Suchergebnisse

Volcanic and related hazards / William E. Scott -- Volcanic-hazard zonation and long-term forecasts / William E. Scott -- Volcano monitoring and short-term forecasts / Norman G. Banks [and others] -- Recent case histories / Raymundo S. Punongbayan and Robert I. Tilling -- Scientific and public response / Robert I. Tilling and Raymundo S. Punongbayan

Machine generated contents note: Introduction; Volcanoes and plate tectonics; Volcanic form and structure; Types and characteristics of central eruptions and extended lateral eruptions; Physics of volcanism; Historical eruptions; Volcano magnitudes and impacts; Volcanic products: volatiles; Volcanic products; pyroclastics; Volcanic products: Lava flows and shallow intrusions; Volcanic products: Craters, calderas, and super-eruptions; Volcanoes and water/Lahars; Paleoeruptions and dating; Volcanic stratigraphy and tephrochronology; Archaeological evidence of volcanism; Volcanoes and mythology; Volcanic hazard and prediction (periodicities); Field investigation techniques; Community coping strategies

This paper explores some psychological aspects of community vulnerability following the 1995 and 1996 eruptions at Ruapehu volcano, New Zealand. A model comprising three psychological factors (sense of community, coping style and self‐efficacy) is used to investigate this issue. The results suggest that self‐efficacy and problem‐focused coping reduce vulnerability and that this model has a role to play in identifying vulnerable communities. The differential implications of physical and economic hazard consequences for community vulnerability were also examined. Data is presented that reinforces the view that the salience of volcanic hazard consequences is a result of their implications for community functions and resources. The implications for mitigation, threat communication and the development of resilient communities are discussed.

Abstract. Katla volcano, located beneath the Mýrdalsjökull ice cap in southern Iceland, is capable of producing catastrophic jökulhlaup. The Icelandic Civil Protection (ICP), in conjunction with scientists, local police and emergency managers, developed mitigation strategies for possible jökulhlaup produced during future Katla eruptions. These strategies were tested during a full-scale evacuation exercise in March 2006. A positive public response during a volcanic crisis not only depends upon the public's knowledge of the evacuation plan but also their knowledge and perception of the possible hazards. To improve the effectiveness of residents' compliance with warning and evacuation messages it is important that emergency management officials understand how the public interpret their situation in relation to volcanic hazards and their potential response during a crisis and apply this information to the ongoing development of risk mitigation strategies. We adopted a mixed methods approach in order to gain a broad understanding of residents' knowledge and perception of the Katla volcano in general, jökulhlaup hazards specifically and the regional emergency evacuation plan. This entailed field observations during the major evacuation exercise, interviews with key emergency management officials and questionnaire survey interviews with local residents. Our survey shows that despite living within the hazard zone, many residents do not perceive that their homes could be affected by a jökulhlaup, and many participants who perceive that their homes are safe, stated that they would not evacuate if an evacuation warning was issued. Alarmingly, most participants did not receive an evacuation message during the exercise. However, the majority of participants who took part in the exercise were positive about its implementation. This assessment of resident knowledge and perception of volcanic hazards and the evacuation plan is the first of its kind in this region. Our data can be used as a baseline by the ICP for more detailed studies in Iceland's volcanic regions.

This paper summarizes research involving a multidisciplinary team of volcanologists and social scientists. It describes collaboration in relation to social and physical risk and vulnerability following the Mount Ruapehu eruptions of 1995‐1996. This work stresses a key role for such multidisciplinary teams in reducing the social impact of volcanic hazards through assisting communities, organizations, and individuals following an eruption and, importantly, during quiescent periods. We present an overview of a multidisciplinary approach and related research. In stressing the role of the physical science community in managing societal hazards and risk, the paper addresses how this role can be enhanced through collaboration with social scientists and others. The emphasis here is the facilitation of volcanological knowledge and expertise in threat communication, mitigation, community development, emergency planning, and response management. Our research has examined mechanisms for integration, multi‐disciplinary training, and preparing volcanologists for the social demands encountered in playing an active crisis management role. One area of overlap that can tie together disciplines and assist the public is the idea that volcanic activity and the related uncertainties are, at their essence, simply problems that with increasingly integrated efforts likewise have increasingly attainable solutions.

Volcanic eruptions represent one of the most serious geologic hazards facing the Pacific Northwest, with several volcanoes located within striking distance of the most highly populated areas in the region. This paper describes the hazards associated with these eruptive centers and discusses the best practices for preparing communities for potential eruptions and mitigating volcanic hazards. This study is based on data collected by the United States Geological Survey (USGS) on volcanic systems such as Mt. St. Helens and Mt. Rainier. Many other scientific organizations have studied analogous volcanic systems beyond the Pacific Northwest, such as the volcanically active island of Indonesia; where numerous populated areas lie in close proximity to active volcanic systems. A common misconception is that many of the volcanoes in the Pacific Northwest are dormant or extinct, but research shows that these systems are active. Further, these active volcanoes have significant populations living well within their mapped hazard zones. The lack of preparedness and understanding of the true state of volcanic activity in the region could be related to a lack of education, or to inaction on the part of local government agencies in preparing for volcanic hazards. With this being said, it is imperative for local governments to prepare for volcanic activity in the inevitable future. It would be in the best interest of these governments to work with schools to educate not just students, but communities as a whole on how to prepare for a major volcanic eruption. This would be most important for the Pacific Northwest, as this is one of the more volcanically active regions on Earth.

