A fuzzy logic methodology for assessing the resilience of past communities to tephra fall: a Laacher See eruption 13,000 year BP case

Tephra from large explosive eruptions can cause damage to buildings over wide geographical areas, creating a variety of issues for post-eruption recovery. This means that evaluating the extent and nature of likely building damage from future eruptions is an important aspect of volcanic risk assessment. However, our ability to make accurate assessments is currently limited by poor characterisation of how buildings perform under varying tephra loads. This study presents a method to remotely assess building damage to increase the quantity of data available for developing new tephra fall building vulnerability models. Given the large number of damaged buildings and the high potential for loss in future eruptions, we use the Kelud 2014 eruption as a case study. A total of 1154 buildings affected by falls 1–10 cm thick were assessed, with 790 showing signs that they sustained damage in the time between pre- and post-eruption satellite image acquisitions. Only 27 of the buildings surveyed appear to have experienced severe roof or building collapse. Damage was more commonly characterised by collapse of roof overhangs and verandas or damage that required roof cladding replacement. To estimate tephra loads received by each building we used Tephra2 inversion and interpolation of hand-contoured isopachs on the same set of deposit measurements. Combining tephra loads from both methods with our damage assessment, we develop the first sets of tephra fall fragility curves that consider damage severities lower than severe roof collapse. Weighted prediction accuracies are calculated for the curves using K-fold cross validation, with scores between 0.68 and 0.75 comparable to those for fragility curves developed for other natural hazards. Remote assessment of tephra fall building damage is highly complementary to traditional field-based surveying and both approaches should ideally be adopted to improve our understanding of tephra fall impacts following future damaging eruptions.

Vegetation plays a key role in preventing the remobilisation of tephra and aeolian activity following tephra fall. Recent volcanic eruptions in Iceland have highlighted the consequences of tephra fall for ecosystems and human health. Improved understanding of the mechanisms behind ecosystem recovery following tephra fall is particularly important for Iceland. Today ~42% of the country is classified as desert and unvegetated and sparsely vegetated areas are unable to trap tephra fall and prevent subsequent wind erosion. This paper presents palaeoenvironmental reconstructions before and after the Hekla 4 tephra from two lakes in Northwest Iceland, from within a woodland in the lowland, and in open woodland under stress at the highland margin. The c. 4,200 cal bp. Hekla 4 tephra is one of the most extensive Icelandic Holocene tephra layers and the eruption produced an estimated ~9 km3 of tephra. The palaeoecological reconstructions provide an insight into the responses of two relatively stable ecosystems to thick tephra deposits during a period of cooling climate. The understory vegetation in the lowland woodland was buried by the tephra, however Betula pubescens trees were not severely affected and the woodland recovered relatively quickly. In contrast, open woodland at the highland margin that was already at its ecological limit, shifted to dwarf shrub heath, a more resilient vegetation community in response to the tephra fall and cooling climate.

Volcanic hazard impacts to critical infrastructure: A review

Probabilistic volcanic impact assessment and cost-benefit analysis on network infrastructure for secondary evacuation of farm livestock: A case study from the dairy industry, Taranaki, New Zealand

To facilitate the assessment of hazards and risk from volcanoes, we have created a comprehensive global database of Quaternary Large Magnitude Explosive Volcanic Eruptions (LaMEVE). This forms part of the larger Volcanic Global Risk Identification and Analysis Project (VOGRIPA), and also forms part of the Global Volcano Model (GVM) initiative (http://www.globalvolcanomodel.org). A flexible search tool allows users to select data on a global, regional or local scale; the selected data can be downloaded into a spreadsheet. The database is publically available online at http://www.bgs.ac.uk/vogripa and currently contains information on nearly 3,000 volcanoes and over 1,800 Quaternary eruption records. Not all volcanoes currently have eruptions associated with them but have been included to allow for easy expansion of the database as more data are found. Data fields include: magnitude, Volcanic Explosivity Index (VEI), deposit volumes, eruption dates, and rock type. The scientific community is invited to contribute new data and also alert the database manager to potentially incorrect data. Whilst the database currently focuses only on large magnitude eruptions, it will be expanded to include data specifically relating to the principal volcanic hazards (e.g. pyroclastic flows, tephra fall, lahars, debris avalanches, ballistics), as well as vulnerability (e.g. population figures, building type) to facilitate risk assessments of future eruptions.

