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Here, we investigate Mid- to Late-Holocene vegetation changes in low-lying coastal areas in Tonga and how changing sea levels and recurrent volcanic eruptions have influenced vegetation dynamics on four islands of the Tongan archipelago (South Pacific). To investigate past vegetation and environmental change at Ngofe Marsh (‘Uta Vava’u), we examined palynomorphs (pollen and spores), charcoal (fire), and sediment characteristics (volcanic activity) from a 6.7-m-long sediment core. Radiocarbon dating indicated the sediments were deposited over the last 7700 years. We integrated the Ngofe Marsh data with similar previously published data from Avai’o’vuna Swamp on Pangaimotu Island, Lotofoa Swamp on Foa Island, and Finemui Swamp on Ha’afeva Island. Plant taxa were categorized as littoral, mangrove, rainforest, successional/ disturbance, and wetland groups, and linear models were used to examine relationships between vegetation, relative sea level change, and volcanic eruptions (tephra). We found that relative sea level change has impacted vegetation on three of the four islands investigated. Volcanic eruptions were not identified as a driver of vegetation change. Rainforest decline does not appear to be driven by sea level changes or volcanic eruptions. From all sites analyzed, vegetation at Finemui Swamp was most sensitive to changes in relative sea level. While vegetation on low-lying Pacific islands is sensitive to changing sea levels, island characteristics, such as area and elevation, are also likely to be important factors that mediate specific island responses to drivers of change.

In the AD 1450s, one of the three largest climate-forcing eruptions of the largest 1000 years took place, with similar impacts as the AD 1815 event of Tambora, Indonesia, that caused the ‘year without a summer’ of AD 1816. The submarine caldera of Kuwae, Vanuatu, has long been suggested to be the source of the AD 1450s eruption, but this is still highly debated.Today, the 12-by-6 km large Kuwae caldera lies between the islands of Epi and Tongoa. Here, an eruption occurred in the 15th century eruption and locally caused devastation, covering the islands surrounding it with vast amounts of pyroclastic material. We present the first full stratigraphy of the event, enabling us to reconstruct the eruptive sequence. First, a small ash plume produced fine ash deposits overlying faulted soil sequences, indicating a low-energy, precursory phase. Afterwards, the eruption built a Plinian eruption column, causing lapilli fall in excess of 3 m in proximal locations, and sending volcanic particles and gases high up into the atmosphere. This column then collapsed, producing the first pyroclastic flows that devastated the islands surrounding the caldera, incorporating many trees that became charcoalised and are still fully preserved in the deposits. Following further pyroclastic flow activity, a massive lithic lag breccia contains megaclasts (>10 m breccia), recording the collapse of a pre-existent edifice. Later pumice-rich pyroclastic flows occurred bring the total thickness of the sequence to between 30 and >80 m in proximal locations.These results are combined with initial results from a recent bathymetric study, mapping the submarine caldera floor, addressing the question of whether the entire caldera was generated during the mid-15th century event, or whether earlier eruptions have played a part in its collapse. This is essential for estimating the total collapse volume of the mid-15th century event at Kuwae, representative of the total erupted volume.We will use information on a) the eruptive sequence (based on field observations), b) eruptive volume (based on bathymetry), c) total emitted sulphur (based on eruptive volume and preliminary geochemistry data), and d) the eruptive date (based on radiocarbon analysis of collected charcoal samples) to characterise the mid-15th century eruption of the Kuwae caldera and test whether it was the source of the AD 1450s volcanic event that had a global climate impact.

Submarine eruptions dominate volcanism on Earth, but the recent eruption of Hunga Tonga–Hunga Haʻapai volcano in January 2022 was one of the most explosive eruptions ever recorded. Many large calderas collapse during eruptions and the resulting morphology provides unvaluable information for understanding the processes during highly unpredictable eruptions.Here we present a detailed analyses of the post-eruption morphology of the caldera of the Hunga Tonga–Hunga Haʻapai submarine volcano. We use the first multibeam bathymetry of the caldera, acquired only 5 months after the eruption on the MV Pacific Horizon, in May 2022.The multibeam data shows landslides with 0.5-1 km wide scars, mainly on the southern rim, with the deposits extending to the central part of the caldera. However, the flat inner caldera suggests that most of the material was deposited simultaneously to the caldera drop following the eruption, on the order of 800 m. Sediment cores collected inside the caldera show repeated turbidity current sedimentation pointing to ongoing mass wasting, which could have potentially led to eventual breaching of the rim on the north and east side. Submarine ridges were preserved on these sites, separating the inner caldera and two erosional channels on the outer part, which point to the main debris transport paths during the eruption. More than 50 active gas plumes are observed on the eastern side, located following a straight W-E transect, and on the northern side, where the vents are covering the collapse walls close to the eastern Hunga Tonga–Hunga Haʻapai island. The presence of these vents and their distribution related to the morphology of the caldera, indicate the most energetic parts of the volcano, which can potentially still be hazardous. Our morphological analyses provide new insights of transport and depositional processes following highly energetic submarine eruptions.

