Assessing risk from ballistic impacts through aerial hazard mapping, numeric modelling, and laboratory experiments to enhance risk management and risk communication

Ben Kennedy, University of Canterbury (EQC funded project 16/727)

Non-Technical Abstract

We have been investigating the hazard caused by rocks and lava thrown from volcanoes (ballistics) by mapping and modelling their distribution. By combining this information with air cannon experiments and knowledge of where people are on a volcano we can provide the necessary ingredients to quantify risk around New Zealand and Vanuatu’s most active volcanoes.  

We have developed several new methodologies to remotely map and monitor ballistics using Unmanned Aerial Vehicles (UAVs) and tethered balloons. These methodologies allow ballistics to be automatically distinguished from the surrounding geology and to detect the sound waves created during ballistic producing explosions. This has allowed us to quantify this hazard at Yasur, Whakaari (White island), and Red Crater volcanoes.

Our computer model can simulate different eruption styles and be used to reproduce the flight paths and landing positions of ballistics seen in eruptions. We successfully combined our ballistic model outputs with a rockfall runout model at Ngauruhoe volcano to quantify the elevated combined hazard of ballistics and their subsequent behaviour when landing on slopes.

We have additionally used our air cannon to fire ballistics toward the ground to help quantify the lethal radius of impacts to various surfaces and calculate and mitigate the different resistance of roofing in New Zealand to ballistic impact.

Our new methodologies and modelling capabilities have reduced the required time and improved the accuracy of ballistic hazard calculations for future eruptions.

Our publication of ballistic hazard communication case studies has outlined best practice and opportunities to improve this in New Zealand

Technical Abstract

We have been investigating the hazard caused by rocks and lava flung from volcanoes (ballistics) by mapping and modelling their distribution. By combining this information with experimental analysis of vulnerability and the end users’ knowledge of exposure, we provide the necessary ingredients to quantify ballistic risk proximal to New Zealand and Vanuatu’s most active volcanoes.  

We have developed several new methodologies to remotely map and monitor ballistics using Unmanned Aerial Vehicles (UAVs) and tethered balloons. These methodologies allow ballistics to be automatically distinguished from the surrounding geology and to detect the sound waves created during ballistic producing explosions. This has allowed us to quantify this hazard at Yasur, Whakaari (White island), and Red Crater volcanoes.

The newly developed Ballista interface and subsequent workshop has improved usability and accessibility of the program. We successfully modelled the combined rockfall and ballistic hazard at Ngauruhoe volcano to quantify the elevated combined hazard.

We have additionally used an air canon to fire ballistics to help quantify the lethal radius of impacts to various surfaces and calculate and mitigate the different vulnerabilities of roofing in New Zealand to ballistic impact.

Our new methodologies and modelling capabilities have reduced the required time and improved the accuracy of ballistic hazard calculations for future eruptions.

Our publication of ballistic hazard communication case studies has outlined best practice and opportunities to improve this in New Zealand.