia lava dome (a well exposed ~ 700-year-old lava dome), how these facilitating structures enable exogenous extrusion at Ruawahia dome, and link this to collapse episodes along the fringes of the dome during growth. Ruawahia dome is part of the Tarawera dome complex, a chain of domes running parallel to regional structures across the Okataina caldera complex in the Taupo Volcanic Zone, New Zealand. Ruawahia dome consists of (1) a high porosity (44–52%), crystalline (65% DRE), locally brecciated carapace facies with rare bread-crusting and ‘ropey’ flow textures; (2) a core facies of dominantly low to moderate porosity (20–25%) with elongate vesicles that mark weak flow bands; and (3) thin (< 5 m thick) interior breccia zones. Flow bands at Ruawahia are complex and do not fit with hypothesised flow band orientations attributed to a single phase of exogenous or endogenous dome growth. Inward dipping flow bands on ramp structures on the flow surface suggest a flow-like (coulée) morphology; however, steeply dipping and multidirectional flow bands on the edges of the dome challenge this hypothesis. Widespread block and ash flow deposits have been sourced from the leading dome fronts to the NW and SE; these collapse events left behind inflated and bread-crusted outcrops on these dome fronts, suggesting syn-eruption collapse events that led to expansion of a hot, pressurised dome interior. We consider Ruawahia erupted from multiple, aligned vents, either as lobes confined within the crater of a pyroclastic cone formed during the initial Plinian phase of the eruption or those able to flow down the cone flank. The confined lobes formed steep internal breccia zones as individual dome lobes extruded past one another. Lobes that were able to overcome the pyroclastic cone rim (or where the vent was outside the crater) were able to flow down the flanks as bulldozing, thickening flows with dominantly ductile interiors and brittle exteriors; these flows collapsed as the front thickened, possibly due to a decrease in gradient, producing widespread block and ash flows. The removal of lava associated with collapse generated a decompression event which resulted in fragmentation, cracking and vesiculation in the hot interior of the lava flows. These events left behind a re-vesiculated and bread-crusted lava flow front and produced block and ash flows with abundant breadcrust bombs that reached the base of Tarawera.

The collapse of lava domes, inherently heterogeneous structures, represents a significant volcanic hazard. Numerical and analogue models designed to model dome instability and collapse have incorporated heterogeneity in the form of discrete zones with homogeneous properties. Based on an assessment of dome rock heterogeneity, we explore whether material property heterogeneity (“diffuse” heterogeneity) within these discrete zones can promote dome instability. X-ray computed tomography shows that dome samples are characterised by high microstructural heterogeneities; e.g. porosity varies from 0.07 to 0.20 over millimetric length scales. To explore how microstructural heterogeneity influences sample-scale strength, we performed numerical simulations using Rock Failure and Process Analysis. The mean mechanical properties of the numerical samples were constant, and we introduced heterogeneity by varying their distribution using a Weibull probability function. The models show that increasing heterogeneity can reduce sample-scale strength by more than a factor of 2. To explore the influence of dome-scale heterogeneity, we numerically generated lava domes in Particle Flow Code. The domes have the same bulk strength but are characterised by different degrees of heterogeneity by varying the distribution of cohesion using a Weibull probability function. The models show that a greater degree of heterogeneity induces higher dome-scale displacements and that, when there is also a discrete weakened zone, the addition of diffuse heterogeneity leads to more widely distributed deformation. Therefore, alongside discrete zones defined by different material properties, we find that the diffuse heterogeneity inherent to a dome is sufficient to compromise dome stability and should be incorporated in future modelling endeavours.