Josh Hayes

• PhD
• Senior Natural Hazard and Risk Scientist at GNS Science

Tephra falls can cause a range of impacts to communities by disrupting, contaminating and damaging buildings and infrastructure systems, as well as posing a potential health hazard. Coordinated clean-up operations minimise the impacts of tephra on social and economic activities. However, global experience suggests clean-up operations are one of the...

Cities near volcanoes expose dense concentrations of people, buildings, and infrastructure to volcanic hazards. Identifying cities globally that are exposed to volcanic hazards helps guide local risk assessment for better land-use planning and hazard mitigation. Previous city exposure approaches have used the city centroid to represent an entire ci...

When disasters occur, rapid impact assessments are required to prioritise response actions, support in-country efforts and inform the mobilisation of aid. The 15 January 2022 eruption of Hunga volcano, Tonga, and the resulting atmospheric shockwave, ashfall, underwater mass disturbance and tsunami, caused substantial impacts across the Kingdom of T...

La caída y acumulación de ceniza volcánica es un riesgo importante para las operaciones aeroportuarias, que ha provocado más de 40 cierres de operaciones en los últimos 45 años debido a la acumulación de ceniza en el terreno, así como muchos más ocasionados por la ceniza aerotransportada/atmosférica. Como apoyo a nuestro conjunto de datos globales...

When disasters occur, rapid impact assessments are required to direct response priorities, support in-country efforts and inform the mobilisation of aid. The 15 January 2022 eruption of Hunga volcano, Tonga, and the resulting atmospheric shockwave, ashfall, underwater mass disturbance and tsunami, caused substantial impacts across the Kingdom of To...

The recent destruction of thousands of homes by lava flows from La Palma volcano, Canary Islands, and Nyiragongo volcano, Democratic Republic of Congo, serves as a reminder of the devastating impact that lava flows can have on communities living in volcanically active regions. Damage to buildings and infrastructure can have widespread and long-last...

Volcanic eruptions can cause significant impacts on communities and infrastructure. There is an increasing need for effective risk assessments to inform decision-making and minimise the impact of volcanic hazards. Vulnerability models play a crucial role in these assessments, connecting the intensity of the hazard with the elements that are exposed...

Effective risk management requires accurate assessment of population exposure to volcanic hazards. Assessment of this exposure at the large-scale has often relied on circular footprints of various sizes around a volcano to simplify challenges associated with estimating the directionality and distribution of the intensity of volcanic hazards. Howeve...

The recent destruction of thousands of homes by lava flows from Cumbre Vieja, La Palma, Spain and Nyiragongo volcano, Democratic Republic of Congo, serves as a reminder of the devastating impact that lava flows can have on communities living in volcanically active regions. Damage to buildings and infrastructure in particular can have widespread and...

Fire from volcanic activity (FFVA) is a highly dangerous and largely understudied hazard arising from volcanic activity. FFVA can be caused by a variety of volcanic hazards and can greatly compound the damage and losses associated with volcanic activity, in addition to creating complications for event response and mitigation. In this study, we deve...

Road networks in volcanically active regions can be exposed to various volcanic hazards from multiple volcanoes. Exposure assessments are often used in these environments to prioritise risk management and mitigation efforts towards volcanoes or hazards that present the greatest threat. Typically, road exposure has been assessed by quantifying the a...

Cataloguing damage and its correlation with hazard intensity is one of the key components needed to robustly assess future risk and plan for mitigation as it provides important empirical data. Damage assessments following volcanic eruptions have been conducted for buildings and other structures following hazards such as tephra fall, pyroclastic den...

Frequency-magnitude relationships are a fundamental aspect of volcanic hazard and risk analysis. Typically, frequencies of previously recorded eruptions are used to identify such relationships. This works well for volcanoes that are well-studied, but it can take a long, sustained, and resource intensive research effort to compile complete eruption...

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...

Over the past 20 years, our understanding of volcanic eruption impacts on the built environment has transformed from being primarily observational with small datasets to one grounded in field investigations, laboratory experiments, and quantitative modeling, with an emphasis on stakeholder collaboration and co-creation. Here, we summarize key advan...

Regional assessments provide a large-scale comparable vision of the threat posed by multiple sources and are useful for prioritising risk-mitigation actions. There is a need for such assessments from international, regional and national agencies, industries and governments to prioritise where further study and support could be focussed. Most existi...

Traditional disaster response plans are struggling to adapt to the increasingly complex, unique, and uncertain disaster impacts. Decision-making under deep uncertainty suggests the consideration of decision trigger points and adaptive processes to develop plans that are flexible for any oncoming challenge. Two disaster response planning situations...

Disasters can generate substantial quantities of disaster waste that must be managed for effective response and recovery. Modelling the potential quantities and types of waste expected after disasters has been widely applied for a variety of hazards (e.g., earthquake, hurricane, flood, tsunami). However, there has been limited consideration of mode...