Volcanic Hazards: A Sourcebook on the Effects of Eruptions provides a comprehensive discussion of volcanic eruptions and their effects. This volume provides background data on volcanic activity with attention directed specifically at those types of activity and those characteristics which are hazardous. It establishes the direct effects of volcanic eruptions on humans in terms of death and injuries, and social aspects such as perception of eruption hazards, evacuation, panic, looting, and religious beliefs. It discusses the indirect consequences of volcanic eruptions for humans by illustrating

Abstract. The main purpose of this article is to emphasize the
importance of clarifying the probabilistic framework adopted for volcanic
hazard and eruption forecasting. Eruption forecasting and volcanic hazard
analysis seek to quantify the deep uncertainties that pervade the modeling
of pre-, sin-, and post-eruptive processes. These uncertainties can be
differentiated into three fundamental types: (1) the natural variability of
volcanic systems, usually represented as stochastic processes with
parameterized distributions (aleatory variability); (2) the uncertainty in our knowledge of how
volcanic systems operate and evolve, often represented as subjective
probabilities based on expert opinion (epistemic uncertainty); and (3) the possibility that our
forecasts are wrong owing to behaviors of volcanic processes about which we
are completely ignorant and, hence, cannot quantify in terms of
probabilities (ontological error). Here we put forward a probabilistic framework for hazard
analysis recently proposed by Marzocchi and Jordan (2014), which unifies
the treatment of all three types of uncertainty. Within this framework, an
eruption forecasting or a volcanic hazard model is said to be complete only
if it (a) fully characterizes the epistemic uncertainties in the model's
representation of aleatory variability and (b) can be unconditionally tested
(in principle) against observations to identify ontological errors.
Unconditional testability, which is the key to model validation, hinges on
an experimental concept that characterizes hazard events in terms of exchangeable data sequences
with well-defined frequencies. We illustrate the application of this unified
probabilistic framework by describing experimental concepts for the
forecasting of tephra fall from Campi Flegrei. Eventually, this example may
serve as a guide for the application of the same probabilistic framework to
other natural hazards.

Abstract. Long-term hazard assessment, one of the bastions of risk-mitigation programs, is required for land-use planning and for developing emergency plans. To ensure quality and representative results, long-term volcanic hazard assessment requires several sequential steps to be completed, which include the compilation of geological and volcanological information, the characterisation of past eruptions, spatial and temporal probabilistic studies, and the simulation of different eruptive scenarios. Despite being a densely populated active volcanic region that receives millions of visitors per year, no systematic hazard assessment has ever been conducted on the Canary Islands. In this paper we focus our attention on El Hierro, the youngest of the Canary Islands and the most recently affected by an eruption. We analyse the past eruptive activity to determine the spatial and temporal probability, and likely style of a future eruption on the island, i.e. the where, when and how. By studying the past eruptive behaviour of the island and assuming that future eruptive patterns will be similar, we aim to identify the most likely volcanic scenarios and corresponding hazards, which include lava flows, pyroclastic fallout and pyroclastic density currents (PDCs). Finally, we estimate their probability of occurrence. The end result, through the combination of the most probable scenarios (lava flows, pyroclastic density currents and ashfall), is the first qualitative integrated volcanic hazard map of the island.

While a considerable body of work concerning citizens' perceptions of risk for volcanic hazards has been done in the United States and New Zealand, no comparable study has focused on residents near Italy's two major volcanoes: Vesuvio and Etna. This survey study, involving 174 participants, focused on various measures of risk perception, feelings of personal vulnerability to the volcanic threat, and confidence in government officials' preparedness for potential eruptions. Although it was expected that due to a recent eruption of Etna, residents there would have higher levels of perceived risk than those at Vesuvio, findings mostly demonstrated the reverse. Additionally, residents living in the highest risk areas at Vesuvio demonstrated low levels of awareness concerning evacuation plans and low levels of confidence in the success of such plans.

Abstract. Regional volcanic threat assessments provide a large-scale comparable vision of the threat posed by multiple volcanoes. They are useful for prioritising risk-mitigation actions and are required by local through international agencies, industries and governments to prioritise where further study and support could be focussed. Most regional volcanic threat studies have oversimplified volcanic hazards and their associated impacts by relying on concentric radii as proxies for hazard footprints and by focussing only on population exposure. We have developed and applied a new approach that quantifies and ranks exposure to multiple volcanic hazards for 40 high-threat volcanoes in Southeast Asia. For each of our 40 volcanoes, hazard spatial extent, and intensity where appropriate, was probabilistically modelled for four volcanic hazards across three eruption scenarios, giving 697 080 individual hazard footprints plus 15 240 probabilistic hazard outputs. These outputs were overlain with open-access datasets across five exposure categories using an open-source Python geographic information system (GIS) framework developed for this study (https://github.com/vharg/VolcGIS, last access: 5 April 2022). All study outputs – more than 6500 GeoTIFF files and 70 independent estimates of exposure to volcanic hazards across 40 volcanoes – are provided in the "Data availability" section in user-friendly format. Calculated exposure values were used to rank each of the 40 volcanoes in terms of the threat they pose to surrounding communities. Results highlight that the island of Java in Indonesia has the highest median exposure to volcanic hazards, with Merapi consistently ranking as the highest-threat volcano. Hazard seasonality, as a result of varying wind conditions affecting tephra dispersal, leads to increased exposure values during the peak rainy season (January, February) in Java but the dry season (January through April) in the Philippines. A key aim of our study was to highlight volcanoes that may have been overlooked perhaps because they have not been frequently or recently active but that have the potential to affect large numbers of people and assets. It is not intended to replace official hazard and risk information provided by the individual country or volcano organisations. Rather, this study and the tools developed provide a road map for future multi-source regional volcanic exposure assessments with the possibility to extend the assessment to other geographic regions and/or towards impact and loss.