Glacial Lake Outburst Floods (GLOFs) – the sudden release of water dammed by moraines, ice, or bedrock – are among the most dynamic perturbations of Earth's surface, with geomorphic evidence persisting for hundreds to thousands of years. Several recent cases in mountainous terrain also demonstrate their potential for loss and destruction when floods descend steep elevation gradients and impact downstream communities that may are often unprepared. Despite advances in remote sensing, numerical modelling, and field reconnaissance, many fundamental questions on GLOF sources and triggers, flow behaviour, and future consequences remain unanswered:
• How can we determine the formation of paleo-dams and constrain the origin, magnitude and sediment flux of paleo-GLOFs?
• What are the long-term rates and return periods of these events, and what explains their observed regional differences?
• To what degree can the frequency, intensity, duration, and impacts of individual GLOFs be attributed to natural versus anthropogenic atmospheric warming?
• How can we better incorporate the roles of triggers and preconditioning factors in flood hazard models?
• What controls the spatial variability of outburst flood hazard at local, regional, and global scales, and how will this hazard evolve as lakes respond to changing climatic conditions?
• How can flow models and risk assessments account for a dynamically changing size distribution of glacial lakes?
• What are best-practice strategies to manage risk, prevent the initiation of GLOFs, and implement early warning systems?
• How vulnerable are downstream communities and how do they perceive, and cope with, the risk from outburst floods?
We invite contributions addressing these and related challenges, spanning paleo-lake and -flood analyses; case studies; process-based modelling; susceptibility, vulnerability, hazard, and risk assessments; and projections of changes in lake abundance, size, and GLOF hazard.
Christian Huggel