ROTTnROCK · Assessing the role of hydrothermal alteration on volcano morphology, instability, and unpredictable volcanic hazards

More than 10% of the world’s population are at risk to the direct impacts of volcanic eruptions. Volcano monitoring aims to detect and correctly interpret volcanic hazards and to provide early and accurate warnings of impending eruptions. Yet, despite technical and scientific advances, volcanoes still produce unexpected explosive eruptions or sudden flank collapses. Each year, such unpredictable events result in volcanic disasters that devastate unprepared communities and destroy unprotected infrastructures. Previous work by the PIs indicates that volcanic hazards are caused by hydrothermal alteration, which progressively and imperceptibly changes the chemical and physical state of rocks inside a volcano, creating a soft and unstable (or “rotten”) interior. However, the link between “soft” volcanoes and unpredictable volcanic events remains enigmatic. The ROTTnROCK project aims to achieve a ground-breaking advance in our understanding of hydrothermal alteration processes that act inside active volcanic systems. Specifically, we will identify where and at which scales alteration occurs (WP1), explore the chemical fingerprint of alteration and effects on rock properties and strength using laboratory methods (WP2), and develop 4D volcano stability simulations and, therefore, an innovative and optimised hazard assessment workflow (WP3). The ROTTnROCK project combines innovative approaches from traditionally distinct geoscience disciplines (remote sensing, mineralogy and chemistry, rock mechanics, and modelling). This project will revolutionise our understanding of hydrothermal alteration and its effects on volcano hazards, and pave the way for strategies to forecast and mitigate unexpected volcanic events caused by hydrothermal alteration and circumvent disasters at volcanoes worldwide.