How is drone technology advancing our understanding of future volcanism?

Improved early warning systems are crucial for minimising loss of life and effectively planning for volcanic emergencies. Typically, volcanologists use seismic monitoring as their main indicator of imminent volcanic activity. As technology advances, alternative early warning system methods are being explored by volcanologists.

A better understanding of the chemistry within a volcanic plume, and the clues about future eruptions that might be contained within, may lead to more accurate forecasting of future volcanism.

Adapted drones, equipped with gas sensors and cameras, could be the answer and a recently published study in Science Advances, led by Dr. Emma Liu (University College London), investigates how aerial measurements of volcanic gases using unoccupied aerial systems (drones) transform our ability to measure and monitor plumes remotely whilst also obtaining greater knowledge on global volatile fluxes from volcanoes.

Aerial robotic strategies using drone technology are changing the landscape of volcanological research and monitoring, contributing to accurate and repeatable data at spatial resolutions often exceeding ground or space-based equivalents as well as being more cost effective than manned aircraft alternatives.

Research for this study was carried out on a small volcanic island off the Northeast coast of Papua New Guinea. Manam has two simultaneously active vents and is one of the most active volcanoes in Papua New Guinea. Since historical records began it has been characterized by persistent passive degassing and intermittent Strombolian activity, punctuated by paroxysmal sub-Plinian eruptions on sub-decadal time scales. It is currently ranked among the strongest volcanic emission sources globally and, with a carbon dioxide emission rate of ~1 Mt CO2/year between 2005 to 2015, Manam is among the most significant volcanic carbon sources currently active, therefore it was a fitting study site for this research by Liu et al. (2020).

Close flyovers of the volcano were completed in October 2018 and May 2019 – an abundance of geochemistry data was obtained including concentrations of carbon dioxide, sulfur dioxide and hydrogen sulfide, flux rates, and carbon isotope compositions via isotopic analysis of plume samples. Results indicated degassing at the volcano's southern crater between October 2018 and May 2019, a likely precursor to an eruption. One month later, Manam Volcano erupted.

Improving the ability to measure and monitor volcanic plumes remotely will have transformative consequences for the quantification of global volatile budgets and for our understanding of volcanic plume dynamics and chemistry more generally. Advances in drone technology within modern volcanology may translate into tangible monitoring strategies that could assist in the identification of future precursory changes in volcanic activity at inaccessible, remote volcanic systems.

However, this study cautions that volcanic emissions alone are not a reliable indicator of imminent volcanism – they should be used collectively with other accurate measurements and observations.