Overview Tephra erupted in volcanic plumes can be transported over distances of thousands of kilometers, causing respiratory problems to humans and animals, serious damage to buildings and infrastructure, and affecting economic sectors such as aviation, agriculture, and tourism. Models with different degrees of complexity have been developed over the last few decades to describe tephra dispersal. Depending on the application, different simplifications and assumptions can be introduced to make the problem tractable. Highly sophisticated models are not suited for the computationally expensive probabilistic calculations required by long-term hazard assessments. In contrast, the simplified models typically used for probabilistic assessments have to compromise the sophistication of the physical formulation for computational speed. A comprehensive understanding of tephra deposits and hazards can only result from a critical and synergistic application of models with different levels of sophistication, ranging from purely empirical to fully numerical. A review of the main approaches to tephra dispersal modeling is presented in this chapter. Introduction Explosive volcanic eruptions have intrigued scientists because of their dramatic display of physical processes, their crucial role in the geological evolution of Earth, and their potentially catastrophic consequences for society. A key way of improving our understanding of explosive volcanism is to study the resulting pyroclastic deposits, which often represent the only direct evidence of explosive eruptions. Tephra deposits retain a considerable amount of information about the nature of the eruption, such as erupted mass, bulk grain-size distribution, and eruption intensity. However, tephra falls also represent significant hazards for people living close to active volcanoes. These hazards include collapse of buildings, disruption to water and electricity supplies, disruption to transportation networks, as well as health hazards from respirable ash, crop pollution, and lahar generation. Developing an understanding of tephra fall is crucial to public safety. In this chapter tephra is used in the original sense of Thorarinsson (1944) as a collective term for all particles ejected from volcanoes, irrespective of size, shape, and composition, whereas tephra fall indicates the process of particle fallout.

Emerging foodborne pathogens

Vibrio cholerae is a human pathogenic marine bacterium inhabiting coastal regions and is vectored into human food and water supplies via attachment to particles including detritus, phytoplankton, and zooplankton. Particle colonization by the pathogen is inhibited by an antagonistic interaction with the particle-associated Vibrionales bacterium SWAT3, a producer of the antibiotic andrimid. By analyzing the individual movement behaviors of V. cholerae exposed to a gradient of andrimid in a microfluidics device, we show that the pathogen has a concentration dependent avoidance response to sub-lethal concentrations of the pure antibiotic and to the metabolites produced by a growing colony of SWAT3-wild-type. This avoidance behavior includes a 25% increase in swimming speeds, 30% increase in run lengths, and a shift in the direction of the bacteria away from the andrimid source. Consequently, these behavioral shifts at low concentrations of andrimid would lead to higher diffusivity and result in the dispersion of bacteria away from the competitor and source of the antibiotic. Such alterations in motility were not elicited in response to a non-andrimid-producing SWAT3 mutant, suggesting andrimid may be a negative effector of chemotaxis for V. cholerae. The behavioral response of colonizing bacteria to sub-inhibitory concentrations of competitor-produced antibiotics is one mechanism that can influence microbial diversity and interspecific competition on particles, potentially affecting human health in coastal communities and element cycling in the ocean.

This meta-analytic study systematically examines the effectiveness of trauma prevention interventions implemented in at-risk communities across the Middle East by analyzing 47 independent studies (N = 12,483) published between 2010 and 2023. Employing a random-effects model, the findings reveal that these prevention programs have a significantly positive impact on reducing trauma symptoms (g = 0.73, 95% CI [0.65, 0.81], p < .001). Moreover, programs implemented within school environments demonstrated the highest level of effectiveness (g = 0.86), followed by community-based interventions (g = 0.71), and programs involving families (g = 0.62). Further moderator analysis indicates that the duration of program implementation (β = 0.31, p < .01) and the degree of family involvement (β = 0.28, p < .01) are significant predictors of intervention success. Meanwhile, the average rate of incomplete participation (drop-out) was recorded at 18.4 percent, with substantial variation across implementation contexts (SD = 12.3 percent). Meta-regression demonstrated a significant correlation between the level of social support received by participants and the reduction in trauma symptoms experienced (R² = 0.42, p < .001). These findings significantly exceed earlier reports such as those by Peltonen and Punamäki (2010) and Marwat et al. (2025), who estimated program effects within a moderate range (g = 0.45–0.52). Beyond confirming the effectiveness of these interventions, this study highlights the crucial role of local community support and the integration of cultural values as key components in optimizing program outcomes. Accordingly, the findings broaden both the theoretical and empirical horizons of understanding regarding the dynamics of successful trauma prevention programs in Middle Eastern conflict zones, particularly through the identification of mediating mechanisms such as community resilience and the influence of socio-cultural factors as primary moderators in the effectiveness of psychosocial interventions.