Auckland Volcanic Field (AVF) is a basaltic intraplate volcanic field in North Island, New Zealand, upon which >1.6 million people live. Seismic velocity tomography and geochemistry suggest a primary mantle source region at a depth of 70–90 km. Geochemical analysis indicates a range of magma compositions, and that melts ascend with little crustal i...

Understanding future eruptions and their potential consequences is an important component of volcanic disaster risk reduction. Suites of scenarios are a useful compromise between fully probabilistic and fully deterministic (single scenario) approaches. In this paper, we present an interdisciplinary approach that combines stakeholder (volcanologists...

Reliable methods for volcanic impact and risk assessments are essential. They provide constructive information to emergency and disaster managers, critical infrastructure providers, the insurance industry, and wider society. Post-eruption clean-up of tephra deposits is a prevalent and expensive (time and resource) activity which is often not planne...

This report presents data and summarises the findings of a reconnaissance trip investigating the impacts of the April 2015 eruption of Calbuco volcano, Chile, undertaken in November- December 2016. This study is mostly focused on the Los Lagos region, focusing on impacts occurring within ~30 km of the volcano, which includes the tourism town of Pue...

Assessing the damage to buildings from volcanic eruptions is an important aspect of volcanic risk assessment and management. However, there is a limited empirical evidence base to draw upon when describing the relation between volcanic hazard intensity and resulting physical damage. The 2015 subplinian eruption of Calbuco volcano, Chile, caused dam...

Auckland is the most populous region in New Zealand with 1.6 million residents and accounts for over one third of New Zealand’s Gross Domestic Product. The Auckland metropolitan area is built upon the monogenetic Auckland Volcanic Field (AVF), which poses a considerable threat due to the high exposure of people and infrastructure to future volcanic...

Volcanic eruptions are multi-hazard events that cause a variety of impacts to exposed societies. One challenge scientists face is communicating intricate interactions between various eruption hazards and societal elements. Complex eruption scenarios that include multiple likely eruption hazards have been found to be an effective tool for communicat...

What happens when a city has a volcanic eruption within its boundaries? To explore the consequences of this rare but potentially catastrophic combination, we develop a detailed multi-hazard scenario of an Auckland Volcanic Field (AVF) eruption; the AVF underlies New Zealand's largest city, Auckland. We start with an existing AVF unrest scenario seq...

As part of Indonesia’s on going improvement to their disaster management strategy, a NDRF is being developed. The legal basis for development of the framework stems from Law 24/2007, as well as Gov. Reg. 21/2008. The NDRF is meant to provide further clarity, understanding, and efficiency to emergency response for Indonesia. An improved awareness of...

Overview of two papers that provide some insights into factors to consider when modelling and planning for tephra clean-up in urban areas.

An effective and efficient disaster response is of critical importance to reducing the loss of lives, livelihoods and health, and of economic, physical, social, cultural, and environmental assets. A national disaster response framework helps meet the aims and objectives of response by acting as a guide to how a nation responds to disasters and emer...

An effective and efficient disaster response is of critical importance to reducing the loss of lives, livelihoods and health, and of economic, physical, social, cultural, and environmental assets. A national disaster response framework helps meet the aims and objectives of response by acting as a guide to how a nation responds to disasters and emer...

Auckland, New Zealand is the economic hub and the most populous city in New Zealand. Problematically, it is also built on the monogenetic Auckland Volcanic Field (AVF), meaning a future volcanic eruption is possible anywhere within the 360 km2 areal extent. When compared to other perils (e.g. earthquakes, floods, and hurricanes), volcanic impact an...

Tephra in urban environments can lead to a reduction of infrastructure service or functionality, public health concerns and impacts, and asset damages. Removing the tephra from the urban area is often a key component to reducing the impacts and restoring urban functionality. However, cleanup operations are often carried out in an ad hoc manner due...

The Economics of Resilient Infrastructure (ERI) research programme is a four year project funded by the New Zealand Government. The final output of the programme is a software tool, MERIT (Modelling the Economics of Resilient Infrastructure Tool) which will quantify the economic consequences of infrastructure failure and explore various post disast...

This report presents a summary of the impacts on agriculture, buildings, utilities and public health from the February 2014 eruption of Kelud volcano in East Java, Indonesia. The VEI 4 eruption ejected around 150 million m3 of pyroclastic material, creating a tephra plume some 20 km in height. Both proximal areas (i.e. the Kelud flanks extending ~3...

Pyroclastic falls and flows can potentially affect urban functionality by disrupting transport, damaging infrastructure, and causing a health hazard. Consequently, efficient clean-up operations are a fundamental component of the response for impacted communities during and following a pyroclastic fall and/or flow event. We present a review of tephr...