This study reports a unique pumice texture generated by the instantaneous bursting of melt inclusions in alkali feldspars during the 946 CE Plinian eruption at Baekdusan. The burst produced super-vesicular (80−90 vol.% voids), subspherical (i.e., non-sheared), and subcentimeter-sized “bubble pockets” indicating their formation at the moment of magma fragmentation. Their volume fraction (6–24 vol.%) suggests that the melt inclusions acted as an additional volcanic gas source and increased significantly the volume of the erupting magma at the moment of magma fragmentation. The “excess explosivity” induced by the bursting melt inclusions should be taken into account when modeling eruption dynamics and assessing volcanic hazards, therefore having broad volcanological implications. Two distinctive feldspar–glass assemblages of either sanidine-bearing trachyte or anorthoclase-bearing rhyolite in the bubble pockets also indicate that the chemical bimodality of the hemisphere-scale, 946 CE Baekdusan tephra resulted from cryptic mixing of two magmas.

Abstract Fissure eruptions initiate with magma ascending and spreading through cracks in the ground that can extend for kilometres at the surface. Eruptions eventually localise to form one or a few persistent conduits and ultimately an array of discrete cones or craters. We built a new experimental apparatus to investigate the influences of fissure shape and wall-rock temperature on localisation within a volcanic fissure, and the thermal feedbacks associated with variability of these parameters. Our artificial fissure, or “Artfish,” has a slot geometry with adjustable shape and wall temperature. We can simulate both starting variability in fissure geometry and wall temperature, as well as changes in these parameters during an experiment to replicate, for example, blockage by wall-rock collapse, widening by wall-rock erosion, and warming by adjacent intrusions. We use polyethylene glycol (PEG 600) for our analogue fluid. A variable-speed pump allows for a range of fluid injection and ascent rates. Initial tests showcase the capabilities of the model and the types of data that may be acquired. Additional key features achieved include a stable and planar injection system, fluid recycling, and the use of particle tracers for monitoring flow patterns and velocities. The thermal evolution of the fluid-wall interface is quantitatively measured with thermal sensors, and the change in state of the PEG provides a clear visual indication of flow behaviour and solidification progress recorded on video. The potential experiments that can be conducted with this highly versatile model are numerous and will be used to gain a better understanding of the thermal controls on flow localisation and conduit development. This will assist hazard modellers to assess controls on eruption evolution and potentially to forecast sites where an initial fissure eruption may focus.

We present the late Holocene eruption history of the poorly known Doña Juana volcanic complex, in SW Colombia, which last erupted in the twentieth century. This represents a case study for potentially active volcanism in the rural Northern Andes, where tropical climate conditions and a fragmented social memory blur the record of dormant volcanoes. We reconstructed the volcanic stratigraphy of the central-summit vent area by integrating new mapping at 1:5000 scale with radiocarbon ages, sedimentology analysis, and historical chronicles. Our results revealed cyclic transitions from lava-dome growth phases and collapse to explosive Vulcanian and possibly subplinian phases. Pyroclastic density currents were generated by dome collapse producing block-and-ash flows or by pyroclastic fountain/column collapse and were rapidly channelized into the deeply incised fluvial valleys around the volcano summit. The pyroclastic density currents were ∼4−10 × 106 m3 in volume and deposited under granular flow− or fluid escape−dominated depositional regimes at high clast concentrations. In places, more dilute upper portions reached a wider areal distribution that affected the inhabited areas on high depositional terraces. The coefficient of friction (ΔH/L) is higher for block-and-ash flows and dense lava−bearing fountain/low-column-collapse pyroclastic density currents compared to pumice-bearing, column-collapse pyroclastic density currents. Associated mass-wasting processes included syneruptive and intereruptive debris flows, with the last one documented in 1936 CE.

The phreatoplinan eruption of the shallow submarine Hunga Volcano Tonga formed global air-pressure waves, regional tsunami and an up to 55 km-high eruption column. Despite its large explosive magnitude, the magma erupted were similar to past compositions, and comprised crystal poor (cpx>opx) andesite with ~57-63 wt% silica glass. Low magnitude Surtseyan eruptions in 2009-2015 formed from small pockets of andesite that ascended slowly, resulting in high microphenocryst and microlite contents. Large eruptions, including events in ~AD200 and AD1100 and the 2022 event drew magma rapidly from a ~5-7 km deep mid-crustal reservoir. Rapid decompression and quenching (augmented by magma-water interaction) records the heterogeneity of the reservoir, with mingled glass textures and cryptic mixing of subtly different melts. The 2022 feldspar phenocrysts show more mafic melt inclusion compositions than host glass, clear uniform cores and thin rims evidencing ~1 month-long changes caused by decompression, rise and internal mingling of subtlety different melts. CPX phenocrysts show uniform cores a variety of more mafic and similar melt inclusions to the bulk glass, and thin overgrowth rims reflecting only decompression and mingling. Lithic fragments (