Forensic assessment of the 1999 Mount Cameroon eruption, West-Central Africa

Background Globally, more than 800 million people live in areas that have the potential to be affected by volcanic hazards, and this number is growing [Chapter 4]. The need for informed judgements regarding the global extent of potential volcanic hazards and the relative threats is therefore more pressing than ever. There is also an imperative to identify areas of relatively high hazard where studies and risk reduction measures may be best focussed. Various authors have tackled this task at a range of spatial scales, using a variety of techniques. At some well-studied volcanoes, the geological record has been used in combination with numerical modelling to create probabilistic hazard maps of volcanic flows and tephra fall [Chapter 6 and 20]. Such sources of information can be hugely beneficial in land use planning during times of quiescence and in emergency planning during times of unrest. Unfortunately, creating high-resolution probabilistic hazard maps for all volcanoes is not yet feasible. There is therefore a need for a methodology for volcanic hazard assessment that can be applied universally and consistently, which is less data-and computing-intensive. The aim of such an approach is to identify, on some objective overall basis, those volcanoes that pose the greatest danger, in order that more indepth investigations and disaster risk reduction efforts can then be focused on them. Previous methods An index-based approach to volcanic hazard assessment involves assigning scores to a series of indicators, which are then combined to give an overall hazard score. Indicators typically include measures of the frequency of eruptions, the relative occurrence of different kinds of eruptions and their related hazards, the footprints of these hazards, and eruption size. Indices are well suited to the problem of volcanic hazard assessment, as they allow the decomposition of the complex system into a suite of volcanic system controls and simple quantitative variables and factors that jointly characterise threat potential. Ewert (2007) presented an index-based methodology for assessing volcanic threat (the combination of hazard and exposure) in the USA, to permit prioritisation of research, monitoring and mitigation.

The contamination of food or water supplies with radioactive materials centers the attack on the ingestion pathway, where the aims may be to: expose the public who consume the contaminated food or drink the contaminated water; stop the provision of food or water supplies to the public; and cause widespread panic and public alarm. The radiological consequences may include: contamination of water treatment plants, service reservoirs, header tanks and water supply systems; contamination of food products, wholesale food markets, supermarkets or food processing facilities; and the loss or disruption of the water and/or food supply chain. The occurrence of immediate fatalities or casualties suffering from the effects of radiation exposure via the ingestion pathway is very unlikely since extremely large amounts of radioactive material would be required to achieve sufficiently high concentrations and, even if this occurs, it is very unlikely that it would affect a large number of people. The radionuclides that can be used or released during a radiological emergency, where a significant radiation dose could be received as a result of consumption of contaminated food, could be: The radionuclides listed above are expected to be the predominant contributors to radiation dose through ingestion in the most of the scenarios. When more than one radionuclide is released, the relative contribution that a radionuclide makes to radiation dose from ingestion of subsequently contaminated food depends on the specifics of the accident and the mode of release. In unique circumstances other radionuclides (like Po-210) may contribute radiation doses through the food ingestion pathway. Although the deliberate act to contaminate food or water supplies with radioactive materials it is unlikely (though not impossible), there is a need to co-operate with radiological experts and media specialists to quickly assess the potential medical impact of such acts and provide public information to alleviate fears in the potentially affected public. There is also a need to develop a plan, at the national level, to monitor a representative sample of the potentially affected population to confirm the health risk assessment and reassure the public.

Fate and agricultural consequences of leachable elements added to the environment from the 2011 Cordón Caulle tephra fall

Tephra fall is among the set of hazardous phenomena associated with volcanic activity that can impact water resources and services. The aim of this paper is to characterize the potential impacts of tephra fall on the groundwater-fed water supply system of Ponta Delgada (São Miguel, Azores) by comparing two scenarios of explosive eruptions. Vulnerability matrices were used to compute indexes, by multiplying the thickness of tephra fall deposits, corresponding to increasing hazard levels, by descriptors of the water supply system, representing the elements at risk. In a worst-case scenario, tephra covers a large area inland, severely constraining the abstraction of water to public supply, as 84.8% of the springs are affected. In 12 springs the expected hazard level is of perturbation (5157 m3/day; 12.1% of the daily abstraction) or damage (16,094 m3/day; 37.8%). The same trend is observed considering the storage capacity, as 75.4% of the reservoirs may be somehow affected. Moreover, 72.4% of the 68,392 inhabitants served by the water supply system will be in a zone where the damage level will be achieved. Results point out to the need of preparedness measures to mitigate consequences of a volcanic crisis over the water supply.

Prospects and pitfalls in integrating volcanology and archaeology: A review