The January 2022 eruption of Hunga Volcano, Tonga is likely the most explosive mafic eruption yet documented. It exhibited dynamics of ash plume expansion and atmospheric pressure waves unlike anything seen before. This is remarkable considering that it erupted crystal-poor and microlite-poor andesitic magma (57-63 wt% silica glass). The climactic phase produced an eruptive column of at least 39 km in height, however, the ash volume appears anomalously small for the explosive magnitude. Ash from nine different sites across the Kingdom of Tonga were analyzed for textural and morphological properties and grain size distribution. The tephra comprises light pumice (16%), dark pumice (44%), glassy microlite-rich grains (25%), lithics (7%) and free-crystals (Pl, Cpx, Opx) (8%). Specific gravity of particles range from 0.4 to ~2.5. Secondary electron images show that pumices have a variable vesicularity, from dense glassy blocky particles; glassy particles with isolated vesicles and weakly deformed, thick vesicle walls; and a smaller percentage of microvesicular pumices, coated in finer particles. The general characteristics imply a rapid decompression, fragmentation and chilling. This implies some form of phreatomagmatism but with high-efficiency to generate such a large blast – e.g., via propagation of stress waves and thermal contraction rapidly increasing a magma surface area for interaction. The ash is fine-grained and poorly sorted overall. Less than 20 wt.% of ash particles are >1 mm at 80 km SE of the volcano on the main island of Tongatapu, while 70 km NE of the volcano (Nomuka Island) has finer ash, with only 2% of particles >1 mm. It appears that the dispersion axis for the event was directed toward the E or ESE, across the main population centre of Nuku’alofa on Tongatapu. Of the fine fraction 20 wt.% is < 30 micron, 8 wt.%

Volcanic eruptions that occur without warning can be deadly in touristic and populated areas. Even with real-time geophysical monitoring, forecasting sudden eruptions is difficult because their precursors are hard to recognize and can vary between volcanoes. Here, we describe a general seismic precursor signal for gas-driven eruptions, identified through correlation analysis of 18 well-recorded eruptions in New Zealand, Alaska and Kamchatka. We show that the displacement seismic amplitude ratio, a ratio between high and medium frequency volcanic tremor, has a characteristic rise in the days prior to eruptions that likely indicates formation of a hydrothermal seal that enables rapid pressurization. Applying this model to the fatal 2019 eruption at Whakaari (New Zealand), we identify pressurization in the week before the eruption, and cascading seal failure in the 16 hours prior to the explosion. This method for identifying and proving generalizable eruption precursors can help improve short term forecasting systems.

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A critical factor in the effective use of technology to enhance or support teaching and learning (referred to, among other things, as technology enhanced learning, or e-learning) is that the technology itself does not overshadow or substitute good quality teaching. While these developments in technology do offer increased and enhanced educational opportunities, any new approaches to teaching and learning should be complemented by knowledge of lear ning theory and pedagogy. Too often the danger arises that the technology erroneously represents some form of “magic bullet”, which can reduce the workload on teachers and facilitate new and better means of learning for students. This can frequently be the case, but this assumption can often miss the need for effort, structure and discipline on the part of all stakeholders to make sure that the technology appropriately and effectively supports the learning and that it has a clear role to play in the learning process - that the technology, for lack of a better term - “knows its place”. As Beetham and Sharpe (2013) note, while digital tools and technologies provide opportunities for “informal, self-directed, independent learning activities”, this in itself is not education. Beetham & Sharpe (2013) argue: “Pedagogy is about guiding learning, rather than leaving you to finding your own way […] our digital native students may be able to use technologies, but that does not mean they can learn from them. Being able to read and write never meant you could therefore learn from books. Learners need teachers.” . And while teachers may look to incorporate innovative strategies in their teaching and learning, a focus needs to “place students at the heart of the education process, [...] to shift to more student-centred, immersive learning experiences, deep faculty/student relationships and the development of critical thinking capacities which remain risk-free for the student experience” (Mukerjee 2014; Norris et al 2012). It is in this context that, on behalf of the Cork Institute of Technology, we are delighted to help participate in the project "FlipIT! -Flipped Classroom in the European Vocational Education” and to have been involved in the development of this E-book. We hope that the information contained within will be of help to both teachers and students (and potentially to other stakeholders) in helping to guide and support the planning and the implementation of the flipped classroom in their respective classrooms (flipped or not). We would also like to credit the work performed by project managers Mária Hartyányi and Judit Mezei from iTStudy Hungary in bringing the project to successful completion. Proyecto financiado por la Comisión Europea No data (2018) UEM

It is hard to overestimate the importance of assessment for the learning process. Assessment truly dictates how our learners understand their role and, consequently, how they spend their time: be it in tasks of rote learning or critical reflection and collaborative learning, or, as phenomenographical research suggests, in surface or deep learning approaches. Assessment regimes, however, tend, for various reasons, to be quite conservative and to rely predominantly on written coursework and high stakes written examinations. In this context of such deep seated traditionalism, our paper considers the development of a new video-based “assessment productivity” solution called “RedInk” as a way to support an authentic and alternative assessment approach that may well satisfy what are often conflicting requirements for assessment reliability and validity and for assessment that performs both a summative and a formative function.